KR20110138002A - Anti-static polarizing plate with adhesive and image display apparatus comprising the same - Google Patents

Abstract

PURPOSE: An antistatic property adhesion type polarizer is provided to efficiently reduce the generation of the static electricity by including an antistatic property adhesion layer as well as antistatic property coating layer. CONSTITUTION: An optical film(1), a polarized light device(2), an antistatic agent low absorbent optical film(3), an antistatic property coating layer(4), and an antistatic property adhesion layer(5) are successively laminated. The antistatic property coating layer includes ethylenedioxythiophene, a carbon nanotube and their mixture. The surface resistivity of the antistatic property coating layer is below 7×106Ω. The antistatic property adhesion layer includes an ion solid.

Description

Antistatic adhesive polarizing plate and image display device having same {ANTI-STATIC POLARIZING PLATE WITH ADHESIVE AND IMAGE DISPLAY APPARATUS COMPRISING THE SAME}

The present invention relates to an antistatic adhesive polarizing plate having excellent initial antistatic property as well as suppressing the antistatic property caused by changes over time, and an image display device having the same.

In general, a liquid crystal display device (LCD) includes a liquid crystal panel and a polarizer stacked on both sides of the liquid crystal panel.

In the In-Plane Switching liquid crystal panel, red, green, and blue layers are sequentially formed in black matrix and pixel regions that block light leakage in a matrix form, and the over coating layer is formed thereon. The upper substrate, which is a color filter substrate, and the lower substrate, which is an array substrate on which the common electrode and the pixel electrode are formed, are spaced apart from each other, and a liquid crystal layer is interposed between the upper and lower substrates. It is operated by the horizontal electric field by the common electrode and the pixel electrode of the lower substrate.

In addition, the polarizing plate has a structure in which an iodine-based polyvinyl alcohol (PVA) polarizer and an optical film represented by triacetyl cellulose (TAC) are laminated to protect both sides of the polarizer. In addition, one surface of the polarizing plate is further laminated with a functional coating layer such as an anti-reflection layer, a hard coating layer, and the other side of the polarizing plate is laminated with an adhesive layer and a release film for attaching to the liquid crystal panel.

Since the polarizing plate is formed of a plurality of organic films close to the insulating film in its structure, a large amount of static electricity is generated in the process of attaching the polarizing plate to the transverse field type liquid crystal panel. The static electricity generated in this way may cause foreign matter to be adsorbed on the optical member to contaminate the surface, staining due to distortion of the liquid crystal alignment, and damage to the thin film transistor circuit.

In particular, in the case of a transverse electric field type liquid crystal panel, both the common electrode and the pixel electrode are formed only on the lower substrate, so that static electricity is a problem in the process of attaching the polarizer to the upper substrate. In order to prevent this, a method of attaching a polarizer to the formed transparent electrode after forming a transparent electrode through a sputtering process of indium tin oxide (ITO), which is a transparent conductive material, on the upper substrate is used. It became. However, as the demand for lowering the price of LCDs is increasing recently, the necessity for a liquid crystal panel in which an expensive ITO transparent electrode is omitted is increasing.

In order to solve this problem, a method of imparting antistatic property to a polarizing plate has been used.

As a method for imparting antistatic property to a polarizing plate, a method of forming an antistatic coating layer by applying a conductive material such as a conductive polymer or a metal oxide between the polarizing plate and the pressure-sensitive adhesive layer has been proposed (Korean Patent Publication No. 2004-0091556, Japanese Patent Application Laid-Open No. 2004-338379, 2005-271573). However, this method has a disadvantage in that the performance of the antistatic coating layer is lowered by the pressure sensitive adhesive layer so that the required antistatic property cannot be sufficiently expressed.

As another method, a method of adding a conductive polymer, a metal oxide, a carbon ruler, an ionic material, etc. to the pressure-sensitive adhesive layer has been proposed (Korean Patent Publication Nos. 1998-0081608, 2001-0111715, 2004-0032058, 2006) -0018495, 2004-0030919, 2001-0010433, 1999-0072487, Japanese Patent Laid-Open No. 2004-114665, Japanese Patent No. 6-313807, 2003-294951, 2005-306937. However, this method has a disadvantage in that transparency, reworkability, durability, etc. are deteriorated because a large amount of conductive material must be contained to express the required antistatic property.

As another method, a method of simultaneously applying an antistatic coating layer and an antistatic adhesive layer has been proposed (Korean Patent Publication No. 2009-0027930). This method is excellent in initial antistatic property, but over time, the ionic liquid, which is a conductive material contained in the pressure-sensitive adhesive layer, is transferred to the outside of the pressure-sensitive adhesive layer and then passed through the antistatic coating layer to a TAC film, which is an optical film. As a result, there is a disadvantage that the antistatic property is weakened.

Therefore, there is a further demand for a polarizing plate capable of expressing sufficient initial antistatic property and at the same time suppressing the antistatic property caused by changes over time.

In the present invention, since it is excellent in the antistatic property according to the change over time as well as the initial time, it is economical in terms of cost without requiring a separate ITO transparent electrode when applied to an image display device such as a transverse electric field type liquid crystal display device, An object of the present invention is to provide an antistatic adhesive polarizing plate having excellent durability under conditions.

Another object of the present invention is to provide an image display device having the antistatic adhesive polarizing plate.

1. Optical film; Polarizer; Antistatic agent low absorption optical film; An antistatic coating layer comprising poly (3,4-ethylenedioxythiophene), carbon nanotubes, or mixtures thereof; And an antistatic adhesive polarizing plate laminated in the order of the antistatic adhesive layer containing an ionic solid.

2. In the above 1, the antistatic agent low-absorptive optical film is an antistatic adhesive polarizing plate that is less than 200g / ㎡ · day moisture permeability at 40 ℃ and 90% RH.

3. In the above 1, the antistatic agent low absorption optical film is an antistatic adhesive polarizing plate is selected from the group consisting of cycloolefin-based film, acrylic film, polyester film, polynorbornene-based film and polyolefin-based film.

4. In the above 1, the antistatic coating layer has a surface resistivity of 7 × 10 ⁶ Ω / □ or less antistatic adhesive polarizing plate.

5. In the above 1, the antistatic adhesive layer has a surface resistivity of 1 × 10 ⁹ to 5 × 10 ¹¹ Ω / □ Antistatic adhesive polarizing plate.

6. In the above 1, the antistatic pressure-sensitive adhesive layer comprises an acrylic copolymer as the pressure-sensitive adhesive, the ionic solid is an antistatic containing 0.5 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer (based on the solid content) Pressure-sensitive adhesive polarizer.

7. In the above 6, the ionic solid is an antistatic adhesive polarizing plate that is a combination of pyridinium cation and PF ₆ ^- anion.

8. according to the above 1, the antistatic pressure-sensitive adhesive polarizing plate is less than 10% of the antistatic property after leaving for 500 hours at room temperature.

9. The image display device having an antistatic adhesive polarizing plate of any one of the above 1 to 8.

The antistatic adhesive polarizing plate according to the present invention not only has excellent initial antistatic property, but also prevents weakening of antistatic property due to changes over time, and thus has excellent antistatic effect, and excellent durability under high temperature or high humidity conditions.

In addition, it is possible to express a sufficient antistatic effect without separately forming an ITO transparent electrode between the liquid crystal panel and the polarizing plate of an image display device such as a transverse electric field type liquid crystal display device.

In addition, the use of expensive ITO can be eliminated, which is economic in terms of cost.

1 is a cross-sectional view of an antistatic adhesive polarizing plate according to an embodiment of the present invention.

The present invention relates to an antistatic adhesive polarizing plate having excellent initial antistatic property as well as suppressing the antistatic property caused by changes over time, and an image display device having the same.

Hereinafter, the present invention will be described in detail.

An antistatic adhesive polarizing plate of the present invention, as shown in Figure 1, an optical film (1); Polarizer 2; Antistatic agent low absorption optical film (3); An antistatic coating layer 4 comprising poly (3,4-ethylenedioxythiophene), carbon nanotubes or mixtures thereof; And an antistatic adhesive layer 5 including an ionic solid.

In addition, in the antistatic adhesive flat polarizing plate of the present invention, the release film 6 may be further laminated on the antistatic adhesive layer 5.

The optical film 1 is a film for protecting the polarizer 2, and if the film is excellent in transparency, mechanical strength, thermal stability, moisture shielding, isotropy, etc., its kind is not particularly limited. Specifically, polyester-based resin, such as polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate; Cellulose resins such as diacetyl cellulose and triacetyl cellulose; Polycarbonate resin; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; Styrene resins such as polystyrene and acrylonitrile-styrene copolymers; Cycloolefin-based resins; Polyolefin resin; Norbornene-based resins; Vinyl chloride-based resins; Polyamide resins such as nylon and aromatic polyamide; Imide resin; Polyether sulfone resin; Sulfone resins; Polyether ketone resins: sulfide polyphenylene resins; Vinyl alcohol-based resins; Vinylidene chloride-based resins; Vinyl butyral resin; Allyl resins; Polyoxymethylene resin; And films composed of thermoplastic resins such as epoxy resins, and the like, and films composed of blends of the above thermoplastic resins may also be used. Moreover, you may use the film which consists of thermosetting resins or ultraviolet curable resins, such as (meth) acrylic-type, urethane type, epoxy type, and silicone type. Among these, films made of cellulose resins such as triacetyl cellulose are preferred from the viewpoint of polarization characteristics and durability.

The optical film may be unstretched, uniaxially or biaxially stretched, and the thickness is usually 1 to 500 µm, preferably 1 to 300 µm, more preferably 20 to 100 µm.

A functional coating layer, such as a hard coating layer, an antireflection layer, an antiglare layer, an anti-sticking layer, a diffusion coating layer, an antiglare coating layer, and the like may be further laminated on one surface that is not bonded to the polarizer of the optical film.

The polarizer 2 is not specifically limited, For example, a dichroic substance is adsorption-oriented to a polymer film.

The polymer film constituting the polarizer is not particularly limited as long as it is a film that can be dyed with a dichroic substance, for example, iodine, and specifically, a polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymer film, and an ethylene-vinyl alcohol air. Hydrophilic polymer films such as coalesced films, cellulose films, partially gumified films thereof, and the like; Or a polyene oriented film such as a dehydrated polyvinyl alcohol film or a dehydrochloric acid treated polyvinyl alcohol film. Among them, polyvinyl alcohol-based films are preferred in that they are excellent in effect of enhancing uniformity in polarization degree and excellent in dyeing affinity for dichroic substances.

A polarizer is usually manufactured through the process of uniaxial stretching of the above-mentioned polymer film, the process of dyeing and adsorbing with a dichroic substance, the process of treating with boric acid aqueous solution, and the process of washing with water and drying. In addition, the polarizer may include boric acid, zinc sulfate, zinc chloride, or the like as necessary.

The thickness of the polarizer is not particularly limited, and may be usually 5 to 80 μm.

In the present invention, the antistatic agent low-absorbance optical film is particularly selected and used as the film laminated on the other side of the polarizer 2.

The antistatic agent low absorbency optical film 3 is a film that protects the polarizer 2 and has a low absorption rate of the ionic solid contained in the antistatic adhesive layer 5.

In general, when the antistatic pressure sensitive adhesive layer contains an ionic solid as an antistatic agent, the ionic solid transitions to the surface of the pressure sensitive adhesive layer over time, and then passes through the antistatic coating layer to be transferred to the optical film. When the optical film absorbs the transitioned ionic solid, it causes the antistatic weakness. Therefore, in the present invention, as the optical film positioned between the polarizer and the antistatic coating layer, a film having a low absorption rate of the antistatic agent can be used to suppress the movement of the antistatic agent, thereby preventing the antistatic weakening due to the lapse of time.

In the antistatic agent low absorbency optical film, the absorption rate of the ionic solid contained in the antistatic adhesive layer is preferably 50% or less. Absorption rate of the ionic solid can be measured by bonding the pressure-sensitive adhesive layer containing the ionic solid to the optical film, heating for 24 hours at the durability test conditions, for example, 60 ℃ after changing the amount of ionic solid content in the pressure-sensitive adhesive. have. When the absorption rate of the ionic solid is more than 50%, it is difficult to suppress the decrease in the antistatic property with the change over time.

Further, the antistatic agent low absorption optical film is preferably a low moisture permeability film having a water vapor transmission rate of 200 g / m 2 · day or less at 40 ° C. and 90% RH, more preferably 100 g / m 2 · day or less, most preferably 70 g / m 2 · It should be less than days. If the moisture permeability is more than 200 g / m 2 · day, it is difficult to maintain the absorption rate of the ionic solid at 50% or less, and thus it is difficult to suppress the deterioration of the antistatic property due to the change over time.

As an antistatic agent low water absorption optical film, Polyester type resins, such as a polyethylene terephthalate, a polyethylene isophthalate, a polybutylene terephthalate; Acrylic resins such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; A cycloolefin ring-opening polymer, a hydrogenated product of a ring-opening polymer using two or more cycloolefins, an addition copolymer of a cycloolefin with a chain olefin or an aromatic compound having a vinyl group such as styrene, α-methylstyrene, or nucleoalkyl substituted styrene, etc. Cycloolefin-based resins; Polyolefin resins such as polyethylene, polypropylene, ethylene propylene copolymers, polymers or copolymers of α-olefins such as poly-4-methylpentene-1 having 1 to 6 carbon atoms; Introduced and modified by introducing a polar group such as maleic acid and cyclopentadiene to the polymer or copolymer of ring-open norbornene, hydrogenated resin, norbornene addition polymer, norbornene and ethylene, α-olefin and the like A film made of a thermoplastic resin such as an addition copolymer of an olefin compound, norbornene-based resin such as an addition polymer of a cyclic olefin such as norbornene and cyclopentene, cyclooctene, 5,6-dihydrodicyclopentadiene, etc. The film comprised from the blend of the said thermoplastic resins can also be used. Among these, cycloolefin (COP) film, polyethylene terephthalate (PET) film, polymethyl methacrylate (PMMA) film, and polypropylene film (PP) are preferable. As commercially available films, Esshina, SCA40 (Sekisui Kagaku Kogyo Co., Ltd.), Aton (JSR Co., Ltd.), Zeonor (Optes Co., Ltd.), I-Film (Optes Co., Ltd.), etc. can also be used.

The antistatic agent low absorbing optical film may be unstretched, uniaxially or biaxially stretched, and the thickness is usually 1 to 500 µm, preferably 1 to 300 µm, and more preferably 20 to 100 µm.

In addition, the antistatic agent low absorption optical film may be combined with an optical compensation function such as a phase difference function.

The antistatic agent low absorbing optical film may be subjected to an activation process on the surface on which the antistatic coating layer 4 is laminated. The activation treatment is not particularly limited, and for example, corona treatment, low pressure UV treatment, plasma treatment, electron beam irradiation, anchoring agent coating, or the like can be used.

Lamination of the optical film 1 and the antistatic agent low absorbing optical film 3 on each side of the polarizer 2 may be performed using an aqueous adhesive. Examples of the aqueous adhesive include polyvinyl alcohol adhesives, polyurethane adhesives, isocyanate adhesives, gelatin adhesives, vinyl latex adhesives, and the like, and polyvinyl alcohol adhesives are preferable.

The antistatic coating layer 4 is a main layer for imparting antistatic properties in order to solve the electrostatic problem caused when the adhesive polarizing plate of the present invention is attached to an image display device, especially an IPS type LCD. (3,4-ethylenedioxythiophene), carbon nanotubes or mixtures thereof.

An antistatic agent that is water soluble or water dispersible can form an antistatic coating layer without causing quality change and deterioration of the optical film, and is also preferable in terms of process convenience and environmental friendliness.

The antistatic coating layer is formed from an antistatic coating liquid composition comprising a binder resin together with the antistatic agent. The binder resin plays a role of improving the adhesion between the optical film and the antistatic coating layer, as well as improving the adhesion between the antistatic coating layer and the antistatic adhesive layer, and at the same time, improving the conductivity to improve the antistatic performance. As such a water-soluble or water-dispersible binder resin, any polymer known in common may be used as long as its solubility in water is 0.1% by weight or more. Specifically, as a homopolymer or copolymer containing a hydrophilic unit, for example, polyvinyl alcohol (containing partially saponified), polyacrylic acid, polymethacrylic acid, poly (2-hydroxyethyl (meth) acrylate), Poly (4-hydroxybutyl (meth) acrylate), poly (glycosyloxyethyl (meth) acrylate), polyvinylmethyl ether, polyvinylpyrrolidone, polyethylene glycol, polyvinyl acetal (containing partial acetalide) , Polyethyleneimine, polyethylene oxide, styrene-maleic anhydride copolymer, polyvinylamine, oxazoline group-containing water-soluble resin, polyurethane resin, polyester resin, acrylic resin, alkyd resin, polyether resin, melamine resin And cellulose resins, and the like, and these may be used alone or in combination of two or more thereof in a fixed ratio or copolymerized. Of these, polyurethane resins, polyester resins, acrylic resins, and polyvinyl alcohol resins are preferable.

The antistatic agent may be included in an amount of 10 to 300 parts by weight based on 100 parts by weight of the binder resin (based on the solid content), and preferably 50 to 200 parts by weight. If the content is less than 10 parts by weight can not give sufficient antistatic performance, if more than 300 parts by weight may cause coating failure during coating.

The method of laminating the antistatic coating layer is not particularly limited as long as it is a method commonly used in the art. For example, the antistatic coating liquid composition on the antistatic agent low absorption optical film in a suitable development method using a flow casting method and a coating method such as air knife, gravure, reverse roll, kiss roll, spray, blade or bar coater, etc. It can be applied directly, dried and laminated.

It is preferable that the thickness of an antistatic coating layer is 0.01-3 micrometers normally, More preferably, it is 0.01-1 micrometer. If the thickness is less than 0.01 μm, the adhesion with the substrate is poor and the effect of imparting antistatic property is insignificant. If the thickness is more than 3 μm, the effect of improving the antistatic property is no longer increased. There is this.

The antistatic coating layer preferably has a surface resistivity of 7 × 10 ⁶ Ω / □ or less. If the surface resistivity exceeds 7 × 10 ⁶ Ω / □, it is difficult to secure sufficient antistatic properties required for the adhesive polarizing plate.

The antistatic adhesive layer 5 is an auxiliary layer that serves to fix the polarizing plate to the liquid crystal panel and at the same time provides an antistatic property for solving the electrostatic problem that is difficult to solve only with the antistatic coating layer 4, and particularly, an antistatic agent It is characterized in that it comprises an ionic solid.

An antistatic adhesive layer is formed from the adhesive composition which contains an adhesive resin and a crosslinking agent with the said antistatic agent, and further contains a silane coupling agent and various additives as needed.

Examples of the pressure-sensitive adhesive resins include acrylic resins, silicone resins, polyester resins, polyurethanes, polyimides, polyethers, fluorine or rubber resins, among which are excellent in optical transparency and suitable for wettability, cohesiveness, adhesiveness, and the like. Acrylic resins excellent in adhesive properties, physical properties such as weather resistance and heat resistance are preferably used.

Acrylic resin is a resin having adhesive force that can act as an adhesive, an acrylic copolymer composed of an alkyl (meth) acrylate monomer having 4 to 12 carbon atoms, a polymerizable monomer having a crosslinkable functional group, and other monomers copolymerizable as necessary. Can be used. Here, (meth) acrylate means both acrylate and methacrylate.

Examples of the alkyl (meth) methacrylate monomer having 4 to 12 carbon atoms include (meth) acrylates derived from aliphatic alcohols having 4 to 12 carbon atoms, such as n-butyl (meth) acrylate and 2-butyl (meth). Acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, Lauryl (meth) acrylate, etc. are mentioned, These can be used individually or in mixture of 2 or more types. Among them, it is preferable to use n-butyl acrylate, 2-ethylhexyl acrylate or a mixture thereof.

The alkyl (meth) methacrylate monomer having 4 to 12 carbon atoms is included in an amount of 80 to 99% by weight, preferably 90 to 95% by weight, based on 100% by weight of the total monomers used to prepare the acrylic copolymer. If the content is less than 80% by weight, the adhesion may be lowered, and if it is more than 99% by weight, the cohesion may be reduced.

The polymerizable monomer having a crosslinkable functional group acts to impart cohesion force or adhesive strength by chemical bonding so as not to cause cohesive breakage of the pressure sensitive adhesive under high temperature or high humidity by reacting with a crosslinking agent. The polymerizable monomer having a carboxyl group and a hydroxyl group And a polymerizable monomer having an amide group, a polymerizable monomer having an amide group or a tertiary amine group.

Examples of the polypolymerizable monomer having a carboxyl group include monovalent acids such as (meth) acrylic acid and crotonic acid; Diacids such as maleic acid, itaconic acid and fumaric acid, and monoalkyl esters of the diacids; 3- (meth) acryloylpropionic acid; Succinic anhydride ring-opening adduct to 2-hydroxyalkyl (2-3 carbon) (meth) acrylate, Succinic anhydride ring-opening adduct to polyoxyalkylene (2-4 carbon) glycol mono (meth) acrylate, 2 The compound etc. which ring-opened and added amber acid anhydride to the caprolactone adduct to -hydroxyalkyl (C2-3) (meth) acrylate are mentioned, Among these, acrylic acid is preferable.

Examples of the polymerizable monomer having a hydroxy group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and polyoxyalkylene (carbon number 2 to 4) glycol mono (meth) acrylate, etc. are mentioned, Among these, 2-hydroxyethyl (meth) acrylate is preferable.

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

Examples of the polymerizable monomer having a tertiary amine group include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminopropyl acrylate, and the like. .

The polymerizable monomer having a crosslinkable functional group is included in an amount of 1 to 10% by weight, preferably 1 to 5% by weight, based on 100% by weight of the total monomers used for preparing the acrylic copolymer. If the content is less than 1% by weight, cohesion may be lowered, and if it is more than 10% by weight, cohesiveness may be lowered.

Other monomers copolymerizable as necessary are not particularly limited in kind, and are included in an amount of 0 to 10% by weight, preferably 0 to 5% by weight, based on 100% by weight of the acrylic copolymer. When the content is more than 10% by weight, the adhesive force of the pressure-sensitive adhesive composition may be lowered. It indicates that the '0' component is not included in the content.

The acrylic copolymer has a weight average molecular weight (polystyrene equivalent) measured by gel permeation chromatography (GPC) in general of 50,000 to 2,000,000, preferably 100,000 to 1,800,000, and more preferably 500,000 to 1,500,000. good. If the weight average molecular weight is less than 50,000, the durability may be lowered, and if the weight average molecular weight is more than 2,000,000, the viscosity may be increased to reduce the coatability.

A crosslinking agent is used in order to strengthen the cohesion force of an adhesive by crosslinking an acryl-type copolymer suitably, An isocyanate compound is preferable.

As an isocyanate compound, tolylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, 2, 4- diphenyl methane diisocyanate, 4, 4- diphenyl methane diisocyanate, isophorone diisocyanate, tetramethyl xylene diisocyanate, etc. The diisocyanate compound and the adduct to polyhydric-alcohol type compounds, such as the trimethylol propane, of the said diisocyanate are mentioned.

Melamine resins such as hexamethylolmelamine, hexamethoxymethylmelamine, and hexabutoxymethylmelamine with an isocyanate compound; Polyepoxy compounds, such as bisphenol A and an epoxy compound of epichlorohydrin condensate type, polyglycidyl ether of polyoxyalkylene polyol, glycerin diglycidyl ether, glycerin triglycidyl ether, tetraglycidyl xylenediamine, etc. At least one crosslinking agent selected from the group consisting of an epoxy compound may be further used.

The crosslinking agent is included in an amount of 1 to 15 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the acrylic copolymer (based on the solid content). If the content is less than 1 part by weight, the cohesion may be reduced due to insufficient crosslinking degree, and durability may be lowered. If the content is more than 15 parts by weight, the cohesion may be reduced due to excessive crosslinking reaction.

An ionic solid, which is an antistatic agent, is formed by an ion combination of a cation and an anion, and means a salt in a solid state at room temperature (25 ° C.). Ionic solids can achieve sufficient antistatic interaction effect with the antistatic coating layer, there is no dispersibility problem and instability during application, and transparency and low haze value, even in the adhesiveness without lowering the contrast ratio It is preferable at the point which shows the outstanding characteristic.

Specific examples of the cation constituting the ionic compound include alkali metal cations such as Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Cs ⁺ ; Tetraalkylammoniums such as tetramethylammonium, tetraethylammonium, tetrabutylammonium, tetrahexyl ammonium, trialkylsulfonium, tetraalkylphosphonium, and cations in which some of their alkyl groups are substituted with alkenyl, alkoxyl or epoxy groups; Pyridinium cation, piperidinium cation, pyrrolidinium cation, cation with pyrroline skeleton, cation with pyrrole skeleton, imidazolium cation, tetrahydropyridinium cation, dihydropyrimidinium cation, pyrazollium cation and pyra A zolinium cation. Further, specific examples of the ^{anion, Cl -, Br -, I} -, AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, CO 3 2-, CH 3 _{^{COO -, CF 3 COO -,}} CH 3 SO 3 -, CF 3 SO 3 -, (CF 3 SO 2) 2 N -, (CF 3 SO 2) 3 C -, AsF 6 -, SbF 6 -, NbF 6 _{^{-, TaF 6 -, F (}} HF) n -, (CN) 2 N -, C 4 F 9 SO 3 -, (C 2 F 5 SO 2) 2 N -, C 3 F 7 COO -, C 6 H _{^{5 COO -, (CF 3 SO}} 2) (CF 3 CO) N -, OTf - ( methanesulfonate trifluoroacetate), OTs ^- (toluene sulfonate), OMS ^- (methanesulfonate), or BPh ₄ ^- (tetrahydro Phenyl borate), and the like. Among these, compounds composed of a pyridinium cation and a PF ₆ ^- anion are preferable, for example, 4-octyl-1-methylpyridinium hexafluorophosphate and 4-hexyl-1-methylpyridinium hexafluorophosphate are preferable. .

The antistatic agent is preferably included in 0.5 to 10 parts by weight with respect to 100 parts by weight of the acrylic copolymer (based on the solid content), and more preferably 0.8 to 8 parts by weight. If the content is less than 0.5 parts by weight, it is difficult to impart sufficient antistatic properties, and if it is more than 10 parts by weight, transparency may be lowered.

The silane coupling agent is for better adhesion at the time of joining with the substrate, for example, vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimeth Methoxysilane, 3-glycidoxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 2- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, or acetoacetylate-based silane coupling agent, and the like. It can be used as a mixture. The silane coupling agent is preferably included 0.1 to 1 parts by weight based on 100 parts by weight of the acrylic copolymer (based on the solid content). When the content is less than 0.1 part by weight, the effect of improving adhesion with the liquid crystal cell may be insignificant, and when the content is more than 1 part by weight, the reworkability may be reduced.

In addition, the additives are to adjust the adhesion, cohesion, viscosity, elastic modulus, glass transition temperature, etc. required according to the use, tackifying resin, plasticizer, antioxidant, corrosion inhibitor, leveling agent, surface lubricant, dye, pigment, Antifoaming agents, fillers, light stabilizers and the like.

The method of laminating the antistatic adhesive layer on the antistatic coating layer is not particularly limited as long as it is a method commonly used in the art. For example, the antistatic pressure-sensitive adhesive composition is applied directly onto the antistatic coating layer in a suitable development method using a flow casting method and a coating method such as air knife, gravure, reverse roll, kiss roll, spray, blade or bar coater, and the like. It can be dried and laminated. In addition, the pressure-sensitive adhesive layer is formed on the release film coated with the silicone release film in the same manner as above to prepare an adhesive sheet, and then may be laminated on the antistatic coating layer using a roll pressing device.

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

It is preferable that an antistatic adhesive layer has surface specific resistance, ie, the surface specific resistance of an antistatic adhesive type polarizing plate is 1 * 10 <^9> -5 * 10 <^{11> (} ohm) / square. If the surface resistivity is less than 1 × 10 ⁹ Ω / □, transparency may be degraded. If it is more than 5 × 10 ¹¹ Ω / □, the effect as an auxiliary layer for solving the problem of static electricity generation is insignificant.

The release film 6 is a film for protecting the antistatic pressure-sensitive adhesive layer, the type is not particularly limited as long as it is a film commonly used in the art. For example, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethylacryl Polyolefin type films, such as a rate copolymer and an ethylene-vinyl alcohol copolymer; Polyester-based films such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; Acrylic film; Polystyrene film; Polyamide films such as nylon 6 and partially aromatic polyamides; Polyvinyl chloride film; Polyvinylidene chloride film; Polycarbonate film etc. are mentioned. These may be those which have been appropriately released by a release agent such as silicon-based, fluorine-based or silica powder.

The antistatic adhesive polarizing plate of the present invention configured as described above can effectively solve the problem of static electricity generation by including an antistatic adhesive layer together with the antistatic coating layer. In particular, by using an antistatic agent low absorbing optical film as a substrate on which an antistatic coating layer is laminated, an ionic solid, which is an antistatic agent contained in an antistatic adhesive layer, migrates to the surface of the adhesive layer over time. Transition to the optical film through the protective coating layer, it is possible to suppress the movement of the ionic solid to prevent the antistatic property is weakened. That is, the antistatic adhesive polarizing plate of the present invention is a polarizing plate in which not only the initial antistatic property is excellent but also the antistatic property due to the change with time is suppressed.

The antistatic adhesive polarizing plate of the present invention preferably has a change rate of antistatic property due to change over time, for example, a rate of change of antistatic property after being left at room temperature (25 ° C.) for 500 hours, that is, lower than 10%. When the antistatic property fall rate is more than 10%, it is difficult to suppress the weakening of the antistatic property.

The antistatic adhesive polarizing plate of the present invention is particularly preferably applied to a transverse electric field type liquid crystal display in that it can express a sufficient antistatic effect without separately forming a conventionally required ITO transparent electrode.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

[Example]

Preparation Example 1-1: Antistatic Coating Liquid Composition A

Antistatic coating solution composition A by adding 150 parts by weight (based on solids content) of polyethylene dioxythiophene dispersion (Conisol-H4, Inscon) as an antistatic agent to 100 parts by weight (based on solids content) of polyvinyl alcohol (PVA) binder resin Was prepared.

Preparation Example 1-2: Antistatic Coating Liquid Composition B

Prepared in the same manner as in Preparation Example 1-1, 50 parts by weight (based on solids content) of polyethylenedioxythiophene dispersion (Conisol-H4, Inscon) was used.

Preparation Example 1-3 Antistatic Coating Liquid Composition C

Prepared in the same manner as in Preparation Example 1-1, 150 parts by weight of carbon nanotubes (SA100, NanoSolution Co., Ltd.) was used instead of the polyethylenedioxythiophene dispersion.

Preparation Example 1-4 Antistatic Coating Liquid Composition D

Prepared in the same manner as in Preparation Example 1-1, 150 parts by weight of an alkali metal salt (LiI, Chemetall) was used in place of the polyethylenedioxythiophene dispersion.

Preparation Example 2-1 Antistatic Adhesive Sheet A

(1) acrylic copolymer

98.1 parts by weight of n-butyl acrylate (BA), 0.5 parts by weight of acrylic acid (AA), 2-hydroxyethyl methacrylate (2- HEMA) 1.4 parts by weight was added, and then 100 parts by weight of ethyl acetate (EA) was added as a solvent. Thereafter, to remove oxygen, nitrogen gas was added for 1 hour to be replaced, and the temperature was maintained at 62 ° C. After the mixture was stirred uniformly, 0.07 parts by weight of azobis isobutyronitrile (AIBN) was added as a reaction initiator and reacted for 8 hours to prepare an acrylic copolymer having a weight average molecular weight of 600,000 or more.

(2) antistatic adhesive composition

100 parts by weight of the acrylic copolymer (1) based on (1), 0.5 parts by weight of tolylene diisocyanate adduct (TMP-TDI, COR-L, Japan Polyurethane Industry Co., Ltd.) of trimethylolpropane as a crosslinking agent, 4 as an antistatic agent. 3 parts by weight of octyl-1-methylpyridinium hexafluorophosphate (IL-P18-2-60T, Co., Ltd.), 3-glycidoxypropyltrimethoxysilane (KBM-403, Shin-Etsu) 0.5 as a silane coupling agent After mixing parts by weight, the coating composition was diluted to an appropriate concentration to prepare a pressure-sensitive adhesive composition.

(3) Antistatic adhesive sheet

The prepared pressure-sensitive adhesive composition was coated on a film coated with a silicone release agent to have a thickness of 25 μm, and dried at 100 ° C. for 1 minute to form an antistatic pressure-sensitive adhesive layer. On top of that, another layer of the release film was laminated and cured at 25 ° C. for 7 days to prepare an adhesive sheet A.

Preparation Example 2-2: Antistatic Adhesive Sheet B

Manufactured in the same manner as in Preparation Example 2-1, 1 part by weight of 4-octyl-1-methylpyridinium hexafluorophosphate (IL-P18-2-60T, Co., Ltd.) was used as an antistatic agent.

Preparation Example 2-3: Antistatic Adhesive Sheet C

Manufactured in the same manner as in Preparation Example 2-1, 7 parts by weight of 4-octyl-1-methylpyridinium hexafluorophosphate (IL-P18-2-60T, Co., Ltd.) was used as an antistatic agent.

Preparation Example 2-4: Adhesive Sheet D

Prepared in the same manner as in Preparation Example 2-1, but did not use an antistatic agent.

Example 1

(1) polarizer

After drying the water-based adhesive on both sides of the polyvinyl alcohol (PVA) polarizer and coating it so that the thickness is 0.1 μm, the triacetyl cellulose (thickness 40 μm, TAC) film and the Zeonor (Optes) film are respectively bonded. And dried at a temperature of 50-80 ° C. for 5 minutes to prepare a polarizing plate, wherein, as the water-based adhesive, 3 parts by weight of carboxyl group-modified polyvinyl alcohol resin (Kurarefobal KL318, Kuraray Co., Ltd.) in 100 parts by weight of water. The part and 1.5 weight part of polyamide epoxy resins (30 weight% of solid content, Sumires resin 650, Sumitomo Chemical Co., Ltd.) were used.

(2) antistatic adhesive polarizing plate

Bar coater (# 4) so as to have a thickness of 0.1 μm after drying the antistatic coating liquid composition A of Preparation Example 1-1 on the ZEONOR (Optes) film of the polarizing plate of (1) It was applied using, and dried for 1 minute at 80 ℃ to form an antistatic coating layer.

The release film of the antistatic adhesive sheet A of Preparation Example 2-1 was peeled off on the formed antistatic coating layer, and the antistatic adhesive layer was laminated at a pressure of 0.25 MPa to prepare an adhesive polarizing plate.

Example 2

The same process as in Example 1, but in (2) was used in the antistatic coating solution composition B of Preparation Example 1-2.

Example 3

In the same manner as in Example 1, but in (2) to use the antistatic adhesive sheet C of Preparation Example 2-3.

Example 4

It carried out similarly to Example 1, but used the antistatic adhesive sheet B of Preparation Example 2-2 in (2).

Example 5

In the same manner as in Example 1, in (1), instead of ZEONOR (Optes) film was used an ATON (ARTON, JSR Co., Ltd.) film.

Example 6

In the same manner as in Example 1, in (1), instead of a zeonor (ZEONOR, (Optes) film, a polyethylene terephthalate (PET) film was used.

Example 7

In the same manner as in Example 1, in (1) a polypropylene (PP) film was used instead of ZEONOR (Optes) film.

Example 8

In the same manner as in Example 1, in (1) I-film (Optes Co., Ltd.) was used instead of ZEONOR (Optes, Inc.) film.

Example 9

In the same manner as in Example 1, (2) to use the antistatic coating solution composition C of Preparation Example 1-3.

Comparative Example 1

In the same manner as in Example 1, in (1), instead of ZEONOR (Optes) film was used a TAC film having a thickness of 40㎛.

Comparative Example 2

In the same manner as in Example 1, in (1), instead of ZEONOR (Optes) film was used a TAC film having a thickness of 60㎛.

Comparative Example 3

In the same manner as in Example 1, in (1), instead of ZEONOR (Optes) film was used a TAC film having a thickness of 80㎛.

Comparative Example 4

In the same manner as in Example 1, (2) to use the antistatic coating solution composition D of Preparation Example 1-4.

Comparative Example 5

It carried out in the same manner as in Example 1, but in (2) was used the adhesive sheet D of Preparation Example 2-4.

division Optical film Antistatic Coating Layer Antistatic Adhesive Layer Kinds Moisture permeability
(g / m ² / day) Coating solution
Kinds Surface resistivity
(Ω / □) Adhesive Sheet
Kinds Antistatic agent
(Parts by weight) Surface resistivity
(Ω / □) Example 1 ZEONOR 3.9 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Example 2 ZEONOR 3.9 B 5 × 10 ⁶ A 3 3 × 10 ¹⁰ Example 3 ZEONOR 3.9 A 5 × 10 ⁵ C 7 3 × 10 ⁹ Example 4 ZEONOR 3.9 A 5 × 10 ⁵ B One 3 × 10 ¹¹ Example 5 ARTON 67.5 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Example 6 PET 16 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Example 7 PP 0.8 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Example 8 I-film 13 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Example 9 ZEONOR 3.9 C 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Comparative Example 1 TAC (40 μm) 791 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Comparative Example 2 TAC (60 μm) 750 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Comparative Example 3 TAC (80 μm) 573 A 5 × 10 ⁵ A 3 3 × 10 ¹⁰ Comparative Example 4 ZEONOR 3.9 D 5 × 10 ⁹ A 3 3 × 10 ¹² Comparative Example 5 ZEONOR 3.9 A 5 × 10 ⁵ D - over

Test Example

One. Antistatic property with time change

1-1. Initial surface resistivity (Ω / □) measurement

(1) antistatic coating layer

The surface resistivity value of the formed antistatic coating layer was measured at an applied voltage of 10V under the condition of 23 ° C. and 60% RH.

(2) pressure-sensitive adhesive layer (polarizing plate)

The release film of the prepared adhesive polarizing plate was peeled off, and the surface specific resistance value of the adhesive layer was measured. At this time, the polarizing plate in which the antistatic adhesive layer was laminated | stacked was measured by the applied voltage 500V under the conditions of 23 degreeC and 60% RH. Surface resistivity of more than 10 ¹⁴ Ω / □ is generally considered to be over antistatic.

Measuring instrument: Surface resistance measuring instrument (MCP-HT450, MITSUBISHI CHEMICAL), probe bar (URS, UR100), probe bar measuring instrument (URS, for UR100)

-Measurement method: The three points of the surface were measured 10 times, and the average value was shown.

1-2. Surface resistivity (Ω / □) measurement over time

The prepared pressure-sensitive adhesive polarizing plate was left at room temperature (25 ° C.) for 500 hours and then measured in the same manner as in Test Example 1. The amount of change (fall) of the measured value relative to the initial value was calculated and evaluated based on the following criteria.

(Circle): The change amount of surface resistivity with time compared with an initial antistatic property is less than 10%.

X: The amount of change in surface specific resistance with respect to initial stage antistatic property is 10% or more.

2. Electrostatic Rating (ESD)

The prepared pressure-sensitive adhesive polarizing plate is cut to a size of 10 cm × 10 cm, the release film is peeled off, and then bonded to a 32-inch liquid crystal panel. The panel was placed on a backlight having a luminance of 10,000 cd, generating 10 mV of static electricity using an electrostatic generator (ESD, ESS-2002, NoiseKen), causing liquid crystal orientation disturbance. The phenomenon of display defects (liquid crystal distortion, whitening) due to orientation defects was visually observed, and the recovery time of the display defects was measured and evaluated based on the following criteria.

<Evaluation Criteria>

(Double-circle): There is no display bad phenomenon.

○: Some display defects occur but recover within 3 seconds.

X: A lot of display defects generate | occur | produce and do not recover within 3 second.

3. Heat resistance

The prepared pressure-sensitive adhesive polarizing plate was cut to a size of 15 cm × 15 cm, and then bonded to glass (# 1737, Corning) to prepare a specimen. The prepared specimens were treated in an autoclave for 5 minutes under conditions of 5 atm and 50 ° C. After the treated specimen was allowed to stand at a temperature of 80 ° C. for 500 hours, it was observed whether bubbles or peeling occurred. At this time, it was observed after leaving for 25 hours at room temperature immediately before evaluating the state of the specimen, and evaluated based on the following criteria.

<Evaluation Criteria>

(Circle): There is no peeling phenomenon and bubble generation (good).

X: There exists peeling phenomenon and bubble (defect).

4. Water vapor permeability (g / ㎡ · day)

Specimens were prepared by cutting the optical film to be measured to a size of 10 cm × 10 cm. About 7 g of dried calcium chloride (CaCl ₂ ) and the specimen were placed in a cup for measuring the moisture permeability and then sealed. The sealed cup was placed in an oven for temperature / humidity control at 40 ° C. and 90% RH, and left for 24 hours. Then, the weight change was measured using an electronic balance and calculated by Equation 1 below.

(Wherein A is the weight of the initially sealed cup (g), B is the weight of the sealed cup (g) after standing for 24 hours, and R is 0.0026 m 2 by area of the cup for measuring moisture permeability).

division Antistatic over time Static electricity rating Heat resistance Example 1 ○ ○ ○ Example 2 ○ ○ ○ Example 3 ○ ◎ ○ Example 4 ○ ◎ ○ Example 5 ○ ○ ○ Example 6 ○ ○ ○ Example 7 ○ ○ ○ Example 8 ○ ○ ○ Example 9 ○ ◎ ○ Comparative Example 1 × ○ ○ Comparative Example 2 × ○ ○ Comparative Example 3 × ○ ○ Comparative Example 4 ○ × ○ Comparative Example 5 ○ × ○

As shown in the above table, the adhesive polarizers of Examples 1 to 9, in which the antistatic coating layer and the antistatic adhesive layer were sequentially stacked on the antistatic agent low absorption optical film according to the present invention, were excellent in initial antistatic property. In addition, there was almost no deterioration of the antistatic property with time, and thus the static electricity evaluation result was good and the heat resistance was confirmed to be satisfied.

On the other hand, the polarizing plates of Comparative Examples 1 to 3 using the conventional TAC film instead of the antistatic low absorbing optical film was found to have a large decrease in the antistatic property with respect to the change over time. In addition, the polarizing plate of Comparative Example 4 using an alkali metal salt in the antistatic coating layer and Comparative Example 5 in which a normal pressure-sensitive adhesive layer other than an antistatic property was laminated did not exhibit sufficient antistatic property.

1: optical film 2: polarizer
3: antistatic agent low absorption optical film 4: antistatic coating layer
5: antistatic adhesive layer 6: release film

Claims (9)

Optical film;
Polarizer;
Antistatic agent low absorption optical film;
An antistatic coating layer comprising poly (3,4-ethylenedioxythiophene), carbon nanotubes, or mixtures thereof; And
An antistatic adhesive type polarizing plate laminated in the order of an antistatic adhesive layer containing an ionic solid.
The antistatic adhesive polarizing plate according to claim 1, wherein the antistatic agent low absorption optical film has a water vapor transmission rate of 200 g / m 2 · day or less at 40 ° C. and 90% RH.
The antistatic adhesive polarizing plate according to claim 1, wherein the antistatic agent low absorbing optical film is selected from the group consisting of a cycloolefin film, an acrylic film, a polyester film, a polynorbornene film, and a polyolefin film.
The antistatic adhesive polarizing plate according to claim 1, wherein the antistatic coating layer has a surface resistivity of 7 × 10 ⁶ Ω / □ or less.
The antistatic adhesive layer according to claim 1, wherein the antistatic adhesive layer has a surface resistivity of 1 × 10 ⁹ to 5 × 10 ¹¹ Ω / □.
The antistatic adhesive of claim 1, wherein the antistatic adhesive layer comprises an acrylic copolymer as an adhesive resin, and the ionic solid is contained in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the acrylic copolymer (based on the solid content). Type polarizer.
The antistatic adhesive polarizing plate according to claim 6, wherein the ionic solid is ion-combined pyridinium cation and PF ₆ ⁻ anion.
The antistatic adhesive polarizing plate according to claim 1, wherein the rate of antistatic reduction after leaving for 500 hours at room temperature is less than 10%.
An image display device provided with the antistatic adhesive polarizing plate of any one of claims 1 to 8.

Images