TW201830103A - Polarizing plate and liquid crystal display device - Google Patents

Abstract

The present invention provides a polarizing plate capable of efficiently manufacturing a liquid crystal display device without causing multiple taking and product defects, and capable of making a touch panel excellent in operability. The polarizing plate of the present invention has a 1st transparent resin layer on one side of a polarizer and a 2nd transparent resin layer on the other side; wherein the thickness of the polarizer is 15 [mu]m or less; the surface resistance value of the 1st transparent resin layer is 1.0*10<SP>9</SP> [Omega]/□ or more and 1.0*10<SP>11</SP> [Omega]/□ or less; the 2nd transparent resin layer has an antistatic function; the distance between the 1st transparent resin layer and the 2nd transparent resin layer is 80 [mu]m or less.

Description

   Polarizing plate and liquid crystal display device   

The present invention relates to a polarizing plate and a liquid crystal display device.

Liquid crystal display devices are used in various display devices, taking advantage of their low power consumption, low voltage operation, light weight and thinness. Among liquid crystal display devices and the like, a liquid crystal display device in which an image display device and a touch panel are combined is becoming common. Among them, capacitive touch panels are rapidly becoming widespread due to their functionality.

In Patent Document 1, it is described that a transparent resin layer having a surface resistance value of 1.0 × 10 ¹³ Ω / □ or less is arranged on the far side (view side) from the liquid crystal cell of the viewing-side polarizing plate. Specifically, it is a polarizing plate in which a triethyl cellulose film is laminated on both sides of a polarizer having a thickness of 20 μm, and an adhesive layer is laminated on each of the triethyl cellulose films, so that they are on the viewing side. The adhesive layer contains an ionic compound, and the polarizing plate is provided with an antistatic function.

When a liquid crystal display device is manufactured using the polarizing plate described in Patent Document 1, if the polarizing plate is taken out one by one from the laminated body of the polarizing plate cut into a sheet and supplied, there will be multiple acquisitions of taking out a plurality of polarizing plates at once. The problem.

In addition, when a liquid crystal display device is manufactured using the polarizing plate described in Patent Document 1, when the step of peeling the surface protective film from the cover glass is included, static electricity is generated with the peeling, the orientation of the liquid crystal is disturbed, and the product may be defective. On the other hand, since the operability of the touch panel must be ensured, the surface resistance value cannot be easily reduced.

    [Prior technical literature]         [Patent Literature]    

[Patent Document 1] Japanese Patent Laid-Open No. 2015-200698

An object of the present invention is to provide a polarizing plate, which can efficiently manufacture a liquid crystal display device without causing multiple acquisitions, defective products, and can be a good operability of a touch panel.

[1] A polarizing plate, which is a polarizing plate having a first transparent resin layer on one side of the polarizer and a second transparent resin layer on the other side; the thickness of the polarizer is 15 μm or less; and the first transparent resin layer The surface resistance value is 1.0 × 10 ⁹ Ω / □ or more and 1.0 × 10 ¹¹ / □ or less; the second transparent resin layer has an antistatic function; the distance between the first transparent resin layer and the second transparent resin layer It is 80 μm or less.

[2] The polarizing plate according to [1], wherein a protective film is provided between the first transparent resin layer or the second transparent resin layer and the polarizer.

[3] The polarizing plate according to [1] or [2], wherein the protective film is selected from a cyclic olefin resin film, a cellulose resin film, a polycarbonate resin film, a polyolefin resin film, At least one of a polyethylene terephthalate resin film, a methyl methacrylate resin film, and a brightness enhancement film.

[4] The polarizing plate according to any one of [1] to [3], wherein the first transparent resin layer and the second transparent resin layer are layers disposed on the outermost sides of the polarizing plate, respectively.

[5] A liquid crystal display device, wherein the polarizing plate according to any one of [1] to [4] is disposed on a viewing side of a liquid crystal cell, and a front panel is disposed on the polarizing plate.

According to the present invention, it is possible to provide a polarizing plate, which can efficiently manufacture a liquid crystal display device without causing multiple acquisitions, defective products, and can be a good operability of a touch panel.

1‧‧‧ polarizer

2‧‧‧ front panel

3‧‧‧ LCD cell

4‧‧‧ double arrow

10‧‧‧The first transparent resin layer

11‧‧‧The second transparent resin layer

20,21‧‧‧protective film

30‧‧‧ Adjacent layer

100,101,102‧‧‧polarizing plate

200,201,202‧‧‧LCD display device

FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of a polarizing plate.

FIG. 2 is a schematic cross-sectional view showing an example of a layer structure of a liquid crystal display device.

FIG. 3 is a schematic cross-sectional view of a polarizing plate for explaining the distance between the first transparent resin layer and the second transparent resin layer.

    <Polarizer>    

FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of a polarizing plate. As shown in FIG. 1 (a), the polarizing plate of the present invention includes a first transparent resin layer 10 on one side of the polarizer 1 and a second transparent resin layer 11 on the other side. As shown in FIG. 1 (b) and FIG. 1 (c), the polarizing plate of the present invention may have a protective film 20 between the first transparent resin layer 10 and the polarizer 1, and the second transparent resin layer 11 and A protective film 21 may be provided between the polarizers 1. The polarizing plate of the present invention may further include another film. Of course, a protective film may be provided on the outside of the first transparent resin layer 10 and the second transparent resin layer 11, or may have other films.

Furthermore, in the polarizing plate of the present invention, the distance between the first transparent resin layer 10 and the second transparent resin layer 11 is 80 μm or less, and may be 70 μm or less. Generally, the distance between the first transparent resin layer 10 and the second transparent resin layer 11 is 20 μm or more. When using FIG. 3 to describe in detail, the distance between the first transparent resin layer 10 and the second transparent resin layer 11 refers to the second transparent layer from the surface of the first transparent resin layer 10 near the polarizer 1 side. The distance of the surface of the resin layer 11 near the polarizer 1 side corresponds to the distance shown by the double arrow 4 in FIG. 3. According to the present invention, even if the distance between the first transparent resin layer 10 and the second transparent resin layer 11 is short, and it is susceptible to static electricity, it is not likely to cause defects when manufacturing a liquid crystal display device. In addition, even if the distance between the first transparent resin layer 10 and the second transparent resin layer 11 is short, and a structure in which multiple acquisitions are likely to occur, a liquid crystal display device can be manufactured efficiently.

In the polarizing plate of the present invention, the first transparent resin layer and the second transparent resin layer are preferably layers disposed on the outermost sides of the polarizing plate, respectively. In addition, the polarizing plate is a case where a protective film and a separator are laminated during the manufacturing process of the liquid crystal display device. Since the protective film and the separator are not incorporated into the liquid crystal display device at the end, they are not regarded as the layer disposed on the outermost side of the polarizing plate in the present invention.

Hereinafter, each member constituting the polarizing plate of the present invention will be described.

    (Polarizer)    

The polarizer used in the present invention is generally a step of extending a polyvinyl alcohol-based resin film through one axis, a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol-based resin film with a dichroic dye, and adsorbing two A step of treating a polyvinyl alcohol-based resin film of a chromatic dye with a boric acid aqueous solution and a step of washing with a boric acid aqueous solution after being processed.

As the polyvinyl alcohol-based resin film, a saponified polyvinyl acetate-based resin can be used. Examples of the polyvinyl acetate-based resin include copolymers of vinyl acetate and other monomers copolymerizable therewith, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, and preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, aldehyde-modified polyvinylformal, polyvinylacetal, or the like may be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, and preferably about 1,500 to 5,000.

A film made of a polyvinyl alcohol resin can be used as a raw material film of a polarizer. A method of forming a polyvinyl alcohol-based resin into a film can be performed by a conventional method. The thickness of the polyvinyl alcohol-based raw material film is preferably about 5 to 35 μm, and more preferably about 5 to 20 μm in consideration of the thickness of the obtained polarizer being 15 μm or less. When the film thickness of the raw material film is 35 μm or more, the stretching magnification during the production of the polarizer must be high, and the size shrinkage of the obtained polarizer tends to increase.

On the other hand, when the film thickness of the raw material film is 5 μm or less, the workability at the time of stretching is lowered, and defects such as cutting during production tend to be more likely to occur.

The uniaxial extension of the polyvinyl alcohol-based resin film may be performed before dyeing of the dichroic pigment, simultaneously with dyeing, or after dyeing. When the one-axis extension is performed after dyeing, the one-axis extension may be performed before or during the boric acid treatment. Furthermore, one-axis extension may be performed in such plural stages.

In terms of one-axis extension, one-axis extension can be performed between rollers with different rotation speeds, and one-axis extension can also be performed using hot rollers. Further, the uniaxial stretching may be a dry stretching in the atmosphere, or a wet stretching in which the polyvinyl alcohol-based resin film is swollen using a solvent. The stretching ratio is usually about 3 to 8 times.

As a method of dyeing a polyvinyl alcohol-based resin film with a dichroic dye, for example, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a dichroic dye can be adopted. As the dichroic dye, specifically, iodine and a dichroic dye can be used. In addition, it is preferable that the polyvinyl alcohol-based resin film is impregnated with water before the dyeing treatment.

When using iodine as a dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film by immersing it in an aqueous solution containing iodine and potassium iodide is generally adopted. The iodine content of the aqueous solution is usually about 0.01 to 1 part by weight per 100 parts by weight of water. The content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ° C.

The immersion time (dyeing time) of the aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when a dichroic dye is used as a dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is generally adopted. The content of the dichroic dye in the aqueous solution is usually about 1 × 10 ^-4 to 10 parts by weight, preferably about 1 × 10 ^-3 to 1 part by weight, per 100 parts by weight of water. This aqueous solution may contain an inorganic salt such as sodium sulfate as a coloring aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually about 20 to 80 ° C. The immersion time (dyeing time) of the aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing with a dichroic dye is usually performed by immersing the dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid.

The amount of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by weight, preferably about 5 to 12 parts by weight, per 100 parts by weight of water. When using iodine as a dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight, preferably about 5 to 12 parts by weight, per 100 parts by weight of water. The immersion time (dyeing time) for an aqueous solution containing boric acid is usually about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C or higher, preferably 50 to 85 ° C, and more preferably 60 to 80 ° C.

The polyvinyl alcohol-based resin film after the boric acid treatment is usually subjected to a water washing treatment. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol-based resin film in water. The temperature of the water for the water washing treatment is usually about 5 to 40 ° C. The immersion time is usually about 1 to 120 seconds.

After washing with water, drying was performed to obtain a polarizer. Drying can be performed using a hot air dryer or a far-infrared heater. The temperature of the drying treatment is usually about 30 to 100 ° C, preferably 50 to 80 ° C. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds.

By drying, the water content of the polarizer can be reduced to a practical level. The moisture ratio is usually 5 to 20% by weight, and preferably 8 to 15% by weight. When the moisture content is less than 5% by weight, the polarizer loses its flexibility, and the polarizer may be damaged or broken after it is dried.

When the moisture content is higher than 20% by weight, the thermal stability of the polarizer may be deteriorated.

The stretching, dyeing, boric acid treatment, water washing step, and drying step of the polyvinyl alcohol-based resin film in the manufacturing step of the polarizer can be performed according to, for example, the method described in Japanese Patent Application Laid-Open No. 2012-159778. In the method described in this document, a polyvinyl alcohol-based resin layer is formed as a polarizer by applying a polyvinyl alcohol-based resin to a substrate film.

In the present invention, the thickness of the polarizing plate constituting the polarizing plate is 15 μm or less. When the thickness of the polarizer is 15 μm or less, it becomes easy to adjust the distance between the first transparent resin layer 10 and the second transparent resin layer 11, and the shrinkage of the polarizer itself can be reduced, so it can be prevented from high temperatures. Peeling under ambient conditions. From such a viewpoint, the polarizer of the present invention is preferably 13 μm or less, and may be 10 μm or less. In terms of easily imparting desired optical characteristics, the thickness of the polarizer is usually 2 μm or more.

    (Protective film)    

The protective film may be composed of a resin film or a transparent resin film. In particular, it is preferable to use a material having excellent transparency, mechanical strength, thermal stability, moisture shielding property, and the like. When the first transparent resin layer is an optical layer such as a hard coat layer, an anti-glare layer, a light diffusion layer, or an anti-reflection layer, a protective film may be used as a base material for forming the optical layer. In this specification, the term "transparent" means that the monomer transmittance in the visible light region is 80% or more. Moreover, you may use the hardened layer of an active-energy-ray-curable resin composition as a protective film.

In the case of a two-layer protective film for a polarizer, the protective films may be the same as each other or different from each other.

The resin forming the protective film is not particularly limited, and examples thereof include methyl methacrylate resin, polyolefin resin, cyclic olefin resin, polyvinyl chloride resin, cellulose resin, styrene resin, and acrylic resin. Nitrile / butadiene / styrene resin, acrylonitrile / styrene resin, polyvinyl acetate resin, polyvinylidene chloride resin, polyamide resin, polyacetal resin, polycarbonate resin Resin, modified polyphenylene ether resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyfluorene resin, polyether fluorene resin, polyarylate resin, polymer A film made of amidamine, imine-based resin, and polyimide-based resin.

These resins can be used individually or in combination of 2 or more types. In addition, these resins can be used after any suitable polymer modification. Examples of the polymer modification include copolymerization, cross-linking, modification of molecular terminals, regulation of stereoregularity, and reactions involving different types of polymers. Modifications such as mixing.

Among these, as a material of the protective film, a methyl methacrylate resin, a polyethylene terephthalate resin, a polyolefin resin, or a cellulose resin is preferably used. The polyolefin-based resin herein includes a chain-shaped polyolefin-based resin and a cyclic polyolefin-based resin.

The methyl methacrylate resin refers to a polymer containing 50% by weight or more of a methyl methacrylate unit. The content of the methyl methacrylate unit is preferably 70% by weight or more, and may also be 100% by weight. The methyl methacrylate unit is a 100% by weight polymer, and is a methyl methacrylate homopolymer obtained by polymerizing methyl methacrylate alone.

The methyl methacrylate resin is usually obtained by polymerizing a monofunctional monomer having methyl methacrylate as a main component in the presence of a radical polymerization initiator. During polymerization, it can coexist with polyfunctional monomers and chain transfer agents as required.

The monofunctional monomer that can be copolymerized with methyl methacrylate is not particularly limited, and examples thereof include ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, and phenyl methacrylate. Methacrylates other than methyl methacrylate such as benzyl methacrylate, 2-ethylhexyl methacrylate and 2-hydroxyethyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate Acrylates such as esters, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate; 2- (hydroxymethyl) acrylate, 3- (hydroxy Hydroxyalkyl acrylates such as methyl ethyl acrylate, ethyl 2- (hydroxymethyl) acrylate and butyl 2- (hydroxymethyl) acrylate; unsaturated acids such as methacrylic acid and acrylic acid; chlorostyrene and Halogenated styrenes such as bromostyrene; substituted styrenes such as vinyl toluene and α-methylstyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; maleic anhydride and methyl maleic acid Unsaturated acid anhydrides such as acid anhydrides; and phenylmalaya Unsaturated pyrimides such as amines and cyclohexylmaleimide. Such monomers may be used alone or in combination of two or more kinds.

The polyfunctional monomer that can be copolymerized with methyl methacrylate is not particularly limited, and examples thereof include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and triethylene glycol Glycols such as alcohol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, and tetradecyl ethylene glycol di (meth) acrylate, or Those whose terminal hydroxyl groups of their oligomers are esterified with acrylic acid or methacrylic acid; those whose terminal hydroxyl groups of propylene glycol or its oligomers are esterified with acrylic acid or methacrylic acid; neopentyl glycol di (meth) acrylate, Dihydroxy alcohols such as hexanediol di (meth) acrylate and butanediol di (meth) acrylate are hydroxylated with acrylic acid or methacrylic acid; alkylene oxide addition of bisphenol A and bisphenol A Those whose two terminal hydroxyl groups are esterified with acrylic acid or methacrylic acid; those whose polyhydric alcohols such as trimethylolpropane and neopentyl alcohol are esterified with acrylic acid or methacrylic acid; Alcohol's terminal hydroxyl ring-opening addition to epoxy groups with glyceryl acrylate or glyceryl methacrylate; in succinic acid Ring-opening additions of dibasic acids such as adipic acid, terephthalic acid, phthalic acid, and these halogen substitutes, and such alkylene oxide adducts, include glyceryl acrylate or glyceryl methacrylate Epoxy groups; allyl (meth) acrylate; and aromatic divinyl compounds such as divinylbenzene. Among them, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate are preferably used.

The methyl methacrylate resin may be modified by a reaction between functional groups copolymerized with the resin. This reaction can be exemplified by the de-methanol condensation reaction of the methyl ester group of methyl acrylate and the hydroxyl group of methyl 2- (hydroxymethyl) acrylate, or the carboxyl group of acrylic acid and methyl 2- (hydroxymethyl) acrylate Dehydration condensation reaction in the polymer chain of the hydroxyl group of the ester.

The polyethylene terephthalate resin refers to a resin composed of 80 mol% or more of repeating units composed of ethylene terephthalate, and may also include other dicarboxylic acid components and diol components. The other dicarboxylic acid components are not particularly limited, and examples thereof include isophthalic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxybenzophenone, and bis (4-carbonylphenyl). Ethane, adipic acid, sebacic acid and 1,4-dicarboxycyclohexane.

Other diol components are not particularly limited, and examples thereof include propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, ethylene oxide adducts of bisphenol A, and polyethylene glycol. , Polypropylene glycol and polybutylene glycol.

These dicarboxylic acid components and diol components may be used in combination of two or more kinds as necessary. Further, hydroxycarboxylic acids such as p-hydroxybenzoic acid and p-β-hydroxyethoxybenzoic acid can be used in combination. Further, as other copolymerization components, a dicarboxylic acid component or a diol component containing a small amount of an amine bond, an amine ester bond, an ether bond, or a carbonate bond may be used.

As a method for producing a polyethylene terephthalate-based resin, a method of directly polycondensing terephthalic acid and ethylene glycol (and other dicarboxylic acids or other diols as necessary) can be used to make terephthalic acid Method for polycondensation after transesterification of dialkyl ester of formic acid and ethylene glycol (and dialkyl ester of other dicarboxylic acid or other diol as needed) and terephthalic acid (and other dicarboxylic acid as needed) A method of polycondensing a glycol ester (and other glycol esters as needed) in the presence of a catalyst. Furthermore, solid phase polymerization may be performed as needed to increase the molecular weight and reduce the low molecular weight components.

The cyclic polyolefin resin is obtained by polymerizing cyclic olefin monomers such as norbornene and other cyclopentadiene derivatives in the presence of a catalyst. The use of such a cyclic polyolefin resin is preferable because a protective film having a predetermined hysteresis value, which will be described later, is easily obtained.

Examples of the cyclic polyolefin-based resin include norbornene or cyclopentadiene from an olefin or (meth) acrylic acid or an ester thereof through a Diels-Alder reaction. Derivatives, ring-opening shift polymerization of the norbornene or its derivatives as monomers, and then the resin obtained by hydrogenation; by the Diels-Adel reaction from dicyclopentadiene and olefins or (Meth) acrylic acid or its esters are used to obtain tetracyclododecene or its derivative, and the obtained tetracyclododecene or its derivative is used as a monomer to perform ring-opening shift polymerization, and then the resin obtained by hydrogenation ; At least two monomers selected from norbornene, tetracyclododecene, derivatives thereof, and other cyclic olefin monomers are similarly subjected to ring-opening shift copolymerization, and then the resin obtained by hydrogenation ; A resin obtained by addition copolymerization of a cyclic olefin such as norbornene, tetracyclododecene or a derivative thereof with a chain olefin and / or an aromatic compound having a vinyl group, and the like.

Typical examples of the chain polyolefin resin are a polyethylene resin and a polypropylene resin. Among them, it is suitable to use a homopolymer of propylene; or propylene as a main body, and copolymerize a comonomer with which propylene can be copolymerized, such as ethylene, in a proportion of 1 to 20% by weight, preferably 3 to 10% by weight. Thing.

The polypropylene-based resin may contain an alicyclic saturated hydrocarbon resin. By containing an alicyclic saturated hydrocarbon resin, it becomes easy to adjust a hysteresis value. The content of the alicyclic saturated hydrocarbon resin is preferably 0.1 to 30% by weight relative to the polypropylene-based resin, and a more preferable content is 3 to 20% by weight. When the content of the alicyclic saturated hydrocarbon resin is less than 0.1% by weight, the effect of controlling the hysteresis value cannot be fully obtained. On the other hand, when the content exceeds 30% by weight, the alicyclic saturated hydrocarbon resin may leak out from the protective film over time Doubts.

The cellulose resin refers to a part or all of the hydrogen atoms of the hydroxyl groups of the cellulose of cellulose obtained from raw cellulose such as cottonseed velvet, wood pulp (broadwood pulp, coniferous pulp), etc., through ethyl, propyl, and / or butyl. Substituted cellulose organic acid esters or cellulose organic acid esters. Examples include cellulose acetate, propionate, butyrate, and mixed esters thereof. Among them, a triethylfluorene-based cellulose film, a diethylfluorene-based cellulose film, a cellulose acetate propionate film, a cellulose acetate butyrate film, and the like are preferred.

A method for forming a protective film for a polarizer by using a methyl methacrylate resin, a polyethylene terephthalate resin, a polyolefin resin, and a cellulose resin, as long as the resin is appropriately selected The method is not particularly limited. For example, a solvent-casting method in which a resin dissolved in a solvent is cast into a metal belt or barrel, and the solvent is dried to remove the solvent to obtain a film; and the resin is heated / kneaded above its melting temperature and extruded from a die to borrow A melt extrusion method to obtain a film by cooling. In this melt extrusion method, a single-layer film may be extruded, or a multilayer film may be extruded simultaneously.

It is possible to easily obtain a commercially available product by using a film as a protective film. As a methyl methacrylate resin film, the product names can be listed separately: SUMIPEX (made by Sumitomo Chemical Co., Ltd.), ACRYLITE (registered trademark), ACRYPLEN (registered (Trademark) (Mitsubishi Rayon Corporation), DERAGLASS (registered trademark) (Asahi Kasei Corporation), PARAGLAS (registered trademark), COMOGLAS (registered trademark) (Kuraray Corporation), and ACRYVIEWA (registered trademark) Media joint-stock company system) and so on. Examples of the polyolefin-based resin film include a trade name of ZEONOR (registered trademark) (Japanese ZEON Corporation), ARTON (registered trademark) (made by JSR Corporation), and the like. Examples of the polyethylene terephthalate-based resin film include NOVA CLEAR (registered trademark) (manufactured by Mitsubishi Chemical Corporation) and Teijin A-PET sheet (manufactured by Teijin Kasei Co., Ltd.), etc. under the trade name. The polypropylene resin film can be listed by its trade name: FILMAX CPP film (manufactured by FILMAX), SUNTOX (registered trademark) (manufactured by SunTox), TOHCELLO (registered trademark) (manufactured by TOHCELLO), Toyobo PYLEN FILM (registered) (Trademark) (manufactured by Toyobo Industries Co., Ltd.), TORAYFAN (registered trademark) (manufactured by TORAY FILM Processing Co., Ltd.), NIHONPOLYACE (manufactured by Japan Polyace Co., Ltd.), and Taihe (registered trademark) FC (manufactured by FUTAMURA Chemical Co., Ltd.) In addition, as the cellulose-based resin film, there may be listed, under a trade name, FUJITAC (registered trademark) TD (manufactured by FUJIFILM Corporation), and KC2UA and Konica Minolta TAC FILM KC (manufactured by Konica Minolta Corporation).

The protective film used in the present invention can impart anti-glare properties (haze). The method for imparting anti-glare properties is not particularly limited. For example, a method in which inorganic fine particles or organic fine particles are mixed with the aforementioned raw material resin to form a thin film, and the multilayer extrusion is used, and one resin mixed with fine particles and another A method of forming a two-layer thin film by mixing a resin containing fine particles; or a method of forming a three-layer thin film by using a resin mixed with particles as an outer side; and coating one side of a film by mixing inorganic fine particles or organic fine particles with a hardening adhesive resin The coating solution to be formed is a method of hardening the binder resin and providing an antiglare layer.

Moreover, the protective film may contain an additive as needed. Examples of the additive include a lubricant, an anti-caking agent, a heat stabilizer, an antioxidant, a light resistance agent, and an impact resistance improver.

The thickness of the protective film is usually about 1 to 50 μm, preferably 10 to 40 μm, and more preferably 10 to 30 μm from the viewpoints of strength and handling properties.

The protective film is preferably a saponification treatment, a corona treatment, or a plasma treatment before being bonded to the polarizer.

As a protective film, a brightness enhancement film can also be used. The thickness of the brightness enhancement film is preferably 35 μm or less, and more preferably 30 μm or less.

As the brightness enhancement film, a polarization conversion element having a function of separating emitted light from a light source (backlight) into transmitted polarized light, reflected polarized light, or scattered polarized light can be used. Such a brightness-enhancing film can improve the efficiency of linearly polarized light output by using reflected or scattered polarized light from the backlight.

Examples of the brightness enhancement film include an anisotropic reflective polarizer. Examples of the anisotropic reflective polarizer include an anisotropic multilayer film that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in another vibration direction. Examples of the anisotropic multilayer film include the trade name "APF" manufactured by 3M Corporation. Examples of the anisotropic reflective polarizer include a composite of a cholesteric liquid crystal layer and a λ / 4 plate. Examples of such a composite include the trade name "PCF" manufactured by Nitto Denko Corporation. Examples of the anisotropic reflective polarizer include a reflective grid polarizer. Examples of the reflective grid-shaped polarizer include a metal grid reflective polarizer that finely processes metal and emits reflective polarized light in the visible light region. Among them, a brightness enhancement film made of an anisotropic multilayer film is preferred.

Examples of the hardened layer of the active energy ray-curable resin composition include a layer hardened by irradiating the active energy ray-curable resin composition with an active energy ray. Examples of the active energy ray-curable resin composition include a polymerizable compound and a photopolymerization initiator, a photoreactive resin, a binder resin, and a photoreactive crosslinker. Examples of the polymerizable compound include a photopolymerizable monomer such as a photocurable epoxy-based monomer, a photocurable acrylic-based monomer, and a photocurable amine ester-based monomer; and an oligomer derived from the photopolymerizable monomer. Polymer. Examples of the photopolymerization initiator include a substance containing an active species such as a radical, a cation, or an anion by irradiation with an active energy ray such as ultraviolet rays. As the active energy ray-curable resin composition containing a polymerizable compound and a photopolymerization initiator, those containing a photocurable epoxy-based monomer and a photocationic polymerization initiator can be suitably used.

When using an active energy ray-curable resin composition, after coating the active energy ray-curable resin composition on a polarizer or a protective film, a drying step is performed as necessary, and then the active energy ray is hardened by irradiation with the active energy ray. A hardening step in which the resin composition is hardened. The light source of the active energy ray is not particularly limited, and it is preferably ultraviolet light having a luminous distribution below a wavelength of 400 nm. Specifically, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, and black light lamps can be used. , Microwave excited mercury lamp, metal halide lamp, etc.

The composition may contain additives. Examples of the additives include ion trapping agents, antioxidants, chain transfer agents, sensitizers, tackifiers, thermoplastic resins, fillers, flow modifiers, plasticizers, and defoamers.

The hardened layer of the active energy ray-curable resin composition has a protective layer for protecting the surface of a polarizer. The hardened layer of the active-energy-ray-curable resin composition is thinner than a normal protective film, and is therefore effective for reducing the thickness of a polarizing plate.

The thickness of the hardened layer of the active energy ray-curable resin composition is preferably 0.01 to 20 μm, more preferably 0.01 to 10 μm, and still more preferably 0.01 to 5 μm.

    (First transparent resin layer)    

The surface resistance value of the first transparent resin layer is 1.0 × 10 ⁹ Ω / □ or more and 1.0 × 10 ¹¹ / □ or less, and preferably 5.0 × 10 ⁹ Ω / □ or more and 5.0 × 10 ¹⁰ / □ or less. With such a surface resistance value and the second transparent resin layer having an antistatic function, a liquid crystal display device can be efficiently manufactured without causing multiple acquisitions and defective products. The surface resistance value can be measured by a method described in Examples described later.

The first transparent resin layer may be formed of an optical layer or an adhesive layer such as a hard coat layer, an anti-glare layer, a light diffusion layer, or an anti-reflection layer. Among them, the first transparent resin layer is preferably a hard coat layer. When the first transparent resin layer is provided with the surface resistance characteristics, for example, the first transparent resin layer may include an antistatic agent. In addition, in this specification, the term "transparent" means that the unit transmittance in the visible light region is 80% or more.

The hard coat layer may be formed by coating an active energy ray-curable resin composition on a transparent resin film and then irradiating the active energy ray to harden the coating layer. When a photocurable resin or the like is used as the active energy ray curable resin, the coating liquid usually contains a photopolymerization initiator. The photopolymerization initiator can be appropriately selected depending on the resin used, and examples thereof include acetophenone-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzophenone-based photopolymerization initiator, and sulfur. Allanone photopolymerization initiator, three Photopolymerization initiator, Diazole-based photopolymerization initiators and the like. The coating liquid may contain other additives such as a solvent such as an organic solvent, a leveling agent, a dispersant, and an antifouling agent.

The coating method of the coating liquid may be, for example, a gravure coating method, a micro gravure coating method, a roll coating method, a rod coat method, a knife coating method, an air knife coating method, an anastomotic coating method, Traditionally known methods such as die coating.

The irradiated active energy ray can be appropriately selected from ultraviolet rays, electron rays, near-ultraviolet rays, visible light, near-infrared rays, infrared rays, and X-rays according to the type of the active energy ray-curable resin, and ultraviolet rays or electron rays are preferred, particularly In terms of easy handling and high energy, ultraviolet rays are preferred.

The anti-glare layer is an optical functional layer for preventing a surface reflected by external light from being given a predetermined uneven shape. The anti-glare layer can be formed by, for example, the following method: (a) a method of hardening the coating layer after coating a coating liquid containing light-transmitting fine particles and a light-transmitting resin on a transparent resin film, if necessary ( (It can form surface irregularities caused by light-transmitting fine particles); (b) After coating a transparent resin film with a coating liquid containing a light-transmitting resin (which may further contain light-transmitting fine particles), it will have predetermined surface irregularities A method in which a mold having a shape is pressed against the coating layer, and if necessary, the coating layer is hardened to provide unevenness on the surface of the coating layer.

The translucent resin constituting the anti-glare layer is not particularly limited as long as it has translucency. For example, the translucent resin may be a cured product of a thermosetting resin other than the cured product of the active energy ray-curable resin; a thermoplastic resin; Metal alkoxide-based polymers and the like. Among these, the hardened | cured material of an active energy ray hardening resin is suitable. When an ultraviolet curable resin or the like is used as the active energy ray-curable resin, the coating liquid contains a photopolymerization initiator (radical polymerization initiator) as described above, and the coating is applied by irradiating the active energy ray. Layer hardened.

Examples of the thermosetting resin include a thermosetting amine ester resin made of an acrylic polyol and an isocyanate prepolymer, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, and a silicone resin. .

Examples of the thermoplastic resin include cellulose derivatives such as ethyl cellulose, nitro cellulose, ethyl butyl cellulose, ethyl cellulose, and methyl cellulose; vinyl acetate and copolymers thereof, and chlorine Vinyl resins such as ethylene and its copolymers, vinylidene chloride and its copolymers; acetal resins such as polyethylene formal and polyvinyl butyral; acrylic resins and their copolymers, methacrylic resins and their copolymers Etc. (meth) acrylic resins; polystyrene resins; polyamide resins; polyester resins; polycarbonate resins and the like.

As the metal alkoxide-based polymer, a silicon oxide-based matrix or the like using a silicon alkoxide-based material as a raw material can be used. Specifically, the metal alkoxide-based polymer may be an inorganic or organic-inorganic composite-based matrix, which is obtained by dehydrating and condensing a hydrolyzate of an alkoxysilane such as tetramethoxysilane and tetraethoxysilane.

When a hardening resin or a metal alkoxide polymer is used as the light-transmitting resin, it may be necessary to apply heat after coating the coating liquid.

Examples of the light-transmitting fine particles include organic fine particles such as (meth) acrylic resin, melamine resin, polyethylene, polystyrene, organic polysiloxane, acrylic-styrene copolymer, and calcium carbonate and silicon oxide. , Alumina, barium carbonate, barium sulfate, titanium oxide, glass and other inorganic fine particles. As the light-transmitting fine particles, one kind or two or more kinds of fine particles can be used. In order to obtain desired anti-glare properties and other optical characteristics, the type, particle size, refractive index, and content of the light-transmitting fine particles can be appropriately adjusted.

The light diffusing layer is an optical functional layer for diffusing light passing through the backlight of the liquid crystal cell for the purpose of widening the viewing angle of the liquid crystal display device. The light-diffusing layer can be formed by, for example, applying a coating solution containing light-transmitting fine particles (light-diffusing agent) and a light-transmitting resin to a transparent resin film, and then hardening the coating layer as necessary. As the light-transmitting fine particles and the light-transmitting resin, the same as those described in the anti-glare layer can be used.

In order to obtain desired light diffusivity, the type of the transparent resin film, the type of the light-transmitting resin, the type of the light-transmitting fine particles, the particle diameter, the refractive index, the content, the thickness of the light-diffusing layer, and the like can be appropriately adjusted.

The anti-reflection layer is an optical functional layer for reducing or preventing reflection of external light, and may be, for example, one having a low refractive index layer. Further, a multilayer structure including a high refractive index layer and / or a medium refractive index layer between the transparent resin film and the low refractive index layer may be used. The above-mentioned hard coat layer may be provided between the anti-reflection layer and the transparent resin film.

The low-refractive-index layer can be coated with a coating liquid containing a hardened body of the above-mentioned active energy ray-curable resin, a light-transmissive resin such as a metal alkoxide-based polymer, and an inorganic fine particle, and then the coating layer can be applied as necessary Formed by hardening. Examples of the inorganic fine particles include low refractive indices such as LiF (refractive index 1.4), MgF (refractive index 1.4), 3NaF‧AlF (refractive index 1.4), AlF (refractive index 1.4), and Na ₃ AlF ₆ (refractive index 1.33). Rate particles, hollow silica particles, etc.

The high-refractive index layer may be coated with a coating solution containing a light-transmitting resin such as a cured product of the active energy ray-curable resin, a metal alkoxide-based polymer, and the inorganic fine particles and / or organic fine particles, and then, if necessary, It is formed by hardening a coating layer. Examples of the inorganic fine particles include zinc oxide, titanium oxide, cerium oxide, aluminum oxide, silane oxide, tantalum oxide, yttrium oxide, hafnium oxide, zirconia, antimony oxide, and indium tin oxide (ITO). By forming such a high refractive index layer, antistatic properties can also be imparted.

As the adhesive for forming the adhesive layer, for example, an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyvinyl ether, a vinyl acetate / vinyl chloride copolymer, Modified polyolefin, epoxy-based, fluorine-based, natural rubber, synthetic rubber and other rubber-based polymers are matrix polymers. As the adhesive, particularly good ones are those having good optical transparency, exhibiting suitable wetting properties, cohesiveness, and adhesiveness, and excellent weather resistance and heat resistance.

Examples of the antistatic agent that the first transparent resin layer may have include alkali metal salts and / or organic cation-anion salts. As the alkali metal salt, organic and inorganic salts of alkali metals can be used. In addition, the "organic cation-anion salt" in the present invention refers to an organic salt in which the cation portion is composed of an organic substance, and the anion portion may be an organic substance or an inorganic substance. "Organic cation-anion salt" is also called ionic liquid or ionic solid. The antistatic agent may be used singly or in combination.

Examples of the alkali metal ion constituting the cation portion of the alkali metal salt include lithium, sodium, and potassium. Among these alkali metal ions, lithium ions are preferred.

The anion portion of the alkali metal salt may be composed of an organic substance or an inorganic substance. Examples of the anion portion constituting the organic salt may be used, for ^{_{example: CH 3 COO -, CF 3}} COO -, CH 3 SO 3 -, CF 3 SO 3 -, (CF 3 SO 2) 3 C -, C 4 F 9 SO 3 ^{_{-, C 3 F 7 COO -}} , (CF 3 SO 2) (CF 3 CO) N -, - O 3 S (CF 2) 3 SO 3 -, PF 6 -, CO 3 2-, the following formula ( 1) to (4), etc.,

_{(1) :( C n F 2n} + 1 SO 2) 2 N - ( but, n is an integer of 1 to 10)

_{(2): CF 2 (C} m F 2m SO 2) 2 N - ( but, m is an integer of 1 to 10)

_{^{(3): - O 3 S}} (CF 2) 1 SO 3 - ( provided that, a represents an integer of 1 to 10)

_{(4) :( C p F 2p} + 1 SO 2) N - (C q F 2q + 1 SO 2) ( but, p, q is an integer of 1 to 10). In particular, an anion portion containing a fluorine atom can be suitably used because an ionic compound having excellent ion dissociation properties can be obtained. Examples of the anionic portion constituting the inorganic salt may be used ^{Cl -, Br -, I -} , AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, AsF 6 -, SbF ^{_{6 -, NbF 6 -, TaF}} 6 -, (CN) 2 N - and the like. Examples of the anionic portion is preferably _{(CF 3 SO 2) 2 N} -, (C 2 F 5 SO 2) 2 N -, and the like (acyl sulfo perfluoroalkyl) alkylene XI to the general formula (1) amines, especially it is _{(CF 3 SO 2) 2 N} - ( trifluoromethane sulfonic acyl) represented by (PEI) is preferred.

The organic cation-anion salt used in the present invention is composed of a cationic component and an anionic component, and the aforementioned cationic component is composed of an organic substance. Specific examples of the cationic component include pyridine cation, piperidine cation, pyrrolidine cation, cation having pyrroline skeleton, cation having pyrrole skeleton, imidazole cation, tetrahydropyrimidine cation, dihydropyrimidine cation, and pyrazole Cation, tetraalkylammonium cation, trialkylphosphonium cation, tetraalkylphosphonium cation, and the like.

As an anion component, may be used, for ^{example: Cl -, Br -, I} -, AlCl 4 -, Al 2 Cl 7 -, BF 4 -, PF 6 -, ClO 4 -, NO 3 -, CH 3 COO -, CF 3 _{^{COO -, CH 3 SO 3 -}} , CF 3 SO 3 -, (CF 3 SO 2) 3 C -, AsF 6 -, SbF 6 -, NbF 6 -, TaF 6 -, (CN) 2 N -, C 4 _{^{F 9 SO 3 -, C 3}} F 7 COO -, (CF 3 SO 2) (CF 3 CO) N -, - O 3 S (CF 2) 3 SO 3 -, the following formula (1) to (4 ), Etc.

_{(1) :( C n F 2n} + 1 SO 2) 2 N - ( but, n is an integer of 1 to 10)

_{(2): CF 2 (C} m F 2m SO 2) 2 N - ( but, m is an integer of 1 to 10)

_{^{(3): - O 3 S}} (CF 2) 1 SO 3 - ( provided that, a represents an integer of 1 to 10)

_{(4) :( C p F 2p} + 1 SO 2) N - (C q F 2q + 1 SO 2) ( but, p, q is an integer of 1 to 10). Among these, an anionic component containing a fluorine atom is particularly suitable because it can obtain an ionic compound having excellent ion dissociation properties.

In terms of easily imparting the surface resistance characteristics, the antistatic agent is preferably 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the first transparent resin layer, and may be 3 parts by mass or more.

The thickness of the first transparent resin layer is, for example, preferably 0.01 to 20 μm, and more preferably 0.01 to 5 μm.

    (Second transparent resin layer)    

The second transparent resin layer is a layer having an antistatic function. Since the second transparent resin layer has an antistatic function and the first transparent resin layer has a predetermined surface resistance value, a liquid crystal display device can be efficiently manufactured without causing multiple acquisitions and defective products.

The second transparent resin layer may be formed of an optical layer or an adhesive layer such as a hard coat layer, an anti-glare layer, a light diffusion layer, an anti-reflection layer, and the like. Among them, the second transparent resin layer is preferably an adhesive layer. When the second transparent resin layer is an adhesive layer, it may be an adhesive layer for bonding the second transparent resin layer to the liquid crystal cell.

In order to provide an antistatic function to the second transparent resin layer, for example, the second transparent resin layer may include an antistatic agent. That is, when the second transparent resin layer contains an antistatic agent, the second transparent resin layer can be said to have an antistatic function. The method of forming the second transparent resin layer can be the same as the method of forming the first transparent resin layer. The first transparent resin layer and the second transparent resin layer may be formed of mutually the same layer, but are preferably formed of mutually different layers.

The thickness of the second transparent resin layer is, for example, preferably from 0.1 to 40 μm, and more preferably from 5 to 30 μm.

    (Manufacturing method of polarizing plate)    

The members described above can be bonded to each other through, for example, an adhesive layer or an adhesive layer.

The adhesive layer is, for example, a layer for adhering a polarizer and a protective film, and examples of the adhesive forming the adhesive layer include an active energy ray-curable adhesive and an aqueous adhesive. Furthermore, the above-mentioned active energy ray-curable resin composition can also be used.

When using a water-based adhesive, it is preferable to perform a step of removing the water contained in the water-based adhesive after drying the polarizer and the protective film. After the drying step, an aging step such as aging at a temperature of about 20 to 45 ° C. may be provided.

When an active energy ray-curable adhesive is used, after attaching the polarizer and the protective film, a drying step is performed as necessary, and then a hardening step of curing the active energy ray-curable adhesive by irradiating the active energy ray. The light source of the active energy ray is not particularly limited, but it is preferably ultraviolet light having a light emission distribution below 400 nm. Specifically, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, and black light lamps , Microwave excited mercury lamp, metal halide lamp, etc.

When the polarizer and the protective film are bonded, a saponification treatment, a corona treatment, a plasma treatment, or the like may be performed on the bonding surface of at least one of these.

An adhesive layer can be used for the lamination of the polarizer and the protective film and the adhesion of the optical laminate to the liquid crystal cell. Examples of the adhesive layer include acrylic adhesives, polysiloxane adhesives, and rubber adhesives. In terms of transparency, weather resistance, heat resistance, and processability, acrylic adhesives are preferred. Agent. When the adhesive layer is a layer corresponding to the second transparent resin layer, the adhesive layer preferably has an antistatic function, and preferably has an antistatic agent.

For the adhesive, fillers, pigments, colorants, antioxidants, ultraviolet absorbers, silanes, and other fillers made of adhesives, plasticizers, glass fibers, glass beads, metal powders, and other inorganic powders can be appropriately blended as needed. Various additives such as coupling agents.

The adhesive layer is usually formed by applying a solution of an adhesive on a release sheet and drying it. For coating on the release sheet, for example, roll coating method such as reverse coating, gravure coating, spin coating method, screen coating method, spray coating method, dip coating method, and spray can be used. Coating method, etc. A release sheet provided with an adhesive layer is used by a method such as transferring it.

The thickness of the adhesive layer disposed between the polarizer and the protective film (especially the brightness enhancement film) may be, for example, 3 to 15 μm. The thickness of the adhesive layer for bonding the optical laminate to the liquid crystal cell may be, for example, 5 to 30 μm.

    <Liquid crystal display device>    

FIG. 2 is a schematic cross-sectional view showing an example of a layer structure of a liquid crystal display device. In FIG. 2, the backlight and the polarizing plate on the back side are omitted. The liquid crystal display device of the present invention shown in FIG. 2 (a) is sequentially laminated: a front panel 2, an adhesive layer 30, a polarizing plate 100, and a liquid crystal cell 3. The liquid crystal display device of the present invention shown in FIG. 2 (b) is a laminated layer in order: a front panel 2, an adhesive layer 30, a polarizing plate 101, and a liquid crystal cell 3. The liquid crystal display device of the present invention shown in FIG. 2 (c) is sequentially laminated: a front panel 2, an adhesive layer 30, a polarizing plate 102, and a liquid crystal cell 3 in order. It is to be noted that the adhesive layer 30 may be provided instead of the air layer. In the liquid crystal display device of the present invention, the polarizing plate of the present invention is preferably laminated on the liquid crystal cell so that the first transparent resin layer is closer to the visible side than the second transparent resin layer.

The liquid crystal display device of the present invention is preferably a touch input type liquid crystal display device having a touch panel function. A touch input type liquid crystal display device includes a touch input element including a liquid crystal cell. The structure of the touch panel can be any conventionally known method such as out-cell, on-cell or in-cell, and is preferably in-cell. In addition, the operation mode of the touch panel may be any conventionally known method such as a resistive film method, a capacitive method (surface-type capacitor method, and projected-type capacitor method).

The liquid crystal cell 50 includes a pair of transparent substrates and a liquid crystal layer held therebetween. The display mode of the liquid crystal cell can be various display modes such as STN, TN, OCB, HAN, VA, and IPS. From the viewpoint of obtaining high contrast, it is better to use the VA mode, and from the viewpoint of obtaining a wide viewing angle, it is better to use the IPS mode.

As described above, since the front panel is disposed on the visible side of the liquid crystal cell, specifically, it is disposed on the outermost side in the final product, so it is assumed to be used outdoors or semi-outdoor. Therefore, from the viewpoint of durability, it is suitable to be composed of inorganic materials such as glass and tempered glass, organic materials such as polycarbonate resin, and acrylic resin.

The bonding layer of the front panel and the polarizing plate of the present invention is suitable for those whose refractive index is close to that of the front panel. As the adhesive, the aforementioned adhesive layer or adhesive layer can be used. By laminating the polarizing plate and the front panel, the reflection and light scattering at the interface between the front panel and the polarizing plate can be eliminated, thereby improving visibility.

    [Example]    

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited by these examples. In the examples, the content and percentage of use are expressed in terms of% and parts, unless otherwise stated, based on mass. The evaluation methods used in the examples are as follows.

    (1) Thickness:    

The measurement was performed using a digital micrometer MH-15M manufactured by Nikon Corporation.

    (2) Surface resistance value:    

The surface resistance value (Ω / □) of the surface of the first transparent resin layer was measured using MCP-HT450 manufactured by Mitsubishi Chemical Analytech Co., Ltd.

    (3) Evaluation of multiple acquisitions due to static electricity after sectioning:    

The polarizing plate slices obtained in the examples and comparative examples were cut to a size of 5.5 inches diagonally, and a stack of 100 sheets was made, and the number of multiple acquisitions generated when inspecting the product one by one was counted. The evaluation criteria are as follows.

○: The number of occurrences is 0

△: The number of occurrences is 1 time or more and 10 times or less

×: Occurred more than 10 times

    (4) Operational evaluation of touch panel    

The person who plans to remove the polarizer on the visible side from the liquid crystal display device built in the in-cell touch sensor of the Galaxy (registered trademark) On7 model made by Samsung Wireless. The adhesive-attached polarizing plates obtained in each example were laminated and subjected to an autoclave treatment, and the operability of the touch panel was confirmed. The evaluation criteria are as follows.

○: No problem with the operability of the touch panel

×: Poor operation during touch panel operation

    (5) ESD test evaluation:    

The cover glass and the polarizing plate on the viewing side were peeled from the liquid crystal panel (a liquid crystal display device with an in-cell touch sensor built into Samsung Wireless ’s model name Galaxy (registered trademark) On7), and examples and comparisons were attached to the peeling surface. Examples of polarizers with adhesives. Then attach the front panel as an evaluation sample.

The above evaluation sample was placed on a backlight having a brightness of 20000 cd, and ESD (manufactured by SANKI Corporation, ESD-8012A) using a static electricity generating device was used, and the orientation of the liquid crystal was disturbed by generating 6 kv static electricity. An instantaneous multiple photometric detector (manufactured by Otsuka Electronics Co., Ltd., MCPD-3000) was used to measure the recovery time (s) of poor display due to this poor orientation.

    (6) Evaluation of heat endurance test    

The polarizers with adhesives obtained in the examples and comparative examples were cut to a size of 40 mm in length and 40 mm in width, and laminated to an alkali-free glass via an adhesive, and placed under high pressure at 50 ° C with a negative playback of 5 kg. It was allowed to mature in the kettle for 20 minutes, and was left to stand in an environment of 23 ° C./60% RH for 10 hours. Next, the endurance test was performed by using a constant temperature and humidity machine made by Espec Corporation and left in a dry environment at 85 ° C. for 500 hours. The following criteria were used to visually evaluate the presence or absence of peeling immediately after taking out.

○: No peeling was observed at all

(Triangle | delta): A small peeling visually recognized is observed

×: Obvious peeling was observed

    (Production Example 1: Production of Polarizer A)    

A polyvinyl alcohol film with a thickness of 20 μm (average degree of polymerization of about 2,400, saponification degree of 99.9 mol% or more) was subjected to uniaxial stretching by dry stretching to about 5 times, and then kept in a tight state, immersed in a pure solution of 60 ° C After 1 minute of water, it was immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Then, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water at 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, it was washed with pure water at 26 ° C. for 20 seconds, and then dried at 65 ° C. to obtain a 9 μm-thick polarizer having an iodine adsorption orientation on a polyvinyl alcohol film.

    (Production Example 2: Production of Polarizer B)    

A polyvinyl alcohol film with a thickness of 30 μm (average degree of polymerization of about 2,400, saponification degree of 99.9 mol% or more) was subjected to uniaxial stretching by dry stretching to about 4 times, and then kept in a tight state and immersed in a pure solution at 60 ° C After 1 minute of water, it was immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Then, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water at 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, it was washed with pure water at 26 ° C. for 20 seconds, and then dried at 65 ° C. to obtain a 12 μm-thick polarizer with iodine adsorption oriented on the polyvinyl alcohol film.

    (Production Example 3: Production of Polarizer C)    

A 75 μm-thick polyvinyl alcohol film (average degree of polymerization of about 2,400, saponification degree of 99.9 mol% or more) was uniaxially stretched by dry stretching to about 4 times, and then kept in a tight state, immersed in a pure, 60 ° C After 1 minute of water, it was immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 5/100 at 28 ° C for 60 seconds. Then, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water at 8.5 / 8.5 / 100 at 72 ° C for 300 seconds. Subsequently, it was washed with pure water at 26 ° C. for 20 seconds, and then dried at 65 ° C. to obtain a 28 μm-thick polarizer having an iodine adsorption orientation on a polyvinyl alcohol film.

    (Production Example 4: Production of Water-based Adhesive)    

3 parts by weight of carboxy-modified polyvinyl alcohol [trade name "KL-318" obtained from Kuraray Co., Ltd.] was dissolved in 100 parts by weight of water, and 1.5 parts by weight of a water-soluble epoxy resin was added to the aqueous solution. Phenamine epoxy-based additives [trade name "SUMIREZ RESIN (registered trademark) 650 (30)" obtained from Taoka Chemical Industry Co., Ltd., an aqueous solution having a solid content concentration of 30% by weight] was used to prepare an aqueous adhesive.

    (Preparation of adhesive layer)    

Prepare the following adhesive layers.

Adhesive layer A: 25 μm thick sheet adhesive with antistatic function [KZ manufactured by Lintec Corporation]

Adhesive layer B: 25 μm-thick sheet adhesive without antistatic function [KT] by Lintec Corporation

    (Preparation of the protective film)    

Prepare the following protective films.

Protective film A: Konica Minolta, cellulose resin film KC4UA, thickness 40 μm

Protective film B: Konica Minolta Co., Ltd., cellulose resin film KC2UA, thickness 25 μm

Protective film C: Konica Minolta Co., Ltd., cellulose resin film KC4CT, thickness 40 μm

Protective film D: Cyclic olefin resin film ZF14-023, made by Japan Zeon Co., Ltd., thickness 23 μm

Protective film E: Cyclic olefin resin film ZF14-013, made by Japan Zeon Co., Ltd., thickness 13 μm

Protective film F: hardened layer of active energy ray-curable resin composition, thickness 3 μm

    [Example 1]    

Water-based adhesive is coated on both sides of polarizer B, and protective film A and protective film D are bonded to obtain polarized light composed of protective film A / water-based adhesive layer / polarizer / water-based adhesive layer / protective film D board. Then, a composition containing a transparent hard coat resin mixed with an antistatic agent is applied to the protective film A, and is irradiated with ultraviolet rays to harden to form a hard coat layer (first transparent resin layer) having an antistatic function. An adhesive layer A (second transparent resin layer) was laminated on the protective film D to obtain a polarizing plate with an adhesive.

The surface resistance value of the first transparent resin layer was 5.0 × 10 ⁹ Ω / □. The distance between the hard coat layer (the first transparent resin layer) and the adhesive layer A (the second transparent resin layer) was 75 μm.

    [Examples 2 to 10, Comparative Examples 1 to 10]    

In addition to adjusting the amount of the antistatic agent mixed into the hard coat layer (the first transparent resin layer) to change the surface resistance value as shown in Table 1, the types of protective films bonded to both sides of the polarizer were changed to Table 1 The type of the adhesive layer was changed to that shown in Table 1, and the type of the polarizer was changed to that shown in Table 1. The same operation as in Example 1 was performed to produce a polarizing plate with an adhesive.

When a hardened layer of the active energy ray-curable resin composition is used as the protective film F, the active energy ray-curable resin composition is applied to a polarizer so that the thickness after curing is 3 μm, and then ultraviolet rays are irradiated. A hardened layer is formed. In Comparative Example 10, no antistatic agent was mixed into the hard coat layer (the first transparent resin layer).

About these polarizing plates with an adhesive, the surface resistance value of the hard-coat layer was measured similarly to Example 1. For Examples 1 to 10 and Comparative Examples 1 to 10, the layer structure of the polarizing plate, the surface resistance value of the hard coating layer, whether the adhesive layer has an antistatic function, and the distance between the hard coating layer and the adhesive layer are summarized in Table 1.

For the polarizers with adhesives prepared in Examples 1 to 10 and Comparative Examples 1 to 10, evaluation of generation of multiple acquisitions due to static electricity after sectioning, evaluation of touch panel operability, ESD test evaluation, and heat endurance test were performed. Evaluation. The above results are shown in Table 2.

In Table 2, the judgment is made when the evaluation of multiple acquisitions, the touch panel operability evaluation, and the ESD test evaluation due to static electricity after slicing is defective, and ○ when there is no defect. In addition, regarding the evaluation of the ESD test, if the recovery time is less than 1 s, there is no defect, and if the recovery time is more than 1 s, there is no defect.

    [Industrial availability]    

According to the present invention, the present invention is useful because it can provide a polarizing plate, which can efficiently manufacture a liquid crystal display device without causing multiple acquisitions and defective products, and can be a good operator of a touch panel.

Claims (5)

A polarizing plate is a polarizing plate having a first transparent resin layer on one side of the polarizer and a second transparent resin layer on the other side; a thickness of the polarizer is 15 μm or less; and a surface resistance of the first transparent resin layer The value is 1.0 × 10 ⁹ Ω / □ or more and 1.0 × 10 ¹¹ / □ or less; the second transparent resin layer has an antistatic function; the distance between the first transparent resin layer and the second transparent resin layer is 80 μm or less .     The polarizing plate according to item 1 of the scope of patent application, wherein a protective film is provided between the first transparent resin layer or the second transparent resin layer and the polarizer.         The polarizing plate according to item 1 or 2 of the scope of patent application, wherein the protective film is selected from the group consisting of a cyclic olefin resin film, a cellulose resin film, a polycarbonate resin film, a polyolefin resin film, and a polymer film. At least one of an ethylene terephthalate resin film, a methyl methacrylate resin film, and a brightness enhancement film.         The polarizing plate according to any one of claims 1 to 3 in the scope of patent application, wherein the first transparent resin layer and the second transparent resin layer are layers disposed on the outermost sides of the polarizing plate, respectively.         A liquid crystal display device is one in which the polarizing plate according to any one of claims 1 to 4 of the scope of patent application is arranged on the visible side of a liquid crystal cell, and a front panel is arranged on the polarizing plate.