KR20100127954A - Antireflection film and polarizing plate comprisind the same - Google Patents

Abstract

PURPOSE: A reflection preventing film and a polarizing plate thereof are provided to have a superior reflective exterior and to have a low reflectivity. CONSTITUTION: A triacetate cellulose transparent base(10) is used for the protection of a polyvinyl alcohol polarizer. A high refraction high hardness layer(20) is coated on a transparent substrate and has an antistatic function. A low refraction layer(30) is coated on the high hardness high hardness layer by a wet method.

Description

Anti-reflective film and polarizing plate including the same {ANTIREFLECTION FILM AND POLARIZING PLATE COMPRISIND THE SAME}

The present invention relates to an antireflection film and a polarizing plate including the same, and more particularly, to an antireflection film having excellent reflection appearance and a very low reflectance by reducing the vibration width of a reflectance spectrum wavelength and a polarizing plate including the same.

In general, antireflective films are used in various image displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), electroluminescent displays (ELDs), and cathode ray tube displays (CRTs). In addition, the anti-reflection film is used in eyeglass lenses and cameras. Such antireflective films have generally been used with multilayer antireflective films having a stack of thin transparent metal oxide layers. The use of such a plurality of transparent layers is to prevent the reflection of light in the widest possible wavelength range in the visible light region.

Thin transparent metal oxide films, on the other hand, are formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD), in particular vacuum deposition or sputtering, classified as PVD techniques. Thin transparent metal oxide films have excellent optical properties as antireflective coats, while productivity is low and unsuitable for large scale production when vacuum deposition and sputtering are used to form these films.

In addition, a method of forming an antireflection film by wet coating using inorganic particles has been proposed as an alternative to vapor deposition technology. As an example, JP-B-60-59250 contains an antireflective layer containing granulated inorganic material and having microvoids, which is obtained by coating. The antireflective layer having such micropores is obtained by applying a coating composition and treating the coating layer with an active gas. JP-A-2-245702 also discloses an antireflection film containing two or more kinds of ultrafine particles (eg, MgF ₂ and SiO ₂ ). The mixing ratio of the particles here is changed in the film thickness direction to change the refractive index, thereby achieving optical properties similar to the antireflective film of JP-A-59-50401 having a refractive layer / low refractive layer combination. The ultrafine particles are bound by SiO ₂ produced by thermal decomposition of ethyl silicate. Pyrolysis of ethyl silicate involves the combustion of the ethyl portion to produce carbon dioxide and steam, which is released from the coating layer leaving gaps in the ultrafine particles. JP-A-5-13021 also proposes to fill the gaps described above among the ultrafine particles with a binder. JP-A-7-48527 discloses an antireflection film containing a granulated inorganic component containing porous silica and a binder. JP-A-11-6902 describes an all-wet coating technique for low cost production of antireflective films with high film strength and low reflection, and is a three layered reflection formed by wet coating. A film having a protective layer is disclosed, wherein two or more inorganic particles are laminated on the low reflection layer to form a layer containing fine pores.

On the other hand, known means for imparting antiglare to antireflective films formed by wet coating techniques reflect substrates having surface unevenness as described in JP-A-2000-275401 and JP-A-2000-275404. Coating with an anti-reflective layer, incorporating matting particles into the anti-reflective layer to make the surface non-uniform, and embossing the smooth anti-reflective film to form surface non-uniformity.

However, the antireflection film formed by vacuum deposition or sputtering has an average reflectance of 0.4% or less in the wavelength region of 450 to 650 nm, and the color of the reflected light is strongly colored to red or blue magenta, and the light source is viewer. If behind, these rainbow reflected light impairs display quality. On the other hand, the antireflective film formed by the wet coating has a near-neutral reflected light, but has an average reflectance of 1% or more, which is particularly anti-reflective performance in use situations in which external light is directly incident on the front of the display. This is insufficient.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an antireflection film having an excellent reflection appearance and a very low reflectance by reducing the vibration width of the reflectance spectrum wavelength and a polarizing plate including the same. will be.

These and other objects and advantages of the present invention will become more apparent from the following description of a preferred embodiment thereof.

The object is a cellulose triacetate (TAC) transparent substrate used for polyvinyl alcohol (PVA) polarizer protection, and a high refractive index high hardness layer coated on the transparent substrate, the refractive index is 1.50 to 1.60, antistatic function A high refractive index layer comprising a high refractive index layer and a low refractive index layer coated on the high refractive index layer, the refractive index of which is 1.31 to 1.40, and includes a wet-coated low refractive layer, 5 out of 480 to 680 nm wavelength range It is achieved by an antireflection film, characterized in that it has an average specular reflectance of 0.1 to 0.4% at an incident angle.

Here, the antistatic value of the antireflection film is characterized in that E ^ 4 ~ E ^ 10.

Preferably, the thickness of the high refractive index layer is 0.1 to 20㎛, the thickness of the low refractive layer is characterized in that 90 to 130 nm.

Preferably, the adhesive layer further comprises an adhesive layer between the low refractive index layer and the high refractive index layer, wherein the high refractive index layer comprises the adhesive layer and contacts the lower surface of the low refractive layer. The center line average roughness Ra of the surface is characterized by being 0.001 to 0.030 μm.

Preferably, the high refractive index hard layer is at least one metal oxide particles selected from titanium oxide, zirconium oxide, indium oxide, zinc oxide, tin oxide, aluminum oxide or antimony oxide, anionic dispersant, and trifunctional or higher polymerization It is coated with curable resin containing a sexual group, and the coating composition containing a polymerization initiator and a solvent.

Preferably, the high refractive index layer of the high refractive index is characterized in that the coating composition and dried to remove the solvent, and then cured by applying at least one of heat or ionizing radiation.

Preferably, the low refractive layer comprises a fluorine-containing compound that can be cured by at least one of heat or ionizing radiation, has a dynamic coefficient of friction of 0.03 to 0.15 and a contact angle to water of 95 ° to 120 °. It is characterized by.

In addition, the object, in the polarizing plate comprising an anti-reflection film, a polarizer and a surface protective film is attached to at least one surface of the polarizer, the surface protective film is the anti-reflection film, the low refractive layer is The transparent substrate surface opposite to the surface to be formed is formed by saponification by forming a low refractive layer or after coating with an alkaline solution, heating the coated substrate, and then washing or neutralizing with water to attach to the polarizer. It is achieved by a polarizing plate comprising an anti-reflection film.

The object is also achieved by a display device comprising a polarizing plate comprising the anti-reflection film or the anti-reflection film.

According to the present invention, it has the effect of low reflectance and excellent reflection appearance.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention. These examples are only presented by way of example only to more specifically describe the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

The basic layer structure as a cross-sectional view of the antireflection film according to the present invention is shown in FIG. As can be seen in Figure 1, the anti-reflection film according to the present invention is a reflection of a substantially two-layer structure as a high refractive index layer 20 and a low refractive index layer 30 is coated on the transparent substrate 10 in order It has a prevention layer. In the case of having such two antireflection layers, the wavelength of the spectrum can be adjusted by changing the optical thickness of each layer, that is, the refractive index and the film thickness of the product.

Since the antireflection film according to the present invention having the two-layer structure can achieve both a low reflection effect and a reduction effect of the rainbow (Rainbow), when the antireflection film according to the present invention is applied to the outermost layer of the display, It is possible to provide a display (e.g., an LCD) with high visibility which has not been obtained conventionally. In addition, since the antireflection film according to the present invention has an average value in the 480 nm to 680 nm wavelength region of specular reflectance at a 5 ° incidence angle of 0.4% or less, the visibility due to reflection of external light from the front of the display is reduced. Can be satisfactorily prevented.

The antireflection film of the present invention has no rainbow phenomenon due to reflected light of red light or blue light, which is a problem associated with a conventional multilayer antireflection film, and has an ultra low reflectivity. In addition, when the antireflection film according to the present invention is applied to an LCD, the color of the reflected light caused by the reflection of light from high brightness external light, for example, indoor fluorescent light, becomes blurry and negligible.

The transparent substrate of the antireflection film according to the present invention preferably has a refractive index of 1.45 to 1.55, for example, a cellulose triacetate (TAC, refractive index: 1.49) substrate. In this case, the refractive index n1 of the high refractive high hardness layer is 1.50 to 1.60, and the refractive index n2 of the low refractive layer is required to be 1.40 or less, preferably 1.31 to 1.40. Combination of a plurality of layers containing a layer having a refractive index higher than the desired refractive index and a layer having a refractive index lower than the desired refractive index when it is impossible or impossible to obtain materials having a desirable refractive index as the high refractive index layer and the low refractive index layer. By using the above, it is possible to achieve substantial optical uniformity for the set high refractive resin layer or the low refractive layer as known in the art. The expression "substantially two-layer structure" used for the antireflection layer in the present invention means a structure containing such an optically equivalent layer, and is intended to include an antireflection layer which may have a structure of three or more layers. It is intention.

In the antireflection film according to the present invention, as a result of the remarkable reduction in the above-mentioned reflection light coloring, the nonuniformity in the color taste of the reflected light due to the thickness change of the antireflection layer is also greatly reduced. That is, the range of allowable thickness variations is widened, which can have the effect of increasing the production yield and further reducing the production cost.

The transparent substrate of the antireflective film according to the present invention preferably comprises a plastic film. Polymers suitable for plastic film production include cellulose esters (e.g., cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate and nitrocellulose), polyamides, polycarbonates, polyesters Examples include polyethylene terephthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, polyethylene 1,2-diphenoxyethane-4,4'-dicarboxylate and polybutylene terephthalate) , Polystyrene (eg, syndiotactic polystyrene), polyolefins (eg, polypropylene, polyethylene, and polymethylpentene), polysulfones, polyether sulfones, polyarylates, polyether-imide, polymethyl meta Acrylates and polyether ketones.

When the antireflection film according to the present invention is used as one of the protective films of the polarizer when the LCDs, organic ELDs, etc. are applied, cellulose triacetate is most preferred as the transparent substrate. The cellulose triacetate substrate is preferably prepared by the method disclosed in the technical disclosure manual 2001-1745. Also in applications where the antireflective film is attached to a faceplate made of glass or the like, such as in planar CTRs, PDPs, etc., polyethylene terephthalate or polyethylene naphthalate is preferably used.

The transparent substrate preferably has a light transmittance of 80% or more, in particular 86% or more, a haze of 2.0% or less, in particular 1.0% or less, and a refractive index of 1.4 to 1.7. In addition, the thickness of the transparent substrate is not limited thereto, but is preferably 30 to 200 µm, more preferably 75 to 125 µm.

Next, the high refractive index high hardness layer of the antireflection film according to the present invention, the coating composition containing inorganic particles having a high refractive index, heating or ionizing radiation curing monomers, a polymerization initiator and a solvent on a transparent substrate, It is formed by drying to remove the solvent and then curing the coating film by applying at least one of heat or ionizing radiation. The high refractive index high hardness layer thus formed is excellent in adhesion to those formed by applying a polymer solution having scratch resistance and high refractive index and drying the coating film. In addition, as well described in JP-A-11-153703 and US Pat. No. 6,210,858, a polyfunctional (meth) acrylate monomer and an anionic group-containing (meth) acrylate dispersant (anionic dispersant) are added to the coating composition to disperse it. It is desirable to improve the stability and strength of the cured film.

The inorganic particles are preferably particles of at least one metal oxide selected from oxides of titanium, zirconium, indium, zinc, tin or antimony. In addition, the inorganic particles are preferably an average particle size of 1 to 100 nm as measured by Coulter (Coulter) counter. Particles smaller than 1 nm are so large that their specific surface area is not sufficient to ensure sufficient stability in the dispersion, and particles larger than 100 nm may scatter visible light due to differences in binders in terms of refractive index, resulting in high haze and poor transmittance. Can be.

On the other hand, the haze of the said high refractive high hardness layer becomes like this. Preferably it is 3% or less, More preferably, it is 1% or less.

In addition, the low refractive index layer of the antireflective film according to the present invention includes a fluorine-containing compound that can be cured when thermal or ionizing radiation is applied, the low refractive index layer has a dynamic friction coefficient of 0.03 to 0.15, the contact angle to water Is 95 ° to 120 °. If the coefficient of dynamic friction is greater than 0.15, the layer is easily scratched upon friction. Also, if the contact angle with water is less than 95 °, the layer has poor resistance to contamination with fingerprints or oily stains.

The thermal or ionizing radiation cured fluorine-containing compound may also include perfluoroalkyl-containing silane compounds (e.g., heptadeca fluoro-1,1,2,2-tetradecyl) triethoxysilane) and fluorine-containing monomers and crosslinks. Fluorine-containing copolymers containing monomers that provide a bonding group. Fluorine-containing monomers providing fluorine-containing polymers are fluoroolefins such as fluoroethylene, vinylidene fluorine, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, and perfluoro-2,2-dimethyl -1,3-dioxonol; Partially or fully fluorinated alkyl (meth) acrylates such as Viscote 6FM (available from Osaka Organic Chemical Industry Ltd), and M-2020 [Daikin Industries, Ltd. Available from; And partially or fully fluorinated vinyl ethers. Hexafluoropropylene is preferred in view of the low refractive index and ease of handling of the resulting polymer.

In addition, the monomer providing the crosslinkable group may be a (meth) acrylate monomer having a crosslinkable group in a molecule such as glycidyl methacrylate, and a (meth) having a carboxyl group, a hydroxyl group, an amino group or a sulfonic acid group, or the like. ) Acrylate monomers such as (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate), and allyl acrylate. It is known that the latter group of monomers can introduce crosslinked structures after copolymerization, and these are particularly preferred (JP-A-10-25388 and JP-A-10-147739).

In addition, fluorine-free comonomers can be used in combination with fluorine-containing monomers. Such comonomers include, but are not limited to, olefins (eg, ethylene, propylene, isoprene, vinyl chloride, and vinylidene chloride), acrylate esters (methyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate) , Methacrylic acid esters (eg methyl methacrylate, ethyl methacrylate, butyl methacrylate, and ethylene glycol dimethacrylate), styrene derivatives (eg styrene, divinylbenzene, vinyltoluene, and α) Methyl styrene), vinyl ethers (eg methylvinyl ether), vinyl esters (eg vinyl acetate, vinyl propionate, and vinyl cinnamates), acrylamides (eg Nt-butylacrylamide and N- Cyclohexylacrylamide), methacrylamide, and acrylonitrile derivatives. Details are disclosed in JP-A-10-25388 and JP-A-10-147739.

In addition, the fluorine-containing polymer further contains comonomer units provided for improving slip and reducing the coefficient of dynamic friction, which will improve scratch resistance. As an example, introduction into the main chain of polydimethylsiloxane segments, such as those shown in JP-A-11-228631, is preferably adopted. It is also desirable to disperse the ultrafine particles of silicon oxide in the fluorine-containing polymer in order to improve scratch resistance.

In addition, although the low refractive index layer of the antireflection film according to the present invention has a low refractive index, it is more preferable for the antireflection, but the scratch resistance decreases as the refractive index decreases. Thus, the refractive index of the fluorine-containing polymer and the amount of silicon oxide particles added are optimized to provide the best balance of scratch resistance and low refractive index. Preparation of Silica Sol in Commercially Available Organic Solvents or Silica Powder in Commercially Available Organic Solvents A dispersion may be added to the coating composition for the low refractive index layer. The ultrafine particles of the oxides preferably have an average particle size of 0.001 to 0.2 μm, in particular 0.001 to 0.05 μm and as narrow a size distribution as possible (monodisperse). The ultrafine particles of the oxide are suitably added in an amount of 5 to 90%, preferably 10 to 70%, more preferably 10 to 50%, based on the total weight of the low refractive layer.

In addition, the anti-reflection film according to the present invention may further include an adhesive layer between the low refractive layer and the high refractive layer, the high refractive layer of the high refractive index includes an adhesive layer, the lower surface of the low refractive layer The center line average roughness Ra of the surface of the adhesive layer in contact with is characterized in that 0.001 to 0.030 ㎛.

The adhesive layer is a layer showing excellent adhesion to both the upper layer and the lower layer. In the present invention, the top layer (the layer provided directly on the adhesive layer) is generally a low refractive material having poor adhesion to other layers. The antireflective film of the present invention exhibits very high resistance to scratches due to this adhesive improvement effect of the adhesive layer. The adhesive layer of the present invention is characterized by the roughness on its surface. The adhesive layer is believed to provide good anchorage so that the low refractive layer provides improved adhesion. The adhesive layer preferably has a thickness of 0.001 to 0.030 μm, in particular 0.001 to 0.020 μm, in particular 0.001 to 0.010 μm, so as not to affect the antireflection function based on optical interference. If the centerline average roughness Ra of the adhesive layer is too small, the fixing effect is lost, and when the centerline average roughness Ra of the adhesive layer is too large, disturbance of the interface occurs, which is bad for antireflection performance based on optical interference. Has no effect.

When the refractive index of the adhesive layer is the same as the refractive index of the low refractive layer (upper layer), the thickness of the adhesive layer is selected so that the total thickness of the adhesive layer and the low refractive layer is the thickness originally set for the low refractive layer. When the refractive index of the adhesive layer is the same as the refractive index of the lower layer, it is conceivable to select the thickness of the adhesive layer such that the total thickness of the adhesive layer and the lower layer is the same as originally set for the lower layer. It is more preferred that the adhesive layer replace the underlying layer, ie combine the functions of the originally set underlying layer. That is, the adhesive layer may be a high refractive index layer that is an adhesive layer, a hard coat layer that is an adhesive layer, or a matte layer that is an adhesive layer. In such a case, the thickness of the adhesive layer may be one set for the corresponding functional layer.

The surface roughness of the adhesive layer is represented by the center line average roughness Ra determined according to JIS B-0601. Ra is obtained by analyzing the surface profile measured for an evaluation length of 4 μm using an atomic force microscope. If the surface has a matte non-uniformity due to matting particles as described below, this period of non-uniformity is excluded from the data.

The material capable of making the adhesive layer with Ra mentioned above is not particularly limited. A preferred construction for obtaining the mentioned average roughness is a two-component system consisting of an organic binder and fine particles, wherein the organic binder is provided to ensure adhesion to the underlying layer and the adhesive film strength, and the particles are provided to make surface nonuniformity. Preferred particle contents are 20 to 95% by weight, in particular 50 to 95% by weight, based on the total weight of the adhesive layer. It is desirable in terms of transparency that the particles are as fine as possible. Preferred volume average particle diameters are from 0.001 to 0.2 μm, in particular from 0.005 to 0.1 μm. Volume average particle diameters can be determined by dynamic light scattering using a particle size analyzer N4 available from Beckman Coulter, Inc. It is also desirable for the inorganic particles to provide an adhesive layer having film strength.

The form of the inorganic particles is not particularly limited but includes spherical, table, fibrous, rod, amorphous or hollow forms. Spherical particles are preferred in view of dispersibility. The material of the inorganic particles is also not particularly limited. Amorphous materials are preferred. Metal oxides, nitrides, sulfides or halides are preferred, with metal oxides being particularly preferred. Useful metal species are Na, K, Mg, Ca, Ba, Al, Zn, Fe, Cu, Ti, Sn, In, W, Y, Sb, Mn, Ga, V, Nb, Ta, Ag, Si, B, Bi, Mo, Ce, Cd, Be, Pb and Ni. In addition, the method of using the inorganic particles is not particularly limited. By way of example, the particles can be added in a dry state or dispersed in water or an organic solvent.

It is also preferable to use a combination of dispersion stabilizers for the purpose of suppressing aggregation or sedimentation of the inorganic particles. Useful dispersion stabilizers include polyvinyl alcohol, polyvinylpyrrolidone, cellulose derivatives, polyamides, phosphate esters, polyethers, surfactants, silane coupling agents, and titanium coupling agents. Particular preference is given to silane coupling agents which introduce functional groups copolymerizable with the organic binder to the surface of the inorganic particles to give a strong cured film. For example, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and the like are effective for curing organic binders through radical polymerization of vinyl groups, and γ-glycidyloxypropyltrimethoxysilane and the like are used as epoxy groups. It is effective for organic binders curable through cationic polymerization. Although not limited, the silane coupling agent as the dispersion stabilizer is preferably added in an amount of at least 1 part by weight per 100 parts by weight of the inorganic particles. The silane coupling agent may be hydrolyzed prior to addition or the silane coupling agent may be mixed with the inorganic particles and then hydrolyzed and concentrated. The latter addition method is preferred.

In addition, the organic binder used in the adhesive layer should provide excellent adhesion to the underlying layer and have a strong film forming ability. In order to meet these requirements, polymers having a saturated hydrocarbon or polyether as the main chain are preferred. Polymers having saturated hydrocarbons as the main chain are preferred. It is also preferred that the binder polymers have a crosslinked structure.

Binder polymers having a saturated hydrocarbon as the main chain are preferably those containing ethylenically unsaturated monomers. Binder polymers having a saturated hydrocarbon chain and a crosslinked structure as the main chain include homo- or copolymers containing monomers having two or more ethylenically unsaturated groups per molecule. In order to obtain a high refractive adhesive layer, it is preferable to use at least one atom selected from monomers having two or more ethylenically unsaturated groups and aromatic rings or halogens except fluorine, sulfur, phosphorus and nitrogen.

Examples of the monomer having two or more ethylenically unsaturated groups include esters with polyhydric alcohols and (meth) acrylic acid, such as ethylene glycol di (meth) acrylate, 1,4-dicyclohexane diacrylate, pentaerythritol tetra (Meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerytate Lititol penta (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate, and polyester polyacrylate; Vinylbenzene and its derivatives such as 1,4-divinylbenzene, 2-acryloylethyl 4-vinylbenzoate and 1,4-divinylcyclohexanone; Vinylsulfone (eg divinylsulphone), acrylamide (eg methylenebisacrylamide), and methacrylamide.

Examples of monomers that also provide a high refractive binder include bis (4-methacryloylthiophenyl) sulfide, vinylnaphthalene, vinylphenyl sulfide, and 4-methacryloxyphenyl-4'-methoxyphenyl thioether do.

The monomers with ethylenically unsaturated groups are also polymerized by applying ionizing radiation or heat in the presence of a radical radical initiator or a thermal radical initiator.

In addition, the binder polymer having a polyether as the main chain preferably includes a ring-opening polymer of polyfunctional epoxy compounds. The ring-opening polymerization of the polyfunctional epoxy compounds can be carried out by ionizing radiation or heat application in the presence of a photoacid generator or a thermal acid generator.

It is also possible to use a monomer having a crosslinkable functional group instead of or in addition to a monomer having two or more ethylenically unsaturated groups to introduce a crosslinkable functional group which reacts to introduce a crosslinked structure into the binder polymer. Crosslinkable functional groups include isocyanate groups, epoxy groups, aziridine groups, oxazoline groups, aldehyde groups, carbonyl groups, hydrazine groups, carboxyl groups, methylol groups, and active methylene groups. Vinylsulfonic acids, acid anhydrides, cyanoacrylate derivatives, melamines, etherified methylol compounds, esters, urethanes, and metal alkoxides such as tetramethoxysilane are also useful as monomers for introducing crosslinked structures. Functional groups that express crosslinkability after degradation, such as blocked isocyanates, can also be used. That is, the crosslinkable functional group may be reactable immediately or exhibit reactivity as a result of decomposition. The binder polymer having the crosslinkable functional group described above is heated after application as a film to form a crosslinked structure.

On the other hand, the voids in the adhesive layer are expressed by the void volume (vol%), which is obtained by the difference between the refractive index of the adhesive layer and the refractive index calculated based on the adhesive layer composition, due to the air (refractive index: 1.00) contained in the adhesive layer. Pore volume can also be obtained by observing thin slices of the layer under transmission electron microscopy (TEM). The adhesive layer of the invention preferably has from 0.5 to 30% by volume, in particular from 1 to 25% by volume. The preferred lower limit of the void volume is the limit for ensuring the fixing effect, and the preferred upper limit is the limit for ensuring the adhesive layer strength. The material capable of making the adhesive layer having the above-mentioned pore volume is not particularly limited. A preferred construction for obtaining the mentioned pore volume is a two component system consisting of an organic binder and fine particles and the organic binder is provided to ensure adhesion to the underlying layer and strength of the adhesive layer, which particles are used to make voids in themselves. Is provided. The preferred content of the particles is 60 to 95% by weight, in particular 80 to 95% by weight. The particles are preferably as fine as possible in terms of transparency. Preferred volume average particle diameters are from 0.001 to 0.2 μm, in particular from 0.005 to 0.1 μm. The type of organic binder and particles used in this example is the same as described for the example where the adhesive layer has a specific Ra.

If desired, the antireflection film according to the present invention may have a hard coat layer, a front-scattering layer, an antistatic layer and / or a protective layer.

The antistatic value of the antireflective film according to the present invention is characterized in that E ^ 4 ~ E ^ 10.

The hard coat layer makes the transparent substrate scratch resistant. It is also provided to improve the adhesion between the transparent substrate and the top layer. The hard coat layer preferably contains a coating composition containing oligomers of polyfunctional acrylic monomers, acrylates such as urethane acrylates, epoxy acrylates, polymerization initiators, and solvents that may include inorganic fillers (such as silica or alumina). And drying the coating layer by removing the solvent, and curing the coating layer by applying heat and / or ionizing radiation. The thickness of the hard coat layer is preferably 0.1 to 20 µm, preferably 1 to 10 µm, particularly preferably 2 to 8 µm. The pencil hardness of the hard coat layer is preferably at least H, still preferably at least 2H, particularly preferably at least 3H. The refractive index of the hard coat layer is preferably 1.50 to 1.60, in particular 1.52 to 1.56.

Such hard coat layer may be an inorganic layer mainly containing silicon dioxide, an organic layer containing a polymer having a polyether or a saturated hydrocarbon as a main chain, or a hybrid layer containing a mixture of an inorganic compound and an organic compound. Particular preference is given to layers made of polymers having saturated hydrocarbons as the main chain. The polymer preferably has a crosslinked structure. Polymers having saturated hydrocarbons as the main chain are preferably prepared by polymerizing ethylenically unsaturated monomers. Monomers having two or more ethylenically unsaturated groups are preferably used to provide a crosslinked binder polymer.

Examples of monomers having two or more ethylenically unsaturated groups include esters between polyhydric alcohols and (meth) acrylic acids, such as ethylene glycol di (meth) acrylate, 1,4-dicyclohexane diacrylate, pentaerythritol tetra ( Meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerytate Lititol penta (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate and polyester polyacrylate; Vinylbenzene and its derivatives such as 1,4-divinylbenzene, 2-acryloylethyl 4-vinylbenzoate, and 1,4-divinylcyclohexanone); Vinylsulfone (eg, divinylsulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide.

The monomers having ethylenically unsaturated groups are cured by ionizing radiation- or heat-induced polymerization after wet coating. In addition, polymers having a polyether as the main chain are preferably synthesized by ring-opening polymerization of a polyfunctional epoxy compound.

In addition, instead of or in addition to monomers having two or more ethylenically unsaturated groups, monomers having crosslinkable functional groups can be used to introduce crosslinked structures into the binder polymer. Crosslinkable functional groups include isocyanate groups, epoxy groups, aziridine groups, oxazoline groups, aldehyde groups, carbonyl groups, hydrazine groups, carboxyl groups, methylol groups, and active methylene groups. Vinylsulfonic acids, acid anhydrides, cyanoacrylate derivatives, melamines, etherified methylol compounds, esters, urethanes and metal alkoxides such as tetramethoxysilanes are also useful as monomers for introducing crosslinked structures. Compounds having functional groups that express crosslinkability as a result of decomposition, such as compounds having blocked isocyanate groups, can also be used. The binder polymers having the crosslinkable functional groups described above are crosslinked by wet coating in a film, then by heat application or the like.

In addition, the hard coat layer may contain inorganic particles in order to adjust the refractive index or increase the film strength. Inorganic particles having an average particle size of 0.001 to 0.5 μm, in particular 0.001 to 0.2 μm, are preferably used. Suitable inorganic particles are particles of silicon dioxide, titanium dioxide, aluminum oxide, tin oxide, calcium carbonate, barium sulfate, talc, kaolin and calcium sulfate. Particular preference is given to particles of silicon dioxide, titanium dioxide and aluminum oxide. The inorganic particles are preferably added in an amount of 10 to 90% by weight, in particular 20 to 80% by weight, in particular 30 to 60% by weight, based on the hard coat layer.

The front-scattering layer is provided for LCDs application for viewing angle enlargement purposes in the vertical and horizontal directions. The hard coat layer described above containing fine particles having different refractive indices can function as a front-scattering layer.

In addition, when the multilayer anti-reflection film of the present invention formed by the wet coating exhibits surface non-uniformity and exhibits matte properties (blurrs the reflection on the back of the observer), on the layer having surface non-uniformity containing matting particles and the like. It is more preferable to produce the surface nonuniformity by embossing the antireflection layer formed on the substrate rather than forming the antireflection layer. The preceding method achieves better uniformity of film thickness to improve antireflection performance.

Each layer constituting the antireflective layer comprises various wet coating techniques such as dip coating, air knife coating, curtain coating, roller coating, wire bar coating, Gravure coating, microgravure coating, and extrusion coating (see US Pat. No. 2,681,294). Microgravure coatings and gravure coatings are preferred for minimizing spread to reduce dry non-uniformity. Gravure coatings are preferred to ensure uniformity of thickness in the cross direction. Two or more layers can be formed simultaneously. For simultaneous coating, see US Pat. Nos. 2,761,791, 2,941,898, 3,508,947 and 3,526,528 and Yuji Harasaki, Coating Kogaku, p. 253, Asakura Shoten (1973).

In addition, the polarizing plate using the antireflection film according to the present invention contains at least one antireflection film. When manufacturing the polarizing plate using the antireflection film according to the present invention as one of the surface protection films (protective layers) of the polarizer, the transparent substrate surface opposite to the antireflection layer (low refractive index) surface should be saponified with alkali. Saponification using an alkali can be carried out according to the following methods (1) and (2).

Method (1): The back surface of the substrate is saponified by immersing the transparent substrate on which the low refractive layer is formed on the alkali solution one or more times.

Method (2): An antireflection film by coating the transparent substrate surface opposite to the surface on which the low refractive layer is formed with an alkaline solution after or forming the low refractive layer, heating the coated substrate, and then washing and / or neutralizing with water. Only saponify the rear of the.

Method (1) is excellent in that it can be carried out in the same processing steps as a general purpose cellulose triacetate film. However, the method (1) has the disadvantage of hydrolyzing not only the back surface of the substrate but also the antireflection layer surface, which can lead to deterioration of the antireflection layer, and the alkali treatment solution remains on the antireflection layer to cause staining. If these shortcomings are a problem, it is desirable to follow method (2) comprising certain steps.

The polarizer includes an iodine-based polarizer, a dichroic dye polarizer, and a polyene-based polarizer. The iodine based polarizer and the dichroic dye polarizer are generally prepared by dyeing a polyvinyl alcohol (PVA) film before or after stretching. Generally, polyvinyl alcohol (PVA) prepared by saponifying polyvinylacetate is used. Modified PVAs are also useful. The dyeing of the PVA film can be carried out by any means, for example by dipping in an aqueous solution of iodine-potassium iodine or by spread coating or spraying with an iodine solution or a dyeing solution. In the stretching of the PVA film, an additive for crosslinking the PVA, for example a boric acid compound, is preferably used. It is preferred that the polarizer has a transmittance of 30 to 50%, in particular 35 to 50%, at a wavelength of 550 nm, and a polarization degree of 90 to 100%, in particular 95 to 100%, especially 99 to 100% at a wavelength of 550 nm. .

The polarizing plate having the antireflection film of the present invention as a protective film on one side thereof is suitable for application to transmissive, reflective or transflective LCDs in TN mode, STN mode, VA mode, IPS mode or OCB mode. When applied to transmissive or transflective LCDs, when combined with a commercially available brightness enhancing film, ie a polarizing light splitting film having a polarization selective layer, e.g. DBEF (dual brightness improving film) available from Sumitomo 3M Ltd. The polarizing plate ensures higher visibility. The polarizing plate can be combined with a quarter wave plate to provide a surface protective plate for organic ELDs that reduces reflected light from both the surface and the interior. The antireflective film of the present invention having a polyethylene terephthalate (PET) film or a polyethylene naphthalate (PEN) film as a transparent substrate is applicable to image displays such as PDPs and CRTs.

In addition, it will be apparent to those skilled in the art that the scope of the present invention also extends to a display device comprising the antireflection film and a display device comprising the polarizing plate.

Hereinafter, the present invention will be described in more detail using examples and comparative examples according to the present invention.

1. High Hardness Layer Fabrication

1.1 High Refractive Hardness Layer

The refractive index of the high refractive index high hardness layer which is an essential thin film layer of the antireflection film which concerns on this invention is 1.50-1.60, More preferably, it is 1.52-1.56. As a method for forming such a high refractive index hard layer, a transparent thin film of an inorganic oxide formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD), in particular vacuum deposition or sputtering, which is a kind of physical vapor deposition, may be used. Thin films formed by all-wet coating are preferred.

In addition, the highly refractive high hardness layer is curable containing inorganic fine particles comprising an oxide of at least one metal selected from Ti, Zr, In, Zn, Sn, Al, and Sb, an anionic dispersant, and a trifunctional or higher functional polymer. Applying a coating composition containing a resin (hereinafter sometimes referred to as a "binder"), a polymerization initiator and a solvent, drying the solvent, and curing the coating by one or both means of heating and irradiation with ionizing radiation. It is preferable to form by making. In the case of using the curable resin or the initiator, the curable resin is cured through a polymerization reaction under the influence of heating and / or ionizing radiation after coating, thereby forming a high refractive index high hardness layer excellent in scratch resistance and adhesion.

1.2 Inorganic Particulates

As the inorganic fine particles, oxides of metals (eg, Ti, Zr, In, Zn, Sn, Sb, Al) are preferable, and fine particles of zirconium oxide are most preferable in terms of refractive index. However, from the viewpoint of conductivity, it is preferable to use inorganic fine particles mainly composed of an oxide of at least one metal of Sb, In and Sn. The refractive index can be adjusted to a predetermined range by changing the amount of the inorganic fine particles. When using zirconium oxide as a main component, 1-120 nm is preferable, as for the average particle diameter of the inorganic fine particle in a layer, 1-60 nm is more preferable, and its 2-40 nm are still more preferable. This range is desirable because it reduces haze and improves adhesion to the top layer by dispersion stability and proper irregularities on the surface. The refractive index of the inorganic fine particles containing zirconium oxide as a main component used in the present invention is preferably 1.90 to 2.80, more preferably 2.10 to 2.80, and most preferably 2.20 to 2.80. The addition amount of the inorganic fine particles varies depending on the layer to which the inorganic fine particles are added, and the addition amount in the high refractive layer is 40 to 85% by mass, preferably 50 to 75% by mass, and 60 to 70% by mass relative to the solids of the entire high refractive layer. More preferred. The particle diameter of the inorganic fine particles can be measured by light scattering or electron micrographs. The specific surface area of the inorganic fine particles is preferably 10 to 400 m 2 / g, more preferably 20 to 200 m 2 / g, and most preferably 30 to 150 m 2 / g.

In order to stabilize the dispersion in the dispersion or coating solution or to improve the affinity or binding property with the binder component, physical surface treatments such as plasma discharge treatment and corona discharge treatment, or surfactants, coupling agents and the like are applied to the inorganic fine particles. Chemical surface treatment can also be performed. Particular preference is given to using coupling agents.

As said coupling agent, it is preferable to use an alkoxy metal compound (for example, a titanium coupling agent and a silane coupling agent). In particular, the treatment with a silane coupling agent having an acryloyl or methacryloyl group is effective. Chemical surface treating agents, solvents, catalysts and dispersion stabilizers of inorganic fine particles are described in paragraphs [0058] to [0083] of JP-A-2006-17870.

1.3 Curable Resin

As curable resin, a polymeric compound is preferable and it is preferable to use an ionizing radiation-curable polyfunctional monomer or a polyfunctional oligomer as a polymeric compound. As a functional group in this compound, a photo-, electron beam-, or radiation-polymerizable functional group is preferable, and a photopolymerizable functional group is more preferable.

Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as (meth) acryl group, vinyl group, styryl group and allyl group. Among these, a (meth) acryl group is preferable.

Specific examples of the photopolymerizable polyfunctional monomer having a photopolymerizable functional group include (meth) of alkylene glycols such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate and propylene glycol di (meth) acrylate. ) Acrylic acid diesters; (Meth) acrylic acid of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate and polypropylene glycol di (meth) acrylate Diesters; (Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate; And (meth) ethylene oxide or propylene oxide adducts such as 2,2-bis {4-acryloxydiethoxy) phenyl} propane and 2-2-bis {4- (acryloxypolypropoxy) phenyl} propane Acrylic acid diesters are included.

In addition, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

Among these, esters of a polyhydric alcohol and (meth) acrylic acid are preferable, and a polyfunctional monomer having three or more (meth) acryl groups in one molecule is more preferable. Specific examples thereof include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexane tetra (meth) acrylate, pentaglycerol triacrylate, and pentaerythritol. Tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol penta arc releasing, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, tripentaerythritol triacrylate, and tripentaerythritol hexatriacrylate. You may use combining two or more types of polyfunctional monomers. The usage-amount of curable resin may be adjusted in the range which satisfy | fills the refractive index of each layer mentioned above.

1.4 polymerization initiator

It is preferable to use a photoinitiator as a polymerization initiator. As a photoinitiator, an optical radical polymerization initiator or a photocationic polymerization initiator is preferable, and an optical radical polymerization initiator is more preferable.

Examples of the radical photopolymerization initiator include acetophenones, benzophenones, benzoyl benzoate of Michler, α-amyl oxime ester, tetramethylthiuram monosulfide and thioxanthones. Examples of commercially available radical photopolymerization initiators include Nippon Kayaku Co., Ltd. KAYACURE of manufacture (eg, DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, ITX, QTX, BTC, MCA); Ciba Specialty Chemicals Corp. Irgacure of manufacture (eg, 651, 184, 127, 500, 907, 369, 1173, 2959, 4265, 4263); And Sartomer Company Inc. Esacure of manufacture (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, TZT). In particular, photocleavage-type photoradical polymerization initiators are preferred. The fission type radical photopolymerization initiator is known as Technical Information Institute Co., Ltd. (Published by Kazuhiro Takausu) (1991), described on page 159 of the latest UV curing technology. Examples of commercially available photo split optical radical polymerization initiators include Ciba Specialty Chemicals Corp. Irgacure of manufacture (eg, 651, 184, 127, 907). 0.1-15 mass parts is preferable with respect to 100 mass parts of curable resin, and, as for the usage-amount of a photoinitiator, 1-10 mass parts is more preferable.

In addition to the said photoinitiator, a photosensitizer can also be used. Specific examples of photosensitizers include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketones and thioxanthones. Examples of commercially available photosensitizers include Nippon Kayaku Co., Ltd. KAYACURE (eg DMBI, EPA) of the manufacture.

The photopolymerization reaction is preferably performed by ultraviolet irradiation after coating and drying the high refractive index layer.

In addition to the above-described components (e.g., inorganic fine particles, curable resins, polymerization initiators, photosensitizers), high refractive index high hardness layers may include surfactants, antioxidants, coupling agents, thickeners, colorants, colorants (e.g. pigments, Dyes), antifoaming agents, leveling agents, flame retardants, ultraviolet absorbers, infrared absorbers, tackifiers, polymerization inhibitors, antioxidants, surface modifiers, conductive metal fine particles and the like.

1.5 solvent

As a solvent, it is preferable to use the liquid whose boiling point is 60-170 degreeC. Specific examples thereof include water, alcohols (such as methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketones (such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), esters (such as 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, tetrahydrofuran), and Ether alcohols (eg 1-methoxy-2-propanol). Among these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are preferable. In particular, as the dispersion medium, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone is preferable.

It is preferable to use the said solvent so that the coating composition for high refractive index layers may become 2-30 mass% of solid content concentration, and it is more preferable to use so that it may become 3-20 mass% of solid content concentration.

1.6 Formation of High Refractive Hard Layer

It is preferable that the inorganic fine particles containing zirconium oxide as a main component used for a high refractive index high hardness layer are used for formation of a high refractive index layer in a dispersion state. The inorganic fine particles can be dispersed using a disperser. Examples of dispersers include sand grinder mills (eg, bead mills with pins), high speed impeller mills, pebble mills, roller mills, adjusters and colloid mills. Among these, a sand grinder mill and a high speed impeller mill are preferable. Preliminary dispersion processing may be performed. Examples of dispersers used in the predispersion treatment include ball mills, three-roll mills, kneaders and extruders.

The inorganic fine particles are preferably dispersed to have the smallest particle size possible in the dispersion medium. The mass average particle diameter is 10-120 nm, 20-100 nm is preferable, 30-90 nm is more preferable, 30-80 nm is still more preferable. By dispersing the inorganic fine particles in a small particle size of 200 nm or less, a high refractive index layer can be formed without impairing transparency.

The high refractive index high hardness layer used for this invention is formed as follows. To the dispersion obtained by dispersing the inorganic fine particles in the dispersion medium as described above, a curable resin (e.g., the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer described above), a photopolymerization initiator, and the like as a binder precursor necessary for matrix formation are added To prepare a coating composition for forming a high refractive index layer or a medium refractive index layer, the obtained coating composition for forming a high refractive index layer or a medium refractive index layer is coated on a transparent support and cured through a crosslinking reaction or a polymerization reaction of a curable resin. Simultaneously with or after the coating of the high refractive index layer, the binder of the layer is preferably crosslinked or polymerized with a dispersant.

The binder of the high refractive index layer or the medium refractive index layer thus prepared is, for example, the anionic group of the dispersant is taken into the binder as a result of the crosslinking reaction or polymerization reaction of the above-described preferred dispersant and the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer. Losing form. The anionic groups taken in the binder of the high refractive index layer or the medium refractive index layer have a function of maintaining the dispersed state of the inorganic fine particles, and the crosslinked or polymerized structure gives the binder a film-forming ability, thereby high refractive index containing inorganic fine particles The coating layer is improved in physical strength, chemical resistance and weather resistance.

At the time of formation of a high refractive index high hardness layer, the crosslinking or polymerization reaction of the curable resin is preferably performed in an atmosphere having an oxygen concentration of 10% by volume or less. By forming a high refractive index high hardness layer in an atmosphere having an oxygen concentration of 10 vol% or less, the high refractive index high hardness layer can improve physical strength, chemical resistance, weather resistance and adhesion between the high refractive layer and a layer adjacent to the high refractive layer.

The layer formation through the crosslinking reaction or the polymerization reaction of the curable resin is preferably performed in an atmosphere having an oxygen concentration of 6 vol% or less, more preferably in an atmosphere having an oxygen concentration of 4 vol% or less, and in an atmosphere having an oxygen concentration of 2 vol% or less Even more preferably, it is most preferably carried out in an atmosphere having an oxygen concentration of 1 vol% or less.

0.1-20 micrometers is preferable and, as for the thickness of the high refractive hardness layer, 2-8 micrometers is more preferable. Specifically, for example, the main composition is determined by selecting the type of the fine particles and the type of the resin and determining the blending ratio thereof so as to satisfy the film thickness and the refractive index of the high refractive index layer.

2. Low refractive layer manufacturing

2.1 low refractive layer

The low refractive index layer of the antireflection film according to the present invention preferably has a refractive index of 1.31 to 1.40, more preferably 1.38 or less. This range is preferable because the film strength can be maintained while reducing the reflectance. Similarly to the method for forming the low refractive layer, a transparent thin film of an inorganic oxide formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD), in particular, vacuum deposition or sputtering, which is a kind of physical vapor deposition method, is used. Although it can also be used, the method by the all-wet coating which uses the coating composition for low refractive index formation mentioned later is preferable. It is preferable that the low refractive layer contains inorganic fine particles. Among the inorganic fine particles, at least one kind of inorganic fine particles is preferably hollow particles, and hollow particles containing silica as a main component (hereinafter also referred to as "hollow silica particles"). More preferred.

90-130 nm is preferable and, as for the thickness of this refractive layer, 100-120 nm is more preferable.

Further, the haze of the low refractive layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less.

In addition, the strength of the antireflection film having the layers up to the low refractive index layer is preferably at least H, more preferably at least 2H, and most preferably at least 3H, in a pencil hardness test of 500 g load.

In addition, in order to improve the anti-fingerprint performance of the antireflection film, the contact angle with respect to water on the surface is preferably 95 ° to 120 ° contact angle.

2.2 Inorganic Particulates

The inorganic fine particles that can be used for the low refractive layer are preferably hollow particles.

The refractive index of the hollow particles is preferably 1.40 or less, more preferably 1.28 to 1.38, and most preferably 1.32 to 1.36. The hollow particles are preferably hollow silica particles, and the inorganic particles will be described with reference to the hollow silica particles below. The refractive index used herein represents the refractive index of all the particles, and does not represent the refractive index of silica alone as the outer shell forming the hollow silica particles. At this time, assuming that the radius of the cavity inside the particle is a and the radius of the outer shell of the particle is b, the porosity x represented by the following formula (1) is preferably 10 to 60%, and 20 to 60% is More preferably, 30 to 60% is most preferred.

Equation (1): x = (4πa 3/3) (4πb 3/3) × 100

If the hollow silica particles are intended to have lower refractive index and higher porosity, the outer shell becomes thinner and the strength as particles is lowered. Therefore, from the viewpoint of scratch resistance, particles having a refractive index within the above range are preferable.

Here, the refractive index of the hollow silica particles can be measured by an Abbe refractometer (manufactured by ATAGO K.K.). Methods for producing hollow silica are described, for example, in JP-A-2001-233611 and JP-A-2002-79616. In addition, commercially available hollow silica particles can also be used.

In addition, the coating amount of the hollow silica particles is preferably 1 to 100 mg / m 2, more preferably 5 to 80 mg / m 2, and even more preferably 10 to 60 mg / m 2. Within this range, a favorable effect of reducing the refractive index or improving the scratch resistance can be obtained, and the occurrence of minute unevenness on the surface of the low refractive layer can be prevented, and the appearance (e.g. rich black appearance) and integral reflectance can be improved. It can be kept well.

Further, the average particle diameter of the hollow silica particles is preferably 30 to 150%, more preferably 35 to 80%, even more preferably 40 to 60% with respect to the thickness of the low refractive layer. That is, if the thickness of the low refractive layer is 100 nm, the particle diameter of the hollow silica particles is preferably 30 to 150 nm, more preferably 35 to 80 nm, even more preferably 40 to 60 nm. If the particle diameter is within this range, the ratio of the cavity can be maintained satisfactorily, the refractive index can be sufficiently reduced, the occurrence of fine irregularities on the surface of the low refractive layer can be prevented, and the appearance (eg, a dense black appearance) ) And integrated reflectance can be kept good. The silica fine particles may be crystalline or amorphous, and monodisperse particles are preferable. Although the shape is the most preferable spherical form, there is no problem even if it is indefinite. The average particle diameter of the hollow silica particles can be determined from electron micrographs.

In the present invention, silica particles without cavities may be used in combination with hollow silica particles. The particle size of the silica without cavity is preferably 5 to 150 nm, more preferably 10 to 80 nm, and most preferably 15 to 60 nm.

Further, at least one kind of silica fine particles (also referred to as "small particle size silica fine particles") having an average particle diameter of less than 25% of the thickness of the low refractive layer may be silica fine particles having the above-described particle diameters ("large particle size silica fine particles"). It is preferable to use in combination with "."

The small particle sized silica fine particles may be present in the gap between the large particle sized silica fine particles, and thus may serve as a retainer for the large particle sized silica fine particles. The average particle size of the small particle size silica fine particles is preferably 1 to 20 nm, more preferably 5 to 15 nm, and even more preferably 10 to 15 nm. The use of such silica fine particles is preferable from the viewpoint of raw material cost and oil retainer effect. In order to stabilize the dispersion in the dispersion or coating solution or to improve affinity or binding to the binder component, physical surface treatments such as plasma discharge treatment and corona discharge treatment for hollow particles, or by surfactants, coupling agents, etc. Chemical surface treatment may also be performed. Particular preference is given to the use of coupling agents. As a coupling agent, it is preferable to use an alkoxy metal compound (for example, a titanium coupling agent and a silane coupling agent). Among these, the treatment with a silane coupling agent having acryloyl or methacryloyl group is effective. Chemical surface treating agents, solvents, catalysts and dispersion stabilizers of hollow particles are described in paragraphs [0058] to [0083] of JP-A-2006-17870.

The low refractive layer is also formed by applying a coating composition containing a film-forming solute and one or more solvents, drying the solvent, and curing the coating by either or both means of irradiation of heating and ionizing radiation. It is preferable to be.

The solute is preferably a composition containing a heat-curable or ionizing radiation-curable fluorine-containing curable resin, a hydrolyzate of an organosilyl compound, or a partial condensate thereof.

Moreover, it is preferable to use the composition containing a fluorine-containing curable resin, and, as for the low refractive layer, the aspect which uses the hydrolyzate of organosilyl compound or its partial condensate auxiliary is more preferable. The addition amount of the hydrolyzate or partial condensate of the organosilyl compound used auxiliary is 10 to 40 mass% with respect to the fluorine-containing curable resin.

2.3 Fluorine-containing curable resins

Fluorine-containing curable resins (hereinafter sometimes referred to as "fluorine-containing polymers") include perfluoroalkyl group-containing silane compounds (e.g., (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trie Hydroxysilane), a dehydrated condensate thereof, and a fluorine-containing copolymer containing as a component a structural unit for imparting crosslinking reactivity with a fluorine-containing monomer unit. In particular, the low refractive index layer used in the present invention is formed by a cured film of a copolymer containing repeating units derived from a fluorine-containing vinyl monomer and repeating units having a (meth) acryloyl group in its side chain as essential components. It is preferable. In addition, from the viewpoint of satisfying both the reduction of the refractive index and the film strength, it is preferable to use a combination of a curing agent such as polyfunctional (meth) acrylate. The mixing ratio of the fluorine-containing polymer and the polyfunctional (meth) acrylate is not particularly limited, but a mixing ratio which does not cause phase separation therebetween in the film after drying is preferred. Of course, only one may be used. Specific examples of the polyfunctional (meth) acrylate include a photopolymerizable polyfunctional monomer described for the high refractive index layer.

Hereinafter, the preferable fluorine-containing curable resin used for the low refractive layer of this invention is demonstrated in detail.

Examples of fluorine-containing vinyl monomers include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene), partial or fully fluorinated alkyl ester derivatives of (meth) acrylic acid (eg , VISCOAT 6FM (trade name, manufactured by Osaka Organic Chemical Industry Ltd.), M-2020 (trade name, manufactured by Daikin Industries, Ltd.), and fully or partially fluorinated vinyl ethers. Among these, perfluoroolefins are preferable, and hexafluoropropylene is more preferable from a viewpoint of refractive index, solubility, transparency, availability, etc. In this invention, it is preferable to introduce a fluorine-containing vinyl monomer so that the fluorine content of a copolymer may be 20-60 mass%, It is more preferable that a fluorine content is 25-55 mass%, 30-30 mass% of fluorine content Is even more preferred. When the composition ratio of the fluorine-containing vinyl monomer is within this range, not only can the refractive index be satisfactorily reduced, but also the film strength can be maintained.

It is preferable that the fluorine-containing curable resin used for a low refractive layer has a crosslinking reactive group. Examples of structural units for imparting crosslinking reactivity include structural units obtained by polymerization of monomers having a self-crosslinkable functional group in the molecule, such as glycidyl (meth) acrylate and glycidyl vinyl ether; Monomer ((meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether having a carboxyl group, hydroxy group, amino group, sulfo group, etc.) , Maleic acid and crotonic acid); And a structural unit obtained by introducing a crosslinking reactive group such as a (meth) acryloyl group into the above-described structural unit by a polymer reaction (eg, the crosslinking reactive group can be introduced by causing acrylic acid chloride to act on a hydroxy group). . The copolymer as the fluorine-containing polymer used in the low refractive layer preferably contains a repeating unit having a (meth) acryloyl group in its side chain as an essential component. Although it may change according to the kind of repeating unit derived from a fluorine-containing vinyl monomer, generally, it is preferable that the (meth) acryloyl-group containing repeating unit occupies 5-90 mass%, and it occupies 30-70 mass%. More preferably, it is still more preferable to occupy 40-60 mass%. When the composition ratio of the (meth) acryloyl group-containing repeating unit is increased, the film strength is improved and the refractive index is high, which is preferable.

In copolymers useful in the present invention, in addition to repeating units derived from fluorine-containing vinyl monomers and repeating units having a (meth) acryloyl group in the side chain, adhesion to a transparent support, Tg (contributing to film hardness) of the polymer, Other vinyl monomers may be appropriately copolymerized from various viewpoints such as solubility in solvents, transparency, slipperiness, antidust and antifouling properties. It is also possible to combine a plurality of these vinyl monomers according to the purpose, and these monomers are preferably introduced at a total of 0 to 65 mol%, more preferably 0 to 40 mol%, more preferably 0 to 30 mol% in the copolymer. Even more preferably.

The vinyl monomers that can be used in combination are not particularly limited, and examples thereof include olefins (eg, ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride), acrylic esters (eg, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate), methacrylic acid esters (eg methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate), styrene Derivatives (eg styrene, p-hydroxymethylstyrene, p-methoxystyrene), vinyl ethers (eg methyl vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl Ethers), vinyl esters (eg vinyl acetate, vinyl propionate, vinyl cinnamate), unsaturated carboxy Acids (eg acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid), acrylamides (eg N, N-dimethylacrylamide, N-tert-butylacrylamide, N-cyclohexylacrylamide), Methacrylamides (eg, N, N-dimethylmethacrylamide), and acrylonitrile.

About such a polymer, you may use combining a hardening | curing agent suitably as described in JP-A-10-25388 and JP-A-10-147739.

Preferable forms of the fluorine-containing curable resin used in the present invention include a resin represented by the formula (1).

[Formula 1]

In formula (1), L represents a linking group having 1 to 10 carbon atoms, a linking group having 1 to 6 carbon atoms is preferable, a linking group having 2 to 4 carbon atoms is more preferable, and the linking group has a linear or branched structure or a cyclic structure. It may have a hetero atom selected from O, N and S.

Preferred examples thereof include *-(CH2) 2-O-**, *-(CH2) 2-NH-**, *-(CH2) 4-O-**, *-(CH2) 6-O- **, *-(CH2) 2-O- (CH2) 2-O-**, * -CONH- (CH2) 3-O-**, * -CH2CH (OH) CH2-O-** and * -CH2CH2OCONH (CH2) 3-O-** (where * indicates a linking site to the polymer main chain side and ** indicates a linking site to the (meth) acryloyl group side). m represents 0 or 1.

In addition, in general formula (1), X represents a hydrogen atom or a methyl group, and a hydrogen atom is preferable from a hardening reactivity viewpoint.

In addition, in Formula 1, A represents a repeating unit derived from any vinyl monomer. The repeating unit is not particularly limited as long as it is a constituent of a monomer copolymerizable with hexafluoropropylene, and is not particularly limited as long as it is an adhesive to a transparent support, Tg of the polymer (contributing to film hardness), solubility in a solvent, transparency, slippage, dust It may be appropriately selected from various aspects such as prevention and fouling prevention properties. This repeating unit may consist of a single vinyl monomer or a plurality of vinyl monomers, depending on the purpose.

Preferred examples of such vinyl monomers are methyl vinyl ether, ethyl vinyl ether, tert-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether And vinyl ethers such as allyl vinyl ether; Vinyl esters such as vinyl acetate, vinyl propionate and vinyl butyrate; With methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate and (meth) acryloyloxypropyltrimethoxysilane Same (meth) acrylates; Styrene derivatives such as styrene and p-hydroxymethylstyrene; And unsaturated carboxylic acids and derivatives thereof such as crotonic acid, maleic acid and itaconic acid. Among these, vinyl ether derivatives and vinyl ester derivatives are preferable, and vinyl ether derivatives are more preferable.

In addition, in Formula 1, x, y and z represent the mole% of each component, and represent the value which satisfy | fills 30 <= <= 60, 5 <= y <= 70 and 0 << 276> z <= 65, provided x + y + z = 100. It is more preferable to satisfy 35≤x≤55, 30≤y≤60 and 0≤z≤20, and even more preferably satisfy 40≤x≤55, 40≤y≤55 and 0≤z≤10. .

Particularly preferred forms of the copolymers used in the present invention include compounds represented by the formula (2).

[Formula 2]

In the formula (2), X, x and y have the same meaning as in formula (1), the preferred range thereof is also the same.

n represents an integer of 2 ≦ n ≦ 10, preferably 2 ≦ n ≦ 6, and more preferably 2 ≦ n ≦ 4.

B represents a repeating unit derived from any vinyl monomer and may consist of a single composition or a plurality of compositions. Examples include those described above as examples of A in formula (1).

z1 and z2 represent mol% of each repeating unit, and represent values satisfying 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65, except that x + y + z1 + z2 = 100. It is more preferable to satisfy 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10, and even more preferably satisfy 0 ≦ z1 ≦ 10 and 0 ≦ z2 ≦ 5.

The copolymer represented by the formula (1) or (2) can be prepared by, for example, introducing a (meth) acryloyl group into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any means described above. , Can be synthesized.

Although the preferable example of the copolymer useful for this invention is demonstrated below, this invention is not limited to this.

Synthesis of the copolymer as a fluorine-containing curable resin used in the present invention is synthesized after synthesis of precursors such as hydroxyl group-containing polymers by various polymerization methods such as solution polymerization, precipitation polymerization, suspension polymerization, bulk polymerization and emulsion polymerization. , By introducing the (meth) acryloyl group by the above-described polymer reaction. The polymerization reaction can be carried out by known operations such as batch systems, semi-continuous systems and continuous systems.

Examples of methods for initiating polymerization include methods using radical initiators and methods of irradiating light or radiation. These polymerization methods and polymerization-initiation methods are described, for example, in the method of polymer synthesis by Teiji Tsuruta, in the Nikkan Kogyo Shimbun (1971) edition, and in the method of polymer synthesis by Takayuki Ohtsu and Masayoshi Kinoshita, pages 124-154, Kagaku Dojin (1972). It is described in.

Among these polymerization methods, a solution polymerization method using a radical initiator is preferable. Examples of the solvent used for solution polymerization include ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane, N, N-dimethylformamide, N, N- Solvents of one of these solvents, including various organic solvents such as dimethylacetamide, benzene, toluene, acetonitrile, methylene chloride, chloroform, dichloroethane, methanol, ethanol, 1-propanol, 2-propanol and 1-butanol May be used alone or a mixture of two or more solvents thereof may be used. It is also possible to use a mixed solvent with water.

The polymerization temperature needs to be set according to the molecular weight of the polymer produced, the kind of initiator, and the like, and the polymerization temperature may be used from 0 ° C or lower than 0 ° C to 100 ° C or higher than 100 ° C, but the polymerization is 50 to It is preferably carried out in the range of 100 ° C.

The reaction pressure may be appropriately selected, but 0.098 to 9.8 MPa (1 to 100 kg / cm 2) is conventional, with approximately 0.098 to 2.94 MPa (1 to 30 kg / cm 2) being preferred. The reaction time is approximately 5 to 30 hours. The solvent for reprecipitation of the obtained polymer is preferably isopropanol, hexane, methanol or the like. In addition, as a fluorine-containing curable resin, a commercially available product may be used. The amount of the fluorine-containing curable resin thus obtained is preferably 10 to 98% by mass, more preferably 30 to 95% by mass, based on the total solids of the coating composition with respect to the low refractive layer. In particular, when using in combination with an inorganic fine particle, the usage-amount is 30-80 mass% is preferable, and 40-75 mass% is more preferable.

2.4 Coating Composition for Forming Low Refractive Layer

Typically, the coating composition for forming the low refractive index layer is in liquid form, by dissolving the above-mentioned inorganic fine particles and fluorine-containing curable resin, preferably contained in a suitable solvent, and dissolving various additives and radical polymerization initiators as necessary. Are manufactured. Here, the concentration of the solid content may be appropriately selected depending on the use, but about 0.01 to 60% by mass is common, more preferably 0.5 to 50% by mass, still more preferably about 1 to 20% by mass.

The radical polymerization initiator may be either of a type generating radicals under thermal action or a type generating radicals under light action. For compounds which initiate radical polymerization under thermal action, organic or inorganic peroxides, organic azo or diazo compounds and the like may be used.

More specifically, examples of the organic peroxide include benzoyl peroxide, halogen perbenzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide and butyl hydroperoxide; Examples of inorganic peroxides include hydrogen peroxide, ammonium persulfate and potassium persulfate; Examples of azo compounds include 2-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile and 2-azo-bis-cyclohexanedinitrile; Examples of diazo compounds include diazoaminobenzenes and p-nitrobenzenediazonium.

When using the compound which starts radical polymerization under light action, a film hardens by irradiation of ionizing radiation. Examples of such radical photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, and 2,3-dialkyldione compounds. Logistics, disulfide compounds, fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones are 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethyl phenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-mo Leporinopropiophenone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone. Examples of benzoins include benzoin benzenesulfonic acid ester, benzoin toluenesulfonic acid ester, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. In addition, a sensitizing dye can also be preferably used in combination with such an optical radical polymerization initiator.

The amount of the compound which initiates radical polymerization under the action of heat or light is sufficient if the amount is large enough to initiate the polymerization of the carbon-carbon double bond, and the amount is 0.1 to 15% by mass based on the total solids of the composition for forming the low refractive index layer. It is preferable that it is, It is more preferable that it is 0.5-10 mass%, It is further more preferable that it is 2-5 mass%.

2.5 solvent

The solvent contained in the coating composition for low refractive index layer is not particularly limited as long as the fluorine-containing curable resin can be uniformly dissolved or dispersed without causing precipitation, and may be used in combination of two or more solvents. Preferred examples thereof are ketones (e.g. acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (e.g. ethyl acetate, butyl acetate), ethers (e.g. tetrahydrofuran, 1,4 Dioxane), alcohols (eg methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol), aromatic hydrocarbons (eg toluene, xylene) and water.

2.6 Other Compounds Properly Contained in the Coating Composition for Forming Low Refractive Layer

In order to impart properties such as anti-fingerprint properties, water resistance, chemical resistance and slipperiness, a known silicone-based or fluorine-based fingerprint agent, lubricant, or the like may be appropriately added. In the case of adding such an additive, the amount of the additive added is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, even more preferably 0 to 5% by mass, based on the total solids of the low refractive layer.

The low refractive layer may contain an inorganic filler, a silane coupling agent, a lubricant, a surfactant, and the like. In particular, it is preferable that inorganic fine particles, a silane coupling agent, and a lubricant are contained.

As an example of the said silane coupling agent, the silane coupling agent containing a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, an alkoxysilyl group, an acyloxy group, or an acylamino group is preferable, and an epoxy group, a polymerizable acyloxy group More preferred are silane coupling agents containing (eg, (meth) acryloyl) or a polymerizable acylamino group (eg, acrylamino, methacrylamino).

The lubricant is preferably a fluorine-containing compound into which a silicone compound, such as dimethylsilicone, or a polysiloxane moiety is introduced.

2.7 Organosilyl Compounds

The organosilyl compound becomes a hydrolyzate and / or a partial condensate by hydrolysis and condensation in the coating composition for forming the low refractive index layer, and acts as a binder in the composition as well as enables softening of the film coating and improves alkali resistance.

In the present invention, the organosilyl compound preferably used in the coating composition for forming the low refractive index includes a compound represented by the following formula (2).

(3)

R ¹¹ mSi (X ¹¹ ) n

X ¹¹ represents an —OH, a halogen atom, an —OR ¹² group or an —OCOR ¹² group, R ¹¹ represents an alkyl group, an alkenyl group or an aryl group, R ¹² represents an alkyl group, m + n is 4, m and n each represents a positive integer. More specifically, R ¹¹ represents a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms (eg, methyl, ethyl, propyl, i-propyl, butyl, hexyl, octyl) A substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms (eg, vinyl, allyl or 2-buten-1-yl) or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms (eg, Phenyl, naphthyl), and R ¹² represents a group having the same meaning as the alkyl group represented by R ¹¹ . When the group represented by R ¹¹ or R ¹² has a substituent, preferred examples of the substituent include halogen (eg, fluorine, chlorine, bromine), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (eg, Methyl, ethyl, i-propyl, propyl, tert-butyl), aryl groups (e.g. phenyl, naphthyl), aromatic heterocyclic groups (e.g. furyl, pyrazolyl, pyridyl), alkoxy groups (e.g. For example, methoxy, ethoxy, i-propoxy, hexyloxy), aryloxy group (e.g., phenoxy), alkylthio group (e.g., methylthio, ethylthio), arylthio group ( For example, phenylthio), alkenyl groups (eg, vinyl, allyl), acyloxy groups (eg, acetoxy, acryloyloxy, methacryloyloxy), alkoxycarbonyl groups (eg, Methoxycarbonyl, ethoxycarbonyl), aryloxycarbonyl groups (eg phenoxycarbonyl), carbamoyl groups (eg carba 1, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl), and acylamino groups (eg, acetylamino, benzoylamino, acrylamino, methacrylamino )

The compound of formula 3 forms a matrix by the so-called sol-gel method which includes hydrolysis and mutual condensation. The compound of formula 3 is represented by the following four formulas.

[Formula 3a] Si (X ¹¹ ) ₄

[Formula 3b] R ¹¹ Si (X ¹¹ ) ₃

[Formula 3c] R ¹¹ ₂ Si (X ¹¹ ) ₂

[Formula 3d] R ¹¹ ₃ SiX ¹¹

The component of general formula (3a) is demonstrated in detail below.

Specific examples of the compound represented by the formula (3a) include tetramethoxysilane, tetraethoxysilane, tetra-i-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-s-part Methoxysilane and tetra-tert-butoxysilane. In particular, tetramethoxysilane and tetraethoxysilane are preferable.

The component of General formula (3b) is demonstrated below.

In the component of formula 3b, R ¹¹ represents a group having the same meaning as that of Formula 3 R ^11, and examples thereof include methyl, ethyl, n- propyl, and i- propyl groups such as alkyl group, γ- chloropropyl group, a vinyl group, CF ₃ CH ₂ CH ₂ CH _2- , C ₂ F ₅ CH ₂ CH ₂ CH _2- , C ₃ F ₇ CH ₂ CH ₂ CH _2- , C ₂ F ₅ CH ₂ CH _2- , CF ₃ OCH ₂ CH ₂ CH _2- , C ₂ F ₅ OCH ₂ CH ₂ CH _2- , C ₃ F ₇ OCH ₂ CH ₂ CH _2- , (CF ₃ ) ₂ CHOCH ₂ CH ₂ CH _2- , C ₄ F ₉ CH ₂ OCH ₂ CH ₂ CH _2- , 3- (perfluorocyclohexyloxy) propyl group, H (CF ₂ ) ₄ CH ₂ OCH ₂ CH ₂ CH _2- , H (CF ₂ ) ₄ CH ₂ CH ₂ CH _2- , 3 -Glycidoxypropyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group, 3-mercaptopropyl group, phenyl group and 3,4-epoxycyclohexylethyl group.

X ¹¹ represents a -OH, a halogen atom, an -OR ¹² group, or an -OCOR ¹² group. R ¹² represents a group having the same meaning as R ¹² in formula (2), preferably an acyloxy group having an alkoxy group or 1 to 4 carbon atoms, a has a range of 1 to 5 carbon atoms, and examples thereof include a chlorine atom, a methoxy group , Ethoxy group, n-propyloxy group, i-propyloxy group, n-butyloxy group, s-butyloxy group, tert-butyloxy group and acetyloxy group.

Specific examples of the component of formula 3b include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i -Propyltrimethoxysilane, i-propyltriethoxysilane, chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltri Methoxysilane, 3-glycidoxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryl Oxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3,4-epoxycyclohexylethyltrimethoxy Silane, 3,4-epoxycyclohexylethyltriethoxysilane, CF ₃ CH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ −, C ₂ H ₅ CH ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ −, C ₂ F ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ −, C ₃ F ₇ CH ₂ CH ₂ CH ₂ Si (OCH ₃ ) _3- , C ₂ F ₅ OCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) _3- , C ₃ F ₇ OCH ₂ CH ₂ CH ₂ Si (OC ₂ H ₅ ) _3- , (CF ₃ ) ₂ CHOCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) _3- , C ₄ F ₉ CH ₂ OCH ₂ CH ₂ CH ₂ Si (OCH ₃ ) _3- , H (CF ₂ ) It includes, and 3- (perfluoro-cyclohexyloxy) silane _{- 4 CH 2 OCH 2 CH 2} CH 2 Si (OCH 3) 3.

Among these, organosilyl compounds having a fluorine atom are preferable. When using the organosil compound which does not have a fluorine atom as R, it is preferable to use methyl trimethoxysilane or methyl triethoxysilane. One of these organosilyl compounds may be used alone, or two or more thereof may be used in combination.

The component of general formula (3c) is demonstrated below.

The component of formula 3c is an organosilyl compound represented by the formula R ¹¹ ₂ Si (X ¹¹ ) ₂ {R ¹¹ and X ¹¹ are synonymous with R ¹¹ and X ¹¹ defined in the organosylyl compound used as component of formula 3b. Has}.

Here, the plurality of R ¹¹ may not be the same group. Specific examples of the organosilyl compound include dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane and di -i-propyldimethoxysilane, di-i-propyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, (CF ₃ CH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ , (CF ₃ CH ₂ CH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ , (C ₃ F ₇ OCH ₂ CH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ , [H (CF ₂ ) ₆ CH ₂ OCH ₂ CH ₂ CH ₂ ] ₂ Si (OCH ₃ ) ₂ and (C ₂ F ₅ OCH ₂ CH ₂ ) ₂ Si (OCH ₃ ) ₂ . Organosilyl compounds having fluorine atoms are preferred. When using the organosilyl compound which does not have a fluorine atom as R11, dimethyl dimethoxysilane or dimethyl diethoxysilane is preferable. One of the organosilyl compounds represented by the component of the formula (3c) may be used alone or in combination of two or more thereof.

The component of general formula (3d) is demonstrated below.

The component of formula 3d is an organosilyl compound represented by the formula R ¹¹ ₃ SiX ¹¹ (where R ¹¹ and X ¹¹ have the same meaning as R ¹¹ and X ¹¹ defined in the organosylyl compound used as component of formula 3b). }. Here, the plurality of R ¹¹ may not be the same. Specific examples of this organosilyl compound include trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, tri-n-propylmethoxysilane, tri-n-propylethoxysilane and tri -i-propylmethoxysilane, tri-i-propylethoxysilane, triphenylmethoxysilane and triphenylethoxysilane.

In the present invention, each of the components of Formulas 3a to 3d may be used alone but may be used as a mixture. In this case, the mixing ratio is 0 to 100 parts by mass based on 100 parts by mass of the component Formula 3a. It is preferably 1 to 60 parts by mass, more preferably 1 to 40 parts by mass; The component of the formula (3c) is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, even more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the formula (3a); The component of the formula 3d is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, even more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the component of formula 3a. Among the formulas (3a) to (3d), the proportion of the formula (3a) is preferably 30 mass% or more in 100 mass% of the total organosilyl compounds. When the proportion of the component of the formula (3a) is 30% by mass or more, it is preferable because problems such as a decrease in adhesiveness or hardenability of the obtained film coating do not occur. In addition to the components of Formulas 3a to 3d, the compounds described in paragraphs [0039] and [0052] to [0067] of JP-A-2006-30740 may be preferably added, or the coating composition for forming a low refractive layer described herein may be It is also possible to produce preferably.

2.8 Formation of Low Refractive Layer

The low refractive layer is applied with a coating composition in which hollow particles, a fluorine-containing curable resin, an organosilyl compound, and optionally other components are dissolved or dispersed therein, and simultaneously with or after coating and drying, ionizing radiation. It is preferably formed by curing the coating via irradiation (for example, irradiation of light or irradiation of an electron beam) or by crosslinking or polymerization under heating.

In particular, when the low refractive layer is formed through the crosslinking or polymerization reaction of the ionizing radiation-curable compound, the crosslinking or polymerization reaction is preferably performed in an atmosphere having an oxygen concentration of 10 vol% or less. By forming the low refractive layer in an atmosphere having an oxygen concentration of 10 vol% or less, the outermost layer excellent in physical strength and chemical resistance can be obtained.

It is preferable that oxygen concentration is 6 volume% or less, It is more preferable that it is 4 volume% or less, It is further more preferable that it is 2 volume% or less, It is most preferable that it is 1 volume% or less.

As a means for reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration: about 79% by volume, oxygen concentration: about 21% by volume) with another gas, and replace with nitrogen (nitrogen purge). This is more preferable.

Example 1

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.2 micrometers in thickness and 1.51 in refractive index.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. Thus, the antireflection film of the present invention was obtained.

Example 2

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the high refractive index high hardness layer of 4.5 micrometers in thickness, and 1.54 in refractive index.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. Thus, the antireflection film of the present invention was obtained. The resulting antireflective film was evaluated according to the following method.

Example 3

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the high refractive index layer of high refractive index whose thickness is 4.6 micrometers and the refractive index is 1.57.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. Thus, the antireflection film of the present invention was obtained.

Example 4

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.3 micrometers in thickness and 1.54 in refractive index.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 115 nm and a low refractive index of 1.33. A layer was formed. Thus, the antireflection film of the present invention was obtained.

Example 5

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.2 micrometers in thickness, and refractive index 1.54.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. Thus, the antireflection film of the present invention was obtained.

Example 6

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.2 micrometers in thickness, and refractive index 1.54.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.38. A layer was formed. Thus, the antireflection film of the present invention was obtained.

Comparative Example 1

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.3 micrometers in thickness and 1.45 in refractive index.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. This yielded an antireflection film according to a comparative example.

Comparative Example 2

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 3.9 micrometers in thickness, and 1.48 in refractive index.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. This yielded an antireflection film according to a comparative example.

Comparative Example 3

A high refractive index coating composition was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater, and 100 It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.5 micrometers in thickness, and 1.63 in refractive index.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. This yielded an antireflection film according to a comparative example.

Comparative Example 4

The coating composition for high refractive index hard layer was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater. It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.2 micrometers in thickness and 1.68 in refractive index.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.36. A layer was formed. This yielded an antireflection film according to a comparative example.

Comparative Example 5

The coating composition for high refractive index hard layer was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater. It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.2 micrometers in thickness, and refractive index 1.54.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.43. A layer was formed. This yielded an antireflection film according to a comparative example.

Comparative Example 6

The coating composition for high refractive index hard layer was applied to a cellulose triacetate substrate (TAC-TD8OU, refractive index: 1.49, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 µm using a 110 mesh gravure coater. It dried at 2 degreeC for 2 minutes, hardened | cured by ultraviolet irradiation, and formed the highly refractive high hardness layer of 4.2 micrometers in thickness, and refractive index 1.54.

Next, the coating composition for the low refractive index layer was applied to the high refractive layer using a 180 mesh gravure coater, dried at 100 ° C. for 2 minutes, and cured by ultraviolet irradiation to have a thickness of 110 nm and a low refractive index of 1.48. A layer was formed. This yielded an antireflection film according to a comparative example.

The antireflective films prepared in Examples and Comparative Examples were evaluated according to the following experimental examples, and the results are shown in Table 1.

Experimental Example 1: Evaluation of Surface Reflectance

Using a UV Spectrophometer [Shimazu UV-PC3600] equipped with an adapter for surface reflectance at an angle of incidence (= reflection angle) of 5 ° in the wavelength region of 380 to 780 nm, a black matte tape or matte paint is used on the opposite side of the antireflective film. After reflecting the surface in black, the surface reflectance was measured. The obtained reflection spectrum is shown in FIG. The antireflection performance was evaluated by calculating the average specular reflectance in the range of 480 to 680 nm.

Experimental Example 2 Evaluation of Reflective Appearance

Black matte tape or matte paint was used on the opposite side of the anti-reflective film of A4 size, and the backside was black to check the visual appearance (Rainbow) under the incandescent lamp. The evaluation criteria of the reflex appearance were expressed as ((excellent), ((good), △ (normal) and X (bad).

TABLE 1

Refractive Index (n1) of High Refractive Hard Layer Refractive index of the low refractive index layer (n2) At 480 ~ 680nm
Average surface reflectance (%) Reflection Example 1 1.51 1.36 0.32 ○ Example 2 1.54 1.36 0.25 ◎ Example 3 1.57 1.36 0.35 ○ Example 4 1.54 1.33 0.15 ◎ Example 5 1.54 1.36 0.25 ◎ Example 6 1.54 1.38 0.40 ○ Comparative Example 1 1.45 1.36 0.92 △ Comparative Example 2 1.48 1.36 1.12 △ Comparative Example 3 1.63 1.36 1.16 △ Comparative Example 4 1.68 1.36 1.25 X Comparative Example 5 1.54 1.43 1.23 X Comparative Example 6 1.54 1.48 1.34 X

As can be seen in Figure 2, the antireflection film according to the present invention, in the conventional antireflection film having a surface reflectivity of 1% or more because the vibration width of the reflectance spectrum wavelength is large, the reflection appearance was not good, but the antireflection film according to the present invention As the surface average reflectance is 0.4% or less, the oscillation width of the reflectance spectrum wavelength is reduced, and thus the appearance of reflection is excellent, and as can be seen from Table 1 above, the embodiments have a wavelength range of 480 to 680 nm. It has a very low average surface reflectivity of 0.4% or less at a 5 ° incidence angle, and can achieve a reduction effect of a rainbow. The antireflection film according to the present invention has a low reflectance and an excellent reflection appearance. Have

1 is a cross-sectional view of the antireflection film according to the present invention.

Figure 2 is a graph comparing the reflection wavelength of the UV spectrum of the anti-reflection film and the conventional anti-reflection film according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

1: Reflected UV spectral wavelength of the antireflection film according to the present invention

2: Reflected UV spectral wavelength of conventional antireflection film

10: transparent substrate 20: high refractive hardness layer

30: low refractive layer

Claims (10)

In anti-reflection film, A cellulose triacetate (TAC) transparent substrate used for protecting polyvinyl alcohol (PVA) polarizers, A high refractive index high hardness layer coated on the transparent substrate, the refractive index is 1.50 to 1.60, and a high refractive index layer of high refractive index including an antistatic function, A low refractive index layer is coated on the high refractive index layer, and has a refractive index of 1.31 to 1.40, and includes a wet-coated low refractive layer. An anti-reflection film, characterized in that it has an average specular reflectance of 0.1 to 0.4% at a 5 ° incidence in the wavelength region of 480 to 680 nm. The method of claim 1, The antistatic value of the antireflective film is characterized in that E ^ 4 ~ E ^ 10, antireflection film. The method of claim 1, The thickness of the high refractive index of the high hardness layer is 0.1 to 20㎛, the thickness of the low refractive layer is characterized in that the 90 to 130 nm, anti-reflection film. The method of claim 1, An adhesive layer is further included between the low refractive index layer and the high refractive index layer, wherein the high refractive index layer includes the adhesive layer, and the center line average roughness of the surface of the adhesive layer that contacts the lower surface of the low refractive layer. (Ra) is an antireflection film, characterized in that 0.001 to 0.030 ㎛. The method of claim 1, The high refractive index hard layer comprises at least one metal oxide particles selected from titanium oxide, zirconium oxide, indium oxide, zinc oxide, tin oxide, aluminum oxide or antimony oxide, an anionic dispersant, and a trifunctional or higher functional polymer. An antireflection film, which is coated with a coating composition containing a curable resin, a polymerization initiator, and a solvent. The method of claim 5, The high refractive index layer of the high refractive index, characterized in that the coating composition and dried to remove the solvent, and then cured by applying at least one of heat or ionizing radiation. The method of claim 1, The low refractive layer comprises a fluorine-containing compound that can be cured by at least one of heat or ionizing radiation, the dynamic friction coefficient is 0.03 to 0.15, characterized in that the contact angle to water is 95 ° to 120 ° , Antireflection film. In the polarizing plate comprising an anti-reflection film, A polarizer and a polarizing plate having a surface protection film attached to at least one side of the polarizer, The surface protective film is an antireflection film according to any one of claims 1 to 7, wherein the transparent substrate surface opposite to the surface on which the low refractive layer is formed is coated with an alkaline solution after or after the formation of the low refractive layer And saponification, heating the coated substrate, followed by washing or neutralization with water to attach the polarizer to the polarizer. An apparatus for display, comprising the antireflection film according to any one of claims 1 to 7. The polarizing plate of Claim 8 is included, The display apparatus characterized by the above-mentioned.

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