JP2008003423A - Polarizing plate for liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate for liquid crystal display which does not cause light leakage, color unevenness due to interference fringes and a viewing defect due to coloring and reflection of external light, has high surface hardness, flexibility and is excellent in scratch resistance, and to provide a liquid crystal display. <P>SOLUTION: A resin composition is obtained by dispersing elastic body particles having ≤2.0 μm number average particle diameter in a thermoplastic resin. A viewing side protective layer which has a structure of a thermoplastic resin layer-a resin composition layer-the thermoplastic resin layer and <100 μm average thickness and wherein the elastic body particles are unevenly distributed in the center in the film thickness direction is obtained by coextruding the thermoplastic resin and the resin composition. A glare preventing means is provided on a side far from a polarizer of the viewing side protective layer. The viewing side protective layer having the glare preventing means and a liquid crystal cell side protective layer are layered with the polarizer between to obtain the polarizing plate for liquid crystal display having 10 to 60% haze value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polarizing plate for liquid crystal display. More specifically, the present invention relates to a polarizing plate for liquid crystal display that protects the viewing-side surface of a liquid crystal display device, does not cause color unevenness due to interference fringes or the like, or poor visibility due to reflection of external light, has a high surface hardness, and has flexibility. .

The viewing side surface (display screen) of a display device or the like has many occasions where a human touches the surface, and the surface becomes dirty or the surface is scratched, and the display image may be difficult to see. Therefore, a protective layer is stuck on the display screen surface.
As a film used for protecting a display screen of a display device or the like, for example, Patent Document 1 discloses an acrylic made of 50 to 70 parts by mass of methyl methacrylate, 10 to 20 parts by mass of maleic anhydride, and 20 to 35 parts by mass of styrene. A composition containing a resin based resin (A) and a toughness improving agent (B) made of an impact-resistant acrylic rubber-methyl methacrylate graft copolymer, butyl-modified acetylcellulose, or the like at a mass ratio of 60 to 90 / 40-10 A polarizing film protective film made of a material has been proposed.

Patent Document 2 discloses an acrylic resin film containing 60 to 90% by mass of an acrylic resin (A) containing a glutaric anhydride unit and 7 to 40% by mass of acrylic elastic particles (B). An acrylic resin film in which the average particle diameter of the body particles (B) is 70 to 300 nm, the breaking elongation of the film is 15% or more, and the 1% deformation temperature under high tension is 100 ° C. or more has been proposed. However, these protective layers have a problem in that the surface hardness is small and the surface is scratched or soiled by rubbing the surface.
Japanese Patent Laid-Open No. 5-119217 JP 2005-314534 A

  On the other hand, in Patent Document 3, a rubber-like elastic body is dispersed in the form of particles having a particle diameter of 0.15 to 4 μm in a continuous resin phase mainly composed of methyl methacrylate and dispersed in an amount of 5 to 70% by mass. 0.5 μm on one surface or both surfaces of the base material portion, with the impact-resistant acrylic resin used as the base material portion and the general acrylic resin having an alkyl methacrylate unit having an alkyl group having 1 to 4 carbon atoms as the laminated portion. The haze value is 1.0% or less and the glossiness is 130% or more when the thickness is 100 μm to 100 μm and the total thickness of the laminated part is within 30% of the total thickness of the sheet. An impact-resistant acrylic resin laminate sheet having optical properties and excellent weather resistance has been proposed. Patent Document 3 discloses that this film is used for applications that require impact resistance, such as signs, lighting covers, and automobile sun visors.

Patent Documents 4 and 5 propose an acrylic resin laminated film including a layer containing acrylic rubber particles and an acrylic resin, and an acrylic resin layer not containing an impact-resistant material. It is disclosed that this film is used for exteriors of household electrical appliances, automobile interiors, building materials, etc. that require high impact strength.
JP-A-4-59246 JP 2002-292808 A JP 2001-260288 A

Patent Document 6 includes an acrylic resin layer that includes an acrylic resin layer in which rubber particles are dispersed in methacrylic resin as a film for protecting a display screen of a portable information terminal, and has a thickness of 100 μm or more and 1,800 μm or less. A scratch-resistant acrylic resin film in which a scratch-resistant film obtained by curing a curable paint is formed on the surface of a resin film has been proposed. This protective layer is suitable for a narrow viewing side such as a portable information terminal, but has insufficient surface hardness as a protective layer for a display device having a wide display screen.
JP 2004-143365 A

  An object of the present invention is to provide a liquid crystal display that does not cause color unevenness due to light leakage, interference fringes, etc., coloration or poor visibility due to reflection of external light, has a high surface hardness, is flexible, and has excellent scratch resistance. It is providing the polarizing plate for liquid crystals and a liquid crystal display device.

  As a result of investigations to achieve the above object, the inventors of the present invention include a thermoplastic resin as a main component, and an elastic particle having a number average particle size of 2.0 μm or less is in the center in the thickness direction of the viewing side protective layer. A polarizing plate having a viewing side protective layer, a polarizer, and a liquid crystal cell side protective layer, which are unevenly distributed in a part and having an average thickness of less than 100 μm, are laminated in this order and have a haze of 10 to 60% By using the liquid crystal display device, no color unevenness due to light leakage, interference fringes, etc., coloration or poor visibility due to reflection of external light does not occur, the surface hardness is hard, the flexibility is high, and the scratch resistance is excellent. Found that you can get. The present invention has been completed as a result of further studies based on this finding.

That is, the present invention includes the following.
(1) A visual recognition comprising a thermoplastic resin, wherein elastic particles having a number average particle diameter of 2.0 μm or less are unevenly distributed in the central portion in the thickness direction of the visual recognition side protective layer, and the average thickness is less than 100 μm. Side protective layer,
A polarizer and a protective layer on the liquid crystal cell side are laminated at least in this order.
A polarizing plate for liquid crystal display having a haze of 10 to 60%.
(2) An average thickness of a layer comprising a thermoplastic resin and elastic particles having a number average particle diameter of 2.0 μm or less and a layer comprising a thermoplastic resin laminated on both sides of the layer is less than 100 μm A viewing side protective layer,
A polarizer and a protective layer on the liquid crystal cell side are laminated at least in this order.
A polarizing plate for liquid crystal display having a haze of 10 to 60%.
(3) The polarizing plate for liquid crystal display according to (1) or (2), wherein an antiglare layer is laminated directly or via another layer on the surface of the viewing side protective layer far from the polarizer.

(4) The liquid crystal display according to (1) or (2), wherein an antiglare layer and an antireflection layer are laminated directly or via another layer on the surface of the viewing side protective layer far from the polarizer. Polarizing plate.
(5) The polarizing plate for liquid crystal display according to any one of (1) to (4), wherein the viewing-side protective layer contains an infrared absorber.
(6) The polarizing plate for liquid crystal display according to any one of (1) to (5), wherein the viewing-side protective layer contains an ultraviolet absorber.
(7) The polarizing plate for liquid crystal display according to any one of (1) to (6), wherein the viewing-side protective layer has a moisture permeability of 10 g · m ⁻² day ⁻¹ or more and 200 g · m ⁻² day ⁻¹ or less. .
(8) The polarizing plate for liquid crystal display according to any one of (1) to (7), wherein a surface of the viewing side protective layer far from the polarizer has an uneven shape.
(9) In any one of (1) to (8), the viewing-side protective layer has a layer including a region where the refractive index is discontinuous, directly or via another layer, on the surface far from the polarizer. The polarizing plate as described.
(10) A liquid crystal display device comprising the polarizing plate according to any one of (1) to (9).

  The polarizing plate of the present invention is flexible and excellent in flexibility, and does not cause visual defects such as interference fringes on the display screen, and further has no visual defects due to light leakage, color unevenness, coloring, etc. near the frame of the display screen. Equipment can be provided. Furthermore, since the surface hardness is high, it has excellent scratch resistance. Furthermore, the polarizing plate of the present invention has little reflection of external light and is excellent in antiglare property.

The polarizing plate of the present invention comprises a viewing side protective layer, a polarizer, and a liquid crystal cell side protective layer, and a viewing side protective layer and a liquid crystal cell side protective layer are laminated on both sides of the polarizer, respectively. is there. There is no particular limitation on the method of laminating the viewing side protective layer and the liquid crystal cell side protective layer on the polarizer, for example, a protective film that becomes the viewing side protective layer and a protective film that becomes the liquid crystal side protective layer, if necessary. What is necessary is just to employ | adopt the general method laminated | stacked on a polarizer through an acrylic adhesive etc. FIG.
The polarizing plate of the present invention has a haze of 10 to 60%, preferably 30 to 60%. By having a haze in such a range, reflection of external light can be prevented and antiglare properties can be improved. The method for adjusting the haze of the polarizing plate is not particularly limited, but it is possible to apply anti-glare means such as a method of forming on the surface of the viewing-side protective layer having a concavo-convex shape or a method of laminating on the viewing-side protective layer as described later. Good.

(Polarizer)
The polarizer used in the present invention is obtained by adsorbing iodine or dichroic dye on a polyvinyl alcohol film and then uniaxially stretching in a boric acid bath, or iodine or dichroic dye on a polyvinyl alcohol film. And the like obtained by adsorbing and stretching, and further modifying a part of the polyvinyl alcohol unit in the molecular chain into a polyvinylene unit. In addition, a polarizer having a function of separating polarized light into reflected light and transmitted light, such as a grid polarizer, a multilayer polarizer, and a cholesteric liquid crystal polarizer, can also be used as the polarizer. Among these, a polarizer comprising polyvinyl alcohol is preferable. The polarization degree of the polarizer is preferably 98% or more, more preferably 99% or more. The thickness (average thickness) of the polarizer is preferably 5 μm to 80 μm.

(Viewing side protective layer)
The viewing-side protective layer used in the present invention comprises a thermoplastic resin, elastic particles having a number average particle size of 2.0 μm or less are unevenly distributed in the central portion in the thickness direction of the viewing-side protective layer, and have an average thickness. Is less than 100 μm.

  The thermoplastic resin used for the viewing side protective layer is not particularly limited as long as it is a transparent resin. For example, polycarbonate resin, polyether sulfone resin, polyethylene terephthalate resin, polyimide resin, polymethyl methacrylate resin, polysulfone resin, polyarylate Examples thereof include resins, polyethylene resins, polyvinyl chloride resins, diacetyl cellulose, triacetyl cellulose, and alicyclic olefin polymers. Of these, a thermoplastic acrylic resin is preferred.

As the thermoplastic acrylic resin, a homopolymer of (meth) acrylic acid alkyl ester such as methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate; the hydrogen of the alkyl group is OH group, COOH group or NH ₂ group Homopolymer of (meth) acrylic acid alkyl ester substituted with a functional group such as: or (meth) acrylic acid alkyl ester and styrene, vinyl acetate, α, β-monoethylenically unsaturated carboxylic acid, vinyl toluene, Examples thereof include a copolymer with a vinyl monomer having an unsaturated bond such as α-methylstyrene. As a thermoplastic acrylic resin, only 1 type may be used among these and it may use it in combination of 2 or more type. More preferably, the thermoplastic acrylic resin contains polymethyl methacrylate and polybutyl methacrylate as monomer units.

  The thermoplastic resin used in the present invention preferably has a glass transition temperature Tg in the range of 80 to 120 ° C. Furthermore, the thermoplastic resin used in the present invention has a high surface hardness when formed into a film, specifically, pencil hardness (according to JIS K5600-5-4 except that the test load is 500 g). More than 2H is preferable.

  Thermoplastic resins include colorants such as pigments and dyes, optical brighteners, dispersants, heat stabilizers, light stabilizers, infrared absorbers, ultraviolet absorbers, antistatic agents, antioxidants, lubricants, solvents, etc. These can be used in which compounding agents other than the elastic particles described later are appropriately blended. In addition, it is preferable that these compounding agents are unevenly distributed in the thickness direction center part of a visual recognition side protective layer like the elastic body particle mentioned later. For example, a layer made of a thermoplastic resin containing an infrared absorber and / or an ultraviolet absorber and a layer made of a thermoplastic resin not containing an infrared absorber and / or an ultraviolet absorber sandwiching this layer are laminated. The viewing-side protective layer is a preferred embodiment.

The ultraviolet absorber is added to improve durability by absorbing ultraviolet rays of 400 nm or less.
As the ultraviolet absorber, known ones such as a benzophenone ultraviolet absorber, a benzotriazole ultraviolet absorber, and an acrylonitrile ultraviolet absorber can be used. Among them, 2,2'-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2'-hydroxy-3 '-Tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2,4-di-tert-butyl-6- (5-chlorobenzotriazol-2-yl) phenol, 2,2'-dihydroxy- 4,4′-dimethoxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone and the like are preferably used. Among these, 2,2′-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol) is particularly preferable. The concentration of the ultraviolet absorber can be selected within a range where the transmittance at a wavelength of 370 nm or less is preferably 10% or less, more preferably 5% or less, and still more preferably 2% or less. Examples of the method of containing the ultraviolet absorber include a method of previously blending the ultraviolet absorber into the thermoplastic resin; a method of directly supplying the melt during the melt extrusion molding, and any method may be employed.

  It is preferable that the ultraviolet absorber is unevenly distributed in the central portion in the thickness direction of the viewing side protective layer. When the viewing-side protective layer is composed of a laminate, the UV absorber concentration contained in the thermoplastic resin layer containing elastic particles is the UV absorption contained in the thermoplastic resin layer not containing elastic particles. The concentration should be higher than the agent concentration. Specifically, the concentration of the ultraviolet absorber in the thermoplastic resin layer not containing elastic particles is preferably 0 to 1.0% by weight, more preferably 0 to 0.5% by weight. The concentration of the ultraviolet absorber in the thermoplastic resin layer containing particles is preferably 0.5 to 10% by weight, more preferably 1.0 to 5.0% by weight. When the content of the ultraviolet absorber is within the above range, it is possible to efficiently block ultraviolet rays without deteriorating the color tone of the polarizing plate, and to prevent a decrease in the degree of polarization during long-term use. If the content of the ultraviolet absorber in the thermoplastic resin layer containing the elastic particles is too small, the light transmittance at a wavelength of 370 nm or less increases, and the degree of polarization tends to decrease. On the other hand, when the content of the ultraviolet absorber is too large, the light transmittance on the short wavelength side becomes small, and the laminate tends to be yellowish.

  Infrared absorbers include nitroso compounds, metal complexes thereof, cyanine compounds, squarylium compounds, thiol nickel complex compounds, phthalocyanine compounds, naphthalocyanine compounds, triallylmethane compounds, imonium compounds, diimonium compounds, Infrared absorption of naphthoquinone compounds, anthraquinone compounds, amino compounds, aminium salt compounds, carbon black, indium tin oxide, antimony tin oxide, oxides of metals belonging to Group 4A, 5A or 6A, carbides, borides, etc. An agent etc. can be mentioned. These infrared absorbers are preferably selected so that the entire infrared ray (about 800 nm to 1100 nm) can be absorbed, and two or more kinds thereof may be used in combination. The amount of the infrared absorber can be appropriately adjusted so that, for example, the transmittance at a wavelength of 800 nm or more is 10% or less.

<Elastic particles>
The elastic particles used in the present invention are particles made of a rubber-like elastic body. Examples of the rubber-like elastic body include an acrylate-based rubber-like polymer, a rubber-like polymer containing butadiene as a main component, and an ethylene-vinyl acetate copolymer. Examples of the acrylic ester rubbery polymer include those containing butyl acrylate, 2-ethylhexyl acrylate, or the like as a main component. Of these, acrylate polymers based on butyl acrylate and rubbery polymers based on butadiene are preferred. The elastic particles may be formed by laminating two kinds of polymers, and typical examples thereof include an alkyl acrylate such as butyl acrylate, a grafted rubber elastic component of styrene, and polymethyl. Examples thereof include elastic particles in which a hard resin layer made of a copolymer of methacrylate and / or methyl methacrylate and an alkyl acrylate forms a core-shell structure.

  The elastic particles used in the present invention have a number average particle size of 2.0 μm or less, preferably 0.1 to 1.0 μm, more preferably 0.1 to 0.5 μm in a state dispersed in a thermoplastic resin. is there. Even if the primary particle size of the elastic particles is small, if the number average particle size of the secondary particles formed by aggregation or the like is large, the haze (cloudiness) of the protective layer becomes too high and the light transmittance is low. , Not suitable for the viewing side. Moreover, when the number average particle size becomes too small, the flexibility tends to decrease.

In the present invention, the refractive index _{n a} (lambda) is the wavelength 380nm~780nm of elastic particles, between the refractive index _{n b (λ)} at a wavelength 380nm~780nm thermoplastic resin as a matrix, _{| n} a ( It is preferable that the relationship of λ) −n _b (λ) | ≦ 0.05 is satisfied. In particular, it is more preferable that | n _a (λ) −n _b (λ) | ≦ 0.045. Note that n _a (λ) and n _b (λ) are average values of the main refractive indices at the wavelength λ. When the value of | n _a (λ) −n _b (λ) | exceeds the above value, transparency may be impaired due to interface reflection caused by a difference in refractive index at the interface.

  The elastic particles are unevenly distributed in the central portion in the thickness direction of the viewing-side protective layer mainly composed of a thermoplastic resin. That is, there are few elastic particles in the vicinity of the surface of the viewing side protective layer, and many elastic particles are distributed in the central portion in the thickness direction of the viewing side protective layer. The distribution of the elastic particles in the thickness direction of the viewer-side protective layer may increase gradually from the surface toward the center or may increase stepwise.

  As an aspect that increases stepwise, a layer composed of a thermoplastic resin and elastic particles having a number average particle diameter of 2.0 μm or less and a layer composed of a thermoplastic resin are laminated on both sides of the layer. A viewing-side protective layer having an average thickness of less than 100 μm can be mentioned. There is no particular limitation on the method for obtaining the visible-side protective layer. For example, a base film is obtained by molding a composition comprising a thermoplastic resin and elastic particles having a number average particle size of 2.0 μm or less. The method of apply | coating the thermoplastic resin which does not contain an elastic body particle | grain on both surfaces of a material film is mentioned. As another method, there is a method in which a film formed by molding a thermoplastic resin not containing elastic particles is bonded to both surfaces of the base film with an adhesive if necessary. Another method includes a method of co-extrusion of a composition comprising a thermoplastic resin and elastic particles having a number average particle size of 2.0 μm or less and a thermoplastic resin not containing elastic particles. . In addition, a method in which a film in which elastic particles having a number average particle size of 2.0 μm or less are unevenly distributed on one side is bonded so that the surfaces in which the elastic particles are unevenly contacted is also mentioned.

  As described above, the elastic particles are unevenly distributed in the central portion in the thickness direction of the layer, whereby the central portion in the thickness direction of the viewing-side protective layer becomes a flexible layer, and both surfaces of the viewing-side protective layer become hard layers. By setting it as such a structure, the flexibility of a polarizing plate can be improved, ensuring sufficient hardness of the surface of the visual recognition side protective layer.

  In obtaining a visible-side protective layer in which a layer made of thermoplastic resin and elastic particles and a layer made of thermoplastic resin not containing elastic particles are laminated on both sides of the layer, an adhesive (including an adhesive) is obtained. ), The average thickness of the adhesive layer made of an adhesive is usually 0.01 μm to 30 μm, preferably 0.1 μm to 15 μm. The adhesive layer is a layer having a tensile fracture strength according to JIS K7113 of 40 MPa or less. The adhesive constituting this adhesive layer includes acrylic adhesive, urethane adhesive, polyester adhesive, polyvinyl alcohol adhesive, polyolefin adhesive, modified polyolefin adhesive, polyvinyl alkyl ether adhesive, rubber adhesive, vinyl chloride, Vinyl acetate adhesive, styrene / butadiene / styrene copolymer (SBS copolymer) adhesive, hydrogenated product (SEBS copolymer) adhesive, ethylene / vinyl acetate copolymer, ethylene-styrene copolymer, etc. Ethylene adhesives and acrylic ester adhesives such as ethylene / methyl methacrylate copolymers, ethylene / methyl acrylate copolymers, ethylene / ethyl methacrylate copolymers, and ethylene / ethyl acrylate copolymers And so on.

The viewing-side protective layer has a thickness (average thickness) of less than 100 μm, preferably 80 μm or less, more preferably 40 μm or more and 80 μm or less.
The difference between the thickness of the thermoplastic resin layer that does not include one elastic particle and the thickness of the thermoplastic resin layer that does not include the other elastic particle on both sides of the viewing-side protective layer is 20 μm or less. Preferably, it is 10 μm or less, more preferably closer to 0 μm.

The viewing-side protective layer preferably has a residual solvent content of 0.01% by mass or less. When the residual solvent amount is in the above range, for example, it is possible to prevent the protective layer from being deformed in a high temperature / high humidity environment and to prevent the optical performance from deteriorating. The viewing-side protective layer in which the residual solvent amount falls within the above range can be obtained, for example, by co-extrusion molding a plurality of resins or by laminating a single thermoplastic resin layer by dry lamination or thermal lamination. . What was obtained by coextrusion molding from the point of productivity is preferable. In the case of coextrusion molding, it is not necessary to go through a complicated process (for example, a drying process or a coating process). Therefore, there is little mixing of external foreign matters such as dust, and excellent optical performance can be exhibited.
The residual solvent content was determined by adding 50 mg of a protective layer to a 4 mm inner diameter glass tube sample container from which moisture and organic substances adsorbed on the surface were completely removed, and then heating the container at a temperature of 200 ° C. for 30 minutes. It is the value which collected the gas which came out of the gas continuously, and analyzed the collected gas with the thermal desorption gas chromatography mass spectrometer (TDS-GC-MS).

The viewing-side protective layer preferably has a moisture permeability of 10 g · m ⁻² day ⁻¹ or more and 200 g · m ⁻² day ⁻¹ or less. By setting the moisture permeability of the viewing-side protective layer within the above-described preferable range, the adhesion between the layers constituting the viewing-side protective layer can be improved. The moisture permeability can be measured by the cup method described in JIS Z 0208 under the test conditions for 24 hours in an environment of 40 ° C. and 92% RH.

  In order to adjust the haze value of the polarizing plate, an appropriate antiglare means can be provided on the surface of the protective layer. Anti-glare means, for example, (a) forming fine irregularities on the viewing side and causing light scattering, (b) forming a layer composed of two or more components having a difference in refractive index in the protective layer By doing so, those that cause light scattering due to a difference in refractive index can be mentioned.

(Anti-glare means)
The method for forming fine irregularities is not particularly limited, and an appropriate method can be adopted. For example, in a state where the viewing side protective layer is laminated directly or with other layers, the unevenness is transferred by a method such as sandblasting, embossing roll, chemical etching, etc. to give fine unevenness or by shaping film In addition to the method (for example, Japanese Patent Application Laid-Open No. 2005-331901), a method of dispersing fine particles in the resin constituting the protective layer, and an antiglare layer made of a transparent resin material containing fine particles are formed on the protective layer on the viewing side (Japanese Patent Laid-Open No. 11-305010, Japanese Patent Laid-Open No. 2002-107512, Japanese Patent Laid-Open No. 10-246802, etc.). These methods may be used in combination of two or more.
In addition, the degree of unevenness is not particularly limited as long as the haze value is in the above range. Usually, the center line average roughness (Ra) is 0.04 to 0.5 μm, and the average peak-to-valley spacing (Sm) is 20 to 100 μm. It is.

  As the transparent resin material used for forming the antiglare layer, fine particles can be dispersed, sufficient strength as a film can be given, and a transparent material can be used without particular limitation. Examples of the resin include thermosetting resins, thermoplastic resins, ultraviolet curable resins, and electron beam curable resins. Among these, an ultraviolet curable resin that can efficiently form an antiglare layer by a simple processing operation by a curing treatment by ultraviolet irradiation is preferable.

  Examples of the ultraviolet curable resin include various types such as polyester, acrylic, urethane, amide, silicone, and epoxy, and these include ultraviolet curable monomers, oligomers, polymers, and the like. Examples of the ultraviolet curable resin preferably used include those having an ultraviolet polymerizable functional group, particularly those containing an acrylic monomer or oligomer having 2 or more, particularly 3 to 6 functional groups.

Further, the transparent resin material may contain 10 parts by weight or more and 100 parts by weight or less of solvent-drying resin with respect to 100 parts by weight of the resin. As the solvent-drying resin, a thermoplastic resin is mainly used.
In particular, when a mixture of polyester acrylate and polyurethane acrylate is used as the ionizing radiation curable resin, polymethyl methacrylate, polybutyl methacrylate, or cellulose acetate propionate is preferably used as the solvent-drying resin.

  The fine particles may be inorganic fine particles or organic fine particles, or may be modified fine particles such as those obtained by coating inorganic fine particles with an organic material. For example, fine particles that exhibit a diffusion effect due to a difference in refractive index with the transparent resin material and fine particles that exhibit a diffusion effect by forming irregularities on the surface of the resin layer can be used in combination.

  The shape of the fine particles may be a true sphere, an ellipse or the like, preferably a true sphere. Examples of the inorganic fine particles include silica and alumina. The organic fine particles are preferably resin beads having a refractive index of 1.40 to 1.60. Resin beads include polymethyl methacrylate beads (refractive index: 1.49), melamine beads (refractive index 1.57), polycarbonate beads (refractive index: 1.58), polystyrene beads (refractive index: 1.60). And acrylic styrene resin beads (refractive index: 1.57), polyvinyl chloride beads (refractive index: 1.54), and polyethylene beads.

  These resin beads preferably have an average particle diameter of 1 to 8 μm, and 5 to 22 parts by weight, preferably 10 to 25 parts by weight, are used with respect to 100 parts by weight of the resin. When such resin beads are mixed, the resin beads precipitated on the bottom of the container at the time of coating need to be stirred and dispersed well. In order to eliminate such inconvenience, silica beads having a particle diameter of 0.5 μm or less, preferably 0.1 to 0.25 μm may be included in the coating liquid as an anti-settling agent for resin beads. The more silica beads are added, the more effective the prevention of sedimentation of the resin beads is, but it adversely affects the transparency of the coating film. Therefore, the amount of the anti-settling agent is preferably less than 0.1 parts by weight with respect to 100 parts by weight of the resin, to the extent that the transparency as the antiglare layer is not impaired.

  The fine particles may exist in a uniformly dispersed form in the cured film or may be unevenly distributed in the film thickness direction. The fine particles may be present in a form protruding from the surface. However, from the viewpoint of improving the clarity of the transmitted image described later, the fine particles protruding from the surface of the antiglare layer is preferably 0.5 μm or less. .

  The transparent resin material for forming the antiglare layer may contain other materials such as an antistatic agent, a leveling agent, and an ultraviolet absorber as necessary.

  As a method for forming an antiglare function by internal scattering by forming a layer including a region where the refractive index is discontinuous, two or more kinds of compositions having different refractive indexes are used to form a phase separation structure by ultraviolet irradiation or the like. And a method of forming a layer containing fine particles having a refractive index different from that of the transparent resin material and the transparent resin material.

  As a method for forming a layer having a phase separation structure, for example, a known method such as a method described in Japanese Patent No. 3446737 using two kinds of photopolymerizable monomers and / or oligomers can be employed.

  Examples of these photopolymerizable monomers and oligomers include 2,4,6-tribromophenyl acrylate, tribromophenoxyethyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, tetrahydrofurfuryl acrylate, ethyl carbitol acrylate Pentenyloxyethyl acrylate, phenyl carbitol acrylate, polyol polyacrylate, isocyanuric acid skeleton polyacrylate, melamine acrylate, hydantoin skeleton polyacrylate, urethane acrylate, and the like.

  Two or more kinds of the above photopolymerizable monomers and oligomers having different refractive indexes are used. Examples of the combination include two types selected from monomers, one type of monomer and one type of oligomer, two types selected from oligomers, or a combination of these in addition to one or more types of monomers or oligomers. In these combinations, it is preferable that at least two of them have a refractive index difference of 0.03 or more in order to obtain a necessary light scattering ability.

  Furthermore, it is preferable to use a photopolymerization initiator in order to improve the curability of the composition containing the materials having different refractive indexes. Examples of the photopolymerization initiator include benzophenone, 2-hydroxy-2-methylpropiophenone, benzyl, Michler's ketone, and 2-chlorothioxanthone as exemplified in JP-A-7-64069.

  A composition containing a material having a different refractive index can contain a compound having a refractive index different from that of a photopolymerizable monomer or oligomer and having no photopolymerizability. Examples include styrene resins such as polystyrene, acrylic resins such as polymethyl methacrylate, resins such as polyethylene oxide, polyvinyl pyrrolidone, and polyvinyl alcohol, and plastic additives such as organic halogen compounds, organic silicon compounds, plasticizers, and stabilizers. It is done. These can also be mix | blended in said composition as a high refractive index component or a low refractive index component. The difference in refractive index between the photopolymerizable monomer or oligomer and the non-photopolymerizable compound is preferably 0.03 or more.

  Furthermore, 0.01 to 5 parts by weight of a filler having an average particle diameter of 0.05 to 20 μm can be blended, or an ultraviolet absorber can be added.

  The transparent resin material for forming the antiglare layer utilizing the scattering phenomenon caused by the difference in refractive index between the transparent resin material and the fine particles can be selected from those exemplified as the transparent resin material constituting the fine uneven layer.

  In order to obtain an antiglare effect due to the difference in refractive index between the transparent resin material and the fine particles, the difference between the refractive index of the transparent resin material and the refractive index of the fine particles is preferably 0.03 or more, more preferably 0.04. It is 0.5 or less. When the difference in refractive index is less than 0.03, the light diffusion effect cannot be obtained. When the difference in refractive index is greater than 0.5, the light diffusibility is too strong and the image sharpness is lowered.

  The film thickness (when cured) of the antiglare layer is 0.1 to 20 μm, preferably 0.8 to 10 μm. When the film thickness is within this range, the function as an antiglare layer can be sufficiently exhibited.

  In addition, when forming the anti-glare layer by a cured film on the said transparent base material, a hydrophilic treatment can be given to the surface of a transparent base material. The hydrophilic treatment means is not particularly limited, and for example, a surface treatment method such as corona discharge treatment, sputtering treatment, low-pressure UV irradiation, or plasma treatment can be suitably employed. Moreover, the process which improves adhesiveness, such as a thin-layer application | coating process of a cellulose-type material and a polyester-type material, can be given.

  Furthermore, the polarizing plate of the present invention may have a functional layer such as a hard coat layer, an antireflection layer, and an antifouling layer on the viewing side.

(Hard coat layer)
The hard coat layer is a layer having a function of increasing the surface hardness of the viewer-side protective layer, and exhibits a hardness of “H” or higher in a pencil hardness test (a test plate is a glass plate) shown in JIS K5600-5-4. It is preferable. The viewing-side protective layer provided with such a hard coat layer preferably has a pencil hardness of 4H or higher. The material for forming the hard coat layer (hard coat material) is preferably a material that is cured by heat or light. For example, organic hard such as organic silicone, melamine, epoxy, acrylic, urethane acrylate, etc. Coating materials; inorganic hard coat materials such as silicon dioxide; and the like. Among these, urethane acrylate-based and polyfunctional acrylate-based hard coat materials are preferable from the viewpoint of good adhesive strength and excellent productivity.

  The hard coat layer contains various fillers for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage, and improving heat resistance, antistatic properties, and antiglare properties, as desired. it can. Further, the hard coat layer can contain additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a leveling agent, and an antifoaming agent.

(Antireflection layer)
The antireflection layer is a layer for preventing the transfer of external light, and is laminated directly or via another layer such as a hard coat layer on the surface (surface exposed to the outside) of the viewing side protective layer. The viewing-side protective layer provided with the antireflection layer preferably has a reflectance of 2.0% or less at an incident angle of 5 ° and a wavelength of 430 nm to 700 nm, and a reflectance of 1.0% or less at a wavelength of 550 nm. It is preferable.

  The thickness of the antireflection layer is preferably 0.01 μm to 1 μm, more preferably 0.02 μm to 0.5 μm. The antireflection layer has a refractive index smaller than the refractive index of a layer (such as a protective layer or a hard coat layer) on which the antireflection layer is laminated, specifically a low refractive index of 1.30 to 1.45. Examples thereof include those composed of a refractive index layer; those obtained by alternately laminating a plurality of low refractive index layers of a thin film made of an inorganic compound and high refractive index layers of a thin film made of an inorganic compound.

  The material for forming the low refractive index layer is not particularly limited as long as it has a low refractive index. Examples thereof include a resin material such as an ultraviolet curable acrylic resin, a hybrid material in which inorganic fine particles such as colloidal silica are dispersed in the resin, and a sol-gel material using a metal alkoxide such as tetraethoxysilane. The material for forming these low refractive index layers may be a polymerized polymer, or may be a monomer or oligomer serving as a precursor. Moreover, it is preferable that each material contains the compound containing a fluorine group, in order to provide antifouling property.

As the sol-gel material, a sol-gel material containing a fluorine group is preferably used. Examples of the sol-gel material containing a fluorine group include perfluoroalkylalkoxysilane. The perfluoroalkylalkoxysilane is, for example, CF ₃ (CF ₂ ) _n CH ₂ CH ₂ Si (OR) ₃ (wherein R represents an alkyl group having 1 to 5 carbon atoms, and n is 0 to 12 A compound represented by an integer). Specifically, as perfluoroalkylalkoxysilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, tridecafluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane , And heptadecafluorodecyltriethoxysilane. Among these, the compound whose said n is 2-6 is preferable.

  The low refractive index layer can be made of a cured product of a thermosetting fluorine-containing compound or an ionizing radiation curable fluorine-containing compound. The cured product preferably has a dynamic friction coefficient of 0.03 to 0.15, and a contact angle with water of 90 to 120 degrees. Examples of the curable fluorine-containing compound include a perfluoroalkyl group-containing silane compound (for example, (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane) and the like, and a fluorine-containing polymer having a crosslinkable functional group. Can be mentioned.

  The fluorine-containing polymer having a crosslinkable functional group is obtained by copolymerizing a fluorine-containing monomer and a monomer having a crosslinkable functional group, or by copolymerizing a fluorine-containing monomer and a monomer having a functional group, and then in the polymer. It can be obtained by adding a compound having a crosslinkable functional group to the functional group.

  Fluoroolefins such as fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole; biscoat 6FM (Osaka Organic) Chemical), M-2020 (manufactured by Daikin), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives, fully or partially fluorinated vinyl ethers, and the like.

  Monomers having a crosslinkable functional group or compounds having a crosslinkable functional group include monomers having a glycidyl group such as glycidyl acrylate and glycidyl methacrylate; monomers having a carboxyl group such as acrylic acid and methacrylic acid; hydroxyalkyl acrylate and hydroxyalkyl Monomers having a hydroxyl group such as methacrylate; methylol acrylate, methylol methacrylate; monomers having a vinyl group such as allyl acrylate and allyl methacrylate; monomers having an amino group; monomers having a sulfonic acid group;

  As a material for forming the low refractive index layer, a material containing a sol in which fine particles such as silica, alumina, titania, zirconia, magnesium fluoride and the like are dispersed in an alcohol solvent is used because it can improve scratch resistance. Can do. From the viewpoint of antireflection properties, the fine particles preferably have a lower refractive index. Such fine particles may have voids, and silica hollow fine particles are particularly preferable. The average particle size of the hollow fine particles is preferably 5 nm to 2,000 nm, and more preferably 20 nm to 100 nm. Here, the average particle diameter is a number average particle diameter obtained by observation with a transmission electron microscope.

(Anti-fouling layer)
The antifouling layer is a layer that can impart water repellency, oil repellency, sweat resistance, antifouling properties, and the like. As a material used for forming the antifouling layer, a fluorine-containing organic compound is suitable. Examples of the fluorine-containing organic compound include fluorocarbon, perfluorosilane, and polymer compounds thereof. As a method for forming the antifouling layer, a physical vapor deposition method such as vapor deposition or sputtering, a chemical vapor deposition method, a wet coating method, or the like can be used depending on the material to be formed. The average thickness of the antifouling layer is preferably 1 nm to 50 nm, more preferably 3 nm to 35 nm.
Moreover, you may provide other layers, such as a gas barrier layer, a transparent antistatic layer, a primer layer, an electromagnetic shielding layer, an undercoat layer, in the visual recognition side protective layer.

When the functional layer as described above is formed, it is preferable to perform chemical treatment on the surface to be formed. Examples of the chemical treatment include corona discharge treatment, sputtering treatment, low-pressure UV irradiation treatment, and plasma treatment. In addition to the chemical treatment, the visual side protective layer of the present invention is subjected to mechanical treatment by etching, sandblasting, embossing roll, etc. for the purpose of enhancing adhesion with the functional layer and imparting antiglare property. May be.
There is no particular limitation on the method for forming these functional layers, and a general method may be employed for forming each functional layer.

(Liquid crystal cell side protective layer)
The liquid crystal cell side protective layer used in the present invention may be the same as the above-described viewing side protective layer, or may be a liquid crystal cell side protective layer conventionally used for polarizing plates. The liquid crystal cell-side protective layer is preferably formed of a material having a light transmittance in the visible region of 400 to 700 nm at a thickness of 1 mm of 80% or more, more preferably 85% or more, and even more preferably 90% or more. As the resin constituting the conventional protective layer on the liquid crystal cell side, polycarbonate resin, polyethersulfone resin, polyethylene terephthalate resin, polyimide resin, polymethyl methacrylate resin, polysulfone resin, polyarylate resin, polyethylene resin, polystyrene resin, polychlorinated resin A vinyl resin, a cellulose ester, an alicyclic olefin polymer, etc. can be mentioned. Examples of the alicyclic olefin polymer include cyclic olefin random multi-component copolymers described in JP-A No. 05-310845 or US Pat. No. 5,179,171, JP-A No. 05-97978 or US Pat. No. 5,202,388. Examples thereof include the hydrogenated polymers described, thermoplastic dicyclopentadiene ring-opening polymers described in JP-A No. 11-124429 (WO 99/20676), and hydrogenated products thereof. .

The polarizing plate of the present invention may be obtained by laminating a film showing birefringence on the liquid crystal cell side protective layer side in addition to the above-mentioned viewing side protective layer, polarizer and liquid crystal cell side protective layer. In this case, the liquid crystal cell side is preferably optically isotropic. Specifically, Re is preferably 10 nm or less, more preferably 5 nm or less. The absolute value of Rth is preferably 10 nm or less, more preferably 5 nm or less.
The in-plane direction retardation Re, retardation Rth in the thickness direction, the thickness of the film upon the _{d (nm), Re = (} n x -n y) × d, Rth = ((n _x + n _y ) / 2−n _z ) × d. _nx and _ny are in-plane main refractive indexes ( _nx ≧ _ny ); _nz is a refractive index in the thickness direction; and d is an average thickness.

Moreover, you may use the film which shows birefringence as a liquid crystal cell side protective layer.
When a birefringent film is used as the liquid crystal cell side protective layer, or when a birefringent film is laminated on the liquid crystal cell side protective layer, optical compensation functions such as color compensation and viewing angle compensation are provided. The visibility of the liquid crystal display device is improved.

  Birefringent films include those obtained by stretching a film containing a thermoplastic resin, those obtained by forming an optically anisotropic layer on an unstretched thermoplastic resin film, and optical on a film containing a thermoplastic resin. After forming the anisotropic layer, it can be further stretched. The film showing birefringence may be a single layer film or a laminated film.

<A stretched film containing a thermoplastic resin>
The thermoplastic resin used for obtaining a film exhibiting birefringence can be selected from those exemplified as the resin constituting the liquid crystal cell side protective layer. Of these, alicyclic olefin polymers and cellulose esters are preferred because of their excellent transparency, low birefringence, dimensional stability, and the like. A retardation increasing agent can be added to these resins as needed.

  As a method of stretching the film containing the thermoplastic resin, a uniaxial stretching method such as a method of stretching uniaxially in a transverse direction using a tenter; a gap between fixed clips is opened and a guide rail spreads simultaneously with stretching in the longitudinal direction. Simultaneous biaxial stretching method that stretches in the transverse direction depending on the angle, or sequential stretching that stretches in the longitudinal direction using the difference in peripheral speed between rolls and then grips both ends of the clip and stretches in the transverse direction using a tenter. Biaxial stretching method such as axial stretching method; Tenter stretching machine that can add feed force or pulling force or pulling force at different speeds in the horizontal or vertical direction; Alternatively, using a tenter stretching machine that can add a pulling force or a pulling force so that the moving distance is the same and the stretching angle θ can be fixed, or the moving distance is different. How to order stretching: and the like.

  Stretching can usually be performed in the range of Tg to Tg + 20 ° C., where Tg is the glass transition temperature of the resin that has the lowest glass transition temperature among the materials that form the liquid crystal cell side protective layer, particularly the resin. Moreover, what is necessary is just to adjust a draw ratio in order to obtain a desired optical characteristic in the range of 1.1 to 3.0 times normally.

<Those formed with an optically anisotropic layer on an unstretched thermoplastic resin film>
For the formation of the optically anisotropic layer, a polymer compound or a liquid crystal compound can be used. These may be used alone or in combination.

  As the polymer compound, polyamide, polyimide, polyester, polyether ketone and the like can be used. Specific examples include compounds described in JP-T-8-511812 (International Publication No. WO94 / 24191) and JP-T 2000-511296 (International Publication No. WO97 / 44704).

  Further, the liquid crystalline compound may be a rod-like liquid crystal or a discotic liquid crystal, and these include a polymer liquid crystal or a low-molecular liquid crystal, and those in which a low-molecular liquid crystal is cross-linked and no longer exhibits liquid crystallinity. . Preferable examples of the rod-like liquid crystal include those described in JP 2000-304932A. Preferred examples of the discotic liquid crystal include those described in JP-A-8-50206.

  The optically anisotropic layer is generally formed by applying a solution of a discotic compound and other compounds (eg, plasticizer, surfactant, polymer, etc.) dissolved in a solvent onto the alignment film, drying, and then discotic nematic. It can be obtained by heating to the phase formation temperature and then cooling while maintaining the orientation state (discotic nematic phase). Alternatively, the optically anisotropic layer may be formed by applying a solution obtained by dissolving a discotic compound and another compound (for example, a polymerizable monomer, a photopolymerization initiator) in a solvent onto the alignment film, drying, and then discotic It can be obtained by heating to a nematic phase formation temperature, followed by polymerization by irradiation with UV light, etc., and further cooling.

  The thickness of the optically anisotropic layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm, and most preferably 0.7 to 5 μm. However, depending on the mode of the liquid crystal cell, it may be thickened (3 to 10 μm) in order to obtain high optical anisotropy. The method for forming the optically anisotropic layer is not particularly limited. For example, the polymer compound and / or liquid crystal compound is applied to a film containing a thermoplastic resin to produce a coating film, It can be produced by further stretching or shrinking the coating film.

The haze of the polarizing plate of the present invention formed by laminating the above-mentioned layers is 10 to 60%, preferably 10 to 50%, and the total light transmittance of the polarizing plate is usually 25% to 50%, preferably 30. -50%, more preferably 35-50%.
In addition, the total light transmittance of the viewing-side protective layer constituting the polarizing plate is preferably 70 to 100%, more preferably 80 to 100%, still more preferably 85 to 100% (for example, 85 to 95%), in particular. Preferably, it is about 90 to 100% (for example, 92 to 99%).
The haze and total light transmittance can be measured using a haze meter “NDH-300A” manufactured by Nippon Denshoku Industries Co., Ltd.

  In addition, the polarizing plate of the present invention preferably exhibits a hardness of “3H” or more in a pencil hardness test (test plate is a glass plate) shown in JIS K5600-5-4, and more preferably exhibits a hardness of “4H” or more. preferable.

<Liquid crystal display device>
The liquid crystal display device of the present invention can be manufactured using the polarizing plate of the present invention. In the liquid crystal display device, a light source, an incident side polarizing plate, a liquid crystal cell, and an output side polarizing plate are usually arranged in this order. The polarizing plate of the present invention is provided on the emission side (viewing side) of the device. The liquid crystal display device of the present invention may further include a retardation plate, a brightness enhancement film, a light guide plate, a light diffusion plate, a light diffusion sheet, a light collection sheet, a reflection plate, and the like.

An Example and a comparative example are shown and this invention is demonstrated in detail. Parts and% are based on mass unless otherwise specified.
The protective films obtained in Examples and Comparative Examples were evaluated by the following methods.

<Bending elastic modulus>
Using a thermoplastic resin used to form each layer, a test piece is formed so as to meet the provisions of JIS K 7171. According to JIS K 7171, a tensile tester (“Autograph AG-100kNIS” manufactured by Shimadzu Corporation) is used. ).

<Thickness of each resin layer>
After embedding the protective film in an epoxy resin, it was sliced using a microtome (“RUB-2100” manufactured by Yamato Kogyo Co., Ltd.), and the cross section was observed and measured using a scanning electron microscope.

<Haze of protective film>
Based on JISK7361-1997, it measures using a haze meter ("NDH-300A" by Nippon Denshoku Industries Co., Ltd.). In addition, the same measurement is performed 5 times and the arithmetic average value is set as the representative value of haze.

(Production of polarizer)
A polyvinyl alcohol film having a refractive index of 1.545 at a wavelength of 380 nm and a refractive index of 1.521 at a wavelength of 780 nm and a thickness of 75 μm is uniaxially stretched 2.5 times to obtain 0.2 g of iodine and 60 g of potassium iodide. Was immersed in an aqueous solution containing 30 g / L for 30 seconds and then immersed in an aqueous solution containing 70 g / L of boric acid and 30 g / L of potassium iodide and simultaneously uniaxially stretched 6.0 times and held for 5 minutes. Finally, it was dried at room temperature for 24 hours to obtain a polarizer P having an average thickness of 30 μm and a polarization degree of 99.95%.

Production Example 1
(Preparation of protective film 1)
A polymethylmethacrylate resin not containing elastic particles (tensile elastic modulus 3.3 GPa, flexural modulus 3.3 GPa; hereinafter referred to as “PMMA”) is applied to a leaf disk-shaped polymer filter having an aperture of 10 μm. It is put into a hopper mounted on the installed double flight type single screw extruder (ratio of screw effective length L and screw diameter D L / D = 28), the extruder outlet temperature is 260 ° C., and the speed of the gear pump of the extruder At 6 rpm, the molten resin was supplied to one of the multi-manifold dies having a die slip surface roughness Ra of 0.1 μm.
On the other hand, polymethylmethacrylate resin (tensile elastic modulus 2.8 GPa, flexural modulus 2.1 GPa; hereinafter may be referred to as “R ¹ -PMMA”) containing elastic particles having a number average particle diameter of 0.4 μm. And a multi-manifold having a die-slip surface roughness Ra of 0.1 μm introduced into a double-flight type single-screw extruder equipped with a leaf disk-shaped polymer filter having an opening of 10 μm and an extruder outlet temperature of 260 ° C. Feeded to the other side of the die.

The molten PMMA and R ¹ -PMMA are each discharged from the multi-manifold die at 260 ° C., cast into a cooling roll adjusted to 130 ° C., and then passed through a cooling roll adjusted to 50 ° C. Thus, a protective film 1 having a width of 600 mm and a thickness of 80 μm composed of three layers of PMMA layer (20 μm) / R ¹ -PMMA layer (40 μm) / PMMA layer (20 μm) was obtained by coextrusion molding. The haze of the protective film 1 was 1% or less.

(Preparation of anti-glare protective film 1 <addition of anti-glare layer>)
12 parts of polystyrene particles having an average particle size of 3.5 μm, 5 parts of benzophenone photopolymerization initiator, 2.5 parts of thixotropic agent (mica) per 100 parts of acrylic urethane UV curable resin (urethane acrylate monomer) A coating solution with a solid content concentration of 40% by weight mixed with a toluene solvent was applied to the upper surface of the protective film 1 and dried at 120 ° C. for 5 minutes. Thereafter, the coating film was cured by ultraviolet irradiation to form an antiglare layer on the surface of the fine concavo-convex structure having a film thickness of 7 μm, whereby the antiglare protective film 1 was obtained.

Production Example 2
(Preparation of anti-glare protective film 2)
Instead of the polymethyl methacrylate resin not containing elastic particles used in Production Example 1, polystyrene resin not containing elastic particles (melt mass flow rate 4.0 g / 10 min, flexural modulus 3330 MPa; hereinafter referred to as “PS”. In place of the polymethyl methacrylate resin containing the elastic particles used in Production Example 1, a norbornene resin (dicyclopentadiene and tetracyclododecene ring-opening copolymer hydride, Tg 100 ° C.) may be used. PS layer (same as in Production Example 1) except that a resin having elastic particles having a number average particle size of 0.4 μm blended with a flexural modulus of 2.2 GPa (hereinafter sometimes referred to as “NB”) is used. 20 μm) / NB layer (40 μm) / PS layer (20 μm) of a three-layer structure, a protective film 2 having a width of 600 mm and a thickness of 80 μm is formed by coextrusion molding. Obtained. An antiglare layer was added to this protective film 2 in the same manner as in Production Example 1 to obtain an antiglare protective film 2. The haze of the protective film 2 was 1% or less.

Production Example 3
(Preparation of anti-glare protective film 3)
Instead of polystyrene resin containing no elastic particles used in Production Example 2, a polycarbonate containing no elastic particles (melt volume flow rate 2.5 cm ^3/10 min, a flexural modulus 2200 MPa; hereinafter referred to as "PC" Protective film 3 having a width of 600 mm and a thickness of 80 μm, comprising a three-layer structure of PC layer (20 μm) / NB layer (40 μm) / PC layer (20 μm) in the same manner as in Production Example 2 Was obtained by coextrusion molding. An antiglare layer was added to the protective film 3 in the same manner as in Production Example 2 to obtain an antiglare protective film 3. The haze of the protective film 3 was 1% or less.

Production Example 4
(Preparation of anti-glare protective film 4)
A polymethylmethacrylate resin (tensile modulus 3.3 GPa, flexural modulus 3.3 GPa; PMMA) not containing elastic particles was extruded to obtain a single-layer protective film 4 having a thickness of 80 μm. The haze of the protective film 4 was 1% or less.
An antiglare layer was added to this protective film 4 in the same manner as in Production Example 1 to obtain an antiglare protective film 4.

Examples 1 to 3 and Comparative Example 1
The anti-glare protective films 1 to 4 obtained in Production Examples 1 to 4 are bonded to one surface of the polarizer P via an acrylic adhesive (trade name: DP-8005 clear, manufactured by Sumitomo 3M), A film made of triacetyl cellulose (haze 0.1% or less, total light transmittance 95% or more) having a thickness of 40 μm is bonded to the other surface of the polarizer P through the same acrylic adhesive, Polarizing plates 1 to 4 were created. The obtained polarizing plate was evaluated by the following method. The results are shown in Table 1.

<Measurement of haze and total light transmittance>
Based on JISK7361-1997, it measures using the Nippon Denshoku Industries Co., Ltd. turbidimeter "NDH-300A". In addition, about haze, the same measurement is performed 5 times and let the arithmetic mean value be a representative value of haze.

<Flexibility test>
A polarizing plate was punched into 1 cm × 5 cm to obtain a test film. The obtained test film was wound around a steel rod having a diameter of 3 mmφ, and whether or not the wound film was broken at the rod was tested. The test was conducted a total of 10 times, and the flexibility was expressed by the following index according to the number of times the test was not broken.
○: No broken film pieces △: One broken film piece ×: Two or more broken film pieces

<Evaluation of reflection>
A polarizing plate is installed in a room with a brightness of 1000 lux, the surface on which the antiglare layer is formed is placed on top, and reflection of reflected light is visually evaluated by the fluorescent lamp contour reflected on the surface.
○: The contour is not visible △: The contour is slightly visible ×: The contour is clearly visible

Claims (9)

A viewing-side protective layer comprising a thermoplastic resin, wherein elastic particles having a number average particle size of 2.0 μm or less are unevenly distributed in the central portion in the thickness direction of the viewing-side protective layer, and the average thickness is less than 100 μm ,
A polarizer and a protective layer on the liquid crystal cell side are laminated at least in this order.
A polarizing plate for liquid crystal display having a haze of 10 to 60%. The visual recognition side having an average thickness of less than 100 μm having a layer composed of a thermoplastic resin and elastic particles having a number average particle size of 2.0 μm or less and a layer composed of a thermoplastic resin laminated on both sides of the layer Protective layer,
A polarizer and a protective layer on the liquid crystal cell side are laminated at least in this order.
A polarizing plate for liquid crystal display having a haze of 10 to 60%.   The polarizing plate for liquid crystal display of Claim 1 or 2 by which the glare-proof layer is laminated | stacked directly or through another layer on the surface of the visual recognition side protective layer far from the polarizer.   The polarizing plate for liquid crystal display of Claim 1 or 2 by which the glare-proof layer and the antireflection layer are laminated | stacked on the surface of the side far from the polarizer of the visual recognition side protective layer directly or through another layer.   The polarizing plate for liquid crystal display according to any one of claims 1 to 4, wherein the viewing side protective layer contains an ultraviolet absorber. The polarizing plate for liquid crystal display according to any one of claims 1 to 5, wherein the viewing side protective layer has a water vapor transmission rate of 10 g · m ^-2 day ^-1 or more and 200 g · m ^-2 day ^-1 or less.   The polarizing plate for liquid crystal displays according to any one of claims 1 to 6, wherein a surface of the viewing-side protective layer far from the polarizer has an uneven shape.   The polarizing plate according to any one of claims 1 to 7, further comprising a layer including a region where the refractive index is discontinuous, directly or via another layer, on a surface of the viewing side protective layer far from the polarizer. A liquid crystal display device provided with the polarizing plate in any one of Claims 1-8.