JP6366969B2 - Substrate-less double-sided pressure-sensitive adhesive tape and method for producing the substrate-less double-sided adhesive tape - Google Patents

Description

  The present invention relates to a substrate-less double-sided pressure-sensitive adhesive tape and a method for producing the substrate-less double-sided pressure-sensitive adhesive tape. Specifically, the present invention relates to a base material-less double-sided pressure-sensitive adhesive tape in which the pressure-sensitive adhesive layer is produced by coextrusion molding and has different adhesiveness on both sides, and a method for producing the base material-less double-sided pressure-sensitive adhesive tape. .

In general, baseless double-sided pressure-sensitive adhesive tapes have the same adhesiveness on each side of the double-sided pressure-sensitive adhesive tape, and the release sheet from the double-sided pressure-sensitive adhesive tape can be made different by changing the nature of the release surface of the release sheet laminated on each side. The ease of peeling is different.
Substrate-less double-sided pressure-sensitive adhesive tapes are widely used mainly for optical applications, and recently, substrate-less double-sided pressure-sensitive adhesive tapes have been proposed in which each surface of double-sided pressure-sensitive adhesive tapes has different adhesive properties. (For example, Patent Document 1).

Japanese Patent No. 4025405

  The substrate-less double-sided pressure-sensitive adhesive tape disclosed in Patent Document 1 forms a pressure-sensitive adhesive layer by applying a pressure-sensitive adhesive or a solution thereof on a release paper, and laminates a separately manufactured base material pressure-sensitive adhesive on the pressure-sensitive adhesive layer. Furthermore, it is manufactured by a manufacturing method in which a pressure-sensitive adhesive or a solution thereof is applied onto the substrate pressure-sensitive adhesive to form a pressure-sensitive adhesive layer. Such a manufacturing method is complicated and inferior in productivity. Further, as shown in Comparative Example 2 to be described later, the baseless double-sided pressure-sensitive adhesive tape formed by bonding the pressure-sensitive adhesive layers is likely to cause delamination due to a decrease in adhesion between the pressure-sensitive adhesive layers bonded together. There is a tendency to become.

  The present invention has been made in view of the actual situation as described above, and an object thereof is to provide a baseless double-sided pressure-sensitive adhesive tape comprising an adhesive layer which is manufactured without going through complicated steps and hardly causes delamination. And Another object of the present invention is to provide a method for producing the above-mentioned substrate-less double-sided pressure-sensitive adhesive tape.

The present invention provided to solve the above problems is as follows.
(1) A first pressure-sensitive adhesive layer, a second pressure-sensitive adhesive layer laminated on one surface of the first pressure-sensitive adhesive layer, and a first peel peelable laminated on the other surface of the first pressure-sensitive adhesive layer A substrate-less double-sided pressure-sensitive adhesive tape comprising a sheet, wherein the substrate-less double-sided pressure-sensitive adhesive tape forms a first release resin composition for forming the first release sheet, and the first pressure-sensitive adhesive layer. A first resin composition and a second resin composition for forming the second pressure-sensitive adhesive layer, wherein the first release sheet is peeled from the first pressure-sensitive adhesive layer. A substrate-less double-sided adhesive tape characterized by being capable of being used.

(2) at 220 ° C., a shear rate ^{of 10} 0 - 10 ³ (Unit: 1 / s) the average value of the viscosity of the first peeling resin composition in the range of shear rate ^{of 10} 0 - 10 ³ (Unit: 1 / s The baseless double-sided pressure-sensitive adhesive tape according to (1), wherein the ratio of the viscosity of the first resin composition in the range of 1) to 1 is 4.3 to 4.3.

(3) The first resin composition contains a first additive resin that is a non-crosslinked resin having compatibility with the first main resin and the first main resin, and the second resin composition comprises: Substrate-less both sides according to the above (1) or (2) satisfying at least one of containing a second main resin and a second additive resin that is a non-crosslinked resin having compatibility with the second main resin Adhesive tape.

(4) The first resin composition contains the first additive resin, the second resin composition contains the second additive resin, and the first additive resin and the second additive resin are in terms of polystyrene. The substrate-less double-sided pressure-sensitive adhesive tape according to (3), wherein the weight average molecular weight (Mw) is 500,000 or more.

(5) The content of the first additive resin in the first resin composition is more than 0.01% by mass and less than 10% by mass, and the content of the second additive resin in the second resin composition is 0.00. The substrate-less double-sided pressure-sensitive adhesive tape according to (4), which is more than 01% by mass and less than 10% by mass.

(6) Said 1st main resin and said 1st addition resin, said 2nd main resin, and said 2nd addition resin are (meth) acrylic-ester type resin, As described in said (4) or (5) Baseless double-sided adhesive tape.

(7) The baseless double-sided pressure-sensitive adhesive tape according to (6), wherein the first main resin and the second main resin are made of a (meth) acrylic acid ester triblock copolymer.

(8) The substrate may further include a second release sheet laminated on the surface on the second resin layer side, and the substrate-less double-sided adhesive tape may include the first release resin composition, the first resin composition, and the second resin. A co-extrusion molded body formed from a resin composition and a second release resin composition for forming the second release sheet, wherein the first release sheet is peelable from the first pressure-sensitive adhesive layer; The substrate-less double-sided pressure-sensitive adhesive tape according to any one of (1) to (7), wherein the second release sheet is peelable from the second pressure-sensitive adhesive layer.

(9) at 220 ° C., a shear rate ^{of 10} 0 - 10 ³ (Unit: 1 / s) the average value of the viscosity of the first peeling resin composition in the range of shear rate ^{of 10} 0 - 10 ³ (Unit: 1 / The ratio of the range of s) to the average value of the viscosity of the first resin composition is 1 or more and 4.3 or less, and the shear rate at 220 ° C. is in the range of 10 ⁰ to 10 ³ (unit: 1 / s). The ratio of the average value of the viscosity of the second release resin composition to the average value of the viscosity of the second resin composition in the shear rate range of 10 ⁰ to 10 ³ (unit: 1 / s) is 1 or more and 4. The substrate-less double-sided pressure-sensitive adhesive tape according to (8), which is 3 or less.

(10) A method for producing a substrate-less double-sided pressure-sensitive adhesive tape according to any one of (1) to (7), wherein the first release resin composition, the first resin composition, and the second resin composition Is formed of the first release sheet, the first pressure-sensitive adhesive layer, and the second pressure-sensitive adhesive layer, and the first release sheet is peelable from the first pressure-sensitive adhesive layer. A method for producing a substrate-less double-sided pressure-sensitive adhesive tape, comprising a first co-extrusion molding step for obtaining an extruded product as the substrate-less double-sided pressure-sensitive adhesive tape.

(11) The base material-less double-sided pressure-sensitive adhesive tape according to any one of (1) to (7) above and a second release sheet laminated on the surface on the second resin layer side of the base-material-less double-sided pressure-sensitive adhesive tape A method for producing a substrate-less double-sided pressure-sensitive adhesive tape comprising the first release resin composition, the first resin composition, and the second resin composition, wherein the first release sheet, the first A first coextrusion molding step for obtaining a coextrusion molded body comprising one pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, wherein the first release sheet is peelable from the first pressure-sensitive adhesive layer; Laminating the second release sheet on the surface of the second pressure-sensitive adhesive layer side of the co-extrusion molded body obtained by one co-extrusion molding step, the first release sheet, the first pressure-sensitive adhesive layer, the second A structure in which the pressure-sensitive adhesive layer and the second release sheet are laminated, Characterized in that it comprises a release sheet lamination step of obtaining a wood-less double-sided pressure-sensitive adhesive tape, the manufacturing method of the laminated structure.

(12) A method for producing a substrate-less double-sided pressure-sensitive adhesive tape according to (8) or (9), wherein the first release resin composition, the first resin composition, the second resin composition, and The second release resin composition is coextruded and the first release sheet is peelable from the first pressure-sensitive adhesive layer, and the second release sheet is peelable from the second pressure-sensitive adhesive layer. A method for producing a substrate-less double-sided pressure-sensitive adhesive tape, comprising a second co-extrusion molding step for obtaining an extruded product as the base-material-less double-sided pressure-sensitive adhesive tape.

  According to the present invention, it is possible to obtain a substrate-less double-sided pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer that has different adhesive surfaces and hardly causes delamination as a product that is manufactured without going through complicated steps. Is possible. Moreover, according to this invention, the manufacturing method of said base-material-less double-sided adhesive tape is also provided.

It is a schematic sectional drawing of the base-material-free double-sided adhesive tape which concerns on one Embodiment of this invention. It is a schematic sectional drawing of the base-material-free double-sided adhesive tape which concerns on another one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described.

1. Substrate-less double-sided pressure-sensitive adhesive tape As shown in FIG. 1, the base-material-less double-sided pressure-sensitive adhesive tape 1 provided in the laminated structure according to an embodiment of the present invention includes a first pressure-sensitive adhesive layer 11 and a first pressure-sensitive adhesive layer 11. The 2nd adhesive layer 12 laminated | stacked on one surface and the 1st peeling sheet 21 laminated | stacked on the other surface of said 1st adhesive layer 11 so that peeling was possible are provided.

  When using the base material-less double-sided pressure-sensitive adhesive tape 1, the first release sheet 21 is peeled off. Accordingly, the first application surface 1A, which is one application surface of the base material-less double-sided pressure-sensitive adhesive tape 1, is composed of the surface of the first adhesive layer 11, and is the other application surface of the base material-less double-sided pressure-sensitive adhesive tape 1. The two pasting surfaces 1 </ b> B are configured from the surface of the second pressure-sensitive adhesive layer 12. Therefore, a bonding surface between the materials constituting the two pasting surfaces 1A and 1B of the baseless double-sided pressure-sensitive adhesive tape 1 (the material constituting the first pressure-sensitive adhesive layer 11 and the material constituting the second pressure-sensitive adhesive layer 12). The base material-less double-sided pressure-sensitive adhesive tape 1 provided in the laminated structure according to an embodiment of the present invention is provided.

  Usually, the adhesiveness (peeling resistance) of such a joint surface is relatively low, and peeling often occurs on this joint surface during use. For this reason, the base-less double-sided pressure-sensitive adhesive tape disclosed in Patent Document 1 does not have a bonding surface between the pressure-sensitive adhesive layers constituting the sticking surface of the double-sided pressure-sensitive adhesive tape, and is provided with a base material pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer constituting the sticking surface of the double-sided pressure-sensitive adhesive tape is laminated on the material adhesive layer.

  On the other hand, the base material-less double-sided pressure-sensitive adhesive tape 1 according to one embodiment of the present invention is obtained by coextrusion molding of a laminate including two pressure-sensitive adhesive layers (first pressure-sensitive adhesive layer 11 and second pressure-sensitive adhesive layer 12). Since it is formed, peeling at the interface between the first pressure-sensitive adhesive layer 11 and the second pressure-sensitive adhesive layer 12 hardly occurs.

  However, even if the first resin composition for forming the first pressure-sensitive adhesive layer 11 and the second resin composition for simply forming the second pressure-sensitive adhesive layer 12 are simply co-extruded, they will be shown in the examples described later. As described above, it is difficult to form a coextruded product having excellent shape stability. The base material-less double-sided pressure-sensitive adhesive tape 1 according to an embodiment of the present invention uses a first release resin composition for forming a first release sheet 21 together with a first resin composition and a second resin composition. It is a co-extruded product. Thus, it becomes possible to improve shape stability by setting it as a coextrusion molded object provided with an adhesive layer and a peeling sheet.

The material which comprises the 1st peeling sheet 21, the 1st adhesive layer 11, and the 2nd adhesive layer 12 is not limited as long as these laminated bodies are obtained as a co-extrusion molded object. From the viewpoint of facilitating obtaining a co-extruded product, the shear rate of the average value of the viscosity of the first release resin composition at a shear rate of 10 ⁰ to 10 ³ (unit: 1 / s) at 220 ° C. The ratio of the first resin composition in the range of 10 ⁰ to 10 ³ (unit: 1 / s) to the average value of viscosity (also referred to as “first viscosity ratio” in this specification) is 1 or more and 4.3 or less. It is preferable that In the present specification, 220 ° C. is positioned as a typical example of the temperature when a plurality of resin compositions are in contact with each other in the case of performing coextrusion molding.

In the present specification, the viscosity of the resin composition is a value derived using a Cross model. In this case, the index is derived by inserting the shear rate, apparent viscosity, and temperature measured using a capillary rheometer into the following formulas 1 and 2 and fitting.

In the above formula, η is a viscosity (unit: Pa · s) at an arbitrary temperature / shear rate obtained from the regression equation, γ is a shear rate (unit: 1 / s), and τ ^* is a critical shear stress (unit: Pa · s). s), c is an index, η ₀ is critical viscosity (unit: 1 / s), a is viscosity (unit: Pa · s), T _b is a temperature coefficient (unit: K), and T is temperature (unit: K) Indicates.

  When the first viscosity ratio is in the above range, the first release sheet 21 and the first pressure-sensitive adhesive layer 11 can be easily laminated appropriately. When the first viscosity ratio is excessively higher than 4.3, the sheet-like member formed from the first release resin composition is easily disposed so as to surround the first resin composition. In the present specification, this phenomenon is sometimes referred to as “encapsulation”. Moreover, when the first viscosity ratio is particularly high, a member having a structure in which the first resin composition is dispersed may be formed in a sheet-like member formed from the first release resin composition. From the viewpoint of more stably obtaining the substrate-less double-sided pressure-sensitive adhesive tape 1, the first viscosity ratio is preferably 1 or more and 4.0 or less, more preferably 1 or more and 3.5 or less, and particularly 1 or more and 2 .5 or less is preferable.

  From the viewpoint of facilitating satisfying the condition regarding the first viscosity ratio, the first resin composition contains the first main resin and the first additive resin which is a non-crosslinked resin having compatibility with the first main resin. It is preferable. Moreover, it is preferable that a 2nd resin composition contains the 2nd addition resin which is non-crosslinked resin which has compatibility with 2nd main resin and 2nd main resin.

  In this specification, the term “additive resin” is used as a general term for the first additive resin and the second additive resin. The term “main resin” is used as a general term for the first main resin and the second main resin. The term “resin composition” is used as a general term for the first resin composition and the second resin composition. The term “resin viscosity” is used as a general term for the first resin viscosity and the second resin viscosity.

  In this specification, “compatible with the main resin” means a temperature range set for extruding the resin composition containing the main resin and the additive resin (as a specific example, 200 ° C. to 220 ° C. In the following, the same applies to the temperature region of the main resin. Since the additive resin is a non-crosslinked resin having compatibility with the main resin, there is a possibility that the main resin and the additive resin are likely to interact in the resin composition.

  The kind of main resin is not limited. These resin materials are components that are directly involved in the occurrence of adhesiveness of the pressure-sensitive adhesive layer, and specific examples of the main resin include rubber resins, acrylic resins, silicone resins, and polyvinyl ether resins. Among these, acrylic resins are preferable from the viewpoints of ease of handling and availability. Specific examples of the acrylic resin include (meth) acrylic acid ester trimethyl such as polymethyl methacrylate-polybutyl acrylate-polymethyl methacrylate, polymethyl methacrylate-polyacrylic acid-2-ethylhexyl-polymethyl methacrylate, and the like. A block polymer is mentioned. In this specification, “(meth) acrylic acid” means both acrylic acid and methacrylic acid. The same applies to other similar terms.

  The main resin may be composed of one type of material or may be composed of a plurality of types of materials. The material constituting the first main resin and the material constituting the second main resin may be the same or different. In the case where they are different, it may be easier to make the adhesiveness of both surfaces of the base material-less double-sided pressure-sensitive adhesive tape 1 different.

  The polystyrene equivalent weight average molecular weight (Mw) of the main resin is not limited. From the viewpoint of facilitating that the additive resin is compatible with the main resin, the weight average molecular weight (Mw) in terms of polystyrene of the main resin is preferably in the range of 10,000 to 1,000,000, and is preferably in the range of 20,000 to 700,000. More preferably, it is in the range.

In addition, in this specification, the value of polystyrene conversion weight average molecular weight (Mw) is a value when measured by gel permeation chromatography method (GPC) method (polystyrene standard). The measurement by such a method is performed with the following apparatus and conditions, for example.
Device name: HLC-8220GPC, manufactured by Tosoh Corporation Column: TSKgelGMHXL, TSKgelGMHXL and TSKgel2000HXL sequentially connected Solvent: Tetrahydrofuran (THF)
Injection volume: 80 μl
Measurement temperature: 40 ° C
Flow rate: 1 ml / min Detector: Differential refractometer Sample concentration: 1% (w / v)

  The specific kind of the additive resin is not limited as long as it is a non-crosslinked resin having compatibility with the main resin. As will be described later, the additive resin is preferably a resin that can be powdered in a temperature region in the hopper of the extruder.

  From the viewpoint of more stably realizing that the additive resin has compatibility with the main resin, the additive resin is preferably a resin of the same series as the main resin. That is, when the main resin is made of an acrylic resin, the additive resin is also preferably an acrylic resin. Similarly, from the viewpoint of improving the adhesion between the first pressure-sensitive adhesive layer 11 and the second pressure-sensitive adhesive layer 12, it is preferable that the first main resin and the second main resin are the same series of resins. As a specific example in such a case, the first main resin and the second main resin are acrylic acid resins.

  The content of the additive resin in the resin composition is not limited as long as the function of adjusting the viscosity of the resin composition can be achieved. Both the content of the first additive resin in the first resin composition and the content of the second additive resin in the second resin composition are preferably more than 0.01% by mass and less than 10% by mass. It is more preferably 1% by mass or more and 5% by mass or less, and particularly preferably 0.5% by mass or more and 3% by mass or less.

  The resin composition may contain components other than the main resin and the additive resin depending on the required function. For example, when high tackiness is required, a tackifier resin may be contained. When it is required to change the adhesiveness, an energy beam polymerizable compound may be contained. The content of these additive components in the resin composition is set according to the desired function.

  The thickness of the 1st adhesive layer 11 and the thickness of the 2nd adhesive layer 12 should be suitably set according to a use, and are not limited. These thicknesses are usually about 3 μm to 500 μm, preferably about 5 μm to 200 μm.

  The composition of the first release resin composition is not limited as long as the first release sheet 21 can be released from the first pressure-sensitive adhesive layer 11 laminated on the first release sheet 21 by coextrusion molding. When the first resin composition contains an acrylic resin, the first release resin composition preferably contains an olefin polymer.

  The thickness of the first release sheet 21 is not particularly limited, and is usually about 20 μm to 150 μm.

  The substrate-less double-sided pressure-sensitive adhesive tape 1 according to an embodiment of the present invention may include components other than the first release sheet 21, the first pressure-sensitive adhesive layer 11, and the second pressure-sensitive adhesive layer 12. For example, as shown in FIG. 2, the base material-less double-sided pressure-sensitive adhesive tape 1 may further include a second release sheet 22 laminated on the surface on the second pressure-sensitive adhesive layer 12 side.

  The 2nd peeling sheet 22 may be affixed on the surface at the side of the 2nd adhesive layer 12 of the base materialless double-sided adhesive tape 1 of the structure shown by FIG.

  As the second release sheet 22 in such a case, for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate. Film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene- (meth) acrylic acid copolymer film, ethylene- (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, A film such as a polyimide film or a fluororesin film, or a paper such as glassine paper or high-quality paper can be used. Moreover, you may use these bridge | crosslinking films. Furthermore, a laminated film in which a plurality of these films are laminated may be used.

  The release surface of the second release sheet 22 (the surface attached to the second pressure-sensitive adhesive layer 12) is preferably subjected to a release treatment. Examples of the release agent used for the release treatment include alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax release agents.

  The substrate-less double-sided pressure-sensitive adhesive tape 1 according to an embodiment of the present invention is a coextruded molded body composed of a first release sheet 21, a first pressure-sensitive adhesive layer 11, a second pressure-sensitive adhesive layer 12, and a second release sheet 22. May be. That is, the base material-less double-sided pressure-sensitive adhesive tape 1 was formed from the second release resin composition for forming the first release resin composition, the first resin composition, the second resin composition, and the second release sheet 22. It may be a co-extruded product. In this case, the first release sheet 21 may be peelable from the first pressure-sensitive adhesive layer 11 and the second release sheet 22 may be peelable from the second pressure-sensitive adhesive layer 12.

In the above case, the materials constituting the first release sheet 21, the first pressure-sensitive adhesive layer 11, the second pressure-sensitive adhesive layer 12, and the second release sheet 22 are as long as these laminates can be obtained as a coextrusion molded body. It is not limited. From the viewpoint of facilitating the formation of a co-extruded product, the shear of the average value of the viscosity of the second release resin composition at a shear rate of 10 ⁰ to 10 ³ (unit: 1 / s) at 220 ° C. The ratio with respect to the average value of the viscosity of the second resin composition in the range of speeds 10 ⁰ to 10 ³ (unit: 1 / s) is preferably 1 or more and 4.3 or less, and is 1 or more and 4.0 or less. More preferably, it is 1 or more and 3.5 or less.

  The thickness of the second release sheet 22 is not particularly limited, and is usually about 20 μm to 150 μm.

  When the substrate-less double-sided pressure-sensitive adhesive tape 1 is configured as shown in FIG. 2, that is, when the first release sheet 21 and the second release sheet 22 are provided, the relationship between the release forces of these release sheets is not limited. . From the viewpoint of improving the handleability at the time of use of the substrate-less double-sided pressure-sensitive adhesive tape 1, the first peeling force that is the peeling force with respect to the first pressure-sensitive adhesive layer 11 of the first release sheet 21 and the second pressure-sensitive adhesive of the second release sheet 22. It is preferable that the second peel force, which is the peel force for the agent layer 12, is different.

  When the first peel force and the second peel force are different, the peel force of the heavy surface release sheet, which is a release sheet having a relatively high peel force, that is, the heavy surface peel force is 100 to 400 mN / 50 mm. Is preferably about 150 to 350 mN / 50 mm, and more preferably about 200 to 300 mN / 50 mm. In the above case, the peel strength of the light surface release sheet, which is a release sheet having a relatively low peel force, that is, the light surface peel force is preferably about 30 to 200 mN / 50 mm, and preferably about 50 to 150 mN / 50 mm. More preferably, it is more preferably about 70 to 120 mN / 50 mm. In addition, in this specification, a heavy surface peeling force and a light surface peeling force mean the value measured by the measuring method shown in the Example mentioned later.

  The difference between the heavy surface peeling force and the light surface peeling force is preferably 30 mN / 50 mm or more, more preferably 50 mN / 50 mm or more, and further preferably 80 mN / 50 mm or more. When the difference between the peeling forces is 30 mN / 50 mm or more, when the light-sided release sheet is peeled from the substrate-less double-sided pressure-sensitive adhesive tape 1, between the heavy-sided release sheet and the pressure-sensitive adhesive layer facing the sheet. It becomes possible to stably prevent the occurrence of floating and the peeling of the double-sided release sheet from the pressure-sensitive adhesive layer facing the sheet.

2. Manufacturing method of base material-less double-sided pressure-sensitive adhesive tape The manufacturing method of base material-less double-sided pressure-sensitive adhesive double-sided tape 1 having the configuration shown in FIG. 1 includes a first release resin composition, a first resin composition, and a second resin composition. Is formed of the first release sheet 21, the first pressure-sensitive adhesive layer 11, and the second pressure-sensitive adhesive layer 12, and the first release sheet 21 is peelable from the first pressure-sensitive adhesive layer 11. You may provide the 1st co-extrusion molding process which obtains an extrusion-molded body as the base-material-free double-sided adhesive tape 1. FIG.

  When the pressure-sensitive adhesive layer is produced by extrusion molding, usually, at least a part of the resin composition, specifically, a pellet that gives the main resin is supplied to the hopper of the molding machine, and the pellets in the hopper are made of other materials. At the same time, it is fed into the screw part and melted and kneaded, and the resin composition in a molten state is discharged into the feed block. Usually, since a resin composition is comparatively soft, a pellet may adhere itself in a hopper. In this case, pellets are not properly fed into the screw part of the molding machine, and the supply amount of the resin composition from the die becomes unstable. Therefore, it is preferable to avoid self-adhesion of the pellets in the hopper, stabilize the supply amount of the resin composition, and stabilize the shape of the pressure-sensitive adhesive layer obtained by extrusion molding.

  From the viewpoint of facilitating the extrusion molding of the resin composition, when the resin composition contains an additive resin, the additive resin is preferably a powder in the hopper of the extruder. At this time, the additive resin can suppress the self-adhesion of the pellet made of the main resin or the like in the hopper. In the case where the additive resin is powder, the shape thereof is not limited as long as the above-described self-adhesion of the pellets in the hopper can be suppressed.

  An example of the manufacturing method of the base material-less double-sided pressure-sensitive adhesive tape 1 as shown in FIG. 2 may include the first co-extrusion molding step; and the release sheet lamination step described below. In the release sheet laminating step, the second release sheet 22 is laminated on the second pressure-sensitive adhesive layer 12 side surface of the co-extruded product obtained by the first co-extrusion molding step, and the first release sheet 21 and the first adhesive The structure formed by laminating the agent layer 11, the second pressure-sensitive adhesive layer 12, and the second release sheet 22 is obtained as the base material-less double-sided pressure-sensitive adhesive tape 1.

  Another example of the manufacturing method of the base material-less double-sided pressure-sensitive adhesive tape 1 as shown in FIG. 2 includes a first release resin composition, a first resin composition, a second resin composition, and a second release resin composition. A co-extruded product that is extrudable so that the first release sheet 21 can be peeled from the first pressure-sensitive adhesive layer 11 and the second release sheet 22 can be peeled from the second pressure-sensitive adhesive layer 12 is formed into a substrate-less double-sided pressure-sensitive adhesive. A second coextrusion molding process obtained as the tape 1 may be provided.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, the baseless double-sided pressure-sensitive adhesive tape 1 may further include a third pressure-sensitive adhesive layer laminated on the surface of the second pressure-sensitive adhesive layer 12. In this case, the third pressure-sensitive adhesive layer may be formed together with the first pressure-sensitive adhesive layer 11 and the first release sheet 21 by coextrusion as in the case of the second pressure-sensitive adhesive layer 12, or may be separately subjected to a coating process or the like. It may be formed through.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Example 1]
(Meth) acrylic acid triblock pressure-sensitive adhesive as the second main resin ("Kuraray LA2330" manufactured by Kuraray Co., Ltd., polymethyl methacrylate (PMMA) -polybutyl acrylate (PBA) -PMMA triblock copolymer, PMMA ratio: 26. 5 mol%, polystyrene-converted weight average molecular weight (Mw): 103,000 parts by mass, and another type of (meth) acrylic acid triblock pressure-sensitive adhesive ("Kuraray LA4285" manufactured by Kuraray Co., Ltd., polymethyl methacrylate (PMMA)- Polybutyl acrylate (PBA) -PMMA triblock copolymer, PMMA ratio: 55.8 mol%, polystyrene-converted weight average molecular weight (Mw): 57,000) Non-crosslinked as a second additive resin Polymethacrylic acid fine particles (manufactured by Sekisui Chemical Co., Ltd. Remer MB-4 ”, average particle size: 5.4 μm, polystyrene-converted weight average molecular weight (Mw): 775,000) 1 part by mass was added and mixed for 10 minutes with a tumbler to obtain the pressure-sensitive adhesive composition (A). Obtained as a second resin composition. When the pressure-sensitive adhesive composition (A) was pelletized, no adhesion (self-adhesion phenomenon) was observed in the obtained pellets under an environment of ordinary temperature (23 ° C.).

  (Meth) acrylic acid triblock pressure-sensitive adhesive as the first main resin ("Kuraray LA2330" manufactured by Kuraray Co., Ltd., polymethyl methacrylate (PMMA) -polybutyl acrylate (PBA) -PMMA triblock copolymer, PMMA ratio: 26. Non-crosslinked polymethacrylic acid fine particles (Sekisui Kasei Co., Ltd., “Techpolymer MB-4”, average) as a first additive resin with respect to 100 parts by mass of 5 mol%, polystyrene-converted weight average molecular weight (Mw): 103,000) Particle size: 5.4 μm, polystyrene equivalent weight average molecular weight (Mw): 775,000) 1 part by mass is added and mixed for 10 minutes with a tumbler to obtain the pressure-sensitive adhesive composition (B) as the first resin composition. It was. When this pressure-sensitive adhesive composition (B) was pelletized, no adhesion (self-adhesion phenomenon) was observed in the obtained pellets under an environment of ordinary temperature (23 ° C.).

  An extruder having first to third extruders was prepared. The above-mentioned pressure-sensitive adhesive composition (A) was charged into a hopper in the first extruder, and the pressure-sensitive adhesive composition (A) was kneaded and melted in the screw portion of the first extruder. The above-mentioned pressure-sensitive adhesive composition (B) was introduced into a hopper in the second extruder, and the pressure-sensitive adhesive composition (B) was kneaded and melted in the screw part of the second extruder. Low-density polyethylene (LDPE, manufactured by Nippon Polyethylene Co., Ltd., “Novatech LD LC604”) as the first release resin composition is charged into the hopper of the third extruder, LDPE was kneaded and melted in the screw portion of the extruder.

  The molten pressure-sensitive adhesive composition (A) discharged from the first extruder, the molten pressure-sensitive adhesive composition (B) discharged from the second extruder, and the third extruder. The melted LDPE was laminated using a feed block so as to be arranged in the order of pressure-sensitive adhesive composition (A) / pressure-sensitive adhesive composition (B) / LDPE. Further, using a T-die, the thickness of the second pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A) is 20 μm, and the thickness of the first pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (B) A laminate having a thickness of 20 μm and a first release sheet formed from LDPE of 40 μm was obtained. A release surface of a release sheet (manufactured by Lintec Corporation, “SP-PET3801”) as a second release sheet was attached to the surface of the laminate on the second adhesive layer side to obtain a substrateless double-sided adhesive tape. . The temperature of the feed block and the T die was set to 220 ° C.

The resin viscosity in the feed block having an internal temperature of 220 ° C. was simulated using simulation software (“Materialfit” manufactured by HASL) and the aforementioned Cross model. The average value of the viscosity in the range of the shear rate of 10 ⁰ to 10 ³ (unit: 1 / s) of the pressure-sensitive adhesive composition (B) at 220 ° C. was calculated as 766.9 Pa · s. Shear rate ¹⁰ 0 - 10 ³ LDPE at 220 ° C. (Unit: 1 / s) the average value of the viscosity in the range of was calculated to 1787.3Pa · s. Therefore, these viscosity ratios (LDPE / adhesive composition (B)) were 2.3.

[Example 2]
An extruder having first to fourth extruders was prepared. The pressure-sensitive adhesive composition (A) prepared in Example 1 was charged into the hopper in the first extruder, and the pressure-sensitive adhesive composition (A) was kneaded and melted in the screw portion of the first extruder. The pressure-sensitive adhesive composition (B) prepared in Example 1 was put into a hopper in the second extruder, and the pressure-sensitive adhesive composition (B) was kneaded and melted in the screw portion of the second extruder. Low-density polyethylene (LDPE, manufactured by Nippon Polyethylene Co., Ltd., “Novatech LD LC604”) as the first release resin composition is charged into the hopper of the third extruder, LDPE was kneaded and melted in the screw portion of the extruder. An α-olefin copolymer (made by Mitsui Chemicals, “Toughmer P028G”) as a second release resin composition was charged into the hopper in the fourth extruder, The α-olefin copolymer was kneaded and melted in the screw portion of the extruder.

  Melted pressure-sensitive adhesive composition (A) discharged from the first extruder, molten pressure-sensitive adhesive composition (B) discharged from the second extruder, and melt discharged from the third extruder LDPE in the state and the α-olefin copolymer in the molten state discharged from the fourth extruder, using a feed block, α-olefin copolymer / adhesive composition (A) / adhesive composition The layers were laminated so as to be arranged in the order of (B) / LDPE. Further, using a T-die, the thickness of the second release sheet formed from the α-olefin copolymer is 40 μm, and the thickness of the second pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A) is A laminate in which the thickness of the first pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (B) is 20 μm and the thickness of the first release sheet formed from LDPE is 40 μm, Obtained as a substrate-less double-sided adhesive tape.

The resin viscosity in the feed block where the internal temperature was 220 ° C. was simulated using simulation software (HASL, “Materialfit”). The average value of the viscosity of the pressure-sensitive adhesive composition (A) at 220 ° C. within the shear rate range of 10 ⁰ to 10 ³ (unit: 1 / s) was calculated to be 598.5 Pa · s. The average value of the viscosity in the range of the shear rate of 10 ⁰ to 10 ³ (unit: 1 / s) of the pressure-sensitive adhesive composition (B) at 220 ° C. was calculated as 766.9 Pa · s. Shear rate ¹⁰ 0 - 10 ³ LDPE at 220 ° C. (Unit: 1 / s) the average value of the viscosity in the range of was calculated to 1787.3Pa · s. The average value of the viscosity in the range of the shear rate of 10 ⁰ to 10 ³ (unit: 1 / s) of the α-olefin copolymer at 220 ° C. was calculated as 1652.8 Pa · s. Therefore, the first viscosity ratio of the viscosity ratio of LDPE to the pressure-sensitive adhesive composition (B) (LDPE / pressure-sensitive adhesive composition (B)) was 2.3. The viscosity ratio of the α-olefin copolymer to the pressure-sensitive adhesive composition (A) (α-olefin copolymer / pressure-sensitive adhesive composition (A)) was 2.8.

[Comparative Example 1]
In Example 1, without using the third extruder, only the first extruder and the second extruder were used, and the layer constitution in the feed block was the pressure-sensitive adhesive composition (A) and the pressure-sensitive adhesive composition (B The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A) is in contact with one release sheet (“SP-PET 3801” manufactured by Lintec Corporation) and formed from the pressure-sensitive adhesive composition (B). The resin layer was laminated with two release sheets so that the adhesive layer to be in contact with the other release sheet (“SP-PET3811” manufactured by Lintec Corporation). However, the shape, particularly the thickness, is not stable, and a desired pressure-sensitive adhesive layer (having a film-like shape) cannot be obtained.

[Comparative Example 2]
The pressure-sensitive adhesive composition (A) was diluted with ethyl acetate so that the solid content concentration was 40% by mass to obtain a coating liquid (α). The pressure-sensitive adhesive composition (B) was diluted with ethyl acetate so that the solid content concentration was 40% by mass to obtain a coating liquid (β).
On the release surface of the release sheet (“SP-PET3811”, manufactured by Lintec Corporation), the coating liquid (α) is applied so that the film thickness after drying is 20 μm, and the coating film is dried to give an adhesive. Layer (X) was obtained. A laminate in which another release sheet (“SP-PET 3801”, manufactured by Lintec Corporation) is pasted on the surface of the pressure-sensitive adhesive layer (X), and the pressure-sensitive adhesive layer (X) is sandwiched between two release sheets. Got.

  On the release surface of the release sheet (“SP-PET38 2050”, manufactured by Lintec Corporation), the coating liquid (β) is applied so that the film thickness after drying is 20 μm, and the coating film is dried and adhered. An agent layer (Y) was obtained. While peeling off one release sheet (“SP-PET3801” manufactured by Lintec Corporation) from the above laminate to expose the surface of the adhesive layer (X), the surface of the exposed adhesive layer (X) is adhered. Affixed to the surface of the adhesive layer (Y), a release sheet (manufactured by Lintec, “SP-PET3811”), an adhesive layer (X), an adhesive layer (Y) and a release sheet (manufactured by Lintec, “SP- A substrate-less double-sided pressure-sensitive adhesive tape comprising a laminate of PET38 2050 ") was obtained.

[Test Example 1] Adhesion test On the surface of the pressure-sensitive adhesive layer formed on the basis of the pressure-sensitive adhesive composition (A) in the base material-less double-sided pressure-sensitive adhesive tapes produced in Examples 1 and 2 and Comparative Example 2, Cuts (longitudinal direction: 21 pieces, lateral direction: 21 pieces) were made in (5 mm × 5 mm) to form 400 grids. An adhesive tape (Cello Tape (registered trademark) No. 405 manufactured by Nichiban Co., Ltd.) was attached to the surface of the 400 grids formed. In this state, it was left for 20 minutes in an environment of 23 ° C. and 50% relative humidity. Thereafter, the adhesive tape was peeled off at a peeling angle of 180 °, and the number of grids peeled off was measured. The measurement results are shown in Table 1.

[Test Example 2] Measurement of light surface peeling force The base material-less double-sided adhesive tapes produced in Examples 1 and 2 and Comparative Example 2 were cut to a width of 50 mm to prepare a laminate for measuring light surface peeling force. The release sheet affixed to the surface of the pressure-sensitive adhesive layer formed based on the pressure-sensitive adhesive composition (A) corresponds to a light-faced release sheet. The release sheet on the opposite side of the light release sheet is fixed to the support plate, and the light release sheet of the laminate for measuring the light release force is measured under the conditions of 23 ° C. and 50% relative humidity in accordance with JIS Z0237. The bent 180 ° peeling method (peeling speed: 300 m / min) was carried out, and the light surface peeling force (unit: mN / 50 mm) was measured. The measurement results are shown in Table 1.

[Test Example 3] Measurement of heavy surface peeling force The substrate-less double-sided pressure-sensitive adhesive tapes produced in Examples 1 and 2 and Comparative Example 2 were cut into a width of 50 mm. The release sheet affixed to the surface of the pressure-sensitive adhesive layer formed on the basis of the pressure-sensitive adhesive composition (B) corresponds to the double-sided release sheet. The release sheet attached to the surface of the pressure-sensitive adhesive layer formed on the basis of the pressure-sensitive adhesive composition (A) is peeled off, and the exposed surface is pasted on a base film made of polyethylene terephthalate (PET) having a thickness of 50 μm. did. In this way, the laminated body for heavy surface peeling force measurement was prepared, and said PET base film was fixed to the support plate. In accordance with JIS Z0237, the 180 ° peeling method (peeling speed: 300 m / min) was performed by bending the heavy surface release sheet of the laminate for measuring the heavy surface peeling force under the conditions of 23 ° C. and 50% relative humidity. Then, the peel strength (unit: mN / 50 mm) was measured. The measurement results are shown in Table 1.

  As shown in Table 1, the base material-less double-sided pressure-sensitive adhesive tape according to the example was excellent in adhesiveness between the pressure-sensitive adhesive layers, and had a heavy surface peeling force. On the other hand, the base material-less double-sided pressure-sensitive adhesive tape according to Comparative Example 2 manufactured through the coating process was inferior in adhesiveness between the pressure-sensitive adhesive layers and had a high surface peeling force.

  The substrate-less double-sided pressure-sensitive adhesive tape according to the present invention can be suitably used for various applications such as optical applications.

DESCRIPTION OF SYMBOLS 1 ... Base-material-less double-sided adhesive tape 1A ... 1st sticking surface 1B ... 2nd sticking surface 11 ... 1st adhesive layer 12 ... 2nd adhesive layer 21 ... 1st release sheet 22 ... 2nd release sheet

Claims (11)

A first pressure-sensitive adhesive layer, a second pressure-sensitive adhesive layer laminated on one surface of the first pressure-sensitive adhesive layer, and a first release sheet laminated on the other surface of the first pressure-sensitive adhesive layer in a peelable manner The base material-less double-sided adhesive tape,
The base material-less double-sided pressure-sensitive adhesive tape comprises a first release resin composition for forming the first release sheet, a first resin composition for forming the first adhesive layer, and the second adhesive layer. A coextrusion molded body formed from the second resin composition for forming
The first resin composition contains a first main resin composed of a (meth) acrylic acid ester triblock copolymer,
The second resin composition contains a second main resin made of a (meth) acrylic acid ester-based triblock copolymer,
The substrate-less double-sided pressure-sensitive adhesive tape, wherein the first release sheet is peelable from the first pressure-sensitive adhesive layer. At 220 ° C., a shear rate ^{of 10} 0 - 10 ³ (Unit: 1 / s): the range of the average value of the viscosity of the first peeling resin composition in the range of shear rate ^{of 10} 0 - 10 ³ (1 / s units) The baseless double-sided pressure-sensitive adhesive tape according to claim 1, wherein the ratio of the first resin composition to the average value of the viscosity is 1 or more and 4.3 or less. It said first resin composition, before Symbol contain the first additive resin is a non-crosslinked resin having compatibility with the first main resin, and the second resin composition, to the previous SL second main resin The base material-less double-sided pressure-sensitive adhesive tape according to claim 1 or 2, satisfying at least one of containing a second additive resin which is a non-crosslinked resin having compatibility. The first resin composition contains the first additive resin;
The second resin composition contains the second additive resin;
The substrate-less double-sided pressure-sensitive adhesive tape according to claim 3, wherein the first additive resin and the second additive resin have a polystyrene-equivalent weight average molecular weight (Mw) of 500,000 or more. The content of the first additive resin in the first resin composition is more than 0.01% by mass and less than 10% by mass,
The content of the second additive resin in the second resin composition is more than 0.01% by mass and less than 10% by mass.
The base material-less double-sided pressure-sensitive adhesive tape according to claim 4. Before Symbol first additive resin and before Symbol second additive resin, a (meth) acrylate-based resin, base material-less double-sided pressure-sensitive adhesive tape according to claim 4 or 5. A second release sheet laminated on the second resin layer side surface;
The substrate-less double-sided pressure-sensitive adhesive tape is formed from a second release resin composition for forming the first release resin composition, the first resin composition, the second resin composition, and the second release sheet. and a co-extrudate, wherein the first release sheet is peelable from said first pressure-sensitive adhesive layer, the second release sheet can be peeled off from the second pressure-sensitive adhesive layer, of claims 1-6 The base material-less double-sided pressure-sensitive adhesive tape according to any one of the above. At 220 ° C., a shear rate ^{of 10} 0 - 10 ³ (Unit: 1 / s) the average value of the viscosity of the first peeling resin composition in the range of shear rate ^{of 10} 0 - 10 ³ (Unit: 1 / s) of The ratio of the range to the average value of the viscosity of the first resin composition is 1 or more and 4.3 or less, and the second in the range of a shear rate of 10 ⁰ to 10 ³ (unit: 1 / s) at 220 ° C. The ratio of the average value of the viscosity of the release resin composition to the average value of the viscosity of the second resin composition in the range of the shear rate of 10 ⁰ to 10 ³ (unit: 1 / s) is 1 or more and 4.3 or less. The base material-less double-sided pressure-sensitive adhesive tape according to claim 7, which is present. It is a manufacturing method of the substrate-less double-sided pressure-sensitive adhesive tape according to any one of claims 1 to 6 ,
The first release resin composition, the first resin composition, and the second resin composition are coextruded to form the first release sheet, the first pressure-sensitive adhesive layer, and the second pressure-sensitive adhesive layer. The first release sheet comprises a first co-extrusion molding step for obtaining a co-extruded molded body that can be peeled from the first pressure-sensitive adhesive layer as the base material-less double-sided pressure-sensitive adhesive tape. A method of manufacturing a material-less double-sided adhesive tape. A base material-less comprising the base material-less double-sided pressure-sensitive adhesive tape according to any one of claims 1 to 6 and a second release sheet laminated on a surface of the base material-less double-sided pressure-sensitive adhesive tape on the second resin layer side. A method of manufacturing a double-sided adhesive tape,
The first release resin composition, the first resin composition, and the second resin composition are coextruded to form the first release sheet, the first pressure-sensitive adhesive layer, and the second pressure-sensitive adhesive layer. A first coextrusion molding step for obtaining a coextrusion molding body in which the first release sheet is peelable from the first pressure-sensitive adhesive layer; and a coextrusion molding body obtained by the first coextrusion molding step. The second release sheet is laminated on the surface of the second pressure-sensitive adhesive layer, and the first release sheet, the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the second release sheet are laminated. The manufacturing method of a laminated structure characterized by including the peeling sheet lamination | stacking process which obtains a structure as said base material-less double-sided adhesive tape. A method for producing a substrate-less double-sided pressure-sensitive adhesive tape according to claim 7 or 8 ,
The first release resin composition, the first resin composition, the second resin composition, and the second release resin composition are coextruded, and the first release sheet is formed from the first pressure-sensitive adhesive layer. A second co-extrusion molding step is provided, wherein the second exfoliation sheet is peelable and the second exfoliation sheet can be exfoliated from the second pressure-sensitive adhesive layer as the base material-less double-sided pressure-sensitive adhesive tape. A method for producing a baseless double-sided adhesive tape.

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