KR101783209B1 - Adhesive composition, polarizing plate and liquid crystal display device comprising the same - Google Patents

Abstract

.The present invention relates to a pressure-sensitive adhesive composition, a polarizing plate and a liquid crystal display including the same, and more particularly, to an acrylic pressure-sensitive adhesive composition which comprises an acrylic copolymer and a crosslinking agent together with an ionic solid as an antistatic agent, A pressure-sensitive adhesive composition which does not cause a problem of outflow of an ionic compound under a high temperature and high humidity environment, is capable of significantly suppressing the crystallization of an ionic compound and being highly dispersible in a pressure-sensitive adhesive, ≪ / RTI > apparatus:
[Chemical Formula 1]

.

Description

TECHNICAL FIELD [0001] The present invention relates to a pressure-sensitive adhesive composition, a polarizing plate including the same, and a liquid crystal display device using the pressure-

The present invention relates to a pressure-sensitive adhesive composition capable of significantly improving antistatic properties without causing a problem of leakage of an ionic compound under a high-temperature or high-temperature / high-humidity environment, and a polarizing plate and a liquid crystal display including the same.

2. Description of the Related Art A liquid crystal display device (LCD) includes a liquid crystal cell and a liquid crystal panel including a polarizing plate bonded to both sides of the liquid crystal cell via an adhesive layer.

In general, a polarizing plate is formed by laminating a polarizer protective film typified by triacetyl cellulose (TAC) and a surface protective film, if necessary, on one side of a polyvinyl alcohol (PVA) polarizer, A pressure-sensitive adhesive layer for bonding with a liquid crystal cell, and a release film are laminated in this order.

In the process of bonding the polarizing plate having such a structure to the liquid crystal cell, the release film and the surface protection film are peeled off and removed. Since the release film and the surface protection film are made of a plastic material having high electrical insulation property, do. The static electricity generated in this way may cause a problem of contamination of the surface by foreign matter adsorbed on the optical member, a problem of staining due to the distortion of the liquid crystal alignment, and a fear of damaging the thin film transistor line.

In order to solve the above problems, a pressure-sensitive adhesive to which an ionic compound is added is used. Japanese Patent Application Laid-Open No. 2006-11365 discloses a pressure-sensitive adhesive composition containing an ionic liquid which is in a liquid state at room temperature as an ionic compound. However, the ionic liquid has a disadvantage in that the ionic liquid flows out to the outside under high temperature or high temperature / high humidity environment. In consideration of this, an ionic solid having a high melting point and being solid at room temperature has been proposed as an ionic compound. However, an ionic solid having a high melting point, for example, a melting point of 50 ° C or higher, has a high crystallinity and can be crystallized under a high temperature or a high temperature / high humidity environment, thereby deteriorating the dispersibility and lowering the antistatic property.

An object of the present invention is to provide a pressure-sensitive adhesive composition which can maintain the physical properties as a pressure-sensitive adhesive, prevent outflow of an ionic compound under high temperature or high temperature and high humidity, and is excellent in dispersibility and capable of improving antistatic performance.

Another object of the present invention is to provide a polarizing plate in which a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition is laminated.

It is another object of the present invention to provide a liquid crystal display device having the polarizing plate on at least one surface of a liquid crystal cell.

1. A pressure-sensitive adhesive composition comprising an acrylic copolymer, a crosslinking agent, and an ionic solid of the following formula (1) as an antistatic agent:

2. The pressure-sensitive adhesive composition according to 1 above, which comprises 0.1 to 10 parts by weight of an ionic solid based on 100 parts by weight of an acrylic copolymer based on the solid content.

3. A polarizing plate laminated with a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition of the above 1 or 2.

4. A liquid crystal display device comprising a liquid crystal cell having a polarizing plate on at least one side thereof.

The pressure-sensitive adhesive composition according to the present invention does not cause the problem of leakage of the ionic compound under high temperature or high temperature / high humidity environment while maintaining the durability and adhesive strength, but also the crystallization of the ionic compound is suppressed and the dispersibility in the pressure- Can be greatly improved.

Further, the pressure-sensitive adhesive composition of the present invention is low in cost and economical in terms of cost.

The present invention relates to a pressure-sensitive adhesive composition capable of significantly improving antistatic properties without causing a problem of leakage of an ionic compound under a high-temperature or high-temperature / high-humidity environment, and a polarizing plate and a liquid crystal display including the same.

Hereinafter, the present invention will be described in detail.

The pressure-sensitive adhesive composition of the present invention is characterized by containing an acrylic copolymer, a crosslinking agent, and an antistatic agent, particularly an ionic solid of the following general formula (1) as an antistatic agent:

[Chemical Formula 1]

.

.

The acrylic copolymer may be a copolymer of a (meth) acrylate monomer having an alkyl group of 1-12 carbon atoms and a monomer having a crosslinkable functional group as a pressure-sensitive adhesive resin. Here, (meth) acrylate means both acrylate and methacrylate.

Examples of the (meth) acrylate monomer having an alkyl group of 1 to 12 carbon atoms include n-butyl (meth) acrylate, 2-butyl (meth) acrylate, (Meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (Meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl These may be used alone or in combination of two or more. Of these, n-butyl acrylate, 2-ethylhexyl acrylate or a mixture thereof is preferable.

The (meth) acrylate monomer having an alkyl group of 1-12 carbon atoms is preferably contained in an amount of 80 to 99% by weight, more preferably 90 to 95% by weight, based on 100% by weight of the total monomers used in the production of the acrylic copolymer %. When the content is less than 80% by weight, the adhesive strength is not sufficient. When the content is more than 99% by weight, the cohesive strength may be lowered.

The monomer having a crosslinkable functional group is a component which imparts cohesive force or cohesive strength by chemical bonding, and examples thereof include a monomer having a hydroxyl group, a monomer having a carboxyl group, a monomer having an amide group, and a monomer having a tertiary amine group, Or a mixture of two or more thereof.

Examples of the monomer having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl Hydroxypropyleneglycol (meth) acrylate, hydroxyalkylene glycol having 2 to 4 carbon atoms in the alkylene group (e.g., methoxyethyl (meth) acrylate, Methacrylate, etc. Among these, 2-hydroxyethyl (meth) acrylate is preferable.

Examples of the monomer having a carboxyl group include monovalent acids such as (meth) acrylic acid and crotonic acid; Dicarboxylic acids such as maleic acid, itaconic acid, and fumaric acid, and monoalkyl esters thereof; 3- (meth) acryloylpropionic acid; A succinic anhydride ring-opening addition adduct of 2-hydroxyalkyl (meth) acrylate in which the alkyl group has 2 to 4 carbon atoms, anhydrous succinic ring opening adduct of a hydroxyalkylene glycol (meth) acrylate having 2 to 4 carbon atoms in the alkylene group And compounds obtained by ring-opening addition of succinic anhydride to a caprolactone adduct of 2-hydroxyalkyl (meth) acrylate having 2-3 carbon atoms in the alkyl group. Of these, acrylic acid is preferable.

Examples of the monomer having an amide group include (meth) acrylamide, N-isopropylacrylamide and N-tertiarybutylacrylamide. Of these, (meth) acrylamide is preferable.

Examples of the monomer having a tertiary amine group include N, N- (dimethylamino) ethyl (meth) acrylate, N, N- (diethylamino) ethyl (meth) ) Acrylate, and the like.

The monomer having a crosslinkable functional group is preferably contained in an amount of 1 to 20% by weight, more preferably 1 to 10% by weight, based on 100% by weight of the total monomers used in the production of the acrylic copolymer. When the content is less than 1% by weight, the cohesive force may be lowered, and when it is more than 20% by weight, the adhesive strength may be lowered.

In addition, other polymerizable monomers other than the above-mentioned monomers may be further added in such a range as not to lower the adhesive force, for example, 10% by weight or less.

The method for producing the copolymer is not particularly limited and can be produced by methods such as bulk polymerization, solution polymerization, emulsion polymerization or suspension polymerization, which are commonly used in the art, and solution polymerization is preferable. In addition, a solvent, a polymerization initiator, a chain transfer agent for molecular weight control and the like which are usually used in polymerization can be used.

The acrylic copolymer generally has a weight average molecular weight (in terms of polystyrene) measured by gel permeation chromatography (GPC) of usually 50,000 to 2,000,000, preferably 1,000,000 to 2,000,000.

The crosslinking agent is a component for reinforcing the cohesive force of the pressure-sensitive adhesive by properly crosslinking the copolymer, and the kind thereof is not particularly limited. Examples thereof include isocyanate compounds and epoxy compounds, which may be used alone or in combination of two or more.

Examples of the isocyanate compound include tolylene diisocyanate, xylene diisocyanate, 2,4-diphenylmethane diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tetramethyl xylene diisocyanate , Diisocyanate compounds such as naphthalene diisocyanate; An adduct obtained by reacting 3 moles of a diisocyanate compound with 1 mole of a polyhydric alcohol compound such as trimethylolpropane, an isocyanurate compound in which 3 moles of a diisocyanate compound is self-condensed, a diisocyanate obtained from 2 moles of 3 moles of a diisocyanate compound And multifunctional isocyanate compounds containing three functional groups such as burette, triphenylmethane triisocyanate and methylene bistriisocyanate in which the remaining one mole of diisocyanate is condensed in urea.

Examples of the epoxy compound include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol Hexanediol diglycidyl ether, polytetramethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, glycerol diglycidyl ether, glycerol diglycidyl ether, Diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, resorcinol diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, trimethylol propane triglycidyl ether, pentaerythritol Polyglycidyl ether, sorbitol polyglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, tris (glycidyl) isocyanurate N, N ', N'-tetraglycidyl-m-glycidoxyethyl isocyanurate, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, Xylylenediamine, and the like.

In addition, an isocyanate compound, an epoxy compound, and a melamine compound may be used alone or in admixture of two or more.

Examples of the melamine-based compound include hexamethylol melamine, hexamethoxymethyl melamine, and hexabutoxymethyl melamine.

The crosslinking agent is preferably contained in an amount of 0.1 to 15 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the acrylic copolymer based on the solid content. When the content is less than 0.1 parts by weight, the cohesive force becomes small due to insufficient crosslinking, resulting in deterioration of durability such as peeling and deterioration of cutability. If the content is more than 15 parts by weight, excessive crosslinking reaction may cause a problem of relaxation of residual stress have.

In the present invention, it is characterized in that it includes an ionic solid formed by combining ions of anion and cation as an antistatic agent, particularly N-butyl-3-methylpyridinium hexafluorophosphate which is an ionic solid represented by the general formula (1) .

Usually an ionic solid means a salt in a solid state at room temperature, for example at about 25 캜. The ionic liquid in a liquid state at room temperature may be precipitated as a solid in an environment lower than its melting point, or may be outflowed under a high temperature or high temperature / high humidity environment. The ionic liquid precipitated or discharged in this manner may deteriorate other optical members, metal members, and the like. However, since the antistatic agent of the present invention is an ionic solid, the above-described problems can be prevented.

The cation constituting the ionic solid of the formula (1) can prevent the crystallization by substituting the methyl group at the meta position particularly in the pyridine, so that the ionic solid in the pressure-sensitive adhesive composition can be amorphous even under high temperature or high temperature / So that it can be distributed well in the form. At the same time, since the butyl group is bonded to the nitrogen atom, the molecular weight of the ionic solid is controlled to be relatively low as compared with other types of ionic solid, so that the number of moles of the antistatic agent is increased as compared with the solid content. As a result, the antistatic property can be greatly improved.

[Chemical Formula 1]

The antistatic agent preferably has a melting point of from 40 캜 to less than 50 캜. In the case of having such a melting point, crystallinity is not high, and crystallization is not performed under a high temperature or high temperature / high humidity environment, so that good dispersibility and antistatic property can be ensured.

The antistatic agent is preferably contained in an amount of 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the acrylic copolymer based on the solid content. If the content is less than 0.1 part by weight, it may be difficult to give sufficient antistatic property. If the content is more than 10 parts by weight, bubbles or peeling may occur and durability may be deteriorated.

Further, the pressure-sensitive adhesive composition may further include a silane coupling agent.

The kind of the silane coupling agent is not particularly limited, and examples thereof include vinylchlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- 3-glycidoxypropyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, Acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane , N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) Methyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3- Dimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatepropyltriethoxysilane, and the like. These may be used alone or in combination of two or more.

The silane coupling agent may be contained in an amount of 0 to 10 parts by weight, preferably 0.005 to 5 parts by weight, based on 100 parts by weight of the acrylic copolymer based on the solid content. If the content exceeds 10 parts by weight, the durability may be lowered.

In addition to the above components, the pressure-sensitive adhesive composition may further contain additives such as a tackifier resin, an antioxidant, a corrosion inhibitor, a leveling agent, a surface lubricant, a dye, a pigment, and the like in order to control adhesion, cohesion, viscosity, , Defoaming agents, fillers, light stabilizers, and the like.

The pressure-sensitive adhesive composition of the present invention constituted as described above contains an ionic solid of the general formula (1) as an antistatic agent, so that it does not cause the problem of leakage of the ionic compound under high temperature or high temperature / high humidity environment and at the same time, crystallization of the ionic solid is suppressed, So that the antistatic property can be greatly improved.

The pressure-sensitive adhesive composition of the present invention can be used not only as a pressure-sensitive adhesive for a polarizing plate for bonding with a liquid crystal cell but also as a pressure-sensitive adhesive for a surface protective film. In addition, it can be used not only as a protective film, a reflective sheet, a structural adhesive sheet, a photographic adhesive sheet, a lane marking adhesive sheet, an optical adhesive product, an electronic component adhesive, but also a general commercial adhesive sheet product or a medical patch.

The polarizing plate of the present invention is characterized in that a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive composition is laminated.

The thickness of the pressure-sensitive adhesive layer can be adjusted in accordance with the adhesive strength, and is preferably 3 to 100 탆, more preferably 10 to 100 탆.

Such a polarizing plate can be applied to all conventional liquid crystal display devices, and specifically a liquid crystal display device including a liquid crystal panel in which a polarizing plate in which a pressure-sensitive adhesive layer is laminated is bonded to at least one surface of a liquid crystal cell can be constituted.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Example

Production Example 1. Preparation of acrylic copolymer

98.1 parts by weight of n-butyl acrylate (BA), 1.4 parts by weight of acrylic acid (AA), 2 parts by weight of 2-hydroxyethyl methacrylate (2-HEMA) ), And 100 parts by weight of ethyl acetate (EA) was added as a solvent. Thereafter, a nitrogen gas was poured in for 1 hour to remove oxygen, and the temperature was maintained at 62 ° C. After homogeneously stirring the monomer mixture, 0.07 part by weight of azobisisobutyronitrile (AIBN) was added as a reaction initiator and reacted for 8 hours to prepare an acrylic copolymer having a weight average molecular weight of 600,000 or more.

Example 1

(1) Pressure-sensitive adhesive composition

Based on the solid content, 100 parts by weight of the acrylic copolymer prepared in Preparation Example 1, 0.5 part by weight of a toluene diisocyanate adduct of trimethylolpropane (COR-L, manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent, 0.3 part by weight of glycidoxypropyltrimethoxysilane (KBM-403, Shin-Etsu) and 2 parts by weight of an ionic solid N-butyl-3-methylpyridinium hexafluorophosphate represented by Chemical Formula 1 as an antistatic agent and having a melting point of 45 ° C And the mixture was diluted to a proper concentration in consideration of coating properties to prepare a pressure-sensitive adhesive composition.

(2) Pressure-sensitive adhesive sheet

The pressure-sensitive adhesive composition thus prepared was dried on a film coated with silicone release agent, and then applied to a thickness of 25 탆 and dried at 100 캜 for 1 minute to form a pressure-sensitive adhesive layer. And another layer of release film was laminated thereon to produce a pressure-sensitive adhesive sheet.

(3) Polarizer with adhesive

After peeling the release film of the produced pressure sensitive adhesive sheet, the pressure sensitive adhesive layer was laminated on an iodine polarizing plate having a thickness of 185 탆, and the film was aged at 23 캜 and 55% RH for 7 days to complete a polarizing plate with a pressure-sensitive adhesive.

Example  2

0.3 parts by weight of N-butyl-3-methylpyridinium hexafluorophosphate, which is an antistatic agent, was used in the same manner as in Example 1.

Example 3

4.5 parts by weight of N-butyl-3-methylpyridinium hexafluorophosphate, which is an antistatic agent, was used in the same manner as in Example 1.

Example 4

9 parts by weight of N-butyl-3-methylpyridinium hexafluorophosphate, which is an antistatic agent, was used in the same manner as in Example 1.

Comparative Example 1

Except that 2 parts by weight of ionic solid N-hexylpyridinium hexafluorophosphate having a melting point of 45 ° C was used instead of N-butyl-3-methylpyridinium hexafluorophosphate as an antistatic agent Respectively.

Comparative Example 2

Except that 2 parts by weight of an ionic liquid (HQ-115, 3M) was used in place of N-butyl-3-methylpyridinium hexafluorophosphate as an antistatic agent.

Comparative Example 3

Except that 2 parts by weight of N-hexyl-3-methylpyridinium hexafluorophosphate having a melting point of 25 占 폚 was used instead of N-butyl-3-methylpyridinium hexafluorophosphate as an antistatic agent Respectively.

The components and contents of the compositions prepared in the above Examples and Comparative Examples are shown in Table 1 below. Here, the content of each component represents parts by weight.

division Acrylic
Copolymer Cross-linking agent Silane coupling agent Antistatic agent COR-L KBM-403 Ⅰ Ⅱ Ⅲ IV Example 1 100 0.5 0.3 2 - - - Example 2 100 0.5 0.3 0.3 - - - Example 3 100 0.5 0.3 4.5 - - - Example 4 100 0.5 0.3 9 - - - Comparative Example 1 100 0.5 0.3 - 2 - - Comparative Example 2 100 0.5 0.3 - - 2 - Comparative Example 3 100 0.5 0.3 - - - 2 COR-L: Tolylene diisocyanate adduct of trimethylolpropane (Japan Polyurethane Industry)
KBM-403: 3-glycidoxypropyltrimethoxysilane (Shin-Etsu)
I: N-Butyl-3-methylpyridinium hexafluorophosphate
II: N-hexylpyridinium hexafluorophosphate
III: bis (trifluoromethanesulfonyl) imide lithium (HQ115, 3M)
IV: N-hexyl-3-methylpyridinium hexafluorophosphate

Test Example

The properties of the pressure-sensitive adhesive composition, the pressure-sensitive adhesive sheet and the polarizer with a pressure-sensitive adhesive prepared in Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2 below.

1. Antistatic property (surface resistivity, Ω / □)

The prepared release film of the polarizing plate with a pressure-sensitive adhesive was peeled off, and three points of the pressure-sensitive adhesive layer were measured five times each using a surface resistance meter (MCP-HT450, Mitsubishi Chemical Co.).

2. Durability ( Wet heat )

The prepared polarizer with a pressure-sensitive adhesive was cut into a size of 90 mm × 170 mm, and the release film was peeled off. Then, the optical absorption axis was perpendicularly attached to both sides of the glass substrate (110 mm × 190 mm × 0.7 mm). At this time, the applied pressure was 5 kg / cm < 2 >, and the clean room operation was performed so that bubbles or foreign matter would not occur. The wet heat resistance characteristics were observed for 1000 hours after being left under the conditions of a temperature of 60 ° C and a humidity of 90% RH, and then the occurrence of bubbles or peeling was observed. At this time, the sample was allowed to stand at room temperature for 24 hours immediately before evaluation of the state of the specimen, and then observed and evaluated based on the following criteria.

<Evaluation Criteria>

Ⓞ: No bubbles or peeling.

○: Bubbles or peeling <5

?: 5 pieces? Bubbles or peeling <10 pieces

X: 10 pieces &lt; bubble &

3. Adhesion (N / 25 mm)

The prepared polarizing plate with a pressure-sensitive adhesive was cut into a size of 25 mm x 100 mm, the release film was peeled off, laminated on a glass substrate (# 1737, Corning) at a pressure of 0.25 MPa, The specimens were prepared by clave treatment. The prepared specimens were allowed to stand for 24 hours at 23 ° C and 50% RH, and then left for 48 hours under conditions of 50 ° C and 50% RH. Using a universal tensile tester (UTM, Instron) , And the peel strength at 180 deg. Peeling angle was measured. At this time, measurement was carried out at 23 ° C and 50% RH.

4. Dispersibility

The surface resistivity was measured at any five points of the produced polarizer with a pressure-sensitive adhesive, and the dispersibility was confirmed by the deviation of the measured values.

<Evaluation Criteria>

?: Deviation? 50%

?: 50% <deviation? 150%

×: 150% <deviation

division Antistatic property
(Ω / □) durability Adhesive force (N / 25 mm) Dispersibility 23 ℃, 24 hours 50 캜, 48 hours Example 1 4.3 × 10 ¹⁰ ○ 2.0 5.7 ○ Example 2 5.3 × 10 ¹¹ ○ 2.5 7.2 ○ Example 3 1.3 × 10 ¹⁰ ○ 1.7 4.3 ○ Example 4 7.3 × 10 ⁹ △ 1.0 3.1 ○ Comparative Example 1 5.3 × 10 ¹⁰ △ 1.8 5.2 × Comparative Example 2 7.2 × 10 ¹⁰ △ 2.1 6.1 △ Comparative Example 3 4.3 × 10 ¹⁰ × 1.6 5.1 △

As shown in Table 2, the pressure-sensitive adhesive compositions of Examples 1 to 4 including the acrylic copolymer, the crosslinking agent and the ionic solid of the formula (1) according to the present invention exhibited durability and adhesive strength It was confirmed that the dispersibility was good and the antistatic property was also greatly improved.

Claims (4)

A pressure-sensitive adhesive composition comprising an acrylic copolymer, a crosslinking agent, and an ionic solid of the following formula (1) as an antistatic agent:
[Chemical Formula 1]

.
The pressure-sensitive adhesive composition according to claim 1, comprising 0.1 to 10 parts by weight of an ionic solid based on 100 parts by weight of the acrylic copolymer based on the solid content.
A polarizing plate laminated with a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to claim 1 or 2,
Wherein the pressure-sensitive adhesive layer is directly attached on the polarizing plate.
Wherein the polarizing plate of claim 3 is provided on at least one side of the liquid crystal cell.