KR20150124400A - Adhesive composition - Google Patents

Abstract

The present invention provides an adhesive composition, which is capable of suppressing change in viscosity after preparation and can be used with low viscosity for a long period of time, and an adhesive sheet which has excellent processability by having a short time required for curing until conducting a process such as cutting or the like after forming the adhesive composition into a sheet form. In addition, the present invention provides an adhesive-attached optical film, which is prepared by applying the adhesive sheet to an optical film, and an optical laminate which is prepared by binding the adhesive-attached optical film to a glass substrate including a liquid crystal cell as a typical example. In the present invention, the adhesive composition comprises: (A) an acryl resin which is a copolymer of monomers containing (meth)acrylic acid ester (A-1) represented by formula (I); (B) a cross-linking agent; (C) an organic acid salt; and (D) organic acids, and the adhesive sheet is formed by making the adhesive composition into a sheet form. In the formula, R^1 represents a hydrogen atom or a methyl group, and R^2 represents an alkyl group having 14 or fewer carbon atoms.

Description

[0001] ADHESIVE COMPOSITION [0002]

The present invention relates to a pressure-sensitive adhesive composition suitable for application to an optical film, and also relates to a pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition and an optical film with a pressure-sensitive adhesive applied to the optical film. Examples of the optical film to be used in the present invention include a polarizing plate and a retardation film. The present invention also relates to an optical laminate in which the optical film with a pressure-sensitive adhesive is laminated on a glass substrate and suitably used in a liquid crystal display device.

The polarizing plate is widely used in a liquid crystal display device. In general, a polarizing plate has a structure in which a transparent protective film is laminated on both sides or one side of a polarizing film, and a retardation film is laminated on the side of the liquid crystal cell to be bonded to the liquid crystal cell. In some cases, the pressure-sensitive adhesive layer / release film is adhered to the surface of the protective film or retardation film bonded to the liquid crystal cell in this order.

This pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition comprising an acrylic resin as a main component and a crosslinking agent blended therein. By the crosslinking agent, a crosslinking structure is formed in the acrylic resin with the lapse of time, the necessary cohesive force is expressed, and the processability is also improved. A method has been developed for accelerating the crosslinking reaction for such a pressure-sensitive adhesive and shortening the time required until sufficient workability is exhibited. For example, Japanese Patent Laid-Open Publication No. 2009-173772 (Patent Document 1) discloses a method in which an acrylic resin having a hydroxyl group is mixed with a silane compound having an amino group and an isocyanate-based cross-linking agent to reduce the aging time in the cross- Sensitive adhesive layer for an optical member, which is capable of improving the adhesion of the pressure-sensitive adhesive layer to the surface of the pressure-sensitive adhesive layer, and forming a pressure-sensitive adhesive layer having durability and the like.

The method of forming the pressure-sensitive adhesive layer on the surface of the optical film includes, for example, a method in which a pressure-sensitive adhesive composition is coated on a suitable base film and dried to obtain a pressure-sensitive adhesive sheet, and the pressure- The pressure-sensitive adhesive sheet is generally cured until the crosslinking proceeds to such an extent that it can be processed without any problem after drying. Japanese Patent No. 3065922 (Patent Document 2) discloses an acrylic pressure-sensitive adhesive composition capable of shortening the curing time required for completing crosslinking. In the acrylic pressure-sensitive adhesive composition, methyltriethylammonium octyl An example in which an acid salt is blended is disclosed. According to this method, the crosslinking reaction after the production of the pressure-sensitive adhesive sheet is promoted. However, since the crosslinking reaction is promoted immediately after preparation of the pressure-sensitive adhesive composition (solution state) and the viscosity of the pressure-sensitive adhesive composition is remarkably increased in a short period of time, There was a problem that it was difficult to maintain.

With respect to the above problems, as a method for achieving both the suppression of the crosslinking reaction in the solution state of the pressure-sensitive adhesive composition and the promotion of the crosslinking reaction after the formation of the pressure-sensitive adhesive sheet, for example, JP-A-2013-129813 ) Discloses a method in which an organic acid is added to a pressure-sensitive adhesive composition using an acrylic resin containing a carboxyl group at the side chain. However, since the acrylic resin described in this document contains a carboxyl group end on the side chain, unreacted acid components may remain in the pressure-sensitive adhesive sheet formed from the pressure-sensitive adhesive composition. In recent years, a pressure sensitive adhesive layer such as a capacitive touch panel is often disposed in direct contact with a transparent conductive film. The transparent electrode is generally made of indium oxide (ITO), zinc oxide, tin oxide or the like to which tin oxide is added. In this case, the transparent conductive film is corroded by the acid component remaining in the pressure-sensitive adhesive layer, and the electric resistance value of the conductive film is increased.

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2009-173772 [Patent Document 2] Japanese Patent No. 3065922 (Japanese Patent Laid-Open Publication No. 1997-157623) [Patent Document 3] JP-A-2013-129813

Disclosure of the Invention Problems to be Solved by the Invention A problem to be solved by the present invention is to provide a pressure-sensitive adhesive composition which can suppress viscosity change of a pressure-sensitive adhesive composition after preparation and can be used at a low point for a long time, And the time is short so that the pressure-sensitive adhesive sheet is excellent in workability. It is another object of the present invention to provide an optical laminate obtained by bonding an optical film with a pressure sensitive adhesive to which the pressure sensitive adhesive sheet is applied to an optical film and an optical film with the pressure sensitive adhesive to a glass substrate typified by a liquid crystal cell .

(A), a crosslinking agent (B), an organic acid salt (C) and an organic acid (D), which are polymers of a monomer containing a (meth) acrylic acid ester (A- ). ≪ / RTI > In the formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 14 or less carbon atoms.

The acrylic resin (A) described above can be obtained by copolymerizing a monomer mixture comprising a (meth) acrylic monomer (A-2) having a hydroxyl group in addition to the (meth) acrylic acid ester (A- Lt; / RTI > The acrylic resin (A) may be a copolymer of a monomer mixture further comprising a (meth) acrylic acid ester (A-3) having an aromatic ring represented by the following formula (II). In the following formula (II), R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an aryl group, X represents a single bond or oxyethylene represented by - (C ₂ H ₄ O) _n - n represents an integer of 1 to 4;

The crosslinking agent (B) may contain an isocyanate compound. In addition, the organic acid salt (C) may contain at least one carboxylate. The organic acid (D) is preferably a carboxylic acid.

The above-mentioned pressure-sensitive adhesive composition may further contain a silane compound (E). Further, the pressure-sensitive adhesive composition may further contain an antistatic agent (F).

The pressure-sensitive adhesive sheet of the present invention may be formed in a sheet form with the pressure-sensitive adhesive composition described in any one of the above.

The pressure-sensitive adhesive sheet of the present invention may be formed by applying the pressure-sensitive adhesive composition in a solution state onto a substrate and drying the pressure-sensitive adhesive sheet. After the application and drying, the pressure-sensitive adhesive sheet may be substantially free of the organic acid (D). In the pressure-sensitive adhesive sheet of the present invention, a release film may be adhered to at least one surface of the pressure-sensitive adhesive layer.

The pressure-sensitive adhesive sheet of the present invention may be an optical film bonded to an optical film and having a pressure-sensitive adhesive. This optical film is preferably a polarizing film or a retardation film. The optical film with a pressure-sensitive adhesive may be laminated on a glass substrate on the pressure-sensitive adhesive layer side to obtain an optical laminate.

According to the present invention, since the progress of the crosslinking reaction can be suppressed after the pressure-sensitive adhesive composition is prepared and before it is formed into a sheet form, that is, in a solution state, the pressure-sensitive adhesive composition has excellent applicability, The crosslinking reaction proceeds quickly, and the curing time till the predetermined gel fraction is reached can be shortened. Therefore, the workability of the pressure-sensitive adhesive sheet can be improved.

In addition, since the organic acid (D) volatilizes from the pressure-sensitive adhesive layer in the process of forming the pressure-sensitive adhesive sheet, it is possible to produce a pressure-sensitive adhesive sheet substantially free of the organic acid (D). This makes it possible to provide a pressure-sensitive adhesive sheet which has excellent processability and can be used without any problem even in a configuration such as a capacitive touch panel in which the pressure-sensitive adhesive layer directly contacts the transparent conductive film.

Fig. 1 is a schematic cross-sectional view showing an example of a suitable layer structure of an optical laminate according to the present invention.

Hereinafter, the present invention will be described in detail.

[Pressure sensitive adhesive composition]

The pressure-sensitive adhesive composition of the present invention contains an acrylic resin (A), a crosslinking agent (B), an organic acid salt (C), and an organic acid (D). First, each component constituting the pressure-sensitive adhesive composition will be described.

≪ Acrylic resin (A) >

The acrylic resin (A) is a polymer of a monomer containing a (meth) acrylic acid ester (A-1) represented by the following formula (I) and is a monomer mixture comprising a (meth) acrylic acid ester (A- May be used. The term "(meth) acrylic acid" means that either acrylic acid or methacrylic acid can be used, and "(meth)" when the term "(meth) acrylate" is used also means the same. In the present specification, the (meth) acrylic acid ester (A-1) represented by the following formula (I) may be simply referred to as "monomer (A- (Meth) acrylate ester (A-3) having an aromatic ring represented by the formula (A-2) and the formula (II) There is a case.

In the formula (I), R ¹ is a hydrogen atom or a methyl group, and R ² is an alkyl group having 14 or less carbon atoms.

Examples of the monomer (A-1) include acrylic acid straight chain alkyl esters such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, and lauryl acrylate; Acrylic acid branched chain alkyl esters such as isobutyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; Methacrylic acid straight chain alkyl esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, and lauryl methacrylate; And methacrylic acid branched chain alkyl esters such as isobutyl methacrylate, 2-ethylhexyl methacrylate, and dioctyl methacrylate.

Of these, n-butyl acrylate is preferred as the linear alkyl ester of acrylic acid, and n-butyl acrylate is preferably 50% by weight or more based on 100% by weight of the total monomers used for copolymerization of the acrylic resin (A).

These monomers (A-1) may be used in combination of two or more compounds in addition to the compounds represented by the above formula (I).

(Meth) acrylic monomer (A-2) further having a hydroxyl group in addition to the above-mentioned (A-1), from the viewpoint that the adhesive force of the pressure-sensitive adhesive sheet is enhanced and durability is further improved. A copolymer of a monomer mixture. As a result, the structure derived from the (meth) acrylic monomer (A-2) having a hydroxyl group in the acrylic resin (A) and the crosslinking agent (B) are crosslinked with each other to give a sufficient adhesive force by the adhesive sheet, .

Examples of the (meth) acrylic monomer (A-2) having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl 2- (2-hydroxyethoxy) ethyl acrylate, and the like. Of these, it is preferable to use 2-hydroxyethyl acrylate as one of the monomers (A-2) constituting the acrylic resin (A).

In the present invention, when the (meth) acrylic acid ester (A-1) represented by the formula (I) and the (meth) acrylic monomer (A-2) having a hydroxyl group are used in combination for copolymerization of the acrylic resin (A) The blending amount of the monomer (A-1) is preferably 50% by weight or more and less than 100% by weight with respect to 100% by weight of the total monomers of the monomer mixture, and the amount of the (meth) acrylic monomer (A- Is preferably less than 50% by weight. By adopting an acrylic resin obtained by copolymerizing the monomers (A-1) and (A-2) at such a ratio, a pressure-sensitive adhesive composition can be obtained which gives an excellent pressure-sensitive adhesive sheet by its processability. The blending amount of the monomer (A-1) is more preferably 60 to 99.9% by weight, and still more preferably 70 to 99.5% by weight. The total amount of the blend of the monomers (A-1) and (A-2) does not exceed 100% by weight.

The acrylic resin (A) used in the present invention may be a copolymer of a monomer mixture containing monomers other than the above-mentioned monomers (A-1) and (A-2). Examples of the monomers other than the monomers (A-1) and (A-2) include (meth) acrylic ester (A-3) having an aromatic ring in the molecule represented by the following formula (II) (Meth) acrylic acid ester having a cycloaliphatic structure in the molecule, a styrenic monomer, a vinyl monomer, a (meth) acrylamide derivative, a plurality of (meth) acryloyl groups in the molecule, And the like.

In the formula (II), R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an aryl group, X represents a single bond or oxyethylene represented by - (C ₂ H ₄ O) _n -, wherein n Represents an integer of 1 to 4, but it is particularly preferably 0, 1 or 2. Examples of R ⁴ include, in addition to the phenyl group, the benzyl group and the naphthyl group, a nuclear alkyl-substituted phenyl group including a tolyl group, a xylyl group and an ethylphenyl group, a biphenylyl group, and a triphenyl group.

Examples of the (meth) acrylic ester (A-3) having an aromatic ring in the molecule represented by the formula (II) include 2-phenoxyethyl (meth) acrylate, 2- (Meth) acrylate of ethylene oxide modified nonylphenol, and 2- (4-biphenylyl) ethyl (meth) acrylate. Among them, it is particularly preferable to use 2-phenoxyethyl (meth) acrylate or 2- (2-phenoxyethoxy) ethyl (meth) acrylate as one of the monomers (A-3). As the monomer (A-3), the compound represented by the formula (II) may be used alone, or two or more compounds may be used in combination.

Examples of the (meth) acrylic monomer having a carboxyl group include (meth) acrylic acid, 2-carboxyethyl (meth) acrylate, 3-carboxypropyl (meth) acrylate and 4-carboxybutyl (meth) acrylate.

The unsaturated monomer having a polar functional group means an unsaturated monomer having a polar functional group as a compound other than the monomer (A-1), the monomer (A-2) and the (meth) acrylic acid ester monomer having a carboxyl group. Examples of the polar functional group include a heterocyclic group including an epoxy ring and the like. Examples of the unsaturated monomer having a heterocyclic group include acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylcarbazole, tetrahydrofurfuryl (meth) acrylate, caprolactone- Furyl acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and glycidyl (meth) acrylate.

With respect to (meth) acrylic esters having an alicyclic structure in the molecule, the alicyclic structure is a cycloparaffin structure having a carbon number of usually 5 or more, preferably 5 to 7 or so. Examples of the acrylic ester having an alicyclic structure include acrylic acid esters such as isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, Cyclohexyl methoxyacrylate, cyclohexylphenyl acrylate, and the like. Examples of the methacrylic acid ester having an alicyclic structure include methacrylic esters such as isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, cyclododecyl methacrylate, methylcyclohexyl methacrylate, methacrylic Trimethylcyclohexyl methacrylate, tert-butylcyclohexyl methacrylate, cyclohexylphenyl methacrylate, and the like.

Examples of the styrene-based monomer include alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene in addition to styrene; Halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; Further, nitrostyrene, acetylstyrene, methoxystyrene, divinylbenzene and the like can be given.

Examples of the vinyl monomer include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; Vinyl halides such as vinyl chloride and vinyl bromide; Vinylidene halides such as vinylidene chloride; Nitrogen-containing aromatic vinyls such as vinylpyridine and vinylpyrrolidone; Conjugated diene monomers such as butadiene, isoprene, and chloroprene; Further, acrylonitrile, methacrylonitrile and the like can be given.

(Meth) acrylamide derivatives include N- (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (Meth) acrylamide, N- (4-hydroxybutyl) (meth) acrylamide, N- (5-hydroxypentyl) (Meth) acrylamide, N- (methoxymethyl) (meth) acrylamide, N- (ethoxymethyl) (Meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N- (Meth) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl] (meth) acrylamide, 2-acryloylamino- -1-propanesulfonic acid and the like.

Examples of the monomer having plural (meth) acryloyl groups in the molecule include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, (Meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and tripropylene glycol di (meth) A monomer having a (meth) acryloyl group; And monomers having three (meth) acryloyl groups in the molecule such as trimethylolpropane tri (meth) acrylate.

As described above, the acrylic resin (A) is preferably a copolymer of a monomer mixture containing not less than 50% by weight of the monomer (A-1), more preferably a copolymer of a monomer other than the monomer (A- The total amount is preferably less than 50% by weight, more preferably not more than 30% by weight, and particularly preferably not more than 20% by weight, based on 100% by weight of the total monomers of the monomer mixture. When the monomer (A-3) is blended, the blending amount thereof is preferably 0.5 to 50 wt%, more preferably 1 to 30 wt%, and still more preferably 5 to 15 wt% . By adding the monomer (A-3) in this range, it is possible to effectively suppress the occurrence of white spots and color unevenness in the optical laminate. When the monomer mixture to be copolymerized with the acrylic resin (A) contains one or more monomers other than the monomer (A-1) in addition to the monomer (A-1), the total amount of the monomers is 100% There is no case to exceed.

It is preferable that the acrylic resin (A) obtained by copolymerizing the monomers described above 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 from 500,000 to 1,800,000. If 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 peeling or peeling between the glass substrate and the pressure sensitive adhesive sheet tends to be lowered. Therefore, it is desirable. If the weight average molecular weight is less than 2,000,000, even if the size of the optical film bonded to the pressure-sensitive adhesive sheet changes, the pressure-sensitive adhesive layer follows and fluctuates following the dimensional change. And there is a tendency that white spots and color unevenness are suppressed. The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is not limited, but is preferably in the range of about 3 to 7.

It is preferable that the acrylic resin (A) has a glass transition temperature in the range of -10 to -60 占 폚 in order to exhibit adhesiveness. The glass transition temperature of the resin can be measured by a differential scanning calorimeter (DSC).

The 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 the acrylic resin (A), usually a polymerization initiator is used. The polymerization initiator is used in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the total amount of all the monomers used in the production of the acrylic resin.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, and the like are used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and the like. As the thermal polymerization initiator, for example, 2,2'-azobisisobutylonitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile Azo compounds such as 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxy valeronitrile) Azo compounds such as azobis (2-methylpropionate), and 2,2'-azobis (2-hydroxymethylpropionitrile); Butyl peroxide, lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, Organic peroxides such as neodecanoate, tert-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl) peroxide; Inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. A redox initiator in which a peroxide and a reducing agent are used in combination may also be used as a polymerization initiator.

As a method for producing an acrylic resin, a solution polymerization method is preferable among the methods shown above. A specific example of the solution polymerization method will be described. A desired monomer and an organic solvent are mixed, and a thermal polymerization initiator is added under a nitrogen atmosphere. The solution is heated at a temperature of about 40 to 90 캜, preferably about 50 to 80 캜, Followed by stirring. Further, in order to control the reaction, a monomer or a thermal polymerization initiator may be added continuously or intermittently during polymerization, or may be added in a state dissolved in an organic solvent. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; Esters such as ethyl acetate or butyl acetate; Aliphatic alcohols such as propyl alcohol or isopropyl alcohol; Ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and the like can be used.

≪ Crosslinking agent (B) >

Specific examples of the cross-linking agent (B) contained in the pressure-sensitive adhesive composition include an isocyanate compound, an epoxy compound, a metal chelate compound, and an aziridine compound. As the crosslinking agent (B), a compound having at least two functional groups capable of crosslinking an acrylic resin is compounded so that the functional group in the acrylic resin reacts with the isocyanato group in the crosslinking agent over time to form a crosslinked structure, .

As the above-mentioned isocyanate compound, it is preferable to use a compound having at least two isocyanato groups (-NCO) in the molecule. Examples thereof include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane Triisocyanate, and the like. Also, an adduct obtained by reacting these isocyanate compounds with a polyol such as glycerol or trimethylolpropane, or an isocyanate compound in the form of a dimer, a trimer, or the like, may be a crosslinking agent used in a pressure-sensitive adhesive. Two or more isocyanate compounds may be mixed and used.

The epoxy compound is, for example, a compound having at least two epoxy groups in the molecule, such as bisphenol A type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglyceride N, N, N ', N'-tetraglycidyl-m, N, N'-tetramethyl aniline, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, -Xylene diamine, and the like. Two or more kinds of epoxy compounds may be mixed and used.

Examples of the metal chelate compound include compounds in which acetylacetone or ethyl acetoacetate is added to polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium have.

The aziridine compound is a compound having at least two skeletons of a three-membered ring composed of one nitrogen atom and two carbon atoms, which is also called ethyleneimine, in the molecule, and examples thereof include diphenylmethane-4,4'-bis (1-aziridine Carboxamide), toluene-2,4-bis (1-aziridine carboxamide), triethylene melamine, isophthaloylbis-1- (2-methyl aziridine), tris- Oxides, hexamethylene-1,6-bis (1-aziridine carboxamide), trimethylolpropane tris-? -Aziridinylpropionate, tetramethylolmethane tris-? -Aziridinylpropionate, .

Among these crosslinking agents, isocyanate compounds, particularly adducts obtained by reacting tolylene diisocyanate with polyols, dimers of tolylene diisocyanate, trimers of tolylene diisocyanate, adducts obtained by reacting hexamethylene diisocyanate with polyol, A dimer of methylene diisocyanate, a trimer of hexamethylene diisocyanate, an adduct in which xylene diisocyanate is reacted with a polyol, an adduct in which hydrogenated xylylene diisocyanate is reacted with a polyol, isophorone diisocyanate, and / or An isocyanate compound, an isocyanate compound, an isophorone diisocyanate, and an isocyanate compound are reacted with a polyol.

The crosslinking agent (B) may be compounded in a proportion of 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic resin (A). This blending amount is preferably about 0.05 to 3 parts by weight, more preferably about 0.1 to 2 parts by weight, based on 100 parts by weight of the acrylic resin (A). When the amount of the crosslinking agent (B) relative to 100 parts by weight of the acrylic resin (A) is 0.01 parts by weight or more, particularly 0.1 parts by weight or more, the durability of the pressure-sensitive adhesive sheet tends to be improved. The white spots when the optical film with a pressure-sensitive adhesive is applied to a liquid crystal display device are not conspicuous, which is preferable.

≪ Organic acid salt (C) >

In the present invention, in addition to the acrylic resin (A) and the crosslinking agent (B), an organic acid salt (C) is further blended to obtain a pressure-sensitive adhesive composition. The organic acid salt (C) is preferably a salt composed of an organic acid having a carboxylic acid terminal and a base, that is, an organic carboxylic acid salt.

When an organic carboxylic acid salt is used as the organic acid salt (C), it is preferable that the counter cation of the carboxylate anion is a counter cation of not more than 3 equivalents.

Examples of the counter cation include a metal ion, an ammonium ion, and a cation having a heterocyclic structure. Preferable examples of the metal ion include an alkali metal ion and an alkaline earth metal ion. Preferred examples of the cation having a heterocyclic structure include a pyrrolinium ion, an imidazolium ion, a triazonium ion, a pyrrolidinium ion, Pyridinium ions, and piperidinium ions.

Examples of the carboxylate anion of the organic acid salt include straight chain saturated alkylcarboxylate ions such as formate ion, acetate ion, propionic acid ion, heptanoic acid ion, octanoic acid ion and lauric acid ion; Linear unsaturated alkyl carboxylate ions such as acrylic acid ion and oleic acid ion; Aromatic carboxylate ions such as benzoic acid ion and cinnamic acid ion; Carboxylate ions having a heterocyclic structure such as nicotinate ion; Dicarboxylate ions such as succinic acid ion, fumaric acid ion and phthalic acid ion; And carboxylate anions having an oxyethylene skeleton such as 2- (2-ethoxy) ethoxycarboxylate ion.

The organic acid salt formed with anion and cation as described above may be used alone, or two or more kinds of salts may be used in combination.

The blending amount of the organic acid salt (C) can be arbitrarily adjusted according to the curing time of the required pressure-sensitive adhesive sheet. For example, the blending amount of the organic acid salt (C) is preferably 0.0001 to 3 parts by weight, more preferably 0.001 To 2 parts by weight, more preferably 0.001 to 0.1 part by weight. If the compounding amount of the organic acid salt (C) is less than 0.0001 part by weight, the catalytic effect of the organic acid salt (C) can not be easily obtained and the effect of shortening the curing time is lowered. On the other hand, if the blending amount of the organic acid salt (C) exceeds 3 parts by weight, the crosslinking reaction proceeds before the pressure-sensitive adhesive composition is processed into the pressure-sensitive adhesive sheet, and the viscosity is increased to deteriorate the coating property.

<Organic acid (D)>

The pressure-sensitive adhesive composition of the present invention further contains an organic acid (D) in addition to the above-described organic acid salt (C) having at least one carboxylate anion. The organic acid (D) preferably contains at least one of a carboxylic acid, a sulfonic acid, a thiol, an alcohol or an enol, and the organic acid (D) is more preferably a carboxylic acid. Examples of the organic acid include monovalent carboxylic acids having a straight chain alkyl chain such as acrylic acid, formic acid, acetic acid, propionic acid, butanoic acid, pentanoic acid and pentanoic acid, divalent carboxylic acids represented by oxalic acid, trivalent carboxylic acids represented by citric acid And the like. The organic acid is not limited to these exemplified compounds, and other organic acids may be added. A plurality of organic acids may be used in combination.

The organic acid is preferably liquid or solid at 25 DEG C from the viewpoint of ease of handling when preparing the pressure-sensitive adhesive composition. The organic acid (D) preferably has a vapor pressure of 0.001 mmHg or more, more preferably 0.003 mmHg or more, at 20 캜, from the viewpoint of suppressing the residual amount of the acid component in the pressure-sensitive adhesive sheet. The boiling point of the organic acid (D) is preferably 300 ° C or lower, more preferably 270 ° C or lower. The boiling point is preferably 25 캜 or higher, and more preferably 70 캜 or higher. Adopting such an organic acid makes it possible to obtain a pressure-sensitive adhesive sheet substantially containing no acid because the organic acid (D) is volatilized in the step of forming the pressure-sensitive adhesive layer when the pressure-sensitive adhesive sheet is produced using the pressure-

From the viewpoint of neutralizing the organic acid salt (C) as a crosslinking catalyst, the blending amount of the organic acid (D) is preferably in the range from the viewpoint of maintaining the applicability of the adhesive composition in consideration of the number of the organic acid salt (C) Can be arbitrarily adjusted in consideration of the storage time required for the state. The blending amount of the organic acid (D) is preferably 0.001 to 3 parts by weight, more preferably 0.005 to 2 parts by weight, based on 100 parts by weight of the acrylic resin (A). If the blending amount is less than 0.001 part by weight, the viscosity increase of the pressure-sensitive adhesive composition tends to be not sufficiently suppressed. If the blending amount is more than 3 parts by weight, the organic acid (D) remains in the pressure- There is a case where the crosslinking reaction of the acrylic resin (A) is inhibited by reacting with the earthenware.

&Lt; Silane compound (E) &gt;

The pressure-sensitive adhesive composition of the present invention preferably contains a silane compound (E) in order to improve the adhesion between the pressure-sensitive adhesive layer and the glass substrate after the pressure-sensitive adhesive sheet or the optical film with the pressure-sensitive adhesive is formed.

Examples of the silane compound (E) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl Methyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3- Butoxypropyldimethylsilane and the like. Two or more kinds of silane compounds (E) may be used.

The silane compound (E) may be a silicone oligomer type. Examples of the silicone oligomer in the form of a (monomer) - (monomer) copolymer include the following.

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer , And mercaptopropyl group-containing copolymers such as 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer;

Mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, Copolymers containing mercaptomethyl groups such as ethoxysilane-tetraethoxysilane copolymer;

3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane copolymer Tetramethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane- 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-methacryloyloxypropyl methyl Copolymers containing methacryloyloxypropyl groups such as diethoxysilane-tetraethoxysilane copolymer;

3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane- 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane copolymer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, Copolymers containing acryloyloxypropyl groups such as copolymers;

Vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetraethoxysilane copolymer Polymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinylmethyldimethoxysilane-tetraethoxysilane copolymer, vinylmethyldiethoxysilane-tetramethoxysilane copolymer, and vinylmethyldiethoxysilane-tetra Vinyl group-containing copolymers such as methoxy silane copolymers, and the like.

These silane compounds are often liquid at room temperature (25 캜). The blending amount of the silane compound (E) in the pressure-sensitive adhesive composition is usually about 0.01 to 10 parts by weight, preferably 0.03 to 2 parts by weight, more preferably 0.03 to 1 part by weight, based on 100 parts by weight of the acrylic resin (A) Of the total. When the amount of the silane compound relative to 100 parts by weight of the solid content of the acrylic resin (A) is 0.01 parts by weight or more, particularly 0.03 parts by weight or more, adhesiveness between the pressure-sensitive adhesive sheet and the glass substrate is improved. If the amount is 10 parts by weight or less, particularly 2 parts by weight or less or 1 part by weight or less, the silane compound tends to be inhibited from bleeding out from the pressure-sensitive adhesive sheet.

&Lt; Other components &gt;

The pressure-sensitive adhesive composition of the present invention may further contain additives other than those described above in addition to an antistatic agent, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, It is also good. Further, the pressure-sensitive adhesive composition may further contain an ultraviolet curing compound. This is a useful method because a pressure-sensitive adhesive sheet is formed with a pressure-sensitive adhesive composition, and then the pressure-sensitive adhesive sheet is cured by irradiating ultraviolet rays thereto.

The above-described pressure-sensitive adhesive composition shows good performance, but it is preferable that the pressure-sensitive adhesive composition does not contain an amino group in order to avoid a strong adhesion when it comes into contact with a specific release film. It is particularly preferred that it does not have a tertiary amino group.

[Adhesive sheet]

The pressure-sensitive adhesive sheet of the present invention is obtained by obtaining the pressure-sensitive adhesive composition in a solution state by mixing the components constituting the above-described pressure-sensitive adhesive composition in a state in which they are dissolved in an arbitrary solvent and then applying the pressure- . The substrate film used herein is generally a plastic film, and a typical example thereof is a release film (sometimes referred to as a separator) on which a release treatment has been performed. The release film may be a release treatment such as a silicone treatment on a surface of a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate, etc. on which a pressure-sensitive adhesive sheet is formed . The pressure-sensitive adhesive sheet of the present invention is characterized in that the cross-linking reaction rapidly proceeds after coating in the form of a sheet to exhibit a relatively high gel fraction value.

Here, the gel fraction is a value measured according to the following (1) to (4).

(1) A pressure-sensitive adhesive sheet having an area of about 8 cm × about 8 cm and a metal mesh (weight of Wm) made of SUS304 of about 10 cm × about 10 cm are bonded.

(2) The joint obtained in the above (1) is weighed, its weight is defined as Ws, then folded four times so as to surround the adhesive sheet, fixed with a stapler, and weighed.

(3) In the above (2), the stitch-fixed mesh is placed in a glass container with a lid, and 60 mL of ethyl acetate is added to the glass container. The glass container is then kept at 25 DEG C for 3 days.

(4) Take out the mesh from the glass container, dry it at 120 DEG C for 24 hours, weigh the weight, and calculate the gel fraction based on the following equation.

Gel fraction (% by weight) = [{Wa- (Wb-Ws) -Wm} / (Ws-Wm)

As described above, the pressure-sensitive adhesive sheet is often used after being cured for a certain period of time after its production, and is used in a state in which a crosslinking reaction proceeds to show a certain degree of gel fraction. The gel fraction in the state in which the crosslinking reaction has proceeded, that is, in the state where the curing is completed can be adjusted depending on the kind of the acrylic resin (A) as an effective component of the pressure-sensitive adhesive composition for forming it and the amount of the crosslinking agent (B) have. Specifically, the amount of the monomer (A-2) used for copolymerization of the acrylic resin (A) and / or the monomer having another polar functional group is increased, or the amount of the crosslinking agent (B) , The gel fraction is increased. Therefore, the gel fraction can be adjusted by adjusting these amounts.

[Optical film with pressure-sensitive adhesive]

The optical film with a pressure-sensitive adhesive of the present invention is obtained by bonding the above-described pressure-sensitive adhesive sheet to an optical film. Here, the optical film is, for example, a polarizing plate or a retardation film as the film having optical characteristics. The pressure-sensitive adhesive sheet may be bonded to only one side of the optical film or may be bonded to both sides of the optical film. In the optical film with a pressure-sensitive adhesive of the present invention in which the pressure-sensitive adhesive sheet is bonded to the optical film, the layer between the optical film and the base film constituting the pressure-sensitive adhesive sheet may be simply referred to as a "pressure-sensitive adhesive layer" in this specification.

The above-mentioned polarizing plate is an optical film having a function of emitting polarized light to incident light such as natural light. A polarizing plate is provided with a linear polarizer that absorbs linearly polarized light having a vibration plane in a certain direction and transmits linearly polarized light having a vibration plane orthogonal thereto, reflects linearly polarized light having a vibration plane in a certain direction, A polarizing plate having a property of transmitting linearly polarized light having a polarizing plate, and an elliptically polarizing plate in which a polarizing plate and a retardation film described later are laminated. As a suitable example of a polarizing plate, particularly a polarizing film (also referred to as a polarizer) which functions as a linear polarizing plate, a dichroic dye such as iodine or a dichroic dye is adhered to a uniaxially stretched polyvinyl alcohol- . The polarizing plate usually has a structure in which a protective film is bonded to one or both surfaces of the polarizing film.

The retardation film is an optical film exhibiting optical anisotropy, and includes, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, cyclic polyolefin, polystyrene, polysulfone, polypropylene, polyether sulfone, polyvinyl A stretched film obtained by stretching a polymer film of about 1.01 to 6 times such as ethylene / vinyl acetate copolymer, diene fluoride / polymethyl methacrylate, liquid crystal polyester, acetyl cellulose, saponified ethylene-vinyl acetate copolymer and polyvinyl chloride. Among them, a polymer film obtained by uniaxially stretching or biaxially stretching a polycarbonate film or a cyclic polyolefin film is preferable. A uniaxial retardation film, a wide viewing angle retardation film, and a low light elasticity retardation film, but any film or a retardation film can be used.

A film exhibiting optical anisotropy by application and orientation of a liquid crystal compound or a film exhibiting optical anisotropy by application of an inorganic layered compound can also be used as a retardation film. Such a retardation film is referred to as a temperature-compensated retardation film, a film in which rod-shaped liquid crystals sold under the trade name of "NH film " from JX Nikkoseki Energy Co., Quot; WV film ", a completely biaxial orientation type film sold by Sumitomo Chemical Co., Ltd. under the trade name of "VAC film ", a film obtained from Sumitomo Chemical Co., quot; new VAC film "and the like.

Further, a protective film adhered to these optical films can also be used as an optical film. As the protective film, a transparent resin film is used. As the transparent resin, for example, an acetylcellulose resin represented by triacetylcellulose or diacetylcellulose, a methacrylic resin represented by polymethylmethacrylate, a polyester resin , A polyolefin resin, a polycarbonate resin, a polyether ether ketone resin, and a polysulfone resin. The resin constituting the protective film may be blended with a UV absorber such as a salicylic ester compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyanoacrylate compound or a nickel complex salt. As the protective film, an acetylcellulose-based resin film such as a triacetylcellulose film is suitably used.

Among the optical films described above, the linear polarizer is often used in a state in which a protective film is adhered to one or both sides of a polarizing film constituting the linear polarizer, for example, a polarizing film formed of a polyvinyl alcohol-based resin. The above-mentioned elliptically polarizing plate is obtained by laminating a linearly polarizing plate and a retardation film, but the linearly polarizing plate often has a protective film adhered to one or both sides of the polarizing film in many cases. When the pressure-sensitive adhesive sheet according to the present invention is bonded to such an elliptically polarizing plate, it is usually bonded to the retardation film side.

In the optical film with a pressure-sensitive adhesive sheet provided with the pressure-sensitive adhesive sheet on the above-described optical film, it is preferable to adhere the release film on which the mold releasing treatment has been performed as described above to the surface of the pressure-sensitive adhesive layer to protect the surface of the pressure- Do. The optical film with a pressure-sensitive adhesive on which the release film is provided can be obtained by, for example, a method of laminating the obtained pressure-sensitive adhesive sheet onto an optical film by applying the pressure-sensitive adhesive composition described above to the release- To form a pressure-sensitive adhesive sheet, and bonding a release film to the pressure-sensitive adhesive surface to protect the pressure-sensitive adhesive sheet, thereby forming an optical film with a pressure-sensitive adhesive.

The thickness of the pressure-sensitive adhesive layer formed on the optical film is not particularly limited, but is usually preferably 30 占 퐉 or less, more preferably 10 占 퐉 or more, and further preferably 15 to 25 占 퐉. If the thickness of the pressure-sensitive adhesive layer is 30 占 퐉 or less, the adhesiveness at high temperature and high humidity is improved, the possibility of peeling or peeling between the glass substrate and the pressure-sensitive adhesive layer tends to be lowered, desirable. When the thickness of the adhesive layer is 10 占 퐉 or more, the pressure sensitive adhesive layer follows and changes in accordance with the dimensional change even if the dimensions of the optical film bonded thereto change, so that there is no difference between the brightness at the periphery of the liquid crystal cell and the brightness at the center, White spots and color unevenness tend to be suppressed.

[Optical laminate]

In the optical film with a pressure-sensitive adhesive of the present invention, the pressure-sensitive adhesive layer side can be laminated on a glass substrate to obtain an optical laminate. In order to laminate an optical film with a pressure-sensitive adhesive on a glass substrate to form an optical laminate, for example, the release film may be peeled off from the optical film with the pressure-sensitive adhesive, and the exposed pressure-sensitive adhesive layer surface may be bonded to the surface of the glass substrate. Examples of the glass substrate include a glass substrate constituting a liquid crystal cell, an antireflection glass, and glass for sunglasses. Among them, an optical film (upper polarizing plate) with a pressure-sensitive adhesive is laminated on a glass substrate on the front side (viewing side) of a liquid crystal cell and another optical film with a pressure-sensitive adhesive (lower polarizing plate) is laminated on the glass substrate on the back side of the liquid crystal cell 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, and alkali-free glass, and a non-alkali glass is suitably used for the liquid crystal cell.

For the optical laminate according to the present invention, an example of several suitable layer constructions is shown in a schematic cross-sectional view in Fig. 1 (A), a protective film 3 having a surface treatment layer 2 is adhered to one surface of a polarizing film 1 on a surface opposite to the surface treatment layer 2 , And a polarizing plate (5). In this example, the polarizing plate 5 is also used as the optical film 10 in the present invention at the same time. On the surface of the polarizing film (1) opposite to the protective film (3), a pressure-sensitive adhesive layer (20) is formed to constitute an optical film (25) with an adhesive. The surface of the pressure-sensitive adhesive layer 20 opposite to the polarizing plate 5 is bonded to the liquid crystal cell 30 serving as a glass substrate to constitute the optical laminate 40.

1B, the first protective film 3 having the surface treatment layer 2 is formed on one surface of the polarizing film 1 on the surface opposite to the surface treatment layer 2 And the second protective film 4 is adhered to the other surface of the polarizing film 1 to constitute the polarizing plate 5. [ In this example as well, the polarizing plate 5 simultaneously constitutes the optical film 10 referred to in the present invention. A pressure sensitive adhesive layer 20 is formed on the outside of the second protective film 4 constituting the polarizing plate 5 to constitute an optical film 25 with a pressure sensitive adhesive. The surface of the pressure-sensitive adhesive layer 20 opposite to the polarizing plate 5 is bonded to the liquid crystal cell 30 serving as a glass substrate to constitute the optical laminate 40.

1C, the protective film 3 having the surface treatment layer 2 is adhered to one surface of the polarizing film 1 on the surface opposite to the surface treatment layer 2 , And a polarizing plate (5). The optical film 10 is formed by adhering the retardation film 7 to the surface of the polarizing film 1 opposite to the protective film 3 through the interlayer adhesive 8. On the outer side of the retardation film 7 constituting the optical film 10, a pressure-sensitive adhesive layer 20 is formed to constitute an optical film 25 with a pressure-sensitive adhesive. The surface of the pressure-sensitive adhesive layer 20 opposite to the optical film 10 is bonded to the liquid crystal cell 30 serving as a glass substrate to form the optical laminate 40. [

1 (D), a first protective film 3 having a surface treatment layer 2 is formed on one surface of the polarizing film 1 so as to be in contact with the surface treatment layer 2 And the second protective film 4 is adhered to the other surface of the polarizing film 1 to constitute the polarizing plate 5. [ A retardation film 7 is bonded to the outside of the second protective film 4 constituting the polarizing plate 5 through the interlayer adhesive 8 to constitute the optical film 10. On the outer side of the retardation film 7 constituting the optical film 10, a pressure-sensitive adhesive layer 20 is formed to constitute an optical film 25 with a pressure-sensitive adhesive. The surface of the pressure-sensitive adhesive layer 20 opposite to the optical film 10 is bonded to the liquid crystal cell 30 as a glass substrate to constitute the optical laminate 40. [

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

When a retardation film 7 is laminated on the polarizing plate 5 as in the examples shown in Figs. 1C and 1D, in a medium-and-small-sized liquid crystal display device, as a suitable example of the retardation film 7, And a 1/4 wavelength plate. In this case, the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7, which is a 1/4 wave plate, are arranged so as to intersect at almost 45 degrees. However, depending on the characteristics of the liquid crystal cell 30, There is a case where it is shifted to some degree at 45 degrees. On the other hand, in a large-sized liquid crystal display device such as a television, a retardation film having various retardation values is used in accordance with the characteristics of the liquid crystal cell 30 for purposes of retardation compensation and viewing angle compensation of the liquid crystal cell 30. 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 almost orthogonal or nearly parallel. When the retardation film 7 is constituted by a 1/4 wavelength plate, a uniaxially or biaxially stretched film is suitably used. When the retardation film 7 is provided for compensation of phase difference of the liquid crystal cell 30 or viewing angle compensation, in addition to the uniaxial or biaxially stretched film, a film oriented in the thickness direction in addition to uniaxial or biaxial stretching, Such as a film in which a phase difference developing substance such as a liquid crystal is coated on the polarizing film and is oriented and fixed, may be used as the retardation film 7.

 When the polarizing plate 5 and the retardation film 7 are bonded to each other through the interlaminar adhesive 8 as shown in Figs. 1C and 1D, a general acrylic adhesive But in this case, it is of course possible to use the pressure-sensitive adhesive sheet defined in the present invention. The polarizing plate 5 and the retardation film 7 are disposed such that the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 are in a substantially orthogonal or nearly parallel relationship, In place of the interlayer pressure-sensitive adhesive 8 shown in Figs. 1C and 1D, in the case where the roll-to-roll bonding can be performed between the two rolls, It is also possible to use an adhesive which is firmly bonded and can not be peeled off. Examples of such an adhesive include an aqueous adhesive which is composed of an aqueous solution or an aqueous dispersion and exhibits an adhesive force by evaporating water as a solvent, an ultraviolet curable adhesive which is cured by irradiation with ultraviolet rays and exhibits an adhesive force.

1 (C) and 1 (D), it is possible to circulate the retardation film 7 itself, and the optical film with a pressure-sensitive adhesive according to the present invention . The optical film with a pressure-sensitive adhesive on which a pressure-sensitive adhesive layer is formed on a retardation film can be formed into an optical laminate by bonding the pressure-sensitive adhesive layer to a liquid crystal cell as a glass substrate. In addition to bonding the polarizing plate to the retardation film, It may be an optical film.

1 shows an example in which the optical film 25 with a pressure-sensitive adhesive is disposed on the visual side of the liquid crystal cell 30, the optical film with a pressure-sensitive adhesive according to the present invention has a back side of the liquid crystal cell, As shown in Fig. When the optical film with a pressure-sensitive adhesive of the present invention is disposed on the back side of the liquid crystal cell, a protective film having no surface treatment layer is adopted in place of the protective film 3 having the surface treatment layer 2 shown in Fig. And the others are the same as those shown in Figs. 1 (A) to 1 (D). In this case, various optical films known to be disposed on the back surface 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 constituting the polarizing plate.

INDUSTRIAL APPLICABILITY As described above, the optical laminate of the present invention can be suitably used in organic EL display devices and liquid crystal display devices. The liquid crystal display device formed by the optical laminate of the present invention can be applied to a liquid crystal display for a personal computer including a notebook type, a desktop type, a PDA (Personal Digital Assistant), a television, a vehicle- Cameras, digital video cameras, electronic calculators, clocks, and more.

Example

Hereinafter, the present invention is described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, &quot; part (s) &quot; and &quot;% &quot; used in the amounts and contents are by weight unless otherwise specified. In the following examples, the (meth) acrylic acid ester (A-1) represented by the above formula (I) is referred to as "monomer (A- (Meth) acrylate ester (A-3) having an aromatic ring represented by the above formula (II) is referred to as "monomer (A-2)".

In the following examples, the measurement of the weight average molecular weight and the number average molecular weight was carried out by using four columns "TSK gel XL" manufactured by Tosoh Co., Ltd., a column made by Showa Denko Co., Five shots were connected in series, and the sample concentration was 5 mg / mL, the amount of the sample introduced was 100 μl, and the amount of the sample was measured using tetrahydrofuran as an eluent. At a temperature of 40 DEG C and a flow rate of 1 mL / min, in terms of standard polystyrene.

First, a polymerization example in which the acrylic resin (A) specified in the present invention is produced is shown.

[Polymerization Example 1]

81.8 parts of ethyl acetate as a solvent, 70.4 parts of butyl acrylate as a monomer (A-1) and 20.0 parts of methyl acrylate were charged in a reaction vessel equipped with a stirrer, a thermometer and a stirrer, -Hydroxyethyl (1.0 part), 2-phenoxyethyl acrylate (A-3) as a monomer (A-3) and 0.6 part of acrylic acid as another monomer were introduced, and the air in the apparatus was replaced with nitrogen gas, While the internal temperature was raised to 55 ° C. Thereafter, a total amount of a solution obtained by dissolving 0.14 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. 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, and the concentration of the acrylic resin was 35% The addition of ethyl acetate was stopped and the temperature was maintained at this temperature for 12 hours from the start of the addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the acrylic resin to 20%, and an ethyl acetate solution of an acrylic resin was prepared. The acrylic resin thus obtained had a weight average molecular weight (Mw) of 4.50 in terms of polystyrene as measured by GPC and a Mw / Mn value of 4.3. This is referred to as acrylic resin solution A.

[Polymerization Example 2]

81.8 parts of ethyl acetate as a solvent, 68.0 parts of butyl acrylate as a monomer (A-1) and 20.0 parts of methyl acrylate as monomer components and 20.0 parts of acrylic acid 2 as a monomer (A-2) were placed in a reaction vessel equipped with a stirrer, a thermometer, -Hydroxyethyl (4.0 parts) and 8.0 parts of 2-phenoxyethyl acrylate as monomer (A-3) were poured into the flask, and the air inside the apparatus was replaced with nitrogen gas to raise the internal temperature to 55 deg. Thereafter, a total amount of a solution obtained by dissolving 0.14 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. 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 DEG C, and the concentration of the acrylic resin was 35% The addition of ethyl acetate was stopped and the temperature was maintained at this temperature for 12 hours from the start of the addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the acrylic resin to 20%, and an ethyl acetate solution of an acrylic resin was prepared. The acrylic resin thus obtained had a weight average molecular weight (Mw) of 1.4 million in terms of polystyrene as measured by GPC, and Mw / Mn of 4.9. This is referred to as an acrylic resin solution B.

[Polymerization Example 3]

81.8 parts of ethyl acetate as a solvent, 54.0 parts of butyl acrylate as monomer (A-1), and 35.0 parts of methyl acrylate as monomer components were added to a reaction vessel equipped with a stirrer, a thermometer and a stirrer, -Hydroxyethyl acrylate as a monomer (A-3) and 8.0 parts of 2-phenoxyethyl acrylate as a monomer (A-3) were injected in the same manner as in Polymerization Example 1. The obtained acrylic resin had a weight average molecular weight (Mw) of 147,000 as measured by GPC in terms of polystyrene, and Mw / Mn of 3.5. This is referred to as an acrylic resin solution C.

[Polymerization Example 4]

81.8 parts of ethyl acetate as a solvent, 46.0 parts of butyl acrylate as a monomer (A-1) and 40.0 parts of methyl acrylate as a solvent and 40.0 parts of acrylic acid 2 as a monomer (A-2) were placed in a reaction vessel equipped with a stirrer, a thermometer, -Hydroxyethyl acrylate as a monomer (A-3), 8.0 parts of 2-phenoxyethyl acrylate as a monomer (A-3), and 2.0 parts of acrylic acid as another monomer, Ethyl acetate solution was prepared. The obtained acrylic resin had a weight average molecular weight (Mw) in terms of polystyrene as measured by GPC of 800,000, and Mw / Mn of 6.0. This is referred to as an acrylic resin solution D.

Table 1 shows the monomer composition, the weight average molecular weight of the obtained acrylic resin, and a list of Mw / Mn in Polymerization Examples 1 to 4 above. In the tables, the symbols in the column of monomer composition mean the next monomer, respectively.

&Lt; Monomer (A-1) &gt;

BA: butyl acrylate

MA: methyl acrylate

&Lt; Monomer (A-2) &gt;

HEA: 2-hydroxyethyl acrylate

&Lt; Monomer (A-3) &gt;

PEA: 2-phenoxyethyl acrylate

<Other monomers>

AA: Acrylic acid

Next, examples and comparative examples in which a pressure-sensitive adhesive is prepared using the acrylic resin prepared above and applied to an optical film will be shown. As the crosslinking agent, the silane compound and the antistatic agent, the following were respectively used.

&Lt; Crosslinking agent (B) &gt;

Colonate L: Trimethylol propane of tolylene diisocyanate An ethyl acetate solution (solid content concentration 75%) of the duct body was obtained from Nippon Polyurethane Co., Ltd. Hereinafter referred to as "Cor-L ".

Takenate D-110N: An ethyl acetate solution of trimethylolpropane adduct of xylylene diisocyanate (solids concentration 75%) was obtained from Mitsui Kagaku Co., Ltd. Hereinafter, it is abbreviated as "D110N ".

&Lt; Organic acid salt (C) &gt;

Sodium acetate: Obtained from Wako Junyaku Kogyo Co., Ltd. To the pressure-sensitive adhesive composition, 0.5 wt% solution was prepared by dissolving in ethyl alcohol.

Sodium octanoate: Obtained from Wako Junyaku Kogyo Co., Ltd. To the pressure-sensitive adhesive composition, 0.2 wt% solution was prepared by dissolving in ethyl alcohol.

Tetra-n-butylammonium acetate: Obtained from Tokyo Kasei High School. To the pressure-sensitive adhesive composition, 1 wt% solution was prepared by dissolving in methyl ethyl ketone.

Potassium Acetate: Obtained from Wako Junyaku Kogyo Co., Ltd. The pressure-sensitive adhesive composition was previously dissolved in acetic acid added at the same time to prepare a 2.4 wt% acetic acid solution and added.

p-tBu Sodium benzoate: Obtained from Wako Junyaku Kogyo Co., Ltd. The pressure-sensitive adhesive composition was previously dissolved in acetic acid added at the same time to prepare a 2.4 wt% acetic acid solution and added.

Sodium nicotinate: Obtained from Tokyo Kasei High School. The pressure-sensitive adhesive composition was previously dissolved in acetic acid added at the same time to prepare a 2.4 wt% acetic acid solution and added.

Cesium Acetate: Acquired from Tokyo Kasei High School. The pressure-sensitive adhesive composition was previously dissolved in acetic acid added at the same time to prepare a 2.4 wt% acetic acid solution and added.

Barium Acetate: Obtained from Sigma-Aldrich Japan. The pressure-sensitive adhesive composition was previously dissolved in acetic acid added at the same time to prepare a 2.4 wt% acetic acid solution and added.

<Organic acid (D)>

Acetic acid: Vapor pressure 11.4 mmHg (20 캜), boiling point 97 캜, available from Wako Pure Chemical Industries, Ltd.

Acrylic acid: Vapor pressure 3.1 mmHg (20 캜), boiling point 142 캜, available from Nippon Shokubai Co.,

Octanoic acid: Vapor pressure 0.004 mmHg (20 ° C), boiling point 237 ° C, available from Wako Pure Chemical Industries, Ltd.

&Lt; Silane compound (E) &gt;

KBM-403: 3-glycidoxypropyltrimethoxysilane, liquid, obtained from Shin-Etsu Kagaku Kogyo Co., Ltd. Hereinafter, it is abbreviated as "KBM403 ".

&Lt; Antistatic agent (F) &gt;

N-hexyl-4-methylpyridinium hexafluorophosphate (having the structure of the following formula).

[Examples 1 to 25 and Comparative Examples 1 to 12]

(a) Preparation of pressure-sensitive adhesive composition

The pressure-sensitive adhesive compositions 1 to 37 were each prepared by the following prescription. In addition, as described above, the crosslinking agent is added as an ethyl acetate solution, the organic acid salt is added as an ethyl alcohol or methyl ethyl ketone solution, or an organic acid and an organic acid salt are premixed and then an organic acid solution is added to the acrylic resin solution. The addition amount in Table 2 is the amount of the solid content.

(a-1) Preparation of pressure-sensitive adhesive compositions 1 to 6

The crosslinking agent (B), the organic acid salt (C) and the organic acid (D) were blended in the respective amounts shown in Table 2 with respect to 100 parts of the solid content of the acrylic resin solution A prepared in Polymerization Example 1. Methyl ethyl ketone was further added so that the solid content concentration was 14%, and the mixture was stirred and mixed at 300 rpm for 30 minutes using a stirrer ("Three One Motor", manufactured by Yamato Kagaku Co., Ltd.) Respectively.

(a-2) Preparation of pressure-sensitive adhesive compositions 12 to 16

(B), an organic acid salt (C), an organic acid (D), and a silane compound (D) were added to 100 parts of the solid content of the acrylic resin solution B Sensitive adhesive compositions 12 to 16 were prepared by the same prescription and preparation method as in the above (a-1) except that the antistatic agent (E) and the antistatic agent (F)

(a-3) Preparation of pressure-sensitive adhesive compositions 17 to 24

The acrylic resin solution A was changed to the acrylic resin solution C prepared in Polymerization Example 3 and a crosslinking agent (B), an organic acid salt (C), an organic acid (D) and a silane compound Sensitive adhesive compositions 17 to 24 were prepared by the same prescription and preparation method as in the above (a-1) except that the antistatic agent (E) and the antistatic agent (F)

(a-4) Preparation of pressure-sensitive adhesive compositions 7 to 11 and 25

The acrylic resin solution A was changed to the acrylic resin solution D prepared in Polymerization Example 4 and the crosslinking agent (B), the organic acid salt (C), the organic acid (D) and the silane compound Sensitive adhesive compositions 7 to 11 and 25 were prepared by the same prescription and preparation method as in the above (a-1) except that the antistatic agent (E) and the antistatic agent (F)

(a-5) Preparation of pressure-sensitive adhesive compositions 26, 27 and 32

The acrylic resin solution A or B and the crosslinking agent (B) were compounded in the respective kinds and amounts shown in Table 2 without using the organic acid salt (C) and the organic acid (D) for the preparation of the pressure-sensitive adhesive composition. Methyl ethyl ketone was further added so that the solid content concentration was 14%, and the mixture was stirred for 30 minutes at 300 rpm using a stirrer ("Three One Motor", manufactured by Yamato Kagaku Co., Ltd.) . The crosslinking agent (B) was prepared by blending the amount shown in Table 2 with 100 parts by solid content in the acrylic resin solution.

(a-6) Preparation of pressure-sensitive adhesive compositions 28 and 30

The crosslinking agent (B) and the organic acid salt (C) were compounded in the respective kinds and amounts shown in Table 2, with respect to 100 parts of the solid content of the acrylic resin solution A, without using the organic acid (D) for the preparation of the pressure- Methyl ethyl ketone was further added so that the solid content concentration became 14%, and the mixture was stirred and mixed at 300 rpm for 30 minutes using a stirrer ("Three One Motor", manufactured by Yamato Kagaku Co., Ltd.) Respectively.

(a-7) Preparation of pressure-sensitive adhesive compositions 29, 31 and 33 to 35

The pressure-sensitive adhesive compositions 29, 31 and 33 to 35 were prepared by the same prescription and preparation method as in the above-mentioned (a-6) except that the acrylic resin solution A was changed to the acrylic resin solution B prepared in Polymerization Example 2 .

(a-8) Preparation of pressure-sensitive adhesive composition 36

The crosslinking agent (B), the organic acid salt (C), the silane compound (E) and the antistatic agent (F) were compounded in the respective kinds and amounts shown in Table 2 with respect to 100 parts of the solid content of the acrylic resin solution B. Methyl ethyl ketone was further added so that the solid content concentration became 14%, and the mixture was stirred and mixed at 300 rpm for 30 minutes using a stirrer ("Three One Motor", manufactured by Yamato Kagaku Co., Ltd.) to prepare a pressure-sensitive adhesive composition.

(a-9) Preparation of pressure-sensitive adhesive composition 37

A pressure-sensitive adhesive composition 37 was prepared by the same prescription and preparation method as in the above (a-8) except that the acrylic resin solution B was changed to the acrylic resin solution C.

(b) Viscosity measurement of pressure-sensitive adhesive composition

With respect to the pressure-sensitive adhesive composition prepared in the above (a), the change in viscosity with time in the solution state was confirmed. The viscosity of the pressure-sensitive adhesive composition immediately after preparation and the viscosity of the pressure-sensitive adhesive composition after storage at 23 DEG C for 24 hours were measured with a Brookfield viscometer (product name: MODEL LV T manufactured by Brookfield Engineering Laboratories Co., Ltd. "). The results of the measurement immediately after preparation of the pressure-sensitive adhesive composition are shown in the column of " Viscosity Change Initial Viscosity &quot; in Table 3, and the measurement results after 24 hours are shown in the column of &quot; Viscosity 24 hours after Viscosity Change &quot;.

Since the pressure-sensitive adhesive composition is applied in the form of a sheet in the step of preparing the pressure-sensitive adhesive sheet, the viscosity of the pressure-sensitive adhesive composition is deteriorated when the viscosity of the pressure-sensitive adhesive composition is too high. As practical conditions of the pressure-sensitive adhesive composition, it is preferable that the initial viscosity after preparation of the pressure-sensitive adhesive composition is defined as μ ₀ (mPa · s) and the viscosity after storage for 24 hours is μ ₁ (mPa · s) It is preferable that the viscosity change rate (DELTA mu) of 24 hours is 10% or less. The viscosity change rate in the initial 24 hours obtained for the pressure-sensitive adhesive composition prepared in the above (a) is shown in the column of &quot; initial 24-hour viscosity change rate &quot;

Initial 24-hour viscosity change rate (?) (%) = (Μ ₁ / μ ₀ -1) × 100

(c) Production of a pressure-sensitive adhesive sheet

Each of the pressure-sensitive adhesive compositions prepared in the above (a) was applied to the releasably treated surface of a polyethylene terephthalate film (product name "SP-PLR382050", trade name, manufactured by LINTEC CORPORATION, The pressure-sensitive adhesive layer was applied so that the thickness of the pressure-sensitive adhesive layer was 20 占 퐉 and dried at 100 占 폚 for 1 minute to prepare a pressure-sensitive adhesive sheet.

(d) Gel fraction measurement of adhesive sheet

The pressure-sensitive adhesive sheet prepared in the above (c) was stored and cured under conditions of a temperature of 23 ° C and a relative humidity of 65%. The gel fraction was measured according to the above gel fraction measurement method for each of the one-day curing and the three-day curing. The results of measurement after storage for 1 day are shown in the column of &quot; After 1 day of gel fraction change &quot; in Table 3, and the results of measurement after storage for 3 days are shown in the column of &quot; 3 days after gel fraction change &quot; .

Completion of the curing was judged by the fact that the gel fraction reached a certain value or more and the time variation of the gel fraction became sufficiently small. As a numerical value for judging the progress of the curing, a crosslinking ratio ratio (T) expressed by the following formula was used. The closer the crosslinking ratio ratio (T) is to 1, the more preferable that the crosslinking reaction is a convergence tendency and the curing is completed in a shorter time. The crosslinking ratio ratio obtained for the pressure-sensitive adhesive sheet prepared in the above (c) is shown in the column of &quot; crosslinking ratio ratio &quot;

Crosslinkage ratio ratio (T) = gel fraction after storage for 3 days / gel fraction after storage for 1 day

(e) Quantification of remaining amount of acid in the pressure-sensitive adhesive

The pressure-sensitive adhesive sheets prepared in (c) Example 17 and Examples 20 to 21 were cured at a temperature of 23 캜 and a relative humidity of 65% for 7 days. Subsequently, a pressure-sensitive adhesive sheet piece (8 cm x 8 cm) cut from the pressure-sensitive adhesive sheet was immersed in acetonitrile to extract non-crosslinked components. The acetonitrile solution containing the extracting component was filtered through a filter (pore diameter 0.45 μm, PTFE, GE Healthcare Life Sciences), and the amount of the organic acid (D) in the extract was measured by high performance liquid chromatography (Shimadzu Corporation, LC-20A manufactured by Seisakusho Co., Ltd.), and the amount of the organic acid (D) remaining in the pressure-sensitive adhesive sheet was calculated by the calibration curve method. Table 4 shows the residual acid concentration in the pressure-sensitive adhesive sheet obtained by this analysis.

In the tables, the symbols in the column of monomer composition mean the next monomer, respectively.

AA: Acrylic acid

CEA: 2-carboxyethyl acrylate

AcOH: acetic acid

In Example 17 in which acrylic acid was added as the organic acid (D), residual acrylic acid itself was suppressed to the lower limit of detection, but a small amount of 2-carboxyethyl acrylate initially contained in acrylic acid as an impurity component remained in the pressure- And 70 ppm, respectively. In contrast, in Examples 20 and 21 in which the organic acid (D) was changed to acetic acid having a higher vapor pressure, the residual organic acid component in the adhesive sheet was suppressed to a detection lower limit or lower, Can be obtained. The lower limit of detection in the present evaluation method is 0.001%.

From Table 2 and Table 3, it can be seen that in the examples using the pressure-sensitive adhesive composition in which the organic acid salt (C) and the organic acid (D) having at least one carboxylate anion specified in the present invention coexist, either one or both of them are not blended In comparison with the comparative example, the values of the viscosity change rate? 占 and the crosslinkage ratio ratio T at the initial 24 hours are all small. From these results, it can be seen that the progress of the crosslinking reaction in the solution state is sufficiently suppressed in these pressure-sensitive adhesive compositions, and it can be stored in a state of no change in viscosity over a long period after preparation thereof. Further, in these pressure-sensitive adhesive compositions, the organic acid (D) is removed in the pressure-sensitive adhesive sheet forming step, and thereafter the crosslinking is promoted by the base derived from the organic acid salt present in the pressure-sensitive adhesive sheet, and the curing time can be shortened .

In Examples 1 to 6, in which acrylic resin A having a carboxyl group was used as the main component, and in Examples 12 to 16, in which acrylic resin B having no carboxyl group was used in the acrylic resin (A) And the curing time after formation of the pressure-sensitive adhesive sheet is shortened. Therefore, according to the present invention, it is possible to efficiently produce the pressure-sensitive adhesive sheet even when the acrylic resin (A) does not contain an acid component .

(f) Production of Polarizer with Adhesive

A polarizing plate in which one side of a polarizing film in which iodine is adsorbed and oriented on a polyvinyl alcohol based resin film is a protective film made of triacetyl cellulose and the other side is a protective film made of cycloolefin, The surface of the protective film made of olefin was subjected to corona treatment and the surface (pressure-sensitive adhesive side) opposite to the separator of the pressure-sensitive adhesive sheet prepared in (c) was bonded by a laminator. Cured for 7 days to prepare a polarizing plate with a pressure-sensitive adhesive.

(g) Heat resistance test, wet heat resistance test and heat shock test of adhesive sheet

The separator was peeled off from the polarizing plate with a pressure sensitive adhesive prepared in the above (f), and the pressure sensitive adhesive surface was adhered to both sides of a glass substrate for liquid crystal cell [trade name "EAGLE XG" Respectively. This optical laminate was subjected to an anti-moisture heat test in which a heat resistance test was conducted in which the temperature was kept at 80 ° C for 500 hours (indicated as "heat resistance" in Table 5) and stored at a temperature of 60 ° C and a relative humidity of 90% for 500 hours ("Wet heat resistance" in Table 5), and the process of lowering the temperature to -30 ° C in the state of heating to 70 ° C and then raising the temperature to 70 ° C in one cycle (one hour) , And the case where an internal shock test in which this was repeated for 100 cycles (indicated as &quot; inner HS &quot; in Table 5) was observed by visually observing the optical laminate after the test. The results were classified into the following criteria and summarized in Table 5.

<Evaluation Criteria of Heat Resistance Test, Humidity Heat Test and Internal Heat Shock Test>

◎: No change in appearance such as peeling, peeling, and foaming can be seen at all.

○: Almost no change in appearance such as peeling, peeling, and foaming is observed.

Δ: Appearance of peeling, peeling, foaming and the like are slightly visible.

X: Appearance changes such as lifting, peeling, foaming and the like are remarkably confirmed.

(h) Evaluation of adhesion of optical laminate

The polarizing plate on which the pressure-sensitive adhesive layer prepared in (f) was formed was cut into test pieces having a size of 25 mm x 150 mm. The separator was peeled off from the test piece, and the pressure sensitive adhesive surface was bonded to a glass substrate for liquid crystal cell (trade name "EAGLE XG", obtained from Corning Incorporated) by a bonding apparatus (trade name "Lamy Packer" manufactured by Fuji Plastics Co., Ltd.). The obtained test piece (optical laminate with the glass substrate adhered thereto) was pressed in an autoclave at a temperature of 50 캜 and a pressure of 5 kgf / cm ² (490.3 kPa) for 20 minutes. The sample was allowed to stand in an atmosphere at a temperature of 23 캜 and a relative humidity of 55% for 24 hours. After standing, the sample was chucked by a tensile tester (AUTOGRAPH AGS-X, manufactured by Shimadzu Corporation) and subjected to a tensile test at a temperature of 23 ° C and a relative humidity of 55% at 180 ° Lt; / RTI &gt; The peel strength measured at this time was evaluated as an adhesive force. The results are shown in Table 5.

As shown in Table 5, the pressure-sensitive adhesive sheet obtained from the pressure-sensitive adhesive composition prepared according to the prescription of the present invention exhibits a high adhesive force with respect to the glass substrate, and sufficient heat resistance, anti-wet heat and anti-HS properties are secured.

The pressure-sensitive adhesive composition of the present invention is capable of suppressing a change in viscosity over a long period of time and has excellent coating properties. Further, the pressure-sensitive adhesive sheet using this pressure-sensitive adhesive composition can shorten the curing time required until the pressure-sensitive adhesive sheet can be processed after being formed into a sheet shape, and is excellent in workability. Further, since the pressure-sensitive adhesive sheet can be substantially free from an acid component, the optical film obtained by bonding the pressure-sensitive adhesive sheet to the pressure-sensitive adhesive sheet is suitably used for a liquid crystal display device.

1: polarizing film
2: Surface treatment layer
3: (first) protective film
4: Second protective film
5: polarizer
7: retardation film
8: Interlayer adhesive
10: Optical film
20: pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) bonded to liquid crystal cell (glass substrate)
25: Optical film with adhesive
30: Liquid crystal cell (glass substrate)
40: Optical laminate

Claims (14)

(A), a crosslinking agent (B), an organic acid salt (C), and an organic acid (D), which is a polymer of a monomer containing a (meth) acrylic acid ester (A- &Lt; tb &gt;&lt; SEP &gt;

In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 14 or less carbon atoms. The acrylic resin composition according to claim 1, wherein the acrylic resin (A) comprises a (meth) acrylic monomer (A-2) having a hydroxyl group in addition to the (meth) acrylic acid ester (A- &Lt; / RTI &gt; The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the acrylic resin (A) is a copolymer of a monomer mixture further comprising a (meth) acrylate ester (A-3) represented by the following formula (II)

Wherein R ³ represents a hydrogen atom or a methyl group, R ⁴ represents an aryl group, X represents a single bond or oxyethylene represented by - (C ₂ H ₄ O) _n -, wherein n is an integer of 1 to 4 Lt; / RTI &gt; The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the cross-linking agent (B) contains an isocyanate-based compound. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the organic acid salt (C) is an organic carboxylic acid salt containing at least one carboxylate anion. 3. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the organic acid (D) comprises a carboxylic acid. The pressure-sensitive adhesive composition according to claim 1 or 2, further comprising a silane compound (E). The pressure-sensitive adhesive composition according to claim 1 or 2, further comprising an antistatic agent (F). A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition according to claim 1. A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive composition according to claim 1 applied on a substrate and dried. The pressure-sensitive adhesive sheet according to claim 9 or 10, wherein a release film is adhered to at least one side. An optical film with a pressure-sensitive adhesive, wherein the pressure-sensitive adhesive sheet according to claim 9 or 10 is bonded to an optical film. The optical film with a pressure-sensitive adhesive according to claim 12, wherein the optical film is a polarizing film or a retardation film. An optical laminate characterized in that the optical film with a pressure-sensitive adhesive according to claim 12 is laminated on a glass substrate at the pressure-sensitive adhesive layer side.

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