JP2009223292A - Filter for display and display equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter for a display having superior antireflection properties, even if another function layer is formed on a mesh-like electromagnetic-wave shielding layer. <P>SOLUTION: The filter for a display includes a transparent substrate 110, the mesh-like electromagnetic-wave shielding layer 120 formed on the transparent substrate, and a first function layer 131, formed on the electromagnetic-wave shielding layer and is such that the surface roughness Ra of the outermost layer on the electromagnetic-wave shielding layer is 0.1 μm or smaller. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is applicable to various displays such as a plasma display panel (PDP), a cathode ray tube (CRT) display, a liquid crystal display, an organic EL (electroluminescent) display, and a field emission display (FED) including a surface electric field display (SED). The present invention relates to a filter having various functions such as antireflection, near-infrared shielding, and electromagnetic shielding, and a display provided with this filter.

  In recent years, flat panel displays such as liquid crystal displays, plasma displays (PDPs), EL displays, and CRT displays have been mainly used for large-screen displays, and PDPs have become common as next-generation large-screen display devices. However, in this PDP, high-frequency pulse discharge is performed on the light emitting unit for image display, and therefore there is a risk of unnecessary electromagnetic radiation and infrared radiation causing malfunction of an infrared remote controller or the like.

  For this reason, a filter having an electromagnetic wave shielding layer formed on a transparent substrate is known as a filter used for a display such as a PDP. In the electromagnetic wave shielding layer, for example, (1) a transparent conductive thin film containing metallic silver, (2) a conductive mesh in which a metal wire or conductive fiber is made into a net, (3) an opening is provided in a metal foil such as a copper foil. A conductive layer such as a mesh-like one or (4) a conductive ink printed in a mesh-like shape is used. Especially, since a high light transmittance is acquired by an opening part, the mesh-shaped electroconductive layer of (2)-(4) is used suitably. Electromagnetic waves are shielded by the conductive mesh portion, and light transmission is ensured by the opening.

  Furthermore, conventional display filters have a hard coat layer for imparting scratch resistance, and an antireflection layer for improving the visibility by suppressing the reflection of light rays irradiated from an external light source such as a fluorescent lamp. Laminated. Furthermore, a display filter in which a near-infrared shielding layer is provided on one surface of a transparent substrate in order to shield infrared rays has been proposed.

  For example, Patent Document 1 discloses a display filter including a laminate in which a single transparent substrate, a conductive mesh, an outermost antireflection film, and a near-infrared cut film are laminated and integrated. Has been. The electromagnetic wave shielding layer, the hard coat layer, the antireflection layer, and the near-infrared shielding layer are laminated and used according to the use of the display filter.

International Publication No. 2006/309660 Pamphlet

  It is known that the display filter preferably has a mesh-like electromagnetic wave shielding layer on the transparent substrate so as to be on the user side because high electromagnetic wave shielding properties can be obtained. In order to produce other functional layers such as an antireflection layer and a near-infrared absorbing layer on a mesh-like electromagnetic shielding layer, mesh a coating solution containing uncured synthetic resin monomer and fine particles as necessary. For example, a method is used in which coating is directly performed on a solid electromagnetic shield layer and cured by irradiation with active rays such as ultraviolet rays or heating. However, such a method has a problem that a display filter having excellent antireflection properties cannot be obtained.

  Therefore, an object of the present invention is to provide a display filter having excellent antireflection properties even when another functional layer is formed on a mesh-like electromagnetic wave shielding layer.

  In the conventional display filter, the projections of the mesh-like electromagnetic shielding layer cause large irregularities on the surface of other functional layers, and the irregularities may cause irregular reflection of light, thereby reducing the antireflection property. . As a result of various studies paying attention to such a situation, the present inventors have been remarkably improved by reducing the surface roughness of the functional layer formed on the mesh-like electromagnetic shielding layer. It has been found that a display filter having antireflection properties can be obtained.

That is, the present invention is a display filter comprising a transparent substrate, a mesh-shaped electromagnetic wave shielding layer formed on the transparent substrate, and a first functional layer formed on the electromagnetic wave shielding layer. And
The above problem is solved by the display filter, wherein the surface roughness Ra of the outermost layer on the electromagnetic wave shielding layer is 0.1 μm or less.

  In the present invention, the surface roughness Ra of the outermost layer among the layers formed on the electromagnetic wave shielding layer is 0.1 μm or less, so that irregular reflection of light is suppressed by having a smoothed surface, which is excellent. It is possible to provide a display filter having antireflection properties. Therefore, the display filter has excellent visibility of an image displayed on the display, and is useful as a display filter installed on the entire surface of a display such as a plasma display (PDP), a liquid crystal display, an organic EL display, and a field emission display. is there.

Sectional drawing of the filter for displays of this invention is shown.

  The display filter of the present invention has a transparent base material, a mesh-like electromagnetic wave shielding layer formed on the transparent base material, and a first functional layer formed on the electromagnetic wave shielding layer, The surface roughness Ra of the outermost layer on the electromagnetic wave shielding layer is 0.1 μm or less, preferably 0.01 to 0.1 μm, more preferably 0.01 to 0.08 μm. Since the outermost layer of the layers formed on the electromagnetic wave shielding layer has a surface roughness within the above range, it is possible to provide a display filter having a smooth surface and excellent antireflection properties. Become.

  The surface roughness Ra of the outermost layer on the electromagnetic wave shielding layer can be measured using a surface roughness meter (Surfcom 480A manufactured by Tokyo Seimitsu Co., Ltd.) according to JIS B 0601 (1994).

  In the present invention, the first functional layer may be any layer as long as it includes a synthetic resin having a certain function formed on the electromagnetic wave shielding layer. In the present invention, the first functional layer generally includes a near-infrared absorbing layer or a hard coat layer. The first functional layer is preferably a hard coat layer because a layer having high surface smoothness can be formed. In the present invention, the hard coat layer means a layer having a hardness of H or higher in a pencil hardness test specified by JIS-K-5400.

(Hard coat layer)
The thickness of the hard coat layer is usually 1 to 50 μm, preferably 5 to 40 μm, particularly preferably 5 to 35 μm. Thereby, a layer having high surface smoothness is obtained.

  The hard coat layer is a layer mainly composed of a synthetic resin such as an acrylic resin layer, an epoxy resin layer, a urethane resin layer, or a silicon resin layer. The synthetic resin is generally a thermosetting resin or an ultraviolet curable resin, and an ultraviolet curable resin is preferable. The ultraviolet curable resin is preferable because it can be cured in a short time and is excellent in productivity.

  Examples of the thermosetting resin include phenol resin, resorcinol resin, urea resin, melamine resin, epoxy resin, acrylic resin, urethane resin, furan resin, and silicon resin.

  The hard coat layer is preferably a cured layer of an ultraviolet curable resin composition containing an ultraviolet curable resin monomer and / or oligomer, a photopolymerization initiator, and the like.

  Examples of the UV curable resin monomer and oligomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-ethylhexyl polyethoxy (meth) acrylate, Benzyl (meth) acrylate, isobornyl (meth) acrylate, phenyloxyethyl (meth) acrylate, tricyclodecane mono (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, acryloylmorpholine, N-vinylcaprolactam, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, o-phenylphenyloxyethyl (meth) acrylate, neopentylglyco Rudi (meth) acrylate, neopentyl glycol dipropoxy di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, 1,6-hexanediol di (meth) Acrylate, nonanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, tris [(meth) acryloxyethyl] isocyanurate, ditrimethylolpropane (Meth) acrylate monomers such as tetra (meth) acrylate; polyol compounds (for example, ethylene glycol, propylene glycol, neopentyl glycol, 1 6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butyl-1,3-propanediol, trimethylolpropane, diethylene glycol, dipropylene glycol, polypropylene glycol , 1,4-dimethylolcyclohexane, bisphenol A polyethoxydiol, polytetramethylene glycol and other polyols, succinic acid, maleic acid, itaconic acid, adipic acid, hydrogenated dimer acid, phthalic acid, isophthalic acid Polyester polyols which are reaction products of polybasic acids such as terephthalic acid or their anhydrides, polycaprolactone polyols which are reaction products of the polyols and ε-caprolactone, the polyols and the poly Basic acid or this Reaction products of acid anhydrides of ε-caprolactone, polycarbonate polyols, polymer polyols, etc.) with organic polyisocyanates (for example, tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, dicyclohexane) Pentanyl diisocyanate, hexamethylene diisocyanate, 2,4,4′-trimethylhexamethylene diisocyanate, 2,2′-4-trimethylhexamethylene diisocyanate, etc.) and a hydroxyl group-containing (meth) acrylate (for example, 2-hydroxyethyl (meth)) Acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate , Cyclohexane-1,4-dimethylol mono (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerin di (meth) acrylate, etc.) (Meth) acrylate such as polyurethane (meth) acrylate, bisphenol A type epoxy resin, bisphenol F type epoxy resin, etc. ) Acrylate oligomers and the like. These compounds can be used alone or in combination. These ultraviolet curable resin monomers and oligomers may be used as a thermosetting resin together with a thermal polymerization initiator.

  In order to form a hard coat layer, among the monomers and oligomers of the above-mentioned UV curable resin, hard hard layers such as pentaerythritol tri (meth) acrylate, pentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate are used. It is preferable to mainly use functional monomers.

  Any compound suitable for the properties of the ultraviolet curable resin can be used as the photopolymerization initiator for the ultraviolet curable resin. For example, acetophenone such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1 Benzoin series such as benzyldimethyl ketal, benzophenone, 4-phenylbenzophenone, benzophenone series such as hydroxybenzophenone, thioxanthone series such as isopropylthioxanthone, 2-4-diethylthioxanthone, and other special ones include methylphenyl glyoxylate Etc. can be used. Particularly preferably, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, Examples include benzophenone. These photopolymerization initiators may be optionally selected from one or more known photopolymerization accelerators such as benzoic acid type or tertiary amine type such as 4-dimethylaminobenzoic acid. It can be used by mixing at a ratio. Moreover, it can be used by 1 type, or 2 or more types of mixture of only a photoinitiator. In particular, 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Specialty Chemicals, Irgacure (registered trademark) 184) is preferable.

  Generally the quantity of a photoinitiator is 0.1-10 mass% with respect to a resin composition, Preferably it is 0.1-5 mass%.

  Further, the hard coat layer may contain a small amount of an ultraviolet absorber, an infrared absorber, an anti-aging agent, a paint processing aid, a colorant and the like. In particular, it is preferable to contain an ultraviolet absorber (for example, a benzotriazole-based ultraviolet absorber or a benzophenone-based ultraviolet absorber), whereby yellowing of the filter can be efficiently prevented. The amount thereof is generally 0.1 to 10% by mass, preferably 0.1 to 5% by mass, based on the resin composition.

  The hard coat layer preferably contains silicone oil. Thereby, the hard-coat layer excellent in surface smoothness can be formed. Preferred examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, and methylhydrogen silicone oil. These may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  The content of silicone oil in the hard coat layer is preferably 0.0005 to 0.1 mass%, more preferably 0.001 to 0.05 mass%, based on the resin composition.

(Antireflection layer)
It is preferable that an antireflection layer is further provided on the hard coat layer. Thereby, a display filter having high antireflection properties can be obtained. The antireflection layer includes (1) a low refractive index layer having a refractive index lower than that of the hard coat layer, or (2) a high refractive index layer having a refractive index higher than that of the hard coat layer, and being refracted more than the high refractive index layer. A composite film in which a low refractive index layer having a low refractive index is laminated is preferred.

(Low refractive index layer)
The thickness of the low refractive index layer is usually in the range of 10 to 500 nm, preferably 20 to 200 nm.

  The low refractive index layer is a layer in which fine particles such as 10 to 40% by mass (preferably 10 to 30% by mass) of silica and fluororesin, preferably hollow silica are dispersed in a synthetic resin (preferably an ultraviolet curable resin) ( Preferably, it is a hardened layer). The refractive index of this low refractive index layer is preferably 1.35 to 1.45. If the refractive index is more than 1.45, the antireflection characteristic may be deteriorated.

  As the hollow silica, those having an average particle diameter of 10 to 100 nm, preferably 10 to 50 nm, and a specific gravity of 0.5 to 1.0, preferably 0.8 to 0.9 are preferable.

Silica, preferably hollow silica, may be treated with a silane coupling agent. Thereby, stability and antireflection can be improved. Examples of the silane coupling agent include a general formula: R _n SiX _(4-n) (wherein R is an alkoxy group having 1 to 4 carbon atoms, a methacryloylalkyl group, a methacryloyloxy group, an acryloyloxy group, or A perfluoro (meth) acryloyl group, wherein X represents an alkoxy group having 1 to 4 carbon atoms, a silanol group, a halogen atom, or a hydrogen atom, and n represents an integer of 1 to 3, preferably 1. Preferred are those mentioned above.

  In order to treat silica with a silane coupling agent, a conventionally known method such as a method in which a silane coupling agent is added to a dispersion of silica and an acid or alkali is added as a hydrolysis catalyst as necessary. Can be used.

  The low refractive index layer preferably contains silicone oil. The content of silicone oil in the low refractive index layer is preferably 0.0005 to 0.1 parts by mass, and more preferably 0.001 to 0.05 parts per 100 parts by mass of the synthetic resin contained in the low refractive index layer. Part by mass.

(High refractive index layer)
The thickness of the high refractive index layer is usually 10 to 500 nm, preferably 20 to 200 nm.

The high refractive index layer is made of synthetic resin (preferably UV curable resin), ITO, ATO, Sb ₂ O ₃ , ZrO ₂ , SbO ₂ , In ₂ O ₃ , SnO ₂ , ZnO, ZnO doped with Al, A layer (cured layer) in which conductive metal oxide fine particles (inorganic compound) such as TiO ₂ are dispersed is preferable. The metal oxide fine particles preferably have an average particle size of 10 to 10,000 nm, preferably 10 to 50 nm. In particular, ITO (especially having an average particle diameter of 10 to 50 nm) is preferable. Those having a refractive index of 1.64 or more are suitable.

  When the high refractive index layer is a conductive layer, the minimum reflectance of the surface reflectance of the antireflection layer should be within 1.5% by setting the refractive index of the high refractive index layer to 1.64 or more. The minimum reflectance of the surface reflectance of the antireflection layer can be made to be within 1.0% by setting it to 1.69 or more, preferably 1.69 to 1.82.

  The high refractive index layer preferably contains silicone oil. The content of silicone oil in the high refractive index layer is preferably 0.0005 to 0.1 parts by mass, more preferably 0.001 to 0.05 parts per 100 parts by mass of the synthetic resin contained in the high refractive index layer. Part by mass.

  The low refractive index layer and the high refractive index layer are preferably a cured layer of an ultraviolet curable resin composition containing an ultraviolet curable resin monomer and / or oligomer, a photopolymerization initiator, the above-described fine particles, and the like. Specific examples of the synthetic resin, the UV curable resin monomer, the oligomer, the photopolymerization initiator, and the silicone oil in the low refractive index layer and the high refractive index layer are the same as those listed in the hard coat layer. It is done. The hard coat layer, the high refractive index layer, and the low refractive index layer all preferably have a visible light transmittance of 85% or more.

  In the display filter of the present invention, the layer formed on the electromagnetic wave shielding layer is preferably (1) only a hard coat layer and (2) a hard coat layer and a low refractive index layer laminated in this order. (3) A layer formed by laminating a hard coat layer, a high refractive index layer, and a low refractive index layer in this order. Therefore, as the outermost layer having a surface roughness Ra of 0.1 μm or less formed on the electromagnetic wave shielding layer, the hard coat layer in the case of (1), and the low refractive index layer in the cases of (2) and (3) It is.

  In order to form each layer on the electromagnetic wave shielding layer, it is preferable to apply a coating solution made of an ultraviolet curable resin composition containing an organic solvent. For example, as described above, an organic solvent is blended with a synthetic resin (preferably a monomer or oligomer of an ultraviolet curable resin) and a photopolymerization initiator, and other components such as the above-described fine particles are blended as necessary. The liquid may be applied on a transparent substrate having a mesh-like electromagnetic wave shielding layer with a gravure coater or the like, then dried, and then cured by ultraviolet irradiation. This wet coating method has the advantage that the film can be uniformly formed at high speed at low cost.

  In addition, in order to make the surface roughness Ra of the outermost layer disposed on the electromagnetic wave shielding layer to be 0.1 μm or less, it is obtained after coating the coating liquid on the transparent substrate having the meshed electromagnetic wave shielding layer. Means for scraping the surface of the coated layer with a squeegee, etc., means for laminating a substrate having excellent surface flatness on the coated layer and irradiating with ultraviolet rays to cure the coated layer, and then peeling the substrate. Etc. are preferably used.

  The organic solvent is not particularly limited, but an organic solvent in which each component is dispersed or dissolved and easy to dry is preferable. Specific examples include ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, alcohol solvents, cellosolve solvents, petroleum solvents and the like. These may be used individually by 1 type, and 2 or more types may be mixed and used for them.

  In the case of ultraviolet curing, many light sources that emit light in the ultraviolet to visible range can be used as the light source, such as ultra-high pressure, high pressure, low pressure mercury lamp, chemical lamp, xenon lamp, halogen lamp, mercury lamp, carbon arc lamp, incandescent lamp. And laser light. The irradiation time cannot be determined unconditionally depending on the type of lamp and the intensity of the light source, but is about several seconds to several minutes. Moreover, in order to accelerate curing, the laminate may be preheated to 40 to 120 ° C. and irradiated with ultraviolet rays.

(Electromagnetic wave shielding layer)
In the display filter of the present invention, the mesh-shaped electromagnetic wave shielding layer formed on the transparent substrate contains a metal and has conductivity. For example, (1) what consists of metals, such as copper, (2) what disperse | distributed electroconductive particle in binder resin can be mentioned.

  (1) In the electromagnetic wave shielding layer made of a metal such as copper, copper, stainless steel, aluminum, nickel, iron, brass, or an alloy thereof, preferably copper, stainless steel, or aluminum is used as the metal.

  In order to produce the electromagnetic wave shielding layer of (1), first, a vapor deposition method such as sputtering, ion plating, electron beam vapor deposition, vacuum vapor deposition or chemical vapor deposition, or a method such as printing or coating is used. What is necessary is just to perform using well-known methods, such as the method of forming the metal foil which consists of the said metal on a transparent base material, and then making the mesh shape by etching the said metal foil and providing an opening part.

  In order to produce the electromagnetic shielding layer of (1), in addition to the above method, dots are formed on a transparent substrate with a material soluble in a solvent, and the film surface is insoluble in a solvent. A method in which a conductive material layer made of a conductive material is formed and the film surface is brought into contact with a solvent to remove the dots and the conductive material layer on the dots may be used. Such a method is described in, for example, Japanese Patent Application Laid-Open No. 2001-332889.

  In order to produce the electromagnetic shielding layer of (1), in addition to the above, an electroless plating catalyst ink is printed in a mesh shape on a transparent substrate, and the resulting mesh-like electroless plating catalyst layer A mesh-like electromagnetic wave shielding layer can be obtained by electroless plating the above-described metal.

Various electroless plating catalyst inks can be used, and examples include ink containing an electroless plating catalyst, a binder resin, and an organic solvent. As electroless plating catalysts, high catalytic activity can be obtained, such as chlorides of metal atoms such as palladium, silver, platinum, and gold, ammine complexes such as hydroxides, oxides, sulfates, and ammonium salts. Used. In particular, a palladium compound, especially palladium chloride is preferable. In addition, as the electroless plating catalyst, a composite metal oxide and a composite metal oxide hydrate can also be used. Examples of the complex metal _{oxide, PdSiO 3, Ag 2 SiO 3} , PdTiO 3, such as Ag ₂ TiO _3, PdZrO ₃ and Ag ₂ TiO ₃ and the like. The binder resin is preferably an acrylic resin, a polyester resin, a polyurethane resin, or a vinyl chloride resin. The electroless plating catalyst ink printed on the transparent substrate is preferably dried by heating at 80 to 160 ° C., particularly 90 to 130 ° C.

  The electroless plating can be performed at room temperature or under heating according to a conventional method using an electroless plating bath.

  (2) In the electromagnetic wave shielding layer in which conductive particles are dispersed in a binder resin, examples of the conductive particles include aluminum, nickel, indium, chromium, gold, vanadium, tin, cadmium, silver, platinum, copper, Metals such as titanium, cobalt, lead, alloys; or ITO, indium oxide, tin oxide, zinc oxide, indium oxide-tin oxide (ITO, so-called indium-doped tin oxide), tin oxide-antimony oxide (ATO, so-called antimony-doped oxide) Tin), and conductive oxides such as zinc oxide-aluminum oxide (ZAO; so-called aluminum-doped zinc oxide). In particular, ITO is preferable.

  Examples of the binder resin include acrylic resin, polyester resin, epoxy resin, polyurethane resin, phenol resin, maleic acid resin, melamine resin, urea resin, polyimide resin, and silicon-containing resin. Furthermore, it is preferable that it is a thermosetting resin among these resins.

  In order to produce the electromagnetic wave shielding layer of (2), a method of printing a conductive ink in which conductive particles are dispersed in a binder resin in a mesh shape on a transparent substrate can be used. In addition to the conductive particles and the binder resin, the conductive ink may further contain a solvent in order to adjust to an appropriate viscosity. Examples of the solvent include alcohols such as hexanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, stearyl alcohol, seryl alcohol, cyclohexanol, terpineol; ethylene glycol monobutyl ether (butyl cellosolve), ethylene Examples thereof include alkyl ethers such as glycol monophenyl ether, diethylene glycol, diethylene glycol monobutyl ether (butyl carbitol), cellosolve acetate, butyl cellosolve acetate, carbitol acetate, and butyl carbitol acetate.

  In order to print the conductive ink in a mesh on the transparent substrate, a known method such as gravure printing, flexographic printing, gravure offset printing, screen printing, ink jet printing, or electrostatic printing may be used. Then, it is made to dry and harden at room temperature-120 degreeC as needed.

  As the electromagnetic wave shielding layer, it is preferable to use the electromagnetic wave shielding layer of (1) among the above-described ones because it is excellent in antiglare property and electrical conductivity.

  The shape of the opening surrounded by the line of the electromagnetic wave shielding layer can be any shape such as a circle, an ellipse, and a square (quadrangle, hexagon), but is generally a square, and particularly preferably a square. . The lines are net-like, but are preferably grid-like.

  The shape of the mesh pattern in the electromagnetic wave shielding layer is not particularly limited, and examples thereof include a lattice shape in which square openings are formed, and a punching metal shape in which circular, hexagonal, triangular or elliptical openings are formed. It is done. Further, the openings are not limited to those regularly arranged, and may be a random pattern.

  The line width of the mesh-like (including lattice-like) electromagnetic wave shielding layer is generally 20 μm or less, preferably 1 to 15 μm, and particularly 1 to 12 μm. The line pitch is preferably 200 μm or less. Further, the aperture ratio is preferably 75 to 95%, particularly 80 to 95%. The aperture ratio is obtained by calculation from the line width of the mesh and the number of lines existing in 1 inch width.

  In order to improve the electromagnetic shielding effect by setting the electromagnetic shielding layer to a lower resistance value, it is preferable to form a metal plating layer on the electromagnetic shielding layer.

  The metal plating layer can be formed by a known electrolytic plating method or electroless plating method. Generally, copper, copper alloy, nickel, silver, gold, zinc or tin can be used as the metal used for plating. These can be used alone or as two or more kinds of alloys. You may do it. Especially, it is preferable to use the layer which consists of an alloy of nickel and zinc or an alloy of nickel and tin for a metal plating layer. Thereby, the black alloy electroconductive layer excellent in black degree and electroconductivity is obtained, and while anti-glare property can be improved, anti-glare property can be provided.

  The mass ratio (Ni / Zn) of nickel to zinc or tin in the black alloy conductive layer made of an alloy of nickel and zinc or tin is 0.4 to 1.4, particularly 0.2 to 1.2. Is preferred. Thereby, a black alloy conductive layer having a uniform black color tone can be obtained, and an electromagnetic wave shielding layer having high antiglare property can be obtained even if the thickness is thin.

  The thickness of the black alloy conductive layer is preferably 0.001 to 1 μm, particularly preferably 0.01 to 0.1 μm. If the thickness of the black alloy conductive layer is less than 0.001 μm, sufficient antiglare property may not be imparted to a sufficient electromagnetic shielding layer. If the thickness exceeds 1 μm, the thickness of the electromagnetic shielding layer increases, and the display filter This is not desirable from the viewpoint of surface planarization.

  Moreover, you may provide anti-glare performance to an electromagnetic wave shield layer. This antiglare treatment may be performed by performing a blackening treatment on the surface of the electromagnetic wave shielding layer and providing a blackening layer. For example, it can be performed by oxidation treatment of a metal film, black plating of a chromium alloy or the like, application of black or dark ink, or the like.

(Transparent substrate)
The transparent substrate used in the display filter of the present invention is not particularly limited as long as it has transparency and flexibility and can withstand subsequent processing. Examples of the material for the transparent substrate include glass, polyester (eg, polyethylene terephthalate, (PET), polybutylene terephthalate), acrylic resin (eg, polymethyl methacrylate (PMMA)), polycarbonate (PC), polystyrene, and cellulose triacetate. , Polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyethylene, ethylene-vinyl acetate copolymer, polyvinyl butyral, metal ion crosslinked ethylene-methacrylic acid copolymer, polyurethane, cellophane, etc. PET, PC, and PMMA, which are less transparent due to processing (heating, solvent, bending) and are highly transparent, are preferable. Among these, PET is preferable because it is inexpensive and has excellent durability. A transparent base material is used as a sheet | seat, a film, or a board which consists of these materials.

  The thickness of the transparent substrate is not particularly limited, but is preferably about 6 to 250 μm, particularly about 6 to 150 μm.

(Second functional layer)
In the display filter of the present invention, it is preferable that a second functional layer is further provided on the surface of the transparent substrate opposite to the surface on which the electromagnetic wave shielding layer is formed. The second functional layer may be any layer as long as it is formed on the surface of the transparent substrate opposite to the surface on which the electromagnetic wave shielding layer is formed and includes a synthetic resin exhibiting some function. The second functional layer is generally a near-infrared absorbing layer, a transparent adhesive layer, or a combination thereof. Specifically as a 2nd functional layer, it consists of (1) what consists only of a near-infrared absorption layer, (2) what consists of a transparent adhesive layer, or (3) consists of a near-infrared absorption layer and a transparent adhesive layer. It is preferable to consist of things (provided on the transparent substrate in this order).

(Near-infrared absorbing layer)
The near-infrared absorbing layer (that is, the near-infrared shielding layer) used as the second functional layer is generally obtained by forming a layer containing a pigment or the like on the surface of the transparent substrate. The near-infrared absorbing layer can be obtained, for example, by applying a coating liquid containing a thermosetting, ultraviolet curable, or electron beam curable synthetic resin as a dye and a binder, and if necessary, drying and curing. When used as a film, it is generally a near-infrared cut film, such as a film containing a pigment or the like.

  The dye generally has an absorption maximum at a wavelength of 800 to 1200 nm. Examples include phthalocyanine dyes, metal complex dyes, nickel dithiolene complex dyes, cyanine dyes, squarylium dyes, polymethine dyes, Examples thereof include azomethine dyes, azo dyes, polyazo dyes, diimonium dyes, aminium dyes, and anthraquinone dyes, and cyanine dyes and squarylium dyes are particularly preferable. These dyes can be used alone or in combination.

  As an example of the synthetic resin as the binder, acrylic resin, fluororesin, polyester resin, vinyl chloride resin, styrene resin, norbornene resin and the like are preferably used. These may be used individually by 1 type and may be used in mixture of 2 or more types.

  In the present invention, the near-infrared absorbing layer may be provided with a function of adjusting color tone by providing a function of absorbing neon light emission. For this purpose, a neon-emission absorption layer may be provided, but a neon-emission selective absorption dye may be included in the near-infrared absorption layer.

  Neon luminescent selective absorption dyes include cyanine dyes, squarylium dyes, anthraquinone dyes, phthalocyanine dyes, polymethine dyes, polyazo dyes, azurenium dyes, diphenylmethane dyes, and triphenylmethane dyes. it can. Such a selective absorption dye is required to have a selective absorption of neon emission near 585 nm and a small absorption at other visible light wavelengths, so that the absorption maximum wavelength is 575 to 595 nm and the absorption spectrum half width is What is 40 nm or less is preferable.

  Also, when combining multiple types of near-infrared or neon luminescent absorbing dyes, if there is a problem with the solubility of the dye, if there is a reaction between the dyes due to mixing, if there is a decline in heat resistance, moisture resistance, etc. All the near-infrared absorbing dyes need not be contained in the same layer, and may be contained in another layer.

  Further, as long as the optical properties are not greatly affected, coloring pigments, ultraviolet absorbers, antioxidants and the like may be further added.

  As a near-infrared absorption characteristic of the display filter of the present invention, it is preferable that the transmittance at 850 to 1000 nm is 20% or less, and further 15%. Moreover, as selective absorptivity, it is preferable that the transmittance | permeability of 585 nm is 50% or less. Especially in the former case, there is an effect of reducing the transmittance in a wavelength region where malfunction of a remote controller of a peripheral device is pointed out. In the latter case, an orange color having a peak at 575 to 595 nm is color reproducibility. This has the effect of absorbing the orange wavelength, thereby improving the redness and improving the color reproducibility.

  The thickness of the near-infrared absorbing layer is not particularly limited, but is preferably about 0.5 to 50 μm in terms of near-infrared absorption and visible light transmission.

  It is preferable that the near-infrared absorbing layer contains a color correction pigment. Alternatively, a color tone correction layer containing a color tone correction pigment may be provided in the same manner as the near infrared absorption layer.

  As the color correction pigment, in order to neutralize the yellowish brown to green color tone of the near-infrared shielding layer and adjust the color balance, those which are complementary colors thereof are preferable. Examples of such pigments include general pigments such as inorganic pigments, organic pigments, organic dyes, and pigments. Examples of inorganic pigments include cobalt compounds, iron compounds, chromium compounds, and examples of organic pigments include azo-based, indolinone-based, quinacridone-based, vat-based, phthalocyanine-based, naphthalocyanine-based, Examples of the organic dyes and pigments include azo, azine, anthraquinone, indigoid, oxazine, quinophthalone, squalium, stilbene, triphenylmethane, naphthoquinone, pyrarozone, and polymethine. Of these, organic pigments are preferably used in view of the balance between color developability and durability.

(Transparent adhesive layer)
The transparent adhesive layer is a layer for adhering the display filter of the present invention to the display, and any resin can be used as long as it has an adhesive function.

  Examples of the resin having an adhesive function in the transparent adhesive layer include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer, acrylic resin (eg, ethylene- (meth) acrylic acid copolymer). , Ethylene- (meth) acrylic acid ethyl copolymer, ethylene- (meth) methyl acrylate copolymer, metal ion crosslinked ethylene- (meth) acrylic acid copolymer), partially saponified ethylene-vinyl acetate copolymer, Examples include ethylene-based copolymers such as carboxylated ethylene-vinyl acetate copolymer, ethylene- (meth) acryl-maleic anhydride copolymer, ethylene-vinyl acetate- (meth) acrylate copolymer (note that And “(meth) acryl” means “acryl or methacryl”.) In addition, polyvinyl butyral (PVB) resin, epoxy resin, phenol resin, silicone resin, polyester resin, urethane resin, rubber adhesive, SEBS (styrene / ethylene / butylene / styrene), SBS (styrene / butadiene / styrene), etc. Thermoplastic elastomers and the like can also be used, but it is acrylic resin-based pressure-sensitive adhesives and epoxy resins that can easily obtain good adhesiveness.

  The thickness of the transparent adhesive layer is generally 10 to 50 μm, preferably 20 to 30 μm. In general, the display filter can be equipped by heat-pressing the pressure-sensitive adhesive layer to a glass plate of the display.

  When EVA is used as the material of the transparent adhesive layer, the EVA has a vinyl acetate content of 5 to 50% by weight, preferably 15 to 40% by weight. When the vinyl acetate content is less than 5% by weight, there is a problem in transparency, and when it exceeds 40% by weight, the mechanical properties are remarkably deteriorated and the film formation becomes difficult and the films are easily blocked.

  When EVA or the like is used, the transparent pressure-sensitive adhesive layer may further contain a crosslinking agent. As the cross-linking agent, an organic peroxide is suitable for heat cross-linking and is selected in consideration of sheet processing temperature, cross-linking temperature, storage stability, and the like. Examples of peroxides that can be used include 2,5-dimethylhexane-2,5-dihydroperoxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane-3; -Butyl peroxide; t-butylcumyl peroxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; dicumyl peroxide; α, α'-bis (t-butylperoxyisopropyl) ) Benzene; n-butyl-4,4-bis (t-butylperoxy) valerate; 2,2-bis (t-butylperoxy) butane; 1,1-bis (t-butylperoxy) cyclohexane; , 1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane; t-butylperoxybenzoate; benzoyl peroxide; Luperoxyacetate; 2,5-dimethyl-2,5-bis (tertiarybutylperoxy) hexyne-3; 1,1-bis (tertiarybutylperoxy) -3,3,5-trimethylcyclohexane; 1-bis (tert-butylperoxy) cyclohexane; methyl ethyl ketone peroxide; 2,5-dimethylhexyl-2,5-bisperoxybenzoate; tert-butyl hydroperoxide; p-menthane hydroperoxide; p-chlorobenzoyl Peroxides; tertiary butyl peroxyisobutyrate; hydroxyheptyl peroxide; chlorohexanone peroxide. These peroxides are used singly or in combination of two or more, and are usually used at a ratio of 5 parts by mass or less, preferably 0.5 to 5.0 parts by mass with respect to 100 parts by weight of EVA. .

  The organic peroxide is usually kneaded with EVA using an extruder, a roll mill or the like, but may be dissolved in an organic solvent, a plasticizer, a vinyl monomer or the like and added to the EVA film by an impregnation method.

  In order to improve the physical properties of EVA (mechanical strength, optical properties, adhesion, weather resistance, whitening resistance, crosslinking speed, etc.), various acryloxy group or methacryloxy group and allyl group-containing compounds are added to the transparent adhesive layer. Further, it can be added. As the compound used for this purpose, acrylic acid or methacrylic acid derivatives, for example, esters and amides thereof are the most common. As the ester residue, in addition to alkyl groups such as methyl, ethyl, dodecyl, stearyl, lauryl, cyclohexyl groups , Tetrahydrofurfuryl group, aminoethyl group, 2-hydroxyethyl group, 3-hydroxypropyl group, 3-chloro-2-hydroxypropyl group and the like. Further, esters with polyfunctional alcohols such as ethylene glycol, triethylene glycol, polyethylene glycol, trimethylolpropane, and pentaerythritol can also be used. A typical amide is diacetone acrylamide.

  Examples thereof include polyfunctional esters such as acrylic or methacrylic acid esters such as trimethylolpropane, pentaerythritol, glycerin, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, diallyl maleate, etc. Examples include allyl group-containing compounds. These are used alone or in combination of two or more, and are usually used in an amount of 0.1 to 2 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of EVA. .

  When EVA is cross-linked by light, the photosensitizer in the transparent adhesive layer is usually 5 parts by mass or less, preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of EVA instead of the peroxide. used.

  In this case, usable photosensitizers include, for example, benzoin, benzophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, dibenzyl, 5-nitroacenaphthene, hexachlorocyclopentadiene, p-nitrodiphenyl. , P-nitroaniline, 2,4,6-trinitroaniline, 1,2-benzanthraquinone, 3-methyl-1,3-diaza-1,9-benzanthrone, and the like. Alternatively, two or more types can be mixed and used.

  Moreover, a silane coupling agent may be used together as an adhesion promoter in the transparent adhesive layer. As this silane coupling agent, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycid Xylpropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N- β (aminoethyl) -γ-aminopropyltrimethoxysilane and the like can be mentioned.

  The silane coupling agent is generally used in an amount of 0.001 to 10 parts by mass, preferably 0.001 to 5 parts by mass, based on 100 parts by mass of EVA, and one or more types are mixed and used.

  In addition, the transparent adhesive layer according to the present invention may contain a small amount of an ultraviolet absorber, an infrared absorber, an anti-aging agent, a coating processing aid, a colorant and the like. Further, a small amount of a filler such as hydrophobic silica and calcium carbonate may be included.

  For example, EVA and the above-mentioned additive are mixed and kneaded with an extruder, a roll, etc., and then the transparent adhesive layer is formed into a predetermined shape by a film forming method such as calendar, roll, T-die extrusion, inflation, etc. It is manufactured by.

  It is preferable that a release sheet is further provided on the transparent adhesive layer. As a material for the release sheet, a transparent polymer having a glass transition temperature of 50 ° C. or higher is preferable. Examples of such a material include polyester resins such as polyethylene terephthalate, polycyclohexylene terephthalate, and polyethylene naphthalate, nylon 46, and modified nylon. In addition to polyamide resins such as 6T, nylon MXD6, polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, and sulfone resins such as polysulfone and polyether sulfone, polyether nitrile, polyarylate, poly Resins based on polymers such as ether imide, polyamide imide, polycarbonate, polymethyl methacrylate, triacetyl cellulose, polystyrene and polyvinyl chloride can be used. . Of these, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polystyrene, and polyethylene terephthalate can be suitably used. The thickness is preferably 10 to 200 μm, particularly preferably 30 to 100 μm.

  1 is a schematic cross-sectional view of a display filter having an antireflection layer comprising a hard coat layer, a high refractive index layer and a low refractive index layer, a near-infrared absorbing layer, and a transparent adhesive layer as described above, which is a preferred embodiment of the present invention. Is shown in FIG. The display filter shown in FIG. 1 includes a transparent substrate 110, a mesh-shaped electromagnetic wave shield layer 120 formed on the transparent substrate 110, a hard coat layer 131 formed on the electromagnetic wave shield layer 120, It has a high refractive index layer 132 formed on the coat layer 131 and a low refractive index layer 133 formed on the high refractive index layer. Further, the display filter has a near-infrared absorbing layer 141 and a transparent adhesive layer 142 on the surface of the transparent substrate 110 opposite to the surface on which the electromagnetic wave shielding layer 120 is formed.

  As described above, the display filter of the present invention is characterized in that the outermost layer among the layers formed on the electromagnetic wave shielding layer has a predetermined surface roughness Ra. Thereby, the display filter which suppresses irregular reflection of light and is excellent in antireflection property is obtained.

  Such a display filter of the present invention is not particularly limited, but can be applied to a display using means such as bonding to the surface of an image display glass plate of the display via a transparent adhesive layer. At this time, the outermost layer having the surface roughness Ra of 0.1 μm or less is disposed on the viewer side. The display includes a field emission display (FED) including a surface electric field display (SED), a liquid crystal display (LCD), a plasma display panel (PDP), a flat panel display (FPD) such as an EL display, and a CRT display. Can be mentioned.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not limited to a following example.

Example 1
1. Formation of mesh-shaped electromagnetic wave shielding layer A 20% aqueous solution of polyvinyl alcohol was printed in a dot shape on a polyethylene terephthalate film (thickness: 100 μm). The size of one dot is a square shape with one side of 150 μm, the interval between dots is 30 μm, and the dot arrangement is a square lattice. The printing thickness is 0.1 μm after drying.

  On top of that, copper was vacuum-deposited so as to have an average film thickness of 4.1 μm. Next, it was immersed in room temperature water and rubbed with a sponge to dissolve and remove the dot portion, then rinsed with water and dried to form a mesh-like electromagnetic wave shielding layer on the entire surface of the polyethylene film.

  The electromagnetic wave shielding layer on the surface of the film has a square lattice shape corresponding to the negative pattern of dots accurately, the average thickness is 3.8 μm, the average line width is 30 μm, the average pitch is 170 μm, and the aperture ratio is 68%. Met.

2. Formation of Black Alloy Conductive Layer A black alloy conductive layer (thickness 0.2 μm) covering the entire surface of the electromagnetic shield layer by performing zinc-nickel alloy plating on the electromagnetic shield layer formed on the PET film under the following conditions. ) Was formed.

(Plating conditions)
Plating solution temperature: 40 ° C
Current density: 5 to 10 A / dm ²
Plating time: 10 seconds Plating solution amount: 120 m ³
(Plating solution composition)
ZnCl ₂ with Zn ²⁺ concentration of 2.0 g / l, NiCl ₂ .6H ₂ O with Ni ²⁺ concentration of 0.5 g / l, KCl with K ⁺ concentration of 250 g / l, pH 10 plating solution Was used.

3. Formation of Hard Coat Layer 5 parts by mass of a polymerization initiator (Irgacure (registered trademark) 184 (manufactured by Ciba Specialty Chemicals)) is added to 100 parts by mass of dipentaerythritol triacrylate as a resin component to obtain a solid content A It was. On the other hand, solvent A was obtained by mixing 2-propanol and cyclohexanone at a mass ratio of 7: 3. Solid content A and solvent A are mixed at a mass ratio of 2: 8, 0.02% by mass of silicone oil (KF96-200CS Shin-Etsu Silicone) is added, and the mixture is stirred at room temperature for 1 hour, thereby coating the hard coat layer. Was prepared.

Next, the hard coat layer coating was applied to the entire surface of the black alloy conductive layer with a bar coater, the surface of the coating layer was scraped with a squeegee and dried at 120 ° C. for 30 seconds, and then the accumulated light amount was 600 mJ / cm ² . Ultraviolet rays were irradiated to form a hard coat layer (thickness 10 μm) on the black alloy conductive layer.

4). Formation of high refractive index layer Composite colloidal sol of titanium dioxide and zirconium dioxide (average particle size 13.1 μm, solid content concentration 30% by mass, methanol solvent, mass ratio of titanium dioxide and zirconium dioxide = 85: 15) with respect to 200 parts by mass , 50 parts by mass of trimethylolpropane acrylate (EO 3 mol addition) as a resin component, 7 parts by mass of a polymerization initiator (Irgacure (registered trademark) 1800 (manufactured by Ciba Specialty Chemicals)), 50 parts by mass of isopropyl alcohol as a solvent, and silicone 0.01 parts by mass of oil (KF96-50CS Shin-Etsu Silicone) was added, stirred for 1 hour at room temperature, and then filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating material for a high refractive index layer.

Next, a coating material for a high refractive index layer is applied onto the hard coat layer with a bar coater, dried at 80 ° C. for 10 seconds, and then irradiated with ultraviolet rays having an integrated light amount of 600 mJ / cm ² to form a coating on the hard coat layer. A high refractive index layer (thickness 1.0 nm, refractive index 1.67) was formed.

5. Formation of Low Refractive Index Layer 3-Methacryloxypropyltrimethoxysilane (KBM-503 Shin-Etsu Silicone) as a silane coupling agent with respect to 100 parts by mass of methanol dispersion of silica fine particles (average particle size 15 nm, solid content concentration 50% by mass) 3 parts by weight, 1 part by weight of 1N hydrochloric acid as a catalyst was added, stirred at room temperature for 12 hours, and then allowed to stand at room temperature for 50 hours to prepare a silane-coupled silica fine particle dispersion.

  With respect to 5 parts by mass of this silica fine particle dispersion, 25 parts by mass of pentaerythritol triacrylate as a resin component, 94 parts by mass of methyl isobutyl ketone and 5 parts by mass of isobutyl alcohol as a solvent, a polymerization initiator (Irgacure (registered trademark) 907 (Ciba Specialty) Chemical company)) 2 parts by mass, and further 0.001 part by mass of silicone oil (KF96-50CS Shin-Etsu Silicone), stirred for 1 hour at room temperature, and then filtered through a polypropylene filter with a pore size of 1 μm. A layer coating was prepared.

Next, a coating material for low refractive index adjustment is applied onto the high refractive index layer with a bar coater, dried at 80 ° C. for 10 seconds, and then irradiated with ultraviolet rays having an integrated light amount of 600 mJ / cm ² to form a hard coat layer. A low refractive index layer (thickness 90 nm, refractive index 1.45) was formed thereon. Thereby, a filter for display was obtained.

(Example 2)
In the coating material for hard coat layer of Example 1, the resin component was changed from 100 parts by mass of dipentaerythritol triacrylate to 50 parts by mass of pentaerythritol tetraacrylate and 50 parts by mass of ethoxycabisphenol A diacrylate (EO 4 mol addition). A display filter was produced in the same manner as in Example 1 except that the thickness of the hard coat layer was 16 μm.

(Example 3)
In Example 1, the thickness of the polyethylene terephthalate film was changed to 150 μm, the average thickness of the meshed electromagnetic wave shielding layer was changed to 3.4 μm, the average line width was changed to 35 μm, the average pitch was changed to 250 μm, and the thickness of the hard coat layer was changed. A display filter was produced in the same manner as in Example 1 except that the thickness was 30 μm.

Example 4
1. Formation of Electromagnetic Shielding Layer An electroless plating catalyst ink in which 10% by mass of an electroless plating catalyst (PdCl ₂ ) is mixed with a polyester resin on a PET film (thickness 100 μm) is gravure-printed in a mesh shape, and then 100 ° C. Was dried for 1 minute to obtain a mesh-like electroless plating catalyst layer. The electroless plating catalyst layer has a square lattice shape in which square openings are regularly arranged, the line width is 20 μm, one side of the openings (lattice) is 191 μm, and the opening ratio is 78%. The thickness was 2 μm.

  This electroless plating catalyst layer is degreased with 5% sulfuric acid, and then electrolessly plated using an electroless copper plating solution (liquid temperature 60 ° C.) having the following composition to form a mesh on the electroless plating catalyst layer. A copper foil was formed. This copper foil has a square lattice shape in which square openings are regularly arranged, the line width is 23 μm, one side of the opening (lattice) is 188 μm, the opening ratio is 77%, and the thickness is Was 2 μm.

(Electroless copper plating solution)
Copper sulfate pentahydrate: 13 g / L
NaOH: 7.5 g / L
HCOH: 13 ml / L
Complexing agent (triammonium citrate): 2 g / L

  A mesh-like copper plating layer was formed on the copper foil by electrolytic plating using an electrolytic copper plating solution (solution temperature 30 ° C.) having the following composition. The electrolytic plating conditions were 20A, 10 minutes, a copper plate (dimension 600 × 1000 mm) was used as the adherend, and a titanium case-containing copper sphere was used as the anode. This copper plating layer has a square lattice shape in which square openings are regularly arranged, the line width is 23 μm, one side of the opening (grid) is 188 μm, the opening ratio is 77%, Was 2 μm.

2. Formation of black alloy conductive layer Black alloy conductive layer covering the entire surface of the electromagnetic shielding layer by performing zinc-nickel alloy plating on the electromagnetic shielding layer formed on the PET film in the same manner as in Example 1. (Thickness 0.2 μm) was formed.

3. Formation of Hard Coat Layer, High Refractive Index Layer, and Low Refractive Index Layer A hard coat layer (thickness of 10 μm) and a high refractive index layer (thickness) were formed on the black alloy conductive layer prepared above in the same manner as in Example 1. 1.0 nm, refractive index 1.67), and low refractive index layer (thickness 90 nm, refractive index 1.45) were formed.

(Comparative Example 1)
A display filter was produced in the same manner as in Example 1 except that the electromagnetic wave shielding layer was not formed and the thickness of the hard coat layer was 15 μm.

(Comparative Example 2)
A display filter was produced in the same manner as in Example 2 except that the electromagnetic wave shielding layer was not formed and the thickness of the hard coat layer was 27 μm.

(Comparative Example 3)
In the formation of the hard coat layer, a display filter was applied in the same manner as in Example 1 except that the hard coat layer coating was applied to the entire surface of the electromagnetic wave shielding layer with a bar coater and then the surface of the coating layer was not scratched with a squeegee. Was made.

(Comparative Example 4)
In the formation of the hard coat layer, the display filter was applied in the same manner as in Example 2 except that the hard coat layer coating was applied to the entire surface of the electromagnetic wave shielding layer with a bar coater and the surface of the coating layer was not scratched with a squeegee. Was made.

(Evaluation)
1. Thickness of the hard coat layer The thickness of the hard coat layer was measured using a thin film measuring meter F20 (manufactured by Filmetrics Co., Ltd.). The results are shown in Table 1.

2. Surface roughness Ra of low refractive index layer
The surface roughness Ra of the low refractive index layer, which is the outermost layer in the display filter, is measured using the surface roughness meter (Surfcom 480A, manufactured by Tokyo Seimitsu Co., Ltd.) and the measurement conditions and measurement defined by JIS B 0601 (1994). Measurements were taken at a length of 4 mm and a cut-off value of 0.8 mm. The results are shown in Table 1.

3. Reflectance (minimum reflectance, luminous reflectance)
A black vinyl tape is attached to the back surface of the display filter (the back surface of the electromagnetic wave shield layer forming surface) using a hand roller, and a spectrophotometer (U-4000 manufactured by Hitachi High-Technologies Corporation) is used to obtain a 5 ° regular reflectance. By measuring, the reflectance (minimum reflectance, luminous reflectance) of the display filter was measured. The lowest reflectance within the wavelength range of 400 nm to 700 nm is defined as the minimum reflectance, and the average reflectance within the wavelength range of 400 to 700 nm is defined as the luminous reflectance. The results are shown in Table 1.

4). Pencil Hardness of Hard Coat Layer Based on JIS-K-5400, the prepared hard coat layer was measured with a load of 500 g. Place a pencil on the hard coat layer, apply a load of 500 g from the top at an angle of 45 degrees, and scratch about 5 mm to check the degree of damage. The results are shown in Table 1.

  Since the display filter of the present invention is excellent in the visibility of the image displayed on the display, it is used as a display filter installed on the entire surface of a display such as a plasma display (PDP), a liquid crystal display, an organic EL display, and a field emission display. Useful.

110 transparent substrate,
120 mesh electromagnetic wave shielding layer,
131 hard coat layer,
132 high refractive index layer,
133 low refractive index layer,
141 Near-infrared absorbing layer,
142 Transparent adhesive layer.

Claims (8)

A display filter comprising a transparent substrate, a mesh-shaped electromagnetic wave shielding layer formed on the transparent substrate, and a first functional layer formed on the electromagnetic wave shielding layer,
The display filter, wherein the surface roughness Ra of the outermost layer on the electromagnetic wave shielding layer is 0.1 μm or less.   2. The display filter according to claim 1, wherein the surface roughness Ra of the outermost layer on the electromagnetic wave shielding layer is 0.01 to 0.08 μm.   The display filter according to claim 1, wherein the first functional layer is a hard coat layer.   The display filter according to claim 3, wherein the hard coat layer has a thickness of 5 to 35 μm.   The display according to claim 3 or 4, wherein the hard coat layer includes at least one silicone oil selected from the group consisting of dimethyl silicone oil, methylphenyl silicone oil, and methyl hydrogen silicone oil. Filter.   The display filter according to claim 3, wherein a low refractive index layer having a refractive index lower than that of the hard coat layer is provided on the hard coat layer.   A high refractive index layer having a higher refractive index than the hard coat layer and a low refractive index layer having a lower refractive index than the high refractive index layer are provided on the hard coat layer. Item 6. The display filter according to any one of Items 3 to 5.   A display comprising the display filter according to claim 1.

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