KR20120091854A - Adhesive composition, polarizing plate and liquid crystal display device comprising the same - Google Patents

Abstract

PURPOSE: An adhesive composition is provided not to leak ionic compounds under high temperature and high humidity environment, maintaining durability and adhesion, and to restrain crystallization of an ionic compound at the same time. CONSTITUTION: An adhesive composition comprises an ionic solid in chemical formula 1 as an acrylic copolymer, a crosslinking agent, and an antistatic agent. The adhesive composition comprises 0.1-10 parts by weight of an ionic solid based on 100.0 parts by weight of the acrylic copolymer on the basis of solid phase content. A polarizer comprises a pressure-sensitive layer consisting of the adhesive composition. A liquid crystal display comprises the polarizer on at least one side of a liquid crystal cell.

Description

Adhesive composition, polarizing plate and liquid crystal display including the same {ADHESIVE COMPOSITION, POLARIZING PLATE AND LIQUID CRYSTAL DISPLAY DEVICE COMPRISING THE SAME}

The present invention relates to a pressure-sensitive adhesive composition, a polarizing plate and a liquid crystal display including the same, which can greatly improve the antistatic property without causing a problem of leakage of the ionic compound in a high temperature or high temperature and high humidity environment.

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

In general, the polarizing plate is a polarizer protective film represented by triacetyl cellulose (TAC) on one surface of a polyvinyl alcohol (PVA) polarizer and a surface protective film is laminated as needed, the polarizer protective film on the other side , A pressure-sensitive adhesive layer and a release film for bonding to the liquid crystal cell is a multi-layer structure laminated in 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. Since the release film and the surface protection film are made of a plastic material having high electrical insulation, static electricity is generated when the peeling is removed. do. The static electricity generated in this way may cause foreign matter to be adsorbed on the optical member to contaminate the surface, staining due to distortion of the liquid crystal alignment, and damage to the thin film transistor circuit.

In order to solve the above problems, an adhesive having an ionic compound added thereto was used. Japanese Laid-Open Patent Publication No. 2006-11365 discloses a pressure-sensitive adhesive composition containing an ionic liquid in a liquid state at room temperature as an ionic compound. However, the ionic liquid has a disadvantage in that the ionic liquid is leaked to the outside under high temperature or high temperature and high humidity environment. In consideration of this, an ionic solid having a high melting point as an ionic compound at room temperature has been proposed. However, ionic solids having a high melting point, for example, a melting point of 50 ° C. or higher, have high crystallinity and may be crystallized under high temperature or high temperature and high humidity conditions, and thus, dispersibility may be lowered, thereby causing deterioration of antistatic property.

An object of the present invention is to provide a pressure-sensitive adhesive composition which can improve the antistatic performance while maintaining the physical properties of the pressure-sensitive adhesive, there is no fear of leakage of the ionic compound in a high temperature or high temperature and high humidity environment and good dispersibility.

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

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

1.A pressure-sensitive adhesive composition comprising an ionic solid of Formula 1 as an acrylic copolymer, a crosslinking agent, and an antistatic agent:

2. In the above 1, the pressure-sensitive adhesive composition containing 0.1 to 10 parts by weight of the ionic solid based on 100 parts by weight of the acrylic copolymer based on the solid content.

3. Polarizing plate of the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of 1 or 2 above.

4. Liquid crystal display device provided with the above polarizing plate on at least one side of the liquid crystal cell.

The pressure-sensitive adhesive composition according to the present invention, while maintaining durability and adhesion, does not cause the problem of spilling the ionic compound under a high temperature or high temperature and high humidity environment, while the crystallization of the ionic compound is suppressed and the dispersibility in the pressure-sensitive adhesive is antistatic Can greatly improve.

In addition, 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, a polarizing plate and a liquid crystal display including the same, which can greatly improve the antistatic property without causing a problem of leakage of the ionic compound in a high temperature or high temperature and high humidity environment.

Hereinafter, the present invention will be described in detail.

The pressure-sensitive adhesive composition of the present invention includes an acrylic copolymer, a crosslinking agent, and an antistatic agent, and in particular, an ionic solid of the following Chemical Formula 1 as an antistatic agent:

[Formula 1]

.

.

The acrylic copolymer may be a copolymer of a monomer having a functional group capable of crosslinking with a (meth) acrylate monomer having an alkyl group having 1 to 12 carbon atoms as an adhesive resin. Here, (meth) acrylate means both acrylate and methacrylate.

As a (meth) acrylate type monomer which has a C1-C12 alkyl group, n-butyl (meth) acrylate, 2-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) Acrylate, 2-ethylbutyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, pentyl (meth) acryl Late, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate These can be mentioned, These can be used individually or in mixture of 2 or more types. Among these, n-butyl acrylate, 2-ethylhexyl acrylate, or a mixture thereof is preferable.

The (meth) acrylate monomer having an alkyl group having 1 to 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 to prepare the acrylic copolymer. It is good to be%. If the content is less than 80% by weight, the adhesive force is not sufficient, and when the content is more than 99% by weight, cohesion may be lowered.

Examples of the monomer having a crosslinkable functional group include a hydroxy group, a monomer having a carboxyl group, a monomer having an amide group, a monomer having a tertiary amine group, and the like. Or it can mix and use 2 or more types.

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.

As a monomer which has a carboxy group, Monovalent acids, such as (meth) acrylic acid and a crotonic acid; Diacids such as maleic acid, itaconic acid and fumaric acid, and monoalkyl esters thereof; 3- (meth) acryloylpropionic acid; Succinic anhydride ring-opening adduct of 2-hydroxyalkyl (meth) acrylate with 2-3 carbon atoms of an alkyl group, Succinic anhydride ring opening adduct of hydroxyalkylene glycol (meth) acrylate with 2-4 carbon atoms of an alkylene group And a compound obtained by ring-opening addition of succinic anhydride to a caprolactone adduct of 2-hydroxyalkyl (meth) acrylate having 2 to 3 carbon atoms of an alkyl group, among which acrylic acid is preferred.

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

Monomers having a tertiary amine group include N, N- (dimethylamino) ethyl (meth) acrylate, N, N- (diethylamino) ethyl (meth) acrylate, and N, N- (dimethylamino) propyl (meth ) Acrylates and the like.

It is preferable that the monomer which has a crosslinkable functional group is contained in 1 to 20 weight% with respect to 100 weight% of total monomers used for manufacture of an acryl-type copolymer, More preferably, it is 1 to 10 weight%. If the content is less than 1% by weight cohesion may be lowered, if more than 20% by weight may be reduced cohesion.

In addition, other polymerizable monomers in addition to the monomers may be further included in a range that does not lower the adhesion, such as 10% by weight or less.

The production method of the copolymer is not particularly limited, and may be prepared using a method 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 the polymerization, may be used.

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

A crosslinking agent is a component for strengthening the cohesion force of an adhesive by crosslinking a copolymer suitably, The kind is not specifically limited. For example, an isocyanate type compound, an epoxy type compound, etc. are mentioned, These can be used individually or in mixture of 2 or more types.

As the isocyanate compound, 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; Diisocyanate obtained from 2 moles of an adduct obtained by reacting 3 moles of a diisocyanate compound with 1 mole of a polyhydric alcohol compound such as trimethylolpropane, an isocyanurate obtained by self-condensing 3 moles of the diisocyanate compound, and 3 moles of the diisocyanate compound And polyfunctional isocyanate compounds containing three functional groups such as biuret, triphenylmethanetriisocyanate, and methylenebistriisocyanate, in which the remaining 1 mole of diisocyanate is condensed to 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, and polypropylene glycol. Diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polytetramethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, Diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, resorcin diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, trimethylolpropanetriglycidyl ether, pentaerythritol Polyglycidyl ether, sorbitol polyglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, tris (glycidyl) isocyanur Tris (glycidoxyethyl) isocyanurate, 1,3-bis (N, N-glycidylaminomethyl) cyclohexane, N, N, N ', N'-tetraglycidyl-m- Xylylenediamine etc. are mentioned.

Moreover, melamine type compound can be used individually or in mixture of 2 or more types together with an isocyanate type compound and an epoxy type compound.

Hexamethylol melamine, hexamethoxymethylmelamine, hexabutoxymethylmelamine, etc. are mentioned as a melamine type compound.

The crosslinking agent is preferably included in an amount of 0.1 to 15 parts by weight, and more preferably 0.1 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, the cohesion force becomes small due to insufficient crosslinking degree, which may cause durability deterioration such as lifting and damage of cutting property. If the content is more than 15 parts by weight, problem of relaxation of residual stress may occur due to excessive crosslinking reaction. have.

The present invention includes an ionic solid formed by ion combination of a cation and an anion as an antistatic agent, and in particular, N-butyl-3-methylpyridinium hexafluorophosphate which is an ionic solid represented by the formula (1). It is done.

By ionic solid is meant salts in the solid state at room temperature, such as about 25 ° C. Ionic liquids, which are liquid at room temperature, may precipitate as solids in environments below their melting point, or may flow out of the environment under high temperature or high temperature and high humidity conditions. The ionic liquid deposited or leaked in this way may deteriorate other optical members, metal members, or the like. However, since the antistatic agent of the present invention is an ionic solid, the above problems can be prevented.

The cation constituting the ionic solid of Formula 1 can prevent crystallization by the methyl group being substituted at the meta position, especially in the pyridine, so that the ionic solid is amorphous in the pressure-sensitive adhesive composition even under high temperature or high temperature and high humidity environment. It is well dispersed in form. At the same time, the butyl group is bonded to the nitrogen atom, so that the molecular weight is controlled to be relatively low compared to other types of ionic solids so that the number of moles of the antistatic agent is higher than the solid content. Through this, the antistatic property can be greatly improved.

[Formula 1]

It is preferable that melting | fusing point of an antistatic agent is 40 degreeC or more and less than 50 degreeC. In the case of having such a melting point, the crystallinity is not high, and it does not crystallize in a high temperature or a high temperature and high humidity environment, and thus dispersibility and antistatic property can be ensured.

The antistatic agent is preferably included in an amount of 0.1 to 10 parts by weight, and 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 parts by weight, it may be difficult to give sufficient antistatic properties, and if it exceeds 10 parts by weight, bubbles or peeling may occur and durability may be reduced.

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

The kind of the silane coupling agent is not particularly limited, and for example, vinylchlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxy Propyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-metha Krilloxypropyl triethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyl diethoxysilane, 3-acryloxypropyl trimethoxysilane , N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyl Methyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethylbutylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyl Dimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3-isocyanatepropyltriethoxysilane, and the like. These can be used individually or in mixture of 2 or more types.

The silane coupling agent may be included in an amount of 0 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer based on the solid content, preferably 0.005 to 5 parts by weight. If the content is more than 10 parts by weight, durability may be reduced.

In addition to the above components, the pressure-sensitive adhesive composition is a tackifying resin, antioxidant, corrosion inhibitor, leveling agent, surface lubricant, dye, pigment in order to adjust the adhesion, cohesion, viscosity, modulus, glass transition temperature, etc. required according to the application It may further include additives such as antifoaming agent, filler, light stabilizer.

The pressure-sensitive adhesive composition of the present invention configured as described above contains an ionic solid of Formula 1 as an antistatic agent, which does not cause a problem of spilling the ionic compound under high temperature or high temperature and high humidity conditions, and at the same time suppresses crystallization of the ionic solid and Good dispersibility of the antistatic property can be greatly improved.

The pressure-sensitive adhesive composition of the present invention can be used both as a pressure-sensitive adhesive for surface protection film as well as pressure-sensitive adhesive for polarizing plate for bonding with a liquid crystal cell. In addition, it can be used as a protective film, a reflective sheet, a structural adhesive sheet, a photo adhesive sheet, a lane display adhesive sheet, an optical adhesive product, an adhesive for an electronic component, as well as a general commercial adhesive sheet product and a medical patch.

The polarizing plate of the present invention is characterized in that an adhesive layer made of an adhesive composition is laminated.

The thickness of the pressure-sensitive adhesive layer can be adjusted according to the adhesive force, it is usually preferably 3 to 100㎛, more preferably 10 to 100㎛.

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 on which an adhesive layer is laminated is bonded to at least one surface of a liquid crystal cell can be configured.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but these examples are merely illustrative of the present invention and are not intended to limit the scope of the appended claims. It is apparent to those skilled in the art that various changes and modifications can be made to the present invention, and such modifications and changes belong to the appended claims.

Example

Preparation 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-hydroxyethyl methacrylate (2-HEMA) in a 1 L reactor equipped with a refrigeration system for easy reflux of nitrogen gas ) After adding a monomer mixture consisting of 0.5 parts by weight, 100 parts by weight of ethyl acetate (EA) was added as a solvent. Thereafter, nitrogen gas was added for 1 hour to remove oxygen, and then the temperature was maintained at 62 ° C. After stirring the monomer mixture uniformly, 0.07 parts 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

100 parts by weight of the acrylic copolymer prepared in Preparation Example 1 based on the solid content, 0.5 parts by weight of tolylene diisocyanate adduct of trimethylolpropane (COR-L, Japan Polyurethane Industry) as a crosslinking agent, 3- as a silane coupling agent 0.3 parts by weight of glycidoxypropyltrimethoxysilane (KBM-403, Shin-Etsu) and an ionic solid N-butyl-3-methylpyridinium hexafluorophosphate having a melting point of 45 ° C. After mixing the parts, the coating composition was diluted to an appropriate concentration to prepare a pressure-sensitive adhesive composition.

(2) adhesive sheet

The pressure-sensitive adhesive composition was dried on a film coated with a silicone release agent and then applied to have a thickness of 25 μm, and dried at 100 ° C. for 1 minute to form a pressure-sensitive adhesive layer. An adhesive sheet was prepared by laminating another release film thereon.

(3) polarizing plate with pressure-sensitive adhesive

After peeling the release film of the prepared pressure-sensitive adhesive sheet, the pressure-sensitive adhesive layer was laminated on an iodine-based polarizing plate having a thickness of 185 μm, and then fully aged at 23 ° C. and 55% RH for 7 days to prepare a pressure-sensitive adhesive polarizing plate.

Example  2

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

Example 3

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

Example 4

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

Comparative Example 1

The same procedure as in Example 1, except that 2 parts by weight of an ionic solid N-hexylpyridinium hexafluorophosphate having a melting point of 45 ° C instead of N-butyl-3-methylpyridinium hexafluorophosphate as an antistatic agent It was.

Comparative Example 2

In the same manner as in Example 1, 2 parts by weight of an ionic liquid (HQ-115, 3M) was used instead of N-butyl-3-methylpyridinium hexafluorophosphate as an antistatic agent.

Comparative Example 3

In the same manner as in Example 1, 2 parts by weight of N-hexyl-3-methylpyridinium hexafluorophosphate having a melting point of 25 ° C instead of N-butyl-3-methylpyridinium hexafluorophosphate as an antistatic agent It was.

The components and contents of the compositions prepared in Examples and Comparative Examples are shown in Table 1 below. At this time, 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 physical properties of the pressure-sensitive adhesive composition, pressure-sensitive adhesive sheet and pressure-sensitive adhesive polarizing plate prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 2 below.

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

After peeling the release film of the prepared pressure-sensitive adhesive polarizing plate, three points of the pressure-sensitive adhesive layer were measured 5 times by using a surface resistance measuring instrument (MCP-HT450, Mitsubishi Chemical Co., Ltd.), and the average values were indicated.

2. Durable ( Heat resistance )

The prepared pressure-sensitive adhesive polarizing plate was cut to a size of 90 mm x 170 mm, the release film was peeled off, and the specimens were prepared by attaching the optical absorption axis perpendicular to both surfaces of the glass substrate (110 mm x 190 mm x 0.7 mm). At this time, the applied pressure was 5kg / ㎠ and the clean room work so as not to generate bubbles or foreign matter. The heat and humidity resistance was observed for 1000 hours at a temperature of 60 ° C. and a humidity condition of 90% RH, and then bubbles or peeling were observed. At this time, it was observed after leaving for 24 hours at room temperature immediately before evaluating the state of the specimen, and evaluated based on the following criteria.

<Evaluation Criteria>

Ⓞ: No bubbles or peeling.

○: Bubbles or peeling <5

△: 5 ≤ air bubbles or exfoliation <10

×: 10 ≤ air bubbles or peeling

3. Adhesion (N / 25㎜)

The prepared pressure-sensitive adhesive polarizing plate was cut into a size of 25 mm × 100 mm, the release film was peeled off, and then laminated on a glass substrate (# 1737, Corning) at a pressure of 0.25 MPa, and autoclaved at 50 ° C. and 5 atmospheres for 20 minutes. The specimen was prepared by the clave treatment. After the prepared specimens were left for 24 hours at 23 ° C. and 50% RH, and for 48 hours at 50 ° C. and 50% RH, the peel rate was 10 m / min using a universal tensile tester (UTM, Instron). And adhesive force at the time of peeling at 180 degree peeling angle were measured. At this time, the measurement was carried out at 23 ℃, 50% RH.

4. Dispersibility

The surface resistivity of any five points of the prepared pressure-sensitive adhesive polarizing plate was measured, and the dispersion was confirmed by the deviation of these measured values.

<Evaluation Criteria>

○: deviation ≤ 50%

△: 50% <deviation ≤ 150%

×: 150% <deviation

division Antistatic
(Ω / □) durability Adhesion (N / 25㎜) Dispersibility 23 ℃, 24 hours 50 ° C, 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, according to the present invention, the pressure-sensitive adhesive composition of Examples 1 to 4 including the acrylic copolymer, the crosslinking agent, and the ionic solid of Formula 1 maintains durability and adhesive strength as compared with those of Comparative Examples 1 to 3. It was also confirmed that the dispersibility and antistatic properties were greatly improved.

Claims (4)

Pressure-sensitive adhesive composition comprising an ionic solid of formula 1 as an acrylic copolymer, a crosslinking agent, and an antistatic agent:
[Formula 1]

.
The pressure-sensitive adhesive composition of claim 1, comprising 0.1 to 10 parts by weight of the ionic solid based on 100 parts by weight of the acrylic copolymer based on the solid content.
Polarizing plate in which the pressure-sensitive adhesive layer made of the pressure-sensitive adhesive composition of claim 1 or 2 is laminated.
Liquid crystal display device comprising a polarizing plate of claim 3 on at least one side of the liquid crystal cell.