JP2023004299A - surface protection film - Google Patents

Abstract

To provide a surface protection film including a urethane-based pressure-sensitive adhesive layer having an excellent surface modulus.SOLUTION: A surface protection film includes a urethane-based pressure-sensitive adhesive layer formed from a urethane-based pressure-sensitive adhesive composition. The composition typically comprises a urethane prepolymer, a polyol, and a polyfunctional isocyanate compound, the urethane prepolymer and/or the polyol having a constituent unit represented by formula (1). The urethane-based pressure-sensitive adhesive layer has a surface modulus of 0.8 MPa or greater.SELECTED DRAWING: Figure 1

Description

The present invention relates to a surface protection film.

Surface protective films are attached to optical members and electronic members to prevent their surfaces from being scratched during processing, assembly, inspection, transportation, and the like. Such a surface protective film is peeled off from an optical member or an electronic member when surface protection is no longer necessary (Patent Document 1).

Adhesive layers composed of various adhesives are known as adhesive layers provided in such surface protective films. In terms of excellent reworkability, wettability, and transparency, a urethane-based adhesive layer composed of a urethane-based adhesive is preferable as the adhesive layer included in the surface protection film to be attached to the optical member or electronic member. Adopted.

However, a urethane-based pressure-sensitive adhesive layer composed of a urethane-based pressure-sensitive adhesive tends to have a smaller surface elastic modulus than a pressure-sensitive adhesive layer composed of other pressure-sensitive adhesives. Therefore, the surface protective film may not be able to sufficiently relax the stress applied from the outside, and may not be able to sufficiently reduce the damage to the adherend. Therefore, it is desired to improve the surface elastic modulus of the urethane pressure-sensitive adhesive layer.

JP 2016-17109 A

An object of the present invention is to provide a surface protective film containing a urethane pressure-sensitive adhesive layer with excellent surface elastic modulus.

（一般式（１）中、Ｒ^１は、水素原子、炭素数１～４のアルキル基、および、炭素数１～６のヒドロキシアルキル基からなる群から選択される１種を表す。複数のＲ^１は、互いに同一であってもよく互いに異なっていてもよい。ｎは１～４の整数を表す。ｍは、構成単位の繰り返し数であって、１～２００の整数を表す。） A surface protection film according to an embodiment of the present invention is
A surface protective film comprising a urethane-based pressure-sensitive adhesive layer,
The urethane-based pressure-sensitive adhesive layer is composed of a urethane-based pressure-sensitive adhesive formed from a urethane-based pressure-sensitive adhesive composition,
The urethane pressure-sensitive adhesive composition is
(A) contains a urethane prepolymer, a polyol, and a polyfunctional isocyanate compound, the urethane prepolymer and/or the polyol having a structural unit represented by the following general formula (1), or
(B) contains a urethane prepolymer having a structural unit represented by the following general formula (1) and a polyfunctional isocyanate compound, or
(C) contains a polyol having a structural unit represented by the following general formula (1) and a polyfunctional isocyanate compound,
The urethane pressure-sensitive adhesive layer has a surface elastic modulus of 0.8 MPa or more.
surface protection film.

(In general formula (1), R ¹ represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a hydroxyalkyl group having 1 to 6 carbon atoms. Multiple R ¹ may be the same or different from each other, n represents an integer of 1 to 4, and m represents the number of repetitions of the structural unit and represents an integer of 1 to 200.)

（一般式（２）中、Ｒ^２は、水素原子および炭素数１～４のアルキル基からなる群から選択される１種を表す。複数のＲ^２は、互いに同一であってもよく互いに異なっていてもよい。ｐは、構成単位の繰り返し数であって、１～３００の整数を表す。） In one embodiment, the urethane prepolymer and/or the polyol has a structural unit represented by the following general formula (2), and the structure represented by the above general formula (1) in the urethane-based pressure-sensitive adhesive composition The content ratio of the units is higher than the content ratio of the structural units represented by the following general formula (2).

(In general formula (2), R ² represents one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms. A plurality of R ² may be the same or different from each other. p is the number of repeating structural units and represents an integer of 1 to 300.)

In one embodiment, the urethane-based pressure-sensitive adhesive composition contains an ionic compound,
A content ratio of the ionic compound is 0.05 parts by weight or more with respect to a total of 100 parts by weight of the urethane prepolymer and the polyol.

In one embodiment, the urethane-based pressure-sensitive adhesive composition contains at least one selected from the group consisting of fluorine-based additives and silicone-based additives, relative to a total of 100 parts by weight of the urethane prepolymer and the polyol , the total content of the fluorine-based additive and the silicone-based additive is 0.01 part by weight or more.

In one embodiment, the urethane-based pressure-sensitive adhesive layer is attached to a glass plate, and after 30 minutes at 23° C., the peel force is 0.5 gf/25 mm to 2.0 gf/25 mm.

In one embodiment, the urethane pressure-sensitive adhesive layer has a haze of 3.5% or less.

In one embodiment, the urethane-based pressure-sensitive adhesive layer is attached to a glass plate and after 24 hours at 23 ° C., the glass plate after peeling from the glass plate at a peeling angle of 180 degrees and a peeling speed of 0.3 m / min. A residual adhesion rate is 80% or more.

ADVANTAGE OF THE INVENTION According to this invention, the surface protection film containing the urethane-type adhesive layer which has the outstanding surface elastic modulus can be provided.

1 is a schematic cross-sectional view of a surface protection film according to a preferred embodiment of the invention; FIG.

<<<1. Surface protection film>>>>
A surface protective film according to an embodiment of the present invention includes a urethane pressure-sensitive adhesive layer. Any appropriate release liner having releasability may be adhered to the adhesive surface side of the urethane-based adhesive layer as long as the effects of the present invention are not impaired.

A surface protective film according to an embodiment of the present invention preferably has a substrate layer and a urethane pressure-sensitive adhesive layer. The base material layer may consist of only one layer, or may consist of two or more layers. The urethane pressure-sensitive adhesive layer may consist of only one layer, or may consist of two or more layers. The surface protective film of the present invention may have any appropriate other layer in addition to the substrate layer and the urethane pressure-sensitive adhesive layer within a range that does not impair the effects of the present invention.

FIG. 1 is a schematic cross-sectional view of a surface protection film according to a preferred embodiment of the invention. The surface protective film 10 includes a base material layer 1 and an adhesive layer 2 . The surface protection film of the present invention may further have any appropriate other layer such as a release liner (not shown) as necessary.

For the surface of the substrate layer 1 on which the adhesive layer 2 is not attached, for the purpose of forming a roll that can be easily unwound, for example, fatty acid amide, polyethyleneimine, long-chain alkyl A release treatment may be performed by adding an additive or the like, or a coat layer made of any appropriate release agent such as a silicone-based, long-chain alkyl-based, or fluorine-based release agent may be provided.

Examples of the release liner that can be provided on the adhesive surface side of the urethane-based adhesive layer include a release liner in which the surface of a base material (liner base material) such as paper or plastic film is treated with silicone, or a base material such as paper or plastic film. A release liner in which the surface of the (liner substrate) is laminated with a polyolefin resin can be mentioned.

Examples of the plastic film as the base material of the release liner include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, and polybutylene. Examples include terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film and the like.

The thickness of the release liner is preferably 1 μm to 500 μm, more preferably 3 μm to 450 μm, even more preferably 5 μm to 400 μm, particularly preferably 10 μm to 300 μm.

The thickness of the surface protective film according to the embodiment of the present invention can be set to any appropriate thickness depending on the application. The thickness of the surface protective film is preferably 10 μm to 300 μm, more preferably 15 μm to 250 μm, even more preferably 20 μm to 200 μm, and particularly preferably 25 μm to 150 μm.

In the surface protection film according to the embodiment of the present invention, it is possible to improve the surface elastic modulus of the urethane pressure-sensitive adhesive layer. Therefore, the surface elastic modulus of the urethane pressure-sensitive adhesive layer contained in the surface protective film of the present invention is typically 0.8 MPa or higher, preferably 1.2 MPa or higher, more preferably 1.5 MPa or higher, further preferably 2 0 MPa or more, particularly preferably 2.5 MPa or more, and for example 4.0 MPa or less. If the surface elastic modulus of the urethane pressure-sensitive adhesive layer is at least the above lower limit, the surface protective film according to the embodiment of the present invention can exhibit excellent surface protective properties.
The surface elastic modulus of the urethane pressure-sensitive adhesive layer can be measured according to ISO14577.

When protecting an adherend having a step, the surface protective film is sometimes required to be thick so that it can follow the step. The surface protective film according to the embodiment of the present invention can have a thick urethane pressure-sensitive adhesive layer. Therefore, the lower limit of the thickness of the urethane pressure-sensitive adhesive layer contained in the surface protection film of the present invention is preferably 1 µm or more, preferably 5 µm or more, more preferably 10 µm or more, still more preferably 20 µm or more, and still more preferably 30 µm. The thickness is more preferably 40 μm or more, more preferably 50 μm or more, particularly preferably 60 μm or more, and most preferably 65 μm or more. If the thickness of the urethane-based pressure-sensitive adhesive layer can be increased in this way, the surface protective film according to the embodiment of the present invention can be used to protect a display with a large step, such as an organic EL display. can follow. In addition, the upper limit of the thickness of the urethane pressure-sensitive adhesive layer is typically 150 μm or less. The upper limit of the thickness of the urethane-based pressure-sensitive adhesive layer can be appropriately changed according to the application, and can be, for example, 100 μm or less.

The surface protection film is sometimes required to have light releasability so that it can be smoothly peeled off from the adherend when the surface protection of the adherend is no longer necessary. The surface protective film according to the embodiment of the present invention can exhibit easy peelability. The surface protective film of the present invention is peeled when the urethane-based pressure-sensitive adhesive layer it contains is attached to a glass plate and after 30 minutes at 23 ° C., the film is peeled off from the glass plate at a peeling angle of 180 degrees and a peeling speed of 300 mm / min. The force is preferably 0.5 gf/25 mm to 5.0 gf/25 mm, more preferably 0.5 gf/25 mm to 4.0 gf/25 mm, still more preferably 0.5 gf/25 mm to 3.0 gf/25 mm , particularly preferably 0.5 gf/25 mm to 2.5 gf/25 mm, most preferably 0.5 gf/25 mm to 2.0 gf/25 mm. If the peel force is within the above range, the surface protective film according to the embodiment of the present invention can exhibit excellent easy peelability.

The surface protection film is sometimes required to have transparency (low haze) that allows inspection of the adherend while attached to the adherend. Surface protective films according to embodiments of the present invention can achieve low haze. The haze of the urethane pressure-sensitive adhesive layer contained in the surface protective film of the present invention is preferably 4.5% or less, more preferably 4.0% or less, and still more preferably 3.5% or less. It is preferably 3.0% or less, most preferably 2.5% or less. If the haze is within the above range, the surface protective film according to the embodiment of the present invention can achieve excellent low haze and, for example, exhibit excellent testability.

The surface protective film is sometimes required to reduce the adhesive residue that remains on the adherend when the film is peeled off from the adherend. The surface protective film according to the embodiment of the present invention is peeled from the glass plate at a peeling angle of 180 degrees at a peeling speed of 0.3 m / min after 24 hours at 23 ° C. after pasting the urethane-based pressure-sensitive adhesive layer it contains to a glass plate. The residual adhesion rate to the glass plate after the coating is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, particularly preferably 85% or more, and most preferably is 90% or more. If the residual adhesion rate is within the above range, the surface protective film according to the embodiment of the present invention can reduce adhesive residue.

From the viewpoint of reducing damage to the adherend, the surface protective film is sometimes required to suppress charging when peeled off from the adherend. When the surface protective film according to the embodiment of the present invention is peeled from the glass plate at a peeling angle of 150 degrees and at a peeling speed of 30 m / min after 24 hours at 23 ° C. after pasting the urethane-based pressure-sensitive adhesive layer it contains to a glass plate. is preferably 15 kV or less, more preferably 10 kV or less, still more preferably 5 kV or less, particularly preferably 2 kV or less, and most preferably 1 kV or less. If the peeling electrification voltage is within the above range, the surface protective film according to the embodiment of the present invention can effectively prevent electrification during peeling.

<<1-1. Urethane adhesive layer≫
The urethane-based pressure-sensitive adhesive layer is composed of a urethane-based pressure-sensitive adhesive formed from a urethane-based pressure-sensitive adhesive composition. That is, the urethane-based pressure-sensitive adhesive formed from the urethane-based pressure-sensitive adhesive composition forms a layer shape to form the pressure-sensitive adhesive layer.

A urethane-based pressure-sensitive adhesive may be defined as being formed from a urethane-based pressure-sensitive adhesive composition. This is because the urethane-based pressure-sensitive adhesive becomes a urethane-based pressure-sensitive adhesive when the urethane-based pressure-sensitive adhesive composition undergoes a cross-linking reaction by heating, ultraviolet irradiation, or the like. However, due to the fact that it is impossible and almost impractical (“impossible/impractical circumstances”), urethane It is a valid specification of the system adhesive as a "thing".

As a method for forming the urethane-based pressure-sensitive adhesive layer, any suitable forming method can be adopted as long as the effects of the present invention are not impaired. As such a forming method, for example, the urethane pressure-sensitive adhesive composition is directly applied to any appropriate base film (for example, the base layer in the surface protection film according to the embodiment of the present invention) and dried or cured. method (direct method), a urethane-based pressure-sensitive adhesive layer is formed on the surface of a release liner (release surface) by applying a urethane-based pressure-sensitive adhesive composition to the surface (release surface) of the release liner and then drying or curing the composition to form a substrate film (for example, this method). A method (transfer method) of transferring the urethane-based pressure-sensitive adhesive layer to the substrate layer of the surface protective film according to the embodiment of the invention) can be mentioned. From the viewpoint of the anchoring property of the pressure-sensitive adhesive layer, typically, a direct method can be preferably employed.

Examples of methods for applying (typically coating) such a urethane pressure-sensitive adhesive layer include roll coating, gravure coating, reverse coating, kiss coating, dip roll coating, bar coating, and roll brushing. Various conventionally known methods such as coating method, spray coating method, knife coating method, air knife coating method, spray coating method, comma coating method, direct coating method, and coating method using a die coater can be appropriately employed.

Drying of the urethane pressure-sensitive adhesive composition can be performed under heating (for example, by heating to about 60° C. to 150° C.), if necessary. As means for curing the urethane pressure-sensitive adhesive composition, for example, ultraviolet rays, laser rays, α rays, β rays, γ rays, X rays, and electron beams can be appropriately employed.

（一般式（１）中、Ｒ^１は、水素原子、炭素数１～４のアルキル基、および、炭素数１～６のヒドロキシアルキル基からなる群から選択される１種を表す。複数のＲ^１は、互いに同一であってもよく互いに異なっていてもよい。ｎは１～４の整数を表す。ｍは、構成単位の繰り返し数であって、１～２００の整数を表す。）
ウレタン系粘着剤が、上記一般式（１）に示す構成単位を有するウレタンプレポリマーおよび／またはポリオールを含むウレタン系粘着剤組成物から形成されるので、ウレタン系粘着剤層の表面弾性率の向上を十分に図ることができる。 The urethane-based pressure-sensitive adhesive composition is
(A) contains a urethane prepolymer, a polyol, and a polyfunctional isocyanate compound, the urethane prepolymer and/or the polyol having a structural unit represented by the following general formula (1), or
(B) contains a urethane prepolymer having a structural unit represented by the following general formula (1) and a polyfunctional isocyanate compound, or
(C) contains a polyol having a structural unit represented by the following general formula (1) and a polyfunctional isocyanate compound.

(In general formula (1), R ¹ represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a hydroxyalkyl group having 1 to 6 carbon atoms. Multiple R ¹ may be the same or different from each other, n represents an integer of 1 to 4, and m represents the number of repetitions of the structural unit and represents an integer of 1 to 200.)
Since the urethane-based pressure-sensitive adhesive is formed from a urethane-based pressure-sensitive adhesive composition containing a urethane prepolymer and/or a polyol having structural units represented by the general formula (1), the surface elastic modulus of the urethane-based pressure-sensitive adhesive layer is improved. can be sufficiently planned.

In the present specification, "urethane prepolymer" is generally called "urethane prepolymer" by those skilled in the art in the production of urethane resins, and is different from "polyol". In other words, "polyol" shall not include urethane prepolymers (typically polyurethane polyols).

Examples of alkyl groups represented by R ¹ in general formula (1) include linear alkyl groups such as methyl group, ethyl group and n-propyl group; branched alkyl groups such as isopropyl group, isobutyl group and 2-ethylhexyl group; group;

The hydroxyalkyl group represented by R ¹ in general formula (1) includes, for example, a hydroxymethyl group, a 2-hydroxyethyl group, a 2-methyl-1,4-hydroxybutyl group and the like.

Among R ¹ in the general formula (1), the above alkyl group and hydrogen atom are preferred, and methyl group and hydrogen atom are more preferred.

In general formula (1), n is preferably 1 to 3, more preferably 1 or 2, still more preferably 2.

In general formula (1), m is preferably 10-100, more preferably 15-75, even more preferably 20-50.

（一般式（２）中、Ｒ^２は、水素原子および炭素数１～４のアルキル基からなる群から選択される１種を表す。複数のＲ^２は、互いに同一であってもよく互いに異なっていてもよい。ｐは、構成単位の繰り返し数であって、１～３００の整数を表す。） Moreover, the urethane prepolymer and/or the polyol preferably have a structural unit (polyoxyalkylene unit) represented by the following general formula (2).
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the aspect (A) above, preferably the urethane prepolymer contains a structural unit (polyoxyalkylene unit) represented by the following general formula (2), and/ Alternatively, the polyol includes a polyol having a structural unit (polyoxyalkylene unit) represented by the following general formula (2).
Further, when the urethane-based pressure-sensitive adhesive composition is in the aspect (B) above, the urethane prepolymer preferably has a structural unit (polyoxyalkylene unit) represented by the following general formula (2).
Further, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (C), the polyol preferably contains a polyol having a structural unit (polyoxyalkylene unit) represented by the following general formula (2).

(In general formula (2), R ² represents one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms. A plurality of R ² may be the same or different from each other. p is the number of repeating structural units and represents an integer of 1 to 300.)

Examples of the alkyl group represented by R ² in the general formula (2) include linear alkyl groups such as methyl group, ethyl group and n-propyl group; branched alkyl groups such as isopropyl group and isobutyl group; .

In general formula (2), p is preferably 10-250, more preferably 20-200, even more preferably 30-150.

The content of the structural unit represented by the general formula (1) in such a urethane pressure-sensitive adhesive composition is, for example, 40% by weight or more, preferably 50% by weight or more, and more preferably 60% by weight or more. and is, for example, 100% by weight or less, preferably 80% by weight or less.

The content ratio of the structural unit represented by the general formula (1) in the urethane pressure-sensitive adhesive composition is higher than the content ratio of the structural unit represented by the general formula (2).
The ratio of the structural unit represented by the general formula (1) to the total of the structural units represented by the general formula (1) and the structural units represented by the general formula (2) is, for example, 50% by weight or more, preferably 60%. % by weight or more, more preferably 65% by weight or more, for example 100% by weight or less, preferably 80% by weight or less.
If the ratio of the structural unit represented by the general formula (1) is at least the lower limit, the surface elastic modulus of the urethane-based pressure-sensitive adhesive layer can be stably improved.

<1-1-A. Aspect in which the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer, a polyol, and a polyfunctional isocyanate compound>
In the aspect of (A) above, the urethane-based pressure-sensitive adhesive is a urethane-based pressure-sensitive adhesive produced by a prepolymer method, and is formed from a urethane-based pressure-sensitive adhesive composition containing a urethane prepolymer, a polyol, and a polyfunctional isocyanate compound. be done. The urethane-based pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive manufactured by the prepolymer method in this way can be made thicker. It can follow the steps well.
More specifically, the urethane-based pressure-sensitive adhesive is formed by curing a urethane-based pressure-sensitive adhesive composition containing a urethane prepolymer, a polyol and a polyfunctional isocyanate compound. Urethane prepolymers and polyols preferably react with polyfunctional isocyanate compounds to form urethane resins.

As described above, in the aspect of (A), the urethane prepolymer and/or polyol has a structural unit represented by the general formula (1). Preferably, at least the urethane prepolymer has a structural unit represented by general formula (1) above, and more preferably the urethane prepolymer and polyol have a structural unit represented by general formula (1) above. . When the urethane prepolymer has the structural unit represented by the general formula (1), the urethane-based pressure-sensitive adhesive layer can can stably improve the surface elastic modulus of
Since the urethane prepolymer and/or polyol have the structural unit represented by the general formula (1) as described above, the urethane-based resin obtained by the urethane reaction of the urethane prepolymer and/or polyol with the polyfunctional isocyanate compound is , structural units derived from the structural units represented by the general formula (1) (hereinafter referred to as structural units derived from the general formula (1)).
When the structural unit represented by the general formula (1) contains a hydrogen atom and/or an alkyl group as R ¹ , the hydrogen atom and/or the alkyl group does not react in the urethane reaction, and the structural unit derived from the general formula (1) Included in the unit.
When the structural unit represented by the general formula (1) contains a hydroxyalkyl group as R ¹ , the hydroxyalkyl group may be contained in the structural unit derived from the general formula (1) without reacting in the urethane reaction, A crosslinked structure (for example, a crosslinked structure containing a urethane bond formed by a reaction between a hydroxyl group of a hydroxyalkyl group and an isocyanate group of a polyfunctional isocyanate compound (intramolecular bond or molecular interbonds) may be formed.
The content of structural units derived from general formula (1) in the urethane resin is, for example, 40% by weight or more, preferably 50% by weight or more, more preferably 60% by weight or more, and for example 100% by weight or less. and preferably 80% by weight or less. The content of structural units can be measured by ¹ H-NMR and ¹³ C-NMR.

Further, as described above, in the aspect of (A), the urethane prepolymer and/or polyol preferably have the structural unit represented by the general formula (2). It contains a structural unit represented by formula (2). The hydrogen atom and/or alkyl group included as R ² in the structural unit represented by the general formula (2) does not react in the urethane reaction.
The content of the structural unit represented by general formula (2) in the urethane resin is, for example, 10% by weight or more, preferably 15% by weight or more, more preferably 20% by weight or more, for example 50% by weight. or less, preferably 40% by weight or less.
The ratio of structural units derived from general formula (1) to the sum of structural units derived from general formula (1) and structural units represented by general formula (2) exceeds, for example, 50% by weight, preferably 55% by weight. more preferably 60% by weight or more, for example 100% by weight or less, preferably 80% by weight or less.
If the ratio of the structural unit represented by the structural unit derived from general formula (1) is at least the above lower limit, the surface elastic modulus of the urethane-based pressure-sensitive adhesive layer can be improved more stably.

The weight ratio of the total amount of the urethane prepolymer, polyol and polyfunctional isocyanate compound in the urethane pressure-sensitive adhesive composition is preferably 50 wt% to 100 wt%, more preferably 70 wt% to 100 wt%. more preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, and most preferably 98% to 100% by weight. By adjusting the weight ratio of the total amount of the urethane prepolymer and the polyol in the urethane pressure-sensitive adhesive composition within the above range, the surface protective film of the present invention can effectively exhibit the effects of the present invention. .

The weight ratio of the urethane prepolymer and the polyol in the urethane pressure-sensitive adhesive composition is preferably urethane prepolymer:polyol=(50-100):(0-50), more preferably (50-99): (1 to 50), more preferably (50 to 90): (10 to 50), particularly preferably (50 to 80): (20 to 50), particularly preferably (50 to 70 ): (30-50). By adjusting the weight ratio of the urethane prepolymer to the polyol in the urethane pressure-sensitive adhesive composition within the above range, the surface protection film of the invention can effectively exhibit the effects of the invention.

The equivalent ratio of NCO groups and OH groups in the urethane prepolymer and polyol and the polyfunctional isocyanate compound is preferably 1.0 to 2.0, more preferably 1.1 to 1 as NCO group/OH group. .9, more preferably 1.2 to 1.8, and particularly preferably 1.2 to 1.7. By adjusting the NCO group/OH group equivalent ratio within the above range, the surface protective film according to the embodiment of the present invention exhibits excellent wettability even when attached to an adherend having a large surface step. Furthermore, since the step followability is superior, a sufficiently high adhesion rate can be achieved.

The content of the polyfunctional isocyanate compound in the urethane pressure-sensitive adhesive composition is preferably 2.5 parts by weight to 40 parts by weight, more preferably 4 parts by weight, with respect to the total 100 parts by weight of the urethane prepolymer and polyol. parts to 30 parts by weight, more preferably 5 parts to 20 parts by weight, particularly preferably 6 parts to 15 parts by weight. By adjusting the content of the polyfunctional isocyanate compound within the above range, the surface protective film according to the embodiment of the present invention exhibits excellent wettability even when attached to an adherend having a large surface step. , it is possible to achieve a sufficiently high adhesion rate because it is more excellent in step followability.

<1-1-A-1. Urethane prepolymer>
Urethane prepolymers are typically polyurethane polyols, and are preferably obtained by reacting a polyether polyol and an organic polyisocyanate compound with the organic polyisocyanate compound in the presence or absence of a catalyst. be. A commercially available urethane prepolymer may be employed as the urethane prepolymer.

Only one kind of urethane prepolymer may be used, or two or more kinds thereof may be used.

The number average molecular weight Mn of the urethane prepolymer is preferably 1,000 to 100,000.

Any appropriate polyether polyol can be used as the polyether polyol as long as the effects of the present invention are not impaired. Examples of such polyether polyols include water, propylene glycol, ethylene glycol, glycerin, trimethylolpropane, and other low-molecular-weight polyols as initiators, and ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, and other oxirane compounds. Examples include polyether polyols obtained by polymerization. Examples of such polyether polyols include polyether polyols having two or more functional groups, such as polypropylene glycol, polyethylene glycol, and polytetramethylene glycol.

As the molecular weight of the polyether polyol, it is possible to use from low molecular weight to high molecular weight. As for the molecular weight of the polyether polyol, the number average molecular weight is preferably 1,000 to 5,000. If the number average molecular weight is less than 1,000, the reactivity becomes high and gelation may easily occur. If the number-average molecular weight exceeds 5,000, the reactivity may become low, and the cohesive strength of the polyurethane polyol itself may become small. The amount of polyether polyol (p2) used is preferably 10 mol % to 100 mol % of the polyol constituting the urethane prepolymer (typically polyurethane polyol).

Part of the polyether polyol, if necessary, for example, glycols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, pentaerythritol, and ethylenediamine , N-aminoethylethanolamine, isophoronediamine, and xylylenediamine.

As the polyether polyol, only a bifunctional polyether polyol may be used, or a polyether polyol having a number average molecular weight of 1000 to 5000 and at least 3 or more hydroxyl groups in one molecule is used. Part or all may be used. When a polyether polyol having an average molecular weight of 1000 to 5000 and having at least 3 or more hydroxyl groups in one molecule is partially or wholly used as the polyether polyol, the adhesive strength and removability are well balanced. obtain. In such a polyether polyol, if the number average molecular weight is less than 1000, the reactivity becomes high and there is a possibility that gelation is likely to occur. Further, in such a polyether polyol, if the number average molecular weight exceeds 5000, the reactivity may be lowered, and furthermore, the cohesive force of the urethane prepolymer (typically, polyurethane polyol) itself may be lowered. be. The number average molecular weight of such polyether polyols is more preferably 2500-3500.

Such polyether polyols can be used alone or in combination.

When the urethane prepolymer has a structural unit represented by general formula (1) above, the polyether polyol preferably contains a polyether polyol having a structural unit represented by general formula (1) above.
The polyether polyol having a structural unit represented by the above general formula (1) is preferably a polyether polyol containing a structural unit (polyoxyalkylene unit) having 3 or more carbon atoms in which all of a plurality of R ¹ are hydrogen atoms. and more preferably polytetramethylene glycol.

The content of the polyether polyol having the structural unit represented by the general formula (1) is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, relative to the total amount of the polyether polyol, For example, it is 100% by weight or less, preferably 90% by weight or less.

When the urethane prepolymer has a structural unit represented by the general formula (2), the polyether polyol preferably has the structural unit represented by the general formula (1) in addition to the polyether polyol represented by the general formula (2). ) contains polyether polyols having structural units shown in
The polyether polyol having the structural unit represented by the general formula (2) preferably contains a structural unit (polyoxypropylene unit) in which one of the plurality of R ² is a methyl group and the rest are hydrogen atoms. Polyether polyol, more preferably polypropylene glycol.

The content of the polyether polyol having the structural unit represented by the general formula (2) with respect to the total amount of the polyether polyol is, for example, 0% by weight or more, preferably 10% by weight or more, for example 50% by weight or less, preferably It is 40% by weight or less, more preferably 30% by weight or less.

Further, when the urethane prepolymer does not have the structural unit represented by the general formula (1), the urethane prepolymer preferably comprises a polyether polyol not having the structural unit represented by the general formula (1) and a polyester It is obtained by reacting a polyol with an organic polyisocyanate compound.
In this case, the polyether polyol is preferably a polyether polyol having a structural unit represented by general formula (2) above, more preferably polypropylene glycol.

Any appropriate polyester polyol can be used as the polyester polyol as long as the effects of the present invention are not impaired. Examples of such polyester polyols include polyester polyols obtained by reacting an acid component and a glycol component. Examples of acid components include terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, and trimellitic acid. Examples of glycol components include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexane glycol, 3-methyl-1,5-pentanediol, 3,3′-dimethylolheptane, polyoxyethylene glycol, Examples include polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, and polyol components such as glycerin, trimethylolpropane, and pentaerythritol. Examples of polyester polyols include, in addition to these, polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone.

As the molecular weight of the polyester polyol, it is possible to use from low molecular weight to high molecular weight. As for the molecular weight of the polyester polyol, the number average molecular weight is preferably 500 to 5,000. If the number average molecular weight is less than 500, the reactivity becomes high and gelation may easily occur. If the number average molecular weight exceeds 5,000, the reactivity may become low, and furthermore, the cohesive strength of the polyurethane polyol itself may become small. The polyester polyol is used in an amount of preferably 10 mol % to 90 mol % of the polyol constituting the urethane prepolymer (typically polyurethane polyol).

Any appropriate organic polyisocyanate compound can be used as the organic polyisocyanate compound as long as the effects of the present invention are not impaired. Examples of such organic polyisocyanate compounds include aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates.

Examples of aromatic polyisocyanates include 1,3-phenylene diisocyanate, 4,4'-diphenyldiisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6 - aromatic diisocyanates such as tolylene diisocyanate and 4,4'-toluidine diisocyanate; aromatic triisocyanates such as 4,4′,4″-triphenylmethane triisocyanate;

Examples of aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, Aliphatic diisocyanates such as 2,4,4-trimethylhexamethylene diisocyanate can be mentioned.

Examples of araliphatic polyisocyanates include ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, ω,ω'-diisocyanate-1,4-diethylbenzene , 1,4-tetramethylxylylene diisocyanate and 1,3-tetramethylxylylene diisocyanate.

Examples of alicyclic polyisocyanates include 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2 ,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane and other lipids Cyclic diisocyanates are mentioned.

As the organic polyisocyanate compound, a trimethylolpropane adduct, a water-reacted biuret, and an isocyanurate having an isocyanurate ring (for example, a trimer) can be used in combination.

Such organic polyisocyanate compounds can be used alone or in combination.
The organic polyisocyanate compound is more preferably diisocyanate, still more preferably aliphatic diisocyanate, and most preferably hexamethylene diisocyanate.

Any appropriate catalyst can be used as the catalyst that can be used in producing the urethane prepolymer (typically, polyurethane polyol) as long as the effects of the present invention are not impaired. Examples of such catalysts include tertiary amine compounds and organometallic compounds.

Examples of tertiary amine compounds include triethylamine, triethylenediamine, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU).

Examples of organometallic compounds include tin-based compounds and non-tin-based compounds.

Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin Tin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate and tin 2-ethylhexanoate.

Examples of non-tin compounds include titanium compounds such as dibutyl titanium dichloride, tetrabutyl titanate, and butoxy titanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate. iron-based compounds such as iron 2-ethylhexanoate and iron acetylacetonate; cobalt-based compounds such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc-based compounds such as zinc naphthenate and zinc 2-ethylhexanoate; zirconium-based compounds such as zirconium naphthenate;

When catalysts are used in making urethane prepolymers (typically polyurethane polyols), catalysts can be used alone or in combination. Among the catalysts, tin-based compounds are preferred, and dibutyltin dilaurate (DBTDL) is more preferred.

When a catalyst is used in producing a urethane prepolymer (typically, a polyurethane polyol), the amount of the catalyst used is preferably 0.01% by weight with respect to the total amount of the polyol and the organic polyisocyanate compound. ~1.0% by weight.

When a catalyst is used in making urethane prepolymers (typically polyurethane polyols), the reaction temperature is preferably below 100°C, more preferably between 85°C and 95°C. If the temperature is 100° C. or higher, it may become difficult to control the reaction rate and the crosslinked structure, and it may be difficult to obtain a urethane prepolymer (typically, polyurethane polyol) having a predetermined molecular weight.

A catalyst may not be used when producing a urethane prepolymer (typically, a polyurethane polyol). In that case, the reaction temperature is preferably 100° C. or higher, more preferably 110° C. or higher. Moreover, when obtaining a urethane prepolymer (typically, polyurethane polyol) in the absence of a catalyst, it is preferable to carry out the reaction for 3 hours or longer.

Methods for producing urethane prepolymers (typically, polyurethane polyols) include, for example, 1) a method of charging a polyol such as polyether polyol, a catalyst, and an organic polyisocyanate compound into a volumetric flask; A method of adding a polyol and a catalyst in a flask and adding an organic polyisocyanate compound dropwise may be mentioned. As a method for producing a urethane prepolymer (typically, polyurethane polyol), method 2) is preferable in terms of controlling the reaction.

Any suitable solvent can be used in the production of the urethane prepolymer (typically polyurethane polyol) as long as the effects of the present invention are not impaired. Such solvents include, for example, methyl ethyl ketone, ethyl acetate, toluene, xylene, and acetone. Among these solvents, ethyl acetate and toluene are preferred.

<1-1-A-2. Polyol>
Examples of polyols include polyester polyols, polyether polyols, polycaprolactone polyols, polycarbonate polyols, and castor oil-based polyols.

A polyester polyol can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

Polyol components include, for example, ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl-1 ,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl -1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, polypropylene glycol.

Examples of acid components include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-methyl-1, 4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid , and acid anhydrides thereof.

Examples of polyether polyols include water, low-molecular-weight polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzenes (catechol, resorcinol, hydroquinone, etc.). is used as an initiator, polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like.

Examples of polycaprolactone polyols include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

Polycarbonate polyols include, for example, polycarbonate polyols obtained by subjecting the above polyol component and phosgene to a polycondensation reaction; Polycarbonate polyols obtained by transesterification condensation with carbonic acid diesters such as propylene carbonate, diphenyl carbonate, and dibenzyl carbonate; Copolycarbonate polyols obtained by using two or more of the above polyol components in combination; Various polycarbonate polyols above and carboxyl group-containing polyols Polycarbonate polyol obtained by esterifying a compound; Polycarbonate polyol obtained by etherifying the above various polycarbonate polyols and a hydroxyl group-containing compound; Obtained by transesterifying the above various polycarbonate polyols and an ester compound. Polycarbonate polyols; Polycarbonate polyols obtained by transesterification of various polycarbonate polyols and hydroxyl group-containing compounds; Polyester-based polycarbonate polyols obtained by polycondensation reaction of various polycarbonate polyols and dicarboxylic acid compounds; Various polycarbonate polyols and a copolymerized polyether-based polycarbonate polyol obtained by copolymerizing an alkylene oxide;

Examples of castor oil-based polyols include castor oil-based polyols obtained by reacting castor oil fatty acids with the above polyol components. Specific examples include castor oil-based polyols obtained by reacting castor oil fatty acids with polypropylene glycol.

The polyol preferably includes a polyether polyol, and more preferably includes a polyether polyol having a structural unit represented by the general formula (1).
The polyether polyol having the structural unit represented by the general formula (1) preferably contains a structural unit having 3 or more carbon atoms in which one of the plurality of R ¹ is a hydroxyalkyl group and the rest are hydrogen atoms. It is a polyether polyol, and more preferably a polyether polyol containing a structural unit having 4 carbon atoms in which one of a plurality of R ¹ is a hydroxyalkyl group and the rest are hydrogen atoms.

Polyols typically include a first polyol having a number average molecular weight Mn of 5,000 to 20,000 and a second polyol having a number average molecular weight Mn of 300 to 4,999. By containing the first polyol having a number average molecular weight Mn of 5,000 to 20,000 and the second polyol having a number average molecular weight Mn of 300 to 4,999, the effects of the present invention can be further exhibited.

The number of first polyols may be one, or two or more.

Only one kind of the second polyol may be used, or two or more kinds thereof may be used.

The content of the total amount of the first polyol and the second polyol in the polyol is preferably 80% by weight to 100% by weight, more preferably 90% by weight, from the viewpoint that the effects of the present invention can be further expressed. ~100% by weight, more preferably 95% to 100% by weight, particularly preferably 98% to 100% by weight, most preferably substantially 100% by weight.

The number average molecular weight Mn of the first polyol is 5,000 to 20,000, preferably 6,000 to 18,000, more preferably 7,000 to 16,000, still more preferably 8,000 to 15,000, and particularly preferably 9,000 to 14,000. be. If the number average molecular weight Mn of the first polyol is within the above range, the effects of the present invention can be exhibited more effectively.

The number average molecular weight Mn of the second polyol is 300 to 4999, preferably 350 to 4500, more preferably 400 to 4000, still more preferably 500 to 3800, particularly preferably 700 to 3500. be. If the number average molecular weight Mn of the second polyol is within the above range, the effects of the present invention can be exhibited more effectively.

The weight ratio of the first polyol and the second polyol is preferably 1.0 ≤ (first polyol/second polyol) ≤ 3.5, more preferably 1.0 ≤ (first polyol) polyol/second polyol)≦3.0, more preferably 1.0≦(first polyol/second polyol)≦2.5, and particularly preferably 1.0≦(first polyol) polyol/second polyol)≦2.0. If the weight ratio of the first polyol and the second polyol is within the above range, the haze of the surface protection film can be further reduced.

The number of OH groups that the first polyol has is preferably 3 to 6, more preferably 3 to 5, and still more preferably, from the viewpoint that the effects of the present invention can be more expressed. is 3 to 4, particularly preferably 3.

The first polyol preferably contains 50% to 100% by weight, more preferably 70% to 100% by weight, of a triol having 3 OH groups, in order to further express the effects of the present invention. %, more preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, most preferably substantially 100% by weight.

The first polyol is particularly preferably a polyether polyol containing structural units represented by the above general formula (2).

The second polyol preferably has 3 to 6 OH groups, more preferably 3 to 5, still more preferably 3 to 5 OH groups, in that the effects of the present invention can be more expressed. is 3 to 4, particularly preferably 3.

The second polyol preferably contains 50% to 100% by weight, more preferably 70% to 100% by weight, of a triol having 3 OH groups in order to further express the effects of the present invention. %, more preferably 90% to 100% by weight, particularly preferably 95% to 100% by weight, most preferably substantially 100% by weight.

The second polyol is particularly preferably a polyether polyol containing a structural unit represented by the above general formula (1) or a polyether polyol containing a structural unit represented by the above general formula (2), particularly preferably It is a polyether polyol containing a structural unit represented by the general formula (1).

<1-1-A-3. Polyfunctional isocyanate compound>
Only one kind of polyfunctional isocyanate compound may be used, or two or more kinds thereof may be used.

Any appropriate polyfunctional isocyanate compound that can be used in the urethanization reaction can be adopted as the polyfunctional isocyanate compound. Examples of such polyfunctional isocyanate compounds include polyfunctional aliphatic isocyanate compounds, polyfunctional alicyclic isocyanates, polyfunctional aromatic isocyanate compounds, and polyfunctional araliphatic diisocyanate compounds.

Polyfunctional aliphatic isocyanate compounds include, for example, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4, Aliphatic diisocyanates such as 4-trimethylhexamethylene diisocyanate can be mentioned.

Examples of polyfunctional alicyclic isocyanate compounds include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, Examples include alicyclic diisocyanates such as hydrogenated tolylene diisocyanate and hydrogenated tetramethylxylylene diisocyanate.

Polyfunctional aromatic diisocyanate compounds include, for example, phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4 ,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate and other aromatic diisocyanates.

Examples of polyfunctional araliphatic diisocyanate compounds include aromatic diisocyanates such as xylylene diisocyanate.

Examples of polyfunctional isocyanate compounds include trimethylolpropane adducts of various polyfunctional isocyanate compounds such as those described above, biuret compounds reacted with water, and isocyanurate compounds having an isocyanurate ring (eg, trimers). Moreover, you may use these together.

The polyfunctional isocyanate compound preferably has an average functional group number of isocyanate groups of 2 to 6, more preferably 2 to 5, in that the effects of the present invention can be more expressed, More preferably, the number is 3 to 4.

The polyfunctional isocyanate compound is more preferably an isocyanate compound having an average functionality of 3 or more, more preferably an isocyanurate of an aliphatic diisocyanate, particularly preferably an isocyanurate of hexamethylene diisocyanate. .

<1-1-B. Aspect in which the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyfunctional isocyanate compound>
In the aspect (B), the urethane-based pressure-sensitive adhesive is a urethane-based pressure-sensitive adhesive produced by a prepolymer method, and is formed from a urethane-based pressure-sensitive adhesive composition containing a urethane prepolymer and a polyfunctional isocyanate compound.
In the aspect (B), the urethane prepolymer contained in the urethane pressure-sensitive adhesive composition is the same as the urethane prepolymer described in <1-1-A-1> above, and is contained in the urethane pressure-sensitive adhesive composition. The polyfunctional isocyanate compound used is the same as the polyfunctional isocyanate compound described in <1-1-A-3> above. In the aspect (B), the urethane pressure-sensitive adhesive composition does not contain the polyol described in <1-1-A-2> above.
More specifically, in the aspect (B), the urethane-based pressure-sensitive adhesive is formed by curing a urethane-based pressure-sensitive adhesive composition containing a urethane prepolymer and a polyfunctional isocyanate compound. The urethane prepolymer preferably reacts with a polyfunctional isocyanate compound to form a urethane resin.

In the aspect (B), the urethane prepolymer has a structural unit represented by the general formula (1). Therefore, the urethane-based resin formed by the urethane reaction between the urethane prepolymer and the polyfunctional isocyanate compound is a structural unit derived from the structural unit represented by the general formula (1) (hereinafter referred to as a structural unit derived from the general formula (1) .)including. Regarding the constituent units derived from general formula (1) in the urethane resin and the content thereof, see <1-1-A. > as described above.

In addition, in the aspect of (B), the urethane prepolymer preferably has a structural unit represented by the general formula (2), so that the urethane-based resin has the structural unit represented by the general formula (2). include. Regarding the content ratio of the structural unit represented by general formula (2) in the urethane resin, see <1-1-A. > as described above.

The range of the weight ratio of the total amount of the urethane prepolymer and the polyfunctional isocyanate compound in the urethane-based pressure-sensitive adhesive composition is the weight ratio of the total amount of the urethane prepolymer, polyol, and polyfunctional isocyanate compound in the aspect (A) above. is the same as the range of
The range of the equivalent ratio of NCO groups and OH groups in the urethane prepolymer and the polyfunctional isocyanate compound in the urethane pressure-sensitive adhesive composition is It is the same as the range of the equivalent ratio of the NCO group and the OH group.
The range of the content of the polyfunctional isocyanate compound with respect to 100 parts by weight of the urethane prepolymer is the same as the range of the content of the polyfunctional isocyanate compound with respect to the total of 100 parts by weight of the urethane prepolymer and the polyol in the aspect (A).

<1-1-C. Aspect in which the urethane-based pressure-sensitive adhesive composition contains a polyol and a polyfunctional isocyanate compound>
In the aspect (C), the urethane-based pressure-sensitive adhesive is a urethane-based pressure-sensitive adhesive manufactured by a one-shot method, and is formed from a urethane-based pressure-sensitive adhesive composition containing a polyol and a polyfunctional isocyanate compound.
In the aspect of (C), the polyol contained in the urethane-based pressure-sensitive adhesive composition is the same as the polyol described in <1-1-A-2> above, and the polyfunctional isocyanate contained in the urethane-based pressure-sensitive adhesive composition. The compound is the same as the polyfunctional isocyanate compound described in <1-1-A-3> above. In the aspect (C), the urethane pressure-sensitive adhesive composition does not contain the urethane prepolymer described in <1-1-A-1> above.
More specifically, in the aspect (C), the urethane-based pressure-sensitive adhesive is formed by curing a urethane-based pressure-sensitive adhesive composition containing a polyol and a polyfunctional isocyanate compound. The polyol preferably reacts with the polyfunctional isocyanate compound to form a urethane-based resin.

In the aspect (C), the polyol has a constitutional unit represented by the general formula (1). Therefore, a urethane-based resin formed by a urethane reaction between a polyol and a polyfunctional isocyanate compound has a structural unit derived from the structural unit represented by the general formula (1) (hereinafter referred to as a structural unit derived from the general formula (1).) including. Regarding the constituent units derived from general formula (1) in the urethane resin and the content thereof, see <1-1-A. > as described above.

Further, in the aspect of (C), the polyol is preferably a polyol having a structural unit derived from the structural unit represented by the general formula (1) and a polyol having a structural unit represented by the general formula (2). include. Therefore, the urethane-based resin contains the structural unit represented by the general formula (2). Regarding the content ratio of the structural unit represented by general formula (2) in the urethane resin, see <1-1-A. > as described above.

The range of the weight ratio of the total amount of the polyol and the polyfunctional isocyanate compound in the urethane-based pressure-sensitive adhesive composition is the range of the weight ratio of the total amount of the urethane prepolymer, the polyol, and the polyfunctional isocyanate compound of the aspect (A). is similar to
The range of the equivalent ratio of the NCO groups and OH groups in the polyol and the polyfunctional isocyanate compound in the urethane-based pressure-sensitive adhesive composition is the NCO group in the urethane prepolymer and the polyol of the aspect (A) and the polyfunctional isocyanate compound. and the range of the equivalent ratio of the OH group.
The range of the content of the polyfunctional isocyanate compound with respect to 100 parts by weight of the polyol is the same as the range of the content of the polyfunctional isocyanate compound with respect to the total of 100 parts by weight of the urethane prepolymer and the polyol in the aspect (A).

<1-2. Other Ingredients>
The urethane-based adhesive composition may contain any appropriate other component within a range that does not impair the effects of the present invention. Examples of such other components include resin components other than the urethane prepolymer and polyol, cross-linking agents other than the polyfunctional isocyanate compound, cross-linking retarders, ionic compounds, fluorine-based additives, silicone-based additives, Fatty acid esters, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, anti-aging agents, conductive agents, UV absorbers, antioxidants, light stabilizers, surface lubricants, Leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents and catalysts.

[Ionic compound]
When an ionic compound is included as another component, it is possible to improve the antistatic performance of the surface protection film according to the embodiment of the present invention.

As the content of the ionic compound, any appropriate content can be adopted as long as the effects of the present invention are not impaired. In order to further improve the antistatic performance of the surface protective film of the present invention, the content of the ionic compound is preferably 0.05 parts by weight or more with respect to the total 100 parts by weight of the urethane prepolymer and the polyol, It is more preferably 0.10 to 50 parts by weight, still more preferably 0.20 to 30 parts by weight, particularly preferably 0.30 to 10 parts by weight, most preferably 0.30 to 10 parts by weight. 30 parts by weight to 0.5 parts by weight.
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (A), since the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyol, the content of the ionic compound is as described above. .
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (B) mode, since the urethane-based pressure-sensitive adhesive composition does not contain a polyol (that is, it is 0 parts by weight), the ion The range of the content ratio of the organic compound is as described above.
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (C) mode, since the urethane-based pressure-sensitive adhesive composition does not contain a urethane prepolymer (that is, it is 0 parts by weight), ion The range of the content ratio of the organic compound is as described above.
If the content of the ionic compound is within the above range, the antistatic performance of the surface protective film of the present invention can be further improved. If the content of the ionic compound is out of the above range and is too small, the surface protective film of the present invention may not have sufficient antistatic performance. If the content of the ionic compound is out of the above range and is too high, contamination of the adherend may increase.

As the ionic compound, any suitable ionic compound can be adopted as long as the effects of the present invention are not impaired. Only one kind of ionic compound may be used, or two or more kinds thereof may be used.

The ionic compound is preferably an ionic compound containing at least one selected from onium cations and metal cations and a fluoroorganic anion, and an ionic group-containing silicone oligomer, in that the effects of the present invention can be further exhibited. An ionic compound containing at least one selected from onium cations and metal cations and a fluoroorganic anion is more preferable in that the appearance of the pressure-sensitive adhesive layer can be improved.

The ionic compound may be an ionic liquid. An ionic liquid means a molten salt (ionic compound) that exhibits a liquid state at 25°C.

As the ionic group-containing silicone oligomer, any suitable ionic group-containing silicone oligomer can be employed as long as the effects of the present invention are not impaired. Examples of ionic group-containing silicone oligomers include the trade name “X-40-2450” manufactured by Shin-Etsu Chemical Co., Ltd.

As the onium cation, any appropriate onium cation can be adopted as long as the effects of the present invention are not impaired. From the viewpoint that the effects of the present invention can be more expressed, such onium cations are preferably ammonium cations (nitrogen-containing onium cations), sulfonium cations (sulfur-containing onium cations), and phosphorus-containing onium cations (phosphonium cations). At least one selected, more preferably an ammonium cation.

Any appropriate metal cation can be employed as the metal cation as long as the effects of the present invention are not impaired. Such metal cations are preferably alkali metal cations such as Li cations, Na cations, and K cations, in that the effects of the present invention can be expressed more effectively.

As the fluoroorganic anion, any suitable fluoroorganic anion can be employed as long as the effects of the present invention are not impaired. The fluoroorganic anions may be fully fluorinated (perfluorinated) or partially fluorinated.

Such fluoroorganic anions include, for example, fluorinated arylsulfonates, perfluoroalkanesulfonates, bis(fluorosulfonyl)imides, bis(perfluoroalkanesulfonyl)imides, cyanoperfluoroalkanesulfonylamides, bis(cyano) perfluoroalkanesulfonylmethide, cyano-bis-(perfluoroalkanesulfonyl)methide, tris(perfluoroalkanesulfonyl)methide, trifluoroacetate, perfluoroalkylate, tris(perfluoroalkanesulfonyl)methide, (perfluoroalkane sulfonyl)trifluoroacetamide and the like.

Among these fluoroorganic anions, perfluoroalkylsulfonates, bis(fluorosulfonyl)imides, and bis(perfluoroalkanesulfonyl)imides are preferred from the viewpoint that the effects of the present invention can be more expressed. More specifically, is for example trifluoromethanesulfonate, pentafluoroethanesulfonate, heptafluoropropanesulfonate, nonafluorobutanesulfonate, bis(fluorosulfonyl)imide, bis(trifluoromethanesulfonyl)imide, preferably bis(fluorosulfonyl)imide, Bis(trifluoromethanesulfonyl)imide.

As the ionic compound, an ionic compound composed of an onium cation and a fluoroorganic anion is more preferable in that the effects of the present invention can be exhibited more effectively.

The onium cation preferably has at least one selected from structures represented by general formulas (3) to (6).

In general formula (3), Ra represents a hydrocarbon group having 4 to 20 carbon atoms and may contain a heteroatom; Rb and Rc are the same or different from each other and are hydrogen or It represents a hydrocarbon group and may contain a heteroatom. However, when the nitrogen atom contains a double bond, there is no Rc.

In general formula (4), Rd represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom; represents 16 hydrocarbon groups which may contain heteroatoms.

In general formula (5), Rh represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a heteroatom; represents 16 hydrocarbon groups which may contain heteroatoms.

In general formula (6), Z represents a nitrogen atom, a sulfur atom, or a phosphorus atom; Rl, Rm, Rn, and Ro are the same or different and represent a hydrocarbon group having 1 to 20 carbon atoms It may contain heteroatoms. However, when Z is a sulfur atom, there is no Ro.

Examples of the cation structure represented by the general formula (3) include a pyridinium cation structure, a pyrrolidinium cation structure, a piperidinium cation structure, a cation structure having a pyrroline skeleton, a cation structure having a pyrrole skeleton, and the like.

Specific examples of the cation represented by the general formula (3) include 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1-butyl -3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-octyl-4-methylpyridinium cation, 1-butyl-3,4-dimethylpyridinium cation, pyridinium cations such as 1,1-dimethylpyrrolidinium cation; 1-ethyl-1-methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexylpyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1 -ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium cation, 1 , 1-dipropylpyrrolidinium cation, 1-propyl-1-butylpyrrolidinium cation, 1,1-dibutylpyrrolidinium cation and other pyrrolidinium cations; 1-propylpiperidinium cation, 1-pentylpi peridinium cation, 1-methyl-1-ethylpiperidinium cation, 1-methyl-1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium Cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1-heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation , 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1-hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1-propyl-1-butylpiperidinium cation, Piperidinium cations such as 1,1-dimethylpiperidinium cation, 1,1-dipropylpiperidinium cation, 1,1-dibutylpiperidinium cation; 2-methyl-1-pyrroline cation; 1,2-dimethylindole cation; 1-ethylcarbazole cation; these cations further form vinyl groups (CH ₂ =CH- groups) and allyl groups (CH ₂ =CH-CH ₂ - groups). ) and a cation having at least one selected from;

Among these, 1-ethylpyridinium cation, 1-butylpyridinium cation, 1-hexylpyridinium cation, 1-ethyl-3-methylpyridinium cation, 1 -pyridinium cations such as butyl-3-methylpyridinium cation, 1-hexyl-3-methylpyridinium cation, 1-butyl-4-methylpyridinium cation, 1-octyl-4-methylpyridinium cation; 1-ethyl-1- methylpyrrolidinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-butylpyrrolidinium cation, 1-methyl-1-pentylpyrrolidinium cation, 1-methyl-1-hexyl pyrrolidinium cation, 1-methyl-1-heptylpyrrolidinium cation, 1-ethyl-1-propylpyrrolidinium cation, 1-ethyl-1-butylpyrrolidinium cation, 1-ethyl-1-pentylpyrrolidinium cation cation, 1-ethyl-1-hexylpyrrolidinium cation, 1-ethyl-1-heptylpyrrolidinium cation; 1-methyl-1-ethylpiperidinium cation, 1-methyl -1-propylpiperidinium cation, 1-methyl-1-butylpiperidinium cation, 1-methyl-1-pentylpiperidinium cation, 1-methyl-1-hexylpiperidinium cation, 1-methyl-1 -heptylpiperidinium cation, 1-ethyl-1-propylpiperidinium cation, 1-ethyl-1-butylpiperidinium cation, 1-ethyl-1-pentylpiperidinium cation, 1-ethyl-1- piperidinium cations such as hexylpiperidinium cation, 1-ethyl-1-heptylpiperidinium cation, 1-propyl- ₁ -butylpiperidinium cation; group) and an allyl group (CH ₂ ═CH—CH ₂ — group); Cation, 1-butyl-3-methylpyridinium cation, 1-octyl-4-methylpyridinium cation, 1-methyl-1-propylpyrrolidinium cation, 1-methyl-1-propylpiperidinium cation , these cations further have at least one selected from a vinyl group (CH ₂ =CH- group) and an allyl group (CH ₂ =CH-CH ₂ - group).

Examples of the cation structure represented by general formula (4) include an imidazolium cation structure, a tetrahydropyrimidinium cation structure, and a dihydropyrimidinium cation structure.

Specific examples of the cation represented by the general formula (4) include 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1-butyl -3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3-methylimidazolium cation lithium cation, 1-tetradecyl-3-methylimidazolium cation, 1,2-dimethyl-3-propylimidazolium cation, 1-ethyl-2,3-dimethylimidazolium cation, 1-butyl-2,3-dimethylimidazolium cation imidazolium cations such as lithium cations, 1-hexyl-2,3-dimethylimidazolium cations; 1,3-dimethyl-1,4,5,6-tetrahydropyrimidinium cations, 1,2,3-trimethyl- 1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,4-tetramethyl-1,4,5,6-tetrahydropyrimidinium cation, 1,2,3,5-tetramethyl- Tetrahydropyrimidinium cations such as 1,4,5,6-tetrahydropyrimidinium cations; 1,3-dimethyl-1,4-dihydropyrimidinium cations, 1,3-dimethyl-1,6-dihydropyrimidinium cations cation, 1,2,3-trimethyl-1,4-dihydropyrimidinium cation, 1,2,3-trimethyl-1,6-dihydropyrimidinium cation, 1,2,3,4-tetramethyl- Dihydropyrimidinium cations such as 1,4-dihydropyrimidinium cation, 1,2,3,4 _- tetramethyl-1,6-dihydropyrimidinium cation; - group) and an allyl group (CH ₂ =CH-CH ₂ - group); and the like.

Among these, 1,3-dimethylimidazolium cation, 1,3-diethylimidazolium cation, 1-ethyl-3-methylimidazolium cation, 1 -butyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, 1-octyl-3-methylimidazolium cation, 1-decyl-3-methylimidazolium cation, 1-dodecyl-3- methylimidazolium cation, 1-tetradecyl-3-methylimidazolium cation, and at least one of these cations further selected from a vinyl group (CH ₂ =CH- group) and an allyl group (CH ₂ =CH-CH _2- group) imidazolium cations such as cations having a seed, more preferably 1-ethyl-3-methylimidazolium cation, 1-hexyl-3-methylimidazolium cation, these cations further having a vinyl group (CH ₂ = CH— group) and an allyl group (CH ₂ ═CH—CH ₂ — group).

Examples of the cation structure represented by general formula (5) include a pyrazolium cation structure and a pyrazolinium cation structure.

Specific examples of the cation represented by the general formula (5) include, for example, 1-methylpyrazolium cation, 3-methylpyrazolium cation, 1-ethyl-2-methylpyrazolinium cation, 1-ethyl- pyrazolium cations such as 2,3,5-trimethylpyrazolium cation, 1-propyl-2,3,5-trimethylpyrazolium cation, 1-butyl-2,3,5-trimethylpyrazolium cation; pyrazolinium cation such as 1-ethyl-2,3,5-trimethylpyrazolinium cation, 1-propyl-2,3,5-trimethylpyrazolinium cation, 1-butyl-2,3,5-trimethylpyrazolinium cation zolinium cations; cations further having at least one selected from a vinyl group (CH ₂ =CH- group) and an allyl group (CH ₂ =CH-CH ₂ - group); and the like.

Examples of the cation structure represented by the general formula (6) include, for example, a tetraalkylammonium cation structure, a trialkylsulfonium cation structure, a tetraalkylphosphonium cation structure, and a part of the above alkyl group being an alkenyl group, an alkoxyl group, or an epoxy group. , and the like.

Specific examples of the cation represented by formula (6) include tetramethylammonium cation, tetraethylammonium cation, tetrabutylammonium cation, tetrapentylammonium cation, tetrahexylammonium cation, tetraheptylammonium cation, and triethylmethylammonium. cations, tributylethylammonium cation, trimethylpropylammonium cation, trimethyldecylammonium cation, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium cation, glycidyltrimethylammonium cation, diallyldimethylammonium cation, N, N-dimethyl-N-ethyl-N-propylammonium cation, N,N-dimethyl-N-ethyl-N-butylammonium cation, N,N-dimethyl-N-ethyl-N-pentylammonium cation, N,N- Dimethyl-N-ethyl-N-hexylammonium cation, N,N-dimethyl-N-ethyl-N-heptylammonium cation, N,N-dimethyl-N-ethyl-N-nonylammonium cation, N,N-dimethyl- N,N-dipropylammonium cation, N,N-diethyl-N-propyl-N-butylammonium cation, N,N-dimethyl-N-propyl-N-pentylammonium cation, N,N-dimethyl-N-propyl -N-hexylammonium cation, N,N-dimethyl-N-propyl-N-heptylammonium cation, N,N-dimethyl-N-butyl-N-hexylammonium cation, N,N-diethyl-N-butyl-N -heptylammonium cation, N,N-dimethyl-N-pentyl-N-hexylammonium cation, N,N-dimethyl-N,N-dihexylammonium cation, trimethylheptylammonium cation, N,N-diethyl-N-methyl- N-propylammonium cation, N,N-diethyl-N-methyl-N-pentylammonium cation, N,N-diethyl-N-methyl-N-heptylammonium cation, N,N-diethyl-N-propyl-N- Pentylammonium cation, triethylpropylammonium cation, triethylpentylammonium cation, triethylheptylammonium cation, N,N-dipropyl-N-methyl-N-ethylammonium cation, N,N-dipropyl-N-methyl-N-pentylammonium cation, N,N-dipropyl-N-butyl-N-hexylammonium cation, N,N-dipropyl-N,N-dihexylammonium cation, N, N-dibutyl-N-methyl-N-pentylammonium cation, N,N-dibutyl-N-methyl-N-hexylammonium cation, trioctylmethylammonium cation, N-methyl-N-ethyl-N-propyl-N- tetraalkylammonium cations such as pentylammonium cation; trialkylsulfonium cations such as trimethylsulfonium cation, triethylsulfonium cation, tributylsulfonium cation, trihexylsulfonium cation, diethylmethylsulfonium cation, dibutylethylsulfonium cation, dimethyldecylsulfonium cation; tetramethyl tetraalkylphosphonium cations such as phosphonium cations, tetraethylphosphonium cations, tetrabutylphosphonium cations, tetrahexylphosphonium cations, tetraoctylphosphonium cations, triethylmethylphosphonium cations, tributylethylphosphonium cations, trimethyldecylphosphonium cations; cations having at least one selected from (CH ₂ =CH- group) and allyl groups (CH ₂ =CH-CH ₂ - group); and the like.

The ionic compound is preferably an ionic compound containing at least one selected from the above onium cations and the above metal cations and the above fluoroorganic anion, or an ionic group-containing silicone oligomer, more preferably the above and at least one selected from the above metal cations and the above fluoroorganic anion, and more preferably an ionic compound containing the above onium cation and the above fluoroorganic anion.

The ionic compound is preferably 1-hexylpyridinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylpyridinium trifluoromethanesulfonate, 1 - ethyl-3-methylpyridinium pentafluoroethanesulfonate, 1-ethyl-3-methylpyridinium heptafluoropropanesulfonate, 1-ethyl-3-methylpyridinium nonafluorobutanesulfonate, 1-butyl-3-methylpyridinium trifluoromethanesulfonate, 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide, 1-octyl-4-methylpyridinium bis(fluorosulfonyl)imide, 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1 -methyl-1-propylpyrrolidinium bis(fluorosulfonyl)imide, 1-methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpiperidinium bis(fluorosulfonyl)imide , 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium heptafluoropropanesulfonate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3 -methylimidazolium bis(fluorosulfonyl)imide, 1-hexyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-allyl-3-methyl-imidazolium trifluoromethanesulfonate, 1-allyl-3-methyl-imidazo Lithium Heptafluoropropanesulfonate, 1-allyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide, 1-allyl-3-methyl-imidazolium bis(fluorosulfonyl)imide, methyltrioctylammonium bis(trifluoromethanesulfonyl) ) imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, more preferably 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl ) imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl) imide, 1-allyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide, methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide imide, particularly preferably 1-butyl-3-methylpyridinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1-allyl-3-methyl-imidazolium bis(trifluoromethanesulfonyl)imide, methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, and trimethylpropylammonium bis(trifluoromethanesulfonyl)imide.

Commercially available ionic compounds may be used, or those synthesized by any appropriate method may be used. For example, ionic liquids can be obtained by the halide method, hydroxide method, acid ester method, complex formation method, as described in "Ionic liquids - the front line of development and the future" (published by CMC Publishing). and may be synthesized by a neutralization method or the like.

[Fluorine-based additive]
When a fluorine-based additive is included as another component, it becomes possible to further improve the easy release property and antistatic performance of the surface protective film according to the embodiment of the present invention.

As the fluorine-based additive, any suitable fluorine-based additive can be employed as long as the effects of the present invention are not impaired.

The fluorine-based additive may be used alone or in combination of two or more.

The content of the fluorine-based additive is preferably 0.01 parts by weight or more, more preferably 0.03 parts by weight to 30 parts by weight, and still more preferably 100 parts by weight in total of the urethane prepolymer and the polyol. is 0.05 to 10 parts by weight, particularly preferably 0.05 to 1 part by weight.
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (A), since the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyol, the content of the fluorine-based additive is as described above. be.
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (B) mode, the urethane-based pressure-sensitive adhesive composition does not contain a polyol (that is, it is 0 parts by weight), so fluorine relative to 100 parts by weight of the urethane prepolymer The range of content of the system additive is as described above.
In addition, when the urethane-based pressure-sensitive adhesive composition is in the above (C) mode, the urethane-based pressure-sensitive adhesive composition does not contain a urethane prepolymer (that is, it is 0 parts by weight), so fluorine with respect to 100 parts by weight of polyol The content of the system additive is as described above.
If the content of the fluorine-based additive is within the above range, it becomes possible to further improve the easy peelability and antistatic performance of the surface protective film according to the embodiment of the present invention.

Examples of fluorine-based additives include at least one selected from fluorine-containing compounds, hydroxyl group-containing fluorine-based compounds, and crosslinkable functional group-containing fluorine-based compounds.

The fluorine-containing compound includes, for example, a compound having a fluoroaliphatic hydrocarbon skeleton, a fluorine-containing organic compound obtained by copolymerizing an organic compound and a fluorine compound, and a fluorine-containing compound containing an organic compound. Fluoroaliphatic hydrocarbon backbones include, for example, fluoroC1-C10 alkanes such as fluoromethane, fluoroethane, fluoropropane, fluoroisopropane, fluorobutane, fluoroisobutane, fluoro-t-butane, fluoropentane, and fluorohexane. . Here, the notation "C1-C10" means 1-10 carbon atoms.

A preferred embodiment of the fluorine-containing compound is an oligomer (“specific fluorine compound”) having a fluorine-containing group and a hydrophilic group and/or a lipophilic group. By adopting such a "specific fluorine-based compound", it is possible to improve the easy releasability and antistatic performance of the surface protective film according to the embodiment of the present invention. In particular, by using such a "specific fluorine-based compound" together with an ionic compound, it becomes possible to further improve the easy release property and antistatic performance of the surface protective film according to the embodiment of the present invention. This is presumably because the specific fluorine-based compound causes the ionic compound to be unevenly distributed on the surface side of the urethane-based pressure-sensitive adhesive layer (the side to be bonded to the adherend). Typical fluorine-containing groups include fluorine-containing alkyl groups (eg, CF ₃ —) and/or fluorine-containing alkylene groups (eg, —CF ₂ —CF ₂ —). A hydrophilic group is a group having hydrophilicity, and hydrophilicity is translated into English as "hydrophilic" and is a property generally known to those skilled in the art as "having an affinity for water". (See, for example, McGraw-Hill Encyclopedia of Science and Technology Terms (revised 3rd edition, Nikkan Kogyo Shimbun, Ltd.), etc.). A lipophilic group is a group having lipophilic properties, and lipophilicity is translated in English as "lipophilic" and is a property generally known to those skilled in the art as "having an affinity for oils". (See, for example, McGraw-Hill Encyclopedia of Science and Technology Terms (revised 3rd edition, Nikkan Kogyo Shimbun, Ltd.), etc.).

The fluorine-containing compound preferably has a surface tension of 19.0% in a 0.1% toluene solution from the viewpoint of further improving the antistatic performance and easy peelability of the surface protective film according to the embodiment of the present invention. It is 0 mJ/m ² to 28.0 mJ/m ² , more preferably 19.0 mJ/m ² to 26.0 mJ/m ² (the surface tension of toluene is 27.9 mN/m). As described above, if the surface tension of the fluorine-containing compound in a 0.1% toluene solution is within the above range, the antistatic performance and easy peelability of the surface protective film according to the embodiment of the present invention are further improved. can let

Commercially available fluorine-containing compounds include, for example, the following.

Megafuck series manufactured by DIC Corporation:
Typically, "Megafuck F-114", "Megafuck F-251", "Megafuck F-253", "Megafuck F-281", "Megafuck F-410", "Megafuck F- 430", "Megafuck F-444", "Megafuck F-477", "Megafuck F-510", "Megafuck F-551-A", "Megafuck F-553", "Megafuck F- 554", "Megafuck F-555-A", "Megafuck F-556", "Megafuck F-557", "Megafuck F-558", "Megafuck F-559", "Megafuck F- 560", "Megafuck F-561", "Megafuck F-562", "Megafuck F-563", "Megafuck F-565", "Megafuck F-568", "Megafuck F-569" , “Megafuck F-570”, “Megafuck F-576”, “Megafuck R-01”, “Megafuck R-40”, “Megafuck R-40-LM”, “Megafuck R-41” , "Megafuck R-41-LM", "Megafuck R-94", "Megafuck RS-56", "Megafuck RS-72-K", "Megafuck RS-75-A", "Megafuck RS-75-NS", "Megafac RS-78", "Megafac RS-90", etc.

Surflon series manufactured by AGC Seimi Chemical Co., Ltd.:
Typical examples are "S-242", "S-243", "S-386" and the like.

FC series manufactured by Sumitomo 3M:
Typical examples are "FC-4430" and "FC-4432".

Futergent series manufactured by Neos Co., Ltd.:
Representative examples are "Ftergent 100", "Ftergent 100C", "Ftergent 110", "Ftergent 150", "Ftergent 150CH", "Ftergent 250", "Ftergent 400SW" and the like.

PF series manufactured by Kitamura Chemical Industry Co., Ltd.:
Typically, "PF-136A", "PF-156A", "PF-151N", "PF-636", "PF-6320", "PF-656", "PF-6520", "PF- 651”, “PF-652”, “PF-3320”, etc.

As the hydroxyl group-containing fluorine-based compound, for example, conventionally known resins can be used. No. 97/11130 pamphlet, and International Publication No. 96/26254 pamphlet. Other hydroxyl group-containing fluororesins include, for example, JP-A-8-231919, JP-A-10-265731, JP-A-10-204374, JP-A-8-12922, and the like. A polymer etc. are mentioned. In addition, a copolymer of a compound having a fluorinated alkyl group in a hydroxyl group-containing compound, a fluorine-containing organic compound obtained by copolymerizing a fluorine-containing compound in a hydroxyl group-containing compound, a fluorine-containing compound containing a hydroxyl group-containing organic compound, and the like. Examples of such hydroxyl group-containing fluorine-based compounds include commercially available products such as "Lumiflon" (manufactured by Asahi Glass Co., Ltd.), "Cefral Coat" (manufactured by Central Glass Co., Ltd.), and "Zaflon" (trade name). (manufactured by Toagosei Co., Ltd.), trade name "Zeffle" (manufactured by Daikin Industries, Ltd.), and the like.

Examples of crosslinkable functional group-containing fluorine-based compounds include carboxylic acid compounds having a fluorinated alkyl group such as perfluorooctanoic acid, and compounds having a crosslinkable functional group-containing compound having a fluorinated alkyl group. Polymers, fluorine-containing organic compounds obtained by copolymerizing fluorine-containing compounds with crosslinkable functional group-containing compounds, fluorine-containing compounds containing crosslinkable functional group-containing compounds, and the like. Examples of such crosslinkable functional group-containing fluorine-based compounds include commercially available products such as "Megafac F-570", "Megafac RS-55", "Megafac RS-56", and "Megafac RS-72-K", "Megafac RS-75", "Megafac RS-76-E", "Megafac RS-76-NS", "Megafac RS-78", "Megafac RS-90" (manufactured by DIC Corporation).

Among commercially available fluorine-containing compounds, those corresponding to the above-mentioned "oligomer having a fluorine-containing group and a hydrophilic group and/or a lipophilic group" are typically available from DIC Corporation. made of
"Megafac F-477" (fluorine-containing group-hydrophilic group-lipophilic group-containing oligomer, surface tension = 26.4 mN/m when used as a 0.1% toluene solution),
"Megafac F-551-A" (fluorinated group/lipophilic group-containing oligomer, surface tension = 25.6 mN/m when used as a 0.1% toluene solution),
"Megafac F-553" (fluorine-containing group/hydrophilic group/lipophilic group-containing oligomer, surface tension = 26.4 mN/m when used as a 0.1% toluene solution),
"Megafac F-554" (fluorinated group/lipophilic group-containing oligomer, surface tension = 25.0 mN/m when used as a 0.1% toluene solution),
"Megafac F-555-A" (fluorine-containing group-hydrophilic group-lipophilic group-containing oligomer, surface tension = 20.4 mN / m when used as a 0.1% toluene solution),
"Megafac F-557" (fluorine-containing group-hydrophilic group-lipophilic group-containing oligomer, surface tension = 26.3 mN/m when used as a 0.1% toluene solution),
"Megafac F-559" (fluorine-containing group-hydrophilic group-lipophilic group-containing oligomer, surface tension = 26.1 mN/m when used as a 0.1% toluene solution),
"Megafac F-563" (fluorinated group/lipophilic group-containing oligomer, surface tension = 20.2 mN/m when used as a 0.1% toluene solution),
"Megafac F-569" (fluorinated group/hydrophilic group-containing oligomer, surface tension = 19.7 mN/m when used as a 0.1% toluene solution),
etc.

[Silicone additive]
When a silicone-based additive is included as another component, it becomes possible to further improve the easy release property of the surface protection film according to the embodiment of the present invention.

As the silicone additive, any appropriate silicone additive can be employed as long as the effects of the present invention are not impaired.

Only one type of silicone additive may be used, or two or more types may be used.

The content of the silicone additive is preferably 0.01 parts by weight or more, more preferably 0.015 parts by weight to 30 parts by weight, and still more preferably 100 parts by weight in total of the urethane prepolymer and the polyol. is 0.020 to 10 parts by weight, particularly preferably 0.025 to 1 part by weight.
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (A), since the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyol, the content of the silicone additive is as described above. be.
In addition, when the urethane-based pressure-sensitive adhesive composition is in the above (B) mode, the urethane-based pressure-sensitive adhesive composition does not contain a polyol (that is, it is 0 parts by weight), so silicone with respect to 100 parts by weight of the urethane prepolymer The range of content of the system additive is as described above.
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (C) mode, since the urethane-based pressure-sensitive adhesive composition does not contain a urethane prepolymer (that is, it is 0 parts by weight), the silicone to 100 parts by weight of the polyol The content of the system additive is as described above.
If the content of the silicone-based additive is within the above range, it is possible to further improve the easy peelability of the surface protective film according to the embodiment of the present invention.

From the point of view that the effect of the present invention can be more expressed, the content ratio of the total amount of the fluorine-based additive and the silicone-based additive to 100 parts by weight of the urethane prepolymer and the polyol is 0.01 part by weight or more. , more preferably 0.03 to 30 parts by weight, still more preferably 0.05 to 10 parts by weight, and particularly preferably 0.05 to 1 part by weight.
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (A), since the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyol, the total amount of the fluorine-based additive and the silicone-based additive is The content ratio is as described above.
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (B) mode, the urethane-based pressure-sensitive adhesive composition does not contain a polyol (that is, it is 0 parts by weight), so fluorine relative to 100 parts by weight of the urethane prepolymer The range of the content ratio of the total amount of the silicone additive and the silicone additive is as described above.
In addition, when the urethane-based pressure-sensitive adhesive composition is in the above (C) mode, the urethane-based pressure-sensitive adhesive composition does not contain a urethane prepolymer (that is, it is 0 parts by weight), so fluorine with respect to 100 parts by weight of polyol The content ratios of the system additive and the silicone additive are as described above.

Any appropriate silicone-based additive can be adopted as the silicone-based additive as long as it does not impair the effects of the present invention. Examples of such silicone additives include reactive silicone oils and non-reactive silicone oils.

Reactive silicone oils include, for example, side chain type reactive silicone oils in which organic groups are bonded as side chains to Si atoms that provide siloxane bonds, and double-end type in which organic groups are bonded to Si atoms located at both ends of the structure. Reactive silicone oil, single-end reactive silicone oil in which an organic group is bonded to only one of the Si atoms located at both ends of the structure, organic groups are bonded as side chains to the Si atoms used for siloxane bonding, and both ends of the structure Side chain double-ended reactive silicone oils in which an organic group is bonded to the Si atom located at the end are exemplified.

Examples of side-chain reactive silicone oils include amino-modified side-chain reactive silicone oils, epoxy-modified side-chain reactive silicone oils, carbinol-modified side-chain reactive silicone oils, mercapto Modified side-chain reactive silicone oils, carboxyl-modified side-chain reactive silicone oils, and methylhydrogensilicone oil-type side-chain reactive silicone oils can be used. Examples of these commercial products include various silicone oils marketed as side-chain reactive silicone oils manufactured by Shin-Etsu Chemical Co., Ltd.

Examples of the double-end reactive silicone oil include amino-modified double-end reactive silicone oil, epoxy-modified double-end reactive silicone oil, carbinol-modified double-end reactive silicone oil, methacryl Modified type reactive silicone oil at both ends, polyether-modified reactive silicone oil at both ends, mercapto-modified reactive silicone oil at both ends, carboxyl-modified reactive silicone oil at both ends, phenol-modified type reactive silicone oil, silanol-terminated reactive silicone oil, acrylic-modified reactive silicone oil, and carboxylic acid anhydride-modified reactive silicone oil. be done. Examples of these commercial products include various silicone oils marketed as double-ended reactive silicone oils manufactured by Shin-Etsu Chemical Co., Ltd. In particular, carbinol-modified double-ended reactivity such as "KF-6000", "KF-6001", "KF-6002", "KF-6003", and "KF-6028" manufactured by Shin-Etsu Chemical Co., Ltd. Silicone oil can be preferably employed.

The single-end reactive silicone oil includes, for example, a single-end reactive modified type single-end reactive silicone oil and an average single-end carboxyl-modified single-end reactive silicone oil. Examples of these commercial products include various silicone oils marketed as single-ended reactive silicone oils manufactured by Shin-Etsu Chemical Co., Ltd. In particular, carbinol-modified single-ended reactive silicone oils such as "X-22-170BX", "X-22-170DX" and "X-22-4015" manufactured by Shin-Etsu Chemical Co., Ltd. can be preferably employed. .

Examples of the side-chain both-terminal reactive silicone oil include side-chain amino/both-terminal methoxy-modified side-chain both-terminal reactive silicone oil and epoxy-modified side-chain both-terminal reactive silicone oil. . Examples of these commercial products include various silicone oils marketed as reactive silicone oils with both side chain ends manufactured by Shin-Etsu Chemical Co., Ltd.

Non-reactive silicone oils include, for example, side-chain non-reactive silicone oils in which organic groups are bonded as side chains to Si atoms that provide siloxane bonds, and organic groups in which organic groups are bonded to Si atoms located at both ends of the structure. A terminal type non-reactive silicone oil may be mentioned.

Examples of side-chain non-reactive silicone oils include polyether-modified side-chain non-reactive silicone oils, aralkyl-modified side-chain non-reactive silicone oils, and batho alkyl-modified side-chain non-reactive silicone oils. Reactive silicone oil, long-chain alkyl-modified side-chain non-reactive silicone oil, higher fatty acid ester-modified side-chain non-reactive silicone oil, higher fatty acid-containing side-chain non-reactive silicone oil, phenyl Modified side chain type non-reactive silicone oils are included. Examples of these commercial products include various silicone oils marketed as side-chain non-reactive silicone oils manufactured by Shin-Etsu Chemical Co., Ltd. In particular, "KF-351A", "KF-352A", "KF-353", "KF-354L", "KF-355A", "KF-615A", "KF-945" manufactured by Shin-Etsu Chemical Co., Ltd., Polyether modified type such as "KF-640", "KF-642", "KF-643", "KF-644", "KF-6020", "KF-6204", "X-22-4515" side chain type non-reactive silicone oil can be preferably employed.

Among these polyether-modified side-chain non-reactive silicone oils, the HLB value is preferably 3 or more, more preferably 8 or more, and still more preferably 9 or more, in terms of further reducing adhesive residue. Polyether-modified type side chain non-reactive silicone oils of 10 or more are particularly preferred. Examples of such polyether-modified side chain non-reactive silicone oils include "KF-351A" (HLB = 12), "KF-353" (HLB = 10), "KF-354L" (HLB = 16), “KF-355A” (HLB = 12), “KF-615A” (HLB = 10), “KF-640” (HLB = 14), “KF-642” (HLB = 12), “KF -643” (HLB=14), “KF-644” (HLB=11), and “KF-6204” (HLB=10).

Examples of the double-ended non-reactive silicone oil include polyether-modified double-ended non-reactive silicone oil. Examples of these commercial products include various silicone oils marketed as double-ended non-reactive silicone oils manufactured by Shin-Etsu Chemical Co., Ltd. In particular, a polyether-modified double-ended non-reactive silicone oil such as "KF-6004" manufactured by Shin-Etsu Chemical Co., Ltd. can be preferably used.

As the silicone-based additive, in addition to the above, any suitable silicone-based additive conventionally known can be employed. Examples of such silicone additives include siloxane bond-containing polymers other than those described above, hydroxyl group-containing silicone compounds other than those described above, and silicone compounds containing crosslinkable functional groups other than those described above.

Examples of commercial products of siloxane bond-containing polymers other than those described above include, for example, the product name "LE-302" (manufactured by Kyoeisha Chemical Co., Ltd.), BYK series leveling agent manufactured by BYK Chemie Japan Co., Ltd. ("BYK-300 , BYK-301/302, BYK-306, BYK-307, BYK-310, BYK-315, BYK-313, BYK-320, BYK-322 ”, “BYK-323”, “BYK-325”, “BYK-330”, “BYK-331”, “BYK-333”, “BYK-337”, “BYK-341”, “BYK-344”, "BYK-345/346", "BYK-347", "BYK-348", "BYK-349", "BYK-370", "BYK-375", "BYK-377", "BYK-378", "BYK-UV3500", "BYK-UV3510", "BYK-UV3570", "BYK-3550", "BYK-SILCLEAN3700", "BYK-SILCLEAN3720", etc.), AC series leveling agents manufactured by Algin Chemie (" AC FS180", "AC FS360", "AC S20", etc.), Polyflow series leveling agents manufactured by Kyoeisha Chemical Co., Ltd. ("Polyflow KL-400X", "Polyflow KL-400HF", "Polyflow KL-401") , "Polyflow KL-402", "Polyflow KL-403", "Polyflow KL-404", etc.), KP series leveling agents manufactured by Shin-Etsu Chemical Co., Ltd. ("KP-323", "KP-326", "KP-341", "KP-104", "KP-110", "KP-112", etc.), leveling agents manufactured by Dow Corning Toray Co., Ltd. ("LP-7001", "LP-7002", "8032ADDITIVE", "57ADDITIVE", "L-7604", "FZ-2110", "FZ-2105", "67ADDITIVE", "8618ADDITIVE", "3ADDITIVE", "56ADDITIVE", etc.).

Examples of commercially available hydroxyl group-containing silicones other than those mentioned above include "BYK-370", "BYK-SILCLEAN3700" and "BYK-SILCLEAN3720" manufactured by BYK-Chemie Japan.

Examples of commercially available crosslinkable functional group-containing silicone compounds other than those described above include "BY16-855", "SF8413", "BY16-839", and "SF8421" manufactured by Dow Corning Toray Co., Ltd. "BY16-750", "BY16-880", and "BY16-152C".

〔Antioxidant〕
The urethane-based pressure-sensitive adhesive composition may contain an antioxidant as another component from the viewpoint of suppressing deterioration of the urethane-based pressure-sensitive adhesive layer. Only one kind of antioxidant may be used, or two or more kinds thereof may be used.

Any appropriate content can be adopted as the content of the antioxidant in the urethane-based pressure-sensitive adhesive composition as long as the effects of the present invention are not impaired. Such a content ratio is preferably 0.01 parts by weight to 10 parts by weight or more, more preferably 0.05 parts by weight, as a content ratio of the antioxidant with respect to the total 100 parts by weight of the urethane prepolymer and the polyol. to 5 parts by weight, more preferably 0.1 to 3 parts by weight, and particularly preferably 0.2 to 1 part by weight.
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (A), since the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyol, the antioxidant content is as described above. .
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (B) mode, the urethane-based pressure-sensitive adhesive composition does not contain a polyol (that is, it is 0 parts by weight), so oxidation with respect to 100 parts by weight of the urethane prepolymer The range of content of the inhibitor is as described above.
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (C) mode, the urethane-based pressure-sensitive adhesive composition does not contain a urethane prepolymer (that is, it is 0 parts by weight), so oxidation with respect to 100 parts by weight of polyol The content of the inhibitor is as described above.

Antioxidants include, for example, radical chain inhibitors and peroxide decomposers.

Examples of radical chain inhibitors include phenol antioxidants and amine antioxidants.

Examples of peroxide decomposers include sulfur-based antioxidants and phosphorus-based antioxidants.

Examples of phenolic antioxidants include monophenolic antioxidants, bisphenolic antioxidants, and polymeric phenolic antioxidants.

Examples of monophenol antioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearin-β-( 3,5-di-t-butyl-4-hydroxyphenyl)propionate.

Examples of bisphenol antioxidants include 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4' -thiobis(3-methyl-6-t-butylphenol), 4,4′-butylidenebis(3-methyl-6-t-butylphenol), 3,9-bis[1,1-dimethyl-2-[β-( 3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane.

Examples of polymeric phenolic antioxidants include 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4, 6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane , bis[3,3′-bis-(4′-hydroxy-3′-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3′,5′-di-t-butyl -4′-hydroxybenzyl)-S-triazine-2,4,6-(1H,3H,5H)trione, tocopherol.

Examples of sulfur-based antioxidants include dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, and distearyl 3,3'-thiodipropionate.

Phosphorus-based antioxidants include, for example, triphenylphosphite, diphenylisodecylphosphite, and phenyldiisodecylphosphite.

[Ultraviolet absorber]
The urethane-based pressure-sensitive adhesive composition may contain an ultraviolet absorber as another component from the viewpoint of suppressing deterioration of the urethane-based pressure-sensitive adhesive layer. Only one ultraviolet absorber may be used, or two or more ultraviolet absorbers may be used.

Any appropriate content can be adopted as the content of the ultraviolet absorber in the urethane-based pressure-sensitive adhesive composition as long as the effects of the present invention are not impaired. Such a content ratio is preferably 0.01 parts by weight to 10 parts by weight or more, more preferably 0.05 parts by weight, as a content ratio of the ultraviolet absorber with respect to the total 100 parts by weight of the urethane prepolymer and polyol. It is from 0.1 to 3 parts by weight, and particularly preferably from 0.2 to 1 part by weight.
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (A), since the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyol, the content of the ultraviolet absorber is as described above. .
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (B) mode, the urethane-based pressure-sensitive adhesive composition does not contain a polyol (i.e., it is 0 parts by weight), so ultraviolet rays with respect to 100 parts by weight of the urethane prepolymer The range of content ratio of the absorbent is as described above.
In addition, when the urethane-based pressure-sensitive adhesive composition is in the above (C) mode, since the urethane-based pressure-sensitive adhesive composition does not contain a urethane prepolymer (that is, it is 0 parts by weight), ultraviolet rays with respect to 100 parts by weight of polyol The content ratio of the absorbent is as described above.

Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylic acid-based ultraviolet absorbers, oxalic acid anilide-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, and triazine-based ultraviolet absorbers. .

Benzophenone-based UV absorbers include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2' -dihydroxy-4-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis(2-methoxy-4-hydroxy-5-benzoylphenyl ) methane.

Benzotriazole-based UV absorbers include, for example, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, 2-( 2′-hydroxy-3′,5′-di-tert-butylphenyl)benzotriazole, 2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzotriazole, 2 -(2'-hydroxy-3',5'-di-tert-butylphenyl)5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole, 2-(2'-hydroxy-4'-octoxyphenyl)benzotriazole, 2-[2'-hydroxy-3'-(3'',4'',5'',6'',-tetrahydrophthalimidomethyl )-5′-methylphenyl]benzotriazole, 2,2′methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl)phenol], [2 (2'-Hydroxy-5'-methacryloxyphenyl)-2H-benzotriazole.

Examples of salicylic acid-based ultraviolet absorbers include phenyl salicylate, p-tert-butylphenyl salicylate, and p-octylphenyl salicylate.

Examples of cyanoacrylate ultraviolet absorbers include 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate and ethyl-2-cyano-3,3'-diphenyl acrylate.

[Light stabilizer]
The urethane-based pressure-sensitive adhesive composition may contain a light stabilizer as another component from the viewpoint of suppressing deterioration of the urethane-based pressure-sensitive adhesive layer. Only one kind of light stabilizer may be used, or two or more kinds thereof may be used.

Any appropriate content can be adopted as the content of the light stabilizer in the urethane-based pressure-sensitive adhesive composition as long as the effects of the present invention are not impaired. Such a content ratio is preferably 0.01 parts by weight to 10 parts by weight or more, and more preferably 0.05 parts by weight, as a content ratio of the light stabilizer with respect to the total 100 parts by weight of the urethane prepolymer and polyol. part to 5 parts by weight, more preferably 0.1 to 3 parts by weight, and particularly preferably 0.2 to 1 part by weight.
More specifically, when the urethane-based pressure-sensitive adhesive composition is in the above aspect (A), since the urethane-based pressure-sensitive adhesive composition contains a urethane prepolymer and a polyol, the content of the light stabilizer is as described above. .
In addition, when the urethane-based pressure-sensitive adhesive composition is in the above (B) mode, since the urethane-based pressure-sensitive adhesive composition does not contain a polyol (that is, it is 0 parts by weight), the light with respect to 100 parts by weight of the urethane prepolymer The range of content of the stabilizer is as described above.
Further, when the urethane-based pressure-sensitive adhesive composition is in the above (C) mode, the urethane-based pressure-sensitive adhesive composition does not contain a urethane prepolymer (that is, it is 0 parts by weight), so the light with respect to 100 parts by weight of the polyol The content ratio of the stabilizer is as described above.

Light stabilizers include, for example, hindered amine light stabilizers and ultraviolet stabilizers.

Examples of hindered amine light stabilizers include [bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate] and bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate. , methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate.

UV stabilizers include, for example, nickel bis(octylphenyl) sulfide, [2,2′-thiobis(4-tert-octylphenolate)]-n-butylamine nickel, nickel complex-3,5-di-tert- Butyl-4-hydroxybenzyl-phosphate monoethylate, nickel-dibutyldithiocarbamate, benzoate-type quenchers, nickel-dibutyldithiocarbamate.

[Fatty acid ester]
From the viewpoint of improving the wettability of the urethane-based pressure-sensitive adhesive layer, the urethane-based pressure-sensitive adhesive composition may contain a fatty acid ester as another component. Only one kind of fatty acid ester may be used, or two or more kinds thereof may be used.

The number average molecular weight Mn of the fatty acid ester is preferably 200 to 400, more preferably 210 to 395, still more preferably 230 to 380, particularly preferably 240 to 360, most preferably 250 to 350. is. By adjusting the number average molecular weight Mn of the fatty acid ester within the above range, the wetting speed can be further improved. If the number average molecular weight Mn of the fatty acid ester is too small, the wetting speed may not improve even if the number of parts added is large. If the number average molecular weight Mn of the fatty acid ester is too large, the curability of the pressure-sensitive adhesive during drying may deteriorate, which may adversely affect not only wettability but also other pressure-sensitive adhesive properties.

As the fatty acid ester, any suitable fatty acid ester can be adopted as long as it does not impair the effects of the present invention. Examples of such fatty acid esters include polyoxyethylene bisphenol A laurate, butyl stearate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, monoglyceride behenate, cetyl 2-ethylhexanoate, and myristic acid. Isopropyl, isopropyl palmitate, cholesteryl isostearate, lauryl methacrylate, methyl cocoate, methyl laurate, methyl oleate, methyl stearate, myristyl myristate, octyldodecyl myristate, pentaerythritol monooleate, pentaerythritol monostearate , pentaerythritol tetrapalmitate, stearyl stearate, isotridecyl stearate, 2-ethylhexanoic acid triglyceride, butyl laurate, and octyl oleate.

<<1-3. Base layer≫
Any appropriate thickness can be adopted as the thickness of the base material layer depending on the application. The thickness of the substrate layer is preferably 5 μm to 300 μm, more preferably 10 μm to 250 μm, even more preferably 15 μm to 200 μm, particularly preferably 20 μm to 150 μm.

The substrate layer may be a single layer or a laminate of two or more layers. The substrate layer may be stretched.

Any appropriate material can be adopted as the material of the base material layer depending on the application. Examples include plastics, paper, metal films, and non-woven fabrics. Preferably, it is plastic. The base material layer may be composed of one kind of material, or may be composed of two or more kinds of materials. For example, it may be composed of two or more types of plastics.

Examples of the plastic include polyester-based resins, polyamide-based resins, and polyolefin-based resins. Polyester-based resins include, for example, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin-based resins include homopolymers of olefin monomers and copolymers of olefin monomers. Specific examples of polyolefin-based resins include, for example, homopolypropylene; block-, random-, and graft-based propylene-based copolymers having an ethylene component as a copolymerization component; reactor TPO; low-density, high-density, linear Ethylene-based polymers with low density, ultra-low density, etc.; ethylene/propylene copolymer, ethylene/vinyl acetate copolymer, ethylene/methyl acrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/acrylic acid ethylene-based copolymers such as butyl copolymers, ethylene/methacrylic acid copolymers, and ethylene/methyl methacrylate copolymers;

The base material layer may contain any appropriate additive as needed. Additives that can be contained in the substrate layer include, for example, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, fillers, and pigments. The type, number, and amount of additives that can be contained in the base material layer can be appropriately set according to the purpose. In particular, when the material of the substrate layer is plastic, it is preferable to contain some of the above additives for the purpose of preventing deterioration. From the viewpoint of improving weather resistance, particularly preferred additives include antioxidants, ultraviolet absorbers, light stabilizers, and fillers.

Any appropriate antioxidant can be employed as the antioxidant. Examples of such antioxidants include phenol-based antioxidants, phosphorus-based processing heat stabilizers, lactone-based processing heat stabilizers, sulfur-based heat-resistant stabilizers, and phenol/phosphorus-based antioxidants. The content of the antioxidant is preferably 1% by weight or less, more preferably 1% by weight or less, relative to the base resin of the base layer (when the base layer is a blend, the blend is the base resin). It is 0.5 wt % or less, more preferably 0.01 wt % to 0.2 wt %.

Any appropriate UV absorber can be adopted as the UV absorber. Examples of such ultraviolet absorbers include benzotriazole-based ultraviolet absorbers, triazine-based ultraviolet absorbers, and benzophenone-based ultraviolet absorbers. The content of the ultraviolet absorber is preferably 2% by weight or less with respect to the base resin forming the base layer (when the base layer is a blend, the blend is the base resin), and more It is preferably 1 wt % or less, more preferably 0.01 wt % to 0.5 wt %.

Any suitable light stabilizer can be employed as the light stabilizer. Examples of such light stabilizers include hindered amine light stabilizers and benzoate light stabilizers. The content of the light stabilizer is preferably 2% by weight or less with respect to the base resin forming the base layer (when the base layer is a blend, the blend is the base resin), and more It is preferably 1 wt % or less, more preferably 0.01 wt % to 0.5 wt %.

Any appropriate filler can be adopted as the filler. Examples of such fillers include inorganic fillers. Specific examples of inorganic fillers include carbon black, titanium oxide, and zinc oxide. The content of the filler is preferably 20% by weight or less, more preferably 20% by weight or less, relative to the base resin forming the base layer (when the base layer is a blend, the blend is the base resin). is 10% by weight or less, more preferably 0.01% to 10% by weight.

Further, the additive preferably includes inorganic, low-molecular-weight, and high-molecular-weight antistatic agents such as surfactants, inorganic salts, polyhydric alcohols, metal compounds, and carbon for the purpose of imparting antistatic properties. In particular, high-molecular-weight antistatic agents and carbon are preferred from the viewpoint of contamination and maintenance of adhesiveness.

<<<2. Method for producing surface protective film>>>>
The surface protection film of the invention can be produced by any appropriate method. As such a manufacturing method, for example,
(1) A method of applying a solution or hot melt of a material for forming an adhesive layer onto a substrate layer,
(2) a method in which a pressure-sensitive adhesive layer coated and formed in the form of a separator is transferred onto a substrate layer according to the method;
(3) A method of extruding and coating the material for forming the pressure-sensitive adhesive layer onto the substrate layer,
(4) A method of extruding a substrate layer and an adhesive layer in two layers or multiple layers,
(5) A method of laminating a single adhesive layer on a substrate layer or a method of laminating two adhesive layers together with a laminate layer,
(6) A method of two-layer or multi-layer lamination of an adhesive layer and a substrate layer-forming material such as a film or laminate layer,
It can be performed according to any appropriate manufacturing method such as.

Examples of coating methods that can be used include a roll coater method, a comma coater method, a die coater method, a reverse coater method, a silk screen method, and a gravure coater method.

<<<3. Applications of Surface Protection Films>>>>
Surface protection films according to embodiments of the present invention may be used in any suitable application. Since the surface protective film of the present invention has a urethane-based pressure-sensitive adhesive layer having an excellent surface elastic modulus, it is preferably used for surface protection of optical members and electronic members. Examples of optical members include LCDs, touch panels using LCDs, color filters used in LCDs, and polarizing plates.

A member to which the surface protective film according to the embodiment of the present invention is attached, such as an optical member or an electronic member, can be repeatedly attached and peeled manually with the attached surface protective film. .

That is, the optical member according to the embodiment of the present invention has the surface protective film of the present invention adhered thereto. Further, an electronic member according to an embodiment of the present invention has the surface protection film of the present invention adhered thereto.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. The tests and evaluation methods used in Examples and the like are as follows. "Parts" means "parts by weight" unless otherwise specified, and "%" means "% by weight" unless otherwise specified.

<Adhesive strength to glass>
A surface protective film (width 25 mm×length 140 mm) from which the separator was peeled off was adhered to glass (soda lime glass, manufactured by Matsunami Glass Industry Co., Ltd.) with one reciprocation of a 2 kg hand roller. After that, it was left for 30 minutes under an environmental temperature of 23°C. The obtained evaluation sample was measured with a tensile tester. As the tensile tester, a trade name "Autograph AG-Xplus HS 6000 mm/min high speed model (AG-50NX plus)" manufactured by Shimadzu Corporation was used. After setting the evaluation sample in the tensile tester, the tensile test was started. The conditions of the tensile test were a peeling angle of 180 degrees and a peeling speed (pulling speed) of 300 mm/min. The load when the surface protective film was peeled off from the glass was measured, and the average load at that time was defined as the adhesive strength (peeling force) of the surface protective film to glass.

<Residual adhesion rate to glass>
A surface protective film is attached to a glass plate (manufactured by Matsunami Glass, 1.35 mm × 10 cm × 10 cm) with a hand roller and stored for 24 hours in an atmosphere of 23 ° C. and 55% RH. = 180 degrees, the surface protective film was peeled off at a speed of 0.3 m/min, and a No. 19 mm wide piece cut to a length of 150 mm. A 31B tape (manufactured by Nitto Denko Corporation, substrate thickness: 25 μm) was adhered by one reciprocation of a 2.0 kg roller in an atmosphere of temperature 23° C. and humidity 55% RH. After curing for 30 minutes in an atmosphere with a temperature of 23 ° C. and a humidity of 55% RH, a tensile tester (trade name “Autograph AG-Xplus HS 6000 mm / min high speed model (AG-50NX plus)” manufactured by Shimadzu Corporation). was used, the adhesive force was measured by peeling at a peeling angle of 180 degrees and a pulling speed of 300 mm/min.
Separately, a No. 19 mm wide glass plate was similarly applied to a glass plate that had not been subjected to the above treatment. The adhesive strength of the 31B tape was measured, and the residual adhesion rate was calculated by the following formula.
Residual adhesion rate (%) = (No. 31B adhesive strength to glass plate after peeling surface protective film / No. 31B adhesive strength to glass plate) x 100
This residual adhesion rate is an index of how much the adhesive component of the surface protective film is transferred to the surface of the adherend and contaminates it. It can be said that the higher the value of the residual adhesion rate, the better the surface protection film without contamination of the adherend, and the lower the value of the residual adhesion rate, the more the surface of the adherend is contaminated with adhesive components. .

<Glass peeling electrostatic voltage resistance>
The surface protective film from which the separator was removed was cut into a size of 70 mm in width and 100 mm in length, and one end of the surface protective film was attached to the surface of glass (soda lime glass, manufactured by Matsunami Glass Industry Co., Ltd.). It was press-bonded with a hand roller so as to protrude 30 mm from the edge of the tape. After leaving this sample in an environment of 23° C. and 50% RH for one day, it was set at a predetermined position on a sample fixing table having a height of 20 mm. The end of the surface protection film protruding 30 mm from the adherend was fixed to an automatic winding machine (not shown), and the film was peeled off at a peeling angle of 150° and a peeling speed of 30 m/min. The potential on the surface of the adherend generated at this time was measured by a potential measuring device (manufactured by Shishido Electrostatic Co., Ltd., model "STATIRON DZ-4") fixed at a height of 30 mm from the center of the adherend. Peeling electrification voltage" was measured. The measurement was performed under the environment of 23° C. and 50% RH.

<Haze>
A urethane-based pressure-sensitive adhesive composition was applied to the release-treated surface of a 75 μm-thick polyester film (trade name: Diafoil MRF75, manufactured by Mitsubishi Chemical Corporation) whose one side was release-treated with silicone, under the conditions of Examples and Comparative Examples. After drying, a urethane pressure-sensitive adhesive layer was produced. Next, on the surface of the urethane-based adhesive layer, a 75 μm-thick polyester film (trade name: Diafoil MRE75, manufactured by Mitsubishi Chemical Corporation) with one side treated with silicone for release is applied, and the release-treated surface of the polyester film is a urethane-based adhesive. It was coated with the agent layer side, and aged at room temperature for 5 days.
Two pieces of 50 mm×50 mm cardboard with a hole of 20 mm×20 mm in the center were prepared, and the sample alone was adhered to one side by one reciprocation of a hand roller, and then the other side was adhered.
The haze of the evaluation sample obtained as described above was measured with "HM-150N" manufactured by Murakami Color Research Laboratory.

<Surface Elastic Modulus of Adhesive Layer>
The surface protective film from which the separator was removed was cut into a size of 10 mm square and fixed to a sample stand. The elastic modulus (MPa) of the pressure-sensitive adhesive surface was measured using a nanoindenter "TI950 TriboIndenter/a spherical diamond indenter (Conical indenter) with a radius of curvature of 10 μm, manufactured by Epson Co., Ltd. The measurement conditions are shown below.
・Measurement mode: single indentation test ・Holding time when maximum displacement is reached: 0 seconds
・Push-in/pull-out depth speed: 500 nm/sec
・Indentation depth: 5 μm
・Measurement environment: 23°C 50% RH

[Production Example 1]: Production of Urethane Prepolymer Solution A Equipped with a 1 L round-bottom separable flask, a separable cover, a separating funnel, a thermometer, a nitrogen inlet tube, a Liebig condenser, a vacuum seal, a stirring rod, and a stirring blade. In a polymerization experimental apparatus, 333 g of polytetramethylene glycol (product name "PTMG3000", manufactured by Mitsubishi Chemical Corporation), 83 g of polypropylene glycol (product name "Sannix GP-1500", manufactured by Sanyo Kasei Co., Ltd.), acetic acid as a solvent 110 g of ethyl (manufactured by Tosoh Corporation) was added, and while stirring, 0.041 g of dibutyltin dilaurate (IV) (manufactured by Wako Pure Chemical Industries, Ltd.) was added as a catalyst, and nitrogen substitution was performed at room temperature for 1 hour. After that, 13.0 g of hexamethylene diisocyanate (polyfunctional isocyanate compound, product name “HDI”, manufactured by Tosoh Corporation) was added while stirring under nitrogen flow, and the solution temperature in the experimental apparatus was brought to 90±2° C. in a water bath. After holding for 4 hours while controlling so as to obtain a urethane prepolymer solution A. During the polymerization, ethyl acetate was added dropwise as appropriate in order to control the temperature during the polymerization and to prevent deterioration of the stirrability due to an increase in viscosity. The total amount of ethyl acetate added dropwise was 320 g. The solid content concentration of the urethane prepolymer solution A was 50% by weight. This urethane prepolymer A was used in the examples.

[Production Example 2]: Production of Urethane Prepolymer Solution B Equipped with a 1 L round-bottom separable flask, a separable cover, a separating funnel, a thermometer, a nitrogen inlet tube, a Liebig condenser, a vacuum seal, a stirring rod, and a stirring blade. In a polymerization experimental apparatus, 197 g of polypropylene glycol (product name "Sannics PP-2000", manufactured by Sanyo Chemical Industries, Ltd.), 197 g of polyester polyol (product name "Kuraray Polyol P-2010", manufactured by Kuraray Co., Ltd.), a solvent 110 g of toluene (manufactured by Tosoh Corporation) as a catalyst and 0.041 g of dibutyltin dilaurate (IV) (manufactured by Wako Pure Chemical Industries, Ltd.) as a catalyst were added, and nitrogen substitution was performed at room temperature for 1 hour while stirring. After that, 33.5 g of hexamethylene diisocyanate (polyfunctional isocyanate compound, product name "HDI", manufactured by Tosoh Corporation) was added while stirring under nitrogen flow, and the solution temperature in the experimental apparatus was brought to 90±2°C in a water bath. After holding for 4 hours while controlling so that After holding for 2 hours while controlling as follows, 25.4 g of hexamethylene diisocyanate (product name “HDI”, manufactured by Tosoh Corporation) was added, and the solution temperature in the experimental apparatus was 90 ± 2 ° C. in a water bath. While controlling to 2 hours, a urethane prepolymer solution B was obtained. During the polymerization, toluene was added dropwise as appropriate in order to control the temperature during the polymerization and to prevent deterioration of the stirrability due to an increase in viscosity. The total amount of toluene dropped was 380 g. The solid content concentration of the urethane prepolymer solution B was 50% by weight. This urethane prepolymer B was used in Examples and Comparative Examples.

[Example 1]
100 parts by weight of urethane prepolymer A, 3.2 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and , 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (1). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (1). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 2]
95 parts by weight of urethane prepolymer A, 3.5 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000) which is a polyol having three hydroxyl groups as a polyol, Sannics GP3000 (Sanyo) which is a polyol having three hydroxyl groups Kasei Co., Ltd., Mn = 3000) 1.5 parts by weight, 3.8 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, Irganox 1010 (manufactured by BASF) as an antioxidant 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, and a urethane adhesive A solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (2). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protection film (2). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 3]
95 parts by weight of urethane prepolymer A, 3 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 2 parts by weight, 3.9 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (3). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (3). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 4]
80 parts by weight of urethane prepolymer A, 12 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 8 parts by weight, 6.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (4). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (4). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 5]
60 parts by weight of urethane prepolymer A, 28 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 12 parts by weight, 8.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (5). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protection film (5). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 6]
60 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 15 parts by weight, 8.6 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (6). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protection film (6). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 7]
50 parts by weight of urethane prepolymer A, 35 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 15 parts by weight, 9.2 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (7). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (7). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 8]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP4000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 4000) 20 parts by weight, 8.7 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (8). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (8). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 9]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (9). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (9). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 10]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannics GP1000 (manufactured by Sanyo Kasei Co., Ltd., Mn = 3000) 15 parts by weight, a polyol having three hydroxyl groups (Mn = 1000) 5 parts by weight, a polyfunctional isocyanate compound (Coronate HX: C/HX , Nippon Polyurethane Co., Ltd.) 12.9 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 parts by weight as a catalyst, The mixture was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (10). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protection film (10). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 11]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannics GP600 (manufactured by Sanyo Kasei Co., Ltd., Mn = 600) 18 parts by weight, which is a polyol having three hydroxyl groups, and a polyfunctional isocyanate compound (Coronate HX: C/HX) as a cross-linking agent. , Nippon Polyurethane Co., Ltd.) 12.7 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 parts by weight as a catalyst, The mixture was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (11). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (11). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 12]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannix GP400 (manufactured by Sanyo Kasei Co., Ltd., Mn = 3000) 18 parts by weight, which is a polyol having three hydroxyl groups (manufactured by Sanyo Kasei Co., Ltd., Mn = 400) 2 parts by weight, a polyfunctional isocyanate compound (Coronate HX: C/HX , Nippon Polyurethane Co., Ltd.) 14.0 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 parts by weight as a catalyst, The solution was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (12). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (12). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 1 shows the results.

[Example 13]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.05 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (Nippon Kagaku Sangyo Co., Ltd.) as a catalyst 0.03 parts by weight of the adhesive (manufactured by Co., Ltd.) was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (13). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (13). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 14]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.1 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (Nippon Kagaku Sangyo Co., Ltd.) as a catalyst Co., Ltd.) was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (14). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protection film (14). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 15]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (Nippon Kagaku Sangyo Co., Ltd.) as a catalyst 0.03 parts by weight of the adhesive (manufactured by Co., Ltd.) was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (15). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (15). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 16]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.0 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (Nippon Kagaku Sangyo Co., Ltd.) as a catalyst 0.03 parts by weight of the adhesive (manufactured by Co., Ltd.) was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (16). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (16). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 17]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannics GP1000 (manufactured by Sanyo Kasei Co., Ltd., Mn = 3000) 15 parts by weight, a polyol having three hydroxyl groups (Mn = 1000) 5 parts by weight, a polyfunctional isocyanate compound (Coronate HX: C/HX , Nippon Polyurethane Co., Ltd.) 12.8 parts by weight, 1-ethyl-3-methylimidazolium tri(fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight as an ionic compound, antioxidant 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an agent, and 0.03 parts by weight of ferric Nasem (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst, and ethyl acetate so that the total solid content is 50% by weight. to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (17). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (17). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 18]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannics GP600 (manufactured by Sanyo Kasei Co., Ltd., Mn = 600) 18 parts by weight, which is a polyol having three hydroxyl groups, and a polyfunctional isocyanate compound (Coronate HX: C/HX) as a cross-linking agent. , Nippon Polyurethane Co., Ltd.) 12.7 parts by weight, 1-ethyl-3-methylimidazolium tri(fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight as an ionic compound, antioxidant 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an agent, and 0.03 parts by weight of ferric Nasem (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst, and ethyl acetate so that the total solid content is 50% by weight. to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (18). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (18). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 19]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannics GP400 (manufactured by Sanyo Kasei Co., Ltd., Mn = 400) 18 parts by weight, which is a polyol having three hydroxyl groups, and a polyfunctional isocyanate compound (Coronate HX: C/HX) as a cross-linking agent. , Nippon Polyurethane Co., Ltd.) 13.8 parts by weight, 1-ethyl-3-methylimidazolium tri(fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) as an ionic compound 0.5 parts by weight, antioxidant 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an agent, and 0.03 parts by weight of ferric Nasem (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst, and ethyl acetate so that the total solid content is 50% by weight. to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (19). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (19). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 20]
50 parts by weight of urethane prepolymer A, 35 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 15 parts by weight, 9.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (Nippon Kagaku Sangyo Co., Ltd.) as a catalyst 0.03 parts by weight of the adhesive (manufactured by Co., Ltd.) was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (20). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (20). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 21]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.05 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 0.1 parts by weight, Irganox 1010 (BASF) as an antioxidant ) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (21). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (21). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 22]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.1 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 0.1 parts by weight, Irganox 1010 (BASF) as an antioxidant ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (22). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (22). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 23]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 0.1 parts by weight, Irganox 1010 (BASF) as an antioxidant ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (23). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (23). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 24]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 1.0 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 0.1 parts by weight, antioxidant Irganox 1010 (BASF) ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (24). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (24). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 25]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 0.05 parts by weight, Irganox 1010 (BASF) as an antioxidant ) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (25). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (25). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 26]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 0.5 parts by weight, Irganox 1010 (BASF) as an antioxidant ) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (26). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (26). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 27]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 1.0 parts by weight, Irganox 1010 (BASF) as an antioxidant ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (27). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (27). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 28]
50 parts by weight of urethane prepolymer A, 35 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 15 parts by weight, 9.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-477 (manufactured by DIC) 0.1 parts by weight, Irganox 1010 (BASF) as an antioxidant ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (28). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (28). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 2 shows the results.

[Example 29]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.05 parts by weight, Irganox 1010 (BASF) as an antioxidant ) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (29). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (29). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 30]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.1 parts by weight, antioxidant Irganox 1010 (BASF) ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (30). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (30). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 31]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.5 parts by weight, Irganox 1010 (BASF) as an antioxidant ) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare an adhesive layer composed of the urethane-based adhesive (31). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (31). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 32]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 1.0 parts by weight, Irganox 1010 (BASF) as an antioxidant ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (32). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (32). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 33]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-569 (manufactured by DIC) 0.5 parts by weight, Irganox 1010 (BASF) as an antioxidant ) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (33). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (33). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 34]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-552 (manufactured by DIC) 0.5 parts by weight, Irganox 1010 (BASF) as an antioxidant ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (34). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (34). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 35]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-559 (manufactured by DIC) 0.5 parts by weight, antioxidant Irganox 1010 (BASF) ) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (35). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (35). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 36]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-556 (manufactured by DIC) 0.5 parts by weight, antioxidant Irganox 1010 (BASF) ) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. An adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (36). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protection film (36). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 37]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl group-containing reactive silicone oil X-22-4015 (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, antioxidant 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as a catalyst, and 0.03 parts by weight of ferric Nasem (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst with ethyl acetate so that the total solid content is 50% by weight. After dilution, a urethane adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (37). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (37). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 38]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl group-containing reactive silicone oil KF6001 (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, antioxidant Irganox 1010 (BASF) 0.5 parts by weight of Nasem (manufactured by Nippon Kagaku Sangyo Co., Ltd.) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. A system adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (38). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (38). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 39]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl group-containing reactive silicone oil KF6002 (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, antioxidant Irganox 1010 (BASF) 0.5 parts by weight of Nasem (manufactured by Nippon Kagaku Sangyo Co., Ltd.) and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. A system adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (39). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (39). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 3 shows the results.

[Example 40]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl group-containing reactive silicone oil KF6028 (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, antioxidant Irganox 1010 (BASF) 0.5 parts by weight of Nasem (manufactured by Nippon Kagaku Sangyo Co., Ltd.) and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. A system adhesive solution was obtained. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (40). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (40). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 41]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF643 (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (41). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protection film (41). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 42]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF640 (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, Irganox 1010 as an antioxidant (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (42). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (42). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 43]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF615A (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (43). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (43). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 44]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF352A (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, Irganox 1010 as an antioxidant (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (44). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (44). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 45]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF945 (Shin-Etsu Chemical Co., Ltd.) 0.1 parts by weight, Irganox 1010 as an antioxidant (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (45). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (45). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 46]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF615A (Shin-Etsu Chemical Co., Ltd.) 0.05 parts by weight, Irganox 1010 as an antioxidant (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (46). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (46). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 47]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF615A (Shin-Etsu Chemical Co., Ltd.) 0.025 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (47). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (47). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 48]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, hydroxyl-free non-reactive silicone oil KF615A (Shin-Etsu Chemical Co., Ltd.) 0.01 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight and 0.03 parts by weight of Nasem ferric (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight. , to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (48). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (48). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 49]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.5 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.1 parts by weight, hydroxyl-free non-reactive silicone 0.025 parts by weight of oil KF615A (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 0.03 weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (49). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (49). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 50]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (50). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (50). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 4 shows the results.

[Example 51]
50 parts by weight of urethane prepolymer A, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 8.4 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (51). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (51). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 52]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 25 parts by weight, 9.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trisium as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (52). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (52). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 53]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 25 parts by weight, 7.2 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triamine as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (53). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (53). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 54]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 25 parts by weight, 6.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (54). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protective film (54). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 55]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 25 parts by weight, 4.8 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (55). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (55). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 56]
70 parts by weight of urethane prepolymer A, 20 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 10 parts by weight, 4.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (56). Next, on the surface of the obtained pressure-sensitive adhesive layer, a release sheet (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Corporation) made of polyester resin having a thickness of 25 μm and having one surface subjected to silicone treatment is subjected to silicone treatment. The surfaces were laminated to obtain a surface protection film (56). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 57]
50 parts by weight of urethane prepolymer A, 24 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 26 parts by weight, 6.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triamine as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (57). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (57). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 58]
50 parts by weight of urethane prepolymer A, 22 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000) which is a polyol having three hydroxyl groups as a polyol, and PTGL3000 (Hodogaya Chemical Industry Co., Ltd.) which is a polyol having three hydroxyl groups Mn = 3000) 28 parts by weight, 6.2 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (58). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (58). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 59]
50 parts by weight of urethane prepolymer A, 20 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 30 parts by weight, 6.4 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trisium as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (59). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (59). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 60]
40 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 35 parts by weight, 7.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triamine as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (60). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (60). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 61]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 25 parts by weight, 9.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone Oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.3 parts by weight, antioxidant Irganox 1010 (manufactured by BASF) 0.5 parts by weight, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 weight as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 20 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (61). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (61). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 62]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 25 parts by weight, 9.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone 0.5 parts by weight of oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 0.03 weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 20 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (62). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (62). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 63]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 25 parts by weight, 9.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone 1.0 parts by weight of oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 0.03 weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 20 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (63). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (63). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 64]
50 parts by weight of urethane prepolymer A, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 25 parts by weight, 9.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone 2.0 parts by weight of oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 0.03 weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 20 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (64). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (64). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 65]
70 parts by weight of urethane prepolymer B, 20 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 10 parts by weight, 3.9 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium trioxide as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone 2.0 parts by weight of oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 0.03 weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 20 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (65). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (65). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 66]
50 parts by weight of urethane prepolymer B, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups Mn = 3000) 25 parts by weight, 5.9 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone 2.0 parts by weight of oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 0.03 weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 20 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (66). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protection film (66). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Example 67]
40 parts by weight of urethane prepolymer B, 25 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, PTGL3000 (Hodogaya Chemical Industry Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 35 parts by weight, 7.0 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 1-ethyl-3-methylimidazolium triethyl as an ionic compound. (Fluoromethanesulfonyl) imide (AS110, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 0.3 parts by weight, fluorine-based oligomer Megafac F-563 (manufactured by DIC) 0.3 parts by weight, hydroxyl-free non-reactive silicone 2.0 parts by weight of oil KF640 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and 0.03 weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst A part was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a base material made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 20 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of urethane-based pressure-sensitive adhesive (67). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (67). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 5 shows the results.

[Comparative Example 1]
100 parts by weight of urethane prepolymer B, 2.9 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant, and , 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (C1). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (C1). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 6 shows the results.

[Comparative Example 2]
50 parts by weight of urethane prepolymer B, 35 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 15 parts by weight, 9.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of the urethane-based pressure-sensitive adhesive (C2). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (C2). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 6 shows the results.

[Comparative Example 3]
50 parts by weight of urethane prepolymer B, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP4000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 8.6 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of a urethane-based pressure-sensitive adhesive (C3). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (C3). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 6 shows the results.

[Comparative Example 4]
50 parts by weight of urethane prepolymer B, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups (Mn = 3000) 20 parts by weight, 10.1 parts by weight of a polyfunctional isocyanate compound (Coronate HX: C/HX, manufactured by Nippon Polyurethane Co., Ltd.) as a cross-linking agent, and 0.5 parts by weight of Irganox 1010 (manufactured by BASF) as an antioxidant. and 0.03 parts by weight of Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) as a catalyst were diluted with ethyl acetate so that the total solid content was 50% by weight, to obtain a urethane adhesive solution. . Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of a urethane-based pressure-sensitive adhesive (C4). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (C4). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 6 shows the results.

[Comparative Example 5]
50 parts by weight of urethane prepolymer B, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannics GP1000 (manufactured by Sanyo Kasei Co., Ltd., Mn = 3000) 15 parts by weight, a polyol having three hydroxyl groups (Mn = 1000) 5 parts by weight, a polyfunctional isocyanate compound (Coronate HX: C/HX , Nippon Polyurethane Co., Ltd.) 12.9 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 parts by weight as a catalyst, The solution was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of a urethane-based pressure-sensitive adhesive (C5). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (C5). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 6 shows the results.

[Comparative Example 6]
50 parts by weight of urethane prepolymer B, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannics GP600 (manufactured by Sanyo Kasei Co., Ltd., Mn = 3000) 18 parts by weight, which is a polyol having three hydroxyl groups (manufactured by Sanyo Kasei Co., Ltd., Mn = 600) 2 parts by weight, a polyfunctional isocyanate compound (Coronate HX: C/HX , Nippon Polyurethane Co., Ltd.) 12.7 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 parts by weight as a catalyst, The solution was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of a urethane-based pressure-sensitive adhesive (C6). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The surfaces were laminated to obtain a surface protective film (C6). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 6 shows the results.

[Comparative Example 7]
50 parts by weight of urethane prepolymer B, 30 parts by weight of Preminol S3011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having three hydroxyl groups, as a polyol, Sannics GP3000 (Sanyo Kasei Co., Ltd.), which is a polyol having three hydroxyl groups Sannix GP400 (manufactured by Sanyo Kasei Co., Ltd., Mn = 3000) 18 parts by weight, which is a polyol having three hydroxyl groups (manufactured by Sanyo Kasei Co., Ltd., Mn = 400) 2 parts by weight, a polyfunctional isocyanate compound (Coronate HX: C/HX , Nippon Polyurethane Co., Ltd.) 13.8 parts by weight, Irganox 1010 (manufactured by BASF) 0.5 parts by weight as an antioxidant, and Nasem ferric iron (manufactured by Nippon Kagaku Sangyo Co., Ltd.) 0.03 parts by weight as a catalyst, The solution was diluted with ethyl acetate so that the total solid content was 50% by weight to obtain a urethane adhesive solution. Then, the urethane-based adhesive solution was applied to a substrate made of polyester resin (trade name “T100-75S”, thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) so that the thickness after drying was 75 μm, and the drying temperature was 130 ° C. , and dried under the conditions of a drying time of 3 minutes to prepare a pressure-sensitive adhesive layer composed of a urethane-based pressure-sensitive adhesive (C7). Next, on the surface of the obtained pressure-sensitive adhesive layer, a silicone-treated release sheet made of polyester resin having a thickness of 25 μm (trade name “MRF25”, thickness 25 μm, manufactured by Mitsubishi Chemical Co., Ltd.) having one surface treated with silicone is treated with silicone. The faces were laminated to obtain a surface protective film (C7). It was aged at room temperature for 5 days and evaluated. The release sheet was removed just prior to evaluation. Table 6 shows the results.

The surface protective film of the present invention can be used for any suitable application. Preferably, the surface protective film of the present invention is preferably used for surface protection of optical members and electronic members.

REFERENCE SIGNS LIST 1 base layer 2 adhesive layer 10 surface protective film

Claims (7)

A surface protective film comprising a urethane-based pressure-sensitive adhesive layer,
The urethane-based pressure-sensitive adhesive layer is composed of a urethane-based pressure-sensitive adhesive formed from a urethane-based pressure-sensitive adhesive composition,
The urethane pressure-sensitive adhesive composition is
(A) contains a urethane prepolymer, a polyol, and a polyfunctional isocyanate compound, the urethane prepolymer and/or the polyol having a structural unit represented by the following general formula (1), or
(B) contains a urethane prepolymer having a structural unit represented by the following general formula (1) and a polyfunctional isocyanate compound, or
(C) contains a polyol having a structural unit represented by the following general formula (1) and a polyfunctional isocyanate compound,
The urethane pressure-sensitive adhesive layer has a surface elastic modulus of 0.8 MPa or more.
surface protection film.

(In general formula (1), R ¹ represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a hydroxyalkyl group having 1 to 6 carbon atoms. Multiple R ¹ may be the same as or different from each other, n represents an integer of 1 to 4, and m represents the number of repeating structural units and an integer of 1 to 200.) The urethane prepolymer and/or the polyol has a structural unit represented by the following general formula (2),
The surface according to claim 1, wherein the content of the structural unit represented by the general formula (1) in the urethane-based pressure-sensitive adhesive composition is higher than the content of the structural unit represented by the following general formula (2). Protective film.

(In general formula (2), R ² represents one selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms. A plurality of R ² may be the same or different from each other. p is the number of repeating structural units and represents an integer of 1 to 300.) The urethane-based pressure-sensitive adhesive composition contains an ionic compound,
The surface protective film according to claim 1 or 2, wherein the content of said ionic compound is 0.05 parts by weight or more with respect to a total of 100 parts by weight of said urethane prepolymer and said polyol. The urethane-based pressure-sensitive adhesive composition contains at least one selected from the group consisting of fluorine-based additives and silicone-based additives,
Any of claims 1 to 3, wherein the content of the total amount of the fluorine-based additive and the silicone-based additive is 0.01 part by weight or more with respect to the total 100 parts by weight of the urethane prepolymer and the polyol. The surface protective film according to 1. After 30 minutes at 23° C. after bonding the urethane-based pressure-sensitive adhesive layer to a glass plate, the peel force when peeled from the glass plate at a peel angle of 180 degrees and a peel speed of 300 mm/min was 0.5 gf/25 mm to 2. 5. The surface protection film according to any one of claims 1 to 4, which is .0 gf/25 mm. The surface protection film according to any one of claims 1 to 5, wherein the urethane pressure-sensitive adhesive layer has a haze of 3.5% or less. The urethane-based pressure-sensitive adhesive layer was attached to a glass plate, and after 24 hours at 23° C., the residual adhesion rate to the glass plate was The surface protection film according to any one of claims 1 to 6, which is 80% or more.

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