JP2010044128A - Filter for display - Google Patents

Abstract

【Task】
Provided is a filter for a display which is excellent in electromagnetic shielding performance and antireflection performance and at a low price.
[Solution]
On the substrate, a conductive layer made of a conductive mesh, a hard coat layer covering the conductive layer and having a refractive index of 1.50 to 2.00, and a refractive index of 1.30 to 1.40. A display filter comprising a low refractive index layer laminated in this order, wherein the hard coat layer contains an organic compound having a refractive index of 1.55 to 2.05.
[Selection] Figure 1

Description

  The present invention relates to a display filter having functions such as antireflection, light absorption, and electromagnetic wave shielding.

  A display such as a liquid crystal display (hereinafter sometimes referred to as LCD) or a plasma display (hereinafter sometimes referred to as PDP) is a display device capable of clear full color display. Such a display usually includes a front filter (hereinafter sometimes simply referred to as a filter) for the purpose of preventing reflection of external light, shielding electromagnetic waves generated from the display, and protecting the display. Arranged on the viewing side. In particular, PDPs generate strong electromagnetic waves due to their structures and operating principles, and are therefore concerned about their effects on the human body and other equipment. Filters with electromagnetic wave shielding and antireflection functions are usually used. ing.

  A general filter has an adhesive layer composed of an optical functional film having an antireflection function, a color adjustment function, a near-infrared shielding function, and the like, and a plastic film (electromagnetic wave shielding film) provided with a conductive layer (electromagnetic wave shielding layer). And are stacked.

  In recent years, as the price of displays has been reduced, the above filters have been forced to be also reduced in price. In contrast to the filter composed of two films as described above, it is possible to reduce the cost by using only one base material for the plastic film. As one configuration of such a filter composed of only one substrate, functional layers such as a hard coat layer and an antireflection layer are arranged so as to cover a conductive layer having a conductive mesh formed on the substrate. The mode to do is mentioned. The conductive mesh is preferably used because a conductive layer having a low resistance can be obtained at a relatively low cost compared to a metal thin film formed by sputtering or vacuum deposition.

  It has already been proposed to directly form a functional layer such as a hard coat layer or an antireflection layer on the above-described conductive layer having a conductive mesh (see Patent Document 1).

  As an antireflection film, a hard coat type 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 has been proposed (patent). Reference 2). Generally, metal oxide fine particles having a high refractive index are used for the high refractive index layer. In addition, it has also been proposed to increase the refractive index by incorporating the metal oxide fine particles into the hard coat layer (see Patent Documents 3 and 4). However, when a hard coat layer containing metal oxide fine particles and having a high refractive index is applied directly onto a conductive layer having a conductive mesh, the metal oxide is formed near the convex portion (thin line portion) of the conductive mesh. A new problem has arisen in that fine particles are localized and the transparency is deteriorated.

On the other hand, it has been proposed to increase the refractive index by using a specific organic compound in the high refractive index layer (see Patent Documents 5 to 9). However, these patent documents do not describe that a hard coat layer containing the above-described high refractive index organic compound is directly applied and formed on a conductive layer having a conductive mesh.
JP 2007-243158 A JP 2001-350001 A JP 2006-106715 A JP 2007-086455 A JP 2003-327624 A JP 2004-012592 A JP 2007-058101 A JP 2007-084815 A JP2007-29283A

  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 present invention is intended to achieve the above object, and the display filter of the present invention covers a conductive layer made of a conductive mesh on the base material and the conductive layer, and has a refractive index of 1. A display filter comprising a hard coat layer having a refractive index of 1.30 to 1.40 and a hard coat layer having a refractive index of 1.30 to 1.40, which are laminated in this order. It is a display filter containing an organic compound of 1.55 to 2.05 and containing 0 to less than 5% by mass of metal oxide fine particles based on all components of the hard coat layer.

  According to a preferred aspect of the display filter of the present invention, the organic compound having a refractive index of 1.55 to 2.05 is at least a halogen atom other than fluorine, a sulfur atom, a nitrogen atom, a phosphorus atom or an aromatic ring. An organic compound containing one.

  According to a preferred aspect of the display filter of the present invention, the hard coat layer contains 10 to 90% of the organic compound having a refractive index of 1.55 to 2.05 with respect to all components of the hard coat layer. It is contained by mass%.

  According to the preferable aspect of the filter for display of this invention, the thickness of the said electroconductive mesh is 6 micrometers or less.

  According to a preferred embodiment of the display filter of the present invention, the display filter has a light absorbing layer containing one or more dyes, pigments or colorants having a maximum absorption at 450 nm or more.

According to a preferred aspect of the display filter of the present invention, the mesh surface luminance value of the conductive mesh is 0.5 cd / m ² or less.

  ADVANTAGE OF THE INVENTION According to this invention, the filter for a display which was excellent in electromagnetic wave shielding, anti-reflective property, and transparency, and implement | achieved low price is obtained.

  Further, according to the present invention, in order to realize low cost, an antireflection layer including a high refractive index hard coat layer is disposed so as to directly cover a conductive layer made of a conductive mesh, thereby reducing the number of members. And a display filter having excellent transparency can be obtained.

  The display filter of the present invention includes a conductive layer having a conductive mesh on a substrate, a hard coat layer having a refractive index of 1.50 to 2.00 laminated so as to cover the conductive layer, A low refractive index layer having a refractive index of 1.30 to 1.40 laminated on the coat layer is provided. In this way, a high antireflection effect can be obtained, but in order to ensure a further excellent antireflection performance, the refractive index of the hard coat layer is preferably 1.55 or more, particularly 1.60 or more. Is preferred.

  As a general method for increasing the refractive index of the hard coat layer, metal oxide fine particles having a high refractive index, such as titanium oxide, zirconium oxide, zinc oxide, tin oxide, antimony oxide, cerium oxide, iron oxide, antimonic acid Examples of the hard coat layer include zinc, tin oxide-doped indium oxide (ITO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide, gallium-doped zinc oxide, and fluorine-doped tin oxide.

  However, when a functional layer such as a hard coat layer is applied directly on the conductive layer made of the conductive mesh in the present invention, a problem that a uniform coated surface is difficult to be formed due to the unevenness of the conductive mesh of the conductive layer, In particular, when a hard coat layer containing a relatively large amount of metal oxide fine particles having a small average primary particle size is applied directly on a conductive layer made of a conductive mesh, the convex portion (thin line portion) of the conductive mesh. A new problem arises in that metal oxide fine particles are localized in the vicinity and the transparency is deteriorated.

  Therefore, the above-mentioned problem has been solved by including an organic compound having a refractive index of 1.55 or more, which will be described later, as the hard coat layer in the present invention, substantially without containing metal oxide fine particles. More preferably, the metal oxide fine particles are not contained in the hard coat layer at all. However, even when the metal oxide fine particles are contained, the amount is less than 5% by mass with respect to all components of the hard coat layer. That is, the hard coat layer does not contain metal oxide fine particles at all, or when it contains metal oxide fine particles, its content is less than 5% by mass with respect to all components of the hard coat layer.

  In the present invention, in order to obtain a hard coat layer having a refractive index of 1.50 to 2.00, the hard coat layer contains an organic compound having a refractive index of 1.55 to 20.5. A more preferable refractive index of the organic compound is 1.60 to 1.70.

  As such an organic compound having a refractive index of 1.55 to 20.5, an organic compound containing at least one of a halogen atom other than fluorine, a sulfur atom, a nitrogen atom, a phosphorus atom or an aromatic ring is preferably used. For example, a high refractive index resin such as a resin containing a halogen atom other than fluorine, such as a bromine atom, a resin containing a sulfur atom, a resin containing a nitrogen atom, a resin containing a phosphorus atom, and a resin containing an aromatic ring such as a fluorene skeleton (Such a compound may be referred to as Compound A). These resins are only required to be transparent, and publicly known or commercially available resins can be used, and they can be used in combination with other resins.

  Examples of resins containing halogen atoms other than fluorine, such as bromine atoms, include brominated acrylic resins, brominated urethane resins, brominated polyester resins, brominated polyether resins, brominated epoxy resins, brominated spiroacetal resins, bromine A brominated polybutadiene resin, a brominated polythiol polyene resin, or the like can be used. As a raw material component of a resin containing a bromine atom, for example, a compound obtained by brominating the ortho-para position of the phenyl group of acrylate can be used. As this, for example, BR-42 manufactured by Daiichi Kogyo Seiyaku Co., Ltd. can be used as a commercial product. As other commercially available products, BR-42M, BR-30M and BR-31 manufactured by Daiichi Kogyo Seiyaku Co., Ltd., RDX51027 manufactured by Daicel-Cytec, Inc., and the like can be used, and two or more of these can be used in combination. May be.

  Examples of the resin containing a sulfur atom include S, S′-ethylenebis (thio (meth) acrylate), S, S ′-(thiodiethylene) bis (thio (meth) acrylate), S, S′—. [Thiobis (diethylene sulfide)] bis (thio (meth) acrylate), S, S ′-(oxydiethylene) bis (thio (meth) acrylate) and the like can be used. Here, thio (meth) acrylate refers to thiomethacrylate and thioacrylate.

  Among these, S, S′-ethylenebis (thiomethacrylate) and S, S ′-(thiodiethylene) bis (thiomethacrylate) are preferably used. S, S′-ethylenebis (thiomethacrylate) is a nonpolar organic solvent obtained by reacting 1,2-ethanedithiol and an alkali metal salt of methacryloyl chloride obtained by reacting 1,2-ethanedithiol with an alkali metal compound. It can manufacture by the method of making it react in. As S, S ′-(thiodiethylene) bis (thiomethacrylate), those marketed under the trade name S2EG manufactured by Nippon Shokubai Co., Ltd. can be used.

  Examples of the resin containing a sulfur atom and an aromatic ring include S, S ′-(thiodi-p-phenylene) bis (thio (meth) acrylate), S, S ′-[4,4′-thiobis ( 3-chlorobenzene)] bis (thio (meth) acrylate), S, S ′-[4,4′-thiobis (3,5-dichlorobenzene)] (thio (meth) acrylate), S, S ′-[4 , 4′-thiobis (3-bromobenzene)] (thio (meth) acrylate), S, S ′-[4,4′-thiobis (3,5-dibromobenzene)] (thio (meth) acrylate), S , S ′-[4,4′-thiobis (3-methylbenzene)] bis (thio (meth) acrylate), S, S ′-[4,4′-thiobis (3,5-dimethylbenzene)] (thio (Meth) acrylate) and S, S ′-[4,4′-h Or the like can be used bis (3-methyl benzene)] bis (thio (meth) acrylate).

  Among these, S, S ′-(thiodi-p-phenylene) bis (thiomethacrylate) (MPSMA manufactured by Sumitomo Seika Co., Ltd.) is preferably used, which is composed of 4,4′-thiodibenzenethiol and alkali. It can be produced by a method in which an alkali metal salt of 4,4′-thiodibenzenethiol obtained by reacting with a metal compound and methacryloyl chloride are reacted in a nonpolar organic solvent.

  Moreover, as resin containing an aromatic ring, the acrylic resin, epoxy resin, etc. which have 9,9-bisphenoxyfluorene frame | skeleton can be used, for example. For example, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene (NK ester A-BPEF) manufactured by Shin-Nakamura Chemical Co., Ltd., 9,9-bis (3-methyl-4-hydroxy manufactured by JFE Chemical Co., Ltd. Phenyl) fluorene (BCF), 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (BPEF), bisphenol fluorenediglycidyl ether (BPFG), bisphenoxyethanol fluorenediglycidyl ether (BPEFG) manufactured by Osaka Gas Chemical Company ), Bisphenoxyethanol full orange acrylate (BPEF-A), Ogsol PG series, Ogsol EG series, Ogsol EA series, Ogsol EA-F series and “Oncoat” (registered trademark) EX series manufactured by Nagase Sangyo Co., Ltd. It is possible.

  The hard coat layer in the present invention preferably has a high hardness in order to prevent scratches on the surface of the display filter, and the pencil hardness defined by JIS K 5600-5-4 (1999). Is preferably 1H or more, more preferably 2H or more. The upper limit value for hardness is preferably about 5H in consideration of reality.

  Therefore, the hard coat layer in the present invention comprises the above-described various high refractive index resins (compound A) having a refractive index of 1.55 or more, acrylic compounds, urethane compounds, melamine compounds, epoxy compounds and organic silicate compounds. It is preferable to use a mixture of the compound A and the compound B of a curable compound (such a compound may be referred to as a compound B).

  Among these, active energy ray-curable polyfunctional monomers and polyfunctional oligomers are preferable. Specifically, the active energy ray-curable functional group is preferably an unsaturated polymerizable functional group such as a (meth) acryloyl group, a vinyl group, a styryl group and an allyl group, and particularly preferably a (meth) acryloyl group.

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

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

  In addition to the above monomers, polyfunctional monomers and polyfunctional oligomers such as urethane (meth) acrylates, polyester (meth) acrylates, and epoxy (meth) acrylates 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 in the present invention is provided so as to cover the conductive layer having the 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. In order to suppress this, it is preferable to use the above polyfunctional oligomer, and particularly preferably the urethane acrylate oligomer.

  The urethane acrylate oligomer is obtained, for example, by 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, for example, ethylene glycol, propylene glycol, neopentyl glycol, tricyclodecane dimethylol, cyclohexane dimethylol, trimethylol propane, 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 polyethoxy glycol, polycarbonate polyol, pentaerythritol, A compound containing a trivalent or higher hydroxyl group such as trimethylolpropane, glycerin, pentaerythritol, sorbitol, sucrose, quadrol, etc .; bitol, sucrose, quadrol polybutadiene polyol, hydrogenated polybutadiene polyol, hydrogenated dimer diol pentaerythritol, etc. Polyether polyol obtained by modification with cyclic ether compounds such as ethylene oxide (EO), propylene oxide (PO), butylene oxide, tetrahydrofuran; polycaprolactone polyol obtained by modification with caprolactone; from dibasic acid and diol A polyester polyol obtained by modification with a polyester; and a mixture of two or more thereof.

  More specifically, EO-modified trimethylolpropane, PO-modified trimethylolpropane, tetrahydrofuran-modified trimethylolpropane, caprolactone-modified trimethylolpropane, EO-modified glycerol, 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, and tetramethyl. Xylylene diisocyanate, biphenylene diisocyanate, 1,5-naphthylene diisocyanate, o-tolidine diisocyanate, hexamethylene diisocyanate, 4,4'-methylenebiscyclohexyl isocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, 1,3- (isocyanatomethyl) ) Cyclohexane, polycondensates such as bullets and isocyanurates, and mixtures of two or more of these Can. 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 and 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 and 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 product can be used as the urethane acrylate compound. Examples of commercially available products include AT-600, UA-1011, UF-8001 and UF-8003 manufactured by Kyoeisha Chemical Co., Ltd., UV7550B and UV-7600B manufactured by Nippon Synthetic Chemical Co., Ltd., U- 2PPA, UA-NDP, etc., Daicel UCB, Inc., Ebecryl-270, Ebecryl-284, Ebecryl-264, Ebecryl-9260, etc., Kyoeisha Chemical Co., Ltd., UA-306H, UA-306T, and UA-306l UV-1700B, UV-6300B, UV-7600B, UV-7605B, UV-7640B and UV-7650B manufactured by Kagaku Co., Ltd., U-4HA, U-6HA, UA-100H, U-6LPA manufactured by Shin-Nakamura Chemical Co., Ltd. , U-15HA, UA-32P and U-324A, Lee cells UCB Co. Ebecryl-1290, etc. Ebecryl-1290K and Ebecryl-5129, as well as Negami Industries, Ltd. UN-3220HA, UN-3220HB, mention may be made of UN-3220HC and UN-3220HS like.

  The hard coat layer in the present invention contains the above-described organic compound having a refractive index of 1.55 to 2.05 (high refractive index compound A) in a range of 10 to 90% by mass with respect to all components of the hard coat layer. It is preferable to contain in 20-20 mass%, It is more preferable to contain in 30-70 mass% especially.

  Moreover, it is preferable to contain the above-mentioned curable compound (compound B) in the range of 10-90 mass% with respect to all the components of a hard-coat layer, and it is more preferable to contain in the range of 20-80 mass%. It is preferable to contain especially in 30-70 mass.

  By containing the high refractive index compound A and the curable compound B within the above range, a high refractive index and excellent hard coat performance can be realized.

  The hard coat layer in the present invention is formed so as to cover the conductive layer by curing the hard coat layer coated on the conductive layer having the conductive mesh. As a method for curing the hard coat layer, 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.

  Specific examples of the photopolymerization initiator include, for example, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4′-dichloro. Benzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methylbenzoyl formate, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, Carbonyl compounds such as 2,2-dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone, tetramethylthiuram monosulfide, teto Sulfur compounds such as lamethylthiuram 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.

  In the present invention, the amount of the photopolymerization initiator or thermal polymerization initiator used in the hard coat layer is suitably in the range of 0.01 to 10% by mass with respect to 100% by mass of the total amount of 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. Moreover, 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 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 (such as α rays, β rays, and γ rays). It is simple and preferably used. As an ultraviolet ray source, an ultraviolet fluorescent lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-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 operation under an inert gas, but it is not necessary to include a photopolymerization initiator or a photosensitizer in the hard coat layer coating layer. This is advantageous.

  As the heat necessary for the thermosetting used in the present invention, steam or an electric heater, an infrared heater, a far-infrared heater, or the like is used. The heat given by spraying on a base material or a coating film using a nozzle is mentioned. Especially, the heat by the air heated to the temperature of 200 degreeC or more is preferable, and also the heat by the nitrogen heated to the temperature of 200 degreeC or more is preferable at the point that the cure rate is quick.

  In the present invention, the method of curing the hard coat layer is preferably a method of curing by irradiating with ultraviolet rays in that high productivity can be obtained with a relatively simple apparatus.

  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 directly apply the hard coat layer on the conductive layer. Coating methods (coating methods) used for hard coat layer coating include dip coating, spin coating, slit die coating, gravure coating, reversal coating, rod coating, bar coating, spraying, and A known wet coating method such as a roll coating method can be used.

  The coating liquid used for coating the hard coat layer dissolves the above-mentioned compound A, compound B, polymerization initiator and various additives added as necessary, or adjusts the viscosity of the coating liquid. Therefore, it is preferable to contain an organic solvent. The organic solvent mentioned here does not include the liquid polymerizable monomer constituting the hard coat layer.

  The amount of the organic solvent contained in the hard coat layer coating solution is preferably in the range of 50 to 70% by weight and more preferably in the range of 10 to 60% by weight with respect to 100% by weight of the coating solution. 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 containing an organic solvent having a boiling point of 100 to 180 ° C. under atmospheric pressure, the compatibility of the above compound A and the above compound B is increased, and the transparency of the cured coating film is improved. Moreover, the coating property of the coating liquid is improved, and a coating film having a flat surface can be obtained. 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 organic solvents may be used alone or in combination. Of 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, and methyl ethyl ketone. These organic solvents 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, and the thickness of the conductive layer is 100%. On the other hand, the thickness of the hard coat layer is preferably 130% or more, and more preferably 150% or more. By increasing the thickness of the hard coat layer relative to the thickness of the conductive layer, the uneven surface of the conductive mesh can be sufficiently filled and made uniform.

  On the other hand, the upper limit of the thickness of the hard coat layer is preferably 12 μm or less, more preferably 10 μm or less, from the viewpoint of the coating speed, drying speed, curing speed, raw material cost, etc. of the hard coat layer. Moreover, it is preferable that the minimum of the thickness of a hard-coat layer is 1 micrometer or more, More preferably, it is 2 micrometers or more.

  When the thickness of the hard coat layer exceeds 12 μm, it is an intended object of the present invention due to a reduction in production efficiency and an increase in raw material costs due to a decrease in the coating speed, drying speed and curing speed of the hard coat layer. It may be difficult to achieve lower prices. 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 is difficult to obtain a uniform coated surface, it is difficult to cover the conductive layer having a conductive mesh, and transparency is lacking. 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, and the center line average roughness Ra value of the hard coat layer surface is preferably 100 nm or less. By making the Ra value on the surface of the hard coat layer 100 nm or less, the transparency becomes higher, and good coating properties when an ultrathin film low refractive index layer described later is formed on the hard coat layer. Can be secured. Therefore, the center line average roughness Ra value of the surface of the low refractive index layer coated and formed on the hard coat layer is also preferably 100 nm or less. The preferable lower limit of the Ra value of 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 JIS B 0601 (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.

  Next, the display filter of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view illustrating an intermediate state of a display filter according to the present invention, and FIG. 2 is a schematic cross-sectional view illustrating an example of the display filter of the present invention.

  1 and 2, 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 which is a conductive layer and to cover the thin wire portion 3a.

  In order to coat and form the hard coat layer 2 so that the hard coat layer 2 completely covers the conductive mesh 3, the thickness of the hard coat layer 2 (symbol N) is the thickness of the conductive mesh (symbol A). Is preferably 130% or more, more preferably 150% or more. Here, the thickness of the hard coat layer (symbol N) is formed by coating so that the hard coat layer 2 fills the opening 3b of the conductive mesh 3 and covers the thin wire portion 3a as described above. This is the sum of the thickness (reference A) of the fine wire portion of the conductive mesh 3 and the thickness (reference L) of the hard coat layer 2 on the fine wire portion 3a. As described above, the unevenness surface of the metal mesh 3 can be sufficiently filled and made uniform by increasing the thickness (symbol N) of the hard coat layer 2 relative to the thickness of the conductive mesh 3 (symbol A). .

  In this invention, it is preferable that the thickness (code | symbol A) of the electroconductive mesh 3 is 6 micrometers or less from a viewpoint of ensuring uniform coating property in the coating of the hard-coat layer 2. As shown in FIG. As described above, the thickness of the hard coat layer (symbol N) is preferably in the range of 1 to 12 μm. The thickness (symbol L) of the hard coat layer 2 existing on the thin wire portion 3a of the conductive mesh 3 is preferably in the range of 0.5 to 6 μm, more preferably in the range of 1 to 5 μm, and particularly preferably. Is in the range of 2-4 μm.

  The thicknesses of the conductive mesh 3 and the hard coat layer 2 described above can be obtained from an enlarged cross-sectional photograph of a display filter using a scanning electron microscope.

  Next, in FIG. 2, the display filter of the present invention has a low refractive index layer 7 having a refractive index of 1.30 to 1.40 on the hard coat layer 2. The refractive index of the low refractive index layer 7 is preferably 1.38 or less, and the lower limit of the refractive index of the low refractive index layer 7 is preferably about 1.20. Thereby, higher antireflection performance can be obtained.

  Since the low refractive index layer 7 is laminated on the hard coat layer 2 having a refractive index of 1.55 to 2.00, the display filter of the present invention is provided between the hard coat layer 2 and the low refractive index layer 7. Even without a high refractive index layer, high antireflection performance can be obtained. Therefore, in the present invention, the low refractive index layer 7 is preferably laminated directly on the hard coat layer 2, thereby improving the production efficiency.

Such a low refractive index layer is composed of a fluorine-containing polymer, a part of (meth) acrylic acid or an organic material such as a fully fluorinated alkyl ester and fluorine-containing silicone, or an inorganic material such as MgF ₂ , CaF ₂ and SiO _2. Can be composed of materials.

  Next, preferred embodiments of the low refractive index layer will be exemplified.

As one 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 phase method such as vacuum deposition, sputtering, or plasma CVD, or a sol solution containing SiO ₂ sol from SiO 2 ₍₂₎ A method for forming a gel film and the like.

  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. The siloxane polymer formed by combining with silica-based fine particles once forms a silanol compound by a known hydrolysis reaction with an acid catalyst in a solvent in the presence of the silica-based fine particles, and a known condensation reaction. Can be obtained by using

  As such a polyfunctional silane compound, it is preferable to include a polyfunctional fluorine-containing silane compound from the viewpoint of low refractive index and antifouling properties. For example, trifluoromethylmethoxysilane, trifluoromethylethoxysilane, Trifunctional fluorine such as fluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, heptadecafluorodecyltriethoxysilane, tridecafluorooctyltriethoxysilane And a bifunctional fluorine-containing silane compound such as a silane compound and heptadecafluorodecylmethyldimethoxysilane.

  Any of these compounds is preferably used, but trifluoromethylmethoxysilane, trifluoromethylethoxysilane, trifluoropropyltrimethoxysilane and trifluoropropyltriethoxysilane are preferably used from the viewpoint of surface hardness.

  Examples of such polyfunctional fluorine-free silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, methyltrimethoxysilane, methyl Triethoxysilane, hexyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyl Trifunctional silane such as trimethoxysilane, 3-chloropropyltrimethoxysilane, 3- (N, N-diglycidyl) aminopropyltrimethoxysilane, 3-glycidoxy propyltrimethoxysilane, etc. Compounds, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, methylvinyldimethoxysilane, methylvinyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-amino Propylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropylmethyldiethoxysilane, cyclohexylmethyldimethoxysilane, 3-methacryloxypropyldimethoxy Silane, bifunctional silane compounds such as octadecylmethyldimethoxysilane, tetrafunctional silanes such as tetramethoxysilane and tetraethoxysilane Things and the like.

  These are all preferably used, but from the viewpoint of surface hardness, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane and phenyltriethoxysilane Is preferably used.

  The silica-based fine particles are preferably silica-based fine particles having an average particle diameter of 1 nm to 200 nm, and particularly preferable silica-based fine particles are silica-based fine particles having an average particle diameter 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, when 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 such silica-based fine particles, those having a structure having a cavity inside are particularly preferably used for decreasing the refractive index.

  Examples of the silica-based fine particles having cavities inside used in the present invention include silica-based fine particles having cavities surrounded by an outer shell and porous silica-based fine particles having a large number of cavities. Used for. 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 cavity inside the silica-based fine particles, that is, the porosity of the silica-based fine particles is preferably 5% or more, more preferably Includes silica-based fine particles of 30% or more. The silica-based porosity can be measured using, for example, a mercury porosimeter (trade name: Bore Sizer 9320-PC2, manufactured by Shimadzu Corporation). The refractive index of the silica-based fine particles themselves is preferably 1.20 to 1.40, more preferably 1.20 to 1.35. As such silica-based fine particles, for example, silica-based fine particles having cavities inside the outer shell having pores disclosed in JP-A-2001-233611, and patent 3272111 are generally commercially available. And porous silica-based fine particles.

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

  In the present invention, the conductive layer is preferably formed on the substrate without an adhesive layer from the viewpoint of the coatability of the hard coat layer. Here, the adhesive layer means a layer composed of an adhesive material or an adhesive material.

  From the above viewpoint, as a method for forming a conductive mesh suitable for the conductive layer of the display filter of the present invention, (1) a method of etching a metal thin film, (2) a method of metal plating on a printed pattern, (3) Examples include a method using a photosensitive silver salt, (4) a method of developing after laminating a metal film on a printed pattern, and (5) a method of laser ablating a metal thin film. Next, each method will be described in detail.

(1) Method of etching a metal thin film This method forms a metal thin film on a substrate without using an adhesive layer or an adhesive layer, and the metal thin film is subjected to a photolithographic method or a screen printing method. This is a method of etching a metal thin film after making an etching resist pattern using it. The metal thin film can be formed by, for example, a known method such as sputtering, ion plating, vacuum deposition, or plating of metals such as silver, gold, palladium, copper, indium, tin, and alloys of silver and other metals. Can be used.

  In the photolithographic method described above, a photosensitive layer is formed on a metal thin film that is exposed to ultraviolet rays and the like, imagewise exposed using a photomask or the like, and developed to form a resist image. In this method, the thin film is etched to form a conductive mesh, and finally the resist is peeled off.

  The screen printing method is a method in which an etching resist ink is pattern-printed on the surface of a metal thin film, cured, a conductive mesh is formed by an etching process, and then the resist is peeled off.

  Examples of the etching method include a chemical etching method. Chemical etching is a method in which unnecessary conductors other than the conductor part protected by an etching resist are dissolved and removed with an etching solution. As the etchant, ferric chloride aqueous solution, cupric chloride aqueous solution, alkaline etchant and the like are used.

(2) Method of metal plating on printing pattern This method is a method of printing a mesh pattern with a catalyst ink or the like on a base material, and applying metal plating to the mesh pattern. One method is to print a mesh pattern using a catalyst ink made of a palladium colloid-containing paste, soak it in an electroless copper plating solution, apply electroless copper plating, and then apply electrolytic copper plating. Further, there is a method of forming a conductive mesh pattern by performing electrolytic plating of a Ni—Sn alloy.

(3) Method using photosensitive silver salt This method is a method in which a silver salt emulsion layer such as silver halide is coated on a substrate, followed by development after photomask exposure or laser exposure to form a silver mesh. It is. The formed silver mesh is preferably plated with a metal such as copper or nickel. This method is described in WO 2004/7810, JP-A 2004-221564, JP-A 2006-12935, and the like, and can be referred to.

(4) Method of developing after forming metal film on printed pattern In this method, the reverse of the mesh pattern is printed with a resin that can be peeled off on the substrate, and the metal thin film is formed on the printed pattern (1) And forming a metal mesh pattern by developing and peeling the resin and the metal film thereon. As the peelable resin, a resin or resist soluble in water, an organic solvent and an alkali can be used. This method is described in JP-A No. 2001-185834, JP-A No. 2001-332889, JP-A No. 2003-243881, JP-A No. 2006-140346, JP-A No. 2006-156642, and the like. You can refer to it.

(5) Method of laser ablating a metal thin film This method is a method of producing a metal mesh by a laser ablation method on a metal thin film formed on a substrate by the same method as the method of (1) above.

  Laser ablation means that when a solid surface that absorbs laser light is irradiated with laser light with a high energy density, the bonds between the irradiated parts are broken and evaporated, causing the solid surface of the irradiated part to break. It is a phenomenon that is cut away. By utilizing this phenomenon, the solid surface can be processed. Because laser light has high straightness and light condensing performance, it is possible to selectively process a fine area of about 3 times the wavelength of the laser light used for ablation. High processing accuracy is achieved by the laser ablation method. Can be obtained.

  As a laser used for such ablation, any laser having a wavelength that is absorbed by a metal can be used. For example, a gas laser, a semiconductor laser, an excimer laser, and a solid laser using a semiconductor laser as an excitation light source can be used. Further, a second harmonic light source (SHG), a third harmonic light source (THG), and a fourth harmonic light source (FHG) obtained by combining these solid-state lasers and a nonlinear optical crystal can be used.

  Among such solid lasers, it is preferable to use an ultraviolet laser having a wavelength of 254 nm to 533 nm from the viewpoint of not processing the substrate. Among them, a solid laser SHG (wavelength 533 nm) such as Nd: YAG (neodymium: yttrium, aluminum, garnet) is preferably used, and a solid laser THG (wavelength 355 nm) ultraviolet laser such as Nd: YAG is more preferably used. it can.

  As a laser oscillation method, any type of laser can be used. From the viewpoint of processing accuracy, a pulse laser is used, and more preferably, a Q-switch type pulse laser having a pulse width of ns or less is used. preferable.

  It is preferable to laser ablate the metal thin film and the metal oxide layer after further forming a 0.01 to 0.1 μm metal oxide layer on the metal thin film (viewing side). As the metal oxide, metal oxides such as copper, aluminum, nickel, iron, gold, silver, stainless steel, chromium, titanium, and tin can be used. However, copper oxide is used from the viewpoint of price and film stability. Preferably used. As a method for forming the metal oxide, a vacuum deposition method, a sputtering method, an ion plate method, a chemical vapor deposition method, an electroless method, an electrolytic plating method, or the like can be used.

  The conductive layer formed by the above-described method can have a thickness of 6 μm or less, and is suitable for directly forming the hard coat layer on the conductive layer. In particular, from the viewpoint of the coatability of the hard coat layer, the above methods (1) and (2) are preferably used.

  As described above, when the hard coat layer of the present invention is directly formed on a conductive mesh that is generally used in the past and has a relatively large thickness, a uniform coated surface is not formed, It has also been found that there is a new problem that the transparency of the hard coat layer is lowered. The inventors of the present invention tend to have poor permeability to a conductive mesh having a relatively large thickness due to the fluidity limit of the hard coat coating solution, and completely fill the unevenness of the conductive mesh. It was found that fine bubbles intervene and light bubbles cause light scattering and the transparency is impaired, and the smoothness of the surface is deteriorated due to the poor leveling property of the hard coat layer itself. The present inventors have found that this phenomenon is improved by using a conductive mesh having a relatively small thickness. That is, the above problem can be effectively improved by using a conductive mesh having a thickness of preferably 6 μm or less.

  The above-mentioned thickness of the conductive mesh is preferably smaller in order to improve the permeability and coating properties of the hard coat layer, and the thickness of the conductive mesh is more preferably 5.5 μm or less, and particularly 5 μm or less. It is preferable that Moreover, it is preferable that the minimum of the thickness of an electroconductive mesh is 0.5 micrometer or more from a viewpoint of electromagnetic wave shielding performance, More preferably, it is 1 micrometer or more.

  Next, the method for producing the conductive mesh (1) or (2) will be described in detail.

  In the conductive mesh method of (1) above, it is preferable to use a vapor deposition method as a method of forming a metal thin film on a substrate. 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. A combination of methods can be used. 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 multilayered material of one or a combination of two 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.

  Moreover, when using copper as a metal of a metal thin film, it is preferable to use a nickel thin film with a thickness of 5 to 100 nm between a base material and a copper thin film. This improves the adhesion between the substrate and the copper thin film.

  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. A preferable thickness of the metal thin film is 3.5 μm or less, and particularly preferably 3 μm or less. The lower limit of the thickness of the metal thin film is preferably 0.5 μm or more, more preferably 1 μm or more from the viewpoint of electromagnetic shielding performance.

  The metal thin film can be formed directly on the base material. However, when a plastic film is used as the base material, it is preferable to use a plastic film on which a primer layer such as an undercoat layer or an 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 portion is cured and an unexposed portion is dissolved by development, or a positive resist in which an exposed portion 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 preferably used.

  As the developer used for developing the photoresist layer, an alkali developer is preferably used. 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 and lithium hydroxide can be used. Generally, a weak alkaline aqueous solution containing about 0.1 to 3% by mass of the above 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 above 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. As the etchant, ferric chloride aqueous solution, cupric chloride aqueous solution, alkaline etchant and the like are used. 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 etching resist pattern on the metal thin film, the photolithography method is preferably used from the viewpoint that a finer mesh pattern can be obtained.

  The method (2) for producing a conductive mesh is a method for producing a conductive mesh by performing metal plating on a catalyst ink layer printed in a pattern on a substrate.

  In this manufacturing method, a patterned catalyst ink layer is formed on a substrate by printing in a mesh pattern with a catalyst ink containing noble metal ultrafine particles such as Pd, Au, Ag and Pt, which are electroless plating catalysts. In this method, a conductive mesh is produced by metal plating. One method is to print a mesh pattern using a catalyst ink made of a palladium colloid-containing paste, soak it in an electroless copper plating solution, apply electroless copper plating, and then apply electrolytic copper plating. Further, there is a method of forming a conductive mesh pattern by performing electrolytic plating of a Ni—Sn alloy.

  The catalyst ink layer can be printed directly on the base material. However, when a plastic film is used as the base material, it is preferable to previously provide a base layer on the plastic film. As the underlayer, an underlayer (primer layer) described in JP 2007-281290 A can be used.

  The conductive mesh produced by the above (1) and (2) has a low haze value as compared with a conventionally known conductive mesh, and as a result, high transparency can be ensured.

  The haze value of the conductive mesh film in which only the conductive mesh is provided on the plastic film substrate is preferably 5% or less, and particularly preferably 4% 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 (1) and (2) preferably used in the present invention has a haze value of 5% or less, and further a haze value of 4% or less. Can do. The lower limit of the haze value of the conductive mesh film is preferably about 1%. Here, the haze value can be measured according to JIS K 7136 (2000).

  By using a conductive mesh having a low haze value, the haze value after coating and forming a hard coat layer and a low refractive index layer on the conductive mesh can be kept low, and high transparency can be secured. Can do. The haze value after coating and forming the hard coat layer and the low refractive index layer on the conductive mesh is preferably 5% or less, more preferably 4% or less.

  In the present invention, the conductive mesh is preferably blackened. The blackening treatment can be performed by oxidation treatment or black printing. For the blackening process, for example, 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 viewing side, and it is further preferable to blacken both surfaces and both side surfaces of the conductive mesh.

  The blackening treatment is for high contrast when the display filter is actually attached to the display. To reduce the brightness of the conductive mesh itself, oxidation treatment, black printing, blackening plating, etc. To reduce the reflection luminance.

  In the configuration example to be described later, when the light absorption layer is on the panel side from the conductive mesh, external light such as illumination and sunlight is reflected by the conductive mesh before being absorbed by the light absorption layer. There is a problem that the brightness of the mesh is reflected and scattered as it is, and the contrast in the bright place is lowered.

  In the plasma display panel, the bright contrast is the brightness at which the white display of the plasma display panel, that is, the signal light from the panel has the highest brightness (white brightness), and the brightness at which the black display, that is, the signal light from the panel has the lowest brightness ( The black display image becomes white and deteriorates the tightening of black, especially when the black luminance in a bright environment is high.

  As for the white luminance, the reflection component of the external light is much smaller than the white signal light from the panel, and therefore, the white signal light transmitted through the filter can be the main component. That is, there is no particular problem because the white luminance is proportional to and depends on the transmittance of the filter.

  On the other hand, the black luminance is composed of an external light reflection component of the plasma display panel and an external light reflection component on the surface and interface of the display filter. Therefore, the black luminance is affected by scattering from the conductive mesh and reflected light (mainly diffuse reflection intensity). Often done. The external light reflection component from the plasma display panel is not a problem because it is absorbed by the light absorbing layer such as the color tone adjusting layer and the transmittance adjusting layer in the display filter, but the reflected light from the surface and interface of the display filter. The surface reflection intensity changes greatly depending on whether the light absorbing layer is laminated on the viewing side or the panel side than the conductive mesh having strong reflected light.

  When the light absorbing layer is closer to the viewing side than the conductive mesh, the reflected light from the outside of the conductive mesh is absorbed by the light absorbing layer, so that the contrast does not decrease. However, when the light absorbing layer is on the panel side from the conductive mesh, the reflected light from the outside of the conductive mesh is reflected as it is without being absorbed by the light absorbing layer, so that the black luminance is significantly increased. The displayed image is white and the blackness is worsened.

Therefore, the mesh surface luminance value of the black luminance measurement of the conductive mesh layer in the present invention is preferably not more than 0.5 cd / m ^2, it is preferred in particular 0.3 cd / m ² or less. When the mesh surface luminance value at the time of measuring the black luminance in a bright environment is 0.5 cd / m ² or less, black tightening is good and the black display image can be expressed more blackly. The lower limit value of the mesh surface luminance value is practically about 0.01.

  In order to efficiently produce the display filter of the present invention 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 lattice mesh pattern made up of squares, rectangles, rhombuses, etc., a mesh pattern made up of triangles and pentagons or more, a mesh pattern made up of circles and ellipses, and the above 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.

  The conductive mesh in the present invention suitably has a line width (W in FIG. 1) in the range of 3 to 30 μm, and the conductive mesh has a line pitch (P in FIG. 1) of 50 to A range of 500 μm is appropriate. In particular, the following high-definition mesh pattern is effective from the viewpoint of suppressing the occurrence of moire on the scanning lines of the display.

  Among the conductive meshes obtained by the production methods (1) and (2) described above, the conductive mesh obtained by the production method (1) above is from the viewpoint that a high-definition mesh pattern is formed. preferable. Here, the high-definition mesh pattern means that the grid-like mesh pattern has a line width of less than 10 μm and a line pitch of 160 μm or less. If it is the manufacturing method of the electroconductive mesh of said (1), Furthermore, the high-definition mesh whose line width is 3-8 micrometers and line pitch is 50-150 micrometers can also 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 (4 in FIG. 1 and FIG. 2) used for the display filter of the present invention, a plastic film is preferable. As the resin constituting the plastic film, 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, epoxy resins, Examples thereof include a polyimide resin, a polyetherimide resin, a polyamide resin, a polysulfone resin, a polyphenylene sulfide resin, and a polyether sulfone resin. Among these, polyester resins, polyolefin resins, and cellulose resins are preferable, and polyester resins are particularly preferably used.

  The thickness of the plastic film as the substrate is suitably in the range of 50 to 300 μm, but in the 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 of 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 such as an undercoat layer or an easy-adhesion layer for enhancing the adhesion (adhesion strength) with the conductive layer described above or a near-infrared shielding layer described later. Is preferred.

  Such a primer layer is generally known to use a water-soluble resin or a water-dispersible resin, and is preferably used in the present invention. As the water-soluble resin or water-dispersible resin, polyurethane resin, polyester resin, acrylic resin, polyvinyl alcohol resin, and the like are used. The primer layer preferably further contains a cross-linking agent. As a crosslinking agent, an isocyanate compound, an epoxy compound, an oxazoline compound, a melamine compound, etc. are mentioned, for example. 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. The primer layer may be formed after the plastic film is manufactured, or may be formed in-line when the plastic film is manufactured.

  Furthermore, the plastic film used as a substrate in the present invention is preferably a plastic film having an ultraviolet shielding function in order to prevent photodegradation of dyes and pigments contained in a light absorbing layer and a colored layer described later. . In general, since the ultraviolet shielding layer is provided closer to the viewer than the layer containing a dye or pigment, it is most preferable to use a plastic film containing an ultraviolet absorber. The ultraviolet absorber is preferably kneaded into the thermoplastic resin in the melting step before film formation.

  Examples of the ultraviolet absorber include salicylic acid compounds, benzophenone compounds, benzotriazole compounds, cyanoacrylate compounds, benzoxazinone compounds, and cyclic imino ester compounds. As the ultraviolet absorber, a benzoxazinone-based compound is preferably used particularly preferably from the viewpoint of ultraviolet shielding property and color tone at 380 nm to 390 nm. These compounds may be used alone or in combination of two or more. Moreover, combined use of stabilizers, such as HALS (hindered amine light stabilizer) and antioxidant, is a more preferable aspect.

  It is preferable that content of a ultraviolet absorber is 0.1-5 mass%, More preferably, it is 0.2-3 mass%. As for the ultraviolet shielding property, it is preferable that the transmittance at a wavelength of 380 nm or less is 3% or less, so that a dye or a pigment can be protected from ultraviolet rays.

  The thickness of the substrate used in the present invention is preferably 90 to 250 μm, and a substrate having transparency with a total light transmittance of 70% or more measured according to JIS K 7136 (2000) is preferable. .

  As described above, the display filter of the present invention is preferably provided with a light absorbing layer having functions such as a near infrared shielding function, a color tone adjusting function, and a visible light transmittance adjusting function.

  The near-infrared shielding layer having a near-infrared shielding function is preferably adjusted so that the maximum 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 on 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. The embodiment to be used is preferably used. Near infrared absorbers include organic near infrared absorbers such as phthalocyanine compounds, anthraquinone compounds, dithiol compounds and diimonium compounds, titanium oxide, zinc oxide, indium oxide, tin oxide, zinc sulfide and cesium-containing tungsten oxide. An inorganic near-infrared absorber such as can be used.

  When the above-described near-infrared shielding layer is newly provided, the near-infrared shielding layer 5 is provided between the base material and the conductive mesh or on the opposite surface of the base material 4 from the conductive mesh 3 as shown in FIG. Can be provided by coating. When providing a near-infrared shielding function on the viewer side from the base material, it is preferable to use an inorganic near-infrared absorber 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, in order to improve the whiteness, it is preferable to contain a dye having an absorption maximum at a wavelength of 480 to 500 nm. 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 described later, 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 electrically 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 attaching to a display or a highly rigid substrate. FIG. 2 illustrates the adhesive layer 6.

  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 of the thickness of the adhesive layer is preferably 3000 μm or less in consideration of the coating suitability of the adhesive layer.

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

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

(A) Adhesive layer / Near-infrared shielding layer / Substrate / Conductive mesh / High refractive index hard coat layer / Low refractive index layer (b) Adhesive layer / Substrate / Near-infrared shielding layer / Conductive mesh / High refractive index Hard coat layer / low refractive index layer (c) Adhesive layer (having near-infrared shielding function) / base material / conductive mesh / high refractive index hard coat layer / low refractive index layer (d) adhesive layer / base material / conductive Mesh / high refractive index hard coat layer (having a near-infrared shielding function) / low refractive index layer The above-described near-infrared shielding layers (a) and (b) have a color tone adjusting function and / or a visible light transmittance adjusting function. Similarly, the adhesive layer (c) and the hard coat layer (d) described above may have a color tone adjusting function and / or a visible light transmittance adjusting function.

  The base materials (a) and (c) are preferably those having an ultraviolet shielding function, and the near-infrared absorbers (b) and (d) are excellent in light resistance. preferable.

  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.

  Hereinafter, the display filter of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Evaluation methods)
(1) Visibility When placing a photo under the opposite side of the hard coat layer of the display filter and viewing the photo through the display filter from the hard coat layer side, check whether the photo image is clearly visible. Evaluation based on the 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.
A and B were accepted and C and D were rejected.

(2) Refractive index Using a prism coupler (manufactured by Metricon Co., Ltd.) for a coating film having a film thickness of 1.5 μm produced on a silicon wafer using coating materials for the hard coat layer and the low refractive index layer, The refractive index in the vertical direction was measured with respect to the film surface at 633 nm (using a He—Ne laser) at a temperature of 20 ° C.

(3) Centerline average roughness Ra (nm)
The center line average roughness Ra of the surface of the low refractive index layer of the display filter is determined by
Based on the method of 0601-1982, the center line average roughness Ra was measured using a surface roughness measuring instrument SE-3400 (manufactured by Kosaka Laboratory Ltd.). Ra is a parameter defined as Ra by a surface roughness measuring instrument SE-3400 (manufactured by Kosaka Laboratory Ltd.), and the measurement conditions are as follows.
<Measurement conditions>
・ 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: 8 mm.

(4) Pencil hardness The pencil hardness of the surface on which the hard coat layer was applied and formed was measured according to JIS K 5600-5-4 (1999) using HEIDON (manufactured by Shinto Kagaku Co., Ltd.). A sample having a hardness of 1H or more was evaluated as pass ○, and a sample having a pencil hardness of less than 1H was determined as reject X.

(5) Luminous transmittance and luminous reflectance (antireflection)
About the filter sample for displays, the transmittance | permeability with respect to the incident light from a panel side is measured in the range of wavelength 300-1300nm using spectrophotometer UV3150PC (made by Shimadzu Corporation), and visible wavelength region (380-780 nm) ) Is obtained.

  Further, as described below, the reflectance (single-sided reflection) is calculated in the wavelength range of 380 to 780 nm at an incident angle of 5 degrees from the measurement surface, and the luminous reflectance (the reflection defined in JIS Z 8701-1999). Is determined.

In order to avoid the influence of reflection from the non-measurement surface side of the filter sample for display, the water-resistant sandpaper No. 320 to 400 so that the 60 ° C. gloss (JIS Z 8741) is 10 or less on the non-measurement surface side. After uniformly roughening the surface with a black paint, it is colored by applying a black paint so that the visible light transmittance is 5% or less, the spectral solid angle is measured with a spectrophotometer, and the luminous reflection is based on JIS Z 8701. The rate (single-sided light reflection) is calculated. The calculation formula is as follows.
T = K × ∫ [S (λ) × y (λ) × R (λ)] dλ (however, the integration interval is 380 to 780 nm)
T: single-sided light reflectance (%)
S (λ): Standard light distribution used for color display y (λ): Color matching function R (λ) in XYZ display system: Spectral solid angle reflectance Antireflection properties were evaluated according to the following criteria. ○ was accepted and x was rejected.
◯: When the luminous reflectance is 1% or less ×: When the luminous reflectance exceeds 1%

(6) Haze value The haze value of a polytrimethylene terephthalate (PET) film in which a conductive layer is formed, and a hard coat layer and a low refractive index layer laminated on the conductive layer, was measured according to JIS K 7136 (2000). Based on the year, measurement was performed using a haze meter NDH2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). Here, the measurement was performed by making light incident from the conductive layer side or the low refractive index layer side.

(7) The thickness of the conductive mesh (symbol A) and the thickness of the hard coat layer on the thin line portion of the conductive mesh (symbol L)
Three enlarged cross-sectional photographs randomly selected from the sample were taken with a field emission scanning electron microscope JSM-6700F (manufactured by JEOL Ltd., acceleration voltage 10 kV, observation magnification 20000 times), and the enlarged cross-sectional photograph The respective thicknesses were obtained and averaged.

(8) Surface brightness of conductive mesh (black brightness in a light environment)
Filter sample for display is on the viewing side (conductive layer side or hard coat layer, low refraction) on plasma TV (TH-42PX500, manufactured by Matsushita Electric Industrial Co., Ltd., but with genuine filter removed). It was installed so that the surface opposite to the rate layer side) directly faces the plasma display panel. The panel's vertical illuminance and horizontal illuminance are set to be 100 lux and 70 lux, respectively. The light source is a high color rendering AAA type fluorescent lamp (Toshiba Lighting & Technology Co., Ltd. “Neoline Rapid Master” (registered trademark) FLR40S-N -EDL / M color evaluation fluorescent lamp). Align the lens and panel horizontally to a position where the distance from the lens surface of the luminance meter CS1000 (manufactured by Konica Minolta Co., Ltd.) to the outermost surface on the viewing side (low refractive index layer, etc.) of the filter is 1.3 m, and display the panel black The luminance at the time was measured.

  In this case, a black vinyl tape (manufactured by Nitto Denko Corporation) was pasted on the surface of the filter for display opposite to the viewing side of the filter in order to suppress the influence of the external light reflection component from the panel to almost zero. This was carried out in such a manner that external light reflection components from the filter surface and filter interface (conductive mesh layer) could be measured remarkably.

Other measurement conditions were based on the color plasma display module measurement method. The mesh surface brightness was evaluated according to the following criteria. ○ was accepted and x was rejected.
○: When the black luminance in a light environment is 0.5 cd / m ² or less ×: When the black luminance in a light environment exceeds 0.5 cd / m ²

Example 1
<Formation of conductive layer 1>
A nickel film having a thickness of 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 2.5 μm is further vacuum-deposited thereon. Next, an alkali development negative resist film is 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 was peeled off by treatment with a 3% by mass aqueous sodium hydroxide solution, and the thickness was 2.5 μm, the line width was 7 μm, and the line pitch. A conductive layer 1 made of a conductive mesh of 130 μm was formed.

  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 1 produced in this manner was 1.9%.

<Coating of high refractive index hard coat layer 1>
(Composition of high refractive index hard coat paint 1)
・ 50 parts by mass of fluorene acrylic resin (NK ester A-BPEF manufactured by Shin-Nakamura Chemical Co., Ltd.) ・ 25 parts by mass of urethane acrylate A (UN-3220HA manufactured by Negami Industrial Co., Ltd.) ・ Urethane acrylate B (Shin-Nakamura Chemical Co., Ltd.) ) U4HA) 25 parts by mass, 100 parts by mass of methyl ethyl ketone, 100 parts by mass of toluene, 4 parts by mass of “Irgacure” (registered trademark) 184 (manufactured by Ciba Specialty Chemicals Co., Ltd.) Thorough mixing was performed to obtain a high refractive index hard coat paint 1 having a refractive index of 1.61. Next, the high refractive index hard coat paint 1 is applied on the conductive layer 1 formed as described above with a micro gravure coater, dried at a temperature of 80 ° C. for 1 minute, and then a high pressure mercury UV lamp (120 W / cm 2). ) Was irradiated and cured with an integrated light amount of 400 mj / cm ² to form a high refractive index hard coat layer 1. 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.

<Coating of low refractive index layer>
95.2 parts by mass of methyltrimethoxysilane and 65.4 parts by mass of trifluoropropyltrimethoxysilane were dissolved in 300 parts by mass of propylene glycol monomethyl ether and 100 parts by mass of isopropanol to obtain a solution. In this solution, a silica fine particle dispersion having a cavity inside the outer shell having a number average particle diameter of 50 nm (isopropanol dispersion type, solid content concentration 20.5%, manufactured by Catalyst Kasei Kogyo Co., Ltd.) 297.9 parts by mass, water 54 masses And 1.8 parts by mass of formic acid were added dropwise with stirring so that the reaction temperature did not exceed 30 ° C. After the dropwise addition, the obtained solution was heated at a bath temperature of 40 ° C. for 2 hours, and then the solution was heated at a bath temperature of 85 ° C. for 2 hours, the internal temperature was raised to 80 ° C. and heated for 1.5 hours. Until the polymer solution was obtained.

  In the obtained polymer solution, 4.8 parts by mass of aluminum tris (acetyl acetate) (trade name: aluminum chelate A (W), manufactured by Kawaken Fine Chemical Co., Ltd.) as an aluminum-based curing agent is added to 125 parts by mass of methanol. The dissolved one was added, and further 1500 parts by mass of isopropanol and 250 parts by mass of propylene glycol monomethyl ether were added and stirred at room temperature for 2 hours to prepare a low refractive index paint having a refractive index of 1.36. The low refractive index paint obtained above was coated on the hard coat layer with a micro gravure coater, dried and cured at a temperature of 130 ° C. for 1 minute, and a low refractive index layer was formed. The thickness of the low refractive index layer was about 100 nm.

<Coating of near-infrared shielding layer>
Near-infrared shielding paint having both an orange light shielding function on the PET film surface opposite to the conductive layer of the PET film having the conductive layer prepared above (phthalocyanine dye and diimonium dye as near-infrared absorbing dye, and orange A coating material obtained by mixing a tetraazaporphyrin-based pigment as a light-absorbing pigment with an acrylic resin) is applied with a die coater to a dry thickness of 10 μm, dried and cured at a temperature of 130 ° C. for 1 minute, and near-infrared A barrier layer was formed.

<Lamination of adhesive layer>
On a separate film, an acrylic transparent adhesive (SK Dyne 1811L manufactured by Soken Chemical Co., Ltd.) containing a color correction dye was applied with a die coater so that the dry thickness was about 25 μm, and the temperature was 100 ° C. And then dried and cured for 1 minute, and then the adhesive surface was roll-bonded onto the near-infrared shielding layer of each sample for each filter prepared above to obtain each display filter. The final filter transmittance was adjusted to 30 to 40% depending on the content of the color correction pigment and the coating thickness.

(Example 2)
A display filter was produced in the same manner as in Example 1 except that the high refractive index hard coat layer 1 was replaced with the following high refractive index hard coat layer 2.

<Coating of high refractive index hard coat layer 2>
(Composition of high refractive index hard coat paint 2)
・ Sulfur-based acrylic resin (S2EG manufactured by Nippon Shokubai Co., Ltd.) 50 parts by mass • 25 parts by mass of dipentaerythritol hexaacrylate (DPHA manufactured by Nippon Kayaku Co., Ltd.) • Urethane acrylate A (UN-3220HA manufactured by Negami Kogyo Co., Ltd.) ) 25 parts by mass, 100 parts by mass of methyl ethyl ketone, 4 parts by mass of toluene, 4 parts by mass of “Irgacure” (registered trademark) 184 (manufactured by Ciba Specialty Chemicals Co., Ltd.) A high refractive index hard coat coating material 2 having a refractive index of 1.61 was obtained.

Then a high refractive index hard coating composition 2 was coated with a micro gravure coater on the conductive layer, after drying 1 minute at a temperature of 80 ° C., integrating the UV high-pressure mercury UV lamp (120 W / cm) light quantity 400 mj / cm ² Was irradiated and cured to form a high refractive index hard coat layer 2. 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.

(Example 3)
A display filter was produced in the same manner as in Example 1 except that the high refractive index hard coat layer 1 was replaced with the following high refractive index hard coat layer 3.

<Coating of high refractive index hard coat layer 3>
(Composition of high refractive index hard coat paint 3)
Bromine acrylic resin (Daiichi Kogyo Seiyaku Co., Ltd. BR-42) 60 parts by mass Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd. DPHA) 20 parts by mass Urethane acrylate A (Negami Kogyo Co., Ltd.) (UN-3220HA) 20 parts by mass, 100 parts by mass of methyl ethyl ketone, 100 parts by mass of toluene, 4 parts by mass of “Irgacure” (registered trademark) 184 (manufactured by Ciba Specialty Chemicals Co., Ltd.) To obtain a high refractive index hard coat paint 3 having a refractive index of 1.60. Next, a high refractive index hard coat paint 3 is applied on the conductive layer with a micro gravure coater, dried at a temperature of 80 ° C. for 1 minute, and then an ultraviolet ray from a high pressure mercury UV lamp (120 W / cm) is applied to an integrated light quantity of 400 mj / cm. ² and cured to form a high refractive index hard coat layer 3. 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.

Example 4
A display filter was produced in the same manner as in Example 1 except that the conductive layer 1 was replaced with the conductive layer 2 described below.

<Formation of conductive layer 2>
A grid mesh pattern is gravure-printed on a 100 μm-thick PET film (“Lumirror” (registered trademark) manufactured by Toray Industries, Inc.) using a catalyst ink (palladium colloid-containing paste), and this is placed in an electroless copper plating solution. Immersion, electroless copper plating, followed by electrolytic copper plating, and further Ni-Sn alloy electrolytic plating, comprising a conductive mesh having a thickness of 5.5 μm, a line width of 20 μm, and a line pitch of 300 μm. Conductive layer 2 was formed. The haze value of the PET film having the conductive layer 2 produced in this manner was 2.8%.

(Comparative Example 1)
A display filter was produced in the same manner as in Example 4 except that the high refractive index hard coat layer 1 was replaced with the following high refractive index hard coat layer 4.

<Coating of high refractive index hard coat layer 4>
A high refractive index hard coat paint “TYS63-004” with a refractive index of 1.63 manufactured by Toyo Ink Co., Ltd. (antimony oxide fine particles having an average primary particle size of about 70 nm is formed on the conductive layer. Coated with a micro gravure coater and dried for 1 minute at a temperature of 80 ° C., followed by a high-pressure mercury UV lamp (120 W / cm) Were irradiated with an integrated light amount of 400 mj / cm ² and cured to form a high refractive index hard coat layer 4. 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.

(Comparative Example 2)
A display filter was obtained in the same manner as in Example 4 except that the conductive layer 2 was replaced with the following conductive layer 3 and the high refractive index hard coat layer 1 was replaced with the following high refractive index hard coat layer 5. Produced.

<Formation of conductive layer 3>
Two-component adhesive for dry lamination (Toyo Morton Co., Ltd. main agent AD-76P1 / curing agent CAT-) on a PET film with a thickness of 100 μm ("Lumirror" (registered trademark) manufactured by Toray Industries, Inc.) 10L) to obtain a copper foil laminate film.

  Next, an alkali developing 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%.

<Coating of high refractive index hard coat layer 5>
A high refractive index hard coat paint “SEICA BEAM PET-15NS (AS41K)” having a refractive index of 1.54 manufactured by Dainichi Seika Kogyo Co., Ltd. on the conductive layer (antimony-doped tin oxide having an average primary particle size of about 80 nm ( ATO) fine particles were coated with a micro gravure coater (containing 20% by mass of the total solid content (the total amount of non-volatile components excluding organic solvents) forming the hard coat layer), dried at 80 ° C. for 1 minute, The high refractive index hard coat layer 5 was formed by irradiating and curing ultraviolet rays from a high pressure mercury UV lamp (120 W / cm) with an integrated light amount of 400 mj / cm ² . 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.

  From the results of Table 1, the examples of the present invention have good smoothness and high transparency (low in the high refractive index hard coat layer not containing metal oxide fine particles coated on a conductive mesh having a thickness of 6 μm or less. It can be seen that the haze value of the refractive index layer surface is small and the Ra value is small), good visibility, good pencil hardness, and excellent antireflection properties are obtained.

  On the other hand, Comparative Examples 1 and 2 using a high refractive index hard coat layer containing a large amount of metal oxide particles have agglomeration of metal oxide fine particles and a decrease in transparency (the haze value of the low refractive index layer surface is low). Large and the Ra value is large), the visibility is lowered, and sufficient antireflection properties cannot be obtained.

FIG. 1 is a schematic cross-sectional view illustrating an intermediate state of a display filter of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of the display filter of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display filter 2 Hard coat layer 3 Conductive mesh 4 Base material 5 Near-infrared shielding layer 6 Adhesive layer 7 Low refractive index layer A Thickness of conductive mesh L Thickness of hard coat layer on thin wire portion N Hard coat layer Thickness P Conductive mesh line pitch W Conductive mesh line width

Claims (6)

  On the substrate, a conductive layer made of a conductive mesh, a hard coat layer covering the conductive layer and having a refractive index of 1.50 to 2.00, and a refractive index of 1.30 to 1.40. A display filter comprising a low refractive index layer laminated in this order, wherein the hard coat layer contains an organic compound having a refractive index of 1.55 to 2.05, and is based on all components of the hard coat layer. And 0 to less than 5% by mass of metal oxide fine particles.   The display filter according to claim 1, wherein the organic compound is an organic compound containing at least one of a halogen atom other than fluorine, a sulfur atom, a nitrogen atom, a phosphorus atom, or an aromatic ring.   The display filter according to claim 1 or 2, wherein the hard coat layer contains 10 to 90 mass% of an organic compound with respect to all components of the hard coat layer.   The display filter according to claim 1, wherein the conductive mesh has a thickness of 6 μm or less.   The display filter according to claim 1, further comprising a light absorption layer containing one or more dyes, pigments, or colorants having a maximum absorption at 450 nm or more. The display filter according to claim 1, wherein the conductive mesh has a mesh surface luminance value of 0.5 cd / m ² or less.

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