JP2002116323A - Protective film for polarizing plate, polarizing plate and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective film for a polarizing plate having excellent antireflection performance and antidazzle property and causing no change in these performances by saponification treatment, to provide a polarizing plate subjected to the antireflection treatment and antidazzle treatment, and to provide a liquid crystal display device. SOLUTION: The protective film for a polarizing plate having an outermost layer essentially comprising a fluorine-containing compound on a transparent supporting body is obtained by forming the outermost layer on the transparent substrate and then subjecting the film to the saponification treatment. The polarizing plate or the liquid crystal display device uses the film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a protective film for a polarizing plate, a polarizing plate, and a liquid crystal display using the same.

[0002]

2. Description of the Related Art Anti-reflection films and anti-glare films are used in various image display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), and a cathode ray tube display (CRT). In order to prevent a decrease in contrast due to reflection of external light and reflection of an image, the display device is disposed on the surface of the display. In particular, as the size of a liquid crystal display device (LCD) increases, the number of liquid crystal display devices provided with an antireflection film or an antiglare film has increased.
A polarizing plate is an indispensable optical material in a liquid crystal display (LCD). Generally, a polarizing plate has a structure in which a deflection film is protected by two protective films. By providing these protective films with an anti-reflection function and an anti-glare function, it is possible to significantly reduce costs and make display devices thinner. On the other hand, the protective film used for the polarizing plate needs to have sufficient adhesiveness for bonding to the polarizing film. As a technique for improving the adhesion to the deflection film, it is common practice to saponify the protective film to make the surface of the protective film hydrophilic. By performing the saponification treatment after forming the antireflection layer or the antiglare layer on the protective film, the cost can be further reduced. In the saponification treatment, an alkaline solution hydrolyzes the vicinity of the surface of the protective film.
When a saponification treatment is applied to a protective film provided with antireflection performance or antiglare performance, the adhesion of a layer formed on the protection film is deteriorated, or the antireflection performance or antiglare performance is changed.

[0003]

An object of the present invention is to provide inexpensive and large quantities of protective films for polarizing plates having excellent antireflection performance and antiglare performance. Another object of the present invention is to provide a protective film for a polarizing plate in which the antireflection performance and the antiglare performance do not change by saponification treatment. Still another object of the present invention is to provide a polarizing plate and a liquid crystal display device which have been subjected to antireflection treatment and antiglare treatment by appropriate means.

[0004]

SUMMARY OF THE INVENTION The above objects of the present invention are as follows.
This has been achieved by a polarizing plate protective film, a polarizing plate, and a liquid crystal display device having the following configurations. (1) In a protective film for a polarizing plate having an outermost layer mainly composed of a fluorine-containing compound on a transparent support, the protective film is obtained by forming the outermost layer on the transparent support, followed by saponification treatment. Protective film for a polarizing plate. (2) The protective film for a polarizing plate according to (1), wherein the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. (3) a polymer layer adjacent to the outermost layer, wherein the polymer layer is a crosslinking reaction of the ionizing radiation-curable resin composition, or
The protective film for a polarizing plate according to (1) or (2), which is formed by a polymerization reaction. (4) A photopolymerization initiator is used as an initiator in a crosslinking reaction or a polymerization reaction of the ionizing radiation-curable resin composition forming the polymer layer (1) to (1).
The protective film for a polarizing plate according to any one of (3). (5) The protective film for a polarizing plate according to any one of claims 1 to 4, wherein a photo-radical polymerization initiator is used as the initiator. (6) A photo-cleavable photo-radical polymerization initiator is used as the photo-radical polymerization initiator.
The protective film for a polarizing plate according to any one of (5). (7) The polymer layer has an average primary particle size of 0.3 μm.
(1)-characterized by containing the following fine particles:
The protective film for a polarizing plate according to any one of (6). (8) The protective film for a polarizing plate according to any one of (1) to (7), wherein the refractive index of the polymer layer is higher than the refractive index of the transparent support. (9) The protective film for a polarizing plate according to any one of (1) to (8), further including a hard coat layer between the transparent support and the polymer layer. (10) The refractive index between the transparent support and the outermost layer is 1.
The protective film for a polarizing plate according to any one of (1) to (9), having a layer containing particles having a particle size of 40 to 1.80 and an average particle size of 0.5 to 6 μm. (11) Any one of (1) to (10), wherein the particles having a refractive index of 1.40 to 1.80 and an average particle size of 0.5 to 6.0 μm are resin particles. 4. The protective film for a polarizing plate according to any one of the above. (12) Particles having a refractive index of 1.40 to 1.80 and an average particle diameter of 0.5 to 6 μm are contained in the polymer layer and / or the hard coat layer ( 1) ~
The protective film for a polarizing plate according to any one of (11). (13) The fluorine-containing compound of the outermost layer is a fluorine-containing polymer, and the fluorine-containing polymer is a fluorine-containing polymer formed by a crosslinking reaction or a polymerization reaction simultaneously with or after the coating. The protective film for a polarizing plate according to any one of (1) to (12). (14) The polymer layer adjacent to the outermost layer has an oxygen concentration of 1
The protective film for a polarizing plate according to any one of (3) to (13), which is formed in an atmosphere of 5% by volume or less. (15) The protective film for a polarizing plate according to (14), wherein the atmosphere having an oxygen concentration of 15% by volume or less is realized by nitrogen purging. (16) The protective film for a polarizing plate according to (14) or (15), wherein the atmosphere has an oxygen concentration of 6% by volume or less. (17) The transparent support is a transparent support formed from triacetyl cellulose (1) to (1).
The protective film for a polarizing plate according to any one of (16). (18) The coefficient of dynamic friction of the surface having the outermost layer is 0.
The protective film for a polarizing plate according to any one of (1) to (17), wherein the protective film is 25 or less. (19) The surface having the outermost layer has a contact angle with water of 90 ° or more (1) to (18).
The protective film for a polarizing plate according to any one of the above. (20) The transparent support is a triacetylcellulose film, and a triacetylcellulose dope prepared by dissolving triacetylcellulose in a solvent is cast in a single layer, co-cast in multiple layers, or sequentially cast in multiple layers. The protective film for a polarizing plate as described in any one of (1) to (19), which is produced by casting by any one of the casting methods described in (1) to (9). (21) The triacetyl cellulose dope is characterized by being prepared by dissolving triacetyl cellulose in a solvent substantially free of dichloromethane by a cooling dissolution method or a high temperature dissolution method. The protective film for a polarizing plate according to (20). (22) A polarizing plate, comprising the polarizing plate protective film according to any one of (1) to (21) on at least one of the protective films of the polarizing film. (23) A liquid crystal display device comprising the polarizing plate according to (22) disposed on a liquid crystal display surface.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION [Transparent Support] A synthetic resin film is used for a transparent support used for a protective film for a polarizing plate. Examples of the material of the synthetic resin film include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose), polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate, poly-1). , 4-cyclohexane dimethylene terephthalate, polyethylene-
1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone , Polyarylates, polyetherimides, polymethyl methacrylates and polyether ketones. Triacetyl cellulose, polycarbonate, polyethylene terephthalate and polyethylene naphthalate are preferably used, and particularly preferred is triacetyl cellulose.

As the transparent support of the present invention, triacetylcellulose dope prepared by dissolving triacetylcellulose in a solvent may be any one of a single-layer cast, a multi-layer co-cast or a multi-layer sequential cast. It is further preferable to use a triacetyl cellulose film produced by casting by a casting method. In particular, from the viewpoint of environmental conservation, a triacetyl cellulose film prepared using a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent substantially free of dichloromethane by a cooling dissolution method or a high temperature dissolution method. Is preferred.

The monolayer casting of triacetyl cellulose includes drum casting or band casting disclosed in Japanese Patent Application Laid-Open No. Hei 7-11055, and the latter, triacetyl comprising a plurality of layers. The co-casting of cellulose is
Published Japanese Patent Application Laid-Open Nos. 61-94725 and 62-1987
43846 and the like. Sequential casting is performed by repeating single layer casting. In each casting, the raw material flakes are prepared by converting halogenated hydrocarbons (eg, dichloromethane, alcohols (eg, methanol, ethanol, butanol, etc.), esters (eg, methyl formate, methyl acetate, etc.), and ethers (eg, dioxane, dioxolan, diethyl ether, etc.). )) And dissolved in a solvent such as
A solution (referred to as a dope) to which various additives such as an ultraviolet absorber, a deterioration inhibitor, a slipping agent, and a peeling accelerator are added is placed on a support made of a horizontal endless metal belt or a rotating drum. When casting by a dope supply means (referred to as a die), a single dope is cast into a single layer if it is a single layer,
If it is a plurality of layers, co-cast a low-concentration dope on both sides of a high-concentration cellulose ester dope, peel off the rigidity-imparted film dried to some extent on the support, and then by various transport means This is a method comprising removing the solvent by passing through a drying section.

As a solvent for dissolving triacetyl cellulose as described above, dichloromethane is typical. However, technically, halogenated hydrocarbons such as dichloromethane can be used without any problem.However, when a triacetylcellulose dope prepared by dissolving in a solvent substantially containing dichloromethane is produced by a single-layer casting method. , Since dichloromethane is released into the atmosphere during the manufacturing process,
It is preferable that halogenated hydrocarbons such as dichloromethane are not substantially contained. “Substantially free” means that the proportion of halogenated hydrocarbon in the organic solvent is less than 5% by weight, preferably less than 2% by weight. In the case of the co-casting method, even if a dope using a solvent substantially containing dichloromethane is cast by a multi-layer co-casting method, the dope having a higher triacetyl cellulose concentration than the outer casting layer is used. Can be used for the inner casting layer, thereby reducing the amount of dichloromethane released into the atmosphere. Further, the casting speed can be increased, and the productivity is excellent. Of course, even in the case of the co-casting method, it is preferable that halogenated hydrocarbons such as dichloromethane are not substantially contained.

When a dope of triacetylcellulose is prepared using a solvent substantially free of dichloromethane or the like, a special dissolution method as described later is indispensable.

The first melting method is called a cooling melting method, and will be described below. First, the temperature around room temperature (-10 to 40 ° C)
And gradually add triacetyl cellulose to the solvent with stirring. Next, the mixture is -100 to -10C (preferably -80 to -10C, more preferably -50 to-
(20 ° C., most preferably −50 to −30 ° C.). Cooling is performed, for example, in a dry ice / methanol bath (−
75 ° C) or a cooled diethylene glycol solution (-30
-20 ° C). When cooled in this way,
The mixture of triacetyl cellulose and solvent solidifies. Furthermore, this is 0-200 ° C (preferably 0-150 ° C,
More preferably 0-120 ° C, most preferably 0-5.
(0 ° C.), the solution becomes a solution in which triacetyl cellulose flows in the solvent. The temperature may be raised only at room temperature or may be heated in a warm bath.

The second method is called a high-temperature melting method and will be described below. First, triacetyl cellulose is gradually added to a solvent at a temperature near room temperature (-10 to 40 ° C.) with stirring. Triacetyl cellulose solution of the present invention,
It is preferable to add triacetyl cellulose to a mixed solvent containing various solvents and to swell in advance. In this method, the dissolution concentration of triacetyl cellulose is preferably 30% by weight or less, but from the viewpoint of drying efficiency during film formation,
Preferably, the concentration is as high as possible. Next, the organic solvent mixed solution is 70 to 2 under a pressure of 0.2 MPa to 30 MPa.
Heated to 40 ° C (preferably 80-220 ° C, more preferably 100-200 ° C, most preferably 100-1
90 ° C). Next, since these heated solutions cannot be applied as they are, they need to be cooled to the lowest boiling point or lower of the solvent used. In that case, it is common to cool to −10 to 50 ° C. and return to normal pressure. For cooling, the high-pressure high-temperature vessel or line in which the triacetylcellulose solution is incorporated may be simply left at room temperature, and more preferably the apparatus may be cooled using a coolant such as cooling water. The thickness of the transparent support is preferably 1 to 300 μm, and more preferably 30 to 300 μm.
It is 150 μm, particularly preferably 50 to 120 μm.

[Outermost Layer] The protective film for a polarizing plate of the present invention has an outermost layer mainly composed of a fluorine-containing compound. The outermost layer mainly composed of a fluorine-containing compound is used as a low refractive index layer of a protective film for a polarizing plate, or as an antifouling layer covering the low refractive index layer. The refractive index of the fluorine-containing compound is 1.35-1.
Preferably it is 50. More preferably 1.36 to
1.47, and more preferably 1.38 to 1.45. Further, the fluorine-containing compound preferably contains fluorine atoms in a range of 35 to 80% by mass, more preferably 45 to 75% by mass. Examples of the fluorinated compound include a fluorinated polymer, a fluorinated silane compound, a fluorinated surfactant, and a fluorinated ether. Examples of the fluorine-containing polymer include those synthesized by a crosslinking reaction or a polymerization reaction of an ethylenically unsaturated monomer containing a fluorine atom. Examples of the ethylenically unsaturated monomer containing a fluorine atom include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole), Includes esters of fluorinated vinyl ethers and fluorinated alcohols with acrylic acid or methacrylic acid. As the fluorine-containing polymer, a copolymer comprising a repeating unit containing a fluorine atom and a repeating structural unit containing no fluorine atom can also be used. The copolymer can be obtained by a polymerization reaction between an ethylenically unsaturated monomer containing a fluorine atom and an ethylenically unsaturated monomer containing no fluorine atom. Examples of the ethylenically unsaturated monomer containing no fluorine atom include olefins (eg, ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylates (eg, methyl acrylate, ethyl acrylate, acrylic acid-2-) Ethyl hexyl), methacrylic acid esters (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene and its derivatives (eg,
Styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ether (eg, methyl vinyl ether, etc.), vinyl ester (eg, vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamide (eg, N-tert- Butylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamide and acrylonitrile.

Examples of the fluorine-containing silane compound include silane compounds containing a perfluoroalkyl group (eg, (heptadecafluoro-1,2,2,2-tetradecyl) triethoxysilane and the like). The hydrophilic portion of the fluorinated surfactant may be any of anionic, cationic, nonionic and amphoteric. Then, part or all of the hydrogen atoms of the hydrocarbon constituting the hydrophobic portion are replaced by fluorine atoms.

Fluorinated ethers are compounds generally used as lubricants. Examples of the fluorinated ether include perfluoropolyether. For the outermost layer, it is particularly preferable to use a fluoropolymer into which a crosslinked structure has been introduced. The fluoropolymer into which a crosslinked structure has been introduced can be obtained by crosslinking a fluoropolymer having a crosslinkable group. The fluoropolymer having a crosslinkable group can be obtained by introducing a crosslinkable group as a side chain into a fluoropolymer having no crosslinkable group. The crosslinkable group is preferably a functional group that reacts upon irradiation with light, preferably ultraviolet light, electron beam (EB) or heating, so that the fluoropolymer has a crosslinked structure. As the crosslinkable group, acryloyl,
Examples include groups such as methacryloyl, isocyanate, epoxy, aziridine, oxazoline, aldehyde, carbonyl, hydrazine, carboxyl, methylol and active methylene. As the fluorine-containing polymer having a crosslinkable group, a commercially available product may be used. The cross-linking reaction of the fluorine-containing polymer having a cross-linkable group is preferably carried out by applying a coating solution for forming the outermost layer simultaneously with or after application of light, irradiation with an electron beam, or heating.

The outermost layer may contain a filler (for example, inorganic fine particles or organic fine particles), a slipping agent (for example, a silicon compound such as dimethyl silicon), a surfactant, and the like, in addition to the fluorine-containing compound. In the present invention, "mainly containing a fluorine-containing compound" means that the fluorine-containing compound occupies 50 or more, preferably 70 or more, in the outermost layer. The outermost layer is a fluorinated compound or a coating solution in which an optional component contained as desired is dissolved or dispersed simultaneously with the application, or after application, light irradiation, electron beam irradiation or heating, a crosslinking reaction, or polymerization. It is preferably formed by a reaction. When the outermost layer is used as a low refractive index layer, the thickness is preferably 30 to 200 nm, more preferably 50 to 150 nm, and particularly preferably 60 to 120 nm. When the outermost layer is used as an antifouling layer, the thickness is preferably 3 to 50 nm, more preferably 5 to 35 nm, and particularly preferably 7 to 25 nm. In order to improve the physical strength (such as reliability) of the protective film for a polarizing plate, the coefficient of kinetic friction on the surface having the outermost layer is preferably 0.25 or less. The dynamic friction coefficient described here is 0.98 N for a stainless steel hard sphere having a diameter of 5 mm.
And the dynamic friction coefficient between the surface having the outermost layer and the stainless steel hard sphere having a diameter of 5 mm when the surface having the outermost layer is moved at a speed of 60 cm / min. It is preferably 0.17 or less, particularly preferably 0.15.
It is as follows. Further, in order to improve the antifouling performance of the protective film for a polarizing plate, the contact angle with water on the side having the outermost layer is preferably 90 ° or more. More preferably 9
It is at least 5 °, particularly preferably at least 100 °.
It is desirable that the contact angle with water does not change before and after the saponification treatment, and the amount of change is within 10 °, particularly preferably within 5 °.

[Saponification Treatment] The protective film for a polarizing plate of the present invention is obtained by forming an outermost layer mainly composed of a fluorine-containing compound on a transparent support and then performing a saponification treatment. The saponification treatment is performed by a known method, for example, by immersing the film in an alkaline solution for an appropriate time. After immersion in an alkaline solution, it is preferable to sufficiently wash with water or immerse in a dilute acid to neutralize the alkali component so that the alkali component does not remain in the protective film for a polarizing plate. By performing the saponification treatment, the surface of the transparent support opposite to the side having the outermost layer is hydrophilized. The polarizing plate protective film is used by adhering the surface of the transparent support opposite to the side having the outermost layer to the polarizing film. The hydrophilized surface is particularly effective for improving the adhesion to a deflection film containing polyvinyl alcohol as a main component. In addition, since the hydrophilic surface makes it difficult for dust in the air to adhere thereto, dust is less likely to enter between the deflecting film and the polarizing plate protective film when bonding to the deflecting film, thereby preventing point defects due to dust. It is effective for The saponification treatment is preferably performed such that the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. It is more preferably at most 30 °, particularly preferably at most 20 °.

[Polymer Layer] The polymer layer is formed on the layer adjacent to the outermost layer of the present invention (that is, the lower layer in contact with the outermost layer). The polymer layer is formed by a crosslinking reaction or a polymerization reaction of the ionizing radiation-curable resin composition. For example, it can be formed by applying a coating solution containing an ionizing radiation-curable polyfunctional monomer or oligomer on a transparent support and subjecting the polyfunctional monomer or oligomer to a crosslinking reaction or a polymerization reaction. . The functional group of the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer is preferably a light-, electron-beam, or radiation-polymerizable functional group, and particularly preferably a photopolymerizable functional group. As the photopolymerizable functional group, an acryloyloxy group, a methacryloyloxy group,
Examples thereof include unsaturated polymerizable functional groups such as a vinyl group, a styryl group, and an allyl group. Among them, an acryloyloxy group is preferable.

Specific examples of the photopolymerizable polyfunctional monomer having a photopolymerizable functional group include alkylene glycols such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, and propylene glycol di (meth) acrylate. (Meth) acrylic acid diesters; triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate,
(Meth) acrylic acid diesters of polyoxyalkylene glycol such as polyethylene glycol di (meth) acrylate and polypropylene glycol di (meth) acrylate; (meth) acrylic acid diesters of polyhydric alcohol such as pentaerythritol di (meth) acrylate ; 2,2-bis @ 4- (acryloxydiethoxy)
(Meth) of ethylene oxide or propylene oxide adducts such as phenyl} propane and 2-2bis {4- (acryloxypolypropoxy) phenyl} propane
Acrylic acid diesters; and the like. Further, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

Of these, esters of polyhydric alcohol and (meth) acrylic acid are preferred. More preferably, 1
Polyfunctional monomers having three or more (meth) acryloyloxy groups in the molecule are preferred. Specifically, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, pentaerythritol tetra (meth) acrylate, penta Erythritol tri (meth) acrylate, (di) pentaerythritol triacrylate, (di) pentaerythritol pentaacrylate, (di) pentaerythritol tetra (meth) acrylate, (di) pentaerythritol hexa (meth) acrylate, tripentaerythritol triacrylate And tripentaerythritol hexatriacrylate.

Two or more polyfunctional monomers may be used in combination. It is preferable to use a photopolymerization initiator for the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator, a photoradical polymerization initiator and a photocationic polymerization initiator are preferable, and a photoradical polymerization initiator is particularly preferable. Examples of the photoradical polymerization initiator include acetophenones, benzophenones, Michler's benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, and thioxanthone. Commercially available photoradical polymerization initiators include Nippon Kayaku Co., Ltd. KAYACURE (DETX-S, BP-100, BDMK, CT
X, BMS, 2-EAQ, ABQ, CPTX, EPD, ITX, QTX, BTC, MCA
Irgacure (6) manufactured by Ciba-Geigy Japan
51,184,500,907,369,1173,2
959, 4265, 4263), manufactured by Sartomer
Esacure (KIP100F, KB1, EB3, BP, X33, KT046, KT37,
KIP150, TZT) and the like. Particularly, a photo-cleavable photo-radical polymerization initiator is preferable. For photo-cleavable photo-radical polymerization initiators, see the latest UV curing technology (P.159, Publisher: Kazuhiro Takasu, Publishing Office; Technical Information Association, 1991)
Irradiation (651, 184, 907) manufactured by Ciba-Geigy Japan Co., Ltd., etc., can be used as a commercially available photo-cleavable photo-radical polymerization initiator described in US Pat.
The photopolymerization initiator is preferably used in an amount of 0.1 to 15 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the polyfunctional monomer. A photosensitizer may be used in addition to the photopolymerization initiator. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone, and thioxanthone. As commercially available photosensitizers, Nippon Kayaku Co., Ltd.'s KAYACURE (DMBI, EP
A) and the like. The photopolymerization reaction is preferably performed by ultraviolet irradiation after application and drying of the polymer layer.

The polymer layer has an average primary particle size of 0.1.
It is preferable to contain fine particles of 3 μm or less. The average particle diameter here is a weight average diameter. By setting the average particle size of the primary particles to 0.3 μm or less, a polymer layer that does not impair transparency can be formed. Examples of the fine particles include inorganic fine particles and organic fine particles. The fine particles have a function of increasing the hardness of the polymer layer and suppressing curing shrinkage of the polymer layer. It is also added for the purpose of controlling the refractive index of the polymer layer. Specific examples of the inorganic fine particles include fine particles of silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, tin oxide, ITO, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate. Preferably, silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, tin oxide, I
TO and zinc oxide. Specific examples of the organic fine particles include
Methacrylic acid-methyl acrylate copolymer, silicone resin, polystyrene, polycarbonate, acrylic acid-styrene copolymer, benzoguanamine resin, melamine resin, polyolefin, polyester, polyamide,
Fine particles such as polyimide and polyfluoroethylene are exemplified. When used for the purpose of increasing the hardness of the polymer layer or controlling the refractive index, inorganic fine particles are preferred. The preferred average particle diameter of the primary particles of the fine particles is 0.005 to 0.2 μm, more preferably 0.01 to 0.2 μm.
0.15 μm, more preferably 0.02 to 0.2 μm.
It is 10 μm, particularly preferably 0.02 to 0.05 μm. In the polymer layer, the fine particles need not necessarily be finely dispersed until they become primary particles, but are preferably dispersed as finely as possible. The dispersed particle size of the fine particles in the polymer layer is preferably 0.005 to 0.30 μm, more preferably 0.01 to 0.20 μm, more preferably 0.1 to 0.20 μm in average particle diameter.
02 to 0.15 μm, particularly preferably 0.03 to 0.0
8 μm. The content of the fine particles in the polymer layer is
It is preferably from 1 to 65% by volume, more preferably from 3 to 55% by volume, particularly preferably from 5 to 50% by volume, based on the volume of the polymer layer. When producing a protective film for a polarizing plate having better antireflection performance, the refractive index of the polymer layer is preferably higher than the refractive index of the transparent support. The polymer layer having a high refractive index includes an ionizing radiation-curable resin composition containing an aromatic ring, an ionizing radiation-curable resin composition containing a halogen element other than fluorine (eg, Br, I, Cl, etc.), S, N , P, etc. can be formed by a cross-linking reaction or a polymerization reaction of an ionizing radiation-curable resin composition containing atoms. Further, it can also be formed by finely dispersing inorganic fine particles having a high refractive index and including them in the polymer layer. More preferably, inorganic fine particles having a high refractive index are finely dispersed and contained in the polymer layer. Examples of the inorganic fine particles having a high refractive index include titanium dioxide, zirconium oxide, tin oxide, ITO, and zinc oxide. Preferred inorganic fine particles are titanium dioxide, zirconium oxide, and tin oxide. In order to produce a protective film for a polarizing plate having excellent antireflection performance, the refractive index of the polymer layer is preferably from 1.55 to 2.40, more preferably from 1.60 to 2.10, and particularly preferably. Is 1.6
0 to 2.00.

The haze of the polymer layer is preferably at most 5%, more preferably at most 3%, particularly preferably at most 1%. The haze value can be set in this range by dispersing the fine particles having a size of 0.3 μm or less of the present invention more finely in the polymer layer. In the polymer layer, in addition to the above-described components (fine particles, polymerization initiator, photosensitizer, and the like), particles, resin,
Dispersing agents, surfactants, antistatic agents, silane coupling agents, thickeners, coloring inhibitors, coloring agents (pigments, dyes), defoamers, leveling agents, flame retardants, ultraviolet absorbers, adhesion promoters, A polymerization inhibitor, an antioxidant, a surface modifier, and the like can be added. The thickness of the polymer layer can be appropriately designed depending on the application. When designed to have a function as a hard coat layer, it is preferably 0.2 to 10 μm, more preferably 0.5 to 7 μm,
Particularly preferably, it is 0.7 to 5 μm. In order to design to have a function as an optical interference layer (high-refractive-index layer, medium-refractive-index layer, low-refractive-index layer, etc. described later), 0.01 to 0.01%
It is preferably 0.3 μm, more preferably 0.1 μm.
03-0.2 μm, particularly preferably 0.04-0.15
μm. The strength of the polymer layer is determined according to JIS K5400.
In a pencil hardness test according to, preferably H or more,
It is more preferably at least 2H, most preferably at least 3H. In the formation of the polymer layer, the crosslinking reaction or the polymerization reaction of the ionizing radiation-curable resin composition is preferably performed in an atmosphere having an oxygen concentration of 15% by volume or less. By forming the polymer layer in an atmosphere having an oxygen concentration of 15% by volume or less, the adhesiveness between the polymer layer and the outermost layer can be improved. It is preferably formed by a crosslinking reaction or a polymerization reaction of the ionizing radiation-curable resin composition in an atmosphere having an oxygen concentration of 6% by volume or less, more preferably an oxygen concentration of 3% by volume or less, and particularly preferably an oxygen concentration. Is 2% by volume or less. Oxygen concentration 15
As a method of reducing the volume% or less, air (nitrogen concentration of about 79%) is used.
(% By volume, oxygen concentration: about 21% by volume) is preferably replaced by another gas, particularly preferably by nitrogen (nitrogen purging).

[Hard Coat Layer] The hard coat layer is preferably provided on the surface of a transparent support in order to impart physical strength (such as scratch resistance) to the protective film for a polarizing plate and the polarizing plate. The hard coat layer preferably contains a polymer having a crosslinked structure. The hard coat layer containing a polymer having a cross-linked structure can be formed by applying a coating solution containing a polyfunctional monomer and a polymerization initiator on a transparent support, and subjecting the polyfunctional monomer to a cross-linking reaction or a polymerization reaction. it can. As the functional group of the polyfunctional monomer,
Photopolymerizable, ionizing radiation polymerizable such as electron beam and radiation, and thermal polymerizable are preferable, and a photopolymerizable functional group is particularly preferable. Examples of the photopolymerizable functional group include an acryloyloxy group, a methacryloyloxy group, a vinyl group, a styryl group, and an unsaturated polymerizable functional group such as an allyl group.
Among them, an acryloyloxy group is preferable.

As specific examples of the photopolymerizable polyfunctional monomer, those exemplified in the polymer layer of the present invention can be preferably used. Two or more polyfunctional monomers may be used in combination. It is preferable to use a photopolymerization initiator or a photosensitizer for the crosslinking reaction or the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator and the photosensitizer, those exemplified in the polymer layer of the present invention can be preferably used. The photopolymerization initiator is preferably used in an amount of 0.1 to 15 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the polyfunctional monomer. The photopolymerization reaction is preferably performed by ultraviolet irradiation after application and drying of the hard coat layer.

The hard coat layer preferably contains fine particles having an average primary particle diameter of 0.3 μm or less. The fine particles increase the hardness of the hard coat layer,
It has the function of suppressing hardening shrinkage of the hard coat layer. Also,
It is also added for the purpose of controlling the refractive index of the hard coat layer. As the fine particles having an average primary particle size of 0.3 μm or less, those exemplified in the polymer layer of the present invention can be preferably used. Further, it is preferable that the particles are finely dispersed in the hard coat layer so as not to impair the transparency.

The hard coat layer or its coating solution includes
Further, a coloring agent (pigment, dye), an antifoaming agent, a thickener, a leveling agent, a flame retardant, an ultraviolet absorber, an antioxidant, and a modifying resin may be added. The thickness of the hard coat layer is 1 to 1
Preferably it is 5 μm. It is also preferable to form two or more hard coat layers on the transparent support. When the outermost layer of the present invention is formed on the hard coat layer, the hard coat layer can also serve as the above-mentioned polymer layer. The hard coat layer is preferably formed between the transparent support and the above-mentioned polymer layer. The strength of the hard coat layer is
In a pencil hardness test according to JIS K5400, the hardness is preferably H or more, more preferably 2H or more, and most preferably 3H or more.

[Particles having an average particle size of 0.5 to 6.0 μm] In the protective film for a polarizing plate, a layer formed on a transparent support is provided with a refractive index of 1.40 to 6.0 in order to impart an antiglare function. 1.8
0 means that particles having an average particle size of 0.5 to 6.0 μm can be contained. The average particle diameter here is the weight average diameter of the secondary particles (primary particles when the particles are not aggregated). By including the particles, irregularities that scatter light are formed on the surface of the outermost layer of the protective film for a polarizing plate, thereby exhibiting antiglare properties. The particles include inorganic particles and organic particles. Specific examples of the inorganic particles include particles of silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, tin oxide, ITO, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate. Silicon dioxide and aluminum oxide are preferred. As the organic particles, resin particles are preferable. Specific examples of the resin particles include particles made of a silicone resin, a melamine resin, a benzoguanamine resin, a polymethyl methacrylate resin, a polystyrene resin, and a polyvinylidene fluoride resin. Preferably, melamine resin, benzoguanamine resin, polymethyl methacrylate resin,
Particles made of a polystyrene resin, particularly preferably particles made of a benzoguanamine resin or a polystyrene resin. The particles used for imparting the antiglare function to the protective film for a polarizing plate are preferably resin particles. The average particle size of the particles is preferably 1.0
To 5.0 μm, more preferably 1.5 to 4.0 μm, and particularly preferably 1.7 to 3.5 μm. The narrower the particle size distribution of the particles, the better. The refractive index of the particles is 1.50-1.
It is preferably 75, and more preferably 1.55 to 1.70. Further, it is preferable to use particles having a refractive index closer to the refractive index of the layer containing the particles. Particles having a refractive index difference of preferably 0.1 or less, more preferably 0.05 or less, particularly preferably 0.03 or less with respect to the refractive index of the layer containing the particles. It is. A plurality of particles having different average particle sizes may be used in combination. It is also preferable to use a plurality of particles of different materials in combination. The particles can be added to a layer formed on a transparent support to form an antiglare layer. It is particularly preferable to add an antiglare function to the above-mentioned polymer layer and hard coat layer. The haze of the antiglare layer is preferably 3 to 30%,
It is more preferably 20%, most preferably 7 to 20%.

[Configuration of Protective Film for Polarizing Plate] An example of the configuration of the protective film for polarizing plate of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a layer configuration of a protective film for a polarizing plate having an antireflection function or an antiglare function. The embodiment shown in FIG. 1A has a layer structure in the order of a transparent support 1 and a low refractive index layer 2 as an outermost layer. FIG.
The embodiment shown in (b) has a layer structure of a transparent support 1, a hard coat layer 3 as a polymer layer, and a low refractive index layer 2 as an outermost layer. The embodiment shown in FIG. 1C has a layer structure of a transparent support 1, an antiglare layer 4 as a polymer layer, and a low refractive index layer 2 as an outermost layer. Particles 5 contained in the antiglare layer have a refractive index of 1.40 to 1.80 of the present invention.
Are particles having an average particle size of 0.5 to 6 μm. FIG.
The embodiment shown in (d) has a layer structure of a transparent support 1, a hard coat layer 3, an antiglare layer 4 as a polymer layer, and a low refractive index layer 2 as an outermost layer. The particles 5 contained in the anti-glare layer 4 are particles having a refractive index of 1.40 to 1.80 and an average particle size of 0.5 to 6 μm according to the present invention. FIG. 1 (a)-
In the embodiment shown in (d), the transparent support 1 and the low refractive index layer 2 are
It has a refractive index satisfying the following relationship. Refractive index of transparent support> Refractive index of low-refractive-index layer In a layer configuration as shown in FIGS.
Is preferable in that a protective film for a polarizing plate having excellent antireflection performance or antiglare performance can be produced.

[0029]

(Mλ / 4) × 0.7 <n ₁ d ₁ <(mλ / 4) × 1.3 (Formula (I))

In the formula (I), m is a positive odd number (generally 1).
Where n ₁ is the refractive index of the low refractive index layer and d ₁
Is the layer thickness (nm) of the low refractive index layer. Λ is the wavelength of visible light, and is a value in the range of 380 to 680 (nm). Satisfying the formula (I) means that m (positive odd number, generally 1) that satisfies the formula (I) exists in the wavelength range. FIG.
In the above layer structure, the polymer layer of the present invention is preferably higher than the refractive index of the transparent support.

FIG. 2 is a cross-sectional view schematically showing a layer structure of a protective film for a polarizing plate having more excellent antireflection performance. The embodiment shown in FIG. 2A has a layer structure of a transparent support 1, a hard coat layer 3, a high refractive index layer 6 as a polymer layer, and a low refractive index layer 2 as an outermost layer. The transparent support 1, the high refractive index layer 6, and the low refractive index layer 2 have a refractive index that satisfies the following relationship. Refractive index of high refractive index layer> refractive index of transparent support> refractive index of low refractive index layer

In the layer structure shown in FIG.
As described in JP-A-9-50401, the high refractive index layer has the following formula (II), and the low refractive index layer has the following formula (III).
Is preferable in that a protective film for a polarizing plate having more excellent antireflection performance can be produced.

[0033]

(Nλ / 4) × 0.7 <n ₂ d ₂ <(nλ / 4) × 1.3 (Equation (II))

In the formula (II), n is a positive integer (generally 1,
2 or 3), n ₂ is the refractive index of the high refractive index layer, and d ₂ is the layer thickness (nm) of the high refractive index layer.
λ is the wavelength of visible light, and is a value in the range of 380 to 680 (nm).

[0035]

(Hλ / 4) × 0.7 <n ₃ d ₃ <(hλ / 4) × 1.3 (Equation (III))

In the formula (III), h is a positive odd number (generally 1), n ₃ is the refractive index of the low refractive index layer, and d ₃ is the layer thickness (nm) of the low refractive index layer. is there. λ is the wavelength of visible light, and is a value in the range of 380 to 680 (nm). The expression (II) and the expression (III) satisfy n (a positive integer, generally 1, 2, or 3) that satisfies the expression (II) in the range of each wavelength as in the case of the expression (I). 3) and h (positive odd number, generally 1
Is present). Hereinafter, the same applies to formulas (IV) to (VI).

In the embodiment shown in FIG. 2B, the transparent support 1,
The hard coat layer 3, the middle refractive index layer 7, the high refractive index layer 6 which is a polymer layer, and the low refractive index layer 2 which is the outermost layer have a layer structure in this order. Transparent support 1, medium refractive index layer 7, high refractive index layer 6
And the low refractive index layer 2 has a refractive index satisfying the following relationship. The refractive index of the high refractive index layer> the refractive index of the medium refractive index layer> the refractive index of the transparent support> the refractive index of the low refractive index layer In a layer structure as shown in FIG. As described in, the reflection is more excellent when the middle refractive index layer satisfies the following formula (IV), the high refractive index layer satisfies the following formula (V), and the low refractive index layer satisfies the following formula (VI). This is preferable in that a protective film for a polarizing plate having anti-performance properties can be produced.

[0038]

(Iλ / 4) × 0.7 <n ₄ d ₄ <(iλ / 4) × 1.3 (Equation (IV))

In the formula (IV), i is a positive integer (generally 1,
2 or 3), n ₄ is the refractive index of the medium refractive index layer, and d ₄ is the layer thickness (nm) of the medium refractive index layer.
λ is the wavelength of visible light, and is a value in the range of 380 to 680 (nm).

[0040]

(Jλ / 4) × 0.7 <n ₅ d ₅ <(jλ / 4) × 1.3 (Equation (V))

In the formula (V), j is a positive integer (generally 1,
2 or 3), where n ₅ is the refractive index of the high refractive index layer and d ₅ is the layer thickness (nm) of the high refractive index layer.
λ is the wavelength of visible light, and is a value in the range of 380 to 680 (nm).

[0042]

(Kλ / 4) × 0.7 <n ₆ d ₆ <(kλ / 4) × 1.3 (Equation (VI))

In the formula (VI), k is a positive odd number (generally 1).
Where n ₆ is the refractive index of the low refractive index layer and d ₆
Is the layer thickness (nm) of the low refractive index layer. λ is the wavelength of visible light, and is a value in the range of 380 to 680 (nm).
The high refractive index, medium refractive index, and low refractive index described herein refer to the relative refractive index of the layers. The hard coat layer, the medium refractive index layer, and the high refractive index layer contain the above-mentioned particles of the present invention having a refractive index of 1.40 to 1.80 and an average particle diameter of 0.5 to 6 μm, and have an antiglare function. It is also preferable to produce a polarizing plate protective film having the same.

[Other Layers of Protective Film for Polarizing Plate] The high refractive index layer and the medium refractive index layer described above can be provided to produce a protective film for a polarizing plate having more excellent antireflection performance. In particular, it is preferable to provide a high refractive index layer. When a high refractive index layer or a medium refractive index layer is formed in a layer adjacent to the outermost layer of the present invention (that is, a lower layer in contact with the outermost layer), the high refractive index layer or the medium refractive index layer is a polymer of the present invention. Also serves as a layer. The refractive index of the high refractive index layer is 1.65.
〜2.40, more preferably 1.7.
0 to 2.20. The refractive index of the middle refractive index layer is 1.65.
To 1.85, more preferably 1.85.
65 to 1.75.

The high refractive index layer and the medium refractive index layer can be formed in the same manner as described for the polymer layer of the present invention. Preferably, it is preferable that inorganic fine particles having a high refractive index are finely dispersed and contained in the layer. The thickness of the high refractive index layer and the medium refractive index layer is 5 to 5.
It is preferably 200 nm, more preferably 1 nm.
0 to 150 nm, particularly preferably 30 to 100 n
m. The haze of the high refractive index layer and the medium refractive index layer is 5
% Or less, more preferably 3% or less, and particularly preferably 1% or less. The layer adjacent to the outermost layer of the present invention (that is, the lower layer in contact with the outermost layer)
When forming the low refractive index layer, the low refractive index layer also functions as the polymer layer of the present invention. The refractive index of the low refractive index layer is 1.30 to
It is preferably 1.55, more preferably 1.35 to 1.50. The low refractive index layer is particularly preferably a layer containing a polymer formed from the ionizing radiation-curable resin composition and inorganic fine particles, and having fine voids between the particles. As the inorganic fine particles, for example, LiF, Mg
Fine particles such as F ₂ and SiO ₂ are preferred, and SiO ₂ is particularly preferred. The thickness of the low refractive index layer is 30 to 200 nm.
Is preferably 50 to 150 nm, more preferably 60 to 120 nm. The haze of the low refractive index layer is preferably 5% or less, more preferably 3% or less, and more preferably 1%.
It is most preferred that: The strengths of the high refractive index layer, the medium refractive index layer, and the low refractive index layer are based on JIS K 5400.
Is preferably H or more in a pencil hardness test according to
It is more preferably at least H, most preferably at least 3H. Layers other than those described above may be provided on the polarizing plate protective film. For example, an adhesive layer, a shield layer, a slip layer, and an antistatic layer may be provided. The shield layer is provided to shield electromagnetic waves and infrared rays.

[Protective Film for Polarizing Plate] The protective film for polarizing plate of the present invention has a dynamic friction coefficient of 0. 0 on the surface having the outermost layer in order to improve the physical strength (such as scratch resistance).
It is preferably 25 or less. The kinetic friction coefficient described here is the same as the diameter of the surface having the outermost layer when the surface having the outermost layer is moved at a speed of 60 cm / min by applying a load of 0.98 N to a 5 mm diameter stainless steel hard sphere. 5
mm refers to the coefficient of dynamic friction between stainless steel hard balls. Preferably it is 0.17 or less, especially preferably 0.15 or less. In order to improve the antifouling performance of the protective film for a polarizing plate, it is preferable that the surface on the side having the outermost layer has a contact angle with water of 90 ° or more. It is more preferably at least 95 °, particularly preferably at least 100 °. It is preferable that the coefficient of kinetic friction and the contact angle with water are maintained even after using the polarizing plate. When the protective film for a polarizing plate has an antiglare function, the haze is preferably 3% to 30%, more preferably 5% to 20%, and most preferably 7% to 20%.

[Method of Forming Protective Film for Polarizing Plate] Each layer constituting the protective film for polarizing plate of the present invention is preferably formed by a coating method. When formed by coating, each layer is formed by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method or an extrusion coating method (described in US Pat. No. 2,681,294). ). Two or more layers may be applied simultaneously. For the method of simultaneous coating, see US Pat. No. 2,761,
791, 2,941,898, 3,508,9
Nos. 47, 3,526, 528 and Yuji Harazaki, Coating Engineering, 253 pages, Asakura Shoten (1973)
There is a description. Further, in each layer of the protective film for a polarizing plate, in addition to the above-described components (fine particles, polymer, dispersion medium, polymerization initiator, polymerization accelerator, etc.), a polymerization inhibitor, a leveling agent, a thickener, a coloring inhibitor, An ultraviolet absorber, a silane coupling agent, an antistatic agent, an adhesion-imparting agent, and the like may be added.

[Liquid Crystal Display Device] FIG. 3 is a schematic cross-sectional view schematically showing various embodiments in which the protective film for a polarizing plate of the present invention is applied to a liquid crystal display device. FIG. 3 (a) and (b)
Is a preferred embodiment of the protective film for a polarizing plate. FIG.
In (a), in the protective film for a polarizing plate, the transparent support 1 is adhered to the polarizing film 8 via an adhesive layer 9, and the protective film 10 of the polarizing film 8 is bonded to the liquid crystal display device via the adhesive layer 9. Is adhered to the image display surface. In FIG. 3B, in the protective film for a polarizing plate, the transparent support 1 is directly adhered to the polarizing film 8, and the protective film 10 of the polarizing film 8 is bonded to the image display surface of the liquid crystal display via the adhesive layer 9. Glued to.

[0049]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention.

Example 1-1 (Preparation of Coating Solution for Low Refractive Index Layer) Thermally crosslinkable fluoropolymer having a refractive index of 1.42 (OPSTAR JN7228, solid content concentration: 6% by mass, manufactured by JSR Corporation) To 93.0 g, 8.0 g of a dispersion of silica fine particles in methyl ethyl ketone (MEK-ST, solid content concentration 30% by mass, manufactured by Nissan Chemical Industries, Ltd.) and 100.0 g of methyl ethyl ketone were added and stirred. The solution was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a low refractive index layer. (Preparation of antireflection film) The above coating solution for a low refractive index layer was applied to a 80 μm-thick triacetyl cellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) using a bar coater. After drying at 80 ° C., it was further heated at 120 ° C. for 10 minutes to obtain a thickness of 0.09.
A 6 μm low refractive index layer was formed. Thus, an antireflection film was produced. (Preparation of protective film for polarizing plate) A 1.5 N aqueous solution of sodium hydroxide was prepared and kept at 50 ° C. 0.01N
Was prepared. After immersing the prepared anti-reflection film in the above-mentioned sodium hydroxide aqueous solution for 2 minutes,
It was immersed in water and the aqueous sodium hydroxide solution was sufficiently washed away. Then, after immersing in the above-mentioned diluted sulfuric acid aqueous solution for 1 minute,
It was immersed in water and the diluted sulfuric acid aqueous solution was sufficiently washed away. Further, the antireflection film was sufficiently dried at 100 ° C. Thus, a protective film for a polarizing plate was produced. (Evaluation of protective film for polarizing plate) The following items were evaluated for the produced protective film for polarizing plate. Table 1 shows the results. (1) Evaluation of peeling of film by saponification treatment Peeling of the film during the saponification treatment process was evaluated. 100 antireflection films were saponified. The presence or absence of peeling of the film before and after the saponification treatment was visually observed.
Grading was performed. 〇: Peeling was not observed at all in 100 sheets △: Peeling was observed within 5 sheets ×: Peeling was observed in more than 5 sheets (2) Evaluation The polarizing plate protective film was conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%. On the surface of the protective film for a polarizing plate on the side having the outermost layer, 11 vertical and 11 incisions are cut in a grid pattern with a cutter knife, and a polyester adhesive tape (No. 31B) manufactured by Nitto Denko Corporation is used. The adhesion test was repeated three times in the same place. The presence or absence of peeling of the film was visually observed, and the following three-stage evaluation was performed. 〇: No peeling was observed at 100 squares Δ: Peeling was observed within 2 squares ×: Peeling was observed over 2 squares (3) Evaluation of dynamic friction coefficient Polarization The coefficient of kinetic friction was evaluated as an index of the slipperiness of the surface having the outermost layer of the plate protective film. The coefficient of kinetic friction was determined by conditioning the sample at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours, and then measuring the diameter of the sample with a dynamic friction measuring instrument (HEIDON-14).
mm, stainless steel hard sphere, load 0.98N, speed 6
It was measured at 0 cm / min. (4) Evaluation of Pencil Hardness The protective film for a polarizing plate was conditioned for 2 hours at a temperature of 25 ° C. and a relative humidity of 60%. On the surface having the outermost layer of the protective film for a polarizing plate, the pencil hardness is evaluated using a test pencil specified by JIS-S-6006 in accordance with the pencil hardness evaluation method specified by JIS-K-5400. did. However, the load was 4.9N. (5) Evaluation of rubbing resistance of steel wool On the surface having the outermost layer of the protective film for a polarizing plate, 1.96 N / cm ² was applied to # 0000 steel wool.
The load was applied, and the state of the flaw after 10 reciprocations was observed. ：: no scratch at all △: slightly scratched but hard to see ×: markedly scratched (6) Evaluation of contact angle The polarizing plate protective film was treated at a temperature of 25 ° C and a relative humidity of 60%. The condition was adjusted for 2 hours. The contact angle with respect to water on the surface having the outermost layer of the polarizing plate protective film was evaluated. (7) Evaluation of fingerprint wiping property A fingerprint was attached to the surface having the outermost layer of the protective film for a polarizing plate, and the state when the fingerprint was wiped off with a cleaning cloth was observed. . ：: Fingerprint completely wiped off △: Part of fingerprint left without being wiped ×: Fingerprint almost left without being wiped (8) Evaluation of magic wiping property Outermost layer of protective film for polarizing plate Apply oily magic (ZEBRA Mackey, red) to the surface having
After a lapse of minutes, the state of wiping it with a cleaning cloth was observed and evaluated according to the following three grades. ○: Magic was completely wiped off △: Magic was left partially without being wiped ×: Magic was mostly left without being wiped

[0051]

[Table 1]

[Example 1-2] (Preparation of coating solution for hard coat layer) Hard coat material (Desolite Z7526, solid content concentration 72% by mass, JS
R (manufactured by R Co., Ltd.)
2.0 g and 88.0 g of cyclohexanone were added and stirred. The solution was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a hard coat layer. (Preparation of coating liquid for low refractive index layer) A commercially available fluoropolymer having a weight average molecular weight of 200,000 (Cytop CTX-8)
09A, manufactured by Asahi Glass Co., Ltd.) and 8.0 g of a commercially available fluorinated solvent (Fluorinert FC77, manufactured by Sumitomo 3M Co., Ltd.)
92.0 g was added and stirred. The solution was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a low refractive index layer. (Preparation of antireflection film) The above coating solution for a hard coat layer was applied to a 80 μm-thick triacetyl cellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) using a bar coater. After drying at 90 ° C., an illuminance of 400 mW / cm ² was obtained using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm while purging with nitrogen so that the atmosphere had an oxygen concentration of 6 to 8% by volume. The coating layer was cured by irradiating an ultraviolet ray having an irradiation amount of 300 mJ / cm ² to form a hard coat layer having a thickness of 6.0 μm. The above-mentioned coating solution for a low refractive index layer was applied on the hard coat layer using a bar coater.
After drying at 80 ° C., it was further heated at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. Thus, an antireflection film was produced. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

[Example 1-3] (Preparation of antireflection film) A hard disk prepared in Example 1-2 on a triacetylcellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm. The coating liquid for a coat layer was applied using a bar coater. After drying at 90 ° C., an air-cooled metal halide lamp of 160 W / cm (Eye Graphics Co., Ltd.) while purging with nitrogen so that the atmosphere has an oxygen concentration of 2 to 4% by volume.
Illuminance 400 mW / cm ² , irradiation amount 300 m
The coating layer was cured by irradiating ultraviolet rays of J / cm ² to form a hard coat layer having a thickness of 6.0 μm. The coating liquid for a low refractive index layer prepared in Example 1-1 was applied on the hard coat layer using a bar coater. After drying at 80 ° C., it was further heated at 120 ° C. for 10 minutes to obtain a thickness of 0.09.
A 6 μm low refractive index layer was formed. Thus, an antireflection film was produced. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

[Example 1-4] (Preparation of coating liquid for antiglare layer) Crosslinked polystyrene particles (SX-200H, manufactured by Soken Chemical Co., Ltd.) having an average particle size of 2 µm 2
0.0 g was added to 80.0 g of methyl isobutyl ketone, and the mixture was stirred with a high-speed disper at 5000 rpm for 1 hour to prepare a dispersion of crosslinked polystyrene particles. Tetramethylol methane triacrylate (NK ester A-
TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.) 126.0 g
Was added to 165.0 g of methyl isobutyl ketone and stirred. Further, 29.0 g of the above-prepared dispersion of crosslinked polystyrene particles and 7.6 g of a photocleavable photo-radical polymerization initiator (Irgacure 907, manufactured by Nippon Ciba Geigy Co., Ltd.) were added to the solution and stirred. Pore diameter 30μm
The mixture was filtered with a polypropylene filter to prepare a coating solution for an antiglare layer. (Preparation of anti-glare film) The coating solution for the anti-glare layer prepared above was coated on a 80 μm-thick triacetyl cellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) using a bar coater. . After drying at 90 ° C., an illuminance of 4 W / cm was applied using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the atmosphere had an oxygen concentration of 2 to 4% by volume.
The coating layer was cured by irradiating ultraviolet rays of 00 mW / cm ² and irradiation amount of 300 mJ / cm ² to form an antiglare layer having a haze of 17%. The coating liquid for a low refractive index layer prepared in Example 1-1 was applied on the antiglare layer using a bar coater. 80
After drying at ℃, further heated at 120 ℃ for 10 minutes,
A low refractive index layer having a thickness of 0.096 μm was formed. Thus, an antiglare film was produced. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

Comparative Example 1 (Preparation of Antiglare Film) An antiglare film was prepared in exactly the same manner as in Example 1-4, except that the antiglare layer was formed in an air atmosphere. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

[Example 1-5] (Preparation of anti-glare film) Hardness prepared in Example 1-2 on a triacetyl cellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm. The coating liquid for a coat layer was applied using a bar coater.
After drying at 90 ° C., an air-cooled metal halide lamp of 160 W / cm in an air atmosphere (Eye Graphics Co., Ltd.)
Illuminance 400 mW / cm ² , irradiation amount 300
The coating layer was cured by irradiating ultraviolet rays of mJ / cm ² to form a hard coat layer having a thickness of 3.0 μm. The coating solution for the antiglare layer prepared in Example 1-4 was applied on the hard coat layer using a bar coater. After drying at 90 ° C., an illuminance of 4 W / cm was applied using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the atmosphere had an oxygen concentration of 2 to 4% by volume.
The coating layer was cured by irradiating ultraviolet rays of 00 mW / cm ² and irradiation amount of 300 mJ / cm ² to form an antiglare layer having a haze of 17%. The coating liquid for a low refractive index layer prepared in Example 1-1 was applied on the antiglare layer using a bar coater. 80
After drying at ℃, further heated at 120 ℃ for 10 minutes,
A low refractive index layer having a thickness of 0.096 μm was formed. Thus, an antiglare film was produced. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

Example 1-6 (Preparation of Coating Solution for Hard Coat Layer) A transparent high refractive index hard coat material containing zirconium oxide fine particles (Desolite KZ7991, solid content concentration 46% by mass, JSR
100.0 g was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a hard coat layer. (Preparation of antireflection film) The above coating solution for a hard coat layer was applied to a 80 μm-thick triacetyl cellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) using a bar coater. After drying at 90 ° C., an illuminance of 400 mW / cm ² was obtained using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm while purging with nitrogen so that the atmosphere had an oxygen concentration of 2 to 4% by volume. The coating layer was cured by irradiating an ultraviolet ray having an irradiation amount of 300 mJ / cm ² to form a hard coat layer having a thickness of 6.0 μm and a refractive index of 1.71. The coating liquid for a low refractive index layer prepared in Example 1-1 was applied on the hard coat layer using a bar coater. After drying at 80 ° C., it was further heated at 120 ° C. for 10 minutes to obtain a thickness of 0.09.
A 6 μm low refractive index layer was formed. Thus, an antireflection film was produced. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

[Example 1-7] (Preparation of coating liquid for antiglare layer) A transparent high refractive index hard coat material containing zirconium oxide fine particles (Desolite KZ)
7114, solid content concentration 46% by mass, manufactured by JSR Corporation) 2
18.0 g, 91.0 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.)
It was added to 2.0 g of methyl isobutyl ketone and stirred. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet light was 1.61. To this solution, 29.0 g of the dispersion of the crosslinked polystyrene particles prepared in Example 1-4 was added and stirred. The solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution for an antiglare layer. (Preparation of anti-glare film) The coating solution for the anti-glare layer was applied to a 80 μm-thick triacetyl cellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) using a bar coater. After drying at 90 ° C., an illuminance of 400 mW was applied using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm while purging with nitrogen so that the atmosphere had an oxygen concentration of 2 to 4% by volume.
The coating layer was cured by irradiating an ultraviolet ray having an irradiation amount of 300 mJ / cm ^{2 with} an irradiation amount of 300 mJ / cm ² to form an antiglare layer having a haze of 17%. The coating liquid for a low refractive index layer prepared in Example 1-1 was applied on the antiglare layer using a bar coater. After drying at 80 ° C., it was further heated at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. Thus, an antiglare film was produced. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

Comparative Example 2 (Preparation of Antiglare Film) An antiglare film was prepared in exactly the same manner as in Example 1-7, except that the antiglare layer was formed in an air atmosphere. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

[Example 1-8] (Preparation of coating liquid for antiglare layer) Crosslinked polystyrene particles (SX-200H, manufactured by Soken Chemical Co., Ltd.) 2 having an average particle size of 2 μm
0.0 g was added to 80.0 g of a mixed solvent of methyl ethyl ketone / cyclohexanone = 54/46 (weight ratio),
The mixture was stirred with a high-speed disper at 5000 rpm for 1 hour to prepare a dispersion of crosslinked polystyrene particles. A transparent high refractive index hard coat material containing fine zirconium oxide particles (Desolite Z7401, solid content concentration 48% by mass, JS
218.0 g, a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) 9
1.0 g and 10.0 g of a photo-cleavable photo-radical polymerization initiator (Irgacure 907, manufactured by Ciba-Geigy)
0 g of methyl ethyl ketone / cyclohexanone = 54 /
The mixture was added to 46 (weight ratio) of the mixed solvent and stirred. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet light is 1.
It was 61. To this solution, 29.0 g of the dispersion of the crosslinked polystyrene particles prepared above was added and stirred. The solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution for an antiglare layer. (Preparation of anti-glare film) On a triacetyl cellulose film (TAC-TD80UF, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm, the coating solution for hard coat layer prepared in Example 1-2 was coated with a bar coater. And applied.
After drying at 90 ° C., an air-cooled metal halide lamp of 160 W / cm in an air atmosphere (Eye Graphics Co., Ltd.)
Illuminance 400 mW / cm ² , irradiation amount 300
The coating layer was cured by irradiating ultraviolet rays of mJ / cm ² to form a hard coat layer having a thickness of 3.0 μm. The coating solution for the antiglare layer was applied on the hard coat layer using a bar coater. After drying at 90 ° C, the oxygen concentration is 2 ~
While purging with nitrogen so that the atmosphere becomes 4% by volume, 16
Using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 0 W / cm, illuminance 400 mW / cm ²
The coating layer was cured by irradiating an ultraviolet ray having an irradiation amount of 300 mJ / cm ² to form an antiglare layer having a haze of 17%. The coating liquid for a low refractive index layer prepared in Example 1-1 was applied on the antiglare layer using a bar coater. After drying at 80 ° C,
Further heat at 120 ° C. for 10 minutes to obtain a thickness of 0.096 μm.
m low refractive index layer was formed. Thus, an antiglare film was produced. (Preparation of protective film for polarizing plate) A protective film for polarizing plate was prepared in exactly the same manner as in Example 1-1. (Evaluation of protective film for polarizing plate) The protective film for polarizing plate was evaluated in exactly the same manner as in Example 1-1. Table 1 shows the results.

Example 2-1 (Preparation of Protective Film for Polarizing Plate) On the antiglare film prepared in Example 1-8, saponification treatment was performed in the same manner as in Example 1-1, and the side having the outermost layer was obtained. The contact angle of water on the surface of the triacetyl cellulose film on the opposite side to water is 15 to
A 20 ° polarizing plate protective film was prepared. (Preparation of Polarizing Plate) A 75 μm-thick polyvinyl alcohol film (manufactured by Kuraray Co., Ltd.) was immersed in an aqueous solution consisting of 1,000 parts by weight of water, 7 parts by weight of iodine, and 105 parts by weight of potassium iodide for 5 minutes to adsorb iodine. Was. Next, this film was placed in a 4% by mass aqueous solution of boric acid at 40 ° C. for 4.4 hours.
The film was uniaxially stretched twice in the machine direction, and dried under tension to produce a deflection film. Hereinafter, the polarizing plate was manufactured under the environment where the number of dusts of 3 μm or more contained in the air is 1 to 100 per m ³ . Using a polyvinyl alcohol-based adhesive as an adhesive, a saponified triacetyl cellulose film surface of a protective film for a polarizing plate was bonded to one surface of the deflection film. Further, a saponified triacetylcellulose film was bonded to the other surface of the deflection film using the same polyvinyl alcohol-based adhesive so that the contact angle of water was 30 ° or less. (Evaluation of Polarizing Plate) The following items were evaluated for the produced polarizing plate. Table 2 shows the results. (1) Punching test A punching test is performed by punching out 100 sheets of the produced polarizing plate into a 26-inch size using a dumbbell, and the presence or absence of peeling between the polarizing film and the polarizing plate protective film is observed. An evaluation was performed. 〇: No peeling was observed in all 100 sheets △: Less than 5 sheets were peeled ×: More than 5 sheets were peeled (2) Durability test Punching test The 100 polarizing plates, which did not show any peeling in the above, were alternately set to an atmosphere of 70 ° C. and 93% RH and an atmosphere of 25 ° C. and 93% RH for 12 hours alternately in a constant temperature and humidity chamber. After standing for 1000 hours, a durability test was carried out, the presence or absence of peeling between the deflection film and the antireflection film was observed, and the following three grades were evaluated. 〇: No peeling was observed on all 100 sheets △: Peeling was observed within 5 sheets ×: Peeling was observed on more than 5 sheets (3) Point defects due to dust Evaluation The prepared polarizing plate was mounted on a commercially available liquid crystal display device, and the number of dusts that were observed as visually observed point defects and were taken in between the polarizing film and the polarizing plate protective film was counted.
The following three-stage evaluation was performed on the polarizing plate per 1 m ² . Δ: Number of point defects per 1 m ² is 2 or less Δ: Number of point defects per 1 m ² is 3 to 10 ×: Number of point defects per 1 m ² exceeds 10

[0062]

[Table 2]

Comparative Example 3 (Preparation of Polarizing Plate) Polarization was performed in exactly the same manner as in Example 2-1 except that the antiglare film prepared in Example 1-8 was used instead of the protective film for a polarizing plate. A plate was made. Example 1
The contact angle of water on the surface of the triacetyl cellulose film on the side opposite to the side having the outermost layer of the antiglare film prepared in 8 was 60 to 70 °. (Evaluation of Polarizing Plate) The polarizing plate was evaluated in exactly the same manner as in Example 2-1. Table 2 shows the results.

Example 2-2 (Preparation of Protective Film for Polarizing Plate) The time of immersion in an aqueous sodium hydroxide solution was shortened, and the water on the surface of the triacetyl cellulose film on the side opposite to the side having the outermost layer was reduced. A protective film for a polarizing plate having a contact angle of 20 to 30 ° was prepared. Otherwise, the procedure was exactly the same as in Example 2-1. (Evaluation of Polarizing Plate) The polarizing plate was evaluated in exactly the same manner as in Example 2-1. Table 2 shows the results.

Example 2-3 (Preparation of Protective Film for Polarizing Plate) The time of immersion in an aqueous solution of sodium hydroxide was shortened, and the water on the surface of the triacetyl cellulose film on the side opposite to the side having the outermost layer was reduced. A protective film for a polarizing plate having a contact angle of 30 to 40 ° was prepared. Otherwise, the procedure was exactly the same as in Example 2-1. (Evaluation of Polarizing Plate) The polarizing plate was evaluated in exactly the same manner as in Example 2-1. Table 2 shows the results.

[Examples 3-1 to 8 and Comparative Examples 4 and 5] (Preparation of transparent support A) Triacetyl cellulose
4 parts by weight, 2.6 parts by weight of triphenyl phosphate,
66 parts by weight of dichloromethane, 5.8 parts by weight of methanol,
A raw material consisting of 8.2 parts by weight of normal butanol was mixed and dissolved with stirring to prepare triacetyl cellulose dope A. 24 parts by weight of triacetyl cellulose, 4 parts by weight of triphenyl phosphate, 6 parts of dichloromethane
A raw material consisting of 6 parts by weight of methanol and 6 parts by weight of methanol is mixed and dissolved while stirring, and triacetyl cellulose dope B
Was prepared. According to JP-A-11-254594, etc., 3
Using a layer co-casting die, dope A is arranged on both sides of dope B so as to be co-cast, and simultaneously discharged onto a metal drum to perform layer casting. The casting film is peeled off from the drum and dried. And 10 μm, 60 μm, and 10 μm from the drum surface side.
A layer co-cast triacetyl cellulose film A was prepared. In this film, no clear interface was formed between the layers. Protective film 3-1 for polarizing plate in the same manner as in Examples 1-1 to 8 and Comparative examples 1 and 2, except that the 80 μm-thick triacetyl cellulose film was changed to the above triacetyl cellulose film transparent support A.
8, Comparative Examples 4 and 5 were produced. Table 3 shows the results of the same evaluation as described above.

[0067]

[Table 3]

[Examples 4-1 to 3, Comparative Example 6] Example 2
The polarizing plates of Examples 4-1 to 3 and Comparative Example 6 were prepared in the same manner except that the triacetyl cellulose film having a thickness of 80 μm in the polarizing plates of Comparative Examples 3 to 3 was changed to the above triacetyl cellulose film A. . The contact angle of water on the surface of the triacetyl cellulose film on the side opposite to the side having the outermost layer was 15 to 20 ° in Example 4-1, 20 to 30 ° in Example 4-2, and Example 4-3. Is 30-40
゜, Comparative Example 6 was 60 to 70 °. The punching test, the durability test, and the evaluation of the point defect were similarly performed on these polarizing plates. The results are shown in Table 4.

[0069]

[Table 4]

[Example 5] Further, in Examples 4-1 to 3-3, the transparent support A was prepared in the same manner as the transparent support B and the transparent support C prepared in the following manner. As a result, similar results were obtained. (Transparent support B) 20 parts by weight of triacetyl cellulose,
48 parts by weight of methyl acetate, 20 parts by weight of cyclohexanone,
5 parts by weight of methanol, 5 parts by weight of ethanol, 2 parts by weight of triphenyl phosphate / biphenyl diphenyl phosphate (1/2), 0.1 parts of silica (particle diameter: 20 nm)
Parts by weight, 2,4-bis- (n-octylthio) -6
0.2 parts by weight of (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine was added,
The heterogeneous gel solution obtained by stirring was cooled at -70 ° C for 6 hours, and then heated to 50 ° C and stirred to prepare triacetyl cellulose dope C. JP-A-7-1105
According to 5, the above-mentioned triacetylcellulose dope C was cast on a single-layer drum to prepare an 80 μm-thick triacetylcellulose film transparent support B. (Transparent support C) The above-mentioned triacetylcellulose dope C was heated in a stainless steel sealed container at 1 MPa and 180 ° C for 5 minutes, and then put into a 50 ° C water bath and cooled, and triacetylcellulose dope D was cooled. Was prepared. According to JP-A-7-11055, the above-mentioned triacetyl cellulose dope D was cast on a single-layer drum to prepare an 80 μm-thick triacetyl cellulose film transparent support C.

[0071]

The protective film for a polarizing plate of the present invention obtained by forming an outermost layer comprising a fluorine-containing compound on a transparent support and then subjecting the saponification treatment to antireflection performance and antiglare performance. It is possible to provide a large amount of inexpensive protective films for polarizing plates at low cost. Further, it is possible to provide a protective film for a polarizing plate in which the antireflection performance and the antiglare performance are not changed by the saponification treatment. Furthermore, a polarizing plate and a liquid crystal display device that have been subjected to antireflection treatment and antiglare treatment by appropriate means can be provided.

[Brief description of the drawings]

FIG. 1 (a) to (d) all show antireflection performance or
It is a schematic sectional drawing which shows typically the layer structure of the protective film for polarizing plates which has an antiglare performance.

FIGS. 2A and 2B are schematic cross-sectional views schematically showing a layer structure of a protective film for a polarizing plate having even more excellent antireflection performance.

FIGS. 3A and 3B are schematic cross-sectional views schematically showing an embodiment in which a protective film for a polarizing plate is applied to a liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transparent support 2 Low refractive index layer (outermost layer) 3 Hard coat layer 4 Antiglare layer 5 Refractive index 1.40-1.80, average particle size 0.5-
6 μm particles 6 High refractive index layer 7 Medium refractive index layer 8 Deflecting film 9 Adhesive layer 10 Protection film for deflecting film

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G02B 1/10 G02F 1/1335 510 5/02 G02B 1/10 A G02F 1/1335 510 Z F term (reference) 2H042 BA02 BA13 BA15 BA20 2H049 BA02 BB33 BB62 BB65 BC09 BC22 2H091 FA08X FA31X FA37X FC01 FC23 FC25 GA16 LA03 2K009 AA04 AA06 AA15 BB28 CC03 CC09 CC26 CC42 CC47 DD02 DD12 EE00 EE05 4F100 AJ06A01B01 BAK EB01 BAK EJ60C EJ91 EK00 GB41 JB14C JK14A JK14B JK16A JL02 JN01A JN06 JN30 YY00A YY00B

Claims (14)

[Claims] 1. A protective film for a polarizing plate having an outermost layer mainly composed of a fluorine-containing compound on a transparent support. The protective film for polarizing plates characterized by the above. 2. The protective film for a polarizing plate according to claim 1, wherein the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. 3. having a polymer layer adjacent to said outermost layer;
The protective film for a polarizing plate according to claim 1 or 2, wherein the polymer layer is formed by a crosslinking reaction or a polymerization reaction of the ionizing radiation-curable resin composition. 4. The method according to claim 1, wherein the fluorine-containing compound in the outermost layer is a fluorine-containing polymer, and the fluorine-containing polymer is a fluorine-containing polymer formed by a crosslinking reaction or a polymerization reaction simultaneously with or after the coating. The protective film for a polarizing plate according to any one of claims 1 to 3. 5. The protective film for a polarizing plate according to claim 3, wherein the polymer layer adjacent to the outermost layer is formed in an atmosphere having an oxygen concentration of 15% by volume or less. 6. The protective film for a polarizing plate according to claim 5, wherein the atmosphere having an oxygen concentration of 15% by volume or less is realized by nitrogen purge. 7. The protective film for a polarizing plate according to claim 5, wherein the atmosphere has an oxygen concentration of 6% by volume or less. 8. The protective film for a polarizing plate according to claim 1, wherein the transparent support is a transparent support formed from triacetyl cellulose. 9. The protective film for a polarizing plate according to claim 1, wherein a dynamic friction coefficient of the surface having the outermost layer is 0.25 or less. 10. The contact angle of water on the surface having the outermost layer is 90 ° or more.
10. The protective film for a polarizing plate according to any one of items 9 to 9. 11. The transparent support is a triacetylcellulose film, and a triacetylcellulose dope prepared by dissolving triacetylcellulose in a solvent is cast in a single layer, co-cast in a plurality of layers or successively in a plurality of layers. The protective film for a polarizing plate according to any one of claims 1 to 10, wherein the protective film is produced by casting by any casting method. 12. The triacetyl cellulose dope,
The protective film for a polarizing plate according to claim 11, which is a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent substantially free of dichloromethane by a cooling dissolution method or a high temperature dissolution method. . 13. A polarizing plate comprising the polarizing plate protective film according to claim 1 on at least one of the protective films of the polarizing film. 14. A liquid crystal display device comprising the polarizing plate according to claim 13 disposed on a liquid crystal display surface.