WO2015156259A1 - Production method for pressure-sensitive adhesive laminated sheet and pressure-sensitive adhesive laminated sheet - Google Patents

Abstract

A production method for a pressure-sensitive adhesive laminated sheet (F) comprising a pressure-sensitive adhesive layer and a base material layer, said production method including: a polymer gel-containing dispersion liquid preparation step in which a crosslinked body-containing polymer (A) containing a (meth) acrylate ester polymer (A0) as the main component thereof is immersed in a solvent and agitated, and a polymer gel-containing dispersion liquid is prepared; a filtration step in which the polymer gel-containing dispersion liquid is filtered using a mesh having prescribed mesh openings and a filtrate is obtained; a coating step in which the filtrate is coated on at least one surface of the base material layer to a prescribed thickness; and a solvent removal step in which the solvent in the filtrate upon the base material layer is removed and the pressure-sensitive adhesive layer is obtained. The production method for the pressure-sensitive adhesive laminated sheet (F) is characterized by: the prescribed mesh openings being no more than 1.3 times the prescribed thickness; and the gel fraction of a post-filtration crosslinked body-containing polymer (H), obtained by drying the filtrate obtained by supplying the crosslinked body-containing polymer (A) to the polymer gel-containing dispersion liquid preparation step and the filtration step, being at least 65 mass%.

Description

Method for producing pressure-sensitive adhesive laminate sheet, and pressure-sensitive adhesive laminate sheet

The present invention relates to a method for producing a pressure-sensitive adhesive laminate sheet, and a pressure-sensitive adhesive laminate sheet obtained by the production method.

In recent years, a laminated sheet comprising at least two layers having a base material layer on one surface and a pressure-sensitive adhesive layer having pressure-sensitive adhesiveness on the other surface has been used. Such a pressure-sensitive adhesive laminate sheet (hereinafter referred to as “pressure-sensitive adhesive laminate sheet”) is used by attaching the pressure-sensitive adhesive layer side surface to an adherend such as a glass plate.

When the pressure-sensitive adhesive laminate sheet is attached to the adherend, air may be trapped and remain between the pressure-sensitive adhesive laminate sheet and the adherend. Generation | occurrence | production of the remaining air (air pocket) becomes a factor of deterioration of an external appearance and adhesive force fall. Therefore, as a technique for solving such a problem, for example, Patent Document 1 discloses a base material, a decorative layer provided on one side of the base material, and an adhesive provided on the other side of the base material. A pressure-sensitive adhesive sheet comprising a plurality of through-holes penetrating from one surface to the other surface, wherein the through-hole base material, decorative layer, and pressure-sensitive adhesive layer have a hole diameter of 0.1 to 300 μm A pressure-sensitive adhesive sheet characterized by a hole density of 30 to 50,000 / 100 cm ² is disclosed.

Patent Document 2 discloses an adhesive sheet that is used by being attached to a smooth adherend such as a window glass, and is formed on a sheet body made of a synthetic resin film and one surface of the sheet body. Provided with an adhesive layer to be attached to the adhesive body, and a slit formed so as to penetrate the sheet body and the adhesive layer, at least the whole of the slit does not overlap with a straight line connecting one end and the other end, An adhesive sheet is disclosed.

JP 2005-75953 A JP 2012-126855 A

According to the techniques disclosed in Patent Document 1 and Patent Document 2, the air between the sheet and the adherend is discharged through holes or slits that penetrate through the sheet in the thickness direction. Therefore, it is possible to suppress air from remaining between the sheet and the adherend.

However, when a through-hole or a slit is provided in the pressure-sensitive adhesive sheet as in the above prior art, the appearance may be impaired. When the adhesive layer has self-adhesive properties, when the sheet is peeled off to reattach the adhesive sheet, part of the adhesive layer (sheet residue) may remain on the adherend, making it difficult to reattach the adhesive sheet There was sometimes.
In addition, in order to provide fine through holes and slits in the adhesive sheet, it is necessary to perform precision processing using a laser or cutter in addition to the sheet manufacturing process, which complicates the manufacturing process or upgrades the manufacturing equipment May be required.

Therefore, the present invention is a method for producing a pressure-sensitive adhesive laminated sheet that can suppress air entrapment when attached to an adherend and is easy to reattach, and can be produced with simple equipment. An object is to provide a method for producing a pressure-sensitive adhesive laminate sheet, and a pressure-sensitive adhesive laminate sheet obtained by the production method.

As a result of intensive studies in view of the above problems, the present inventors produced a pressure-sensitive adhesive laminated sheet under predetermined conditions. As a result, minute irregularities are formed on the surface of the pressure-sensitive adhesive layer. It has been found that the biting of the resin can be suppressed and re-sticking is easy.

That is, the 1st aspect of this invention is a manufacturing method of a pressure-sensitive-adhesive laminated sheet (F) provided with the pressure-sensitive-adhesive layer and the base material layer, Comprising: (meth) acrylic acid ester polymer ( A polymer gel-containing dispersion preparation step of preparing a polymer gel-containing dispersion by immersing the cross-linked polymer (A) having A0) as a main component in a solvent and stirring to prepare a polymer gel-containing dispersion; A filtration step of obtaining a filtrate by filtering through a mesh having a predetermined opening, a coating step of applying the filtrate to the base material layer to a predetermined thickness, and removing the solvent in the filtrate on the base material layer A solvent removing step for obtaining a pressure-bonding layer, wherein the predetermined opening is 1.3 times or less of the predetermined thickness, and the crosslinked polymer-containing polymer (A) is prepared in a polymer gel-containing dispersion preparation step and filtration The gel fraction of the post-filtration crosslinked polymer (H) obtained by drying the filtrate obtained in the step is 65 masses. Characterized in that at least a method for producing a pressure sensitive adhesive laminated sheet (F).

In this specification, “(meth) acryl” means “acryl and / or methacryl”.
Further, “main component” means having a content of 50% by mass or more.

In the first aspect of the present invention, the (meth) acrylic acid ester polymer (A0) comprises (meth) acrylic acid ester polymer (A1), (meth) acrylic acid ester monomer (α1), In the precursor composition containing the functional monomer (B1), at least a polymerization reaction of the (meth) acrylic acid ester monomer (α1), a (meth) acrylic acid ester polymer (A1) and / or It is preferably obtained by performing a crosslinking reaction of a polymer containing a structural unit derived from a (meth) acrylic acid ester monomer (α1).

In the present specification, “polymerization reaction of (meth) acrylate monomer (α1)” means a polymerization reaction for obtaining a polymer containing a structural unit derived from (meth) acrylate monomer (α1). means. In addition, “(meth) acrylic acid ester polymer (A1) and / or (meth) acrylic acid ester monomer (α1) -derived polymer cross-linking reaction” means (meth) acrylic acid ester Cross-linking reaction between polymers (A1), cross-linking reaction between polymers containing structural units derived from (meth) acrylate monomer (α1), and (meth) acrylate polymer (A1) and ( Among crosslinking reactions with a polymer containing a structural unit derived from a (meth) acrylate monomer (α1), it means one or a plurality of crosslinking reactions.

In the first aspect of the present invention, it is preferable that the predetermined mesh opening is 1000 μm or less.

The second aspect of the present invention is a pressure-sensitive adhesive laminated sheet (F) obtained by the method for producing the pressure-sensitive adhesive laminated sheet (F) according to the first aspect of the present invention.

According to the present invention, it is a method for producing a pressure-sensitive adhesive laminated sheet that can suppress the biting of air when attached to an adherend and is easy to reattach, and can be produced with simple equipment. A method for producing a possible pressure-sensitive adhesive laminate sheet can be provided. Moreover, the pressure sensitive adhesive laminated sheet obtained by this manufacturing method can be provided.

It is a flowchart explaining one Embodiment of the manufacturing method of the pressure sensitive adhesive laminated sheet which concerns on this invention. FIG. 5 is a diagram schematically showing the states of manufacturing steps S1 to S4 of a manufacturing method S10 for pressure-sensitive adhesive laminated sheets according to the present invention.

Hereinafter, embodiments of the present invention will be described. In addition, the form shown below is an illustration of this invention and this invention is not limited to the form shown below. Unless otherwise specified, the notation “A to B” for the numerical values A and B means “A to B”. In this notation, when a unit is attached to only the numerical value B, the unit is also applied to the numerical value A.

1. Method for Producing Pressure-Sensitive Adhesive Laminate Sheet (F) Hereinafter, a method for producing the pressure-sensitive adhesive laminate sheet (F) of the present invention will be described. FIG. 1 is a flowchart for explaining a production method S10 of the pressure-sensitive adhesive laminated sheet (F) of the present invention (hereinafter sometimes abbreviated as “the present production method S10”). As shown in FIG. 1, this manufacturing method S10 includes a polymer gel-containing dispersion preparation step S1, a filtration step S2, a coating step S3, and a solvent removal step S4 in this order. FIG. 2 is a diagram schematically showing the states of steps S1 to S4 of the manufacturing method S10. As shown in the lowermost part of FIG. 2, the pressure-sensitive adhesive laminated sheet (F) 10 produced by the production method S10 includes a base material layer 8 and a pressure-sensitive adhesive layer 9 having irregularities on the surface. Hereinafter, each step will be described.

1.1. Polymer gel-containing dispersion preparation step S1
In the polymer gel-containing dispersion preparation step S1, the crosslinked polymer (A) mainly composed of the (meth) acrylic acid ester polymer (A0) is immersed in a solvent, and stirred to be a polymer gel-containing dispersion. It is a process of producing.

<(Meth) acrylic acid ester polymer (A0)>
In the present invention, the (meth) acrylic acid ester polymer (A0) is a polymer having a (meth) acrylic acid ester monomer unit as a main component.

The (meth) acrylic acid ester polymer (A0) includes a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), a polyfunctional monomer (B1), In the precursor composition containing, at least the polymerization reaction of the (meth) acrylate monomer (α1), the (meth) acrylate polymer (A1) and / or the (meth) acrylate monomer It is preferable that the polymer is obtained by performing a crosslinking reaction of a polymer containing a structural unit derived from (α1).

<Precursor composition>
The precursor composition contains a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), and a polyfunctional monomer (B1). Moreover, as will be described later, the precursor composition may contain a polymerization initiator (C1). In addition, when obtaining a crosslinked polymer (A) using a precursor composition, the polymerization reaction and crosslinking reaction of a (meth) acrylic acid ester monomer ((alpha) 1) are performed at least. By performing the polymerization reaction and the crosslinking reaction, the polymer containing the structural unit derived from the (meth) acrylate monomer (α1) is mixed with the component of the (meth) acrylate polymer (A1) and / or one. Partially combine.
In the present invention, the (meth) acrylic acid ester polymer (A1), the (meth) acrylic acid ester monomer (α1), and the polyfunctional monomer (B1) are collectively referred to as “(meta ) Acrylic resin precursor (P1) ”.

In the present invention, the proportion of the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer (α1) used is (mass) acrylic resin precursor (P1) being 100% by mass, The meth) acrylate polymer (A1) is preferably 5% by mass or more and 70% by mass or less, and the (meth) acrylic acid ester monomer (α1) is preferably 29.9% by mass or more and 94.9% by mass or less. The (meth) acrylic acid ester polymer (A1) is 5% by mass or more and 60% by mass or less, and the (meth) acrylic acid ester monomer (α1) is 39.8% by mass or more and 94.8% by mass or less. Is more preferable, the (meth) acrylic acid ester polymer (A1) is 10% by mass to 50% by mass, and the (meth) acrylic acid ester monomer (α1) is 49.7% by mass to 89.7% by mass. so Rukoto is more preferable. By making the use ratio of the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer (α1) within the above range, the precursor composition can be easily molded.

((Meth) acrylic acid ester polymer (A1))
The (meth) acrylic acid ester polymer (A1) that can be used in the present invention is not particularly limited, but the (meth) acrylic acid ester monomer that forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is preferable to contain the unit (a1) and the monomer unit (a2) having an organic acid group.

The (meth) acrylate monomer (a1m) that gives the unit (a1) of the (meth) acrylate monomer is not particularly limited. For example, ethyl acrylate (the glass transition temperature of the homopolymer is -24 ° C), n-propyl acrylate (-37 ° C), n-butyl acrylate (-54 ° C), sec-butyl acrylate (-22 ° C), n-heptyl acrylate (-60) ° C), n-hexyl acrylate (-61 ° C), n-octyl acrylate (-65 ° C), 2-ethylhexyl acrylate (-50 ° C), n-octyl methacrylate (-25 ° C) A (meth) acrylic acid alkyl ester that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, such as n-decyl methacrylate (-49 ° C.); 2-methoxyethyl acrylate The glass transition temperature is −50 ° C.), 3-methoxypropyl acrylate (-75 ° C.), 3-methoxybutyl acrylate (-56 ° C.), ethoxymethyl acrylate (−50 ° C.), etc. And (meth) acrylic acid alkoxyalkyl esters that form a homopolymer of 20 ° C. or lower. Among them, (meth) acrylic acid alkyl ester forming a homopolymer having a glass transition temperature of −20 ° C. or lower, (meth) acrylic acid alkoxyalkyl ester forming a homopolymer having a glass transition temperature of −20 ° C. or lower (Meth) acrylic acid alkyl ester forming a homopolymer having a glass transition temperature of −20 ° C. or lower is more preferable, and 2-ethylhexyl acrylate is more preferable.

These (meth) acrylic acid ester monomers (a1m) may be used alone or in combination of two or more.

In the (meth) acrylic acid ester monomer (a1m), the monomer unit (a1) derived therefrom is preferably 80% by mass or more and 99.9% by mass in the (meth) acrylic acid ester polymer (A1). Hereinafter, it is used for polymerization in such an amount that it is more preferably 85 mass% or more and 99.5 mass% or less. When the amount of the (meth) acrylic acid ester monomer (a1m) is within the above range, the viscosity of the polymerization system at the time of polymerization can be easily maintained within an appropriate range.

Next, the monomer unit (a2) having an organic acid group will be described. The monomer (a2m) that gives the monomer unit (a2) having an organic acid group is not particularly limited, but representative examples thereof include organic acid groups such as a carboxyl group, an acid anhydride group, and a sulfonic acid group. The monomer which has can be mentioned. In addition to these, monomers containing sulfenic acid groups, sulfinic acid groups, phosphoric acid groups, and the like can also be used.

Specific examples of the monomer having a carboxyl group include, for example, α, β-ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and α, β such as itaconic acid, maleic acid, and fumaric acid. In addition to β-ethylenically unsaturated polyvalent carboxylic acid, α, β-ethylenically unsaturated polyvalent carboxylic acid partial esters such as monomethyl itaconate, monobutyl maleate and monopropyl fumarate can be exemplified. Moreover, what has group which can be induced | guided | derived to a carboxyl group by hydrolysis etc., such as maleic anhydride and itaconic anhydride, can be used similarly.

Specific examples of the monomer having a sulfonic acid group include allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, styrene sulfonic acid, α, β-unsaturated sulfonic acid such as acrylamide-2-methylpropane sulfonic acid, And salts thereof.

As the monomer (a2m), among the monomers having an organic acid group exemplified above, a monomer having a carboxyl group is more preferable, and an α, β-ethylenically unsaturated monocarboxylic acid is more preferable. (Meth) acrylic acid is particularly preferred. These monomers are industrially inexpensive and can be easily obtained, have good copolymerizability with other monomer components, and are preferable in terms of productivity. In addition, a monomer (a2m) may be used individually by 1 type, and may use 2 or more types together.

In the monomer (a2m) having an organic acid group, the monomer unit (a2) derived from the monomer unit (a2) is preferably 0.1% by mass or more and 20% by mass or less in the (meth) acrylic acid ester polymer (A1). More preferably, it is used for the polymerization in such an amount that it is 0.5 to 15% by mass. When the usage-amount of the monomer (a2m) which has an organic acid group exists in the said range, it will become easy to maintain the viscosity of the polymerization system at the time of superposition | polymerization in an appropriate range.

The monomer unit (a2) having an organic acid group is introduced into the (meth) acrylic acid ester polymer (A1) by polymerization of the monomer (a2m) having an organic acid group as described above. Although it is simple and preferable to perform, an organic acid group may be introduced by a known polymer reaction after the (meth) acrylic acid ester polymer (A1) is formed.

Further, the (meth) acrylic acid ester polymer (A1) may contain a monomer unit (a3) derived from a monomer (a3m) having a functional group other than an organic acid group. Examples of the functional group other than the organic acid group include a hydroxyl group, an amino group, an amide group, an epoxy group, and a mercapto group.

Examples of the monomer having a hydroxyl group include (meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 2-hydroxyethyl and (meth) acrylic acid 3-hydroxypropyl.

Examples of the monomer having an amino group include N, N-dimethylaminomethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and aminostyrene.

Examples of monomers having an amide group include α, β-ethylenically unsaturated carboxylic acid amide monomers such as acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, and N, N-dimethylacrylamide. Can be mentioned.

Examples of the monomer having an epoxy group include glycidyl (meth) acrylate and allyl glycidyl ether.

As the monomer (a3m) having a functional group other than the organic acid group, one type may be used alone, or two or more types may be used in combination.

In the monomer (a3m) having a functional group other than these organic acid groups, the monomer unit (a3) derived therefrom is 10% by mass or less in the (meth) acrylate polymer (A1). It is preferable to use it for polymerization in such an amount. By using the monomer (a3m) of 10% by mass or less, it becomes easy to keep the viscosity of the polymerization system during polymerization in an appropriate range.

The (meth) acrylic acid ester polymer (A1) has a (meth) acrylic acid ester monomer unit (a1) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, and an organic acid group. In addition to the monomer unit (a2) and the monomer unit (a3) having a functional group other than an organic acid group, a monomer derived from the monomer (a4m) copolymerizable with the above-described monomer. The monomer unit (a4) may be contained.

The monomer (a4m) is not particularly limited, and specific examples thereof include (meth) acrylate monomers other than the (meth) acrylate monomer (a1m), α, β-ethylenic monomers. Saturated polyvalent carboxylic acid complete ester, alkenyl aromatic monomer, vinyl cyanide monomer, carboxylic acid unsaturated alcohol ester, olefin monomer and the like can be mentioned.

Specific examples of the (meth) acrylate monomer other than the (meth) acrylate monomer (a1m) include methyl acrylate (homopolymer having a glass transition temperature of 10 ° C.), methyl methacrylate. (105 ° C.), ethyl methacrylate (63 ° C.), n-propyl methacrylate (25 ° C.), n-butyl methacrylate (20 ° C.), and the like.

Specific examples of the α, β-ethylenically unsaturated polyvalent carboxylic acid complete ester include dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl maleate, dimethyl itaconate and the like.

Specific examples of the alkenyl aromatic monomer include styrene, α-methylstyrene, methyl α-methylstyrene, vinyltoluene and the like.

Specific examples of the vinyl cyanide monomer include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile and the like.

Specific examples of the carboxylic acid unsaturated alcohol ester monomer include vinyl acetate.

Specific examples of the olefin monomer include ethylene, propylene, butene, pentene and the like.

As the monomer (a4m), one type may be used alone, or two or more types may be used in combination.

In the monomer (a4m), the amount of the monomer unit (a4) derived therefrom is preferably 10% by mass or less, more preferably 5% by mass or less in the (meth) acrylate polymer (A1). It is subjected to polymerization in such an amount.

The (meth) acrylic acid ester polymer (A1) has the above-mentioned (meth) acrylic acid ester monomer (a1m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, and an organic acid group. Monomer (a2m), a monomer containing a functional group other than an organic acid group (a3m) used as necessary, and a monomer copolymerizable with these monomers used as needed It can be particularly suitably obtained by copolymerizing the monomer (a4m).

The polymerization method for obtaining the (meth) acrylic acid ester polymer (A1) is not particularly limited, and may be any of solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, and the like, or any other method. . However, among these polymerization methods, solution polymerization is preferable, and among them, solution polymerization using a carboxylic acid ester such as ethyl acetate or ethyl lactate or an aromatic solvent such as benzene, toluene or xylene is more preferable. In the polymerization, the monomer may be added in portions to the polymerization reaction vessel, but it is preferable to add the whole amount at once. The method for initiating the polymerization is not particularly limited, but it is preferable to use a thermal polymerization initiator as the polymerization initiator. The thermal polymerization initiator is not particularly limited, and for example, a peroxide polymerization initiator or an azo compound polymerization initiator can be used.

Peroxide polymerization initiators include hydroperoxides such as t-butyl hydroperoxide, peroxides such as benzoyl peroxide and cyclohexanone peroxide, and persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate. Can be mentioned. These peroxides can also be used as a redox catalyst in appropriate combination with a reducing agent.

As azo compound polymerization initiators, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile) And so on.

Although the usage-amount of a polymerization initiator is not specifically limited, It is preferable that it is the range of 0.01 to 50 mass parts with respect to 100 mass parts of monomers.

Other polymerization conditions (polymerization temperature, pressure, stirring conditions, etc.) of these monomers are not particularly limited.

After completion of the polymerization reaction, the obtained polymer is separated from the polymerization medium if necessary. The separation method is not particularly limited. For example, in the case of solution polymerization, the (meth) acrylic acid ester polymer (A1) can be obtained by placing the polymerization solution under reduced pressure and distilling off the polymerization solvent.

The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A1) is measured by gel permeation chromatography (GPC method) and may be in the range of 1,000 to 1,000,000 in terms of standard polystyrene. Preferably, it is in the range of 100,000 or more and 500,000 or less. The weight average molecular weight of the (meth) acrylic acid ester polymer (A1) can be controlled by appropriately adjusting the amount of the polymerization initiator used in the polymerization and the amount of the chain transfer agent.

((Meth) acrylic acid ester monomer (α1))
The (meth) acrylate monomer (α1) is not particularly limited as long as it contains the (meth) acrylate monomer, but forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is preferable to contain the (meth) acrylic acid ester monomer (a5m).

As an example of a (meth) acrylate monomer (a5m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, it is used for the synthesis of a (meth) acrylate polymer (A1) (meth) ) The same (meth) acrylate monomer as the acrylate monomer (a1m) can be mentioned. A (meth) acrylic acid ester monomer (a5m) may be used individually by 1 type, and may use 2 or more types together.

The ratio of the (meth) acrylate monomer (a5m) in the (meth) acrylate monomer (α1) is preferably 50% by mass to 100% by mass, more preferably 75% by mass to 100% by mass. It is as follows. By setting the ratio of the (meth) acrylic acid ester monomer (a5m) in the (meth) acrylic acid ester monomer (α1) within the above range, a pressure-sensitive adhesive layer excellent in pressure-sensitive adhesiveness and flexibility is obtained. It becomes easy to obtain.

The (meth) acrylic acid ester monomer (α1) is a (meth) acrylic acid ester monomer (a5m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is good also as a mixture of the monomer (a6m) which has a polymerizable organic acid group.

Examples of the monomer (a6m) include monomers having an organic acid group similar to those exemplified as the monomer (a2m) used for the synthesis of the (meth) acrylic acid ester polymer (A1). be able to. A monomer (a6m) may be used individually by 1 type, and may use 2 or more types together.

The ratio of the monomer (a6m) in the (meth) acrylic acid ester monomer (α1) is preferably 30% by mass or less, and more preferably 10% by mass or less. By making the ratio of the monomer (a6m) in the (meth) acrylic acid ester monomer (α1) within the above range, a pressure-sensitive adhesive layer excellent in pressure-sensitive adhesiveness and flexibility can be easily obtained.

The (meth) acrylic acid ester monomer (α1), in addition to the (meth) acrylic acid ester monomer (a5m) and the monomer (a6m) having an organic acid group that can be optionally copolymerized, It is good also as a mixture containing the monomer (a7m) copolymerizable with these.

Examples of the monomer (a7m) include the monomer (a3m) used for the synthesis of the (meth) acrylic acid ester polymer (A1) and the same amount as those exemplified as the monomer (a4m). The body can be mentioned. A monomer (a7m) may be used individually by 1 type, and may use 2 or more types together.

The ratio of the monomer (a7m) in the (meth) acrylic acid ester monomer (α1) is preferably 20% by mass or less, and more preferably 15% by mass or less.

(Polyfunctional monomer (B1))
In the present invention, the precursor composition contains a polyfunctional monomer (B1). Usually, at the time of polymerization such as radical thermal polymerization, a certain degree of crosslinking reaction proceeds without using a polyfunctional monomer. However, it is possible to reliably form a desired amount of cross-linked structure, to produce a polymer gel having a particle size smaller than the mesh opening, and to form a pressure-sensitive adhesive layer having minute irregularities, so that a polyfunctional monomer It is preferable that a body (B1) is included.

As the polyfunctional monomer (B1) that can be used in the present invention, a monomer that can be copolymerized with the monomer contained in the (meth) acrylic acid ester monomer (α1) is used. Further, the polyfunctional monomer (B1) has a plurality of polymerizable unsaturated bonds, and preferably has the unsaturated bond at the terminal. By using such a polyfunctional monomer (B1), intramolecular and / or intermolecular crosslinking is introduced into the copolymer, and the crosslinked polymer (A) and the crosslinked polymer after filtration (H ) In the desired range.

Examples of the polyfunctional monomer (B1) include 1,6-hexanediol di (meth) acrylate, 1,2-ethylene glycol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, polyethylene Glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, ditri Multifunctional (meth) acrylates such as methylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 2,4-bis (to Other substituted triazines, such as chloromethyl) -6-p-methoxystyrene-5-triazine, etc. monoethylenically unsaturated aromatic ketones such as 4-acryloxy benzophenone can be used. Polyfunctional (meth) acrylates are preferred, and pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate are more preferred. A polyfunctional monomer (B1) may be used individually by 1 type, and may use 2 or more types together.

The amount of the polyfunctional monomer (B1) used is preferably 0.1% by mass or more and 20% by mass or less, with the (meth) acrylic resin precursor (P1) being 100% by mass, and 0.2% by mass. % To 10% by mass, more preferably 0.3% to 8% by mass. By making the use amount of the polyfunctional monomer (B1) in the above range, a polymer gel having a particle size equal to or smaller than the mesh openings can be produced, and a pressure-sensitive adhesive layer having minute irregularities can be easily formed. Become. Moreover, it becomes easy to give an appropriate cohesive force to the pressure-sensitive adhesive layer.

(Polymerization initiator (C1))
When the crosslinked polymer (A) is obtained, the components contained in the (meth) acrylic resin precursor (P1) are polymerized as described above. In order to accelerate the polymerization reaction, it is preferable to use a polymerization initiator (C1). Examples of the polymerization initiator (C1) include a photopolymerization initiator, an azo thermal polymerization initiator, and an organic peroxide thermal polymerization initiator. However, it is preferable to use an organic peroxide thermal polymerization initiator from the viewpoint of imparting a strong adhesive force to the resulting pressure-sensitive adhesive layer.

As the photopolymerization initiator, various known photopolymerization initiators can be used. Of these, acylphosphine oxide compounds are preferred. Preferred examples of the acylphosphine oxide compound that is a photopolymerization initiator include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

As the azo-based thermal polymerization initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile) ) And the like.

Examples of the organic peroxide thermal polymerization initiator include hydroperoxides such as t-butyl hydroperoxide, benzoyl peroxide, cyclohexanone peroxide, 1,6-bis (t-butylperoxycarbonyloxy) hexane, 1,1-bis ( and a peroxide such as t-butylperoxy) -3,3,5-trimethylcyclohexanone. However, those that do not release volatile substances that cause odor during thermal decomposition are preferred. Among organic peroxide thermal polymerization initiators, those having a 1-minute half-life temperature of 100 ° C. or more and 170 ° C. or less are preferable.

The amount of the polymerization initiator (C1) used is preferably 0.01 parts by mass or more and 10 parts by mass or less, and 0.1 parts by mass or more with respect to 100 parts by mass of the (meth) acrylic resin precursor (P1). It is more preferably 5 parts by mass or less, and further preferably 0.3 parts by mass or more and 2 parts by mass or less.
By making the usage-amount of a polymerization initiator (C1) into the said range, it will become easy to make the polymerization conversion rate of a (meth) acrylic acid ester monomer ((alpha) 1) into an appropriate range, and it will be single in a crosslinked polymer (A). It becomes easy to prevent the mass odor from remaining, and the workability in the subsequent steps is excellent.
The polymerization conversion rate of the (meth) acrylic acid ester monomer (α1) is preferably 95% by mass or more. If the polymerization conversion rate of the (meth) acrylic acid ester monomer (α1) is 95% by mass or more, it becomes easy to prevent the monomer odor from remaining in the crosslinked polymer (A), and work in the subsequent steps Excellent in properties.

(Other additives)
In the precursor composition which is a precursor of the pressure-sensitive adhesive layer, various known additives can be added in addition to the substances described so far within a range where the required performance such as pressure-sensitive adhesiveness can be satisfied. it can.
Known additives include, for example, flame retardants such as phosphate esters; foaming agents (including foaming aids); glass fibers; external cross-linking agents; pigments; aluminum hydroxide, aluminum oxide, expanded graphite powder, carbonic acid Examples thereof include fillers such as calcium, silica, titanium dioxide and clay; nanoparticles such as fullerene and carbon nanotubes; antioxidants such as polyphenols, hydroquinones and hindered amines.

Among the other additives described above, the filler content is preferably 0 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic resin precursor (P1). The amount is more preferably 50 parts by mass or less, and particularly preferably 0 part by mass, that is, not contained. When it contains a filler, it is desirable to set the gel fraction of the crosslinked polymer-containing polymer (H) after filtration higher than when no filler is used.

<Cross-containing polymer (A)>
The crosslinked polymer (A) contains a (meth) acrylate polymer (A0) as a main component. The crosslinked polymer (A) contains the (meth) acrylic acid ester polymer (A0), for example, 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 100% by mass. To do.
The crosslinked polymer (A) is prepared by mixing the above-described substances constituting the precursor composition to prepare the precursor composition, and then at least a polymerization reaction of the (meth) acrylate monomer (α1), It is preferable to obtain by performing the crosslinking reaction of the polymer containing the structural unit derived from the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1). Here, it is preferable that the “crosslinked polymer (A)” includes a non-crosslinked component such as a linear polymer or a branched polymer that is not crosslinked and is dissolved in a solvent.

The gel fraction of the crosslinked polymer (A) is preferably 65% by mass or more, and more preferably 75% by mass or more. When the gel fraction is 65% by mass or more, a polymer gel having a particle size equal to or smaller than the mesh opening is prepared, and a post-filtration crosslinked polymer (H) having a desired gel fraction is prepared. It becomes easy to produce a pressure-sensitive adhesive layer having minute irregularities. On the other hand, the gel fraction of the crosslinked polymer (A) is preferably 99% by mass or less, and more preferably 95% by mass or less. When the gel fraction is 99% by mass or less, the pressure-sensitive adhesive layer plays a role of linking cross-linking components with non-cross-linking components. It is possible to effectively prevent the pressure-adhesive layer from peeling off, and to increase the pressure-sensitive adhesiveness of the pressure-sensitive adhesive laminated sheet (F).
The gel fraction in the present invention refers to, for example, wrapping 0.2 g of a dry sample of the crosslinked polymer (A) with a wire mesh having an opening of 234 μm, immersing in 100 ml of ethyl acetate for 23 hours, and performing filtration by taking out, Thereafter, the taken-out wire mesh is dried at 50 ° C. for 1 hour, and the dry mass of the insoluble matter remaining in the wire mesh having a mesh opening of 234 μm is measured.
Gel fraction (mass%) = ((dry mass of insoluble matter remaining in wire mesh with opening of 234 μm after immersion in ethyl acetate) / (dry mass of sample before immersion in ethyl acetate)) × 100

In the polymer gel-containing dispersion preparation step S1, heating is preferably performed when the polymerization and the crosslinking reaction are performed. For the heating, for example, hot air, an electric heater, infrared rays, or the like can be used. The heating temperature at this time is preferably a temperature at which the polymerization initiator is efficiently decomposed and the polymerization of the (meth) acrylate monomer (α1) proceeds. The temperature range varies depending on the type of polymerization initiator used, but is preferably 100 ° C. or higher and 200 ° C. or lower, and more preferably 120 ° C. or higher and 180 ° C. or lower.

From the viewpoint of uniformly heating the entire precursor composition in a short time to produce a homogeneous crosslinked polymer (A), it is preferable to heat the precursor composition after forming it into a sheet. Here, the method for forming the precursor composition into a sheet is not particularly limited. As a suitable method, for example, the above precursor composition is sandwiched between arbitrary substrates to form a sheet, and the precursor composition thus sandwiched is further pressed between two rolls. The method of shape | molding into a sheet form by doing and the method of extruding the said precursor composition using an extruder, and controlling the thickness through a die | dye in that case, etc. are mentioned.
A sheet-like crosslinked polymer (A) can be obtained by forming the precursor composition into a sheet and then carrying out polymerization and crosslinking reaction. It is preferable from the viewpoint of productivity that the cross-linked polymer (A) is in the form of a sheet because the amount of the cross-linked polymer (A) to be immersed in a predetermined amount of solvent can be easily adjusted.

The shape and size of the crosslinked polymer (A) when immersed in a solvent are not particularly limited as long as it does not prevent the crosslinked polymer (A) from being immersed and stirred in a solvent. Therefore, for example, the end of the product that will be discarded in the manufacturing process of the pressure-sensitive adhesive sheet using the precursor composition as a raw material, or the torn used pressure-sensitive adhesive sheet is used as a material. Can do. Therefore, the method for producing a pressure-sensitive adhesive laminated sheet of the present invention can be preferably employed from the viewpoint of economy and effective utilization of resources. On the other hand, as a part of the polymer gel-containing dispersion preparation step S1, in addition to using the sheet-like material of the crosslinked polymer (A) as described above, what was cut out in a block shape or crushed It may be immersed.

<Solvent>
In the polymer gel-containing dispersion preparation step S1, the crosslinked polymer (A) is immersed in a solvent and stirred. As the solvent used at this time, it is preferable to use a solvent capable of at least partially dissolving a linear polymer or a branched polymer having a structural unit similar to that of the crosslinked polymer (A). Examples of such solvents include ester solvents such as ethyl acetate, methyl acetate, and butyl acetate; aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as cyclohexane and n-hexane; acetone , Ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether solvents such as tetrahydrofuran; and the like. Among them, it is more preferable to use ethyl acetate or toluene from the viewpoint of being inexpensive, excellent in handleability, and easily removing the solvent in the solvent removal step S4 described later.
A solvent may be used individually by 1 type and may use multiple types together.

The amount of the solvent in which the crosslinked polymer (A) is immersed may be an amount that can dissolve the non-crosslinked component of the crosslinked polymer (A), and the gel fraction of the crosslinked polymer (A). Can be set as appropriate.

<Polymer gel-containing dispersion>
In the polymer gel-containing dispersion preparation step S1, the polymer-containing dispersion is prepared by immersing the crosslinked polymer (A) in a solvent and stirring. When the crosslinked polymer (A) is immersed in a solvent and stirred, non-crosslinked components such as linear polymers and branched polymers in the crosslinked polymer (A) absorb the solvent and swell, and at least A part of it dissolves in the solvent. On the other hand, the cross-linking component in the cross-linked polymer (A) exhibits a finite swelling property, absorbs the solvent, swells, and becomes a polymer gel without dissolving.
A schematic diagram is shown in S1 of FIG. That is, the polymer-containing dispersion 5 comprising the solution 3 containing the non-crosslinked component and the polymer gel 4 is prepared by immersing the crosslinked polymer (A) 1 in the solvent 2 and stirring. It should be noted that the non-crosslinking component does not necessarily exist, but is preferably present.

The method of stirring after immersing the cross-linked polymer (A) in a solvent gives a sufficient share to the cross-linked polymer (A) and the solvent to produce a polymer gel having a predetermined particle size. If it can do, it will not be specifically limited. For example, when 100 parts by mass of the block-like crosslinked polymer (A) is immersed in 300 parts by mass of ethyl acetate or toluene and then stirred, the crosslinked polymer (A) can be obtained by stirring for 300 minutes at 1000 rpm. And a solvent have a sufficient share, and a polymer gel having a predetermined particle size can be produced. The rotation speed and stirring time of stirring can be appropriately set depending on the mass, shape, or size (volume ratio with respect to the solvent) of the crosslinked polymer (A) immersed in the solvent.

From the viewpoint of preventing the possibility of further crosslinking reaction of the crosslinked polymer (A) in the dispersion during the standing time in the polymer gel-containing dispersion preparation step S1, the crosslinked polymer (A It is preferable to add an antioxidant after dipping in a solvent. Examples of the antioxidant include polyphenol-based, hydroquinone-based and hindered amine-based antioxidants.
The usage-amount of antioxidant is 0.1 mass part or more and 10 mass parts or less with respect to 100 mass parts of (meth) acrylic resin precursors (P1) among the precursor compositions of a crosslinked-containing polymer (A). It is preferably 0.3 parts by mass or more and 8 parts by mass or less, and more preferably 0.5 parts by mass or more and 5 parts by mass or less. By making the usage-amount of antioxidant into the said range, the polymer gel which has a particle diameter below the mesh opening of a mesh will be produced, and it will become easy to form the pressure sensitive adhesive layer which has a micro unevenness | corrugation. Moreover, it becomes easy to give an appropriate cohesive force to the pressure-sensitive adhesive layer.
The timing of adding the antioxidant is not particularly limited as long as it is before the further crosslinking reaction of the crosslinked polymer (A) proceeds in the dispersion, and the crosslinked polymer (A) is immersed in a solvent. You may add to a solvent before or simultaneously with immersion.

1.2. Filtration step S2
The filtration step S2 is a step of obtaining a filtrate by filtering the polymer gel-containing dispersion with a mesh having a predetermined opening. A schematic diagram is shown in S2 of FIG. That is, in the filtration step S2, the polymer gel-containing dispersion 5 is poured onto the fixed mesh 6 to obtain the filtrate 7. At this time, the polymer gel particles 4a having a particle diameter larger than the mesh opening of the mesh 6 remain on the mesh 6 as a residue, and the polymer gel 4b having a particle diameter equal to or smaller than the mesh 6 opening passes through the mesh. And contained in the filtrate 7.

The filtration method is not particularly limited as long as a filtrate that passes through a mesh having a predetermined particle diameter can be obtained. For example, natural filtration at normal temperature and normal pressure may be performed, and vacuum filtration or pressure filtration may be performed for the purpose of shortening the filtration time or improving the yield.

The mesh used in the filtration step S2 is not particularly limited as long as it can prevent fibers from expanding with respect to the solvent and changing the filtration accuracy. Examples of such mesh include metal meshes such as stainless steel mesh and galvanized mesh, and resin meshes such as nylon mesh, polyester mesh, polyethylene mesh, Teflon (registered trademark) mesh, and solvent resistance. From the viewpoint of versatility, low cost, and availability, it is preferable to use a metal mesh.

The mesh opening needs to be 1.3 times or less the thickness of the filtrate to be applied on the base material layer described later. By making the mesh opening less than 1.3 times the thickness of the filtrate, it is possible to prevent the occurrence of pinholes when applying the filtrate, and the solvent is removed from the filtrate in the solvent removal step S4. When the pressure-sensitive adhesive layer is formed, the surface of the pressure-sensitive adhesive layer can be prevented from being excessively uneven, and the self-adhesiveness caused by the minute unevenness of the pressure-sensitive adhesive layer surface is effective. Can be granted.
The mesh opening is preferably 1000 μm or less, more preferably 800 μm or less, and even more preferably 600 μm or less. By setting the mesh opening to 1000 μm or less, the particle diameter of the polymer gel contained in the filtrate can be limited to the mesh opening or less, and even if the applied filtrate is thick, the solvent When the pressure-sensitive adhesive layer is formed by removing the solvent from the filtrate in the removing step S4, it is possible to prevent an excessively large unevenness on the surface of the pressure-sensitive adhesive layer. Self-adhesiveness caused by unevenness can be more effectively imparted.
Further, the mesh opening is preferably 250 μm or more, more preferably 260 μm or more, and further preferably 280 μm or more. By setting the mesh opening to 250 μm or more, when the pressure-sensitive adhesive layer is formed by removing the solvent from the filtrate in the solvent removal step S4, unevenness of an appropriate size is generated on the surface of the pressure-sensitive adhesive layer. It is possible to effectively impart air bleedability and self-adhesion caused by minute irregularities on the pressure-sensitive adhesive layer surface.

The solid concentration of the filtrate obtained by the filtration step S2 is preferably 10 to 40% by mass, more preferably 15 to 35% by mass. When the solid content concentration of the filtrate is in the range of 10 to 40% by mass, the handleability of the filtrate is excellent, and it becomes easy to apply the filtrate to a predetermined thickness in the application step S3 described later. Removal of the solvent is facilitated in the solvent removal step S4.

The gel fraction of the crosslinked polymer (H) after filtration is 65% by mass or more, and preferably 75% by mass or more. When the gel fraction is 65% by mass or more, a polymer gel having a particle diameter equal to or smaller than the mesh opening is produced, and a pressure-sensitive adhesive layer having minute irregularities is easily produced. On the other hand, the gel fraction of the crosslinked polymer (H) after filtration is preferably 99% by mass or less, and more preferably 95% by mass or less. When the gel fraction is 99% by mass or less, the pressure-sensitive adhesive layer plays a role of linking cross-linking components with non-cross-linking components. It is possible to effectively prevent the pressure-adhesive layer from peeling off, and to increase the pressure-sensitive adhesiveness of the pressure-sensitive adhesive laminated sheet (F).
The gel fraction of the crosslinked polymer (H) after filtration in the present invention refers to, for example, 0.2 g of a dried sample of the crosslinked polymer (H) after filtration, wrapped in a wire mesh with an opening of 234 μm and placed in 100 ml of ethyl acetate. It is immersed for 24 hours and filtered, and then the wire mesh taken out is dried at 50 ° C. for 1 hour, and the dry mass of the insoluble matter remaining on the wire mesh with a mesh opening of 234 μm is measured. is there.
Gel fraction (mass%) = ((dry mass of insoluble matter remaining in wire mesh with opening of 234 μm after immersion in ethyl acetate) / (dry mass of sample before immersion in ethyl acetate)) × 100

1.3. Application process S3
The coating step S3 is a step of coating the filtrate on the base material layer to a predetermined thickness. The laminated body by which the filtrate 7 was apply | coated to the base material layer 8 to S3 of FIG. The method for applying the filtrate to the base material layer in the application step S3 is not particularly limited, and a known application method can be applied. For example, a coating method using a die coater, a bar coater, a gravure coater, a knife coater, a roll coater, a doctor blade or the like can be employed.

As described above, the mesh opening used in the filtration step S2 needs to be 1.3 times or less the thickness applied on the base material layer. Therefore, it is necessary that the thickness of the filtrate applied on the base material layer be (1.3 times) or more (that is, 0.77 or more) times the mesh opening. Further, while satisfying such conditions, the thickness of the filtrate to be applied is preferably 200 μm or more and 800 μm or less, more preferably 210 μm or more and 600 μm or less, and further preferably 220 μm or more and 450 μm or less. By setting the thickness of the filtrate to be applied within the above range, sufficient adhesion can be maintained between the pressure-sensitive adhesive layer and the adherend.

<Base material layer>
A base material layer is a layer which apply | coats the filtrate obtained by filtration process S2. Further, the base material layer becomes a base of the pressure-sensitive adhesive layer after the solvent removing step S4, so that the sheet shape can be maintained even when the cohesive force of the pressure-sensitive adhesive layer is somewhat insufficient. Moreover, a pressure sensitive adhesive layer can be reinforced and tearing at the time of use of a pressure sensitive adhesive laminated sheet (F) can be prevented.
The base material layer can be given a specific function depending on the application, and can be a functional layer such as a protective layer, a decorative layer, an insulating layer, a heat conductive layer, a heat diffusion layer, or the like. . Further, another layer may be interposed between the base material layer and the pressure-sensitive adhesive layer as long as the effects intended by the present invention are not hindered.

The base material layer preferably has a strength capable of reinforcing the pressure-sensitive adhesive layer so that the pressure-sensitive adhesive layer is not broken when the pressure-sensitive adhesive laminate sheet (F) is used, and the tensile strength is higher than that of the pressure-sensitive adhesive layer. Larger is preferred. Further, since it is necessary to deform following the pressure-sensitive adhesive layer, it is preferable to have flexibility.

The material constituting the base material layer satisfying the above conditions is paper; cloth; metal foil; polyimide; polyester such as polyethylene terephthalate and polyethylene naphthalate; fluororesin such as polytetrafluoroethylene; polyether ketone; Polysulfone; Polymethylpentene; Polyetherimide; Polysulfone; Polyphenylene sulfide; Polyamideimide; Polyesterimide; Polyamide; Among these, polyester and polyimide are preferable, polyethylene terephthalate and polyimide are more preferable, and polyethylene terephthalate is still more preferable from the viewpoint of availability at low cost. In addition, the base material layer may be composed of one kind of material or may be composed of a combination of plural kinds of materials.

The base material layer is usually made of a material that does not have pressure-sensitive adhesiveness. Therefore, when the object is arranged so as to be in contact with the surface of the base material layer, the surface of the pressure-sensitive adhesive laminated sheet (F) can be prevented from being fixed to the object when the object is removed from the surface of the base material layer. Even when the object is fixed again, the pressure-sensitive adhesive laminated sheet (F) can be reused as it is. However, when fixing an object to the base material layer side of the pressure-sensitive adhesive laminated sheet (F), it is preferable to use a fixing member such as a screw. In addition, the base material layer may be comprised with the material which has pressure sensitive adhesiveness.
Moreover, when providing a specific function to a base material layer, the base material layer may be comprised, for example from the material which has electrical insulation, and a heat conductive material (TIM: Thermal Interface Material).

The thickness of the base material layer can be appropriately set according to the use of the pressure-sensitive adhesive laminate sheet (F) and the function required for the base material layer, but the viewpoint of reducing the thermal resistance, And from the viewpoint of preventing folding at the time of use, the thinner one is preferable. On the other hand, it is preferable that the base material layer has a certain thickness from the viewpoint of providing the pressure-sensitive adhesive laminated sheet (F) with a strength capable of preventing tearing during use. Therefore, the thickness of the base material layer is preferably 1 μm to 200 μm, more preferably 5 μm to 100 μm, still more preferably 10 μm to 70 μm, and particularly preferably 10 μm to 30 μm.

1.4. Solvent removal step S4
The solvent removal step S4 is a step of removing the solvent from the filtrate on the substrate to form a pressure-sensitive adhesive layer. The method for removing the solvent in the solvent removal step S4 is not particularly limited, and a known method can be applied. For example, a method of allowing a laminate having a base material layer and a filtrate coating film to stand in the air and evaporating the solvent spontaneously; A method of performing; a method of heating a laminate having a base material layer and a filtrate coating film into an oven; and the like. The heating temperature in the case of using the heating method is not particularly limited as long as the solvent can be vaporized and the function of the base material layer is not impaired. For example, when the solvent is ethyl acetate (boiling point 77.1 ° C.), the heating temperature may be about 100 ° C., and when the solvent is toluene (boiling point 110 ° C.), the heating temperature may be about 150 ° C. Preferably, it is not lower than the boiling point of the solvent and not higher than 200 ° C. The heating time can be appropriately set according to the amount of the filtrate to be applied on the substrate, and is preferably 10 minutes to 3 hours.

<Pressure sensitive adhesive layer>
In solvent removal process S4, a pressure sensitive adhesive layer is formed on a base material layer by removing a solvent from the filtrate on a base material layer. A schematic view of a pressure-sensitive adhesive laminated sheet (F) 10 in which a pressure-sensitive adhesive layer 9 having irregularities on the surface is laminated on the base material layer 8 in S4 of FIG. 4 is shown.
According to the pressure-sensitive adhesive laminate sheet (F) produced by the present production method S10, the surface of the pressure-sensitive adhesive layer 9 is formed with minute irregularities, whereby the pressure-sensitive adhesive laminate sheet (F). Since the air that is bitten at the time of pasting can be extracted from the concave and convex portion to the outside, the biting of air can be effectively suppressed. In addition, the uneven portion functions like a suction cup and adheres to the adherend by applying pressure so that it is pressed from the base material layer side. There is no decline in sex.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but by forming the pressure-sensitive adhesive layer thin, the deviation between the pressure-sensitive adhesive laminate sheet (F) and the adherend can be reduced. On the other hand, the pressure-sensitive adhesive layer (F) can be easily handled by giving the pressure-sensitive adhesive layer a certain thickness. From these viewpoints, the thickness of the pressure-sensitive adhesive layer is preferably 50 μm or more and 400 μm or less, more preferably 60 μm or more and 300 μm or less, and even more preferably 70 μm or more and 250 μm or less.

According to the through holes and slits formed in the conventional sheet, since the through holes and slits penetrate in the thickness direction of the sheet, when the base material layer has a specific function, the through holes and slits There is a possibility that the function of the base material layer may not be exhibited in the portion. On the other hand, in the pressure-sensitive adhesive laminated sheet (F) according to the present invention, since the unevenness is formed only in the pressure-sensitive adhesive layer, the function of the base material layer is not impaired. Therefore, the pressure-sensitive adhesive laminated sheet (F) according to the present invention provides printing media, protective sheets, and parts transportation used for POPs and product seals, etc., by imparting a function according to the application to the base material layer. It can be suitably used for various applications such as trays and heat conductive sheets. In addition, the production of the pressure-sensitive adhesive laminated sheet (F) by this production method does not require precision processing using a laser or a cutter, and therefore can be performed with simple production equipment.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. The “parts” and “%” used here are based on mass unless otherwise specified.

<Air venting>
After manufacturing a pressure-sensitive adhesive laminated sheet (hereinafter, simply referred to as “sheet”) as described later, it is cut into a square of 100 mm × 100 mm, and the glass is placed so that the surface on the pressure-sensitive adhesive layer side is in contact with it. The sheet was placed on a plate, and a roller with a load of 0.5 gf was reciprocated once from the surface on the base material layer side and attached to the glass plate. At this time, the evaluation was made based on whether or not there is an air pocket in which the area calculated by the following is 100 mm ² or more. The results are shown in Table 2, where “◯” indicates that there is no air pocket where the area calculated as follows is 100 mm ² or more, and “×” indicates that there is an air pocket. If this evaluation is “◯”, it can be said that there is little air to be caught and the adhesiveness and appearance quality are excellent.
The area of the air reservoir was calculated by drawing a rectangle with the smallest area that can surround the largest air reservoir and measuring the area of the rectangle.

<Reworkability>
After carrying out the air bleedability test, it was left for 3 hours. Thereafter, the sheet was peeled off from the glass plate, and evaluation was made based on whether or not the sheet residue, which is a part of the pressure-sensitive adhesive layer, remained on the glass plate. The results are shown in Table 2, where “◯” indicates that no sheet residue remains and “×” indicates that no sheet residue remains. If this evaluation is “◯”, it can be said that re-sticking is easy and the usability is excellent.

<Displayability>
After producing the sheet as described later, it was cut into a square of 100 mm × 100 mm, and “Zeon” was written with oily magic on the surface of the sheet on the base material layer side. After that, we evaluated whether it was possible to wipe the letters with ethanol and write them again. The results are shown in Table 2 with “O” when the work is possible and “X” when the work is not possible. If this evaluation is “◯”, it can be repeatedly used as a sticky note or the like, and can be said to be excellent in usability.

<Preparation of pressure-sensitive adhesive laminate sheet>
Example 1
A reactor was charged with 100 parts of a monomer mixture composed of 94% 2-ethylhexyl acrylate and 6% acrylic acid, 0.03 parts 2,2′-azobisisobutyronitrile and 700 parts ethyl acetate. Then, after substitution with nitrogen, a polymerization reaction was carried out at 80 ° C. for 6 hours. The polymerization conversion rate was 97%. The obtained polymer was dried under reduced pressure to evaporate ethyl acetate to obtain a viscous solid (meth) acrylic acid ester polymer (A1-1). The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A1-1) was 270,000, and the weight average molecular weight (Mw) / number average molecular weight (Mn) was 3.1. The weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined in terms of standard polystyrene by gel permeation chromatography using tetrahydrofuran as an eluent.

Next, 69 parts of 2-ethylhexyl acrylate (2EHA) and an organic peroxide thermal polymerization initiator (1,6-bis (t-butylperoxycarbonyloxy) hexane (1 minute half-life temperature is 150 ° C.). )) A polyfunctional monomer (light acrylate PE-3A, Kyoeisha), which is a mixture of 1 part and pentaerythritol triacrylate, pentaerythritol tetraacrylate and pentaerythritol diacrylate in a ratio of 60: 35: 5 1 part by Chemical Co., Ltd.) was weighed with an electronic balance, and these were mixed with 30 parts of the (meth) acrylic acid ester polymer (A1-1). For the mixing, a thermostatic bath (manufactured by Toki Sangyo Co., Ltd., trade name “Viscomate 150III”) and a Hobart mixer (manufactured by Kodaira Seisakusho, trade name “ACM-5LVT type”, capacity: 5 L) were used. The temperature control of the Hobart container was set to 50 ° C., the vacuum (−0.1 MPaG) was applied, the rotation speed scale was set to 3, and the mixture was stirred for 30 minutes to obtain a precursor composition Z1.

Next, the precursor composition Z1 was dropped on a release PET film having a thickness of 75 μm, and another release PET film having a thickness of 75 μm was further covered on the precursor composition Z1. This laminate, in which the precursor composition Z1 is sandwiched between release PET films, is composed of two rolls whose intervals are adjusted so that the thickness of the precursor composition Z1 (crosslinked polymer (A)) is 1 mm. The precursor composition Z1 was formed into a sheet shape in between. Thereafter, the laminate was put into an oven, heated at 120 ° C. for 15 minutes, and then heated at 150 ° C. for 25 minutes. By this heating step, the (meth) acrylic acid ester monomer and the polyfunctional monomer are polymerized, and at the same time, the polyfunctional monomer as a crosslinking agent allows the (meth) acrylic acid ester polymer ( A polymer containing a structural unit derived from A1-1) and a (meth) acrylic acid ester monomer was crosslinked to obtain a crosslinked polymer (A) having a thickness of 1 mm sandwiched between release films. The polymerization conversion rate of all monomers was calculated from the amount of residual monomers in the crosslinked polymer (A) and found to be 99.9%.

Next, 300 parts by mass of ethyl acetate, 1 part by mass of an antioxidant (AO-60, manufactured by ADEKA Corporation) and 100 parts by mass of the crosslinked polymer (A) are placed in a reactor, and the crosslinked polymer is added. (A) was immersed in ethyl acetate. Thereafter, using a Hobart mixer (Kodaira Seisakusho, trade name: ACM-5 LVT type), the mixture was stirred for 300 minutes at a rotation speed of 1000 rpm to prepare 401 parts by mass of a polymer gel-containing dispersion.

Next, a metal mesh having an opening of 299 μm is fixed on a reactor different from the reactor in which the polymer gel-containing dispersion is placed, and 401 parts by mass of the polymer gel-containing dispersion is placed on the metal mesh. By pouring and passing through a metal mesh, 388 parts by mass of a filtrate was produced (that is, 13 parts by mass was a component that could not pass through a 299 μm mesh). The solid content concentration of the filtrate was 22.4%.
A part of the filtrate obtained after filtration of the crosslinked polymer (A) was vacuum dried to obtain a crosslinked polymer (H) after filtration. It was 80 mass% when the gel fraction was measured about the crosslinked polymer (H) after filtration. Thereby, it is calculated that the gel fraction of the crosslinked polymer (A) measured at an opening of 234 μm is 82.6% by mass.

Next, the filtrate was applied on a PET film having a thickness of 20 μm cut to 200 mm × 300 mm by using a bar coater so as to have a thickness of 230 μm.

Next, a laminate composed of a PET film and a filtrate coating film was placed in an oven and heated at 100 ° C. for 30 minutes. In this heating step, the solvent is evaporated from the filtrate to form a pressure-sensitive adhesive layer having a thickness of 100 μm on the PET film, and the pressure-sensitive adhesive layer is laminated on the PET film as the base material layer. A pressure-sensitive adhesive laminated sheet (F) was obtained.

(Examples 2 and 3 and Comparative Example 1)
The compounding of each substance used for the precursor composition was changed to the precursor composition Z2 or ZC1 in place of the precursor composition Z1 of Table 1 used in Example 1, and was the same as in Example 1. Sheets according to Example 2 and Comparative Example 1 were produced. Moreover, the sheet | seat which concerns on Example 3 was produced like Example 1 except having changed the base material layer from the polyimide film to the polyimide film.

As shown in Table 2, all of the sheets according to Examples 1 to 3 were excellent in air bleeding property, rework property, and display property. On the other hand, the sheet according to Comparative Example 1 in which the precursor composition did not contain a polyfunctional monomer was excellent in display properties, but the evaluation of air bleedability and reworkability was “x”, and adhesion was improved. It was inferior in appearance quality and usability.

1 Crosslinked polymer (A)
2 Solvent 3 Dispersion 4, 4a, 4b Polymer gel 5 Polymer gel-containing dispersion 6 Mesh 7 Filtrate 8 Base material layer 9 Pressure sensitive adhesive layer 10 Pressure sensitive adhesive laminated sheet

Claims (4)

1. A method for producing a pressure-sensitive adhesive laminate sheet (F) comprising a pressure-sensitive adhesive layer and a base material layer,
   A polymer gel-containing dispersion preparation step of preparing a polymer gel-containing dispersion by immersing a cross-linked polymer (A) having a (meth) acrylate polymer (A0) as a main component in a solvent and stirring the solution. When,
   A filtration step of filtering the polymer gel-containing dispersion with a mesh having a predetermined opening to obtain a filtrate;
   An application step of applying the filtrate to the substrate layer to a predetermined thickness;
   Removing the solvent in the filtrate on the substrate layer to obtain a pressure-sensitive adhesive layer; and
   Including
   The predetermined opening is 1.3 times or less of the predetermined thickness;
   A gel fraction of the post-filtration cross-linked polymer (H) obtained by drying the filtrate obtained by subjecting the cross-linked polymer (A) to the polymer gel-containing dispersion preparation step and the filtration step is 65% by mass. It is the above,
   A method for producing a pressure-sensitive adhesive laminated sheet (F).
2. The (meth) acrylic acid ester polymer (A0) is a (meth) acrylic acid ester polymer (A1), a (meth) acrylic acid ester monomer (α1), and a polyfunctional monomer (B1). A polymerization reaction of at least the (meth) acrylate monomer (α1), and a (meth) acrylate polymer (A1) and / or a (meth) acrylate monomer. The method for producing a pressure-sensitive adhesive laminate sheet (F) according to claim 1, which is obtained by performing a crosslinking reaction of a polymer containing a structural unit derived from the body (α1).
3. The method for producing a pressure-sensitive adhesive laminated sheet (F) according to claim 1 or 2, wherein the predetermined opening of the mesh is 1000 µm or less.
4. A pressure-sensitive adhesive laminate sheet (F) obtained by the method for producing a pressure-sensitive adhesive laminate sheet (F) according to any one of claims 1 to 3.

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