JPWO2009096124A1 - Display filter - Google Patents

Abstract

It is an object of the present invention to provide a display filter that is excellent in electromagnetic wave shielding performance and antireflection performance, and at a low price. A conductive layer having a conductive mesh formed by patterning a metal thin film formed by a vapor deposition method on a substrate, or by performing metal plating on a patterned catalyst ink layer, and A display filter having at least a hard coat layer laminated by coating so as to cover a conductive layer and a low refractive index layer laminated on the hard coat layer, wherein the hard coat layer is a metal oxide It contains fine particles, the refractive index of the hard coat layer is 1.55 or more, the refractive index of the low refractive index layer is 1.4 or less, and the thickness of the conductive mesh is less than 4 μm. It is characterized by.

Description

  The present invention relates to a low-cost display filter having electromagnetic shielding properties and antireflection properties and a method for producing the same.

  A display such as a liquid crystal display (hereinafter referred to as LCD) or a plasma display (hereinafter referred to as PDP) is a display device capable of clear full color display. A display is usually provided with a front filter (hereinafter simply referred to as a filter) on the viewing side of the display for the purpose of preventing reflection of external light, shielding electromagnetic waves generated from the display, and protecting the display. In particular, PDP generates strong electromagnetic waves due to its structure and operating principle, so there are concerns about the effects on human bodies and other devices, and filters with an electromagnetic shielding function and an antireflection function are usually used. .

  As an electromagnetic wave shielding layer (conductive layer) for shielding electromagnetic waves, a conductive mesh is generally used from the viewpoint of low resistance and low cost production.

  As a conventionally known method for producing a conductive mesh, a metal foil such as a copper foil is laminated on a base material via an adhesive, and then a resist film is pasted thereon to form a photomask having a desired pattern. There is a method using a photolithographic method in which development, etching, and resist stripping are performed after exposure through the film (for example, Patent Document 1).

  In the method for producing the conductive mesh, a metal foil of about 10 μm or more is usually used in order to uniformly bond the base material and the metal foil (copper foil).

  As another method for producing a conductive mesh, a method of forming a mesh pattern using a photosensitive silver salt and then performing metal plating is known (Patent Document 2).

  Also, a method for producing a conductive mesh targeted by the present invention, that is, a) a method for producing a conductive mesh by etching a metal thin film formed on a substrate by a vapor deposition method, b) a base A method of producing a conductive mesh by performing metal plating on a catalyst core provided in a pattern on a material; c) a resin layer having a pattern reverse to the pattern of the conductive mesh on a substrate with a peelable resin. And then laminating a metal layer on the surface of the substrate on which the resin layer is formed by a vapor deposition method, and then peeling the resin layer, and d) conductive on the substrate The method of applying oil in a pattern opposite to the mesh pattern and then laminating a metal layer on the surface of the base material on which the oil is applied by a vapor deposition method is known, and the method of a) For example, the method of Patent Document 3, b) The method of Patent Document 4, c) and d) are described in Patent Documents 10.

  On the other hand, as an antireflection film, conventionally, a hard coat antireflection film in which a hard coat layer, a high refractive index layer, and a low refractive index layer are laminated in this order on a substrate such as a plastic film is known (for example, Patent Document 5). Metal oxide fine particles having a high refractive index are used for the high refractive index layer.

  In recent years, it has been proposed to increase the refractive index by incorporating the metal oxide fine particles into a hard coat layer (for example, Patent Documents 6 and 7).

  Conventionally known filters for displays such as optical functional films having functional layers such as a hard coat layer, an antireflection layer and an antiglare layer on a substrate such as a plastic film, and plastic films, etc. There is a filter composed of two base materials (two base material filters) in which an electromagnetic wave shielding film having a conductive layer (electromagnetic wave shielding layer) formed on a base material is laminated via an adhesive layer.

  In contrast to the above two-sheet base filter, the display filter of the present invention can be composed of only one base material by directly laminating a functional layer such as a hard coat layer on a conductive mesh. It becomes possible and a significant cost reduction is achieved.

It is known that a hard coat layer is directly formed on a conductive mesh (for example, Patent Documents 8 and 9).
Japanese Patent No. 3388682 JP 2004-221564 A JP 2005-268688 A JP 2006-173189 A JP 2001-350001 A JP 2006-106715 A JP 2007-86455 A JP 2007-140282 A JP 2007-243158 A JP 2006-140346 A

  The conductive mesh formed by etching a copper foil of about 10 μm or more described in Patent Document 1 above has a large thickness of the conductive mesh of about 10 μm or more. It was difficult to form a hard coat layer directly and uniformly on the conductive mesh. In addition, an adhesive layer for laminating the base material and the copper foil is exposed at the opening of the conductive mesh (the portion where the metal foil has been removed by etching), and on the exposed surface of this adhesive layer Usually, since the rough surface shape (fine uneven shape) on the surface of the copper foil is transferred, the coatability of the hard coat layer tended to deteriorate more and more.

  The conductive mesh manufactured using the photosensitive silver salt described in Patent Documents 2 and 8 described above uses a silver salt-containing layer containing the photosensitive silver salt in the manufacturing process. This silver salt-containing layer uses highly hydrophilic gelatin as a binder, and the gelatin is exposed at the opening of the conductive mesh, so that the coatability of a hydrophobic (lipophilic) hard coat layer And the adhesion tends to be lowered.

  In particular, in order to increase the refractive index of the hard coat layer, a hard coat layer containing a relatively large amount of metal oxide fine particles having a small average primary particle diameter is directly applied on a conductive mesh having an uneven surface. When the coating was applied to the conductive mesh, metal oxide fine particles were localized in the vicinity of the convex portion (thin line portion) of the conductive mesh, resulting in a new problem that the transparency was deteriorated.

In Patent Document 8, a conductive mesh is formed using a photosensitive silver salt as described above, and the coatability of the hard coat layer tends to be lowered, and in particular, a relatively large amount of metal oxide fine particles is present. When the hard coat layer contained was used, the coatability further decreased. In addition, Patent Document 8 describes that ZrO ₂ is contained in order to increase the refractive index of the hard coat layer. Specifically, the hard coat layer containing ZrO ₂ is formed on the conductive mesh. The examples coated in are not shown.

  Patent Document 9 does not describe coating a hard coat layer having a refractive index of 1.55 or more on a conductive mesh having a thickness of less than 4 μm.

  Accordingly, an object of the present invention is to provide a display filter that is excellent in electromagnetic wave shielding performance and antireflection performance and is reduced in cost in view of the above-mentioned problems of the prior art. Specifically, in order to reduce the price, in a display filter in which an antireflection layer including a high refractive index hard coat layer is disposed so as to cover a conductive layer having a conductive mesh, the high refractive index hard The purpose is to improve the coatability and transparency of the coating layer.

  The above object of the present invention has been basically achieved by the following invention. That is, the inventions of (1) and (2) below.

(1) At least a conductive layer having a conductive mesh on a substrate, a hard coat layer laminated so as to cover the conductive layer, and a low refractive index layer laminated on the hard coat layer A display filter,
The hard coat layer contains metal oxide fine particles, and the refractive index of the hard coat layer is 1.55 or more,
The refractive index of the low refractive index layer is 1.4 or less,
Furthermore, the thickness of the conductive mesh is less than 4 μm,
A display filter, wherein the conductive mesh is any one of the following a) to d).

  a) A conductive mesh formed by etching a metal thin film formed on a substrate by a vapor deposition method.

  b) A conductive mesh formed by performing metal plating on the catalyst ink layer provided in a pattern on the substrate.

  c) On the base material, a resin layer having a pattern opposite to the pattern of the conductive mesh is formed with a peelable resin, and then on the surface of the base material on which the resin layer is formed, by a vapor deposition method. A conductive mesh formed by laminating metal thin films and then peeling the resin layer.

  d) By applying oil in a pattern opposite to the pattern of the conductive mesh on the base material, and then laminating a metal thin film on the surface of the base material on which the oil has been applied by vapor deposition. Formed conductive mesh.

(2) A step of forming a conductive layer having a conductive mesh having a thickness of less than 4 μm on the substrate by any of the following methods a) to d):
Forming a hard coat layer containing metal oxide fine particles and having a refractive index of 1.55 or more directly on the conductive layer by coating;
Forming a low refractive index layer having a refractive index of 1.4 or less on the hard coat layer by coating;
A method for producing a display filter, comprising:

  a) A method of forming a conductive mesh by etching a metal thin film formed on a substrate by a vapor deposition method.

  b) A method of forming a conductive mesh by performing metal plating on a catalyst ink layer provided in a pattern on a substrate.

  c) On the base material, a resin layer having a pattern opposite to the pattern of the conductive mesh is formed with a peelable resin, and then on the surface of the base material on which the resin layer is formed, by a vapor deposition method. A method of laminating a metal thin film and then peeling the resin layer.

  d) A method in which oil is applied on a substrate in a pattern opposite to the pattern of the conductive mesh, and then a metal thin film is laminated on the surface of the substrate on which the oil is applied by a vapor deposition method.

  ADVANTAGE OF THE INVENTION According to this invention, the filter for a display which was excellent in electromagnetic wave shielding, antireflection property, and transparency, and implement | achieved low price can be provided.

The schematic cross section of an example of the filter for displays of the present invention. The schematic cross section of an example of the filter for displays of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display filter of this invention 2 Hard coat layer 3 Conductive mesh 4 Base material 5 Near-infrared shielding layer 6 Adhesive layer 7 Low refractive index layer P Line pitch of conductive mesh W Line width of conductive mesh

  The display filter of the present invention includes a conductive layer having a conductive mesh on a substrate, a hard coat layer laminated so as to cover the conductive layer, and a low refractive index layer laminated on the hard coat layer. At least.

  The hard coat layer contains metal oxide fine particles with a high refractive index so that the refractive index is 1.55 or more. The refractive index of the hard coat layer is preferably 1.6 or more, and the upper limit of the refractive index of the hard coat layer is preferably 2.0 or less. If the refractive index of the hard coat layer is higher than 2.0, stable antireflection properties may not be obtained in the entire visible light range.

  The present invention has a low refractive index layer having a refractive index of 1.4 or less on a hard coat layer having a refractive index of 1.55 or more. Thereby, a high antireflection effect is obtained. Moreover, in order to ensure the excellent antireflection performance by laminating a low refractive index layer having a refractive index of 1.4 or less, the hard coat layer preferably has a refractive index of 1.6 or more.

  In order to obtain a hard coat layer having a refractive index of 1.55 or more according to the present invention, the average primary particle size of the metal oxide fine particles contained in the hard coat layer is preferably less than 150 nm, and more preferably the average of the metal oxide fine particles. The primary particle size is in the range of 3 to 100 nm. In addition, the average primary particle diameter of this invention shows the particle diameter when a metal oxide fine particle exists independently, and means what shows the most frequent particle diameter. The average primary particle diameter of the metal oxide fine particles can be measured using a dynamic light scattering method. Specifically, it can be measured using “Nanotrack” manufactured by Nikkiso Co., Ltd.

  By using metal oxide fine particles having an average primary particle diameter of less than 150 nm, the refractive index of the hard coat layer can be increased without reducing the transparency of the hard coat layer. In order to increase the refractive index of the hard coat layer by containing metal oxide fine particles, it is preferable to contain 25 mass% or more of metal oxide fine particles with respect to 100 mass% of all components of the hard coat layer. When the content of the metal oxide fine particles is less than 25% by mass with respect to 100% by mass of all components of the hard coat layer, the refractive index of the hard coat layer may not be increased to 1.55 or more.

  The content of the metal oxide fine particles is more preferably 30% by mass or more, further preferably 40% by mass or more, particularly preferably 45% by mass or more with respect to 100% by mass of all components of the hard coat layer. Thereby, the refractive index of the hard coat layer can be increased, and the antireflection property is improved in combination with a low refractive index layer having a refractive index of 1.4 or less. The upper limit of the content of the metal oxide fine particles in the hard coat layer is all components of the hard coat layer from the viewpoint of ensuring high transparency of the hard coat layer and ensuring formability by good coating of the hard coat layer. 95 mass% or less is preferable with respect to 100 mass%, and 90 mass% or less is more preferable.

  When the content of the metal oxide fine particles is 25% by mass or more and less than 45% by mass with respect to 100% by mass of all components of the hard coat layer, a hard mode having a refractive index of 1.6 or more, which is a preferred embodiment of the present invention A coat layer may not be obtained. In this case, in order to further increase the refractive index of the hard coat layer, an organic compound having a high refractive index can be used in the range of 10 to 50 mass% with respect to 100 mass% of all components of the hard coat layer. Examples of organic compounds having a high refractive index include resins containing halogen atoms other than fluorine (for example, resins containing bromine atoms, resins containing chlorine atoms, resins containing iodine atoms), resins containing sulfur atoms, resins containing nitrogen atoms, Examples thereof include a resin containing a phosphorus atom, a resin containing an aromatic ring (for example, a resin containing a fluorene skeleton, a resin containing a phenyl group, etc.). Among these, resins containing an aromatic ring are preferable, and examples thereof include acrylic resins having a 9,9-bisphenoxyfluorene skeleton and acrylic resins having a biphenyl group.

  As described above, in order to increase the refractive index of the hard coat layer, it is preferable to contain a relatively large amount of metal oxide fine particles in the hard coat layer. However, on the other hand, when a hard coat layer containing a relatively large amount of metal oxide fine particles is formed on the conductive mesh by coating, the metal oxide fine particles are localized near the fine lines of the conductive mesh and aggregate. It became clear that a new problem occurred.

  This problem is caused by using metal oxide fine particles having an average primary particle diameter of less than 150 nm, or by containing the metal oxide fine particles in an amount of 25% by mass or more with respect to 100% by mass of all components of the hard coat layer. , Turned out to be conducive. The present invention solves this problem, and details will be described later.

  As the metal oxide fine particles according to the present invention, those having a refractive index of 1.6 or more are preferably used. Examples of the metal oxide fine particles include titanium oxide, zirconium oxide, zinc oxide, tin oxide, antimony oxide, cerium oxide, iron oxide, zinc antimonate, tin oxide-doped indium oxide (ITO), and antimony-doped tin oxide (ATO). ), Aluminum-doped zinc oxide, gallium-doped zinc oxide, fluorine-doped tin oxide and the like, and these metal oxide fine particles may be used alone or in combination. Further, the upper limit of the refractive index of the metal oxide fine particles is preferably 3 or less from the viewpoint of price and availability. An even more preferable range is 1.7 or more and 2.8 or less.

  The hard coat layer of the present invention preferably has a high hardness in order to prevent the surface of the display filter from being scratched. In other words, the hard coat layer referred to in the present invention has a pencil hardness defined by JIS K5600-5-4 (1999) of preferably H or higher, more preferably 2H or higher. The upper limit is about 9H.

  The hard coat layer can contain various resins. Such a resin can be composed of an acrylic compound, a urethane compound, a melamine compound, an epoxy compound, an organic silicate compound, or the like. Among these, active energy ray-curable polyfunctional monomers and polyfunctional oligomers are preferable. As the active energy ray-curable functional group, specifically, an unsaturated polymerizable functional group such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group is preferable, and a (meth) acryloyl group is particularly preferable.

  Examples of the polyfunctional monomer having an active energy ray-curable functional group include monomers having 3 or more, more preferably 4 or more, and still more preferably 5 or more (meth) acryloyl groups in one molecule. . The number of (meth) acryloyl groups in one molecule of the monomer is preferably 10 or less.

  Specific examples of such monomers include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth). ) Acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, tripenta Examples include erythritol triacrylate and tripentaerythritol hexatriacrylate.

  In addition to the above monomers, polyfunctional monomers such as urethane (meth) acrylates, polyester (meth) acrylates, and epoxy (meth) acrylates, or polyfunctional oligomers are also preferably used. Among these, the polyfunctional oligomer is effective in relieving the polymerization shrinkage of the hard coat layer and suppressing the occurrence of curling and cracking.

  Since the hard coat layer of the present invention is provided so as to cover the conductive layer having a conductive mesh, the thickness of the hard coat layer is the same as the thickness of a general hard coat layer applied to a smooth substrate. It needs to be larger than that. Increasing the thickness of the hard coat layer facilitates the occurrence of polymerization shrinkage and cracks. To suppress this, the above polyfunctional oligomers are preferred, and urethane acrylate oligomers are particularly preferred.

  A urethane acrylate oligomer is obtained by, for example, reacting an acrylate compound with a urethane oligomer obtained by a reaction between a polyol compound and a polyisocyanate compound.

  Specific examples of the polyol compound include ethylene glycol, propylene glycol, neopentyl glycol, tricyclodecane dimethylol, cyclohexane dimethylol, trimethylolpropane, glycerin, 1,3-propanediol, 1,4-butanediol, 1, 3-butanediol, 2,3-butanediol, 1,5-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,6-hexanediol, diethylene glycol, tripropylene glycol, 1, 9- Nonanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A polyethoxyglycol, polycarbonate polyol, pentaerythritol, sorbitol , Sucrose, quadroleol polybutadiene polyol, hydrogenated polybutadiene polyol, hydrogenated dimer diol pentaerythritol, etc .; trimethylolpropane, glycerin, pentaerythritol, sorbitol, sucrose, quadrole and other compounds containing a trivalent or higher hydroxyl group, Polyether polyol obtained by modifying with cyclic ether compounds such as ethylene oxide (EO), propylene oxide (PO), butylene oxide, tetrahydrofuran, etc .; polycaprolactone polyol obtained by modifying with caprolactone; consisting of dibasic acid and diol Mention may be made of polyester polyols obtained by modification with polyester; and mixtures of two or more thereof.

  More specifically, EO-modified trimethylolpropane, PO-modified trimethylolpropane, tetrahydrofuran-modified trimethylolpropane, caprolactone-modified trimethylolpropane, EO-modified glycerin, PO-modified glycerol, tetrahydrofuran-modified glycerin, caprolactone-modified glycerol, EO-modified pentaerythritol. , PO-modified pentaerythritol, tetrahydrofuran-modified pentaerythritol, caprolactone-modified pentaerythritol, EO-modified sorbitol, PO-modified sorbitol, caprolactone-modified sorbitol, EO-modified sucrose, PO-modified sucrose, EO-modified sucrose, EO-modified quadrole, etc. Can be mentioned.

  Specific examples of the polyisocyanate compound include 2, 4-tolylene diisocyanate, 2, 6-tolylene diisocyanate, 4, 4-diphenylmethane diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethylxylylene diisocyanate, Biphenylene diisocyanate, 1,5-naphthylene diisocyanate, o-tolidine diisocyanate, hexamethylene diisocyanate, 4,4'-methylenebiscyclohexyl isocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, 1,3- (isocyanatomethyl) cyclohexane, and Examples thereof include polycondensates such as burettes and isocyanurates, and mixtures of two or more thereof. Particularly preferred are xylylene diisocyanate, hexamethylene diisocyanate, and isocyanurate of isophorone diisocyanate.

  As an acrylate compound used for acrylate modification of an isocyanate group of a urethane oligomer, a compound having an acrylate group or a methacrylate group and a functional group capable of reacting with an isocyanate group such as a hydroxyl group, a carboxyl group, an amino group, or an amide group Is mentioned. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, butanediol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate modified with caprolactone, glycidol di (meth) acrylate, pentaerythritol Carboxyl groups such as hydroxyl group-containing (meth) acrylates such as tri (meth) acrylate, (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid Containing (meth) acrylate, amino group-containing (meth) acrylate such as N, N-diethylaminoethyl (meth) acrylate, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl Meth) acrylamide, N- methylol (meth) acrylamide, N- methylol amide group-containing such as trimethylolpropane (meth) acrylamide (meth) acrylate. Among these, a hydroxyl group-containing (meth) acrylate compound is particularly preferably used.

  A commercially available urethane acrylate compound can be used. For example, AT-600, UA-101l, UF-8001, UF-8003, etc. manufactured by Kyoeisha Chemical Co., Ltd., UV7550B, UV-7600B, etc. manufactured by Nippon Synthetic Chemical Co., Ltd., U-2PPA, UA-NDP UV manufactured by Nippon Synthetic Chemical Co., Ltd., such as Ebecryl-270, Ebecryl-284, Ebecryl-264, Ebecryl-9260 manufactured by Daicel UCB, etc. -1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B, UV-7650B, etc., U-4HA, U-6HA, UA-100H, U-6LPA, U-15HA manufactured by Shin-Nakamura Chemical Co., Ltd. Ebecryl-1 manufactured by Daicel UC Corporation, such as UA-32P and U-324A Mention may be made of 90, Ebecryl-1290K, and the like Ebecryl-5129, Negami Chemical Industrial Co., Ltd. of UN-3220HA, UN-3220HB, UN-3220HC, the UN-3220HS, and the like.

  In the hard coat layer of the present invention, the polymerizable compound such as the above-mentioned polyfunctional acrylate or polyfunctional oligomer is 75% by mass or less with respect to 100% by mass of all components (excluding the organic solvent) of the hard coat layer forming material. It is preferably contained, more preferably 70% by mass or less, and still more preferably 60% by mass or less. Moreover, about the minimum of content, 10 mass% or more is preferable, More preferably, it is a case where it contains 20 mass% or less (that is, the hard-coat layer of this invention is like above-mentioned polyfunctional acrylate and a polyfunctional oligomer). It is preferable to contain a resin composed of a polymerizable compound in an amount of 75% by mass or less, more preferably 70% by mass or less, and still more preferably 60% by mass or less, based on 100% by mass of all components of the hard coat layer. The lower limit of the content is preferably 10% by mass or more, and more preferably 20% by mass or less.

  In the present invention, the hard coat layer is formed so as to cover the conductive layer by curing the hard coat layer forming material coated on the conductive layer having the conductive mesh. As a method for curing the hard coat layer forming material, for example, a method of irradiating active energy rays, a high temperature heating method, or the like can be used. When using these methods, it is desirable to add a photopolymerization initiator or a thermal polymerization initiator to the hard coat layer forming material.

  Specific examples of the photopolymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methyl benzoylformate, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, 2, Carbonyl compounds such as 2-dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone, tetramethylthiuram monosulfide, tetramethyl Sulfur compounds such as thiuram disulfide, thioxanthone, 2-chlorothioxanthone, and 2-methylthioxanthone can be used. These photopolymerization initiators may be used alone or in combination of two or more.

  Moreover, as a thermal polymerization initiator, a peroxide compound such as benzoyl peroxide or di-t-butyl peroxide can be used.

  The amount of the photopolymerization initiator or thermal polymerization initiator used in the hard coat layer forming material of the present invention is suitably in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable compounds described above. When an electron beam or gamma ray is used as a curing means, it is not always necessary to add a polymerization initiator. In addition, when thermosetting at a high temperature of 220 ° C. or higher, it is not always necessary to add a thermal polymerization initiator.

  In the present invention, various additives can be further blended in the hard coat layer forming material as required, as long as the effects of the present invention are not impaired. For example, stabilizers such as antioxidants, light stabilizers, ultraviolet absorbers, surfactants, leveling agents, antistatic agents, and the like can be used.

  Examples of active energy rays used in the present invention include electromagnetic waves that polymerize acrylic vinyl groups such as ultraviolet rays, electron beams, and radiation (α rays, β rays, γ rays, etc.). It is preferable. As the ultraviolet ray source, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, or the like can be used. Moreover, when irradiating actinic radiation, if it irradiates under a low oxygen concentration, it can harden | cure efficiently. Furthermore, the electron beam system is expensive and requires an operation under an inert gas, but it does not have to contain a photopolymerization initiator or a photosensitizer in the hard coat layer forming material. It is advantageous.

  The heat required for thermosetting the hard coat layer forming material used in the present invention is air heated to at least 140 ° C. or higher using a steam heater, electric heater, infrared heater, far infrared heater or the like. The heat given by blowing an inert gas to the substrate and the coating film using a slit nozzle is preferable. Among them, heat by air heated to 200 ° C. or higher is preferable, and more preferably 200 ° C. or higher. Heating by heated nitrogen is preferable because the curing speed is high.

  In the present invention, as a method for curing the hard coat layer forming material to form a hard coat layer, a method of curing the hard coat layer forming material by irradiating with ultraviolet rays can achieve high productivity with a relatively simple apparatus. Therefore, it is preferable.

  In the present invention, the hard coat layer is disposed so as to cover the conductive layer having the conductive mesh. However, as the above-described coating method, it is preferable to form the hard coat layer directly on the conductive layer by coating. (That is, it is preferable to form a hard coat layer by directly applying a coating liquid containing a hard coat layer forming material on the conductive layer). As the coating method (coating method) used for coating the coating liquid containing the hard coat layer forming material, dip coating method, spin coating method, slit die coating method, gravure coating method, reversal coating method, rod coating method, Known wet coating methods such as a bar coating method, a spray method, and a roll coating method can be used.

  The coating liquid containing the hard coat layer forming material (hereinafter, the coating liquid containing the hard coat layer forming material may be simply referred to as a coating liquid) includes the above-described polymerizable compound, polymerization initiator, and as necessary. In order to dissolve the various additives added, it is preferable to contain an organic solvent as a dispersion solvent for dispersing the above-mentioned metal oxide fine particles or to adjust the viscosity of the coating liquid. The organic solvent mentioned here does not include a liquid polymerizable monomer that will constitute the hard coat layer.

  The amount of the organic solvent contained in the coating liquid containing the hard coat layer forming material is preferably in the range of 50 to 70% by mass and more preferably in the range of 10 to 60% by mass with respect to 100% by mass of the coating liquid. Thereby, components such as a polymerizable compound constituting the hard coat layer can be sufficiently dissolved, and the viscosity suitable for coating can be adjusted.

  As said organic solvent, it is preferable to mix and use the organic solvent whose boiling point is 100-180 degreeC under atmospheric pressure, and the organic solvent whose boiling point is less than 100 degreeC under atmospheric pressure. By including an organic solvent having a boiling point of 100 to 180 ° C. under atmospheric pressure, the wettability to metal oxide fine particles is improved, the dispersibility with a resin composed of a polymerizable compound is increased, and the transparency of the cured coating film is improved. To do. Moreover, the applicability | paintability of the coating liquid containing a hard-coat layer forming material becomes good, and can obtain the film with a flat surface. Furthermore, by including an organic solvent having a boiling point of less than 100 ° C. under atmospheric pressure, the organic solvent is effectively volatilized at the time of film formation, and a film having high hardness can be obtained. That is, a film having a flat surface and high hardness can be obtained.

  Specific examples of the organic solvent having a boiling point of 100 to 180 ° C. under atmospheric pressure include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol mono Ethers such as butyl ether, propylene glycol mono-t-butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propyl acetate, butyl acetate, isobutyl acetate, 3-methoxybutyl acetate, 3-methyl- -Acetates such as methoxybutyl acetate, methyl lactate, ethyl lactate, butyl lactate, etc., ketones such as acetylacetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, cyclopentanone, 2-heptanone, butanol, isobutyl alcohol, pentano -L, 4-methyl-2-pentanol, 3-methyl-2-butanol, 3-methyl-3-methoxy-1-butanol, alcohols such as diacetone alcohol, and aromatic hydrocarbons such as toluene and xylene Is mentioned. These may be used alone or in combination. Among these, examples of particularly preferable organic solvents are propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, diacetone alcohol and the like.

  Examples of the organic solvent having a boiling point of less than 100 ° C. under atmospheric pressure include methanol, ethanol, isopropanol, t-butanol, methyl ethyl ketone, and the like. These may be used alone or in combination.

  In the present invention, the thickness of the hard coat layer laminated so as to cover the conductive layer having the conductive mesh is preferably larger than the thickness of the conductive layer having the conductive mesh described later. The thickness of the hard coat layer is preferably 130% or more, more preferably 150% or more with respect to 100% of the thickness of the conductive mesh. By increasing the thickness of the hard coat layer relative to the thickness of the conductive layer (the thickness of the conductive mesh), the uneven surface of the conductive mesh can be sufficiently filled and made uniform. The upper limit of the thickness of the hard coat layer with respect to 100% of the thickness of the conductive layer (the thickness of the conductive mesh) is preferably 600% or less, more preferably 500% or less, and particularly preferably 400% or less.

  On the other hand, the upper limit of the thickness of the hard coat layer is preferably 10 μm or less, and more preferably 8 μm or less, from the viewpoints of the coating speed, drying and curing speed, raw material cost, etc. The lower limit of the thickness of the hard coat layer is preferably 1 μm or more, and more preferably 2 μm or more.

  When the thickness of the hard coat layer exceeds 10 μm, the production efficiency decreases due to a decrease in the coating speed, drying, and curing speed of the coating liquid containing the hard coat layer forming material, and the raw material costs increase. It becomes difficult to realize the price reduction that is the intended purpose of the invention. Moreover, when the thickness of the hard coat layer is increased, there may be a problem that cracks are easily generated in the cured film due to stress such as bending. On the other hand, when the thickness of the hard coat layer is smaller than 1 μm, it becomes difficult to obtain a uniform coating surface of the coating liquid containing the hard coat layer forming material, and the conductive layer having the conductive mesh cannot be coated, It will lack transparency. If the thickness of the hard coat layer is less than 1 μm, the original function as the hard coat layer may not be exhibited.

  As described above, the smoothness of the surface of the hard coat layer is improved by making the thickness of the hard coat layer larger than the thickness of the conductive layer and filling the unevenness of the conductive mesh. The smoothness of the hard coat layer surface can be represented by a center line average roughness Ra value. The center line average roughness Ra value of the hard coat layer surface is preferably 200 nm or less, more preferably 180 nm or less, and further 150 nm. The following is preferable, and 110 nm or less is particularly preferable. By making the Ra value of the hard coat layer surface 200 nm or less, the transparency becomes higher, and good coatability when an ultra-thin thin film low refractive index layer described later is formed on the hard coat layer. Can be secured. Accordingly, the center line average roughness Ra value of the surface of the low refractive index layer coated on the hard coat layer is also preferably 200 nm or less, more preferably 180 nm or less, further preferably 150 nm or less, particularly 110 nm or less. preferable. The lower limit of the Ra value on the hard coat layer surface and the low refractive index layer surface is about 10 nm. Here, the center line average roughness Ra value can be measured in accordance with the provisions of JIS B0601 (1982).

  As described above, in the present invention, it is preferable that the thickness of the hard coat layer is made larger than the thickness of the conductive layer so that the hard coat layer completely covers the conductive mesh.

  FIG. 1 is a schematic cross-sectional view of an example of a display filter according to the present invention, in which a conductive mesh 3 is formed on a base material 4 and a hard coat layer 2 is laminated on the conductive mesh 3. Here, the hard coat layer 2 is formed by coating so as to fill the opening 3b surrounded by the thin wire portion 3a constituting the conductive mesh 3 and to cover the thin wire portion 3a.

  That is, covering the conductive layer means a mode in which the opening portion of the conductive mesh is filled with the hard coat layer, and a mode in which the hard coat layer is formed so as to cover both sides and the upper side of the thin wire portion of the conductive mesh. Means.

  In order to coat and form the hard coat layer so that the hard coat layer completely covers the conductive mesh, the thickness of the hard coat layer (N in FIG. 1) is 100% of the thickness of the conductive mesh (FIG. 1). Is preferably 130% or more, more preferably 150% or more with respect to the symbol A). The upper limit is preferably 600% or less, more preferably 500% or less, and particularly preferably 400% or less. Here, the thickness (N) of the hard coat layer is such that the hard coat layer is coated and formed so as to fill the openings of the conductive mesh and cover the fine line portions as described above. Is the sum of the thickness (A) of the part and the thickness (L) of the hard coat layer on the thin line part. As described above, by increasing the thickness (N) of the hard coat layer relative to the thickness (A) of the conductive mesh, the uneven surface of the conductive mesh can be sufficiently filled and made uniform.

  In the present invention, the thickness (A) of the conductive mesh is less than 4 μm. As described above, the thickness (N) of the hard coat layer is preferably in the range of 1 to 10 μm. The thickness (L) of the hard coat layer present on the thin line portion of the conductive mesh is preferably in the range of 0.5 to 6 μm, more preferably in the range of 1 to 5 μm, and particularly preferably in the range of 2 to 4 μm.

  The thicknesses of the conductive mesh and the hard coat layer described above can be obtained from an enlarged cross-sectional photograph of a display filter using a scanning electron microscope.

  The display filter of the present invention has a low refractive index layer having a refractive index of 1.4 or less on the hard coat layer. The refractive index of the low refractive index layer is more preferably 1.38 or less, and the lower limit of the refractive index is about 1.2. Thereby, higher antireflection performance can be obtained.

  In the present invention, since the low refractive index layer is directly laminated on the hard coat layer having a refractive index of 1.55 or more, there is no need to have a high refractive index layer between the hard coat layer and the low refractive index layer. High antireflection performance can be obtained. Accordingly, in the present invention, the low refractive index layer is preferably laminated directly on the hard coat layer, thereby improving the production efficiency.

Such low refractive index layers include fluorine-containing polymers, organic materials such as (meth) acrylic acid partial or fully fluorinated alkyl esters, fluorine-containing silicones, or inorganic materials such as MgF ₂ , CaF ₂ , and SiO _2. Can be configured. Hereinafter, preferred embodiments of the low refractive index layer will be exemplified.

As a preferred embodiment of the low refractive index layer, a method of forming a thin film such as MgF ₂ or SiO ₂ by a vapor deposition method such as vacuum deposition, sputtering, or plasma CVD, or a sol solution containing SiO ₂ sol from SiO ₂ Examples thereof include a method for forming a gel film.

  As another preferred embodiment of the low refractive index layer, a constitution mainly composed of a siloxane polymer bonded to silica-based fine particles can be employed. The term “bond” as used herein means a state in which the silica component of the silica-based fine particles and the siloxane polymer in the matrix are reacted and homogenized. A siloxane polymer formed by combining with silica-based fine particles once forms a silanol compound by a known hydrolysis reaction using a polyfunctional silane compound in a solvent and an acid catalyst in the presence of the silica-based fine particles. It can be obtained by utilizing the reaction.

  The polyfunctional silane compound preferably includes a polyfunctional fluorine-containing silane compound from the viewpoint of low refractive index and antifouling properties, and includes trifluoromethylmethoxysilane, trifluoromethylethoxysilane, and trifluoropropyltrimethoxy. Trifunctional fluorine-containing silane compounds such as silane, trifluoropropyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltriethoxysilane, tridecafluorooctyltriethoxysilane, Examples include bifunctional fluorine-containing silane compounds such as heptadecafluorodecylmethyldimethoxysilane, all of which are preferably used. From the viewpoint of surface hardness, trifluoromethylmethoxysilane, trifluoro Chill silane, trifluoropropyl trimethoxy silane, trifluoropropyl triethoxy silane, more preferably.

  Examples of such polyfunctional fluorine-free silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, methyltrimethoxysilane, and methyltriethoxy. Silane, hexyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxy Trifunctional silanes such as silane, 3-chloropropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, 3-glycidoxysipropyltrimethoxysilane Compound, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-amino Propylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropylmethyldiethoxysilane, cyclohexylmethyldimethoxysilane, 3-methacryloxypropyldimethoxy Bifunctional silane compounds such as silane and octadecylmethyldimethoxysilane, tetrafunctional silane compounds such as tetramethoxysilane and tetraethoxysilane, etc. All of these are preferably used. From the viewpoint of surface hardness, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane are preferable. More preferable.

  The silica-based fine particles are preferably silica-based fine particles having an average particle size of 1 nm to 200 nm, and particularly preferably an average particle size of 1 nm to 70 nm. When the average particle diameter is less than 1 nm, the bond with the matrix material becomes insufficient and the hardness may be lowered. On the other hand, if the average particle diameter exceeds 200 nm, the generation of voids between particles caused by introducing a large amount of particles is reduced, and the effect of lowering the refractive index may not be sufficiently exhibited. Further, among these silica-based fine particles, those having a structure having a cavity inside are particularly preferably used in order to lower the refractive index.

  Examples of such silica-based fine particles having cavities therein include silica-based fine particles having a hollow portion surrounded by an outer shell, porous silica-based fine particles having a large number of hollow portions, and the like. As such an example, for example, it can be produced by the method disclosed in Japanese Patent No. 3272111, and the volume occupied by the cavities inside the fine particles, that is, the porosity of the fine particles is preferably 5% or more, more preferably 30% or more. preferable. The porosity can be measured using, for example, a mercury porosimeter (trade name: Bore Sizer 9320-PC2, manufactured by Shimadzu Corporation). Further, the refractive index of the fine particles themselves is preferably 1.20 to 1.40, more preferably 1.20 to 1.35. Examples of such silica-based fine particles include those disclosed in Japanese Patent Application Laid-Open No. 2001-233611, and those commercially available such as Japanese Patent No. 3272111.

  Still another preferred embodiment of the low refractive index layer includes a resin layer obtained by curing an active energy ray-curable resin composition containing a fluorine-containing compound and the silica-based fine particles having voids inside.

  Examples of the fluorine-containing compound include a fluorine-containing monomer and a fluorine-containing polymer compound.

  Examples of the fluorine-containing monomer include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) ethyl (meth) ) Acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, and other fluorine-containing (meth) acrylic acids Examples include esters.

  Examples of the fluorine-containing polymer compound include a fluorine-containing copolymer having a fluorine-containing monomer and a monomer for imparting a crosslinkable group as constituent units. Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc. ), (Meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, and the like. As a monomer for imparting a crosslinkable group, in addition to a (meth) acrylate monomer having a crosslinkable functional group in the molecule like glycidyl methacrylate, it has a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, etc. ) Acrylate monomers (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, etc.).

  The active energy ray-curable resin composition containing the fluorine-containing compound and the silica-based fine particles having voids therein is polymerized and cured by irradiation with active energy rays to form a resin layer of a low refractive index layer. . Here, active energy rays refer to ultraviolet rays, electron rays, radiation (α rays, β rays, γ rays, etc.) and the like. Practically, electron rays and ultraviolet rays are preferable, and ultraviolet rays are particularly simple and preferable. As the ultraviolet ray source, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a xenon lamp, a carbon arc lamp, or the like can be used. Moreover, when irradiating an active energy ray, if it irradiates under a low oxygen concentration, it can harden | cure efficiently. The electron beam irradiation method is advantageous in that the apparatus is expensive and needs to be operated under an inert gas, but it does not need to contain a photopolymerization initiator or a photosensitizer in the coating solution. is there.

  As the resin component used in the active energy ray-curable resin composition, a polyfunctional (meth) acrylate compound having two or more (meth) acryloyl groups in the molecule is preferably used. Furthermore, polyfunctional (meth) acrylate compounds having 3 or more (meth) acryloyl groups in the molecule are preferred, and polyfunctional (meth) acrylate compounds having 3 to 10 acryloyl groups in the molecule are particularly preferred.

  Examples of such polyfunctional (meth) acrylate compounds include ethylene glycol di (meth) acrylate, dicyclopentenyl di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, and tricyclodecanediyl dimethy. Range (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, both ends (meth) of bisphenol A diglycidyl ether Acrylic acid adduct, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylo Rupropane tri (meth) acrylate, glycerol tri (meth) acrylate, ethylene-modified trimethylolpropane tri (meth) acrylate, tris- (2-hydroxyethyl) -isocyanuric acid ester tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, Examples thereof include dipentaerythritol penta (meth) acrylate and dipentaerythritol hexa (meth) acrylate. In the present invention, “... (Meta) acrylic ...” is an abbreviation of “... acrylic ... or meta acrylic ...”.

  Among the above polyfunctional (meth) acrylate compounds, polyfunctional (meth) acrylate compounds having 3 or more (meth) acryloyl groups in the molecule are preferable, and polyfunctional (having 3 to 10 acryloyl groups in the molecule) ( A (meth) acrylate compound is preferably used.

  In order to accelerate the polymerization and curing of the polyfunctional (meth) acrylate compound, it is preferable to include a photopolymerization initiator in the active energy ray-curable resin composition. As such a photopolymerization initiator, the same photopolymerization initiator as that used in the hard coat layer forming material can be used.

  The thickness of the low refractive index layer is preferably in the range of 0.01 to 0.4 μm, and more preferably in the range of 0.02 to 0.2 μm.

  The conductive layer in the present invention is a layer for shielding electromagnetic waves generated from the display and has a conductive mesh. The surface resistance value of the conductive layer is preferably low, preferably 3Ω / □ or less, more preferably 1Ω / □ or less, and particularly preferably 0.5Ω / □ or less. The lower limit value of the surface resistance is not particularly limited, but is about 0.01Ω / □. The surface resistance value of the conductive layer can be measured by a four-terminal method.

  Examples of the conductive layer having a conductive mesh according to the present invention include a conductive layer in which the entire conductive layer is formed of a conductive mesh, or a conductive layer in which a solid metal portion is disposed on the outer periphery of the conductive mesh portion. . The conductive layer in which the metal solid portion is disposed on the outer periphery of the latter conductive mesh portion is a portion corresponding to the image display area of the display made of a conductive mesh, and its peripheral portion is made of a solid metal. .

  The conductive mesh according to the present invention is a) a conductive mesh formed by etching a metal thin film formed on a base material by vapor deposition, and b) provided in a pattern on the base material. A conductive mesh formed by performing metal plating on the catalyst ink layer; c) a resin layer having a pattern opposite to the pattern of the conductive mesh is formed on the substrate with a peelable resin; A conductive mesh formed by laminating a metal thin film on the surface on which the resin layer is formed by vapor deposition and then peeling the resin layer, or d) a conductive mesh on the substrate. The pattern is a conductive mesh formed by applying oil in a reverse pattern, and then laminating a metal thin film on the surface of the substrate on which the oil is applied by vapor deposition.

  In the present invention, in order to directly and uniformly coat and form a hard coat layer containing metal oxide fine particles on a conductive layer having a conductive mesh, a conductive mesh having a thickness of less than 4 μm is used. I found it effective. Further, in the present invention, when the metal oxide fine particles in the hard coat layer are extremely fine metal oxide fine particles having an average primary particle diameter of less than 150 nm, or the amount of the metal oxide fine particles in the hard coat layer is The present invention has been found to be more effective in the case of a large amount of 25% by mass or more with respect to 100% by mass of all the components of the layer. In particular, the present invention is particularly effective when the hard coat layer contains a very small amount of metal oxide fine particles having an average primary particle diameter of less than 150 nm, such as 25% by mass or more based on 100% by mass of all components of the hard coat layer. This invention has been found to be effective.

  When a hard coat layer containing metal oxide fine particles is directly applied and formed on a conductive mesh that is generally used and has a relatively large thickness, a uniform coated surface is not formed and the hard coat layer is not formed. It has been found that there is a new problem that the transparency of the layer is reduced. This is because the influence of the local aggregation of the metal oxide fine particles in the hard coat layer in the vicinity of the fine lines of the conductive mesh is affected. This phenomenon is caused by the fact that the thickness is less than 4 μm. An improvement was found by using a mesh, and the present invention was achieved.

  In addition, simply using a conductive mesh having a thickness of less than 4 μm cannot sufficiently improve the problem of the present invention. For example, when an adhesive layer is interposed between the substrate and the conductive mesh, Alternatively, when gelatin with high hydrophilicity is interposed between the base material and the conductive mesh, that is, when the adhesive or gelatin is exposed in the openings surrounded by the fine lines of the conductive mesh, The coatability of the hard coat layer is lowered, and the above-described problem, that is, the transparency of the hard coat layer cannot be sufficiently improved.

  In order to improve the above-described problems, it is important to use a conductive mesh having a thickness of less than 4 μm and any one of the above-described a) to d).

  When the conductive mesh is formed by the above-described methods a) to d), the conductive mesh is formed with a thickness of less than 4 μm without interposing an adhesive or gelatin between the base material and the conductive mesh. And good electromagnetic shielding properties can be obtained.

  In the methods a) to d), it is possible to directly form a conductive mesh on the substrate without using an adhesive or gelatin, and the conductive mesh obtained thereby has an opening ( Since the adhesive and gelatin are not present in the fine wire and the portion surrounded by the fine wire constituting the conductive mesh, uniform coatability of the hard coat layer containing metal oxide fine particles can be obtained.

  The thickness of the conductive mesh is preferably smaller in order to improve the coatability of the hard coat layer and local aggregation of the metal oxide fine particles contained in the hard coat layer, and the thickness of the conductive mesh is 4 μm. It is important that it is less than 3.5, preferably 3.5 μm or less, more preferably 3 μm or less, and particularly preferably 2.5 μm or less. Further, the lower limit of the thickness of the conductive mesh is preferably 0.5 μm or more, and more preferably 1 μm or more from the viewpoint of electromagnetic shielding performance.

The conductive meshes a) to d) used in the present invention will be described below.
The conductive mesh a) is formed by etching a metal thin film formed on a substrate by a vapor deposition method. Details will be described below.

  Examples of the vapor deposition method for forming a metal thin film on a substrate include sputtering, ion plating, electron beam vapor deposition, vacuum vapor deposition, chemical vapor deposition, and the like. One of these methods or two or more methods can be used. They can be used in combination. In the present invention, sputtering, ion plating, and vacuum deposition are preferable, and sputtering and vacuum deposition are particularly preferable.

  As a metal for forming a metal thin film, an alloy or a multilayer of one or more of metals such as copper, aluminum, nickel, iron, gold, silver, stainless steel, chromium and titanium is used. can do. Among these, copper is preferably used from the viewpoints of obtaining good electromagnetic shielding properties, easy mesh pattern processing, and low cost.

  In addition, when copper is used as the metal of the metal thin film, it is preferable to use a nickel thin film having a thickness of 5 to 100 nm between the base material and the copper thin film (that is, when copper is used as the metal of the metal thin film, it is conductive). It is preferable that the conductive mesh has a laminated structure of a nickel thin film and a copper thin film. This improves the adhesion between the substrate and the copper thin film.

  Further, a metal compound such as a metal oxide, metal nitride, or metal sulfide can be laminated on the surface of the metal thin film by a vapor deposition method. This metal compound lamination is preferable because the blackening treatment described later can be omitted. Examples of such metal compounds include gold, platinum, silver, mercury, copper, aluminum, nickel, chromium, iron, tin, zinc, indium, palladium, iridium, cobalt, tantalum, antimony, titanium, and other metal oxides, nitriding Or sulfide.

  The thickness of the metal compound is preferably in the range of 0.005 to 0.2 μm, and more preferably in the range of 0.01 to 0.1 μm. This metal compound layer constitutes a part of the metal thin film and further constitutes a part of the conductive mesh.

  The thickness of the metal thin film is formed to be approximately the same as the thickness of the conductive mesh. Therefore, the metal thin film is formed so that its thickness is less than 4 μm. The thickness of the metal thin film is preferably 3.5 μm or less, more preferably 3 μm or less, and particularly preferably 2.5 μm or less. The lower limit of the thickness of the metal thin film is preferably 0.5 μm or more, and more preferably 1 μm or more, from the viewpoint of electromagnetic wave shielding performance.

  The metal thin film can be formed directly on the substrate, but when a plastic film is used as the substrate, it is preferable to use a plastic film on which a primer layer (undercoat layer, easy adhesion layer) is previously laminated. . The primer layer will be described later in detail.

  The metal thin film formed on the substrate is etched after an etching resist pattern is formed thereon, and a metal mesh (conductive mesh) having a mesh pattern is manufactured. As a method for forming an etching resist pattern on a metal thin film, there are a photolithographic method and a printing method.

  The photolithographic method is a method in which a photoresist layer is laminated on a metal thin film, exposed through a photomask having a desired pattern, or directly scanned and exposed with a laser, and developed to form an etching resist pattern. As a method of laminating a photoresist layer on the metal layer, for example, a method of attaching a resist film to the metal layer or a method of applying a liquid resist is used.

  As the photoresist layer, a negative resist in which an exposed part is cured and an unexposed part is dissolved by development, or a positive resist in which an exposed part is dissolved by development can be used. In view of environmental problems in the development process of the photoresist layer, an alkali development type photoresist is preferable.

  The developer used for developing the photoresist layer is preferably an alkaline developer. Examples of the alkali developer include an aqueous solution of an alkali metal or alkaline earth metal carbonate, an aqueous solution of an alkali metal hydroxide, and the like. Specifically, sodium carbonate, potassium carbonate, lithium carbonate An alkaline aqueous solution containing 0.5 to 5% by mass of a hydroxide such as carbonate such as sodium hydroxide, potassium hydroxide, or lithium hydroxide can be used. Generally, a weak alkaline aqueous solution containing about 0.1 to 3% by mass of the carbonate is used. The development temperature is suitably about 10 to 50 ° C, and is generally in the range of 20 to 40 ° C.

  The printing method is a method of forming a desired etching resist pattern on a metal thin film by a screen printing method or an offset printing method.

  As described above, after forming an etching resist pattern on the metal thin film, the metal thin film is etched to form a conductive mesh. Finally, the etching resist pattern remaining on the conductive mesh is peeled off. As an etching method, there is a chemical etching method. Chemical etching is a method in which a metal other than a metal portion protected by a resist image is dissolved and removed with an etching solution. Examples of the etching solution include a ferric chloride aqueous solution, a cupric chloride aqueous solution, and an alkaline etching solution. For stripping and removing the etching resist pattern remaining on the conductive mesh, an alkaline aqueous solution containing about 1 to 4% by mass of sodium hydroxide is usually used.

  Among the methods for forming the above-described etching resist pattern on the metal thin film, the photolithography method is preferable from the viewpoint that a finer mesh pattern can be obtained.

  Further, the resist layer for forming the etching resist pattern described above can be blackened by containing a black pigment such as carbon black or titanium black. The etching resist pattern formed with the black resist, which is the blackened resist layer, is preferably left on the conductive mesh without being removed, so that the blackening treatment described later can be omitted.

  In the present invention, the etching resist pattern formed with the above black resist does not constitute a part of the conductive mesh, but the total thickness of the etching resist pattern formed with the conductive mesh and the black resist is It is preferable from a viewpoint of the coating property of the hard-coat layer containing metal oxide fine particles that it is less than 4 micrometers.

  The conductive mesh b) is formed by performing metal plating on the catalyst ink layer provided in a pattern on the substrate. This will be described in detail below.

  Such a manufacturing method includes providing a pattern-like catalyst ink on a base material by printing in a mesh pattern with a catalyst ink containing noble metal ultrafine particles such as Pd, Au, Ag, Pt, etc., which becomes a catalyst for electroless plating. In this method, a conductive mesh is formed by forming a layer and performing metal plating on the layer. As one of the methods, a catalyst pattern made of a palladium colloid-containing paste is used for printing on a mesh pattern, which is immersed in an electroless copper plating solution, followed by electroless copper plating, followed by electrolytic copper plating. There is a method for forming a conductive mesh pattern by applying electrolytic plating of a Ni-Sn alloy.

  The catalyst ink layer can be provided directly on the base material by printing or the like. As the base material used at this time, a plastic film having a primer layer (undercoat layer, easy adhesion layer) is preferable. Also, a plastic film having an underlayer (ink receiving layer) described in JP-A-2007-281290 can be preferably used as a substrate. Furthermore, the underlayer is preferably laminated on the primer layer. That is, it is preferable to use, as a base material, a film in which a base layer (ink receiving layer), a primer layer (undercoat layer, easy adhesion layer), and a plastic film are laminated in this order.

  In the conductive mesh c), a resin layer having a pattern opposite to the pattern of the conductive mesh is first formed on a substrate with a peelable resin, and then the surface of the substrate on which the resin layer is formed. In addition, a metal thin film is laminated by a vapor deposition method, and then the resin layer is peeled off, and at the same time, the metal thin film on the resin layer is removed. Here, the vapor deposition method used for laminating metal thin films is the same as the vapor deposition method used in the method for producing a conductive mesh a).

  The conductive mesh manufacturing method is a method generally called lift-off, and a resin layer having a pattern opposite to that of the conductive mesh is formed on a substrate in advance using a resin that can be peeled off. In this method, a metal thin film is laminated on the formed side surface by a vapor deposition method, and then the resin layer having the reverse pattern is peeled off. When the resin layer having the reverse pattern is peeled off, the metal thin film on the resin layer is also peeled off at the same time, and the metal thin film in the portion where the resin layer does not exist remains on the substrate as it is. Is formed on the substrate. Therefore, in this manufacturing method, it is necessary to form the peelable resin layer in a pattern opposite to the conductive mesh.

  As the peelable resin used for the peelable resin layer formed in advance on the substrate, a resin soluble in a solvent is preferably used. As such a resin, a water-soluble resin, a resin soluble in an organic solvent, and a resin soluble in an alkali can be used. Among these resins, a water-soluble resin is preferable from the viewpoint of work environment and the like, and a water-soluble polymer resin is particularly preferably used.

  Examples of water-soluble polymer resins include polyvinyl pyrrolidone, polyvinyl alcohol, partially saponified polyvinyl alcohol, soluble starch, carboxymethyl starch, vinyl acetate-maleic acid alternating copolymer, and hydroxypropyl cellulose. One or a mixture of two or more molecular resins can be used.

  Examples of resins that are soluble in organic solvents include polyimide ether resins, polyamide resins, polyamideimide resins, polybenzimidazole resins, polyhydantoin resins, polyparaban resins, and solvent-soluble polyimide resins. Silicone grease or oil-based ink can also be used.

  As the alkali-soluble resin, a general resist can be used.

  As a method for forming a resin layer having a pattern opposite to that of the conductive mesh on a substrate using a releasable resin that is soluble in a solvent, a printing method, a photolithography method, or the like can be used. As a printing method, for example, various methods such as screen printing, inkjet, intaglio printing, relief printing, offset printing, gravure printing, flexographic printing, and the like can be used.

  Photolithography is a method in which a photoresist layer is stacked on a substrate, exposed through a photomask, or directly scanned and exposed with a laser, and developed to form a resist layer with a pattern opposite to the conductive mesh pattern. It is a method to do. As a method of laminating a photoresist layer on a substrate, for example, a method of attaching a resist film or a method of applying a liquid resist is used.

  After the metal thin film is laminated on the surface on which the resin layer having a pattern opposite to that of the conductive mesh is formed, the resin layer is peeled off. The resin layer is peeled off in a solvent in which the resin layer is soluble. And a method of spraying the solvent, and a method of physically detaching in combination with these methods, for example, a method of rubbing with a cloth, sponge, roller or the like can be applied.

  In the conductive mesh d), oil is first applied on a substrate in a pattern opposite to the pattern of the conductive mesh, and then the surface of the substrate on which the oil is applied is formed by a vapor deposition method. It can be formed by forming a metal thin film. When a metal thin film is formed on the surface of the base material on which the oil is applied by a vapor deposition method, as a result, the surface of the base material on which the oil is applied is selectively applied to the portion where the oil is not applied. Further, a metal thin film can be formed. Here, the vapor deposition method used for forming the metal thin film is the same as the vapor deposition method used in the method for producing a conductive mesh a).

The manufacturing method of d) is called an oil margin method, and is a well-known method in the field of metal-deposited film for capacitors. Japanese Patent Publication No. 3-59981, Japanese Patent Application Laid-Open No. 11-147282, and Japanese Patent Application Publication No. 2004. -95606, JP-A-2004-111774, and the like, which can be incorporated into the present invention with reference to these descriptions.
Examples of oils used in the above production method include ester oils such as dibutyl phthalate, dioctyl phthalate and dibutyl sebacate, glycol oils such as polyalkylene glycol oils, and fluorine oils such as perfluoroalkyl polyethers. And hydrocarbon oils such as mineral oil, alkylbenzene, alkylnaphthalene and polyalphaolefin, silicone oils such as dimethylpolysiloxane and phenylmethylpolysiloxane, and liquid paraffin. Since the oil is evaporated at the portion where the oil is applied by heat generated when the metal is attached, the metal is prevented from attaching to the portion.

  As a method of applying oil on the base material in a pattern opposite to that of the conductive mesh, a known method can be used. For example, as described in Japanese Patent Application Laid-Open No. 2001-313227, a method can be used in which oil that has been heated and vaporized is sprayed from pores that have been processed into a shape to be patterned to form an oil pattern on a substrate. . In addition, as described in JP-A-2000-144375, a mask-forming roll having a pattern formed on an oil-adhering roll in which a cloth-like substance such as felt or an oil-impregnated cloth or a porous nonwoven fabric is wound on the surface It is also possible to use a method of transferring oil onto a substrate via

  The conductive meshes produced in the above a) to d) are preferable because they have a low haze value as compared with conventionally known conductive meshes, and as a result, high transparency can be secured.

  The haze value of a conductive mesh film in which only a conductive layer having a conductive mesh is provided on a substrate is preferably 4% or less, and particularly preferably 3% or less. The haze value of the conductive mesh film varies somewhat depending on the line width and line pitch of the conductive mesh, but greatly depends on the method of manufacturing the conductive mesh. The conductive mesh film produced by the above-described production methods a) to d) used for the display filter of the present invention can achieve a haze value of 4% or less, and further 3% or less. The lower limit of the haze value of the conductive mesh film is about 1%. Here, the haze value can be measured according to JIS K 7136 (2000).

  By using the conductive mesh having a low haze value as the conductive layer, a hard coat layer laminated to cover the conductive layer on the conductive layer having the conductive mesh, and laminated on the hard coat layer The haze value of the laminated body having the low refractive index layer can also be kept low, and high transparency can be ensured. The haze value of the laminate after coating and forming a hard coat layer and a low refractive index layer on a conductive layer having a conductive mesh is preferably 10% or less, more preferably 8% or less. The lower limit of the haze value is about 1%.

  In the present invention, the conductive mesh is preferably blackened. The blackening treatment can be performed by oxidation treatment or black printing. For example, the methods described in JP-A-10-41682, JP-A-2000-9484, 2005-317703 and the like can be used. The blackening treatment is preferably performed on the surface and both side surfaces of the conductive mesh on the visual recognition side, and it is further preferable to blacken both surfaces and both side surfaces of the conductive mesh.

  Moreover, in order to manufacture the display filter efficiently on a continuous production line, the conductive mesh is preferably a continuous mesh. The continuous mesh refers to a state in which, for example, when the conductive mesh is formed on a long roll-shaped base material, the conductive mesh is continuously formed in the long direction of the base material. Such a continuous mesh is suitable for applying a hard coat layer.

  Examples of the mesh pattern of the conductive mesh include a grid mesh pattern made up of squares, rectangles, rhombuses, etc., a mesh pattern made up of triangles, pentagons or more polygons, a mesh pattern made up of circles and ellipses, and the above-mentioned composite shape And a random mesh pattern. Among these, a grid mesh pattern is preferable from the viewpoint of productivity and ease of product management, and a grid mesh pattern made of a square is particularly preferable.

  In the conductive mesh according to the present invention, the line width (W in FIG. 1) is suitably in the range of 3 to 30 μm, and the line pitch (P in FIG. 1; between the center lines of two adjacent lines) The distance is suitably in the range of 50 to 500 μm. In particular, from the viewpoint of suppressing the occurrence of moiré with respect to the scanning lines of the display, the line width of the conductive mesh is preferably 20 μm or less, more preferably 15 μm or less, and the following high-definition mesh pattern is effective.

  Among the methods for producing conductive meshes a) to d) described above, from the viewpoint that a high-definition mesh pattern is formed and that there is no defect and stable production is possible, the methods a) and b) are the following. In particular, the method a) is preferable from the viewpoint of being able to stably produce a conductive mesh having a small thickness of excellent electromagnetic wave shielding properties and a thickness of less than 4 μm.

  Here, the high-definition mesh pattern means that the line width of the lattice-like mesh pattern is less than 10 μm and the line pitch is 160 μm or less. If it is the manufacturing method of the electroconductive mesh of a), furthermore, the high-definition mesh whose line width is 3-8 micrometers and line pitch is 50-150 micrometers can be manufactured easily and stably. Such a high-definition conductive mesh is effective in suppressing the occurrence of moire with respect to the scanning lines of the display.

  As a base material used for the display filter of the present invention, a plastic film is preferable. Examples of the resin constituting the plastic film include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as triacetyl cellulose, polyolefin resins such as polyethylene, polypropylene, and polybutylene, acrylic resins, polycarbonate resins, arton resins, and epoxy resins. , Polyimide resin, polyetherimide resin, polyamide resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, and the like. Among these, a polyester resin, a polyolefin resin, and a cellulose resin are preferable, and a polyester resin is particularly preferably used. As the thickness of the plastic film, a range of 50 to 300 μm is appropriate, but a range of 90 to 250 μm is particularly preferable from the viewpoint of cost and ensuring the rigidity of the front filter. The display filter according to the present invention preferably uses only one plastic film as a substrate.

  The plastic film used in the present invention is provided with a primer layer (undercoat layer, easy adhesion layer) for enhancing adhesion (adhesion strength) with the conductive layer described above or a near infrared shielding layer described later. (In other words, the substrate is preferably a plastic film having a primer layer (undercoat layer, easy adhesion layer)).

  As such a primer layer, those using a water-soluble resin or a water-dispersible resin are generally known, and are preferably used in the present invention. As the water-soluble resin or water-dispersible resin, polyurethane resin, polyester resin, acrylic resin, polyvinyl alcohol resin, or the like is used. The primer layer preferably further contains a crosslinking agent. Examples of the crosslinking agent include isocyanate compounds, epoxy compounds, oxazoline compounds, and melamine compounds. The thickness of the primer layer is generally in the range of 10 to 500 nm, preferably in the range of 20 to 300 nm.

  As described above, the display filter of the present invention preferably further includes another functional layer having functions such as a near-infrared shielding function, a color tone adjustment function, or a visible light transmittance adjustment function.

  The near-infrared shielding layer having a near-infrared shielding function is preferably adjusted so that the maximum value of light transmittance in the wavelength range of 800 to 1100 nm is 15% or less. The near-infrared shielding function may be imparted by kneading and dispersing a near-infrared absorber in a base material (plastic film), a hard coat layer, or an adhesive layer described later, or a near-infrared shielding layer is newly provided. May be. The near-infrared shielding function can be imparted by using a near-infrared absorber. In the present invention, a near-infrared shielding layer formed by applying and drying a paint in which a near-infrared absorber is dispersed or dissolved in a resin binder is used, or the above-mentioned near-infrared absorber is contained in a hard coat layer or an adhesive layer. Embodiments are preferably used. Near-infrared absorbers include organic near-infrared absorbers such as phthalocyanine compounds, anthraquinone compounds, dithiol compounds, and diimonium compounds, or titanium oxide, zinc oxide, indium oxide, tin oxide, zinc sulfide, cesium-containing oxides An inorganic near infrared absorber such as tungsten can be used.

  When the above-described near-infrared shielding layer is newly provided, it can be provided between the base material and the conductive layer having the conductive mesh, or on the opposite side of the conductive layer having the conductive mesh with respect to the base material. Moreover, when providing the above-mentioned near-infrared shielding layer newly, it is preferable to provide by coating.

  In the case where the near infrared shielding function is imparted to the conductive layer side having the conductive mesh with respect to the base material, it is preferable to use an inorganic near infrared absorbent having excellent light resistance.

  The color tone adjustment layer having a color tone adjustment function is a function for improving color purity and whiteness by absorbing light of a specific wavelength emitted from the display. In particular, it is preferable to shield orange light that reduces the color purity of red light emission, and it is preferable to include a dye having an absorption maximum in a wavelength range of 580 to 620 nm. Furthermore, it is preferable to contain a dye having an absorption maximum at a wavelength of 480 to 500 nm in order to improve whiteness. For the color tone adjustment function, a layer containing a dye that absorbs light having the above-described wavelength may be newly provided, or a dye may be contained in the above-described near-infrared shielding layer, hard coat layer, or adhesive layer.

  The visible light transmittance adjusting function is a function for adjusting the visible light transmittance, and can be adjusted by containing a dye or a pigment. The visible light transmittance adjusting function may be imparted to a base material (plastic film), a near infrared shielding layer, a hard coat layer, or an adhesive layer, or a transmittance adjusting layer may be newly provided.

  When a layer having the above-described color tone adjusting function and a layer having a visible light transmittance adjusting function are newly provided, these layers are conductive between the base material and the conductive layer having the conductive mesh, or to the base material. It can be provided on the surface opposite to the conductive layer having a conductive mesh.

  The display filter of the present invention can be attached to the display directly or via a known high-rigidity substrate such as a glass plate, an acrylic plate, or a polycarbonate plate. The display filter is preferably provided with an adhesive layer for adhering to a display or a highly rigid substrate.

  As described above, the adhesive layer can be provided with a near-infrared shielding function, a color tone adjusting function, or a visible light transmittance adjusting function. Moreover, it is a preferable aspect to provide the adhesive layer with an impact relaxation function for protecting the display from impact. In order to impart an impact relaxation function to the adhesive layer, the thickness of the adhesive layer is preferably 100 μm or more, and more preferably 300 μm or more. The upper limit thickness is preferably 3000 μm or less in consideration of the coating suitability of the adhesive layer.

  A well-known adhesive material or an adhesive material can be used for an adhesive layer. Examples of the adhesive material include acrylic, silicone, urethane, polyvinyl butyral, and ethylene-vinyl acetate. Adhesives include bisphenol A type epoxy resins, tetrahydroxyphenylmethane type epoxy resins, novolac type epoxy resins, resorcin type epoxy resins, polyolefin type epoxy resins and other epoxy resins, natural rubber, polyisoprene, poly-1, 2- (Di) enes such as butadiene, polyisobutene, polybutene, poly-2-heptyl-1,3-butadiene, poly-1,3-butadiene, polyoxyethylene, polyoxypropylene, polyvinyl ethyl ether, polyvinyl hexyl ether, etc. Polyesters such as polyethers, polyvinyl acetate, polyvinyl propionate, polyurethane, ethyl cellulose, polyvinyl chloride, polyacrylonitrile, polymethacrylonitrile, polysulfone, phenoxy resin Etc.

  The display filter according to the present invention is preferably a single substrate filter composed of only one substrate. Although some of the preferable structural examples of such a single substrate filter are illustrated, this invention is not limited to these.

1) Adhesive layer / Near-infrared shielding layer / Substrate / Conductive layer with conductive mesh / High refractive index hard coat layer / Low refractive index layer 2) Adhesive layer / Substrate / Near-infrared shielding layer / Conductive mesh Conductive layer / high refractive index hard coat layer / low refractive index layer 3) Adhesive layer (having near infrared shielding function) / base material / conductive layer having conductive mesh / high refractive index hard coat layer / low refractive index layer 4 ) Adhesive layer / Substrate / Conductive layer with conductive mesh / High refractive index hard coat layer (having near infrared shielding function) / Low refractive index layer In addition, the adhesive layer of 3) and the hard coat layer of 4) may similarly have a color tone adjusting function and / or a visible light transmittance adjusting function. Good.

  FIG. 2 is a schematic cross-sectional view showing an example of the display filter. In FIG. 2, the display filter 1 has a conductive mesh 3 formed on one surface of a substrate 4 made of a plastic film, and a hard coat layer 2 is directly laminated on the conductive mesh 3. A low refractive index layer 7 is laminated thereon. On the other surface of the substrate 4, a near-infrared shielding layer 5 and an adhesive layer 6 are sequentially laminated.

The method for producing the above-described display filter of the present invention includes at least the following steps. That is,
A step of forming a conductive layer having a conductive mesh having a thickness of less than 4 μm on the substrate by any one of the following methods a) to d);
Directly applying a hard coat layer containing metal oxide fine particles and having a refractive index of 1.55 or more on the conductive layer;
At least a step of coating a low refractive index layer having a refractive index of 1.4 or less on the hard coat layer.

  a) A method of forming a conductive mesh by etching a metal thin film formed on a substrate by a vapor deposition method.

  b) A method of forming a conductive mesh by performing metal plating on a catalyst ink layer provided in a pattern on a substrate.

  c) On the base material, a resin layer having a pattern opposite to the pattern of the conductive mesh is formed with a peelable resin, and then on the surface of the base material on which the resin layer is formed, by a vapor deposition method. A method of laminating a metal thin film and then peeling the resin layer.

  d) A method in which oil is applied on a substrate in a pattern opposite to the pattern of the conductive mesh, and then a metal thin film is laminated on the surface of the substrate on which the oil is applied by a vapor deposition method.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples.
(Evaluation methods)
(1) Visibility In the display filter, when a photograph is placed under the surface opposite to the hard coat layer with respect to the substrate, and the photograph is viewed through the display filter from the hard coat layer side with respect to the substrate. Whether the photographic image was clearly visible was evaluated according to the following criteria.
A: The image looks clear.
B: Although slightly inferior to the above A, the image looks sufficiently clear.
C: The image is blurred and difficult to see.
D: The image cannot be seen.
(2) Refractive index Using a coating material of a hard coat layer and a low refractive index layer, a 1.5 μm-thick coating film formed on a silicon wafer by a spin coater is used as a prism coupler (manufactured by Metricon Corporation). ), The refractive index in the direction perpendicular to the film surface at 633 nm (using a He—Ne laser) at 20 ° C. was measured.
(3) Centerline average roughness Ra
The center line average roughness Ra on the surface of the low refractive index layer of the display filter was measured using a surface roughness measuring instrument SE-3400 (manufactured by Kosaka Laboratory) based on the method of JIS B0601-1982.
·Measurement condition:
Feeding speed: 0.5mm / S
Cut-off value λc;
When Ra is 20 nm or less, λc = 0.08 mm
When Ra is greater than 20 nm and less than or equal to 100 nm, λc = 0.25 mm
When Ra is greater than 100 nm and less than or equal to 2000 nm, λc = 0.8 mm
Evaluation length: 8mm
Ra: A parameter defined as Ra by a surface roughness measuring instrument SE-3400 (manufactured by Kosaka Laboratory Ltd.).
(4) Pencil hardness Using a HEIDON (manufactured by Shinto Kagaku Co., Ltd.), the pencil hardness of the surface on which the hard coat layer is coated and formed is measured according to JIS K5600-5-4 (1999). H or higher was evaluated as ◯ (good), and pencil hardness of less than H was determined as x (impossible).
(5) Antireflection property Measurement was performed using a spectrophotometer UV-3150 manufactured by Shimadzu Corporation. The sample is a water resistant sandpaper of # 320 to 400, and the surface opposite to the coating film surface (surface opposite to the low refractive index layer with respect to the substrate) is uniformly scratched, and black paint (black magic ink) (Registered Trademark) solution was applied, the reflection from the surface opposite to the surface coated with the low refractive index layer was completely eliminated, and the surface of the low refractive index layer was pressed against an integrating sphere for measurement. The incident angle was 5 °, and the inspection wavelength region was 380 nm to 780 nm. The light reflectance was a minimum value and was evaluated according to the following criteria.
○ (good): When the light reflectance of the minimum value is 1% or less × (impossible); When the light reflectance of the minimum value exceeds 1% (6) Haze value PET film on which a conductive layer is formed, and further Based on JIS K 7136 (2000), the haze value in a state where the hard coat layer and the low refractive index layer are laminated on the conductive layer is measured using a direct reading haze computer (NDH 2000) manufactured by Suga Test Instruments Co., Ltd. went. Here, for the PET film on which the conductive layer is formed, the measurement is performed by making light incident from the side having the conductive layer, and the hard coat layer and the low refractive index are further formed on the conductive layer on the PET film on which the conductive layer is formed. About the laminated body with which the refractive index layer was laminated | stacked, it measured by making light inject from the side which has a low refractive index layer.
(7) Measurement of thickness (A) of conductive mesh, measurement of thickness (L) of hard coat layer on thin line portion of conductive mesh, and calculation of thickness (N) of hard coat layer Randomly selected from samples Three enlarged cross-sectional photographs were taken with a field emission scanning electron microscope (JSM-6700F manufactured by JEOL Ltd., acceleration voltage 10 kV, observation magnification 20000 times). From the enlarged cross-sectional photograph, the thickness of the conductive mesh ( A) and the thickness (L) of the hard coat layer on the thin wire portion of the conductive mesh were obtained and averaged. The thickness (A) of the obtained conductive mesh and the thickness (L) of the hard coat layer on the thin wire portion of the conductive mesh were added to obtain the thickness (N) of the hard coat layer.

Further, the ratio of the thickness (N) of the hard coat layer to the thickness (A) of the obtained conductive mesh, that is, (N / A) × 100) was calculated.
(8) Measurement of thickness of low refractive index layer The thickness of the low refractive index layer is measured as follows. A cross section of the display filter sample is observed with a transmission electron microscope (H-7100FA type, manufactured by Hitachi) at an acceleration voltage of 100 kV. Sample preparation uses an ultrathin section method. Observe at a magnification of 100,000 times and measure the thickness of the low refractive index layer.
(9) Average primary particle diameter of metal oxide fine particles The metal oxide fine particle dispersion was measured with a particle size analyzer (Nanotrack particle size distribution measuring device manufactured by Nikkiso Co., Ltd.) using a dynamic light scattering method.

Example 1
<Formation of conductive layer>
A nickel layer (thickness 0.02 μm) is formed on a 100 μm thick PET film (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) by sputtering, and a copper layer having a thickness of 2.5 μm is further vacuum-deposited thereon. Formed by the method.

  Next, an alkali developing negative resist film was laminated on the surface of the copper layer, exposed to ultraviolet rays through a photomask having a lattice pattern, and developed using a developer containing 1% by mass of sodium carbonate. Next, after etching with a ferric chloride solution, the resist layer is peeled off by treatment with a 3% by mass aqueous sodium hydroxide solution, and a conductive mesh having a line width of 7 μm, a line pitch of 130 μm, and a thickness of 2.5 μm. A conductive layer was obtained.

  Subsequently, the conductive mesh was blackened using an oxidation treatment agent (adjusted at a ratio of Enplate MB-438A / B / pure water = 8/13/79 manufactured by Meltex Co., Ltd.).

  The haze value of the PET film having the conductive layer thus produced was 2.3%.

<Coating formation of hard coat layer>
Next, on the conductive layer, Toyo Ink Co., Ltd. high refractive index coating material for hard coat layer (coating solution containing hard coat layer forming material) “TYS63-004” (antimony oxide having an average primary particle size of 40 nm) Fine particles are coated with a micro gravure coater, containing 80% by mass of 100% by mass of the total solids (total amount of non-volatile components excluding organic solvents) forming the hard coat layer, dried at 120 ° C., and then high-pressure mercury A hard coat layer was formed by irradiating with UV light from a UV lamp (120 W / cm) at an integrated light quantity of 450 mW / cm ² and curing.

  The thickness of the hard coat layer was adjusted so that the thickness (L) on the thin wire portion of the conductive mesh was 3 μm. The refractive index of the hard coat layer was 1.63.

<Preparation of low refractive index layer forming material>
4.15 g of tridecafluorooctyltrimethoxysilane (manufactured by Toshiba Silicone Co., Ltd.) and 19 g of isopropyl alcohol were placed in the flask, and 1.03 g of formic acid aqueous solution prepared to 2.0 N was stirred while being dropped over about 10 minutes. After completion of the dropwise addition, the temperature was adjusted to 50 to 55 ° C. and stirred for 2 hours. Next, 3.89 g of methyltrimethoxysilane (manufactured by Shin-Etsu Silicone) and 26.6 g of propylene glycol monoethyl ether were added, and then 1.54 g of purified water was dropped and mixed at 20 to 25 ° C. over about 10 minutes. . Subsequently, the mixture was heated to 60 ° C. and stirred and reacted for 2 hours. Next, after cooling to room temperature, 10.4 g of isopropyl alcohol was added to adjust the concentration to obtain a copolymer solution (A).

  Next, 53.16 g of methyltrimethoxysilane (manufactured by Shin-Etsu Silicone) and 38.31 g of trifluoropropyltrimethoxysilane (manufactured by Shin-Etsu Silicone) were added to the flask, and 100 g of propylene glycol monoethyl ether was added as a solvent. 104.53 g of isopropyl alcohol-dispersed hollow silica sol (Catalyst Kasei Chemical Industry Co., Ltd., solid content 20.5 mass%, particle size 50 nm), porous silica sol (Osaka Sumitomo Cement Co., Ltd., silica sol, particle size of about 25 nm, porosity 214.29 g of about 40% solid content) was added. Thereafter, the temperature was set to about 20 ° C., and 30.66 g of a formic acid aqueous solution prepared to 1.0 N was added over about 20 minutes while stirring with a stirring spring at a rotational speed of about 270 rpm, and subsequently using an oil bath. The temperature of the reaction solution was set to 60 ° C. and stirred for 3 hours to complete the reaction, and the reaction solution was cooled to room temperature to obtain a silica fine particle solution reacted with polysiloxane.

  The copolymer solution (A) and the silica fine particle solution are mixed, and 363.3 g of methyl alcohol, 2058 g of isopropyl alcohol, and 600 g of propylene glycol monoethyl ether are added, and then 4.0 g of aluminum trisacetylacetonate is added and dissolved by stirring. Thus, a low refractive index layer forming material (a coating material for forming a low refractive index layer) was obtained.

The ratio of (A) compound having perfluoro group / (B) silica fine particles / (C) porous silica fine particles in the low refractive index layer forming material (coating material) is 55 parts by mass / 22.5 parts by mass / 22. The ratio of the curing agent to 100 parts by mass in total was 4 parts by mass.
<Coating formation of low refractive index layer>
Apply 1.5cc of the low refractive index layer forming material (coating material) prepared above to the hard coat layer by hand coating using a 6th metaling bar, and take care not to get bubbles. We applied while applying.

Immediately after coating the coating material, it was placed in an oven having a temperature of 130 ° C. and heat-treated for 2 minutes. Thereafter, UV irradiation (about 300 mJ / cm ² when converted to UV intensity) was performed on a conveyor type UV irradiation apparatus equipped with a high pressure mercury lamp (120 w) at a speed of 5 m / min. The thickness of the low refractive index layer thus formed was about 100 nm. The refractive index of the low refractive index layer was 1.36.
<Lamination of near-infrared shielding layer>
A near-infrared shielding layer having both an orange light shielding function (a phthalocyanine-based dye and a diimonium-based dye as near-infrared absorbing dyes, and orange) on the PET film surface opposite to the conductive layer of the PET film having the conductive layer prepared above. A layer obtained by coating a paint obtained by mixing a tetraazaporphyrin-based dye as a light-absorbing dye with an acrylic resin so that the dry film thickness is 12 μm) is provided.
<Lamination of adhesive layer>
A UV curable urethane acrylate resin (Hybon (registered trademark) manufactured by Hitachi Chemical Co., Ltd.) was applied on a separate film with a slit die coater to a thickness of 100 μm, and then applied using a UV irradiation device. Then, a separate film was attached to obtain an adhesive layer sandwiched between the separate films. Next, an adhesive layer was laminated on the near-infrared shielding layer of each sample prepared above while peeling off one of the separate films, whereby the display filter of Example 1 was obtained.

(Example 2)
A display filter was produced in the same manner as in Example 1 except that the following conductive layer was used.
<Formation of conductive layer>
A grid mesh pattern is gravure-printed using a catalyst ink (palladium colloid-containing paste) on a PET film with a thickness of 100 μm (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) and immersed in an electroless copper plating solution. Electroless copper plating, followed by electrolytic copper plating and further electrolytic plating of a Ni-Sn alloy, and a conductive layer made of a conductive mesh having a thickness of 3.5 μm, a line width of 20 μm, and a line pitch of 300 μm. Formed. The haze value of the PET film having the conductive layer thus produced was 2.5%.

(Example 3)
The hard coat layer forming material is Pertron XJC-0357-2 (antimony oxide fine particles having an average primary particle diameter of 50 nm, the total solid content forming the hard coat layer, which is a high refractive index hard coat layer paint manufactured by Pernox Co., Ltd. A display filter was produced in the same manner as in Example 1 except that (the total amount of nonvolatile components excluding the organic solvent) was 80% by mass with respect to 100% by mass). The refractive index of the hard coat layer was 1.69.

Example 4
As a coating liquid containing a hard coat layer forming material, 60 parts by mass of tin-containing indium oxide particles (ITO) having an average primary particle size of 30 nm, 20 parts by mass of polyfunctional acrylate, 18 parts by mass of methanol, 54 parts by mass of propylene glycol monomethyl ether , 20 parts by mass of isopropyl alcohol, 1 part by mass of a photopolymerization initiator (Ciba Specialty Chemicals (Irgacure 184)), and 1 part by mass of a leveling agent (“Polyflow KL-600” manufactured by Kyoeisha Chemical Co., Ltd.) A display filter was produced in the same manner as in Example 1 except that the coating liquid prepared in this manner was used. The content ratio of ITO, which is metal oxide fine particles, is 73% by mass with respect to 100% by mass of all components of the hard coat layer. The refractive index of this hard coat layer was 1.67.

(Example 5)
A display filter was produced in the same manner as in Example 1 except that the following low refractive index layer (refractive index 1.37) was used.
(Preparation of coating material for low refractive index layer)
219 parts by mass of methyltrimethoxysilane (KBM-13 manufactured by Shin-Etsu Silicone) was hydrolyzed with 89 parts by mass of 0.5N formic acid while stirring at 20 ° C. ± 5 ° C. After 60 minutes, 412 parts by mass of isopropyl alcohol was mixed to prepare a treatment liquid (X1). Similarly, 158 parts by mass of 3,3,3-trifluoropropyltrimethoxysilane (KBM-7103 manufactured by Shin-Etsu Silicone) was hydrolyzed with 41 parts by mass of 1N formic acid while stirring at 30 ° C. ± 10 ° C. After 60 minutes, 521 parts by mass of isopropyl alcohol was mixed to prepare a treatment liquid (X2). Next, a silica slurry (X3) composed of 144 parts by mass of porous silica particles having an outer shell with a primary particle diameter of 50 nm (porosity 40%) and 560 parts by mass of isopropyl alcohol was prepared. Treatment liquid (X1) 720 parts by mass, treatment liquid (X2) 720 parts by mass, silica slurry (X3) 704 parts by mass, methanol 356 parts by mass, isopropyl alcohol 4272 parts by mass, polypropylene glycol monoethyl ether 713 parts by mass were mixed. Thereafter, 15 parts by mass of acetoacetoxyaluminum as a curing catalyst and 5 parts by mass of “Megafac F479” manufactured by Dainippon Ink & Chemicals, Inc. as a leveling agent were added and stirred and mixed again to prepare a coating material.

(Example 6)
A display filter was produced in the same manner as in Example 1 except that the following low refractive index layer (refractive index 1.37) was used.
(Formation of a low refractive index layer)
Commercially available low refractive index paint (TU2180 manufactured by JSR Corporation: refractive index 1.37: polyfunctional (meth) acrylate compound, fluorine-based polymer, hollow silica fine particles, photopolymerization initiator, and organic solvent concentration 10% by weight), diluted with methyl isobutyl ketone and propylene glycol monobutyl ether (propylene glycol monobutyl ether containing 6% by weight of all organic solvents), and diluted to a solid content concentration of 3% by weight. A refractive index layer forming material (coating material) was prepared. This low refractive index layer forming material (coating material) is applied by a reverse coating method using a small-diameter gravure roll, dried at 90 ° C., and then cured by irradiation with ultraviolet rays of 400 mJ / cm ² , and has a thickness of about 100 nm. A refractive index layer was provided.

(Example 7)
A display filter was produced in the same manner as in Example 6 except that the following conductive layer was used.

<Formation of conductive layer>
A nickel layer (thickness: 0.02 μm) is formed on a PET film having a thickness of 100 μm (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) by a sputtering method, and a copper layer having a thickness of 1.5 μm is formed thereon by vacuum deposition. A copper nitride layer having a thickness of 0.02 μm was further formed thereon by a vacuum deposition method.

  Next, an alkali developing negative resist film was laminated on the surface of the copper nitride layer, exposed to ultraviolet rays through a photomask having a lattice pattern, and developed using a developer containing 1% by mass of sodium carbonate. . Next, after etching with a ferric chloride solution, the resist layer is peeled off by treatment with a 3% by mass aqueous sodium hydroxide solution, and a conductive mesh having a line width of 8 μm, a line pitch of 150 μm, and a thickness of 1.5 μm. A conductive layer was obtained. The haze value of the PET film having the conductive layer thus produced was 2.0%.

(Example 8)
A display filter was produced in the same manner as in Example 6 except that the conductive layer had a black resist layer on the conductive mesh described below.
<Formation of conductive layer>
A nickel layer (thickness 0.02 μm) is formed on a PET film having a thickness of 100 μm (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) by sputtering, and a copper layer having a thickness of 2 μm is further formed thereon by vacuum deposition. Formed.

  Subsequently, the following photosensitive black resist layer was laminated | stacked on the surface of this copper layer so that thickness (dry film thickness) might be set to 1 micrometer. The optical density (OD value) of this black resist layer was 4.4.

  The black resist layer was then scanned and exposed in a grid pattern using a 405 nm blue-violet semiconductor laser. Subsequently, development processing was performed using an alkali developer to form a black resist layer having a mesh pattern. Next, the metal thin film portion not covered with the black resist layer was etched with a ferric chloride solution to obtain a conductive mesh having a line width of 8 μm, a line pitch of 150 μm, and a thickness of 2.5 μm.

The total thickness of the mesh pattern (resist laminated conductive mesh) made of the conductive mesh and the black resist layer thus produced was 3.5 μm. Moreover, the haze value of the PET film having the conductive layer was 2.4%.
<Black resist layer>
Mitsubishi Materials Corp. titanium black 13M-T (titanium nitride) 42.11 parts by mass, Daido Kasei Co., Ltd. acid-treated carbon black 9930CF 62.32 parts by mass, Degussa Co., Ltd. carbon black PRINTEX25 62. 32 parts by mass, 1.68 parts by mass of “Solspers (registered trademark)” 12000 (manufactured by Abyssia) and 56.14 parts by mass of a 45% by mass 3-methyl-3-methoxybutanol solution of an acrylic polymer (see below), “Disperbyk (registered trademark)” 167 (dispersant) manufactured by Big Chemi Japan Co., Ltd. 24.29 parts by mass and 751.1 parts by mass of propylene glycol monomethyl ether acetate were weighed, and a mill type disperser filled with zirconia beads was measured. And dispersed at 2500 rpm for 3 hours to obtain a pigment dispersion having a pigment concentration of 16.843 mass%.

  To 57.74 parts by mass of this pigment dispersion, 0.63 parts by mass of a 45% by mass 3-methyl-3-methoxybutanol solution of an acrylic polymer (see below), a bisphenoxyethanol fluorene-based tetrafunctional acrylate compound (see below) 3- Methyl-3-methoxy-butyl acetate 30 mass% 7.56 parts by mass, dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd. DPHA) as a polyfunctional monomer 30 mass of 3-methyl-3-methoxy-butyl acetate % Solution 3.24 parts by weight, “Irgacure (registered trademark)” 379 0.24 parts by weight as photopolymerization initiator, Asahi Denka Kogyo Co., Ltd. “Adeka (registered trademark) Optomer” N-1919 1.47 parts by weight and N, N'-tetraethyl-4,4'-diaminobenzophenone 0.19 parts by mass, improved adhesion 0.14 parts by weight of vinyltrimethoxysilane as a chemical agent and 0.28 parts by weight of a 10% by weight solution of propylene glycol monomethyl ether acetate as a silicone surfactant are dissolved in 28.51 parts by weight of 3-methyl-3-methoxy-butyl acetate. The prepared solution was added and mixed to prepare a black resist layer (solid content concentration: 17.5% by mass).

The content ratio of the black pigment in the black resist layer is 55% by mass with respect to all components of the black resist layer excluding the organic solvent.
<Acrylic polymer>
After synthesizing methyl methacrylate / methacrylic acid / styrene copolymer (weight composition ratio 33/34/33) by the method described in Example 1 of Japanese Patent No. 3120476, 33 parts by weight of glycidyl methacrylate was added, and purified water was added. Then, an acrylic polymer (P1) powder having an average molecular weight (Mw) of 9,000 and an acid value of 70 (mg KOH / g: according to JIS K-5407) was obtained.
<Bisphenoxyethanol fluorene-based tetrafunctional acrylate compound>
First, 296 parts by mass of bisphenoxyethanol fluorenediglycidyl ether (epoxy equivalent 296 g / eq), 3.4 parts by mass of dimethylbenzylamine, 0.34 parts by mass of p-methoxyphenol, 72.06 parts by mass of acrylic acid (1 Mol) and the temperature was raised while blowing air at a flow rate of 20 ml / min, and the reaction was carried out at a temperature of 110 to 120 ° C. During this time, the acid value was measured, and heating and stirring were continued until it became less than 2.0 mgKOH / g. It took 10 hours for the acid value to reach the target. Thereby, bisphenoxyethanol fluorene type acrylate was obtained.

  Next, in the container, 184.0 parts by mass of the bisphenoxyethanol fluorene acrylate synthesized above (hydroxyl equivalent: 368 g / eq, calculated value), 100 parts by mass of 3-methoxy-3-methyl-butyl acetate, 26.6 parts by mass of triethylamine (0.263 mol) was charged and dissolved and cooled in a water bath, and then 25.38 parts by mass of isophthal chloride (0.125 mol: an amount necessary for reacting half of the hydroxyl group with the acid chloride) was converted to 3-methoxy- A solution dissolved in 100 parts by mass of 3-methyl-butyl acetate was added dropwise. The mixture was further reacted at room temperature for 2 hours, diluted with 267.3 parts by mass of 3-methoxy-3-methyl-butyl acetate, and the resulting white precipitate was filtered under pressure to obtain 30% by mass of the bisphenoxyethanol fluorene-based tetrafunctional acrylate compound. A solution was obtained.

Example 9
A display filter was produced in the same manner as in Example 1 except that the following conductive layer was used.

<Formation of conductive layer>
A 20% by mass aqueous solution of polyvinyl alcohol was printed in a dot shape (corresponding to the reverse pattern of the conductive mesh pattern) on a PET film having a thickness of 100 μm (Lumirror (registered trademark) manufactured by Toray Industries, Inc.). The size of one dot is a square whose side is 280 μm, the interval between the dots is 20 μm, and the dot arrangement is a square lattice.

  Next, a nickel layer (thickness: 0.02 μm), a copper layer (thickness: 2.5 μm), and a copper oxide layer (thickness: 0.02 μm) are formed on the surface on which the dot printing of the PET film is performed by a vacuum deposition method. Laminated sequentially.

  Next, the PET film laminated with the metal layer is immersed in water at room temperature and rubbed with a sponge to dissolve and remove the dot-like polyvinyl alcohol portion, and at the same time, remove the metal layer on the dot-like polyvinyl alcohol portion. A conductive layer made of a conductive mesh having a thickness of 2.5 μm, a line width of 20 μm, and a line pitch of 300 μm was prepared.

  The haze value of the PET film having the conductive layer thus produced was 2.5%.

(Example 10)
A display filter was produced in the same manner as in Example 1 except that the following conductive layer was used.
<Formation of conductive layer>
Fluorine-based oil (Krytox, DuPont) is formed on a PET film (Toray Co., Ltd. Lumirror (registered trademark)) in a reverse pattern of the lattice from an oil adhering roll via a mask forming roll to a 100 μm thick PET film Subsequently, a copper layer (thickness 2.5 μm) and a copper oxide layer (0.02 μm) were sequentially laminated on the surface of the PET film on which the oil was applied by vacuum deposition.

The conductive mesh thus obtained had a thickness of 2.5 μm, a line width of 30 μm, and a line pitch of 400 μm. The haze value of the PET film having a conductive layer was 2.8%.
(Example 11)
A display filter was produced in the same manner as in Example 6 except that the coating liquid containing the following hard coat layer forming material was used.
<Coating liquid containing hard coat layer forming material>
20 parts by mass of a fluorene acrylic resin (NK ester A-BPEF manufactured by Shin-Nakamura Chemical Co., Ltd.), 150 parts by mass of a titanium oxide dispersion (solid content concentration 20% by mass) prepared as follows, dipentaerythritol hexa 46 parts by mass of acrylate (DPHA manufactured by Nippon Kayaku Co., Ltd.), 30 parts by mass of methyl isobutyl ketone, 20 parts by mass of isopropyl alcohol, 3 parts by mass of a photopolymerization initiator (Ciba Specialty Chemicals (Irgacure 184)), and A coating liquid containing a hard coat layer forming material containing 1 part by mass of a leveling agent (“Polyflow KL-600” manufactured by Kyoeisha Chemical Co., Ltd.) was prepared. This coating solution was applied in the same manner as in Example 1 and cured to form a hard coat layer. The content ratio of titanium oxide which is metal oxide fine particles is 30% by mass with respect to 100% by mass of all components of the hard coat layer. The refractive index of this hard coat layer was 1.65.

<Preparation of titanium oxide dispersion>
10 parts by weight of rutile titanium oxide (TTO51 manufactured by Ishihara Sangyo Co., Ltd.), 1 part by weight of a dispersant (Disperbic 161 manufactured by Big Chemie Japan Co., Ltd.), and 39 parts by weight of methyl isobutyl ketone were weighed, and glass beads (φ0 0.1 mm) as a medium, the mixture was stirred with a paint shaker for 10 hours, and after stirring, the glass beads were filtered to obtain a titanium oxide dispersion. The solid content concentration of the obtained dispersion was 20% by mass, and the average primary particle diameter of the titanium oxide particles was 64 nm.

(Example 12)
A display filter was produced in the same manner as in Example 6 except that the coating liquid containing the following hard coat layer forming material was used.
<Coating liquid containing hard coat layer forming material>
50 parts by mass of tin-containing indium oxide particles (ITO) having an average primary particle size of 30 nm, 23 parts by mass of urethane acrylate (NK Oligo U-4HA manufactured by Shin-Nakamura Chemical Co., Ltd.), dipentaerythritol hexaacrylate (Nippon Kayaku) (DPHA) 23 parts by mass, methanol 18 parts by mass, propylene glycol monomethyl ether 54 parts by mass, isopropyl alcohol 20 parts by mass, photopolymerization initiator (Ciba Specialty Chemicals (Irgacure 184) 3 parts by mass, and leveling agent A coating liquid containing a hard coat layer forming material containing 1 part by mass of “Polyflow KL-600” manufactured by Kyoeisha Chemical Co., Ltd. was prepared. This coating solution was applied in the same manner as in Example 1 and cured to form a hard coat layer. The content ratio of ITO, which is metal oxide fine particles, is 50% by mass with respect to 100% by mass of all components of the hard coat layer. The refractive index of this hard coat layer was 1.60.

(Comparative Example 1)
A display filter was produced in the same manner as in Example 1 except that the following conductive layer was used.
<Formation of conductive layer>
A grid mesh pattern is gravure-printed using a catalyst ink (palladium colloid-containing paste) on a PET film with a thickness of 100 μm (Lumirror (registered trademark) manufactured by Toray Industries, Inc.) and immersed in an electroless copper plating solution. Electroless copper plating, followed by electrolytic copper plating and further electrolytic plating of Ni-Sn alloy to form a conductive layer made of a conductive mesh having a thickness of 5 μm, a line width of 20 μm, and a line pitch of 300 μm. did. The haze value of the PET film having the conductive layer thus produced was 2.6%.

(Comparative Example 2)
A display filter was produced in the same manner as in Example 1 except that the following hard coat layer was used.

<Hard coat layer>
Dipentaerythritol hexaacrylate (DPHA) 80 parts by mass ITO (average particle size 150 nm) 20 parts by mass Methyl ethyl ketone 100 parts by mass Toluene 100 parts by mass Irgacure 184 (manufactured by Ciba Specialty Chemicals) 4 parts by mass Hard formed as described above The refractive index of the coat layer was 1.52.

(Comparative Example 3)
A coating material for the low refractive index layer was prepared in the same manner except that the amount of the porous silica particles in the coating material for the low refractive index layer of Example 5 was changed to 14.4 parts by mass. A display filter was produced in the same manner as in Example 1 except that this low refractive index layer (refractive index 1.45) was used.

(Comparative Example 4)
A display filter was produced in the same manner as in Example 1 except that the following conductive layer was used.

<Formation of conductive layer>
Two-component adhesive for dry lamination (Toyo Morton Co., Ltd. main agent AD-76P1 / curing agent CAT-10L) to 100 μm thick PET film (Toray Co., Ltd. Lumirror (registered trademark)) and 10 μm thick copper foil Was laminated to obtain a copper foil laminate film.

Next, an alkali development type negative resist film was laminated on the surface of the copper foil, exposed to ultraviolet rays through a photomask having a lattice pattern, and developed using a developer containing 1% by mass of sodium carbonate. Next, after etching with a ferric chloride solution, the resist layer is peeled off by treatment with a 3% by mass aqueous sodium hydroxide solution to form a conductive mesh having a line width of 12 μm, a line pitch of 300 μm, and a thickness of 10 μm. A conductive layer was obtained. Subsequently, the conductive mesh was blackened using an oxidation treatment agent (adjusted at a ratio of Enplate MB-438A / B / pure water = 8/13/79 manufactured by Meltex Co., Ltd.). The haze value of the PET film having the conductive layer thus produced was 53.9%.
(Evaluation of each sample)
According to the method mentioned above, the sample of the Example and the comparative example was evaluated. The results are summarized in Table 1.

  From the results of Table 1, the examples of the present invention have no aggregation of metal oxide fine particles contained in the hard coat layer, high transparency (low haze value of low refractive index layer surface, low Ra value), good It can be seen that visibility, good pencil hardness, and excellent antireflection properties are obtained.

  On the other hand, Comparative Example 1 in which the thickness of the conductive mesh is 4 μm or more has agglomeration of metal oxide fine particles, and it is visually recognized that the transparency is lowered (the haze value of the low refractive index layer surface is large and the Ra value is large). The deterioration of the property is seen, and the pencil hardness is also inferior.

  In Comparative Example 2 using a hard coat layer having a refractive index smaller than 1.55, sufficient antireflection properties cannot be obtained. Similarly, Comparative Example 3 using a low refractive index layer having a refractive index greater than 1.4 cannot provide sufficient antireflection properties.

  Comparative Example 4 using a conductive mesh having a thickness of 10 μm formed between the PET film as the base material and an adhesive layer had poor coating properties of the hard coat layer, and metal oxide fine particles Agglomeration of was significantly generated. As a result, the visibility and transparency of the obtained display filter are low (the haze value of the low refractive index layer surface is large and the Ra value is large), and the pencil hardness is also inferior.

  The display filter according to the present invention is used as a display filter disposed in front of a display such as a plasma display, a liquid crystal display, or an organic EL display. In particular, the display filter of the present invention is effective as a filter for a plasma display that generates electromagnetic waves.

Claims (5)

A display filter comprising at least a conductive layer having a conductive mesh on a substrate, a hard coat layer laminated so as to cover the conductive layer, and a low refractive index layer laminated on the hard coat layer. Because
The hard coat layer contains metal oxide fine particles, and the refractive index of the hard coat layer is 1.55 or more,
The refractive index of the low refractive index layer is 1.4 or less,
Furthermore, the thickness of the conductive mesh is less than 4 μm,
A display filter, wherein the conductive mesh is any one of the following a) to d).
a) A conductive mesh formed by etching a metal thin film formed on a substrate by a vapor deposition method.
b) A conductive mesh formed by performing metal plating on the catalyst ink layer provided in a pattern on the substrate.
c) On the base material, a resin layer having a pattern opposite to the pattern of the conductive mesh is formed with a peelable resin, and then on the surface of the base material on which the resin layer is formed, by a vapor deposition method. A conductive mesh formed by laminating metal thin films and then peeling the resin layer.
d) By applying oil in a pattern opposite to the pattern of the conductive mesh on the base material, and then laminating a metal thin film on the surface of the base material on which the oil has been applied by vapor deposition. Formed conductive mesh.   The display filter according to claim 1, wherein an average primary particle diameter of the metal oxide fine particles is less than 150 nm.   The display filter according to claim 1 or 2, wherein the metal oxide fine particles are contained in an amount of 25% by mass or more based on 100% by mass of all components of the hard coat layer.   The metal oxide fine particles are titanium oxide, zirconium oxide, zinc oxide, tin oxide, antimony oxide, cerium oxide, iron oxide, zinc antimonate, tin oxide doped indium oxide (ITO), antimony doped tin oxide (ATO), aluminum. The display filter according to claim 1, which is at least one selected from doped zinc oxide, gallium-doped zinc oxide, and fluorine-doped tin oxide.   The display filter according to any one of claims 1 to 4, wherein a thickness of the hard coat layer is 130% or more with respect to a thickness of 100% of the conductive mesh.

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