JP2001107005A - Pressure-sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide pressure-sensitive adhesive sheets which can shorten the seasoning period and can cope with the required performance in permanent adhesion, removal and various other applications and have a wide application range as products. SOLUTION: A pressure-sensitive adhesive sheet is obtained by forming a thin film of a compound comprising 100 pts.wt. acrylic polymer (A) obtained by polymerization of a monomer whose major component is a 1-18C alkyl (meth) acrylate and at least 1-100 pts.wt. acrylic polymer (B) having a radiation polymerizable group in the side chain on a substrate or a release sheet and subjecting the film to radiation crosslinking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure-sensitive adhesive sheet and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a pressure-sensitive adhesive sheet is prepared by applying a mixed solution containing, for example, a crosslinking agent and an acrylic polymer having an active group to the crosslinking agent onto a substrate, and then heating the mixture to form a crosslinked material. It is produced by reacting an agent with an acrylic polymer to crosslink the acrylic polymer.

As such a pressure-sensitive adhesive sheet, there is a sheet using a heat crosslinking agent as a crosslinking agent, but has a disadvantage that a seasoning period is too long. On the other hand, a pressure-sensitive adhesive sheet which is cross-linked by using a polyfunctional radiation-curable monomer (photocrosslinkable compound) as a crosslinking agent (for example, Japanese Patent No. 2592875, Claim 5,
Example 3) can shorten the seasoning period, but has the disadvantage that it is difficult to obtain a high adhesive force and a high tack when trying to obtain a high cohesive force. A pressure-sensitive adhesive sheet obtained by radiation-crosslinking an acrylic polymer having a radiation-polymerizable group in the side chain is also known (JP-A-49-5145). The type of monomer used in the main chain of the acrylic polymer is limited depending on the reaction conditions and the like at the time of introducing the acryl polymer, and there is a disadvantage that it is difficult to obtain desired adhesive properties. Furthermore, there is also a technique of directly performing radiation crosslinking from a composition of a radiation-curable monomer without using an acrylic polymer, but unreacted monomers remain, and the performance of the obtained pressure-sensitive adhesive sheet, The durability may be adversely affected, and the types of monomers that can be used as the pressure-sensitive adhesive are limited, so that the applicable range of the product is also limited.

Further, a pressure-sensitive adhesive sheet formed by laminating optical components such as a polarizing plate is required to have various durability such as heat resistance, moisture resistance and white spot resistance. With a pressure-sensitive adhesive sheet to be shortened, it is extremely difficult to satisfy all of these.

[0005]

DISCLOSURE OF THE INVENTION The present invention can reduce the seasoning period, and can respond to the required performance in various applications such as permanent bonding, re-peeling, and other applications, and has a wide range of application as a pressure-sensitive adhesive. It is intended to provide an agent sheet.

[0006]

The present invention includes the following inventions. (1) Acrylic polymer (A) 100 weight parts obtained by polymerizing a monomer having a C1-C18 alkyl group-containing (meth) acrylic acid alkyl ester as a main component on a support or a release sheet. Acrylic polymer (B) having at least a radiation polymerizable group in a side chain with respect to the
A pressure-sensitive adhesive sheet formed by forming a thin film composed of a blend containing parts by weight and crosslinking by radiation.

(2) The pressure-sensitive adhesive sheet according to (1), wherein the support is a sheet-shaped optical component. (3) With respect to 100 parts by weight of an acrylic polymer (A) obtained by polymerizing a monomer mainly containing an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms, at least A pressure-sensitive adhesive sheet comprising 1 to 100 parts by weight of an acrylic polymer (B) having a radiation-polymerizable group in a chain, forming a thin film on a support or a release sheet, and then performing radiation crosslinking. Manufacturing method.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, (meth) is used as a main component of a raw material monomer of an acrylic polymer (A).
As the alkyl acrylate, various alkyl acrylates or alkyl methacrylates in which the alkyl group constituting the ester group is an alkyl group having 1 to 18 carbon atoms can be used. Specifically, methyl acrylate, acrylic acid Ethyl, propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-acrylate
Examples include ethylhexyl, isooctyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, and isooctyl methacrylate.

In the present invention, the acrylic polymer (A)
May be used singly or in combination of two or more of the above (meth) acrylic acid alkyl esters, or may be used in combination with other copolymerizable monomers. Other copolymerizable monomers include vinyl acetate,
Various monomers known as monomers for modifying acrylic pressure-sensitive adhesives such as styrene, acrylonitrile, acrylamide, acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, glycidyl methacrylate, and 4-hydroxybutyl acrylate. Any of the monomers can be used. The content of these other monomers is preferably not more than 50% by weight based on the total amount of the (meth) acrylic acid alkyl esters in terms of adhesive properties.

In the present invention, the acrylic polymer (A) used as a main component of the pressure-sensitive adhesive is a homopolymer or a copolymer of an acrylic monomer mainly containing the alkyl (meth) acrylate. The weight-average molecular weight, which is formed by coalescence and measured by gel permeation chromatography (hereinafter, referred to as "GPC method"), is usually 200,000 to 2.5 million, preferably 500,000 to 1.5 million. Further, the glass transition temperature of the acrylic polymer (A) is usually −20 ° C. or less, preferably about −30 to −60 ° C.

The acrylic polymer having the above-mentioned molecular weight can be obtained by, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, or the like, using the above-mentioned monomer by using a polymerization catalyst such as an azo compound or a peroxide. Can be easily obtained by the various polymerization methods described above. The acrylic polymer (B) having a radiation polymerizable group in the side chain used in the present invention has an acrylic polymer (b1) having a functional group-containing monomer unit and a substituent reactive with the functional group. It is obtained by reacting with a radiation polymerizable group-containing compound (b2).

The functional group-containing monomer is a monomer having a polymerizable double bond and a functional group such as a hydroxyl group, a carboxyl group, an amino group, a substituted amino group, an isocyanate group or an epoxy group in the molecule. Preferably, a hydroxyl group-containing unsaturated compound and a carboxyl group-containing unsaturated compound are used.

More specific examples of such functional group-containing monomers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate,
Examples include hydroxyl group-containing acrylates such as 4-hydroxybutyl acrylate, and carboxyl group-containing compounds such as acrylic acid, methacrylic acid, and itaconic acid.

The above-mentioned functional group-containing monomers may be used alone.
Alternatively, two or more kinds may be used in combination. The acrylic polymer (b1) includes a structural unit derived from the functional group-containing monomer and a structural unit derived from the alkyl (meth) acrylate monomer or a derivative thereof.
(Meth) acrylic acid alkyl ester monomers include:
Alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms, cycloalkyl (meth) acrylate, and benzyl (meth) acrylate are used. Among these, an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms, which is the same as the raw material monomer of the acrylic polymer (A), is more preferably used.

The acrylic polymer (b1) contains a structural unit derived from the functional group-containing monomer in an amount of usually 3 to 50% by weight, preferably 5 to 30% by weight, and (meth) acrylic acid Usually, 50 to 97% by weight, preferably 70% by weight of a structural unit derived from an ester monomer or a derivative thereof.
９５95% by weight.

The acrylic polymer (b1) can be obtained by copolymerizing the above-mentioned functional group-containing monomer with an alkyl (meth) acrylate monomer or a derivative thereof in a conventional manner. However, in addition to these monomers, vinyl formate, vinyl acetate, styrene and the like may be copolymerized in a small amount (for example, 10% by weight or less, preferably 5% by weight or less). The acrylic polymer (b1) having the functional group-containing monomer unit is reacted with the radiation-polymerizable group-containing compound (b2) having a substituent that reacts with the functional group to form a radiation-polymerizable group on the side chain. Is obtained.

The radiation polymerizable group-containing compound (b2) includes
It contains a substituent capable of reacting with a functional group in the acrylic polymer (b1). This substituent varies depending on the type of the functional group. For example, when the functional group is a hydroxyl group or a carboxyl group, the substituent is preferably an isocyanate group, an epoxy group, a chlorosilane group, or the like. When the functional group is an amino group or a substituted amino group, the substituent is an isocyanate group or the like. When the functional group is an epoxy group, the substituent is preferably a carboxyl group. One such substituent is contained in each molecule of the radiation polymerizable group-containing compound (b2).

Further, the radiation-polymerizable group-containing compound (b2)
Contains 1 to 5, preferably 1 to 2, radiation polymerizable groups, for example, a radiation polymerizable carbon-carbon double bond per molecule. Specific examples of the radiation polymerizable group-containing compound (b2) having a carbon-carbon double bond include, for example, methacryloyloxyethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, Methacryloyl isocyanate, allyl isocyanate; diisocyanate compound or polyisocyanate compound and (meth) acrylic acid 2
Acryloyl monoisocyanate compound obtained by reaction with -hydroxyethyl; acryloyl monoisocyanate compound obtained by reaction of diisocyanate compound or polyisocyanate compound, polyol compound and 2-hydroxyethyl (meth) acrylate Glycidyl (meth) acrylate; (meth) acrylic acid; 3-methacryloxypropyldimethylchlorosilane;

The radiation-polymerizable group-containing compound (b2) is a functional group-containing monomer of the acrylic polymer (b1).
20 to 100 equivalents, preferably 40 to 100 equivalents per equivalent
Used in a proportion of 95 equivalents. Acrylic polymer (b
The reaction between 1) and the radiation-polymerizable group-containing compound (b2) is as follows:
Usually, at a temperature of about room temperature to about 40 ° C. under normal pressure, 4-48
It takes about an hour. This reaction is preferably performed in a solution such as ethyl acetate using a catalyst such as an organotin compound (eg, dibutyltin laurate) or a substituted amine compound.

As a result, the functional group present on the side chain in the acrylic polymer (b1) reacts with the substituent in the radiation polymerizable group-containing compound (b2), and the radiation polymerizable group (for example, carbon -Carbon double bond) is an acrylic polymer (b1)
An acrylic polymer (B) which is introduced into a side chain therein and has a radiation polymerizable group in the side chain is obtained. The reaction rate between the functional group and the substituent in this reaction is usually at least 70%, preferably at least 80%, and the unreacted functional group in the acrylic polymer (B) having a radiation polymerizable group in the side chain. May remain.

The weight average molecular weight of the acrylic polymer (B) having a radiation polymerizable group in the side chain measured by GPC is usually 1,000 to 1,000,000, preferably 50,000 to 500,000. Further, the glass transition temperature of the acrylic polymer (B) is usually 20 ° C. or lower, preferably about −65 to 10 ° C. Such an acrylic polymer (B) having a radiation-polymerizable group in the side chain contains a radiation-polymerizable group, and thus is cross-linked by irradiation with radiation.

The composition used in the production of the pressure-sensitive adhesive sheet of the present invention is based on 100 parts by weight of an acrylic polymer (A) composed of a monomer having the above-mentioned alkyl (meth) acrylate as a main component. On the other hand, at least the acrylic polymer (B) having a radiation polymerizable group in the side chain is 1 to 10
0 parts by weight, preferably 5 to 50 parts by weight. If the blending ratio of the acrylic polymer (B) is less than 1 part by weight, the resulting pressure-sensitive adhesive will not be able to obtain sufficient cross-linking, and it will be difficult to obtain high durability, while if it exceeds 100 parts by weight. In addition, the adhesive strength and tack may be insufficient, and the performance of the acrylic polymer (A) as the main agent may be difficult to obtain.

The pressure-sensitive adhesive sheet of the present invention is obtained by forming a thin film (pressure-sensitive adhesive layer) composed of the above-mentioned composition on a support or a release sheet, irradiating the thin film with radiation and crosslinking. be able to. As the radiation, specifically, an ultraviolet ray, an electron beam, or the like is used. The irradiation amount varies depending on the type of radiation. For example, when ultraviolet rays are used, the irradiation amount is preferably about 40 to 400 W / cm,
When an electron beam is used, about 10 to 1000 krad is preferable. When ultraviolet rays are used as the radiation, it is preferable to incorporate a photopolymerization initiator (C) into the composition.

As such a photopolymerization initiator (C),
Specifically, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, 2,4
-Diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide,
Tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β
-Chloroanthraquinone and the like. The blending amount of the photopolymerization initiator (C) is 100% of the acrylic polymer (B).
It is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight with respect to parts by weight.

Further, a radiation-polymerizable compound (D) having a low molecular weight can be added to the above composition in order to control the curing properties against radiation. The molecular weight of the compound (D) is usually 10,000 or less, preferably 100 to 80.
It is about 00, more preferably about 100 to 3000.

Specific examples of the radiation polymerizable compound (D) include monofunctional acrylate monomers, polyfunctional acrylate monomers, urethane acrylate oligomers, polyester acrylate oligomers, and epoxy acrylate oligomers.

The amount of the radiation polymerizable compound (D) is usually 30 parts by weight or less, preferably 10 parts by weight or less, based on 100 parts by weight of the acrylic polymer (A). If the compounding amount of the compound (D) is too large, sufficient adhesive strength and tack cannot be obtained. Further, in the above composition, in order to improve the adhesion and the like with the material to be laminated, a heat crosslinking agent such as an organic polyvalent isocyanate compound, an organic polyvalent epoxy compound, a metal chelate compound, and an organic polyvalent imine compound. Can also be added. In this case, there is some variation in the adhesive properties after radiation crosslinking, but the duration of the variation is substantially shorter than with these heated crosslinking agents alone.

The organic polyvalent isocyanate compound includes aromatic polyvalent isocyanate compounds, aliphatic polyvalent isocyanate compounds, alicyclic polyvalent isocyanate compounds, and trimers of these polyvalent isocyanate compounds. And a terminal isocyanate urethane prepolymer obtained by reacting these polyvalent isocyanate compounds with a polyol compound. More specific examples of the organic polyvalent isocyanate compound include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate And a reaction product of these organic polyisocyanate compounds with a polyhydric alcohol (for example, trimethylolpropane tris (4-methyl-3-isocyanatophenylcarbamate)).

Specific examples of the above-mentioned organic polyepoxy compound include bisphenol A type epoxy compound, bisphenol F type epoxy compound, 1,3-bis (N, N-diglycidylaminomethyl) benzene, 1,3-bis ( (N, N-diglycidylaminomethyl) toluene, N, N, N ', N'-tetraglycidyl
-4,4'-diaminodiphenylmethane and the like. Specific examples of the metal chelate compound include a coordination compound of a polyvalent metal such as aluminum trisethylacetoacetate, aluminum ethylacetoacetate diisopropylate, and trisacetylacetonatoaluminum.

Specific examples of the organic polyvalent imine compound include N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxamide), trimethylolpropane-tri-
β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, N, N'-
Toluene-2,4-bis (1-aziridinecarboxamide)
Triethylene melamine and the like can be mentioned.

The amount of the heat crosslinking agent is usually 5 parts by weight or less based on 100 parts by weight of the acrylic polymer (A).
It is preferably at most 1 part by weight. If the amount of the heating crosslinking agent is too large, the physical properties after radiation crosslinking greatly fluctuate,
It becomes difficult to shorten the seasoning period. The thickness of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive sheet of the present invention is usually about 1 to 100 μm, preferably about 5 to 50 μm, and more preferably about 10 to 30 μm.

In the pressure-sensitive adhesive sheet of the present invention, a support may be provided on one side of the pressure-sensitive adhesive layer. The support used herein is not particularly limited, and may be, for example, a sheet-like plastic material used for various optical components such as polyvinyl alcohol, triacetyl cellulose, polymethyl methacrylate, polycarbonate, polysulfone-based resin, and polynorbornene-based resin. Resin films such as polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, ethylene-vinyl acetate copolymer, polyurethane, polystyrene, polyimide, etc., paper such as high-quality paper, coated paper, laminated paper, metal foil, woven fabric, non-woven fabric, Alternatively, these laminates are used. The thickness of such a support is usually 6 to 300 μm, preferably 12 to 200 μm
It is.

A release sheet is laminated on the surface of the pressure-sensitive adhesive sheet opposite to the side on which the support is provided to protect the pressure-sensitive adhesive. As the release sheet, for example, a sheet material selected from the above-mentioned support and subjected to a release treatment such as a silicone resin is used. Further, the pressure-sensitive adhesive sheet of the present invention may be in a form not using the above-mentioned support. In this case, the pressure-sensitive adhesive sheet is used in a shape in which both surfaces are protected by release sheets.

In the production of the pressure-sensitive adhesive sheet of the present invention, the above-mentioned composition of the pressure-sensitive adhesive is mixed and agitated, and then a known coater such as a knife coater, a roll knife coater, a reverse roll coater, a gravure coater or a die coater is used. Is applied to a desired thickness on the above-described support or release sheet. When the composition is a solution, a suspension, or the like, volatile components such as a solvent are removed by drying to form a pressure-sensitive adhesive layer. Next, radiation is directly applied from the support (release sheet) side or from the pressure-sensitive adhesive layer side to crosslink the pressure-sensitive adhesive layer, and the release sheet or the support is placed on the exposed pressure-sensitive adhesive layer side. The laminate is laminated to produce the pressure-sensitive adhesive sheet of the present invention.

Irradiation is performed on both sides of the pressure-sensitive adhesive layer,
It may be performed after laminating a support or a release sheet. In this case, without performing the coating step and the radiation irradiation step continuously, for example, it is possible to perform the radiation irradiation immediately before the pressure-sensitive adhesive sheet is attached to the adherend. When the radiation is applied through a support or a release sheet, the support or the release sheet needs to be transparent to the radiation to be used.

The adhesive strength (after radiation crosslinking) of the pressure-sensitive adhesive sheet of the present invention is 100 g, similar to a general-purpose pressure-sensitive adhesive sheet.
/ 25 mm or more, preferably 300 to 3000 g / 25
mm or more. As long as the adhesive force falls within such a range, it can be applied as various general-purpose pressure-sensitive adhesive sheets such as a permanent adhesive type and a removable type. In addition, the pressure-sensitive adhesive sheet of the present invention is a polarizing plate, a retardation plate, an analyzer, and an analyzer that require more severe performance than general-purpose pressure-sensitive adhesive sheets, such as heat resistance, moisture resistance, and white spot resistance. It can also be suitably used for optical components such as photons.

[0037]

The present invention will be described in more detail with reference to Examples and Comparative Examples, which do not limit the scope of the present invention. The various physical properties and the test methods in the examples and comparative examples are as follows.

(Aging) The adhesive strength after one day was measured on a glass plate with a width of 25 mm one day after the preparation of the pressure-sensitive adhesive sheets of Examples 1 to 6 and Comparative Examples 1 to 4 to be described later (one day after irradiation). It was affixed and measured by the 180-degree peeling method (JIS Z0237) (g / 25 mm). After 14 days, the adhesive strength was determined by applying a pressure-sensitive adhesive sheet 14 days after the preparation of the pressure-sensitive adhesive sheet (14 days after the irradiation) to a glass plate with a width of 25 mm and peeling it off at 180 degrees (JIS Z02).
37) (g / 25 mm).

The evaluation of the shortening of aging was based on the adhesive strength after one day.
After 14 days, evaluation was made based on the ratio of change in adhesive strength with adhesive strength. ：: 0% to less than 15%, ×: 15% or more (Ball tack test) The ball tack was measured in Example 1 described later.
7 days after the preparation of the pressure-sensitive adhesive sheets of Comparative Examples 1 to 6 and Comparative Examples 1 to 4, measurement was made by the J. Dow method.

(Holding force) The holding force was determined in Examples 1 to 6 described later.
7 days after the preparation of the pressure-sensitive adhesive sheets of Comparative Examples 1 to 4, 25
It was affixed to a stainless steel plate with a size of 25 mm, and a time of 2 kg was applied at 40 ° C. until the sample was peeled off. When held for 70,000 seconds, the deviation width was measured.

(White spots) White spots are observed in Examples 7 to 1 to be described later.
The pressure-sensitive adhesive sheets of Comparative Examples 2 and 5 to 8 were affixed to both sides of the glass so as to form a cross Nicol, and allowed to stand for 100 hours under a dry condition of 90 ° C. for 100 hours. ○: no light transmission, ×: light leakage

(Durability test) The durability was measured in Example 7 described later.
The pressure-sensitive adhesive sheets of Nos. To 12 and Comparative Examples 5 to 8 were adhered to glass, and the appearance change after standing at 60 ° C. and 90% Rh for 100 hours was visually evaluated. ◎: no change, ：: fine foam or crack at end,
×: There is peeling off (Examples 1 to 12 and Comparative Examples 1 to 8)

(1) Production of Acrylic Polymer A To a composition comprising each monomer described below, 0.33 parts by weight of azobisisobutyronitrile as a polymerization initiator and 250 parts by weight of ethyl acetate as a solvent were added. , While replacing with nitrogen 6
After reacting at 0 ° C. for 7 hours, the mixture was refluxed for 5 hours to carry out polymerization. The obtained polymer solution was adjusted to have a solid content of 25% by weight.

(A1) A weight average molecular weight of 100 parts by weight of 96 parts by weight of n-butyl acrylate and 4 parts by weight of acrylic acid
25% ethyl acetate solution of 10,000 copolymers (glass transition temperature: -48 ° C). (A2) A 25% ethyl acetate solution of a copolymer (glass transition temperature: -54 ° C) having a weight average molecular weight of 1.3 million and consisting of 99 parts by weight of n-butyl acrylate and 1 part by weight of 2-hydroxyethyl acrylate. (A3) A 25% ethyl acetate solution of a copolymer having a weight average molecular weight of 200,000 (glass transition temperature: -45 ° C) consisting of 90 parts by weight of n-butyl acrylate and 10 parts by weight of acrylic acid.

(2) Production of Acrylic Polymer B Having Radiation-Polymerizable Group in Side Chain The acrylic polymer solution mentioned in each (b1) was produced by the same operation as the above-mentioned acrylic polymer A. To 100 parts by weight of the obtained 25% by weight polymer solution, the compound described in (b2) and 0.3 parts by weight of dibutyltin laurate as a catalyst were added, and the mixture was reacted at room temperature and pressure for 24 hours.

(B1) Weight average molecular weight 200,000, glass transition temperature: -45 ° C. (b1) 25% ethyl acetate solution of the acrylic copolymer A3 (b2) 4.5 parts by weight of glycidyl methacrylate ((b
91 equivalents per 100 equivalents of carboxyl groups of 1))

(B2) Weight average molecular weight 300,000, glass transition temperature: -49 ° C. (b1) Weight of 300,000 weight average molecular weight consisting of 80 parts by weight of n-butyl acrylate and 20 parts by weight of 2-hydroxyethyl acrylate (B2) Methacryloyloxyethyl isocyanate 6
Parts by weight (90 equivalents per 100 equivalents of hydroxyl groups in (b1))

(B3) Weight average molecular weight 300,000, glass transition temperature: -39 ° C. (b1) Weight consisting of 70 parts by weight of n-butyl acrylate, 20 parts by weight of 2-hydroxyethyl acrylate and 10 parts by weight of methyl methacrylate 25% ethyl acetate solution of a copolymer having an average molecular weight of 300,000 (b2) methacryloyloxyethyl isocyanate 6
Parts by weight (90 equivalents per 100 equivalents of hydroxyl groups in (b1))

(B4) Weight average molecular weight 300,000, glass transition temperature: -39 ° C. (b1) Weight consisting of 70 parts by weight of n-butyl acrylate, 20 parts by weight of 2-hydroxyethyl acrylate and 10 parts by weight of methyl methacrylate 25% ethyl acetate solution of a copolymer having an average molecular weight of 300,000 (b2) 8.5 parts by weight of 3-methacryloxypropyldimethylchlorosilane (89 equivalents per 100 equivalents of hydroxyl groups of (b1))

(3) Production of Pressure-Sensitive Adhesive Sheet A solution of the pressure-sensitive adhesive composition having a solid weight ratio shown in Table 1 was applied to a polyethylene terephthalate film (thickness: 5).
0 μm), so that the coating amount after drying is 25 g / m ^2, and after drying at 90 ° C. for 1 minute, a UV-transparent release sheet (manufactured by Lintec, trade name: SP-PET381)
Example 1 having a polyethylene terephthalate film on the support, except that the substrate was laminated with 1) and, except for Comparative Examples 1 and 2, was irradiated with ultraviolet rays from the side of the release sheet (120 W 2 high-pressure mercury lamp, irradiation distance 10 cm, line speed 5 m / min). 1 to
6 and Comparative Examples 1-4 were obtained.

Separately, the solution of the same pressure-sensitive adhesive composition as in Examples 1 to 6 and Comparative Examples 1 to 4 was applied to a release sheet (manufactured by Lintec Co., Ltd., trade name: SP-PET3811) at a coating amount of 25 g / m 2 after drying. ² and dried at 90 ° C. for 1 minute, and then bonded to a polarizing plate (trade name: SR-1862A, manufactured by Sumitomo Chemical Co., Ltd.) composed of three layers of triacetyl cellulose / polyvinyl alcohol / triacetyl cellulose.
Except for Comparative Examples 5 and 6, ultraviolet rays were irradiated from the release sheet side to obtain pressure-sensitive adhesive sheets of Examples 7 to 12 and Comparative Examples 5 to 8 having a polarizing plate on the support. Various physical properties of the obtained pressure-sensitive adhesive sheet were evaluated. The results are shown in Tables 2 and 3.

[0052]

[Table 1]

As the photopolymerization initiator, 1-hydroxycyclohexyl phenyl ketone was used. As the organic polyvalent isocyanate compound, trimethylolpropane / tris (4-methyl-3-isocyanatophenylcarbamate) (trade name: Coronate L, manufactured by Nippon Polyurethane Co., Ltd.) was used. As the radiation polymerizable compound,
Trimethylolpropane triacrylate was used.

[0054]

[Table 2]

Cf (cohesive failure): cohesive failure, NC (non
creep): No gap

[0056]

[Table 3]

[0057]

The pressure-sensitive adhesive sheet of the present invention requires only a short seasoning period and can meet the required performances for permanent bonding, re-peeling and other various uses, and the production method of the present invention. Pressure-sensitive adhesive sheet has a wide range of application as a product.

Continued on the front page (72) Inventor Toshio Sugizaki 5-14-42 Nishikicho, Warabi-shi, Saitama F-term (reference) in Lintec Co., Ltd. 4F070 AA32 AB17 GA04 GC09 HA04 HA05 HB11 4J004 AA10 AB01 BA02 CA02 CA03 CA04 CA05 CA06 CA08 CB02 CC02 CC03 DA04 DB02 DB03 FA10 GA01 4J040 DF041 DF042 DF051 GA05 GA07 GA11 GA14 GA15 GA20 GA31 JA09 JB07 JB09 LA06 NA17 QA01

Claims (3)

[Claims] Claims: 1. A support or a release sheet having 1 to 1 carbon atoms.
A radiation polymerizable group in at least a side chain is based on 100 parts by weight of an acrylic polymer (A) obtained by polymerizing a monomer having a (meth) acrylic acid alkyl ester having 18 alkyl groups as a main component. Acrylic polymer (B) 1 having
A pressure-sensitive adhesive sheet formed by forming a thin film made of a composition containing 100 to 100 parts by weight and then crosslinking the radiation. 2. The pressure-sensitive adhesive sheet according to claim 1, wherein the support is a sheet-shaped optical component. 3. At least 100 parts by weight of an acrylic polymer (A) obtained by polymerizing a monomer containing an alkyl (meth) acrylate having an alkyl group having 1 to 18 carbon atoms as a main component is used. And 1 to 100 parts by weight of an acrylic polymer (B) having a radiation polymerizable group in a side chain,
A method for producing a pressure-sensitive adhesive sheet, comprising forming a thin film on a support or a release sheet, followed by radiation crosslinking.