TW201718805A - Adhesive, adhesive sheet using the same, polarizing plate adhesive sheet and liquid crystal cell member wherein the adhesive has excellent peeling property, and is difficult to produce blister or peeling from the adherend when exposure to a high temperature environment or a high temperature and high humidity environment - Google Patents

Abstract

The present invention provides an adhesive and an adhesive sheet using the same. The said adhesive has excellent peeling property, and is difficult to produce blister or peeling from the adhered matter when exposure to a high temperature environment or a high temperature and high humidity environment. The adhesive of the present invention comprises an acrylic copolymer (A), a crosslinking agent (B), a silane coupling agent (C), and a compound (D) having an epoxy group or an epoxycyclohexyl group, wherein the copolymer (A) is a copolymer containing at least a monomer unit (a-1) having a carboxyl group and a monomer unit (a-2) having a hydroxyl group, and the compound (D) is a compound represented by the following formula [I] or formula [II]. (In these formulas, p, q, and r are integers, 1 ≤ p ≤ 30, 5 ≤ q ≤ 50, 5 ≤ r ≤ 50, 10 ≤ q+r ≤ 100, X1~X4 are alkyl groups, X5 is a divalent organic residue with carbon number of 1~10, Y represents an epoxy group or an epoxycyclohexyl group).

Description

Adhesive and adhesive sheet using the same

The present invention relates to an adhesive, an adhesive sheet, a polarizing plate adhesive sheet, and a liquid crystal cell member. More specifically, it relates to an adhesive, an adhesive sheet, a polarizing plate adhesive sheet, and a liquid crystal cell member which can be suitably used for members such as plastic or glass.

Display devices such as liquid crystal displays used in various devices such as electronic computers, electronic timepieces, mobile phones, and televisions, etc., have been increasing in size, and in particular, large-scale LCD TVs and plasma TVs have become large. In addition, in recent years, a touch panel type liquid crystal display represented by a smart phone or a tablet computer has been rapidly popularized, and a large market is expected to expand in the future. On the other hand, the liquid crystal display is also used for an in-vehicle device such as a car navigation system, and requires durability that can be used in a harsh interior environment such as a high temperature and high humidity environment. Further, in the liquid crystal display, a polarizing plate or a phase difference plate having various optical functions is used, and these members are attached to an adherend such as a liquid crystal cell using glass or a transparent plastic via an adhesive.

The polarizing plate is usually a laminate in which a polyvinyl alcohol film is sandwiched between a triethylenesulfonated cellulose film or a cycloolefin film. Further, since these films have different mechanical properties, the dimensional change rates during heating are different. Therefore, when placed in a high-temperature environment, warpage often occurs in the laminated body.

Here, for example, when a member for a liquid crystal cell in which a polarizing plate/adhesive layer/glass (a surface member of a liquid crystal cell is used as a liquid crystal cell) is placed in a high-temperature environment, there is a case in which a problem arises between the constituent members of the polarizing plate. The warpage caused by the dimensional change rate, or the occurrence of bubbles (foaming) in the adhesion interface between the adhesive layer and the glass, or the polarizing plate floating off from the glass to peel off. In addition, the stress distribution of the member for liquid crystal cells becomes uneven due to the warpage, and the stress is concentrated toward the peripheral end portion of the member for liquid crystal cells. As a result, there are cases in which the four corners or the peripheral end of the member for the liquid crystal cell are present. The so-called "light leakage phenomenon" in which light leaks out. The problem is also produced in a high temperature and high humidity environment.

On the other hand, in the manufacturing process of a liquid crystal display or the like, when the polarizing plate is bonded to an optical component such as a liquid crystal cell, when the bonding position is shifted, the polarizing plate is peeled off after a certain period of time after bonding. Reuse expensive liquid crystal cells. Therefore, the following characteristics (reworkability) are required for the adhesive: after a certain period of time after attachment, the polarizing plate can be peeled off from the liquid crystal cell.

In order to solve these problems, Patent Document 1 discloses a technique of improving stress relaxation and preventing light leakage by including an acrylic copolymer using a monomer containing an aromatic ring. However, the adhesive using the aromatic ring-containing monomer exemplified in Patent Document 1 has a problem that white spots are generated and optical characteristics are deteriorated in light leakage evaluation.

Further, Patent Document 2 discloses a technique in which a high molecular weight acrylic polymer having a weight average molecular weight of 500,000 or more is blended with a high acid value and a weight average molecular weight of 0.20 to 100,000 in order to impart removability. A molecular weight acrylic polymer. However, the adhesive described in Patent Document 2 has a problem that the drying conditions of the adhesive are limited.

On the other hand, Patent Document 3 discloses a technique of improving durability or adhesion characteristics under heating or humidification conditions by using a block polymer using two or more kinds of monomers. However, the adhesive described in Patent Document 3 has a problem that the transmittance under heating or humidification conditions is lowered.

Further, Patent Document 4 discloses a technique in which an acrylic copolymer containing a glass transition temperature of -55 ° C or more and less than 0 ° C and an acrylic copolymer having a glass transition temperature of 0 ° C or more and 180 ° C or less are dispersed. The type of adhesive is difficult to generate depolarization, and imparts reworkability and recycling. However, the adhesive described in Patent Document 4 has a problem in that reworkability after attachment for a long period of time is insufficient due to various additives used in the adhesive.

Further, Patent Document 5 discloses a technique of constructing an interpenetrating network structure in a hardened state by using an acrylic copolymer containing a hydroxyl group or an epoxy group and a polyfunctional isocyanate curing agent to suppress high temperature and high temperature. Float and peel in a wet environment. However, the adhesive described in Patent Document 5 has a problem that when it is placed in a high-temperature and high-humidity environment over a long period of time, decomposition of an alkylene oxide group occurs, and floating and peeling occur.

Further, Patent Document 6 discloses a technique of suppressing the floating and peeling of the adhesive sheet when the acrylic copolymer containing a hydroxyl group and a carboxyl group and the decane compound containing a mercapto group and an alcohol are used in a high-temperature and high-humidity environment for a long period of time. . However, the adhesive described in Patent Document 6 has a problem in that when a highly volatile decane compound is used, when the adhesive is applied and dried, the decane compound volatilizes, and a sufficient amount remains in the adhesive layer after application. The decane compound thus produces floating flaking. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. 2010-100. Japanese Patent Laid-Open Publication No. JP-A-2004-059277

[Problems to be Solved by the Invention] The problem to be solved by the present invention is to solve the above problems, and an object thereof is to provide an adhesive and an adhesive sheet using the same, which is excellent in peelability when used for an adhesive sheet After exposure to a high temperature environment or a high temperature and high humidity environment, it is difficult to generate floating or peeling from the adherend. Further, it is an object of the invention to provide an adhesive which has good adhesion and does not contaminate adherends such as glass, and an adhesive sheet using the same, and when the adhesive is used for polarizing plate fixing, the light leakage evaluation is extremely small even after exposure. In the case of high temperature and high humidity, high transparency can also be maintained. [Means for solving the problem]

The present invention is an adhesive comprising an acrylic copolymer (A), a crosslinking agent (B), a decane coupling agent (C), and a compound having at least one epoxy group or epoxycyclohexyl group in the molecule ( The adhesive is characterized in that the acrylic copolymer (A) is a unit containing at least a carboxyl group-containing monomer (a-1) unit and a hydroxyl group-containing monomer (a-2). a copolymer constituting a monomer unit of a copolymer, the crosslinking agent (B) containing an isocyanate compound, and the compound (D) having at least one epoxy group or epoxycyclohexyl group in the molecule is represented by the following formula a compound represented by [I] or formula [II], [Chemical Formula 1] (wherein, p, q, r are integers representing repeating units, 1≦p≦30, 5≦q≦50, 5≦r≦50, 10≦q+r≦100; X ₁ to X ₄ are independently It represents an alkyl group, X ₅ represents a divalent organic residue having 1 to 10 carbon atoms, and Y represents an epoxy group or an epoxycyclohexyl group).

Further, an embodiment of the present invention relates to the above-mentioned adhesive, wherein the epoxy resin contains at least one epoxy group or epoxy group in an amount of 0.05 part by weight to 2 parts by weight based on 100 parts by weight of the acrylic copolymer (A). The cyclohexyl compound (D) is formed.

Further, an embodiment of the present invention relates to the above-mentioned adhesive, wherein the crosslinking agent (B) is an isocyanate compound.

Further, an embodiment of the present invention relates to the adhesive, wherein the decane coupling agent (C) is a decane coupling agent having an ethoxy group.

Further, the embodiment of the present invention relates to the pressure-sensitive adhesive, which comprises 0.5 parts by weight to 20 parts by weight of the crosslinking agent (B) based on 100 parts by weight of the acrylic copolymer (A).

Further, an embodiment of the present invention relates to an adhesive sheet comprising a substrate and an adhesive layer containing the adhesive.

Further, an embodiment of the present invention relates to a polarizing plate adhesive sheet comprising a polarizing plate and an adhesive layer containing the adhesive.

Further, an embodiment of the present invention relates to a liquid crystal cell member comprising a glass plate, an adhesive layer containing the adhesive, and an optical member. [Effects of the Invention]

According to the present invention, it is possible to provide excellent removability, and it is difficult to cause floating or peeling from the adherend after exposure to a high temperature environment or a high temperature and high humidity environment, for example, on glass or plastic, and it is difficult to cause light leakage. Adhesive for the adhesive sheet.

Hereinafter, the present invention will be described in detail. In addition, in this specification, a (meth)acrylate is a generic term of an acrylate and a methacrylate. In addition, the epoxycyclohexyl group means a group represented by the following formula [III]. [Chemical 2]

The adhesive of the present invention is characterized by comprising: an acrylic copolymer (A), a crosslinking agent (B), a decane coupling agent (C), and a compound having at least one epoxy group or epoxycyclohexyl group in the molecule. (D) (The following may be described only as the compound (D)). <Acrylic copolymer (A)>

The acrylic copolymer (A) in the present specification is a copolymer containing at least a carboxyl group-containing monomer (a-1) unit and a hydroxyl group-containing monomer (a-2) unit as a monomer unit constituting the copolymer. It can be obtained by copolymerizing a monomer mixture containing at least a carboxyl group-containing monomer (a-1) and a hydroxyl group-containing monomer (a-2).

The carboxyl group-containing monomer (a-1) means a monomer having a carboxyl group (hereinafter, abbreviated as a monomer (a-1)). The monomer (a-1) forms a polymer network not only by a crosslinking reaction with a crosslinking agent but also forms a hydrogen bond with the surface of the adherend, thereby contributing to suppression of floating and peeling and suppressing light leakage. The monomer (a-1) is preferably a carboxyl group-containing monomer having no hydroxyl group.

Specific examples of the monomer (a-1) include (meth)acrylic acid, p-carboxybenzyl acrylate, β-carboxyethyl acrylate, maleic acid, monoethyl maleic acid, itaconic acid. , citraconic acid, fumaric acid, etc. These monomers may be used singly or in combination of two or more.

The monomer (a-1) is preferably contained in the acrylic copolymer as 0.1 to 20% by weight, and more preferably 0.5 to 10% by weight, based on the monomer unit constituting the copolymer. When the content is 0.1% by weight or more, the cohesive force is further improved. In addition, when the content is 20% by weight or less, it is easy to have both cohesive force and stress relaxation property.

The hydroxyl group-containing monomer (a-2) means a monomer having a hydroxyl group (hereinafter, abbreviated as a monomer (a-2)). The monomer (a-2) forms a polymer network by crosslinking reaction with a crosslinking agent, thereby contributing to suppression of floating and peeling and suppression of light leakage. The monomer (a-2) is preferably a hydroxyl group-containing monomer having no carboxyl group.

Specific examples of the monomer (a-2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and (methyl). 2-hydroxybutyl acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate Or hydroxyalkyl (meth) acrylate, or polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, 1,4-cyclohexane dimethanol mono (meth) acrylate Ethylene glycol mono (meth) acrylate, caprolactone modified (meth) acrylate, and the like. Further, these monomers may be used singly or in combination of two or more.

The monomer (a-2) is preferably contained in the acrylic copolymer as 0.05 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, as the monomer unit constituting the copolymer. When the content is 0.05 parts by weight or more, the cohesive force is further improved. Further, when the content is 10% by weight or less, it is easy to have both cohesive force and stress relaxation property.

Examples of the monomer unit constituting the acrylic copolymer (A) include a (meth)acrylic acid alkyl ester and a further vinyl monomer. Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and pentane (meth)acrylate. Ester, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, (A) Base) lauryl acrylate, tetradecyl (meth) acrylate, cetyl (meth) acrylate, octadecyl (meth) acrylate, and the like. Among these monomers, butyl (meth)acrylate is preferable from the viewpoint of easily obtaining good adhesion properties. These monomers may be used singly or in combination of two or more.

The alkyl (meth)acrylate is preferably contained in the acrylic copolymer as 70% by weight to 99.85% by weight, more preferably 85% by weight to 99.8% by weight, based on the monomer unit constituting the copolymer. When the content is 70% by weight or more, the cohesive force is further improved. Further, when the content is 99.85% by weight or less, it is easy to have both cohesive force and stress relaxation property.

Examples of the other vinyl monomer include a monomer containing a guanamine bond, a monomer containing an epoxy group, a monomer containing an amine group, a monomer having an alkylene oxide unit, vinyl acetate, and butene. The vinyl acetate, styrene, acrylonitrile or the like is not particularly limited to these monomers as long as it can be copolymerized.

Examples of the monomer having a guanamine bond include (meth) acrylamide, N-methyl acrylamide, N-isopropyl acrylamide, N, N-dimethyl decylamine, N, N. - diethyl acrylamide, N,N-dimethylaminopropyl (meth) acrylamide, diacetone acrylamide, N-(hydroxymethyl) acrylamide, N-(butoxy a (meth) acrylamide compound such as methyl acrylamide or a compound containing a hetero ring such as N-vinylpyrrolidone, N-vinylcaprolactam or acryloylmorpholine, N-vinylformamidine Amine, N-vinylacetamide, N-vinyl-N-methylacetamide, and the like.

Examples of the epoxy group-containing monomer include glycidyl (meth)acrylate, methyl glycidyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl (meth)acrylate. Base) 6-methyl-3,4-epoxycyclohexylmethyl acrylate or the like.

Examples of the amino group-containing monomer include monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, and monomethylaminopropyl (meth)acrylate. A monoalkylamino (meth)acrylate such as monoethylaminopropyl methacrylate.

The monomer having an alkylene oxide unit is preferably a unit having ethylene oxide, propylene oxide or the like. Specific examples thereof include 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-phenoxyethyl acrylate, methoxypolyethylene glycol (meth) acrylate, and B. Oxypoly polyethylene glycol (meth) acrylate, methoxy polypropylene glycol (meth) acrylate, ethoxypolypropylene glycol (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate , phenoxy polypropylene glycol (meth) acrylate, and the like.

Other vinyl monomers may be used alone or in combination of two or more. The other vinyl monomer is preferably contained in the acrylic copolymer as 80% by weight to 99.9% by weight, and more preferably 85% by weight to 99.5% by weight, as the monomer unit constituting the copolymer. When the content is 80% by weight or more, the cohesive force is further improved. Further, when the content is 99.9% by weight or less, it is easy to have both cohesive force and stress relaxation property.

The weight average molecular weight of the acrylic copolymer (A) is preferably from 500,000 to 2,000,000, and more preferably from 700,000 to 1,800,000. By further increasing the cohesive force in the range of 500,000 to 2,000,000, it is possible to suppress floating and peeling, and the stress relaxation property is further improved. Further, the molecular weight distribution (molecular weight distribution (Mw/Mn)) indicating the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the acrylic polymer (A) is preferably 2 to 20. By being in the above range, it is difficult to cause floating and peeling, and the adhesion is further improved. Further, the weight average molecular weight and the number average molecular weight are values in terms of polystyrene measured by a gel permeation chromatography (GPC) method. Details of the measurement method of GPC are described in the examples.

The acrylic copolymer (A) can be obtained by polymerizing a monomer mixture. The polymerization may be a known polymerization method such as solution polymerization, bulk polymerization, emulsion polymerization, or suspension polymerization, and is preferably solution polymerization. The solvent used in the solution polymerization is preferably acetone, methyl acetate, ethyl acetate, toluene, xylene, anisole, methyl ethyl ketone, cyclohexanone or the like. The boiling point reaction is preferably carried out at a polymerization temperature of from 60 ° C to 120 ° C, and the polymerization time is preferably from 5 hours to 12 hours.

The polymerization initiator is preferably a radical polymerization initiator. The radical polymerization initiator is not particularly limited as long as it can generate a radical at a polymerization temperature, and a known compound such as a peroxide or an azo compound can be used.

Examples of the peroxide include di-tert-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, and α,α'-bis (t-butyl peroxy-different). a dialkyl peroxide such as propyl, 2,5-di(t-butylperoxy)hexyne-3; a third butyl peroxybenzoate; a third butyl peroxyacetate; Peroxy esters such as 5-dimethyl-2,5-bis(benzhydrylperoxy)hexane; cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide, Ketone peroxides such as methylcyclohexanone peroxide; 2,2-bis(4,4-di-tert-butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxide) 3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, n-butyl-4,4-bis(t-butylperoxy)pentanoic acid Peroxy ketals such as esters; hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylcyclohexane-2,5-dihydroperoxide Benzyl sulfhydryl peroxide, sulfhydryl peroxide, lauryl peroxide, 2,4-dichlorobenzhydryl peroxide, etc. Cyclohexyl) peroxy dicarbonate diisopropyl peroxydicarbonate organic peroxides such as esters, or mixtures of these compounds.

As the azo compound, for example, 2,2'-azobisisobutyronitrile (abbreviation: AIBN) or 2,2'-azobis(2-methylbutyronitrile) can be used. , 2'-azobisbutyronitrile; 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4- 2,2'-azobisvaleronitrile such as dimethyl valeronitrile; 2,2'-azobispropionitrile such as 2,2'-azobis(2-hydroxymethylpropionitrile); 1,1'-azobis-1-alkanene nitrile such as 1'-azobis(cyclohexane-1-carbonitrile).

The polymerization initiators may be used singly or in combination of two or more. The polymerization initiator is preferably used in an amount of from 0.01 part by weight to 10 parts by weight, more preferably from 0.1 part by weight to 2 parts by weight, per 100 parts by weight of the monomer mixture. <crosslinking agent (B)>

Next, the crosslinking agent (B) will be described. The cross-linking agent reacts with the acrylic polymer to form a resin network, thereby obtaining the following effects: suppressing floating and peeling, suppressing light leakage, and maintaining high transparency even when exposed to a high-temperature and high-humidity environment. Sex.

Examples of the crosslinking agent (B) include an isocyanate compound, an epoxy compound, an aziridine compound, an acid anhydride group-containing compound, a carbodiimide compound, a N-methylol group-containing compound, and a metal chelate compound. Wait. Among these compounds, an isocyanate compound is preferably required. Here, the crosslinking agent (B) is other than the decane coupling agent (C) and the compound (D) having at least one epoxy group or epoxycyclohexyl group in the molecule.

The isocyanate compound is specifically an isocyanate monomer having two or more isocyanate groups, and specifically, an isocyanate such as an aromatic polyisocyanate, an aliphatic polyisocyanate, an aromatic aliphatic polyisocyanate or an alicyclic polyisocyanate is preferable. Monomers, as well as biuret, urea esters and adducts.

Examples of the aromatic polyisocyanate include 1,3-benzene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and 2,4. -toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4 4'-diphenyl ether diisocyanate, 4,4',4"-triphenylmethane triisocyanate or the like.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (alias: HMDI), pentamethylene diisocyanate, and 1,2-propyl group. Diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and the like.

Examples of the aromatic aliphatic polyisocyanate include ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, and ω,ω'-diisocyanate. -1,4-diethylbenzene, 1,4-tetramethylbenzenedimethyl diisocyanate, 1,3-tetramethylbenzenedimethyl diisocyanate or the like.

Examples of the alicyclic polyisocyanate include 3-isocyanatemethyl-3,5,5-trimethylcyclohexyl isocyanate (alias: IPDI, isophorone diisocyanate), 1,3-ring Pentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanatemethyl)cyclohexane, and the like.

The biuret body refers to a self-condensation product having a biuret bond formed by self-condensation of an isocyanate monomer. Specifically, for example, a biuret body of hexamethylene diisocyanate or the like can be mentioned.

The urea ester body refers to a trimer of an isocyanate monomer, and examples thereof include a trimer of hexamethylene diisocyanate, a trimer of isophorone diisocyanate, and a trimer of tolylene diisocyanate.

The adduct is a difunctional or higher isocyanate compound obtained by reacting an isocyanate monomer with a difunctional or higher active hydrogen-containing low molecular compound, and examples thereof include trimethylolpropane and hexamethylene diisocyanate. a compound obtained by the reaction, a compound obtained by reacting trimethylolpropane with toluene diisocyanate, a compound obtained by reacting trimethylolpropane with phenyldimethyl diisocyanate, and trimethylolpropane and A compound obtained by reacting isophorone diisocyanate, a compound obtained by reacting 1,6-hexanediol and hexamethylene diisocyanate, or the like.

Examples of the difunctional or higher active hydrogen-containing low molecular compound include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. , 3,3'-dimethylol heptane, 2-methyl-1,8-octanediol, 3,3'-dimethylol heptane, 2-butyl-2-ethyl-1, 3-propanediol, polyoxyethylene glycol (addition molar number of ethylene oxide is 10 or less), polyoxypropylene glycol (addition molar number of propylene oxide is 10 or less), 1,4-butanediol 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, neopentyl glycol, butylethylpentanediol, 2-ethyl An aliphatic or alicyclic diol such as 1,3-hexanediol, cyclohexanediol, cyclohexanedimethanol, tricyclodecane dimethanol, cyclopentadiene dimethanol or dimer diol; 1,3-bis(2-hydroxyethoxy)benzene, 1,2-bis(2-hydroxyethoxy)benzene, 1,4-bis(2-hydroxyethoxy)benzene, 4,4'- Methylene diphenol, 4,4'-(2-norbornyl) diphenol, 4,4'-dihydroxybiphenol, o-dihydroxybenzene, m-dihydroxybenzene, and p-dihydroxybenzene, 4, 4'-isopropylidene phenol, or bisphenol A or bisphenol F, etc. An aromatic diol such as a bisphenol such as an alkylene oxide such as ethane or propylene oxide; 1,1,1-trimethylolpropane or 1,1,1-trimethylolbutane; 1,1-trimethylolpentane, 1,1,1-trimethylolhexane, 1,1,1-trimethylolpheptane, 1,1,1-trimethylol octane, 1,1,1-trishydroxymethyl decane, 1,1,1-trishydroxymethyl decane, 1,1,1-trimethylolundecane, 1,1,1-trimethylol Dodecane, 1,1,1-trimethyloltridecane, 1,1,1-trimethyloltetradecane, 1,1,1-trimethylolpentadecane, 1,1, 1-trimethylolhexadecane, 1,1,1-trimethylolhexadecane, 1,1,1-trishydroxymethyloctadecane, 1,1,1-trimethylol-19 Alkane, 1,1,1-trishydroxymethyl-second butane, 1,1,1-trishydroxymethyl-tripentane, 1,1,1-trishydroxymethyl-tridecane, 1,1,1-trishydroxymethyl-tri-tridecane, 1,1,1-trishydroxymethyl-tri-heptadecane, 1,1,1-trishydroxymethyl-2-methyl Base-hexane, 1,1,1-trishydroxymethyl-3-methyl-hexane, 1,1,1-trishydroxymethyl-2-ethyl-hexane, 1,1,1-three Trimethylol branched alkanes such as hydroxymethyl-3-ethyl-hexane, 1,1,1-trishydroxymethyl isopentadecane, trimethylolbutene, trimethylol heptene, three Methylpentene, trimethylol hexene, trimethylol heptene, trimethylol octene, trimethylol decene, trimethyloldodecene, trimethyloltridecene, three Hydroxymethylpentadecene, trimethylolhexadecene, trimethylolhexadecene, trimethyloloctadecene, 1,2,6-butanetriol, 1,2,4-butanetriol a trifunctional polyol such as glycerin; a tetrafunctional or higher polyhydric alcohol such as pentaerythritol, dipentaerythritol, sorbitol or xylitol; ethylenediamine, propylenediamine, butanediamine, pentanediamine, hexamethylenediamine, Heptanediamine, octanediamine, decanediamine, diaminodicyclohexylmethane, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, 1,3-bis(aminomethyl) An aliphatic polyamine such as cyclohexane, tri-ethyltetramine, di-ethyltriamine or triaminopropane; phenylenediamine, toluenediamine, diaminodiphenylmethane, diamine-based An aromatic polyamine such as phenyl ether; ethanedithiol, propylene dithiol, butyl dithiol, pentanethiol, hexanedithiol, heptanedithiol, octanedithiol, decanedithiol, Dimercaptodicyclohexylmethane, 3-mercaptomethyl-3,5,5-trimethylcyclohexyl mercaptan, 1,3-double (巯A polythiol such as cyclomethyl, 1,4-bis(3-mercaptobutyloxy)butane or pentaerythritol tetrakis(3-mercaptobutyrate). These polyfunctional active hydrogen-containing low molecular compounds may be used singly or in combination of two or more.

From the viewpoint of forming a sufficient crosslinked structure, the isocyanate curing agent is preferably a trifunctional isocyanate compound, and more preferably an adduct of a reactant of an isocyanate monomer and a trifunctional active hydrogen-containing low molecular compound. Specifically, it is preferably a trimethylolpropane adduct of hexamethylene diisocyanate, a trimethylolpropane adduct of toluene diisocyanate, and a trimethylolpropane adduct of isophorone diisocyanate. a urea ester of isophorone diisocyanate or a trimethylolpropane adduct of benzodimethyl diisocyanate, particularly preferably an adduct of trimethylolpropane of toluene diisocyanate, benzoic acid An aromatic aliphatic polyisocyanate compound such as a trimethylolpropane adduct of a diisocyanate. These polyisocyanate compounds may be used singly or in combination of two or more.

Examples of the epoxy compound include bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, and glycerol triglycidyl ether. 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, N,N,N',N'-tetraglycidyl-m-xylylenediamine 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidylaminophenylmethane, and the like.

Examples of the aziridine compound include N,N'-diphenylmethane-4,4'-bis(1-aziridine carbonyl), N,N'-toluene-2,4-bis(1-nitrogen Propionate carbonyl), bis-m-xylylene-1-(2-methylaziridine), tri-1-aziridine phosphine oxide, N,N'-hexamethylene-1,6 - bis(1-aziridine carbonyl), 2,2'-bishydroxymethylbutanol-tris[3-(1-aziridine)propionate], trimethylolpropane tri-β- Aziridine propionate, tetramethylol methane tris-β-aziridine propionate, tris-2,4,6-(1-aziridine)-1,3,5-triazine 4,4'-bis(ethylethylaminocarbonylamino)diphenylmethane or the like.

The carbodiimide compound is a high molecular weight polycarbodiimide produced by subjecting a diisocyanate compound to a decarboxylation condensation reaction in the presence of a carbodiimide catalyst. Such a high molecular weight polycarbodiimide can be exemplified by the Carbodilite series of Nisshin Textile Co., Ltd. Among them, Carbodilite V-01, 03, 05, 07, and 09 are excellent in compatibility with an organic solvent, and therefore are preferable.

The acid anhydride group-containing compound is a compound having two or more carboxylic anhydride groups, and is not particularly limited, and is preferably a copolymer of tetracarboxylic dianhydride, hexacarboxylic acid trihydride, hexacarboxylic dianhydride, and maleic anhydride. Resin, etc. Further, a polycarboxylic acid, a polycarboxylate or a polycarboxylic acid half ester which can be an anhydride through a dehydration reaction in the reaction is contained in the "anhydride group-containing compound" of the present invention.

Examples of the tetracarboxylic dianhydride include pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, oxydiphthalic dianhydride, and diphenylphosphonium tetracarboxylic acid. Diacetone, diphenyl sulfide tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, perylenetetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, and the like.

Examples of the metal chelate compound include polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, ruthenium, magnesium, vanadium, chromium, and zirconium, and are compatible with ethyl acetonate or ethyl acetate. Compounds, etc. Specific examples thereof include ethyl acetoacetic acid, aluminum diisopropoxide, aluminum triethyl decyl acetonate, bisethyl acetonitrile acetic acid, aluminum monoethyl phthalate, and alkyl acetoacetic acid. Alcohol aluminum.

These crosslinking agents may be used singly or in combination of two or more. Among these crosslinking agents, a polyisocyanate compound is preferable from the viewpoint of having both substrate adhesion and removability.

The crosslinking agent (B) is preferably contained in an amount of from 0.1 part by weight to 25 parts by weight, more preferably from 0.5 part by weight to 20 parts by weight, per 100 parts by weight of the acrylic copolymer. If it is in the said range, it is easy to combine cohesive force and stress relaxation. <Hydrane coupling agent (C)>

The adhesive of the present invention comprises a decane coupling agent. By using a decane coupling agent, it is possible to suppress floating or peeling in the case of exposure to a high temperature environment or a high temperature and high humidity environment.

The decane coupling agent in the present specification may, for example, be 3-(meth)acryloxypropyltrimethoxydecane, 3-(meth)acryloxypropyltriethoxydecane, 3-( Methyl)propenyloxypropyltripropoxydecane, 3-(meth)acryloxypropyltributoxydecane, 3-(methyl)propenyloxypropylmethyldimethoxy Alkoxydecane compound having a (meth) propylene fluorenyl group such as decane or 3-(meth) propylene methoxy propyl methyl diethoxy decane; vinyl trimethoxy decane, vinyl triethyl Alkoxydecane compound having a vinyl group such as oxydecane, vinyl triisopropoxydecane, vinyl tributoxydecane, vinylmethyldimethoxydecane, vinylmethyldiethoxydecane 3-aminopropyltrimethoxydecane, 3-aminopropyltriethoxydecane, 3-aminopropyltripropoxydecane, 3-aminopropylmethyldimethoxydecane, 3-aminopropylmethyldiethoxydecane, N-(2-aminoethyl)-3-aminopropyltrimethoxydecane, N-(2-aminoethyl)-3-amine Propyltriethoxydecane, N-(2-aminoethyl)-3-amino Methyldimethoxydecane, N-(2-aminoethyl)-3-aminopropylmethyldiethoxydecane, N-phenyl-3-aminopropyltrimethoxydecane, etc. Alkoxydecane compound having an amine group; 3-mercaptopropyltrimethoxydecane, 3-mercaptopropyltriethoxydecane, 3-mercaptopropyltripropoxydecane, 3-mercaptopropylmethyldi An alkoxydecane compound having a mercapto group such as methoxydecane or 3-mercaptopropylmethyldiethoxydecane; 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropyltriethyl Oxydecane, 3-glycidoxypropyltripropoxydecane, 3-glycidoxypropyl tributoxydecane, 3-glycidoxypropylmethyldimethoxydecane, 3- An alkoxydecane compound having an epoxy group such as glycidoxypropylmethyldiethoxydecane or 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane; tetramethoxynonane a tetraalkoxydecane compound such as tetraethoxydecane, tetrapropoxydecane or tetrabutoxydecane; 3-chloropropyltrimethoxydecane, n-hexyltrimethoxydecane, n-hexyltriethoxy Alkane, n-decyltrimethoxydecane, n-decyltriethoxydecane, styryltrimethoxydecane,phenyltrimethoxydecane,diphenyldimethoxydecane,3-triethoxydecane Benzyl-N-(1,3-dimethylbutylidene)propylamine, 1,3,5-tris(3-trimethoxydecylpropyl)isocyanurate, 3-isocyanatepropyltrimethyl An oxoxane, a 3-isocyanate propyl triethoxy decane, a hexamethyldioxane, an fluorenone resin having an alkoxyalkyl group in the molecule, and the like.

The decane coupling agent may be used singly or in combination of two or more. Among these decane coupling agents, a decane coupling agent having an ethoxy group is preferable from the viewpoint of having both substrate adhesion and removability. The decane coupling agent is preferably used in an amount of from 0.01 part by weight to 2 parts by weight, more preferably from 0.05 part by weight to 1 part by weight, per 100 parts by weight of the acrylic copolymer (A). <Compound (D) having at least one epoxy group or epoxycyclohexyl group in the molecule>

The compound (D) having at least one epoxy group or epoxycyclohexyl group in the molecule in the present specification contributes to suppression of floating and peeling and suppresses light leakage by forming a covalent bond or a hydrogen bond with the surface of the substrate.

The compound (D) is a compound represented by the formula [I] or the formula [II], and p is an integer in the range of 1≦p≦30, preferably an integer in the range of 1≦p≦30, more preferably 5≦. An integer in the range of p≦20.

In the above formula [II], X ₁ to X ₄ each independently represent an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group and the like. Among them, a methyl group, an ethyl group, a propyl group, and a butyl group are preferable, and a methyl group is more preferable.

X ₅ is a divalent organic residue having 1 to 10 carbon atoms, and examples thereof include a methylene group, a 1,2-extended ethyl group, a 1,3-propenyl group, a 1,4-tert-butyl group, and a 1,5- a linear alkyl group such as a pentyl group, a 1,6-extension hexyl group, a 1,7-anthylene group, a 1,8-exenyl group, a 1,9-extension group, a 1,10-extension group, and the like , 1-extended ethyl, 1,2-extended propyl, 1,1-extended propyl, 1-methyl-1,3-butylene, 2-methyl-1,3-butylene, 1 a branched alkyl group such as 2-dimethyl-1,2-butylene, 1,1-butylene, ethyl-1,2-extended ethyl or the like. Among these alkylene groups, a linear alkylene group is preferable, and a methylene group, a 1,2-extended ethyl group, a 1,3-propanyl group, and a 1,4-tert-butyl group are more preferable.

Y represents an epoxy group or an epoxycyclohexyl group. Among them, an epoxycyclohexyl group is more preferable.

q is an integer in the range of 5 ≦ q ≦ 50, preferably an integer in the range of 10 ≦ q ≦ 50, and more preferably an integer in the range of 10 ≦ q ≦ 40.

r is an integer in the range of 5≦r≦50, preferably an integer in the range of 10≦r≦50, and more preferably an integer in the range of 10≦r≦40.

q+r is an integer in the range of 10≦q+r≦100, preferably an integer in the range of 10≦q+r≦80, and more preferably an integer in the range of 20≦q+r≦80.

In the compound (D), the compound represented by the formula [I] may specifically be: Denacol EX810, Denacol EX811, Denacol EX850, Dan. Denacol EX851, Denacol EX821, Denacol EX830, Denacol EX832, Denacol EX841, Denacol (Denacol) ) EX861 "Manufactured by Nagase ChemteX Co., Ltd.".

In the compound (D), the compound represented by the formula [II] specifically includes KR-516, X-41-1810, X-40-2651, X-40-9296, KR-513, KR-. 511 (all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

The compound (D) is preferably contained in an amount of from 0.01 part by weight to 10 parts by weight, more preferably from 0.05 part by weight to 5 parts by weight, even more preferably from 0.05 part by weight to 2 parts by weight, per 100 parts by weight of the acrylic copolymer (A). . When the content is 0.01 parts by weight or more, sufficient substrate adhesion can be obtained. When the content is within the above range, it is easy to have both substrate adhesion and removability.

In the adhesive of the present invention, various resins, oils, softeners, dyes, pigments, antioxidants, ultraviolet absorbers, weathering stabilizers, plastics, which are optional components, can be blended as long as they do not impair the effects of the present invention. Chemical agents, fillers, anti-aging agents and antistatic agents.

In addition to being suitable as an adhesive for optical members, the adhesive of the present invention can be used very usefully as various plastic sheets, general labels, sheets, paints, elastic wall materials, water-repellent materials for coating materials, flooring materials, and adhesion-imparting agents. Adhesives, adhesives for laminated structures, sealants, molding materials, coating agents for surface modification, adhesives (magnetic recording media, ink adhesives, casting adhesives, burnt brick adhesives, grafting) Materials, microcapsules, glass fiber sizing, etc., urethane foams (hard, semi-rigid, soft), urethane reaction injection molding (RIM), Ultraviolet (UV), electron beam (EB) hardening resin, high solid paint, thermosetting elastomer, microcellular, fiber processing agent, plasticizer, sound absorbing material, Damping material, surfactant, gel coating agent, resin for artificial marble, impact resistance imparting agent for artificial marble, resin for ink, film (lamination) Adhesives, protective films, etc., laminated glass resins, reactive diluents, various molding materials, elastic fibers, artificial leather, synthetic leather, etc., and can also be used as various resin additives and raw materials thereof. . <adhesive sheet>

The adhesive sheet of the present invention comprises a substrate and an adhesive layer comprising the adhesive of the present invention. The adhesive sheet is obtained, for example, by applying an adhesive to a substrate and drying it to form an adhesive layer. Further, the adhesive sheet is obtained by applying an adhesive to a release sheet and drying it to form an adhesive layer, and bonding the substrate. Further, the adhesive layer may be provided on at least one side of the substrate. Further, in the present invention, the sheet, the film and the tape are synonymous. Further, of course, the release sheet is bonded to the surface of the adhesive layer that is not in contact with the substrate.

When applying the adhesive, a suitable liquid medium such as a hydrocarbon solvent such as toluene, xylene, hexane or heptane; an ester solvent such as ethyl acetate or butyl acetate; acetone or methyl ethyl group; A ketone solvent such as a ketone; a halogenated hydrocarbon solvent such as dichloromethane or chloroform; an ether solvent such as diethyl ether, methoxytoluene or dioxane, or an organic solvent such as another hydrocarbon solvent to adjust the viscosity. In addition, the adhesive may be heated to lower the viscosity. Among them, water or alcohol or the like is preferably prevented from being used because it hinders the crosslinking reaction between the acrylic copolymer (B) and the polyisocyanate compound.

Examples of the substrate include cellophane, plastic, rubber, foam, cloth, rubberized cloth, resin impregnated cloth, glass plate, and wood. The substrate may be in the form of a plate or a film. Moreover, it is preferable that the base material has a structure in which a plurality of base materials are laminated alone or in layers.

Examples of the plastics include polyolefin resins such as polyvinyl alcohol or triethylenesulfonyl cellulose, polypropylene, polyethylene, polycycloolefin, and ethyl-vinyl acetate copolymer, and polyethylene terephthalate. Polybutylene terephthalate, polyester resin such as polyethylene naphthalate, polycarbonate resin, polynorbornene resin, polyarylate resin (PAR: bisphenol A and a copolymerized resin of phthalic acid), a polyacrylic resin, a polyphenylene sulfide resin, a polystyrene resin, a polyamide resin, a polyimide resin, or an epoxy resin (epoxy group-containing resin) A resin obtained by reacting a resin with a polyamine or a carboxylic acid anhydride).

In the present invention, the adhesive can be applied by a known method. For example, Meyer bar, applicator, brush, spray, roll, gravure coater, pattern coater, lip coater, angle wheel coater, knife coater, reverse A coater, a spin coater, or the like. The drying method is not particularly limited, and examples thereof include a method of drying by hot air, infrared rays, or a reduced pressure method. The drying conditions are usually heated by hot air of about 60 to 160 °C.

The thickness of the adhesive layer is preferably from 0.1 μm to 300 μm, and more preferably from 1 μm to 100 μm. When the thickness is less than 0.1 μm, sufficient adhesion may not be obtained, and even if it exceeds 300 μm, the performance such as adhesion does not increase further.

The adhesive sheet of the present invention can be suitably used for the bonding of optical members. That is, it is preferred to use an optical member on the substrate. Specific examples of the optical member include a polarizing plate, a retardation film, an elliptically polarizing film, an antireflection film, and a brightness enhancement film.

The adhesive sheet of the present invention using an optical member on a substrate is also preferably used as a liquid crystal cell member by being attached to a glass member of a liquid crystal cell. When the optical member is a polarizing plate, when placed in a high-temperature environment and a high-temperature and high-humidity environment, the adhesive layer is excellent in stress relaxation property, so that light leakage caused by warpage of the polarizing plate can be suppressed.

The adhesive sheet of the present invention can be preferably used for various electronic related components such as a liquid crystal display, a plasma display, a touch panel, an electrode peripheral member, or a glass member such as a protective film, a building material, or a window glass of a vehicle, but can also be used for a polyolefin. , acrylonitrile butadiene styrene (ABS), acrylic and other plastics, cardboard, wood, plywood, stainless steel, aluminum and other metals. [Examples]

Hereinafter, the present invention will be specifically described by way of examples, but the invention is not limited to the examples. In the example, "parts" means "parts by weight", and "%" means "% by weight". <Synthesis of Acrylic Copolymer (A)>

<Synthesis Example 1> 99.4 parts of butyl acrylate and 0.5 parts of a reaction container (hereinafter, simply referred to as a "reaction container") equipped with a stirrer, a thermometer, a reflux cooling tube, a dropping device, and a nitrogen introduction tube were placed. After the acrylic acid, 0.1 part of 2-hydroxyethyl acrylate, 100 parts of ethyl acetate, and 0.025 part of 2,2'-azobisisobutyronitrile (AIBN), the air in the reaction container was replaced with nitrogen. Then, the mixture was heated to 80 ° C while stirring under a nitrogen atmosphere to start the reaction. Further, the reaction solution was allowed to react at reflux temperature for 7 hours. After completion of the reaction, the mixture was cooled and diluted with ethyl acetate to obtain a copolymer solution having a nonvolatile content of 30% and a viscosity of 3,000 mPa·s. Further, the weight average molecular weight (Mw) of the acrylic copolymer was measured by GPC, and as a result, the weight average molecular weight was 1,000,000. The obtained copolymer was referred to as a copolymer (A-1).

<Synthesis Example 2 to Synthesis Example 20> Acrylic copolymers were synthesized in the same manner as in Synthesis Example 1 except that the raw materials and amounts shown in Tables 1 and 2 were changed instead of the materials used in Synthesis Example 1. (A-2) - Acrylic copolymer (A-20). The weight average molecular weight of each obtained acrylic copolymer is shown in Table 1 and Table 2.

<Measurement of Weight Average Molecular Weight (Mw)> The weight average molecular weight (Mw) was measured using a GPC "LC-GPC system" manufactured by Shimadzu Corporation, and was determined based on the converted value of polystyrene as a standard material. The measurement conditions are shown below. Device name: manufactured by Shimadzu Corporation, LC-GPC system "Prominence" Column: Four GCL-H manufactured by Tosoh Corporation and one HXL-H manufactured by Tosoh Corporation are connected in series. Mobile phase solvent: tetrahydrofuran (THF) Flow rate: 1.0 mL/min Column temperature: 40 °C

(Example 1) The copolymer solution obtained in Synthesis Example 1 of the acrylic copolymer (A) (the amount of the acrylic copolymer (A-1 in the solution in an amount of 100 parts) was adjusted, and 1 part was used as a crosslinking agent. (B) an adduct of trimethylolpropane of toluene diisocyanate, 0.1 part of 3-glycidoxypropyltriethoxydecane as a decane coupling agent (C), and 1 part as a compound (D) Further, the compound (D-1) shown in Table 5 was prepared, and an amount of ethyl acetate having a nonvolatile content of 20% was prepared to obtain an adhesive.

The adhesive was applied to a polyethylene terephthalate peelable sheet having a thickness of 38 μm so that the thickness after drying became 25 μm (Cerapeel MF: Toray Film (Toray) The film was dried at 100 ° C for 2 minutes to form an adhesive layer. Then, on both sides of the adhesive layer, a polyvinyl alcohol (PVA)-based polarizing element is sandwiched between triacetyl cellulose (hereinafter referred to as "TAC film"). On one side of a polarizing plate (HLC2-5618: manufactured by SANRITZ) having a laminated structure, an adhesive sheet comprising a structure of a so-called "release film/adhesive layer/TAC film/PVA/TAC film" was obtained. Then, the obtained adhesive sheet was aged for 1 week under the conditions of a temperature of 35 ° C and a relative humidity of 55% to obtain a laminate.

(Examples 2 to 34, Comparative Examples 1 to 10) The materials and the amounts shown in Tables 3 and 4 were changed to be the same as in Example 1 except that the materials used in Example 1 were replaced. The way to get the adhesive separately. Further, an adhesive sheet and a laminate were respectively obtained in the same manner as in Example 1. The details of the compound (D) used are shown in Table 5. The obtained laminate was evaluated by the following method.

(1) Evaluation of heat resistance and heat and humidity resistance The obtained laminate was cut into a size of 160 mm in width and 120 mm in length. Then, the peelable sheet was peeled off from the cut laminated body, and attached to the alkali-free glass plate using a laminator. Then, the glass plate to which the laminated body was attached was held in an autoclave under the conditions of 50 ° C and 5 atmospheres for 20 minutes, and the respective members were brought into close contact with each other to obtain a measurement sample. The heat resistance was evaluated for the measurement sample, and the resistance was evaluated as a high temperature environment. That is, after the measurement sample was allowed to stand at 85 ° C for 500 hours, the presence or absence of foaming, floating, and peeling was visually observed.

Further, the measurement sample was evaluated for moisture resistance and heat resistance as a resistance evaluation in a high temperature and high humidity environment. That is, after the measurement sample was allowed to stand at 60 ° C and a relative humidity of 95% for 500 hours, the presence or absence of foaming, floating, and peeling was visually observed. Both heat resistance and moist heat resistance were evaluated based on the following criteria. ◎: Foaming, floating, and peeling were not confirmed at all, and it was good. ○: Although any of foaming, floating, and peeling of 0.5 mm or less was confirmed, there was no problem in practical use. ×: There is foaming, floating, and peeling in a comprehensive manner, and it cannot be used.

(2) Light leakage evaluation The obtained laminated body was cut into a size of 160 mm in width and 120 mm in length. Then, the peelable sheet was peeled off from the cut laminated body, and the two laminated sheets were attached to each other on the both sides of the alkali-free glass plate by using a laminator so that the absorption axes of the polarizing plates were orthogonal to each other. Obtain a crimp. Then, the pressure-sensitive adhesive was held in an autoclave under the conditions of 50 ° C and 5 atmospheres for 20 minutes, and the members were brought into close contact with each other to obtain a measurement sample. After the measurement sample was allowed to stand at 85 ° C for 500 hours, light leakage when light was transmitted through the polarizing plate was visually observed. Light leakage is evaluated based on the following criteria. ◎: No white spots, good. ○: Although white spots were confirmed in a very small part, no comprehensive white spots were confirmed, and there was no problem in practical use. ×: White spots are completely present and cannot be used.

(3) Evaluation of re-peelability The obtained laminate was cut into a size of 160 mm in width and 120 mm in length. Then, the peelable sheet was peeled off from the cut laminated body, and attached to the alkali-free glass plate using a laminator. Then, the sample was held in an autoclave under the conditions of 50 ° C and 5 atmospheres for 20 minutes, and the respective members were brought into close contact with each other to obtain a measurement sample. After the measurement sample was allowed to stand at 85 ° C for 3 hours, a tensile tester ("Tensilon" manufactured by Orientec Co., Ltd.) was used in an environment of 23 ° C and a relative humidity of 50%. A peeling test was conducted in which the stretching was performed at a speed of 300 mm/min in the 180° direction. Then, the blur of the glass surface after peeling was visually observed, and it evaluated based on the following criteria. ○: Residual glue was not confirmed, and it was good. ×: It is confirmed that the residual glue is blurred and cannot be used.

(4) Adhesion evaluation The obtained laminate was cut into a size of 25 mm in width and 100 mm in length. Then, the peelable sheet was peeled off from the cut laminated body, and attached to the alkali-free glass plate using a laminator. Then, the sample was held in an autoclave under the conditions of 50 ° C and 5 atmospheres for 20 minutes, and the respective members were brought into close contact with each other to obtain a measurement sample. After the measurement sample was allowed to stand at 23 ° C for one day, a tensile tester (Tensilon) manufactured by Orientec Co., Ltd. was used in an environment of 23 ° C and a relative humidity of 50%. The adhesion (adhesion force after bonding for one day) was measured under the conditions of a peeling speed of 300 mm/min and a peeling angle of 180°. Further, after the measurement sample was allowed to stand at 23 ° C for 14 days, the adhesion (adhesion force after 14 days of bonding) was measured by the same method.

According to the results of Tables 6, 7 and 8, the adhesives of the present invention are excellent in durability, light leakage, and removability in a high-temperature environment and a high-temperature and high-humidity environment as shown in Examples 1 to 34. On the other hand, Comparative Examples 1 to 10 did not satisfy all of the above characteristics.

[Table 1] AA: acrylic acid MAA: methacrylic acid HEA: 2-hydroxyethyl acrylate HEMA: 2-hydroxyethyl methacrylate BA: butyl acrylate EHA: 2-ethylhexyl acrylate MA: methyl acrylate

[Table 2] AA: acrylic acid MAA: methacrylic acid HEA: 2-hydroxyethyl acrylate HEMA: 2-hydroxyethyl methacrylate BA: butyl acrylate EHA: 2-ethylhexyl acrylate MA: methyl acrylate

[table 3] (Note) [Parts] in the table are formulated as a solid component by weight B-1: trimethylolpropane adduct C-1 of 3-toluene diisocyanate: 3-glycidoxypropyltriethoxydecane B -2: Trimethylolpropane adduct of phenyldimethyl diisocyanate C-2: 3-glycidoxypropyltrimethoxydecane B-3: Trimethylolpropane of hexamethylene diisocyanate Adduct

[Table 4] (Note) [Parts] in the table are formulated as a solid component by weight B-1: trimethylolpropane adduct C-1 of 3-toluene diisocyanate: 3-glycidoxypropyltriethoxydecane B -2: Trimethylolpropane adduct of phenyldimethyl diisocyanate C-2: 3-glycidoxypropyltrimethoxydecane B-3: Trimethylolpropane of hexamethylene diisocyanate Adduct

[table 5]

[Table 6]

[Table 7]

[Table 8]

no

no

no

Claims (8)

An adhesive comprising an acrylic copolymer (A), a crosslinking agent (B), a decane coupling agent (C), and a compound (D) having at least one epoxy group or an epoxycyclohexyl group in the molecule. The adhesive is characterized in that the acrylic copolymer (A) is at least a carboxyl group-containing monomer (a-1) unit and a hydroxyl group-containing monomer (a-2) unit as a constituent copolymer. a copolymer of a monomer unit, the crosslinking agent (B) comprising an isocyanate compound, and the compound (D) having at least one epoxy group or epoxycyclohexyl group in the molecule is represented by the following formula [I] Or a compound represented by the formula [II], Wherein p, q, r are integers representing repeating units, 1≦p≦30, 5≦q≦50, 5≦r≦50, 10≦q+r≦100; X ₁ to X ₄ are independently represented The alkyl group, X ₅ represents a divalent organic residue having 1 to 10 carbon atoms, and Y represents an epoxy group or an epoxycyclohexyl group. The adhesive according to claim 1, wherein the adhesive contains 0.05 parts by weight to 2 parts by weight of the molecule having at least one epoxy group or ring with respect to 100 parts by weight of the acrylic copolymer (A). Oxycyclohexyl compound (D). The adhesive according to claim 1 or 2, wherein the crosslinking agent (B) is an isocyanate compound. The adhesive according to any one of claims 1 to 3, wherein the decane coupling agent (C) is a decane coupling agent having an ethoxy group. The adhesive according to any one of claims 1 to 4, wherein the crosslinking agent is contained in an amount of from 0.5 part by weight to 20 parts by weight per 100 parts by weight of the acrylic copolymer (A). The agent (B) is formed. An adhesive sheet comprising: a substrate; and an adhesive layer comprising the adhesive according to any one of claims 1 to 5. A polarizing plate adhesive sheet comprising the following members: a polarizing plate, and an adhesive layer comprising the adhesive according to any one of claims 1 to 5. A liquid crystal cell member comprising: a glass plate, an adhesive layer comprising the adhesive according to any one of claims 1 to 5, and an optical member.