JP2006039472A - Polarizing plate and liquid crystal display device - Google Patents

Abstract

Disclosed is a polarizing plate and a liquid crystal display device that are excellent in transparency, mechanical strength, antireflection performance, scratch resistance, and adhesion by making a transparent protective layer of a polarizer specific. is there.
A resin film (A) having a moisture permeability of 50 to 1500 g / m ² · 24 hr, a hard coat layer (B), and an antireflection layer (C) are sequentially laminated on one surface of a polarizer, Of the alicyclic structure-containing resin, the moisture permeability is 0.3 to 40 g / m ² · 24 hr, the photoelastic coefficient is 12.0 × 10 ⁻¹² Pa ⁻¹ or less, and the maximum die line depth is 50 nm or less. A polarizing plate formed by laminating a resin film (D) having a minimum width of 500 nm or more is used for a liquid crystal display device.
[Selection figure] None

Description

  The present invention relates to a polarizing plate, and more specifically, it is composed of a laminate formed by laminating a transparent protective layer on both sides of a polarizer, and is excellent in all of transparency, mechanical strength, antireflection performance, scratch resistance, and adhesion. The present invention relates to a polarizing plate and a liquid crystal display device.

A liquid crystal display device (hereinafter referred to as “LCD”) is characterized by being thin, lightweight, and having low power consumption. The field of use of LCDs is expanding from conventional calculators and watches to automobile applications that require durability and heat resistance, such as car navigation systems and automobile inner panels.
In general, an LCD is a liquid crystal cell that has a function of switching between passing and blocking of polarized light by controlling the orientation direction of liquid crystal molecules by applying an electric field, and two pieces of polarized light with transmission axes arranged at right angles between them. Consists of plates.
As a polarizing plate, what laminated | stacked the polarizing plate protective film on both polarizers is used. The protective film is a film that is attached to the outside of the polarizer for scratch resistance, antireflection properties, and the like of the liquid crystal display element.

As the protective film, a cellulose ester film, particularly triacetyl cellulose (hereinafter referred to as “TAC”) has been used because of its excellent optical properties.
However, since TAC has high hygroscopicity, it tends to expand and contract due to humidity and generate stress strain. Therefore, the distortion due to moisture absorption generates internal stress and causes uneven color. The TAC cannot sufficiently satisfy the durability of the polarizing plate that is required as the LCD becomes thinner, larger, brighter, and the like.

In the polarizing plate, for example, a protective film for protecting the polarizer is bonded to a highly stretched polarizer such as polyvinyl alcohol. The polarizer protective film has 1) a small retardation expressed by the product of birefringence and thickness, 2) the retardation of the film hardly changes due to external stress, etc. 3) the planar direction and the thickness direction 4) It is required that the unevenness of the phase difference is small, and 4) the phenomenon of image distortion due to the so-called lens effect due to the unevenness of the film surface is difficult to occur.
In other words, if the phase difference is large, the phase difference changes due to external stress, etc., the in-plane retardation is large, or there is a lens effect due to irregularities on the film surface, the image quality of the liquid crystal display device is significantly reduced. Let In other words, color jumping phenomenon such as partial color fading, and adverse effects such as image distortion occur.
Therefore, instead of TAC, a thermoplastic saturated norbornene-based resin sheet having a low photoelastic modulus, that is, a small change in birefringence when external stress is applied and hardly affecting optical properties, is used as a protective layer for a polarizer. It is proposed to use as (patent documents 1-4). However, those using norbornene-based resin films simply as a protective layer for polarizers have insufficient scratch resistance, antireflection properties, adhesion, frame failure, color irregularities, bright spot defects, etc. Sometimes occurred.
JP 2001-272534 A JP 2003-207637 A JP 2003-232930 A JP 2003-097031 A

  The object of the present invention has been made in view of the state of the prior art, and has a small change in birefringence with respect to transparency, external stress, mechanical strength, antireflection properties, heat resistance, scratch resistance, It is to provide a polarizing plate and a liquid crystal display device having excellent adhesion.

  As a result of diligent research to achieve the above object, the present inventors have used a specific film as a protective film for a polarizing plate, and sequentially laminated a hard coat layer and an antireflection layer on one of the protective films. The present inventors have found that an optimal polarizing plate can be obtained, and have completed the present invention based on this finding.

Thus, according to the present invention,
(1) Resin film (A) having a thickness of 5 to 200 μm, a moisture permeability of 50 to 1500 g / m ² · 24 hr, and a maximum in-plane retardation of 4 nm or less on one surface of the polarizer, hard coat The layer (B) and the antireflection layer (C) are sequentially laminated,
The other surface of the polarizer is made of an alicyclic structure-containing resin, has a thickness of 5 to 200 μm, a moisture permeability of 0.3 to 40 g / m ² · 24 hr, and a photoelastic modulus of 12.0 × 10 ⁻¹² Pa. ^A polarizing plate formed by laminating a resin film (D) having a maximum of ⁻¹ or less and a maximum depth of 50 nm or less and a minimum width of 500 nm or more.
(2) The polarizing plate according to (1), wherein the film (A) contains a cellulose ester as a main component.
(3) The polarizing plate according to any one of (1) and (2), wherein the antireflection layer (C) has a refractive index of 1.36 or less.
(4) The polarizing plate according to any one of (1) to (3), wherein the antireflection layer (C) is made of airgel.
(5) The polarizing plate according to any one of (1) to (4), wherein the resin film (D) is a film showing retardation.
(6) A liquid crystal display device in which the polarizing plate of any one of (1) to (5) is installed with the antireflection layer (C) side facing the viewing side.
Are provided respectively.

  The polarizing plate of the present invention is a polarizing plate excellent in transparency, mechanical strength, antireflection performance, scratch resistance, and adhesion, and the polarizing plate can be suitably used as a liquid crystal display device.

The polarizing plate of the present invention has a resin film (A) having a thickness of 5 to 200 μm, a moisture permeability of 50 to 1500 g / m ² · 24 h, and a maximum in-plane retardation of 4 nm or less on one surface of the polarizer. ), A hard coat layer (B) and an antireflection layer (C) are sequentially laminated,
The other surface of the polarizer is made of an alicyclic structure-containing resin, has a thickness of 5 to 200 μm, a moisture permeability of 0.3 to 40 g / m ² · 24 hr, and a photoelastic coefficient of 12.0 × 10 ⁻¹² Pa. ^The polarizing plate is formed by laminating a resin film (D) having a maximum depth of ⁻¹ or less and a maximum depth of 50 nm or less and a minimum width of 500 nm or more.

  The polarizing plate of the present invention will be briefly described below with reference to FIG. The polarizing plate shown in FIG. 1 is obtained by sequentially laminating a resin film (A) 4, a hard coat layer (B) 5, and an antireflection layer (C) 6 on the resin film (A) 4 side. Attached to one side with a primer. On the other surface of the polarizer 3, the resin film (D) 2 is bonded with a primer layer.

Polarizer The polarizer that can be used in the present invention is not particularly limited as long as it has a function as a polarizer. For example, (1) vinyl alcohol polymer (PVA) / iodine polarizer, (2) PVA / dye polarizer with dichroic dye adsorbed and oriented on PVA film, (3) dehydrated from PVA film A polyene polarizer in which a polyene is formed by inducing a reaction or by dehydrochlorination of a polyvinyl chloride film, (4) the surface and / or the inside of a PVA film comprising a modified PVA containing a cationic group in the molecule And a polarizer having a dichroic dye. From the viewpoint of the initial polarization performance of the polarizer, (1) a PVA / iodine polarizer is preferable, and from the viewpoint of heat resistance, (2) a PVA / dye polarizer is preferable.

The polarizer that can be used in the present invention is not particularly limited by the production method. For example, 1) a method of adsorbing iodine ions after stretching a PVA-based film, 2) a method of stretching a PVA-based film after dyeing with a dichroic dye, and 3) after stretching a PVA-based film, using a dichroic dye There are known methods such as a dyeing method, 4) a method of drawing a dichroic dye on a PVA film and then stretching, and 5) a method of printing a dichroic dye after stretching the PVA film.
For example, in the method of 1), more specifically, iodine is dissolved in a potassium iodide solution to form iodine ions, the ions are adsorbed on a PVA film and stretched, and then bathed in a 1 to 4% boric acid aqueous solution. A polarizing plate is produced by dipping at a temperature of 30 to 40 ° C. More specifically, in the method of 2), the PVA film is dipped in a boric acid aqueous solution in the same manner as in 1), and then stretched about 3 to 7 times in the uniaxial direction, and 0.05 to 5% dichroic dye. It is immersed in an aqueous solution at a bath temperature of 30 to 40 ° C. to adsorb the dye, dried at 80 to 100 ° C. and thermally fixed to produce a polarizer. The polarization degree of the polarizer is preferably 99.993% or more.

Resin film (A)
The thickness of the resin film (A) is 5 to 200 μm, more preferably 20 to 100 μm.
If the thickness of the resin film (A) is less than 5 μm, the durability, mechanical strength and scratch resistance of the polarizing plate will be reduced. If the thickness exceeds 200 μm, warping will easily occur when placed in a high-temperature and high-humidity environment. The light transmittance is also reduced. Therefore, when the thickness of the resin film (A) is in the above range, a polarizing plate excellent in durability, mechanical strength, scratch resistance and optical performance can be obtained.

Further, the moisture permeability of the resin film (A) is 50 to 1500 g / m ² · 24 hr, preferably 100 to 800 g / m ² · 24 hr. If the moisture permeability is too low, drying of the primer for adhering the resin film (A) to the polarizer becomes insufficient, and if the moisture permeability is too high, the resin film absorbs moisture in the usage environment. Therefore, when the moisture permeability is in the above range, when used as a protective film for a polarizing plate, the moisture-proof balance is good, so that moisture can be prevented from entering from the front and back surfaces of the polarizing plate. Even when a water-based primer is used for adhesion to the polarizing plate, peeling between the resin film and the polarizer hardly occurs. Therefore, when the film is used, the reliability as a polarizing plate is improved.

  In the present invention, the maximum value of the in-plane retardation (hereinafter referred to as “Re”) of the resin film (A) is 4 nm or less. When Re is 4 nm or less, color unevenness when incorporated in a liquid crystal display unit can be suppressed.

The material constituting the resin film (A) is not particularly limited as long as the moisture permeability when the resin film is in the above-mentioned film thickness range is within the above range. For example, an ethylene-vinyl alcohol copolymer, cellulose ester, etc. Among them, acetylated cellulose ester is preferable.
Examples of the acetylated cellulose ester include diacetyl cellulose and triacetyl cellulose. In particular, triacetyl cellulose is most preferable from the viewpoints of transparency, mechanical strength, and the like.
The resin film (A) may be subjected to alkali saponification treatment, plasma treatment, glow discharge treatment, corona discharge treatment, high frequency treatment, electron beam treatment, etc. in order to improve the adhesion to the polarizing film. I do not care.

In this invention, it has a hard-coat layer (B) on a resin film (A). The hard coat layer (B) preferably has a high refractive index. By making the refractive index high, reflection such as reflection of external light can be prevented, and a polarizing plate having excellent scratch resistance and antifouling properties can be obtained. In addition to the hard coat layer (B), the hard coat layer (B) may be provided with a high refractive index layer on the surface of the hard coat layer.
Here, a high refractive index means a refractive index larger than the refractive index of the antireflection layer (C) laminated | stacked later, Preferably it is 1.55 or more.
The refractive index can be measured using, for example, a known spectroscopic ellipsometer.

The material for forming the hard coat layer is not particularly limited as long as it shows a hardness of “HB” or higher in the pencil hardness test specified in JIS K5700. Examples thereof include organic hard coat materials such as organic silicone, melamine, epoxy, acrylate, and urethane acrylate polyfunctional acrylates; inorganic hard coat materials such as silicon dioxide; and the like.
Of these, urethane acrylate-based and polyfunctional acrylate-based hard coat materials are preferably used from the viewpoint of good adhesive strength and excellent productivity.

The formation method in particular of a hard-coat layer (B) is not restrict | limited, For example, an active energy ray curable resin coating liquid is apply | coated on the resin film (A) with a well-known coating method, and energy rays, such as an ultraviolet-ray, are used. Can be formed by irradiating and curing. The average thickness of the hard coat layer is usually 0.5 to 30 μm, preferably 3 to 15 μm.
By containing an active energy ray-curable resin, a high refractive index hard coat layer having sufficient strength, durability, adhesion, and transparency can be obtained.

  The active energy ray-curable resin is a resin obtained by curing a prepolymer, an oligomer and / or a monomer having a polymerizable unsaturated bond or an epoxy group in a molecule by irradiation with active energy rays. An active energy ray refers to an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or crosslinking molecules, and usually an ultraviolet ray or an electron beam is used.

  Examples of prepolymers and oligomers having a polymerizable unsaturated bond or epoxy group in the molecule include unsaturated polyesters such as a condensation product of unsaturated dicarboxylic acid and polyhydric alcohol; polyester methacrylate, polyether methacrylate, polyol methacrylate And methacrylates such as melamine methacrylate, polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, polyol acrylate, acrylates such as melamine acrylate, and epoxy compounds.

Examples of the monomer having a polymerizable unsaturated bond or epoxy group in the molecule include styrene monomers such as styrene and α-methylstyrene; methyl acrylate, ethyl acrylate, -2-ethylhexyl acrylate, methoxy acrylate Acrylic esters such as ethyl, butoxyethyl acrylate, butyl acrylate, methoxybutyl acrylate, and phenyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, methoxyethyl methacrylate, ethoxymethyl methacrylate, methacrylic acid Methacrylic acid esters such as phenyl and lauryl methacrylate; acrylic acid-2- (N, N-diethylamino) ethyl, acrylic acid-2- (N, N-dimethylamino) ethyl, acrylic acid-2- (N, N -Dibenzylamino) methyl, acrylic -2-(N, N-diethylamino) substituted amino alcohol esters of unsaturated substituted and propyl; acrylamide, unsaturated carboxylic acid amides such as methacrylamide;

Ethylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, ethylene glycol diacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate 2-hydroxy acrylate, 2-hexyl acrylate, phenoxyethyl acrylate, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate Multifunctional Acrela such as REIT G
Polythiols having two or more thiol groups in the molecule, such as trimethylolpropane trithioglycolate, trimethylolpropane trithiopropylate, pentaerythritol tetrathioglycolate;
Examples include glycidyl acrylate, glycidyl methacrylate, glycidyl phenyl ether, glycidyl ethyl ether, epichlorohydrin, allyl glycidyl ether, ethylene oxide, and propylene oxide.
In the present invention, these prepolymers, oligomers and / or monomers can be used singly or in combination of two or more.

  The content of the prepolymer, oligomer and / or monomer in the active energy ray curable resin to be used is preferably 5% by weight to 95% by weight from the viewpoint of obtaining excellent coating suitability.

The hard coat layer preferably further contains inorganic oxide particles.
By adding inorganic oxide particles, a hard coat layer having excellent scratch resistance and a refractive index of 1.55 or more can be easily formed.

  As the inorganic oxide particles that can be used for the hard coat layer (B), those having a high refractive index are preferable. Specifically, inorganic oxide fine particles having a refractive index of 1.7 or more, particularly 1.7 to 2.3 are preferable.

Examples of such a high refractive index inorganic oxide include, for example, titania (titanium oxide), zirconia (zirconium oxide), zinc oxide, tin oxide, cerium oxide, antimony pentoxide, tin-doped indium oxide (ITO), Examples include tin oxide doped with antimony (ATO), indium oxide doped with zinc (IZO), zinc oxide doped with aluminum (AZO), and tin oxide doped with fluorine (FTO).
Among these, antimony pentoxide is suitable as a component for adjusting the refractive index because it has a high refractive index and an excellent balance between conductivity and transparency.
These inorganic oxide particles can be used singly or in combination of two or more.

  Inorganic oxide particles having a so-called ultrafine particle size, more specifically, a primary particle size of 1 nm to 100 nm, preferably 1 nm to 50 nm are preferably used so as not to lower the transparency of the hard coat layer.

  The primary particle diameter of the inorganic oxide particles may be visually measured from a secondary electron emission image photograph obtained by a scanning electron microscope (SEM) or the like, or a dynamic light scattering method or a static light scattering method may be used. Mechanical measurement may be performed by a particle size distribution meter to be used.

  If the primary particle diameter of the inorganic oxide particles is within the above range, the particle shape can be used in the present invention regardless of whether it is spherical, needle-shaped, or any other shape. In the case of a needle shape, the length is viewed as the particle diameter.

  Further, as the inorganic oxide particles that can be used in the present invention, at least a part of the surface thereof is coated with an organic compound or an organometallic compound having an anionic polar group in order to enhance dispersibility in an organic solvent. It is preferable that

  As the organic compound having an anionic polar group, those having an anionic polar group such as a carboxyl group, a phosphate group, or a hydroxyl group can be used. For example, stearic acid, lauric acid, oleic acid, linoleic acid, linolenic acid, pentaerythritol triacrylate, dipentaerythritol pentaacrylate, modified phosphoric acid triacrylate, epichlorohydrin modified glycerol triacrylate and the like can be mentioned.

  Examples of the organometallic compound having an anionic polar group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) 3-aminopropylmethyldiethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane Silane coupling agents such as vinyltris (2-methoxyethoxy) silane and 3-methacryloxypropyltrimethoxysilane; KR-TTS, KR-46B, KR-55, KR-41B, KR-38S, KR-138S, KR -238S, 338X, KR-44, KR-9S , KR-ET (above, titanate coupling agent manufactured by Ajinomoto Fine Techno Co., Ltd.), tetramethoxy titanium, tetraethoxy titanium, tetraisopropoxy titanium, tetra n-propoxy titanium, tetra n-butoxy titanium, tetra sec-butoxy And titanate coupling agents such as titanium and tetra-tert-butoxytitanium;

  The surface of the inorganic oxide particles is coated with an organic compound and / or an organometallic compound to impart hydrophobicity. Obtained by dissolving the organic compound and / or organometallic compound having an anionic polar group in an organic solvent, dispersing the inorganic oxide in the solution, and then completely evaporating and removing the organic solvent. Can do. Through this process, the dispersibility of the inorganic fine particles can be improved and re-aggregation can be prevented.

Two or more inorganic oxide particles may be used in combination. In this case, a transparent thin film having a plurality of functions in a balanced manner can be formed by combining inorganic oxide particles having different main functions. For example, a predetermined refractive index is obtained by combining rutile-type titanium oxide fine particles having a very high refractive index but low conductivity and the above-described conductive inorganic oxide having extremely high conductivity but a refractive index smaller than that of rutile-type titanium oxide. It is possible to form a hard coat layer having good antistatic performance.
Further, the amount of the inorganic oxide fine particles is not particularly limited, but from the viewpoint of easily obtaining a hard coat layer having excellent scratch resistance and a refractive index of 1.55 or more, an active energy ray curable resin. It is preferable that it is 40-90 weight part with respect to 100 weight part whole coating liquid.

When the active energy ray-curable resin is cured by ultraviolet irradiation, a photopolymerization initiator or a photopolymerization accelerator is added. As photopolymerization initiators, radical polymerization initiators such as acetophenones, benzophenones, thioxanthones, benzoin, benzoin methyl ether; aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, metathelone compounds, benzoin sulfonic acids Cationic polymerizable initiators such as esters; These can be used individually by 1 type or in combination of 2 or more types.
The addition amount of the photopolymerization initiator is usually 0.1 to 10 parts by weight with respect to 100 parts by weight of the active energy ray-curable resin.

Further, an organic reactive silicon compound may be added to the active energy ray curable resin. Examples of organic reactive silicon compounds that can be used include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, and tetra-tert- Butoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethylethoxysilane, dimethylmethoxysilane, dimethylpropoxysilane, dimethylbutoxysilane, methyldimethoxy silane, methyl diethoxy silane, hexyl trimethoxy silane, _{formula: R m Si (oR ')} n ( wherein, R and R' each independently represent an alkyl group having 1 to 10 carbon atoms, , N represents each independently satisfy the relationship of m + n = 4 is a positive integer) the organosilicon compound represented by.;

  3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, 3- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltriethoxysilane 3-methacryloxypropylmethoxysilane, N-3- (N-vinylbenzylaminoethyl) -3-aminopropylmethoxysilane / hydrochloride, 3-glycidoxypropyltrimethoxysilane, aminosilane, methylmethoxysilane, vinyltri Acetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, hexamethyldisilazane, vinyltris (3-methoxyethoxy) silane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, Le trichlorosilane, silane coupling agents such as dimethyldichlorosilane;

  One-end vinyl group-substituted polysilane, both-end vinyl group-substituted polysilane, one-end vinyl group-substituted polysiloxane, both-end vinyl group-substituted polysiloxane, vinyl group-substituted polysilane obtained by reacting these compounds, or vinyl group-substituted poly Active energy ray-curable silicon compounds such as siloxane; other organosilicon compounds such as 3- (meth) acryloxypropyltrimethoxysilane and (meth) acryloxysilane compounds such as 3- (meth) acryloxypropylmethyldimethoxysilane And the like.

  The active energy ray-curable resin coating solution that can be used is a prepolymer, an oligomer and / or a monomer having a polymerizable unsaturated bond or an epoxy group in the molecule, and optionally inorganic oxide particles. It can be prepared by dissolving or dispersing in an organic solvent.

  Examples of the organic solvent that can be used in the active energy ray-curable resin coating solution include alcohols such as methanol, ethanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, ethylene glycol monobutyl ether, and ethylene glycol monoacetate. Glycols such as ethyl ether, diethylene glycol, diethylene glycol monobutyl ether, diacetone glycol; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as n-hexane and n-heptane; esters such as ethyl acetate and butyl acetate Ketones such as methyl ethyl ketone and methyl isobutyl ketone; oximes such as methyl ethyl ketoxime; and combinations of two or more thereof.

  The method for coating the active energy ray-curable resin on the resin film (A) is not particularly limited, and a known coating method can be employed. Examples of the coating method include a wire bar coating method, a dip method, a spray method, a spin coating method, and a roll coating method.

After obtaining the coating film of the active energy ray curable resin, it can be dried and cured by irradiating the active energy ray to form a hard coat layer.
The irradiation intensity and irradiation time of the active energy ray are not particularly limited, and irradiation conditions such as irradiation intensity and irradiation time can be appropriately set according to the active energy ray curable resin to be used.

Antireflection layer (C)
The antireflection layer (C) used in the present invention refers to a layer having a refractive index lower than that of the hard coat layer (B). The refractive index of the antireflection layer (C) may satisfy the above conditions, but is preferably 1.36 or less, more preferably 1.35 to 1.25, and 1.34 to 1.30. It is particularly preferred that By satisfying the above preferable conditions, an antireflection layer excellent in the balance between antireflection performance, scratch resistance and strength is formed.

The material constituting the antireflection layer (C) is not particularly limited, but airgel is preferable in that the refractive index can be easily controlled and the water resistance is excellent.
The airgel is a transparent porous body in which minute bubbles are dispersed in a matrix. Most of the size of the bubbles is 200 nm or less, and the content of the bubbles is usually 10% by volume or more and 60% by volume or less, preferably 20% by volume or more and 40% by volume or less.
Specific examples of the airgel in which minute bubbles are dispersed include silica aerogel and a porous body in which hollow particles are dispersed in a matrix.

  Silica airgel is a wet state composed of a silica skeleton obtained by hydrolysis polymerization reaction of alkoxysilane, as disclosed in US Pat. No. 4,402,927, US Pat. No. 4,432,956, US Pat. No. 4,610,863 and the like. The gel compound can be produced by drying in a supercritical state above the critical point of the solvent in the presence of a solvent (dispersion medium) such as alcohol or liquefied carbon dioxide. In supercritical drying, for example, a gel compound is immersed in liquefied carbon dioxide, and all or part of the solvent contained in the gel compound is replaced with liquefied carbon dioxide having a critical point lower than that of the solvent. It can be carried out by drying under supercritical conditions of a single system of or a mixed system of carbon dioxide and a solvent. Silica airgel may be produced in the same manner as described above using sodium silicate as a raw material as disclosed in US Pat. No. 5,137,279, US Pat. No. 5,124,364, and the like.

  Here, as disclosed in JP-A-5-279011 and JP-A-7-138375, the gel-like compound obtained by hydrolysis and polymerization reaction of alkoxysilane as described above is hydrophobized. It is preferable to impart hydrophobicity to the silica airgel. Hydrophobic silica airgel imparted with hydrophobicity as described above can prevent moisture, water, and the like from entering, and prevent the performance of the silica airgel from being degraded in refractive index, light transmittance, and the like.

  This hydrophobization treatment step can be performed before or during supercritical drying of the gel compound. The hydrophobization treatment is performed to make the hydrophobization by reacting the hydroxyl group of the silanol group present on the surface of the gel compound with the functional group of the hydrophobization treatment agent and replacing it with the hydrophobic group of the hydrophobization treatment agent. . As a method of performing the hydrophobization treatment, the gel is immersed in a hydrophobization treatment solution in which the hydrophobization treatment agent is dissolved in a solvent, mixed, and so on. There is a method in which the hydrophobization reaction is performed by heating accordingly.

  Examples of the solvent used for the hydrophobic treatment include methanol, ethanol, isopropanol, xylene, toluene, benzene, N, N-dimethylformamide, hexamethyldisiloxane, and the like, but the hydrophobic treatment agent can be easily dissolved. And what is necessary is just to be able to substitute for the solvent which the gel before hydrophobization treatment contains, and it is not limited to these. Further, when supercritical drying is performed in a later step, a medium that can be easily supercritically dried, such as methanol, ethanol, isopropanol, liquefied carbon dioxide, or the like, is preferable. Examples of the hydrophobizing agent include hexamethyldisilazane, hexamethyldisiloxane, trimethylmethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, trimethylethoxysilane, dimethyldiethoxysilane, and methyltriethoxysilane. Etc.

The refractive index of silica airgel can be freely changed by the raw material compounding ratio of silica airgel.
The formation method of the antireflection layer (C) made of silica aerogel is not particularly limited. For example, the gel compound is coated on the hard coat layer by a known coating method, and the supercritical drying is performed. The method of forming by performing is mentioned. Further, the hydrophobization treatment may be performed before or during supercritical drying. In the supercritical drying, for example, the gel compound is immersed in liquefied carbon dioxide, and all or a part of the solvent containing the gel compound is replaced with liquefied carbon dioxide having a lower critical point than the solvent. It can be carried out by drying under supercritical conditions of a single system of carbon dioxide or a mixed system of carbon dioxide and a solvent.

As a porous material in which hollow fine particles are dispersed in a matrix, hollow fine particles having voids inside fine particles as disclosed in JP-A Nos. 2001-233611 and 2003-149642 are used as binder resins. And a porous material dispersed in the substrate.
The binder resin can be selected from resins suitable for conditions such as dispersibility of hollow fine particles, transparency of the porous body, and strength of the porous body. For example, conventionally used polyester resins and acrylic resins Resin, urethane resin, vinyl chloride resin, epoxy resin, melamine resin, fluorine resin, silicone resin, butyral resin, phenol resin, vinyl acetate resin, UV curable resin, electron beam curable resin, emulsion resin, water-soluble resin, hydrophilic resin Further, a mixture of these resins, a coating resin such as a copolymer or a modified product of these resins, a hydrolyzable organosilicon compound such as alkoxysilane, and a hydrolyzate thereof can be used.
Among these, hydrolyzable organosilicon compounds such as acrylic resins, epoxy resins, urethane resins, silicone resins, alkoxysilanes and hydrolysates thereof are preferred from the viewpoint of the dispersibility of the fine particles and the strength of the porous body.

The hydrolyzable organosilicon compound such as alkoxysilane and the hydrolyzate thereof are formed from one or more compounds selected from the group consisting of the following (a) to (c), and in the molecule: -(O-Si) _m -O- (wherein _m represents a natural number) has a bond.
(A) A compound represented by formula (1): SiX ₄ .
(B) At least one partial hydrolysis product of the compound represented by the formula (1).
(C) At least one complete hydrolysis product of the compound represented by the formula (1).

  In the formula (1), X is a halogen atom such as a chlorine atom or a bromine atom; a monovalent hydrocarbon group which may have a substituent; an oxygen atom; an organic acid radical such as an acetate radical or a nitrate radical; A 3-diketonate group such as acetonate; an inorganic acid group such as nitrate or sulfate; an alkoxy group such as methoxy, ethoxy, n-propoxy, or n-butoxy; or a hydroxyl group.

Examples of the monovalent hydrocarbon group which may have a substituent include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group; a cyclopentyl group, A cycloalkyl group such as a cyclohexyl group; an allyl group optionally having a substituent such as a phenyl group, a 4-methylphenyl group, a 1-naphthyl group, and a 2-naphthyl group; an alkenyl group such as a vinyl group and an allyl group; Aralkyl groups such as benzyl group, phenethyl group and 3-phenylpropyl group; haloalkyl groups such as chloromethyl group and 3-chloropropyl group; 3,3,3-trifluoropropyl group, methyl-3,3,3-tri A perfluoroalkyl group such as a fluoropropyl group, a heptadecafluorodecyl group, a trifluoropropyl group, a tridecafluorooctyl group; An alkenylcarbonyloxyalkyl group such as a tacryloxypropyl group; an alkyl group having an epoxy group such as a 3-glycidoxypropyl group or a 3,4-epoxycyclohexylethyl group; an alkyl group having a mercapto group such as a 3-mercaptopropyl group An alkyl group having an amino group such as a 3-aminopropyl group; Among these, an alkyl group having 1 to 4 carbon atoms, a perfluoroalkyl group, and a phenyl group are preferable because of easy synthesis, easy availability, and low reflection characteristics.
Among these compounds (a), formula (2): R _a SiY _4-a [wherein, R represents a monovalent hydrocarbon group which may have a substituent, and a represents 0-2. Represents an integer, and when a is 2, R may be the same or different. Y represents a hydrolyzable group, and Y may be the same or different. ] The silicon compound represented by this is preferable.

In the formula (2), Y represents a hydrolyzable group. Here, the hydrolyzable group refers to a group that is hydrolyzed in the presence of an acid or a base catalyst as desired to form a — (O—Si) _m —O— bond.
Specific examples of the hydrolyzable group include alkoxy groups such as methoxy group, ethoxy group and propoxy group; acyloxy groups such as acetoxy group and propionyloxy group; oxime group (—O—N═C—R ′ (R ″) )), Enoxy group (—O—C (R ′) ═C (R ″) R ′ ″), amino group, aminoxy group (—O—N (R ′) R ″), amide group (— N (R ′) — C (═O) —R ″) and the like. In these groups, R ′, R ″, and R ′ ″ each independently represent a hydrogen atom or a monovalent hydrocarbon group. Among these, Y is preferably an alkoxy group from the viewpoint of availability.

 The silicon compound represented by the formula (2) is preferably a silicon compound in which a is an integer of 0 to 2 in the formula (2). Specific examples thereof include alkoxysilanes, acetoxysilanes, oxime silanes, enoxysilanes, aminosilanes, aminoxysilanes, amidosilanes and the like. Among these, alkoxysilanes are more preferable because of their availability.

  In the formula (2), examples of the tetraalkoxysilane in which a is 0 include tetramethoxysilane and tetraethoxysilane. Examples of the organotrialkoxysilane in which a is 1 include methyltrimethoxysilane and methyltriethoxy. Examples include silane, methyltriisopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, and the like. Examples of the diorganodialkoxysilane in which a is 2 include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, and methylphenyldimethoxysilane.

 The molecular weight of the compound represented by the formula (1) is not particularly limited, but is preferably 40 to 300, and more preferably 100 to 200.

 At least one partial hydrolysis product (hereinafter referred to as “compound (3)”) of the compound represented by formula (1) of (b), and represented by formula (1) of (c). At least one complete hydrolysis product of the compound (hereinafter referred to as “compound (4)”) is obtained by completely or partially hydrolyzing one or more of the compounds represented by the formula (1). Can be obtained by condensation.

Compound (3) and compound (4) are, for example, a metal tetraalkoxide represented by Si (Or) ₄ (r represents a monovalent hydrocarbon group) and a molar ratio [H ₂ O] / [Or ] Can be obtained by hydrolysis in the presence of water in an amount of 1.0 or more, 1.0 to 5.0, preferably 1.0 to 3.0. Hydrolysis can be performed by stirring the whole volume at a temperature of 5 to 100 ° C. for 2 to 100 hours.

When hydrolyzing the compound represented by the formula (1), a catalyst may be used as necessary. The catalyst to be used is not particularly limited, but the obtained partial hydrolyzate and / or complete hydrolyzate is likely to have a two-dimensional cross-linked structure, and the condensed compound is easily made porous. From the viewpoint of shortening the time required for this, an acid catalyst is preferred.
The acid catalyst to be used is not particularly limited. For example, acetic acid, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, maleic acid, malonic acid, toluenesulfonic acid, Organic acids such as acids; inorganic acids such as hydrochloric acid, nitric acid, and halogenated silane; acidic sol-like fillers such as acidic colloidal silica and oxidized titania sol; These acid catalysts can be used alone or in combination of two or more.
Instead of the acid catalyst, a base catalyst such as an aqueous solution of an alkali metal or alkaline earth metal hydroxide such as sodium hydroxide or calcium hydroxide, an aqueous ammonia or an aqueous solution of amines may be used.

  The molecular weights of the compound (3) and the compound (4) are not particularly limited, but usually the weight average molecular weight is in the range of 200 to 5,000.

The hollow fine particles are not particularly limited as long as they are fine particles of an inorganic compound, but inorganic hollow fine particles in which cavities are formed inside the outer shell are preferable, and use of silica-based hollow fine particles is particularly preferable.
As the inorganic compound, an inorganic oxide is common. As the inorganic _{oxide, SiO 2, Al 2 O 3} , B 2 O 3, TiO 2, ZrO 2, SnO 2, Ce 2 O 3, P 2 O 5, Sb 2 O 3, MoO 3, ZnO 2, WO One or two or more of ₃ or the like can be mentioned. Examples of the two or more inorganic oxides include TiO ₂ —Al ₂ O ₃ , TiO ₂ —ZrO ₂ , In ₂ O ₃ —SnO ₂ , and Sb ₂ O ₃ —SnO ₂ . These can be used alone or in combination of two or more.

  The inorganic hollow fine particles include (a) a single layer of an inorganic oxide, (b) a single layer of a composite oxide composed of different types of inorganic oxides, and (c) a double layer of (a) and (b) above. What is included can be used.

  The outer shell may be porous with pores, or the pores may be closed and the cavity sealed with respect to the outside of the outer shell. The outer shell is preferably a plurality of inorganic oxide coating layers comprising an inner first inorganic oxide coating layer and an outer second inorganic oxide coating layer. By providing the second inorganic oxide coating layer on the outer side, the fine pores of the outer shell can be closed to make the outer shell dense, and furthermore, inorganic hollow fine particles in which the inner cavity is sealed can be obtained. In particular, when a fluorine-containing organosilicon compound is used for forming the second inorganic oxide coating layer, the coating layer containing fluorine atoms is formed, so that the resulting particles have a lower refractive index and are reduced to an organic solvent. The dispersibility is good, and further, it is effective for imparting antifouling property to the low refractive index layer, which is preferable. Such fluorine-containing organic silicon compounds include 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, heptadecafluorodecyl. Examples thereof include trichlorosilane, heptadecafluorodecyltrimethoxysilane, trifluoropropyltrimethoxysilane, and tridecafluorooctyltrimethoxysilane.

  The thickness of the outer shell is preferably in the range of 1 to 50 nm, particularly 5 to 20 nm. If the thickness of the outer shell is less than 1 nm, the inorganic hollow fine particles may not maintain a predetermined particle shape. On the other hand, when the thickness of the outer shell exceeds 50 nm, the cavities in the inorganic hollow fine particles are small, and as a result, the ratio of the cavities may be reduced and the refractive index may not be sufficiently lowered.

When the first inorganic oxide coating layer and the second inorganic oxide coating layer are provided as outer shells as described above, the total thickness of these layers may be in the range of 1 to 50 nm. In particular, in the case of a densified outer shell, the thickness of the second inorganic oxide coating layer is preferably in the range of 20 to 40 nm.
Further, the solvent used when preparing the inorganic hollow fine particles and / or a gas that enters during drying may be present in the cavity.

  The average particle size of the inorganic hollow fine particles is not particularly limited, but is preferably 5 to 2000 nm, and more preferably 20 to 100 nm. If it is smaller than 5 nm, the effect of lowering the refractive index tends to be small. Conversely, if it is larger than 2000 nm, the transparency is deteriorated and the contribution due to diffuse reflection tends to be large. Here, the average particle diameter is a number average particle diameter by observation with a transmission electron microscope.

  The inorganic hollow fine particles that can be used in the present invention can be produced, for example, based on the method described in detail in JP-A No. 2001-233611, and commercially available inorganic hollow fine particles can also be used.

  The blending amount of the inorganic hollow fine particles is not particularly limited, but is preferably 10 to 30% by weight with respect to the whole antireflection layer (C). When the blending amount of the inorganic hollow fine particles is within this range, a laminated film having both antireflection properties and scratch resistance can be obtained.

  When the antireflection layer (C) is a porous body in which hollow particles are dispersed in a matrix, the formation method is not particularly limited. For example, the antireflection layer (C) contains hollow fine particles and a binder resin on the hard coat layer. The coating liquid which becomes is apply | coated by the well-known coating method, and the method of performing a drying and heat processing as needed is mentioned. The temperature of the heating performed as necessary is usually 50 to 200 ° C, preferably 80 to 150 ° C.

  In the present invention, the average thickness of the antireflection layer (C) is 10 to 1000 nm, preferably 30 to 500 nm.

Resin film (D)
The average thickness of the resin film (D) made of the alicyclic structure-containing polymer resin of the present invention is 5 to 200 μm, preferably 30 to 100 μm.
When the thickness is less than 5 μm, the mechanical strength as a protective film is lowered, and warpage or the like is likely to occur when the polarizing plate is placed in a high temperature and high humidity environment. When thickness exceeds 200 micrometers, the light transmittance of a protective film will fall. Therefore, when the thickness of the resin film (D) is in the above range, a laminate having excellent mechanical strength and durability can be obtained.

The photoelastic coefficient of the resin film (D) is preferably 12.0 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 9.0 × 10 ⁻¹² Pa ⁻¹ or less. If the photoelastic coefficient is too high, the generation of stress due to heat or the like is alleviated, birefringence occurs, and uneven color causes light leakage. That is, when a polarizing plate using a resin film (D) having a photoelastic coefficient in the above range is incorporated in a liquid crystal display device, uneven color and light leakage can be prevented.
The photoelastic coefficient is also referred to as a piezo optical coefficient and is a material constant that describes the magnitude of the piezo optical effect (photoelastic effect) and can be measured using an ellipsometer. The photoelastic coefficient is a value indicating the degree of optical distortion with respect to external stress. The smaller the value, the better the optical film as a protective film for a polarizing plate.
For the photoelastic coefficient, a retardation measuring device (manufactured by Oji Scientific Instruments Co., Ltd., “KOBRA-21ADH”) is used to calculate retardation (Re) in the film surface while applying a load in the range of 50 to 150 g to the resin film. The birefringence value Δn is obtained by dividing this by the thickness of the film. Δn is obtained while changing the load, and a load-Δn curve is created. The inclination is defined as a photoelastic coefficient.

  The resin film (D) used in the present invention is made of an alicyclic structure-containing polymer resin. The alicyclic structure-containing polymer resin has an alicyclic structure in the main chain and / or side chain, and preferably contains an alicyclic structure in the main chain from the viewpoint of mechanical strength, heat resistance and the like. .

Examples of the alicyclic structure polymer include a saturated alicyclic hydrocarbon (cycloalkane) structure and an unsaturated alicyclic hydrocarbon (cycloalkene) structure. From the viewpoint of mechanical strength, heat resistance, etc., the cycloalkane structure. Or a cycloalkene structure is preferable, and a cycloalkane structure is most preferable.
The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20, more preferably 5 to 15 in the mechanical strength, The properties of heat resistance and film formability are highly balanced and suitable. The proportion of the repeating unit containing the alicyclic structure in the alicyclic structure-containing polymer used in the present invention may be appropriately selected according to the purpose of use, but is preferably 30% by weight or more, Preferably it is 50% by weight or more, particularly preferably 70% by weight or more, and most preferably 90% by weight or more. It is preferable from the viewpoints of transparency and heat resistance of the film that the ratio of the repeating unit having an alicyclic structure in the polymer resin having an alicyclic structure is in this range.

Specifically, the polymer resin having an alicyclic structure includes (1) a norbornene polymer, (2) a monocyclic olefin polymer, (3) a cyclic conjugated diene polymer, and (4) vinyl. Examples thereof include alicyclic hydrocarbon polymers and hydrogenated products thereof. Among these, norbornene-based polymers are more preferable from the viewpoints of transparency and moldability.
Specific examples of the norbornene-based polymer include ring-opening polymers of norbornene-based monomers, ring-opening copolymers of norbornene-based monomers and other monomers capable of ring-opening copolymerization, and hydrogenated products thereof, norbornene-based polymers Examples include addition polymers of monomers and addition copolymers with other monomers copolymerizable with norbornene monomers. Among these, from the viewpoint of transparency, a ring-opening (co) polymer hydrogenated product of a norbornene-based monomer is most preferable.
Examples of the polymer resin having the alicyclic structure include known polymers disclosed in Japanese Patent Application Laid-Open No. 2002-321302.

Among norbornene polymers suitably used for the resin film of the present invention, X: bicyclo [3.3.0] octane-2,4-diyl-ethylene structure and Y: tricyclo [4.3 are used as repeating units. .0.1 ^2,5 ] decane-7,9-diyl-ethylene structure, and the content of these repeating units is 90% by weight or more based on the total repeating units of the thermoplastic norbornene resin. And the ratio of the content ratio of X and the content ratio of Y is preferably 100: 0 to 40:60 in terms of a weight ratio of X: Y. By using such a resin, it is possible to obtain a resin film having no dimensional change over a long period of time and excellent optical property stability.

Examples of the monomer that gives a repeating unit having the structure of X by polymerization include norbornene-based monomers having a structure in which a 5-membered ring is bonded to a norbornene ring. More specifically, tricyclo [4.3.0. 1 ^2,5 ] deca-3,7-diene (common name: dicyclopentadiene) and derivatives thereof, 7,8-benzotricyclo [4.3.0.1 ^0,5 ] dec-3-ene (conventional) Name: methanotetrahydrofluorene), and derivatives thereof.

As the monomer polymerized to provide the repeating units of the structure Y, tetracyclo [4.4.0.1 ^{2, 5.} 1 ^7,10 ] deca-3,7-diene (common name: tetracyclododecene) and its derivatives.
Here, examples of the substituent include an alkyl group, an alkylene group, and a polar group. In addition, these substituents may be the same or different and a plurality may be bonded to the ring. Norbornene monomers can be used alone or in combination of two or more.

  Specifically, as means for obtaining such a norbornene-based polymer, a) a monomer that is polymerized to give a repeating unit of the structure of X and a monomer that is polymerized to give a repeating unit of the structure of Y A method of polymerizing by controlling the copolymerization ratio, and if necessary, hydrogenating unsaturated bonds in the polymer; b) having a polymer having the X structure as a repeating unit, and having the Y structure as a repeating unit The method of controlling by the blend ratio with a polymer is mentioned.

  The molecular weight of the alicyclic structure-containing polymer resin used in the present invention is a polyisoprene or polystyrene equivalent weight measured by gel permeation chromatography (hereinafter abbreviated as “GPC”) using cyclohexane as a solvent. The average molecular weight (Mw) is usually 8,000 to 100,000, preferably 10,000 to 80,000, more preferably 15,000 to 50,000. When the weight average molecular weight is in such a range, the mechanical strength and moldability of the film are highly balanced and suitable.

  The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the alicyclic structure-containing polymer resin used in the present invention is not particularly limited, but is usually 1.0 to 10.0, preferably 1.0. It is -4.0, More preferably, it is the range of 1.2-3.5.

  The alicyclic structure-containing polymer resin that can be used in the present invention may contain a compounding agent. The compounding agent is not particularly limited, but is a layered crystal compound; inorganic fine particles; antioxidants, heat stabilizers, light stabilizers, weathering stabilizers, ultraviolet absorbers, near infrared absorbers and other stabilizers; lubricants, plastics Resin modifiers such as agents; Colorants such as dyes and pigments; Antistatic agents and the like. These compounding agents can be used alone or in combination of two or more, and the compounding amount is appropriately selected within a range not impairing the object of the present invention.

In the present invention, the thickness variation of the resin film (D) is determined by installing a contact web thickness meter (RC-101 rotary caliper meter, manufactured by Meisho Co., Ltd.), moving the thickness meter to the side, Measurements are made at intervals of 0.48 mm in the width direction. The arithmetic average value (average thickness), maximum thickness, and minimum thickness of the measured values were obtained. The difference between the maximum thickness and the average thickness and the difference between the minimum thickness and the average thickness were compared, and the larger one was determined to determine what percentage of the average thickness, and this was regarded as the thickness variation.
The thickness variation of the resin film (D) is preferably within 3.0% of the average thickness, and more preferably within 2.5%. By setting the thickness of the resin film (D) within the above range, color unevenness when the resin film (D) of the present invention is incorporated in a liquid crystal display device can be reduced.

In the resin film (D) used in the present invention, the content of the volatile component of the resin film is preferably 0.1% by weight or less, more preferably 0.05% by weight or less. Due to the content of the volatile component within the above range, the dimensional change due to the use environment can be reduced, and the stability of the optical characteristics such as display non-uniformity does not occur even if used for a long time in a liquid crystal display. Excellent.
The volatile component is a relatively low boiling point substance having a molecular weight of 200 or less contained in a trace amount in the resin film, and examples thereof include residual monomers and solvents. The content of the volatile component is the sum of the substances having a molecular weight of 200 or less contained in a small amount in the alicyclic structure-containing polymer resin, and can be quantified by analysis by gas chromatography.

In the die line of the resin film (D) used in the present invention, the maximum depth of the die line formed in the longitudinal direction of the resin film is 50 nm or less, and the minimum width of the die line is 500 nm or more.
The depth of the die line and the width thereof can be measured by using a three-dimensional structural analysis microscope (manufactured by Saigo Co., Ltd.) and scanning the uneven surface of the film from the bottom to the top at a constant speed and observing the interference fringes.
When the die line is within the above range, even when the die line is incorporated in a liquid crystal display unit having a high-brightness backlight unit, there is no bright spot and a good display state can be obtained.

Here, when measuring the depth and width from the top of the adjacent peak of the die line to the bottom of the valley, the base line 12 is drawn as shown in FIG. Measure the distance to the intersections 17 and 18 of the lines 15 and 16 drawn perpendicularly to the baseline 12 and the baseline 12, and measure the distance from the peak to the baseline and the distance from the valley bottom to the baseline. The sum is the die line depth.
Also, the distance to the valley 13 on the left side of the vertex 14 (distance between 17 and 18) and the distance to the next valley 19 on the right side of the vertex 14 (distance between 17 and 19) are measured, and the total Is the width of the die line having the apex 14.

In-plane retardation (Re) can be obtained by Re = (nx−ny) × d, where the main refractive index in the film plane is nx, ny, and the thickness of the film is d.
The retardation (Rth) in the film thickness direction is defined as Rth, where the main refractive index in the film plane is nx, ny, the refractive index in the film thickness direction is nz, and the thickness of the film is d (nm). = {(Nx + ny) / 2-nz} × d.
Re and Rth can be measured using a commercially available automatic birefringence meter (“KOBRA-21ADH” manufactured by Oji Scientific Instruments).

  The resin film of the present invention can be obtained by molding by a solution casting method or a melt extrusion method, preferably a melt extrusion method.

  The surface of the resin film (D) can be roughened as necessary. The means for roughening is not particularly limited, and examples thereof include corona discharge treatment, sand blasting, etching, and fine particle adhesion. Adhesion can be improved by roughening the surface of the resin film (D).

The resin film (D) is preferably a film having retardation. There is no restriction | limiting in particular in the value of the retardation of a resin film (D).
For example, a material that gives an in-plane retardation Re with respect to a predetermined wavelength functions as a half-wave plate. A material that gives an in-plane retardation Re functions as a quarter-wave plate.
A film made of another resin may be further laminated on the resin film (D). For example, when the film (D) is a ¼ wavelength plate, a broadband ¼ wavelength plate can be obtained by laminating a ½ wavelength plate on the film (D).

As another aspect of a resin film (D), what has the relationship in any one of (1)-(4) is mentioned.
nx≈ny <nz (1)
nx≈ny> nz (2)
nx> ny≈nz (3)
nx≈nz> ny (4)
nx, ny, and nz represent refractive indexes in the X-axis, Y-axis, and Z-axis directions in the retardation plate or the like, and the X-axis direction is a direction in which the refractive index in the plane of the layer is maximized. (In-plane slow axis direction), and the Y-axis direction is a direction (in-plane fast axis direction) perpendicular to the X-axis direction in the plane of the layer, and the Z-axis direction is The thickness direction of the layer is perpendicular to the X-axis direction and the Y-axis direction.

  In the resin film (D) of the present invention, a plurality of retardation films may be laminated such that each slow axis intersects or is parallel at a predetermined angle. When laminating, a known laminating method may be used. Moreover, you may use an adhesive etc. in the case of lamination | stacking.

Primer The polarizing plate of this invention may provide a primer between a polarizer and the said resin film (A), and between a polarizer and the said resin film (D). By providing the primer, adhesion with the polarizer is improved, and mechanical strength, durability of the polarizer, and optical characteristics are improved.

  As a primer, a layer comprising a vinyl alcohol polymer, a silicone layer, a urethane layer, an acrylic layer, a primer containing a conjugated diene polymer having a cyclized structure inside or a hydrogenated product thereof, etc. Is mentioned. From the viewpoint of reliability, mechanical strength, optical properties, etc., from a primer comprising a vinyl alcohol polymer or a primer containing a conjugated diene polymer having a cyclized structure inside or a hydrogenated product thereof, or a vinyl alcohol polymer Is preferred.

  A vinyl alcohol polymer (sometimes referred to as PVA) is a generally known polymer. This PVA is obtained by, for example, polymerizing a vinyl monomer mainly composed of a vinyl ester monomer by a conventionally known method to produce a vinyl ester polymer (that is, a vinyl ester monomer homopolymer, two or more kinds). A vinyl ester monomer copolymer and a copolymer of a vinyl ester monomer and another ethylenically unsaturated monomer), and then saponifying the vinyl ester polymer by a conventional method. Is obtained. The saponification degree of the PVA used in the present invention is preferably 70 to 99%, and the polymerization degree is 200 to 3000. The PVA used in the present invention may be one in which, for example, acrylic acid, crotonic acid, itaconic acid and the like are copolymerized to a few mol% within a range that does not impair the object of the present invention. Further, a compound having an epoxy group, a carbonyl group, a silanol group, a thiol group, or the like may be modified by graft addition or the like.

  In the primer, for example, a curing agent; a coupling agent such as a silane coupling agent and a titanium coupling agent; a terpene resin, a phenol resin, a terpene-phenol resin, a rosin resin, and a xylene resin. Tackifiers such as calcium carbonate, clay, titanium oxide, carbon black and other inorganic fillers; aerosil, disvalon and other thixotropic agents; UV absorbers, antioxidants, heat stabilizers, hydrolysis stabilizers, etc. Stabilizers and the like may be contained.

    The method for forming the primer is not particularly limited, and examples thereof include a method in which a primer forming coating solution is applied on a resin film by a known coating method. The thickness of the primer is not particularly limited, but is usually 0.01 to 5 μm, preferably 0.1 to 20 μm.

  Although the polarizing plate of this invention is not specifically limited by the manufacturing method, a hard-coat layer (B) and an antireflection layer (C) are laminated | stacked beforehand on a resin film (A), and then the resin film (A) becomes an inner side. Thus, it is preferable to overlap the polarizer and laminate the resin film (D) on the other surface of the polarizer.

In the laminating method using a primer, a solution containing a primer component is applied, and the resin film (A) and the resin film (D) are bonded to both sides of the polarizer before the coating film is dried, Next, a method of removing the solvent and bonding (hereinafter referred to as “wet lamination”),
And after applying the solution containing the primer component, removing the solvent and drying the coating film, the resin film (A) and the resin film (D) are bonded to both sides of the polarizer, And a method of bonding by pressure and / or heating (hereinafter referred to as “dry lamination”).
In the case of wet lamination, the solution is applied or dropped onto a polarizing film or / and film with a Meyer bar, gravure coater, micro gravure coater, etc., and the solvent is removed by heating while laminating the laminate with, for example, two rolls. To do.
In the case of dry lamination, the solution is applied to the polarizing film or / and the film with a bar coater, roll coater, gravure coater or the like, and the solvent in the coating film is removed using means such as passing through a drying furnace.

In the above, the kind of the intervening primer and the method of laminating the resin film on the polarizer are respectively between the polarizer and the resin film (A) and between the polarizing plate and the resin film (D). May be different.
In the present invention, when the resin film (A) and the resin film (D) in which the hard coat layer (B) and the antireflection layer (C) are laminated on a polarizer are bonded together, a vinyl alcohol polymer is used. It is preferable to produce a laminate by wet lamination using the above solution. In that case, the viscosity of the vinyl alcohol polymer solution used is preferably in the range of 10 to 20000 cP (centipoise), more preferably 100 to 12000 cP. When the pressure is less than 10 cP, the solution flows excessively out of the laminate due to pressurization at the time of lamination, and the thickness of the primer becomes thin. On the other hand, when the pressure exceeds 20000 cP, the coating property is deteriorated.
In wet lamination, it is preferable to use water as the solvent because the adhesive strength between the layers of the laminate is excellent.

  In any of wet lamination and dry lamination, lamination of each film and a polarizer may be performed by any known means, but is preferable because it is easy to use a nip roll and is excellent in productivity. As the nip roll, a rubber roll and a metal roll, or a rubber roll and a rubber roll can be combined. The pressure at the time of lamination is usually 1 to 100 kgf / cm, preferably 3 to 30 kgf / cm in terms of nip line pressure.

By curing the polarizing plate obtained by the above method, the adhesive strength between the polarizer and each film and the durability of the polarizer can be improved, and the warpage of the polarizing plate in a high temperature and high humidity environment can be reduced. The curing conditions are such that the temperature is preferably 2 to 150 ° C, more preferably 20 to 80 ° C, and the holding time is 0.5 to 200 hours, preferably 48 to 100 hours. When the curing temperature and holding time are within the above ranges, a polarizing film excellent in durability, optical performance and the like can be obtained.
Moreover, after bonding each film and a polarizer through a primer, it is preferable to control the thickness of a primer by applying a pressure to this.

In the polarizing plate of the present invention, an antifouling layer can be further formed on the antireflection layer (C) in order to enhance the antifouling performance of the antireflection layer (C).
The antifouling layer forming material is not particularly limited as long as the function of the antireflection layer is not hindered and the required performance as the antifouling layer is satisfied. Usually, a compound having a hydrophobic group can be preferably used.
As specific examples, a perfluoroalkylsilane compound, a perfluoropolyethersilane compound, or a fluorine-containing silicone compound can be used. As the method for forming the antifouling layer, for example, a physical vapor deposition method such as vapor deposition or sputtering; a chemical vapor deposition method such as CVD; a wet coating method; The thickness of the antifouling layer is not particularly limited, but is usually preferably 20 nm or less, and more preferably 1 to 10 nm.

  In the polarizing plate of the present invention, the reflectance of the surface on which the resin film (A), the hard coat layer (B) and the antireflection layer (C) are sequentially laminated is usually 0.7% or less, preferably 0.5%. It is as follows. The reflectance can be obtained as a reflectance at a wavelength of 550 nm by measuring a reflection spectrum at a predetermined incident angle using a known spectrophotometer, for example.

  The surface on the antireflection layer (C) side of the polarizing plate of the present invention is excellent in scratch resistance. For example, even after a test (steel wool test) in which the surface of the antireflection layer (C) side of the polarizing plate is rubbed 10 times with a load of 0.025 MPa applied to steel wool, No scratches are observed on the film surface.

FIG. 2 shows an example of the panel configuration of the liquid crystal display device of the present invention. The liquid crystal display device is composed of the polarizing plate 1 of the present invention, which is arranged perpendicularly to the transmission axis (crossed Nicols) at the outermost portion with the liquid crystal cell sandwiched between the polarizing plate 22 and the cell 21 in which liquid crystal is sealed. The The light source is incident from the lower side of the figure, passes through the polarizing plate, the liquid crystal cell, and the upper polarizing plate arranged below, and the image is projected on the outermost part of the upper polarizing plate.
The polarizing plate of the present invention is installed on the viewing side of the liquid crystal cell with the antireflection layer (C) side facing the viewing side.

  The liquid crystal mode used in the liquid crystal cell includes an in-plane switching (IPS) mode, a vertical alignment (VA) mode, a multi-domain vertical alignment (MVA) mode, a continuous spin wheel alignment (CPA) mode, and a twisted nematic (TN) mode. , Super twisted nematic (STN) mode, hybrid alignment nematic (HAN) mode, and optically compensated bend (OCB) mode.

The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples. Parts and% are based on weight unless otherwise specified.
Evaluation in this example is performed by the following method.

(1) Depth and width of die line Using a three-dimensional structural analysis microscope (manufactured by Saigo Co., Ltd.), measurement was performed by observing interference fringes by scanning the uneven surface of the film from the bottom to the top at a constant speed.
As shown in FIG. 3, the base line 12 is drawn to the bottom 13 of the adjacent valley and the peak 14 of the mountain, and the line is drawn perpendicularly from the valley bottom 13 or the peak 14 to the baseline 12. Measure the distances between the intersections 15 and 16 and the baseline 12 to the intersections 17 and 18, and the die line depth is the sum of the distance from the peak to the baseline and the distance from the valley bottom to the baseline. .
The width of the die line is measured by measuring the distance to the valley 13 on the left side of the vertex 14 (distance between 17 and 18) and the distance to the next valley 19 on the right side of the vertex 14 (distance between 17 and 19). The total distance is defined as the width of the die line having the apex 14.

(2) Film thickness (average thickness and thickness variation)
A contact-type web thickness meter (RC-101 rotary caliper meter, manufactured by Meisho Co., Ltd.) is installed on a 1350 mm width resin film, and the thickness meter is moved sideways at intervals of 0.48 mm in the width direction of the resin film. taking measurement. The arithmetic average value (average thickness), maximum thickness, and minimum thickness of the measured values were obtained. The difference between the maximum thickness and the average thickness and the difference between the minimum thickness and the average thickness were compared, and the larger one was determined to determine what percentage of the average thickness, and this was regarded as the thickness variation.

(3) Moisture permeability The moisture permeability of the film was measured at a temperature of 40 ° C and a humidity of 90% using a cup method according to JIS Z0280.

(4) Using a retardation measuring device (manufactured by Oji Scientific Instruments, “KOBRA-21ADH”) for in-plane retardation (Re) while applying a load in the range of 50 to 150 g to the photoelastic coefficient resin film. The birefringence value Δn is obtained by dividing this by the thickness of the film. Δn was obtained while changing the load, and a load-Δn curve was created. The slope was taken as the photoelastic coefficient.

(5) Measurement of in-plane Re and thickness direction Rth (Re) in the film plane is set to nx (TD direction) and ny (MD direction) as the main refractive index in the film plane, and the thickness of the film is d ( nm), Re = (nx−ny) × d.
Also, (Rth) in the film thickness direction is defined as Rth = {ny, where the main refractive index in the film plane is nx, ny, the refractive index in the film thickness direction is nz, and the thickness of the film is d (nm). (Nx + ny) / 2−nz} × d.
The value was measured using an automatic birefringence meter [manufactured by Oji Scientific Instruments, KOBRA-21ADH].

(6) Polarizing plate pencil hardness It measured with the load of 500g according to JIS-K5700.

(7) Polarizing plate reflectance (%)
Using a spectrophotometer (manufactured by JASCO Corporation, UV-visible near-infrared spectrophotometer V-750), the reflection spectrum was measured at an incident angle of 5 degrees, and the reflectance at a wavelength of 550 nm was determined.

(8) Total light transmittance Measured in accordance with ASTM D1003 using a “turbidimeter NDH-300A” manufactured by Nippon Denshoku Industries Co., Ltd. In addition, the same measurement is performed 5 times and the arithmetic average value is set as a representative value of the total light transmittance.

(9) Polarizing plate steel wool test The surface of the antireflection layer of the polarizing plate was rubbed 10 times in a state where a load of 0.025 MPa was applied to steel wool # 0000, followed by microscopic observation and evaluation according to the following index.
○: No scratch △: Slight scratch ×: Many conspicuous scratches

(10) Durability test A polarizing plate (50 cm ² ) was placed in an oven at a temperature of 60 ° C. and a humidity of 90% and left for 300 hours, and changes in the polarizing plate were observed.
○: No change.
Δ: Sled at both ends.
X: Deformation, shrinkage, and winding occurred at both ends.

(11) Evaluation of display performance A liquid crystal display panel is removed from a commercially available liquid crystal television (a 20V liquid crystal television of MVA mode and a 20V liquid crystal television of IPS mode), and a polarizing plate and a viewing angle sandwiching the liquid crystal cell Of the compensation film, the polarizing plate and viewing angle compensation film installed on the viewing side are peeled off,
Instead, the polarizing plates obtained in Examples and Comparative Examples were bonded to the liquid crystal cell, and the liquid crystal display panel was reassembled and installed in the original liquid crystal television.
A white character is displayed with a black background, and the line of sight is moved up and down, left and right from the front, and the angle at which the white character cannot be read is measured.

(12) Frame failure (color unevenness) evaluation The liquid crystal display device produced in evaluation (11) was darkly displayed and left for 300 hours at a temperature of 60 ° C. and a humidity of 90%. Thereafter, the display was darkened in a dark room, the entire display screen was observed from the front, and evaluated according to the following indicators.
○: A uniform black display as a whole and no light leakage.
Δ: Color unevenness of dark display is seen on the top, bottom, left and right of the frame.
X: Light leakage is observed on the top, bottom, left and right of the frame.

(13) Bright spot defect evaluation The liquid crystal display device produced in the evaluation (11) is darkly displayed and left for 300 hours at a temperature of 60 ° C. and a humidity of 90%, and the entire display screen is observed from the front in a dark room. The number of points was counted.

(Preparation of hard coat agent)
Antimony pentoxide modified alcohol sol (solid content concentration 30%, manufactured by Catalyst Kasei Co., Ltd.), UV curable urethane acrylate purple light UV7000B (manufactured by Nippon Gosei Kagaku) and photoinitiator Irgacure-184 (Ciba Geigy) ) 0.4 part was mixed to obtain a UV curable hard coat agent.

(Preparation of coating solution for antireflection layer)
An oligomer of tetramethoxysilane (“Methyl silicate 51” manufactured by Colcoat Co.), methanol, water, and 0.01N hydrochloric acid aqueous solution were mixed at a mass ratio of 21: 36: 2: 2, and this was mixed in a high-temperature bath at 25 ° C. The mixture was stirred for 2 hours to adjust the weight average molecular weight to 850 to obtain a silicone resin.
Next, hollow silica isopropanol dispersion sol (manufactured by Catalyst Kasei Kogyo Co., Ltd., solid content 20%, average primary particle diameter of about 35 nm, outer shell thickness of about 8 nm) is added to the silicone resin as hollow silica fine particles, and hollow silica fine particles / silicone resin ( (Condensation compound equivalent) was blended so that the weight ratio was 8: 2 based on the solid content, and then diluted with methanol so that the total solid content was 1% to prepare a coating solution for the antireflection layer.

(Preparation of primer solution)
Hydrogenated maleic anhydride-modified styrene / butadiene / styrene block copolymer (Asahi Kasei Co., Ltd., Tuftec M1913, melt index value at 200 ° C. under 5 kg load, 1.0 g / 10 min, styrene block content 30 parts 2 parts of a hydrogenation rate of 80 parts or more and maleic anhydride addition amount 2%) are dissolved in a mixed solvent of 8 parts of xylene and 40 parts of methyl isobutyl ketone, and filtered through a polytetrafluoroethylene filter having a pore size of 1 μm. Only the complete solution was prepared as a primer solution.

(Production Example 1)
A triacetyl cellulose (TAC) film (manufactured by Konica Minolta, KC 4UX2M) having an average thickness of 40 μm was used as the resin film (A1). The resin film (A1) exhibits the following properties.
The moisture permeability was 300 g / m ² · 24 hr.
The maximum value of in-plane retardation was 2.1 nm.
The photoelastic modulus was 25 × 10 ⁻¹² Pa ⁻¹ .
Then, the hard coat agent is applied onto the resin film (A1) using a die coater, dried at 80 ° C. for 5 minutes, and then irradiated with ultraviolet rays (integrated light amount 300 mJ / cm ² ). It was cured and a hard coat layer having a thickness of 5 μm was laminated.
Further, an antireflection layer coating solution is applied to the hard coat layer side surface of the resin film, and the coating film is heat treated at 120 ° C. for 10 minutes to obtain a resin film (A2) having an antireflection layer having a thickness of 200 nm. It was.

(Production Example 2)
A resin film (D1) having a width of 1350 mm and an average thickness of 80 μm made of an alicyclic structure-containing polymer resin (ZEONOR 1420, manufactured by Nippon Zeon Co., Ltd .; glass transition temperature Tg 136 ° C.) produced by melt extrusion molding was used. The in-plane (Re) was 2.1 nm.
This resin film (D1) has the following properties.
When the die line was measured for the resin film according to the evaluation (1), the maximum depth of the die line was 25 nm and the minimum width was 1100 nm.
When the thickness variation was measured according to Evaluation (2), it was 1.6%.
The moisture permeability was 2.6 g / m ² · 24 hr.
The photoelastic modulus was 6.3 × 10 ⁻¹² Pa ⁻¹ .
Further, the resin film (D1) was stretched 1.3 times in a 140 ° C. atmosphere by a longitudinal stretching machine (a method of uniaxial stretching in the longitudinal direction using the difference in peripheral speed on the roll side), and an average thickness of 68 μm. In-plane (Re): 35 nm, and in the thickness direction (Rth): a resin film (D2) having a retardation of 130 nm was obtained.
This resin film (D2) has the following properties.
When the die line of the resin film was measured according to the evaluation (1), the maximum depth of the die line was 32 nm and the minimum width was 900 nm.
When the thickness variation was measured according to Evaluation (2), it was 2.1%.
The water vapor transmission rate was 2.8 g / m ² · 24 hr.
The photoelastic modulus was 7.5 × 10 ⁻¹² Pa ⁻¹ .

(Production Example 3)
A resin film (D3) having a width of 1350 mm and an average thickness of 80 μm made of an alicyclic structure-containing polymer resin (ZEONOR1420, manufactured by Nippon Zeon Co., Ltd .; glass transition temperature Tg 136 ° C.) produced by melt extrusion molding was used.
This resin film (D3) has the following properties.
When the film was measured according to the evaluation (1), the maximum depth of the die line was 180 nm and the minimum width was 450 nm.
When the thickness variation was measured according to Evaluation (2), it was 1.2%.
The moisture permeability was 2.2 g / m ² · 24 hr.
The photoelastic modulus is 6.5 × 10 ⁻¹² Pa ^−1.

Further, using the resin film (D3), the film was stretched 1.3 times in a 140 ° C. atmosphere by a longitudinal stretching machine (a method of uniaxial stretching in the longitudinal direction using the difference in peripheral speed on the roll side), and the average thickness A resin film (D4) having a thickness of 70 μm, Re: 32 nm, and Rth: 135 nm was obtained.
This resin film (D4) has the following properties.
When the film was measured according to the evaluation (1), the maximum depth of the die line was 160 nm and the minimum width was 300 nm.
When the thickness variation was measured according to the evaluation (2), it was 1.9%.
The water vapor transmission rate was 3.2 g / m ² · 24 hr.
The photoelastic modulus is 7.5 × 10 ⁻¹² Pa ^−1.

Production Example 4 PVA Polarizer A PVA film having a thickness of 85 μm (Kuraray Vinylon # 8500) is mounted on a chuck, stretched 2.5 times, and composed of 0.2 g / l iodine and 60 g / l potassium iodide. Immerse it in an aqueous solution at 30 ° C. for 240 seconds, then immerse it in an aqueous solution having a composition of boric acid 70 g / l and potassium iodide 30 g / l and simultaneously uniaxially stretch 6.0 times for 5 minutes. Acid treatment was performed. Finally, it was dried at room temperature for 24 hours to obtain a polarizer (E1) having an average thickness of 30 μm and a polarization degree of 99.993%.

Example 1
The polarizer (E1) is bonded to the resin film (A2) side of the resin film (A1) via a primer solution, and then the resin film (D2) is attached to the other surface of the polarizer (E1) as a primer. It bonded together through the solution and obtained the polarizing plate.
The evaluation results are shown in Tables 1 and 2.

(Comparative Example 1)
A polarizing plate was obtained in the same manner as in Example 1 except that the resin film (D2) was changed to the resin film (D4). The evaluation results are shown in Tables 1 and 2.

(Example 2)
A polarizing plate was obtained in the same manner as in Example 1 except that the resin film (D2) was changed to the resin film (D1). The evaluation results are shown in Tables 1 and 2.

(Comparative Example 2)
A 80 μm thick triacetyl cellulose (TAC) film (D5): (Konica Minolta, KC 8UX2M) was used as the resin film.
The resin film (D5) exhibited the following properties.
The moisture permeability was 640 g / m ² · 24 hr.
The maximum value of in-plane retardation (Re) was 3.6 nm.
The photoelastic modulus was 22 × 10 ⁻¹² Pa ⁻¹ .
A polarizing plate was obtained in the same manner as in Example 1 except that the resin film (D2) was changed to the resin film (D5). The evaluation results are shown in Tables 1 and 2.

From the results in Table 1, the following can be understood.
As shown in the examples, the polarizing plate of the present invention uses a TAC film in which a hard coat layer and an antireflection layer are laminated on one surface of a polarizer, and an alicyclic structure-containing polymer resin on the other surface. It is configured using.
It can be seen that a polarizing plate excellent in all of transparency, mechanical strength, antireflection performance, scratch resistance and adhesion can be formed. Further, in a durability test (a test placed in an environment of standing at a temperature of 60 ° C. and a humidity of 90% for 300 hours), the retardation plate is free from warpage, retardation unevenness, color unevenness, and bright spot defect of a polarizing plate. It is obvious.
As shown in Table 2, when a liquid crystal display device was produced and the viewing angle was measured in accordance with various liquid crystal modes, it was found that the viewing angle characteristics of the retardation plate of the present invention were improved. Moreover, in the comparative example, the viewing angle was measured, but it was also confirmed that the brightness was lowered in addition to the viewing angle reduction as a whole.

It is a figure explaining the polarizing plate of this invention. It is a figure explaining the panel structure of a liquid crystal display device. It is a figure for demonstrating a die line.

Explanation of symbols

1 Polarizing plate 2 Resin film (D)
3 Polarizer 4 Resin film (A).
5 Hard coat layer (B)
6 Antireflection layer (C)
21 Liquid crystal cell 22 Polarizing plate
12-19 Codes describing the die line

Claims (6)

On one surface of the polarizer, a resin film (A) having a thickness of 5 to 200 μm, a moisture permeability of 50 to 1500 g / m ² · 24 hr, and a maximum in-plane retardation of 4 nm or less, a hard coat layer (B ) And an antireflection layer (C) are sequentially laminated,
The other surface of the polarizer is made of an alicyclic structure-containing resin, has a thickness of 5 to 200 μm, a moisture permeability of 0.3 to 40 g / m ² · 24 hr, and a photoelastic coefficient of 12.0 × 10 ⁻¹² Pa. ^A polarizing plate formed by laminating a resin film (D) having a maximum of ⁻¹ or less and a maximum depth of 50 nm or less and a minimum width of 500 nm or more.   The polarizing plate according to claim 1, wherein the film (A) contains a cellulose ester as a main component.   The polarizing plate according to claim 1 or 2, wherein the antireflection layer (C) has a refractive index of 1.36 or less.   The polarizing plate according to claim 1, wherein the antireflection layer (C) is made of airgel.  The polarizing plate according to claim 1, wherein the resin film (D) is a film showing retardation. A liquid crystal display device in which the polarizing plate according to claim 1 is installed with the antireflection layer (C) side facing the viewing side.

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