JP6721322B2 - Adhesive composition, adhesive sheet and optical film with adhesive - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive composition suitable for an optical film, a pressure-sensitive adhesive sheet using the same, and a pressure-sensitive adhesive-attached optical film. The present invention also relates to an optical laminate in which the optical film with an adhesive is laminated on a glass substrate and is suitably used for a liquid crystal display.

The polarizing plate is mounted on a liquid crystal display device and is widely used. A polarizing plate is generally distributed in a state where a transparent protective film is laminated on both surfaces of a polarizing film, an adhesive layer is formed on the surface of at least one protective film, and a release film is attached on the adhesive layer. doing. In addition, a retardation film is laminated on a polarizing plate in which protective films are attached to both sides of a polarizing film to form an elliptically polarizing plate, and an adhesive layer/release film is attached in this order on the retardation film side. Sometimes Further, the pressure-sensitive adhesive layer/release film may be attached to the surface of the retardation film in this order. In the present specification, a polarizing plate, an elliptical polarizing plate, a retardation film, and the like on which the pressure-sensitive adhesive layer is thus provided are collectively referred to as an optical film. Such an adhesive-attached optical film is laminated on a glass substrate such as a liquid crystal cell to form a liquid crystal display device.

The pressure-sensitive adhesive composition that forms the pressure-sensitive adhesive layer applied to the optical film includes, in terms of transparency and weatherability, an acrylic acid ester as a main component, and a monomer having a polar functional group such as a hydroxyl group or a carboxyl group. A (meth)acrylic resin produced by copolymerizing a body is often used. A cross-linking agent is added to such a (meth)acrylic resin to give the required cohesive force. Further, by blending such a (meth)acrylic resin with a silane compound, the adhesiveness between the pressure-sensitive adhesive layer and the glass substrate is improved. As the silane-based compound, for example, 3-glycidoxypropyltrimethoxysilane is widely used (see JP 2013-181086 A).

JP, 2013-181086, A

An appropriate pressure-sensitive adhesive force is required for the pressure-sensitive adhesive layer of the pressure-sensitive adhesive-attached optical film. The pressure-sensitive adhesive-attached optical film is, for example, laminated on a glass substrate of a liquid crystal cell to give an optical laminate for a liquid crystal display. Under conditions and under the environment where heating and cooling are repeated, the pressure-sensitive adhesive layer absorbs and relaxes the stress caused by the dimensional change of the optical film and the glass substrate, so that the local stress concentration is reduced and the stress on the glass substrate is reduced. Floating or peeling of the adhesive layer is suppressed. That is, it has excellent durability.

While the pressure-sensitive adhesive layer of the pressure-sensitive adhesive optical film is required to have an appropriate pressure-sensitive adhesive force as described above, when the pressure-sensitive adhesive-attached optical film is attached to the liquid crystal cell, if there is a defect, the optical film Since the film is once peeled off and a new film is attached again, it is also required that the peelability at that time is good. If the releasability is low, problems such as the adhesive remaining on the glass substrate may occur.

The present invention has a suitable pressure-sensitive adhesive force to a glass substrate, a novel pressure-sensitive adhesive composition that can improve the peelability by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate at the time of peeling, Also provided are an adhesive sheet, an adhesive-attached optical film and an optical laminate using the same.

The present invention provides the following adhesive composition, adhesive sheet, adhesive-attached optical film and optical laminate.

[1] (Meth)acrylic resin, cross-linking agent, and the following formula (I)

(In the above formula (I), R ₁ represents an alkyl group having 1 to 14 carbon atoms, an aralkyl group, an aryl group or an alkenyl group; R ₂ represents an alkyl group having 1 to 6 carbon atoms)
A pressure-sensitive adhesive composition containing a silane compound represented by:

[2] The pressure-sensitive adhesive composition according to [1], wherein the silane compound is contained in an amount of 0.03 to 2 parts by weight based on 100 parts by weight of the (meth)acrylic resin.

[3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the silane compound is 3-ureidopropyltrialkoxysilane.

[4] The pressure-sensitive adhesive composition according to [1] to [3], wherein the crosslinking agent is an isocyanate crosslinking agent.

[5] A pressure-sensitive adhesive sheet formed into a sheet using the pressure-sensitive adhesive composition according to [1] to [4].

[6] The pressure-sensitive adhesive sheet according to [5], which is formed on a plastic film.
[7] The pressure-sensitive adhesive sheet according to [6], wherein the plastic film is a release film that has been subjected to a release treatment.

[8] A pressure-sensitive adhesive-attached optical film comprising an optical film and the pressure-sensitive adhesive sheet according to any one of [5] to [7] bonded to the optical film.

[9] The pressure-sensitive adhesive-attached optical film according to [8], wherein the optical film is a polarizing plate or a retardation film.

[10] An optical laminate in which the pressure-sensitive adhesive-attached optical film according to [8] or [9] is attached to a glass substrate on the pressure-sensitive adhesive sheet side.

According to the present invention, a pressure-sensitive adhesive layer having an appropriate pressure-sensitive adhesive force to a glass substrate, which shows excellent peelability by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate during peeling. It is possible to provide a pressure-sensitive adhesive composition capable of forming a film, a pressure-sensitive adhesive sheet using the same, and a pressure-sensitive adhesive-attached optical film.

It is a cross-sectional schematic diagram which shows the example of the suitable laminated constitution of the optical laminated body which concerns on this invention.

Hereinafter, the present invention will be described in detail. The pressure-sensitive adhesive composition of the present invention contains a (meth)acrylic resin (A), a cross-linking agent (B), and a silane compound (C) represented by the following formula (I).

In the above formula (I), R ₁ is an alkyl group having 1 to 14 carbon atoms, an aralkyl group, an aryl group or an alkenyl group. R ₂ represents an alkyl group having 1 to 6 carbon atoms. According to the pressure-sensitive adhesive composition of the present invention, by containing the silane-based compound (C) represented by the above formula (I), the pressure-sensitive adhesive composition has excellent adhesiveness to a glass substrate, moderate adhesiveness, and durability. A pressure-sensitive adhesive layer capable of forming an excellent pressure-sensitive adhesive layer and exhibiting excellent peelability by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate when peeling the pressure-sensitive adhesive layer from the glass substrate. Can be formed. First, each component which comprises an adhesive composition is demonstrated.

[(Meth)acrylic resin (A)]
The (meth)acrylic resin (A) that constitutes the pressure-sensitive adhesive composition of the present invention contains a structural unit derived from the (meth)acrylic acid ester (A-1) as a main component, and has a hydroxyl group (meth)acrylic single resin. Those containing a structural unit derived from the monomer (A-2) are preferable. Further, those containing a structural unit derived from a carboxyl group-containing (meth)acrylic acid ester (A-3) are preferable.

The (meth)acrylic acid ester (A-1) is represented by the following formula (II).

In the above formula (II), R ₃ represents a hydrogen atom or a methyl group; R ₄ represents an alkyl group having 14 or less carbon atoms or an aralkyl group, and the hydrogen atom constituting these groups is a group —O—( C ₂ H ₄ O) _m —R ₅ may be substituted, where m represents 0 or an integer of 1 to 4, and R ₅ represents an alkyl group or an aryl group having 12 or less carbon atoms.

The carboxy group-containing (meth)acrylic acid ester (A-3) is represented by the following formula (III).

In the above formula (III), R ₆ represents a hydrogen atom or a methyl group; A represents a divalent organic group having 2 to 4 carbon atoms.

In the present specification, (meth)acrylic acid means that either acrylic acid or methacrylic acid may be used, and the same applies to "(meth)" when referring to (meth)acrylate, (meth)acrylic resin, and the like. Is the purpose. In the present specification, the (meth)acrylic acid ester (A-1) represented by the above formula (I) is simply referred to as a “monomer (A-1)” and a (meth)acrylic monomer having a hydroxyl group ( A-2) is simply referred to as "monomer (A-2)", and the carboxyl group-containing (meth)acrylic acid ester (A-3) represented by the above formula (III) is simply referred to as "monomer (A-)". 3)”, respectively.

Among the monomers (A-1), as R ₄ in the above formula (II) being an unsubstituted alkyl group, specifically, methyl acrylate, ethyl acrylate, propyl acrylate, n-acrylate Linear alkyl acrylates such as butyl, n-octyl acrylate, and lauryl acrylate; branched alkyl acrylates such as isobutyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; Linear alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, and lauryl methacrylate; and isobutyl methacrylate, 2-methacrylic acid Examples are branched alkyl methacrylates such as ethylhexyl and isooctyl methacrylate.

Among these, n-butyl acrylate is preferable, and specifically, n-butyl acrylate accounts for 50% by weight or more of all monomers constituting the (meth)acrylic resin (A). And it is preferable to use it so that the above-mentioned regulation regarding the monomer (A-1) may be satisfied.

Further, in the monomer (A-1), as R ₄ in the formula (II) being an aralkyl group, benzyl acrylate, benzyl methacrylate and the like are specifically exemplified.

Next, in the monomer (A-1), the hydrogen atom of the alkyl group or aralkyl group constituting R ₄ in the formula (II) is substituted with the group —O—(C ₂ H ₄ O) _m —R ₅ . What is done is explained. In this group _{-O- (C 2 H 4 O)} m -R 5, m is as defined above, is a 0 or an integer of 1 to 4, it is preferred especially is 0, 1 or 2. R _{5 is} also an alkyl group or an aryl group having 12 or less carbon atoms as defined above, and may be linear or branched as long as the alkyl group has 3 or more carbon atoms. Examples of the aryl group constituting R ₅ include phenyl and naphthyl, nuclear alkyl-substituted phenyl including tolyl, xylyl, and ethylphenyl, biphenylyl (or phenylphenyl), and the like. R ₅ is particularly preferably these aryl groups.

In the monomer (A-1), R ₄ in formula (II) is an alkyl group, and its hydrogen atom is substituted with a group —O—(C ₂ H ₄ O) _m —R _5. Specifically, of 2-methoxyethyl acrylate, ethoxymethyl acrylate, 2-phenoxyethyl acrylate, 2-(2-phenoxyethoxy)ethyl acrylate, and 2-(o-phenylphenoxy)ethyl acrylate. Such as alkoxyalkyl-, aryloxyalkyl- or aryloxyethoxyalkyl-esters of acrylic acid; 2-methoxyethyl methacrylate, ethoxymethyl methacrylate, 2-phenoxyethyl methacrylate, 2-(2-phenoxyethoxy)methacrylate. Examples thereof include alkoxyalkyl-, aryloxyalkyl- or aryloxyethoxyalkyl-esters of methacrylic acid such as ethyl and 2-(o-phenylphenoxy)ethyl methacrylate.

Each of these monomers (A-1) can be used alone, or a plurality of different monomers may be used. As described above, the monomer (A-1) particularly preferably contains n-butyl acrylate as a main component, but in addition to that, other (meth)acrylic acid ester corresponding to the formula (II) is added. Copolymerization is also effective. As one of preferred compositions of the monomer (A-1), n-butyl acrylate is 50% by weight or more of all monomers constituting the (meth)acrylic resin (A), Apart from that, the hydrogen atom represented by the above formula (II) and constituting R ₄ in the formula as described above has a group —O—(C ₂ H ₄ O) _m —R ₅ (where m and R ₅ Is as defined above), and a (meth)acrylic acid ester that is an alkyl group substituted with 3 to 15% by weight can be used.

Examples of the (meth)acrylic monomer (A-2) having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxy (meth)acrylate. Butyl, 2-(2-hydroxyethoxy)ethyl (meth)acrylate and the like can be mentioned. Of these, 2-hydroxyethyl acrylate is preferably used as one of the monomers (A-2) constituting the (meth)acrylic resin (A).

The carboxyl group-containing (meth)acrylic acid ester (A-3) is represented by the above formula (III). In this formula (III), R ₆ is a hydrogen atom or a methyl group, and A is a divalent organic group having 2 to 4 carbon atoms. The divalent organic group represented by A is typically alkylene, which is also preferably linear alkylene, but has a (meth)acrylic acid moiety CH ₂ ═C(R ₆ )COO— and If the carbon chain connecting the terminal carboxyl group —COOH is at least 2 in series, it may be branched as long as it has 3 or more carbon atoms. Among formula (III), it is preferable to use an acrylate ester as the monomer (A-3), and examples thereof include 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, and 4-carboxylate acrylate. Butyl and the like can be mentioned. Of course, a compound in which these acrylic acid esters are changed to methacrylic acid esters can also be the monomer (A-3).

The above-mentioned 2-carboxyethyl acrylate is usually produced by dimerization of acrylic acid, and in that case, in addition to 2-carboxyethyl acrylate as a main component, acrylic acid itself or a trimer of acrylic acid. It is often obtained as a mixture with the above oligomers, and is often sold as a mixture as it is. In this way, it is of course possible to copolymerize the other (meth)acrylic monomer containing a carboxyl group with the monomer (A-3).

In the (meth)acrylic resin (A) defined in the present invention, the content of the structural unit derived from the (meth)acrylic acid ester represented by the above formula (II), that is, the monomer (A-1) is 90. The content of the structural unit derived from the (meth)acrylic monomer having a hydroxyl group, that is, the monomer (A-2) is 0.1 to 6% by weight, and The content of the carboxyl group-containing (meth)acrylic acid ester represented by the formula (III), that is, the structural unit derived from the monomer (A-3) can be 0.01 to 0.4% by weight. .. By copolymerizing the monomers (A-1) and (A-2) in such a limited ratio, a pressure-sensitive adhesive composition that gives a pressure-sensitive adhesive sheet having excellent processability can be prepared. Of course, the total amount of the structural units derived from each of the monomers (A-1), (A-2) and (A-3) does not exceed 100% by weight.

The (meth)acrylic resin (A) used in the present invention contains a structural unit derived from a monomer other than the monomers (A-1), (A-2) and (A-3) described above. You can leave. Examples of the monomers other than the monomers (A-1), (A-2) and (A-3) include monomers and molecules other than the formula (III) having a polar functional group other than a hydroxyl group. (Meth)acrylic acid ester having an alicyclic structure, a styrene monomer, a vinyl monomer, a (meth)acrylamide derivative, a monomer having a plurality of (meth)acryloyl groups in the molecule, and the like is there.

The monomer other than formula (III) having a polar functional group other than the hydroxyl group will be described. The polar functional group other than the hydroxyl group may be a free carboxyl group or a heterocyclic group such as an epoxy ring. The acrylic acid itself and the oligomers of trimer or higher of acrylic acid described above in the section of the monomer (A-3) correspond to monomers other than the formula (III) having a free carboxyl group. In addition, examples of the monomer having a heterocyclic group include acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, and 3,4-epoxy. Examples include cyclohexylmethyl (meth)acrylate and glycidyl (meth)acrylate.

When copolymerizing a monomer having a polar functional group other than a hydroxyl group, the (meth)acrylic monomer (A-2) having a hydroxyl group and the carboxyl group-containing (meth)acrylic represented by the above formula (III) are used. Including the acid ester (A-3), the total amount of the monomers having a polar functional group is 8% by weight or less based on the total monomers constituting the (meth)acrylic resin (A). Preferably.

Next, the (meth)acrylic acid ester having an alicyclic structure in the molecule will be described. The alicyclic structure is a cycloparaffin structure having 5 or more carbon atoms, preferably about 5 to 7 carbon atoms. Specific examples of the acrylate ester having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, trimethylcyclohexyl acrylate, tert-acrylate. Examples thereof include butyl cyclohexyl, cyclohexyl α-ethoxyacrylate, and cyclohexylphenyl acrylate. Specific examples of the methacrylic acid ester having an alicyclic structure include isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, cyclododecyl methacrylate, methylcyclohexyl methacrylate, trimethylcyclohexyl methacrylate, and methacrylic acid. Examples include tert-butylcyclohexyl and cyclohexylphenyl methacrylate.

Examples of styrene-based monomers include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, and octylstyrene. Alkyl styrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; and also nitrostyrene, acetylstyrene, methoxystyrene, divinylbenzene and the like.

Examples of vinyl monomers include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and fatty acid vinyl esters such as vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; Vinylidene halides such as vinylidene chloride; nitrogen-containing aromatic vinyls such as vinylpyridine, vinylpyrrolidone, and vinylcarbazole; conjugated diene monomers such as butadiene, isoprene, and chloroprene; and also acrylonitrile, methacrylonitrile, etc. ..

Examples of the (meth)acrylamide derivative include N-methylol(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(4- Hydroxybutyl)(meth)acrylamide, N-(5-hydroxypentyl)(meth)acrylamide, N-(6-hydroxyhexyl)(meth)acrylamide, N-(methoxymethyl)(meth)acrylamide, N-(ethoxymethyl) ) (Meth)acrylamide, N-(propoxymethyl)(meth)acrylamide, N-(butoxymethyl)(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N- Isopropyl (meth)acrylamide, N-(3-dimethylaminopropyl)(meth)acrylamide, N-(1,1-dimethyl-3-oxobutyl)(meth)acrylamide, N-[2-(2-oxo-1- Imidazolidinyl)ethyl](meth)acrylamide, 2-acryloylamino-2-methyl-1-propanesulfonic acid and the like.

Examples of the monomer having a plurality of (meth)acryloyl groups in the molecule include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and 1,9-nonane. Two (in the molecule, such as diol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate. A monomer having a (meth)acryloyl group; a monomer having three (meth)acryloyl groups in the molecule, such as trimethylolpropane tri(meth)acrylate.

Copolymerizing a monomer other than the monomers (A-1), (A-2) and (A-3) which are components of the (meth)acrylic resin (A) and having no polar functional group. In this case, the amount is preferably 5% by weight or less based on all the monomers constituting the (meth)acrylic resin (A).

The resin component constituting the pressure-sensitive adhesive composition is the (meth)acrylic acid ester represented by the formula (II) described above, that is, the monomer (A-1) and a (meth)acrylic monomer having a hydroxyl group. Body, that is, an acrylic resin having a structural unit derived from each of the monomer (A-2) and the carboxyl group-containing (meth)acrylic acid ester represented by the formula (III), that is, the monomer (A-3) It may be a mixture of two or more kinds of (A). Moreover, a (meth)acrylic resin (A) having structural units derived from the monomers (A-1), (A-2) and (A-3) in a predetermined ratio is different from the (meth)acrylic resin. Resins may be mixed. Examples of different (meth)acrylic resins mixed in this case include those having a structural unit derived from the (meth)acrylic acid ester of the above formula (II) and having no polar functional group. The (meth)acrylic resin (A) having the structural units derived from the monomers (A-1), (A-2) and (A-3) in a predetermined ratio is the following (meth)acrylic resin: It is preferably 80% by weight or more, more preferably 90% by weight or more.

The (meth)acrylic resin (A) preferably has a weight average molecular weight Mw in terms of standard polystyrene by gel permeation chromatography (GPC) in the range of 500,000 to 2,000,000. The weight average molecular weight Mw is particularly preferably 500,000 to 1,700,000. When the weight average molecular weight in terms of standard polystyrene is 500,000 or more, the adhesiveness under high temperature and high humidity is improved, and the possibility of floating or peeling between the glass substrate and the pressure-sensitive adhesive sheet is reduced. And the reworkability tends to be improved, which is preferable. Further, if the weight average molecular weight is 2,000,000 or less, even if the dimensions of the optical film bonded to the pressure-sensitive adhesive sheet change, the pressure-sensitive adhesive layer changes following the dimensional change, so that the liquid crystal cell It is preferable because there is no difference between the brightness of the peripheral portion and the brightness of the central portion, and white spots and color unevenness tend to be suppressed. The molecular weight distribution represented by the ratio Mw/Mn of the weight average molecular weight Mw and the number average molecular weight Mn is not particularly limited, but is preferably in the range of about 3 to 7, for example.

In addition, the glass transition temperature of the (meth)acrylic resin (A) is preferably in the range of -10 to -60°C because of its adhesiveness. The glass transition temperature of the resin can be measured by a differential scanning calorimeter.

The (meth)acrylic resin (A) can be produced by various known methods such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method and a suspension polymerization method. In the production of this (meth)acrylic resin, a polymerization initiator is usually used. The polymerization initiator is used in an amount of about 0.001 to 5 parts by weight based on 100 parts by weight of all the monomers used for producing the (meth)acrylic resin.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator or the like is used. Examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone. As the thermal polymerization initiator, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 1,1′-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropio) And azo compounds such as 2,2′-azobis(2-hydroxymethylpropionitrile); lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroper. Organics such as oxides, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, tert-butyl peroxy neodecanoate, tert-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl)peroxide Peroxides: potassium persulfate, ammonium persulfate, and inorganic peroxides such as hydrogen peroxide. In addition, a redox type initiator in which a peroxide and a reducing agent are used in combination can also be used as the polymerization initiator.

Among the methods described above, the solution polymerization method is preferable as the method for producing the (meth)acrylic resin. Explaining with a specific example of the solution polymerization method, a desired monomer and an organic solvent are mixed, a thermal polymerization initiator is added under a nitrogen atmosphere, and the temperature is about 40 to 90° C., preferably 50 to 80° C. A method of stirring at about C for about 3 to 15 hours can be mentioned. Further, in order to control the reaction, a monomer or a thermal polymerization initiator may be added continuously or intermittently during the polymerization, or may be added in a state of being dissolved in an organic solvent. Here, examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; acetone, methyl ethyl ketone, and methyl isobutyl. Ketones such as ketones can be used.

[Crosslinking agent (B)]
The crosslinking agent (B) is blended with the (meth)acrylic resin (A) as described above. The cross-linking agent (B) is a compound having at least two functional groups capable of cross-linking the (meth)acrylic resin in the molecule by reacting with a hydroxyl group or a carboxyl group which are polar functional groups in the (meth)acrylic resin (A). Specifically, an isocyanate compound, an epoxy compound, a metal chelate compound, an aziridine compound, etc. are exemplified.

The isocyanate compound is a compound having at least two isocyanato groups (-NCO) in the molecule, and examples thereof include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, Examples thereof include hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate and the like. Further, adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, and dimers and trimers of isocyanate compounds can also be used as the crosslinking agent for the pressure-sensitive adhesive. It is also possible to use a mixture of two or more isocyanate compounds.

The epoxy compound is a compound having at least two epoxy groups in the molecule, and examples thereof include bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, and glycerin triglycidyl ether. , 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, N,N-diglycidylaniline, N,N,N′,N′-tetraglycidyl-m-xylenediamine and the like. It is also possible to use a mixture of two or more epoxy compounds.

Examples of the metal chelate compound include a compound in which acetylacetone or ethyl acetoacetate is coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium. Can be mentioned.

The aziridine compound is a compound having at least two 3-membered ring skeletons each having one nitrogen atom and two carbon atoms, which is also called ethyleneimine, in the molecule. For example, diphenylmethane-4,4′-bis( 1-aziridinecarboxamide), toluene-2,4-bis(1-aziridinecarboxamide), triethylenemelamine, isophthaloylbis-1-(2-methylaziridine), tris-1-aziridinylphosphine oxide, hexamethylene Examples include -1,6-bis(1-aziridinecarboxamide), trimethylolpropane tris-β-aziridinylpropionate, and tetramethylolmethane tris-β-aziridinylpropionate.

Among these cross-linking agents, isocyanate-based compounds, especially xylylene diisocyanate, tolylene diisocyanate or hexamethylene diisocyanate, or adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolpropane, and isocyanate compounds. Dimers, trimers, and the like, mixtures of these isocyanate compounds, and the like are preferably used.

Particularly preferred isocyanate compounds include tolylene diisocyanate, adducts obtained by reacting tolylene diisocyanate with polyol, dimers of tolylene diisocyanate, and trimers of tolylene diisocyanate.

The crosslinking agent (B) is blended in a proportion of 0.01 to 5 parts by weight with respect to 100 parts by weight of the (meth)acrylic resin (A). The compounding amount of the crosslinking agent (B) is preferably about 0.1 to 3 parts by weight, more preferably about 0.1 to 1 part by weight, based on 100 parts by weight of the (meth)acrylic resin (A). When the amount of the cross-linking agent (B) is 0.01 parts by weight or more, and particularly 0.1 parts by weight or more, relative to 100 parts by weight of the (meth)acrylic resin (A), the pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition. It is preferable that the durability is improved, and if it is 5 parts by weight or less, white spots are not noticeable when the optical film with an adhesive is applied to a liquid crystal display device, which is preferable.

[Silane-based compound (C)]
The pressure-sensitive adhesive composition of the present invention is a silane compound (C) represented by the above formula (I) in order to improve the adhesiveness between the pressure-sensitive adhesive sheet or the optical film with a pressure-sensitive adhesive when it is formed. )including. The silane compound (C) is preferably contained in the (meth)acrylic resin (A) before the addition of the crosslinking agent.

In the present invention, by containing the silane compound (C) represented by the above formula (I), it is possible to form a pressure-sensitive adhesive layer having excellent adhesiveness with a glass substrate and having a suitable pressure-sensitive adhesive force, When peeling the pressure-sensitive adhesive layer from the glass substrate, by adding water to the interface between the pressure-sensitive adhesive layer and the glass substrate, a pressure-sensitive adhesive layer exhibiting excellent peelability can be formed.

In the silane-based compound (C) represented by the above formula (I), R ₁ represents an alkyl group having 1 to 14 carbon atoms, an aralkyl group, an aryl group or an alkenyl group, and as a specific example, R ₁ is a methyl group. , Ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, and hexyl group. In the silane-based compound (C) represented by the above formula (I), R ₂ represents an alkyl group having 1 to 6 carbon atoms, and specific examples are compounds in which R ₂ is a methyl group, an ethyl group or a propyl group. Are listed. Among these, 3-ureidopropyltrialkoxysilane is preferable as the silane compound (C) represented by the above formula (I). In addition, you may contain 2 or more types of silane type compounds (C) represented by Formula (I).

The silane-based compound contained in the pressure-sensitive adhesive composition of the present invention may be the silane-based compound (C) represented by the above-mentioned formula (I) alone or may be contained in the formula (I ) And a silane compound other than (C) other than the silane compound represented by the formula (I) may be contained together with the silane compound (C) represented by the formula (I). Examples of silane compounds other than the silane compound (C) represented by the formula (I) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, and 3-glycidoxypropyltri. Methoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltri Methoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethylsilane Etc., and may be of the silicone oligomer type. Examples of the silicone oligomer in the form of (monomer)-(monomer) copolymer include the following.

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer, and 3-mercaptopropyltriethoxysilane-tetraethoxy Copolymers containing mercaptopropyl groups, such as silane copolymers;
Mercaptomethyl groups such as mercaptomethyltrimethoxysilane-tetramethoxysilane copolymers, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymers, mercaptomethyltriethoxysilane-tetramethoxysilane copolymers, and mercaptomethyltriethoxysilane-tetraethoxysilane copolymers. Containing copolymers;
3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane -Tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and Copolymers containing methacryloyloxypropyl groups, such as 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymers;
3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane -Tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and Copolymers containing acryloyloxypropyl groups, such as 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymers;
Vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetraethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, Copolymers containing vinyl groups, such as vinylmethyldimethoxysilane-tetraethoxysilane copolymers, vinylmethyldiethoxysilane-tetramethoxysilane copolymers, and vinylmethyldiethoxysilane-tetraethoxysilane copolymers. Two or more kinds of silane compounds other than the silane compound (C) represented by the formula (I) may be used.

Silane-based compounds are often liquids. The amount of the silane compound (C) represented by the formula (I) in the adhesive composition is 0.01 to 10 parts by weight based on 100 parts by weight of the solid content of the (meth)acrylic resin (A). %, preferably 0.03 to 2 parts by weight, and more preferably 0.2 to 1 part by weight. When a silane-based compound other than the silane-based compound (C) represented by the formula (I) is contained, the (meth)acrylic resin (including the silane-based compound (C) represented by the formula (I) ( The amount is about 0.01 to 10 parts by weight, preferably 0.03 to 2 parts by weight, and more preferably 0.2 to 1 part by weight, based on 100 parts by weight of the solid content of A). When the amount of the silane compound (C) represented by the formula (I) is 0.01 parts by weight or more, particularly 0.03 parts by weight or more, relative to 100 parts by weight of the solid content of the (meth)acrylic resin (A), It is preferable because the adhesiveness between the pressure-sensitive adhesive layer and the glass substrate and the durability are improved. Further, it is preferable that the amount is 0.2 parts by weight or more because the adhesive force when water is added to the interface between the pressure-sensitive adhesive layer and the glass substrate can be significantly reduced and the peeling property can be further improved. When the combined content of the silane compound (C) represented by the formula (I) and the other silane compounds is 10 parts by weight or less, particularly 2 parts by weight or less or 1 part by weight or less, Bleedout of the silane compound from the pressure-sensitive adhesive layer tends to be suppressed, which is preferable.

[Ionic compound]
The pressure-sensitive adhesive composition may further contain an ionic compound as an antistatic agent for imparting antistatic properties to the pressure-sensitive adhesive layer. The ionic compound is a compound having an inorganic cation or an organic cation and an inorganic anion or an organic anion. Two or more ionic compounds may be used.

Examples of the inorganic cations include alkali metal ions such as lithium cations [Li ⁺ ], sodium cations [Na ⁺ ] and potassium cations [K ⁺ ], beryllium cations [Be ²⁺ ], magnesium cations [Mg ²⁺ ]. , Alkaline earth metal ions such as calcium cation [Ca ²⁺ ] and the like.

Examples of the organic cation include an imidazolium cation, a pyridinium cation, a pyrrolidinium cation, an ammonium cation, a sulfonium cation, and a phosphonium cation.

Among the above-mentioned cation components, the organic cation component is preferably used because it has excellent compatibility with the pressure-sensitive adhesive composition. Among the organic cation components, the pyridinium cation and the imidazolium cation are particularly preferably used from the viewpoint of being difficult to be charged when the release film provided on the pressure-sensitive adhesive layer is peeled off.

Examples of the inorganic anion include chloride anion [Cl ^- ], bromide anion [Br ^- ], iodide anion [I ^- ], tetrachloroaluminate anion [AlCl ₄ ^- ], heptachlorodialuminate anion [Al ₂ Cl ₇ ^- ], tetrafluoroborate anion [BF ₄ ^- ], hexafluorophosphate anion [PF ₆ ^- ], perchlorate anion [ClO ₄ ^- ], nitrate anion [NO ₃ ^- ], hexafluoroarsenate anion [AsF ₆ ^- ], hexafluoroantimonate anion [SbF ₆ ^- ], hexafluoroniobate anion [NbF ₆ ^- ], hexafluorotantalate anion [TaF ₆ ^- ], dicyanamide anion [(CN) ₂ N ^- ], and the like. To be

Examples of the organic anion include acetate anion [CH ₃ COO ⁻ ], trifluoroacetate anion [CF ₃ COO ⁻ ], methanesulfonate anion [CH ₃ SO ₃ ⁻ ], trifluoromethanesulfonate anion [CF ₃ SO ₃ ⁻ ], p- toluenesulfonate anion _{[p-CH 3 C 6 H 4} SO 3 - ], bis (fluorosulfonyl) imide anion [(FSO _{2) 2} N ^-], bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N ^-], tris (trifluoromethanesulfonyl) meth acetonide anion _{[(CF 3 SO 2) 3 C} - ], dimethyl phosphinate anion [(CH _{3) 2} POO ^-], (poly) hydrofluoroether fluoride anion [ F(HF) _n ^- ] (n is about 1 to 3), thiocyanate anion [SCN ^- ], perfluorobutane sulfonate anion [C ₄ F ₉ SO ₃ ^- ], bis(pentafluoroethanesulfonyl)imide anion [(C ₂ F ₅ SO ₂ ) ₂ N ⁻ ], perfluorobutanoate anion [C ₃ F ₇ COO ⁻ ], (trifluoromethanesulfonyl)(trifluoromethanecarbonyl)imide anion [(CF ₃ SO ₂ )(CF ₃ CO) N ^-], perfluoro-1,3-disulfonate anion ^{_{[- O 3 S (CF 2)}} 3 SO 3 - ], carbonate anions [CO ₃ ^2-], and the like.

Among the above-mentioned anion components, the anion component containing a fluorine atom is preferably used because it gives an ionic compound having excellent antistatic performance. Specific examples include a bis(fluorosulfonyl)imide anion, a hexafluorophosphate anion, or a bis(trifluoromethanesulfonyl)imide anion.

Specific examples of the ionic compound can be appropriately selected from a combination of the above cation component and anion component. Examples of ionic compounds having an organic cation are listed below by classifying them according to the structure of the organic cation.

Pyridinium salt:
N-hexylpyridinium hexafluorophosphate,
N-octylpyridinium hexafluorophosphate,
N-octyl-4-methylpyridinium hexafluorophosphate,
N-butyl-4-methylrupyridinium hexafluorophosphate,
Tetrabutylammonium hexafluorophosphate,
N-decylpyridinium bis(fluorosulfonyl)imide,
N-dodecylpyridinium bis(fluorosulfonyl)imide,
N-tetradecylpyridinium bis(fluorosulfonyl)imide,
N-hexadecylpyridinium bis(fluorosulfonyl)imide,
N-dodecyl-4-methylpyridinium bis(fluorosulfonyl)imide,
N-tetradecyl-4-methylpyridinium bis(fluorosulfonyl)imide,
N-hexadecyl-4-methylpyridinium bis(fluorosulfonyl)imide,
N-benzyl-2-methylpyridinium bis(fluorosulfonyl)imide,
N-benzyl-4-methylpyridinium bis(fluorosulfonyl)imide N-hexylpyridinium bis(trifluoromethanesulfonyl)imide,
N-octylpyridinium bis(trifluoromethanesulfonyl)imide,
N-octyl-4-methylpyridinium bis(trifluoromethanesulfonyl)imide,
N-butyl-4-methyl rupyridinium bis(trifluoromethanesulfonyl)imide.

Imidazolium salt:
1-ethyl-3-methylimidazolium hexafluorophosphate,
1-ethyl-3-methylimidazolium p-toluenesulfonate,
1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide 1-butyl-3-methylimidazolium methanesulfonate,
1-Butyl-3-methylimidazolium bis(fluorosulfonyl)imide.

Pyrrolidinium salt:
N-butyl-N-methylpyrrolidinium hexafluorophosphate,
N-butyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide.

Quaternary ammonium salt:
Tetrabutylammonium p-toluenesulfonate,
(2-hydroxyethyl)trimethylammonium bis(trifluoromethanesulfonyl)imide,
(2-Hydroxyethyl)trimethylammonium dimethylphosphinate.

Examples of the ionic compound having an inorganic cation are as follows.
Lithium bromide,
Lithium iodide,
Lithium tetrafluoroborate,
Lithium hexafluorophosphate,
Lithium thiocyanate,
Lithium perchlorate,
Lithium trifluoromethanesulfonate,
Lithium bis(fluorosulfonyl)imide lithium bis(trifluoromethanesulfonyl)imide,
Lithium bis(pentafluoroethanesulfonyl)imide,
Lithium tris(trifluoromethanesulfonyl)methanide,
Lithium p-toluenesulfonate,
Sodium hexafluorophosphate,
Sodium bis(fluorosulfonyl)imide,
Sodium bis(trifluoromethanesulfonyl)imide,
Sodium p-toluenesulfonate,
Potassium hexafluorophosphate,
Potassium bis(fluorosulfonyl)imide,
Potassium bis(trifluoromethanesulfonyl)imide,
Potassium p-toluene sulfonate.

The ionic compound is preferably solid at room temperature. As compared with the case of using an ionic compound that is liquid at room temperature, the antistatic performance can be maintained for a long period of time. From the viewpoint of the long-term stability of the antistatic property, the ionic compound preferably has a melting point of 30° C. or higher, more preferably 35° C. or higher. On the other hand, if the melting point is too high, the compatibility with the (meth)acrylic resin (A) deteriorates. Therefore, the melting point is preferably 90°C or lower, more preferably 70°C or lower, and further preferably less than 50°C. Is.

The content of the ionic compound in the pressure-sensitive adhesive composition is preferably 0.2 to 8 parts by weight, and more preferably 0.2 to 5 parts by weight, based on 100 parts by weight of the (meth)acrylic resin (A). Parts, more preferably 0.3 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight. The content of the ionic compound of 0.2 parts by weight or more is advantageous for improving the antistatic performance, and the content of 8 parts by weight or less is advantageous for maintaining the durability of the pressure-sensitive adhesive layer.

[Other ingredients]
The pressure-sensitive adhesive composition is an additive such as a crosslinking catalyst, a weathering stabilizer, a tackifier, a plasticizer, a softening agent, a dye, a pigment, an inorganic filler, light-scattering fine particles, and a resin other than the (meth)acrylic resin (A). Can be included. If a cross-linking catalyst is added to the pressure-sensitive adhesive composition together with a cross-linking agent, the pressure-sensitive adhesive sheet can be prepared by curing for a short time, and in the obtained pressure-sensitive adhesive-attached optical film, floating between the optical film and the pressure-sensitive adhesive sheet is achieved. It is possible to suppress the occurrence of peeling and foaming in the pressure-sensitive adhesive sheet. In addition, it is also useful to mix an ultraviolet-curable compound in the pressure-sensitive adhesive composition, form the pressure-sensitive adhesive layer, and then irradiate it with ultraviolet rays to cure it to form a harder pressure-sensitive adhesive layer. Examples of the crosslinking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resins and melamine resins.

[Preparation of adhesive composition]
The components described above are mixed in a state of being dissolved in a solvent to form a pressure-sensitive adhesive composition. Here, examples of the solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; acetone, methyl ethyl ketone, and methyl isobutyl ketone. Such as ketones can be used. Although this pressure-sensitive adhesive composition exhibits good performance, it preferably does not contain an amino group in order to avoid strong adhesion when it comes into contact with a specific release film. In particular, it is preferable not to have a tertiary amino group.

The pressure-sensitive adhesive composition dissolved in the above solvent is applied onto a suitable base material and dried to form a pressure-sensitive adhesive sheet. The substrate used here is generally a plastic film, and a typical example thereof is a release film subjected to a release treatment. The release film is, for example, a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate, and the like, on the surface of which the pressure-sensitive adhesive sheet is formed, a release treatment such as silicone treatment is applied. be able to.

[Adhesive sheet]
As described above, the pressure-sensitive adhesive sheet of the present invention is formed into a sheet shape from the pressure-sensitive adhesive composition described above. In the present specification, the “adhesive sheet” in the laminate may be referred to as “adhesive layer”. The pressure-sensitive adhesive sheet of the present invention is preferably used for a certain period of time after production, preferably for a period of 7 days or more, to allow the crosslinking reaction to proceed before use. The pressure-sensitive adhesive sheet of the present invention preferably has a gel fraction of 65 to 85% after the sheet is applied in a sheet shape and allowed to stand at room temperature for 7 days. The adhesive sheet having such gel fraction exhibits excellent durability.

Here, the gel fraction is a value measured according to the following (1) to (4).
(1) An adhesive sheet having an area of about 8 cm×about 8 cm and a metal mesh made of SUS304 of about 10 cm×about 10 cm (whose weight is Wm) are laminated.
(2) The bonded product obtained in (1) above is weighed, its weight is set to Ws, and then the adhesive sheet is folded 4 times so as to wrap it and fastened with a stapler (stapler), and then weighed. The weight is Wb.
(3) The mesh stapled in (2) above is placed in a glass container, 60 mL of ethyl acetate is added and immersed, and the glass container is stored at room temperature for 3 days.
(4) The mesh is taken out from the glass container, dried at 120° C. for 24 hours, and then weighed, and the weight is defined as Wa.
Gel fraction (% by weight)=[{Wa-(Wb-Ws)-Wm}/(Ws-Wm)]×100
Calculate the gel fraction based on

The gel fraction after standing for 7 days can be adjusted by, for example, the type of the (meth)acrylic resin (A) or the amount of the cross-linking agent, which is the active ingredient of the pressure-sensitive adhesive composition forming the gel composition. Specifically, the amount of the monomer having a polar functional group including the monomer (A-2) and the monomer (A-3) in the (meth)acrylic resin (A) is increased, or When the amount of the cross-linking agent (B) in the pressure-sensitive adhesive composition is increased, the gel fraction increases, so the gel fraction may be adjusted by adjusting these amounts.

The adhesive strength of the pressure-sensitive adhesive sheet to glass is preferably 1.0 to 8.0 N/25 mm. When it is 1.0 N/25 mm, the adhesive force is too low and the glass substrate and the adhesive sheet are easily peeled from each other. If it exceeds 8.0 N/25 mm, the followability of the pressure-sensitive adhesive sheet with respect to the dimensional change of the optical film may be lowered, and the durability may be lowered. The adhesive strength of the pressure-sensitive adhesive sheet to glass can be controlled by adjusting the elasticity of the base polymer of the pressure-sensitive adhesive composition or adjusting the compounding amount of an additive (for example, a silane compound).

The adhesive strength of the pressure-sensitive adhesive sheet with respect to glass is preferably significantly reduced when water is added to the interface between the pressure-sensitive adhesive sheet and the glass substrate. When the adhesive force of the pressure-sensitive adhesive sheet to the glass substrate when water is not added is P ₁ and the adhesive force of the adhesive sheet when water is added to the glass substrate is P ₂ , the following formula:
Adhesive force decrease rate (%) at the time of adding water=(P ₁ −P ₂ )/P ₁ ×100
As the rate of decrease in adhesive strength when water is added calculated based on, the adhesive strength can be reduced and peelability can be greatly improved by simply adding water during peeling, resulting in excellent reworkability. ..

[Optical film with adhesive]
The pressure-sensitive adhesive-attached optical film of the present invention is obtained by laminating the pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition as described above on at least one surface of the optical film. The optical film used for the pressure-sensitive adhesive-attached optical film is a film having optical characteristics, and examples thereof include a polarizing plate and a retardation film.

The polarizing plate is an optical film having a function of emitting polarized light with respect to incident light such as natural light. The polarizing plate absorbs linearly polarized light having an oscillating surface in a certain direction and transmits linearly polarized light having an oscillating surface orthogonal to the linearly polarizing plate, and reflects linearly polarized light having an oscillating surface in a certain direction. There are a polarization separation plate having a property of transmitting linearly polarized light having a vibration plane orthogonal to it, an elliptically polarizing plate in which a polarizing plate and a retardation film described later are laminated. As a preferred specific example of a polarizing film, particularly a polarizing film (also referred to as a polarizer) that exhibits the function of a linear polarizing plate, a uniaxially stretched polyvinyl alcohol-based resin film is used, and two colors such as iodine and a dichroic dye Examples thereof include those in which a sex dye is adsorbed and oriented.

The retardation film is an optical film exhibiting optical anisotropy, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, cyclic polyolefin, polystyrene, polysulfone, polyether sulfone, polyvinylidene fluoride. /Polymethyl methacrylate, liquid crystal polyester, acetyl cellulose, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc. A stretched film obtained by stretching the polymer film about 1.01 to 6 times. To be Above all, a polymer film obtained by uniaxially or biaxially stretching a polycarbonate film or a cyclic polyolefin film is preferable. There are those called uniaxial retardation film, wide viewing angle retardation film, low photoelasticity retardation film, etc., but they are applicable to any of them.

Further, a film in which optical anisotropy is expressed by coating/orientation of a liquid crystal compound or a film in which optical anisotropy is expressed by coating of an inorganic layered compound can be used as the retardation film. Such a retardation film is called a temperature compensation type retardation film, and a rod-shaped liquid crystal which is sold by JX Nippon Mining & Energy Corporation under the trade name of "LC film" is twisted and aligned. Film, which is also sold by JX Nikko Nisseki Energy Co., Ltd. under the brand name of "NH film", is a film with tilted alignment of rod-shaped liquid crystals, and is sold by Fuji Film Co., Ltd. under the brand name of "WV film". A film in which a disc-shaped liquid crystal is tilt-aligned, a fully biaxially-oriented film sold by Sumitomo Chemical Co., Ltd. under the product name of "VAC film", and a product of "new VAC film" also from Sumitomo Chemical Co., Ltd. There is a biaxially oriented film sold under the name.

Furthermore, those obtained by adhering a protective film to these optical films can also be used as the optical film. As the protective film, a transparent resin film is used, and as the transparent resin, for example, acetyl cellulose resin represented by triacetyl cellulose or diacetyl cellulose, methacrylic resin represented by polymethyl methacrylate, polyester resin, polyolefin. Examples thereof include resins, polycarbonate resins, polyetheretherketone resins, polysulfone resins and the like. An ultraviolet absorber such as a salicylic acid ester-based compound, a benzophenone-based compound, a benzotriazole-based compound, a triazine-based compound, a cyanoacrylate-based compound, and a nickel complex salt-based compound may be blended with the resin forming the protective film. As the protective film, an acetyl cellulose-based resin film such as a triacetyl cellulose film is preferably used.

Among the optical films described above, the linear polarizing plate is often used in a state in which a protective film is attached to one or both surfaces of a polarizing film that constitutes the linear polarizing film, for example, a polarizing film made of polyvinyl alcohol-based resin. .. Further, the elliptically polarizing plate described above is a laminate of a linear polarizing plate and a retardation film, but the linear polarizing plate is also often in a state in which a protective film is attached to one side or both sides of the polarizing film. .. When the pressure-sensitive adhesive sheet according to the present invention is attached to such an elliptically polarizing plate, it is usually attached to the retardation film side.

In the pressure-sensitive adhesive-attached optical film, it is preferable that the release film, which has been subjected to the above-described release treatment, is attached to the surface of the pressure-sensitive adhesive layer to protect the pressure-sensitive adhesive layer surface until use. Thus, the pressure-sensitive adhesive-attached optical film provided with the release film, for example, the release-treated surface of the release film is coated with the above-mentioned pressure-sensitive adhesive composition to form a pressure-sensitive adhesive sheet, the obtained pressure-sensitive adhesive sheet A method of laminating on an optical film, a method of applying a pressure-sensitive adhesive composition on an optical film to form a pressure-sensitive adhesive sheet, and attaching a release film to the pressure-sensitive adhesive surface to protect the pressure-sensitive adhesive optical film. Can be manufactured.

The thickness of the pressure-sensitive adhesive layer formed on the optical film is not particularly limited, but is usually 30 μm or less, preferably 10 μm or more, and more preferably 15 to 25 μm. When the thickness of the pressure-sensitive adhesive layer is 30 μm or less, the adhesiveness under high temperature and high humidity is improved, and the possibility of floating or peeling between the glass substrate and the pressure-sensitive adhesive layer tends to decrease. Moreover, it is preferable because the reworkability tends to be improved, and when the thickness is 10 μm or more, the adhesive layer follows the dimensional change even if the size of the optical film stuck thereto changes. This is preferable because there is no difference between the brightness of the peripheral portion of the liquid crystal cell and the brightness of the central portion of the liquid crystal cell, and white spots and color unevenness tend to be suppressed.

The pressure-sensitive adhesive-attached optical film of the present invention is applied to the interface between the pressure-sensitive adhesive layer and the glass substrate when the optical film is adhered to the glass substrate to form an optical laminate and then the optical film is peeled from the glass substrate due to some trouble. By adding water, the adhesive strength of the pressure-sensitive adhesive layer is greatly reduced and excellent peelability is exhibited. Therefore, the pressure-sensitive adhesive layer is peeled off along with the optical film, and almost no fog or adhesive residue is generated on the surface of the glass substrate that was in contact with the pressure-sensitive adhesive layer. It is easy to reattach the optical film. When reattaching the adhesive-coated optical film to the glass substrate after peeling, if the water added at the time of peeling adheres to the glass substrate, wipe off such water and then reattach it. It is preferable because it has good properties. Similarly, when the pressure-sensitive adhesive-attached optical film after peeling is adhered to a glass substrate, if water adheres to the pressure-sensitive adhesive layer, wipe off the water and then re-attach it to obtain good adhesiveness. Is preferred.

[Optical layered product]
The pressure-sensitive adhesive-attached optical film of the present invention can be bonded to the glass substrate on the pressure-sensitive adhesive layer side to form an optical laminate. In order to form an optical laminate by laminating an optical film with an adhesive on a glass substrate, for example, the release film is peeled off from the optical film with an adhesive obtained as described above, and the exposed adhesive layer surface is the surface of the glass substrate. You can attach it to. Examples of the glass substrate include glass substrates for liquid crystal cells, antiglare glass, sunglasses glass, and the like. Above all, an optical film with an adhesive (upper polarizing plate) is laminated on the glass substrate on the front side (viewing side) of the liquid crystal cell, and another optical film with an adhesive (lower polarizing plate) is laminated on the glass substrate on the back side of the liquid crystal cell. An optical layered body formed by laminating the above) is preferable because it can be used as a panel (liquid crystal panel) for a liquid crystal display device. Examples of the material of the glass substrate include soda lime glass, low alkali glass, non-alkali glass, and the like, and non-alkali glass is preferably used for the liquid crystal cell.

About the optical laminated body which concerns on this invention, the example of some suitable layer structure was shown with the cross-sectional schematic diagram in FIG. In the example shown in FIG. 1A, a protective film 3 having a surface treatment layer 2 is attached to one surface of a polarizing film 1 on the surface opposite to the surface treatment layer 2 to form a polarizing plate 5. ing. In this example, the polarizing plate 5 also serves as the optical film 10 in the present invention. An adhesive layer 20 is provided on the surface of the polarizing film 1 opposite to the protective film 3 to form an adhesive-attached optical film 25. Then, the surface of the pressure-sensitive adhesive layer 20 on the side opposite to the polarizing plate 5 is bonded to the liquid crystal cell 30 which is a glass substrate to form the optical laminate 40.

In the example shown in FIG. 1(B), the first protective film 3 having the surface treatment layer 2 is attached to one surface of the polarizing film 1 on the surface opposite to the surface treatment layer 2, and A second protective film 4 is attached to the other surface to form a polarizing plate 5. Also in this example, the polarizing plate 5 simultaneously serves as the optical film 10 in the present invention. The pressure-sensitive adhesive layer 20 is provided on the outside of the second protective film 4 forming the polarizing plate 5 to form the pressure-sensitive adhesive-attached optical film 25. Then, the surface of the pressure-sensitive adhesive layer 20 on the side opposite to the polarizing plate 5 is bonded to the liquid crystal cell 30 which is a glass substrate to form the optical laminate 40.

In the example shown in FIG. 1C, a protective film 3 having a surface treatment layer 2 is attached to one surface of the polarizing film 1 on the surface opposite to the surface treatment layer 2 to form a polarizing plate 5. There is. On the surface of the polarizing film 1 opposite to the protective film 3, the retardation film 7 is adhered via the interlayer adhesive 8 to form the optical film 10. The pressure-sensitive adhesive layer 20 is provided outside the retardation film 7 forming the optical film 10 to form the pressure-sensitive adhesive-attached optical film 25. Then, the surface of the pressure-sensitive adhesive layer 20 opposite to the optical film 10 is bonded to the liquid crystal cell 30 which is a glass substrate to form an optical laminate 40.

In the example shown in FIG. 1D, the first protective film 3 having the surface treatment layer 2 is attached to one surface of the polarizing film 1 on the surface opposite to the surface treatment layer 2 to form a polarizing film. The second protective film 4 is attached to the other surface of the polarizing plate 5 to form the polarizing plate 5. On the outer side of the second protective film 4 constituting the polarizing plate 5, the retardation film 7 is attached via the interlayer adhesive 8 to form the optical film 10. The pressure-sensitive adhesive layer 20 is provided outside the retardation film 7 forming the optical film 10 to form the pressure-sensitive adhesive-attached optical film 25. Then, the surface of the pressure-sensitive adhesive layer 20 opposite to the optical film 10 is bonded to the liquid crystal cell 30 which is a glass substrate to form an optical laminate 40.

In these examples, the first protective film 3 and the second protective film 4 are generally composed of a triacetyl cellulose film, but may be composed of the various transparent resin films described above. it can. The surface treatment layer formed on the surface of the first protective film 3 can be a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, or the like. It is also possible to provide a plurality of layers among these.

When the retardation film 7 is laminated on the polarizing plate 5 as in the example shown in FIGS. 1C and 1D, a suitable example of the retardation film 7 is a medium or small liquid crystal display device. , 1/4 wavelength plate. In this case, it is general that the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 which is a quarter-wave plate intersect each other at an angle of about 45 degrees. Depending on the characteristics, the angle may be deviated from 45 degrees to some extent. On the other hand, in the case of a large-sized liquid crystal display device such as a television, a retardation film having various retardation values according to the characteristics of the liquid crystal cell 30 is used for the purpose of compensating for the retardation of the liquid crystal cell 30 and viewing angle compensation. .. In this case, it is general that the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 are arranged so as to be substantially orthogonal or substantially parallel to each other. When the retardation film 7 is composed of a quarter-wave plate, a uniaxially or biaxially stretched film is preferably used. When the retardation film 7 is provided for the purpose of compensating the retardation of the liquid crystal cell 30 or compensating for the viewing angle, in addition to the uniaxially or biaxially stretched film, it is also oriented in the thickness direction in addition to the uniaxially or biaxially stretched film. What is called an optical compensation film, such as a film or a film in which a retardation-developing substance such as liquid crystal is applied on the support film to fix the orientation, can be used as the retardation film 7.

Similarly, when the polarizing plate 5 and the retardation film 7 are bonded together via the interlayer adhesive 8 as in the example shown in (C) and (D) of FIG. It is customary to use a typical acrylic pressure-sensitive adhesive, but it is of course possible to use the pressure-sensitive adhesive sheet defined in the present invention here. In the case where the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 are arranged so as to be substantially orthogonal or substantially parallel to each other, as in the large-sized liquid crystal display device described above, the polarizing plate 5 and In applications where the phase difference film 7 can be roll-to-roll laminated and removability between the two is not required, the interlayer adhesive 8 shown in FIGS. 1C and 1D is used instead. It is also possible to use an adhesive that, once adhered, is firmly joined and cannot be peeled off. Examples of such an adhesive include, for example, an aqueous adhesive composed of an aqueous solution or an aqueous dispersion, which exhibits adhesive strength by evaporating water as a solvent, and ultraviolet curable which exhibits adhesive strength and is cured by ultraviolet irradiation. Examples include mold adhesives.

It should be noted that, as shown in FIGS. 1C and 1D, the retardation film 7 on which the pressure-sensitive adhesive layer 20 is formed itself can be circulated by itself. It can be a film. An optical film with a pressure-sensitive adhesive having a pressure-sensitive adhesive layer formed on a retardation film can be bonded to a liquid crystal cell that is a glass substrate to form an optical laminate, and a polarizing plate is provided on the retardation film side. It is also possible to bond them to form another optical film with an adhesive.

FIG. 1 shows an example in which the pressure-sensitive adhesive-attached optical film 25 is arranged on the viewing side of the liquid crystal cell 30, but the pressure-sensitive adhesive-attached optical film according to the present invention is a back side of the liquid crystal cell, that is, a back side. It can also be placed on the light side. When the pressure-sensitive adhesive-attached optical film of the present invention is arranged on the back side of the liquid crystal cell, a protective film having no surface treatment layer is adopted instead of the protective film 3 having the surface treatment layer 2 shown in FIG. Others can be configured similarly to (A) to (D) of FIG. In this case, various optical films known to be arranged on the back side of the liquid crystal cell, such as a brightness enhancement film, a light condensing film, and a diffusion film, may be provided outside the protective film that constitutes the polarizing plate. It is possible.

As described above, the optical layered body of the present invention can be suitably used for a liquid crystal display device. A liquid crystal display device formed from the optical layered body of the present invention is, for example, a liquid crystal display for a personal computer including a notebook type, a desktop type, a PDA (Personal Digital Assistant), a television, an in-vehicle display, an electronic dictionary, a digital camera. It can be used for digital video cameras, electronic desk calculators, clocks, etc.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples,% and parts indicating the content or the amount used are based on weight unless otherwise specified. First, Polymerization Examples A to C in which the (meth)acrylic resin (A) that is the main component of the pressure-sensitive adhesive composition is manufactured will be shown.

<Polymerization Examples A to C of (meth)acrylic resin (A)>
In a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer, 81.8 parts of ethyl acetate, butyl acrylate (hereinafter also referred to as “BA”) as a monomer (A-1), methyl acrylate (Hereinafter, also referred to as “MA”), 2-(2-phenoxyethoxy)ethyl acrylate (hereinafter, also referred to as “PEA2”), 2-hydroxyethyl acrylate (hereinafter, also referred to as “A-2”) “HEA” is also referred to as 2-carboxyethyl acrylate (hereinafter also referred to as “CEA”) as the monomer (A-3), and the monomers (A-1), (A-2) and ( Acrylic acid (hereinafter, also referred to as "AA") was charged as a monomer other than A-3) in an amount shown in Table 1, and the internal temperature was adjusted while the air in the apparatus was replaced with nitrogen gas to make oxygen free. Raised to 55°C. Then, a total amount of a solution prepared by dissolving 0.14 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. The temperature was maintained for 1 hour after the addition of the initiator, and then ethyl acetate was continuously added into the reaction vessel at an addition rate of 17.3 parts/hr while maintaining the internal temperature at 54 to 56° C. ) When the concentration of the acrylic resin reached 35%, the addition of ethyl acetate was stopped, and the temperature was kept at this temperature for 12 hours after the start of addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the (meth)acrylic resin to 20% to prepare an ethyl acetate solution of the (meth)acrylic resin.

In the above, as the 2-carboxyethyl acrylate (CEA), the trade name “β-CEA” sold by Daicel Cytec Co., Ltd. was used. Its chemical composition is
CH ₂ =CH(COOCH ₂ CH ₂ ) _n COOH (n = 1 on average)
Specifically, 40% of 2-carboxyethyl acrylate (that is, a dimer of acrylic acid) acrylic acid, 40% of a trimer or more oligomer of acrylic acid, and 20% of acrylic acid.

Next, examples and comparative examples in which a pressure-sensitive adhesive is prepared using the (meth)acrylic resin produced in Polymerization Examples A to C and applied to an optical film will be shown. In each of Examples and Comparative Examples, the crosslinking agent (B) and the silane compound shown in Table 2 were used. The cross-linking agent (B) and silane compound shown in Table 2 are shown below. The names given at the beginning are all trade names.

<Crosslinking agent (B)>
Coronate L: a solution of trimethylolpropane adduct of tolylene diisocyanate in ethyl acetate (solid content concentration 75%), obtained from Nippon Polyurethane Co., Ltd.

<Silane-based compound (C) represented by formula (I)>
KBM-585:3-ureidopropyltrialkoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.

<Silane compounds other than the silane compound (C) represented by the formula (I)>
KBM-403: 3-glycidoxypropyltrimethoxysilane, liquid, manufactured by Shin-Etsu Chemical Co., Ltd.
KBM-4803: Glycidoxyoctyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.
A100: acetoacetylpropyltrimethoxysilane, manufactured by Soken Chemical Co., Ltd.
KBM-573: N-phenyl-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.

<Ionic compound>
N-octyl-4-methylpyridinium hexafluorophosphate (mp 44°C).

[Examples 1 to 4 and Comparative Examples 1 to 6]
(A) Production of pressure-sensitive adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 6 Solid content of 20% ethyl acetate solution of (meth)acrylic resin obtained in any of Polymerization Examples A to C shown in Table 2. 0.5 parts by weight of the cross-linking agent in solid content and 100 parts by weight of the above silane-based compound were mixed in an amount shown in Table 2, and ethyl acetate was added so that the solid content concentration became 13%. Thus, the pressure-sensitive adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were prepared.

(B) Preparation of pressure-sensitive adhesive sheet Each of the pressure-sensitive adhesive compositions prepared in the above (a) was subjected to a release treatment with a polyethylene terephthalate film [trade name "SP-PLR382050", obtained from Lintec Co., Ltd., separator Referred to as [1] is applied to the release-treated surface using an applicator so that the thickness after drying is 20 μm, and dried at 100° C. for 1 minute to prepare a pressure-sensitive adhesive sheet.

(C) Measurement of gel fraction of pressure-sensitive adhesive sheet After the pressure-sensitive adhesive sheet prepared in (b) was left at room temperature for 7 days, the gel fraction was measured by the method described above. Table 2 shows the measurement results.

(D) Preparation of Polarizing Plate with Adhesive A polarizing plate having a three-layer structure in which both sides of a polarizing film in which iodine is adsorbed and oriented in polyvinyl alcohol is sandwiched by protective films made of triacetyl cellulose The surface of the pressure-sensitive adhesive sheet opposite to the separator (pressure-sensitive adhesive layer surface) prepared in step 1) was pasted with a laminator, and then cured for 7 days at a temperature of 23° C. and a relative humidity of 65% to give a pressure-sensitive adhesive-attached polarizing plate. It was made.

(E) Preparation and Evaluation of Optical Laminated Body After peeling the separator from the pressure-sensitive adhesive-attached polarizing plate prepared in (d) above, the pressure-sensitive adhesive layer surface of the glass substrate for liquid crystal cell [trade name "EAGLE XG", manufactured by Corning Incorporated] It was adhered to both sides of the [Acquisition] so as to form a crossed nicols to prepare an optical laminate. When the heat resistance test of this optical layered body is carried out under the dry condition of the temperature of 80° C. for 300 hours (referred to as “heat resistance” in Table 2), the humidity and heat resistance test of storing the temperature of 60° C. and relative humidity of 90% for 300 hours. When it was performed (indicated as “moisture resistance” in Table 2), and the process of lowering the temperature from −70° C. to −40° C. and then raising the temperature to 70° C. was defined as one cycle (1 hour), and In each of the cases where the heat shock resistance test was repeated 100 times (indicated as “HS resistance” in Table 2), the optical layered body after the test was visually observed. The results are classified according to the following criteria and summarized in Table 2.

<Heat resistance test, moist heat resistance test and heat shock resistance test evaluation criteria>
A: No change in appearance such as floating, peeling or foaming was observed,
B: Almost no change in appearance such as floating, peeling, foaming,
C: The appearance changes such as floating, peeling, and foaming are slightly conspicuous,
D: Changes in appearance such as floating, peeling and foaming are noticeable.

(F) Evaluation of Adhesive Strength of Adhesive Optical Film Against Glass Adhesive polarizing plate prepared in (d) above was cut into a size of 25 mm×200 mm so that the absorption axis of the polarizing film was parallel to the long side. , And used as an evaluation sample. After peeling the separator from the sample for evaluation, the pressure-sensitive adhesive layer surface was attached to a non-alkali glass plate (“Eagle-XG” manufactured by Corning Co., Ltd.), and then in an autoclave at a temperature of 50° C. and a pressure of 5 MPa. Pressure treatment was carried out for 20 minutes, and subsequently, it was left for 1 day in an atmosphere of a temperature of 23° C. and a relative humidity of 60%. After that, using an autograph (“AGS-50NX” manufactured by Shimadzu Corporation), under an environment of a temperature of 23° C. and a relative humidity of 60%, one end in the length direction of the evaluation sample is grasped and a peeling speed of 300 mm/min. 180° peeling test was carried out, and the stress at the time of peeling was measured to obtain an adhesion to glass (without addition of water) P ₁ . In addition, for the evaluation sample stuck to the alkali-free glass plate prepared in the same manner, 1 ml of water was dropped at the interface between the alkali-free glass plate and the adhesive layer surface, and one end in the length direction of the evaluation sample was grasped and peeled off. A 180° peeling test was performed at a speed of 300 mm/min, and the stress at peeling was measured to obtain an adhesive force against glass (with water addition) P ₂ . In addition, using P ₁ and P ₂ , the rate of decrease in adhesive strength when water was added was calculated by the method described above. The results are shown in Table 2.

As shown in Table 2, with respect to the pressure-sensitive adhesive composition using the (meth)acrylic resin obtained in Polymerization Example A, Example 1 has a lower rate of reduction in adhesive force than Comparative Examples 1, 4, 5, and 6. It was expensive. Regarding the pressure-sensitive adhesive compositions using the (meth)acrylic resin obtained in Polymerization Example B, Examples 2 and 3 had a higher reduction rate of the adhesive force than Comparative Example 2. Regarding the pressure-sensitive adhesive composition using the (meth)acrylic resin obtained in Polymerization Example C, Example 4 had a higher reduction rate of the adhesive force than Comparative Example 3.

1 polarizing film, 2 surface treatment layer, 3 (first) protective film, 4 second protective film, 5 polarizing plate, 7 retardation film, 8 interlayer adhesive, 10 optical film, 20 liquid crystal cell (glass substrate) An adhesive layer (adhesive sheet) to be attached to, 25 an optical film with an adhesive, 30 a liquid crystal cell (glass substrate), 40 an optical laminate.

Claims (11)

(Meth)acrylic resin (however, excluding (meth)acrylic resin containing a silane-based monomer as a structural unit) , a cross-linking agent, and a silane-based compound,
The silane compound has the following formula (I)

(In the above formula (I), R ₁ represents an alkyl group having 1 to 14 carbon atoms, an aralkyl group, an aryl group or an alkenyl group; R ₂ represents an alkyl group having 1 to 6 carbon atoms)
The pressure-sensitive adhesive composition, which is a compound represented by: or 3-ureidopropyltrialkoxysilane . Contains a (meth)acrylic resin, a cross-linking agent, and a silane compound,
The silane compound has the following formula (I)

(In the above formula (I), R ₁ Represents an alkyl group having 1 to 14 carbon atoms, an aralkyl group, an aryl group or an alkenyl group; R _Two Represents an alkyl group having 1 to 6 carbon atoms)
A compound represented by, or 3-ureidopropyltrialkoxysilane,
The (meth)acrylic resin has the following formula (II)

(In the above formula (II), R ₃ Represents a hydrogen atom or a methyl group; R _Four Represents an alkyl group having 14 or less carbon atoms, and at least one hydrogen atom constituting those groups is a group —O—(C ₂ H _Four O) _m -R _Five And m is 0 or an integer of 1 to 4, R _Five Represents an aryl group having 12 or less carbon atoms. )
A pressure-sensitive adhesive composition comprising the structural unit represented by: The silane-based compound, the (meth) includes 0.03 to 2 parts by weight per 100 parts by weight of the acrylic resin pressure-sensitive adhesive composition according to claim 1 or 2. The pressure-sensitive adhesive composition according to claim 1, wherein the silane-based compound is 3-ureidopropyltrialkoxysilane. The crosslinking agent is, pressure-sensitive adhesive composition according to any one of claims 1 to 4, an isocyanate crosslinking agent. It formed into a sheet using an adhesive composition according to any one of claims 1 to 5 adhesive sheet. The pressure-sensitive adhesive sheet according to claim 6 , which is formed on a plastic film. The pressure-sensitive adhesive sheet according to claim 7 , wherein the plastic film is a release film subjected to a release treatment. An optical film with a pressure-sensitive adhesive, comprising an optical film and the pressure-sensitive adhesive sheet according to any one of claims 6 to 8 bonded to the optical film. The pressure-sensitive adhesive-attached optical film according to claim 9 , wherein the optical film is a polarizing plate or a retardation film. An optical laminate in which the optical film with an adhesive according to claim 9 or 10 is attached to a glass substrate on the adhesive sheet side.