KR20180097970A - Composition for barrier layer, polarizing plate comprising the same and optical display apparatus comprising the same - Google Patents

Abstract

The present invention relates to a composition for a barrier layer which contains an elastomer, an epoxy based compound, a (meth)acrylate based compound, and a photoinitiator. 1 to 20 wt% of elastomer is included for the total weight of the elastomer, the epoxy based compound, and the (meth)acrylate based compound based on the solid components. The composition for a barrier layer has the modulus of 1,000 MPa or more at 85°C after photocuring. The present invention also relates to a polarizing plate comprising the composition, and an optical display apparatus comprising the same.

Description

TECHNICAL FIELD The present invention relates to a composition for a barrier layer, a polarizing plate including the same, and an optical display device including the same. BACKGROUND ART [0002]

The present invention relates to a composition for a barrier layer, a polarizing plate including the same, and an optical display device including the same.

The liquid crystal display device includes a liquid crystal panel and a polarizing plate formed on both sides of the liquid crystal panel. The polarizing plate includes a polarizer and a protective film formed on both sides of the polarizer. Recently, a protective film is formed on one surface of a polarizer and a coating layer (barrier layer) is formed on the other surface of the polarizer to thin the polarizer.

In a liquid crystal display device, it is indispensable to dispose a polarizing plate on both sides of a glass substrate which forms the liquid crystal panel surface from the image forming system. As the polarizing plate, a polarizing plate made of a dichroic material such as a polyvinyl alcohol-based film and iodine, or a transparent protective film for a polarizer using triacetyl cellulose or the like is bonded to one side or both sides of the polarizing plate with a polyvinyl alcohol-based adhesive . In addition, the endurance performance required of the polarizing plate is becoming difficult, and high durability under a severe environment at low temperature and high temperature is required (JP-A-2006-220732)

The pressure-sensitive adhesive layer is usually applied to a polarizing plate provided with a transparent protective film on both sides of the polarizer, and the pressure-sensitive adhesive layer is laminated on the transparent protective film in the polarizing plate. On the other hand, from the viewpoint of thinning, a polarizing plate provided with a transparent protective film only on one side of the polarizer is used, but in this polarizing plate, a pressure-sensitive adhesive layer is provided on the other side of the polarizer. However, in the case of a thin adhesive polarizing plate provided with a transparent protective film only on one side of the polarizer, there is a problem that the durability is poor and cracks tend to occur in the stretching direction (MD direction) of the polarizer under such a harsh environment. In addition, a polarizing plate in which a protective film is formed on at least one side of a polarizer for a thinning problem has been proposed (Japanese Patent Application No. 2009-122796)

There are various attempts to protect the polarizer by forming a barrier layer on one side. An adhesive type polarizing plate characterized in that the barrier layer forming agent is a cyanoacrylate type forming agent, an epoxy type forming agent, an isocyanate type forming agent, or an acrylic type forming agent (Japanese Patent Application No. 2009-122796). A first protective layer made of a cured product of a curable resin composition containing an active energy ray-curable compound containing an epoxy compound having at least one epoxy group in a molecule laminated on one surface of a polarizing film, and an adhesive layer, And a second protective layer made of a thermoplastic resin film laminated on the surface of the polarizing plate (Japanese Patent Application No. 2008-203419).

A problem to be solved by the present invention is to provide a composition for a barrier layer capable of suppressing cracking of a polarizer by suppressing shrinkage of the polarizer under a thermal shock condition.

Another object to be solved by the present invention is to provide a composition for a barrier layer which is excellent in compatibility, storage stability, and coating ability and can realize a barrier layer of a thin film.

Another object of the present invention is to provide a composition for a barrier layer which can improve the durability of a polarizing plate by lowering the rate of change of light transmittance at high temperature and / or high humidity.

Another object of the present invention is to provide a composition for a barrier layer capable of realizing a barrier layer excellent in adhesion to a polarizer and cutability.

The composition for a barrier layer of the present invention is a composition for a barrier layer comprising an elastomer, an epoxy compound, a (meth) acrylate compound and a photoinitiator, wherein the elastomer comprises the elastomer, the epoxy compound and the (meth) 1 to 20% by weight of the total amount of the compound, and the composition for the barrier layer may have a modulus of 1000 MPa or more at 85 캜 after photo-curing.

The polarizing plate of the present invention comprises a barrier layer; And a polarizer and a protective layer are sequentially laminated on one surface of the barrier layer, and the barrier layer may be formed of the composition for a barrier layer of the present invention.

The optical display device of the present invention may include the polarizing plate of the present invention.

The present invention provides a composition for a barrier layer capable of suppressing cracking of a polarizer by suppressing shrinkage of the polarizer in a thermal shock condition.

The present invention provides a composition for a barrier layer capable of realizing a thin film barrier layer with good compatibility, good storage stability, and good applicability.

The present invention provides a composition for a barrier layer capable of increasing the durability of a polarizing plate by lowering the rate of change of transmittance at high temperature and high humidity.

The present invention provides a composition for a barrier layer capable of realizing a barrier layer having good adhesion to a polarizer and excellent cutability.

1 is a cross-sectional view of a polarizer according to an embodiment of the present invention.
2 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.

Embodiments of the present application will now be described in more detail with reference to the accompanying drawings. However, the techniques disclosed in this application are not limited to the embodiments described herein but may be embodied in other forms. It should be understood, however, that the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the width, thickness, and the like of the components are enlarged in order to clearly illustrate the components of each device. Like numbers refer to like elements throughout the several views.

The terms "upper" and "lower" in this specification are defined with reference to the drawings, wherein "upper" may be changed to "lower", "lower" What is referred to as "on" may include not only superposition, but also intervening other structures in the middle. On the other hand, what is referred to as "directly on" or "directly above "

Herein, the "modulus" of the barrier layer is a storage modulus, and the modulus is obtained by photocuring a composition for a barrier layer to a thickness of 10 [micro] m and measuring a length x width (30 mm x 10 mm) Lt; 0 > C to 120 < 0 > C.

As used herein, "(meth) acrylic" means acrylic and / or methacrylic.

In the present specification, the moisture permeability of the "protective layer" is a value measured at 40 ° C. and a relative humidity of 90% in accordance with KS A1013.

In the present specification, "in-plane retardation (Re)" and "thickness direction retardation (Rth)" of the protective layer are values measured by the following formulas A and B, respectively:

<Formula A>

Re = (nx - ny) xd

(In the above formula A, nx and ny are the refractive indexes in the slow axis direction and the fast axis direction of the protective layer at a wavelength of 550 nm, respectively, and d is the thickness (unit: nm) of the protective layer).

<Formula B>

Rth = ((nx + ny) / 2 - nz) xd

(Nx, ny, and nz are the refractive indexes in the slow axis direction, the fast axis direction, and the thickness direction of the protective layer at a wavelength of 550 nm, respectively, and d is the thickness (unit: nm) of the protective layer).

The composition for a barrier layer according to an embodiment of the present invention may include an elastomer, an epoxy compound, a (meth) acrylate compound, and a photo initiator.

The elastomer is included in the composition for the barrier layer to prevent the modulus of the epoxy compound and the (meth) acrylate compound from reacting with each other or by mutual reaction, to increase the modulus at high temperature and to suppress the shrinkage of the polarizer under the thermal shock condition, The occurrence can be reduced. For example, the composition for a barrier layer may have a modulus of at least 1000 MPa at 85 캜 after photo-curing. Within the above range, the shrinkage of the polarizer can be suppressed under the thermal shock condition, and the durability at high temperature and high humidity can be increased. Therefore, the polarizing plate comprising the barrier layer formed of the barrier layer composition of the present invention can have a maximum crack length of 2 mm or less in the absorption axis direction (generally, MD (machine direction)) of the polarizer under thermal shock. Within the above range, the occurrence of cracks in the polarizer during thermal shock is low, so that the reliability of the polarizer can be enhanced. Specifically, the composition for a barrier layer may have a modulus of 1000 MPa to 1500 MPa at 85 캜 after photo-curing. Within the above-mentioned range, the shrinkage of the polarizer can be suppressed under the thermal shock condition, the adhesion to the polarizer and the cuttability can be improved, and the durability and reliability of the polarizer can be improved.

The elastomer may comprise an elastomer which is non-reactive in the presence of a photoinitiator for each of the epoxy compound, (meth) acrylate compound. Since the non-reactive elastomer does not react with the epoxy compound or (meth) acrylate compound even in the curing process of the composition for the barrier layer, the degradation of the modulus at high temperatures can be remarkably prevented. In addition, the non-reactive elastomer can suppress the influence of the stress at the time of curing shrinkage of the composition for the barrier layer to the minimum to suppress the deformation of the barrier layer and thereby suppress deformation of the polarizer. Means that the elastomer does not react with each of the epoxy compound, (meth) acrylate compound in the presence of the photoinitiator upon photo-curing of the composition for the barrier layer.

The elastomer may comprise an elastomer comprising a (meth) acrylate-based repeating unit. The elastomer may comprise a block copolymer consisting of a hard segment comprising a methacrylate unit and a soft segment comprising an acrylate unit. Wherein the hard segment is composed of polymethylmethacrylate (PMMA) and has a glass transition temperature of 100 占 폚 to 120 占 폚, a soft segment of polybutyl acrylate (PnBA) and a glass transition temperature of -50 占 폚 to -40 占 폚 . The elastomer may have a weight average molecular weight of 10,000 g / mol to 300,000 g / mol. Within this range, it can be used for the barrier layer.

The elastomer may be synthesized by conventional methods known to those skilled in the art, or may include, but is not limited to, commercially available products such as elastomer kurarity LA4285 (kuraray), elastomer kurarity LB550 (kuraray).

The elastomer may be contained in an amount of 1 to 20% by weight based on the total amount of the elastomer based on the solid component, the epoxy compound and the (meth) acrylate compound. Within the above range, it is possible to prevent the cracking due to the thermal shock of the polarizer by increasing the modulus at a high temperature after curing the composition for the barrier layer, to prevent the viscosity of the composition for the barrier layer from becoming excessively high, Can be prevented from dropping, and the cuttability and adhesiveness of the polarizer can be prevented from being lowered. Preferably, the elastomer may comprise from 5 wt% to 20 wt%, 5 wt% to 15 wt%, and 5 wt% to 10 wt% of the total of the elastomer, epoxy compound, and (meth) acrylate compound.

The elastomer may be included in an amount of 1 part by weight to 20 parts by weight, for example, 5 parts by weight to 15 parts by weight, based on 100 parts by weight of the epoxy compound. Within the above range, it is possible to prevent the cracking due to the thermal shock of the polarizer by increasing the modulus at a high temperature after curing the composition for the barrier layer, to prevent the viscosity of the composition for the barrier layer from becoming excessively high, You can prevent falling.

The elastomer may be included in an amount of 20 to 100 parts by weight, for example, 30 to 100 parts by weight based on 100 parts by weight of the (meth) acrylate-based compound. Within this range, there may be a high temperature modulus synergistic effect.

The epoxy-based compound may include an alicyclic epoxy-based compound.

The alicyclic epoxy compound can be polymerized by cations initiated by light energy. Bifunctional alicyclic epoxy compounds among the alicyclic epoxy compounds may be used. The bifunctional alicyclic epoxy compound has a high glass transition temperature of the homopolymer to support the laminate structure between the polarizer and the barrier layer to enhance the durability and to improve the interfacial adhesion between the polarizer and the barrier layer due to chemical bonds and excellent wettability . The bifunctional alicyclic epoxy compound may have a glass transition temperature of the homopolymer of 150 占 폚 or higher, for example, 150 占 폚 to 250 占 폚. Within this range, there may be an effect of increasing the glass transition temperature of the barrier layer.

The bifunctional alicyclic epoxy compound is a compound having two alicyclic epoxy groups. The alicyclic epoxy group has a functional group in which the C3 to C20 alicyclic group is epoxidized, a C2 to C20 alicyclic group having a functional group in which the C3 to C20 alicyclic group is epoxidized, or a functional group in which the C3 to C20 alicyclic group is epoxidized Means a C1 to C10 alkyl group. Specifically, the alicyclic epoxy group means at least one of an epoxycyclohexyl group, an epoxycyclopentyl group and a glycidyl group.

In one embodiment, the bifunctional alicyclic epoxy compound is epoxycyclohexylmethyl epoxycyclohexanecarboxylate-based, epoxycyclohexanecarboxylate-based alkane diol, epoxycyclohexylmethylester-based dicarboxylic acid ester, epoxy of polyethylene glycol Epoxycyclohexylmethyl ether, cyclohexyl methyl ether, alkane diol, epoxycyclohexyl methyl ether, diepoxy trispyrene, diepoxy monospiro, vinylcyclohexene diepoxide, epoxycyclopentene ether, and diepoxytricyclodecane compounds .

The bifunctional alicyclic epoxy-based compound is 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-3', 4'- -6'-methylcyclohexanecarboxylate, and bis (3,4-epoxy-6-methylcyclohexyl) adipate. For example, the bifunctional alicyclic epoxy compound may be CELLOXIDE 2021P (manufactured by DIACEL), but the present invention is not limited thereto.

The alicyclic epoxy compound may be contained in an amount of 50% by weight to 90% by weight based on the total amount of the elastomer based on the solid component, the epoxy compound and the (meth) acrylate compound. In the above range, the modulus of the barrier layer is increased to ensure a modulus of at least 1000 MPa at 85 캜, and the glass transition temperature of the entire composition for the barrier layer is increased to prevent cracking of the polarizer due to thermal shock, The barrier layer can be formed and the adhesion to the polarizer can be good. Preferably, the alicyclic epoxy compound is contained in an amount of 60% by weight to 90% by weight and 60% by weight to 80% by weight of the total amount of the elastomer, the epoxy compound and the (meth) acrylate compound.

The epoxy compound may further include at least one of an aromatic epoxy compound and an aliphatic epoxy compound.

At least one of an aromatic epoxy compound and an aliphatic epoxy compound binds in the middle of the curing reaction of the alicyclic epoxy compound to facilitate the control of the curing rate of the composition for the barrier layer, Helps improve cohesion. Further, at least one of the aromatic epoxy compound and the aliphatic epoxy compound can prevent an excessive increase in the viscosity of the composition for the barrier layer as a reactive diluent.

The aromatic epoxy compound may include at least one of a monofunctional aromatic epoxy compound and a bifunctional aromatic epoxy compound. For example, aromatic epoxy compounds include phenyl glycidyl ether, cresyl glycidyl ether, nonylphenyl glycidyl ether, aromatic epoxy compounds include bisphenol A, F, and phenol novolak, cresol novolac, bisphenol A- , Dichloropentadiene novolac, glycidyl ether of triphenolmethane, triglycidyl p-aminophenol, and tetraglycidyl methylenedianiline.

The aliphatic epoxy compound may include at least one of a monofunctional aliphatic epoxy compound and a bifunctional aliphatic epoxy compound. For example, the aliphatic epoxy compound may be ethyl glycidyl ether, butyl glycidyl ether, hexyl glycidyl ether, octyl glycidyl ether, 2-ethylhexyl glycidyl ether, dodecyl glycidyl ether, octa Hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglyceride, trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, Sebac ether, polyethylene glycol diglycidyl ether, glycerin triglycidyl ether, polypropylene glycol diglycidyl ether; Diglycidyl ethers of polyether polyols obtained by adding one or more alkylene oxides to aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol and glycerin; Diglycidyl esters of aliphatic long chain dibasic acids; Diglycidyl ethers of aliphatic higher alcohols; And bifunctional aliphatic epoxy compounds such as diglycidyl ethers of higher fatty acids.

At least one of an aromatic epoxy compound and an aliphatic epoxy compound may be contained in an amount of 5 to 30% by weight based on the total amount of the elastomer based on a solid basis, the epoxy based compound and the (meth) acrylate based compound. Within the above range, the cohesive force of the composition for the barrier layer is good, the reaction rate of the composition for the barrier layer is not slowed, and the crack resistance due to thermal shock may not be lowered. For example, at least one of the aromatic epoxy compound and the aliphatic epoxy compound may be contained in an amount of 10 to 30% by weight, 10 to 25% by weight, and 10 to 30% by weight, based on the total amount of the elastomer based on the solid fraction, , 10 wt% to 20 wt%, and 10 wt% to 15 wt%.

The epoxy compound is contained in an amount of 70 to 95% by weight, specifically 75 to 95% by weight, more specifically 75 to 90% by weight, based on the total amount of the elastomer based on the solid fraction, the epoxy compound and the (meth) &Lt; / RTI &gt; Within the above range, the adhesion between the polarizer and the barrier layer can be improved, the crack resistance of the polarizer can be enhanced, and the cuttability can be improved.

The (meth) acrylate compound is included in the composition for the barrier layer to lower the viscosity, thereby improving the coating property of the composition, increasing the hardness of the barrier layer, and accelerating the curing of the composition for the barrier layer. The (meth) acrylate-based compound may include at least one of a monofunctional (meth) acrylic compound and a bifunctional (meth) acrylic compound.

(Meth) acrylate having a C1 to C10 alkyl group having at least one hydroxyl group, a (meth) acrylate having a C3 to C10 alicyclic group having at least one hydroxyl group, (Meth) acrylate having a C6 to C20 aryl group, or a (meth) acrylate having a C7 to C20 arylalkyl group. Specific examples of the monofunctional (meth) acrylic compound include t-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy- (Meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, and benzyl (meth) acrylate.

The monofunctional (meth) acrylic compound may be at least one selected from the group consisting of tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, dimethylaminoethyl (meth) (Meth) acrylate, trimethylolpropane mono (meth) acrylate, pentaerythritol mono (meth) acrylate, and phenoxypolyethylene glycol mono (meth) acrylate.

The bifunctional (meth) acrylic compound may be an unsubstituted alkylene glycol di (meth) acrylate, polyoxyalkylene glycol di (meth) acrylate, halogen substituted alkylene glycol di (meth) Di (meth) acrylate of di (meth) acrylate, hydrogenated dicyclopentadiene or tricyclodecanedialanol, di (meth) acrylate of dioxane glycol or dioxanedialanol, alkyl of bisphenol A or bisphenol F Di (meth) acrylate of a phenoxy resin, a di (meth) acrylate of a phenoxy resin, a di (meth) acrylate of a phenol oxide adduct, and an epoxy di (meth)

Specifically, the bifunctional (meth) acrylic compound is at least one compound selected from the group consisting of ethylene glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4- Acrylate such as di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylol propane di (meth) acrylate, pentaerythritol di (Meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, dipropylene glycol di , Poly (ethylene glycol) di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, silicone di (meth) acrylate, hydroxypivalic acid ester neopentyl (Meth) acryloyloxyethoxyethoxyphenyl] propane, 2,2-bis [4- (meth) acryloyloxyethoxyethoxyphenyl] propane, Hexyl] propane, hydrogenated dicyclopentadienyl di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, 1,3-dioxane-2,5-diyl di (meth) (Hydroxyethyl) isocyanurate di (meth) acrylate.

Preferably, the (meth) acrylate-based compound may include a monofunctional or bifunctional (meth) acryl-based compound containing at least one hydroxyl group. This can increase the adhesion between the polarizer and the barrier layer by acting with the hydroxyl group of the polarizer. In addition, the monofunctional or bifunctional (meth) acrylic compound containing at least one hydroxyl group does not inhibit the curing reaction by moisture, so that it can stably cure without being inhibited by the water content of the polarizer, thereby enhancing the reliability of the barrier layer have. Specifically, a monofunctional (meth) acrylic compound containing at least one hydroxyl group is preferably a (meth) acrylate having a C1 to C10 alkyl group having at least one hydroxyl group, such as 2-hydroxyethyl (meth) acrylate (Meth) acrylate, 2- or 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate.

(Meth) acrylic compound is contained in an amount of 1 to 20% by weight, specifically 5 to 20% by weight, more specifically 5 to 15% by weight, based on the total amount of the elastomer based on solid component, epoxy compound and (meth) % &Lt; / RTI &gt; by weight. Within the above range, the adhesion between the polarizer and the barrier layer can be improved, the crack resistance of the polarizer can be enhanced, and the cuttability can be improved.

The photoinitiator may include at least one of a photoacid generator and a photo radical initiator.

As the photoacid generator, those conventionally known to those skilled in the art can be used. Specifically, the photoacid generator may be an onium salt including a cation and an anion. Specifically, the cation is at least one selected from the group consisting of diphenyl iodonium, 4-methoxydiphenyl iodonium, bis (4-methylphenyl) iodonium, bis (4-tert- butylphenyl) iodonium, bis (dodecylphenyl) Triarylsulfonium such as diaryliodonium such as [(methylphenyl) [(4- (2-methylpropyl) phenyl) iodonium, triphenylsulfonium and diphenyl- 4- (phenylthio) phenylsulfonium, 4- (diphenylsulfono) phenyl] sulfide, and the like. Specifically, the anion is phosphate (PF ₆ ^-) hexafluoropropane, borates (BF ₄ ^-) tetrafluoroborate, antimonate hexafluorophosphate (SbF ₆ ^-), are Senate hexafluorophosphate (AsF ₆ ^-), hexamethylene And chlorantimonate (SbCl ₆ ^- ).

The photoacid generator may be added in an amount of 0.1 part by weight to 10 parts by weight, specifically 1 part by weight to 10 parts by weight, based on 100 parts by weight of the total amount of the elastomer based on solid component, epoxy compound and (meth) acrylate compound. Within this range, it can be sufficiently cured, and the remaining amount of the initiator remains, thereby preventing the transparency of the barrier layer from deteriorating.

As the photo-radical initiator, those conventionally known to those skilled in the art can be used. Specifically, the photo radical initiator may be at least one of a hydroxy ketone type, a thioxanthone type, a phosphorus type, a triazine type, an acetophenone type, a benzophenone type, a benzoin type, and a oxime type.

The photo-radical initiator may be included in an amount of 0.1 to 10 parts by weight, specifically 0.1 to 6 parts by weight, based on 100 parts by weight of the total amount of the elastomer based on the solid fraction, the epoxy compound and the (meth) acrylate compound. Within this range, it can be sufficiently cured, and the remaining amount of the initiator remains, thereby preventing the transparency of the barrier layer from deteriorating.

The photoinitiator may be contained in an amount of 1 to 15 parts by weight, for example, 1 to 10 parts by weight, per 100 parts by weight of the total of the elastomer, the epoxy compound and the (meth) acrylate compound. Within this range, it can be sufficiently cured, and the remaining amount of the initiator remains, thereby preventing the transparency of the barrier layer from deteriorating.

The composition for a barrier layer may have a viscosity change rate of 5% or less, for example, 0.1% to 3% in the following formula (1). Within this range, the storage stability is high and the productivity is good:

<Formula 1>

Viscosity change rate = | V1 - V0 | V0 x 100

(In the above formula 1, V0 represents the initial viscosity (unit: cps) of the composition for the barrier layer at 25 DEG C,

V1 is the viscosity (unit: cps) at 25 DEG C after the barrier layer composition is left at 25 DEG C for one week.

The composition for a barrier layer may be a solvent-free composition that does not contain a solvent, but may further include a solvent to facilitate coatability, coatability, or processability. The solvent may include, but is not limited to, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate and the like.

The composition for the barrier layer may further comprise an additive. The additive may provide additional functionality to the barrier layer. Specifically, the additive may include at least one of a UV absorber, a reaction inhibitor, an adhesion improver, a thixotropic agent, a conductivity imparting agent, a colorant adjusting agent, a stabilizer, an antistatic agent, an antioxidant, Do not.

The composition for the barrier layer can further increase the hardness and mechanical strength of the barrier layer by further including fine particles. Specifically, by including the hygroscopic fine particles, the fine particles can further enhance the moisture blocking effect of the barrier layer.

The fine particles may include, but are not limited to, at least one of silica, aluminum oxide, zirconium oxide, and titanium oxide. The fine particles may be surface-treated with epoxy groups, (meth) acrylate groups or vinyl groups in whole or in part of the surface of the fine particles to improve compatibility. The fine particles are not limited in shape and size. Specifically, the fine particles may include particles having a shape such as a spherical shape, a plate shape, or an amorphous shape. The fine particles may have an average particle diameter of 1 nm to 200 nm, specifically 8 nm to 50 nm. The hardness of the barrier layer can be increased without affecting the surface roughness and transparency of the barrier layer in the above range.

The fine particles may be contained in the composition for the barrier layer based on solid basis in an amount of 3% by weight to 30% by weight, specifically 5% by weight to 20% by weight. Within this range, the hardness of the barrier layer can be increased without affecting the surface roughness and transparency of the barrier layer.

The composition for the barrier layer may have a viscosity of 5 cP to 200 cP, specifically 10 cP to 150 cP at 25 캜. The barrier layer can be easily formed in the above range.

The polarizing plate of the present invention comprises a barrier layer; And a polarizer and a protective layer are sequentially laminated on one side of the barrier layer, and the barrier layer may be formed of the composition for a barrier layer of the present invention.

Hereinafter, a polarizing plate according to an embodiment of the present invention will be described with reference to FIG. 1 is a cross-sectional view of a polarizer according to an embodiment of the present invention.

Referring to FIG. 1, a polarizer 100 may include a polarizer 110, a protective layer 120, and a barrier layer 130. The barrier layer 130, the polarizer 110, and the protective layer 120 are sequentially stacked. The barrier layer 130 may be formed from the composition for a barrier layer of the present invention. The barrier layer 130 is formed directly on the polarizer 110. This "directly formed" means that no other adhesive layer, adhesive layer, is interposed between the barrier layer and the polarizer.

The polarizing plate 100 includes the barrier layer 130 so that the polarizer 100 is allowed to stand at -40 占 폚 for 30 minutes, elevated from -40 占 폚 to 85 占 폚, left at 85 占 폚 for 30 minutes, The maximum length of the crack in the absorption axis direction can be 2 mm or less. In the above range, cracking of the polarizer at a thermal shock is low, and the reliability of the polarizing plate can be enhanced.

In addition, the polarizing plate 100 can have a light transmittance change rate of 1% or less in the following formula (2): Within this range, the polarizing plate can have high durability at high temperature and high humidity and can be used for an optical display device.

<Formula 2>

Transmittance change rate = | T 1 - T 0 | T 0 x 100

(In the formula (2), T0 is the initial light transmittance (unit:%) of the polarizing plate,

T1 is the light transmittance (unit:%) measured after putting the polarizing plate in a chamber of 85 ° C and 85% relative humidity, after 500 hours and then at 25 ° C for 1 hour,

T1? T0 in the formula (2), and T1 and T0 may be 30% or more, specifically 30% to 50%, respectively. In the light transmittance range, it can be used in an optical display device.

The polarizer 110 can polarize external light incident on the polarizing plate 100.

The polarizer 110 may include a polarizer made of a polyvinyl alcohol-based resin film. In one embodiment, the polarizer may be a polyvinyl alcohol-based polariser on which at least one of iodine and dichroic dye is adsorbed to a polyvinyl alcohol-based resin film. In another embodiment, the polarizer may be a polyene polarizer prepared by dewatering a polyvinyl alcohol-based resin film.

The polyvinyl alcohol resin film may have a saponification degree of 85 mol% to 100 mol%, specifically 98 mol% to 100 mol%. The degree of polymerization of the polyvinyl alcohol resin film may be 1,000 to 10,000, specifically 1,500 to 10,000. The thickness of the polyvinyl alcohol-based resin film may be 50 占 퐉 to 200 占 퐉. Polarizers can be produced within the range of saponification degree, degree of polymerization and thickness.

Specifically, the polyvinyl alcohol polarizer is a film obtained by adsorbing at least one of iodine and dichroic dye to a polyvinyl alcohol-based resin film, and performing a machine direction uniaxial stretching at a final stretching ratio of 2 to 8 times, specifically 3 to 6 times . The stretching may include dry stretching, wet stretching, or a combination thereof. The "final stretching ratio" means the ratio of the length of the final polyvinyl alcohol-based polarizer to the initial length of the polyvinyl alcohol-based resin film. After stretching, color correction through immersion in an aqueous solution of boric acid or an aqueous solution of potassium iodide may be added. Specifically, the polyene polarizer can be produced by adding an acid catalyst to a polyvinyl alcohol-based resin film and dehydrating and drying it. The acid catalyst may include an organic acid containing an aromatic sulfonic acid such as toluenesulfonic acid including para-toluenesulfonic acid, an inorganic acid, or a mixture thereof.

The thickness of the polarizer 110 may be 5 占 퐉 to 100 占 퐉, specifically, 5 占 퐉 to 50 占 퐉. In the above range, it can be used for a polarizing plate.

The protective layer 120 may be formed on one side of the polarizer 110 to protect the polarizer 110.

The protective layer 120 may have a moisture permeability 30g / m ² and 24hr or less, specifically, 1g / m ² and 24hr to about 20g / m ² and 24hr, more specifically, 5g / m ² and 24hr to about 15g / m ² and 24hr . By preventing the external moisture from penetrating the polarizer in the above range, the durability of the polarizer at high temperature and high humidity can be increased, and the durability of the polarizer at high temperature and high humidity can be further increased together with the barrier layer.

The protective layer 120 may be a protective coating layer or a protective film.

The protective coating layer may be formed of an active energy ray-curable resin composition comprising an active energy ray-curable compound and a polymerization initiator. The active energy ray-curable compound may include at least one of a cationic polymerizable curable compound, a radically polymerizable curable compound, a urethane resin, and a silicone resin. The cationic polymerizable curable compound may be an epoxy compound having at least one epoxy group in the molecule, or an oxetane compound having at least one oxetane ring in the molecule. The radical polymerizable curable compound may be a (meth) acrylic compound having at least one (meth) acryloyloxy group in the molecule. The epoxy compound may be at least one of a hydrogenated epoxy compound, a chained aliphatic epoxy compound, a cyclic aliphatic epoxy compound, and an aromatic epoxy compound. The radical polymerizable curable compound can be obtained by reacting two or more (meth) acrylate monomers having at least one (meth) acryloyloxy group in the molecule, a compound having a functional group and at least two (meth) acryloyloxy (Meth) acrylate oligomer having a &lt; / RTI &gt; (Meth) acrylate monomers include monofunctional (meth) acrylate monomers having one (meth) acryloyloxy group in the molecule, difunctional (meth) acrylates having two (meth) acryloyloxy groups in the molecule (Meth) acrylate monomers having three or more (meth) acryloyloxy groups in the molecule. (Meth) acrylate oligomer may be a urethane (meth) acrylate oligomer, a polyester (meth) acrylate oligomer, an epoxy (meth) acrylate oligomer, or the like. The polymerization initiator can cure the active energy ray-curable compound. The polymerization initiator may include at least one of a photocationic initiator and a photosensitizer.

The Gwangyang ionic initiator may be any of those conventionally known to those skilled in the art. Specifically, an onium salt including a cation and an anion can be used as the initiator of the photon ion. Specifically, the cation is at least one selected from the group consisting of diphenyl iodonium, 4-methoxydiphenyl iodonium, bis (4-methylphenyl) iodonium, bis (4-tert- butylphenyl) iodonium, bis (dodecylphenyl) Triarylsulfonium such as diaryliodonium such as [(methylphenyl) [(4- (2-methylpropyl) phenyl) iodonium, triphenylsulfonium and diphenyl-4-thiophenoxyphenylsulfonium, 4- (diphenylsulfono) phenyl] sulfide, and the like. Specifically, examples of the anion include hexafluorophosphate, tetrafluoroborate, hexafluoroantimonate, hexafluoroarsenate, and hexachloroantimonate. The photosensitizer may be any of those conventionally known to those skilled in the art. Specifically, the photosensitizer may be at least one selected from the group consisting of thioxanthone, phosphorus, triazine, acetophenone, benzophenone, benzoin, and oxime. The polymerization initiator may be included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the total active energy ray-curable compound. Within this range, curing is sufficient, mechanical strength is high, and adhesion with the polarizer is good. The active energy ray curable resin composition may further include conventional additives such as silicone leveling agents, ultraviolet absorbers, and antistatic agents. The additive may be included in an amount of 0.01 to 1 part by weight per 100 parts by weight of the total active energy ray-curable compound. The protective coating layer may be a liquid crystal coating layer.

The protective film may be a lead-free film or a stretched film. The stretched film may have a retardation in a predetermined range to provide an additional function to the polarizer. The stretched film may have an in-plane retardation (Re) of 5,000 nm or more, specifically 5,000 nm to 15,000 nm, more specifically 6,000 nm to 12,000 nm. The stretched film may have a thickness direction retardation (Rth) of 15,000 nm or less, specifically 5,000 nm to 15,000 nm, more specifically 6,000 nm to 12,000 nm. In the above range, rainbow stains can be prevented from occurring when the polarizing plate is used.

The protective film may be a film formed of an optically transparent resin. Specifically, the resin may be selected from the group consisting of a cellulose resin such as triacetyl cellulose, a polyester resin such as polyethylene terephthalate (PET film), polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, a cyclic olefin polymer, COP), polycarbonate resin, polyether sulfone resin, polysulfone resin, polyamide resin, polyimide resin, non-cyclic-polyolefin resin, polymethylmeter Acrylate resin, polyvinyl alcohol-based resin, polyvinyl chloride-based resin, and polyvinylidene chloride-based resin. In one embodiment of the present invention, the protective layer is preferably a polyester resin such as polyethylene terephthalate (PET film), polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate and the like, and a PET film is most preferable.

Although not shown in FIG. 1, the protective layer 120 may further include a functional coating layer on one side of the protective layer 120 to provide additional functions to the polarizing plate. Specifically, the functional coating layer may be at least one of a hard coating layer, an antireflection layer, an antistatic layer, an antistatic layer, and a low reflection layer, but is not limited thereto. The functional coating layer may have a thickness of 1 탆 to 100 탆, specifically 1 탆 to 50 탆, more specifically 1 탆 to 20 탆. In this range, it is possible to provide an additional function to the polarizing plate without affecting the protective layer and can be used for the polarizing plate.

In addition, although not shown in FIG. 1, when the protective layer 120 is a protective film, the polarizer 110 and the protective film can be more adhered to each other by further including a primer layer on the other surface of the protective film. When the protective layer is a protective coating layer, the protective layer can be formed directly on the polarizer.

The thickness of the protective layer 120 may be 5 占 퐉 to 200 占 퐉, specifically 10 占 퐉 to 150 占 퐉, more specifically 50 占 퐉 to 120 占 퐉. Within the above range, it can be used for a polarizing plate, and warping of the polarizing plate can be suppressed together with the barrier layer.

The barrier layer 130 is formed on the other surface of the polarizer 110 to protect the polarizer 110 from the surface opposite to the protective film 120 with respect to the polarizer 110 and to prevent external moisture from penetrating into the polarizer 110 The durability of the polarizing plate 100 at high temperature and high humidity can be increased.

The barrier layer 130 is formed immediately below the polarizer 110 and has a high adhesion to the polarizer 110 so that the barrier layer 130 is directly formed on the polarizer 110 without an adhesive layer to realize a thinning effect of the polarizer 100. [

The thickness of the barrier layer 130 may be 20 占 퐉 or less, specifically 1 占 퐉 to 15 占 퐉, more specifically 1 占 퐉 to 12 占 퐉. In the above range, it can be used for a polarizing plate, and the thickness of the protective layer and the entire adhesive layer can be appropriately adjusted to suppress the warpage of the polarizing plate, and barrier property can be enhanced to prevent cracks.

Although not shown in FIG. 1, when the protective layer 120 is a protective film, an adhesive layer may be formed between the protective film and the polarizer to bond the polarizer and the protective film. The adhesive layer may be formed of an adhesive for a water-based, UV light curing type polarizing plate.

Hereinafter, a method for manufacturing a polarizing plate according to an embodiment of the present invention will be described.

A polarizing plate according to an embodiment of the present invention can be manufactured by forming a protective layer on one surface of a polarizer, applying a composition for a barrier layer to the other surface of the polarizer, and curing the composition for a barrier layer.

The composition for the barrier layer may each be applied by a conventional application method. Specifically, it can be applied by die coating, gravure coating or the like. Curing can include irradiation with active energy ray in the UV specifically, 100mW / cm ² to ^{2000mW / cm 2, 100mJ / cm} 2 to 1000mJ / cm ^2.

Hereinafter, a polarizing plate according to another embodiment of the present invention will be described with reference to FIG. 2 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.

Referring to FIG. 2, the polarizing plate 200 may include a polarizer 110, a protective layer 120, a barrier layer 130, and an adhesive layer 140. In the polarizing plate 200, the adhesive layer 140 is formed on the lower surface of the barrier layer 130, so that the polarizing plate can be adhered to the panel for the optical display device such as the liquid crystal panel. Is substantially the same as the polarizing plate according to one embodiment of the present invention, except that an adhesive layer is further formed. Hereinafter, only the adhesive layer will be described.

The adhesive layer 140 may be formed on the lower surface of the barrier layer to adhere the polarizing plate to a panel or the like. The adhesive layer 140 may have a modulus of 0.1 MPa or less at 25 占 폚. In this range, even if the modulus is high at the high temperature of the barrier layer, the thermal shrinkage expansion of the polarizer can be relaxed. In the case of a hard type adhesive having a modulus exceeding 0.1 MPa, the shrinkage expansion behavior of the device may be adversely affected. The pressure-sensitive adhesive layer may be formed of a (meth) acrylic, urethane, or silicone pressure-sensitive adhesive composition.

An optical display device according to an embodiment of the present invention may include a polarizing plate according to embodiments of the present invention. The optical display device may be a liquid crystal display device, an organic light emitting diode display device or the like, but is not limited thereto.

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to embodiments of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples.

Specific specifications of the components used in Examples and Comparative Examples are as follows.

① Elastomer: kurarity LA4285, kuraray company

② Elastomer: kurarity LB550, kuraray company

③ Epoxy compounds: 3 ', 4'-Epoxycyclohexane) methyl 3,4-epoxycyclohexylcarboxylate, Celloxide 2021P, Daicel Co.

④ Epoxy compounds: aromatic epoxy compounds, Phenyl Glycidyl Ether, EX-141, Nagase

⑤ Epoxy compounds: aliphatic epoxy compounds, 2-Ethylhexyl Glycidyl Ether, EX-121, Nagase

⑥ (Meth) acrylate compound: 4-hydroxybutyl acrylate, Sigma-Aldrich Corp.

(7) Photoacid generators: diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, CPI-100P, San-Apro

(8) Photo radical initiator: 1-hydroxycyclohexyl phenyl ketone, Irgacure 184, BASF

Example One

10 parts by weight of an elastomer, 70 parts by weight of an alicyclic epoxy compound, 10 parts by weight of an aromatic epoxy compound, 10 parts by weight of a (meth) acrylate compound, 6 parts by weight of a photo acid generator and 1 part by weight of a photo radical initiator, A composition was prepared.

Example  2 to Example  7

A composition for a barrier layer was prepared in the same manner as in Example 1, except that the kind and / or the content of the elastomer, the epoxy-based compound, the photoacid generator, and the photo-radical initiator were changed to the following Table 1 (unit: Respectively.

Comparative Example  1 to Comparative Example  3

A composition for a barrier layer was prepared in the same manner as in Example 1, except that the kind and / or the content of the elastomer, the epoxy-based compound, the photoacid generator, and the photo-radical initiator were changed to the following Table 1 (unit: Respectively.

Elastomer Epoxy compound (Meth)
Acrylate series Photoacid generator Photo radical initiator ① ② ③ ④ ⑤ ⑥ ⑦ ⑧ Example 1 - 10 70 10 - 10 6 One Example 2 10 - 60 15 - 15 6 One Example 3 5 - 80 10 - 5 6 One Example 4 5 - 70 10 - 15 6 One Example 5 - 5 70 10 - 15 6 One Example 6 5 - 70 - 10 15 6 One Example 7 5 - 75 - 10 10 6 One Comparative Example 1 5 - 40 40 - 15 6 One Comparative Example 2 - - 70 15 - 15 6 One Comparative Example 3 30 - 60 - - 10 6 One

The properties of the compositions for barrier layers of Examples and Comparative Examples were evaluated in Table 2 below.

(1) Modulus: The barrier layer composition of the examples and comparative examples was applied between release films, and then cured with a metal halide lamp at 400 mW / cm ² and 1000 mJ / cm ² to prepare a cured sample having a thickness of 10 탆. The cured sample was cut into a length of 30 mm and a width of 10 mm, and the modulus was measured by raising the temperature from 0 ° C to 120 ° C at a frequency of 1 Hz. The modulus was measured using a DMA Q800 instrument. The modulus was taken at 85 [deg.] C.

(2) Adhesion: A polyvinyl alcohol film (saponification degree: 99.5 mol%, degree of polymerization: 2000) having a thickness of 80 탆 was immersed in an aqueous 0.3% iodine solution and then drawn to give a draw ratio of 5.0. Subsequently, the stretched substrate film was immersed in a boric acid solution of 3% concentration and an aqueous solution of 2% potassium iodide to perform color correction and dried at 50 DEG C for 4 minutes to prepare a polarizer (thickness: 18 mu m).

PET film (water permeability: 10 g / m ² ∙ 24 hr, Re: 10,200 nm, Rth: 12,000 nm, thickness: 80 탆 at a wavelength of 550 nm, Toyobo Co., Ltd. The water permeability was measured at 40 캜 and 90% relative humidity in accordance with KS A1013 Measured value) was corona treated at 250 mJ / cm &lt; ^{2 &} gt ;. On the corona-treated surface of the PET film, an adhesive for UV curing type polarizing plate was applied in a thickness of 2 탆 and one side of the polarizer was adhered.

Applying a barrier layer composition of Examples and Comparative Examples on the other side of the polarizer with a thickness 3㎛ and temperature 22 ~ 25 ℃, 20 to 60% relative humidity in the environment by laminating ^{Metal halide lamp 400 mW / cm 2} , 1000 mJ / cm ² to prepare a polarizing plate in which a protective film, a polarizer, and a barrier layer were sequentially laminated. The barrier layer is formed directly on the polarizer.

The prepared polarizing plate was cut into a length of 100 mm and a width of 25 mm, and a cutter cutter was inserted between the polarizer and the barrier layer at the end of the polarizing plate. A that the edge of the sword did not enter between the barrier layer and the polarizer,? Was that the edge of the sword was slightly inclined,? Was the edge of the edge of the sword,

(3) Cutting property: A polarizing plate was prepared in the same manner as in (2).

The polarizer was punched out from the side of the barrier layer using a cutter blade in the size of width x length (500 mm x 500 mm). The peeled state of the end portions of the four faces of the punched polarizing plate was visually observed. A when the barrier layer was not peeled off;? When the barrier layer was peeled by 1 mm or less; B when the barrier layer was pealed more than 1 mm and 2 mm or less;

(4) Crack length: A polarizing plate was produced in the same manner as in (2).

A polarizing plate having a length x width (50 mm x 50 mm) was laminated on a glass plate to prepare a sample. The sample was allowed to stand at -40 占 폚 for 30 minutes, elevated from -40 占 폚 to 85 占 폚, and allowed to stand at 85 占 폚 for 30 minutes. The sample was visually checked for cracks in the MD of the polarizer in the reflection mode under the fluorescent lamp and the back light mode. The maximum length of cracks was evaluated.

(5) High Temperature and Humidity Durability: A polarizing plate was prepared in the same manner as in (2).

The prepared polarizing plate was cut into a length x width (25 mm x 25 mm) and laminated in the middle of a slide glass (length x width, 25 mm x 100 mm) to prepare a sample. The initial light transmittance (T0, unit:%) of the polarizing plate was measured using V-7170 (JASCO). The sample was placed in a chamber at 85 ° C and 85% relative humidity, and after 500 hours passed, the sample was allowed to stand at 25 ° C for 1 hour, and the light transmittance (T1, unit:%) was measured using V-7170 in the same manner as described above. And the rate of change of light transmittance was calculated according to the following formula (2). When the rate of change of the light transmittance is 1% or less,?, When it is more than 1% is 3% or less, and when it is more than 3%, it is X.

<Formula 2>

Transmittance change rate = | T 1 - T 0 | T 0 x 100

(6) Viscosity change rate: Initial viscosity (V0, unit: cps) was measured for the barrier layer composition of the examples and comparative examples at 25 DEG C using Physica MCR 501 (Anton Paar). The composition for the barrier layer was left at 25 캜 for one week, and then the viscosity (V 1, unit: cps) was measured at 25 캜 by using the Physica MCR 501 (Anton Paar) apparatus at 25 캜. Using this, the viscosity change rate was calculated by the following formula 1:

<Formula 1>

Viscosity change rate = | V1 - V0 | V0 x 100

Modulus
(MPa,
@ 85 ° C) Adhesiveness Cutting Crack length
(mm) High temperature and high humidity
durability
(@ 85 ° C, 85%) Viscosity
Rate of change
(%) Example
One 1330 ◎ ◎ 1.2 ◎ 2.8 Example
2 1360 ○ ◎ 1.0 ◎ 2.6 Example
3 1290 ◎ ◎ 0.9 ◎ 2.2 Example
4 1220 ◎ ◎ 0.9 ◎ One Example
5 1120 ◎ ◎ 1.0 ◎ 0.8 Example
6 1210 ◎ ◎ 0.9 ◎ 1.2 Example
7 1200 ◎ ◎ 0.9 ◎ 1.3 Comparative Example
One 380 X X 1.1 △ 0.2 Comparative Example
2 560 ◎ ○ 2.6 △ 0.7 Comparative Example
3 1780 X X 1.3 ◎ 7.1

As shown in Table 2, the barrier layer composition of the present invention has a low rate of change in viscosity, has good storage stability, can lower the rate of change of light transmittance at high temperature and / or high humidity to improve the polarizer plate reconstitution, An excellent barrier layer can be formed.

However, Comparative Example 1, which includes an elastomer but has a modulus of 1000 MPa or less at 85 캜 after photo-curing, has poor adhesion to a polarizer and poor cutability, and has a high rate of change of light transmittance at high temperature and / or high humidity.

In Comparative Example 2 which did not contain an elastomer, cracking of the polarizer was high, and the rate of change of light transmittance was high at high temperature and / or high humidity.

Comparative Example 3, which had a modulus of at least 1000 MPa at 85 ° C after photo-curing but contained an elastomer outside the scope of the present invention, exhibited poor adhesiveness to a polarizer and poor cutability, a high viscosity change rate and poor storage stability, The inhibition of crack generation was also lower than that of the present invention.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (14)

A composition for a barrier layer comprising an elastomer, an epoxy compound, a (meth) acrylate compound, and a photoinitiator,
The elastomer is contained in an amount of 1 wt% to 20 wt% of the total amount of the elastomer, the epoxy compound, and the (meth) acrylate compound based on the solid content
Wherein the composition for a barrier layer has a modulus of at least 1000 MPa at 85 캜 after photo-curing.
The composition for a barrier layer according to claim 1, wherein the elastomer is non-reactive with respect to each of the epoxy compound and the (meth) acrylate compound in the presence of the photoinitiator.
The composition of claim 1, wherein the elastomer comprises a block segment comprising a hard segment comprising a methacrylate unit and a soft segment comprising an acrylate unit.
The composition for a barrier layer according to claim 1, wherein the epoxy compound comprises a bifunctional alicyclic epoxy compound.
5. The composition for a barrier layer according to claim 4, wherein the epoxy compound further comprises at least one of an aromatic epoxy compound and an aliphatic epoxy compound.
The composition for a barrier layer according to claim 1, wherein the (meth) acrylate-based compound comprises a monofunctional or bifunctional (meth) acrylic compound containing at least one hydroxyl group.
The composition for a barrier layer according to claim 1,
The total amount of the elastomer, the epoxy compound, and the (meth) acrylate compound
1% to 20% by weight of the elastomer,
70% by weight to 95% by weight of the epoxy compound,
1 to 20% by weight of the (meth) acrylate compound,
Wherein the photoinitiator comprises 1 to 15 parts by weight of the photoinitiator based on 100 parts by weight of the total of the elastomer, the epoxy compound and the (meth) acrylate compound.
The composition for a barrier layer according to claim 1, wherein the composition for barrier layer has a viscosity change ratio of 5%
<Formula 1>
Viscosity change rate = | V1 - V0 | V0 x 100
(In the above formula 1, V0 represents an initial viscosity (unit: cps) of the composition for a barrier layer at 25 deg. C,
V1 is the viscosity (unit: cps) at 25 캜 after the barrier layer composition is left at 25 캜 for one week.
Barrier layer; And a polarizer and a protective layer are sequentially laminated on one surface of the barrier layer,
Wherein the barrier layer is formed of the composition for a barrier layer according to any one of claims 1 to 8.
The polarizer according to claim 9, wherein the polarizer has a temperature of -40 ° C to 85 ° C for 30 minutes, a temperature of 85 ° C for 30 minutes, a cycle of 100 cycles, Wherein the maximum crack length is 2 mm or less.
The polarizing plate according to claim 9, wherein the protective layer has a water permeability of 30 g / m ² .24 hr or less.
The polarizing plate according to claim 9, wherein the protective layer is a polyester resin.
The method as claimed in claim 9, further comprising the step of forming an adhesive layer on the other surface of the barrier layer,
Wherein the pressure-sensitive adhesive layer has a modulus of 0.1 MPa or less at 25 占 폚.
An optical display device comprising the polarizing plate of claim 9.

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