KR101613765B1 - Adhesive for polarizing plate and polarizing plate manufactured using thereof - Google Patents

Abstract

(B) an epoxy compound having a glass transition temperature of 60 ° C or lower; (c) an epoxy compound having a glass transition temperature of 150 ° C or higher, an acrylate having a glass transition temperature of 150 ° C or higher, And (d) a cyclic-monoacrylate compound.

Description

[0001] The present invention relates to an adhesive composition for a polarizing plate and a polarizing plate prepared using the adhesive composition.

The present invention relates to an adhesive composition for a polarizing plate used for attaching a protective film or a compensation film to a polarizer, and a polarizing plate prepared using the same. More specifically, the present invention relates to a polarizing plate for a polarizing plate having a low viscosity and excellent adhesive strength and heat resistance And a polarizing plate produced using the same.

BACKGROUND ART [0002] In recent years, a liquid crystal display device has been used in various display devices with low power consumption, low voltage operation, light weight and thin features. The liquid crystal display device is made up of many materials such as a liquid crystal cell, a polarizing plate, a phase difference film, a light condensing sheet, a diffusion film, a light guide plate, and a light reflection sheet. Therefore, improvements have been actively made aiming at productivity, light weight, and brightness improvement by reducing the number of constituent films or decreasing the thickness of a film or a sheet.

A polarizing plate is a device that converts natural light into linearly polarized light. A large number of polarizing plates currently in practical use for a liquid crystal display device are produced by dyeing and adsorbing a dichromatic material such as iodine or dichromatic dye to a base film made of a polyvinyl alcohol film, A polarizing film (polarizer) made by aligning a polarizing film and a protective film having optically transparent and mechanical strength is bonded to both sides or one side of the polarizing film.

Conventionally, a cellulose-based film has been used as the protective film, and triacetate cellulose (hereinafter referred to as TAC) film has been generally used. However, since the TAC film has insufficient heat resistance, when the polarizing plate made of the TAC film is used for a long time under a high temperature or high humidity atmosphere, there is a disadvantage that the degree of polarization is lowered and the polarizer and protective film are separated or the optical characteristics are deteriorated. In addition, the TAC film has not only a large dimensional change ratio due to environmental temperature / humidity environment change, but also a relatively large photoelastic coefficient value, resulting in a change in phase retardation property locally after evaluation of durability in a heat- and moisture- . In addition, since the TAC film is expensive and complicated in process, there is a problem that the TAC film is not suitable for a liquid crystal display device which is enlarged.

Accordingly, studies on an acrylic film as a protective film for a polarizing plate which has excellent optical characteristics, low cost, and simplifies the process and can replace the TAC film have been increasing, and accordingly, the polarizing film (polarizer) There is also a demand for development of an adhesive composition having excellent adhesion between acrylic films and a polarizing plate produced using the same.

On the other hand, as the adhesive for the polarizing plate, acrylic adhesive, adhesive for dry lamination mixed with polyurethane resin solution and polyisocyanate resin solution, styrene butadiene rubber adhesive, epoxy adhesive, polyvinyl alcohol adhesive, polyurethane adhesive, polyester- an adhesive containing a compound having an ionomer-type urethane resin and a glycidyloxy group, a thermosetting adhesive, and the like are known. In particular, an aqueous adhesive of an aqueous solution of a polyvinyl alcohol resin is generally used.

However, in the case of the water-based adhesive, when an acrylic film or a COP film other than TAC is used as a protective film, the adhesive strength is weak, so that the use thereof is limited depending on the film material. In addition, in the case of the water-based adhesive, in addition to the problem of defective adhesive force depending on the material, when the material of the protective film applied to both surfaces of the PVA element is different, a problem of curling of the polarizer due to the drying process of the water- Problems such as lowering of physical properties occur. Therefore, a non-aqueous adhesive has been developed as an alternative to solve this problem.

However, since the non-aqueous adhesive generally has a high viscosity, the thickness of the final adhesive layer tends to be thicker than that of the water-based adhesive. When the thickness of the adhesive layer is increased, defects such as wrinkles are generated in the TD and MD directions of the outer surface of the polarizing plate, so that the thickness of the adhesive layer is preferably small.

Accordingly, it has been proposed to add a hydrophilic monomer to the non-aqueous adhesive composition in order to minimize the viscosity of the adhesive. However, when the hydrophilic monomer is added, there is a problem that the water resistance is poor. Such lowering of the water resistance can be solved by adding a polyfunctional monomer or a hydrophobic monomer, but in this case, there is a problem that the adhesive strength is lowered. A method of adding an isocyanate compound as another solution for solving a decrease in water resistance due to the addition of a hydrophilic monomer has been proposed. However, in the case of an isocyanate compound, reactivity with a hydrophilic monomer is high.

As another method of lowering the viscosity of the non-aqueous adhesive, a method of lowering the content of the oligomer contained in the adhesive and adding a monofunctional monomer may be considered. However, in this method, the glass transition temperature of the adhesive is lowered and the heat resistance and water resistance are poor It becomes. On the other hand, when the glass transition temperature of the adhesive is lower than the glass transition temperature of the polarizer, defects such as cracking of the polarizer may occur. In order to improve the heat resistance and the water resistance of the adhesive, a method of adding a monomer having a high glass transition temperature of a polyfunctional monomer or a homopolymer may be considered, but in this case, there is a problem that the adhesive strength is lowered.

As described above, the present invention provides an adhesive composition excellent in adhesive strength between a polarizer and a protective film, excellent in water resistance and heat resistance, and a polarizing plate excellent in thermal shock resistance, Researches and developments are continuing.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an adhesive for a polarizing plate having a low viscosity and an excellent adhesive strength and heat resistance. Another aspect of the present invention is to provide a display device including the polarizer.

(B) an epoxy compound having a glass transition temperature of 60 ° C or lower; (c) an epoxy compound having a glass transition temperature of 150 ° C or higher, an acrylate having a glass transition temperature of 150 ° C or higher, And (d) a cyclic-monoacrylate compound.

(B) 20 to 300 parts by weight of an epoxy compound having a glass transition temperature of 60 占 폚 or less; (c) an epoxy compound having a glass transition temperature of 120 占 폚 or higher; c) from 10 to 150 parts by weight of an acrylate compound having a glass transition temperature of not lower than 150 DEG C of the homopolymer and from 40 to 120 parts by weight of a cyclic-monoacrylate compound (d).

The epoxy compound having a glass transition temperature of 120 ° C or higher of the homopolymer (a) may be one or more selected from the group consisting of compounds represented by the following formulas (2) to (5) including an alicyclic epoxy compound structure represented by the following formula .

[Chemical Formula 1]

(2)

Each of R ₁ and R ₂ independently represents hydrogen or an alkyl group.

(3)

Each of R ₃ and R ₄ independently represents hydrogen or an alkyl group.

[Chemical Formula 4]

R ₅ represents hydrogen or an alkyl group.

[Chemical Formula 5]

R ₆ represents hydrogen or an alkyl group.

In the general formulas (2) to (5), the alkyl group is a linear, branched or cyclic substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and the substituent which may be substituted on the alkyl group is an alkyl group, An alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, or an aryl group.

The epoxy compound (b) having a glass transition temperature of 60 占 폚 or less of the homopolymer may be a polyglycidyl ether of an aliphatic polyhydric alcohol; Polyglycidyl ethers of alkylene oxide adducts of aliphatic polyhydric alcohols; Polyglycidyl ethers of polyester polyols of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of polyester polycarboxylic acids of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Dimers, oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate; And oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate and other vinyl monomers.

The acrylate compound having a glass transition temperature of 150 ° C or higher of the homopolymer (c) may be selected from the group consisting of dimethyloltricyclodecane diacrylate, (trishydroxyethylisocyanurate) diacrylate, 9,9-bis [4- 2-acryloxyethoxy) phenylfluorene, hydroxypivalaldehyde-modifϊed trimethylolpropane diacrylate, (trishydroxyethylisocyanurate) triacrylate, trimethylpropanetriacrylate, pentaerythritol triacryl Dimethylol propane tetraacrylate, dipentaerythritol hexaacrylate, and ditrimethylol propane tetraacrylate. The amount of the initiator may be at least one selected from the group consisting of dimethylol propane tetraacrylate, dipentaerythritol hexaacrylate, and ditrimethylol propane tetraacrylate.

The cyclic-monoacrylate compound (d) may be at least one selected from the group consisting of isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate.

The glass transition temperature of the adhesive composition for a polarizing plate may be 80 占 폚 or higher.

The viscosity of the adhesive composition for a polarizing plate may be 15 to 150 cP.

The present invention also provides a polarizing plate produced using any one of the adhesive compositions for a polarizing plate.

The present invention includes, for example, a polarizer, a transparent base film attached to one or both sides of the polarizer, and an adhesive layer for attaching the polarizer and the transparent base film, wherein the adhesive layer comprises: (a) (B) an epoxy compound having a glass transition temperature of 60 DEG C or lower of the homopolymer, (c) an acrylate compound having a glass transition temperature of 150 DEG C or higher of the homopolymer, and (d) a cyclic monoacrylate compound The present invention also provides a polarizing plate comprising the adhesive composition for a polarizing plate.

The thickness of the adhesive layer may be more than 0 and 5 탆 or less.

The transparent base film may be an acrylic film.

The polarizing plate may further include a primer layer between the adhesive layer and the transparent base film.

The primer layer may have a surface water contact angle of 40 ° to 100 °.

The thickness of the primer layer may be 100 nm to 1 탆.

The primer layer may be formed from 100 parts by weight of a primer composition comprising 1 to 50 parts by weight of a urethane polymer, 0.1 to 20 parts by weight of water-dispersible fine particles, and the balance of water.

The urethane polymer may include a carboxyl group.

The water-dispersible fine particles may have an average diameter of 10 to 200 nm.

The primer composition may further comprise a crosslinking agent, and the content of the crosslinking agent may be 0.1 to 30 parts by weight based on 100 parts by weight of the primer composition.

The present invention also provides a display device including the polarizer.

Since the adhesive composition for a polarizing plate of the present invention has a low viscosity property, a relatively thin adhesive layer can be formed, the adhesive strength between the polarizer and the transparent base film is excellent, and the heat resistance is good. Further, by using the above-mentioned adhesive composition for a polarizing plate, a polarizing plate excellent in adhesion strength between the polarizer and the transparent base film and having excellent thermal shock resistance can be produced. Further, the present invention can provide a display device including the polarizer.

Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art.

(B) an epoxy compound having a glass transition temperature of 60 DEG C or lower, (c) a homopolymer having a glass transition temperature of 150 And (d) a cyclic-monoacrylate compound.

When two or more kinds of epoxy compounds having different glass transition temperatures are used as in the present invention, a homopolymer having a low glass transition temperature as shown in (b) above has an advantageous effect in adhesion and viscosity, and the glass transition temperature High homopolymer prevents the glass transition temperature of the adhesive composition for a polarizing plate from being lowered and thus has an advantageous role in thermal shock resistance.

In this specification, the epoxy compound means a compound having at least one epoxy group in the molecule, preferably a compound having at least two epoxy groups in the molecule, and may be in the form of a monomer, a polymer or a resin ≪ / RTI > Preferably, the epoxy compound of the present invention may be in the form of a resin.

The epoxy compound having a glass transition temperature of 120 ° C or higher of the homopolymer (a) may be an epoxy cyclohexylmethyl epoxycyclohexanecarboxylate compound, an epoxycyclohexanecarboxylate compound of an alkanediol, an epoxycyclohexylmethyl ester compound of a dicarboxylic acid , Epoxycyclohexylmethyl ether compounds of polyethylene glycol, epoxycyclohexylmethyl ether compounds of alkanediol, diepoxy trispyrene compounds, diepoxy monospiro compounds, vinylcyclohexene diepoxide compounds, epoxycyclopentyl ether compounds Compound and a diepoxytricyclodecane compound. ≪ tb >< TABLE >

The epoxy compound having a glass transition temperature of 120 ° C or higher of the homopolymer (a) may be one or more selected from the group consisting of compounds represented by the following Chemical Formulas 2 to 5 including an alicyclic epoxy compound structure represented by the following Chemical Formula 1 .

 [Chemical Formula 1]

(2)

In Formula 2, R ₁ and R ₂ each independently represent hydrogen or an alkyl group.

(3)

In Formula 3, R ₃ and R ₄ each independently represent hydrogen or an alkyl group.

[Chemical Formula 4]

In Formula 4, R ₅ represents hydrogen or an alkyl group.

[Chemical Formula 5]

In Formula 5, R ₆ represents hydrogen or an alkyl group.

As used herein, the term alkyl group may mean a straight, branched or cyclic substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, unless otherwise specified. Examples of the substituent which may be substituted in the specific functional group in the present specification include an alkyl group, an alkoxy group, an alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, An aryloxy group, an aryloxy group, an aryloxy group, an aryloxy group, an aryloxy group,

Specifically, for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin and a brominated bisphenol type epoxy resin may be used as the epoxy compound having a glass transition temperature of 120 ° C or higher of the homopolymer (a). Novolak type epoxy resins such as phenol novolak type epoxy resin and cresol novolak type epoxy resin; Cresol epoxy, resorcinol glycidyl ether, and the like, but the present invention is not limited thereto.

By using an epoxy compound having a glass transition temperature of 120 ° C or higher of the homopolymer (a), the curing degree and durability of the adhesive layer can be satisfied after UV light irradiation.

On the other hand, the epoxy compound (b) having a glass transition temperature of 60 占 폚 or less may be an aliphatic epoxy compound. As the aliphatic epoxy compound, an epoxy compound having an aliphatic epoxy group other than an alicyclic epoxy group can be exemplified. As the aliphatic epoxy compound, the use of a compound containing no alicyclic epoxy group and containing at least three epoxy groups, preferably three epoxy groups, is suitable in view of curability, weatherability and refractive index characteristics. However, It is not.

The epoxy compound (b) having a glass transition temperature of 60 占 폚 or less may be specifically exemplified by polyglycidyl ether of an aliphatic polyhydric alcohol; Polyglycidyl ethers of alkylene oxide adducts of aliphatic polyhydric alcohols; Polyglycidyl ethers of polyester polyols of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of polyester polycarboxylic acids of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Dimers, oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate; And oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate and other vinyl monomers. Preferably, polyglycidyl ether of an aliphatic polyhydric alcohol or polyglycidyl ether of an alkylene oxide adduct of an aliphatic polyhydric alcohol may be used, but is not limited thereto.

Examples of the aliphatic polyhydric alcohol include, for example, aliphatic polyhydric alcohols having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms, Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl- Pentanediol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, Pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl- Aliphatic diols such as octanediol, 1,9-nonanediol, and 1,10-decanediol; Alicyclic diols such as cyclohexane dimethanol, cyclohexanediol, hydrogenated bisphenol A and hydrogenated bisphenol F; Trimethylol ethane, trimethylol propane, hexitol, pentitol, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, tetramethylol propane and the like.

Examples of the alkylene oxides include alkylene oxides having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, Seed, propylene oxide, or butylene oxide may be used.

Examples of the aliphatic polycarboxylic acid include aliphatic polycarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, Methyl adipic acid, 3-methyl adipic acid, 3-methyl pentane diacid, 2-methyl octane diacid, 3,8-dimethyl decane diacid, 3,7-dimethyl decane diacid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-dicarboxylic methylene cyclohexane, 1,2,3-propanetricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 1,2-propanetricarboxylic acid, 3,4-cyclobutanetetracarboxylic acid, and the like, but are not limited thereto.

More specifically, the epoxy compound having a glass transition temperature of 60 占 폚 or less of the homopolymer (b) is 1,4-cyclohexanedimethanol diglycidyl ether, 1,4-butanediol diglycidyl ether, neopentyl glycol di Glycidyl ether, and trimethylol propane triglycidyl ether.

By using an epoxy compound having a glass transition temperature of 60 占 폚 or less of the homopolymer (b), the adhesive strength to the polarizing element can be ensured and the viscosity of the final adhesive can be lowered.

The content of the epoxy compound having a glass transition temperature of 60 ° C or lower of the homopolymer (b) may be about 20 to 300 parts by weight, preferably about 20 to 300 parts by weight, based on 100 parts by weight of the epoxy compound having a glass transition temperature of 120 ° C or higher, Or about 50 to 200 parts by weight, or about 100 to 150 parts by weight. If it is included in the range of 20 to 300 parts by weight, the adhesive force can be maintained without a sudden drop in the adhesive glass transition temperature.

On the other hand, the acrylate compound having a glass transition temperature of 150 ° C or higher of the homopolymer (c) is preferably selected from the group consisting of dimethyloltricyclodecane diacrylate, (trishydroxyethylisocyanurate) diacrylate, 9,9-bis [ - (2-acryloxyethoxy) phenylfluorene, hydroxypivalaldehyde-modifϊed trimethylolpropane diacrylate, (trishydroxyethylisocyanurate) triacrylate, trimethylpropane triacrylate, pentaerythritol Triacrylate, dimethylol propane tetraacrylate, dipentaerythritol hexaacrylate, and ditrimethylol propane tetraacrylate.

At this time, the content of the acrylate compound having a glass transition temperature of 150 ° C or higher of the homopolymer (c) is preferably 10 to 150 parts by weight (about 100 parts by weight) relative to 100 parts by weight of the epoxy compound having a glass transition temperature , Or about 20 to 120 parts by weight, or about 50 to 100 parts by weight. When the content is in the range of 10 to 150 parts by weight, the increase in viscosity of the adhesive does not rise sharply and the adhesive durability after curing can be satisfied.

The (d) cyclic-monoacrylate compound may be at least one selected from the group consisting of isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate.

By using the (d) cyclic-monoacrylate compound, it is possible to obtain the viscosity, curing degree and thermal properties of the adhesive composition for a polarizing plate.

The content of the cyclic-monoacrylate compound (d) is in the range of 40 to 120 parts by weight, or 60 to 120 parts by weight, based on 100 parts by weight of the epoxy compound having a glass transition temperature of 120 ° C or higher, Or about 60 to 100 parts by weight. When included in the range of 40 to 120 parts by weight, the adhesive can be made to have a low viscosity which enables the desired thin film coating on the substrate without lowering the adhesive composition glass transition temperature.

(B) 20 to 300 parts by weight of an epoxy compound having a glass transition temperature of 60 占 폚 or less; (c) an epoxy compound having a glass transition temperature of 120 占 폚 or higher; c) from 10 to 150 parts by weight of an acrylate compound having a glass transition temperature of not lower than 150 DEG C of the homopolymer and from 40 to 120 parts by weight of a cyclic-monoacrylate compound (d). By satisfying the above ratios, it is possible to provide a transparent optical protective film such as TAC, COP, PET and acrylic film that is excellent in coating properties, can be low in viscosity, can achieve good adhesion with a polarizer, The thermal properties of the layer can be excellent.

Further, the adhesive for a polarizing plate of the present invention may further include a cationic photopolymerization initiator. The cationic photopolymerization initiator is a compound which produces a cationic species or Lewis acid by irradiation with an active energy ray. For example, But are not limited to, aromatic diazonium salts, onium salts such as aromatic iodo aluminum salts and aromatic sulfonium salts, iron-arene complexes, and the like. On the other hand, the content of the cationic photopolymerization initiator is about 0.5 to 20 parts by weight, preferably about 0.5 to 15 parts by weight, more preferably about 0.5 to 15 parts by weight, relative to 100 parts by weight of the epoxy compound having a glass transition temperature of 150 캜 or higher Is about 0.5 to 10 parts by weight.

Meanwhile, the adhesive composition for a polarizing plate may further include a photosensitizer, an antioxidant, an oligomer, and an adhesion promoter, if necessary.

The adhesive composition for a polarizing plate is excellent in heat resistance at a glass transition temperature of 80 占 폚 or higher, preferably 80 占 폚 to 120 占 폚 after curing. Further, the viscosity at 25 캜 is as low as about 15 to 150 cP, or as low as about 30 to 100 cP, so that the workability is excellent.

Another embodiment of the present invention provides a polarizing plate produced using an adhesive composition for a polarizing plate.

Wherein the polarizing plate is a polarizing plate including a polarizer, an adhesive layer formed on at least one surface of the polarizer, and a transparent base film formed on the adhesive layer, wherein the adhesive layer is formed by the adhesive for a polarizing plate of the present invention, Optionally, a primer layer may further be provided between the adhesive layer and the transparent base film.

The present invention includes, for example, a polarizer, a transparent base film attached to one or both sides of the polarizer, and an adhesive layer for attaching the polarizer and the transparent base film, wherein the adhesive layer comprises: (a) (B) an epoxy compound having a glass transition temperature of 60 DEG C or lower of the homopolymer, (c) an acrylate compound having a glass transition temperature of 150 DEG C or higher of the homopolymer, and (d) a cyclic monoacrylate compound The present invention also provides a polarizing plate comprising the adhesive composition for a polarizing plate.

The polarizer is not particularly limited, and a film made of polyvinyl alcohol (PVA) including a polarizer well-known in the art, for example, iodine or a dichroic dye, may be used. In the present specification, the polarizer means a state not including a protective film (transparent base film), and the polarizer means a state including a protective film (transparent base film).

Next, the adhesive layer is formed by the above-described adhesive composition for a polarizing plate of the present invention. The details of the adhesive composition for a polarizing plate are the same as those described above, so that a description thereof will be omitted. On the other hand, the thickness of the adhesive layer formed by the adhesive composition for a polarizing plate of the present invention may be in the range of more than 0 to 5 μm or less, or 0.1 to 3 μm or so. When the thickness of the adhesive layer is less than 0.1 탆, the uniformity of the adhesive layer and the adhesive strength may be deteriorated. If the thickness of the adhesive layer exceeds 5 탆, the appearance of the polarizing plate may be wrinkled.

Next, the transparent base film is a compensation film for compensating the polarizer protective film or the optical characteristics of the polarizer, and a polymer film known in the art can be used. More specifically, though not limited thereto, the transparent base film may be an acrylic film, a PET film, an acrylic primer treated PET film, a polynorbornene (PNB) film, a COP film, a polycarbonate film, and an NRT And a TAC film including a polyester film (Fuji Film), N TAC (Konica), V TAC (Fuji Film), UZ TAC (Fuji Film), and the like. Of these, an acrylic film is particularly preferable.

In the present invention, the acrylic film which can be used as the transparent base film may contain a (meth) acrylate resin. The film containing the (meth) acrylate resin can be obtained by molding a molding material containing, for example, a (meth) acrylate resin as a main component by extrusion molding.

The acrylic film may be a film comprising a copolymer containing an alkyl (meth) acrylate unit and a styrene unit, and an aromatic resin having a carbonate moiety in the main chain, or may be a film containing an alkyl (meth) acrylate unit, A 3 to 6 membered heterocyclic unit substituted with at least one carbonyl group, and a vinyl cyanide unit.

Alternatively, the acrylic film may be a film comprising a (meth) acrylate-based resin having an aromatic ring. Examples of the (meth) acrylate-based resin having an aromatic ring include (i) a (meth) acrylate-based unit comprising at least one (meth) acrylate-based derivative described in Korean Patent Laid-open No. 10-2009-0115040; (ii) an aromatic-based unit having a chain and an aromatic moiety having a hydroxyl group-containing moiety; And (iii) a styrene-based unit containing at least one styrenic derivative. The units (i) to (iii) may be included in the resin composition in the form of separate copolymers, and two or more of the units (i) to (iii) may be included in the resin composition in the form of one copolymer have.

Alternatively, the acrylic film may be a film containing an acrylic resin having a lactone ring structure. Specific examples of the (meth) acrylate resin having a lactone ring structure include, for example, lactones described in Japanese Unexamined Patent Application Publication No. 2000-230016, Japanese Unexamined Patent Application Publication No. 2001-151814, Japanese Unexamined Patent Application Publication No. 2002-120326, (Meth) acrylate-based resin having a cyclic structure.

The method for producing the acrylic resin film is not particularly limited, and for example, a thermoplastic resin composition may be prepared by thoroughly mixing a (meth) acrylate resin, other polymers, additives, and the like by any appropriate mixing method, (Meth) acrylate resin, other polymers, additives and the like may be prepared as separate solutions and then mixed to form a uniform mixture liquid, followed by film formation.

The thermoplastic resin composition is prepared by pre-blending the film raw material with any suitable mixer such as an omni mixer, and then extruding and kneading the resulting mixture. In this case, the mixer used for the extrusion kneading is not particularly limited, and any suitable mixer such as an extruder such as a single screw extruder, a twin screw extruder, or a press kneader can be used.

As the film forming method, any suitable film forming method such as a solution casting method (solution casting method), a melt extrusion method, a calendering method, a compression molding method and the like can be used. Among these film forming methods, a solution casting method (solution casting method) and a melt extrusion method are preferable.

Examples of the solvent used in the solution casting method (solution casting method) include aromatic hydrocarbons such as benzene, toluene and xylene; Aliphatic hydrocarbons such as cyclohexane and decalin; Esters such as ethyl acetate and butyl acetate; Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, methyl cellosolve, ethyl cellosolve and butyl cellosolve; Ethers such as tetrahydrofuran and dioxane; Halogenated hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride; Dimethylformamide; Dimethyl sulfoxide and the like. These solvents may be used alone or in combination of two or more.

Examples of the apparatus for carrying out the solution casting method (solution casting method) include a drum casting machine, a band casting machine and a spin coater. Examples of the melt extrusion method include a T-die method and an inflation method. The molding temperature is preferably 150 to 350 占 폚, more preferably 200 to 300 占 폚.

When a film is formed by the T-die method, a T-die is attached to the tip of a known single-screw extruder or a twin-screw extruder, and a rolled film is obtained by winding a film extruded in a film form. At this time, uniaxial stretching can also be performed by stretching in the extrusion direction by appropriately adjusting the temperature of the winding roll. Further, simultaneous biaxial stretching, sequential biaxial stretching, and the like can also be carried out by stretching the film in a direction perpendicular to the extrusion direction.

The acrylic film may be either an unoriented film or a stretched film. In the case of a stretched film, it may be a uniaxially stretched film or a biaxially stretched film, and in the case of a biaxially stretched film, it may be a simultaneous biaxially stretched film or a sequential biaxially stretched film. When biaxially stretched, the mechanical strength is improved and the film performance is improved. By mixing other thermoplastic resins, the acrylic film can suppress an increase in retardation even when stretching, and can maintain optical isotropy.

The stretching temperature is preferably in the vicinity of the glass transition temperature of the thermoplastic resin composition as the raw material of the film and is preferably (glass transition temperature-30 占 폚) to (glass transition temperature + 100 占 폚) Temperature -20 占 폚) to (glass transition temperature + 80 占 폚). If the stretching temperature is lower than (glass transition temperature -30 占 폚), there is a possibility that a sufficient stretching ratio may not be obtained. On the other hand, if the stretching temperature exceeds (glass transition temperature + 100 deg. C), the resin composition may flow (flow), and stable drawing may not be performed.

The stretching ratio defined by the area ratio is preferably 1.1 to 25 times, more preferably 1.3 to 10 times. If the draw ratio is less than 1.1 times, there is a possibility that the toughness accompanying the draw may not be improved. If the stretching magnification exceeds 25 times, there is a possibility that the effect of increasing the stretching magnification may not be recognized.

The stretching speed is preferably 10 to 20,000% / min, more preferably 100 to 10,000% / min in one direction. When the drawing speed is less than 10% / min, it takes a long time to obtain a sufficient drawing magnification, which may increase the manufacturing cost. If the stretching speed is higher than 20,000% / min, the stretched film may be broken.

The acrylic film may be subjected to a heat treatment (annealing) after the stretching treatment so as to stabilize its optical isotropy or mechanical properties. The heat treatment conditions are not particularly limited and any suitable conditions known in the art can be employed.

On the other hand, if necessary, the acrylic film may be subjected to a surface treatment for improving the adhesive strength. For example, at least one surface of the acrylic film may be subjected to at least one surface treatment selected from the group consisting of alkali treatment, corona treatment, Can be performed.

Next, the primer layer is formed of a primer composition containing a urethane polymer to improve adhesion between the transparent base film and the adhesive layer. For example, the primer composition comprises a urethane polymer, water-dispersible fine particles and water. More specifically, the primer composition comprises 1 to 50 parts by weight of a urethane polymer and 100 to 10 parts by weight of water- Parts by weight and water of the remainder.

The urethane polymer is obtained by reacting a polyol and a polyisocyanate. The polyol is not particularly limited as long as it has two or more hydroxyl groups in the molecule, and any appropriate polyol may be employed. For example, the polyol may be a polyester polyol, a polyether polyol, a polycarbonate diol or the like, and at least one selected from the group consisting of these may be used alone or in combination of two or more.

The polyol may be selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 1,6- Diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene, polypropylene, polypropylene, polypropylene, polypropylene, Glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, bisphenol A, bisphenol F, glycerin, 1,1,1-trimethylol propane, 1,2,5-hexatriol, It is preferably at least one selected from the group consisting of glucose, glucose, sucrose, and sorbitol.

On the other hand, the polyester polyol is typically obtained by reacting a polybasic acid component with a polyol component. Examples of the polybasic acid component include ortho-phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalene dicarboxylic acid, 2,5-naphthalene dicarboxylic acid, 2,6- Aromatic dicarboxylic acids such as phenyl dicarboxylic acid and tetrahydrophthalic acid; Aliphatic dicarboxylic acids such as oxalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, linoleic acid, maleic acid, fumaric acid, mesaconic acid and itaconic acid; Alicyclic dicarboxylic acids such as hexahydrophthalic acid, tetrahydrophthalic acid, 1,3-cyclohexanedicarboxylic acid and 1,4-cyclohexanedicarboxylic acid; Or reactive derivatives thereof such as acid anhydrides, alkyl esters, acid halides and the like. These may be used alone or in combination of two or more. Further, it is more preferable to use at least one selected from the group consisting of polytetramethylene glycol (PTMG), polypropylene glycol (PPG), and polyethylene glycol (PEG).

The polycarbonate polyol is preferably at least one selected from the group consisting of poly (hexamethylene carbonate) glycol and poly (cyclohexanecarbonate) glycol.

The polyether polyol is typically obtained by ring-opening polymerization of an alkylene oxide to a polyhydric alcohol. Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, and trimethylolpropane. These may be used alone or in combination of two or more.

The isocyanate is not limited as long as it is a compound having two or more NCO groups, and examples thereof include toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI) (XDI), such as isocyanuric diisocyanate (TODI), hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), p-phenylenediisocyanate, transcyclohexane, 1,4-diisocyanate and xylene diisocyanate Can be used alone or in combination of two or more.

The urethane resin may be produced by any suitable method known in the art. Specifically, a single shot method in which each component is reacted at a time, and a multi-step method in which the components are reacted stepwise. When the urethane resin has a carboxyl group, it is preferably prepared by a multi-stage method, and a carboxyl group can be easily introduced by a multi-stage method. Further, any suitable urethane reaction catalyst can be used in the production of the urethane resin.

In the production of the urethane resin, other polyols and / or other chain extender may be reacted in addition to the above components.

Examples of other polyols include polyols having three or more hydroxyl groups such as sorbitol, glycerin, trimethylol ethane, trimethylol propane, and pentaerythritol.

Examples of other chain extenders include but are not limited to acetylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, Glycols such as hexanediol, propylene glycol and the like; Aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, 1,4-butanediamine and aminoethylenecanolamine; Alicyclic diamines such as isophoronediamine and 4,4'-dicyclohexylmethanediamine; And aromatic diamines such as xylylenediamine and tolylene diamine.

Further, in the production of the urethane resin, a neutralizing agent can be used. By using a neutralizing agent, the stability of the urethane resin in water can be improved. Examples of the neutralizing agent include ammonia N-methylmorpholine, triethylamine, dimethylethanolamine, methyldiethanolamine, triethanolamine, morpholine, tripropylamine, ethanolamine, triisopropanolamine and the like. These may be used alone or in combination of two or more.

In the production of the urethane resin, an organic solvent inert to the polyisocyanate and compatible with water is used. Examples of the organic solvent include ester solvents such as ethyl acetate and ethyl cellosolve acetate; Ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; And ether solvents such as dioxane tetrahydrofuran. These may be used alone or in combination of two or more.

On the other hand, the urethane polymer preferably contains a carboxyl group. When the urethane polymer contains a carboxyl group, the water dispersibility is improved and the adhesion between the adhesive layer and the acrylic film is further improved.

The urethane polymer containing the carboxyl group can be obtained, for example, by reacting a chain extender having a free carboxyl group in addition to a polyol and a polyisocyanate. Examples of the chain extender having a carboxyl group include dihydroxycarboxylic acid, dihydroxysuccinic acid, and the like. Dihydroxycarboxylic acids include, for example, dialkylolalkanoic acids including dimethylolacetic acid, dimethylolbutanoic acid, dimethylolpropionic acid, dimethylolbutyric acid, and dimethylolalkanoic acid such as dimethylolpentanoic acid. These may be used alone or in combination of two or more.

On the other hand, the content of the urethane polymer is about 1 to 50 parts by weight, more preferably about 3 to 20 parts by weight, and most preferably about 5 to 15 parts by weight based on 100 parts by weight of the primer composition. When the urethane polymer is contained in an amount of less than 1 part by weight based on 100 parts by weight of the primer composition, the adhesiveness is lowered. When the amount of the urethane polymer is more than 30 parts by weight, viscosity is increased.

The weight average molecular weight of the urethane polymer is preferably from 10,000 to 100,000, and when the molecular weight is less than 10,000, there is a decrease in adhesion, and when the molecular weight is more than 100,000, it is difficult to produce an aqueous dispersion urethane.

Next, the water-dispersible microparticles that can be used in the present invention may be any suitable microparticles, preferably water-dispersible microparticles. Specifically, inorganic fine particles. All organic fine particles can be used. Examples of the inorganic fine particles include inorganic oxides such as silica, titania, alumina, zirconia and antimony. Examples of the organic fine particles include a silicone resin, a fluorine resin, a (meth) acrylic resin, a crosslinked polyvinyl alcohol, and a melamine resin.

Among the water-dispersible fine particles, silica is preferably used, and silica is more excellent in blocking inhibition ability, transparency is excellent, haze is not generated, no coloring is caused, and thus the effect on the optical characteristics of the polarizing plate is smaller. This is because the silica is excellent in dispersibility and dispersion stability with respect to the primer composition and can be more excellent in workability in forming the primer layer.

The average diameter (average primary particle diameter) of the water-dispersible fine particles is preferably 10 to 200 nm, more preferably 20 to 70 nm. When the average diameter of the water-dispersible fine particles is less than 10 nm, the surface energy is increased, so that the aggregation of the silica occurs in the primer solution and precipitation occurs. As a result, the stability of the solution may become a problem. When the average particle diameter is more than 200 nm, When the particles are aggregated because the dispersion is uneven, the size becomes larger than the wavelength of visible light (400 nm-800 nm), so that light of 400 nm or more is scattered and the haze increases. By using the fine particles having the particle diameters in the above-mentioned range, it is possible to appropriately form irregularities on the surface of the primer layer, effectively reducing the frictional force particularly on the contact surface between the acrylic film and the primer layer and / or the primer layer. As a result, blocking ability can be further improved.

On the other hand, the content of the water-dispersible fine particles is preferably about 0.1 to 10 parts by weight based on 100 parts by weight of the primer composition. When the content of the water-dispersible fine particles is less than 0.1 part by weight, slip between the films does not occur during winding and film breakage may occur. If it exceeds 10 parts by weight, haze may occur.

Since the primer composition of the present invention is an aqueous system, the fine particles are preferably formulated as an aqueous dispersion. Specifically, when silica is employed as the fine particles, it is preferably blended as colloidal silica. As the colloidal silica, products commercially available in the technical field can be used as it is. Examples of the colloidal silica include SNOWTEX series manufactured by Nissan Chemical Industries, AEROSIL series manufactured by Air Products, epostar series and soliostar RA series manufactured by Japan Catalyst, Ranco LSH series can be used.

On the other hand, the primer composition may further contain a crosslinking agent, if necessary. As the crosslinking agent, methylol compounds such as oxazoline, boric acid and trimethylolmelamine, carbodiimide, isocyanate, and aziridine compounds can be used.

The crosslinking agent is preferably contained in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the primer composition. When a primer containing a crosslinking agent is used, the primer layer prevents water penetration, so that the optical properties such as water resistance and anti-wet heat are superior.

Meanwhile, when the primer composition is applied to a double-side polarizing plate, the content of the crosslinking agent contained in the primer layer may vary depending on the applied surface. The term " double-sided polarizer " means a polarizer in which a transparent base film is attached to both surfaces of a polarizer, and is distinguished from a cross-section type polarizer in which a transparent base film is adhered to only one side. That is, according to the present invention, the double-sided polarizer means a polarizer comprising a transparent substrate film / primer layer / adhesive layer / polarizer / adhesive layer / primer layer / transparent substrate film. On the other hand, in the production of the double-sided polarizing plate, an active energy ray is irradiated to cure the adhesive layer, wherein the active energy ray may be irradiated in both directions of the polarizing plate, or may be irradiated only in one direction. When the active energy ray is irradiated only in one direction, it is more preferable that the primer layer formed on the active energy ray irradiated surface and the non-irradiated surface have different crosslinking agent contents. More specifically, it is preferable that the content of the crosslinking agent in the primer layer formed on the non-irradiated surface is higher than the content of the crosslinking agent in the primer layer formed on the irradiated surface. If the crosslinking degree of the primer layer is low, the primer layer may be incorporated into the adhesive layer and the adhesive may be unfavorably formed because the adhesive hardening speed is slower than the irradiation surface in the case of the active energy ray untranslated surface.

The primer composition may further contain, if necessary, other additives such as a silane coupling agent, a fluorine-based surfactant, a silane-based surfactant, and a surfactant containing an alkyl group.

On the other hand, the primer layer formed by the primer composition as described above preferably has a thickness of about 100 nm to 1 탆. When the primer layer is 100 nm or less, the adhesive force is decreased. When the primer layer is 1 μm or more, the primer layer may not be dried properly, resulting in blocking between the films.

Further, the water contact angle of the surface of the primer layer of the present invention is preferably 40 to 100, more preferably 50 to 90, and still more preferably 60 to 80. When the water contact angle is less than 40 °, the hydrophilic property of the primer layer is strong. Therefore, the primer layer reacts with the iodine of the polarizer to inhibit the iodine arrangement so that the single color may be disturbed and the polarization degree may be inhibited. The hydrophobicity of the polarizer is strong and the adhesion to the polarizer is difficult.

At this time, the primer layer may further include a primer layer between the adhesive layer and the transparent base film, and the primer layer may include a primer composition comprising 1 to 50 parts by weight of a urethane polymer, 0.1 to 10 parts by weight of water-dispersible fine particles, .

The polarizing plate according to the present invention may be manufactured according to a polarizing plate manufacturing method well known in the art. For example, the adhesive composition for a polarizing plate according to the present invention is applied to one surface of a transparent base film or one surface of a polarizer to form an adhesive layer, then the polarizer and the transparent base film are laminated, and then the adhesive composition is cured ≪ / RTI > On the other hand, in the case of a polarizing plate comprising a primer layer, the primer layer may be formed by coating a primer composition on one side of the transparent base film before applying the adhesive composition.

When the polarizing plate according to the present invention was immersed in water at a temperature of 60 캜 for 24 hours, the discoloration of the polarizing plate in the MD direction was less than 10 mm and the water resistance was excellent.

The polarizing plate of the present invention can be applied to optical devices such as liquid crystal display devices. For example, the optical element of the present invention may be a liquid crystal display including a liquid crystal panel and polarizing plates provided on both sides of the liquid crystal panel, and at least one of the polarizing plates may be a polarizing plate according to the present invention . At this time, the type of the liquid crystal panel included in the liquid crystal display device is not particularly limited. A passive matrix type panel such as a twisted nematic (TN) type, a super twisted nematic (STN) type, a ferroelectic (F) type or a polymer dispersed (PD) type; An active matrix type panel such as a two terminal or a three terminal; A known panel such as an in-plane switching (IPS) panel and a vertical alignment (VA) panel may be used. Further, the other constituent elements constituting the liquid crystal display device, for example, the types of the upper and lower substrates (for example, a color filter substrate or an array substrate) are not particularly limited and the structures known in this field are not limited Can be employed.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the invention by the following examples.

Example  One

(1) Production of acrylic polymer film

A resin composition obtained by uniformly mixing poly (N-cyclohexylmaleimide-co-methylmethacrylate), styrene-maleic anhydride copolymer resin and phenoxystyrene resin at a weight ratio of 100: 2.5: To an extruder was fed to an extruder of 24Φ substituted with nitrogen and melted at 250 ° C to prepare a raw material pellet.

The styrene-maleic anhydride copolymer resin was a mixture of 85% by weight of styrene, 15% by weight of maleic anhydride hydrate, Dylaeck (weight average molecular weight: 332, and the content of N-cyclohexylmaleimide in the poly (N-cyclohexylmaleimide-co-methylmethacrylate) resin was 6.5% by weight.

The obtained raw material pellets were vacuum-dried, melted at 260 占 폚 with an extruder, passed through a coat hanger type T-die, and a 150 占 퐉 -thick acrylic film was produced through a chrome casting roll and a drying roll. The acrylic film was stretched at a rate of 170% using a pile stretching machine at 125 DEG C in the MD direction using the speed difference of the rolls.

The prepared acrylic film was subjected to corona treatment and then a pure water-diluted CK-PUD-F (dimmer urethane dispersion) was applied thereon. To the primer composition having a solid content of 10% by weight was added a carbodiimide type crosslinking agent Light SV-02) was immediately coated and then stretched by 190% in a TD direction at 130 캜 using a tenter to prepare an acrylic film having a primer layer thickness of 400 nm.

(2) Production of Adhesive Composition A

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 45 ° C 30% by weight of trimethylolpropane triglycidyl ether, 30% by weight of isobornyl acrylate having a glass transition temperature of 200 占 폚, dimethyloltricyclodecane diacrylate of 10% by weight and a homopolymer glass transition temperature of 90 占 폚, 6 parts by weight of a cationic initiator CPI 101A (Sanapro) was added to 100 parts by weight of the resin composition. The adhesive composition A had a glass transition temperature of 90 占 폚 and a viscosity of 80 cP.

(3) Polarizing plate manufacture

The adhesive composition A previously prepared with a dropper was coated on both surfaces of the PVA element, the acrylic film was laminated on both surfaces of the PVA element, and the conditions were set so that the thickness of the final adhesive layer was 0.5 to 1 占 퐉. min. Then, a polarizing plate was produced by irradiating ultraviolet rays of 500 mJ / cm ² onto the surface of the acrylic film laminated using a metal halide lamp.

Example  2

A polarizing plate was produced in the same manner as in Example 1 except that the following adhesive composition B was used in place of the adhesive composition A and the acrylic film was laminated on both sides of the PVA element.

≪ Adhesive composition B >

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 45 ° C 30% by weight of trimethylolpropane triglycidyl ether, 20% by weight of dimethyloltricyclodecane diacrylate having a glass transition temperature of 200 DEG C of the homopolymer, 20% by weight of isobonyl acrylate having a glass transition temperature of 90 DEG C %, And 6 parts by weight of a cationic initiator CPI 101A (Sanapro) was added to 100 parts by weight of the resin composition. The adhesive composition B had a glass transition temperature of 100 캜 and a viscosity of 100 cP.

Example  3

A polarizing plate was produced in the same manner as in Example 1 except that the following adhesive composition C was used in place of the adhesive composition A and the acrylic film was laminated on both surfaces of the PVA element.

≪ Adhesive composition C >

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 25 ° C 30% by weight of 1,4-cyclohexanedimethanol diglycidyl ether, homopolymer 20% by weight of dimethylol tricyclodecane diacrylate having a glass transition temperature of 200 ° C, a homopolymer having a glass transition temperature of 90 ° C 6 weight parts of CPI 101A (Sanapro), which is a cationic initiator, was added to 100 weight parts of the resin composition prepared by adding 20 weight% of vinyl acetate. The adhesive composition C had a glass transition temperature of 90 占 폚 and a viscosity of 90 cP.

Example  4

A polarizing plate was produced in the same manner as in Example 1 except that the following adhesive composition D was used in place of the adhesive composition A and the acrylic film was laminated on both surfaces of the PVA element.

≪ Adhesive composition D >

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 25 ° C 10% by weight of dimethyloltricyclodecane diacrylate having a glass transition temperature of 200 DEG C of the homopolymer, 10% by weight of 1,4-cyclohexanedimethanol diglycidyl ether having a glass transition temperature of 90 DEG C 6 parts by weight of CPI 101A (Sanapro Corp.) as a cationic initiator was added to 100 parts by weight of the resin composition prepared by adding 30% by weight of isobornyl acrylate. The adhesive composition D had a glass transition temperature of 90 占 폚 and a viscosity of 70 cP.

Example  5

A polarizing plate was prepared in the same manner as in Example 1 except that the adhesive composition E was used instead of the adhesive composition A and the acrylic film was laminated on both sides of the PVA element.

≪ Adhesive composition E >

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 25 ° C 30% by weight of 1,4-cyclohexanedimethanol diglycidyl ether as a homopolymer, 10% by weight of dimethylol tricyclodecane diacrylate having a glass transition temperature of 200 ° C as a homopolymer, And 30 parts by weight of dicyclopentanyl acrylate were added. To 100 parts by weight of the resin composition, 6 parts by weight of a cationic initiator CPI 101A (Sanapro) was added. The adhesive composition E had a glass transition temperature of 90 占 폚 and a viscosity of 70 cP.

Example  6

A polarizing plate was produced in the same manner as in Example 1 except that the adhesive composition F was used instead of the adhesive composition A and the acrylic film was laminated on both surfaces of the PVA element.

≪ Adhesive composition F >

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 25 ° C 30% by weight of 1,4-cyclohexanedimethanol diglycidyl ether as a homopolymer, 10% by weight of dimethylol tricyclodecane diacrylate having a glass transition temperature of 200 ° C as a homopolymer, And 30 parts by weight of dicyclopentenyl acrylate were added. To 100 parts by weight of the resin composition, 6 parts by weight of a cationic initiator CPI 101A (Sanapro) was added. The adhesive composition F had a glass transition temperature of 90 占 폚 and a viscosity of 70 cP.

Example  7

Except that 20 parts by weight of an oxazoline crosslinking agent (Japan Catalyst, WS700) was added instead of 10 parts by weight of a carbodiimide crosslinking agent (Cabodil SV-02 made by Nisshinbo) as a crosslinking agent in the above primer composition A polarizing plate was prepared in the same manner as in Example 1 above.

Example  8

A polarizing plate was produced in the same manner as in Example 7 except that the following adhesive composition B was used in place of the adhesive composition A, and the acrylic film was laminated on both surfaces of the PVA element.

≪ Adhesive composition B >

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 45 ° C 30% by weight of trimethylolpropane triglycidyl ether, 20% by weight of dimethyloltricyclodecane diacrylate having a glass transition temperature of 200 DEG C of the homopolymer, 20% by weight of isobonyl acrylate having a glass transition temperature of 90 DEG C %, And 6 parts by weight of a cationic initiator CPI 101A (Sanapro) was added to 100 parts by weight of the resin composition. The adhesive composition B had a glass transition temperature of 100 캜 and a viscosity of 100 cP.

Comparative Example  One

A polarizing plate was produced in the same manner as in Example 1, except that the adhesive composition G was used instead of the adhesive composition A and the acrylic film was laminated on both surfaces of the PVA element.

≪ Adhesive composition G >

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 25 ° C 30 parts by weight of 1,4-cyclohexanedimethanol diglycidyl ether and 40 parts by weight of isobornyl acrylate having a glass transition temperature of 90 DEG C of a homopolymer were added to 100 parts by weight of a resin composition, CPI 101A (Sanapro Corp.) were added. The adhesive composition G had a glass transition temperature of 75 캜 and a viscosity of 50 cP.

Comparative Example  2

A polarizing plate was produced in the same manner as in Example 1 except that the adhesive composition H was used instead of the adhesive composition A and the acrylic film was laminated on both surfaces of the PVA element.

<Adhesive composition H>

30% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Dicel, Celloxide 2021P) having a glass transition temperature of the homopolymer of 190 ° C, a glass transition temperature of the homopolymer of 25 ° C 10% by weight of dimethyloltricyclodecane diacrylate having a glass transition temperature of 200 DEG C of the homopolymer, 10% by weight of 1,4-cyclohexanedimethanol diglycidyl ether having a glass transition temperature of 15 DEG C And 30 parts by weight of 2-hydroxy-3-phenoxypropyl acrylate were added. To 100 parts by weight of the resin composition, 6 parts by weight of CPI 101A (Sanapro) as a cationic initiator was added. The adhesive composition H had a glass transition temperature of 50 캜 and a viscosity of 40 cP.

Experimental Example  1: polarizer Peel force  evaluation

The peeling power of the polarizer and the polymer film was measured for the polarizing plates of Examples 1 to 8, Comparative Examples 1 and 2. The peeling test was carried out by using a polarizing plate having a width of 20 mm and a length of 100 mm and measuring the peeling force at the time of peeling at a speed of 300 mm / min and 90 degrees. The results are shown in Table 1 below. Cm &lt; 3 &gt; / cm and a case where the peeling force was less than 1.5 N / cm was rated as poor.

Experimental Example  2: Thermal shock  Property evaluation

The polarizing plates of Examples 1 to 8, Comparative Examples 1 and 2 were laminated on a glass substrate, left to stand at -40 占 폚 for 30 minutes, and then left to stand at 80 占 폚 for 30 minutes, . Then, the appearance of the polarizing plate was visually evaluated for deformation. The case where cracks of not more than 2 mm occurred only at the ends of the polarizing plate was evaluated as being excellent and the cases where only cracks of a line of not less than 5 mm and not more than 5 mm were confirmed as good and the case where a large number of cracks occurred all over the polarizing plate was shown as poor. The results are shown in Table 1 below.

division
primer glue
Peel force
Thermal shock
UV irradiation surface Non-UV surface Example 1 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight A Great Great Example 2 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight B Great Great Example 3 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight C Great Great Example 4 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight D Great Great Example 5 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight E Great Great Example 6 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight F Great Great Example 7 CkPUD F + WS700 20 parts by weight CkPUD F + WS700 20 parts by weight A Great Good Example 8 CkPUD F + WS700 20 parts by weight CkPUD F + WS700 20 parts by weight B Great Good Comparative Example 1 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight G Great Poor Comparative Example 2 CkPUD F + SV-02 10 parts by weight CkPUD F + SV-02 10 parts by weight H Poor Poor

As in Examples 1 to 8, the polarizing plate prepared using the adhesive composition for a polarizing plate according to the present invention exhibited an excellent effect on the peeling force because of excellent adhesion between the polarizer and the transparent base film, Effect.

Further, since the viscosity of the adhesive composition for a polarizing plate was kept at a low point, the thickness of the adhesive layer could be formed as thin as 0.5 to 1.5 占 퐉.

On the other hand, (c) Comparative Example 1, which was produced using an adhesive composition for a polarizing plate that does not contain an acrylate compound having a glass transition temperature of 150 ° C or higher of the homopolymer, was relatively excellent in peel strength evaluation, but had poor thermal shock resistance.

Further, in the case of Comparative Example 2 using a 2-hydroxy-3-phenoxypropyl acrylate compound instead of the (d) cyclic-monoacrylate compound of the present invention, both the peelability evaluation and the thermal shock resistance were poor.

That is, only the polarizing plate including the adhesive layer made of the adhesive composition for a polarizing plate according to the present invention showed excellent effects in peel strength and thermal shock evaluation.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be obvious to those of ordinary skill in the art.

Claims (20)

(a) an epoxy compound having a glass transition temperature of 120 DEG C or higher of the homopolymer;
(b) an epoxy compound having a glass transition temperature of 60 占 폚 or less of the homopolymer;
(c) an acrylate compound having a glass transition temperature of 150 DEG C or higher of the homopolymer; And
(d) a cyclic-monoacrylate compound,
Based on 100 parts by weight of an epoxy compound having a glass transition temperature of 120 DEG C or higher of the homopolymer (a)
(b) 20 to 300 parts by weight of an epoxy compound having a glass transition temperature of 60 占 폚 or less of the homopolymer;
(c) 10 to 150 parts by weight of an acrylate compound having a glass transition temperature of 150 DEG C or higher of the homopolymer; And
(d) 40 to 120 parts by weight of a cyclic-monoacrylate compound. delete The method according to claim 1,
Wherein the epoxy compound having a glass transition temperature of 120 캜 or higher of the homopolymer (a) is at least one selected from the group consisting of compounds represented by the following formulas (2) to (5).
(2)

Each of R ₁ and R ₂ independently represents hydrogen or an alkyl group.
(3)

Each of R ₃ and R ₄ independently represents hydrogen or an alkyl group.
[Chemical Formula 4]

R ₅ represents hydrogen or an alkyl group.
[Chemical Formula 5]

R ₆ represents hydrogen or an alkyl group.
In the general formulas (2) to (5), the alkyl group is a linear, branched or cyclic substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, and the substituent which may be substituted on the alkyl group is an alkyl group, An alkenyl group, an epoxy group, a cyano group, a carboxyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, or an aryl group. The method according to claim 1,
The epoxy compound (b) having a glass transition temperature of 60 占 폚 or less of the homopolymer may be a polyglycidyl ether of an aliphatic polyhydric alcohol; Polyglycidyl ethers of alkylene oxide adducts of aliphatic polyhydric alcohols; Polyglycidyl ethers of polyester polyols of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of aliphatic polyvalent carboxylic acids; Polyglycidyl ethers of polyester polycarboxylic acids of aliphatic polyhydric alcohols and aliphatic polyvalent carboxylic acids; Dimers, oligomers or polymers obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate; And an oligomer or polymer obtained by vinyl polymerization of glycidyl acrylate or glycidyl methacrylate and other vinyl monomers. The method according to claim 1,
The acrylate compound having a glass transition temperature of 150 ° C or higher of the homopolymer (c) may be selected from the group consisting of dimethyloltricyclodecane diacrylate, (trishydroxyethylisocyanurate) diacrylate, 9,9-bis [4- 2-acryloxyethoxy) phenylfluorene, hydroxypivalaldehyde-modifϊed trimethylolpropane diacrylate, (trishydroxyethylisocyanurate) triacrylate, trimethylpropanetriacrylate, pentaerythritol triacryl Wherein the adhesive composition is at least one selected from the group consisting of dimethylol propane tetraacrylate, dipentaerythritol hexaacrylate, and ditrimethylol propane tetraacrylate. The method according to claim 1,
(d) the cyclic-monoacrylate-based compound is at least one selected from the group consisting of isobornyl acrylate, dicyclopentenyl acrylate, and dicyclopentanyl acrylate. The method according to claim 1,
Wherein the adhesive composition for a polarizing plate has a glass transition temperature of 80 캜 or higher. The method according to claim 1,
Wherein the viscosity of the adhesive composition for a polarizing plate is 15 to 150 cP. A polarizer produced by using the adhesive composition for a polarizer according to any one of claims 1 to 8. A polarizer;
A transparent base film adhered to one surface or both surfaces of the polarizer; And
And an adhesive layer for attaching the polarizer and the transparent base film,
(B) an epoxy compound having a glass transition temperature of 60 DEG C or lower, (c) an acrylate having a glass transition temperature of 150 DEG C or higher of the homopolymer, (c) an epoxy compound having a glass transition temperature of 150 DEG C or higher, And (d) a cyclic-monoacrylate-based compound,
Based on 100 parts by weight of an epoxy compound having a glass transition temperature of 120 DEG C or higher of the homopolymer (a)
(b) 20 to 300 parts by weight of an epoxy compound having a glass transition temperature of 60 占 폚 or less of the homopolymer;
(c) 10 to 150 parts by weight of an acrylate compound having a glass transition temperature of 150 DEG C or higher of the homopolymer; And
(d) 40 to 120 parts by weight of a cyclic-monoacrylate compound. 11. The method of claim 10,
Wherein the thickness of the adhesive layer is more than 0 占 퐉 and 5 占 퐉 or less. 11. The method of claim 10,
Wherein the transparent base film is an acrylic film. 11. The method of claim 10,
And a primer layer between the adhesive layer and the transparent base film. 14. The method of claim 13,
Wherein the primer layer has a surface water contact angle of 40 DEG to 100 DEG. 14. The method of claim 13,
Wherein the thickness of the primer layer is 100 nm to 1 占 퐉. 14. The method of claim 13,
Wherein the primer layer is formed from 100 parts by weight of a primer composition comprising 1 to 50 parts by weight of a urethane polymer, 0.1 to 20 parts by weight of water-dispersible fine particles, and the balance water. 17. The method of claim 16,
Wherein the urethane polymer comprises a carboxyl group. 17. The method of claim 16,
The water-dispersible fine particles have an average diameter of 10 to 200 nm. 17. The method of claim 16,
Wherein the primer composition further comprises a crosslinking agent and the content of the crosslinking agent is 0.1 to 30 parts by weight based on 100 parts by weight of the primer composition. A display device comprising a polarizing plate according to any one of claims 10 to 19.