JP2018092083A - Polarizing plate and liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate with which a liquid crystal display can be efficiently manufactured without causing multiple take-out and product defects and operability of a touch panel can be made excellent.SOLUTION: A polarizing plate has a first transparent resin layer on one side of a polarizer and a second transparent resin layer on the other side. The polarizer has a thickness of 15 μm or less; the first transparent resin layer has a surface resistance value of 1.0×10Ω/sq. or more and 1.0×10Ω/sq. 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.SELECTED DRAWING: Figure 1

Description

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

  Liquid crystal display devices are used in various display devices by taking advantage of low power consumption, operation at low voltage, light weight and thinness. Among liquid crystal display devices and the like, liquid crystal display devices in which an image display device and a touch panel are combined have become widespread. In particular, capacitive touch panels are rapidly spreading due to their functionality.

Patent Document 1 describes that a transparent resin layer having a surface resistance value of 1.0 × 10 ¹³ Ω / □ or less is arranged on the side (viewing side) far from the liquid crystal cell in the viewing side polarizing plate. Specifically, in a polarizing plate in which a triacetyl cellulose film is bonded on both sides of a polarizer having a thickness of 20 μm and an adhesive layer is laminated on the triacetyl cellulose film, the adhesive layer on the viewing side is ionic. A polarizing plate containing a compound and imparting an antistatic function is described.

  When manufacturing a liquid crystal display device using the polarizing plate described in Patent Document 1, when trying to take out and supply the polarizing plate one by one from the laminated body of polarizing plates cut into single sheets, There was a problem of multiple taking out a plurality of polarizing plates.

  In addition, when a liquid crystal display device is manufactured using the polarizing plate described in Patent Document 1, in the case of including a step of peeling the surface protective film from the cover glass, the orientation of the liquid crystal is caused by the generation of static electricity along with the peeling. The product may be defective. On the other hand, since it is necessary to ensure the operability of the touch panel, the surface resistance value cannot be easily lowered.

Japanese Patent Laid-Open No. 2015-200698

  An object of this invention is to provide the polarizing plate which can manufacture a liquid crystal display device efficiently, without causing multiple picking and a product defect, and can make the touch panel excellent in the operativity.

[1] A polarizing plate having a first transparent resin layer on one side of a polarizer and a second transparent resin layer on the other side,
The polarizer has a thickness of 15 μm or less,
The surface resistance value of the first transparent resin layer is 1.0 × 10 ⁹ Ω / □ or more and 1.0 × 10 ¹¹ Ω / □ or less,
The second transparent resin layer has an antistatic function,
The polarizing plate whose distance between the said 1st transparent resin layer and the said 2nd transparent resin layer is 80 micrometers or less.
[2] The polarizing plate according to [1], having a protective film between the first transparent resin layer or the second transparent resin layer and the polarizer.
[3] The protective film is selected from a cyclic olefin resin film, a cellulose resin film, a polycarbonate resin film, a polyolefin resin film, a polyethylene terephthalate resin resin film, a methyl methacrylate resin film, and a brightness enhancement film. The polarizing plate according to [1] or [2], wherein the polarizing plate is at least one 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 arranged on the outermost side of the polarizing plate, respectively.
[5] A liquid crystal display device in which the polarizing plate according to any one of [1] to [4] is disposed on the viewing side of the liquid crystal cell, and a front plate is further disposed on the polarizing plate.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the polarizing plate which can manufacture a liquid crystal display device efficiently, without causing multiple picking and a product defect, and can make the touch panel excellent in the operativity. is there.

It is a schematic sectional drawing which shows an example of the laminated constitution of a polarizing plate. It is a schematic sectional drawing which shows an example of the laminated constitution of a liquid crystal display device. It is a schematic sectional drawing of the polarizing plate for demonstrating the distance between a 1st transparent resin layer and a 2nd transparent resin layer.

<Polarizing plate>
FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of the polarizing plate of the present invention. As shown in FIG. 1A, the polarizing plate of the present invention has a first transparent resin layer 10 on one side of a polarizer 1 and a second transparent resin layer 11 on the other side. As shown in FIGS. 1B and 1C, the polarizing plate of the present invention may have a protective film 20 between the first transparent resin layer 10 and the polarizer 1, The protective film 21 may be provided between the two transparent resin layers 11 and the polarizer 1. Furthermore, the polarizing plate of the present invention may contain other films. Of course, a protective film may be provided outside the first transparent resin layer 10 and the second transparent resin layer 11, or other films may be provided.

  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. Usually, the distance between the 1st transparent resin layer 10 and the 2nd transparent resin layer 11 is 20 micrometers or more. If it explains in full detail using FIG. 3, the distance between the 1st transparent resin layer 10 and the 2nd transparent resin layer 11 is 2nd from the surface near the polarizer 1 in the 1st transparent resin layer 10. This means the distance to the surface of the transparent resin layer 11 closer to the polarizer 1 and corresponds to the distance indicated by the double arrow 4 in FIG. According to the present invention, even when the distance between the first transparent resin layer 10 and the second transparent resin layer 11 is close and easily affected by static electricity, a defect occurs in manufacturing a liquid crystal display device. Can be difficult. In addition, the liquid crystal display device can be efficiently manufactured even when the distance between the first transparent resin layer 10 and the second transparent resin layer 11 is short and the configuration in which multiple images are likely to occur.

  In the polarizing plate of the present invention, it is preferable that the first transparent resin layer and the second transparent resin layer are layers arranged on the outermost sides of the polarizing plate, respectively. The polarizing plate may be laminated with a protective film and a separator that are peeled off during the manufacturing process of the liquid crystal display device. Since the protective film and the separator are not finally incorporated into the liquid crystal display device, they are not regarded as the outermost layer of the polarizing plate in the present invention.

Hereinafter, each member which comprises the polarizing plate of this invention is demonstrated.
(Polarizer)
The polarizer used in the present invention is usually a step of uniaxially stretching a polyvinyl alcohol resin film, a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol resin film with a dichroic dye, a dichroic dye It is manufactured through a step of treating the polyvinyl alcohol-based resin film adsorbed with boric acid aqueous solution and a step of washing with water after the treatment with boric acid aqueous solution.

  As the polyvinyl alcohol resin, a saponified polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers with other monomers copolymerizable with 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 resin is usually about 85 to 100 mol%, preferably 98 mol% or more. This polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal and polyvinyl acetal modified with aldehydes can also be used. Moreover, the polymerization degree of polyvinyl alcohol-type resin is about 1,000-10,000 normally, and about 1,500-5,000 are preferable.

  What formed the polyvinyl alcohol-type resin into a film is used as a raw film of a polarizer. The method for forming a polyvinyl alcohol-based resin can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film is preferably about 5 to 35 μm, more preferably 5 to 20 μm, considering that the thickness of the obtained polarizer is 15 μm or less. When the film thickness of the original film is 35 μm or more, it is necessary to increase the draw ratio when producing the polarizer, and the dimensional shrinkage of the obtained polarizer tends to increase. On the other hand, when the film thickness of the raw film is 5 μm or less, the handling property at the time of stretching is lowered, and there is a tendency that problems such as cutting are likely to occur during production.

  Uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing of the dichroic dye, simultaneously with dyeing, or after dyeing. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Moreover, you may uniaxially stretch in these several steps.

  In uniaxial stretching, it may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a hot roll. Further, the uniaxial stretching may be dry stretching in which stretching is performed in the air, or may be wet stretching in which stretching is performed in a state where a solvent is used and the polyvinyl alcohol-based resin film is swollen. The draw ratio is usually about 3 to 8 times.

  As a method of dyeing the polyvinyl alcohol resin film with the dichroic dye, for example, a method of immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye is employed. Specifically, iodine or a dichroic dye is used as the dichroic dye. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a dyeing process.

  When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this 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. Moreover, the immersion time (dyeing time) in this aqueous solution is usually about 20 to 1800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution is usually about 1 × 10 ⁻⁴ to 10 parts by weight and 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 dyeing assistant. The temperature of the aqueous dichroic dye solution used for dyeing is usually about 20 to 80 ° C. Moreover, the immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

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

  The amount of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by weight and preferably 5 to 12 parts by weight per 100 parts by weight of water. When iodine is used as the 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 and preferably about 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution 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 resin film after the boric acid treatment is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually about 5 to 40 ° C. Further, the immersion time is usually about 1 to 120 seconds.

  After washing with water, a drying process is performed to obtain a polarizer. The drying process 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, and preferably 50 to 80 ° C. The time for the drying treatment is usually about 60 to 600 seconds, and preferably 120 to 600 seconds.

  By the drying process, the moisture content of the polarizer is reduced to a practical level. The water content is usually 5 to 20% by weight, preferably 8 to 15% by weight. When the moisture content is less than 5% by weight, the flexibility of the polarizer is lost, and the polarizer may be damaged or broken after drying. On the other hand, if the moisture content exceeds 20% by weight, the thermal stability of the polarizer may be inferior.

  Further, the stretching, dyeing, boric acid treatment, water washing step, and drying step of the polyvinyl alcohol resin film in the production process of the polarizer may be performed in accordance with, for example, the method described in JP2012-159778A. . In the method described in this document, a polyvinyl alcohol resin layer to be a polarizer is formed by coating a polyvinyl alcohol resin on a base film.

  In the present invention, the thickness of the polarizer constituting the polarizing plate is 15 μm or less. By setting the thickness of the polarizer to 15 μm or less, the distance between the first transparent resin layer 10 and the second transparent resin layer can be easily adjusted, and the contraction force of the polarizer itself can be reduced. Can also be prevented. From such a viewpoint, in the present invention, the polarizer is preferably 13 μm or less, and may be 10 μm or less. The thickness of the polarizer is usually 2 μm or more because it is easy to impart desired optical characteristics.

(Protective film)
The protective film is composed of a resin film and can be composed of a transparent resin film. In particular, it is preferable to use a material that is excellent in transparency, mechanical strength, thermal stability, moisture shielding properties, and the like. When the first transparent resin layer is an optical layer such as a hard coat layer, an antiglare layer, a light diffusion layer, or an antireflection layer, a protective film can also be used as a base material for forming the optical layer. In this specification, “transparent” means that the single transmittance is 80% or more in the visible light region. Moreover, the hardened layer of an active energy ray curable resin composition can also be used as a protective film.

  When laminating protective films on both sides of the polarizer, the same protective films may be used, or different protective films may be used.

  The resin for forming the protective film is not particularly limited. For example, methyl methacrylate resin, polyolefin resin, cyclic olefin resin, polyvinyl chloride resin, cellulose resin, styrene resin, acrylonitrile.・ Butadiene / styrene resins, acrylonitrile / styrene resins, polyvinyl acetate resins, polyvinylidene chloride resins, polyamide resins, polyacetal resins, polycarbonate resins, modified polyphenylene ether resins, polybutylene terephthalate resins, Examples thereof include films made of polyethylene terephthalate resin, polysulfone resin, polyethersulfone resin, polyarylate resin, polyamideimide resin, polyimide resin, and the like.

  These resins can be used alone or in combination of two or more. These resins can also be used after any appropriate polymer modification. Examples of the polymer modification include copolymerization, crosslinking, molecular terminal modification, stereoregularity control, and reaction between different polymers. Modifications such as mixing including the case involving the.

  Among these, as the material for the protective film, it is preferable to use a methyl methacrylate resin, a polyethylene terephthalate resin, a polyolefin resin, or a cellulose resin. The polyolefin resin here includes a chain polyolefin resin and a cyclic polyolefin resin.

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

  This methyl methacrylate resin can be usually obtained by polymerizing a monofunctional monomer mainly composed of methyl methacrylate in the presence of a radical polymerization initiator. In the polymerization, a polyfunctional monomer and a chain transfer agent can coexist if necessary.

  The monofunctional monomer that can be copolymerized with methyl methacrylate is not particularly limited. For example, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, methacrylic acid 2 -Methacrylic acid esters other than methyl methacrylate such as ethylhexyl and 2-hydroxyethyl methacrylate; methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-acrylate Acrylic esters such as ethylhexyl and 2-hydroxyethyl acrylate; methyl 2- (hydroxymethyl) acrylate, methyl 3- (hydroxyethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, And hydroxyalkyl acrylates such as 2- (hydroxymethyl) butyl acrylate; unsaturated acids such as methacrylic acid and acrylic acid; halogenated styrenes such as chlorostyrene and bromostyrene; vinyltoluene and α-methylstyrene Substituted styrenes; unsaturated nitriles such as acrylonitrile and methacrylonitrile; unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; and unsaturated imides such as phenylmaleimide and cyclohexylmaleimide it can. Such monomers may be used alone or in combination of two or more.

  The polyfunctional monomer that can be copolymerized with methyl methacrylate is not particularly limited. For example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , The hydroxyl groups at both ends of ethylene glycol or its oligomers such as tetraethylene glycol di (meth) acrylate, nonaethylene glycol di (meth) acrylate, and tetradecaethylene glycol di (meth) acrylate were esterified with acrylic acid or methacrylic acid Propylene glycol or its oligomers with both terminal hydroxyl groups esterified with acrylic acid or methacrylic acid; Neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate Lilate and hydroxyl group of dihydric alcohol such as butanediol di (meth) acrylate esterified with acrylic acid or methacrylic acid; Bisphenol A, alkylene oxide adduct of bisphenol A, or both terminal hydroxyl groups of these halogen-substituted products Esterified with acrylic acid or methacrylic acid; polyhydric alcohols such as trimethylolpropane and pentaerythritol esterified with acrylic acid or methacrylic acid, and terminal hydroxyl groups of these polyhydric alcohols with glycidyl acrylate or glycidyl methacrylate Epoxy group ring-opening addition; succinic acid, adipic acid, terephthalic acid, phthalic acid, dibasic acids such as halogen substitution products, and alkylene oxide adducts Those with an epoxy group of glycidyl acrylate or glycidyl methacrylate by ring-opening addition; allyl (meth) acrylate; and aromatic divinyl compounds such as divinylbenzene and the like. Among these, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and neopentyl glycol dimethacrylate are preferably used.

  As the methyl methacrylate resin, those modified by a reaction between functional groups copolymerized with the resin are also used. As the reaction, for example, demethanol condensation reaction in the polymer chain of a methyl ester group of methyl acrylate and a hydroxyl group of methyl 2- (hydroxymethyl) acrylate, or a carboxyl group of acrylic acid and 2- (hydroxymethyl) acrylic Examples thereof include a dehydration condensation reaction within a polymer chain of a hydroxyl group of methyl acid.

  The polyethylene terephthalate resin means a resin in which 80 mol% or more of repeating units are composed of ethylene terephthalate, and may contain other dicarboxylic acid components and diol components. Other dicarboxylic acid components are not particularly limited, and examples thereof include isophthalic acid, 4,4′-dicarboxydiphenyl, 4,4′-dicarboxybenzophenone, bis (4-carboxyphenyl) ethane, and adipic acid. , Sebacic acid, 1,4-dicarboxycyclohexane and the like.

  Other diol components are not particularly limited, but propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, ethylene oxide adduct of bisphenol A, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol Etc.

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

  Polyethylene terephthalate resin can be produced by direct polycondensation of terephthalic acid and ethylene glycol (and other dicarboxylic acids or other diols as required), dialkyl esters of terephthalic acid and ethylene glycol (and if necessary) A transesterification reaction with a dialkyl ester of another dicarboxylic acid or other diol), and a polycondensation, and an ethylene glycol ester of terephthalic acid (and other dicarboxylic acids as required) For example, a method of polycondensation of other diol ester) in the presence of a catalyst is employed. Furthermore, if necessary, solid-state polymerization can be performed to improve the molecular weight or reduce the low molecular weight components.

  The cyclic polyolefin-based resin is obtained by polymerizing cyclic olefin monomers such as norbornene and other cyclopentadiene derivatives in the presence of a catalyst. Use of such a cyclic polyolefin-based resin is preferable because a protective film having a predetermined retardation value described later can be easily obtained.

  As the cyclic polyolefin-based resin, for example, ring-opening metathesis polymerization is performed from cyclopentadiene and olefins or (meth) acrylic acid or esters thereof using norbornene obtained by Diels-Alder reaction or a derivative thereof as a monomer. Resin obtained by hydrogenation; ring-opening metathesis polymerization using dicyclopentadiene and olefins or (meth) acrylic acid or esters thereof by tetracyclododecene or a derivative thereof obtained by Diels-Alder reaction, Resin obtained by subsequent hydrogenation; ring-opening metathesis copolymerization of at least two monomers selected from norbornene, tetracyclododecene, derivatives thereof, and other cyclic olefin monomers, Resins obtained by hydrogenation; resins obtained by addition copolymerization of aromatic compounds having chain olefins and / or vinyl groups with cyclic olefins such as norbornene, tetracyclododecene, or derivatives thereof Can be mentioned.

  Typical examples of the chain polyolefin resin are a polyethylene resin and a polypropylene resin. Among them, a homopolymer of propylene, or a copolymer obtained by copolymerizing propylene as a main component and a comonomer copolymerizable therewith, for example, ethylene in a proportion of 1 to 20% by weight, preferably 3 to 10% by weight. Preferably used.

  The polypropylene resin may contain an alicyclic saturated hydrocarbon resin. By containing the alicyclic saturated hydrocarbon resin, the retardation value can be easily controlled. The content of the alicyclic saturated hydrocarbon resin is advantageously 0.1 to 30% by weight relative to the polypropylene resin, and more preferably 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 retardation value cannot be sufficiently obtained, while when the content exceeds 30% by weight, the protective film Therefore, there is a concern that the alicyclic saturated hydrocarbon resin may bleed out over time.

  Cellulosic resins are those in which some or all of the hydrogen atoms in the hydroxyl groups of cellulose obtained from raw material cellulose such as cotton linter and wood pulp (hardwood pulp, conifer pulp) are substituted with acetyl groups, propionyl groups and / or butyryl groups. Further, it refers to a cellulose organic acid ester or a cellulose mixed organic acid ester. Examples include cellulose acetates, propionic acid esters, butyric acid esters, and mixed esters thereof. Among these, a triacetyl cellulose film, a diacetyl cellulose film, a cellulose acetate propionate film, a cellulose acetate butyrate film, and the like are preferable.

  A method of using a methyl methacrylate resin, a polyethylene terephthalate resin, a polyolefin resin, a cellulose resin, and the like as a protective film for adhering to a polarizer may be selected as appropriate according to each resin. It is not particularly limited. For example, a resin dissolved in a solvent is cast onto a metal band or drum, and a solvent casting method for obtaining a film by drying and removing the solvent, and the resin is heated and kneaded to a temperature higher than its melting temperature and extruded from a die, A melt extrusion method for obtaining a film by cooling is employed. In this melt extrusion method, a single layer film may be extruded or a multilayer film may be simultaneously extruded.

  The film used as the protective film can be easily obtained as a commercial product, and if it is a methyl methacrylate-based resin film, the trade name is Sumipex (manufactured by Sumitomo Chemical Co., Ltd.), Acrylite (registered trademark), Acriprene (registered trademark) (Mitsubishi Rayon Co., Ltd.), Delagras (registered trademark) (Asahi Kasei Co., Ltd.), Paragrass (registered trademark), Comogras (registered trademark) (manufactured by Kuraray Co., Ltd.), Registered trademark) (manufactured by Nippon Shokubai Co., Ltd.). If it is a polyolefin-type resin film, ZEONOR (registered trademark) (Nippon Zeon Co., Ltd.), Arton (registered trademark) (JSR Co., Ltd.), etc. are mentioned by a brand name, respectively. If it is a polyethylene terephthalate-type resin film, Novaclear (trademark) (made by Mitsubishi Chemical Corporation), a Teijin A-PET sheet (made by Teijin Chemicals Ltd.), etc. are mentioned by a brand name, respectively. For polypropylene resin films, FILMAX CPP film (manufactured by FILMAX), Santox (registered trademark) (manufactured by Sun Tox Co., Ltd.), Tosero (registered trademark) (manufactured by Tosero Co., Ltd.), Toyobo Pyrene Film (Registered trademark) (manufactured by Toyobo Co., Ltd.), Treffan (registered trademark) (manufactured by Toray Film Processing Co., Ltd.), Nihon Polyace (manufactured by Nippon Polyace Co., Ltd.), and Dazai (registered trademark) FC (Futamura Chemical Co., Ltd.) Manufactured). In the case of cellulose-based resin films, Fujitac (registered trademark) TD (manufactured by Fuji Film Co., Ltd.), KC2UA and Konica Minolta TAC film KC (manufactured by Konica Minolta Co., Ltd.) and the like can be mentioned.

  The protective film used in the present invention can be provided with antiglare properties (haze). The method for imparting antiglare properties is not particularly limited. For example, a method of mixing inorganic fine particles or organic fine particles into the raw material resin to form a film, the multilayer extrusion described above, and the like. A method of forming a two-layer film from a resin in which fine particles are mixed and a resin in which fine particles are not mixed in the other, or a method of forming a three-layer film with the resin mixed with particles on the outside, and inorganic on one side of the film A method of coating a coating solution obtained by mixing fine particles or organic fine particles with a curable binder resin, curing the binder resin, and providing an antiglare layer is employed.

  Moreover, a protective film can also contain an additive as needed. Examples of the additive include a lubricant, an anti-blocking 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 may be 10 to 30 μm from the viewpoints of strength and handleability.

  The protective film is preferably subjected to saponification treatment, corona treatment, plasma treatment or the like prior to bonding with the polarizer.

  A brightness enhancement film may be used as the protective film. 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 outgoing light from a light source (backlight) into transmitted polarized light, reflected polarized light, or scattered polarized light is used. Such a brightness enhancement film can improve the output efficiency of linearly polarized light by using retroreflected light from a reflected or scattered polarized backlight.

  Examples of the brightness enhancement film include anisotropic reflective polarizers. An example of the anisotropic reflective polarizer is an anisotropic multiple thin film that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in the other vibration direction. An example of the anisotropic multi-thin film is a trade name “APF” manufactured by 3M. An example of the anisotropic reflective polarizer is a composite of a cholesteric liquid crystal layer and a λ / 4 plate. An example of such a composite is a product name “PCF” manufactured by Nitto Denko Corporation. An example of the anisotropic reflective polarizer is a reflective grid polarizer. Examples of the reflective grid polarizer include metal grid reflective polarizers that perform fine processing on metal and emit reflected polarized light even in the visible light region. Of these, a brightness enhancement film comprising an anisotropic multiple thin film is preferred.

  Examples of the cured layer of the active energy ray-curable resin composition include a layer that is cured by irradiating the active energy ray-curable resin composition with active energy rays. Examples of the active energy ray-curable resin composition include those containing a polymerizable compound and a photopolymerization initiator, those containing a photoreactive resin, and those containing a binder resin and a photoreactive crosslinking agent. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable acrylic monomer, and a photocurable urethane monomer, and oligomers derived from the photopolymerizable monomer. As a photoinitiator, what contains the substance which generate | occur | produces active species like a radical, a cation, or an anion by irradiation of active energy rays like an ultraviolet-ray can be mentioned. As the active energy ray-curable resin composition containing a polymerizable compound and a photopolymerization initiator, those containing a photocurable epoxy monomer and a cationic photopolymerization initiator can be preferably used.

  When using an active energy ray-curable resin composition, after applying the active energy ray-curable resin composition on a polarizer or a protective film, a drying process is performed as necessary, and then an active energy ray is irradiated. A curing step for curing the active energy ray-curable resin composition is performed. The light source of the active energy ray is not particularly limited, but ultraviolet light having a light emission distribution at a wavelength of 400 nm or less is preferable. A wave excitation mercury lamp, a metal halide lamp, etc. can be used.

  The composition may contain an additive. Examples of the additive include an ion trap agent, an antioxidant, a chain transfer agent, a sensitizer, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, and an antifoaming agent.

  The cured layer of the active energy ray curable resin composition is useful as a protective layer for protecting the surface of the polarizer. Since the hardened layer of the active energy ray-curable resin composition can be made thinner than an ordinary protective film, it is effective for making the polarizing plate thinner.

  The thickness of the cured 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 first transparent resin layer has a surface resistance value of 1.0 × 10 ⁹ Ω / □ or more and 1.0 × 10 ¹¹ Ω / □ or less, preferably 5.0 × 10 ⁹ Ω / □ or more. 0 × 10 ¹⁰ Ω / □ or less. With such a surface resistance value and the second transparent resin layer having an antistatic function, it is possible to efficiently manufacture a liquid crystal display device without incurring multiple picking and product defects. The surface resistance value can be measured by the method described in Examples described later.

  The first transparent resin layer can be formed from, for example, an optical layer such as a hard coat layer, an antiglare layer, a light diffusion layer, or an antireflection layer, or an adhesive layer. Especially, it is preferable that a 1st transparent resin layer is a hard-coat layer. In order to impart the surface resistance characteristic to the first transparent resin layer, for example, an antistatic agent may be contained in the first transparent resin layer. In the present specification, transparent means that the single transmittance is 80% or more in the visible light region.

  The hard coat layer can be formed by coating the active energy ray-curable resin composition on the transparent resin film and then irradiating the active energy ray to cure 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 is appropriately selected depending on the resin to be used. For example, acetophenone photopolymerization initiator, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone photopolymerization initiator, triazine photopolymer A polymerization initiator, an oxadiazole-based photopolymerization initiator, or the like can be used. 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 is a conventionally known method such as a gravure coating method, a micro gravure coating method, a roll coating method, a rod coating method, a knife coating method, an air knife coating method, a kiss coating method, or a die coating method. It's okay.

  The active energy ray to be irradiated can be appropriately selected from ultraviolet rays, electron beams, near ultraviolet rays, visible light, near infrared rays, infrared rays, X-rays, etc., depending on the type of the active energy ray curable resin. Lines are preferable, and ultraviolet rays are particularly preferable because they are easy to handle and high energy can be easily obtained.

  The antiglare layer is an optical functional layer provided with a predetermined uneven shape on the surface for preventing reflection of external light. The antiglare layer is formed, for example, by (a) applying a coating liquid containing translucent fine particles and a translucent resin on a transparent resin film, and then curing the coating layer as necessary (translucent layer). (I) A coating liquid containing a translucent resin and a coating solution (which may further contain translucent fine particles) was applied on the transparent resin film. Thereafter, the coating layer can be cured as necessary while pressing a mold having a predetermined surface irregularity shape on the coating layer, and can be formed by a method of imparting surface irregularities to the coating layer.

  The translucent resin constituting the antiglare layer is not particularly limited as long as it has translucency. For example, in addition to the cured product of the active energy ray curable resin as described above, Cured product; thermoplastic resin; metal alkoxide polymer and the like. Especially, the hardened | cured material of active energy ray curable 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 is applied by irradiating active energy rays. Harden the construction layer.

  Examples of the thermosetting resin include a thermosetting urethane resin composed 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 thermoplastic resins include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, and methylcellulose; vinyl acetate and copolymers thereof, vinyl chloride and copolymers thereof, vinylidene chloride and copolymers thereof, and the like. Acetal resins such as polyvinyl formal and polyvinyl butyral; (meth) acrylic resins such as acrylic resins and copolymers thereof, methacrylic resins and copolymers; polystyrene resins; polyamide resins; polyester resins; Examples include polycarbonate resins.

  As the metal alkoxide-based polymer, a silicon oxide-based matrix using a silicon alkoxide-based material as a raw material can be used. Specifically, the metal alkoxide polymer can be an inorganic or organic-inorganic composite matrix obtained by dehydration condensation of a hydrolyzate of alkoxysilane such as tetramethoxysilane or tetraethoxysilane.

  When a cured product of a thermosetting resin or a metal alkoxide polymer is used as the translucent resin, heating may be required after coating the coating liquid.

  Translucent fine particles include, for example, organic fine particles such as (meth) acrylic resin, melamine resin, polyethylene, polystyrene, organic silicone resin, acrylic-styrene copolymer, and calcium carbonate, silica, aluminum oxide, barium carbonate And inorganic fine particles such as barium sulfate, titanium oxide, and glass. One kind or two or more kinds of fine particles can be used as the translucent fine particles. In order to obtain desired antiglare properties and other optical characteristics, the kind, particle diameter, refractive index, content, and the like of the light-transmitting fine particles are appropriately adjusted.

  The light diffusion layer is an optical functional layer for diffusing the backlight light that has passed through the liquid crystal cell for the purpose of expanding the viewing angle of the liquid crystal display device. The light diffusion layer is, for example, a method in which a coating liquid containing translucent fine particles (light diffusing agent) and a translucent resin is applied onto a transparent resin film, and then the coating layer is cured as necessary. Can be formed. As the light-transmitting fine particles and the light-transmitting resin, the same materials as those described for the antiglare layer can be used. In order to obtain a desired light diffusibility, the type of transparent resin film, the type of translucent resin, the type of translucent fine particles, the particle diameter, the refractive index, the content, the thickness of the light diffusing layer, and the like are appropriately adjusted. .

  The antireflection layer is an optical functional layer for reducing or preventing reflection of external light, and may include, for example, a low refractive index layer. Moreover, the multilayer structure further provided with a high refractive index layer and / or a middle refractive index layer between a transparent resin film and a low refractive index layer may be sufficient. The hard coat layer described above may be provided between the antireflection layer and the transparent resin film.

The low refractive index layer is coated with a coating solution containing a light-transmitting resin such as a cured product of the above-described active energy ray-curable resin or a metal alkoxide polymer, and inorganic fine particles, and then the coating layer is used as necessary. And can be formed by a method of curing. Examples of the inorganic fine particles include LiF (refractive index 1.4), MgF (refractive index 1.4), 3NaF · AlF (refractive index 1.4), AlF (refractive index 1.4), Na ₃ AlF ₆ ( Examples thereof include low refractive fine particles such as a refractive index of 1.33) and hollow silica fine particles.

  The high refractive index layer is formed by applying a coating liquid containing a light-transmitting resin such as a cured product of the above-described active energy ray-curable resin or a metal alkoxide polymer, and inorganic fine particles and / or organic fine particles. It can form by the method of hardening a construction layer as needed. Examples of the inorganic fine particles include zinc oxide, titanium oxide, cerium oxide, aluminum oxide, silane oxide, tantalum oxide, yttrium oxide, ytterbium oxide, zirconium oxide, antimony oxide, and indium tin oxide (ITO). By forming such a high refractive index layer, antistatic performance can be imparted.

  Examples of the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer include acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy-based, fluorine-based, natural rubber, What uses rubber-type polymers, such as a synthetic rubber, as a base polymer can be selected suitably, and can be used. As the pressure-sensitive adhesive, those having excellent optical transparency, moderate wettability, cohesiveness and adhesive pressure-sensitive adhesive properties, and excellent weather resistance and heat resistance are particularly preferable.

  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, an organic salt or inorganic salt of an alkali metal can be used. The “organic cation-anion salt” in the present invention refers to an organic salt whose cation part is composed of an organic substance, and the anion part may be an organic substance or an inorganic substance. There may be. “Organic cation-anion salt” is also called an ionic liquid or ionic solid. One antistatic agent may be used alone, or a plurality of antistatic agents may be used in combination.

  Examples of the alkali metal ions constituting the cation part of the alkali metal salt include lithium, sodium, and potassium ions. Of these alkali metal ions, lithium ions are preferred.

The anion part of the alkali metal salt may be composed of an organic material or an inorganic material. Examples of the anion part constituting the organic salt include CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , and 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-, or the following general formula ( 1) to (4),
(1): (C _n F _{2n + 1} SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10),
_{(2): CF 2 (C} m F 2m SO 2) 2 N - ( where, m is an integer of from 1 to 10),
^{_{(3): - O 3 S}} (CF 2) l SO 3 - ( where, l is an integer of from 1 to 10),
^{_{(4) :( C p F 2p}} + 1 SO 2) N - (C q F 2q + 1 SO 2), ( where, p, q is an integer of from 1 to 10), in represented by ones like. In particular, an anion moiety containing a fluorine atom is preferably used because an ionic compound having good ion dissociation properties can be obtained. The anion part constituting the inorganic salt includes 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 are used. As the anion moiety, (perfluoroalkylsulfonyl) imide represented by the general formula (1) such as (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , etc. is preferable, (Trifluoromethanesulfonyl) imide represented by CF ₃ SO ₂ ) ₂ N ⁻ is preferable.

  The organic cation-anion salt used in the present invention is composed of a cation component and an anion component, and the cation component is composed of an organic substance. As the cation component, specifically, pyridinium cation, piperidinium cation, pyrrolidinium cation, cation having pyrroline skeleton, cation having pyrrole skeleton, imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation, Examples include pyrazolium cation, pyrazolinium cation, tetraalkylammonium cation, trialkylsulfonium cation, and tetraalkylphosphonium cation.

Examples of the anion component include Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ , and 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 -, or the following general formula (1) to (4 ),
(1): (C _n F _{2n + 1} SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10),
_{(2): CF 2 (C} m F 2m SO 2) 2 N - ( where, m is an integer of from 1 to 10),
_{^{(3): - O 3 S}} (CF 2) l SO 3 - ( where, l is an integer of from 1 to 10),
^{_{(4) :( C p F 2p}} + 1 SO 2) N - (C q F 2q + 1 SO 2), ( where, p, q is an integer of from 1 to 10), in represented by ones like. Among these, an anion component containing a fluorine atom is particularly preferably used because an ionic compound having good ion dissociation properties can be obtained.

  The antistatic agent is preferably 1 part by mass or more and 50 parts by mass or less, and preferably 3 parts by mass or more in that the surface resistance characteristic is easily imparted to 100 parts by mass of the first transparent resin layer. Also good.

  The thickness of the first transparent resin layer is preferably 0.01 to 20 μm, for example, 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, it is possible to efficiently manufacture a liquid crystal display device without causing multiple acquisition or product defects.

  A 2nd transparent resin layer can be formed from optical layers, such as a hard-coat layer, a glare-proof layer, a light-diffusion layer, and an antireflection layer, or an adhesive layer, for example. Especially, it is preferable that a 1st transparent resin layer is an adhesive layer. When a 2nd transparent resin layer is an adhesive layer, it can be set as the adhesive layer for bonding a 2nd transparent resin layer to a liquid crystal cell.

  In order to impart an antistatic function to the second transparent resin layer, for example, an antistatic agent may be contained in the second transparent resin layer. That is, when the second transparent resin layer contains an antistatic agent, it can be said that the second transparent resin layer has an antistatic function. As a method for forming the second transparent resin layer, a method similar to the method for forming the first transparent resin layer can be employed. The first transparent resin layer and the second transparent resin layer may be formed from the same layer, but are preferably formed from different layers.

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

(Production method of polarizing plate)
The members described above can be bonded to each other by, for example, laminating via an adhesive layer or an adhesive layer.

  An adhesive bond layer is a layer for adhere | attaching a polarizer and a protective film, for example, As an adhesive agent which forms an adhesive bond layer, an active energy ray hardening adhesive and a water-system adhesive agent can be mentioned. Moreover, you may use the above-mentioned active energy ray curable resin composition.

  When using a water-based adhesive, it is preferable to carry out a drying step in order to remove water contained in the water-based adhesive after bonding the polarizer and the protective film. After the drying process, for example, a curing process for curing at a temperature of about 20 to 45 ° C. may be provided.

  When using an active energy ray-curable adhesive, after bonding a polarizer and a protective film, a drying step is performed as necessary, and then the active energy ray-curable adhesive is irradiated by irradiating active energy rays. A curing step for curing is performed. The light source of the active energy ray is not particularly limited, but ultraviolet light having a light emission distribution at a wavelength of 400 nm or less is preferable. A wave excitation mercury lamp, a metal halide lamp, etc. can be used.

  In pasting the polarizer and the protective film, saponification treatment, corona treatment, plasma treatment, or the like can be performed on at least one of the pasting surfaces.

  A pressure-sensitive adhesive layer can be used for laminating the polarizer and the protective film and bonding the optical laminate to the liquid crystal cell. Examples of the pressure-sensitive adhesive layer include acrylic pressure-sensitive adhesives, silicone pressure-sensitive adhesives, and rubber-based pressure-sensitive adhesives, and acrylic pressure-sensitive adhesives are preferable in terms of transparency, weather resistance, heat resistance, and workability. When the pressure-sensitive adhesive layer is a layer corresponding to the second transparent resin layer, the pressure-sensitive adhesive layer has an antistatic function and preferably has an antistatic agent.

  For the adhesive, if necessary, a tackifier, plasticizer, glass fiber, glass beads, metal powder, other inorganic powders, fillers, pigments, colorants, fillers, antioxidants, UV absorbers Various additives such as a silane coupling agent may be appropriately blended.

  The pressure-sensitive adhesive layer is usually formed by applying a pressure-sensitive adhesive solution on a release sheet and drying the pressure-sensitive adhesive solution. For application onto the release sheet, for example, roll coating methods such as reverse coating and gravure coating, spin coating methods, screen coating methods, fountain coating methods, dipping methods, spraying methods and the like can be employed. The release sheet provided with the pressure-sensitive adhesive layer is used by a method of transferring the release sheet.

  The thickness of the adhesive layer arrange | positioned between a polarizer and a protective film (especially brightness enhancement film) can be 3-15 micrometers, for example. The thickness of the adhesive layer for bonding an optical laminated body to a liquid crystal cell can be 5-30 micrometers, for example.

<Liquid crystal display device>
FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of the liquid crystal display device of the present invention. In FIG. 2, the backlight and the polarizing plate on the back side are omitted. In the liquid crystal display device of the present invention shown in FIG. 2A, the front plate 2, the adhesive layer 30, the polarizing plate 100, and the liquid crystal cell 3 are laminated in this order. In the liquid crystal display device of the present invention shown in FIG. 2B, the front plate 2, the adhesive layer 30, the polarizing plate 101, and the liquid crystal cell 3 are laminated in this order. In the liquid crystal display device of the present invention shown in FIG. 2C, the front plate 2, the adhesive layer 30, the polarizing plate 102, and the liquid crystal cell 3 are laminated in this order. In addition, it is good also as an air layer without providing the contact bonding layer 30. FIG. 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 viewing side than the second transparent resin layer.

  The liquid crystal display device according to the present invention is preferably a touch input type liquid crystal display device having a touch panel function. The touch input type liquid crystal display device includes a touch input element including a liquid crystal cell. The configuration of the touch panel may be any conventionally known method such as an out-cell type, an on-cell type, an in-cell type, etc., but an in-cell type is preferable. The operation method of the touch panel may be any conventionally known method such as a resistance film method, a capacitance method (surface type capacitance method, projection type capacitance method).

  The liquid crystal cell 50 has a pair of transparent substrates and a liquid crystal layer sandwiched between them. The display mode of the liquid crystal cell may be various display modes such as STN, TN, OCB, HAN, VA, and IPS. From the viewpoint of obtaining a high contrast, the VA mode is preferable, and from the viewpoint of obtaining a wide viewing angle, the IPS mode is preferable.

  As described above, since the front plate is disposed on the viewing side of the liquid crystal cell, specifically, the outermost surface of the final product, it is assumed to be used outdoors or semi-outdoors. Therefore, from the viewpoint of durability, it is preferable to be composed of an inorganic material such as glass and tempered glass, or an organic material such as a polycarbonate resin or an acrylic resin.

  The adhesive layer for bonding the front plate and the polarizing plate of the present invention is preferably a transparent layer having a refractive index close to that of the front plate. As the adhesive layer, the above adhesive layer or pressure-sensitive adhesive layer can be used. By laminating the polarizing plate and the front plate through the adhesive layer, reflection and light scattering at the interface between the front plate and the polarizing plate can be eliminated, and visibility can be improved.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not prescribed | regulated by these examples. In the examples, “%” and “part” representing the content or amount used are based on mass unless otherwise specified. The evaluation methods used in the examples are as follows.

(1) Thickness:
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 occurrences due to static electricity after chip cutting:
The polarizing plates obtained in the examples and comparative examples were chip-cut to a diagonal size of 5.5 inches, made into a bundle of 100 sheets, and then counted the number of multiple shots that occurred during product inspection one by one. The evaluation criteria are as follows.
○: Occurrence count 0 times △: Occurrence count 1 time or more and 10 times or less ×: Occurrence count 10 times

(4) Touch panel operability evaluation:
A product obtained by peeling off the polarizing plate on the viewing side from an in-cell touch sensor built-in liquid crystal display device model name Galaxy (registered trademark) On7 manufactured by Samsung Radio Co., Ltd. was prepared. After sticking the polarizing plate with the adhesive obtained in each example and performing an autoclave process, the operativity of the touch panel was confirmed. The evaluation criteria are as follows.
○: No problem with touch panel operability ×: Operation failure occurred during touch panel operation

(5) ESD test evaluation:
The cover glass and the polarizing plate on the viewing side are peeled off from the liquid crystal panel (model name Galaxy (registered trademark) On7 in-cell touch sensor built-in liquid crystal display device manufactured by Samsung Radio Co., Ltd.), and the adhesive prepared in Examples and Comparative Examples on the release surface The attached polarizing plate was bonded. Furthermore, the front board was bonded and it was set as the evaluation sample.

  The evaluation sample was placed on a backlight having a luminance of 20000 cd, and 6 kv of static electricity was generated using an ESD (SANKI, ESD-8012A) as a static electricity generator, thereby causing alignment disorder of the liquid crystal. The recovery time (s) of display failure due to the orientation failure was measured using an instantaneous multiphotometric detector (MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.).

(6) Thermal durability test evaluation:
The adhesive-attached polarizing plates obtained in the examples and comparative examples were cut into a size of 40 mm in length and 40 mm in width, pressure-bonded to an alkali-free glass through an adhesive layer, and 20 at a load of 50 ° C. and 5 kg. It was allowed to stand in an autoclave for a minute to mature the adhesive state, and left in an environment of 23 ° C./60% RH for 10 hours. Thereafter, the durability test was performed using an Espec constant temperature and humidity chamber, left in an 85 ° C. dry environment for 500 hours, and immediately after removal, the presence or absence of visual peeling was evaluated according to the following criteria.
○: No peeling was observed.
(Triangle | delta): The small peeling which can be confirmed visually is recognized.
X: Clear peeling was recognized.

(Production Example 1: Production of Polarizer A)
A 20 μm-thick polyvinyl alcohol film (average polymerization degree of about 2,400, saponification degree of 99.9 mol% or more) was uniaxially stretched about 5 times by dry stretching and further kept at 60 ° C. After being immersed in pure water for 1 minute, 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 of 8.5 / 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, the film was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a 9 μm thick polarizer in which iodine was adsorbed and oriented on the polyvinyl alcohol film.

(Production Example 2: Production of Polarizer B)
A 30 μm-thick polyvinyl alcohol film (average polymerization degree of about 2,400, saponification degree of 99.9 mol% or more) was uniaxially stretched by about 4 times by dry stretching and further kept at 60 ° C. After being immersed in pure water for 1 minute, 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 of 8.5 / 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, the film was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a 12 μm thick polarizer in which iodine was adsorbed and oriented on the polyvinyl alcohol film.

(Production Example 3: Production of Polarizer C)
A 75 μm-thick polyvinyl alcohol film (average polymerization degree of about 2,400, saponification degree of 99.9 mol% or more) was uniaxially stretched by about 4 times by dry stretching and further kept at 60 ° C. while maintaining the tension state. After being immersed in pure water for 1 minute, 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 of 8.5 / 8.5 / 100 at 72 ° C. for 300 seconds. Subsequently, the film was washed with pure water at 26 ° C. for 20 seconds and then dried at 65 ° C. to obtain a 28 μm thick polarizer in which iodine was adsorbed and oriented on the polyvinyl alcohol film.

(Production Example 4: Production of water-based adhesive)
3 parts by weight of a carboxyl group-modified polyvinyl alcohol [trade name “KL-318” obtained from Kuraray Co., Ltd.] is dissolved in 100 parts by weight of water, and a polyamide epoxy additive [Taoka] which is a water-soluble epoxy resin is dissolved in the aqueous solution. An aqueous adhesive was prepared by adding 1.5 parts by weight of a trade name “Smileze Resin (registered trademark) 650 (30)”, an aqueous solution having a solid content concentration of 30% by weight obtained from Chemical Industries, Ltd.

(Preparation of adhesive layer)
The following pressure-sensitive adhesive layers were prepared.
Adhesive layer A: 25 μm thick sheet-like adhesive having antistatic function [“KZ” manufactured by Lintec Corporation]
Adhesive layer B: 25 μm thick sheet-like adhesive that does not have an antistatic function [“KT” manufactured by Lintec Corporation]

(Preparation of protective film)
The following protective films were prepared.
Protective film A: Cellulose-based resin film KC4UA manufactured by Konica Minolta Co., Ltd., thickness 40 μm.
Protective film B: manufactured by 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: manufactured by Nippon Zeon Co., Ltd., cyclic olefin-based resin film ZF14-023, thickness 23 μm.
Protective film E: manufactured by Nippon Zeon Co., Ltd., cyclic olefin-based resin film ZF14-013, thickness 13 μm.
Protective film F: Hardened layer of active energy ray-curable resin composition, thickness 3 μm.

[Example 1]
Polarized light composed of protective film A / water-based adhesive layer / polarizer / water-based adhesive layer / protective film D by applying a water-based adhesive on both sides of polarizer B and bonding protective film A and protective film D together. I got a plate. Next, a composition containing a clear hard coat resin kneaded with an antistatic agent is applied on the protective film A and cured by irradiating with ultraviolet rays to form a hard coat layer (first transparent resin layer) having an antistatic function. did. Furthermore, an adhesive layer A (second transparent resin layer) was bonded onto the protective film D to obtain a polarizing plate with an adhesive.

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

[Examples 2 to 10, Comparative Examples 1 to 10]
The amount of antistatic agent kneaded into the hard coat layer (first transparent resin layer) is adjusted to change the surface resistance value as shown in Table 1, and the type of protective film to be bonded to both sides of the polarizer is shown. 1 except that the type of the pressure-sensitive adhesive layer was changed as shown in Table 1 and the type of the polarizer was changed as shown in Table 1, and the same operation as in Example 1 was performed. A polarizing plate with an adhesive was prepared.

  In addition, when using the cured layer of the active energy ray-curable resin composition as the protective film F, the active energy ray-curable resin composition was applied on the polarizer so that the thickness after curing was 3 μm. Thereafter, ultraviolet rays were irradiated to form a cured layer. In Comparative Example 10, no antistatic agent was kneaded into the hard coat layer (first transparent resin layer).

  For these polarizing plates with pressure-sensitive adhesive, the surface resistance value of the hard coat layer was measured in the same manner as in Example 1. About Examples 1-10 and Comparative Examples 1-10, the layer configuration of the polarizing plate, the surface resistance value of the hard coat layer, the presence or absence of an antistatic function of the adhesive layer, and the distance between the hard coat layer and the adhesive layer Are summarized in Table 1.

  For polarizing plates with pressure-sensitive adhesives prepared in Examples 1 to 10 and Comparative Examples 1 to 10, multiple generation occurrence evaluation by static electricity after chip cut, touch panel operability evaluation, ESD test evaluation, and heat durability test evaluation Went. The results are shown in Table 2.

  In Table 2, the judgment was “poor” when there was a defect in any of the evaluation of multiple occurrence due to static electricity after chip cut, touch panel operability evaluation, and ESD test evaluation, and “good” when there was no defect. In addition, regarding the evaluation of the ESD test, the case where the recovery time was less than 1 s was regarded as no problem, and the case where the recovery time was 1 s or more was regarded as defective.

  According to the present invention, the present invention provides a polarizing plate capable of efficiently producing a liquid crystal display device without causing multiple picking and product defects and having excellent touch panel operability. It is useful because it is possible.

DESCRIPTION OF SYMBOLS 1 Polarizer 2 Front plate 3 Liquid crystal cell 4 Double arrow 10 1st transparent resin layer 11 2nd transparent resin layer 20, 21 Protective film 30 Adhesive layer 100, 101, 102 Polarizing plate 200, 201, 202 Liquid crystal display device

Claims (5)

A polarizing plate having a first transparent resin layer on one side of a polarizer and a second transparent resin layer on the other side,
The polarizer has a thickness of 15 μm or less,
The surface resistance value of the first transparent resin layer is 1.0 × 10 ⁹ Ω / □ or more and 1.0 × 10 ¹¹ Ω / □ or less,
The second transparent resin layer has an antistatic function,
The polarizing plate whose distance between the said 1st transparent resin layer and the said 2nd transparent resin layer is 80 micrometers or less. The polarizing plate according to claim 1, further comprising a protective film between the first transparent resin layer or the second transparent resin layer and the polarizer. The protective film is at least selected from a cyclic olefin resin film, a cellulose resin film, a polycarbonate resin film, a polyolefin resin film, a polyethylene terephthalate resin resin film, a methyl methacrylate resin film, and a brightness enhancement film. The polarizing plate according to claim 1, wherein the polarizing plate is a single film. The polarizing plate according to claim 1, wherein each of the first transparent resin layer and the second transparent resin layer is a layer disposed on the outermost side of the polarizing plate. A liquid crystal display device in which the polarizing plate according to claim 1 is disposed on the viewing side of the liquid crystal cell, and a front plate is further disposed on the polarizing plate.

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