WO2018221635A1

WO2018221635A1 - Double-sided adhesive sheet, method for using double-sided adhesive sheet, and method for producing layered body

Info

Publication number: WO2018221635A1
Application number: PCT/JP2018/020899
Authority: WO
Inventors: 貴迪山口; 山本　真之
Original assignee: 王子ホールディングス株式会社
Priority date: 2017-05-31
Filing date: 2018-05-31
Publication date: 2018-12-06
Also published as: JPWO2018221635A1; TW201905132A

Abstract

The present invention addresses the problem of providing a double-sided adhesive sheet with which the occurrence of peeling, air bubbles and/or floating is suppressed, even under high-temperature conditions after adhesion. The present invention relates to a double-sided adhesive sheet that has a thickness of 100 µm or greater, wherein the sheet satisfies at least any of conditions selected from (A) through (C).

Description

Double-sided pressure-sensitive adhesive sheet, method for using double-sided pressure-sensitive adhesive sheet, and method for producing laminate

The present invention relates to a double-sided pressure-sensitive adhesive sheet, a method for using the double-sided pressure-sensitive adhesive sheet, and a method for producing a laminate.

In recent years, liquid crystal displays (LCD) are widely used in mobile phones, smartphones, personal computers, and tablet terminals, and double-sided pressure-sensitive adhesive sheets are used for bonding optical members constituting liquid crystal displays and the like. For example, in a liquid crystal display, it is necessary to dispose polarizing plates on both sides of a liquid crystal cell, and a double-sided pressure-sensitive adhesive sheet is used to adhere the polarizing plate and glass that is a constituent member of the liquid crystal cell.

Particularly in recent years, liquid crystal displays have been used for in-vehicle applications such as car navigation systems and CID (center information display). Since the interior of a vehicle is often in a high temperature environment, liquid crystal displays for in-vehicle use are required to have higher temperature durability than those for smartphones and personal computers. For example, a double-sided pressure-sensitive adhesive sheet used for a liquid crystal display for in-vehicle use is required not to float or peel even when placed in a high temperature environment of 100 ° C. or higher for a long time.

For example, Patent Document 1 discloses a hydroxyl group-containing (meth) acrylate copolymer (A), a carboxyl group-containing (meth) acrylate copolymer (B), an active energy ray-curable compound (C), and a crosslinking agent. A pressure-sensitive adhesive formed from a pressure-sensitive adhesive composition containing (D) is disclosed. Here, a Dual-Cure type pressure-sensitive adhesive composition is used, and such a pressure-sensitive adhesive composition is suitable for in-vehicle use such as car navigation and can form a pressure-sensitive adhesive having excellent durability.

JP 2012-107093 A

In a high temperature environment of 100 ° C. or higher, the optical member to be bonded shrinks, and along with this shrinkage, stress is applied to the double-sided pressure-sensitive adhesive sheet in a direction parallel to the member to be bonded, so the interface between the bonding member and the pressure-sensitive adhesive layer The anchor effect decreases, and peeling may occur between the bonding member and the pressure-sensitive adhesive layer. Further, in a high temperature environment of 100 ° C. or higher, gas may be generated from the optical member to be bonded, and this gas may cause stress in the thickness direction of the double-sided pressure-sensitive adhesive sheet or stress to the member to be bonded. As a result, bubbles and floating may occur. In order to solve such a problem, the use of a double-sided pressure-sensitive adhesive sheet formed from a Dual-Cure type pressure-sensitive adhesive composition as obtained in Patent Document 1 has been studied, but the double-sided pressure-sensitive adhesive sheet obtained in Patent Document 1 However, due to the insufficient cohesive force of the adhesive layer itself, there are problems such as peeling off in a high temperature environment of 100 ° C. or higher and bubbles and / or floating.

Therefore, in order to solve such a problem, the present inventors have suppressed the occurrence of peeling, bubbles and / or floating even when placed under high temperature conditions or harsh environments after bonding. The study was advanced with the aim of providing a double-sided PSA sheet.

As a result of intensive studies to solve the above problems, the present inventors have adjusted the various adhesive forces of the double-sided pressure-sensitive adhesive sheet to a predetermined range and set the thickness to a predetermined value or more, thereby increasing the temperature after bonding. It has been found that a double-sided pressure-sensitive adhesive sheet in which the occurrence of peeling, bubbles and / or lifting is suppressed can be obtained even under conditions and harsh environments.
Specifically, the present invention has the following configuration.

[1] A double-sided pressure-sensitive adhesive sheet having a thickness of 100 μm or more,
A double-sided pressure-sensitive adhesive sheet satisfying at least one selected from the following conditions (A) to (C);
(Condition (A))
In an environment of 80 ° C. and relative humidity of less than 10%, the shear adhesive strength measured by the following measurement method (a1) is 100 N / cm ² or more;
Measurement method (a1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface of 15 mm from one end in the longitudinal direction of 1.1 mm × 40 mm × 150 mm alkali glass A, and 20 mm from one end in the width direction. The adhesive sheet is pasted so that the center point is; the 1.1 mm × 40 mm × 150 mm alkali glass B is overlapped with the width direction of the alkali glass A on the other adhesive surface of the double-sided adhesive sheet, and the longitudinal direction is alkali. The sample is pasted so as to overlap with glass A by 30 mm to obtain a measurement sample; the measurement sample is autoclaved under conditions of 0.5 MPa, 40 ° C. and 30 minutes so that the integrated light quantity becomes 3000 mJ / cm ² with a high-pressure mercury lamp. Is irradiated with active energy rays and left in an environment of 23 ° C. and a relative humidity of 50% for 24 hours, and then in an environment of 80 ° C. and a relative humidity of less than 10%. 3 hours; using a tensile tester, pull the longitudinal end of each alkali glass in the opposite direction in the longitudinal direction at a speed of 25 mm / min in an environment of 80 ° C. and a relative humidity of less than 10%. The stress is measured as shear force.
(Condition (B))
In an environment of 80 ° C. and a relative humidity of less than 10%, the cross adhesive strength measured by the following measurement method (a2) is 400 N / cm ² or more;
Measurement method (a2)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity was 3000 mJ / cm ² with a high-pressure mercury lamp, left in an environment of 23 ° C. and 50% relative humidity for 24 hours, then 80 ° C., Place in an environment of less than 10% relative humidity for 3 hours; using a tensile tester, each alkali glass at 80 ° C. and less than 10% relative humidity at a speed of 5 mm / min. The tensile opposite direction in the thickness direction, to measure the stress at that time as a cross adhesion.
(Condition (C))
In an environment of 23 ° C. and a relative humidity of 50%, the cross adhesive force measured by the following measurement method (a3) is 1000 N / cm ² or more,
Cross adhesive strength after treatment under condition (1) of the following measurement method (b3), cross adhesive strength after treatment under condition (2) of the following measurement method (b3), and conditions of the following measurement method (b3) The cross adhesive strength after the treatment in (3) is 1000 N / cm ² or more;
Measurement method (a3)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity is 3000 mJ / cm ² with a high-pressure mercury lamp, and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; Using each alkali glass in an opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Measured as shaped adhesive strength;
Measurement method (b3)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions: irradiated with active energy rays from a glass surface with a high-pressure mercury lamp so that the integrated light intensity is 3000 mJ / cm ² and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; After the treatment under any of the following conditions (1) to (3), using a tensile tester, the speed is 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Pull the alkali glass in the opposite direction in the thickness direction, to measure the stress at that time as a cross adhesive strength;
Condition (1)-100 cycles of a cycle of 30 minutes at -40 ° C and then 30 minutes at 85 ° C;
Condition (2) Place in an environment of 85 ° C. and 85% relative humidity for 100 hours;
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.
[2] In an environment at 80 ° C. and a relative humidity of less than 10%, the shear adhesion measured by the measurement method (a1) is P,
Double-sided adhesive according to [1], wherein the value of P / Q is 0.70 or more when the shear adhesive strength measured by the following measuring method (b1) is Q in an environment of 23 ° C. and 50% relative humidity. Sheet;
Measurement method (b1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface of 15 mm from one end in the longitudinal direction of 1.1 mm × 40 mm × 150 mm alkali glass A, and 20 mm from one end in the width direction. The adhesive sheet is pasted so that the center point is; the 1.1 mm × 40 mm × 150 mm alkali glass B is overlapped with the width direction of the alkali glass A on the other adhesive surface of the double-sided adhesive sheet, and the longitudinal direction is alkali. The sample is pasted so as to overlap with glass A by 30 mm to obtain a measurement sample; the measurement sample is autoclaved under conditions of 0.5 MPa, 40 ° C. and 30 minutes so that the integrated light quantity becomes 3000 mJ / cm ² with a high-pressure mercury lamp. Is irradiated with active energy rays and left for 24 hours in an environment of 23 ° C. and 50% relative humidity; using a tensile tester, 23 ° C. and relative humidity At 0% RH, pulling the longitudinal ends of the respective alkali glass in opposite directions in the longitudinal direction at a speed 25 mm / min, to measure the stress at that time as a shear adhesive strength.
[3] The double-sided pressure-sensitive adhesive sheet according to [1], wherein the cross adhesive strength measured by the following measurement method (b2) is 1200 N / cm ² or more in an environment of 23 ° C. and relative humidity of 50%;
Measurement method (b2)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity is 3000 mJ / cm ² with a high-pressure mercury lamp, and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; Using each alkali glass in an opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Measured as shaped pressure-sensitive adhesive force.
[4] In an environment of 23 ° C. and a relative humidity of 50%, the cross adhesive force measured by the measurement method (a3) is 1200 N / cm ² or more,
The cross adhesive strength after processing under the condition (1) of the measurement method (b3) is 1200 N / cm ² or more,
The cross adhesive strength after processing under the condition (2) of the measurement method (b3) is 1500 N / cm ² or more,
The double-sided pressure-sensitive adhesive sheet according to [1], wherein the cross adhesive strength after the treatment under the condition (3) of the measurement method (b3) is 1300 N / cm ² or more.
[5] The double-sided PSA sheet comprises a base polymer (A) containing a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group,
A monomer (B) having at least one polymerizable unsaturated group;
A crosslinking agent (C) that reacts with the base polymer (A) by heat;
A polymerization initiator (D) for initiating the polymerization reaction of the monomer (B) by irradiation with active energy rays;
The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [4], comprising a pressure-sensitive adhesive composition comprising a solvent (E) and semi-cured by heating or irradiation with active energy rays.
[6] The double-sided pressure-sensitive adhesive sheet according to [5], wherein the molecular weight of the base polymer (A) is from 600,000 to 1,500,000.
[7] The monomer (B) includes a monofunctional monomer (b1) having one polymerizable unsaturated group and a polyfunctional monomer (b2) having two or more polymerizable unsaturated groups,
The double-sided pressure-sensitive adhesive sheet according to [5] or [6], wherein the mass ratio of the monofunctional monomer (b1) to the polyfunctional monomer (b2) is 10: 1 to 50: 1.
[8] The double-sided pressure-sensitive adhesive sheet according to [7], wherein the monofunctional monomer (b1) has an alkyl group having 10 or more carbon atoms.
[9] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [8], which is used for bonding optical members.
[10] The double-sided pressure-sensitive adhesive sheet according to any one of [1] to [9], which is used for bonding an in-vehicle optical member.
[11] Use of a double-sided pressure-sensitive adhesive sheet in which the double-sided pressure-sensitive adhesive sheet is completely cured by bringing the double-sided pressure-sensitive adhesive sheet according to any one of [1] to [10] into contact with the adherend surface and irradiating active energy rays in that state. Method.
[12] A laminate comprising a step of bringing the double-sided pressure-sensitive adhesive sheet according to any one of [1] to [10] into contact with the surface of the adherend and irradiating active energy rays in that state to completely cure the double-sided pressure-sensitive adhesive sheet. Manufacturing method.

[101] In an environment of 80 ° C. and a relative humidity of less than 10%, the shear adhesive force measured by the following measurement method (a1) is 100 N / cm ² or more,
Double-sided pressure-sensitive adhesive sheet having a thickness of 100 μm or more;
Measurement method (a1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface of 15 mm from one end in the longitudinal direction of 1.1 mm × 40 mm × 150 mm alkali glass A, and 20 mm from one end in the width direction. The adhesive sheet is pasted so that the center point is; the 1.1 mm × 40 mm × 150 mm alkali glass B is overlapped with the width direction of the alkali glass A on the other adhesive surface of the double-sided adhesive sheet, and the longitudinal direction is alkali. The sample is pasted so as to overlap with glass A by 30 mm to obtain a measurement sample; the measurement sample is autoclaved under conditions of 0.5 MPa, 40 ° C. and 30 minutes so that the integrated light quantity becomes 3000 mJ / cm ² with a high-pressure mercury lamp. Is irradiated with active energy rays and left in an environment of 23 ° C. and a relative humidity of 50% for 24 hours, and then in an environment of 80 ° C. and a relative humidity of less than 10%. 3 hours; using a tensile tester, pull the longitudinal end of each alkali glass in the opposite direction in the longitudinal direction at a speed of 25 mm / min in an environment of 80 ° C. and a relative humidity of less than 10%. The stress is measured as shear force.
[102] In an environment at 80 ° C. and a relative humidity of less than 10%, the shear adhesion measured by the measurement method (a1) is P,
Double-sided adhesive according to [101], wherein the value of P / Q is 0.70 or more when the shear adhesive strength measured by the following measuring method (b1) is Q in an environment of 23 ° C. and 50% relative humidity. Sheet;
Measurement method (b1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface of 15 mm from one end in the longitudinal direction of 1.1 mm × 40 mm × 150 mm alkali glass A, and 20 mm from one end in the width direction. The adhesive sheet is pasted so that the center point is; the 1.1 mm × 40 mm × 150 mm alkali glass B is overlapped with the width direction of the alkali glass A on the other adhesive surface of the double-sided adhesive sheet, and the longitudinal direction is alkali. The sample is pasted so as to overlap with glass A by 30 mm to obtain a measurement sample; the measurement sample is autoclaved under conditions of 0.5 MPa, 40 ° C. and 30 minutes so that the integrated light quantity becomes 3000 mJ / cm ² with a high-pressure mercury lamp. Is irradiated with active energy rays and left for 24 hours in an environment of 23 ° C. and 50% relative humidity; using a tensile tester, 23 ° C. and relative humidity At 0% RH, pulling the longitudinal ends of the respective alkali glass in opposite directions in the longitudinal direction at a speed 25 mm / min, to measure the stress at that time as a shear adhesive strength.
[103] The double-sided PSA sheet includes a base polymer (A) containing a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group;
A monomer (B) having at least one polymerizable unsaturated group;
A crosslinking agent (C) that reacts with the base polymer (A) by heat;
A polymerization initiator (D) for initiating the polymerization reaction of the monomer (B) by irradiation with active energy rays;
The double-sided pressure-sensitive adhesive sheet according to [101] or [102], comprising a pressure-sensitive adhesive composition containing the solvent (E) and semi-cured by heating or irradiation with active energy rays.
[104] The double-sided pressure-sensitive adhesive sheet according to [103], wherein the base polymer (A) has a molecular weight of 600,000 to 1,500,000.
[105] The monomer (B) includes a monofunctional monomer (b1) having one polymerizable unsaturated group and a polyfunctional monomer (b2) having two or more polymerizable unsaturated groups,
The double-sided pressure-sensitive adhesive sheet according to [103] or [104], wherein the mass ratio of the monofunctional monomer (b1) to the polyfunctional monomer (b2) is 10: 1 to 50: 1.
[106] The double-sided pressure-sensitive adhesive sheet according to [105], wherein the monofunctional monomer (b1) has an alkyl group having 10 or more carbon atoms.
[107] The double-sided pressure-sensitive adhesive sheet according to any one of [101] to [106], which is used for bonding an optical member.
[108] The double-sided pressure-sensitive adhesive sheet according to any one of [101] to [107], which is used for bonding an in-vehicle optical member.
[109] Use of a double-sided pressure-sensitive adhesive sheet in which the double-sided pressure-sensitive adhesive sheet according to any one of [101] to [108] is brought into contact with the surface of the adherend, and the double-sided pressure-sensitive adhesive sheet is completely cured by irradiation with active energy rays in this state. Method.
[110] A laminate comprising a step of bringing the double-sided pressure-sensitive adhesive sheet according to any one of [101] to [108] into contact with the surface of the adherend, and irradiating active energy rays in that state to completely cure the double-sided pressure-sensitive adhesive sheet. Manufacturing method.

[201] In an environment of 80 ° C. and a relative humidity of less than 10%, the cross adhesive force measured by the following measurement method (a2) is 400 N / cm ² or more.
Double-sided pressure-sensitive adhesive sheet having a thickness of 100 μm or more;
Measurement method (a2)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity was 3000 mJ / cm ² with a high-pressure mercury lamp, left in an environment of 23 ° C. and 50% relative humidity for 24 hours, then 80 ° C., Place in an environment of less than 10% relative humidity for 3 hours; using a tensile tester, each alkali glass at 80 ° C. and less than 10% relative humidity at a speed of 5 mm / min. The tensile opposite direction in the thickness direction, to measure the stress at that time as a cross adhesion.
[202] The double-sided pressure-sensitive adhesive sheet according to [201], wherein the cross adhesive force measured by the following measurement method (b2) is 1200 N / cm ² or more in an environment of 23 ° C. and 50% relative humidity;
Measurement method (b2)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity is 3000 mJ / cm ² with a high-pressure mercury lamp, and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; Using each alkali glass in an opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Measured as shaped pressure-sensitive adhesive force.
[203] The double-sided PSA sheet comprises a base polymer (A) containing a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group;
A monomer (B) having at least one polymerizable unsaturated group;
A crosslinking agent (C) that reacts with the base polymer (A) by heat;
A polymerization initiator (D) for initiating the polymerization reaction of the monomer (B) by irradiation with active energy rays;
The double-sided pressure-sensitive adhesive sheet according to [201] or [202], comprising a pressure-sensitive adhesive composition containing the solvent (E) and semi-cured by heating or irradiation with active energy rays.
[204] The double-sided pressure-sensitive adhesive sheet according to [203], wherein the molecular weight of the base polymer (A) is from 600,000 to 1,500,000.
[205] The monomer (B) includes a monofunctional monomer (b1) having one polymerizable unsaturated group and a polyfunctional monomer (b2) having two or more polymerizable unsaturated groups,
The double-sided pressure-sensitive adhesive sheet according to [203] or [204], wherein the mass ratio of the monofunctional monomer (b1) to the polyfunctional monomer (b2) is 10: 1 to 50: 1.
[206] The double-sided pressure-sensitive adhesive sheet according to [205], wherein the monofunctional monomer (b1) has an alkyl group having 10 or more carbon atoms.
[207] The double-sided pressure-sensitive adhesive sheet according to any one of [201] to [206], which is used for bonding an optical member.
[208] The double-sided pressure-sensitive adhesive sheet according to any one of [201] to [207], which is used for bonding an in-vehicle optical member.
[209] Use of a double-sided pressure-sensitive adhesive sheet in which the double-sided pressure-sensitive adhesive sheet is completely cured by bringing the double-sided pressure-sensitive adhesive sheet according to any one of [201] to [208] into contact with the surface of the adherend and irradiating active energy rays in that state. Method.
[210] A laminate comprising a step of bringing the double-sided pressure-sensitive adhesive sheet according to any one of [201] to [208] into contact with the surface of the adherend, and irradiating active energy rays in that state to completely cure the double-sided pressure-sensitive adhesive sheet. Manufacturing method.

More specifically, the present invention has the following configuration.
[301] In an environment of 23 ° C. and a relative humidity of 50%, the cross adhesive force measured by the following measurement method (a3) is 1000 N / cm ² or more,
Cross adhesive strength after treatment under condition (1) of the following measurement method (b3), cross adhesive strength after treatment under condition (2) of the following measurement method (b3), and conditions of the following measurement method (b3) The cross adhesive strength after processing in (3) is 1000 N / cm ² or more,
Double-sided pressure-sensitive adhesive sheet having a thickness of 100 μm or more;
Measurement method (a3)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity is 3000 mJ / cm ² with a high-pressure mercury lamp, and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; Using each alkali glass in an opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Measured as shaped adhesive strength;
Measurement method (b3)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light quantity becomes 3000 mJ / cm ² with a high-pressure mercury lamp, and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; After the treatment under any of the conditions (1) to (3), each alkali was used at a speed of 5 mm / min using a tensile tester in an environment of 23 ° C. and a relative humidity of 50%. Pulling the lath in the opposite direction in the thickness direction, to measure the stress at that time as a cross adhesive strength;
Condition (1)-100 cycles of a cycle of 30 minutes at -40 ° C and then 30 minutes at 85 ° C;
Condition (2) Place in an environment of 85 ° C. and 85% relative humidity for 100 hours;
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.
[302] In an environment of 23 ° C. and a relative humidity of 50%, the cross adhesive force measured by the measurement method (a3) is 1200 N / cm ² or more,
The cross adhesive strength after processing under the condition (1) of the measurement method (b3) is 1200 N / cm ² or more,
The cross adhesive strength after processing under the condition (2) of the measurement method (b3) is 1500 N / cm ² or more,
The double-sided pressure-sensitive adhesive sheet according to [301], wherein the cross adhesive strength after the treatment under the condition (3) of the measurement method (b3) is 1300 N / cm ² or more.
[303] The double-sided pressure-sensitive adhesive sheet includes a base polymer (A) containing a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group;
A monomer (B) having at least one polymerizable unsaturated group;
A crosslinking agent (C) that reacts with the base polymer (A) by heat;
A polymerization initiator (D) for initiating the polymerization reaction of the monomer (B) by irradiation with active energy rays;
The double-sided pressure-sensitive adhesive sheet according to [301] or [302], comprising a pressure-sensitive adhesive composition containing the solvent (E) and semi-cured by heating or irradiation with active energy rays.
[304] The double-sided pressure-sensitive adhesive sheet according to [303], wherein the base polymer (A) has a molecular weight of 600,000 to 1,500,000.
[305] The monomer (B) includes a monofunctional monomer (b1) having one polymerizable unsaturated group and a polyfunctional monomer (b2) having two or more polymerizable unsaturated groups,
The double-sided pressure-sensitive adhesive sheet according to [303] or [304], wherein the mass ratio of the monofunctional monomer (b1) to the polyfunctional monomer (b2) is 10: 1 to 50: 1.
[306] The double-sided pressure-sensitive adhesive sheet according to [305], wherein the monofunctional monomer (b1) has an alkyl group having 10 or more carbon atoms.
[307] The double-sided pressure-sensitive adhesive sheet according to any one of [301] to [306], which is used for bonding an optical member.
[308] The double-sided pressure-sensitive adhesive sheet according to any one of [301] to [307], which is used for bonding an in-vehicle optical member.
[309] Use of a double-sided pressure-sensitive adhesive sheet in which the double-sided pressure-sensitive adhesive sheet according to any one of [301] to [308] is brought into contact with the adherend surface and the double-sided pressure-sensitive adhesive sheet is completely cured by irradiation with active energy rays Method.
[310] A laminate comprising a step of bringing the double-sided pressure-sensitive adhesive sheet according to any one of [301] to [308] into contact with the surface of the adherend and irradiating active energy rays in that state to completely cure the double-sided pressure-sensitive adhesive sheet. Manufacturing method.

According to the present invention, it is possible to obtain a double-sided pressure-sensitive adhesive sheet in which the occurrence of peeling, bubbles and / or floating is suppressed even when placed under high temperature conditions after bonding.

FIG. 1 is a diagram for explaining a method for measuring shear adhesive strength of a double-sided PSA sheet. FIG. 2 is a diagram illustrating a method for measuring the cross adhesive strength of a double-sided PSA sheet.

Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be made based on representative embodiments and specific examples, but the present invention is not limited to such embodiments.

(Double-sided adhesive sheet)
The present invention relates to a double-sided PSA sheet having a thickness of 100 μm or more and satisfying at least one selected from the following conditions (A) to (C).
(Condition (A))
In an environment of 80 ° C. and a relative humidity of less than 10%, the shear adhesion measured by the following measurement method (a1) is 100 N / cm ² or more.
Measurement method (a1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface on one side of a 1.1 mm × 40 mm × 150 mm alkali glass A at the intersection of 15 mm from one side in the longitudinal direction and 20 mm from one side in the width direction. Bond so that the center point of the adhesive sheet comes. A sample of 1.1 mm × 40 mm × 150 mm of alkali glass B is bonded to the other pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive sheet so that it overlaps the width direction of the alkali glass A and the longitudinal direction overlaps the alkali glass A by 30 mm. Get. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. After being left in the environment for 24 hours, it is placed in an environment at 80 ° C. and a relative humidity of less than 10% for 3 hours. Using a tensile tester, the longitudinal end of each alkali glass was pulled in the opposite direction in the longitudinal direction at a speed of 25 mm / min in an environment of 80 ° C. and a relative humidity of less than 10%. Measure as force.
(Condition (B))
In an environment of 80 ° C. and a relative humidity of less than 10%, the cross adhesive strength measured by the following measurement method (a2) is 400 N / cm ² or more.
Measurement method (a2)
One pressure-sensitive adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm. An alkali glass B having a thickness of 4.0 mm, a width of 30 mm, and a length of 50 mm is bonded from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet so that the two alkali glasses have a cross positional relationship with each other to obtain a measurement sample. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. After being left in the environment for 24 hours, it is placed in an environment at 80 ° C. and a relative humidity of less than 10% for 3 hours. Each alkali glass is pulled in the opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 80 ° C. and a relative humidity of less than 10% using a tensile tester, and the stress at that time is measured as a cross adhesive force.
(Condition (C))
In an environment of 23 ° C. and a relative humidity of 50%, the cross adhesive force measured by the following measurement method (a3) is 1000 N / cm ² or more,
Cross adhesive strength after treatment under condition (1) of the following measurement method (b3), cross adhesive strength after treatment under condition (2) of the following measurement method (b3), and conditions of the following measurement method (b3) The cross adhesive strength after the treatment in (3) is 1000 N / cm ² or more.
Measurement method (a3)
One pressure-sensitive adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm. An alkali glass B having a thickness of 4.0 mm, a width of 30 mm, and a length of 50 mm is bonded from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet so that the two alkali glasses have a cross positional relationship with each other to obtain a measurement sample. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. Leave in the environment for 24 hours. Using a tensile tester, each alkali glass is pulled in the opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%, and the stress at that time is measured as a cross adhesive force.
Measurement method (b3)
One pressure-sensitive adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm. An alkali glass B having a thickness of 4.0 mm, a width of 30 mm, and a length of 50 mm is bonded from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet so that the two alkali glasses have a cross positional relationship with each other to obtain a measurement sample. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays from a glass surface with a high-pressure mercury lamp so that the integrated light amount was 3000 mJ / cm ² , 23 ° C., relative humidity Leave in a 50% environment for 24 hours. Then, after treating under any of the following conditions (1) to (3), each alkali glass was thickened at a speed of 5 mm / min using a tensile tester in an environment of 23 ° C. and relative humidity of 50%. Pulling in the opposite direction of the direction, the stress at that time is measured as a cross adhesive force.
Condition (1) The cycle of placing at −40 ° C. for 30 minutes and then placing at 85 ° C. for 30 minutes is repeated 100 cycles.
Condition (2) Place in an environment of 85 ° C. and relative humidity of 85% for 100 hours.
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.

Since the double-sided pressure-sensitive adhesive sheet of the present invention has the above-described configuration, it is a case where the double-sided pressure-sensitive adhesive sheet is put on an adherend and then placed under a high temperature condition or a severe environment (for example, an environment with a large temperature difference). However, it is suppressed that a double-sided adhesive sheet peels from an adherend. In addition, since the double-sided pressure-sensitive adhesive sheet of the present invention has the above-described configuration, even if the double-sided pressure-sensitive adhesive sheet is bonded to an adherend and then placed under a high temperature condition or a harsh environment, the double-sided pressure-sensitive adhesive sheet has air bubbles. It is possible to prevent the double-sided pressure-sensitive adhesive sheet from floating from the adherend. That is, the double-sided pressure-sensitive adhesive sheet of the present invention is excellent in durability under high temperature conditions and harsh environments.

The occurrence of peeling can be evaluated by placing the double-sided PSA sheet on the adherend and placing it in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours. Specifically, first, one side of the double-sided pressure-sensitive adhesive sheet is bonded to a polarizing plate (MLPH40-1 manufactured by Bikan Co., Ltd.), and the other side of the double-sided pressure-sensitive adhesive sheet is alkali glass (Standard Test Co., Ltd.). Bonded to a piece (float plate glass) to produce a measurement sample. Next, the measurement sample was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, 23 ° C., and relative humidity 50%. The sample is allowed to stand for 24 hours in an environment of 105 ° C. and then placed in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.
In addition, the presence or absence of generation of bubbles and floats can be evaluated by placing the double-sided pressure-sensitive adhesive sheet on an adherend and placing it in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours. Specifically, first, one side of the double-sided pressure-sensitive adhesive sheet is bonded to a polarizing plate (MLPH40-1 manufactured by Bikan Co., Ltd.), and the other side of the double-sided pressure-sensitive adhesive sheet is alkali glass (Standard Test Co., Ltd.). Bonded to a piece (float plate glass) to produce a measurement sample. Next, the measurement sample was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, 23 ° C., and relative humidity 50%. For 24 hours and then placed in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours, and then the presence or absence of bubbles and / or floating is observed.

The double-sided pressure-sensitive adhesive sheet of the present invention is preferably used for optical member bonding. Among them, the double-sided pressure-sensitive adhesive sheet of the present invention may generate bubbles from the double-sided pressure-sensitive adhesive sheet, or the double-sided pressure-sensitive adhesive sheet may float from the adherend or peel off even under high temperature conditions or severe conditions. Therefore, it is preferably used for bonding optical members that are exposed to high temperature conditions. For example, the double-sided pressure-sensitive adhesive sheet of the present invention is particularly preferably used for bonding an in-vehicle optical member such as an in-vehicle display.

The thickness of the double-sided PSA sheet of the present invention may be 100 μm or more, preferably 120 μm or more, and more preferably 150 μm or more. Although the upper limit of the thickness of a double-sided adhesive sheet is not specifically limited, For example, it can be 500 micrometers.

The double-sided PSA sheet of the present invention comprises a base polymer (A) containing a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group, and a polymerization A monomer (B) having at least one polymerizable unsaturated group, a crosslinking agent (C) that reacts with the base polymer (A) by heat, and a polymerization reaction of the monomer (B) by irradiation with active energy rays. A pressure-sensitive adhesive composition containing a polymerization initiator (D) to be started and a solvent (E) is included and includes a pressure-sensitive adhesive that is semi-cured by heating or irradiation with active energy rays.

The double-sided pressure-sensitive adhesive sheet of the present invention includes a pressure-sensitive adhesive obtained by semi-curing the above-mentioned pressure-sensitive adhesive composition by heating or irradiation with active energy rays before being bonded to an adherend. It exhibits a soft semi-cured state. Here, the semi-cured state means that the gel fraction is less than 65%, may be less than 60%, may be less than 55%, may be less than 20%, % Or less than 10%.

Although the double-sided pressure-sensitive adhesive sheet of the present invention exhibits semi-curability, the double-sided pressure-sensitive adhesive sheet is completely cured by applying heat or active energy rays after bonding the double-sided pressure-sensitive adhesive sheet to the adherend surface. That is, the double-sided pressure-sensitive adhesive sheet of the present invention is in a semi-cured state only by heating or irradiation with active energy rays before bonding, but is completely cured by heating or active energy rays after bonding. In addition, although the same method may be sufficient as the hardening method in a semi-hardening process and a complete hardening process, it is preferable to harden | cure by a different method. Specifically, when heat curing is performed in the semi-curing process, it is preferable to irradiate active energy rays in the complete curing process, and when active energy rays are irradiated in the semi-curing process, It is preferable to perform thermosetting. In the present specification, such a two-stage curing double-sided pressure-sensitive adhesive sheet is sometimes referred to as a dual cure double-sided pressure-sensitive adhesive sheet.
In the present specification, the “semi-cured state” means a state in which one of heat and active energy rays is cured, and means a soft state before the second stage curing. The “fully cured state” means a state where the semi-cured double-sided pressure-sensitive adhesive sheet is cured by heating or irradiating active energy rays. Specifically, when the “semi-cured state” is changed to the “fully cured state”, the storage elastic modulus of the dynamic viscoelasticity measured by shear stress or tensile stress at a frequency of 1 Hz is at least Tg (glass transition point). ) 1.5 times or more in the range from higher temperature to 60 ° C. When fully cured, the dynamic viscoelasticity is preferably 1.5 to 1000 times, and more preferably 2 to 100 times. In addition, the storage elastic modulus of dynamic viscoelasticity measured by shear stress or tensile stress at 1 Hz frequency of the pressure-sensitive adhesive constituting the double-sided pressure-sensitive adhesive sheet in the semi-cured state in the present invention is a temperature region higher than Tg (glass transition point) or It is preferably less than 3.5 × 10 ⁴ Pa in the region of 50 ° C. or higher. The storage elastic modulus of dynamic viscoelasticity measured by shear stress or tensile stress at a frequency of 1 Hz of the pressure-sensitive adhesive constituting the double-sided pressure-sensitive adhesive sheet when fully cured is a temperature region higher than Tg (glass transition point) or a region of 50 ° C. or higher. It is preferably 3.5 × 10 ⁴ Pa or more.

The Young's modulus in the semi-cured state of the double-sided PSA sheet is preferably less than 0.1 N / mm ² . If the Young's modulus is within the above range, the semi-cured double-sided PSA sheet tends to have a desirable hardness. The Young's modulus during complete curing is preferably 0.1 N / mm ² or more. In addition, Young's modulus can be made into a desired range by adjusting the addition amount etc. of the monomer mentioned later. The Young's modulus in this specification is a value obtained from a stress-strain diagram measured using Shimadzu Corporation Autograph AGS-X at a pulling speed of 10 (mm / min).

The fully cured double-sided PSA sheet preferably has a haze value of 2% or less, more preferably 0% or more and 1.5% or less, and more preferably 0% or more and 1% in an environment of 23 ° C. and 50% relative humidity. More preferably, it is% or less. When the haze value is within the above range, the transparency required when the double-sided PSA sheet is used for an optical member can be satisfied. Moreover, if a haze value is 2% or less, it is suitable as an optical use.

The total light transmittance (measured in accordance with JIS K 7361-1: 1997) of the double-sided PSA sheet after complete curing in an environment of 23 ° C. and 50% relative humidity is preferably 80% or more. It is preferably 90% or more. When the total light transmittance is within the above range, the transparency is high and it is suitable for optical applications.

The double-sided pressure-sensitive adhesive sheet of the present invention may be a single-layer double-sided pressure-sensitive adhesive sheet, a multilayer double-sided pressure-sensitive adhesive sheet in which a plurality of pressure-sensitive adhesive layers are laminated, or a multilayer double-sided pressure-sensitive adhesive sheet in which pressure-sensitive adhesive layers are laminated on both sides of a support. Also good. Among these, the double-sided pressure-sensitive adhesive sheet of the present invention is preferably a non-carrier type, and preferably a single-sided double-sided pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer or a multilayer double-sided pressure-sensitive adhesive sheet in which a plurality of pressure-sensitive adhesive layers are laminated. A single-layer double-sided PSA sheet made of

When the double-sided pressure-sensitive adhesive sheet of the present invention has a support, examples of the support include polystyrene, styrene-acrylic copolymer, acrylic resin, polyethylene terephthalate, polycarbonate, polyetheretherketone, and triacetylcellulose. Examples thereof include plastic films; optical films such as antireflection films and electromagnetic wave shielding films.

The surface of the double-sided PSA sheet of the present invention is preferably covered with a release sheet. That is, the double-sided pressure-sensitive adhesive sheet of the present invention may be a double-sided pressure-sensitive adhesive sheet with a release sheet. As a release sheet, a peelable laminate sheet having a release sheet substrate and a release agent layer provided on one side of the release sheet substrate, or a polyolefin film such as a polyethylene film or a polypropylene film as a low polarity substrate Is mentioned.
Papers and polymer films are used as the release sheet substrate in the peelable laminate sheet. As the release agent constituting the release agent layer, for example, a general-purpose addition type or condensation type silicone release agent or a long-chain alkyl group-containing compound is used. In particular, an addition type silicone release agent having high reactivity is preferably used.
Specific examples of silicone release agents include BY24-4527 and SD-7220 manufactured by Toray Dow Corning Silicone, KS-3600, KS-774, and X62-2600 manufactured by Shin-Etsu Chemical Co., Ltd. Is mentioned. Further, the silicone-based release agent may contain a silicone resin that is an organosilicon compound having a SiO ₂ unit and (CH ₃ ) ₃ SiO _1/2 unit or CH ₂ ═CH (CH ₃ ) SiO _1/2 unit. preferable. Specific examples of the silicone resin include BY24-843, SD-7292, SHR-1404 manufactured by Toray Dow Corning Silicone, KS-3800, X92-183 manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

In the release sheet, in order to make it easy to peel off, it is preferable that the release sheet bonded to each side of the double-sided pressure-sensitive adhesive sheet has different peelability. When the peelability from one side and the peelability from the other are different, it becomes easy to peel only the release sheet having the higher peelability first.

(First aspect)
The present invention relates to a double-sided pressure-sensitive adhesive sheet having a shear adhesive strength measured by the following measurement method (a1) of 100 N / cm ² or more and a thickness of 100 μm or more in an environment of 80 ° C. and a relative humidity of less than 10%. There may be.
Measurement method (a1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface on one side of a 1.1 mm × 40 mm × 150 mm alkali glass A at the intersection of 15 mm from one side in the longitudinal direction and 20 mm from one side in the width direction. Bond so that the center point of the adhesive sheet comes. A sample of 1.1 mm × 40 mm × 150 mm of alkali glass B is bonded to the other pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive sheet so that it overlaps the width direction of the alkali glass A and the longitudinal direction overlaps the alkali glass A by 30 mm. Get. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. After being left in the environment for 24 hours, it is placed in an environment at 80 ° C. and a relative humidity of less than 10% for 3 hours. Using a tensile tester, the longitudinal end of each alkali glass was pulled in the opposite direction in the longitudinal direction at a speed of 25 mm / min in an environment of 80 ° C. and a relative humidity of less than 10%. Measure as force.

When measuring the shear adhesive strength of the double-sided pressure-sensitive adhesive sheet of the present invention, a double-sided pressure-sensitive adhesive sheet with a release sheet prepared by laminating a release sheet on both sides of the double-sided pressure-sensitive adhesive sheet is prepared, and the double-sided pressure-sensitive adhesive sheet with release sheet is 1 cm × 1 cm. It is preferable to cut into a size, peel off the release sheet on each surface, and bond the exposed adhesive surface to alkali glass. When bonding a double-sided adhesive sheet to alkali glass, it bonds so that a bubble etc. may not enter between a double-sided adhesive sheet and alkali glass. As the alkali glass used in the measurement method (a1), for example, a float plate glass manufactured by Standard Test Piece Co., Ltd. can be used. Note that FIG. 1 illustrates the configuration of a measurement sample used when measuring shear adhesive strength. The upper diagram of FIG. 1 is a diagram of the measurement sample viewed from the plane direction, and the lower diagram of FIG. 1 is a diagram of the side surface in the longitudinal direction of the measurement sample viewed from the cross-sectional direction. As shown in FIG. 1, a measurement sample is configured by bonding

alkali glasses

10 and 20 to each surface of a double-sided pressure-sensitive adhesive sheet 1 so as to have a predetermined positional relationship.

The shear adhesive strength of the double-sided pressure-sensitive adhesive sheet of the present invention in an environment of 80 ° C. and a relative humidity of less than 10% may be 100 N / cm ² or more, preferably 120 N / cm ² or more, and more preferably 150 N / cm ² or more. It is more preferable that In addition, although the upper limit of the shear adhesive force in the environment of 80 degreeC and relative humidity of less than 10% of a double-sided adhesive sheet is not specifically limited, For example, it can be set to 300 N / cm < ² >. In addition, the said shear adhesive force is achieved by adjusting the mixing | blending of the adhesive composition mentioned later, or adjusting the hardening conditions of a double-sided adhesive sheet.

In an environment of a double-sided PSA sheet at 80 ° C. and a relative humidity of less than 10%, the shear adhesive strength measured by the above measurement method (a1) is P, and in an environment at 23 ° C. and a relative humidity of 50%, the following measurement method (b1 ), The value of P / Q is preferably 0.70 or more.
Measurement method (b1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface on one side of a 1.1 mm × 40 mm × 150 mm alkali glass A at the intersection of 15 mm from one side in the longitudinal direction and 20 mm from one side in the width direction. Bond so that the center point of the adhesive sheet comes. A sample of 1.1 mm × 40 mm × 150 mm of alkali glass B is bonded to the other pressure-sensitive adhesive surface of the double-sided pressure-sensitive adhesive sheet so that it overlaps the width direction of the alkali glass A and the longitudinal direction overlaps the alkali glass A by 30 mm. Get. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. Leave in the environment for 24 hours. Using a tensile tester, the longitudinal end of each alkali glass was pulled in the opposite direction in the longitudinal direction at a speed of 25 mm / min in an environment of 23 ° C. and a relative humidity of 50%, and the stress at that time was sheared and adhered. Measure as

In the measurement method (b1), the measurement sample is autoclaved, irradiated with active energy rays with a high-pressure mercury lamp so that the integrated light amount is 3000 mJ / cm ^2, and kept under an environment of 23 ° C. and 50% relative humidity for 24 hours. After leaving, the measurement method is the same as the measurement method (a1) except that the measurement environment is 23 ° C. and the relative humidity is 50%.

The value of P / Q is preferably 0.70 or more, more preferably 0.75 or more, further preferably 0.80 or more, and particularly preferably 0.85 or more. Note that the value of P / Q may be 1.0 or a value larger than 1.0. By setting the value of P / Q within the above range, even if the double-sided PSA sheet is bonded to the adherend and then placed under a high temperature condition, the occurrence of peeling can be effectively suppressed.

(Second aspect)
The present invention relates to a double-sided pressure-sensitive adhesive sheet having a cross adhesive strength of 400 N / cm ² or more and a thickness of 100 μm or more measured by the following measurement method (a2) in an environment of 80 ° C. and a relative humidity of less than 10%. There may be.
Measurement method (a2)
One pressure-sensitive adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm. An alkali glass B having a thickness of 4.0 mm, a width of 30 mm, and a length of 50 mm is bonded from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet so that the two alkali glasses have a cross positional relationship with each other to obtain a measurement sample. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. After being left in the environment for 24 hours, it is placed in an environment at 80 ° C. and a relative humidity of less than 10% for 3 hours. Each alkali glass is pulled in the opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 80 ° C. and a relative humidity of less than 10% using a tensile tester, and the stress at that time is measured as a cross adhesive force.

When measuring the cross adhesive strength of the double-sided pressure-sensitive adhesive sheet of the present invention, a double-sided pressure-sensitive adhesive sheet with a release sheet in which a release sheet is bonded to both sides of the double-sided pressure-sensitive adhesive sheet is prepared, and the double-sided pressure-sensitive adhesive sheet with release sheet is 1 cm × 1 cm. It is preferable to cut into a size, peel off the release sheet on each surface, and bond the exposed adhesive surface to alkali glass. When bonding a double-sided adhesive sheet to alkali glass, it bonds so that a bubble etc. may not enter between a double-sided adhesive sheet and alkali glass. As the alkali glass used in the measurement method (a2), for example, a float plate glass manufactured by Standard Test Piece Co., Ltd. can be used. FIG. 2 illustrates the configuration of the measurement sample used when measuring the cross adhesive force. The upper diagram of FIG. 2 is a diagram of the measurement sample viewed from the plane direction, and the lower diagram of FIG. 2 is a diagram of the side surface of the measurement sample viewed from the cross-sectional direction. As shown in FIG. 2, the measurement sample is configured by bonding the

alkali glasses

10 and 20 to each surface of the double-sided pressure-sensitive adhesive sheet 1 so as to have a cross positional relationship with each other.

The cross adhesive strength of the double-sided pressure-sensitive adhesive sheet of the present invention in an environment of 80 ° C. and a relative humidity of less than 10% may be 400 N / cm ² or more, preferably 500 N / cm ² or more, preferably 600 N / cm ² or more. It is more preferable that In addition, although the upper limit of the cross adhesive force in the environment of 80 degreeC and relative humidity of less than 10% of a double-sided adhesive sheet is not specifically limited, For example, it can be 3000 N / cm < ² >. In addition, the said cross adhesive force is achieved by adjusting the mixing | blending of the adhesive composition mentioned later, or adjusting the hardening conditions of a double-sided adhesive sheet.

In the double-sided pressure-sensitive adhesive sheet of the present invention, the cross adhesive strength measured by the following measurement method (b2) in an environment of 23 ° C. and 50% relative humidity is preferably 1200 N / cm ² or more.
Measurement method (b2)
A measurement sample is prepared in the same manner as in the measurement method (a2). The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. Leave in the environment for 24 hours. Using a tensile tester, each alkali glass is pulled in the opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%, and the stress at that time is measured as a cross adhesive force.

In the measurement method (b2), the measurement sample is autoclaved, irradiated with an active energy ray so that the integrated light quantity becomes 3000 mJ / cm ² with a high-pressure mercury lamp, and kept in an environment of 23 ° C. and 50% relative humidity for 24 hours. After leaving, the measurement method is the same as the measurement method (a2) except that the measurement environment is 23 ° C. and the relative humidity is 50%.

23 ° C. of the double-sided pressure-sensitive adhesive sheet of the present invention, the cross adhesive strength under a relative humidity of 50% may be any 1200 N / cm ² or more, preferably 1500 N / cm ² or more, at 1800 N / cm ² or more More preferably. In addition, the upper limit value of the cross adhesive force in the environment of 23 ° C. and relative humidity of 50% of the double-sided PSA sheet is not particularly limited, but may be, for example, 5000 N / cm ² . Even when the double-sided PSA sheet is bonded to the adherend and then placed under high temperature conditions by setting the cross adhesive strength in an environment of 23 ° C. and 50% relative humidity within the above range, air bubbles and floating Generation | occurrence | production can be suppressed effectively.

(Third aspect)
In the present invention, in an environment of 23 ° C. and 50% relative humidity, the cross adhesive force measured by the following measurement method (a3) is 1000 N / cm ² or more, and the treatment is performed under the condition (1) of the following measurement method (b2). The cross adhesive strength after treatment, the cross adhesive strength after treatment under the condition (2) of the following measurement method (b3), and the cross adhesive strength after treatment under the condition (3) of the following measurement method (b3) are 1000 N / cm ² or more, the thickness may be in respect of double-sided pressure-sensitive adhesive sheet is 100μm or more.
Measurement method (a3)
One pressure-sensitive adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm. An alkali glass B having a thickness of 4.0 mm, a width of 30 mm, and a length of 50 mm is bonded from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet so that the two alkali glasses have a cross positional relationship with each other to obtain a measurement sample. The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. Leave in the environment for 24 hours. Using a tensile tester, each alkali glass is pulled in the opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%, and the stress at that time is measured as a cross adhesive force.
Measurement method (b3)
A measurement sample is prepared in the same manner as the measurement method (a3). The measurement sample was autoclaved under conditions of 0.5 MPa, 40 ° C., 30 minutes, and irradiated with active energy rays so that the integrated light amount was 3000 mJ / cm ² with a high-pressure mercury lamp, at 23 ° C. and 50% relative humidity. Leave in the environment for 24 hours. Then, after treating under any of the following conditions (1) to (3), each alkali glass was thickened at a speed of 5 mm / min using a tensile tester in an environment of 23 ° C. and relative humidity of 50%. Pulling in the opposite direction of the direction, the stress at that time is measured as a cross adhesive force.
Condition (1) The cycle of placing at −40 ° C. for 30 minutes and then placing at 85 ° C. for 30 minutes is repeated 100 cycles.
Condition (2) Place in an environment of 85 ° C. and relative humidity of 85% for 100 hours.
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.

When measuring the cross adhesive strength of the double-sided pressure-sensitive adhesive sheet of the present invention, a double-sided pressure-sensitive adhesive sheet with a release sheet in which a release sheet is bonded to both sides of the double-sided pressure-sensitive adhesive sheet is prepared, and the double-sided pressure-sensitive adhesive sheet with release sheet is 1 cm × 1 cm. It is preferable to cut into a size, peel off the release sheet on each surface, and bond the exposed adhesive surface to alkali glass. When bonding a double-sided adhesive sheet to alkali glass, it bonds so that a bubble etc. may not enter between a double-sided adhesive sheet and alkali glass. As the alkali glass used in the measurement method (a3), for example, a float plate glass manufactured by Standard Test Piece Co., Ltd. can be used. FIG. 2 illustrates the configuration of the measurement sample used when measuring the cross adhesive force. The upper diagram of FIG. 2 is a diagram of the measurement sample viewed from the plane direction, and the lower diagram of FIG. 2 is a diagram of the side surface of the measurement sample viewed from the cross-sectional direction. As shown in FIG. 2, the measurement sample is configured by bonding the

alkali glasses

23 ° C. of the double-sided pressure-sensitive adhesive sheet of the present invention, the cross adhesive strength under a relative humidity of 50% may be any 1000 N / cm ² or more, preferably 1200 N / cm ² or more, at 1500 N / cm ² or more More preferably. In addition, the upper limit value of the cross adhesive force in the environment of 23 ° C. and relative humidity of 50% of the double-sided PSA sheet is not particularly limited, but may be, for example, 5000 N / cm ² . In addition, the said cross adhesive force is achieved by adjusting the mixing | blending of the adhesive composition mentioned later, or adjusting the hardening conditions of a double-sided adhesive sheet.

Cross adhesive strength after processing under condition (1) of measurement method (b3), cross adhesive strength after processing under condition (2) of measurement method (b3), and condition (3) of measurement method (b3) in cross adhesion after treatment may if 1000 N / cm ² or more, preferably 1100 N / cm ² or more, more preferably 1200 N / cm ² or more. In the present invention, it is preferable that all of the cross adhesive strength after the treatment under the conditions (1) to (3) is not less than the above lower limit value. Especially, the cross adhesive force after processing by the condition (1) of the measuring method (b3) is 1200 N / cm ² or more, and the cross adhesive force after processing by the condition (2) of the measuring method (b3) is 1500 N. / cm ² or more, cross adhesion after treatment with conditions (3) measurement method (b3) is preferably at 1300 N / cm ² or more. In particular, in an environment of 23 ° C. and 50% relative humidity, the cross adhesive strength measured by the measurement method (a3) is 1200 N / cm ² or more, and the cross after treatment under the condition (1) of the measurement method (b3) adhesion is at 1200 N / cm ² or more, cross adhesion after treatment with conditions (2) measurement method (b3) is at 1500 N / cm ² or more, and the condition of the measuring method (b3) (3) It is preferable that the cross-adhesive strength after processing with 1 is 1300 N / cm ² or more.

Since the double-sided pressure-sensitive adhesive sheet of the present invention has the above-described structure, even if the double-sided pressure-sensitive adhesive sheet is bonded to an adherend and then placed under severe conditions, bubbles are generated from the double-sided pressure-sensitive adhesive sheet, It is possible to prevent the pressure-sensitive adhesive sheet from floating or peeling off from the adherend. That is, the double-sided pressure-sensitive adhesive sheet of the present invention is excellent in durability under high temperature conditions.
In addition, the presence or absence of generation | occurrence | production of a bubble, a float, and peeling can be evaluated by performing a durability test, after bonding a double-sided adhesive sheet to a to-be-adhered body. Specifically, first, one side of the double-sided pressure-sensitive adhesive sheet is bonded to a polarizing plate (MLPH40-1 manufactured by Bikan Co., Ltd.), and the other side of the double-sided pressure-sensitive adhesive sheet is alkali glass (Standard Test Co., Ltd.). Bonded to a piece (float plate glass) to produce a measurement sample. Next, the measurement sample was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays from the glass surface with a high-pressure mercury lamp so that the integrated light amount was 3000 mJ / cm ² , After being left for 24 hours in an environment with a humidity of 50%, it is treated under any of the following conditions (1) to (3), and thereafter, the occurrence of bubbles, floats, and peeling is observed.
Condition (1) The cycle of placing at −40 ° C. for 30 minutes and then placing at 85 ° C. for 30 minutes is repeated 100 cycles.
Condition (2) Place in an environment of 85 ° C. and relative humidity of 85% for 100 hours.
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.

<Adhesive composition>
The pressure-sensitive adhesive composition comprises a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and a base polymer (A) containing an acrylic monomer unit (a2) having a crosslinkable functional group, a polymerizable non-polymerizable component. The monomer (B) having at least one saturated group, the crosslinking agent (C) that reacts with the base polymer (A) by heat, and the polymerization reaction of the monomer (B) are initiated by irradiation with active energy rays. It is preferable to contain a polymerization initiator (D) and a solvent (E).

(Base polymer (A))
The pressure-sensitive adhesive composition contains a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group as the base polymer (A). Is preferred. In the present specification, the “unit” is a repeating unit (monomer unit) constituting the polymer.

<Non-crosslinking (meth) acrylic acid ester monomer unit (a1)>
The non-crosslinkable (meth) acrylic acid ester monomer unit (a1) is derived from a (meth) acrylic acid alkyl ester. Examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth) Isobutyl acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, ( Isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, (meth) N-dodecyl acrylate, stearyl (meth) acrylate, methoxyethyl (meth) acrylate, (meth ) Ethoxyethyl acrylate, cyclohexyl (meth) acrylate include benzyl (meth) acrylate and the like. These may be used individually by 1 type and may use 2 or more types together.
In the present invention, “(meth) acrylic acid” means containing both “acrylic acid” and “methacrylic acid”.

The content of the non-crosslinkable (meth) acrylic acid ester monomer unit (a1) in the base polymer (A) is preferably 50% by mass or more based on the total mass of the base polymer (A). More preferably, it is more than 70 mass%, and it is still more preferable that it is 70 mass% or more. In addition, the content of the unit (a1) is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, and further preferably 99.0% by mass or less. By setting the content of the unit (a1) within the above range, the double-sided PSA sheet is bonded to the adherend, and then peeled off, bubbles and / or floating even when placed under high temperature conditions or severe conditions Can be effectively suppressed.

<(Meth) acrylic monomer unit (a2) having a crosslinkable functional group>
The (meth) acryl monomer unit (a2) having a crosslinkable functional group includes a hydroxy group-containing monomer unit, an amino group-containing monomer unit, a glycidyl group-containing monomer unit, and a carboxy group-containing monomer. Examples include units. Especially, it is preferable that the (meth) acryl monomer unit (a2) which has a crosslinkable functional group is a hydroxyl group containing monomer unit.
The hydroxy group-containing monomer unit is a repeating unit derived from the hydroxy group-containing monomer. Examples of the hydroxy group-containing monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (Meth) acrylic acid lactones such as (meth) acrylic acid mono (diethylene glycol) (meth) acrylic acid [(mono, di or poly) alkylene glycol] and (meth) acrylic acid monocaprolactone.
Examples of the amino group-containing monomer unit include repeating units derived from amino group-containing monomers such as (meth) acrylamide and allylamine.
Examples of the glycidyl group-containing monomer unit include repeating units derived from glycidyl group-containing monomers such as glycidyl (meth) acrylate.
Examples of the carboxy group-containing monomer unit include acrylic acid and methacrylic acid.

The content of the (meth) acrylic monomer unit (a2) having a crosslinkable functional group in the base polymer (A) is 0.1% by mass or more based on the total mass of the base polymer (A). Preferably, it is 0.5% by mass or more, and more preferably 1.0% by mass or more. The content of the (meth) acryl monomer unit (a2) is preferably 50% by mass or less, and more preferably 40% by mass or less. If the content of the (meth) acrylic monomer unit (a2) is not less than the lower limit of the above range, it has sufficient crosslinkability to maintain a semi-cured state, and the upper limit of the above range. If necessary, the necessary adhesive properties can be maintained.

<Other monomer units>
If necessary, the base polymer (A) may contain other units other than the non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and the (meth) acrylic monomer unit (a2) having a crosslinkable functional group. It may have a monomer unit. The other monomer may be any one that can be copolymerized with a non-crosslinkable (meth) acrylic acid ester and an acrylic monomer having a crosslinkable functional group. For example, (meth) acrylonitrile, vinyl acetate, styrene, Examples include vinyl chloride, vinyl pyrrolidone, and vinyl pyridine. The content of other monomer units in the base polymer (A) is preferably 20% by mass or less, and more preferably 15% by mass or less.

<Physical properties of base polymer (A)>
The weight average molecular weight of the base polymer (A) is preferably 600,000 or more, more preferably 650,000 or more, further preferably 700,000 or more, and particularly preferably 800,000 or more. The weight average molecular weight of the base polymer (A) is preferably 1.5 million or less, more preferably 1.4 million or less, and further preferably 1.3 million or less. By making the weight average molecular weight within the above range, even if the double-sided PSA sheet is bonded to the adherend and then placed under high temperature conditions or severe conditions, peeling, bubbles and / or floating may occur. It can be effectively suppressed. In addition, the weight average molecular weight of a base polymer (A) is a value before bridge | crosslinking with a crosslinking agent (C). The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and obtained on the basis of polystyrene.

The measurement conditions of gel permeation chromatography (GPC) are as follows.
Solvent: Tetrahydrofuran
Column: Shodex KF801, KF803L, KF800L, KF800D (used by connecting four Showa Denko Co., Ltd.)
Column temperature: 40 ° C
Sample concentration: 0.5% by mass
Detector: RI-2031plus (manufactured by JASCO)
Pump: RI-2080plus (manufactured by JASCO)
Flow rate (flow rate): 0.8 ml / min
Injection volume: 10 μl
Calibration curve: Standard polystyrene Shodex standard polystyrene (manufactured by Showa Denko KK) Mw = 1320 to 2,500,000 calibration curves with 10 samples are used.

The glass transition temperature (Tg) of the base polymer (A) is preferably −60 ° C. or higher and 0 ° C. or lower, more preferably −55 ° C. or higher and −10 ° C. or lower, and −40 ° C. or higher and −18 ° C. or lower. More preferably. By setting the glass transition temperature (Tg) of the base polymer (A) within the above range, the cohesive force of the pressure-sensitive adhesive can be further increased. Thereby, the double-sided adhesive sheet which was excellent in durability and excellent in adhesive force is obtained.

<Content of base polymer (A)>
The content of the base polymer (A) is preferably 40% by mass or more, more preferably 50% by mass or more, and 60% by mass or more with respect to the total solid content in the pressure-sensitive adhesive composition. More preferably. The content of the base polymer (A) is preferably 98% by mass or less, more preferably 95% by mass or less, and 90% by mass or less, based on the total solid content in the pressure-sensitive adhesive composition. More preferably.

As the base polymer (A), a commercially available product may be used, or a polymer synthesized by a known method may be used.

(Monomer (B))
The monomer (B) is a monomer containing at least one polymerizable unsaturated group. The monomer (B) contains at least one of a monofunctional monomer (b1) having one polymerizable unsaturated group and a polyfunctional monomer (b2) having two or more polymerizable unsaturated groups. It is preferable that both the monofunctional monomer (b1) having one polymerizable unsaturated group and the polyfunctional monomer (b2) having two or more polymerizable unsaturated groups are contained. Examples of the polymerizable unsaturated group include a group containing an ethylenic double bond, and examples thereof include a (meth) acryloyl group and a vinyl group.

The pressure-sensitive adhesive composition of the present invention contains the monomer (B), and when the pressure-sensitive adhesive composition is heat-cured in the first stage (semi-curing step), the thermo-cured double-sided pressure-sensitive adhesive sheet is half It is in a cured state and can have active energy ray curability. When the pressure-sensitive adhesive composition is cured by irradiation with active energy rays in the first stage, the double-sided pressure-sensitive adhesive sheet of the photocured product is in a semi-cured state and has thermosetting properties. In addition, in this invention, after making it harden | cure in a 1st step and making it a semi-hardened state, it can also make it completely harden | cure by thermosetting again as a 2nd step.

When the monomer (B) includes a monofunctional monomer (b1) having one polymerizable unsaturated group and a polyfunctional monomer (b2) having two or more polymerizable unsaturated groups, The mass ratio of the monomer (b1) and the polyfunctional monomer (b2) is preferably 10: 1 to 50: 1, and more preferably 20: 1 to 40: 1. By setting the mass ratio of the monofunctional monomer (b1) and the polyfunctional monomer (b2) within the above range, the double-sided pressure-sensitive adhesive sheet was bonded to the adherend and then placed under high temperature conditions or severe conditions. Even if it is a case, generation | occurrence | production of peeling, a bubble, and / or a float can be suppressed effectively.

As the monomer (B), one having a vapor pressure at 25 ° C. of 300 Pa or less may be used. This improves the coating suitability, and when the adhesive composition is applied and heat-cured, the adhesive layer has few coating defects such as the occurrence of thick edges and side walls while selectively evaporating the solvent. Can be formed.
The vapor pressure at 25 ° C. of the monomer (B) may be 200 Pa or less, or 100 Pa or less. The lower limit of the vapor pressure is not particularly limited in terms of the coating suitability of the pressure-sensitive adhesive composition. The vapor pressure of the monomer (B) can be measured according to JIS K 2258 “Crude oil and fuel oil—Vapor pressure test method—Reed method” and the like, for example, http: // www. chemspider. The predicted value can be obtained by a website such as com / or software such as ACD / PhysChem Suite.

Further, the melting point of the monomer (B) may be 25 ° C. or less. Thereby, transparency (haze etc.) of the double-sided adhesive sheet formed improves. Further, the melting point of the monomer (B) may be 20 ° C. or less, or 15 ° C. or less. The lower limit of the melting point is not particularly limited. The melting point of the monomer (B) can be measured according to JIS K 0064: 1992 “Measuring Method of Melting Point and Melting Range of Chemical Products”.

Specific examples of the monofunctional monomer (b1) that can be used in the present invention include pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, and n-octyl (meth) acrylate. , Iso-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, ( Examples include lauryl methacrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like. Monofunctional monomers (b1) having a melting point of 25 ° C. or less include pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, n-octyl (meth) acrylate, (meth ) Isooctyl acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, (meth) acrylic Examples thereof include lauryl acid, isostearyl (meth) acrylate, isobornyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

Examples of the polyfunctional monomer (b2) include ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and di (meth) acryl. 1,4-butylene glycol acid, 1,9-nonanediol di (meth) acrylate, 1,6-hexanediol diacrylate, polybutylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Tetraethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetra ( Many such as (meth) acrylic acid pentaerythritol (Meth) acrylic acid esters of alcohols, and vinyl methacrylate.
The monomer (B) may have no functional group that is reactive with the functional group of the (meth) acrylic monomer unit (a2). For example, the monomer (B) may have the same functional group (for example, a hydroxy group) as the (meth) acrylic monomer unit (a2) or may not have a functional group.

The monomer (B) preferably has an alkyl group having 5 or more carbon atoms, and more preferably has an alkyl group having 10 or more carbon atoms. Among these, the monofunctional monomer (b1) preferably has an alkyl group having 5 or more carbon atoms, and more preferably has an alkyl group having 10 or more carbon atoms. In addition, as long as carbon number of an alkyl group is 10 or more, you may have a side chain and a substituent. The number of carbon atoms of the alkyl group may be, for example, 10 to 27, 10 to 25, or 15 to 22. When the monomer (B) contains an alkyl group having a predetermined structure, the double-sided pressure-sensitive adhesive sheet is bonded to the adherend and then peeled off or bubbled even under high temperature conditions or severe conditions. And / or generation | occurrence | production of a float can be suppressed effectively.

Examples of the monomer (B) having an alkyl group having 5 or more carbon atoms include pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, and n-octyl (meth) acrylate. , Iso-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-undecyl (meth) acrylate, ( Examples include lauryl methacrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate.

The monomer (B) may have a polycyclic structure. Thereby, a further excellent holding force can be exhibited after complete curing. The monomer having a polycyclic structure may be a polycyclic aliphatic monomer or a polycyclic aromatic monomer. Examples of the polycyclic structure include a bicyclo structure and a tricyclo structure. A substituent such as an alkyl group may be bonded to these polycyclic structures. Specific examples of the polycyclic structure include a norbornene ring and an adamantane ring.

<Content of monomer (B)>
The content of the monomer (B) in the pressure-sensitive adhesive composition is appropriately selected according to the composition, molecular weight, crosslinking density, etc. of the base polymer (A), and is not particularly limited, but 100 parts by mass of the base polymer (A) On the other hand, it is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, further preferably 25 parts by mass or more, and particularly preferably 30 parts by mass or more. The content of the monomer (B) is preferably 99 parts by mass or less, more preferably 90 parts by mass or less, and 80 parts by mass or less with respect to 100 parts by mass of the base polymer (A). More preferably it is.

When the monomer (B) contains both the monofunctional monomer (b1) and the polyfunctional monomer (b2), the monofunctional monomer (b1) with respect to 100 parts by mass of the base polymer (A) The content of is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, further preferably 25 parts by mass or more, and particularly preferably 30 parts by mass or more. Further, the content of the monofunctional monomer (b1) is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and 80 parts by mass with respect to 100 parts by mass of the base polymer (A). More preferably, it is as follows. The content of the polyfunctional monomer (b2) is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more with respect to 100 parts by mass of the base polymer (A). More preferably, it is at least 0.0 part by mass. The content of the polyfunctional monomer (b2) is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, with respect to 100 parts by mass of the base polymer (A). More preferably, it is as follows.

(Crosslinking agent (C))
The crosslinking agent (C) is a crosslinking agent that reacts with the base polymer (A) by heat. Examples of the cross-linking agent (C) include cross-linkable functional groups possessed by the base polymer (A) among known cross-linking agents such as isocyanate compounds, epoxy compounds, oxazoline compounds, aziridine compounds, metal chelate compounds, butylated melamine compounds. It can be appropriately selected in consideration of the reactivity with the group. For example, when the base polymer (A) contains a hydroxy group as a crosslinkable functional group, an isocyanate compound can be used from the reactivity of the hydroxy group. From the viewpoint that the (meth) acrylic monomer unit (a2) having a crosslinkable functional group can be easily crosslinked, it is preferable to use an isocyanate compound or an epoxy compound.

Examples of the isocyanate compound include tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.
Examples of the epoxy compound include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,6-hexanediol diester. Glycidyl ether, tetraglycidyl xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, trimethylolpropane polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, etc. Can be mentioned.

As the crosslinking agent (C), one type may be used alone, or two or more types may be used in combination. Although content of the crosslinking agent (C) in an adhesive composition is suitably selected according to the desired adhesive physical property etc., it is not specifically limited, 0.01 mass part with respect to 100 mass parts of base polymers (A) The amount can be 5 parts by mass or less, and can be 0.03 parts by mass or more and 3 parts by mass or less.

(Polymerization initiator (D))
A polymerization initiator (D) starts the polymerization reaction of a monomer (B) by irradiation of an active energy ray. As the polymerization initiator (D), any polymerization initiator may be used as long as it can initiate the polymerization reaction of the monomer (B) by irradiation with active energy rays.
Here, “active energy rays” mean those having energy quanta among electromagnetic waves or charged particle beams, and examples include ultraviolet rays, electron beams, visible rays, X-rays, ion rays and the like. Among these, from the viewpoint of versatility, ultraviolet rays or electron beams are preferable, and ultraviolet rays are particularly preferable.

Examples of the polymerization initiator (D) include acetophenone-based initiators, benzoin ether-based initiators, benzophenone-based initiators, hydroxyalkylphenone-based initiators, thioxanthone-based initiators, and amine-based initiators.
Specific examples of the acetophenone initiator include diethoxyacetophenone and benzyldimethyl ketal.
Specific examples of the benzoin ether initiator include benzoin and benzoin methyl ether.
Specific examples of the benzophenone initiator include benzophenone and methyl o-benzoylbenzoate.
Specific examples of the hydroxyalkylphenone initiator include 1-hydroxy-cyclohexyl-phenyl-ketone and the like.
Specific examples of the thioxanthone initiator include 2-isopropylthioxanthone and 2,4-dimethylthioxanthone.
Specific examples of the amine initiator include triethanolamine and ethyl 4-dimethylbenzoate.

As the polymerization initiator (D), one type may be used alone, or two or more types may be used in combination. The content of the polymerization initiator (D) in the pressure-sensitive adhesive composition is appropriately selected according to the content of the monomer (B), the irradiation amount of active energy rays when semi-cured or completely cured, and the like. Although not limited, it can be 0.05 mass% or more and 10 mass% or less with respect to the total mass of a monomer (B), and can be 0.1 mass% or more and 5.0 mass% or less.
Moreover, content of a polymerization initiator (D) can be 0.1 mass part or more and 10 mass parts or less with respect to 100 mass parts of base polymers (A), and 0.5 mass part or more and 5 mass parts or less. It can be.

(Solvent (E))
The pressure-sensitive adhesive composition of the present invention may further contain a solvent (E). The solvent (E) is used for improving the coating suitability of the pressure-sensitive adhesive composition.
Examples of such a solvent (E) include hydrocarbons such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; halogenated hydrocarbons such as dichloromethane, trichloroethane, trichloroethylene, tetrachloroethylene, and dichloropropane. Alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, isobutyl alcohol and diacetone alcohol; ethers such as diethyl ether, diisopropyl ether, dioxane and tetrahydrofuran; acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone and cyclohexanone Ketones; methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, amyl acetate, ethyl butyrate Esters; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, polyols and derivatives thereof such as propylene glycol monomethyl ether acetate.

Examples of the solvent (E) include a solvent having no polymerizable unsaturated group and having a higher vapor pressure at 25 ° C. than that of the monomer (B). Since the larger the difference in vapor pressure between the monomer (B) and the solvent (E), the fewer the coating defects and the easier the production, the vapor pressure of the solvent (E) can be 2000 Pa or higher. This can be done. Although an upper limit is not specifically limited, It is 50000 Pa or less practically. The vapor pressure of the solvent (E) can be measured according to JIS-K2258-2 “Crude oil and petroleum products—Determination of vapor pressure—Part 2: Three-time expansion method”, for example, http: // www. chemspider. com / and software such as ACD / PhysChem Suite.

Solvents that have no polymerizable unsaturated groups and have a higher vapor pressure at 25 ° C. than monomer (B) include hexane, heptane, cyclohexane, benzene, toluene, ethanol, isopropyl alcohol, diisopropyl ether, tetrahydrofuran, and acetone. , Methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate and the like. The said solvent can be suitably selected according to the kind of monomer (B).

Further, the solvent (E) may have a surface tension at 25 ° C. of 20 mN / m or more and less than 40 mN / m, or 22 mN / m or more and less than 36 N / m. If the surface tension is not less than the above lower limit value, it is possible to suppress the formation of a yuzu skin (orange peel), and if it is less than the above upper limit value, coating defects such as occurrence of thick end portions (framing) are unlikely to occur.

Solvent (E) may be used alone or in combination of two or more. In the pressure-sensitive adhesive composition, the content of the solvent (E) is not particularly limited, but can be 25 parts by mass or more and 500 parts by mass or less, and 30 parts by mass or more and 400 parts by mass with respect to 100 parts by mass of the base polymer (A). It can be below mass parts.

(Plasticizer)
The pressure-sensitive adhesive composition of the present invention may contain a plasticizer. When a plasticizer is included, the content of the plasticizer can be 10 parts by mass or less with respect to 100 parts by mass of the base polymer (A), can be 5 parts by mass or less, and 3 parts by mass or less. It can also be.

As the plasticizer, a non-functional acrylic polymer can be used. A non-functional acrylic polymer is a polymer consisting only of an acrylic monomer unit having no functional group other than an acrylate group, or an acrylic monomer unit having no functional group other than an acrylate group and no functional group. It means a polymer composed of non-acrylic monomer units.
As an acrylic monomer unit which does not have functional groups other than an acrylate group, the thing similar to a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) is mentioned, for example.
Non-acrylic monomer units having no functional group include, for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, stearin. Examples thereof include carboxylic acid vinyl esters such as vinyl acid vinyl, vinyl cyclohexanecarboxylate, and vinyl benzoate, and styrene.

(Optional component)
The pressure-sensitive adhesive composition may contain components other than those described above as long as the effects of the present invention are not impaired. Other components include components known as additives for pressure-sensitive adhesives, such as antioxidants, metal corrosion inhibitors, tackifiers, silane coupling agents, ultraviolet absorbers, light stabilizers such as hindered amine compounds, etc. You can select from among them as needed.
Examples of the antioxidant include phenolic antioxidants, amine-based antioxidants, lactone-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, and the like. These antioxidants may be used alone or in combination of two or more.
Examples of the metal corrosion inhibitor include benzoriazol resins.
Examples of the tackifier include rosin resin, terpene resin, terpene phenol resin, coumarone indene resin, styrene resin, xylene resin, phenol resin, and petroleum resin.
Examples of the silane coupling agent include mercaptoalkoxysilane compounds (for example, mercapto group-substituted alkoxy oligomers).
Examples of the ultraviolet absorber include benzotriazole compounds and benzophenone compounds. However, when ultraviolet rays are used for the active energy rays during complete curing, it is necessary to add them in a range that does not inhibit the polymerization reaction.

(Production method of double-sided PSA sheet)
The double-sided pressure-sensitive adhesive sheet of the present invention is obtained by semi-curing the pressure-sensitive adhesive composition by heating or irradiation with active energy rays, containing at least a part of the monomer (B) in an unreacted state, and a crosslinking agent. Among at least one selected from (C) and the polymerization initiator (D), at least a part thereof is contained in an unreacted state. That is, the manufacturing method of the double-sided adhesive sheet of this invention includes the process of heating an adhesive composition or irradiating an active energy ray. Especially, it is preferable that the manufacturing method of the double-sided adhesive sheet of this invention includes the process of heating an adhesive composition.

The production process of the double-sided pressure-sensitive adhesive sheet of the present invention includes a step of coating a pressure-sensitive adhesive composition on a release sheet to form a coating film, a step of heating the coating film to a semi-cured product, or the coating film It is preferable to include a step of forming a semi-cured product by irradiation with active energy rays.

Application of the pressure-sensitive adhesive composition can be performed using a known coating apparatus. Examples of the coating apparatus include a blade coater, an air knife coater, a roll coater, a bar coater, a gravure coater, a micro gravure coater, a rod blade coater, a lip coater, a die coater, and a curtain coater.

In the step of making the coating film into a semi-cured product by heating, the reaction of the base polymer (A) and the crosslinking agent (C) proceeds by heating the coating film to form a semi-cured product (double-sided pressure-sensitive adhesive sheet). In other words, during heating, the polymerization reaction of the monomer (B) by the polymerization initiator (D) does not proceed or is slight in the coating film, so that the resulting semi-cured product (double-sided pressure-sensitive adhesive sheet) is obtained. In the monomer, the monomer (B) and the polymerization initiator (D) contained in the pressure-sensitive adhesive composition remain. For this reason, the double-sided pressure-sensitive adhesive sheet of the present invention has active energy ray curability. In addition, heating of a coating film can be implemented using well-known heating apparatuses, such as a heating furnace and an infrared lamp. Moreover, in order to make an adhesive composition into a semi-hardened state, after removing the solvent after coating, you may give the aging process which leaves a double-sided adhesive sheet still for a fixed period at a fixed temperature. The aging treatment can be performed, for example, by standing for 7 days in an environment of 23 ° C. and a relative humidity of 50%.

(How to use double-sided PSA sheet)
In the method for using the double-sided pressure-sensitive adhesive sheet of the present invention, the double-sided pressure-sensitive adhesive sheet is brought into contact with the surface of the adherend, and the active energy ray is irradiated in this state to completely cure the double-sided pressure-sensitive adhesive sheet.

Before irradiating the active energy ray, the pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive sheet is in a semi-cured state, so that the pressure-sensitive adhesive layer can follow the unevenness even if the adherend has a stepped portion. . Thus, after pasting the double-sided pressure-sensitive adhesive sheet and following the irregularities, the adhesive layer is completely cured with active energy rays, so that the cohesive force of the pressure-sensitive adhesive layer is increased and the adhesiveness to the adherend is increased. improves.

Examples of the active energy rays include ultraviolet rays, electron beams, visible rays, X-rays, ion rays and the like, and can be appropriately selected according to the polymerization initiator (D) contained in the pressure-sensitive adhesive layer. Among these, from the viewpoint of versatility, ultraviolet rays or electron beams are preferable, and ultraviolet rays are particularly preferable.
As the ultraviolet light source, for example, a high pressure mercury lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, a metal halide lamp, a carbon arc, a xenon arc, an electrodeless ultraviolet lamp, or the like can be used.
As the electron beam, for example, an electron beam emitted from various electron beam accelerators such as a cockloftwald type, a bandecraft type, a resonant transformation type, an insulating core transformer type, a linear type, a dynamitron type, and a high frequency type can be used.

(Laminate)
The present invention may relate to a laminate having an adherend on at least one surface of the double-sided pressure-sensitive adhesive sheet described above. A laminated body is obtained through the process of making a double-sided adhesive sheet contact the surface of a to-be-adhered body, irradiating an active energy ray in that state, and completely curing a double-sided adhesive sheet.

The adherend is preferably an optical member. As an optical member, each structural member in optical products, such as a touch panel and an image display apparatus, can be mentioned. As a constituent member of the touch panel, for example, an ITO film in which an ITO film is provided on a transparent resin film, an ITO glass in which an ITO film is provided on the surface of a glass plate, a transparent conductive film in which a transparent polymer film is coated with a conductive polymer, Examples thereof include a hard coat film and an anti-fingerprint film. Examples of the constituent member of the image display device include an antireflection film, an alignment film, a polarizing film, a retardation film, and a brightness enhancement film used for a liquid crystal display device.
Examples of materials used for these members include glass, polycarbonate, polyethylene terephthalate, polymethyl methacrylate, polyethylene naphthalate, cycloolefin polymer, triacetyl cellulose, polyimide, and cellulose acylate.

The double-sided pressure-sensitive adhesive sheet of the present invention can be used for bonding two adherends. In this case, the double-sided pressure-sensitive adhesive sheet of the present invention includes bonding of ITO films inside the touch panel, bonding of the ITO film and ITO glass, bonding of the ITO film of the touch panel and the liquid crystal panel, cover glass and ITO film, It is used for bonding, and bonding between a cover glass and a decorative film.

(Laminate manufacturing method)
The present invention also relates to a method for producing a laminate. The manufacturing method of the laminated body of this invention includes the process which makes the double-sided adhesive sheet of the semi-hardened state mentioned above contact to a to-be-adhered body surface, and irradiates an active energy ray in the state, and hardens a double-sided adhesive sheet completely.

Examples of the active energy rays include the energy rays described above, and ultraviolet rays or electron rays are preferable, and ultraviolet rays are particularly preferable.
Radiation output of the UV light, it is preferable that the integrated quantity of light is made to be a 100 mJ / cm ² or more 10000 mJ / cm ² or less, and more preferably made to be 500 mJ / cm ² or more 5000 mJ / cm ² or less.

In the method for producing a laminate, the pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive sheet is in a semi-cured state before being irradiated with active energy rays, so even if the adherend has a stepped portion or a curved surface, the pressure-sensitive adhesive layer Can follow the irregularities. Thus, after pasting the double-sided pressure-sensitive adhesive sheet and following the irregularities, the adhesive layer is completely cured with active energy rays, so that the cohesive force of the pressure-sensitive adhesive layer is increased and the adhesiveness to the adherend is increased. improves. Moreover, even if it is a case where it puts on a to-be-adhered body after a double-sided adhesive sheet is put on a high temperature condition or severe conditions, generation | occurrence | production of peeling, a bubble, and / or a float can be suppressed effectively.

Hereinafter, the features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(Examples 1 to 3 and Comparative Examples 1 to 5)
Each component was mixed so that it might become a composition (solid content conversion) shown in Table 1, and also ethyl acetate was added as a solvent, and the coating liquid (adhesive composition) prepared so that solid content concentration might be 30 mass% Got. In Comparative Example 5, since the molecular weights of the base polymers A and B were large, ethyl acetate was added to prepare a solid content concentration of 15% by mass.

Each component in Table 1 is as follows.
(* 1) BA / 2HEA: Copolymer of butyl acrylate (BA) and 2-hydroxyethyl acrylate (HEA) (* 2) BA / AA: Copolymer of butyl acrylate (BA) and acrylic acid (AA) Polymer (* 3) Monofunctional monomer: ISTA ... Isostearyl acrylate (* 4) Multifunctional monomer: M360 ... Trimethylolpropane ethylene oxide-modified triacrylate (Aronix, manufactured by Toagosei Co., Ltd.) M-360)
M315: isocyanuric acid EO-modified diacrylate and isocyanuric acid EO-modified triacrylate (manufactured by Toagosei Co., Ltd., Aronix M-315)
(* 5) Polymerization initiator A: 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by BASF Japan, IRGACURE 184)
Polymerization initiator B: Mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone (mass ratio 1: 1)
(* 6) Crosslinking agent: Trimethylolpropane-modified tolylene diisocyanate (Nihon Polyurethane Co., Ltd., Coronate L)
(* 7) Silane coupling agent: 3-glycidoxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM-403)

(Production of double-sided PSA sheet)
A 100 μm thick PET film (manufactured by Oji F-Tex Co., Ltd., 100RL-07 (2)) was prepared as a separator. On this separator, the pressure-sensitive adhesive composition obtained above was applied so that the thickness after drying was 150 μm to form a coating film, which was formed at 60 ° C. for 3 minutes, 80 ° C. for 5 minutes, 100 ° C. The coating film was cured by drying for 18 minutes in the order of 5 minutes at 120 ° C. for 5 minutes, and an adhesive layer was formed on the separator. Next, a 75 μm-thick separator (manufactured by Oji F-Tex Co., Ltd., 75RL-07 (L)) was bonded to the surface of the pressure-sensitive adhesive layer. Thus, a double-sided pressure-sensitive adhesive sheet with a release sheet having a separator / pressure-sensitive adhesive layer / separator configuration in which the pressure-sensitive adhesive layer was sandwiched between a pair of separators having a difference in peeling force was obtained. This double-sided PSA sheet with a release sheet was cured for 7 days in a light-shielded environment at 23 ° C. and a relative humidity of 50%.
In addition, since the adhesive composition of the comparative example 5 had low solid content concentration, it was not able to apply so that the thickness after drying might be 100 micrometers or more.

(Measurement and evaluation)
(Measurement of shear adhesive strength)
First, the double-sided pressure-sensitive adhesive sheet with a release sheet was cut into a size of 1 cm × 1 cm, and a separator (light release film) having a thickness of 75 μm was peeled off. Next, the adhesive surface of the exposed double-sided pressure-sensitive adhesive sheet is 15 mm from one end in the longitudinal direction of an alkali glass A (float plate glass manufactured by Standard Test Piece) 1.1 mm × 40 mm × 150 mm, and one end in the width direction. It was pasted by hand so that the center point of the double-sided PSA sheet was at an intersection of 20 mm from the side. Thereafter, the separator (heavy release film) having a thickness of 100 μm is peeled off, and the same alkali glass B (manufactured by Standard Test Piece, float plate glass) is overlapped with the width direction of the alkali glass A so that air does not enter. And it bonded so that a longitudinal direction might overlap with alkali glass A 30 mm (refer FIG. 1). The sample prepared in this manner was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays so that the integrated light intensity was 3000 mJ / cm ² with a high-pressure mercury lamp, 23 ° C., relative humidity After being left for 24 hours in a 50% environment, it was left for 3 hours in an environment of less than 10% relative humidity at 80 ° C. Then, using a tensile tester (manufactured by Tester Sangyo Co., Ltd., TE-7001 tensile tester with a constant temperature and humidity chamber), the respective alkalis at a speed of 25 mm / min in an environment of 80 ° C. and a relative humidity of less than 10%. The glass was pulled in the opposite direction in the longitudinal direction (the direction of the arrow in FIG. 1), and the stress (shear adhesive strength) at that time was measured.
The sample produced by the same method as described above was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays with a high-pressure mercury lamp so that the integrated light amount was 3000 mJ / cm ^2, and 23 ° C. And left in an environment with a relative humidity of 50% for 24 hours. Thereafter, each alkali glass was used at a speed of 25 mm / min under an environment of 23 ° C. and a relative humidity of 50% using a tensile tester (manufactured by Tester Sangyo Co., Ltd., TE-7001 tensile tester with a constant temperature and humidity chamber). The longitudinal end of each was pulled in the opposite direction in the longitudinal direction (the direction of the arrow in FIG. 1), and the stress (shear adhesive strength) at that time was measured.

(Durability evaluation)
First, the double-sided pressure-sensitive adhesive sheet with a release sheet was cut into a size of 160 mm × 210 mm, and a separator (light release film) having a thickness of 75 μm was peeled off. Next, the adhesive surface of the exposed double-sided pressure-sensitive adhesive sheet is manually pasted to a polarizing plate (MLPH40-1 manufactured by Bikan Co., Ltd.), and the laminate of the double-sided pressure-sensitive adhesive sheet and the polarizing plate has a size of 140 mm × 190 mm. Cut to be. Thereafter, the separator (heavy release film) having a thickness of 100 μm was peeled off and bonded to alkali glass (float plate glass manufactured by Standard Test Piece Co., Ltd.) having a size of 150 mm × 250 mm so that air did not enter. The sample thus prepared was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays from a glass surface with a high-pressure mercury lamp so that the integrated light amount was 3000 mJ / cm ^2, and 105 ° C. It was left for 100 hours in an environment of less than 5% relative humidity. Thereafter, the occurrence of peeling of the double-sided PSA sheet was observed.
A: No peeling at all.
○: Less than 3 peelings with a maximum width of less than 100 μm occur.
X: Three or more peelings with a maximum width of less than 100 μm occur, or peeling occurs with a maximum width of 100 μm or more.

In the examples, the occurrence of peeling was suppressed. In Comparative Example 5, the double-sided pressure-sensitive adhesive sheet having a thickness of 100 μm or more could not be prepared, and thus could not be evaluated.

(Examples 201 to 203 and Comparative Examples 201 to 205)
Each component was mixed so that it may become a composition (solid content conversion) shown in Table 3, and also ethyl acetate was added as a solvent, and the coating liquid (adhesive composition) prepared so that solid content concentration might be 30 mass% Got. Comparative Example 205 was prepared so that the solid content concentration was 15% by mass by adding ethyl acetate because the base polymers A and B had large molecular weights.
Each component in Table 3 is as described above.

(Production of double-sided PSA sheet)
A 100 μm thick PET film (manufactured by Oji F-Tex Co., Ltd., 100RL-07 (2)) was prepared as a separator. On this separator, the pressure-sensitive adhesive composition obtained above was applied so that the thickness after drying was 150 μm to form a coating film, which was formed at 60 ° C. for 3 minutes, 80 ° C. for 5 minutes, 100 ° C. The coating film was cured by drying for 18 minutes in the order of 5 minutes at 120 ° C. for 5 minutes, and an adhesive layer was formed on the separator. Next, a 75 μm-thick separator (manufactured by Oji F-Tex Co., Ltd., 75RL-07 (L)) was bonded to the surface of the pressure-sensitive adhesive layer. Thus, a double-sided pressure-sensitive adhesive sheet with a release sheet having a separator / pressure-sensitive adhesive layer / separator configuration in which the pressure-sensitive adhesive layer was sandwiched between a pair of separators having a difference in peeling force was obtained. This double-sided PSA sheet with a release sheet was cured for 7 days in a light-shielded environment at 23 ° C. and a relative humidity of 50%.
In addition, since the adhesive composition of Comparative Example 205 had a low solid content concentration, it could not be applied such that the thickness after drying was 100 μm or more.

(Measurement and evaluation)
(Measurement of cross adhesive strength)
First, the double-sided pressure-sensitive adhesive sheet with a release sheet was cut into a size of 1 cm × 1 cm, and a separator (light release film) having a thickness of 75 μm was peeled off. Subsequently, the adhesive surface of the exposed double-sided pressure-sensitive adhesive sheet was bonded to the center of alkali glass A (manufactured by Standard Test Piece, float plate glass) having a thickness of 4.0 mm, a width of 30 mm, and a length of 50 mm by hand bonding. Thereafter, the separator (heavy release film) having a thickness of 100 μm was peeled off, and the same alkali glass B was bonded so that the two alkali glasses were in a cross positional relationship so as not to enter air (see FIG. 2). The sample prepared in this manner was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays so that the integrated light intensity was 3000 mJ / cm ² with a high-pressure mercury lamp, 23 ° C., relative humidity After being left in a 50% environment for 24 hours, it was left in an environment at 80 ° C. and a relative humidity of less than 10% for 3 hours. Thereafter, using a tensile tester (manufactured by Tester Sangyo Co., Ltd., TE-7001 tensile tester with a constant temperature and humidity chamber), each alkali glass was applied at a speed of 5 mm / min in an environment of less than 10% relative humidity at 80 ° C. The film was pulled in the opposite direction (the direction of the arrow in FIG. 2) in the thickness direction, and the stress (cross adhesive force) at that time was measured.
The sample produced by the same method as described above was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays with a high-pressure mercury lamp so that the integrated light amount was 3000 mJ / cm ^2, and 23 ° C. And left in an environment with a relative humidity of 50% for 24 hours. Thereafter, each alkali glass was used at a speed of 5 mm / min under an environment of 23 ° C. and a relative humidity of 50% using a tensile tester (manufactured by Tester Sangyo Co., Ltd., TE-7001 tensile tester with a constant temperature and humidity chamber). Was pulled in the opposite direction in the thickness direction (the direction of the arrow in FIG. 2), and the stress (cross adhesive force) at that time was measured.

(Durability evaluation)
First, the double-sided pressure-sensitive adhesive sheet with a release sheet was cut into a size of 160 mm × 210 mm, and a separator (light release film) having a thickness of 75 μm was peeled off. Next, the adhesive surface of the exposed double-sided pressure-sensitive adhesive sheet is manually pasted to a polarizing plate (MLPH40-1 manufactured by Bikan Co., Ltd.), and the laminate of the double-sided pressure-sensitive adhesive sheet and the polarizing plate has a size of 140 mm × 190 mm. Cut to be. Thereafter, the separator (heavy release film) having a thickness of 100 μm was peeled off and bonded to alkali glass (manufactured by Standard Test Piece, float plate glass) having a size of 150 mm × 250 mm so that air did not enter. The sample thus prepared was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays from a glass surface with a high-pressure mercury lamp so that the integrated light amount was 3000 mJ / cm ^2, and 23 ° C. The sample was left in an environment with a relative humidity of 50% for 24 hours and then placed in an environment with a relative humidity of less than 5% at 105 ° C. for 100 hours. Thereafter, the presence or absence of bubbles and floating was observed.
○: There is no generation of bubbles and floating.
X: Bubbles and / or floating are generated.

In the examples, the generation of bubbles and floats was suppressed. In Comparative Example 205, evaluation could not be performed because a double-sided PSA sheet having a thickness of 100 μm or more could not be produced.

(Examples 301 to 303 and Comparative Examples 301 to 305)
Each component was mixed so that it might become a composition (solid content conversion) shown in Table 5, and also ethyl acetate was added as a solvent, and the coating liquid (adhesive composition) prepared so that solid content concentration might be 30 mass% Got. In addition, since the comparative polymer 305 had the large molecular weight of the base polymers A and B, ethyl acetate was added and it prepared so that solid content concentration might be 15 mass%.
Each component in Table 5 is as follows.

(Production of double-sided PSA sheet)
A 100 μm thick PET film (manufactured by Oji F-Tex Co., Ltd., 100RL-07 (2)) was prepared as a separator. On this separator, the pressure-sensitive adhesive composition obtained above was applied so that the thickness after drying was 150 μm to form a coating film, which was formed at 60 ° C. for 3 minutes, 80 ° C. for 5 minutes, 100 ° C. The coating film was cured by drying for 18 minutes in the order of 5 minutes at 120 ° C. for 5 minutes, and an adhesive layer was formed on the separator. Next, a 75 μm-thick separator (manufactured by Oji F-Tex Co., Ltd., 75RL-07 (L)) was bonded to the surface of the pressure-sensitive adhesive layer. Thus, a double-sided pressure-sensitive adhesive sheet with a release sheet having a separator / pressure-sensitive adhesive layer / separator configuration in which the pressure-sensitive adhesive layer was sandwiched between a pair of separators having a difference in peeling force was obtained. This double-sided PSA sheet with a release sheet was cured for 7 days in a light-shielded environment at 23 ° C. and a relative humidity of 50%.
In addition, since the adhesive composition of Comparative Example 305 had a low solid content concentration, it could not be applied such that the thickness after drying was 100 μm or more.

(Measurement and evaluation)
(Measurement method (a3); measurement of cross adhesive strength in an environment of 23 ° C. and 50% relative humidity)
First, the double-sided pressure-sensitive adhesive sheet with a release sheet was cut into a size of 1 cm × 1 cm, and a separator (light release film) having a thickness of 75 μm was peeled off. Subsequently, the adhesive surface of the exposed double-sided pressure-sensitive adhesive sheet was bonded to the center of alkali glass A (manufactured by Standard Test Piece, float plate glass) having a thickness of 4.0 mm, a width of 30 mm, and a length of 50 mm by hand bonding. Thereafter, the separator (heavy release film) having a thickness of 100 μm was peeled off, and the same alkali glass B was bonded so that the two alkali glasses were in a cross relationship with each other so that air could not enter (see FIG. 2). The sample prepared in this manner was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays so that the integrated light intensity was 3000 mJ / cm ² with a high-pressure mercury lamp, 23 ° C., relative humidity It was left in a 50% environment for 24 hours. Thereafter, using a tensile tester (manufactured by Tester Sangyo Co., Ltd., TE-7001 tensile tester with a constant temperature and humidity chamber), each alkali glass was placed at 23 ° C. and 50% relative humidity at a speed of 5 mm / min. The film was pulled in the opposite direction (the direction of the arrow in FIG. 2) in the thickness direction, and the stress (cross adhesive force) at that time was measured.

(Measurement method (b3); measurement of cross adhesive strength after endurance test)
A sample for measuring adhesive strength was prepared in the same manner as in the measurement method (a3). The sample prepared in this manner was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays so that the integrated light intensity was 3000 mJ / cm ² with a high-pressure mercury lamp, 23 ° C., relative humidity It was left in a 50% environment for 24 hours. Then, after treating under any of the following conditions (1) to (3), each alkali glass was thickened at a speed of 5 mm / min using a tensile tester in an environment of 23 ° C. and relative humidity of 50%. It pulled in the direction opposite to the direction (the direction of the arrow in FIG. 2), and the stress at that time was measured as a cross adhesive force.
Condition (1) The cycle of placing at −40 ° C. for 30 minutes and then placing at 85 ° C. for 30 minutes is repeated 100 cycles.
Condition (2) Place in an environment of 85 ° C. and relative humidity of 85% for 100 hours.
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.

(Durability evaluation)
First, the double-sided pressure-sensitive adhesive sheet with a release sheet was cut into a size of 160 mm × 210 mm, and a separator (light release film) having a thickness of 75 μm was peeled off. Next, the adhesive surface of the exposed double-sided pressure-sensitive adhesive sheet is manually pasted to a polarizing plate (MLPH40-1 manufactured by Bikan Co., Ltd.), and the laminate of the double-sided pressure-sensitive adhesive sheet and the polarizing plate has a size of 140 mm × 190 mm. Cut to be. Thereafter, the separator (heavy release film) having a thickness of 100 μm was peeled off and bonded to alkali glass (manufactured by Standard Test Piece, float plate glass) having a size of 150 mm × 250 mm so that air did not enter. The sample prepared in this manner was autoclaved (0.5 MPa, 40 ° C., 30 minutes), irradiated with active energy rays from a glass surface with a high-pressure mercury lamp so that the integrated light amount was 3000 mJ / cm ^2, and 23 ° C. And left in an environment with a relative humidity of 50% for 24 hours. Thereafter, after treatment under any of the following conditions (1) to (3), the presence or absence of generation of bubbles, floats and peeling was observed.
Condition (1) The cycle of placing at −40 ° C. for 30 minutes and then placing at 85 ° C. for 30 minutes is repeated 100 cycles.
Condition (2) Place in an environment of 85 ° C. and relative humidity of 85% for 100 hours.
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.
<Evaluation criteria for bubbles and floats>
○: No bubble or float is generated.
Δ: Either slight bubbles of less than 0.5 mmφ or floating are generated at the edge portion.
X: There are bubbles of 0.5 mmφ or more, and floating occurs.
<Evaluation criteria for peeling>
A: There is no occurrence of peeling.
○: Slight peeling of less than 0.5 mm width occurs at the edge portion.
X: The peeling of 0.5 mm width or more occurs.

In the examples, the occurrence of bubbles, floating and peeling was suppressed. In Comparative Example 305, a double-sided PSA sheet having a thickness of 100 μm or more could not be produced, so evaluation could not be performed.

1 Double-sided adhesive sheet 10 Alkali glass A
20 Alkali glass B

Claims

A double-sided pressure-sensitive adhesive sheet having a thickness of 100 μm or more,
A double-sided pressure-sensitive adhesive sheet satisfying at least one selected from the following conditions (A) to (C);
(Condition (A))
In an environment of 80 ° C. and relative humidity of less than 10%, the shear adhesive strength measured by the following measurement method (a1) is 100 N / cm 2 or more;
Measurement method (a1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface of 15 mm from one end in the longitudinal direction of 1.1 mm × 40 mm × 150 mm alkali glass A, and 20 mm from one end in the width direction. The adhesive sheet is pasted so that the center point is; the 1.1 mm × 40 mm × 150 mm alkali glass B is overlapped with the width direction of the alkali glass A on the other adhesive surface of the double-sided adhesive sheet, and the longitudinal direction is alkali. The sample is pasted so as to overlap with glass A by 30 mm to obtain a measurement sample; the measurement sample is autoclaved under conditions of 0.5 MPa, 40 ° C. and 30 minutes so that the integrated light quantity becomes 3000 mJ / cm 2 with a high-pressure mercury lamp. Is irradiated with active energy rays and left in an environment of 23 ° C. and a relative humidity of 50% for 24 hours, and then in an environment of 80 ° C. and a relative humidity of less than 10%. 3 hours; using a tensile tester, pull the longitudinal end of each alkali glass in the opposite direction in the longitudinal direction at a speed of 25 mm / min in an environment of 80 ° C. and a relative humidity of less than 10%. Measuring stress as shear adhesion;
(Condition (B))
In an environment of 80 ° C. and a relative humidity of less than 10%, the cross adhesive strength measured by the following measurement method (a2) is 400 N / cm 2 or more;
Measurement method (a2)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity was 3000 mJ / cm 2 with a high-pressure mercury lamp, left in an environment of 23 ° C. and 50% relative humidity for 24 hours, then 80 ° C., Place in an environment of less than 10% relative humidity for 3 hours; using a tensile tester, each alkali glass at 80 ° C. and less than 10% relative humidity at a speed of 5 mm / min. Tensile in the opposite direction in the thickness direction, to measure the stress at that time as a cross adhesive strength;
(Condition (C))
In an environment of 23 ° C. and a relative humidity of 50%, the cross adhesive force measured by the following measurement method (a3) is 1000 N / cm 2 or more,
Cross adhesive strength after treatment under condition (1) of the following measurement method (b3), cross adhesive strength after treatment under condition (2) of the following measurement method (b3), and conditions of the following measurement method (b3) The cross adhesive strength after the treatment in (3) is 1000 N / cm 2 or more;
Measurement method (a3)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity is 3000 mJ / cm 2 with a high-pressure mercury lamp, and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; Using each alkali glass in an opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Measured as shaped adhesive strength;
Measurement method (b3)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions: irradiated with active energy rays from a glass surface with a high-pressure mercury lamp so that the integrated light intensity is 3000 mJ / cm 2 and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; After the treatment under any of the following conditions (1) to (3), using a tensile tester, the speed is 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Pull the alkali glass in the opposite direction in the thickness direction, to measure the stress at that time as a cross adhesive strength;
Condition (1)-100 cycles of a cycle of 30 minutes at -40 ° C and then 30 minutes at 85 ° C;
Condition (2) Place in an environment of 85 ° C. and 85% relative humidity for 100 hours;
Condition (3): Place in an environment of 105 ° C. and a relative humidity of less than 5% for 100 hours.
In an environment of 80 ° C. and a relative humidity of less than 10%, the shear adhesive force measured by the measurement method (a1) is P,
The double-sided adhesive according to claim 1, wherein the value of P / Q is 0.70 or more when the shear adhesive strength measured by the following measuring method (b1) is Q in an environment of 23 ° C and 50% relative humidity. Sheet;
Measurement method (b1)
A double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm has a double-sided adhesive surface of 15 mm from one end in the longitudinal direction of 1.1 mm × 40 mm × 150 mm alkali glass A, and 20 mm from one end in the width direction. The adhesive sheet is pasted so that the center point is; the 1.1 mm × 40 mm × 150 mm alkali glass B is overlapped with the width direction of the alkali glass A on the other adhesive surface of the double-sided adhesive sheet, and the longitudinal direction is alkali. The sample is pasted so as to overlap with glass A by 30 mm to obtain a measurement sample; the measurement sample is autoclaved under conditions of 0.5 MPa, 40 ° C. and 30 minutes so that the integrated light quantity becomes 3000 mJ / cm 2 with a high-pressure mercury lamp. Is irradiated with active energy rays and left for 24 hours in an environment of 23 ° C. and 50% relative humidity; using a tensile tester, 23 ° C. and relative humidity At 0% RH, pulling the longitudinal ends of the respective alkali glass in opposite directions in the longitudinal direction at a speed 25 mm / min, to measure the stress at that time as a shear adhesive strength.
The double-sided pressure-sensitive adhesive sheet according to claim 1, wherein the cross adhesive force measured by the following measurement method (b2) is 1200 N / cm 2 or more in an environment of 23 ° C and 50% relative humidity;
Measurement method (b2)
One adhesive surface of a double-sided pressure-sensitive adhesive sheet having a size of 1 cm × 1 cm is bonded to the central portion of alkali glass A having a thickness of 4.0 mm × width 30 mm × length 50 mm; the thickness is measured from the other pressure-sensitive adhesive side of the double-sided pressure-sensitive adhesive sheet. The alkali glass B of 4.0 mm × width 30 mm × length 50 mm is bonded so that the two alkali glasses are in a cross positional relationship to obtain a measurement sample; the measurement sample is 0.5 MPa, 40 ° C., 30 minutes. Autoclaved under the following conditions, irradiated with active energy rays so that the integrated light intensity is 3000 mJ / cm 2 with a high-pressure mercury lamp, and left in an environment of 23 ° C. and 50% relative humidity for 24 hours; Using each alkali glass in an opposite direction in the thickness direction at a speed of 5 mm / min in an environment of 23 ° C. and a relative humidity of 50%. Measured as shaped pressure-sensitive adhesive force.
In an environment of 23 ° C. and a relative humidity of 50%, the cross adhesive force measured by the measurement method (a3) is 1200 N / cm 2 or more,
The cross adhesive strength after processing under the condition (1) of the measurement method (b3) is 1200 N / cm 2 or more,
The cross adhesive strength after processing under the condition (2) of the measurement method (b3) is 1500 N / cm 2 or more,
The double-sided pressure-sensitive adhesive sheet according to claim 1, wherein the cross adhesive strength after the treatment under the condition (3) of the measurement method (b3) is 1300 N / cm 2 or more.
The double-sided pressure-sensitive adhesive sheet comprises a base polymer (A) containing a non-crosslinkable (meth) acrylic acid ester monomer unit (a1) and an acrylic monomer unit (a2) having a crosslinkable functional group;
A monomer (B) having at least one polymerizable unsaturated group;
A crosslinking agent (C) that reacts with the base polymer (A) by heat;
A polymerization initiator (D) for initiating a polymerization reaction of the monomer (B) by irradiation with active energy rays;
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 4, comprising a pressure-sensitive adhesive obtained by semi-curing the pressure-sensitive adhesive composition containing the solvent (E) by heating or irradiation with active energy rays.
The double-sided pressure-sensitive adhesive sheet according to claim 5, wherein the base polymer (A) has a molecular weight of 600,000 to 1,500,000.
The monomer (B) includes a monofunctional monomer (b1) having one polymerizable unsaturated group and a polyfunctional monomer (b2) having two or more polymerizable unsaturated groups,
The double-sided pressure-sensitive adhesive sheet according to claim 5 or 6, wherein a mass ratio of the monofunctional monomer (b1) and the polyfunctional monomer (b2) is 10: 1 to 50: 1.
The double-sided pressure-sensitive adhesive sheet according to claim 7, wherein the monofunctional monomer (b1) has an alkyl group having 10 or more carbon atoms.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 8, which is used for bonding optical members.
The double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 9, which is used for laminating an in-vehicle optical member.
A method for using a double-sided pressure-sensitive adhesive sheet in which the double-sided pressure-sensitive adhesive sheet is completely cured by bringing the double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 10 into contact with the surface of the adherend and irradiating active energy rays in that state.
Production of a laminate comprising a step of bringing the double-sided pressure-sensitive adhesive sheet according to any one of claims 1 to 10 into contact with an adherend surface and irradiating an active energy ray in that state to completely cure the double-sided pressure-sensitive adhesive sheet. Method.