JP2006227162A - Antireflection film, method of manufacturing antireflection film, polarizing plate, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film which is improved in scratch resistance, cracking resistance, haze light resistance and coating evenness, to provide a method of manufacturing the antireflection film, and to provide a polarizer and a display device which are excellent in visibility by using the antireflection film. <P>SOLUTION: The antireflection film is formed by sequentially laminating a high refractive index layer: consisting of a composition which includes metal oxide fine particles (a) having an average particle size of 10 to 200 nm, a metal compound (b) and an ionizing radiation curable resin (c); and having a refractive index higher than that of a transparent substrate film, and a low refractive index layer: consisting of a composition which includes organic silicone compound expressed by general formula Si(OR)<SB>4</SB>or polymer (d) comprising the same and hollow silica fine particles (e) having outer core layers and porous or hollow inner part; and having a refractive index lower than that of a transparent substrate film, with respect to the antireflection film having optical interference layers of two layers or more disposed on the transparent substrate film. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antireflection film, a method for producing an antireflection film, a polarizing plate, and a display device, and more specifically, an antireflection film having improved scratch resistance, cracks, haze, light resistance, and coating unevenness, and a method for producing an antireflection film. Further, the present invention relates to a polarizing plate and a display device having excellent visibility using the antireflection film.

  For an antireflection film used on the outermost surface of an image display device such as a liquid crystal, a technique has been proposed in which an antireflection layer of an optical interference system is provided to achieve a low reflectance.

  As a technique for reducing the reflectance, there is a method of reducing the refractive index of the low refractive index layer on the outermost surface, and a low refractive index material or a method of reducing the refractive index by increasing the number of voids has been proposed. However, in any technique, the film strength and scratch resistance are weak points.

  A recently proposed technique using hollow silica-based fine particles having an outer shell layer and having a porous or hollow interior (see, for example, Patent Documents 1 to 3) maintained a decrease in refractive index due to voids. This is a technique for improving the film strength. Nevertheless, the film strength is insufficient, and the low refractive index layer containing 20% by mass or more of hollow fine particles has a problem that the film strength falls below the practical film strength.

  In addition, a method of forming a metal oxide film by applying a metal alkoxide typified by titanium alkoxide or silane alkoxide on the surface of a support, drying, and heating has been performed. However, this method requires a high heating temperature of 300 ° C. or higher and damages the support, and the heating temperature as described in JP-A-8-75904 has a relatively low heating temperature of 100 ° C. A long time was required for the production, and both had problems.

  On the other hand, as a method of forming a metal oxide film, for example, a method of forming a silica-based film as a base film of a functional film by a so-called sol-gel method (see Patent Document 4), and further, a low refractive index layer is formed. Similarly, a method of forming by a sol-gel method (see Patent Document 5) is known. However, this method also had insufficient scratch resistance.

Also, techniques using a fluorine-based resin as a binder component (for example, see Patent Documents 6 to 8) have a problem that the film strength is weak although the refractive index is lowered. That is, there is a trade-off relationship between lowering the refractive index and film strength, and there is a need for improvement.
Japanese Patent Laid-Open No. 2001-167637 JP 2001-233611 A JP 2002-79616 A JP-A-11-269657 JP 2000-910 A JP 2003-236970 A JP 2003-240906 A JP 2003-255103 A

  The present invention has been made in view of the above problems, and an object thereof is to provide an antireflection film with improved scratch resistance, cracks, haze light resistance, and coating unevenness, and a method for producing the antireflection film. An object of the present invention is to provide a polarizing plate and a display device having excellent visibility by using the antireflection film.

  The above object of the present invention is achieved by the following configurations.

(Claim 1)
In the antireflection film having a high refractive index layer having a higher refractive index than the transparent substrate film and a low refractive index layer having a lower refractive index than the transparent substrate film on the transparent substrate film, the high refractive index The layer is formed by coating a coating solution containing the following (a) to (c), and the low refractive index layer is formed by coating a coating solution containing the following (d) and (e): An antireflection film.
(A) Metal oxide fine particles having an average particle diameter of 10 to 200 nm (b) Metal compound (c) Ionizing radiation curable resin (d) Organosilicon compound represented by the following general formula (1) or a hydrolyzate thereof Or its polycondensate General formula (1) Si (OR) ₄
(In the formula, R is an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms.)
(E) Hollow silica-based fine particles having an outer shell layer and having a porous or hollow interior (Claim 2)
The metal oxide fine particles are at least one selected from zirconium oxide, antimony oxide, tin oxide, zinc oxide, indium-tin oxide (ITO), antimony-doped tin oxide (ATO), and zinc antimonate. The antireflection film according to claim 1.

(Claim 3)
The metal compound is a compound represented by the following general formula (2) or a chelate compound thereof, and the content of the metal oxide derived from the metal compound contained in the high refractive index layer is 0.3 to 5% by mass. The antireflection film according to claim 1, wherein the antireflection film is provided.

General formula (2) _An MB _xn
(In the formula, M represents a metal atom, A represents a hydrolyzable functional group or a hydrocarbon group having a hydrolyzable functional group, B represents an atomic group covalently or ionically bonded to the metal atom M. x represents a metal. The valence of atom M, n represents an integer of 2 or more and x or less.)
(Claim 4)
The said metal compound is at least 1 sort (s) chosen from the group which consists of titanium alkoxide, zirconium alkoxide, and those chelate compounds, The antireflection film in any one of Claims 1-3 characterized by the above-mentioned.

(Claim 5)
The antireflection film according to any one of claims 1 to 4, wherein the ionizing radiation curable resin has an acrylic compound having two or more unsaturated bonds capable of being polymerized in a molecule.

(Claim 6)
6. The acrylic compound according to claim 5, wherein the acrylic compound is a compound selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. The antireflection film as described.

(Claim 7)
The ionizing radiation curable resin contains a photopolymerization initiator and an acrylic compound having two or more unsaturated bonds polymerizable in a molecule in a mass ratio of 3: 7 to 1: 9. Item 7. The antireflection film according to any one of Items 1 to 6.

(Claim 8)
The high refractive index layer formed using a composition containing (a) metal oxide fine particles having an average particle diameter of 10 to 200 nm, (b) a metal compound, and (c) an ionizing radiation curable resin. And (b) having a high refractive index layer in which the ratio of the mass of the metal oxide derived from the metal compound to the mass of (c) the ionizing radiation curable resin is 1: 3 to 1: 100. The antireflection film according to any one of claims 1 to 7.

(Claim 9)
The antireflective film according to any one of claims 1 to 8, wherein the high refractive index layer and the low refractive index layer contain (f) a fluorine-based or silicone-based surfactant.

(Claim 10)
The antireflection film according to any one of claims 1 to 9, wherein the antireflective film is heat-treated at 50 to 160 ° C after the low refractive index layer is laminated.

(Claim 11)
In a method for producing an antireflection film in which at least a high refractive index layer and a low refractive index layer are provided on a transparent substrate film directly or via another layer, (a) metal oxide fine particles having an average particle diameter of 10 to 200 nm (B) a step of providing a high refractive index layer having a refractive index higher than that of the substrate using a composition containing a metal compound and (c) an ionizing radiation curable resin, and (d) the following general formula (1) And a hydrolyzate thereof or a polycondensate thereof, and (e) a composition containing hollow silica-based fine particles having an outer layer and porous or hollow inside. And a process for providing a low refractive index layer having a refractive index lower than that of the substrate.

General formula (1) Si (OR) ₄
(In the formula, R is an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms.)
(Claim 12)
The method for producing an antireflection film according to claim 11, wherein the low-refractive index layer is provided and then wound into a roll, and then heat-treated at 50 to 160 ° C.

(Claim 13)
A polarizing plate having the antireflection film according to any one of claims 1 to 10 on one side and an optical compensation film on the other side.

(Claim 14)
A display device comprising the antireflection film according to claim 1 or the polarizing plate according to claim 13.

  According to the present invention, it is possible to provide an antireflection film having improved scratch resistance, cracks, haze, light resistance, and coating unevenness, and a method for producing the antireflection film. Further, by using the antireflection film, the visibility is excellent. A polarizing plate and a display device can be provided.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

The invention according to claim 1 of the present invention includes a high refractive index layer having a refractive index higher than that of the transparent substrate film and a low refractive index layer having a refractive index lower than that of the transparent substrate film on the transparent substrate film. In the antireflective film, the high refractive index layer is formed by coating at least a coating liquid containing the following (a) to (c), and the low refractive index layer contains at least the following (d) and (e) The present inventors have found that an antireflection film with improved scratch resistance, cracks, haze, light resistance, and coating unevenness can be obtained by an antireflection film formed by coating a coating liquid.
(A) Metal oxide fine particles having an average particle diameter of 10 to 200 nm (b) Metal compound (c) Ionizing radiation curable resin (d) Organosilicon compound represented by the general formula (1) or a hydrolyzate thereof Or the polycondensate (e) hollow silica-based fine particles having an outer shell layer and having a porous or hollow inside. As a result of intensive studies to solve the above problems, the present inventors have obtained a low refractive index layer. It has been found that the composition strength of the adjacent layer significantly improves the film strength of the low refractive index layer containing the hollow silica fine particles, and the adjacent layer (high refractive index layer according to the present invention) having a specific configuration is hollow. By disposing it below the low refractive index layer containing silica-based fine particles, the object of the present invention can be achieved.

  The present invention will be described in detail below.

<High refractive index layer>
(Metal oxide fine particles of high refractive index layer)
The high refractive index layer according to the present invention contains metal oxide fine particles. The kind of metal oxide fine particles is not particularly limited, and Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P and S A metal oxide having at least one element selected from the above can be used, and these metal oxide fine particles are doped with a trace amount of atoms such as Al, In, Sn, Sb, Nb, a halogen element, and Ta. May be. A mixture of these may also be used. In the present invention, at least one metal oxide fine particle selected from among zirconium oxide, antimony oxide, tin oxide, zinc oxide, indium-tin oxide (ITO), antimony-doped tin oxide (ATO), and zinc antimonate is used. It is preferably used as a main component, and particularly preferably indium tin oxide (ITO).

  The average particle diameter of the primary particles of these metal oxide fine particles is in the range of 10 nm to 200 nm, particularly preferably 10 to 150 nm. The average particle diameter of the metal oxide fine particles can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like. You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc. If the particle size is too small, aggregation tends to occur and the dispersibility deteriorates. If the particle size is too large, the haze is remarkably increased. The shape of the metal oxide fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a needle shape, or an indefinite shape.

  Specifically, the refractive index of the high refractive index layer is higher than the refractive index of the transparent substrate film as the support, and is preferably in the range of 1.50 to 1.70 at 23 ° C. and a wavelength of 550 nm. . The means for adjusting the refractive index of the high refractive index layer is that the kind and addition amount of the metal oxide fine particles are dominant, so that the refractive index of the metal oxide fine particles is preferably 1.80 to 2.60, More preferably, it is 1.85 to 2.50.

  The metal oxide fine particles may be surface-treated with an organic compound. By modifying the surface of the metal oxide fine particles with an organic compound, the dispersion stability in an organic solvent is improved, the dispersion particle size can be easily controlled, and aggregation and sedimentation over time can be suppressed. . For this reason, the surface modification amount with a preferable organic compound is 0.1 mass%-5 mass% with respect to metal oxide particle, More preferably, it is 0.5 mass%-3 mass%. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Among these, the silane coupling agent mentioned later is preferable. Two or more kinds of surface treatments may be combined.

  The thickness of the high refractive index layer containing the metal oxide fine particles is preferably 5 nm to 1 μm, more preferably 10 nm to 0.2 μm, and most preferably 30 nm to 0.1 μm.

  The ratio of the metal oxide fine particles to be used and a binder such as ionizing radiation curable resin, which will be described later, varies depending on the type of metal oxide fine particles, the particle size, etc. The latter one is preferable.

  The amount of the metal oxide fine particles used in the present invention is preferably 5% by mass to 85% by mass in the high refractive index layer, more preferably 10% by mass to 80% by mass, and most preferably 20% to 75% by mass. preferable. If the amount used is small, the desired refractive index and the effect of the present invention cannot be obtained, and if it is too large, the film strength is deteriorated.

  The metal oxide fine particles are supplied to a coating solution for forming a high refractive index layer in a dispersion state dispersed in a medium. As a dispersion medium for metal oxide particles, it is preferable to use a liquid having a boiling point of 60 to 170 ° C. Specific examples of the dispersion solvent include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ketone alcohol (eg, diacetone alcohol). , Esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene) Chloride, chloroform, carbon tetrachloride), aromatic hydrocarbons (eg, benzene, toluene, xylene), amides (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ethers (eg, diethyl ether, dioxane, Tiger hydrofuran), ether alcohols (e.g., 1-methoxy-2-propanol). Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are particularly preferable.

  The metal oxide fine particles can be dispersed in the medium using a disperser. Examples of the disperser include a sand grinder mill (eg, a bead mill with pins), a high-speed impeller mill, a pebble mill, a roller mill, an attritor, and a colloid mill. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

  In the present invention, metal oxide fine particles having a core / shell structure may be further contained. One layer of the shell may be formed around the core, or a plurality of layers may be formed in order to further improve the light resistance. The core is preferably completely covered by the shell.

  For the core, titanium oxide (rutile type, anatase type, amorphous type, etc.), zirconium oxide, zinc oxide, cerium oxide, indium oxide doped with tin, tin oxide doped with antimony, etc. can be used. Titanium may be the main component.

  The shell is preferably formed of a metal oxide or sulfide containing an inorganic compound other than titanium oxide as a main component. For example, an inorganic compound mainly composed of silicon dioxide (silica), aluminum oxide (alumina) zirconium oxide, zinc oxide, tin oxide, antimony oxide, indium oxide, iron oxide, zinc sulfide, or the like is used. Of these, alumina, silica, and zirconia (zirconium oxide) are preferable. A mixture of these may also be used.

  The coating amount of the shell with respect to the core is 2 to 50% by mass as an average coating amount. Preferably it is 3-40 mass%, More preferably, it is 4-25 mass%. When the coating amount of the shell is large, the refractive index of the fine particles is lowered, and when the coating amount is too small, the light resistance is deteriorated. Two or more inorganic fine particles may be used in combination.

  The titanium oxide used as a core can use what was produced by the liquid phase method or the gaseous-phase method. As a method for forming the shell around the core, for example, U.S. Pat. No. 3,410,708, JP-B-58-47061, U.S. Pat. No. 2,885,366, and U.S. Pat. No. 1, British Patent No. 1,134,249, US Pat. No. 3,383,231, British Patent No. 2,629,953, No. 1,365,999, etc. Can do.

(Metal compound)
As the metal compound used in the present invention, a compound represented by the following general formula (2) or a chelate compound thereof can be used.

General formula (2) _An MB _xn
In the formula, M represents a metal atom, A represents a hydrolyzable functional group or a hydrocarbon group having a hydrolyzable functional group, and B represents an atomic group covalently or ionically bonded to the metal atom M. x represents the valence of the metal atom M, and n represents an integer of 2 or more and x or less.

  Examples of the hydrolyzable functional group A include halogens such as alkoxyl groups and chloro atoms, ester groups and amide groups. The metal compound belonging to the above formula (2) includes an alkoxide having two or more alkoxyl groups bonded directly to a metal atom, or a chelate compound thereof. Preferable metal compounds include titanium alkoxide, zirconium alkoxide, or chelate compounds thereof. Titanium alkoxide has a high reaction rate and a high refractive index and is easy to handle. However, since it has a photocatalytic action, its light resistance deteriorates when added in a large amount. Zirconium alkoxide has a high refractive index but tends to become cloudy, so care must be taken in dew point management during coating. Moreover, since titanium alkoxide has the effect of promoting the reaction between the ultraviolet curable resin and the metal alkoxide, the physical properties of the coating film can be improved even by adding a small amount.

  Surprisingly, the scratch resistance of the low refractive index layer laminated on the high refractive index layer containing the metal compound could be remarkably improved.

  Examples of the titanium alkoxide include tetramethoxy titanium, tetraethoxy titanium, tetra-iso-propoxy titanium, tetra-n-propoxy titanium, tetra-n-butoxy titanium, tetra-sec-butoxy titanium, tetra-tert-butoxy titanium, and the like. Is mentioned.

  Examples of the zirconium alkoxide include tetramethoxy zirconium, tetraethoxy zirconium, tetra-iso-propoxy zirconium, tetra-n-propoxy zirconium, tetra-n-butoxy zirconium, tetra-sec-butoxy zirconium, tetra-tert-butoxy zirconium and the like. Is mentioned.

  Preferred chelating agents for forming a chelate compound by coordination with a free metal compound include alkanolamines such as diethanolamine and triethanolamine, glycols such as ethylene glycol, diethylene glycol and propylene glycol, acetylacetone and acetoacetic acid. Examples thereof include ethyl and the like having a molecular weight of 10,000 or less. By using these chelating agents, it is possible to form a chelate compound that is stable against water mixing and is excellent in the effect of reinforcing the coating film.

  The addition amount of the metal compound is preferably adjusted so that the content of the metal oxide derived from the metal compound contained in the high refractive index layer is 0.3 to 5% by mass. If it is less than 0.3% by mass, the scratch resistance is insufficient, and if it exceeds 5% by mass, the light resistance tends to deteriorate.

(Ionizing radiation curable resin)
The ionizing radiation curable resin is added as a binder for the metal oxide fine particles to improve the film formability and physical properties of the coating film. As the ionizing radiation curable resin, a monomer or oligomer having two or more functional groups that cause polymerization reaction directly by irradiation of ionizing radiation such as ultraviolet rays or electron beams or indirectly by the action of a photopolymerization initiator is used. Can be used. Examples of the functional group include a group having an unsaturated double bond such as a (meth) acryloyloxy group, an epoxy group, and a silanol group. Among these, radically polymerizable monomers and oligomers having two or more unsaturated double bonds can be preferably used. You may combine a photoinitiator as needed. Examples of such ionizing radiation curable resins include polyfunctional acrylate compounds and the like, and the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. It is preferable that it is a compound chosen from these. Here, the polyfunctional acrylate compound is a compound having two or more acryloyloxy groups and / or methacryloyloxy groups in the molecule.

  Examples of the monomer of the polyfunctional acrylate compound include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethanetriacrylate. Acrylate, tetramethylol methane tetraacrylate, pentaglycerol triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, glycerin triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, Dipen Erythritol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, tetra Methylol methane trimethacrylate, tetramethylol methane tetramethacrylate, pentaglycerol trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerin trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol te La methacrylate, dipentaerythritol penta methacrylate, dipentaerythritol hexa methacrylate preferred. These compounds are used alone or in admixture of two or more. Moreover, oligomers, such as a dimer and a trimer of the said monomer, may be sufficient.

  The addition amount of the ionizing radiation curable resin is preferably 15% by mass or more and less than 50% by mass in the solid content in the high refractive index composition.

  In order to accelerate the curing of the ionizing radiation curable resin according to the present invention, the photopolymerization initiator and the acrylic compound having two or more polymerizable unsaturated bonds in the molecule are in a mass ratio of 3: 7 to 1: 9. It is preferable to contain.

  Specific examples of the photopolymerization initiator include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof, but are not particularly limited thereto.

(solvent)
Examples of the organic solvent used for coating the high refractive index layer of the present invention include alcohols (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol). , Cyclohexanol, benzyl alcohol, etc.), polyhydric alcohols (eg, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexane Triol, thiodiglycol, etc.), polyhydric alcohol ethers (for example, ethylene glycol monomethyl ether) Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol Monoethyl ether, ethylene glycol monophenyl ether, propylene glycol monophenyl ether, etc.), amines (for example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine) , Ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, etc.), amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide) Etc.), heterocyclic rings (for example, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, etc.), sulfoxides (for example, dimethyl sulfoxide, etc.) ), Sulfones (for example, sulfolane, etc.), urea, acetonitrile, acetone and the like, and alcohols, polyhydric alcohols, and polyhydric alcohol ethers are particularly preferable.

<Low refractive index layer>
The refractive index of the low refractive index layer according to the present invention is preferably lower than the refractive index of the transparent substrate film as a support and is in the range of 1.30 to 1.45 at 23 ° C. and a wavelength of 550 nm.

  The film thickness of the low refractive index layer is preferably 5 nm to 0.5 μm, more preferably 10 nm to 0.3 μm, and most preferably 30 nm to 0.2 μm.

  The composition for forming a low refractive index layer used in the present invention comprises (d) an organosilicon compound represented by the following general formula (1) or a hydrolyzate thereof or a polycondensate thereof, and (e) an outer shell layer. Hollow silica-based fine particles having a porous or hollow interior are essential components.

General formula (1) Si (OR) ₄
(In the formula, R is an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms.)
In addition, a silane coupling agent, a curing agent, a surfactant and the like may be added as necessary.

[Hollow silica fine particles]
The hollow silica-based fine particles having the outer shell layer represented by (e) and having a porous or hollow interior will be described.

  The hollow silica-based fine particles are (I) composite particles comprising porous particles and a coating layer provided on the surface of the porous particles, or (II) having cavities inside, and the contents are solvent, gas or porous It is a hollow particle filled with a porous material. Note that the low refractive index layer only needs to contain either (I) composite particles or (II) hollow particles, or both.

  The hollow particles are particles having cavities inside, and the cavities are surrounded by particle walls. The cavity is filled with contents such as a solvent, a gas, or a porous material used at the time of preparation. It is desirable that the average particle size of such hollow fine particles is in the range of 5 to 300 nm, preferably 10 to 200 nm. The average particle diameter of the hollow fine particles used is appropriately selected according to the thickness of the transparent film to be formed, and is in the range of 2/3 to 1/10 of the film thickness of the transparent film such as the low refractive index layer to be formed. It is desirable to be in These hollow fine particles are preferably used in a state of being dispersed in an appropriate medium in order to form a low refractive index layer. As the dispersion medium, water, alcohol (for example, methanol, ethanol, isopropyl alcohol), ketone (for example, methyl ethyl ketone, methyl isobutyl ketone), and ketone alcohol (for example, diacetone alcohol) are preferable.

  The thickness of the coating layer of the composite particles or the thickness of the particle walls of the hollow particles is desirably in the range of 1 to 20 nm, preferably 2 to 15 nm. In the case of composite particles, if the thickness of the coating layer is less than 1 nm, the particles may not be completely covered, and it is easy to use a silicate monomer or oligomer having a low polymerization degree, which is a coating liquid component described later. In some cases, the composite particles enter the inside of the composite particles and the internal porosity is reduced, so that the effect of the low refractive index cannot be sufficiently obtained. When the thickness of the coating layer exceeds 20 nm, the silicic acid monomer and oligomer do not enter the inside, but the porosity (pore volume) of the composite particles is lowered and the effect of low refractive index is sufficiently obtained. It may not be possible. In the case of hollow particles, if the particle wall thickness is less than 1 nm, the particle shape may not be maintained, and even if the thickness exceeds 20 nm, the effect of low refractive index may not be sufficiently exhibited. .

The coating layer of the composite particles or the particle wall of the hollow particles is preferably composed mainly of silica. In addition, components other than silica may be contained. Specifically, Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ , WO _{3 and the} like. Examples of the porous particles constituting the composite particles include those made of silica, those made of silica and an inorganic compound other than silica, and those made of CaF ₂ , NaF, NaAlF ₆ , MgF, and the like. Among these, porous particles made of a composite oxide of silica and an inorganic compound other than silica are particularly preferable. Examples of inorganic compounds other than silica include Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ , WO _{3 and the} like. 1 type or 2 types or more can be mentioned. In such porous particles, the molar ratio MO _X / SiO ₂ when the silica is expressed by SiO ₂ and the inorganic compound other than silica is expressed in terms of oxide (MO _X ) is 0.0001 to 1.0, Preferably it is in the range of 0.001 to 0.3. It is difficult to obtain a porous particle having a molar ratio MO _X / SiO ₂ of less than 0.0001. Even if it is obtained, particles having a small pore volume and a low refractive index cannot be obtained. In addition, when the molar ratio MO _X / SiO _{2 of} the porous particles exceeds 1.0, the ratio of silica decreases, so that the pore volume increases and it is difficult to obtain a low refractive index. is there.

  The pore volume of such porous particles is desirably in the range of 0.1 to 1.5 ml / g, preferably 0.2 to 1.5 ml / g. If the pore volume is less than 0.1 ml / g, particles having a sufficiently reduced refractive index cannot be obtained. If the pore volume exceeds 1.5 ml / g, the strength of the fine particles is lowered, and the strength of the resulting coating may be lowered. is there.

  In addition, the pore volume of such porous particles can be determined by a mercury intrusion method. Examples of the contents of the hollow particles include a solvent, a gas, and a porous substance used at the time of preparing the particles. The solvent may contain an unreacted particle precursor used in preparing the hollow particles, the catalyst used, and the like. Examples of the porous substance include those composed of the compounds exemplified for the porous particles. These contents may be composed of a single component or may be a mixture of a plurality of components.

  As a method for producing such hollow fine particles, for example, the method for preparing composite oxide colloidal particles disclosed in paragraphs [0010] to [0033] of JP-A-7-133105 is suitably employed. Specifically, when the composite particles are composed of silica and an inorganic compound other than silica, hollow fine particles are produced from the following first to third steps.

First Step: Preparation of Porous Particle Precursor In the first step, an alkali aqueous solution of a silica raw material and an inorganic compound raw material other than silica is separately prepared in advance, or a silica raw material and an inorganic compound raw material other than silica are prepared in advance. A mixed aqueous solution is prepared, and this aqueous solution is gradually added to an aqueous alkaline solution having a pH of 10 or more while stirring according to the composite ratio of the target composite oxide to prepare a porous particle precursor.

  As the silica raw material, alkali metal, ammonium or organic base silicate is used. Sodium silicate (water glass) or potassium silicate is used as the alkali metal silicate. Examples of the organic base include quaternary ammonium salts such as tetraethylammonium salt, and amines such as monoethanolamine, diethanolamine, and triethanolamine. The ammonium silicate or the organic base silicate includes an alkaline solution obtained by adding ammonia, a quaternary ammonium hydroxide, an amine compound or the like to a silicic acid solution.

  In addition, alkali-soluble inorganic compounds are used as raw materials for inorganic compounds other than silica. Specifically, an oxo acid of an element selected from Al, B, Ti, Zr, Sn, Ce, P, Sb, Mo, Zn, W, etc., an alkali metal salt or alkaline earth metal salt of the oxo acid, ammonium And salts and quaternary ammonium salts. More specifically, sodium aluminate, sodium tetraborate, zirconyl ammonium carbonate, potassium antimonate, potassium stannate, sodium aluminosilicate, sodium molybdate, cerium ammonium nitrate, and sodium phosphate are suitable.

Although the pH value of the mixed aqueous solution changes simultaneously with the addition of these aqueous solutions, an operation for controlling the pH value within a predetermined range is not particularly required. The aqueous solution finally has a pH value determined by the type of inorganic oxide and the mixing ratio thereof. There is no restriction | limiting in particular in the addition rate of the aqueous solution at this time. Further, in the production of composite oxide particles, a dispersion of seed particles can be used as a starting material. The seed particles are not particularly limited, but inorganic oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ or ZrO ₂ or fine particles of these composite oxides are used. Usually, these sols are used. Can do. Furthermore, the porous particle precursor dispersion obtained by the above production method may be used as a seed particle dispersion. When using a seed particle dispersion, the pH of the seed particle dispersion is adjusted to 10 or higher, and then an aqueous solution of the compound is added to the above-mentioned alkaline aqueous solution while stirring. Also in this case, it is not always necessary to control the pH of the dispersion. When seed particles are used in this way, it is easy to control the particle size of the porous particles to be prepared, and particles with uniform particle sizes can be obtained.

  The silica raw material and the inorganic compound raw material described above have high solubility on the alkali side. However, when both are mixed in this highly soluble pH region, the solubility of oxo acid ions such as silicate ions and aluminate ions decreases, and these composites precipitate and grow into fine particles, or seed particles. It grows on the top and particle growth occurs. Therefore, it is not always necessary to perform pH control as in the conventional method for precipitation and growth of fine particles.

The composite ratio of the silica and the inorganic compound other than silica in the first step is calculated by converting the inorganic compound to silica into an oxide (MO _X ), and the molar ratio of MO _X / SiO ₂ is 0.05 to 2.0, Preferably it is in the range of 0.2-2.0. Within this range, the pore volume of the porous particles increases as the proportion of silica decreases. However, even when the molar ratio exceeds 2.0, the pore volume of the porous particles hardly increases. On the other hand, when the molar ratio is less than 0.05, the pore volume becomes small. When preparing the hollow particles, the molar ratio of MO _X / SiO ₂ is desirably in the range of 0.25 to 2.0.

Second step: Removal of inorganic compound other than silica from porous particles In the second step, inorganic compounds other than silica (elements other than silicon and oxygen) are obtained from the porous particle precursor obtained in the first step. At least a portion is selectively removed. As a specific removal method, the inorganic compound in the porous particle precursor is dissolved and removed using a mineral acid or an organic acid, or is contacted with a cation exchange resin for ion exchange removal.

  The porous particle precursor obtained in the first step is a particle having a network structure in which silicon and an inorganic compound constituent element are bonded through oxygen. By removing the inorganic compound (elements other than silicon and oxygen) from the porous particle precursor in this way, porous particles having a larger porosity and a larger pore volume can be obtained. Further, if the amount of removing the inorganic oxide (elements other than silicon and oxygen) from the porous particle precursor is increased, the hollow particles can be prepared.

  In addition, prior to removing inorganic compounds other than silica from the porous particle precursor, fluorine-substituted, obtained by dealkalizing an alkali metal salt of silica into the porous particle precursor dispersion obtained in the first step. It is preferable to add a silicic acid solution containing an alkyl group-containing silane compound or a hydrolyzable organosilicon compound to form a silica protective film. The thickness of the silica protective film may be 0.5 to 15 nm. Even if the silica protective film is formed, the protective film in this step is porous and thin, so that it is possible to remove inorganic compounds other than silica described above from the porous particle precursor.

  By forming such a silica protective film, inorganic compounds other than silica described above can be removed from the porous particle precursor while maintaining the particle shape. Further, when forming the silica coating layer described later, the pores of the porous particles are not blocked by the coating layer, and therefore the silica coating layer described later is formed without reducing the pore volume. Can do. Note that when the amount of the inorganic compound to be removed is small, the particles are not broken, and thus it is not always necessary to form a protective film.

  When preparing hollow particles, it is desirable to form this silica protective film. When preparing the hollow particles, the inorganic compound is removed to obtain a hollow particle precursor composed of a silica protective film, a solvent in the silica protective film, and an undissolved porous solid content. When a coating layer to be described later is formed on the precursor, the formed coating layer becomes a particle wall to form hollow particles.

The amount of the silica source added for forming the silica protective film is preferably small as long as the particle shape can be maintained. If the amount of the silica source is too large, the silica protective film becomes too thick, and it may be difficult to remove inorganic compounds other than silica from the porous particle precursor. The hydrolyzable organic silicon compound used for the silica protective film formed of the general formula _{R n Si (OR ') 4} -n [R, R': an alkyl group, an aryl group, a vinyl group, such as acrylic group An alkoxysilane represented by a hydrocarbon group, n = 0, 1, 2, or 3] can be used. In particular, tetraalkoxysilanes such as fluorine-substituted tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane are preferably used.

  As an addition method, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilane, pure water, and alcohol is added to the dispersion of the porous particles, and the alkoxysilane is hydrolyzed. The produced silicic acid polymer is deposited on the surface of the inorganic oxide particles. At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

  When the dispersion medium of the porous particle precursor is water alone or when the ratio of water to the organic solvent is high, a silica protective film can be formed using a silicic acid solution. When a silicic acid solution is used, a predetermined amount of the silicic acid solution is added to the dispersion, and at the same time an alkali is added to deposit the silicic acid solution on the surface of the porous particles. In addition, you may produce a silica protective film together using a silicic acid liquid and the said alkoxysilane.

Third step: Formation of silica coating layer In the third step, the porous particle dispersion prepared in the second step (in the case of hollow particles, the hollow particle precursor dispersion) contains a fluorine-substituted alkyl group-containing silane compound. By adding a hydrolyzable organosilicon compound or silicic acid solution, the surface of the particles is coated with a polymer such as a hydrolyzable organosilicon compound or silicic acid solution to form a silica coating layer.

The hydrolyzable organic silicon compound used for the silica coating layer formed, the above-mentioned such general formula _{R n Si (OR ') 4} -n [R, R': an alkyl group, an aryl group, a vinyl group, An alkoxysilane represented by a hydrocarbon group such as an acryl group, n = 0, 1, 2, or 3] can be used. In particular, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane are preferably used.

  As an addition method, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilane, pure water, and alcohol is used as a dispersion of the porous particles (in the case of hollow particles, a hollow particle precursor). In addition, the silicic acid polymer produced by hydrolyzing alkoxysilane is deposited on the surface of the porous particles (in the case of hollow particles, hollow particle precursors). At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

  When the dispersion medium of porous particles (in the case of hollow particles, the hollow particle precursor) is water alone or a mixed solvent with an organic solvent and the mixed solvent has a high ratio of water to the organic solvent, a silicate solution You may form a coating layer using. The silicic acid solution is an aqueous solution of a low silicic acid polymer obtained by dealkalizing an aqueous solution of an alkali metal silicate such as water glass by ion exchange treatment.

  The silicic acid solution is added to the dispersion of porous particles (in the case of hollow particles, hollow particle precursors), and at the same time, alkali is added to make the low-silicic acid polymer into porous particles (in the case of hollow particles, hollow particle precursors). ) Deposit on the surface. In addition, you may use a silicic acid liquid for the coating layer formation in combination with the said alkoxysilane. The addition amount of the organosilicon compound or silicic acid solution used for forming the coating layer only needs to be sufficient to cover the surface of the colloidal particles, and the finally obtained silica coating layer has a thickness of 1 to 20 nm. In such an amount, it is added in a dispersion of porous particles (in the case of hollow particles, hollow particle precursor) in a dispersion. When the silica protective film is formed, the organosilicon compound or the silicate solution is added in such an amount that the total thickness of the silica protective film and the silica coating layer is in the range of 1 to 20 nm.

  Next, the dispersion liquid of the particles on which the coating layer is formed is heat-treated. By the heat treatment, in the case of porous particles, the silica coating layer covering the surface of the porous particles is densified, and a dispersion of composite particles in which the porous particles are coated with the silica coating layer is obtained. In the case of a hollow particle precursor, the formed coating layer is densified to form hollow particle walls, and a dispersion of hollow particles having cavities filled with a solvent, gas, or porous solid content is obtained.

  The heat treatment temperature at this time is not particularly limited as long as it can close the fine pores of the silica coating layer, and is preferably in the range of 80 to 300 ° C. When the heat treatment temperature is less than 80 ° C., the fine pores of the silica coating layer may not be completely closed and densified, and the treatment time may take a long time. Further, when the heat treatment temperature exceeds 300 ° C. for a long time, fine particles may be formed, and the effect of low refractive index may not be obtained.

  The refractive index of the inorganic fine particles thus obtained is as low as less than 1.42. Such inorganic fine particles are presumed to have a low refractive index because the porosity inside the porous particles is maintained or the inside is hollow.

  The content of the hollow silica-based fine particles having an outer shell layer and porous or hollow inside is preferably 10 to 50% by mass. In order to obtain the effect of a low refractive index, the content is preferably 15% by mass or more. Most preferably, it is 20-50 mass%.

  In the organic silicon compound represented by the general formula (1), R represents an alkyl group having 1 to 4 carbon atoms.

  Specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used.

  As a method of adding to the low refractive index layer, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these tetraalkoxysilane, pure water, and alcohol is added to the dispersion of the hollow silica fine particles. The silicic acid polymer produced by hydrolyzing tetraalkoxysilane is deposited on the surface of the hollow silica fine particles. At this time, tetraalkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

  In the present invention, the low refractive index layer may contain a fluorine-substituted alkyl group-containing silane compound represented by the following general formula (3).

  The fluorine-substituted alkyl group-containing silane compound represented by the general formula (3) will be described.

In the formula, R ^{1 to} R ⁶ are alkyl groups having 1 to 16 carbon atoms, preferably 1 to 4 carbon atoms, halogenated alkyl groups having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, 6 to 12 carbon atoms, preferably 6 carbon atoms. 10 to 10 aryl groups, 7 to 14 carbon atoms, preferably 7 to 12 alkylaryl groups, arylalkyl groups, 2 to 8 carbon atoms, preferably 2 to 6 alkenyl groups, or 1 to 6 carbon atoms, preferably 1 to 3 alkoxy groups, a hydrogen atom or a halogen atom.

Rf represents-(C _a H _b F _c )-, a is an integer of 1 to 12, b + c is 2a, b is an integer of 0 to 24, and c is an integer of 0 to 24. Such Rf is preferably a group having a fluoroalkylene group and an alkylene group. Specifically, as such a fluorine-containing silicone compound, (MeO) ₃ SiC ₂ H ₄ C ₂ F ₄ C ₂ H ₄ Si (MeO) ₃ , (MeO) ₃ SiC ₂ H ₄ C ₄ F ₈ C ₂ H ₄ Si (MeO) ₃ , (MeO) ₃ SiC ₂ H ₄ C ₆ F ₁₂ C ₂ H ₄ Si (MeO) ₃ , (H ₅ C ₂ O) ₃ SiC ₂ H ₄ C ₄ F ₈ C ₂ H Examples include methoxydisilane compounds represented by ₄ Si (OC ₂ H ₅ ) ₃ , (H ₅ C ₂ O) ₃ SiC ₂ H ₄ C ₆ F ₁₂ C ₂ H ₄ Si (OC ₂ H ₅ ) ₃ , and the like.

  If the fluorine-containing alkyl group-containing silane compound is included as a binder, the transparent film itself is hydrophobic, so the transparent film is not sufficiently densified and is porous or cracked. Even if it has a void or a void, entry into the transparent film by chemicals such as moisture, acid and alkali is suppressed. Furthermore, fine particles such as metals contained in the conductive layer which is the substrate surface or the lower layer do not react with chemicals such as moisture, acid and alkali. For this reason, such a transparent film has excellent chemical resistance.

  In addition, when a fluorine-substituted alkyl group-containing silane compound is included as a binder, not only the hydrophobic property but also the slipperiness (low contact resistance) is obtained, and thus a transparent film having excellent scratch strength can be obtained. Can do. Furthermore, when the binder contains a fluorine-substituted alkyl group-containing silane compound having such a structural unit, when the conductive layer is formed in the lower layer, the shrinkage of the binder is equal to or close to that of the conductive layer. Since it is a thing, the transparent film excellent in adhesiveness with the conductive layer can be formed. Furthermore, when the transparent film is heat-treated, the conductive layer is not peeled off due to the difference in shrinkage rate, and a portion having no electrical contact is not generated in the transparent conductive layer. For this reason, sufficient electroconductivity can be maintained as a whole film.

  A transparent film containing a fluorine-substituted alkyl group-containing silane compound and hollow silica-based fine particles having the outer shell layer and being porous or hollow inside has high scratch strength and is evaluated by eraser strength or nail strength. The film strength is high, the pencil hardness is high, and a transparent film excellent in strength can be formed.

  The low refractive index layer according to the present invention may contain a silane coupling agent. Silane coupling agents include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane. Ethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltri Acetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltri Ethoxysilane, γ- (β-glycidyloxyethoxy) propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ- Acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, N- Examples include β- (aminoethyl) -γ-aminopropyltrimethoxysilane and β-cyanoethyltriethoxysilane.

  Examples of silane coupling agents having a disubstituted alkyl group with respect to silicon include dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, and γ-glycidyloxypropylmethyldiethoxysilane. Γ-glycidyloxypropylmethyldimethoxysilane, γ-glycidyloxypropylphenyldiethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldi Ethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimeth Shishiran, .gamma.-mercaptopropyl methyl diethoxy silane, .gamma.-aminopropyl methyl dimethoxy silane, .gamma.-aminopropyl methyl diethoxy silane, methyl vinyl dimethoxy silane, and methyl vinyl diethoxy silane.

  Among these, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane having a double bond in the molecule. Γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, and γ-methacryloyloxypropylmethyldiethoxy having a disubstituted alkyl group with respect to silicon Silane, methylvinyldimethoxysilane and methylvinyldiethoxysilane are preferred, and γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxyp Particularly preferred are propyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane and γ-methacryloyloxypropylmethyldiethoxysilane.

  Two or more coupling agents may be used in combination. In addition to the silane coupling agents shown above, other silane coupling agents may be used. Other silane coupling agents include alkyl esters of orthosilicate (eg, methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, i-propyl orthosilicate, n-butyl orthosilicate, sec-butyl orthosilicate, orthosilicate). Acid t-butyl) and its hydrolyzate.

  Examples of the polymer used as the other binder of the low refractive index layer include polyvinyl alcohol, polyoxyethylene, polymethyl methacrylate, polymethyl acrylate, diacetyl cellulose, triacetyl cellulose, nitrocellulose, polyester, and alkyd resin.

  The low refractive index layer preferably contains 5 to 80% by mass of binder as a whole. The binder has a function of adhering the hollow silica fine particles and maintaining the structure of the low refractive index layer including voids. The usage-amount of a binder is adjusted so that the intensity | strength of a low refractive index layer can be maintained, without filling a space | gap.

(solvent)
The low refractive index layer according to the present invention preferably contains an organic solvent. Specific examples of organic solvents include alcohols (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), esters (eg, methyl acetate, ethyl acetate). , Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Group hydrocarbon (eg, benzene, toluene, xylene), amide (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methoxy-2-propanol). Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are particularly preferable.

  The solid content concentration in the low refractive index layer coating composition is preferably 1 to 4% by mass. By making the solid content concentration 4% by mass or less, coating unevenness is less likely to occur, and the content is 1% by mass or more. By doing so, the drying load is reduced.

(Fluorine or silicone surfactant)
In the invention according to claim 9, it is preferable that the high refractive index layer and the low refractive index layer contain a fluorine-based or silicone-based surfactant. Inclusion of the surfactant is effective for reducing coating unevenness and improving the antifouling property of the film surface.

  Fluorosurfactants include perfluoroalkyl group-containing monomers, oligomers, and polymers as the core, and include derivatives such as polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, and polyoxyethylene. It is done.

  Commercially available products may be used as the fluorosurfactant, for example, Surflon “S-381”, “S-382”, “SC-101”, “SC-102”, “SC-103”, “SC-104”. (All manufactured by Asahi Glass Co., Ltd.), Florard “FC-430”, “FC-431”, “FC-173” (all manufactured by Fluorochemical-Sumitomo 3M), Ftop “EF352”, “EF301”, “EF303” (both manufactured by Shin-Akita Kasei Co., Ltd.), Schwego Fureer “8035”, “8036” (both manufactured by Schwegman), “BM1000”, “BM1100” (all manufactured by BM Himmy) , MegaFuck “F-171”, “F-470” (both manufactured by Dainippon Ink & Chemicals, Inc.), and the like.

  The fluorine content of the fluorosurfactant in the present invention is 0.05 to 2%, preferably 0.1 to 1%. The above-mentioned fluorosurfactants can be used alone or in combination of two or more, and can be used in combination with other surfactants.

  The silicone oil or silicone surfactant will be described.

  Silicone oils used in the present invention can be broadly classified into straight silicone oils and modified silicone oils depending on the type of organic groups bonded to silicon atoms. Straight silicone oil refers to those bonded with a methyl group, a phenyl group, or a hydrogen atom as a substituent. A modified silicone oil is one having a component that is secondarily derived from a straight silicone oil. On the other hand, it can be classified from the reactivity of silicone oil. These are summarized as follows.

Silicone oil Straight silicone oil 1-1. Non-reactive silicone oil: dimethyl, methylphenyl substitution, etc. 1-2. Reactive silicone oil: methyl hydrogen substitution, etc. Modified silicone oil Modified silicone oil was born by introducing various organic groups into dimethyl silicone oil 2-1. Non-reactive silicone oil: alkyl, alkyl / aralkyl, alkyl / polyether, polyether, higher fatty acid ester substitution, etc.
Alkyl / aralkyl-modified silicone oil is a silicone oil in which a part of methyl group of dimethyl silicone oil is replaced with a long-chain alkyl group or a phenylalkyl group,
Polyether-modified silicone oil is a silicone-based polymer surfactant in which hydrophilic polyoxyalkylene is introduced into hydrophobic dimethyl silicone,
Higher fatty acid-modified silicone oil is a silicone oil in which a part of methyl group of dimethyl silicone oil is replaced with higher fatty acid ester,
Amino-modified silicone oil is a silicone oil having a structure in which a part of methyl group of silicone oil is substituted with aminoalkyl group,
The epoxy-modified silicone oil is a silicone oil having a structure in which a part of the methyl group of the silicone oil is replaced with an epoxy group-containing alkyl group,
The carboxyl-modified or alcohol-modified silicone oil is a silicone oil having a structure in which a part of the methyl group of the silicone oil is substituted with a carboxyl group or a hydroxyl group-containing alkyl group 2-2. Reactive silicone oil: amino, epoxy, carboxyl, alcohol substitution, etc. Of these, polyether-modified silicone oil is preferably added. The number average molecular weight of the polyether-modified silicone oil is, for example, 1,000 to 100,000, preferably 2,000 to 50,000. When the number average molecular weight is less than 1,000, the drying property of the coating film On the contrary, when the number average molecular weight exceeds 100,000, it tends to be difficult to bleed out on the surface of the coating film.

  As specific products, Nippon Unicar Co., Ltd. L-45, L-9300, FZ-3704, FZ-3703, FZ-3720, FZ-3786, FZ-3501, FZ-3504, FZ-3508, FZ-3705, FZ-3707, FZ-3710, FZ-3750, FZ-3760, FZ-3785, FZ-3785, Y-7499, Shin-Etsu Chemical KF96L, KF96, KF96H, KF99, KF54, KF965, KF968, KF56, KF995, KF351, KF352, KF353, KF354, KF355, KF615, KF618, KF945, KF6004, FL100, and the like.

  The silicone surfactant used in the present invention is a surfactant obtained by substituting a part of the methyl group of the silicone oil with a hydrophilic group. The position of substitution includes a side chain of silicone oil, both ends, one end, both end side chains, and the like. Examples of the hydrophilic group include polyether, polyglycerin, pyrrolidone, betaine, sulfate, phosphate, and quaternary salt.

  As the silicon surfactant, a nonionic surfactant having a hydrophobic group composed of dimethylpolysiloxane and a hydrophilic group composed of polyoxyalkylene is preferable.

  A nonionic surfactant is a generic term for surfactants that do not have a group capable of dissociating into ions in an aqueous solution. In addition to a hydrophobic group, a hydrophilic group includes a hydroxyl group of a polyhydric alcohol, a polyoxyalkylene chain (poly Oxyethylene) or the like as a hydrophilic group. The hydrophilicity becomes stronger as the number of alcoholic hydroxyl groups increases and as the polyoxyalkylene chain (polyoxyethylene chain) becomes longer. The nonionic surfactant according to the present invention is characterized by having dimethylpolysiloxane as a hydrophobic group.

  When a nonionic surfactant composed of a dimethylpolysiloxane having a hydrophobic group and a polyoxyalkylene having a hydrophilic group is used, the unevenness of the low refractive index layer and the antifouling property of the film surface are improved. It is thought that the hydrophobic group made of polymethylsiloxane is oriented on the surface and forms a film surface that is not easily soiled. This effect cannot be obtained by using other surfactants.

  Specific examples of these nonionic surfactants include, for example, Nippon Unicar Co., Ltd., silicone surfactants SILWET L-77, L-720, L-7001, L-7002, L-7604, Y-7006, FZ-2101, FZ-2104, FZ-2105, FZ-2110, FZ-2118, FZ-2120, FZ-2122, FZ-2123, FZ-2130, FZ-2154, FZ-2161, FZ-2162, FZ- 2163, FZ-2164, FZ-2166, FZ-2191 and the like.

  Moreover, SUPERSILWET SS-2801, SS-2802, SS-2803, SS-2804, SS-2805, etc. are mentioned.

  In addition, as a preferable structure of the nonionic surfactant in which the hydrophobic group is composed of dimethylpolysiloxane and the hydrophilic group is composed of polyoxyalkylene, a dimethylpolysiloxane structure portion and a polyoxyalkylene chain are alternately and repeatedly bonded. It is preferably a linear block copolymer. Since the main chain skeleton has a long chain length and a linear structure, it is excellent. This is considered to be due to the fact that one activator molecule can be adsorbed on the surface of the silica fine particle at a plurality of locations so as to cover the surface of the silica fine particle by being a block copolymer in which hydrophilic groups and hydrophobic groups are alternately repeated.

  Specific examples thereof include, for example, silicone surfactants ABN SILWET FZ-2203, FZ-2207, FZ-2208 and the like manufactured by Nippon Unicar Co., Ltd.

  Among these silicone oils or silicone surfactants, those having a polyether group are preferred.

  Other surfactants may also be used in combination. For example, anionic surfactants such as sulfonates, sulfates, phosphates, etc., and ethers having polyoxyethylene chain hydrophilic groups Type, ether ester type nonionic surfactants and the like may be used in combination.

  In the present invention, these silicone oils or silicone surfactants are preferably used in the low refractive index layer and the layer adjacent to the low refractive index layer, specifically, the hard coat layer and the high refractive index layer. When the low refractive index layer is the outermost surface layer of the antireflection film, it not only improves the water repellency, oil repellency and antifouling properties of the coating film, but also exhibits an effect on the scratch resistance of the surface. The content in the coating solution for the high refractive index layer and the low refractive index layer is preferably 0.05 to 2.0% by mass. If it is less than 0.05% by mass, the crack resistance effect is insufficient, and if it exceeds 2.0% by mass, uneven coating occurs.

(Transparent substrate film)
Next, the transparent substrate film that can be used in the present invention will be described.

  The transparent substrate film used in the present invention is easy to manufacture, has good adhesion to the actinic radiation curable resin layer, is optically isotropic, and is optically transparent. Etc. are mentioned as preferable requirements.

  The term “transparent” as used in the present invention means that the visible light transmittance is 60% or more, preferably 80% or more, and particularly preferably 90% or more.

  Although it will not specifically limit if it has said property, For example, a cellulose-ester type film, a polyester-type film, a polycarbonate-type film, a polyarylate-type film, a polysulfone (a polyether sulfone is also included) type film, a polyethylene terephthalate, polyethylene Polyester film such as naphthalate, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose triacetate, cellulose acetate propionate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, Syndiotactic polystyrene film, polycarbonate film, cycloolefin Polymer film (Arton (manufactured by JSR), ZEONEX, ZEONOR (manufactured by ZEON CORPORATION)), polymethylpentene film, polyetherketone film, polyetherketoneimide film, polyamide film, fluororesin film, nylon film, poly A methyl methacrylate film, an acrylic film, a glass plate, etc. can be mentioned. Among them, cellulose triacetate film, polycarbonate film, and polysulfone (including polyethersulfone) are preferable, and in the present invention, cellulose ester film (for example, Konica Minoltack, product names KC8UX2MW, KC4UX2MW, KC8UY, KC4UNY, KC5UN, KC12UR, KC8UCR-3, KC8UCR-4, and KC8UCR-5 (manufactured by Konica Minolta Opto Co., Ltd.) are preferably used from the viewpoints of production, cost, transparency, isotropic properties, adhesiveness, and the like. These films may be films produced by melt casting film formation or films produced by solution casting film formation.

  In the present invention, it is preferable to use a cellulose ester film as the transparent substrate film. As the cellulose ester, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are preferable. Among them, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose acetate propionate are preferably used.

  In particular, when the substitution degree of acetyl group is X and the substitution degree of propionyl group or butyryl group is Y, X and Y are active ray curable resins on a transparent base film having a mixed fatty acid ester of cellulose in the following range. A low reflection laminate having a layer and an antireflection layer is preferably used.

2.3 ≦ X + Y ≦ 3.0
0.1 ≦ Y ≦ 1.2
In particular, 2.5 ≦ X + Y ≦ 2.9
It is preferable that 0.3 ≦ Y ≦ 1.2.

  When cellulose ester is used as the transparent substrate film used in the present invention, the cellulose used as the raw material for the cellulose ester is not particularly limited, but examples include cotton linters, wood pulp (derived from coniferous trees, derived from hardwoods), kenaf and the like. Can do. Moreover, the cellulose ester obtained from them can be mixed and used in arbitrary ratios, respectively. When the acylating agent is an acid anhydride (acetic anhydride, propionic anhydride, butyric anhydride), these cellulose esters use an organic solvent such as acetic acid or an organic solvent such as methylene chloride, and It can be obtained by reacting with a cellulose raw material using a protic catalyst.

When the acylating agent is acid chloride (CH ₃ COCl, C ₂ H ₅ COCl, C ₃ H ₇ COCl), the reaction is carried out using a basic compound such as an amine as a catalyst. Specifically, it can be synthesized with reference to the method described in JP-A-10-45804. In addition, the cellulose ester used in the present invention is obtained by mixing and reacting the amount of the acylating agent in accordance with the degree of substitution. In the cellulose ester, these acylating agents react with hydroxyl groups of cellulose molecules. Cellulose molecules are composed of many glucose units linked together, and the glucose unit has three hydroxyl groups. The number of acyl groups derived from these three hydroxyl groups is called the degree of substitution (mol%). For example, cellulose triacetate has acetyl groups bonded to all three hydroxyl groups of the glucose unit (actually 2.6 to 3.0).

  The cellulose ester used in the present invention is a mixed fatty acid ester of cellulose in which a propionate group or a butyrate group is bonded in addition to an acetyl group such as cellulose acetate propionate, cellulose acetate butyrate, or cellulose acetate propionate butyrate. Is particularly preferably used. The butyryl group that forms butyrate may be linear or branched.

  Cellulose acetate propionate containing a propionate group as a substituent has excellent water resistance and is useful as a film for liquid crystal image display devices.

  The measuring method of the substitution degree of an acyl group can be measured according to the rule of ASTM-D817-96.

  The number average molecular weight of the cellulose ester is preferably 70000 to 250,000, since it has high mechanical strength when molded and an appropriate dope viscosity, and more preferably 80000 to 150,000.

  These cellulose esters are pressurized by applying a cellulose ester solution (dope) generally called a solution casting film forming method onto, for example, an endless metal belt for infinite transport or a support for casting of a rotating metal drum. It is preferable to manufacture the dope from a die by casting (casting).

  As the organic solvent used for preparing these dopes, it is preferable that the cellulose ester can be dissolved and has an appropriate boiling point. For example, methylene chloride, methyl acetate, ethyl acetate, amyl acetate, methyl acetoacetate, acetone, tetrahydrofuran 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, 1,3-difluoro-2 -Propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3 , 3,3-pentafluoro-1-propanol, nitroethane, 1,3-dimethyl-2-imidazolidinone, etc. Can, organic halogen compounds such as methylene chloride, dioxolane derivatives, methyl acetate, ethyl acetate, acetone, methyl acetoacetate, and the like are preferable organic solvents (i.e., good solvent), and as.

  Moreover, as shown in the following film forming process, it is used from the viewpoint of preventing foaming in the web when the solvent is dried from the web (dope film) formed on the casting support in the solvent evaporation process. The boiling point of the organic solvent is preferably 30 to 80 ° C. For example, the good solvent described above has a boiling point of methylene chloride (boiling point 40.4 ° C), methyl acetate (boiling point 56.32 ° C), acetone (boiling point 56.56 ° C). 3 ° C.), ethyl acetate (boiling point 76.82 ° C.) and the like.

  Among the good solvents described above, methylene chloride or methyl acetate, which is excellent in solubility, is preferably used.

  In addition to the organic solvent, it is preferable to contain 0.1 to 40% by mass of an alcohol having 1 to 4 carbon atoms. It is particularly preferable that the alcohol is contained at 5 to 30% by mass. After casting the dope described above onto a casting support, the solvent starts to evaporate and the alcohol ratio increases and the web (dope film) gels, making the web strong and peeling from the casting support. It is also used as a gelling solvent for facilitating the dissolution, and when these ratios are small, it also has a role of promoting the dissolution of the cellulose ester of the non-chlorine organic solvent.

  Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol and the like.

  Of these solvents, ethanol is preferred because it has good dope stability, relatively low boiling point, good drying properties, and no toxicity. It is preferable to use a solvent containing 5 to 30% by mass of ethanol with respect to 70 to 95% by mass of methylene chloride. Methyl acetate can be used in place of methylene chloride. At this time, the dope may be prepared by a cooling dissolution method.

  When a cellulose ester film is used for the antireflection film of the present invention, it is preferable to contain the following plasticizer. Examples of plasticizers include phosphate ester plasticizers, phthalate ester plasticizers, trimellitic acid ester plasticizers, pyromellitic acid plasticizers, glycolate plasticizers, citrate ester plasticizers, and polyesters. A plasticizer or the like can be preferably used.

  For phosphate plasticizers, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenylbiphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. For phthalate ester plasticizers, diethyl phthalate, dimethoxy For trimellitic acid plasticizers such as ethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, diphenyl phthalate, dicyclohexyl phthalate, tributyl trimellitate, triphenyl trimellitate, triethyl For pyromellitic acid ester plasticizers such as trimellitate, tetrabutylpyromellitate, In the case of glycolate plasticizers such as lupyromelitate and tetraethylpyromellitate, triacetin, tributyrin, ethylphthalylethyl glycolate, methylphthalylethyl glycolate, butylphthalylbutyl glycolate, etc. Citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl tri-n- (2-ethylhexyl) citrate and the like can be preferably used. Examples of other carboxylic acid esters include trimethylolpropane tribenzoate, butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  As the polyester plasticizer, a copolymer of a dibasic acid and a glycol such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid can be used. The aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid, and the like can be used. As glycol, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used. These dibasic acids and glycols may be used alone or in combination of two or more.

  The amount of these plasticizers used is preferably from 1 to 20% by mass, particularly preferably from 3 to 13% by mass, based on the cellulose ester, in terms of film performance, processability and the like.

  For the long film for the low reflection laminate of the present invention, an ultraviolet absorber is preferably used.

  As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties.

  Specific examples of the ultraviolet absorber preferably used in the present invention include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. However, it is not limited to these.

  Specific examples of the benzotriazole-based ultraviolet absorbers include the following ultraviolet absorbers, but the present invention is not limited thereto.

UV-1: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole UV-3 : 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-Chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol)
UV-7: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole UV-8: 2- (2H-benzotriazol-2-yl) -6 (Linear and side chain dodecyl) -4-methylphenol (TINUVIN171, manufactured by Ciba)
UV-9: Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl- 4-Hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate (TINUVIN109, manufactured by Ciba)
Moreover, although the following specific example is shown as a benzophenone series ultraviolet absorber, this invention is not limited to these.

UV-10: 2,4-dihydroxybenzophenone UV-11: 2,2'-dihydroxy-4-methoxybenzophenone UV-12: 2-hydroxy-4-methoxy-5-sulfobenzophenone UV-13: Bis (2-methoxy -4-hydroxy-5-benzoylphenylmethane)
As the ultraviolet absorber preferably used in the present invention, a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber that are highly transparent and excellent in preventing the deterioration of the polarizing plate and the liquid crystal are preferable, and unnecessary coloring is less. A benzotriazole-based ultraviolet absorber is particularly preferably used.

  Moreover, the ultraviolet absorber whose distribution coefficient described in Unexamined-Japanese-Patent No. 2001-187825 is 9.2 or more improves the surface quality of a long film, and is excellent also in applicability | paintability. In particular, it is preferable to use an ultraviolet absorber having a distribution coefficient of 10.1 or more.

  Further, the polymer ultraviolet absorbers described in the general formula (1) or general formula (2) described in JP-A-6-148430 and the general formulas (3), (6), and (7) of Japanese Patent Application No. 2000-156039 ( Alternatively, an ultraviolet absorbing polymer) is also preferably used. As a polymer ultraviolet absorber, PUVA-30M (manufactured by Otsuka Chemical Co., Ltd.) and the like are commercially available.

  Moreover, in order to provide slipperiness to the cellulose-ester film used for this invention, the microparticles | fine-particles similar to what is described with the coating layer containing the below-mentioned actinic radiation curable resin can be used.

<Fine particles>
The cellulose ester film preferably contains fine particles.

  As fine particles, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, Mention may be made of magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

  The average primary particle size of the fine particles is preferably 5 to 50 nm, and more preferably 7 to 20 nm. These are preferably contained mainly as secondary aggregates having a particle size of 0.05 to 0.3 μm. The content of these fine particles in the cellulose ester film is preferably 0.05 to 1% by mass, particularly preferably 0.1 to 0.5% by mass. In the case of a cellulose ester film having a multilayer structure by the co-casting method, it is preferable to contain fine particles of this addition amount on the surface.

  Silicon dioxide fine particles are commercially available, for example, under the trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.). it can.

  Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Examples of the polymer include silicone resin, fluororesin, and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. It is marketed by name and can be used.

  Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the turbidity of the cellulose ester film low. In the cellulose ester film used in the present invention, the dynamic friction coefficient on the back side of the active energy ray-curable resin layer is preferably 1.0 or less.

<Method for producing cellulose ester film>
Next, the manufacturing method of a cellulose-ester film is demonstrated.

  The cellulose ester film is produced by dissolving the cellulose ester and additives in a solvent to prepare a dope, casting the dope on a belt-like or drum-like metal support, and drying the cast dope as a web. It is performed by the process of carrying out, the process of peeling from a metal support body, the process of extending | stretching or maintaining width, the process of drying further, and the process of winding up the finished film.

  The process for preparing the dope will be described. The concentration of cellulose ester in the dope is preferably higher because the drying load after casting on the metal support can be reduced. However, if the concentration of cellulose ester is too high, the load during filtration increases and the filtration accuracy increases. Becomes worse. The concentration for achieving both of these is preferably 10 to 35% by mass, and more preferably 15 to 25% by mass.

  The solvent used in the dope may be used alone or in combination of two or more, but it is preferable to use a mixture of a good solvent and a poor solvent of cellulose ester in terms of production efficiency, and there are many good solvents. This is preferable from the viewpoint of the solubility of the cellulose ester. The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. With a good solvent and a poor solvent, what dissolve | melts the cellulose ester to be used independently is defined as a good solvent, and what poorly swells or does not melt | dissolve is defined as a poor solvent. Therefore, depending on the acyl group substitution degree of the cellulose ester, the good solvent and the poor solvent change. For example, when acetone is used as the solvent, the cellulose ester acetate ester (acetyl group substitution degree 2.4) and cellulose acetate propionate are good. As a solvent, cellulose acetate (acetyl group substitution degree 2.8) is a poor solvent.

  Although the good solvent used for this invention is not specifically limited, Organic halogen compounds, such as a methylene chloride, dioxolanes, acetone, methyl acetate, methyl acetoacetate, etc. are mentioned. Particularly preferred is methylene chloride or methyl acetate.

  Moreover, although the poor solvent used for this invention is not specifically limited, For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, etc. are used preferably. Moreover, it is preferable that 0.01-2 mass% of water contains in dope.

  A general method can be used as a dissolution method of the cellulose ester when preparing the dope described above. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure. It is preferable to stir and dissolve while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and that the solvent does not boil under pressure, in order to prevent the generation of massive undissolved materials called gels and mamacos. Moreover, after mixing a cellulose ester with a poor solvent and making it wet or swell, the method of adding a good solvent and melt | dissolving is also used preferably.

  The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  The heating temperature with the addition of the solvent is preferably higher from the viewpoint of the solubility of the cellulose ester, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  Alternatively, a cooling dissolution method is also preferably used, whereby the cellulose ester can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose ester solution is filtered using a suitable filter medium such as filter paper. As the filter medium, it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like. However, if the absolute filtration accuracy is too small, there is a problem that the filter medium is likely to be clogged. For this reason, a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is more preferable.

  There are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable. It is preferable to remove and reduce impurities, particularly bright spot foreign matter, contained in the raw material cellulose ester by filtration.

A bright spot foreign substance is when two polarizing plates are placed in a crossed Nicol state, a cellulose ester film is placed between them, light is applied from the side of one polarizing plate, and observed from the side of the other polarizing plate. It is a point (foreign matter) where light from the opposite side appears to leak, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm ² or less. More preferably, it is 100 pieces / cm < ² > or less, More preferably, it is 50 pieces / m < ² > or less, More preferably, it is 0-10 pieces / cm < ² > or less. Further, it is preferable that the number of bright spots of 0.01 mm or less is small.

  The dope can be filtered by a normal method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration. The increase in the difference (referred to as differential pressure) is small and preferable. A preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and even more preferably 45 to 55 ° C.

  A smaller filtration pressure is preferred. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.

  Here, the dope casting will be described.

  The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support. The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is set to −50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferred because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate. A preferable support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. . In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

  In order for the cellulose ester film to exhibit good flatness, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Especially preferably, it is 20-30 mass% or 70-120 mass%.

  In the present invention, the amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Note that M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  Further, in the drying step of the cellulose ester film, the web is peeled off from the metal support, and further dried, and the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, Especially preferably, it is 0-0.01 mass% or less.

  In the film drying process, generally, a roll drying method (a method in which a plurality of rolls arranged on the upper and lower sides are alternately passed through and dried) or a method of drying while transporting the web by a tenter method is adopted.

  In order to produce the cellulose ester film for the antireflection film of the present invention, the web is stretched in the conveying direction where the residual solvent amount of the web immediately after peeling from the metal support is large, and both ends of the web are gripped with clips or the like. It is particularly preferable to perform stretching in the width direction by a tenter method. A preferable draw ratio in both the machine direction and the transverse direction is 1.05 to 1.3 times, and more preferably 1.05 to 1.15 times. It is preferable that the area is 1.12 to 1.44 times, and preferably 1.15 to 1.32 times due to longitudinal and lateral stretching. This can be determined by the draw ratio in the longitudinal direction × the draw ratio in the transverse direction. If one of the draw ratios in the machine direction and the transverse direction is less than 1.05 times, the deterioration of flatness due to ultraviolet irradiation when forming the active energy ray-curable resin layer is unfavorable. Moreover, even if a draw ratio exceeds 1.3 times, since planarity deteriorates and haze also increases, it is not preferable.

  In order to stretch in the machine direction immediately after peeling, it is preferable to stretch by peeling tension and subsequent transport tension. For example, it is preferable to peel at a peeling tension of 210 N / m or more, and particularly preferably 220 to 300 N / m.

  The means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web drying step is preferably increased stepwise from 30 to 150 ° C, and more preferably from 50 to 140 ° C in order to improve dimensional stability.

  Although the film thickness of a cellulose-ester film is not specifically limited, 10-200 micrometers is used preferably. In particular, it was difficult to obtain an antireflection film excellent in flatness and hardness with a thin film of 10 to 70 μm, but according to the present invention, a thin antireflection film excellent in flatness and hardness was obtained, Moreover, since it is excellent also in productivity, it is especially preferable that the film thickness of a cellulose-ester film is 10-70 micrometers. More preferably, it is 20-60 micrometers. Most preferably, it is 35-60 micrometers. Moreover, the cellulose ester film made into the multilayer structure by the co-casting method can also be used preferably. Even when the cellulose ester has a multilayer structure, it has a layer containing an ultraviolet absorber and a plasticizer, and it may be a core layer, a skin layer, or both.

  The antireflection film of the present invention preferably has a width of 1.4 to 5 m. Moreover, the centerline average roughness (Ra) of the surface which provides the active energy ray hardening resin layer of a cellulose-ester film can use a 0.001-1 micrometer thing.

  When the width of the cellulose ester film becomes wider, the illuminance unevenness of the irradiated light during UV curing cannot be ignored, not only the flatness deteriorates but also the hardness unevenness. When the antireflection layer is formed on this, the reflection unevenness There was a problem that became prominent. Since the antireflection film of the present invention can provide sufficient hardness with a small amount of irradiation, even if there is unevenness of the irradiation amount in the width direction of the irradiation light, unevenness of the hardness in the width direction is unlikely to occur, and the flatness is excellent. Since an antireflection film is obtained, a remarkable effect is recognized with a wide cellulose ester film. In particular, those having a width of 1.4 to 4 m are preferably used, and particularly preferably 1.4 to 3 m. If it exceeds 4 m, conveyance becomes difficult.

  Next, the production of the antireflection film according to the present invention using the cellulose ester as a transparent substrate film will be described in detail.

[Hard coat layer]
In the antireflection film of the present invention, it is preferable to provide a hard coat layer between the transparent substrate film and the high refractive index layer. The hard coat layer is preferably an active energy ray curable resin layer.

  The active energy ray-curable resin layer is a layer mainly composed of a resin that is cured through a crosslinking reaction or the like by irradiation with active rays such as ultraviolet rays and electron beams. As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active energy ray curable resin layer is cured by irradiation with an active ray such as an ultraviolet ray or an electron beam. It is formed. Typical examples of the active energy ray curable resin include an ultraviolet curable resin and an electron beam curable resin, and a resin curable by ultraviolet irradiation is preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used. Of these, ultraviolet curable acrylate resins are preferred.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylates) in addition to products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate. For example, those described in JP-A-59-151110 can be used.

  For example, a mixture of 100 parts Unidic 17-806 (Dainippon Ink Co., Ltd.) and 1 part Coronate L (Nihon Polyurethane Co., Ltd.) is preferably used.

  Examples of UV curable polyester acrylate resins include those that are easily formed when 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers are generally reacted with polyester polyols. Can be used.

  Specific examples of the ultraviolet curable epoxy acrylate resin include an epoxy acrylate as an oligomer, a reactive diluent and a photopolymerization initiator added thereto, and reacted to form an oligomer. Those described in US Pat. No. 105738 can be used.

  Specific examples of UV curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

  Specific examples of photopolymerization initiators for these ultraviolet curable resins include benzoin and its derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer. The photopolymerization initiator can also be used as a photosensitizer. In addition, when using an epoxy acrylate photopolymerization initiator, a sensitizer such as n-butylamine, triethylamine, tri-n-butylphosphine can be used. The photopolymerization initiator or photosensitizer used in the ultraviolet curable resin composition is 0.1 to 15 parts by mass, preferably 1 to 10 parts by mass with respect to 100 parts by mass of the composition.

  Examples of the resin monomer include common monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate, and styrene as monomers having one unsaturated double bond. In addition, monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the above trimethylolpropane. Examples thereof include triacrylate and pentaerythritol tetraacryl ester.

  Examples of commercially available ultraviolet curable resins that can be used in the present invention include ADEKA OPTMER KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (Asahi Denka ( Co., Ltd.); Koeihard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS -101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S), PHC X-9 (K-3), PHC2213, DP -10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (manufactured by Dainichi Seika Kogyo Co., Ltd.) KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UCB); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120 RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by Dainippon Ink & Chemicals, Inc.); 340 clear (manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries); SP -1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), etc. Can be selected as appropriate.

  Examples of specific compounds include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, and the like. .

  The cured resin layer thus obtained may contain fine particles of an inorganic compound or an organic compound in order to adjust the scratch resistance, slipperiness and refractive index, and to impart antiglare properties to the produced antireflection film.

  Examples of inorganic fine particles used in the hard coat layer include silicon oxide, titanium oxide, aluminum oxide, tin oxide, indium oxide, ITO, zinc oxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium carbonate, talc, clay, and calcined kaolin. And calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. In particular, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide and the like are preferably used.

  Organic particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder. Polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or polyfluoroethylene resin powder can be added to the ultraviolet curable resin composition. Particularly preferred are cross-linked polystyrene particles (for example, SX-130H, SX-200H, SX-350H, manufactured by Soken Chemical) and polymethyl methacrylate-based particles (for example, MX150, MX300, manufactured by Soken Chemical).

  The average particle size of these fine particle powders is preferably 0.01 to 5 μm, more preferably 0.1 to 5.0 μm, and particularly preferably 0.1 to 4.0 μm. Moreover, it is preferable to contain 2 or more types of microparticles | fine-particles from which a particle size differs. The proportion of the ultraviolet curable resin composition and the fine particles is desirably blended so as to be 0.1 to 30 parts by mass with respect to 100 parts by mass of the resin composition.

  These hard coat layers can be coated by a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method. After application, it is heat-dried and UV-cured.

As a light source for curing an ultraviolet curable resin by a photocuring reaction to form a cured film layer, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 150 mJ / cm ² , and particularly preferably 20 to 100 mJ / cm ² .

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 300 N / m. The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. This makes it possible to obtain a film having further excellent flatness.

  The hard coat layer coating solution may contain a solvent, or may be appropriately contained and diluted as necessary. Examples of the organic solvent contained in the coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), These may be appropriately selected from esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or may be used by mixing them. Propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms of the alkyl group) is 5% by mass or more, more preferably 5 to 80%. It is preferable to use the organic solvent containing at least mass%.

  The hard coat layer is a clear hard coat layer having a center line average roughness (Ra) defined by JIS B 0601 of 0.001 to 0.1 μm, or an antiglare hard coat layer having Ra of 0.1 to 1 μm. Is preferred. The center line average roughness (Ra) is preferably measured by an optical interference type surface roughness measuring instrument, and can be measured, for example, using a non-contact surface fine shape measuring device WYKO NT-2000 manufactured by WYKO.

  Furthermore, it is also preferable that the hard coat layer contains the fluorine-based or silicone-based surfactant. These improve the applicability to the lower layer. These components are preferably added in a range of 0.01 to 3% by mass with respect to the solid component in the coating solution.

  The hard coat layer has a multilayer structure of two or more layers, and one of the layers may be a so-called antistatic layer containing, for example, conductive fine particles or an ionic polymer. As a color correction filter for the element, a color tone adjusting agent having a color tone adjusting function may be contained, and it is preferable to contain an electromagnetic wave blocking agent or an infrared absorber so as to have each function.

  As the coating method of the hard coat layer coating solution, the above-described methods can be used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm, as the wet film thickness. Moreover, as a dry film thickness, it is an average film thickness of 0.1-15 micrometers, Preferably it is 1-8 micrometers.

  The hard coat layer is preferably irradiated with ultraviolet rays after coating and drying, and the irradiation time for obtaining the necessary amount of active ray irradiation is preferably about 0.1 second to 1 minute, and the curing efficiency of the ultraviolet curable resin Or from the viewpoint of work efficiency, 0.1 to 10 seconds is more preferable.

Moreover, it is preferable that the illuminance of these active ray irradiation parts is 50-150 mW / m < ² >.

[Back coat layer]
It is preferable to provide a backcoat layer on the side opposite to the side on which the active energy ray-curable resin layer is provided of the cellulose ester film to be the transparent substrate film for producing the antireflection film of the present invention. The back coat layer is provided in order to correct curl caused by providing an active energy ray-curable resin layer or other layers. That is, the degree of curling can be balanced by imparting the property of being rounded with the surface on which the backcoat layer is provided facing inward. The back coat layer is preferably applied also as an anti-blocking layer. In this case, it is preferable that fine particles are added to the back coat layer coating composition in order to provide an anti-blocking function.

  As fine particles added to the back coat layer, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, and oxidation. Mention may be made of indium, zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low haze, and silicon dioxide is particularly preferable.

  These fine particles are commercially available under the trade names of, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.). . Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used. Examples of the polymer include silicone resin, fluororesin, and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. It is marketed by name and can be used.

  Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large anti-blocking effect while keeping haze low. The antireflection film used in the present invention preferably has a dynamic friction coefficient on the back side of the active energy ray-curable resin layer of 0.9 or less, particularly 0.1 to 0.9.

  The fine particles contained in the backcoat layer are 0.1 to 50% by weight, preferably 0.1 to 10% by weight, based on the binder. When the back coat layer is provided, the increase in haze is preferably 1% or less, more preferably 0.5% or less, and particularly preferably 0.0 to 0.1%.

  Specifically, the back coat layer is formed by applying a composition containing a solvent for dissolving or swelling a cellulose ester film. The solvent used may include a solvent to be dissolved and / or a solvent to be swollen in addition to a solvent to be swelled, a composition in which these are mixed at an appropriate ratio depending on the curl degree of the transparent resin film and the type of resin, and This is done using the coating amount.

  In order to enhance the curl prevention function, it is effective to increase the mixing ratio of the solvent for dissolving the solvent composition to be used and / or the solvent for swelling, and to decrease the ratio of the solvent not to be dissolved. This mixing ratio is preferably (solvent to be dissolved and / or solvent to be swollen) :( solvent to be dissolved) = 10: 0 to 1: 9. Examples of the solvent for dissolving or swelling the transparent resin film contained in such a mixed composition include dioxane, acetone, methyl ethyl ketone, N, N-dimethylformamide, methyl acetate, ethyl acetate, trichloroethylene, methylene chloride, and ethylene chloride. , Tetrachloroethane, trichloroethane, chloroform and the like. Examples of the solvent that does not dissolve include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butanol, cyclohexanol, and hydrocarbons (toluene, xylene).

  These coating compositions are preferably applied to the surface of the transparent resin film with a wet film thickness of 1 to 100 μm using a gravure coater, dip coater, reverse coater, wire bar coater, die coater, spray coating, ink jet coating or the like. Is particularly preferably 5 to 30 μm. Examples of the resin used as the binder of the backcoat layer include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, vinyl acetate-vinyl alcohol copolymer, partially hydrolyzed vinyl chloride-vinyl acetate copolymer. Polymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Vinyl polymer or copolymer, nitrocellulose, cellulose acetate propionate (preferably acetyl group substitution degree 1.8-2.3, propionyl group substitution degree 0.1-1.0), diacetyl cellulose, cellulose Cellulose derivatives such as acetate butyrate resin, maleic acid and / or Or acrylic acid copolymer, acrylic ester copolymer, acrylonitrile-styrene copolymer, chlorinated polyethylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin Rubber resins such as polyvinyl acetal resin, polyvinyl butyral resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene-butadiene resin, butadiene-acrylonitrile resin, Examples thereof include, but are not limited to, silicone resins and fluorine resins. For example, as an acrylic resin, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M-4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR -80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105 BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, etc. (Mitsubishi Rayon Co., Ltd.) acrylic and The methacrylic monomers are commercially available various homopolymers and copolymers, etc. was prepared as a raw material, it is also possible to select a preferred mono from this appropriate.

  Particularly preferred are cellulose resin layers such as diacetylcellulose and cellulose acetate propionate.

  The order of coating the backcoat layer may be before or after coating the active energy ray-curable resin layer of the cellulose ester film, but when the backcoat layer also serves as an antiblocking layer, it is desirable to coat it first. . Alternatively, the backcoat layer can be applied in two or more steps.

(Antireflection layer)
In the present invention, the method for providing the antireflection layer is not particularly limited, but it is preferably formed by coating.

  In the present invention, an antireflection layer is produced by sequentially coating the cellulose ester film provided with a hard coat layer on the above-described high refractive index layer composition and low refractive index layer composition according to the present invention. It is preferable to do.

  Although the structure of a preferable antireflection film is shown below, it is not limited to these.

  Here, the hard coat layer means the aforementioned active energy ray-curable resin layer.

Transparent base film / hard coat layer / high refractive index layer / low refractive index layer Transparent base film / antistatic layer / hard coat layer / high refractive index layer / low refractive index layer Transparent base film / antiglare hard coat Layer / high refractive index layer / low refractive index layer transparent base film / antistatic layer / antiglare hard coat layer / high refractive index layer / low refractive index layer It is preferable to provide the above-mentioned back coat layer on the surface opposite to the coated side.

  In the present invention, after the hard coat layer is formed, the surface of the hard coat layer is subjected to surface treatment, and the high refractive index layer and the low refractive index layer according to the present invention are formed on the surface of the hard coat layer subjected to the surface treatment. Is preferred.

  The reflectance of the antireflection film according to the present invention can be measured with a spectrophotometer. At that time, after the surface on the measurement side of the sample is roughened, the light absorption treatment is performed using a black spray, and then the reflected light in the visible light region (400 to 700 nm) is measured. The reflectance is preferably as low as possible, but the average value in the visible light wavelength is preferably 1.5% or less, and the minimum reflectance is preferably 0.8% or less. Moreover, it is preferable to have a flat reflection spectrum in the wavelength region of visible light.

  In addition, the reflection hue on the surface of the polarizing plate that has undergone antireflection treatment is often colored red or blue due to the high reflectance in the short wavelength region and long wavelength region in the visible light region due to the design of the antireflection film. The color tone of the reflected light varies depending on the application, and when used on the outermost surface of an FPD television or the like, a neutral color tone is desired. In this case, generally preferred reflection hue ranges are 0.17 ≦ x ≦ 0.27 and 0.07 ≦ y ≦ 0.17 on the XYZ color system (CIE1931 color system).

  The film thicknesses of the high refractive index layer and the low refractive index layer can be obtained by calculation according to a conventional method in consideration of the reflectance and the color of reflected light based on the refractive index of each layer.

  Examples of the surface treatment include cleaning methods, alkali treatment methods, flame plasma treatment methods, high frequency discharge plasma methods, electron beam methods, ion beam methods, sputtering methods, acid treatments, corona treatment methods, atmospheric pressure glow discharge plasma methods, and the like. The alkali treatment method and the corona treatment method are preferable, and the alkali treatment method is particularly effective.

The corona treatment is a treatment performed by applying a high voltage of 1 kV or more between the electrodes under atmospheric pressure and discharging it. An apparatus commercially available from Kasuga Electric Co., Ltd. or Toyo Electric Co., Ltd. Can be used. The intensity of the corona discharge treatment depends on the distance between the electrodes, the output per unit area, and the generator frequency. As one electrode (A electrode) of the corona treatment apparatus, a commercially available one can be used, but the material can be selected from aluminum, stainless steel and the like. The other is an electrode (B electrode) for holding a plastic film, and is a roll electrode installed at a certain distance from the A electrode so that the corona treatment is carried out stably and uniformly. A commercially available one can also be used, and the material is preferably a roll made of aluminum, stainless steel, or a metal thereof, and a roll lined with ceramic, silicon, EPT rubber, hyperon rubber, or the like. It is done. The frequency used for the corona treatment used in the present invention is a frequency of 20 kHz to 100 kHz, and a frequency of 30 kHz to 60 kHz is preferable. When the frequency is lowered, the uniformity of the corona treatment is deteriorated and unevenness of the corona treatment occurs. In addition, when the frequency is increased, there is no particular problem when performing high-output corona treatment, but when performing low-output corona treatment, it is difficult to perform stable processing, resulting in uneven processing. Will occur. The output of the corona treatment is 1 to 5 w · min. / M ² but ² to 4 w · min. An output of / m ² is preferred. The distance between the electrode and the film is 5 mm or more and 50 mm or less, preferably 10 mm or more and 35 mm or less. When the gap is opened, a higher voltage is required to maintain a constant output, and unevenness is likely to occur. On the other hand, if the gap is too narrow, the applied voltage becomes too low and unevenness is likely to occur. Furthermore, when the film is transported and continuously processed, the film comes into contact with the electrodes and scratches are generated.

  The alkali treatment method is not particularly limited as long as it is a method in which a film coated with a hard coat layer is immersed in an alkaline aqueous solution.

  As the aqueous alkali solution, an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous ammonia solution or the like can be used, and an aqueous sodium hydroxide solution is particularly preferable.

  The alkali concentration of the aqueous alkali solution, for example, sodium hydroxide concentration is preferably 0.1 to 25% by mass, and more preferably 0.5 to 15% by mass.

  The alkali treatment temperature is usually 10 to 80 ° C, preferably 20 to 60 ° C.

  The alkali treatment time is 5 seconds to 5 minutes, preferably 30 seconds to 3 minutes. The film after the alkali treatment is preferably neutralized with acidic water and then thoroughly washed with water.

  Each layer of the antireflection layer is formed on a transparent substrate film by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, micro gravure coating, and extrusion coating. And can be formed by coating. At the time of application, the transparent substrate film is unwound from a state of being wound in a roll shape with a width of 1.4 to 4 m, applied, dried and cured, and then wound into a roll shape. preferable.

  Furthermore, the antireflection film of the present invention may be manufactured by a manufacturing method in which the optical interference layer is laminated on a transparent substrate film and then heat-treated at 50 to 160 ° C. while being wound in a roll shape. preferable. The period of the heat treatment may be appropriately determined depending on the set temperature. For example, if it is 50 ° C., it preferably ranges from 3 days to less than 30 days, and if it is 160 ° C., it ranges from 10 minutes to 1 day. preferable. Usually, it is preferably set at a relatively low temperature so that the heat treatment effect at the outside of the winding, the center of the winding, and the core is not biased, and is preferably performed at around 50 to 60 ° C. for about 7 days.

  In order to stably perform the heat treatment, it is necessary to perform in a place where the temperature and humidity can be adjusted, and it is preferable to perform in a heat treatment chamber such as a clean room without dust.

  When the optical film coated with the functional thin film is wound into a roll, the winding core is not particularly limited as long as it is a cylindrical core, but is preferably a hollow plastic core, and the plastic material is heat-treated. A heat resistant plastic that can withstand temperature is preferable, and examples thereof include resins such as phenol resin, xylene resin, melamine resin, polyester resin, and epoxy resin. A thermosetting resin reinforced with a filler such as glass fiber is preferable.

  The number of windings on these winding cores is preferably 100 windings or more, more preferably 500 windings or more, and the winding thickness is preferably 5 cm or more.

  In this way, when the heat treatment is performed in a state where the functional thin film is coated on the long plastic film substrate and the roll wound around the plastic core is wound, it is preferable to rotate the roll. The rotation is preferably a speed of 1 rotation or less per minute, and may be continuous or intermittent. Moreover, it is preferable to perform rewinding of the roll once or more during the heating period.

  In order to rotate the long optical film roll wound around the core during the heat treatment, it is preferable to provide a dedicated turntable in the heat treatment chamber.

  In the case of intermittent rotation, the stop time is preferably within 10 hours, the stop position is preferably made uniform in the circumferential direction, and the stop time is within 10 minutes. More preferred. Most preferred is continuous rotation.

  As for the rotation speed in continuous rotation, the time required for one rotation is preferably 10 hours or less, and if it is early, it becomes a burden on the apparatus, so the range of 15 minutes to 2 hours is substantially preferable.

  In the case of a dedicated carriage having a rotation function, it is preferable that the optical film roll can be rotated during movement and storage. In this case, rotation is effective as a countermeasure against black bands that occur when the storage period is long. Function.

〔Polarizer〕
The polarizing plate of the present invention will be described.

  The polarizing plate can be produced by a general method. The back surface side of the antireflection film of the present invention is subjected to alkali saponification treatment, and a completely saponified polyvinyl alcohol aqueous solution is used on at least one surface of a polarizing film prepared by immersing and stretching the treated antireflection film in an iodine solution. It is preferable to bond them together. The antireflection film may be used on the other surface, or another polarizing plate protective film may be used. With respect to the antireflection film of the present invention, the polarizing plate protective film used on the other surface has an in-plane retardation Ro of 590 nm, an optical compensation film having a phase difference of 20 to 70 nm and Rt of 100 to 400 nm. A phase difference film). These can be prepared, for example, by the methods described in JP-A No. 2002-71957 and Japanese Patent Application No. 2002-155395. Alternatively, it is preferable to use a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning a liquid crystal compound such as a discotic liquid crystal. For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348. By using in combination with the antireflection film of the present invention, a polarizing plate having excellent planarity and a stable viewing angle expansion effect can be obtained.

  As a polarizing plate protective film used on the back side, as a commercially available cellulose ester film, KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC8UCR-3, KC8UCR-4, KC8UCR-5 (manufactured by Konica Minolta Opto Co., Ltd.) Etc.) are preferably used.

  The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol film. There are ones in which iodine is dyed on a system film and ones in which a dichroic dye is dyed, but it is not limited to this. As the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxially stretching or dyed, or uniaxially stretched after dyeing, and then preferably subjected to a durability treatment with a boron compound. A polarizing film having a thickness of 5 to 30 μm, preferably 8 to 15 μm, is preferably used. On the surface of the polarizing film, one side of the antireflection film of the present invention is bonded to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

(Image display device)
By incorporating the antireflection film surface of the polarizing plate of the present invention on the viewing surface side of the image display device, the image display device of the present invention having various visibility can be produced. The antireflection film of the present invention is a reflection type, transmission type, transflective type LCD or LCD of various drive systems such as TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, etc. Preferably used. In addition, the antireflection film of the present invention has significantly less color unevenness in the reflected light of the antireflection layer, and has a low reflectance and excellent flatness, and is a plasma display, field emission display, organic EL display, inorganic EL display, electronic It is also preferably used for various display devices such as paper. In particular, an image display device having a large screen of 30 or more screens has an effect that there is little color unevenness and wavy unevenness, and eyes are not tired even during long-time viewing.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Example 1
The refractive index of each layer constituting the antireflection layer was measured by the following method.

(Refractive index)
The refractive index of each refractive index layer was calculated | required from the measurement result of the spectral reflectance of the spectrophotometer about the sample which coated each layer on the hard coat film produced below. The spectrophotometer uses U-4000 type (manufactured by Hitachi, Ltd.), and after roughening the back side of the measurement side of the sample, light absorption treatment is performed with black spray to prevent reflection of light on the back side. The reflectance in the visible light region (400 nm to 700 nm) was measured under the condition of regular reflection at 5 degrees.

(Particle size of metal oxide fine particles)
As for the particle diameter of the metal oxide fine particles used, 100 fine particles were observed with an electron microscope (SEM), the diameter of a circle circumscribing each fine particle was taken as the particle diameter, and the average value was taken as the particle diameter.

<< Production of cellulose triacetate film having hard coat layer and back coat layer >>
The following coating liquid 1 for hard coat layer is filtered through a polypropylene filter having a pore diameter of 0.4 μm on a cellulose triacetate (TAC) film having a film thickness of 40, 80 μm, a refractive index of 1.49, and a winding length of 2500 m, and the hard coat layer is applied. Liquid 1 was prepared and applied using a micro gravure coater, dried at 90 ° C., and then an ultraviolet ray lamp was used to irradiate the irradiated part with an illuminance of 100 mW / cm ² and an irradiation amount of 100 mJ / cm ^2. It was cured to form a hard coat layer 1 having a thickness of 6 μm to produce a hard coat film.

(Hard coat layer coating solution 1)
The following materials were stirred and mixed to obtain hard coat layer coating solution 1.

Acrylic monomer: KAYARAD DPHA (dipentaerythritol hexaacrylate, Nippon Kayaku) 200 parts by mass Irgacure 184 (manufactured by Ciba Specialty Chemicals) 20 parts by mass Propylene glycol monomethyl ether 110 parts by mass Ethyl acetate 110 parts by mass The coating layer composition was applied with an extrusion coater so as to have a wet film thickness of 14 μm, dried at 85 ° C. and wound up to provide a backcoat layer.

<Backcoat layer composition>
Acetone 30 parts by mass Ethyl acetate 45 parts by mass Isopropyl alcohol 10 parts by mass Diacetyl cellulose 0.6 parts by mass Ultrafine silica 2% acetone dispersion (Aerosil 200V manufactured by Nippon Aerosil Co., Ltd.) 0.2 parts by mass << Preparation of Antireflection Film >>
On the hard coat film prepared above, an antireflection layer was coated in the order of a high refractive index layer and then a low refractive index layer as described below to prepare an antireflection film.

<Preparation of antireflection layer: high refractive index layer>
On the hard coat film, the following high refractive index layer coating composition 1 was applied by an extrusion coater, dried at 80 ° C. for 1 minute, then cured by irradiation with ultraviolet rays of 0.1 J / cm ² , and further at 100 ° C. for 1 The high refractive index layer 1 having the composition shown in Table 1 was provided so as to be subjected to partial heat curing and to have a thickness of 78 nm.

  Subsequently, high refractive index layers 2 to 27 having the compositions shown in Table 1 were provided in the same manner except that the components in the coating composition were changed. The refractive index of this high refractive index layer was as shown in Table 1.

<High refractive index layer coating composition 1>
(A) Isopropyl alcohol solution of metal oxide fine particles (solid content 20%, ITO particles, particle size 5 nm) 55 parts by mass (b) Metal compound: Ti (OBu) ₄ (tetra-n-butoxytitanium) 1.3 mass Part (c) Ionizing radiation curable resin: Dipentaerythritol hexaacrylate
3.2 parts by mass Photopolymerization initiator: Irgacure 184 (manufactured by Ciba Specialty Chemicals)
0.8 parts by mass (f) 10% propylene glycol monomethyl ether solution of linear dimethyl silicone-EO block copolymer (FZ-2207, manufactured by Nippon Unicar Co., Ltd.) 1.5 parts by mass Propylene glycol monomethyl ether 120 parts by mass Isopropyl alcohol 240 parts by mass Methyl ethyl ketone 40 parts by mass << Preparation of antireflection layer: low refractive index layer >>
On each of the high refractive index layers, the following low refractive index layer coating composition 1 is applied by an extrusion coater, dried at 100 ° C. for 1 minute, and then cured by irradiation with ultraviolet rays of 0.1 J / cm ^2. The film was further heat-cured at 120 ° C. for 5 minutes, and a low refractive index layer was provided so as to have a thickness of 95 nm. Thus, antireflection films 1 to 28 described in Table 2 were produced. The refractive index of this low refractive index layer was 1.37.

(Preparation of low refractive index layer coating composition 1)
<Preparation of tetraethoxysilane hydrolyzate A>
Hydrolyzate A was prepared by mixing 289 g of tetraethoxysilane and 553 g of ethanol, adding 157 g of 1.6% aqueous acetic acid solution thereto, and stirring in a water bath at 25 ° C. for 30 hours.

(D) Tetraethoxysilane hydrolyzate A 110 parts by mass (e) Hollow silica-based fine particles (P-2 below) 30 parts by mass KBM503 (silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.) 4 parts by mass (f) 10% propylene glycol monomethyl ether solution of chain dimethyl silicone-EO block copolymer (FZ-2207, manufactured by Nippon Unicar Co., Ltd.) 3 parts by mass Propylene glycol monomethyl ether 400 parts by mass Isopropyl alcohol 400 parts by mass <Hollow silica-based fine particles P-2 Preparation>
A mixture of 100 g of silica sol having an average particle diameter of 5 nm and a SiO ₂ concentration of 20% by mass and 1900 g of pure water was heated to 80 ° C. The pH of this reaction mother liquor was 10.5, and 9000 g of 0.98 mass% sodium silicate aqueous solution as SiO ₂ and 9000 g of 1.02 mass% sodium aluminate aqueous solution as Al ₂ O ₃ were simultaneously added to the mother liquor. did. Meanwhile, the temperature of the reaction solution was kept at 80 ° C. The pH of the reaction solution rose to 12.5 immediately after the addition and hardly changed thereafter. After completion of the addition, the reaction solution was cooled to room temperature and washed with an ultrafiltration membrane to prepare a SiO ₂ .Al ₂ O ₃ core particle dispersion having a solid content concentration of 20% by mass. (Process (a))
1700 g of pure water is added to 500 g of this core particle dispersion and heated to 98 ° C., and while maintaining this temperature, a silicic acid solution (SiO ₂₎ obtained by dealkalizing a sodium silicate aqueous solution with a cation exchange resin. A dispersion of core particles in which 3000 g (concentration of 3.5% by mass) was added to form a first silica coating layer was obtained. (Process (b))
Next, 1125 g of pure water is added to 500 g of the core particle dispersion liquid that has been washed with an ultrafiltration membrane to form a first silica coating layer having a solid concentration of 13% by mass, and concentrated hydrochloric acid (35.5%) is further added dropwise. The pH was adjusted to 1.0 and dealumination was performed. Next, the aluminum salt dissolved in the ultrafiltration membrane was separated while adding 10 L of hydrochloric acid aqueous solution of pH 3 and 5 L of pure water, and SiO ₂ · Al from which some of the constituent components of the core particles forming the first silica coating layer were removed. A dispersion of ₂ O ₃ porous particles was prepared (step (c)). A mixture of 1500 g of the above porous particle dispersion, 500 g of pure water, 1,750 g of ethanol, and 626 g of 28% ammonia water is heated to 35 ° C., and then 104 g of ethyl silicate (SiO ₂ 28 mass%) is added. The surface of the porous particles on which the first silica coating layer was formed was coated with a hydrolyzed polycondensate of ethyl silicate to form a second silica coating layer. Subsequently, a dispersion of hollow silica-based fine particles (P-2) having a solid content concentration of 20% by mass in which the solvent was replaced with ethanol using an ultrafiltration membrane was prepared.

The thickness of the first silica coating layer of the hollow silica-based fine particles was 3 nm, the average particle size was 47 nm, MOx / SiO ₂ (molar ratio) was 0.0017, and the refractive index was 1.28. Here, the average particle diameter was measured by a dynamic light scattering method.

<Antireflection film heat treatment>
An antireflection film having the same configuration as that of the antireflection film 5 was produced and wound on a plastic core with a winding length of 2500 m. Using this antireflection film roll, the roll is set on a turntable installed in the heat treatment chamber, and heat treatment is performed at 60 ° C. for 7 days while rotating at a speed of 15 minutes every 12 hours. It was. This film was designated as an antireflection film 29.

"Evaluation methods"
The produced antireflection film samples were evaluated by the following methods. The evaluation results are shown in Table 2.

(Reflectance)
Using a spectrophotometer (U-4000, manufactured by Hitachi, Ltd.), the spectral reflectance at an incident angle of 5 ° was measured in a wavelength region of 380 to 780 nm. Since the antireflection performance is better as the reflectance is smaller in a wide wavelength region, the minimum reflectance at 450 to 650 nm is obtained from the measurement result. In the measurement, the back surface on the observation side was roughened, and then light absorption processing was performed using a black spray to prevent reflection of light on the back surface of the film, and the reflectance was measured.

(SW resistance)
A sample was subjected to a load of 250 g / cm ^{2 on} # 0000 steel wool (SW) in an environment of 23 ° C. and 55% RH, and the number of scratches per 1 cm width was measured after 10 reciprocations. In addition, the number of scratches is measured at a place where the number of scratches is the largest among the portions where the load is applied. If it is 10 / cm or less, there is no practical problem, but 5 / cm or less is preferable, and 3 / cm or less is more preferable.

(crack)
The sample was heat-treated at a temperature of 90 ° C. for 500 hours, and the state of the sample was observed with a microscope (20 ×) and evaluated in the following three stages.

○: No cracks are observed Δ: Partially weak cracks are observed ×: Cracks are observed on the entire surface (UV resistance)
UV irradiation was performed using an eye super UV tester (SUV-F11, manufactured by Iwasaki Electric Co., Ltd.). A sample was taken out every 20 hours, an adhesion test was performed, and an irradiation time at which peeling started was measured. The adhesion was performed according to the cross-cut adhesion test method of JIS-K5400. If it is 50 hours or longer, there is no practical problem, but it is preferably 100 hours or longer, more preferably 200 hours or longer.

(Haze)
Three samples were stacked and haze was measured using a haze meter (T-2600DA, manufactured by Tokyo Denshoku). If it is 2.0% or less, there is no practical problem, but 1.0% or less is preferable.

(Coating unevenness)
Samples were evaluated visually. The evaluation criteria were as follows and evaluated in 5 stages. If it is Δ level or higher, there is no practical problem, but it is preferably O level or higher, and most preferably ○ level.

○: Almost no change in color of reflected light is observed. ○ △: A slight change in color of reflected light is observed. △: Partial change in color of reflected light is observed. △ ×: Reflected light is totally reflected. Change in color tone is observed x: Large change in color tone of reflected light is recognized as a whole From the evaluation results in Table 2, the particle size of the metal oxide fine particles is outside the present invention in the high refractive index layer composition. Compared with the comparative example of the anti-reflection films 2 and 8 and the anti-reflection film 17 containing no metal compound, the sample of the present invention has good SW resistance, cracks, UV resistance, haze, and good coating unevenness. it is obvious. Further, the content of the metal oxide, the mass ratio of the ionizing radiation curable resin and the photopolymerization initiator, and the mass ratio of the metal compound (in metal oxide equivalent) and the ionizing radiation curable resin are described in the claims of the present invention. When it is a preferable range, it turns out that the said characteristic is favorable.

  Furthermore, it can be seen from the comparison between the antireflection films 5 and 29 that the SW resistance is remarkably improved by performing the heat treatment after the preparation of the antireflection film.

Example 2
Subsequently, using the antireflection films 1 to 29 produced in Example 1, polarizing plates were produced as follows, and these polarizing plates were incorporated into a liquid crystal display panel (image display device) to evaluate visibility.

  In accordance with the following method, polarizing plates 1 to 29 were prepared using each of the antireflection film and KC8UCR-5 (manufactured by Konica Minolta Opto), which is a cellulose ester optical compensation film, as a polarizing plate protective film.

(A) Production of Polarizing Film A long polyvinyl alcohol film having a thickness of 70 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. . This was washed with water and dried to obtain a long polarizing film.

(B) Production of Polarizing Plate Then, according to the following steps 1 to 5, a polarizing film and a polarizing plate protective film were bonded to produce polarizing plates 1 to 29.

  Step 1: The optical compensation film and the antireflection film were immersed in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried. A surface of the antireflection film provided with the antireflection layer was previously protected with a peelable protective film (PET).

  Similarly, the optical compensation film was immersed in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried.

  Process 2: The above-mentioned polarizing film was immersed for 1 to 2 seconds in the polyvinyl alcohol adhesive tank of 2 mass% of solid content.

  Step 3: Excess adhesive adhered to the polarizing film in Step 2 was lightly removed, and it was sandwiched between the optical compensation film and the antireflection film that had been subjected to alkali treatment in Step 1, and laminated.

Process 4: It bonded together at the speed | rate of about 2 m / min with the pressure of 20-30 N / cm < ² > with the two rotating rollers. At this time, care was taken to prevent bubbles from entering.

  Step 5: The sample prepared in Step 4 in a dryer at 80 ° C. was dried for 2 minutes to prepare a polarizing plate.

  A polarizing plate on the outermost surface of a commercially available liquid crystal display panel (VA type) was carefully peeled off, and polarizing plates 1 to 29 having the same polarization direction were attached thereto.

  The liquid crystal panels 1 to 29 obtained as described above are placed on a desk 80 cm high from the floor, and a daylight direct tube fluorescent lamp (FLR40S • D / MX) is placed on the ceiling 3 m high from the floor. Matsushita Electric Industrial Co., Ltd.) 40W × 2 sets were set as 10 sets at 1.5 m intervals. At this time, when the evaluator is in front of the display surface of the liquid crystal panel, the fluorescent lamp is arranged so that the fluorescent lamp comes to the ceiling from the evaluator's overhead to the rear. The liquid crystal panel was tilted by 25 ° from the vertical direction with respect to the desk, and a fluorescent lamp was reflected so that the visibility of the screen (visibility) was evaluated as follows.

A: You don't have to worry about the movement of the nearest fluorescent light, and you can clearly read characters with a font size of 8 or less. B: The reflection of the nearby fluorescent light is a little worrisome, but you don't care about the distance. Can manage to read characters with a font size of 8 or less C: It is difficult to read characters with a font size of 8 or less. Worrying, the imprinted part cannot read characters with a font size of 8 or less. As a result of the evaluation, both the antireflection film of the present invention and the liquid crystal panel using the polarizing plate have an evaluation result of B or more. The visibility was better than that of the comparative sample.

Claims (14)

In the antireflection film having a high refractive index layer having a higher refractive index than the transparent substrate film and a low refractive index layer having a lower refractive index than the transparent substrate film on the transparent substrate film, the high refractive index The layer is formed by coating a coating solution containing the following (a) to (c), and the low refractive index layer is formed by coating a coating solution containing the following (d) and (e): An antireflection film.
(A) Metal oxide fine particles having an average particle diameter of 10 to 200 nm (b) Metal compound (c) Ionizing radiation curable resin (d) Organosilicon compound represented by the following general formula (1) or a hydrolyzate thereof Or its polycondensate General formula (1) Si (OR) ₄
(In the formula, R is an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms.)
(E) Hollow silica-based fine particles that have an outer shell layer and are porous or hollow inside The metal oxide fine particles are at least one selected from zirconium oxide, antimony oxide, tin oxide, zinc oxide, indium-tin oxide (ITO), antimony-doped tin oxide (ATO), and zinc antimonate. The antireflection film according to claim 1. The metal compound is a compound represented by the following general formula (2) or a chelate compound thereof, and the content of the metal oxide derived from the metal compound contained in the high refractive index layer is 0.3 to 5% by mass. The antireflection film according to claim 1, wherein the antireflection film is provided.
General formula (2) _An MB _xn
(In the formula, M represents a metal atom, A represents a hydrolyzable functional group or a hydrocarbon group having a hydrolyzable functional group, B represents an atomic group covalently or ionically bonded to the metal atom M. x represents a metal. The valence of atom M, n represents an integer of 2 or more and x or less.) The said metal compound is at least 1 sort (s) chosen from the group which consists of titanium alkoxide, zirconium alkoxide, and those chelate compounds, The antireflection film of any one of Claims 1-3 characterized by the above-mentioned. The antireflection film according to any one of claims 1 to 4, wherein the ionizing radiation curable resin has an acrylic compound having two or more unsaturated bonds capable of being polymerized in a molecule. 6. The acrylic compound is a compound selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. The antireflection film as described. The ionizing radiation curable resin contains a photopolymerization initiator and an acrylic compound having two or more unsaturated bonds polymerizable in a molecule in a mass ratio of 3: 7 to 1: 9. Item 7. The antireflection film according to any one of Items 1 to 6. The high refractive index layer formed using a composition containing (a) metal oxide fine particles having an average particle diameter of 10 to 200 nm, (b) a metal compound, and (c) an ionizing radiation curable resin. And (b) having a high refractive index layer in which the ratio of the mass of the metal oxide derived from the metal compound to the mass of (c) the ionizing radiation curable resin is 1: 3 to 1: 100. The antireflection film according to any one of claims 1 to 7. The antireflective film according to any one of claims 1 to 8, wherein the high refractive index layer and the low refractive index layer contain (f) a fluorine-based or silicone-based surfactant. The antireflection film according to any one of claims 1 to 9, wherein the antireflective film is heat-treated at 50 to 160 ° C after the low refractive index layer is laminated. In a method for producing an antireflection film in which at least a high refractive index layer and a low refractive index layer are provided on a transparent substrate film directly or via another layer, (a) metal oxide fine particles having an average particle diameter of 10 to 200 nm (B) a step of providing a high refractive index layer having a refractive index higher than that of the substrate using a composition containing a metal compound and (c) an ionizing radiation curable resin, and (d) the following general formula (1) And a hydrolyzate thereof or a polycondensate thereof, and (e) a composition containing hollow silica-based fine particles having an outer layer and porous or hollow inside. And a process for providing a low refractive index layer having a refractive index lower than that of the substrate.
General formula (1) Si (OR) ₄
(In the formula, R is an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms.) The method for producing an antireflection film according to claim 11, wherein the low-refractive index layer is provided and then wound into a roll, and then heat-treated at 50 to 160 ° C. A polarizing plate comprising the antireflection film according to any one of claims 1 to 10 on one side and an optical compensation film on the other side. A display device comprising the antireflection film according to claim 1 or the polarizing plate according to claim 13.