KR101019062B1 - Acrylic pressure sensitive adhesive compositions - Google Patents

Abstract

The present invention relates to an acrylic pressure-sensitive adhesive composition, more specifically, a) an acrylic copolymer; b) chelating agents capable of forming bonds with metal ions; c) alkali metal salts; And d) relates to an acrylic pressure-sensitive adhesive composition comprising a plasticizer having an ester value of 200 or more, the acrylic pressure-sensitive adhesive composition according to the present invention is excellent in high-speed peeling and wettability without deterioration of adhesive physical properties, sufficiently inhibit the generation of static electricity to prevent antistatic performance This is excellent.

Acrylic, plasticizer, ester value, antistatic, chelate, alkali metal

Description

Acrylic adhesive composition {ACRYLIC PRESSURE SENSITIVE ADHESIVE COMPOSITIONS}

The present invention relates to an acrylic pressure-sensitive adhesive composition, and more particularly, to an acrylic pressure-sensitive adhesive composition excellent in high-speed peelability and wettability without sufficiently reducing adhesive properties and sufficiently suppressing static electricity generation to improve antistatic performance.

In general, static electricity includes friction charges generated when two different objects are rubbed, peeled charges generated when objects in close contact with each other, etc. It may cause a malfunction or fire. In particular, the demand for liquid crystal displays, such as the spread of mobile-type computers, the expansion of the market by the liquid crystal TV, and the mobile phone's multi-function market, has shown remarkable growth. It is important.

As the demand for liquid crystal display devices increases, the demand for films having optical characteristics such as polarizing plates is rapidly increasing. As the demand increases, the manufacturing process of liquid crystal display devices becomes faster. In addition, the major liquid crystal display manufacturers have focused on producing small panels of 20 inches or less so far, but are recently expanding the product range to large sizes of 20 inches or more by actively utilizing new technologies.

In recent years, the surface treatment of a polarizing plate is performed in various ways. The surface treatment of the polarizing plate includes an anti-glare layer, a low refractive layer and / or a high refractive layer, an antifouling layer, and the like, each having a different surface roughness and surface energy. In particular, the anti-glare layer has a rough surface and lower surface energy than the triacetyl cellulose layer, so the wettability of the adhesive is important when the protective film is attached. In addition, as the polarizing plate manufacturing process is speeded up, when the polarizing plate protective film is peeled off, TFT IC device destruction occurs due to static electricity, which is not generated in the conventional process, and causes a defect of the liquid crystal display panel.

There is a method of forming an antistatic layer on the outer surface of the polarizing plate or the outer surface of the protective film base layer in order to prevent the generation of static electricity as described above, but the effect is insignificant and does not fundamentally suppress the generation of static electricity. Therefore, in order to fundamentally suppress the generation of static electricity, an antistatic function is required for the pressure-sensitive adhesive.

As such, conventional techniques for imparting an antistatic function to an adhesive include a method of adding a substance having a conductive component such as conductive metal powder or carbon particles, a method of adding an ionic or nonionic substance in the form of a surfactant, and the like. . However, the method of adding the conductive metal powder or the carbon particles has a problem that transparency is lowered because an excessive amount of the conductive metal powder or the carbon particles must be used in order to impart an antistatic function. In addition, the method of adding an ionic or nonionic substance in the form of a surfactant is susceptible to the influence of humidity, and there is a problem in that the adhesive physical property is degraded due to migration to the adhesive surface.

In addition, static electricity can be removed by installing an antistatic device during the static electricity generation process, but there is a problem of lowering productivity due to the limitation of the antistatic capacity and the process speed being lowered.

On the other hand, Japanese Patent Application Laid-open No. Hei 5-140519 discloses a method of adding ethylene oxide-modified dioctyl phthalic plasticizer to the inside of the pressure-sensitive adhesive to have flexibility, thereby suppressing static electricity generation. However, the method has a problem that the transfer problem to the surface of the polarizing plate occurs, it is difficult to suppress the static electricity generated in the early stage.

Korean Patent Laid-Open Publication No. 2004-0030919 prepared a pressure-sensitive adhesive by adding 5 wt% or more of an organic salt, and attempted to impart an antistatic effect by obtaining an adhesive surface resistivity of 10 ¹³ Ω / □ or less. The method has a problem in that it is impossible to predict the change of the constant voltage due to static electricity generated during peeling by using an expensive organic salt and reducing only surface resistance.

Japanese Patent Application Laid-Open No. 2004-287199 attempts to impart antistatic performance by adding an ion conductive polymer having a hydroxyl group, but reacts with a general crosslinking agent (isocyanate) to change adhesive and rheological properties, thereby preventing antistatic performance and There was a problem that it is difficult to control the adhesive force.

In addition, Japanese Patent Application Laid-Open No. 6-128539 intends to impart antistatic performance by blending a polyether polyol compound and one or more alkali metal salts. However, this method provides a crosslinking degree when the polyether polyol compound is used when the crosslinking agent is an isocyanate. Not only can affect, but also due to the hydrophilicity of the ether bonds, that is, ethylene oxide, there was a problem that the surface transition to lower the adhesiveness.

The present invention is to solve the problems of the prior art as described above, an object of the present invention is to provide an acrylic pressure-sensitive adhesive composition excellent in high-speed peeling and wettability without satisfactory adhesive properties, sufficiently inhibit the generation of static electricity to improve the antistatic performance To provide.

Another object of the present invention is to provide a protective film including an adhesive layer containing an acrylic pressure-sensitive adhesive composition having excellent physical properties as described above.

Still another object of the present invention is to provide a polarizing plate and a liquid crystal display device to which the protective film is applied.

In order to achieve the above object, the present invention is an acrylic pressure-sensitive adhesive composition,

a) acrylic copolymer;

b) chelating agents capable of forming bonds with metal ions; And

c) alkali metal salts; And

d) plasticizers having an ester value of 200 or greater

It provides an acrylic pressure-sensitive adhesive composition comprising a.

The invention is also described; And

A pressure-sensitive adhesive layer formed on one side or both sides of the base material and containing the acrylic pressure-sensitive adhesive composition according to the present invention

It provides a protective film comprising a.

The present invention also comprises a polarizing plate comprising the protective film; And it provides a liquid crystal display device comprising a liquid crystal panel bonded to the polarizing plate on one side or both sides of the liquid crystal cell.

Hereinafter, the present invention will be described in detail.

The present inventors have excellent compatibility with the pressure-sensitive adhesive, chelating agent capable of binding two or more ligands to a metal ion; An alkali metal salt capable of combining with the chelate to form a chelate complex compound; And when using a plasticizer having an ester value of 200 or more in the acrylic pressure-sensitive adhesive at the same time, it was confirmed that not only excellent high-speed peeling and wettability, but also can sufficiently suppress the generation of static electricity without deterioration of adhesive properties.

Therefore, the acrylic pressure-sensitive adhesive composition according to the present invention is a) acrylic copolymer; b) chelating agents capable of forming bonds with metal ions; c) alkali metal salts; And d) a plasticizer having an ester value of 200 or more. Although the content of the chelating agent, the alkali metal salt and the plasticizer is not particularly limited, 0.01 to 25 parts by weight of the chelating agent capable of forming a bond with the metal ion, and an alkali metal salt of 0.001 based on 100 parts by weight of the acrylic copolymer. To 25 parts by weight, and 0.5 to 10 parts by weight of a plasticizer having an ester value of 200 or more.

The acrylic copolymer of a) used in the present invention is not particularly limited as long as it is commonly used as an adhesive in the art,

Iii) 90 to 99.9 parts by weight of a (meth) acrylic acid ester monomer having an alkyl group having 1 to 12 carbon atoms; And

Ii) It is preferable to include 0.1 to 10 parts by weight of at least one monomer selected from the group consisting of a vinyl monomer having a crosslinkable functional group and an acrylic monomer.

The (meth) acrylic acid ester monomer having an alkyl group having 1 to 12 carbon atoms of (i) may be methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-ethylhexyl (meth) with n-butyl (meth) acrylate, t-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, and 2-ethylbutyl (meth) acrylate ) Acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, etc. can be used individually or in mixture of 2 or more types.

The (meth) acrylic acid ester monomer having an alkyl group having 1 to 12 carbon atoms is preferably contained in an amount of 90 to 99.9 parts by weight. When the content is less than 90 parts by weight, the crosslinking density becomes high and the wettability is insufficient. Degradation of cohesion may cause problems in durability.

The vinyl monomer or acrylic monomer having a crosslinkable functional group of ii) acts to impart cohesive force or adhesive strength by chemical bonding so that the cohesive force of the pressure-sensitive adhesive is not broken under high temperature or high humidity by reacting with the crosslinking agent.

Examples of the vinyl monomer or acrylic monomer having a crosslinkable functional group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and 6-hydroxy. Monomers containing a hydroxy group such as hydroxyhexyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate, or 2-hydroxypropylene glycol (meth) acrylate; Monomers containing a carboxyl group such as (meth) acrylic acid, maleic acid, or fumaric acid; Or monomers containing nitrogen such as acrylamide, N-vinyl pyrrolidone, or N-vinyl caprolactam, or the like, may be used alone or in combination of two or more thereof.

At least one monomer selected from the group consisting of a vinyl monomer having a crosslinkable functional group and an acrylic monomer is preferably included in an acrylic copolymer in an amount of 0.1 to 10 parts by weight, and when the content is less than 0.1 part by weight, high temperature or high humidity conditions. There is a problem in that the cohesive failure is easy to occur in the case, when more than 10 parts by weight there is a problem in that the compatibility is reduced to reduce the flow characteristics.

In addition, the present invention preferably comprises a comonomer as an optional component in order to control the glass transition temperature of the pressure-sensitive adhesive or to impart other functionality when producing the acrylic copolymer.

As the comonomer, as the monomer having a copolymerizable vinyl group, any acrylic adhesive resin having a glass transition temperature of −130 to 50 ° C. without crosslinking may be used, but it is preferable to use a vinyl monomer of Formula 1 below. desirable.

Where

R ₄ represents hydrogen or alkyl,

R ₃ represents cyano, alkyl substituted or unsubstituted phenyl, acetyloxy, or COR ₅ , wherein R ₅ represents amino or glycidyloxy unsubstituted or substituted with alkyl.

Preferred examples of the functional monomers include, but are not limited to, acrylonitrile, (meth) acrylamide, N-methylacrylamide, styrene, methylstyrene, glycidyl (meth) acrylate, and vinyl acetate. The monomers may be used alone or in combination.

The acrylic copolymer composed of the above components can be produced by conventional methods such as solution polymerization, photopolymerization, bulk polymerization, suspension polymerization, or emulsion polymerization, and particularly preferably by solution polymerization. Do. At this time, the polymerization temperature is 50 ~ 140 ℃, it is good to mix the initiator in a state where the monomers are uniformly mixed.

The chelating agent capable of forming a bond with the metal ion of b) used in the present invention and the alkali metal salt of c) serve to reduce the generation of static electricity.

The chelating agent of b) used in the present invention is a compound having a functional group capable of forming a bond with a metal ion in its molecular structure, and the chelating agent is a chelate complex stabilized by binding to a cation of a metal salt dissociated into a cation and an anion. To form. Therefore, the anion concentration of the metal salt is increased in the pressure-sensitive adhesive to have an ion conductivity in the pressure-sensitive adhesive composition, and this ion conductivity imparts conductivity to the pressure-sensitive adhesive composition and then adheres to the release film and the adherend of the release film that protects the pressure-sensitive adhesive layer. The peeling voltage is reduced by reducing the static electricity generated when the protective film is peeled off.

It is preferable that the chelating agent has high solubility in ordinary organic solvents, ie, ethyl acetate, toluene, methyl ethyl ketone, acetone, or alcohols, and has excellent compatibility with an acrylic pressure-sensitive adhesive. Specifically, the chelating agent may be used alone or in combination of two or more kinds of compounds having an oxalate group, a diamine group, a polyvalent carboxyl group, or a β-ketone group, and particularly preferably a compound having an oxalate group.

It is preferable that the compound which has the said oxalate group is a compound represented by following formula (2).

In the formula (2),

R ₁ and R ₂ are each independently hydrogen, halogen, linear or branched C1-C20 alkyl group, linear or branched C1-C20 alkoxy group, linear or branched C2-C20 alkenyl group , An aryl group having 6 to 30 carbon atoms, an arylalkyl group having 6 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, or a cycloalkyl group having 5 to 20 carbon atoms.

Specific examples of the compound represented by Formula 2 include diethyl oxalate, dimethyl oxalate, dibutyl oxalate, di-tert-butyl oxalate, or bis (4-methylbenzyl) oxalate.

It is preferable that the compound which has the said diamine group is a compound represented by following formula (3).

In the formula (3),

R <_3> is a linear or branched C1-C10 alkylene group or a linear or branched C2-C10 alkenylene group.

Specific examples of the compound represented by Formula 3 include ethylenediamine, 1,2-diaminopropane, diaminobutane, and the like.

In addition, the compound having a polyvalent carboxyl group is preferably a compound containing a functional group represented by the following formula (4a, 4b, or 4c) as a compound having a polycarboxylic acid or a carboxylate group.

Specific examples of the compound containing a functional group represented by Formula 4a or 4b include ethylenediamine-N, N, N ', N'tetraacetic acid (EDTA), N, N, N', N '', N ''- Diethylenetriaminepentaacetic acid (DTPA), 1,4,7,10-tetraazacyclododecane-N, N ', N' ', N' ''-tetraacetic acid (DOTA), 1,4,7 10-tetraaza cyclododecane-N, N ', N' '-triacetic acid (DO3A), trans (1,2) -cyclohexanodiethylenetriaminepentaacetic acid, or N, N-biscarboxymethylglycine There is this.

Specific examples of the compound including the functional group represented by Formula 4c include the following Formulas 4c-1 to 4c-5.

[Formula 4c-1]

[Formula 4c-2]

[Formula 4c-3]

[Formula 4c-4]

[Formula 4c-5]

On the other hand, the compound having a β-ketone group is preferably a compound represented by the formula (5).

In the formula (5),

R ₇ and R ₈ are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, a linear or branched alkoxy group having 1 to 20 carbon atoms, a linear or branched alkenyl group having 6 to 20 carbon atoms, or 6 to 20 carbon atoms. An aryl group of 30, an arylalkyl group of 6 to 30 carbon atoms, an aryloxy group of 6 to 30 carbon atoms, or a cycloalkyl group of 5 to 20 carbon atoms,

R ₉ is hydrogen or a linear or branched C1-C20 alkyl group, a linear or branched C1-C20 alkoxy group, a linear or branched C1-C20 alkenyl group, or a C6-C30 aryl group , An arylalkyl group having 6 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, or a cycloalkyl group having 5 to 20 carbon atoms.

Specific examples of the compound represented by Formula 5 include 2,4-pentadione, 1-benzoylacetone, ethyl acetoacetate, dimethyl malonate or diethyl malonate.

The chelating agent capable of forming a bond with the metal ion as described above is preferably included in an amount of 0.01 to 25 parts by weight based on 100 parts by weight of the acrylic copolymer. If the content is less than 0.01 parts by weight, there is a problem that the antistatic performance is lowered due to insufficient bonding with the alkali metal salt, and if it exceeds 25 parts by weight, durability reliability is weak due to the decrease in cohesion.

The alkali metal salt of c) used in the present invention includes a metal cation capable of binding to a chelating agent.

The alkali metal salt is preferably a compound in which the metal ion is easily dissociated from the salt when mixed with a solvent or a chelating agent, and the metal ion being dissociated is more preferable as the ion radius is small and the dissociation energy is small.

Specifically, lithium, sodium, potassium, magnesium, calcium, barium, or cesium ions may be used as the cation of the alkali metal salt, and as anions of the metal salt, Cl ⁻ , Br ⁻ , I ⁻ , BF ₄ ⁻ , _{^{PF 6 -, AsF 6 -,}} ClO 4 -, NO 2 -, CO 3 -, N (CF 3 SO 2) 2 -, N (CF 3 CO) 2 -, N (C 2 F 5 SO 2) 2 - _{, N (C 2 F 5 CO} ) 2 -, N (C 4 F 9 SO 2) 2 -, C (CF 3 SO 2) 3 -, or CF ₃ SO ₃ ^- and the like can be used.

The alkali metal salt is preferably included in an amount of 0.001 to 25 parts by weight based on 100 parts by weight of the acrylic copolymer. If the content is less than 0.001 parts by weight, there is a problem that the antistatic performance is lowered due to insufficient bonding with the chelating agent. If the content is more than 25 parts by weight, crystallization occurs, transparency is poor, and durability is weak. .

The additive of d) used in the present invention is a plasticizer having an ester value of 200 or more. The ester value is defined as the number of mg of potassium hydroxide required to completely saponify the ester contained in 1 g of sample. When the plasticizer having the above ester value of 200 or more is mixed with the acrylic copolymer, the compatibility is very good, there is almost no surface migration to the adherend, there is no change in adhesive properties, and the adherend has a rough surface roughness by softening the acrylic copolymer. The wettability is excellent even when adhered to, and the mixing of fine bubbles is significantly reduced.

The plasticizer having an ester value of 200 or more is preferably contained in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer, and when the content is less than 0.5 parts by weight, the wettability on the surface of the adherend is insufficient and may exceed 10 parts by weight. In this case, the adhesive physical properties are lowered and are not suitable for the purpose of the present invention.

In the composition according to the present invention, a plasticizer having an ester value of 200 or more can be used without limitation, and specific examples include dibutyl phthalate (DBP, ester value 400 to 406), trioctyl trimellitate (TOTM, ester value 303 to 311). ), Bis (2-butoxyethyl) phthalate (DBEP, ester value 301-311), diisononyladipic acid (DINA, ester value 276-284), bis (2-butoxyethyl) adipic acid (ester value 320 330), or acetyltributyl citrate (ATBC, ester value 552-560).

As described above, the acrylic pressure-sensitive adhesive composition of the present invention including an acrylic copolymer, a chelating agent capable of forming a bond with a metal ion, an alkali metal salt, and a plasticizer having an ester value of 200 or more may additionally add a polyoxyalkylene-based compound. have. By adding the polyoxyalkylene compound to the acrylic copolymer, a small amount of the antistatic component is transferred to the surface of the adherend, thereby lowering the peeling electrification voltage when the protective film is peeled off. Specific examples of the polyoxyalkylene-based compound include polyethylene oxide, polypropylene oxide, or polyethylene oxide-propylene oxide copolymer.

The polyoxyalkylene compound is preferably a number average molecular weight of 500 to 10,000. If the molecular weight is less than 500, the amount of transfer to the surface of the adherend increases and there is a possibility of surface contamination. If the molecular weight exceeds 10,000, compatibility with the acrylic copolymer is lowered. The polyoxyalkylene compound is preferably included in an amount of 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the acrylic copolymer. When the content is less than 0.001, the effect of lowering the peeling electrification voltage more effectively is insignificant. It may contaminate the surface and reduce adhesiveness.

As described above, the acrylic pressure-sensitive adhesive composition of the present invention including an acrylic copolymer, a chelating agent capable of forming a bond with a metal ion, an alkali metal salt, and a plasticizer having an ester value of 200 or more may further include a crosslinking agent.

The crosslinking agent may adjust the adhesive properties of the pressure-sensitive adhesive according to the amount used, and serves to improve the cohesive force of the pressure-sensitive adhesive by reacting with a carboxyl group or a hydroxyl group.

The crosslinking agent may be an isocyanate compound, an epoxy compound, an aziridine compound, a metal chelate compound or the like, and particularly preferably an isocyanate compound.

Specifically, the isocyanate compound is tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isoform diisocyanate, tetramethyl xylene diisocyanate, naphthalene diisocyanate, or trimethylolpropane thereof Reactants with polyols and the like can be used.

The epoxy compound is ethylene glycol diglycidyl ether, triglycidyl ether, trimethylol propane triglycidyl ether, N, N, N ', N'- tetraglycidyl ethylenediamine, or glycerin diglycidyl ether Etc. can be used.

The aziridine-based compound is N, N'-toluene-2,4-bis (1-aziridinecarboxide), N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxide) ), Triethylene melamine, bisisoprotaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, or the like can be used.

The metal chelate compound may be a compound in which a polyvalent metal such as aluminum, iron, zinc, tin, titanium, antimony, magnesium, or vanadium is coordinated with acetylacetone or ethyl acetoacetate.

The multifunctional crosslinking agent is preferably included in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the acrylic copolymer, and when the content is less than 0.1 parts by weight, it does not provide sufficient cohesive force, thereby deteriorating high-speed peeling property and exceeding 10 parts by weight. In this case, there is a problem in that the wettability to the adherend is greatly reduced due to deterioration of the point and adhesive properties.

In addition, the acrylic pressure-sensitive adhesive composition of the present invention, if necessary, additives such as tackifier resins, acrylic low molecular weight materials, epoxy resins, curing agents, UV stabilizers, antioxidants, colorants, reinforcing agents, fillers, antifoaming agents, surfactants, foaming agents, and organic salts. Can be used additionally.

The method for producing the acrylic pressure-sensitive adhesive composition of the present invention comprising the above components is not particularly limited, and in this case, the multifunctional crosslinking agent is homogeneous only when the functional group crosslinking reaction of the crosslinking agent is hardly occurred in the compounding process for forming the pressure-sensitive adhesive layer. Coating work can be performed. When the coating is finished and dried and aged, a crosslinked structure is formed, thereby obtaining an adhesive layer having strong elasticity and cohesive force.

It is preferable that the acrylic pressure-sensitive adhesive composition of the present invention as described above has a crosslinking density of 90% or more, and when the crosslinking density is less than 90%, there is a problem that high-speed peeling property is lowered.

In addition, the present invention; And

A pressure-sensitive adhesive layer formed on one side or both sides of the base material and containing the acrylic pressure-sensitive adhesive composition according to the present invention

It relates to a protective film comprising a.

The protective film is composed of a substrate and an adhesive layer as a layer for protecting the surface of the optical film, preferably the polarizing plate.

The base film is not particularly limited, but may include a polyester film such as cellulose, polycarbonate, or polyethylene terephthalate having transparency; Polyether based films such as polyethersulfone; Or polyolefin-based films such as polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, or ethylene propylene copolymers.

The transparent substrate film may be a single layer or a lamination of two or more layers, and the thickness thereof may also be appropriately selected depending on the application, but is preferably 5 to 500 μm, more preferably 10 to 100 μm.

In addition, the transparent base film may be subjected to surface treatment or primer treatment on one or both sides in order to improve the adhesion of the substrate with the adhesive, as well as antistatic layer, or antifouling layer may be provided.

The method for forming the pressure-sensitive adhesive layer on the base film as described above is not particularly limited. For example, a method of applying and drying the pressure-sensitive adhesive using a bar coater or the like directly on the surface of the base film, applying the pressure-sensitive adhesive to the surface of the peelable base material and drying After this, a method of transferring and aging the pressure-sensitive adhesive layer formed on the surface of the peelable substrate to the substrate film may be applied. At this time, it is preferable that the thickness of an adhesion layer is 2-100 micrometers, More preferably, it is 5-50 micrometers. If the thickness is out of the above range, it is difficult to obtain a uniform adhesive layer and there is a problem that the physical properties of the adhesive film become nonuniform.

The invention also provides a polarizing film or polarizing element; And

Protective film according to the present invention

It relates to a polarizing plate comprising a.

The polarizing film or the polarizing element constituting the polarizing plate is not particularly limited. For example, the polarizing film may be a film made by drawing a polyvinyl alcohol-based resin by stretching a polarizing component such as iodine or dichroic dye. It may be used, the thickness of these polarizing film is also not particularly limited, it can form a conventional thickness. In this case, the polyvinyl alcohol-based resin may be polyvinyl alcohol, polyvinyl formal, polyvinyl acetal and ethylene, saponified product of vinyl acetate copolymer.

On both sides of the polarizing film, a cellulose-based film such as triacetal cellulose, a polycarbonate film, a polyester-based film such as polyethylene terephthalate, a polyether sulfone-based film, polyethylene, polypropylene, cyclo-based or polyolefin-based having a norbornene structure And a multilayer film in which protective films such as polyolefins such as ethylene propylene copolymer are laminated. At this time, the thickness of these protective films is also not particularly limited, and may form a conventional thickness.

In addition, in the polarizing plate of the present invention as described above, one or more layers that provide additional functions such as a protective layer, a reflective layer, an antiglare layer, a retardation plate, a wide viewing angle compensation film, or a brightness enhancement film may be stacked. According to the protective film can be applied to the functional layer.

On the other hand, the acrylic pressure-sensitive adhesive composition of the present invention is an industrial sheet, in particular a protective film, a cleaning sheet, a reflective sheet, a structural adhesive sheet, a photo adhesive sheet, a lane display adhesive sheet, an optical adhesive product, an adhesive for electronic parts, etc. It can be used, of course, the multi-layer laminate product, that is, a general commercial adhesive sheet products, medical patches, heat activated pressure sensitive adhesives (such as heat activated pressure sensitive adhesives) can also be applied to the same application field of course.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited to the following examples.

Preparation Example 1 Preparation of Acrylic Copolymer

94.0 parts by weight of 2-ethylhexyl acrylate (2-EHA), 4.0 parts by weight of n-butyl acrylate (BA), and 2- in a 1 L reactor equipped with a refrigeration system for reflux of nitrogen gas and for easy temperature control. After the monomer mixture consisting of 2.0 parts by weight of hydroxyethyl acrylate (2-HEA) was added, 100 parts by weight of ethyl acetate (EAc) was added as a solvent. Then, after purging nitrogen gas for 1 hour to remove oxygen, it was maintained at 55 ℃. To the mixture was added 0.05 part by weight of azobisisobutyronitrile (AIBN) diluted to 50% concentration in ethyl acetate as a reaction initiator, and reacted for 8 hours to prepare an acrylic copolymer.

Preparation Example 2 Preparation of Antistatic Solution A

10 parts by weight of dibutyl oxalate as a chelating agent, 2.6 parts by weight of alkali metal salt LiClO ₄ and 50 parts by weight of methyl ethyl ketone were added thereto, and stirred at room temperature for 1 hour or more to prepare an antistatic agent solution.

Preparation Example 3 Preparation of Antistatic Agent Solution b

10 parts by weight of dibutyl oxalate, a chelating agent, 1.8 parts by weight of alkali metal salt LiTFSI (Lithium (Bis) Trifluoromethanesulfonimide), and 47 parts by weight of methyl ethyl ketone were added to the flask, and stirred at room temperature for 1 hour or more to prepare an antistatic agent solution.

Preparation Example 4 Preparation of Antistatic Solution C

10 parts by weight of diethyl oxalate, a chelating agent, 10 parts by weight of alkali metal salt LiTFSI, and 80 parts by weight of methyl ethyl ketone were added to the flask, followed by stirring at room temperature for 1 hour or more to prepare an antistatic agent solution.

Preparation Example 5 Preparation of Antistatic Solution D

An antistatic agent solution was prepared by adding 10 parts by weight of diethylmalonate as a chelating agent, 4.5 parts by weight of alkali metal salt LiTFSI, and 58 parts by weight of methylethylketone at room temperature for at least 1 hour.

Preparation Example 6 Preparation of Antistatic Solution e

10 parts by weight of polyethylene glycol (molecular weight 1000), 1.0 parts by weight of alkali metal salt LiClO ₄ , and 90 parts by weight of methyl ethyl ketone were added to the flask, and stirred at room temperature for 1 hour or more to prepare an antistatic agent solution.

Example  One

100 parts by weight of the acrylic copolymer prepared above, 3.0 parts by weight of a prepolymer (HDI) of hexamethylene diisocyanate as a crosslinking agent, 1.0 part by weight of an antistatic agent solution, and trioctyl trimellitate (TOTM) 2.0 having an ester value of 303 to 311. After adding the parts by weight, diluted to an appropriate concentration, mixed uniformly, and then coated on one surface of a biaxially stretched polyethylene terephthalate film having a thickness of 38 ㎛, dried to prepare a uniform adhesive layer of 20 ㎛.

(Plywood process)

The release film was laminated on the adhesive layer coated on one side of the polyethylene terephthalate film, and stored for 4 days at a temperature of 40 ° C. for sufficient aging.

The protective film prepared as described above was cut to an appropriate size and attached to the triacetyl cellulose side of the polarizing plate (TAC film, Japan Fuji Film) and the antiglare layer side (AG TAC, Japan DNP, surface roughness 0.3), respectively. Used.

Example  2

A sample was prepared in the same manner as in Example 1, except that 0.5 parts by weight of b was added instead of the antistatic agent a.

Example  3

In Example 1, 0.5 parts by weight of b was added instead of antistatic agent a, and 3.0 parts by weight of dibutyl phthalate (DBP) having an ester value of 400 to 406 was added instead of trioctyl trimellitate. .

Example  4

In Example 1, c was added 1.0 parts by weight of the antistatic agent a, and 3.0 parts by weight of acetyltributyl citrate (ATBC) having an ester value of 552 to 560 was added instead of trioctyl trimellitate. Produced.

Example  5

In Example 1, 1.0 parts by weight of d was added instead of antistatic agent a, and 3.0 parts by weight of acetyltributyl citrate having an ester value of 552 to 560 was added instead of trioctyl trimellitate.

Example  6

A sample was prepared in the same manner as in Example 3, except that 0.05 parts by weight of polypropylene oxide (number average molecular weight 2,000) was additionally added.

Comparative example  One

100 parts by weight of the acrylic copolymer prepared above, 3.0 parts by weight of prepolymer (HDI) of hexamethylene diisocyanate as a crosslinking agent, diluted to an appropriate concentration, mixed uniformly, and then coated on one side of a biaxially stretched polyethylene terephthalate film having a thickness of 38 μm. After coating to dry to prepare a uniform adhesive layer of 20 ㎛ and then produced a sample through the plywood process.

Comparative example  2

A sample was prepared in the same manner as in Example 1 except that 20.0 parts by weight of trioctyl trimellitate having an ester value of 303 to 311 was added.

Comparative example  3

A sample was prepared in the same manner as in Example 2, except that 3.0 parts by weight of C-100 (New Ewha Co., Ltd.) having an ester value of 147 to 161 was added.

Comparative example  4

A sample was prepared in the same manner as in Example 2, except that 0.5 parts by weight of e was added instead of the antistatic agent b.

division
Example Comparative example One 2 3 4 5 6 One 2 3 4 Acrylic Copolymer 100 100 100 100 100 100 100 100 100 100
Daejeon
Inhibitor
solution a 1.0 1.0 b 0.5 0.5 0.5 0.5 c 1.0 d 1.0 e 0.5

Plasticizer

TOTM 2.0 2.0 20 20 DBP 3.0 3.0 ATBC 3.0 3.0 C-100 3.0 PPO 0.05 HDI 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0

Using the protective film prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were measured peeling voltage, peel strength, wettability, and durability in the following manner, and the results are shown in Table 2 below.

A) separation voltage

2 kg of the protective film prepared in Examples 1 to 6 and Comparative Examples 1 to 4 on the triacetyl cellulose (TAC, manufactured by Fujifilm, Japan) and the antiglare layer (AG, manufactured by DNP, Japan) of the polarizing plate. After attaching to, and stored at a temperature of 23 ℃ and a relative humidity of 50% for 24 hours. At this time, the size of the sample was 15 inches, and during peeling at a speed of 40 m / min, the constant voltage generated on the surface of the polarizing plate was measured by using a constant voltage meter STATIRON-M2 at a height of 1 cm from the surface of the polarizing plate, in order to increase the accuracy. Ten measurements were taken to show the mean value.

B) 180 ° peel strength

With a roller of 2 kg on the triacetyl cellulose (TAC, manufactured by Fujifilm, Japan) and the anti-glare layer (AG, manufactured by DNP, Japan) of the protective film polarizing plates prepared in Examples 1 to 6 and Comparative Examples 1 to 4 After attaching, the sample was stored for 24 hours at a temperature of 23 ° C. and a relative humidity of 65%, and then measured using a tensile tester at 0.3 m / min and 30.0 m / min peel rate at an angle of 180 °.

C) wettability

After the protective films prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were attached to the anti-glare layer (AG, DNP, Japan) surface of the polarizing plate (250 mm × 250 mm) with a roller of 2 kg, 75 ℃, After the autoclave process for 90 minutes under 5 kg / cm ² pressure was determined by the presence or absence of bubbles.

Evaluation standard ○ No bubble △ There is some bubble Ｘ There is a lot of bubble

D) durability and reliability

A polarizing plate (200 mm × 200 mm, AG, manufactured by DNP Japan) with a protective film prepared in Examples 1 to 6 and Comparative Examples 1 to 4 was subjected to a high temperature (80 ° C., 1000 hours) and high temperature and high humidity (60 degrees). It was observed whether lifting or peeling occurred under the conditions of (° C., 90% RH, 1000 hours), and the durability was measured according to the following evaluation criteria.

Evaluation standard ○ No lifting or peeling △ Some lifting or peeling phenomenon Ｘ Lifting or peeling

division
Durability Reliability Wettability Peel strength Peeling voltage
Heat resistant
Heat resistance
AG 0.3 m / min 30.0 m / min 40.0 m / min TAC AG TAC AG TAC AG Example 1 ○ ○ ○ 12.0 11.5 90 85 -0.2 -0.3 Example 2 ○ ○ ○ 11.7 11.4 87 80 -0.1 -0.2 Example 3 ○ ○ ○ 10.5 10.2 90 86 -0.3 -0.2 Example 4 ○ ○ ○ 10.0 9.8 80 75 -0.2 -0.1 Example 5 ○ ○ ○ 11.5 10.5 90 84 -0.2 -0.2 Example 6 ○ ○ ○ 10.2 10.0 87 84 -0.2 -0.1 Comparative Example 1 ○ ○ × 13.5 12.0 170 140 -2.0 -1.7 Comparative Example 2 ○ × ○ 4.0 3.5 70 60 -0.3 -0.4 Comparative Example 3 ○ ○ ○ 5.0 4.0 75 70 -0.4 -0.3 Comparative Example 4 ○ × ○ 3.0 3.2 80 90 -0.7 -0.8

As shown in Table 2, the protective film using the acrylic pressure-sensitive adhesive composition of Examples 1 to 6 using a chelating agent, an alkali metal salt, and a plasticizer having an ester value of 200 or more according to the present invention is durable compared to Comparative Examples 1 to 4. Excellent reliability, no significant change in adhesive properties, and excellent wettability in terms of anti-glare layer. In addition, it can be confirmed that the high-speed peelability is excellent and the peeling charge voltage generated on the surface of the polarizing plate during peeling of the protective film is low, so that it does not cause a defect in the liquid crystal display device.

The acrylic pressure-sensitive adhesive composition, the polarizing plate, the protective film, and the liquid crystal display device to which the composition is applied according to the present invention have excellent high-speed peeling property and wettability without deterioration of adhesive properties, and sufficiently suppress static electricity generation, thereby having an excellent antistatic ability.

Although only described in detail with respect to the described embodiments of the present invention, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, it is obvious that such variations and modifications belong to the appended claims. will be.

Claims (22)

a) acrylic copolymer; b) chelating agents capable of forming bonds with metal ions; c) alkali metal salts; And d) plasticizers having an ester value of 200 or greater Acrylic pressure-sensitive adhesive composition comprising a. The method of claim 1, To 100 parts by weight of the acrylic copolymer, 0.01 to 25 parts by weight of a chelating agent capable of forming a bond with a metal ion, 0.001 to 25 parts by weight of alkali metal salt, 0.5 to 10 parts by weight of a plasticizer having an ester value of 200 or more Acrylic adhesive composition characterized in that. The method of claim 1, Acrylic copolymer Iii) 90 to 99.9 parts by weight of a (meth) acrylic acid ester monomer having an alkyl group having 1 to 12 carbon atoms; And Ii) 0.1 to 10 parts by weight of at least one monomer selected from the group consisting of a vinyl monomer having a crosslinkable functional group and an acrylic monomer Acrylic pressure-sensitive adhesive composition comprising a. The method of claim 3, wherein The (meth) acrylic acid ester monomer having an alkyl group having 1 to 12 carbon atoms is methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl ( 2-ethylhexyl (meth) acrylate as meta) acrylate, t-butyl (meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, Acrylic adhesive composition, characterized in that at least one selected from the group consisting of n-octyl (meth) acrylate, isooctyl (meth) acrylate, and isononyl (meth) acrylate. The method of claim 3, wherein The vinyl monomer or acrylic monomer having a crosslinkable functional group is 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (Meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate, 2-hydroxypropylene glycol (meth) acrylate, (meth) acrylic acid, maleic acid, fumaric acid, acrylamide, N-vinyl pyrrolidone, and Acrylic pressure-sensitive adhesive composition, characterized in that at least one member selected from the group consisting of N-vinyl caprolactam. The method of claim 3, wherein Acrylic pressure-sensitive adhesive composition, characterized in that the acrylic copolymer further comprises a vinyl monomer of the formula (1). [Formula 1]

Where R ₄ represents hydrogen or alkyl, R ₃ represents cyano, alkyl substituted or unsubstituted phenyl, acetyloxy, or COR ₅ , wherein R ₅ represents amino or glycidyloxy unsubstituted or substituted with alkyl. The method of claim 1, The acrylic pressure-sensitive adhesive, characterized in that the chelating agent capable of forming a bond with a metal ion is selected from the group consisting of a compound having an oxalate group, a compound having a diamine group, a compound having a polyvalent carboxyl group, and a compound having a β-ketone group. Composition. The method of claim 7, wherein Acrylic pressure-sensitive adhesive composition characterized in that the compound having an oxalate group is a compound represented by the following formula (2): [Formula 2]

In the formula (2), R ₁ and R ₂ are each independently hydrogen, halogen, linear or branched C1-C20 alkyl group, linear or branched C1-C20 alkoxy group, linear or branched C2-C20 alkenyl group , An aryl group having 6 to 30 carbon atoms, an arylalkyl group having 6 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, or a cycloalkyl group having 5 to 20 carbon atoms. The method of claim 8, At least one compound selected from the group consisting of diethyl oxalate, dimethyl oxalate, dibutyl oxalate, di-tert-butyl oxalate, and bis (4-methylbenzyl) oxalate Acrylic pressure-sensitive adhesive composition. The method of claim 7, wherein An acrylic pressure-sensitive adhesive composition characterized in that the compound having a diamine group is a compound represented by the following formula (3): (3)

In the formula (3), R <_3> is a linear or branched C1-C10 alkylene group or a linear or branched C2-C10 alkenylene group. The method of claim 10, The compound which has a diamine group is chosen 1 or more types from the group which consists of ethylenediamine, 1,2-diaminopropane, and diamino butane, The acrylic adhesive composition characterized by the above-mentioned. The method of claim 7, wherein Compound having a polyvalent carboxyl group is represented by the formula (4a). Acrylic pressure-sensitive adhesive composition, characterized in that the compound containing a functional group represented by 4b or 4c: [Chemical Formula 4a]

[Formula 4b]

[Formula 4c]

13. The method of claim 12, Compounds having polyvalent carboxyl groups include ethylenediamine-N, N, N ', N'-tetraacetic acid (EDTA), N, N, N', N '', N ''-diethylenetriaminepentaacetic acid (DTPA) and At least 1 type is selected from the group which consists of N, N-biscarboxymethyl glycine, The acrylic adhesive composition characterized by the above-mentioned. The method of claim 7, wherein Acrylic pressure-sensitive adhesive composition characterized in that the compound having a β-ketone group is a compound represented by the following formula (5): [Chemical Formula 5]

In the formula (5), R ₇ and R ₈ are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, a linear or branched alkoxy group having 1 to 20 carbon atoms, a linear or branched alkenyl group having 2 to 20 carbon atoms, or 6 to 6 carbon atoms. 30 aryl group, a C6-C30 arylalkyl group, a C6-C30 aryloxy group, or a C5-C20 cycloalkyl group, R ₉ is hydrogen or a linear or branched C1-C20 alkyl group, a linear or branched C1-C20 alkoxy group, a linear or branched C2-C20 alkenyl group, or a C6-C30 aryl group , An arylalkyl group having 6 to 30 carbon atoms, an aryloxy group having 6 to 30 carbon atoms, or a cycloalkyl group having 5 to 20 carbon atoms. The method of claim 14, The at least one compound having a β-ketone group is selected from the group consisting of 2,4-pentadione, 1-benzoylacetone, ethyl acetoacetate, dimethyl malonate and diethyl malonate. The method of claim 1, And the alkali metal cation salts are selected from lithium, sodium, potassium, magnesium, calcium, barium, and ^{cesium, Cl -, Br -, I} -, BF 4 -, PF 6 -, AsF 6 -, ClO 4 -, ^{_{NO 2 -, CO 3 -,}} N (CF 3 SO 2) 2 -, N (CF 3 CO) 2 -, N (C 2 F 5 SO 2) 2 -, N (C 2 F 5 CO) 2 -, _{N (C 4 F 9 SO 2} ) 2 -, C (CF 3 SO 2) 3 -, and CF ₃ SO ₃ ^- acrylic pressure sensitive adhesive composition which comprises an anion selected from the. The method of claim 1, Plasticizers having an ester value of 200 or more include dibutylphthalate, trioctyl trimellitate, bis (2-butoxyethyl) phthalate, diisononyladipic acid, bis (2-butoxyethyl) adipic acid, and acetyltributylsheet Acrylic pressure-sensitive adhesive composition, characterized in that at least one member selected from the group consisting of a rate. The method of claim 1, The acrylic pressure sensitive adhesive composition further comprises a polyoxyalkylene compound. The method of claim 1, The acrylic pressure sensitive adhesive composition further comprises a crosslinking agent. materials; And A pressure-sensitive adhesive layer formed on one or both sides of the substrate, and containing the acrylic pressure-sensitive adhesive composition according to any one of claims 1 to 19 Protective film comprising a. Polarizing film or polarizing element; And Protective film according to claim 20 Polarizing plate comprising a. A liquid crystal display device comprising a liquid crystal panel obtained by bonding the polarizing plate of claim 21 to one or both surfaces of a liquid crystal cell.