KR101240852B1 - Acrylic composition, protective film for optical elements, polarizer and liquid crystal display - Google Patents

Abstract

The present invention relates to an acrylic composition, a protective film for an optical member containing the cured product, a polarizing plate, and a liquid crystal display device. In the present invention, by adopting a photocuring method, the manufacturing process can be simplified, while exhibiting high low-speed peeling force and low high-speed peeling force, and excellent balance of low-speed and high-speed peeling force, durability, workability, transparency and charging The acrylic composition excellent in the prevention property, the protective film for optical members containing the hardened | cured material, a polarizing plate, and a liquid crystal display device can be provided.

Acrylic composition, alkylene oxide, polyfunctional acrylate, photoinitiator, metal salt, alkylene oxide chelating agent, polarizing plate, protective film, liquid crystal display device

Description

Acrylic composition, protective film for optical members, polarizing plate and liquid crystal display device {Acrylic composition, protective film for optical elements, polarizer and liquid crystal display}

The present invention relates to an acrylic composition, a protective film for an optical member containing the cured product, a polarizing plate, and a liquid crystal display device.

A liquid crystal display is a device that displays an image by inserting a liquid crystal between two thin glass substrates. In the device, when a voltage is applied through an electrode connected to the liquid crystal, the molecular arrangement of the liquid crystal is changed, and thus, the rate of light passing through the liquid crystal is changed, thereby displaying a picture or color. The liquid crystal display device is a display device that is in the spotlight in various fields because of the low power consumption and the planar thinness.

As the demand for liquid crystal display devices increases, the demand for films having optical properties such as polarizing plates is increasing rapidly, and the speed of production of liquid crystal display devices is also required. In addition, as the production line speeds up, the demand for various raw and subsidiary materials is increasing, and the productivity of the raw and subsidiary materials is also an important problem.

A protective film applied to an optical member such as a polarizing plate is typically manufactured by applying and drying the pressure-sensitive adhesive composition to a substrate and sequentially performing a process such as plywood, aging, inspection, slitting and packaging with a release film. In order to mature the pressure-sensitive adhesive in the step, it takes several tens of hours or more. The aging process is carried out for the reaction of the crosslinking agent and the adhesive resin blended in the pressure-sensitive adhesive composition, in this process the cohesion and durability of the pressure-sensitive adhesive is improved. In order to control the aging conditions as described above, a temperature and humidity control facility and a space therefor are required, which causes an increase in processing costs, thereby degrading product competitiveness.

On the other hand, the protective film for the optical member is very important to control the adhesive force according to the peel rate. For example, when manufacturing a polarizing plate, an appropriate low speed peel force is required for the protective film to play a role. That is, when the low-speed peeling force is too low, lifting phenomenon tends to occur after adhesion of the protective film due to moisture or bubbles on the surface of the adherend or shrinkage of the polarizing film, and the like. In addition, when the low-speed peeling force is low, the protective film of the cut surface is easily lifted during cutting, and is easily left to contamination from the outside.

In addition, in order to inspect the foreign material on the polarizing plate, when the protective film is peeled off and confirmed, it is necessary to be excellent in the property of wetting the adherend again upon reattachment.

In addition, in the case of manufacturing a liquid crystal display by attaching a polarizing plate, the protective film finally attached to the polarizing plate is removed, and at this time, the protective film is peeled off at high speed in terms of productivity. In this case, when the adhesive force is high during high-speed peeling, the thin liquid crystal panel is easily damaged, and the generation of static electricity is also very large, resulting in loss of the driving device of the panel.

Therefore, the pressure-sensitive adhesive of the protective film used for the optical member such as a polarizing plate exhibits a moderate low-speed peeling force, excellent wettability, it is necessary to adjust the properties to show a low peeling force at high peeling.

In general, the crosslinking degree of the pressure-sensitive adhesive for the protective film is set to be very high in order to control the adhesive force change according to the peeling speed. However, in the thermosetting adhesive, when the adhesive force according to the peeling rate is simply adjusted through the degree of crosslinking, the low speed and the high speed peeling force exhibit opposite results. Specifically, if the degree of crosslinking is lowered, the adhesive strength, in particular, the adhesive strength after heating is increased, and the peeling force is greatly increased at high speed peeling, while if the degree of crosslinking is high, the high-speed peeling force is low, but the low-speed peeling force is very low, and the wettability is poor. do.

As the prior arts, Japanese Patent Laid-Open Nos. Hei 5-163468 and Hei 11-256111 disclose an adhesive in which an epoxy crosslinking agent is added to a carboxyl group-containing acrylic copolymer to control gel content. However, in the case of the above technique, there is a problem that the balance of low speed and high speed peeling force is very poor.

Further, Japanese Patent Laid-Open No. 2001-323239 discloses a technique of lowering a high-speed peeling force by copolymerizing a (meth) acrylic acid ester having 12 or more carbon atoms of an alkyl group with a (meth) acrylic acid ester having 3 to 10 carbon atoms. However, the above technique has a problem in that the glass transition temperature of the copolymer increases due to the long-chain alkyl group having 12 or more carbon atoms, the wettability decreases, and the adhesion to the substrate decreases.

In addition, Japanese Patent Laid-Open No. 2005-23143 discloses a technique for controlling the degree of crosslinking of an adhesive in order to adjust the peeling force of a protective film. However, when the degree of crosslinking in the thermosetting system as in the above technology is increased, the low-speed peeling force is also lowered along with the high-speed peeling force, making it difficult to perform the fundamental function of the protective film protecting the panel from external contamination.

An object of this invention is to provide the acrylic composition, the protective film for optical members containing the hardened | cured material, a polarizing plate, and a liquid crystal display device.

MEANS TO SOLVE THE PROBLEM This invention is an acryl-type resin which has a photopolymerizable group in a side chain, and contains an alkylene oxide as a means for solving the said subject; And

It provides an acrylic composition comprising a photoinitiator.

The present invention as another means for solving the above problems, the base; And a pressure-sensitive adhesive layer formed on one or both surfaces of the substrate and containing a cured product of the acrylic composition according to the present invention.

The present invention as another means for solving the above problems, provides a polarizing plate attached to one or both surfaces of the protective film according to the present invention.

The present invention provides another liquid crystal display device in which the polarizing plate according to the present invention is attached to one side or both sides of the liquid crystal panel.

In the present invention, by adopting a photocuring method, the manufacturing process can be simplified, while exhibiting high low-speed peeling force and low high-speed peeling force, and excellent balance of low-speed and high-speed peeling force, durability, workability, transparency and charging The acrylic composition excellent in the prevention property, the protective film for optical members containing the hardened | cured material, a polarizing plate, and a liquid crystal display device can be provided.

The present invention is an acrylic resin having a photopolymerizable group in the side chain and containing an alkylene oxide; And

It relates to an acrylic composition comprising a photoinitiator.

Hereinafter, the acrylic composition according to the present invention will be described in detail.

The acrylic resin used in the present invention may have a weight average molecular weight of 200,000 or more. In the present invention, if the weight average molecular weight of the acrylic resin is less than 200,000, the durability of the cured product may be lowered under high temperature or high humidity conditions. In the present invention, the upper limit of the weight average molecular weight of the acrylic resin is not particularly limited. However, if the weight average molecular weight is excessively increased, there is a possibility that problems such as deterioration of durability of the cured product or deterioration of coating property may occur, so that the weight average molecular weight of the resin can be appropriately controlled within the range of 1 million or less.

In the present invention, the specific composition of the acrylic resin is not particularly limited as long as it has a photopolymerizable group in the side chain and contains an alkylene oxide. In this invention, the polymer of the monomer mixture containing a (meth) acrylic-ester type monomer, the (meth) acrylic-acid alkylene oxide adduct, and a polar group containing monomer as said acrylic resin (henceforth "a main chain" is called.) There are cases); And a photopolymerizable group-containing compound bonded to a polar group included in the polymer.

In the present invention, the kind of the (meth) acrylic acid ester monomer contained in the main chain of the acrylic resin is not particularly limited, and for example, alkyl (meth) acrylate can be used. In this case, when the alkyl group contained in (meth) acrylate becomes too long, the cohesion force of hardened | cured material may fall, and glass transition temperature and adhesive control may become difficult, Therefore, (meth) acrylic acid which has a C1-C14 alkyl group Preference is given to using ester monomers. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl ( Meth) acrylate, sec-butyl (meth) acrylate, pentyl (meth) acrylate, 2-ethylbutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, And a mixture of one or more kinds of isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate and tetradecyl (meth) acrylate.

In the present invention, the (meth) acrylic acid ester monomer in the monomer mixture forming the main chain is 69.9 parts by weight to 99.8 parts by weight, preferably 99 parts by weight to polar group-containing monomer or (meth) acrylic acid alkylene oxide adduct. It may be included in an amount of 99.8 parts by weight. If the content is less than 69.9 parts by weight, there is a fear that the initial adhesive strength is lowered, if it exceeds 99.8 parts by weight, there is a fear that a problem in durability due to the cohesive force is lowered.

In the present invention, the (meth) acrylic acid alkylene oxide adduct included in the monomer mixture forming the main chain serves to impart alkylene oxide to the acrylic resin. The alkylene oxide imparted to the acrylic resin as described above exhibits excellent miscibility with, for example, the polyfunctional acrylate described later, in particular, the acrylate including the ring structure in the molecular structure, and thus high low-speed peeling force after curing and Low fast peel force can be shown. In addition, the alkylene oxide, for example, has a good wettability of the cured product and a stable adhesive force at high temperature or high humidity conditions, and at the same time excellent antistatic performance (ESD characteristics) even in the presence of moisture or moisture You can keep it.

On the other hand, examples of the (meth) acrylic acid alkylene oxide adduct that can be used in the present invention include alkoxy alkylene glycol (meth) acrylic acid esters, alkoxy dialkylene glycol (meth) acrylic acid esters, alkoxy trialkylene glycol (meth) acrylic acid Esters, alkoxy tetraalkylene glycol (meth) acrylic acid esters, phenoxy alkylene glycol (meth) acrylic acid esters, phenoxy dialkylene glycol (meth) acrylic acid esters, phenoxy trialkylene glycol (meth) acrylic acid esters and phenoxy Tetraalkylene glycol (meth) acrylic acid esters, such as one or two or more, but are not limited thereto. In the above, "alkoxy" may represent alkoxy having 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, and more specifically, methoxy, ethoxy, propoxy or butoxy. In addition, the "alkylene glycol" in the above, for example, may be an alkylene glycol having 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms, more specifically, may be ethylene glycol or propylene glycol. .

In the present invention, the content in the monomer mixture of the (meth) acrylic acid alkylene oxide adducts as described above may be appropriately selected in consideration of the above-described properties, for example, compared with the aforementioned (meth) acrylic acid ester monomers or polar group-containing monomers. It may be included in an amount of 0.1 to 40 parts by weight, preferably 0.1 to 30 parts by weight.

By controlling the content of the (meth) acrylic acid alkylene oxide adduct in the above-described range, the pressure-sensitive adhesive can exhibit excellent balance of low and high speed peeling force, wettability, adhesive properties, and antistatic properties.

In the present invention, the polar group-containing monomer included in the monomer mixture forming the main chain imparts a polar group to the main chain, and the polar group thus provided reacts with the photopolymerizable group-containing compound described below to impart a photopolymerizable group to the main chain side chain. Can play a role. Examples of such a polar group include a hydroxy group, a carboxyl group, an isocyanate group, an amino group or an epoxy group. In the present invention, it is preferable to use a hydroxy group or a carboxyl group, but is not limited thereto.

In the present invention, the polar group-containing monomer is not particularly limited as long as it has the aforementioned polar group and unsaturated double bond in the molecule. For example, in the present invention, as the polar group-containing monomer, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxy Hexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 2-hydroxyethylene glycol (meth) acrylate, 2-hydroxypropylene glycol (meth) acrylate, (meth) acrylic acid, 2- ( A kind of meta) acryloyloxy acetic acid, 3- (meth) acryloyloxy propyl acid, 4- (meth) acryloyloxy butyl acid, fumaric acid, acrylic acid duplex, itaconic acid, maleic acid or maleic anhydride or Mixtures of two or more may be used, but are not limited thereto.

The content of the polar group-containing monomer in the monomer mixture of the present invention is not particularly limited depending on the physical properties of the cured product and the amount of the photopolymerizable group to be introduced. In the present invention, for example, the monomer mixture is 0.1 parts by weight to 10 parts by weight, preferably 0.1 parts by weight to 5 parts by weight relative to the (meth) acrylic acid ester monomer or the (meth) acrylic acid alkylene oxide adduct. Preferably, 0.1 parts by weight to 1 part by weight of the polar group-containing monomer may be included. If the content of the polar group-containing monomer is less than 0.1 part by weight, the amount of the photopolymerizable group that can be introduced into the main chain is insufficient, and the cohesive force of the cured product may be lowered. If the content is greater than 10 parts by weight, the compatibility and / or flow characteristics There is a fear that the economic feasibility may decrease due to a decrease in the cost or an increase in raw material costs.

In the present invention, the monomer mixture forming the main chain may further include a monomer represented by the following Formula 1 as necessary. Monomers represented by the following formula (1) may be added for the purpose of glass transition temperature control and other functional provision.

[Formula 1]

Wherein each of R ₁ to R ₃ independently represents hydrogen or alkyl, R ₄ is cyano; Phenyl unsubstituted or substituted with alkyl; Acetyloxy; Or COR < _{5 &} gt ;, wherein R < ₅ > represents amino or glycidyloxy substituted or unsubstituted with alkyl or alkoxyalkyl.

In the definition of R ₁ to R _{5 in} the above formula, alkyl or alkoxy means alkyl or alkoxy having 1 to 8 carbon atoms, preferably methyl, ethyl, methoxy, ethoxy, propoxy or butoxy.

Specific examples of the monomer represented by Formula 1 include nitrogen-containing monomers such as (meth) acrylonitrile, (meth) acrylamide, N-methyl (meth) acrylamide or N-butoxy methyl (meth) acrylamide; Styrene-based monomers such as styrene or methylstyrene; Glycidyl (meth) acrylate; Or carboxylic acid vinyl esters such as vinyl acetate, or the like, or two or more kinds thereof, but are not limited thereto. When the monomer of Formula 1 as described above is included in the polymer of the present invention, the content is preferably 20 parts by weight or less relative to other monomers included in the monomer mixture. When the content exceeds 20 parts by weight, there is a fear that the flexibility and / or peeling strength of the cured product is lowered.

The acrylic resin of the present invention may further include a photopolymerizable group-containing compound which is bonded to the main chain, preferably the side chain of the main chain, to provide a photopolymerizable group together with the main chain which is a polymer of the monomer mixture described above. .

Specific types of such compounds include 1 to 5, preferably 1 to 2, photopolymerizable groups (ex. Carbon-carbon unsaturated double bonds) per molecule, and can react with polar groups included in the main chain. As long as it has a functional group which exists, it will not restrict | limit in particular. Examples of the functional group capable of reacting with the polar group of the main chain include an isocyanate group, an epoxy group, a silane group or a carboxyl group, but are not limited thereto. For example, when a hydroxyl group or a carboxyl group is introduced into the main chain, the functional group included in the compound may be an isocyanate group, an epoxy group or a chlorosilane group, or the like, and when the amino group or a substituted amino group is introduced into the main chain, the compound The functional group included in may be an isocyanate group or the like, and when the epoxy group is included in the main chain, the functional group included in the compound may be a carboxyl group.

Specific examples of the photopolymerizable group-containing compound that can be used in the present invention include 2-isocyanatoethyl (meth) acrylate, 1,1-bis (acryloyloxymethyl) ethyl isocyanate, and (meth) acrylo Iloxy ethyl isocyanate, meta-isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate or allyl isocyanate; An acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with 2-hydroxyethyl (meth) acrylate; An acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or polyisocyanate compound, a polyol compound and 2-hydroxyethyl (meth) acrylate; Glycidyl (meth) acrylate; (Meth) acrylic acid; Or 3-methacryloxypropyldimethylchlorosilane, or the like, or a heterogeneous compound, but is not limited thereto.

The content of the photopolymerizable group-containing compound in the present invention is not particularly limited to be selected according to the intended use, for example, 0.1 parts by weight to 5 parts by weight, preferably 0.1 parts by weight to 100 parts by weight of the main chain. It may be included in an amount of 2 parts by weight. When the content of the photopolymerizable group-containing compound is less than 0.1 part by weight, the peeling force is excessively increased, and the peeling process efficiency may be lowered. There is. In the present invention, in particular, the photopolymerizable group-containing compound may be used in an amount of 3% or less, more preferably 2% or less, even more preferably 1% or less, in consideration of the economics caused by an increase in raw material costs.

In the present invention, the method for producing an acrylic resin containing the above components is not particularly limited. In the present invention, for example, an acrylic resin is prepared by first preparing a polymer that forms a main chain, reacting a polar group introduced into the polymer (chain) with a reactor of a photopolymerizable group-containing compound, and introducing the photopolymerizable group into the polymer. Can be prepared.

In this case, the method for producing the main chain polymer is not particularly limited, and for example, it can be produced through a general polymerization method such as solution polymerization, photopolymerization, bulk polymerization, suspension polymerization or emulsion polymerization. In the present invention, it is particularly preferable to use a solution polymerization method. Specifically, the initiator may be mixed in a state in which each monomer is uniformly mixed, and solution polymerization may be performed at a polymerization temperature of 50 ° C to 140 ° C. Initiators which can be used at this time include azo polymerization initiators such as azobis isobutyronitrile or azobiscyclohexane carbonitrile; And / or conventional initiators such as peroxides such as benzoyl peroxide or acetyl peroxide.

In addition, the method of reacting the main chain prepared as described above with the photopolymerizable group-containing compound is not particularly limited. For example, the polymer and the photopolymerizable group-containing compound constituting the main chain are at room temperature to 40 ° C for 4 hours. It may be prepared by reacting for 48 hours. At this time, the reaction may be carried out using a catalyst such as organic tin in a solvent such as ethyl acetate.

The acrylic composition of the present invention also includes a photoinitiator together with the acrylic resin. The kind of photoinitiator that can be used in the present invention is not particularly limited, and any kind can be used as long as it can play a role of generating a radical by light irradiation and initiating a polymerization reaction. Specific examples of the photoinitiator that can be used in the present invention include benzoin, hydroxy ketone, amino ketone or phosphine oxide, and more specifically, benzoin, benzoin methyl ether, benzoin Ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylanino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy 2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1one, 1-hydroxycyclohexylphenylketone, 2-methyl-1- [4- (methylthio) phenyl] -2 -Morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethyl Aminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthio Xanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, p-dimethylamino benzoic acid ester, oligo [2-hydroxy-2- Methyl-1- [4- (1-methylvinyl) phenyl] propanone] and 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide, and the like, but are not limited thereto. In the present invention, one or more of the above can be used.

In the present invention, the photoinitiator may be included in an amount of 0.01 to 10 parts by weight, preferably 0.01 to 5 parts by weight based on 100 parts by weight of the acrylic resin. In addition, when the acrylic composition of the present invention includes the multifunctional acrylate described below, the photoinitiator may be included in an amount of 0.2 to 20 parts by weight relative to 100 parts by weight of the multifunctional acrylate. In the present invention, when the content of the photoinitiator is too small, the polymerization or curing reaction may not be performed smoothly, when too large, there is a fear that physical properties such as durability, transparency and the like.

The acrylic composition of the present invention may further comprise a multifunctional acrylate together with the aforementioned components. The said polyfunctional acrylate can give a harder crosslinked structure to hardened | cured material, for example, and can play the function which improves durability reliability and cohesion.

In the present invention, the kind of polyfunctional acrylate that can be used is not particularly limited. In the present invention, for example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylic Neopentylglycol adipate di (meth) acrylate, hydroxyl puivalic acid neopentylglycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, Caprolactone modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, di (meth) acryloxy ethyl isocyanurate, allylated cyclohexyl di (meth) acrylate , Tricyclodecane dimethanol (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, ethylene oxide modified hexahydrophthalic acid di (meth) acrylate, tricyclodecane dimethanol (Meth) acrylate, neopentylglycol-modified trimethylpropane di (meth) acrylate, adamantane di (meth) acrylate or 9,9-bis [4- (2-acryloyloxyethoxy) Difunctional acrylates such as phenyl] fluorene and the like; Trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide Trifunctional acrylates such as modified trimethylolpropane tri (meth) acrylate, trifunctional urethane (meth) acrylate or tris (meth) acryloxyethyl isocyanurate; Tetrafunctional acrylates such as diglycerin tetra (meth) acrylate or pentaerythritol tetra (meth) acrylate; 5-functional acrylates, such as propionic acid modified dipentaerythritol penta (meth) acrylate; And dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate or urethane (meth) acrylate (ex. Isocyanate monomers and trimethylolpropane tri (meth) acrylate And 6 functional acrylates such as reactants, but are not limited thereto.

In the present invention, one or more kinds of the above-described multifunctional acrylates may be used in combination, or in particular, the use of an acrylate having a molecular weight of less than 1,000 and more than trifunctional is preferable in terms of more excellent durability, but not limited thereto. It doesn't happen.

Especially in this invention, it is preferable to use the acrylate which contains a cyclic structure and has 3 or more functional groups as a said polyfunctional acrylate in a molecular structure. In this case, the ring structure included in the acrylate may be a carbocyclic structure or a heterocyclic structure; Or any of a monocyclic or polycyclic structure. More specifically, examples of the ring structure included in the multifunctional acrylate include a cycloalkyl ring structure having 3 to 12 carbon atoms, preferably 3 to 8 carbon atoms, such as cyclopentane, cyclohexane or cycloheptane, The ring structure may contain one or more, preferably 1 to 5, more preferably 1 to 3, in the acrylate molecule, and may also contain one or more hetero atoms, such as O, S or N.

As a specific example of the polyfunctional acrylate containing a ring structure as mentioned above which can be used by this invention, the monomer which has isocyanurate structures, such as a tris (meth) acryloxy ethyl isocyanurate, an isocyanate modified urethane acryl Rate (e.g., reactants of isocyanate compounds having a ring structure in a molecule (ex. Isoborone diisocyanate) and acrylate compounds (e.g., trimethylolpropane tri (meth) acrylate or pentaerythritol tri (meth) acrylate)) And the like, but is not limited thereto.

In the acrylic composition of the present invention, the multifunctional acrylate as described above may be included in an amount of 0.1 parts by weight to 15 parts by weight based on 100 parts by weight of the aforementioned acrylic resin. In the present invention, when the content of the multifunctional acrylate is less than 0.1 part by weight, there is a possibility that a change in the adhesive force under high temperature conditions may occur over time, and when it exceeds 15 parts by weight, the adhesive force may be lowered.

The acrylic composition of the present invention may further contain an alkylene oxide chelating agent and a metal salt as a component for imparting antistatic properties together with the aforementioned components.

In the above, the alkylene oxide chelating agent may serve to impart antistatic properties to the cured product by forming a complex by reacting with an included metal salt. Accordingly, the alkylene oxide chelating agent is excellent in charging, while maintaining or improving the durability, transparency, workability, and the like of the cured product even when a small amount of antistatic component (ex. Metal salt) is added, for example. Preventive performance can be given.

The specific kind of alkylene oxide chelating agent that can be used in the present invention is not particularly limited as long as it can perform the above-mentioned action, but the carbon number of the basic unit is 2 or more, preferably 3 to 12, more preferably Preference is given to using alkylene oxide compounds containing alkylene oxide units of 3 to 8, more preferably 3 to 5.

In the present invention, the alkylene oxide compound may have a molecular weight of 5,000 or less, preferably 4,000 or less, more preferably 3,000 or less. The term "molecular weight" used in the present invention means the molecular weight or weight average molecular weight of the compound. In the present invention, when the molecular weight of the alkylene oxide-based compound exceeds 5,000, the viscosity of the chelating agent may be excessively increased, resulting in deterioration of coatability or deterioration of complex formation ability with a metal. On the other hand, the lower limit of the molecular weight of the alkylene oxide-based compound in the present invention is not particularly limited, for example, may be appropriately controlled in the range of 500 or more, preferably 1,000 or more.

Specific examples of the alkylene oxide chelating agent that can be used in the present invention are not particularly limited as long as they exhibit the above-described properties, and for example, a compound represented by the following formula (2) can be used.

[Formula 2]

In Formula 2, A represents an alkylene having 2 or more carbon atoms, n represents 1 to 120, and R ₆ and R ₇ each independently represent hydrogen, hydroxy, alkyl, or -C (= 0) R ₈ . In the above, R ₈ represents hydrogen or an alkyl group.

In the definition of Chemical Formula 2, alkylene represents alkylene having 2 or more carbon atoms, preferably 3 to 12 carbon atoms, more preferably 3 to 8 carbon atoms, still more preferably 3 to 5 carbon atoms, specifically ethylene, propylene, Butylene or pentylene.

In addition, in the definition of Chemical Formula 2, alkyl may represent alkyl having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, and n is preferably 1 to 80 carbon atoms, more preferably. 1 to 40 may be represented.

More specific examples of the compound represented by Formula 2 include polyalkylene oxide (ex. Polyethylene oxide, polypropylene oxide, polybutylene oxide or polypentylene oxide, etc.), polyalkylene oxide (ex. Polyethylene jade) Fatty acid alkyl esters or polyalkylene oxides (e.g. polyethylene oxide, polypropylene oxide, polybutylene oxide or polypentylene oxide) such as seeds, polypropylene oxide, polybutylene oxide or polypentylene oxide Carboxylic acid esters, etc.), but is not limited thereto.

In the present invention, the alkylene oxide chelating agent as described above may be included in the composition in an amount of 0.1 parts by weight to 20 parts by weight, preferably 0.1 parts by weight to 10 parts by weight, based on 100 parts by weight of the acrylic resin described above. If the content is less than 0.1 part by weight, the antistatic properties of the cured product may be lowered. If the content is more than 20 parts by weight, the peeling force may be lowered.

In the acrylic composition of the present invention, the kind of metal salt that may be included with the alkylene oxide chelating agent is not particularly limited, and may be, for example, a metal salt including an alkali metal cation or an alkaline earth metal cation. In this case, specific examples of the cation include lithium ion (Li ⁺ ), sodium ion (Na ⁺ ), potassium ion (K ⁺ ), rubidium ion (Rb ⁺ ), cesium ion (Cs ⁺ ), beryllium ion (Be ^{2 +} ), Magnesium ions (Mg ²⁺ ), calcium ions (Ca ²⁺ ), strontium ions (Sr ²⁺ ) and barium ions (Ba ²⁺ ), and the like, or two or more kinds thereof. (Li ⁺ ), sodium ion (Na ⁺ ), potassium ion (K ⁺ ), cesium ion (Cs ⁺ ), beryllium ion (Be ²⁺ ), magnesium ion (Mg ²⁺ ), calcium ion (Ca ²⁺ ), and One or more ^{kinds of} barium ions (Ba ²⁺ ) may be used, and lithium ions (Li ⁺ ) are more preferable in terms of ion stability and mobility in the pressure-sensitive adhesive, but are not limited thereto.

In addition, in the present invention, the kind of anion included in the metal salt is not particularly limited, and examples thereof include fluoride (F ⁻ ), chloride (Cl ⁻ ), bromide (Br ⁻ ), iodide (I ⁻ ), perchlorate (ClO ₄ ^-), hydroxide (OH ^-), carbonate (CO ₃ ^2-), carboxylate ^{_{(ex CH 3 CO 2 -.}} ), an azide anion (N ₃ ^-), phosphate (HPO ₄ ^2- ), nitrate (NO ₃ ^-), sulfonate (SO ₄ ^2-), methyl benzene sulfonate _{(CH 3 (C 6 H 4} ) SO 3 -), p- toluenesulfonate (CH ₃ C ₆ H ₄ SO ₃ ^-), carboxymethyl sulfonate _{(COOH (C 6 H 4)} SO 3 -), sulfonate as a triple (CF ₃ SO ₂ ^-), benzo carbonate ^{_{(C 6 H 5 COO -)}} , acetate (CH ₃ COO ^-), a triple acetate (CF ₃ COO ^-), tetrafluoroborate (BF ₄ ^-), tetra-benzyl borate _{(B (C 6 H 5)} 4 -), phosphate (PF ₆ hexafluoro ^-), tris-penta fluoro-ethyl trifluoromethyl-phosphate _{(P (C 2 F 5)} 3 F 3 -), The methane sulfonic mid to bistrifluoromethyl _{(N (SO 2 CF 3)} 2 -), bis ethane sulfonic mid pentafluorophenyl _{(N (SOC 2 F 5)} 2 -) is methane-carbonyl imide, the bis trifluoroacetate ( _{N (COC 2 F 5) 2} -), bis-penta-fluoro-ethane-carbonyl imide _{(N (COC 2 F 5)} 2 -), bis perfluoro butane sulfonimide _{(N (SO 2 C 4 F} 9) ₂ ^-), bis perfluorobutane carbonyl imide _{(N (COC 4 F 9)} 2 -), tris trifluoromethane sulfonyl nilme lactide _{(C (SO 2 CF 3)} 3 -), and a tris-trifluoroacetate Methanecarbonylmethide (C (SO ₂ CF ₃ ) ₃ ⁻ ) is preferably selected from the group consisting of, but is not limited thereto.

In the present invention, it is particularly preferable to use an anion including a perfluoroalkyl group, which performs well the role of electron withdrawing and has excellent hydrophobicity among the anions, but is not limited thereto.

In the acrylic composition of the present invention, the metal salt may be included in an amount of 0.001 part by weight to 20 parts by weight, preferably 0.001 part by weight to 10 parts by weight, based on 100 parts by weight of the acrylic resin described above. In the present invention, if the content of the metal salt is less than 0.01 part by weight, the antistatic effect may be insignificant. If it exceeds 50 parts by weight, the compatibility with the cured product may be lowered, or the durability or transparency may be deteriorated.

The acrylic composition of the present invention is also an acrylic low molecular weight, a silane coupling agent, a tackifying resin, an epoxy resin, a crosslinking agent, a curing agent, a foaming agent, an organic salt, an ultraviolet stabilizer, an antioxidant, within a range that does not affect the effect of the invention. It may further comprise one or more additives selected from the group consisting of colorants, adjuvant, fillers, antifoams, surfactants and plasticizers.

The present invention also provides a substrate; And a pressure-sensitive adhesive layer formed on one or both surfaces of the substrate and containing a cured product of the acrylic composition according to the present invention.

As described above, the acrylic composition of the present invention can omit the aging step, simplifying the manufacturing process, and excellent in the balance of low-speed and high-speed peeling force, durability, workability, transparency and antistatic properties Excellent Accordingly, the pressure-sensitive adhesive composition of the present invention can be effectively applied to various optical devices or parts, display devices or parts. In particular, transparent substrates; And a pressure-sensitive adhesive sheet made of the pressure-sensitive adhesive of the present invention formed on the transparent substrate, a surface protective film for protecting optical members such as polarizing plates, retardation plates, optical compensation films, reflecting sheets, and brightness enhancement films used in liquid crystal displays. Can be effectively used.

In addition, the use of the acryl-type composition of this invention is not limited to the use mentioned above, Various industrial sheets, for example, a protective film, a cleaning sheet, a reflective sheet, a structural adhesive sheet, a photosensitive adhesive sheet, the adhesive sheet for lane display It can be effectively used for optical adhesive products or adhesives for electronic components. In addition, the acrylic composition of the present invention can be effectively applied to laminate products, multilayer commercial adhesive sheet products, medical patches, heat-activated pressure-sensitive adhesive (Heat-activated pressure-sensitive adhesive), and the like.

On the other hand, as the base material used in the protective film of the present invention can be used without a general transparency film in this field, for example, polyester film (ex. Polyethylene terephthalate film, polybutylene terephthalate), polytetrafluor And plastic films such as ethylene film, polyethylene film, polypropylene film, polybutene film, polybutadiene film, vinyl chloride copolymer film or polyimide film. Such a base film may consist of a single layer, or two or more layers may be laminated | stacked, and may further contain functional layers, such as an antifouling layer or an antistatic layer, in some cases. In the present invention, it is also possible to perform surface treatment such as primer treatment on one or both surfaces of the substrate from the viewpoint of improving the substrate adhesion.

In the present invention, the thickness of the base film is not particularly limited to be appropriately selected depending on the use, and can be formed in a thickness of usually 5 μm to 500 μm, preferably 10 μm to 100 μm.

In addition, the thickness of the pressure-sensitive adhesive layer included in the protective film of the present invention is not particularly limited, and may be, for example, 2 μm to 100 μm, preferably 5 μm to 50 μm. If the thickness of the pressure-sensitive adhesive layer is out of the above-described range, the formation of a uniform pressure-sensitive adhesive layer becomes difficult and there is a fear that the physical properties of the pressure-sensitive adhesive film become nonuniform.

In the present invention, the method of forming the pressure-sensitive adhesive layer on the substrate is not particularly limited, and for example, a method of coating and curing the acrylic composition on a substrate by conventional means such as a bar coater or the surface of the peelable substrate once the acrylic composition is applied. After apply | coating and hardening to manufacture an adhesive layer, the method etc. which transfer an adhesive layer to a base material using the said peelable base material can be used.

The method of curing the acrylic composition of the present invention in the manufacture of the adhesive polarizing plate is also not particularly limited, and general methods in this field may be applied, but a curing method through irradiation with ultraviolet rays or electron beams is preferable, and double ultraviolet irradiation The hardening method through is more preferable.

Such ultraviolet irradiation can be performed using means, such as a high pressure mercury lamp, an electrodeless lamp, or a xenon lamp, for example.

In the ultraviolet curing method, the irradiation amount is not particularly limited as long as it is controlled to such a degree that sufficient curing is achieved without impairing the overall physical properties of the pressure-sensitive adhesive layer, for example, the illuminance is 50 mW / cm ² to 1,000 mW / cm ² , and the light amount 50 mJ / cm ² to 1,000 mJ / cm ² .

In the present invention, the pressure-sensitive adhesive layer formed as described above, the gel (gel) content represented by the following general formula (1) is preferably 80% to 99%.

[Formula 1]

Gel content = B / A x 100

In the general formula 1, A represents the mass of the pressure-sensitive adhesive, B represents the dry mass of the insoluble content of the pressure-sensitive adhesive after immersing the pressure-sensitive adhesive for 48 hours at room temperature with ethyl acetate.

In the present invention, if the gel content is less than 80%, the adhesive force may be excessively increased. If the gel content is more than 99%, the adhesive force may be excessively lowered.

The present invention also relates to a polarizing plate attached to one or both surfaces of the protective film according to the present invention described above.

Polarizing plate to which the protective film of the present invention may be attached, for example, a polarizing film or a polarizing element; And it may have a structure including a protective film formed on one side or both sides of the polarizing film or polarizing element. In addition, the polarizing plate of the present invention may further include one or more functional layers selected from the group consisting of a protective layer, a reflective layer, an antiglare layer, a retardation plate, a wide viewing angle compensation film, and a brightness enhancing film, as the case may be.

The kind of polarizing film or polarizing element constituting the polarizing plate in the present invention is not particularly limited. For example, in this invention, the film manufactured by extending | stretching and manufacturing polarizing components, such as iodine or a dichroic dye, can be used for the film which consists of polyvinyl alcohol-type resin as a polarizing film or a polarizing element. As the polyvinyl alcohol-based resin, polyvinyl alcohol, polyvinyl formal, polyvinyl acetal or saponified product of ethylene vinyl acetate copolymer may be used. In addition, the thickness of the polarizing film is also not particularly limited, and may be formed in a conventional thickness.

In the polarizing plate of the present invention, a protective film that may be formed on one side or both sides of a polarizing element or a polarizing film is a concept that is distinguished from the above-described adhesive film of the present invention, and a specific kind thereof includes a cellulose-based film such as triacetyl cellulose. ; Polyester film such as polycarbonate film or polyethylene terephthalate film; Polyethersulfone-based films; And / or polyolefin films such as polyethylene films, polypropylene films or polyolefin films having a cyclo or norbornene structure or ethylene-propylene copolymers. At this time, the thickness of the protective film is also not particularly limited, and may be formed in a conventional thickness.

The present invention also relates to a liquid crystal display device in which the polarizing plate according to the present invention is attached to one side or both sides of the liquid crystal panel.

The type of liquid crystal cell constituting the liquid crystal display device of the present invention as described above is not particularly limited, such as TN (Twisted Neumatic), STN (Super Twisted Neumatic), IPS (In Plane Switching) or VA (Vertical Alignment) method It includes all common liquid crystal cells. In addition, the kind and other manufacturing method of the other structure contained in the liquid crystal display device of this invention are not specifically limited, either, The general structure of this field can be employ | adopted and used without a restriction | limiting.

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

Preparation Example 1 Preparation of Acrylic Resin (A)

Preparation of Polymers (Main Chains)

95 parts by weight of 2-ethylhexyl acrylate (2-EHA), 3 parts by weight of methoxyethylene glycol acrylate (MEA), and 2-in a 1 L reactor equipped with a refrigeration system for nitrogen gas reflux and easy temperature control. A monomer mixture comprising 2 parts by weight of hydroxyethyl acrylate (2-HEA) was added together with 0.1 parts by weight of n-dodecyl mercaptan, followed by 100 parts by weight of ethyl acetate (EAc) as a solvent. Input. Subsequently, after purging nitrogen gas for 1 hour for oxygen removal, the temperature was maintained at 62 ° C. Thereafter, 0.03 parts by weight of azobisisobutyronitrile (AIBN) was added as a reaction initiator, and reacted for 8 hours. Subsequently, the mixture was diluted with ethyl acetate (EAc) to prepare a polymer having a solid content concentration of 44% by weight, a weight average molecular weight of 400,000, and a molecular weight distribution of 3.0.

Introduction of Photopolymerization Group

100 parts by weight of the polymer prepared above, 1 part by weight of 2-isocyanatoethyl methacrylate (MOI; 2-isocyanatoethyl methacrylate, Showadenko), 1 part by weight of dibutyl tindilaurate (0.5% toluene diluent) solution, and 12.5 parts by weight of ethyl acetate (EAc) was added and reacted at 40 ° C. for at least 4 hours to prepare an acrylic resin (A) having a solid content of about 40% and having an unsaturated double bond introduced into the side chain (reaction conversion rate: 98%). More than).

Preparation Examples 2 and 3

When preparing the main chain, the same procedure as in Preparation Example 1 was repeated except that the monomer composition of the polymer was changed as shown in Table 1 below, to prepare acrylic resins (B and C) having double bonds introduced into the side chains. .

[Table 1]

Acrylic resin A B C 2-EHA 93 93 98 2-HEA 2 2 2 MEA 5 - - EDA - 5 - AIBN 0.03 0.03 0.03 n-DDM 0.01 0.01 0.01 EAc 100 100 100 Mw (only) 40 38 39 Molecular weight distribution 3.0 2.7 2.8 2-EHA: 2-ethylhexyl acrylate
2-HEA: 2-hydroxy ethyl acrylate
MEA: methoxy ethylene glycol acrylate
EDA: ethoxy diethylene glycol acrylate
AIBN: azobisisobutyronitrile
n-DDM: n-dodecyl mercaptan
EAc: ethyl acetate

Example 1.

Preparation of pressure-sensitive adhesive composition

5 parts by weight of a 6-functional acrylate (isocyanate-modified urethane acrylate; isophorone diisocyanate / pentaerythritol triacrylate adduct) containing a ring structure in a molecular structure based on 100 parts by weight of the acrylic resin (A) prepared, as a photoinitiator, hydroxycyclohexyl 0.5 parts by weight of phenyl ketone (irgacure 184, Swiss Chevas Specialty Chemical), a chelating agent, a mixture of 1 part by weight of polypropylene oxide (M _w = 2,000) and 0.04 parts by weight of LiClO ₄ (solid content concentration = 35%) Was prepared.

Preparation of Adhesive Film

The prepared pressure-sensitive adhesive composition was coated on one surface of a biaxially stretched polyethylene terephthalate (PET, Toray Industries, Inc.) film having a thickness of 38 μm, and dried to prepare a uniform coating layer having a thickness of 20 μm. Subsequently, UV treatment was performed on the dried coating layer under the following conditions, and then cut into appropriate sizes, respectively, on the triacetylcellulose surface (TAC film, Japan Fuji Film) and the antiglare layer surface (AG TAC, Japan DNP) of the polarizing plate, respectively. Attached and applied to evaluation

UV treatment condition

UV irradiator: high pressure mercury lamp

Irradiation condition: illuminance = 600 mW / cm ² , light quantity = 150 mJ / cm ²

Examples 2-6 and Comparative Examples 1-4

A specimen was prepared in the same manner as in Example 1, except that the composition of the coating solution was changed as in Tables 2 and 3 below.

[Table 2]

Example One 2 3 4 5 6 Acrylic Resin A 100 - 100 - 100 - Acrylic resin B - 100 - 100 - 100 MFA (A) - - - - - - MFA (B) 5 5 5 5 10 10 Irg184 1.0 1.0 1.0 1.0 1.0 1.0 Chelate (A) - - One One - - Chelate (B) One One - - One One LiClO ₄ 0.04 0.04 0.04 0.04 0.04 0.04 MFA (A): 6-functional acrylate (dipentaerythritol hexaacrylate)
MFA (B): Pentaerythritol triacrylate adduct of isoboron diisocyanate
Irg184: hydroxycyclohexyl ketone (Ciba specialty chemical (product))
Chelate (A): Polyethylene oxide (Mw = 2,000)
Chelate (B): polypropylene oxide (Mw = 1,300)

[Table 3]

Comparative example One 2 3 4 Acrylic resin C 100 100 100 100 MFA (A) 5 5 10 10 MFA (B) - - - - Irg184 1.0 1.0 1.0 1.0 Chelate (A) One - One - Chelate (B) - One - One LiClO ₄ 0.04 0.04 0.04 0.04 MFA (A): 6-functional acrylate (dipentaerythritol hexaacrylate)
MFA (B): Pentaerythritol triacrylate adduct of isoboron diisocyanate
Irg184: hydroxycyclohexyl ketone (Ciba specialty chemical (product))
Chelate (A): Polyethylene oxide (Mw = 2,000)
Chelate (B): polypropylene oxide (Mw = 1,300)

Physical properties were measured by the methods given below for the Examples and Comparative Examples, and the results are shown in Tables 4 and 5.

1. Measurement of low speed and high speed peeling force

The pressure-sensitive adhesive films (protective films) prepared in Examples and Comparative Examples were subjected to JIS Z 0237 on the triacetyl cellulose (TAC, manufactured by Japan FUJIFILM Corporation) and anti-glare layer (AG, manufactured by DNP, Japan). Based on, attached with a roller of 2 Kg and stored for 24 hours under the temperature of 23 ℃ and relative humidity conditions of 65%. Thereafter, using a tensile tester, the peel force was measured at a peel rate of 0.3 m / min (low speed peel force) and 30 m / min (high speed peel force) at a peel angle of 180 °, respectively.

2. Wetting

The protective film is attached to the polarizing plate attached to the size of 2.5 cm in width, 25 cm in length to prepare a sample, which was attached to the glass substrate using a double-sided tape. Then, after peeling off a protective film, the point which divided the length into three equal parts was pressed with a finger by constant pressure, the time which a protective film fully wets on the surface of a polarizing plate was measured, and wettability was evaluated according to the following reference | standard.

⊙: Less than 10 seconds to completely wet the surface of the polarizer

○: less than 15 seconds to completely wet the surface of the polarizing plate

△: takes less than 20 seconds to completely wet the surface of the polarizing plate

X: It takes 30 seconds or more to completely wet the polarizer surface

3. Heat resistance

The protective films prepared in Examples and Comparative Examples were attached to the triacetyl cellulose (TAC, Fujifilm Co., Ltd.) surface and the antiglare layer (AG, Nippon DNP Co., Ltd.) surface of the polarizing plate with a roller of 2 Kg. After being left for 7 days in an oven at 50 ° C., low and high speed peeling forces were measured at room temperature in the same manner as described above. The heat resistance evaluation criteria are as follows.

(Circle): 1.2 times or less of initial low speed / high speed peeling force after leaving heat-resistant condition

(Triangle | delta): 1.5 times or less of initial stage low speed / high speed peeling force after leaving heat-resistant condition

X: 2 times or more of initial stage low speed / high speed peeling force after leaving heat-resistant condition

4. Peeling constant voltage measurement

The protective films prepared in Examples and Comparative Examples were attached to the triacetyl cellulose (manufactured by Fujifilm Co., Ltd.) and anti-glare layer (manufactured by Japan DNP (manufactured)) surface of the polarizing plate with a roller of 2 Kg, and the temperature was 23 ° C. And stored for 24 hours under 50% relative humidity conditions. Then, while peeling a sample having a size of 15 inches at a speed of 40 m / min, the constant voltage generated on the surface of the polarizing plate was measured 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, the measurement was performed three times and the average value was shown.

5. Heat resistance peeling

The protective films prepared in Examples and Comparative Examples were attached to the triacetyl cellulose (TAC, Fujifilm Co., Ltd.) surface and the antiglare layer (AG, Nippon DNP Co., Ltd.) surface of the polarizing plate with a roller of 2 Kg. After being left for 7 days in an oven at 50 ° C., a peeling electrification voltage was measured at room temperature in the same manner as above.

6. Measurement of Gel Fraction

The pressure sensitive adhesives prepared in Examples and Comparative Examples were left in a constant temperature and humidity (23 ° C., 60% RH) chamber for about 10 days, and then about 0.3 g of pressure sensitive adhesive was placed in a # 200 stainless steel wire and then immersed in 100 ml of ethyl acetate, It was stored for 3 days in a dark room at room temperature. Thereafter, after dissolving the insoluble fraction of the pressure-sensitive adhesive, it was dried in an oven at 70 ° C. for 4 hours, the mass (dry mass) was measured, and the gel fraction was measured according to the general formula (1).

The measurement results are summarized in Tables 4 and 5 below.

[Table 4]

Example One 2 3 4 5 6 Gel content (%) 85 86 84 86 90 89 Peeling force
(gf / 25mm) 7.1 8.1 6.5 7.0 5 5.3 High speed peeling force
(gf / 25mm) 45 55 40 58 35 38 Peeling voltage
(kV) 0.15 0.10 0.2 0.3 0.05 0.05 Heat resistance
Peeling voltage 0.25 0.2 0.5 0.5 0.1 0.15 Wettability ⊙ ⊙ ⊙ ⊙ ○ ○ Heat resistance ○ ○ ○ ○ ○ ○

[Table 5]

Comparative example One 2 3 4 Gel content (%) 85 84 90 92 Slow peeling force
(gf / 25mm) 7.5 8.0 5.0 6.0 High speed peeling force
(gf / 25mm) 120 128 80 85 Peeling Voltage (kV) 0.45 0.40 0.5 0.5 Heat-resistant peeling voltage > 1.0 > 1.0 > 1.0 > 1.0 Wettability △ △ × × Heat resistance △ △ △ △

As can be seen from the results of Table 4, according to the present invention, in Examples 1 and 6 using a resin containing an alkylene oxide group, low-speed and high-speed peeling, while showing a low fast peeling force and a high speed peeling force The ratio of force (high speed / low speed) was also formed in the range of about 6 to 8, showing an excellent balance. It also showed stable ESD characteristics and adhesive durability.

On the other hand, as can be seen from the results in Table 5, when the resin does not contain alkylene oxide, the ratio of low speed and high speed peeling force (high speed / low speed) is about 16, the high speed peeling force is too high, It was confirmed that the balance of both is also poor. In particular, it was confirmed that the change of the adhesiveness with time under wettability and heat resistance was deteriorated according to the increase of the polyfunctional acrylate.

Claims (20)

Acrylic resin which has a photopolymerizable group in a side chain, and contains an alkylene oxide group; An alkylene oxide chelating agent containing an alkylene oxide having 2 or more carbon atoms in the basic unit; And Acrylic composition comprising a photoinitiator The acrylic composition according to claim 1, wherein the acrylic resin has a weight average molecular weight of 200,000 or more. The acrylic resin of claim 1, wherein the acrylic resin is a polymer of a monomer mixture comprising a (meth) acrylic acid ester monomer, an (meth) acrylic acid alkylene oxide adduct and a polar group-containing monomer; And An acrylic composition comprising a photopolymerizable group-containing compound bonded to a polar group included in the polymer. 4. The (meth) acrylic acid alkylene oxide adduct according to claim 3 is alkoxy alkylene glycol (meth) acrylic acid ester, alkoxy dialkylene glycol (meth) acrylic acid ester, alkoxy trialkylene glycol (meth) acrylic acid ester, alkoxy tetra Alkylene glycol (meth) acrylic acid ester, phenoxy alkylene glycol (meth) acrylic acid ester, phenoxy dialkylene glycol (meth) acrylic acid ester, phenoxy trialkylene glycol (meth) acrylic acid ester and phenoxy tetraalkylene glycol At least one acrylic composition selected from the group consisting of (meth) acrylic acid esters. 4. The acrylic composition according to claim 3, wherein the polar group-containing monomer comprises at least one functional group selected from the group consisting of hydroxy group, carboxyl group, isocyanate group, amino group and epoxy group. The compound according to claim 3, wherein the photopolymerizable group-containing compound is 2-isocyanatoethyl (meth) acrylate, 1,1-bis (acryloyloxymethyl) ethyl isocyanate, (meth) acryloyloxy ethyl isocyanate, meta Isopropenyl-α, α-dimethylbenzyl isocyanate, methacryloyl isocyanate, allyl isocyanate; Acryloyl monoisocyanate compounds; Glycidyl (meth) acrylate; (Meth) acrylic acid; And 3-methacryloxypropyldimethylchlorosilane. The acrylic composition according to claim 1, wherein the photoinitiator is a benzoin compound, a hydroxy ketone compound, an amino ketone compound or a phosphine oxide compound. The acrylic composition according to claim 1, wherein the photoinitiator is included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the acrylic resin. The acrylic composition according to claim 1, further comprising a polyfunctional acrylate having a ring structure in the molecular structure. The acrylic composition according to claim 9, wherein the ring structure is a cycloalkyl ring having 3 to 12 carbon atoms. 10. The acrylic composition according to claim 9, comprising 0.1 parts by weight to 15 parts by weight of polyfunctional acrylate based on 100 parts by weight of acrylic resin. delete The acrylic composition of claim 1, wherein the chelating agent is represented by the following Chemical Formula 2: [Formula 2]

In Formula 2, A represents an alkylene having 2 or more carbon atoms, n represents 1 to 120, and R ₆ and R ₇ each independently represent hydrogen, hydroxy, alkyl, or -C (= 0) R ₈ . In the above, R ₈ represents hydrogen or an alkyl group. The acrylic composition according to claim 1, comprising 0.1 to 20 parts by weight of a chelating agent based on 100 parts by weight of acrylic resin. The acrylic composition according to claim 1, further comprising a metal salt. The acrylic composition according to claim 15, comprising 0.001 to 20 parts by weight of the metal salt with respect to 100 parts by weight of the acrylic resin. materials; And a pressure-sensitive adhesive layer formed on one or both surfaces of the substrate and containing a cured product of the acrylic composition according to any one of claims 1 to 11 and 13 to 16. . The protective film for an optical member according to claim 17, wherein the pressure-sensitive adhesive layer has a gel content of 80% to 99% represented by the following general formula (1): [Formula 1] Gel content = B / A x 100 In the general formula 1, A represents the mass of the pressure-sensitive adhesive, B represents the dry mass of the insoluble content of the pressure-sensitive adhesive after immersing the pressure-sensitive adhesive for 48 hours at room temperature with ethyl acetate. A polarizer having a protective film according to claim 17 attached to one or both sides. 20. A liquid crystal display device in which the polarizing plate according to claim 19 is attached to one side or both sides of the liquid crystal panel.