TW201726873A - Adhesive composition, adhesive sheet and optical film with adhesive - Google Patents

Abstract

An object of the present invention is to provide a novel adhesive composition having suitable adhesive force and capable of increasing releasability by adding water to the interface between the adhesive layer and the glass substrate at the time of peeling, by providing an adhesive composition comprising an acrylic resin, a crosslinking agenting, and a silane compound represented by the following formula (In the above formula (I), R1 represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group, an aryl group or an alkenyl group, and R2 represents an alkyl group having 1 to 6 carbon atoms).

Description

Adhesive composition, adhesive sheet and optical film with adhesive

The present invention relates to an adhesive composition suitable for an optical film, an adhesive sheet using the adhesive composition, and an optical film to which an adhesive is attached. The present invention also relates to an optical laminate which is laminated on a glass substrate and which is suitable for a liquid crystal display.

The polarizing plate is widely used in the liquid crystal display device. The polarizing plate is generally a transparent protective film of two areas of a polarizing film, and an adhesive layer is formed on at least one surface of the protective film, and is circulated in a state in which a peeling film is adhered to the adhesive layer.

In addition, a polarizing plate laminated retardation film in which a protective film is bonded to both surfaces of the polarizing film is used as an elliptically polarizing plate, and an adhesive layer/release film is sequentially adhered to the retardation film side. Further, there is also a case where the adhesive layer/release film is sequentially adhered to the surface of the retardation film. In the present specification, a polarizing plate, an elliptically polarizing plate, a retardation film, and the like which are provided with an adhesive layer in this manner are collectively referred to as an optical film. The optical film with an adhesive is laminated on a glass substrate such as a liquid crystal cell to constitute a liquid crystal display device.

An adhesive group forming an adhesive layer suitable for an optical film From the viewpoint of transparency and weather resistance, a (meth)acrylic resin produced by copolymerizing a monomer having a polar functional group such as a hydroxyl group or a carboxyl group with an acrylate as a main component is often used. By formulating a crosslinking agent in such a (meth)acrylic resin, the desired cohesive force can be imparted. Further, by blending a decane-based compound with such a (meth)acrylic resin, the adhesion between the adhesive layer and the glass substrate can be improved. For the decane-based compound, for example, 3-glycidoxypropyltrimethoxydecane is widely used (refer to Japanese Laid-Open Patent Publication No. 2013-181086).

(previous technical literature) (Patent Literature)

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-181086

A moderate adhesion is required in the adhesive layer of the optical film to which the adhesive is attached. The optical film with an adhesive is laminated, for example, on a glass substrate of a liquid crystal cell to obtain an optical laminate for liquid crystal display, and has an appropriate adhesive force, and the optical laminate is heated under high temperature conditions or under hot and humid conditions. In the cooling environment, the stress caused by the dimensional change of the optical film and the glass substrate is alleviated by the adhesive layer, so that the local stress concentration is reduced, and the floating or peeling of the adhesive layer on the glass substrate is suppressed. That is, it is excellent in durability.

In the adhesive layer of the optical film with an adhesive, a moderate adhesive force as described above is required, and on the other hand, when the optical film with an adhesive is attached to the liquid crystal cell, the optical is removed once the defect is caused. Behind the membrane It is necessary to re-attach the new film, and thus it is required to have good peelability at this time. When the peeling property is low, there is a problem that an adhesive or the like remains on the glass substrate.

The present invention relates to a novel adhesive composition, an adhesive sheet using the adhesive composition, an optical film with an adhesive, and an optical laminate, wherein the adhesive composition has a moderate adhesion to the glass substrate. Further, peeling property can be improved by adding water at the interface between the adhesive layer and the glass substrate at the time of peeling.

The present invention provides an adhesive composition, an adhesive sheet, an optical film with an adhesive, and an optical laminate as shown below.

[1] An adhesive composition comprising a (meth)acrylic resin, a crosslinking agent, and a decane compound represented by the following formula (I),

In the above formula (I), R ₁ represents an alkyl group, an aralkyl group, an aryl group or an alkenyl group having 1 to 14 carbon atoms; and R ₂ represents an alkyl group having 1 to 6 carbon atoms.

[2] The adhesive composition according to [1], wherein the decane-based compound is contained in an amount of 0.03 to 10 parts by weight based on 100 parts by weight of the (meth)acrylic resin.

[3] The adhesive composition according to [1] or [2] wherein the decane-based compound is 3-ureidopropyltrialkoxydecane.

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

[5] An adhesive sheet which is formed into a sheet by using the adhesive composition according to [1] to [4].

[6] The adhesive sheet according to [5], which is formed on a plastic film.

[7] The adhesive sheet according to [6], wherein the plastic film is a release film to which a release treatment is applied.

[8] An optical film with an adhesive comprising an optical film, and an adhesive sheet according to [5] to [7] attached to the optical film.

[9] The optical film with an adhesive according to [8], wherein the optical film is a polarizing plate or a retardation film.

[10] An optical layered product comprising the adhesive film according to [8] or [9], wherein the adhesive sheet side is bonded to the glass substrate.

According to the present invention, it is possible to provide an adhesive composition, and an adhesive sheet using the adhesive composition and an optical film with an adhesive, wherein the adhesive composition can form a moderate adhesion to the glass substrate. The adhesive layer, when the adhesive layer is peeled off, exhibits excellent peelability by adding water at the interface between the adhesive layer and the glass substrate.

1‧‧‧ polarizing film

2‧‧‧Surface treatment layer

3‧‧‧(first) protective film

4‧‧‧Second protective film

5‧‧‧Polar plate

7‧‧‧ phase difference film

8‧‧‧Interlayer adhesive

10‧‧‧Optical film

20‧‧‧Adhesive layer (adhesive sheet) attached to liquid crystal cell (glass substrate)

25‧‧‧Optical film with adhesive

30‧‧‧Liquid Crystal Unit (Glass Substrate)

40‧‧‧Optical laminate

Fig. 1 is a schematic cross-sectional view showing an example of a preferred layer constitution of the optical layered body of the present invention.

(formation for implementing the invention)

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

In the above formula (I), R ₁ represents an alkyl group, an aralkyl group, an aryl group or an alkenyl group having 1 to 14 carbon atoms. R ₂ represents an alkyl group having 1 to 6 carbon atoms. When the oxirane compound (C) represented by the above formula (I) is contained in the adhesive composition of the present invention, it is excellent in adhesion to a glass substrate, has an appropriate adhesiveness, and is excellent in durability. When the adhesive layer is peeled off and the adhesive layer is peeled off from the glass substrate, an adhesive layer exhibiting excellent peeling properties can be formed by adding water to the interface between the adhesive layer and the glass substrate. First, each component constituting the adhesive composition will be described.

[(Meth)acrylic resin (A)]

The (meth)acrylic resin (A) constituting the adhesive composition of the present invention contains a structural unit derived from (meth) acrylate (A-1) as a main component, and is derived from a hydroxyl group (A) The structural unit of the acrylic monomer (A-2) is preferred. Further, it is preferred to include a structural unit derived from a carboxyl group-containing (meth) acrylate (A-3).

The above (meth) acrylate (A-1) is represented by the following formula (II).

In the above formula (II), R ₃ represents a hydrogen atom or a methyl group; and R ₄ represents an alkyl group or an aralkyl group having a carbon number of 14 or less, but the hydrogen atom constituting the group may be via a group -O-(C ₂ H ₄ O) _{m -} R _{5 is} substituted, wherein 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 carboxyl group-containing (meth) acrylate (A-3) is represented by the following formula (III).

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

In the present specification, the (meth)acrylic acid may be any of acrylic acid or methacrylic acid, and other (meth)acrylate, (meth)acrylic resin, etc. Also synonymous. In the present specification, the (meth) acrylate (A-1) represented by the above formula (I) is simply referred to as "monomer (A-1)" and a hydroxyl group-containing (meth)acrylic monomer (A). -2) The carboxyl group-containing (meth) acrylate (A-3) represented by the above formula (III) is abbreviated as "monomer (A-3)".

In the monomer (A-1), R ₄ in the above formula (II) is an unsubstituted alkyl group, specifically, for example, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, acrylic acid. a linear alkyl acrylate of n-octyl ester and lauryl acrylate; a branched alkyl acrylate such as isobutyl acrylate, 2-ethylhexyl acrylate and isooctyl acrylate; such as methyl methacrylate, a linear alkyl methacrylate of ethyl acrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate and lauryl methacrylate; and isobutyl methacrylate, A branched alkyl methacrylate of 2-ethylhexyl methacrylate and isooctyl methacrylate.

In the above, the n-butyl acrylate is preferably used in an amount of 50% by weight or more of all the monomers constituting the (meth)acrylic resin (A), and the above is satisfied. The relevant regulations of the monomer (A-1) are preferred.

Further, in the monomer (A-1), R ₄ in the formula (II) is an aralkyl group, and specific examples thereof include benzyl acrylate and benzyl methacrylate.

Next, in the monomer (A-1), the hydrogen atom constituting the alkyl group or the aralkyl group of R ₄ in the formula (II) is substituted with a group -O-(C ₂ H ₄ O) _m -R ₅ Description. In the group -O-(C ₂ H ₄ O) _m -R ₅ , m is as defined above, and is 0 or an integer of 1 to 4, particularly preferably 0, 1 or 2. Further, R ₅ is also an alkyl group or an aryl group having a carbon number of 12 or less as defined above, and the alkyl group has a carbon number of 3 or more, and may be a straight chain or a branched chain. Examples of the aryl group constituting R ₅ include an alkyl-substituted phenyl group, a biphenyl group (or a phenylphenyl group) including a tolyl group, a xylyl group or an ethylphenyl group in addition to a phenyl group and a naphthyl group. )Wait. R _{5 is} particularly preferred as the aryl group.

In the monomer (A-1), R ₄ in the formula (II) is an alkyl group, and a hydrogen atom thereof is substituted with a group -O-(C ₂ H ₄ O) _m -R ₅ , specifically exemplified by: acrylic acid 2-methoxyethyl ester, ethoxymethyl acrylate, 2-phenoxyethyl acrylate, 2-(2-phenoxyethoxy)ethyl acrylate and 2-(o-phenylphenoxy) acrylate Alkoxyalkyl-, aryloxyalkyl- or aryloxyethoxyalkyl-ester of ethyl acrylate; such as 2-methoxyethyl methacrylate, methacrylic acid Oxymethyl ester, 2-phenoxyethyl methacrylate, 2-(2-phenoxyethoxy)ethyl methacrylate and 2-(o-phenylphenoxy)ethyl methacrylate An alkoxyalkyl-, aryloxyalkyl- or aryloxyethoxyalkyl-ester of methacrylic acid, and the like.

These monomers (A-1) may be used alone or in combination of plural kinds. As described above, the monomer (A-1) is particularly preferably composed of n-butyl acrylate as a main component, and is also effective in copolymerizing other methacrylates corresponding to the formula (II). The preferred composition of the monomer (A-1) is such that, in all the monomers constituting the (meth)acrylic resin (A), n-butyl acrylate is 50% by weight or more, and The following (meth) acrylate is blended in a ratio of 3 to 15% by weight, wherein the (meth) acrylate is represented by the above (II), and as described above, R ₄ in the formula is constituting the R ₄ The hydrogen atom is an alkyl group substituted with a group -O-(C ₂ H ₄ O) _m -R ₅ (wherein m and R ₅ are as defined above).

The hydroxyl group-containing (meth)acrylic monomer (A-2) may, for example, be 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate or (meth)acrylic acid. 4-hydroxybutyl ester and 2-(2-hydroxyethoxy)ethyl (meth)acrylate. Among these, 2-hydroxyethyl (meth)acrylate is used. It is preferably used for one of the monomers (A-2) constituting the (meth)acrylic resin (A).

The carboxyl group-containing (meth) acrylate (A-3) is represented by the above formula (III). In the 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, which is typically an alkylene group, is preferably a linear alkyl group, but the (meth)acrylic acid moiety CH ₂ =C(R ₆ )COO- and the terminal It is premised that the carbon chain to which the carboxyl group-COOH is bonded is at least two in series, and may be branched if it has a carbon number of 3 or more. In the formula (III), the acrylate is preferably used as the monomer (A-3), and examples thereof include 2-carboxyethyl acrylate, 3-carboxypropyl acrylate, and 4-carboxybutyl acrylate. Of course, the compound in which the acrylate is changed to a methacrylate may also be a monomer (A-3).

The 2-carboxyethyl acrylate is generally produced by dimerization of acrylic acid. In this case, in addition to the main component of 2-carboxyethyl acrylate, acrylic acid itself and oligomerization with acrylic acid terpolymer can be obtained. The mixture of substances is directly sold as a mixture of the state. Therefore, together with the monomer (A-3), it is of course also possible to copolymerize with other carboxyl group-containing (meth)acrylic monomers.

In the (meth)acrylic resin (A) specified in the present invention, the (meth) acrylate represented by the above formula (II), that is, the structural unit derived from the monomer (A-1) is contained in the range of 90 to 99. % by weight, the (meth)acrylic monomer having a hydroxyl group, that is, the content of the structural unit derived from the monomer (A-2) is from 0.1 to 6% by weight, and the carboxyl group-containing one represented by the above formula (III) The (meth) acrylate, that is, the structural unit derived from the monomer (A-3) may be contained in an amount of from 0.01 to 0.4% by weight. By arranging the monomers (A-1) and (A-2) in such a limited ratio, the preparation can be imparted. An adhesive composition of an adhesive sheet excellent in workability. Of course, the total amount of the structural units derived from the monomers (A-1), (A-2) and (A-3), respectively, does not exceed 100% by weight.

The (meth)acrylic resin (A) used in the present invention may comprise a structural unit derived from a monomer other than the monomers (A-1), (A-2) and (A-3) described above. . Examples of the monomer other than the monomers (A-1), (A-2), and (A-3) include a monomer other than the formula (III) having a polar functional group other than a hydroxyl group, and a molecule. (meth) acrylate having an alicyclic structure, a styrene monomer, a vinyl monomer, a (meth) acrylamide derivative, and a monomer having a plurality of (meth) acrylonitrile groups in the molecule .

A monomer other than the formula (III) having a polar functional group other than a hydroxyl group will be described. The polar functional group other than the hydroxyl group herein may be a heterocyclic group containing a free carboxyl group or an epoxy ring. The oligomer of the acrylic acid itself or the trimer of the acrylic acid described above in the monomer (A-3) corresponds to a monomer other than the formula (III) having a free carboxyl group. Further, examples of the monomer having a heterocyclic group include propylene hydrazinoline, vinyl caprolactam, N-vinyl-2-pyrrolidone, and tetrahydrofuran methyl (meth)acrylate. Caprolactone modified tetrahydrofuran methyl acrylate, 3,4-epoxycyclohexyl methyl (meth)acrylate, and glycidyl (meth) acrylate.

When a monomer having a polar functional group other than a hydroxyl group is copolymerized, it comprises a (meth)acrylic monomer (A-2) having a hydroxyl group and a carboxyl group-containing (meth)acrylate represented by the above formula (III). (A-3) It is preferable to make the total amount of the monomer having a polar functional group 8% by weight or less based on all the monomers constituting the (meth)acrylic resin (A).

Next, the (meth) acrylate having an alicyclic structure in the molecule will be described. The alicyclic structure has a carbon number of usually 5 or more, and preferably has a naphthene structure of about 5 to 7. Specific examples of the acrylate having an alicyclic structure include isodecyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecan acrylate, methylcyclohexyl acrylate, trimethyl acrylate. Cyclohexyl ester, tributyl butyl hexyl acrylate, cyclohexyl α-ethoxy acrylate, and cyclohexyl phenyl acrylate. Further, specific examples of the methacrylate having an alicyclic structure include isodecyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, and cyclododecan methacrylate. And methylcyclohexyl methacrylate, trimethylcyclohexyl methacrylate, tributyl butyl cyclomethacrylate, and cyclohexyl phenyl methacrylate.

Examples of styrene-based monomers include styrene, such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, and triethyl ethane. Alkyl styrenes of styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene and octyl styrene; such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene And halogenated styrene of iodine styrene; and nitrostyrene, ethyl styrene styrene, methoxy styrene and divinyl benzene.

Examples of vinyl monomers include: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate and vinyl laurate; such as vinyl chloride and bromine a vinyl halide of ethylene; a vinylidene halide such as dichloroethylene; a nitrogen-containing aromatic vinyl such as vinyl pyridine, vinyl pyrrolidone or vinyl carbazole; such as butadiene a conjugated diene monomer of pentadiene and chloroprene; and acrylonitrile, methacrylonitrile, and the like.

Examples of the (meth) acrylamide derivatives are N-hydroxymethyl (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)(methyl) decylamine, 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)(methyl)propenamide, N-(1 , 1-dimethyl-3-oxobutyl butyl) (meth) acrylamide, N-[2-(2-o-oxy-1-imidazolidinyl)ethyl](methyl) propylene oxime Amine and 2-acrylamido-2-methyl-1-propanesulfonic acid and the like.

Examples of the monomer having a plurality of (meth) acrylonitrile groups in the molecule are, for example, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(methyl) Acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(methyl) a monomer having two (meth) acrylonitrile groups in the molecule of acrylate and tripropylene glycol di(meth) acrylate; for example, three molecules in the molecule of trimethylolpropane tri(meth) acrylate ( A monomer such as a methyl methacrylate group.

In addition to the monomers (A-1), (A-2), and (A-3) which are components of the (meth)acrylic resin (A), the monomers having no polar functional groups are collectively In the case of the poly(meth)acrylic resin (A), the amount is preferably 5% by weight or less based on the total of the monomers constituting the (meth)acrylic resin (A).

The resin component constituting the adhesive composition may have a (meth) acrylate derived from the formula (II), that is, a monomer (A-1) and a hydroxyl group (meth), respectively, as described above. An acrylic monomer, that is, a monomer (A-2), and a carboxyl group-containing (meth) acrylate represented by the formula (III), that is, an acrylic resin of a structural unit of the monomer (A-3) (A) ), mixing two or more types. Further, the (meth)acrylic resin (A) having a structural unit derived from the monomers (A-1), (A-2) and (A-3), and a different (methyl group) thereof may be used in a predetermined ratio. ) Acrylic resin is mixed. Examples of the different (meth)acrylic resin to be mixed at this time include, for example, those having a structural unit derived from the (meth) acrylate of the above (II) and having no polar functional group. a (meth)acrylic resin (A) having a structural unit derived from the monomers (A-1), (A-2), and (A-3) in a predetermined ratio, in the entire (meth)acrylic resin, It is preferably 80% by weight or more, more preferably 90% by weight or more.

The (meth)acrylic resin (A) is preferably a one having a weight average molecular weight Mw measured by a gel permeation chromatography (GPC) and converted to a standard polystyrene of from 500,000 to 2,000,000. The weight average molecular weight Mw is particularly preferably from 500,000 to 1.7 million. When the weight average molecular weight in terms of standard polystyrene is 500,000 or more, the adhesion under high temperature and high humidity is improved, and the possibility of floating or peeling between the glass substrate and the adhesive sheet tends to decrease, and the rework is repeated. Sex has a tendency to improve and is therefore preferred. Further, when the weight average molecular weight is 2,000,000 or less, even if the size of the optical film attached to the adhesive sheet changes, the adhesive layer follows the size. Since the difference between the brightness of the peripheral portion of the liquid crystal cell and the brightness of the central portion disappears and there is a tendency to suppress white spots or color unevenness, it is preferable. 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 particularly limited, and is preferably in the range of about 3 to 7, for example.

Further, the (meth)acrylic resin (A) preferably has a glass transition temperature in the range of -10 to -60 ° C in order to exhibit 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 methods such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, or a suspension polymerization method. In the production of the (meth)acrylic resin, a polymerization initiator is generally 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 the total of all the monomers used in the production of the (meth)acrylic resin.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, and the like are used. The photopolymerization initiator may, for example, be 4-(2-hydroxyethoxy)phenyl (2-hydroxy-2-phenyl) ketone or the like. The thermal polymerization initiator may, for example, be, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis (ring) Hexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxy An azo compound of valeronitrile), dimethyl-2,2'-azobis(2-methylpropionate) and 2,2'-azobis(2-hydroxymethylpropionitrile); Lauryl peroxide, tertiary butyl hydroperoxide, benzammonium peroxide, tertiary butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, Dipropyl dicarbonate, neodymium peroxide Organic peroxides of tertiary butyl acid esters, tertiary butyl peroxy-3-acetate and (3,5,5-trimethylhexyl) peroxide; such as potassium persulfate, ammonium persulfate and An inorganic peroxide such as hydrogen peroxide. Further, a redox initiator such as a peroxide and a reducing agent may be used as a polymerization initiator.

In the method for producing a (meth)acrylic resin, in the above-described method, a solution polymerization method is preferred. In the case of a specific example of the solution polymerization method, a desired monomer and an organic solvent are mixed, and a thermal polymerization initiator is added under a nitrogen atmosphere, and stirred at about 50 to 80 ° C at about 50 to 80 ° C. 3 to 15 hours or so. Further, in order to control the reaction, the monomer and the thermal polymerization initiator may be added continuously or intermittently in the polymerization or in a state of being dissolved in the organic solvent. Among them, in the case of an organic solvent, for example, an aromatic hydrocarbon such as toluene or xylene; an ester such as ethyl acetate or butyl acetate; an aliphatic alcohol such as propanol or isopropanol; Ketones of methyl ethyl ketone and methyl isobutyl ketone.

[Crosslinking agent (B)]

The crosslinking agent (B) is formulated in the above (meth)acrylic resin (A). The crosslinking agent (B) is reacted with a hydroxyl group or a carboxyl group which is a polar functional group in the (meth)acrylic resin (A), and has at least two functional groups which are crosslinkable with the (meth)acrylic resin in the molecule. Specific examples of the compound include an isocyanate compound, an epoxy compound, a metal chelate compound, and an aziridine compound.

The isocyanate compound is a compound having at least two isocyanato groups (-NCO) in the molecule, and examples thereof include toluene diisocyanate. Hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc. . Further, among the isocyanate compounds, an adduct obtained by reacting a polyol such as glycerin or trimethylolpropane or an isocyanate compound as a dimer or a trimer may be used as an adhesive. The crosslinking agent used in the process. Two or more kinds of isocyanate compounds may be used in combination.

The epoxy compound is a compound having at least two epoxy groups in the molecule, and examples thereof include a bisphenol A type epoxy resin, ethylene glycol diepoxypropyl ether, and polyethylene glycol diepoxypropyl ether. , glycerol diepoxypropyl ether, glycerol triepoxypropyl ether, 1,6-hexanediol diepoxypropyl ether, trimethylolpropane triepoxypropyl ether, N, N - Diglycidyl aniline, N, N, N', N'-tetraepoxypropyl-m-xylylenediamine, and the like. Two or more epoxy compounds may be used in combination.

The metal chelate compound may, for example, be a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, ruthenium, magnesium, vanadium, chromium or zirconium, coordinated with ethyl acetonide or ethyl A compound such as ethyl acetate.

The aziridine-based compound, also known as a compound having at least two 3-membered ring skeletons containing one nitrogen atom and two carbon atoms in the molecule of ethylene diimide, for example, diphenylmethane-4,4 '-Bis(1-aziridinecarbamamine), toluene-2,4-bis(1-aziridinecarboxamide), tri-ethyl melamine, m-xylylenediamine-1-( 2-methylaziridine), tri-1-aziridine phosphine oxide, hexamethylene-1,6-bis(1-aziridinecarboxamide), trimethylolpropane tri- --aziridine propionate, tetramethylol methane tri-β-aziridine propionate, and the like.

Among these crosslinking agents, isocyanate-based compounds, especially xylene diisocyanate, toluene diisocyanate or hexamethylene diisocyanate or these isocyanate compounds, and polyols such as glycerol or trimethylolpropane An adduct obtained by the reaction, a dimer or a trimer of the isocyanate compound, a mixture of the isocyanate compounds, and the like are suitable.

Examples of the particularly preferable isocyanate-based compound include an adduct obtained by reacting toluene diisocyanate, toluene diisocyanate, and a polyhydric alcohol, a dimer of tolylene diisocyanate, and a terpolymer of tolylene diisocyanate.

The crosslinking agent (B) is formulated in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the (meth)acrylic resin (A). The blending amount of the crosslinking agent (B) is preferably from 0.1 to 3 parts by weight, more preferably from 0.1 to 1 part by weight, per 100 parts by weight of the (meth)acrylic resin (A). When the compounding amount of the crosslinking agent (B) is 0.01 parts by weight or more, particularly 0.1 part by weight or more, based on 100 parts by weight of the (meth)acrylic resin (A), the adhesive layer composed of the adhesive composition is used. It is preferable that the durability tends to be improved, and when it is 5 parts by weight or less, the white point when the optical film with an adhesive is applied to the liquid crystal display device becomes inconspicuous.

[decane compound (C)]

The adhesive composition of the present invention forms an adhesive sheet or an adhesive In the case of the optical film, the decane-based compound (C) represented by the above formula (I) is contained in order to improve the adhesion to the glass substrate. The decane-based compound (C) is preferably contained in the (meth)acrylic resin (A) before the crosslinking agent is prepared.

In the present invention, by containing the decane-based compound (C) represented by the above formula (I), an adhesive layer having excellent adhesion to a glass substrate and a moderate adhesive force can be formed, and the adhesive layer can be removed from the adhesive layer. When the glass substrate is peeled off, an adhesive layer exhibiting excellent releasability can be formed by adding water to the interface between the adhesive layer and the glass substrate.

In the decane-based compound (C) represented by the above formula (I), R ₁ represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group, an aryl group and an alkenyl group, and specific examples thereof include, for example, R ₁ is a group. A compound of a group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tertiary butyl group, a pentyl group and a hexyl group. In the decane-based compound (C) represented by the above formula (I), R ₂ represents an alkyl group having 1 to 6 carbon atoms, and specific examples thereof include a compound wherein R ₂ is a methyl group, an ethyl group and a propyl group. Among these, 3-ureidopropyltrialkoxydecane is suitable as the decane-based compound (C) represented by the above formula (I). Further, two or more kinds of the decane-based compound (C) represented by the formula (I) may be contained.

The decane-based compound contained in the adhesive composition of the present invention may be a decane-based compound (C) represented by the above formula (I), or may contain the formula (I). The decane-based compound (C) and a decane-based compound other than the decane-based compound (C) represented by the formula (I). Examples of the decane-based compound other than the decane-based compound (C) represented by the formula (I) include vinyltrimethoxydecane, vinyltriethoxydecane, and vinyltris(2-methoxyethoxyl). Base) decane, 3-glycidoxypropyltrimethoxyfluorene Alkane, 3-glycidoxypropylmethyldimethoxydecane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxydecane, 3-chloropropylmethyldimethoxy Decane, 3-chloropropyltrimethoxydecane, 3-methylpropenyloxypropyltrimethoxydecane, 3-mercaptopropyltrimethoxydecane, 3-glycidoxypropyltrimethoxy Decane, 3-glycidoxypropyltriethoxydecane, 3-glycidoxypropyldimethoxymethyldecane, 3-glycidoxypropylethoxydimethyl decane And the like, and may be an oxygen oligomer type. When the oxime oligomer is represented by a (monomer)-(monomer) copolymer, for example, the following can be mentioned.

Such as 3-mercaptopropyltrimethoxydecane-tetramethoxydecane copolymer, 3-mercaptopropyltrimethoxydecane-tetraethoxydecane copolymer, 3-mercaptopropyltriethoxydecane-tetramethyl a decyl-containing copolymer of a oxydecane copolymer and a 3-mercaptopropyltriethoxydecane-tetraethoxydecane copolymer; such as a mercaptomethyltrimethoxydecane-tetramethoxydecane copolymer, a mercapto group Copolytrimethoxydecane-tetraethoxydecane copolymer, mercaptomethyltriethoxydecane-tetramethoxydecane copolymer and mercaptomethyltriethoxydecane-tetraethoxydecane copolymer a copolymer of methyl; such as 3-methylpropenyloxypropyltrimethoxydecane-tetramethoxydecane copolymer, 3-methylpropenyloxypropyltrimethoxydecane-tetraethoxy Pyrrolizane copolymer, 3-methylpropenyloxypropyltriethoxydecane-tetramethoxydecane copolymer, 3-methylpropenyloxypropyltriethoxydecane-tetraethoxy Vinoxane copolymer, 3-methylpropenyloxypropylmethyldimethoxydecane-tetramethoxydecane copolymer, 3-methylpropenyloxyl Methyl dimethoxy silane-- copolymers of tetraethyl orthosilicate, 3-methacryloxypropyltrimethoxysilane Copolymer of decyloxypropylmethyldiethoxydecane-tetramethoxydecane and 3-methylpropenyloxypropylmethyldiethoxydecane-tetraethoxydecane copolymer a copolymer of methacryloyloxypropyl; such as 3-propenylmethoxypropyltrimethoxydecane-tetramethoxydecane copolymer, 3-propenyloxypropyltrimethoxydecane- Tetraethoxydecane copolymer, 3-propenylmethoxypropyltriethoxydecane-tetramethoxydecane copolymer, 3-propenyloxypropyltriethoxydecane-tetraethoxy Decane copolymer, 3-propenylmethoxypropylmethyldimethoxydecane-tetramethoxydecane copolymer, 3-propenyloxypropylmethyldimethoxydecane-tetraethoxy Copolymer of decane, copolymer of 3-propenylmethoxypropylmethyldiethoxydecane-tetramethoxydecane and 3-propenylmethoxypropylmethyldiethoxydecane-tetraethoxy a copolymer of a decane copolymer containing an acryloyloxypropyl group; for example, a vinyltrimethoxydecane-tetramethoxydecane copolymer, a vinyltrimethoxydecane-tetraethoxydecane copolymer a vinyl triethoxy decane-tetramethoxy decane copolymer, a vinyl triethoxy decane-tetraethoxy decane copolymer, a vinyl methyl dimethoxy decane-tetramethoxy decane copolymer, Vinylmethyldimethoxydecane-tetraethoxydecane copolymer, vinylmethyldiethoxydecane-tetramethoxydecane copolymer and vinylmethyldiethoxydecane-tetraethoxy a vinyl group-containing copolymer of a decane copolymer or the like. Two or more kinds of decane-based compounds other than the decane-based compound (C) represented by the formula (I) can be used.

Most of the decane-based compounds are liquid. In the adhesive composition, it is 100 weights relative to the solid content of the (meth)acrylic resin (A) The amount of the decane-based compound (C) represented by the formula (I) is from 0.01 to 10 parts by weight, preferably from 0.03 to 2 parts by weight, more preferably from 0.2 to 1 part by weight. In addition, when the decane-based compound other than the decane-based compound (C) represented by the formula (I) is contained, the total amount of the decane-based compound (C) represented by the formula (I) is compared with the (meth)acrylic resin (A). The solid content of the solid matter is from 0.01 to 10 parts by weight, preferably from 0.03 to 2 parts by weight, more preferably from 0.2 to 1 part by weight. When the amount of the decane-based compound (C) represented by the formula (I) is 0.01 parts by weight or more, particularly 0.03 parts by weight or more, based on 100 parts by weight of the solid content of the (meth)acrylic resin (A), It is preferable to improve the adhesion and durability of the adhesive layer to the glass substrate. Further, when it is 0.2 parts by weight or more, when water is added to the interface between the pressure-sensitive adhesive layer and the glass substrate, the adhesion can be greatly lowered, and the peeling property can be further improved, which is preferable. In addition, when the total content of the decane-based compound (C) represented by the formula (I) and the decane-based compound is 10 parts by weight or less, particularly preferably 2 parts by weight or less or 1 part by weight or less, the decane-based compound is inhibited from The tendency of the adhesive layer to bleed out is therefore preferred.

[ionic compound]

The adhesive composition may further contain an ionic compound as an antistatic agent for imparting antistatic properties to the adhesive layer. The ionic compound has an inorganic cation or an organic cation and a compound having an inorganic anion or an organic anion. Two or more kinds of ionic compounds can be used.

The inorganic cation may, for example, be an alkali metal ion such as a lithium cation [Li ⁺ ], a sodium cation [Na ⁺ ], a potassium cation [K ⁺ ], and, for example, a ruthenium cation [Be ²⁺ ], a magnesium cation [Mg ²⁺ ] , alkaline earth metal ions of 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 phosphonium cation, and a phosphonium cation.

Among the above cationic components, the organic cation component is excellent in compatibility with the adhesive composition. Among the organic cation components, pyrrolidinium cations and pyridinium cations are suitable from the viewpoint of not easily charging the release film provided on the pressure-sensitive adhesive layer.

Examples of the inorganic anion include a chlorine anion [Cl ^- ], a bromine anion [Br ^- ], an iodine anion [I ^- ], a tetrachloroaluminum anion [AlCl ₄ ^- ], and a heptachlorodisuccinate 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 ^- ], hexafluoroantimonate anion [NbF ₆ ^- ], hexafluoroantimonate anion [TaF ₆ ^- ], dicyanamide anion [(CN) ₂ N ^- ] Wait.

Examples of the organic anion include an acetate anion [CH ₃ COO ^- ], a trifluoroacetate anion [CF ₃ COO ^- ], a methanesulfonate anion [CH ₃ SO ₃ ^- ], and a 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(trifluoromethane) Sulfhydryl)imine anion [(CF ₃ SO ₂ ) ₂ N ^- ], tris(trifluoromethanesulfonyl)methyl anion [(CF ₃ SO ₂ ) ₃ C ^- ], dimethyl phosphate anion [ (CH ₃ ) ₂ POO ^- ], (poly)fluorohydrogen fluoride anion [F(HF) _n ^- ] (n is about 1 to 3), thiocyanate anion [SCN ^- ], perfluorobutanesulfonate anion [C ₄ F ₉ SO ₃ ^- ], bis(pentafluoroethanesulfonyl)imide anion [(C ₂ F ₅ SO ₂ ) ₂ N ^- ], perfluorobutyrate anion [C ₃ F ₇ COO ^- ], (trifluoromethanesulfonyl) (trifluoromethanecarbonyl) imine anion [(CF ₃ SO ₂ )(CF ₃ CO)N ^- ], perfluoropropane-1,3-disulfonate anion [-O ₃ S(CF ₂ ) ₃ SO ₃ ^- ], carbonate anion [CO ₃ ^2- ], and the like.

Among the above anion components, in particular, an anion component containing a fluorine atom is suitable for imparting an ionic compound excellent in antistatic property. Specifically, for example, a bis(fluorosulfonyl)imide anion, a hexafluorophosphate anion or a bis(trifluoromethanesulfonyl)imide anion can be mentioned.

Specific examples of the ionic compound can be appropriately selected from the combination of the above cationic component and anionic component. When the ionic compound having an organic cation is classified according to the structure of the organic cation, the following may be mentioned.

Pyridinium salt:

N-hexylpyridinium hexafluorophosphate, N-hexylpyridinium hexafluorophosphate, N-octyl-4-methylpyridinium hexafluorophosphate, N-butyl-4-methylpyridinium hexafluorophosphate Salt, tetrabutylammonium hexafluorophosphate, bis(fluorosulfonyl)imine N-mercaptopyridinium salt, bis(fluorosulfonyl)imide N-dodecylpyridinium salt, bis(fluorine) Sulfhydryl)imine N-tetradecylpyridinium salt, bis(fluorosulfonyl)imide N-hexadecylpyridinium salt, bis(fluorosulfonyl)imide N-dodecyl -4-methylpyridinium salt, bis(fluorosulfonyl)imine N-tetradecyl-4-methylpyridinium salt, bis(fluorosulfonyl)imide N-hexadecyl-4 -methylpyridinium salt, bis(fluorosulfonyl)imide N-benzyl-2-methylpyridinium salt, bis(fluorosulfonyl)imide N-benzyl-4-methylpyridinium salt , bis(trifluoromethanesulfonyl)imide N- Hexylpyridinium salt, bis(trifluoromethanesulfonyl)imide N-octylpyridinium salt, bis(trifluoromethanesulfonyl)imide N-octyl-4-methylpyridinium salt, double Trifluoromethanesulfonyl)imine N-butyl-4-methylpyridinium salt.

Imidazolium salt:

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

Pyrrolizinium salt:

N-butyl-N-methylpyrrolidinium hexafluorophosphate, N-butyl-N-methylpyrrolidinium salt of bis(fluorosulfonyl)imide, bis(trifluoromethanesulfonyl) Amine N-butyl-N-methylpyrrolidinium salt.

Quaternary ammonium salt:

Tetrabutylammonium p-toluenesulfonate, bis(trifluoromethanesulfonyl)imide (2-hydroxyethyl)trimethylammonium salt, dimethylphosphonic acid (2-hydroxyethyl)trimethylammonium salt.

Further, 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)methyl, lithium p-toluenesulfonate, sodium hexafluorophosphate , sodium bis(fluorosulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, sodium p-toluenesulfonate, potassium hexafluorophosphate, potassium bis(fluorosulfonyl)imide, double (three Potassium fluoromethanesulfonyl)imide, potassium p-toluenesulfonate.

The ionic compound is preferably a solid at room temperature. When compared with the use of an ionic compound which is liquid at normal temperature, it can maintain antistatic properties for a long period of time. From the viewpoint of the long-term stability of the antistatic property, the ionic compound is preferably a melting point of 30 ° C or more and even 35 ° C or more. On the other hand, when the melting point is too high, the compatibility with the (meth)acrylic resin is deteriorated, so the melting point is preferably 90 ° C or less, more preferably 70 ° C or less, and particularly less than 50 ° C. good.

The content of the ionic compound in the adhesive composition is preferably 0.2 to 8 parts by weight, more preferably 0.2 to 5 parts by weight, even more preferably 0.3 to 5 parts by weight based on 100 parts by weight of the (meth)acrylic resin (A). The parts by weight are more preferably, particularly preferably from 0.5 to 3 parts by weight. When the content of the ionic compound is 0.2 parts by weight or more, the antistatic property is improved, and when it is 8 parts by weight or less, it is advantageous to maintain the durability of the adhesive layer.

[Other ingredients]

The adhesive composition may contain a crosslinking catalyst, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, a light-scattering fine particle, or a (meth)acrylic resin (A). An additive such as a resin. If the crosslinking agent and the crosslinking catalyst are simultaneously formulated in the adhesive composition, it can be short The curing of the time modulates the adhesive sheet, and in the obtained optical film with an adhesive, it is possible to suppress floating or peeling occurring between the optical film and the adhesive sheet, or to suppress foaming in the adhesive sheet. Further, it is also useful to prepare an ultraviolet curable compound in an adhesive composition, form an adhesive layer, and then irradiate ultraviolet rays to harden it to form a harder adhesive layer. Examples of the cross-linking catalyst include hexamethylenediamine, ethylenediamine, polyethylenimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, and triamethylene. An amine compound such as a bisamine, a polyamine resin or a melamine resin.

[Modulation of Adhesive Composition]

Each component described above is mixed in a state of being dissolved in a solvent to form an adhesive composition. Here, as the solvent, for example, an aromatic hydrocarbon such as toluene or xylene; an ester such as ethyl acetate or butyl acetate; an aliphatic alcohol such as propanol or isopropanol; such as acetone or methyl group; Ketones of ethyl ketone and methyl isobutyl ketone. Therefore, the adhesive composition exhibits good performance. However, when it is in contact with a specific release film, since it can be prevented from being firmly adhered, it is preferred that it does not contain an amine group. In particular, it is preferred to include a tertiary amine group.

The above-mentioned adhesive composition dissolved in a solvent is applied onto a suitable substrate and dried to form an adhesive sheet. The substrate to be used is generally a plastic film, and a typical example thereof is a release film which is subjected to a release treatment. The release film may be, for example, applied to the surface of the film formed of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate. Such as the release treatment of polyoxane treatment.

[Adhesive tablets]

The adhesive sheet of the present invention is a sheet formed of the above-described adhesive composition as described above. Further, in the present specification, the "adhesive sheet" in the laminated body is also referred to as "adhesive layer". The adhesive sheet of the present invention is preferably used for a period of time after the production, preferably for a period of 7 days or longer, so that the crosslinking reaction is preferably carried out. The adhesive sheet of the present invention is preferably a gel fraction of 65 to 85% after it is applied in a sheet form and left at room temperature for 7 days. Excellent durability is exhibited by the adhesive sheet having the above gel fraction.

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

(1) An adhesive sheet having an area of about 8 cm × about 8 cm is bonded to a metal mesh (having a weight of Wm) composed of SUS304 of about 10 cm × about 10 cm.

(2) The laminate obtained in the above (1) was weighed to have a weight of Ws, and then folded four times in the manner of wrapping the adhesive sheet, and weighed by a stapler (Stapler) and weighed by Wb.

(3) The above-mentioned (2) net bound by a stapler was placed in a glass container, and after immersing in 60 ml of ethyl acetate, the glass container was stored at room temperature for 3 days.

(4) The net was taken out from the glass container, and dried at 120 ° C for 24 hours, and weighed, and the weight was Wa, and the gel fraction was calculated according to the following formula.

Gel fraction (% by weight) = [{Wa - (Wb - Ws) - Wm} / (Ws - Wm)] × 100

Moreover, the gel fraction after 7 days of placement is, for example, The amount of the (meth)acrylic resin (A) or the amount of the crosslinking agent which is the active ingredient of the adhesive composition is adjusted. Specifically, for example, the amount of the monomer having a polar functional group of the monomer (A-2) and the monomer (A-3) in the (meth)acrylic resin (A) is increased, or the adhesive composition is increased. In the amount of the crosslinking agent (B), the gel fraction is increased, and therefore, the gel fraction can be adjusted by adjusting the amounts.

The adhesion of the adhesive sheet to the glass is preferably 1.0 to 8.0 N/25 mm. If it is 1.0 N/25 mm, the adhesion is too low, and it is easy to peel off between the glass substrate and the adhesive sheet. When it exceeds 8.0 N/25 mm, there is a case where the followability of the adhesive sheet to the dimensional change of the optical film is lowered and the durability is lowered. The adhesion of the adhesive sheet to the glass can be controlled by adjusting the elasticity of the base polymer of the adhesive composition or adjusting the amount of the additive (for example, a decane compound).

The adhesion of the adhesive sheet to the glass is preferably such that it is greatly reduced when water is added to the interface between the adhesive sheet and the glass substrate. When the adhesion of the adhesive sheet to the glass substrate when no water is added is P ₁ and the adhesion of the adhesive sheet to the glass substrate when water is added is P ₂ , the adhesion reduction rate when adding water according to the following formula is calculated. The larger the water is added, the less the water is added, the lower the adhesion, the greater the peelability, and the more excellent the workability.

Adhesion reduction rate when adding water (%) = (P _{1 -} P ₂ ) / P ₁ × 100

[Optical film with adhesive]

The optical film with an adhesive according to the present invention is one in which an adhesive sheet formed of the above-described adhesive composition is bonded to at least one surface of the optical film. Attached The optical film used for the optical film of the adhesive has a film having optical characteristics, and examples thereof include a polarizing plate and a retardation film.

The polarizing plate is an optical film that emits polarized light for incident light such as natural light. The polarizing plate is provided with a linear polarizing plate, a polarizing separating plate, and an elliptical separating plate. The linear polarizing plate has linear polarized light that absorbs a vibrating surface having a certain direction, and penetrates a linear polarized light having a vibrating surface orthogonal thereto. The polarized light separation plate has a linear polarized light that reflects a vibration surface having a certain direction and penetrates a linearly polarized light having a vibration surface orthogonal thereto; the elliptical separation plate is provided with a polarizing plate and a retardation film to be described later. Preferred examples of the polarizing plate, particularly the polarizing film (also referred to as a polarizing film) which exhibits the function of the linear polarizing plate, are, for example, the adsorption orientation of the polyvinyl alcohol-based resin film which is uniaxially stretched. A dichroic dye such as iodine or a dichroic dye.

The retardation film is an optical film exhibiting optical anisotropy, and may be, for example, by polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimine, polyolefin, cyclic polyolefin, polyphenylene. A polymer composed of ethylene, polyfluorene, polyether oxime, polydifluoroethylene/polymethyl methacrylate, liquid crystal polyester, acetonitrile cellulose, ethylene/vinyl acetate copolymer saponified product, polyvinyl chloride, etc. The film is stretched to a stretched film of about 1.01 to 6 times or the like. Among them, a polymer film in which a polycarbonate film or a cyclic polyolefin film is uniaxially stretched or biaxially stretched is preferred. A uniaxial retardation film, a wide viewing angle retardation film, or a low photoelastic modulus retardation film can also be used.

Further, the film exhibiting optical anisotropy by coating or orientation of the liquid crystal compound or the coating of the inorganic layered compound A film which is optically anisotropic can be used as a retardation film. Such a retardation film is a film which is a temperature-compensated retardation film and is twisted and oriented by a rod-shaped liquid crystal sold under the trade name "LC film" by JX Nippon Mining & Energy Co., Ltd.; A film in which a rod-shaped liquid crystal which is sold under the trade name of "NH film" is sold by JX Nippon Mining & Energy Co., Ltd.; a disc-shaped liquid crystal sold by Fujifilm Co., Ltd. under the trade name "WV film" Inclined orientated film; a fully biaxially oriented film sold by Sumitomo Chemical Co., Ltd. under the trade name "VAC film"; similarly sold by Sumitomo Chemical Co., Ltd. under the trade name "new VAC film" A biaxially oriented film or the like.

Furthermore, if a protective film is adhered to these optical films, it can also be used as an optical film. For the protective film, a transparent resin film is used, and examples of the transparent resin include an ethyl cellulose resin represented by triethylene glycol cellulose and diethyl cellulose, and a group represented by polymethyl methacrylate. A base acrylic resin, a polyester resin, a polyolefin resin, a polycarbonate resin, a polyether ether ketone resin, a polyfluorene resin, or the like. Among the resins constituting the protective film, a salicylate-based compound, a diphenylketone-based compound, a benzotriazole-based compound, and three may be blended. A UV absorber such as a compound, a cyanoacrylate compound or a nickel complex compound. In the case of the protective film, an acetaminocellulose-based resin film such as a triacetyl cellulose film is suitable.

In the optical film described above, the linear polarizing plate is in a state in which a protective film is adhered to one surface or both surfaces of a polarizing film comprising the polarizing plate, for example, a polarizing film made of a polyvinyl alcohol resin. More. Further, the elliptically polarizing plate is provided with a linear polarizing plate and a retardation film, and the linear polarizing plate is also pasted on one side or both sides of the polarizing film. There are many users with a protective film. In such an elliptically polarizing plate, when the adhesive sheet of the present invention is bonded, it is generally bonded to the side of the retardation film.

The optical film with an adhesive is preferably adhered to the surface of the adhesive layer by applying the release film to which the release treatment is applied until the surface of the adhesive layer is previously protected. The optical film with an adhesive attached to such a release film can be produced, for example, by coating the above-mentioned adhesive composition on the release-treated surface of the release film to form an adhesive sheet, and then obtaining the obtained adhesive. A method of laminating an optical film on a film, applying an adhesive composition on the optical film to form an adhesive sheet, and attaching a release film to the surface of the adhesive to protect the optical film with an adhesive.

The thickness of the adhesive layer formed on the optical film is not particularly limited, but is generally 30 μm or less, preferably 10 μm or more, and more preferably 15 to 25 μm. When the thickness of the adhesive layer is 30 μm or less, the adhesion under high temperature and high humidity is improved, and the possibility of floating or peeling between the glass substrate and the adhesive layer tends to be low, and the reworkability tends to be improved. Therefore, when the thickness is 10 μm or more, even if the size of the optical film to which the film is bonded changes, the adhesive layer fluctuates depending on the size, so that the brightness of the peripheral portion of the liquid crystal cell and the center portion are changed. There is no difference in brightness, and there is a tendency to suppress white spots and color unevenness, and thus it is preferable.

After the optical film with an adhesive of the present invention is adhered to the glass substrate to form an optical laminate, if there is a problem that the optical film needs to be peeled off from the glass substrate, water is added to the interface between the adhesive layer and the glass substrate. The adhesion of the adhesive layer is greatly reduced to exhibit excellent peelability. Therefore, the adhesive layer is peeled off with the optical film and is in contact with the adhesive layer. Since the surface of the glass substrate hardly causes turbidity, residual glue, and the like, it is not difficult to reattach the optical film with the adhesive to the glass substrate after peeling. In addition, when the optical film with an adhesive is reapplied to the glass substrate after peeling, when the water added during the peeling adheres to the glass substrate, the adhesion is excellent when the water is wiped and then reattached. Therefore, it is better. Similarly, when the optical film with the adhesive attached to the adhesive is bonded to the glass substrate, when the adhesive layer has water adhering, it is preferable because the adhesiveness is excellent when the water is wiped and then reattached.

[optical laminate]

In the optical film with an adhesive according to the present invention, the adhesive layer side and the glass substrate can be bonded together to form an optical laminate. When the optical film with an adhesive is laminated on the glass substrate to form an optical laminate, for example, the release film is peeled off from the optical film of the adhesive obtained as described above, and the exposed adhesive layer is attached to the surface of the glass substrate. Can be combined. Examples of the glass substrate include a glass substrate of a liquid crystal cell, glass for antiglare, and glass for sunglasses. Wherein, the glass substrate on the front side (viewing side) of the liquid crystal cell is laminated with an optical film (upper polarizing plate) of an adhesive, and the glass substrate on the back side of the liquid crystal cell is laminated with another optical film with an adhesive (lower polarizing) The optical laminate formed of the plate is preferably used as a panel (liquid crystal panel) for a liquid crystal display device. The material of the glass substrate is, for example, soda lime glass, low alkali glass, and alkali-free glass, but it is suitable for the alkali-free glass in the liquid crystal cell.

For the optical laminate of the present invention, several preferred layers An example of the configuration is shown in the first diagram in a cross-sectional schematic view. In the example shown in FIG. 1(A), the protective film 3 having the surface treated layer 2 is adhered to the surface facing the surface treated layer 2 on one side of the polarizing film 1 to form the polarizing plate 5. . In this example, the polarizing plate 5 simultaneously serves as the so-called optical film 10 of the present invention. The adhesive film 20 is provided on the surface of the polarizing film 1 on the side opposite to the protective film 3 to constitute an optical film 25 with an adhesive. Then, the liquid crystal cell 30 of the glass substrate is bonded to the surface of the adhesive layer 20 and the polarizing plate 5 on the opposite side to form the optical layered body 40.

In the example shown in FIG. 1(B), the first protective film 3 having the surface treated layer 2 is adhered to the surface facing the surface treated layer 2 on one side of the polarizing film 1, and The other surface of the polarizing film 1 is adhered to the second protective film 4 to constitute the polarizing plate 5. In this example, the polarizing plate 5 simultaneously serves as the so-called optical film 10 of the present invention. On the outer side of the second protective film 4 constituting the polarizing plate 5, an adhesive layer 20 is provided to constitute an optical film 25 with an adhesive. Then, the liquid crystal cell 30 of the glass substrate is bonded to the surface of the adhesive layer 20 and the polarizing plate 5 on the opposite side to form the optical layered body 40.

In the example shown in FIG. 1(C), the protective film 3 having the surface treated layer 2 is adhered to the surface facing the surface treated layer 2 on one side of the polarizing film 1 to form the polarizing plate 5. . The optical film 10 is formed by adhering the retardation film 7 to the surface of the polarizing film 1 on the opposite side from the protective film 3 via the interlayer adhesive 8. On the outer side of the retardation film 7 constituting the optical film 10, an adhesive layer 20 is provided to constitute an optical film 25 with an adhesive. Then, the liquid crystal cell 30 of the glass substrate is bonded to the surface of the adhesive layer 20 on the side opposite to the optical film 10 to constitute the optical layered body 40.

Further, in the example shown in FIG. 1(D), the first protective film 3 having the surface treated layer 2 is adhered to the surface facing the surface treated layer 2 on one side of the polarizing film 1, The second protective film 4 is adhered to the other surface of the polarizing film 1 to constitute the polarizing plate 5. The optical film 10 is formed by adhering the retardation film 7 to the outside of the second protective film 4 constituting the polarizing plate 5 via the interlayer adhesive 8. On the outer side of the retardation film 7 constituting the optical film 10, an adhesive layer 20 is provided to constitute an optical film 25 with an adhesive. Then, the liquid crystal cell 30 of the glass substrate is bonded to the surface of the adhesive layer 20 on the side opposite to the optical film 10 to constitute the optical layered body 40.

In these examples, the first protective film 3 and the second protective film 4 are generally composed of a triacetyl cellulose film, and other various transparent resin films described above may be used. Further, 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. A plurality of layers may also be provided in the class.

As an example of the first embodiment (C) and (D), when the retardation film 7 is laminated on the polarizing plate 5, such as a small-sized liquid crystal display device, a preferred example of the retardation film 7 is as follows. 1/4 wavelength plate. In this case, the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 of the quarter-wave plate are generally arranged at a nearly 45 degree cross-correlation. However, depending on the characteristics of the liquid crystal cell 30, the angle is also shifted from 45 degrees. Some degree of situation. On the other hand, in the case of a large-sized liquid crystal display device such as a television, a phase difference film having various retardation values is used in accordance with the characteristics of the liquid crystal cell 30 for the purpose of phase difference compensation or viewing angle compensation of the liquid crystal cell 30. In this case, the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 are generally close to or orthogonal to each other. Configuration. When the retardation film 7 is formed of a 1/4 wavelength plate, it is suitable to use a uniaxial or biaxial stretching film. Further, when the retardation film 7 is provided for the purpose of phase difference compensation or viewing angle compensation of the liquid crystal cell 30, in addition to the uniaxial or biaxial stretching film, it may be uniaxially or biaxially stretched and oriented in the thickness direction. A film, a film obtained by applying a phase difference expression substance such as a liquid crystal or the like on a support film, and the like are referred to as an optical compensation film, and are used as the retardation film 7.

Similarly, as shown in Figs. 1(C) and (D), when the polarizing plate 5 and the retardation film 7 are bonded via the interlayer adhesive 8, the interlayer adhesive 8 is conventionally used. As the acrylic adhesive, it is of course also possible to use the adhesive sheet specified in the present invention. When the large-sized liquid crystal display device as described above is disposed such that the absorption axis of the polarizing plate 5 and the slow axis of the retardation film 7 are nearly orthogonal or nearly parallel, the polarizing plate 5 and the retardation film 7 can be performed. The roll-to-roller is bonded, and in the case where the re-peelability between the two is not required, an adhesive which cannot be peeled off immediately after the bonding can be used instead of the one shown in FIGS. 1(C) and (D). Interlayer adhesive 8. Examples of such an adhesive include a water-based adhesive which is composed of an aqueous solution or an aqueous dispersion, which exhibits an adhesive force by evaporating water as a solvent, and an ultraviolet curing type which is cured by ultraviolet irradiation and exhibits an adhesive force. Followers and so on.

Further, as shown in Figs. 1(C) and (D), the retardation film 7 may be formed by the adhesive layer 20 itself, or may be circulated by itself, and may be an optical film of the present invention as an adhesive. . The optical film with an adhesive layer formed on the retardation film may be bonded to the liquid crystal cell of the glass substrate to form an optical laminate, or may be bonded to the retardation film side. The polarizing plate is made of another optical film with an adhesive.

In the first embodiment, an example is given in which an optical film 25 with an adhesive is disposed on the viewing side of the liquid crystal cell 30, but the optical film with an adhesive of the present invention may be disposed on the back side of the liquid crystal cell. That is, the backlight side. When the optical film with an adhesive of the present invention is disposed on the back side of the liquid crystal cell, a protective film containing no surface treatment layer is used instead of the protective film 3 having the surface treated layer 2 shown in FIG. The first figure (A) to (D) have the same configuration. In addition, in the outside of the protective film constituting the polarizing plate, various conventional optical films such as a brightness enhancement film, a light-concentrating film, and a diffusion film which are disposed on the back side of the liquid crystal cell may be provided.

As described above, the optical layering system of the present invention can be applied to a liquid crystal display device. The liquid crystal display device formed by the optical layered body of the present invention can be used, for example, for a personal computer liquid crystal display including a notebook type, a desktop type, a PDA (personal digital assistant), a television, an automobile display, an electronic dictionary, and a digital Cameras, digital cameras, electronic desktops, and clocks.

[Examples] [optical laminate]

The invention is further illustrated by the following examples, but the invention is not limited by the examples. In the examples, % and parts of the content or the amount used are indicated on a weight basis unless otherwise specified. First, the polymerization examples A to C of the (meth)acrylic resin (A) which is a main component of the adhesive composition were produced.

<Polymeric Examples A to C of (meth)acrylic resin (A)>

In a reaction vessel equipped with a condenser, a nitrogen gas introduction tube, a thermometer, and a stirrer, 81.8 parts of ethyl acetate and butyl acrylate as a monomer (A-1) in the amounts shown in Table 1 were fed (hereinafter also referred to as "BA"), methyl acrylate (hereinafter also referred to as "MA"), and 2-(2-phenoxyethoxy)ethyl acrylate (hereinafter also referred to as "PEA2") as a monomer (A- 2) 2-hydroxyethyl acrylate (hereinafter also referred to as "HEA"), 2-carboxyethyl acrylate (hereinafter also referred to as "CEA") as a monomer (A-3), and as a monomer (A) -1), acrylic acid (hereinafter also referred to as "AA") other than (A-2) and (A-3), replacing the air in the apparatus with nitrogen to prevent oxygen, and raising the internal temperature to 55 ° C. Then, a solution of 0.14 parts of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts of ethyl acetate was added in its entirety. One hour after the addition of the initiator, it was maintained at this temperature, then the internal temperature was maintained at 54 to 56 ° C, and ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts/hour, in the (meth)acrylic resin. When the concentration became 35%, the addition of ethyl acetate was stopped, and the temperature was kept at this temperature for 12 hours from the 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 a (meth)acrylic resin.

In the above, 2-carboxyethyl acrylate (CEA) is sold under the trade name "β-CEA" sold by Daicel Cytec. Its chemical composition is represented by CH ₂ =CH(COOCH ₂ CH ₂ ) _n COOH (n=average 1). Specifically, 2-carboxyethyl acrylate (ie, dimer of acrylic acid) is 40%, acrylic acid. The oligomer of the trimer or higher was 40% and the acrylic acid was 20%.

Next, examples and comparative examples in which an adhesive was prepared using the (meth)acrylic resin produced in Polymerization Examples A to C and applied to an optical film were presented. In each of the examples and the comparative examples, those shown in Table 2 were used as the crosslinking agent (B) and the decane-based compound. The crosslinking agent (B) and the decane-based compound shown in Table 2 are as follows. The first occurrence of the name is the product name.

<crosslinking agent (B)>

Coronate L: an ethyl acetate solution of a trimethylolpropane adduct of toluene diisocyanate (solids concentration: 75%), obtained from Japan Polyurethane.

<The decane compound (C) represented by the formula (I)>

KBM-585: 3-ureidopropyltrialkoxydecane; manufactured by Shin-Etsu Chemical Co., Ltd.

<A decane-based compound other than the decane-based compound (C) represented by the formula (I)>

KBM-403: 3-glycidoxypropyltrimethoxydecane, liquid; manufactured by Shin-Etsu Chemical Co., Ltd.

KBM-4803: Epoxy propoxy octyl trimethoxy decane; manufactured by Shin-Etsu Chemical Co., Ltd.

A100: Ethyl ethyl propyl trimethoxy decane; manufactured by Xiayan Chemical Co., Ltd.

KBM-573: N-phenyl-3-aminopropyltrimethoxydecane; manufactured by Shin-Etsu Chemical Co., Ltd.

<ionic compound>

N-octyl-4-methylpyridinium hexafluorophosphate (melting point 44 ° C).

[Examples 1 to 4 and Comparative Examples 1 to 6] (a) Production of Adhesive Compositions of Examples 1 to 4 and Comparative Examples 1 to 6

The crosslinking agent was 0.5 parts by weight of each solid matter with respect to 100 parts by weight of the solid matter of the 20% ethyl acetate solution of the (meth)acrylic resin obtained in any of the polymerization examples A to C shown in Table 2. The decane-based compound was mixed in an amount shown in Table 2, and ethyl acetate was added so that the solid content concentration was 13%, and the adhesive compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were prepared.

(b) Production of adhesive tablets

The various adhesive compositions prepared in the above (a) are obtained by a release treatment of a polyethylene terephthalate film [trade name "SP-PLR382050"; obtained by Lintec), which is called a separation membrane. The release treatment surface was applied by using an applicator so as to have a thickness of 20 μm after drying, and dried at 100 ° C for 1 minute to prepare an adhesive sheet.

(c) Determination of gel fraction of adhesive tablets

After the adhesive sheet prepared in the above (b) is left at room temperature for 7 days, The gel fraction was determined in the manner previously described. The measurement results are shown in Table 2.

(d) Fabrication of a polarizing plate with an adhesive

An adhesive layer prepared in the above (b) is applied to one surface of a polarizing plate having a three-layer structure sandwiched between a protective film made of triacetyl cellulose on both sides of a polarizing film of a polyvinyl alcohol-based resin film. The opposite side of the separation membrane of the sheet (adhesive layer) was bonded by a bonding machine, and then aged for 7 days under the conditions of a temperature of 23 ° C and a relative humidity of 65% to prepare a polarizing plate with an adhesive.

(e) Fabrication and evaluation of optical laminates

After the separation film is peeled off from the polarizing plate with an adhesive prepared in the above (d), the adhesive layer is attached to the glass substrate for liquid crystal cell so as to be orthogonally polarized [product name "EAGLE XG"; by Corning The company obtained two sides to make optical laminates. The optical laminate was stored in a drying condition at a temperature of 80 ° C for 300 hours to carry out a heat resistance test (described as "heat resistance" in Table 2), and stored at a temperature of 60 ° C and a relative humidity of 90% for 300 hours. When the temperature is lowered to -40 ° C from the state of heating to 70 ° C, and then the temperature is raised to 70 ° C as a cycle (1 hour), this operation is repeated for 100 cycles. The thermal shock resistance test (described as "HS resistance" in Table 2) was carried out, and the optical laminate after the test was visually observed. The results were classified by the following criteria and summarized in Table 2.

<Standards for evaluation of heat resistance test, damp heat resistance test and thermal shock test>

A: No change in appearance such as floating, peeling or foaming is observed at all; B: almost no change in appearance such as floating, peeling or foaming; C: appearance change such as floating, peeling or foaming Obvious; D: Apparent changes in float, flaking or blistering are apparently observed.

(f) Evaluation of glass adhesion of optical films with adhesives

The polarizing plate with an adhesive prepared in the above (d) 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 a sample for evaluation was prepared. After peeling off the separation membrane from the sample for evaluation, the adhesive layer was bonded to an alkali-free glass plate ("EAGLE XG" manufactured by Corning Co., Ltd.), and then placed in an autoclave at a temperature of 50 ° C and a pressure of 5 MPa. The pressure treatment was carried out for 20 minutes, and then left to stand under an atmosphere of a temperature of 23 ° C and a relative humidity of 60% for 1 day. Then, using an autostereograph ("AGS-50NX" manufactured by Shimadzu Corporation), one end in the longitudinal direction of the sample for evaluation was held at a temperature of 23 ° C and a relative humidity of 60%, and the peeling speed was 300 mm / The 180° peel test was performed in minutes, and the glass adhesion (no added water) P ₁ was obtained by measuring the stress at the time of peeling. Further, in the same operation, for the sample for evaluation attached to the adjusted alkali-free glass plate, 1 ml of water was dropped at the interface between the alkali-free glass plate and the adhesive layer, and one end of the length of the evaluation sample was grasped. The 180° peeling test was performed at a peeling speed of 300 mm/min, and the adhesion to the glass (with added water) P ₂ was obtained by measuring the stress at the time of peeling. Further, using P ₁ and P ₂ , the adhesion reduction rate at the time of adding water was determined by the method described previously. The results are presented in Table 2.

As shown in Table 2, the adhesive reduction ratio of Example 1 was higher than that of Comparative Examples 1, 4, 5, and 6 for the adhesive composition of the (meth)acrylic resin obtained in Polymerization Example A. The adhesion reduction ratio of Examples 2 and 3 was higher than that of Comparative Example 2 with respect to the adhesive composition of the (meth)acrylic resin obtained in Polymerization Example B. The adhesive strength reduction rate of Example 4 was higher than that of Comparative Example 3 with respect to the adhesive composition of the (meth)acrylic resin obtained in Polymerization Example C.

1‧‧‧ polarizing film

2‧‧‧Surface treatment layer

3‧‧‧(first) protective film

4‧‧‧Second protective film

5‧‧‧Polar plate

7‧‧‧ phase difference film

8‧‧‧Interlayer adhesive

10‧‧‧Optical film

20‧‧‧Adhesive layer (adhesive sheet) attached to liquid crystal cell (glass substrate)

25‧‧‧Optical film with adhesive

30‧‧‧Liquid Crystal Unit (Glass Substrate)

40‧‧‧Optical laminate

Claims (10)

An adhesive composition comprising a (meth)acrylic resin, a crosslinking agent, and a decane compound represented by the following formula (I), In the above formula (I), R ₁ represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group, an aryl group or an alkenyl group; and R ₂ represents an alkyl group having 1 to 6 carbon atoms. The adhesive composition according to claim 1, wherein the decane-based compound is contained in an amount of 0.03 to 10 parts by weight based on 100 parts by weight of the (meth)acrylic resin. The adhesive composition according to claim 1 or 2, wherein the decane-based compound is 3-ureidopropyltrialkoxydecane. The adhesive composition according to any one of claims 1 to 3, wherein the crosslinking agent is an isocyanate crosslinking agent. An adhesive sheet which is formed into a sheet form by using the adhesive composition according to any one of claims 1 to 4. An adhesive sheet according to claim 5, which is formed on a plastic film. The adhesive sheet according to claim 6, wherein the plastic film is a release film which is subjected to a release treatment. An optical film with an adhesive, comprising an optical film, and an adhesive sheet according to any one of claims 5 to 7 of the above-mentioned optical film. An optical film with an adhesive as described in claim 8 of the patent application, In the above, the optical film is a polarizing plate or a retardation film. An optical laminate comprising an adhesive film according to claim 8 or 9, wherein the adhesive sheet side is bonded to the glass substrate.