JP2001228329A - Polarizing plate having antireflection film, method of manufacturing the same, and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate having an antireflection film having good adhesion property and no foreign matter. SOLUTION: In the polarizing plate, at least one protective film of two protective films 21, 22 which protect both faces of a polarizing film 31 is a triacetylcellulose film layer as a transparent supporting body. The adhesion face of the triacetylcellulose film layer to the polarizing film is subjected to saponification treatment, and an antireflection film and a laminating film layer are applied on the face of the layer not subjected to the saponification treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate having an antireflection film, a liquid crystal display using the same, and a method for manufacturing a polarizing plate.

[0002]

2. Description of the Related Art FIG. 2 shows the structure of a liquid crystal display device to which the polarizing plate of the present invention can be applied. In a general liquid crystal display device, an edge-light type backlight 11 is disposed on the rearmost surface, a light guide plate 12 for emitting light of the backlight to the surface in order from the rear surface, and a scattering sheet for equalizing the brightness of the light. 13, further arranged as one or a plurality of light control sheets 14 having a function of condensing the light uniformized by the scattering sheet in a predetermined direction, or a function of selectively transmitting and reflecting specific polarized light, A liquid crystal cell 1 in which light passing through these films is sandwiched between a pair of polarizing plates 15 and 16
7 is incident. Reference numeral 18 denotes a cold cathode fluorescent tube as a light source, and 19 denotes a reflection sheet.

[0003] The antireflection layer is generally made of CRT, PDP, L
In an image display device such as a CD, in order to prevent a decrease in contrast or reflection of an image due to reflection of external light, the image display device is disposed on the outermost surface of a display that reduces the reflectance using the principle of optical interference. That is, the antireflection layer is provided on the 16 display side in FIG.

[0004]

In the manufacturing process of a polarizing plate, triacetyl cellulose is generally bonded for the purpose of protecting both sides of a polarizing layer made of polyvinyl alcohol. This triacetyl cellulose is saponified in an alkali such as an aqueous sodium hydroxide solution for the purpose of adhesion to the polarizing layer.

The saponification treatment is carried out before coating an antireflection layer or a hard coat layer for imparting scratch resistance on triacetyl cellulose, or when forming an undercoat layer or a hard coat layer on triacetyl cellulose. It may be done after that. In the former, triacetylcellulose on the application surface side is also saponified, so that a water-soluble cellulose film is formed on the surface, and adhesion to the coating film is significantly reduced.
As a method for solving this problem, Japanese Patent Laid-Open No. 10-26428
In No. 4, a compound having a functional group such as an epoxy group is added to a hard coat layer made of acryl. However, there are problems such as a decrease in strength of the hard coat layer and a defect due to adhesion of foreign matter before coating. In the latter case, there is no problem such as a decrease in adhesion, but it is not preferable because it involves a complicated process such as coating-saponification-coating (or vacuum film formation). An object of the present invention is to manufacture a polarizing plate having an antireflection film having good adhesion and no foreign matter by a simple process.

[0006]

The object of the present invention has been attained by the following means. (1) At least one of the two protective films for protecting both sides of the polarizing film is a triacetylcellulose film layer serving as a transparent support, and the triacetylcellulose film layer is in close contact with the polarizing film. Is a saponified surface, and has an antireflection film and a laminate film layer on the non-saponified side. (2) A polarizing plate having an antireflection film according to (1), further comprising an antiglare layer containing particles of 0.5 to 10 μm between the triacetyl cellulose film layer and the laminate film layer. (3) The polarizing plate having the antireflection film according to (1) or (2), wherein the laminate film layer is a removable film. (4) The polarizing plate obtained by removing the laminate film layer from the polarizing plate according to (1), (2) or (3), the display-side polarizing plate of the two polarizing plates arranged on both sides of the liquid crystal cell. A liquid crystal display device characterized by being used as a liquid crystal display. (5) a step of forming an antireflection film on one surface of a triacetylcellulose film using a polarizing plate having an antireflection film, a step of laminating a laminate film on the antireflection film to produce an optical film, Manufacturing a saponified optical film by saponifying the other surface of the film, and manufacturing a polarizing plate using the saponified optical film on at least one of two protective films for protecting both sides of the polarizing film Are carried out in this order, thereby producing a polarizing plate having an antireflection film.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1A to 1C are examples of schematic cross-sectional views showing a layer structure of an antireflection film used in the present invention. The antireflection film shown in (a) has a layer structure in the order of the transparent support 21 and the low refractive index layer 25. The anti-reflection film shown in (b) comprises a transparent support 21, an antiglare layer 22, and a low refractive index layer 2.
It has a layer configuration in the order of 5. The antireflection film shown in (c) has a layer structure in the order of a transparent support 21, an antiglare layer 22, a medium refractive index layer 23, a high refractive index layer 24, and a low refractive index layer 25. The anti-glare layer contains particles 26 for imparting anti-glare properties, and the particles provide the anti-glare properties by forming irregularities on the surface. For the low refractive index layer, a fluorine-containing compound which is crosslinked by heat or ionizing radiation is used. It is preferable that the refractive index and the film thickness of the medium refractive index layer, the high refractive index layer, and the low refractive index layer each satisfy the following expressions.

First layer mλ / 4 × 0.7 <n ₁ d ₁ <mλ / 4 × 1.3 (I)

In the formula, m is a positive integer (generally 1, 2 or 3), n ₁ is the refractive index of the medium refractive index layer, and d ₁ is the thickness (nm) of the medium refractive index layer. It is. λ is the wavelength of the light beam used.

Second layer hλ / 4 × 0.7 <n ₂ d ₂ <hλ / 4 × 1.3 (II)

Where h 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 thickness (nm) of the high refractive index layer. It is. λ is the wavelength of the light beam used.

Third layer kλ / 4 × 0.7 <n ₃ d ₃ <kλ / 4 × 1.3 (III)

Where k is a positive odd number (generally 1);
n ₃ is the refractive index of the low refractive index layer, and d ₃ is the thickness (nm) of the low refractive index layer. λ is the wavelength of the light beam used.

FIG. 3 is an example of a schematic sectional view showing a layer structure of a polarizing plate having an antireflection film. The anti-reflection film has a layer structure in the order of the transparent support 21, the anti-glare layer 22, and the low refractive index layer 25, and the polarizing layer 31 is adjacent to the anti-reflection film having the transparent support 21 on the opposite side, A transparent support 21 is attached to the side of the polarizing layer opposite to the antireflection film. Although not shown, a laminate film layer is formed on the low refractive index layer 25 so as to be peelable.

Triacetyl cellulose is used as a transparent support for the antireflection film and as a protective film for protecting the polarizing layer of the polarizing plate for LCD. The light transmittance of triacetyl cellulose is preferably 80% or more, and more preferably 86% or more. The transparent support preferably has optical isotropy when viewed from the front. The haze of the transparent support is preferably 2.0% or less, more preferably 1.0% or less.

An undercoat layer may be provided on the transparent support in order to impart adhesion to an adjacent layer. The material for forming such an undercoat layer is not particularly limited, but gelatin or poly (meth) can be used on triacetyl cellulose.
Acrylate resins and their substitutes, styrene-butadiene resins and the like are used. Further, a surface treatment such as a chemical treatment, a mechanical treatment, a corona treatment, and a glow discharge treatment may be performed.

It is preferable to provide a hard coat layer on the transparent support for the purpose of imparting scratch resistance. The compound used for the hard coat layer is preferably a polymer having a saturated hydrocarbon or polyether as a main chain, and more preferably a polymer having a saturated hydrocarbon as a main chain. The binder polymer is preferably crosslinked. Polymer having a saturated hydrocarbon as a main chain,
It is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer. In order to obtain a crosslinked binder polymer, it is preferable to use a monomer having two or more ethylenically unsaturated groups.

Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-dichlorohexane diacrylate) Pentaerythritol tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethanetri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta ( (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and the like Conductors (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinylsulfone (eg, divinylsulfone), acrylamide (eg, methylenebisacrylamide), and methacryl Amides are included. The polymer having a polyether as a main chain is preferably synthesized by a ring-opening polymerization reaction of a polyfunctional epoxy compound. These monomers having an ethylenically unsaturated group need to be cured by a polymerization reaction by ionizing radiation or heat after coating.

Instead of or in addition to the monomer having two or more ethylenically unsaturated groups, a crosslinked structure may be introduced into the binder polymer by a reaction of a crosslinkable group.
Examples of the crosslinkable functional group include an isocyanate group, an epoxy group, an aziridine group, an oxazoline group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxyl group, a methylol group, and an active methylene group. Vinyl sulfonic acid, acid anhydride, cyanoacrylate derivative, melamine,
Metal alkoxides such as etherified methylols, esters and urethanes, and tetramethoxysilane can also be used as monomers for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of a decomposition reaction, such as a block isocyanate group, may be used. Further, in the present invention, the cross-linking group is not limited to the above-mentioned compound, but may be one which shows reactivity as a result of decomposition of the above-mentioned functional group. These compounds having a cross-linking group need to be cross-linked by heat or the like after coating.

The binder used for the antiglare layer is not particularly limited, but in order to improve the antireflection property, the binder has a refractive index of 1.57.
To 2.00. It is preferable to have a hard coat property in order to make it difficult to damage itself during processing.

In order to impart a hard coat property to the antiglare layer, a polymer having a saturated hydrocarbon or polyether as a main chain is preferable, and a polymer having a saturated hydrocarbon as a main chain is more preferable. . The binder polymer is preferably crosslinked. The polymer having a saturated hydrocarbon as a main chain is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer. In order to obtain a crosslinked binder polymer, it is preferable to use a monomer having two or more ethylenically unsaturated groups.

In order to increase the refractive index of the binder of the antiglare layer, a high refractive index monomer having a refractive index of 1.57 or more, preferably 1.65 or more can be used. Examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinylnaphthalene, vinylphenylsulfide, 4-methacryloxyphenyl-4′-methoxyphenylthioether and the like. The polymer having a polyether as a main chain is preferably synthesized by a ring-opening polymerization reaction of a polyfunctional epoxy compound. These monomers having an ethylenically unsaturated group need to be cured by a polymerization reaction by ionizing radiation or heat after coating.

In order to increase the refractive index of the binder of the anti-glare layer, the particle size of at least one oxide selected from the group consisting of at least one oxide selected from titanium, zirconium, aluminum, indium, zinc, tin and antimony is preferably 100 nm or less, preferably It is preferable to contain fine particles of 50 nm or less. Examples of the fine particles include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In
Examples include ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , and ITO. The addition amount of the inorganic fine particles is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and more preferably 30 to 60% by mass of the total mass of the hard coat layer.
Is particularly preferred.

In the antiglare layer, scattering particles may be used for the purpose of imparting antiglare properties, preventing deterioration in reflectance due to interference of the hard coat layer, and preventing color unevenness. The scattering particles have an average particle size of 0.0
1 to 1.0 μm, the refractive index is 1.35 to 1.65 or 2.00 to 3.00, and the difference from the refractive index of the binder is 0.03 or more. By adding these scattering particles, internal scattering occurs in the antiglare layer, and the entire antiglare layer becomes a non-uniform refractive index layer whose refractive index is not defined by one value.

In order to impart anti-glare properties to the anti-glare layer, for example, a transparent support described in JP-A-61-209154, which is coated with a bumpy layer obtained by adding particles to a binder, or a special support, may be used. No. 6,168,851, in which a film on which an uneven surface is previously formed is bonded to a coating layer on a transparent support to transfer the unevenness, or another film such as a hard coat layer directly or on the transparent support. One in which unevenness is formed by embossing via a layer is exemplified.
Above all, a method of forming particles by adding particles to a binder is preferable in that it can be manufactured easily and stably.

The particles imparting antiglare properties (antiglare particles) are not particularly limited as long as irregularities are formed on the surface of the antiglare layer, but in order to control internal scattering, the refractive index between the particles and the binder is controlled. Preferably, the difference is less than 0.05, more preferably less than 0.02. Also,
In order to effectively form irregularities on the surface of the antiglare layer, the average particle size is preferably 0.5 to 10 μm, and preferably 1 to 6 μm.
m is more preferable. Examples of particles include polymethyl methacrylate resin, fluorine resin, vinylidene fluoride resin, silicone resin, epoxy resin, nylon resin, polystyrene resin, phenol resin, polyurethane resin, crosslinked acrylic resin, crosslinked polystyrene resin, melamine resin, benzoguanamine resin, etc. Is mentioned. The particles are preferably insoluble in water and organic solvents. The particles to be added to the anti-glare layer may be used in combination of two or more kinds of particles for controlling unevenness.

When the anti-glare particles have a refractive index difference from the binder forming the anti-glare layer of less than 0.03, it is possible to prevent a decrease in contrast due to scattered light, that is, a whitish appearance in a black display of an LCD. . Refractive index difference 0.03
In the above case or when the scattering particles are used, the whiteness is deteriorated, but it is possible to prevent glare caused by the enlargement of pixels due to the lens effect of the surface unevenness in the high definition LCD. Therefore, it is desirable that the refractive index design of the antiglare particles and the use of the scattering particles are properly used depending on the functions required for the LCD used.

The compound used for the low refractive index layer is not particularly limited, but is preferably a fluorine-containing compound having a refractive index of 1.38 to 1.49, and has a dynamic friction coefficient of 0.03 to 0 from the viewpoints of stain resistance and scratch resistance. 15. A fluorine-containing compound which is crosslinked by heat or ionizing radiation having a contact angle of 90 to 120 ° with water is more preferable. It may be used in combination with other compounds in order to adjust coatability, film hardness and the like. Examples of the crosslinkable fluorine-containing compound include a fluorine-containing monomer and a crosslinkable fluorine-containing polymer, and a crosslinkable fluorine-containing polymer is preferable from the viewpoint of applicability.

Examples of the crosslinkable fluoropolymer include perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane) and the like, and a fluorine-containing monomer and a crosslinkable group. A fluorinated copolymer having a monomer for application as a constitutional unit is exemplified. Specific examples of the fluorine-containing monomer unit,
For example, a portion of fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole), (meth) acrylic acid or Perfluorinated alkyl ester derivatives (for example, trade name: Biscoat 6FM (manufactured by Osaka Organic Chemicals) or trade name: M-2020)
(Manufactured by Daikin)) or fully or partially fluorinated vinyl ethers. As a monomer for providing a crosslinkable group, in addition to a (meth) acrylate monomer having a crosslinkable functional group in advance in the molecule, such as glycidyl methacrylate, a carboxyl group, a hydroxyl group, an amino group,
(Meth) acrylate monomers having a sulfonic acid group or the like (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate,
Allyl acrylate, etc.). The latter can introduce a crosslinked structure after copolymerization.
No. 8 and JP-A-10-147739.

In addition to the polymer having the above-mentioned fluorine-containing monomer as a constitutional unit, a copolymer with a monomer containing no fluorine atom may be used. There is no particular limitation on the monomer units that can be used in combination. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylates (methyl acrylate,
Methyl acrylate, ethyl acrylate, acrylic acid 2-
Ethylhexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl vinyl ether) And the like, vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N-tertbutylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamides, acrylonitrile derivatives and the like.

Each layer of the antireflection film is formed by a dip coating method,
It can be formed by coating by 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 (US Pat. No. 2,681,294). Two or more layers may be applied simultaneously. The method of simultaneous coating is described in U.S. Pat. Nos. 2,761,791 and 2,918,898.
Nos. 3,508,947 and 3,526,528, and in Yuji Harazaki, Coating Engineering, page 253, Asakura Shoten (1973).

The laminating step in the present invention comprises laminating a commercially available laminated film such as polyethylene or polyethylene terephthalate on the antireflection layer side using a laminator. FIG. 4 is an explanatory view of the laminating process, in which 41 is a laminated film, 42 is an antireflection layer, 43 is a transparent support, and 44 is a laminating roll. An adhesive may be applied to the bonding surface of the laminate film with the antireflection layer. The laminating roll 44 may be a heat roll that can be heated. In the saponification process described later, an alkaline aqueous solution must not enter between the laminate film and the antireflection layer, and therefore requires a relatively high adhesion. For that purpose, it is preferable to use an adhesive for the laminate film. Lamination to the anti-reflection layer,
What is already used for the purpose of protecting the product surface may be used.

In the saponification step, triacetyl cellulose having a laminated antireflection film is immersed in an alkali solution such as sodium hydroxide, and then immersed in an acid such as sulfuric acid to neutralize the solution, and further to water or washing. After washing in an aqueous solution containing a surfactant and the like, drying is performed.
If the unlaminated surface is saponified with an alkali solution, the saponification step does not necessarily have to be performed in this order.

When winding the saponified triacetyl cellulose, the laminated film may be collected. However, after processing the polarizing plate, the product is again laminated on the antireflection film. Polarizing plate processing may be performed.

Although the thickness of each layer in the polarizing plate of the present invention is not particularly limited, the thickness of the antireflection film is 100 n.
m. Specifically, the thickness of the transparent support is preferably 10 to 500 μm, more preferably 50 to 200 μm.
It is. The thickness of the polarizing layer is preferably 1.0 to 100 μm.
m, more preferably 5.0 to 50 μm. The thickness of the hard coat layer is preferably from 0.1 to 20.0 μm, more preferably from 1.0 to 10.0 μm. The thickness of the antiglare layer is preferably 0.1 to 20.0 μm, more preferably 0.5 to 10.0 μm, and particularly preferably 1.0 to 5.0.
μm. The thickness of the laminate film layer is preferably 2 to 100 μm. EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

[0036]

EXAMPLES (Preparation of Coating Solution A for Hard Coat Layer) A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (trade name: DPH)
A, manufactured by Nippon Kayaku Co., Ltd.) (256.5 g), isopropanol (78.8 g), methyl isobutyl ketone (157.2)
g and methanol in a mixed solvent of 102.1 g. A photopolymerization initiator (trade name: Irgacure 9) was added to the obtained solution.
07, Ciba Specialty Chemicals Co., Ltd.)
5.4 g were added. This was stirred and dissolved to prepare a coating solution A for a hard coat layer. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet light was 1.53.

(Preparation of Coating Solution B for Hard Coat Layer) UV
Crosslinkable hard coat material (trade name: KZ-7874, J
SR Co., Ltd.) was added to a mixed solvent of 673.3 g of isopropanol and 146.7 g of methyl isobutyl ketone.
After stirring, the mixture was filtered through a polypropylene filter having a pore size of 1 μm, and further crosslinked acrylic particles having an average particle size of 5.0 μm (trade name: MX-500H, manufactured by Soken Chemical Co., Ltd.)
Crosslinked acrylic particles having a particle size of 5.0 g and an average particle size of 3.0 μm (trade name: MX-300H, manufactured by Soken Chemical Co., Ltd.) 2.5
g was added and stirred to prepare a coating solution B for a hard coat layer. The coating film obtained by applying this solution and curing with ultraviolet light had a refractive index of 1.51.

(Preparation of Coating Solution C for Hard Coat Layer) 125 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), bis (4-methacryloylthiophenyl) sulfide ( 125 g of trade name: MPSMA, manufactured by Sumitomo Seika Co., Ltd.) was dissolved in 439 g of a mixed solvent of methyl ethyl ketone / cyclohexanone = 50/50% by mass. A photopolymerization initiator (Irgacure 907, Ciba Specialty Chemicals Co., Ltd.) was added to the obtained solution.
5.0 g and a photosensitizer (trade name: Kayacure D)
A solution prepared by dissolving 3.0 g of ETX (produced by Nippon Kayaku Co., Ltd.) in 49 g of methyl ethyl ketone was added. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet light was 1.60. Further, crosslinked polystyrene particles having an average particle size of 2 μm (trade name: SX-200H, Soken Chemical Co., Ltd.)
10g) and 5000mi at high speed disperser
After stirring and dispersing at n ⁻¹ for 1 hour, the mixture was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution for the antiglare layer.

(Preparation of Coating Solution D for Hard Coat Layer)
104.1 g of rohexanone, methyl ethyl ketone
While stirring with 3 g of the mixed solvent using an air
Hard coat coating solution containing luconia dispersion (trade name: KZ
−7886A, manufactured by JSR Corporation) 217.0 g.
did. This solution is coated and cured by UV curing.
The refractive index was 1.61. In addition, the average particle size
2 μm crosslinked polystyrene particles (trade name: SX-200)
H, manufactured by Soken Chemical Co., Ltd.)
5000min at ^-1After stirring and dispersing for 1 hour at
Filter through a 30 μm polypropylene filter
A coating solution C for a docoat layer was prepared. (Preparation of Coating Solution A for Low Refractive Index Layer) Heating with Refractive Index 1.46
Bridging fluorinated polymer (trade name: JN-7221, JS
R (manufactured by R Co., Ltd.)
After adding 0 g and stirring, a polypropylene film having a pore diameter of 1 μm was added.
The mixture was filtered through a filter to prepare a coating liquid A for a low refractive index layer.
Was. (Preparation of Coating Solution B for Low Refractive Index Layer) Heating with Refractive Index of 1.40
Bridging fluorinated polymer (trade name: JN-7227, JS
R Co., Ltd.) 500 g of methyl ethyl ketone to 500 g
After addition and stirring, a 1μm pore size polypropylene fill
The mixture was filtered through a filter to prepare a coating solution B for a low refractive index layer.

Example 1 Triacetylcellulose film having a thickness of 80 μm (manufactured by Fuji Photo Film Co., Ltd.)
The above coating solution A for a hard coat layer was applied using a bar coater, dried at 120 ° C., and then cooled with a 160 W / cm air-cooled metal halide lamp (I-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 6 μm. On top of this, the low refractive index layer coating solution A was applied using a bar coater,
After drying at 80 ° C., it is further thermally crosslinked at 120 ° C. for 10 minutes,
By forming a low refractive index layer having a thickness of 0.096 μm, a film having an antireflection layer was prepared. A commercially available laminated film (trade name: polyethylene terephthalate with an acrylic adhesive) is formed on the antireflection film.
B316PET, manufactured by San-A Kaken Co., Ltd.) using a laminating machine. Wherein the laminated antireflection film was dipped 1.5 mol / m ³ 2 minutes at 55 ° C. in aqueous sodium hydroxide solution, then washed 12 seconds with water, 0.1 mol / m ³ 20 seconds in sulfuric acid aqueous solution It was neutralized by immersion, and further washed with water for 15 seconds. This film was dried at 120 ° C. for 24 seconds and wound up to obtain a saponified antireflection film. (Preparation of Polarizing Plate) Using the saponified antireflection film with a laminate and a triacetyl cellulose film having a thickness of 80 μm (manufactured by Fuji Photo Film Co., Ltd.) as protective films,
The polarizing plate of Example 1 was prepared by adhering to both surfaces of a polarizing layer comprising iodine-doped stretched polyvinyl alcohol.

Example 2 Triacetylcellulose film having a thickness of 80 μm (manufactured by Fuji Photo Film Co., Ltd.)
The above coating solution A for a hard coat layer was applied using a bar coater, dried at 120 ° C., and then cooled with a 160 W / cm air-cooled metal halide lamp (I-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 6 μm. On top of that, TiO ₂ , SiO ₂ , TiO ₂ , and SiO ₂ were sequentially subjected to sputter coating with a thickness of 30 nm, 25 nm, 50 nm, and 100 nm from the support side, thereby forming a film having an antireflection layer. Example 1 using this film
Laminating, saponifying, and polarizing plate processing were performed in the same manner as in Example 1 to prepare a polarizing plate of Example 2.

Example 3 Triacetylcellulose film having a thickness of 80 μm (manufactured by Fuji Photo Film Co., Ltd.)
The above-mentioned coating solution B for hard coat layer is applied using a bar coater, dried at 120 ° C., and then cooled with a 160 W / cm air-cooled metal halide lamp (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 an antiglare hard coat layer having a thickness of 3 μm. The low refractive index layer coating solution B was coated thereon using a bar coater, dried at 80 ° C., and thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. By forming, a film having an antireflection layer was prepared. A polarizing plate of Example 3 was prepared in the same manner as in Example 1 except for this antireflection film.

Example 4 Triacetylcellulose film having a thickness of 80 μm (manufactured by Fuji Photo Film Co., Ltd.)
The above coating solution A for a hard coat layer was applied using a bar coater, dried at 120 ° C., and then cooled with a 160 W / cm air-cooled metal halide lamp (I-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 4 μm. The above-mentioned coating solution C for a hard coat layer was applied thereon using a bar coater, dried at 120 ° C. in an oxygen concentration atmosphere of 0.01% or less by nitrogen purge, and then cooled with a 160 W / cm air-cooled metal halide lamp. (I 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 an antiglare hard coat layer having a thickness of 1.4 μm. The low refractive index layer coating solution B was coated thereon using a bar coater, dried at 80 ° C., and thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. By forming, a film having an antireflection layer was prepared.
A polarizing plate of Example 4 was prepared in the same manner as Example 1 except for this antireflection film.

Example 5 Triacetylcellulose film having a thickness of 80 μm (manufactured by Fuji Photo Film Co., Ltd.)
The above coating solution A for a hard coat layer was applied using a bar coater, dried at 120 ° C., and then cooled with a 160 W / cm air-cooled metal halide lamp (I-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 4 μm. The coating solution D for a hard coat layer was applied thereon using a bar coater, dried at 120 ° C. in an oxygen concentration atmosphere of 0.01% or less by a nitrogen purge, and then cooled with a 160 W / cm air-cooled metal halide lamp. (I 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 an antiglare hard coat layer having a thickness of 1.4 μm. The low refractive index layer coating solution B was coated thereon using a bar coater, dried at 80 ° C., and thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. By forming, a film having an antireflection layer was prepared.
Except for this antireflection film, a polarizing plate of Example 5 was prepared in the same manner as in Example 1.

[Comparative Examples 1 to 5] Using the antireflection films of Examples 1 to 5, saponification and polarizing plate processing were performed without laminating to prepare polarizing plates of Comparative Examples 1 to 5. Comparative Example 6 Saponified 80 μm thick triacetyl cellulose film (Fuji Photo Film Co., Ltd.)
The above coating solution A for a hard coat layer was applied using a bar coater, dried at 120 ° C., and then cooled with a 160 W / cm air-cooled metal halide lamp (I-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 6 μm. On top of this, the low refractive index layer coating solution A was applied using a bar coater,
After drying at 80 ° C., it is further thermally crosslinked at 120 ° C. for 10 minutes,
By forming a low refractive index layer having a thickness of 0.096 μm, a film having an antireflection layer was prepared. Using the saponified anti-reflection film, the polarizing plate processing shown in Example 1 was performed to prepare a polarizing plate of Comparative Example 6.

Comparative Example 7 Triacetylcellulose film having a thickness of 80 μm (manufactured by Fuji Photo Film Co., Ltd.)
The above coating solution A for a hard coat layer was applied using a bar coater, dried at 120 ° C., and then cooled with a 160 W / cm air-cooled metal halide lamp (I-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 6 μm. This hard coat film was saponified by the method described in Example 1. The coating liquid A for a low refractive index layer was coated thereon using a bar coater, dried at 80 ° C., and thermally crosslinked at 120 ° C. for 10 minutes to form a low refractive index layer having a thickness of 0.096 μm. By forming, a film having an antireflection layer was prepared.
Using this saponified anti-reflection film, the polarizing plate processing shown in Example 1 was performed to prepare a polarizing plate of Comparative Example 7.

(Evaluation of Polarizing Plate with Anti-Reflection Layer) The obtained polarizing plate with anti-reflection layer was evaluated for the following items. (1) Appearance The polarizing plate was visually inspected for peeling of the anti-reflection layer, color change, adhesion of foreign matter, and the like. (2) Average reflectance 380-7 using a spectrophotometer (manufactured by JASCO Corporation)
The spectral reflectance at an incident angle of 5 ° was measured in a wavelength region of 80 nm. The average reflectance of 450 to 650 nm was used for the results. (3) Haze The haze of the obtained film was measured using a haze meter MODEL.
It measured using 1001DP (made by Nippon Denshoku Industries Co., Ltd.). (4) Pencil hardness evaluation A pencil hardness evaluation described in JIS K 5400 was performed as an index of scratch resistance. Antireflection film at a temperature of 25 ° C and a humidity of 60
After conditioning for 2 hours at% RH, the occurrence of scratches was evaluated using a 3H test pencil specified in JIS S 6006 at a load of 1 kg according to the following criteria. No scratches were observed in the evaluation of n = 5: ○ 1 or 2 scratches in the evaluation of n = 5: Δ 3 or more scratches in the evaluation of n = 5: × (5) Contact angle, fingerprint adhesion Evaluation As an index of the contamination resistance of the surface, the optical material was heated at a temperature of 25 ° C.
After adjusting the humidity at 60% RH for 2 hours, the contact angle to water was measured. After attaching a fingerprint to the sample surface, the sample was wiped off with a cleaning cloth to observe the state, and the fingerprint adhesion was evaluated as follows. Fingerprints can be completely wiped off: ○ Fingerprints can be seen slightly: △ Fingerprints can hardly be wiped off: ×

(6) Measurement of dynamic friction coefficient The dynamic friction coefficient was evaluated as an index of the surface slip property. Motion
The coefficient of friction was adjusted for 2 hours at 25 ° C and 60% relative humidity.
5mmφ with HEIDON-14 dynamic friction measuring machine
Stainless steel ball, load 100g, speed 60cm / min
The value measured in was used. (7) Evaluation of antiglare property Exposed fluorescence without louver on the prepared antiglare film
Light (8000 cd / m ^Two) And the reflection image is blurred
The degree was evaluated based on the following criteria. The outline of the fluorescent lamp is not known at all: ◎ The outline of the fluorescent lamp is slightly recognized: ○ The fluorescent lamp is blurred, but the outline can be identified: △ The fluorescent lamp is hardly blurred: ×

Table 1 shows the results of Examples and Comparative Examples.

[0050]

[Table 1]

Next, a liquid crystal display device shown in FIG. 2 was prepared using the polarizing plate of Example 5. The created liquid crystal display is
The reflection of external light was not conspicuous, and the display quality was good even outdoors.

[0052]

According to the manufacturing process of the present invention, a polarizing plate having an antireflection film having good adhesion and no foreign matter can be provided at low cost. Further, with the polarizing plate having the antireflection film and the liquid crystal display device using the same, deterioration of display quality due to reflection of external light can be improved.

[Brief description of the drawings]

FIG. 1 is an example of a sectional film diagram showing a layer configuration of an antireflection film (a) to (c).

FIG. 2 is an explanatory diagram of a liquid crystal display device to which the present invention can be applied.

FIG. 3 is a schematic cross-sectional view illustrating a layer configuration of a polarizing plate having an antireflection film.

FIG. 4 is an explanatory diagram of a laminating step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Reflection sheet 12 Light guide plate 13 Scattering sheet 14 Light control film 15 Back polarizing plate 16 Front polarizing plate 17 Liquid crystal cell 18 Cold cathode fluorescent tube 19 Reflection sheet 21 Transparent support 22 Hard coat layer or antiglare layer 23 Medium refractive index layer 24 High refractive index layer 25 Low refractive index layer 26 Particles 31 Polarizing layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hidetoshi Watanabe 210-Nakanuma, Minamiashigara-shi, Kanagawa Prefecture Fuji Photo Film F-term (reference) 2H049 BA02 BB33 BB65 BC22 2H091 FA08X FA08Z FA37X FB02 FC25 FD06 GA16 LA02 LA03 LA07 2K009 AA02 AA15 CC03 CC09 CC23 CC24 CC26 CC33 CC38 CC42 DD17 EE00 4F100 AJ05B AJ05C AJ06B AJ06C AK01A AK01E AK25G AK42 AR00E AS00B AS00C BA03 BA05 BA06 BA07 BA10B BA10C BA10E BA44 DE01E85 EJE EJH EJH46 EJ862 EJ863 GB41 JL11 JN01B JN01C JN06 JN06D JN10 JN10A YY00E 4J002 AB021 GF00

Claims (5)

[Claims] 1. At least one of two protective films for protecting both sides of a polarizing film is a triacetyl cellulose film layer which is a transparent support, and the triacetyl cellulose film layer is applied to the polarizing film. A polarizing plate having an antireflection film, wherein the adhesion surface is a saponified surface, and an antireflection film and a laminate film layer are provided on the non-saponified side. 2. The polarizing plate having an antireflection film according to claim 1, further comprising an antiglare layer containing particles of 0.5 to 10 μm between the triacetylcellulose film layer and the laminate film layer. . 3. The polarizing plate having an antireflection film according to claim 1, wherein the laminate film layer is a removable film. 4. A polarizing plate obtained by removing the laminate film layer from the polarizing plate according to claim 1, 2 or 3, which is used as a display-side polarizing plate among two polarizing plates arranged on both sides of a liquid crystal cell. A liquid crystal display device characterized by the above-mentioned. 5. A step of forming an anti-reflection film on one surface of a triacetyl cellulose film using a polarizing plate having an anti-reflection film, a step of bonding a laminate film on the anti-reflection film to produce an optical film, A process for producing a saponified optical film by saponifying the other surface of an acetylcellulose film, and producing a polarizing plate using the saponified optical film on at least one of two protective films for protecting both sides of the polarizing film The steps of performing the steps in this order.