JP2003294909A - Antireflection film, method for manufacturing the same, polarizing plate and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin antireflection film having excellent smoothness of the film surface and excellent visibility. <P>SOLUTION: The antireflection film comprises a supporting body comprising cellulose acylate and having 10 to 70 μm thickness, a water-soluble polymer layer adjacent to the supporting body, and a antireflection layer directly deposited on the water-soluble polymer layer or with other layers interposed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antireflection film, a method for producing the same, a polarizing plate using the same, and an image display device.

[0002]

2. Description of the Related Art Antireflection films are used in liquid crystal display devices (L
It is provided in various image display devices such as a CD), a plasma display panel (PDP), an electroluminescence display (ELD) and a cathode ray tube display (CRT). Anti-reflection film is also provided on the glasses and the lens of the camera. Above all, an antireflection film made of cellulose acylate has been widely used for various applications, particularly as a protective film for a polarizing plate for a liquid crystal display device.
Japanese Patent Application Laid-Open No. 11-6902 discloses a film having a three-layer antireflection film formed by wet coating, which uses a layer in which at least two inorganic fine particles are stacked in a low refractive index layer to contain microvoids. There is. A technique for providing an antireflection film that achieves both film strength and low reflectance at an inexpensive manufacturing cost by all-wet coating has been disclosed. Antireflection films made of cellulose acylate have been widely used for various applications, particularly as protective films for polarizing plates for liquid crystal display devices. The conventional support made of cellulose acylate has a large thickness of 80 μm, and it has been required to make the antireflection film thinner in order to reduce the thickness of the liquid crystal display device. However, if the thickness of the support made of cellulose acylate is reduced,
When a coating layer having a necessary function is provided thereon, it becomes difficult to maintain the smoothness of the film surface, and there is a problem that visibility is deteriorated.

[0003]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide an antireflection film having a small thickness, excellent film surface smoothness, and excellent visibility, a polarizing plate using the same, and a polarizing plate using the same. It is to provide a used liquid crystal display device.

[0004]

According to the present invention, an antireflection film, a polarizing plate, and a liquid crystal display device having the following constitutions are provided to achieve the above object of the present invention. 1. A support comprising a cellulose acylate having a thickness of 10 to 70 μm, a water-soluble polymer layer adjacent to the support, and an antireflection layer directly or via another layer on the water-soluble polymer layer. Anti-reflection film to do. 2. A method for producing an antireflection film, which comprises providing a water-soluble polymer layer on a support made of cellulose acylate having a thickness of 10 to 70 μm, and forming an antireflection layer on the support directly or through another layer. . 3. 3. The method for producing an antireflection film as described in 2 above, wherein both sides are saponified by immersing the support in an alkaline solution at least once. 4. 3. The method for producing an antireflection film as described in 2 above, wherein after forming the antireflection layer, the back surface of the film is saponified by immersing the film in an alkaline solution at least once. 5. Before forming the water-soluble polymer layer or after forming the antireflection layer, an alkaline solution is applied to the surface of the antireflection film opposite to the surface on which the antireflection layer is formed, and heating, washing with water and / or Alternatively, the method for producing an antireflection film as described in 2 above, wherein only the back surface of the film is saponified by neutralization. 6. Each layer of the antireflection film is formed by applying a coating composition containing a film-forming solute and at least one solvent, drying the solvent, and curing by heat and / or ionizing radiation. 6. The method for producing an antireflection film as described in any one of 2 to 5 above. From specular reflectance of 450 nm at 7.5 degree incidence to 65 nm
CI in the wavelength range from 380 nm to 780 nm with an average value of 0.5% or less in the wavelength range up to 0 nm
E The tint of the specular reflection light with respect to the 5 degree incident light of the standard light source D65 is such that the a * and b * values of the CIE1976L * a * b * color space are −7 ≦ a * ≦ 7 and −10 ≦ b *, respectively. ≤10
The method for producing the antireflection film as described in 1 above or the antireflection film as described in any one of 2 to 6 above, wherein 8. 8. The antireflection film as described in 1 or 7 above, which is a cellulose acylate containing 1% by volume to 99% by volume of a metal oxide having an average particle size of 1 nm to 400 nm in the support. 9. 9. The antireflection film as described in 1, 7, or 8 above, wherein the cellulose acylate is cellulose triacetate. 9. A polarizing plate using the antireflection film described in any one of 1 and 7 to 9 as a protective film on at least one surface. 10. An image display device comprising at least one of the antireflection film as described in 1 or 7 to 9 or the polarizing plate as described in 9 above. 11. TN or S having at least one antireflection film described in 1 or 7 to 9 or a polarizing plate described in 9 above.
A transmissive, reflective, or transflective liquid crystal display device in TN, VA, IPS, OCB, or ECB modes.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The basic constitution of the antireflection film made of the cellulose acylate of the invention will be described with reference to the drawings.

[Structure of Antireflection Film] FIG. 1 is a schematic sectional view showing a basic layer structure of the antireflection film used in the present invention. The embodiment shown in FIG. 1 is an antireflection film comprising a support 1 made of cellulose acylate, a water-soluble polymer layer 2, a hard coat layer 3, a medium refractive index layer 4, a high refractive index layer 5 and a low refractive index layer 6. Show. Such an antireflection film having a three-layer structure includes a medium refractive index layer, a high refractive index layer,
It is preferable that the optical film thickness of each layer of the low refractive index layer, that is, the product of the refractive index and the film thickness is about nλ / 4 with respect to the design wavelength λ, or a multiple thereof.
No. 401 publication. However, in order to realize the low reflectance and the reflectance characteristic in which the tint of the reflected light is reduced according to the present invention, the medium refractive index layer has the following formula (I) for the design wavelength λ (= 500 nm). It is preferable that the high refractive index layer satisfies the following formula (II) and the low refractive index layer satisfies the following formula (III).

[0007]   lλ / 4 × 0.80 <n1d1 <lλ / 4 × 1.00 (I)

[0008]   mλ / 4 × 0.75 <n2d2 <mλ / 4 × 0.95 (II)

[0009]   nλ / 4 × 0.95 <n3d3 <nλ / 4 × 1.05 (III)

Where l is 1, n1 is the refractive index of the medium refractive index layer, and d1 is the thickness of the medium refractive index layer (n
m), m is 2, n2 is the refractive index of the high refractive index layer, and d2 is the layer thickness (nm) of the high refractive index layer, n is 1 and n3 is low refractive index. Is the refractive index of the index layer,
And d3 is the layer thickness (nm) of the low refractive index layer. Furthermore, for example, triacetyl cellulose (refractive index: 1.4
For a transparent support consisting of 9) having a refractive index of 1.45 to 1.55, n1 is 1.60 to 1.65 and n2 is 1.8.
5 to 1.95 and n3 must have a refractive index of 1.35 to 1.45, for example, a refractive index of 1.55 to 1.65 made of polyethylene terephthalate (refractive index: 1.66).
N1 is 1.65 to 1.7.
5, n2 is 1.85 to 2.05, and n3 is 1.35 to 1.5.
It should have a refractive index of 45. When the material for the medium-refractive index layer or high-refractive index layer having the above-mentioned refractive index cannot be selected, it is equivalent to combining a layer having a higher refractive index and a layer having a lower refractive index than the set refractive index. It is well known that the principle of a film can be used to form a layer that is substantially optically equivalent to a medium-refractive index layer or a high-refractive index layer having a set refractive index, and also for realizing the reflectance characteristics of the present invention. Can be used. The “substantially three layers” of the present invention also includes four or five antireflection layers using such an equivalent film.

The reflectance characteristics of the present patent, which are achieved by the above-mentioned layer structure, can achieve both low reflection and reduction of the tint of reflected light, and therefore, for example, on the outermost surface of a liquid crystal display device. When applied, a display device having unprecedented high visibility can be obtained. Since the average value of the specular reflectance at wavelengths of 5 degrees from 450 nm to 650 nm is 0.5% or less, the reduction in visibility due to the reflection of external light on the display device surface is prevented to a sufficient level. it can. Further, the tint of specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 in the wavelength range of 380 nm to 780 nm is a in the CIE1976L * a * b * color space.
* And b * values are −7 ≦ a * ≦ 7 and −10 ≦, respectively.
By setting it within the range of b * ≦ 10, the tint of the reddish purple to blue-violet reflected light, which has been a problem in the conventional multilayer antireflection film, is reduced, and 0 ≦ a * ≦ 5 and − 7 ≦
By setting it within the range of b * ≦ 0, it is significantly reduced, and when applied to a liquid crystal display device, the tint when a high-luminance external light such as an indoor fluorescent lamp is slightly reflected is neutral. ,I do not mind.

[Support] Among the cellulose acylates used for the support of the present invention, triacetyl cellulose is preferred, and the one disclosed in JP-A No. 2001-1745 is particularly preferred.

For the purpose of increasing the surface hardness of the support,
The metal oxide fine particles can be added to the dope of cellulose acylate. As the metal oxide fine particles used in the present invention, metal oxide particles having a Mohs hardness of 7 or more are preferable. Specific examples include silicon dioxide, titanium diacid, zirconium oxide, and aluminum oxide.
Silicon dioxide and aluminum oxide, which have a small difference in refractive index from cellulose acylate, are more preferable.

The average particle diameter of these metal oxide fine particles is 1 nm or more and 400 nm or less, more preferably 5 nm.
Or more and 200 nm or less, more preferably 10 nm or more 1
00 nm or less is preferable. If it is less than 1 nm, it is difficult to disperse, and agglomerated particles are likely to be formed.

The amount of these fine particles added is 1 to 99% by volume of cellulose acylate, preferably 5 to 80% by volume, more preferably 5 to 50% by volume, and 5 to 20% by volume. % Is particularly preferable.

Generally, metal oxide fine particles have a large surface hydrophilicity and a poor affinity with cellulose acylate, so that the interface is easily broken and the film is cracked and scratch resistance is not improved simply by mixing the two. Have difficulty. In order to improve the affinity between the inorganic fine particles and cellulose acylate,
The surface of the inorganic fine particles is preferably surface-treated with a surface modifier containing an organic segment.

The surface modifier is required to form a bond with the inorganic fine particles on the one hand and have a high affinity with the cellulose acylate on the other hand, and the functional group capable of forming a bond with the metal is silane or aluminum. Preferred are metal alkoxide compounds such as titanium and zirconium, compounds having anionic groups such as phosphoric acid, sulfonic acid and carboxylic acid groups, compounds having amino groups and compounds having amide groups. The organic segment preferably has a structure having an affinity for cellulose acylate, and more preferably contains a polar group such as an ester group, an epoxy group, or an ether group. Particularly preferred is a metal alkoxide compound, or a surface modifier having an anionic group and an ester group, an epoxy group or an ether group.

Representative examples of these surface modifiers are listed below. Silane coupling agent _{H 2 C = C (CH 3} ) COOC 3 H 6 Si (OCH 3) 3 H 2 C = CHCOOC 3 H 6 Si (OCH 3) 3

[0019]

[Chemical 1]

ClCH ₂ CH ₂ —CH ₂ OC ₃ H ₆ Si (OCH ₃ ) ₃ R (OCH ₂ CH ₂ ) _n OC ₃ H ₆ Si (OCH ₃ ) ₃ R (OCH ₂ CH (CH ₃ )) _n OC ₃ H ₆ Si (OCH ₃ )
₃ ROCO (CH ₂ ) _n Si (OCH ₃ ) ₃ (n = 1 is an integer of 1 to 10, R is an alkyl group such as methyl, ethyl, propyl, butyl) CH ₃ COCH ₂ COOC ₃ H ₆ Si (OCH ₃ ) _{3 (CH 3 CH 2 O) 3} POC 3 H 6 Si (OCH 2 CH 3) 3 such as titanate coupling agent _{C 17 H 35 COOTi (OCH (} CH 3) 2) 3 specifically Ajinomoto Co. Plane Act (KRTTS,
KR46B, KR55, KR41B, KR38S, KR
138S, KR238S, 338X, KR44, KR9
SA) Aluminum coupling agent Specifically, Planeact AL-M (manufactured by Ajinomoto Co., Inc.)
Saturated carboxylic acid CH ₃ COOH, C ₂ H ₅ COOH, etc. C _n H _{2n + 1} COOH (n = 1 to 10) Unsaturated carboxylic acid Oleic acid, etc. Hydroxycarboxylic acid Citric acid, Tartaric acid, etc. Dibasic acid Oxalic acid, Malon Aromatic carboxylic acid such as acid, succinic acid, etc. Terminal carboxylic acid ester compound such as benzoic acid RCOO (C ₅ H ₁₀ COO) _n H (n = 1 to 5), H ₂ C = CHCOO (C ₅ H ₁₀ COO) _n H ( n = 1,
2,3) etc. Phosphoric acid H ₂ C = C (CH ₃ ) COOC ₂ H ₄ OCOC ₅ H ₁₀ OPO
(OH) ₂ (H ₂ C = C (CH ₃ ) COOC ₂ H ₄ OCOC ₅ H ₁₀ O) ₂
POOH, etc. Phosphonic acid Phenylphosphonic acid, etc. Sulfonic acid Benzenesulfonic acid H ₂ C = C (CH ₃ ) COOC ₂ H ₄ OSO ₃ H, etc. Polyoxyethylene derivative Polyoxyethylene aryl ether Polyoxyethylene alkyl ether Polyoxyethylene aryl ester Poly Oxyethylene alkyl ester, etc.

The surface modification of these fine particles is preferably performed in a solution. Fine particles are added to the solution in which the surface modifier is dissolved, and ultrasonic waves, a stirrer, a homogenizer,
It is preferable to use a dissolver, a planetary mixer, a paint shaker, a sand grinder, a kneader, etc. while stirring and dispersing.

The solution for dissolving the surface modifier is preferably an organic solvent having a large polarity. Specific examples thereof include known solvents such as alcohols, ketones, and esters, but a solvent having the same composition as the solvent for the cellulose acylate dope is preferable.

The metal oxide fine particles can be mixed with the cellulose acylate by adding the metal oxide fine particles to the dope of the cellulose acylate and mixing / dispersing the metal oxide. The metal oxide finely dispersed by surface treatment in advance. A method of adding fine particles to the dope of cellulose acylate is preferable. It is preferable to further disperse after addition, a dissolver, a planetary mixer, a sand grinder, a kneader,
It is preferable to uniformly mix and disperse with a roll mill or the like.

The thickness of the finished (after dried) cellulose acylate film is in the range of 10 to 70 μm in the antireflection film of the present invention. Preferably 20-60μ
The range is m, and the range of 30 to 50 μm is more preferable.

The light transmittance of the support is preferably 80% or more, more preferably 86% or more. The haze of the transparent support is preferably 2.0% or less, more preferably 1.0% or less.
The transparent support preferably has a refractive index of 1.4 to 1.7.

[Water-Soluble Polymer Layer] If the solvent of the coating liquid for forming the layer in contact with the support is a solvent that attacks the support, the smoothness of the film surface is impaired. When a solvent that corrodes the support is used as the solvent of the coating liquid for forming the layer in contact with the support, the above problem can be avoided by providing the water-soluble polymer layer on the support. Gelatin can be preferably used as the water-soluble polymer.
The thickness of the gelatin subbing layer is preferably 0.01 to 1 μm, more preferably 0.02 to 0.5 μm, and most preferably 0.05 to 0.2 μm.

As a solvent for dissolving triacetyl cellulose, ethers having a carbon number of 3 to 12:
Dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-
Ketones having a carbon number of 3 to 12, such as dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole and phenetole: specifically,
Acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, methylcyclohexanone, etc., having 3 to 12 carbon atoms: specifically, ethyl formate, propyl formate, formic acid Organic solvent having two or more kinds of functional groups such as n-pentyl, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, n-pentyl acetate, and γ-ptyrolactone: specifically, 2-methoxymethyl acetate , 2-
Methyl ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-methoxyethanol,
2-propoxyethanol, 2-butoxyethanol,
1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate and the like can be mentioned.

As a solvent that does not dissolve triacetyl cellulose, methanol, ethanol, 1-propanol,
2-propanol, 1-butanol, 2-butanol,
tert-butanol, 1-pentanol, 2-methyl-2-butanol, cyclohexanol, isobutyl acetate, methyl isobutyl ketone, 2-octanone, 2-pentanone, 2-hexanone, 2-heptanone, 3-pentanone, 3-heptanone , 4-heptanone.

[Hard Coat Layer] The hard coat layer is provided to impart scratch resistance to the transparent support. The hard coat layer also has a function of enhancing the adhesion between the lower layer and the upper layer. The hard coat layer was obtained by adding an inorganic filler such as silica or alumina to a composition prepared by dissolving a polyfunctional acrylic monomer, urethane acrylate, an oligomer such as epoxy acrylate, or a polymerization initiator in a solvent, if necessary. It is preferably formed by coating the coating composition, drying the solvent, and curing with heat and / or ionizing radiation.

[High and Medium Refractive Index Layer] The medium and high refractive index layers are coated with a coating composition containing inorganic fine particles having a high refractive index, a heat or ionizing radiation curable monomer, an initiator and a solvent. Formed by drying the solvent, curing with heat and / or ionizing radiation. As inorganic fine particles,
It is preferable to use at least one metal oxide selected from oxides of Ti, Zr, In, Zn, Sn, and Sb. The medium-refractive index layer and the high-refractive index layer thus formed are excellent in scratch resistance and adhesion as compared with those obtained by coating and drying a polymer solution having a high refractive index. In order to secure the dispersion stability and the film strength after curing, etc., JP-A No. 11-153703 and Patent No. US621085.
It is preferable that the coating composition contains a polyfunctional (meth) acrylate monomer and an anionic group-containing (meth) acrylate dispersant as described in 8B1 and the like.

The average particle size of the inorganic fine particles is 1 to 100 nm as the average particle size measured by the Coulter counter method.
Is preferred. If it is 1 nm or less, the specific surface area is too large, and the stability in the dispersion is poor, which is not preferable. When it is 100 nm or more, visible light is scattered due to the difference in refractive index with the binder, which is not preferable. The haze of the high refractive index layer and the medium refractive index layer is preferably 3% or less, and more preferably 1% or less.

[Low Refractive Index Layer] A fluorine-containing compound that is cured by heat or ionizing radiation is used for the low refractive index layer.
The dynamic friction coefficient of the cured product is preferably 0.03 to 0.1.
5. The contact angle with pure water is preferably 100 to 120 degrees. If the coefficient of kinetic friction is higher than 0.15, scratches are likely to occur when the surface is rubbed, which is not preferable. If the contact angle to pure water is less than 100 degrees, fingerprints, oil stains and the like are likely to adhere, which is not preferable from the viewpoint of antifouling property. Examples of the curable fluorine-containing polymer compound include a perfluoroalkyl group-containing silane compound (for example, (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane), a fluorine-containing monomer and a crosslinkable group. Examples thereof include a fluorinated copolymer having a monomer for imparting a constitutional unit. Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc. ),
Partial or fully fluorinated alkyl ester derivatives of (meth) acrylic acid (for example, biscoat 6FM (Osaka Organic Chemicals) or M-2020 (Daikin)), fully or partially fluorinated vinyl ethers, and the like. However, hexafluoropropylene is particularly preferable from the viewpoint of low refractive index and easy handling of the monomer. Examples of the monomer for imparting a crosslinkable group include a (meth) acrylate monomer having a crosslinkable functional group in advance in the molecule such as glycidyl methacrylate, as well as a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, and the like (meth ) Acrylate monomers (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, etc.) can be mentioned. The latter is capable of introducing a crosslinked structure after copolymerization, which is disclosed in JP-A-10-25388 and JP-A-10-147.
No. 739, which is particularly preferable.

Further, not only a polymer having the above-mentioned fluorine-containing monomer as a constitutional unit but also a copolymer with a monomer not containing a fluorine atom may be used. The monomer unit that can be used in combination is not particularly limited, and examples thereof include olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic acid esters (methyl acrylate,
Methyl acrylate, ethyl acrylate, acrylic acid 2-
Ethylhexyl), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl vinyl ether) Etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N-tert-butyl acrylamide, N-cyclohexyl acrylamide, etc.), methacrylamides, acrylonitrile derivatives, and the like. JP-A-10-25388 and JP-A-10-147.
It is disclosed by Japanese Patent No. 739.

Further, as a means for lowering the coefficient of dynamic friction in order to impart scratch resistance, it is possible to introduce a copolymerized unit capable of improving slidability. A method for introducing a polydimethylsiloxane segment into the main chain is disclosed in JP-A-11-228.
It is disclosed in Japanese Patent No. 631 and is particularly preferable.

The fluorine-containing resin used for forming the low refractive index layer is preferably used by adding ultrafine particles of Si oxide in order to impart scratch resistance. From the viewpoint of antireflection property, the lower the refractive index, the more preferable, but as the refractive index of the fluororesin is lowered, the scratch resistance deteriorates. Therefore, by optimizing the refractive index of the fluorine-containing resin and the addition amount of the Si oxide ultrafine particles, it is possible to find the best balance between scratch resistance and low refractive index. As Si oxide ultrafine particles,
The silica sol dispersed in a commercially available organic solvent may be added to the coating composition as it is, or various commercially available silica powders may be dispersed in an organic solvent and used.

[Layer to be provided if desired] The antireflection film may be further provided with a forward scattering layer, an antistatic layer or a protective layer.

The forward scattering layer is provided in order to provide a viewing angle improving effect when the viewing angle is tilted in the vertical and horizontal directions when applied to a liquid crystal display device. By dispersing fine particles having different refractive indexes in the hard coat layer, the hard coat layer can also serve as a hard coat function.

In the case where the multilayer antireflection film formed by wet coating the coating composition of the present invention is used to obscure the background reflection due to surface irregularities and to impart antiglare property, it contains matte particles which are generally used. Rather than forming an antireflection layer on a layer with surface irregularities, forming the surface irregularity structure after forming the antireflection layer by an embossing method improves the film thickness uniformity and improves the antireflection performance. Therefore, it is preferable.

Each layer of the antireflection film has 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, a micro gravure method and an extrusion coating method (US Pat. No. 2,681,294). ), It can be formed by coating. The microgravure method and the gravure method are preferable from the viewpoint of eliminating drying unevenness by minimizing the wet coating amount, and the gravure method is particularly preferable from the viewpoint of film thickness uniformity in the width direction. Two or more layers may be applied simultaneously. For the simultaneous coating method, see US Pat.
61791, 2941898, and 3508947.
Nos. 3526528 and Yuji Harasaki,
Coating Engineering, page 253, Asakura Shoten (1973). The microgravure coating method is particularly preferable.

In the microgravure coating method used in the present invention, a gravure roll having a diameter of about 20 to 50 mm and engraved with a gravure pattern on the entire circumference is provided below the support.
And, while rotating the gravure roll in the reverse direction with respect to the transport direction of the support, the doctor blade scrapes off the excess coating liquid from the surface of the gravure roll, and the fixed amount of the coating liquid is on the upper surface of the support. The coating method is characterized in that the coating liquid is transferred to the lower surface of the support at a position to perform coating.

In order to prevent streak failure on the coating surface, a bead portion of the coating liquid is provided between the roll surface of the gravure roll to which the coating liquid is excessively supplied and the flexible support which continuously runs. In the gravure coating apparatus that applies a desired amount of coating liquid to the flexible support by pressing the flexible support against the gravure roll using a backup roll while forming, in the vicinity of the upstream side of the gravure roll rotation direction of the bead portion. It is preferable that a liquid supply means is provided in and the coating liquid is supplied from the liquid supply means to the gravure roll. In this case, the liquid supply means has an inclined surface which is inclined downward in the roll surface direction of the gravure roll, and the coating liquid is made to flow down to the inclined surface to supply the liquid, and between the tip of the inclined surface and the roll surface. Is 0
It is preferable to have a gap of more than 400 μm and less than 400 μm. This is because the coating liquid is allowed to flow down to the inclined surface, so that stable liquid supply to the roll surface can be performed, and a gap of more than 0 μm and 400 μm or less is provided between the tip of the inclined surface and the roll surface. By forming it, the tip of the inclined surface does not come into contact with the roll surface, and the blocking effect of the coating liquid described above can be exerted. It is more preferable that this gap is more than 0 μm and 200 μm or less. By setting the upper limit of the gap to 200 μm or less, it is possible to reliably prevent the coating liquid from flowing down from the gap, and thus it is possible to reliably prevent the coating liquid from returning. It is important to prevent the excess coating liquid in the bead portion from being immediately dammed and flowing down to the lower portion of the gravure roll even when the liquid returns. Therefore, the roll side tip position of the inclined surface is drawn from the center of the gravure roll toward the contact point where the flexible support contacts the gravure roll, and the line drawn toward the roll surface side tip of the inclined surface. It is preferable that the center angle formed by and is 45 ° or less. Further, if the angle of the inclined surface of the liquid supply means is too large, the coating liquid flowing through the inclined surface is disturbed, so it is preferable that the downward inclination angle of the inclined surface does not exceed 15 ° with respect to the horizontal.

It is preferable to form a multi-layered coating film by a single conveyance from the delivery of the strip-shaped support to the winding, and a multi-layer coating for producing a multi-layered coating film in which a multi-layered coating layer is formed on the strip-shaped support. In a membrane manufacturing apparatus, in a casing having an inlet and an outlet of the strip-shaped support between a feeder for the strip-shaped support and a winder for winding the strip-shaped support arranged on a floor surface of a production chamber. A feed roller that conveys the belt-shaped support along a conveyance path, an applicator that is provided in the conveyance path to form one coating layer on the belt-shaped support, and a dryer that dries the coating layer. It is preferable to arrange as many coating devices as a unit by incorporating them integrally as many as the number of multilayer coating layers formed on the belt-shaped support.

In the manufacturing apparatus, a feed roller for conveying the belt-shaped support along a conveying path in a casing having an inlet and an outlet of the belt-shaped support, and dust on the belt-shaped support provided in the conveying path. A dust remover for removing the dust, a dust remover configured as a unit by at least integrally incorporating it, and a feed roller for conveying the belt-shaped support along a conveyance path in a casing having an inlet and an outlet of the belt-shaped support, A heat treatment apparatus which is provided in the transport path and heat-treats the belt-shaped support, and which is configured as a unit by at least integrally incorporating it, and the belt-shaped support in a casing having an inlet and an outlet of the belt-shaped support. At least a feed roller for transporting the sheet along the transport path, and a surface inspection device provided on the transport path for inspecting the coated surface state of the belt-shaped support. A surface inspection device that is physically incorporated and configured as a unit, the dust removing device is disposed between the delivery device and the coating device, and the strip-shaped support is provided between the coating device and the winding device. It is preferable that the heat treatment apparatus and the surface inspection apparatus are arranged in this order from the upstream side in the body transport direction.

A fan filter unit is provided at the air outlet formed on the ceiling surface of the casing of each device, and an air exhaust port is formed on the bottom surface of the casing so that clean air blown out from the fan filter unit into the casing. Is preferably exhausted from the air exhaust port.

The carrier path of the belt-shaped support in each of the above-mentioned devices has a box-shaped or tubular carrier path case having an inlet and an outlet of the belt-shaped support along the carrier path and an air inlet and an air outlet. It is preferable that clean air is supplied to the air introduction port.

The dryer of the coating device is divided into three or more drying zones along the transport direction of the belt-like support, and a supply means and a discharge means for supplying dry air are provided for each drying zone. In addition, it is preferable that a fine pressure difference meter is provided for controlling the static pressure between the drying zones.

The coating machine is any one of a direct gravure coater, a reverse coater, a kiss coater, a micro gravure coater, a bar coater and an extrusion coater, and the coating machines are preferably interchangeable with each other.

The coating machine in the coating apparatus is preferably arranged so as to be located on the floor surface or in the vicinity of the floor surface.

In order to cure the layer which is cured by ionizing radiation, it is preferable to reduce the oxygen concentration by purging with nitrogen. The oxygen concentration is preferably 6% or less, and 4%
It is more preferably at most, and even more preferably at most 1%.

When the antireflection film of the present invention is used as one side of the surface protective film of a polarizer, the surface of the transparent support opposite to the surface on which the antireflection layer is formed may be saponified with an alkali. is necessary. Specific means for the alkali saponification treatment can be selected from the following two. (1) is superior in that it can be processed in the same process as a general-purpose triacetyl cellulose film, but since the antireflection film surface is saponified, the surface is alkali-hydrolyzed and the film deteriorates. A problem may be that when the liquid remains, it becomes dirty. In that case, although it is a special process, (2) or (3) is excellent. (1) After the antireflection layer is formed on the transparent support, the back surface of the film is saponified by dipping it at least once in an alkaline solution. (2) Before the antireflection layer is formed on the transparent support. Alternatively, after that, an alkali solution is applied to the surface of the antireflection film opposite to the surface on which the antireflection film is formed, and then heated, washed with water and / or neutralized to saponify only the back surface of the film ( 3) By dipping the support in an alkaline solution at least once to saponify both sides and then form an antireflection layer

The antireflection film of the present invention is used for a liquid crystal display (LCD), a plasma display panel (PD
P), electroluminescence display (EL
D) and an image display device such as a cathode ray tube display device (CRT). Since the antireflection film of the present invention has a transparent support, it is used by adhering the transparent support side to the image display surface of the image display device. The antireflection film of the present invention is used in combination with a polarizer, a transparent support and an optical compensation film composed of an optically anisotropic layer in which the orientation of discotic liquid crystal is fixed, and a polarizing plate composed of a light scattering layer. It is preferable. The polarizing plate composed of the light scattering layer is described in, for example, JP-A No. 11-305010.

More specifically, the antireflection film of the present invention, when used as one side of a surface protective film of a polarizer, is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), In-plane switching (IP
S), an optically compensated bend cell (OCB), and other modes of transmission type, reflection type, or semi-transmission type liquid crystal display device. Especially for liquid crystal display devices of TN mode and IPS mode,
As described in JP-A-2001-100043 and the like, an optical compensation film having a viewing angle widening effect is used on the surface opposite to the antireflection film of the present invention, of the two protective films on the front and back of the polarizer. Thus, a polarizing plate having an antireflection effect and a viewing angle widening effect can be obtained with the thickness of one polarizing plate, which is particularly preferable.

As the polarizing film, any polarizing film can be applied. For example, when a polyvinyl alcohol-based film is continuously supplied and the both ends of the film are stretched by applying tension while being held by the holding means, the locus of the holding means from the substantial holding start point to the substantial holding release point at one end of the film L1 and the locus L2 of the holding means from the substantial holding start point at the other end to the substantial holding release point have the relationship of the following equation (2) with respect to the distance W between the left and right substantial holding release points, and the left and right substantial The straight line connecting the holding start points shall be substantially orthogonal to the center line of the film introduced into the holding step, and the straight line connecting the left and right substantial holding release points should be substantially orthogonal to the center line of the film sent to the next step. And may be stretched (see US Patent Publication No. 2002-8840). Formula (2) | L2-L1 |> 0.4W

When used in a transmissive or semi-transmissive liquid crystal display device, a commercially available brightness enhancement film (polarization separation film having a polarization selection layer, for example, Sumitomo 3M Co., Ltd.)
D-BEF etc.) manufactured in this way can be used to obtain a display device with higher visibility. Also, λ
When used in combination with a / 4 plate, it can be used as a polarizing plate for reflective liquid crystal or a surface protective plate for organic EL display for reducing light reflected from the surface and inside. Furthermore, the antireflection layer of the present invention can be formed on a transparent support such as PET or PEN and applied to an image display device such as a plasma display panel (PDP) or a cathode ray tube display device (CRT).

[0055]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.

<Preparation of support 1> (Preparation of fine particle dispersion a) Silica (Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.) 0.67% by mass Cellulose acetate (Acetylated number 2 of hydroxyl groups of cellulose) .8) 2.93 mass% triphenyl phosphate 0.23 mass% biphenyldiphenyl phosphate 0.12 mass% methylene chloride 88.37 mass% methanol 7.68 mass% A solution was prepared and was prepared with an attritor. Dispersion was performed so that the volume average particle diameter was 0.7 μm, and a fine particle dispersion a was prepared.

(Preparation of Raw Material Dope) Cellulose triacetate (number of acetylated hydroxyl groups of cellulose 2.8) 89.3 mass% triphenyl phosphate 7.1 mass% biphenyldiphenylphosphate 3.6 mass 17.9 parts by mass of the fine particle dispersion a was added to 100 parts by mass of the solid content of 100% by mass, and a mixed solvent of methylene chloride 92% by mass methanol 8% by mass was appropriately added and dissolved by stirring to prepare a dope. The solid content concentration of the dope was (18.5)%.
The dope was filtered through a filter paper (Toyo Roshi Kaisha, Ltd., # 63), and then a sintered metal filter (Nippon Seisen Co., Ltd. 06) was used.
N, nominal pore diameter 10 μm), and further filtered with a mesh filter (RM manufactured by Nippon Pole Co., Ltd., pore diameter 45 μm).

(Preparation of Ultraviolet Absorber Solution b) 2 (2′-Hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole 5.83% by Mass 2 (2′-hydroxy- 3 ', 5'-di-tert-amylphenyl) benzotriazole 11.66% by mass Cellulose acetate (the number of cellulose hydroxyl groups that is acetylated 2.8) 1.48% by mass triphenyl phosphate 10% by mass Biphenyldiphenylphosphate 0.05% by mass Methylene chloride 74.38% by mass Methanol 6.47% by mass An ultraviolet absorbent solution was prepared according to the above formulation, and filtered with an Astropore 10 filter manufactured by Fuji Photo Film Co., Ltd. To prepare an ultraviolet absorbent solution b.

(Preparation of Support 1) For the above dope,
Using a static mixer, the above ultraviolet absorbent solution b
The amount of the ultraviolet absorber is 1.04 with respect to the solid content in the dope.
While adjusting the content to be mass%, the dope was added and mixed in the piping route. This dope was cast on an endless support, dried with hot air until it had a self-supporting property, and peeled as a film. The residual solvent at the time of peeling was 21% by mass. This film was introduced into a tenter dryer, dried while holding both ends and applying tension, and the residual solvent was 9% by mass.
Dried until. Thereafter, it was dried in a roller drying zone until the residual solvent became 0.1% by mass. The film thickness of the completed support 1 was 40 μm, and its refractive index was 1.48.

<Preparation of Support 2> (Adjustment of Dope) 20 L stainless steel dissolution tank having a stirring blade (previously thoroughly washed with methylene chloride)
To the above, the following mixed solvent was added, and the cellulose triacetate powder (average size 2 mm) was gradually added while stirring well, and the whole was charged to 10 kg. After the addition, the mixture is allowed to stand at room temperature (25 ° C.) for 3 hours to swell the cellulose triacetate, and the resulting non-uniform gel-like solution is cooled at −70 ° C. for 6 hours, then heated to 50 ° C. and stirred. I adjusted the dope. -Cellulose triacetate (the number of acetylated hydroxyl groups of cellulose is 2.8, viscosity average degree of polymerization is 320) 20 parts by mass-methyl acetate 48 parts by mass-cyclopentanone 10 parts by mass-methanol 5 parts by mass-ethanol 5 Parts by mass Plasticizer A (dipentaerythritol hexaacetate) 5.5 parts by mass Plasticizer B (triphenyl phosphate) 6.5 parts by mass Fine particles (silica (particle size 20 nm)) 0.1 parts by mass UV Agent a: (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine 0.1 part by mass-UV agent b: 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole 0.1 parts by mass UV agent c: 2 (2′-hydroxy-3 ′, 5 ′) -J tert- Ami butylphenyl) -5-chloro-benzotriazole 0.1 parts by mass _{· C 12 H 25 OCH 2 CH} 2 O-P (= O) - (OK) 2 0.05 parts by weight

(Preparation of Support 2) The obtained dope was mixed with 50
At 0 ° C., filtration was performed with a filter paper having an absolute filtration accuracy of 0.01 mm (# 63 manufactured by Toyo Roshi Kaisha, Ltd.), and an absolute filtration accuracy of 0.
It was filtered with 0025 mm filter paper (FH025, manufactured by Pall).

The filtered dope was cast on a glass plate so that the dry film thickness was 40 μm. Dry at 70 ° C for 3
After 5 minutes at 130 ° C. for 5 minutes, the film was peeled off from the glass plate and dried in stages at 160 ° C. for 30 minutes to evaporate the solvent, thereby preparing the support 2. The refractive index of this support was 1.49.

<Preparation of support 3> (Preparation of cellulose triacetate solution) Methyl acetate /
Cellulose triacetate (degree of substitution = 2.7, viscosity average degree of polymerization = 310) was gradually added (16% by weight) to a mixed solution of acetone / methanol (85/15/5;% by weight) while stirring well. It was left to swell at room temperature (25 ° C.) for 3 hours. The resulting swelling mixture was slowly stirred and cooled to -30 ° C at -8 ° C / min, then -70 ° C.
After cooling for 6 hours, the temperature was raised at + 8 ° C./min, and when the sol formation of the content had progressed to a certain extent, stirring of the content was started and heated to 50 ° C. to obtain a dope. The cellulose triacetate dope contains silica particles (particle size 20
nm), triphenyl phosphate / biphenyl diphenyl phosphate (1/2), 2,4-bis- (n
-Octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine was added to each of 0.5% by mass of cellulose acylate and 1
0 mass% and 1.0 mass% were added.

(Adjustment of Filler-Filled Cellulose Triacetate Dope) Alumina having a particle size of about 13 nm (Nippon Aekosil Co., Ltd.) was used so that the filler concentration in the cellulose triacetate was 5% by volume and the treatment amount of the surface modifier was 10% by weight. Made of aluminum oxide C) and CH ₃ COO
(C ₅ H ₁₀ COO) ₂ H was added to a mixed solution of methyl acetate / acetone / methanol (85/15/5; mass%),
A liquid dispersed by a sand grinder mill using glass beads was prepared, added to the above cellulose triacetate dope, and further shear-mixed with a kneader to prepare a filler-filled dope.

Then, the obtained dope was filtered at 50 ° C. with an absolute filtration accuracy of 0.01 mm (# 6 manufactured by Toyo Roshi Kaisha, Ltd.).
It was filtered with 3) and further filtered with a filter paper (FH025, manufactured by Pall) with an absolute filtration accuracy of 0.0025 mm.

(Preparation of Support 3) The solution was cast into a band shape using a band casting machine having an effective length of 6 m, and after drying, the film was peeled from the band. Further, it was dried in an environment of 120 ° C. for 30 minutes and the solvent was evaporated to obtain a cellulose acylate film. The film thickness was adjusted to 40 μm.

(Preparation of Coating Solution A for Hard Coat Layer) 306 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), 16 parts by mass of methyl ethyl ketone and 220 parts by mass. It was dissolved in a mixed solvent of parts by mass of cyclohexanone. After adding 7.5 parts by mass of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) to the obtained solution and stirring until dissolved, 450 parts by mass of M
EK-ST (average particle size 10 to 20 nm, solid content concentration 30)
A mass% SiO ₂ sol methyl ethyl ketone dispersion, manufactured by Nissan Kagaku Co., Ltd. was added and stirred to obtain a mixture, and a polypropylene filter having a pore size of 3 μm (PPE-03).
To prepare a coating solution A for hard coat layer.

(Preparation of Hard Coat Layer Coating Liquid B) 1000 parts by mass of the above hard coat layer coating liquid A (refractive index after solvent drying and UV curing: 1.51) had an average particle size of 1.
Particles with forward scattering property made of 3 μm cross-linked polystyrene (SX-130H, refractive index: 1.61, Soken Chemical Co., Ltd.)
(Manufactured) 150 parts by mass is added, and 10 parts are added with an air dispersion.
The mixture was stirred for a minute to obtain a mixture, and the mixture was filtered through a polypropylene filter (PPE-03) having a pore size of 3 μm to prepare a coating solution B for hard coat layer having forward scattering property.

(Preparation of Titanium Dioxide Dispersion) Titanium dioxide ultrafine particles (TTO-55B, manufactured by Ishihara Sangyo Co., Ltd.) 25
0 g, crosslinking reactive group-containing anionic polymer (Chemical Formula 2) 3
7.5 g, cationic monomer (DMAEA, Kojin Co., Ltd.)
2.5 g of cyclohexanone and 710 g of cyclohexanone were dispersed by Dynomill to prepare a titanium dioxide dispersion liquid having a mass average diameter of 65 nm.

[0070]

[Chemical 2]

(Preparation of coating liquid for medium refractive index layer) A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was added to 155.2 g of the above titanium dioxide dispersion.
89.5 g, photopolymerization initiator (IRGACURE 907, manufactured by Ciba-Geigy Co., Ltd.) 4.68 g, photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.56 g, methyl ethyl ketone 770.4 g, and cyclohexanone 2983.0 g was added and stirred. A polypropylene filter having a pore size of 0.4 μm was filtered to prepare a coating solution for the medium refractive index layer.

(Preparation of coating liquid for high refractive index layer) A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was added to 985.7 g of the above titanium dioxide dispersion.
48.8 g, acrylic-containing silane coupling agent 33.
5 g (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), photopolymerization initiator (Irgacure 907, manufactured by Nippon Ciba-Geigy Co., Ltd.) 4.03 g, photosensitizer (Kayacure DET)
X, manufactured by Nippon Kayaku Co., Ltd.) 1.35 g, methyl ethyl ketone 622.5 g, and cyclohexanone 1865.0
g and stirred. The coating liquid for the high refractive index layer was prepared by filtering with a polypropylene filter having a pore size of 0.4 μm.

(Preparation of coating liquid for low refractive index layer) Refractive index 1.
42 thermally crosslinkable fluorine-containing polymer (OPSTAR JN72
28, solid content concentration 6% by mass, manufactured by JSR Corporation, 93.0
g of silica fine particles in methyl ethyl ketone dispersion (MEK
-ST, solid content concentration 30% by mass, manufactured by Nissan Chemical Co., Ltd.
8.0 g, acrylic group-containing silane coupling agent 8.0
g (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), 100.0 g of methyl ethyl ketone and 5.0 g of cyclohexanone were added and stirred. The coating liquid for the low refractive index layer was prepared by filtering with a polypropylene filter having a pore size of 1 μm.

(Preparation of coating liquid for gelatin layer) The composition of the coating liquid for gelatin layer is as follows. Gelatin 0.54
2 parts by mass, formaldehyde 0.136 parts by mass, salicylic acid 0.160 parts by mass, acetone 39.1 parts by mass, methanol 15.8 parts by mass, methylene chloride 40.6 parts by mass, water 1.2 parts by mass.

Example 1 (Preparation of Antireflection Film) 40 μm prepared above
A gelatin layer having a thickness of 0.1 μm was provided on one surface of the support 1 having a thickness of m. Next, the hard coating layer coating liquid A was applied using a gravure coater and dried at 100 ° C. for 2 minutes. Next, the coating layer is cured by irradiating with ultraviolet rays, and the hard coat layer (refractive index: 1.51, film thickness: 6μ
m) was formed. Subsequently, the above-mentioned coating liquid for a medium refractive index layer was applied using a gravure coater, dried at 100 ° C., and then irradiated with ultraviolet rays to cure the coating layer, and the medium refractive index layer (refractive index: 1.63 , Film thickness: 67 nm). The above-mentioned coating liquid for high refractive index layer was applied onto the medium refractive index layer using a gravure coater, dried at 100 ° C., and then irradiated with ultraviolet rays to cure the coating layer, and the high refractive index layer (refractive index rate:
1.90, film thickness: 107 nm). Furthermore, the coating liquid for a low refractive index layer was applied onto the high refractive index layer using a gravure coater, and the coating layer was cured at 120 ° C. for 8 minutes to obtain a low refractive index layer (refractive index: 1.43 , Film thickness: 86 nm
) Is provided. In this way, an antireflection film was prepared.

(Evaluation of Antireflection Film) The obtained film was evaluated for the following items. (1) The specular reflectance and tint spectrophotometer V-550 (manufactured by JASCO Corporation) was equipped with an adapter ARV-474, and an emission angle of -5 at an incident angle of 5 ° in a wavelength range of 380 to 780 nm. The specular reflectance was measured, the average reflectance from 450 to 650 nm was calculated, and the antireflection property was evaluated. Further, from the measured reflection spectrum, CIE1976L * a showing the tint of specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65.
The L * value, a * value, and b * value in the * b * color space were calculated, and the tint of the reflected light was evaluated. (2) Pencil hardness evaluation As an index of scratch resistance, the pencil hardness evaluation described in JIS K 5400 was performed. Anti-reflection film temperature 25 ℃, humidity 60
After conditioning the humidity for 2 hours at% RH, using a test pencil of 2H to 5H defined in JIS S 6006, the load is 500 g, the evaluation is as follows, and the highest hardness that is OK is evaluated. Value. No scratches to one scratch in the evaluation of n = 5: OK Three or more scratches in the evaluation of n = 5: NG (3) Smoothness evaluation The evaluation was made according to the following judgments. Line-shaped defects cannot be visually recognized: ○ Line-shaped defects can be visually recognized: ×

Example 2 An antireflection film was prepared in the same manner as in Example 1 except that the support 2 having a thickness of 40 μm prepared above was used, and the same evaluation as in Example 1 was performed.

Example 3 An antireflection film was prepared in the same manner as in Example 1 except that the support 3 having a thickness of 40 μm prepared above was used, and the same evaluation as in Example 1 was performed.

Comparative Example 1 An antireflection film for comparison was prepared in the same manner as in Example 1 except that a triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm was used. Then, the same evaluation as in Example 1 was performed.

Comparative Example 2 An antireflection film for comparison was prepared in the same manner as in Example 1 except that the gelatin layer was not provided, and the same evaluation as in Example 1 was performed.

In the antireflection films of Examples 1 to 3, the antireflection film of Comparative Example 1 has a thickness of about 80 μm.
The thickness could be reduced to about 40 μm. Moreover, the smoothness evaluation of the antireflection film of Comparative Example 2 was x, while the antireflection films of Examples 1 to 3 were all o. Moreover, the antireflection films of Examples 1 to 3 all have an average reflectance of 0.28%, a * = 2, and b * = − 6, and both low reflectance and reduction of tint are compatible, which is highly preferable. Has reflective properties. Further, the pencil hardness is 3 in Examples 1 and 2.
H, Example 3 is as high as 4H and is hard to be scratched.

Example 4 The antireflection film prepared in Example 1 was dipped in a 2.0 N NaOH aqueous solution at 55 ° C. for 2 minutes to saponify the triacetyl cellulose surface on the back surface of the film. , A support 1 and a saponified film under the same conditions are used to bond both sides of a polarizer prepared by adsorbing iodine to polyvinyl alcohol and stretching it.
Protected and made a polarizing plate. The polarizing plate prepared in this manner was used for the transmission TN so that the antireflection film side became the outermost surface.
Liquid crystal display device for a notebook computer equipped with a liquid crystal display device (a polarization separation film having a polarization selection layer, Sumitomo 3M
When a polarizing plate on the viewing side (having a D-BEF manufactured by Co., Ltd., which is provided between the backlight and the liquid crystal cell) is replaced, the display of an extremely high display quality is obtained with very little background reflection. Was given.

[Example 5] In Example 4, saponification of the antireflection film was performed by adding a 1.0N KOH aqueous solution to
When applied to a liquid crystal display device in the same manner as in Example 4 except that it was applied to the back surface of the antireflection film with 3 bars, treated at a film surface temperature of 60 ° C. for 10 seconds, washed with water, and dried. A display device with high display quality similar to that in Example 4 was obtained.

Example 6 The support 1 having a thickness of 40 μm was immersed in a 2.0 N NaOH aqueous solution at 55 ° C. for 2 minutes to saponify both sides of the film, and then the same reflection as in Example 1 was performed. A polarizing plate was prepared by adhering and protecting both surfaces of a polarizer using the antireflection film having the antireflection layer and the support saponified under the same conditions.

[Comparative Example 3] In Example 4, the support 1 was used.
Instead of 80 μm thick triacetyl cellulose film (TAC-TD80U, Fuji Photo Film Co., Ltd.)
A polarizing plate was prepared in the same manner as in Example 4, except that

The polarizing plates of Examples 4 and 5 could be thinned to about 160 μm, while the polarizing plate of Comparative Example 3 had a thickness of about 230 μm. In addition, it had excellent smoothness and had very preferable reflection characteristics.

[Embodiment 7] Protective film on the liquid crystal cell side of the polarizing plate on the visible side of the transmissive TN liquid crystal cell to which the antireflection film of Example 1 is attached, and protection on the liquid crystal cell side of the polarizing plate on the backlight side. In the film, the disc surface of the discotic structural unit is inclined with respect to the transparent support surface, and the angle formed by the disc surface of the discotic structural unit and the transparent support surface changes in the depth direction of the optical anisotropic layer. Angle widening film having an optical compensation layer (Wide View Film SA-12B, Fuji Photo Film Co., Ltd.)
Manufactured), a liquid crystal display device having a high contrast in a bright room, a wide viewing angle in the vertical and horizontal directions, a very high visibility, and a high display quality was obtained.

[Example 8] An antireflection film having a forward scattering function was prepared in the same manner as in Example 1 except that the coating solution B for hard coat layer was used instead of the coating solution A for hard coat. In the same manner as in Example 7, the forward scattering antireflection film was formed on the outermost surface side, and the viewing angle widening film wide view film (WV-12) was formed on the liquid crystal cell side.
A transmissive TN liquid crystal display device in which a polarizing plate having A, Fuji Photo Film Co., Ltd. was arranged was prepared. The liquid crystal display device manufactured in this manner has an improved limit angle from 40 degrees to 60 degrees at which gradation inversion occurs when the viewing angle is tilted downward, as compared with Example 7, and the visibility and display quality are improved. It was very good at.

Example 9 When the antireflection film prepared in Example 1 was attached to a glass plate on the surface of an organic EL display device via an adhesive, reflection on the glass surface was suppressed and visibility was improved. A high display device can be obtained.

[Example 10] A glass on the surface of an organic EL display device was prepared by laminating a λ / 4 plate on the opposite surface of the polarizing plate with a single-sided antireflection film prepared in Example 1 from the side having the antireflection film. When it was attached to the board, surface reflection and
Reflection from the inside of the surface glass was cut, and an extremely highly visible display was obtained. [Example 11] A polarizing plate was prepared in the same manner as in Example 4 except that a polarizer prepared by the following method was used as a polarizer prepared by adsorbing iodine on polyvinyl alcohol and stretching. The PVA film is dipped in an aqueous solution of 5.0 g / l iodine and 10.0 g / l potassium iodide at 25 ° C. for 90 seconds, and further immersed in an aqueous solution of 10 g / l boric acid at 25 ° C. for 60 seconds.
After second immersion, Fi of US Patent Publication No. 2002-8840
g. It was introduced into a tenter stretching machine of the form 2, once stretched to 7.0 times and then shrunk to 5.3 times, thereafter the width was kept constant, dried at 70 ° C., and then removed from the tenter. The difference in transport speed between the left and right tenter clips was less than 0.05%, and the angle between the center line of the film introduced and the center line of the film sent to the next step was 0 °. Where | L
Both 1-L2 | and W were 0.7 m. Wrinkles and film deformation at the tenter exit were not observed. The absorption axis direction of the obtained polarizing plate was inclined by 45 ° with respect to the longitudinal direction. The transmittance of this polarizing plate at 550 nm is 4
The degree of polarization was 3.3% and the degree of polarization was 99.98%. It was possible to obtain a polarizing plate with an antireflection function, in which the absorption axis was inclined at 45 ° with respect to the side and which had good area efficiency.

[0091]

INDUSTRIAL APPLICABILITY The antireflection film of the present invention can form an antireflection layer while maintaining the smoothness of the support surface even when a thin cellulose acylate is used. The deterioration of visibility due to is prevented at a high level. In addition, even when a high-luminance light source such as a fluorescent lamp on the back of the user who is facing the display is reflected on the display surface, it does not become reddish purple or bluish purple,
Little deterioration in display quality. When this is applied to a polarizing plate and arranged in a display device such as a liquid crystal display device, a thin liquid crystal display device having excellent visibility is obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing a specific example of an antireflection film of the present invention.

[Explanation of symbols]

1 support 2 Water-soluble polymer layer 3 hard coat layer 4 Middle refractive index layer 5 High refractive index layer 6 Low refractive index layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/1335 G02B 1/10 A // H01J 29/89 Z F term (reference) 2H049 BA02 BB16 BB65 BC22 2H091 FA08X FA08Z FA37X FA37Z FB02 LA02 LA16 LA19 2K009 AA06 AA15 BB28 CC03 DD02 DD05 4F100 AA19 AA20 AJ05A AK01B AK12 AK21 AK25 AR00A BA03 BA07 BA10A BA10C GB41 GB90 JB09B JN30C EY00EE03C03 YY00A5C03

Claims (4)

[Claims] 1. A support comprising a cellulose acylate having a thickness of 10 to 70 μm, a water-soluble polymer layer adjacent to the support, and an antireflection layer directly or via another layer on the water-soluble polymer layer. An antireflection film having. 2. A reflection characterized in that a water-soluble polymer layer is provided on a support made of cellulose acylate having a thickness of 10 to 70 μm, and an antireflection layer is formed thereon directly or through another layer. Method for producing anti-reflection film. 3. A polarizing plate comprising the antireflection film according to claim 1 as a protective film on at least one surface. 4. An image display device comprising at least one of the antireflection film according to claim 1 or the polarizing plate according to claim 3.