JP2007328299A - Filter for display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filter for a display panel with excellent productivity that is continuously manufactured while maintaining preferable conductivity. <P>SOLUTION: The filter for a display panel comprises: an electromagnetic wave shield material 2; and at least one layer of functional coating layer 3, 4, on a base film 1. A conductive member 5 penetrating the filter is provided to a plurality of places along at least a pair of side rims 11 opposing to each other of the filter, preferably along two pairs of side rims opposing to each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display panel filter (hereinafter, also simply referred to as “filter”), and more particularly to a display panel filter that is used in the front of a display panel such as a plasma display panel (PDP).

  Conventionally, a front filter for a plasma display panel generally has a structure in which a plurality of functional films having functions such as electromagnetic wave shielding, antireflection, color tone adjustment, and infrared shielding are bonded together. Recently, a so-called monolithic filter has been developed which improves productivity and cost by securing and consolidating various functions on a single base film.

In order to incorporate such a front filter into a PDP device or the like to exhibit good electromagnetic shielding properties, it is necessary to achieve uniform conduction between the electromagnetic shielding material in the front filter and the conductive surface of the PDP housing. There is. For this reason, conventionally, an optical film that is slightly smaller than the surface having the electromagnetic wave shielding function is used, and this is attached or coated on the electromagnetic wave shielding surface while leaving the electrode portion around, and from the surrounding electrode portion. Electromagnetic shielding is performed by taking conduction (see, for example, Patent Document 1).
JP 2003-66854 A (Claims, [FIG. 2], etc.)

  Since the above-described single filter does not require a bonding step, there is an advantage that continuous production can be easily performed. However, the method of ensuring continuity by leaving the electrode portion over the entire circumference of the filter as described above has a problem in that productivity is lowered because continuous processing cannot be performed in the manufacturing process. In this case, it is possible to use single-wafer coating technology that performs coating one by one, but it is difficult to obtain the same accuracy as the existing single-wafer bonding technology, and the productivity is also significantly reduced. Was supposed to be.

  Therefore, an object of the present invention is to solve the above problems by improving the structure of a single filter, and to ensure good conductivity, while being able to continuously manufacture the display panel filter with excellent productivity. Is to provide.

  As a result of intensive studies, the present inventors have once formed a functional coating layer on the electromagnetic wave shielding material, and then can conduct the post-processing to establish electrical continuity with the electromagnetic wave shielding material, thereby making it possible to solve the above problem. As a result, the present invention has been completed.

That is, the display panel filter of the present invention is a display panel filter comprising an electromagnetic wave shielding material and at least one functional coating layer on a base film.
A conductive member formed by penetrating the filter is provided at a plurality of locations along at least a pair of opposite edge portions of the filter.

  In the filter of the present invention, the functional coating layer preferably includes at least one non-conductive layer. Moreover, in this invention, the electroconductive member which penetrates a filter can also be provided in multiple places along two opposing pairs of edge parts of a filter. Furthermore, it is preferable that the conductive members are provided at substantially equal intervals along the edge portion.

  According to the present invention, because of the above configuration, the display panel excellent in productivity that can be continuously manufactured while ensuring good conduction with the electromagnetic wave shielding material through the conductive member. It became possible to realize the filter.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
FIG. 1 shows (a) a cross-sectional view in the width direction (AA line), (b) a plan view, and (c) a longitudinal cross-sectional view (line BB) of an example of the display panel filter of the present invention. . As shown in the figure, the filter 10 of the present invention includes an electromagnetic wave shielding material 2 and at least one functional coating layer 3, 4 in the illustrated example on a base film 1.

  Moreover, in this invention, the electroconductive member 5 which penetrates a filter is provided in several places along a pair of edge part 11 which the filter 10 opposes so that it may show in figure. That is, in the present invention, after the functional coating layers 3 and 4 are once formed on the edge portion 11 in the width direction (or longitudinal direction) of the electromagnetic wave shielding material 2 where it is difficult to secure an exposed portion in the continuous manufacturing process, By arranging the conductive member 5 penetrating the entire filter by processing and securing the conduction with the electromagnetic wave shielding material 2 through the conductive member 5, a filter that can be manufactured by a continuous manufacturing process, It is now possible to do. Therefore, the present invention is more useful when the functional coating layer includes at least one non-conductive layer.

  The disposition conditions of the conductive member 5 are not particularly limited and can be appropriately determined as desired, but in order to ensure good conduction as a filter, the conductive member 5 is It is preferable to provide it uniformly over the entire edge, and it is particularly preferable to provide it at substantially equal intervals along the edge. Further, for example, as shown in FIG. 2A, the conductive members 5 can be alternately provided in two rows, and in this case, the electromagnetic wave shielding property can be further improved.

  In the example shown in FIGS. 1 and 2A, the conductive member 5 is provided along a pair of opposing edge portions of the filter 10, but in the present invention, as shown in FIG. Conductive members 5 may be provided at a plurality of locations along two opposing edge portions of the filter 10, that is, over the entire circumference of the filter 10 to ensure conduction. As shown in FIG. 1 and the like, it is not necessary when the electromagnetic shielding material 2 is exposed at a pair of edge portions. For example, as shown in FIG. 4 is formed so as to completely cover the electromagnetic wave shielding material 2, it is effective to provide the conductive member 5 over the entire circumference of the filter 10 to achieve conduction with the electromagnetic wave shielding material 2.

  As the conductive member 5 used in the present invention, any member may be used as long as it has conductivity and can be disposed in a state of passing through the filter. For example, as shown in FIGS. 1 and 2, a wire 5 having a length corresponding to the thickness of the filter and made of metal fiber, conductive resin fiber or the like is used by being placed, and FIGS. As shown in FIG. 4, a U-shaped metal fitting 5A can be driven using a stapler to form a conductive member, or the eyelet 5B can be driven in as shown in FIGS. . Furthermore, as shown in FIG. 5, it is also possible to use a conductive yarn 5C made of conductive resin fibers or the like and sew the edge portion with an industrial sewing machine or the like to form a conductive member. Accordingly, the size, shape, arrangement pitch, and the like of the conductive member 5 can be appropriately selected according to the type of the conductive member 5 and the like as long as the conductive member 5 can be reliably connected. It is not a thing.

  In the filter of the present invention, it is important only to conduct with the electromagnetic wave shielding material through the conductive member 5 penetrating the filter, and the specific layer configuration and material are not particularly limited. For example, it can be configured as follows. For example, the layer structure in which the base film 1 and the electromagnetic wave shielding material 2 are laminated in the reverse order in FIG.

  Examples of the base film 1 include polyester (polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.), polymethyl methacrylate (PMMA), acrylic, polycarbonate (PC), polystyrene, cellulose triacetate (TAC), and polyvinyl. Transparent films such as alcohol, polyvinyl chloride, polyvinylidene chloride, polyethylene, ethylene-vinyl acetate copolymer, polyvinyl butyral, metal ion crosslinked ethylene-methacrylic acid copolymer, polyurethane, cellophane, etc. can be used. From the viewpoints of high resistance to load (heat, solvent, bending, etc.) and particularly high transparency, PET, PC, and PMMA films are preferable, and PET is particularly preferable because of excellent workability. Here, “transparent” means transparent to visible light.

  Moreover, although the thickness of the base film 1 changes also with the use etc. of a filter, it is 1 micrometer-10 mm normally, Preferably it is 1 micrometer-5 mm, More preferably, it is about 25-250 micrometers.

  Examples of the electromagnetic wave shielding material 2 include a mesh (lattice) conductive layer and coating layer, a layer obtained by a vapor deposition method (a transparent conductive thin film of a metal oxide (ITO), etc.), a metal oxide such as ITO. Alternating laminates of dielectric layers and metal layers such as Ag can be used, and the surface resistance of the obtained filter is generally 10Ω / □ or less, preferably in the range of 0.001 to 5Ω / □, particularly Select to be in the range of 0.005-5Ω / □.

  Among them, the mesh-like conductive layer is formed by etching a conductive film such as a metal fiber and / or metal-coated organic fiber formed into a net (conductive mesh) or a metal foil using a photolithographic technique. And an opening (etching mesh) provided on the transparent film, and a conductive ink printed on a transparent film (conductive printing mesh).

  As the mesh in the conductive mesh, those having a wire diameter of 1 μm to 1 mm and an aperture ratio of 40 to 95% made of metal fibers and / or metal-coated organic fibers are preferable from the viewpoint of improving light transmittance and preventing the moire phenomenon. When the wire diameter exceeds 1 mm in the conductive mesh, the electromagnetic wave shielding property is improved, but the aperture ratio is lowered, and these cannot be achieved at the same time. On the other hand, if the wire diameter is less than 1 μm, the strength as a mesh is lowered, and handling becomes difficult. Further, when the aperture ratio exceeds 95%, it is difficult to maintain the shape as a mesh. When the aperture ratio is less than 40%, the light transmittance decreases, and the amount of light from the display decreases. A more preferable wire diameter is 10 to 500 μm, and an aperture ratio is 50 to 90%.

  The aperture ratio of the mesh refers to the area ratio occupied by the opening portion in the projected area of the mesh. From the viewpoint of maintaining the aperture ratio and the wire diameter, a mesh made of metal-coated organic fibers excellent in mesh shape maintaining characteristics is preferable.

  Examples of the metal used for the metal fiber or metal-coated organic fiber constituting the conductive mesh include copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, lead, iron, silver, chromium, carbon, and alloys thereof. Preferably, copper, nickel, stainless steel, or aluminum is used. Examples of the organic material used for the metal-coated organic fiber include polyester, nylon, vinylidene chloride, aramid, vinylon, and cellulose.

  Moreover, as a metal of the metal film used for the etching mesh, copper, stainless steel, aluminum, nickel, chromium, iron, brass, or an alloy thereof can be used, and copper, stainless steel, and aluminum are preferably used. These metal films can be formed by vapor deposition or sputtering, or can be formed by bonding these metal foils to the base film 1 with an adhesive. As the adhesive in this case, epoxy, urethane, EVA (ethylene vinyl acetate copolymer), and the like are preferable.

  As the thickness of these metal films, it is not preferable in terms of handleability and workability of pattern etching if it is too thin. On the other hand, if it is too thick, the thickness of the resulting film is affected and the time required for the etching process becomes long. Therefore, it is preferably about 1 to 200 μm.

  The shape of the etching pattern in the etching mesh is not particularly limited, and may be, for example, a lattice shape in which square holes are formed, a punching metal shape in which circular, hexagonal, triangular, or elliptical holes are formed. it can. Further, the holes are not limited to those regularly arranged, and may be a random pattern. The area ratio of the opening portion on the projection surface of the metal foil is preferably about 20 to 95%.

  In the case of an etching mesh, the shape and wire diameter of the conductive portion can be freely designed by using a photolithography technique, so that the aperture ratio can be made higher than that of the conductive mesh.

  The conductive printing mesh is printed on the base film 1 by using a conductive ink as shown below by screen printing, gravure printing, offset printing, ink jet printing, electrostatic printing, or the like. Can be formed. According to such pattern printing, a pattern having a large degree of freedom can be formed, and a conductive layer having an arbitrary wire diameter, interval and opening shape can be formed. Therefore, a film having a desired electromagnetic wave shielding property and light transmittance can be obtained. It can be formed easily.

  As such a conductive ink, carbon black particles having a particle size of 100 μm or less, or particles having conductivity such as particles of metal or alloy such as silver, copper, aluminum, nickel, etc., at a concentration of 50 to 90% by weight, Epoxy-based, urethane-based, EVA-based, melanin-based, cellulose-based, acrylic-based, and polyvinyl acetate-based binder resins can be used. This includes toluene, xylene, methylene chloride, water, etc. It can be diluted or dispersed in a suitable concentration in a solvent and applied onto the substrate film 1 by printing, and then dried at room temperature to 120 ° C. as necessary. In addition, particles obtained by covering the conductive particles with the binder resin may be directly applied by electrostatic printing and fixed by heat or the like.

  The thickness of the conductive printing mesh is not preferable because the electromagnetic shielding properties are insufficient if it is too thin. On the other hand, if the thickness is too thick, the thickness of the resulting film is affected. Therefore, the thickness is preferably about 0.5 to 100 μm. .

  The shape of the pattern of the conductive printed mesh is not particularly limited. Like the etching mesh, for example, a lattice shape in which a square opening is formed, or a circular, hexagonal, triangular or elliptical opening is formed. However, the openings are not limited to those regularly arranged, and may be random patterns. The area ratio of the opening portion on the projection surface of the conductive printing mesh is preferably 20 to 95%.

  As a mesh-like conductive layer, in addition to the above, dots are formed on the film surface with a material soluble in a solvent, and then a conductive material layer made of a conductive material insoluble in the solvent is formed thereon. Then, a mesh-like conductive layer obtained by bringing the film surface into contact with a solvent to remove the dots and the conductive material layer on the dots may be used.

  An example of the coating layer is a coating layer in which conductive particles of an inorganic compound are dispersed in a polymer. Examples of the inorganic compound constituting the conductive particles include metals, alloys such as aluminum, nickel, indium, chromium, gold, vanadium, tin, cadmium, silver, platinum, copper, titanium, cobalt, lead; or ITO, oxidation Indium, tin oxide, zinc oxide, indium oxide-tin oxide (ITO, so-called indium-doped tin oxide), tin oxide-antimony oxide (ATO, so-called antimony-doped tin oxide), zinc oxide-aluminum oxide (ZAO, so-called aluminum-doped oxide) And conductive oxides such as zinc). In particular, ITO is preferable. The average particle size is preferably 10 to 10,000 nm, particularly preferably 10 to 50 nm.

  Examples of the polymer include acrylic resin, polyester resin, epoxy resin, urethane resin, phenol resin, maleic acid resin, melamine resin, urea resin, polyimide resin, and silicon-containing resin. Of these resins, thermosetting resins are preferably used. Furthermore, it is also preferable to use the ultraviolet curable resin used for the hard-coat layer mentioned later as a polymer.

  The electromagnetic shielding material 2 comprising the coating layer is formed by using a solvent as necessary to disperse the conductive particles in the polymer by mixing or the like to prepare a coating solution. It can be performed by coating on 1 and drying and curing as appropriate. When a thermoplastic resin is used, the coating layer can be obtained by drying after coating. In the case of a thermosetting resin, a coating layer can be obtained by drying and thermosetting, and an ultraviolet curable resin is used. In some cases, the coating can be obtained by drying as necessary and irradiating with ultraviolet rays. The thickness of the coating layer is usually 0.01 to 5 μm, particularly 0.05 to 3 μm. If this thickness is less than 0.01 μm, the electromagnetic shielding properties may not be sufficient, while if it exceeds 5 μm, the transparency of the resulting film may be reduced.

  The coating layer can also be made of a conductive polymer. For example, hydrocarbon polymers such as polyacetylene, polyphenylene, polyphenylene vinylene, polyacene, polyphenylacetylene, polynaphthalene; polypyrrole, polyaniline, polythiophene, polyethylene Heteroatom-containing polymers such as vinylene, polyazulene, polyisothianaphthene can be used. Of these, polypyrrole and polythiophene are particularly preferable.

  As the material of the layer (metal oxide transparent conductive thin film) obtained by the vapor deposition method, the above-mentioned inorganic compounds can be used, and the formation methods thereof include sputtering, ion plating, electron beam evaporation, laser. Physical vapor deposition methods such as ablation and vacuum vapor deposition, and chemical vapor deposition methods such as atmospheric pressure CVD method, low pressure CVD method, and plasma CVD method can be used, and it is generally preferable to use a sputtering method. In this case, the layer thickness can be generally 30 to 50,000 nm, particularly about 50 nm.

  As the electromagnetic shielding material 2, an alternate laminated film of the metal oxide dielectric layer and the metal layer may be used, and in particular, dielectric layer / metal layer / dielectric layer / metal layer / dielectric layer 5 A laminate of more than one layer is preferred. For example, an alternating laminate of ITO or other metal oxide dielectric layers and Ag or other metal layers (ITO / silver / ITO / silver / ITO laminates, etc.) can be used.

  In addition, when the electromagnetic wave shielding material 2 (especially mesh-shaped electroconductive layer) is made into a lower resistance value and it wants to improve an electromagnetic wave shielding effect, it is preferable to form a plating layer on it. The plating layer can be formed by ordinary liquid phase plating (electrolytic plating, electroless plating, etc.). Examples of metal materials used for plating include copper, copper alloys, nickel, aluminum, chromium, zinc, tin, silver, and gold. These can be used alone or as two or more alloys. May be. Copper, copper alloy, silver or nickel is preferable, and copper or copper alloy can be preferably used particularly from the viewpoint of economy and conductivity.

  The electromagnetic wave shielding material 2 may be provided with anti-glare (AG) performance. When this anti-glare treatment is performed, the surface of the mesh-like conductive layer may be blackened, for example, oxidation treatment of a metal film, black plating of a chromium alloy, application of black or dark ink, one side Alternatively, it can be performed by means such as black printing on both sides.

  Furthermore, when a mesh-like conductive layer is formed as the electromagnetic wave shielding material 2, a transparent treatment layer may be provided so as to cover the electromagnetic wave shielding material 2. Such a transparent treatment layer has the effect of leveling the unevenness of the conductive mesh and increasing the transparency of the display panel film. This transparent treatment layer includes a transparent pressure-sensitive adhesive or adhesive, for example, an acrylic pressure-sensitive adhesive such as butyl acrylate, a rubber pressure-sensitive adhesive, a styrene-ethylene-butylene-styrene block copolymer (SEBS), and styrene-butadiene. A TPE pressure-sensitive adhesive based on a thermoplastic elastomer resin such as a block copolymer (SBS) can be used. This transparent treatment layer can be formed by, for example, coating, and the thickness is usually about 5 to 500 μm, particularly about 10 to 100 μm. In addition, you may give the role of this transparentization process layer by functional coating layers, such as a hard-coat layer mentioned later.

  On the electromagnetic wave shielding material 2, at least one functional coating layer is provided. Examples of the functional coating layer include an antireflection (AR) layer and a hard coat layer. In the present invention, as shown in the figure, a hard coat layer 3 and an antireflection layer 4 can be sequentially formed on the electromagnetic wave shielding material 2 as a functional coating layer.

  The hard coat layer 3 can be formed of an acrylic resin, an epoxy resin, a urethane resin, a silicone resin or the like, and its thickness is usually 1 to 50 μm, preferably 1 to 10 μm. Either a thermosetting resin or an ultraviolet curable resin may be used, but an ultraviolet curable resin is preferable.

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

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

  For the hard coat layer, among the ultraviolet curable resins (monomers and oligomers), hard materials such as pentaerythritol tri (meth) acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like It is preferable to mainly use polyfunctional monomers.

  As the photopolymerization initiator for the ultraviolet curable resin, any compound suitable for the properties of the ultraviolet curable resin can be used. For example, acetophenone such as 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1 Benzoin series such as benzyldimethyl ketal, benzophenone, 4-phenylbenzophenone, benzophenone series such as hydroxybenzophenone, thioxanthone series such as isopropylthioxanthone, 2-4-diethylthioxanthone, and other special ones include methylphenyl glyoxylate Etc. can be used. Particularly preferably, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1, Examples include benzophenone. These photopolymerization initiators may be optionally selected from one or more known photopolymerization accelerators such as a benzoic acid type such as 4-dimethylaminobenzoic acid or a tertiary amine type. It can be used by mixing at a ratio. Moreover, it can be used by 1 type, or 2 or more types of mixture of only a photoinitiator. In particular, 1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Specialty Chemicals, Irgacure 184) is preferable. The compounding quantity of the said photoinitiator is about 0.1-10 mass% normally with respect to the resin composition which forms the hard-coat layer 3, Preferably it is 0.1-5 mass%.

The hard coat layer 3 is preferably mixed with conductive metal oxide fine particles such as ITO, ATO, Sb ₂ O ₃ , SbO ₂ , In ₂ O ₃ , SnO ₂ , ZnO, etc. By setting the resistance to 5 × 10 ¹⁰ Ω / □ or less, the antistatic function can be provided.

  The hard coat layer 3 preferably has a refractive index lower than that of the base film 1, and in general, it becomes easy to obtain a refractive index lower than that of the base film 1 by using the ultraviolet curable resin. Therefore, it is preferable to use a material having a high refractive index such as PET as the base film 1. From this viewpoint, the hard coat layer is preferably formed with a low refractive index of 1.60 or less. The visible light transmittance of the hard coat layer is preferably 85% or more.

  The antireflection layer 4 is generally formed of a low refractive index layer, and exhibits an antireflection effect by a composite film of a hard coat layer and a low refractive index layer provided thereon. In addition, a high refractive index layer may be provided between the hard coat layer and the low refractive index layer, thereby improving the antireflection function. Each of these layers forming the antireflection layer 4 can be formed using various resins, for example, ultraviolet curable or electron beam curable synthetic resins, in particular, cost reduction, film strength increase, chemical resistance From the viewpoints of improving the property and improving the heat and humidity resistance, a polyfunctional acrylic resin can be suitably used. If the refractive index of the hard coat layer 3 is low, the antireflection effect can be obtained only by the hard coat layer 3 without providing the antireflection layer 4 separately.

The low refractive index layer is a fine particle such as silica (SiO ₂ ), MgF ₂ , Al ₂ O ₃ , fluororesin or the like, preferably hollow silica 10-60 for the purpose of lowering the refractive index, improving scratch resistance, and improving slipping property. It is preferable to make the cured layer dispersed in the polymer, preferably in the ultraviolet curable resin, by weight%, preferably 10 to 50% by mass. The refractive index of this low refractive index layer is preferably 1.40 to 1.51. When the refractive index of the low refractive index layer exceeds 1.51, the antireflection characteristic of the antireflection layer 4 is deteriorated. The film thickness is generally in the range of 10 to 500 nm, preferably 20 to 200 nm. Further, the hollow silica preferably has an average particle size of 10 to 100 nm, particularly 10 to 50 nm, and a specific gravity of 0.5 to 1.0, particularly 0.8 to 0.9.

The high refractive index layer is made of a polymer, preferably an ultraviolet curable resin, in ITO, ATO, Sb ₂ O ₅ , Sb ₂ O ₃ , SbO ₂ , In ₂ O ₃ , SnO ₂ , ZnO, ZrO ₂ , A layer in which conductive metal oxide fine particles (inorganic compounds) having a high refractive index such as ZnO, TiO ₂ , SnO ₂ , and ZrO doped with Al are dispersed is preferable. As the metal oxide fine particles, those having an average particle diameter of 10 to 10,000 nm, particularly 10 to 50 nm are preferable. Among these, ITO (especially having an average particle diameter of 10 to 50 nm) is preferable. Further, those having a refractive index of 1.64 or more are preferable. The film thickness is generally in the range of 10 to 500 nm, preferably 20 to 200 nm.

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

  The visible light transmittance of the low refractive index layer and the high refractive index layer is preferably 85% or more.

  When the antireflection layer 4 is composed of a low refractive index layer and a high refractive index layer and is formed together with the hard coat layer 3, for example, the thickness of the hard coat layer 3 is 2 to 20 μm, It is preferable to adjust the thickness within the range of 75 to 200 nm and the thickness of the low refractive index layer of about 75 to 200 nm.

  In order to form each layer of the antireflection layer 4, as described above, the above fine particles are blended in the polymer as desired, the obtained coating solution is applied, and then dried, and if necessary, heat is applied. It is cured or, after coating, if necessary, dried and irradiated with ultraviolet rays. In this case, each layer may be applied and cured one by one, or all the layers may be applied and then cured together.

  As a specific method of coating, for example, a coating solution in which an ultraviolet curable resin containing an acrylic monomer or the like is made into a solution with a solvent such as toluene is coated with a gravure coater, and then dried, and then with ultraviolet rays. The method of hardening can be mentioned suitably. According to this wet coating method, there is an advantage that a film can be formed uniformly at high speed at low speed. After coating, for example, effects of improving adhesion and increasing film hardness can be obtained by curing by irradiating ultraviolet rays.

  As the light source used for ultraviolet irradiation in the present invention, many light emitting in the ultraviolet to visible region can be adopted, for example, ultra-high pressure, high pressure, low pressure mercury lamp, chemical lamp, xenon lamp, halogen lamp, Mercury halogen lamp. , Carbon arc lamp, incandescent lamp, laser beam and the like. Irradiation time is not generally determined depending on the type and intensity of the light source, but is about several seconds to several minutes. In order to accelerate curing, the laminate may be heated to 40 to 120 ° C. in advance and irradiated with ultraviolet rays.

  The antireflection layer 4 is preferably formed by coating as described above, but may be formed by a vapor deposition method, and the physical vapor deposition method or the chemical vapor deposition method described above can be suitably used. Examples of the physical vapor deposition method include a vacuum vapor deposition method, a sputtering method, an ion plating method, and a laser ablation method, but it is generally preferable to form a film by the sputtering method. Examples of the chemical vapor deposition method include an atmospheric pressure CVD method, a low pressure CVD method, and a plasma CVD method.

  In addition, as an example of the combination of the high refractive index layer and the low refractive index layer in the antireflection layer 4, for example, (a) a high refractive index layer / a low refractive index layer are stacked in total in two layers, one in each order. (B) one in which two layers of high refractive index layer / low refractive index layer are alternately laminated in total 4 layers, (c) 1 in the order of middle refractive index layer / high refractive index layer / low refractive index layer Examples thereof include those obtained by laminating a total of 3 layers, and (d) those obtained by alternately laminating each layer in the order of high refractive index layer / low refractive index layer in a total of 6 layers. Further, a protective layer may be provided on the antireflection layer 4, and the protective layer can be formed in the same manner as the hard coat layer.

  Moreover, it is preferable to form the near-infrared absorption layer 6 in the surface on the opposite side to the electromagnetic wave shielding material 2 formation surface of the base film 1 so that it may show in figure. The near-infrared absorbing layer 6 is generally coated on the surface of the base film 1 with a coating liquid containing a dye having absorption in the near-infrared region and a binder resin such as an ultraviolet curable resin or an electron beam curable resin. And it can obtain by drying and hardening as needed. When used as a film, it is generally a near-infrared cut film, for example, a film containing a pigment or the like.

  As the near-infrared absorbing dye, those having an absorption maximum in a wavelength range of 800 to 1200 nm can be used. For example, phthalocyanine-based, metal complex-based, nickel dithiolene complex-based, cyanine-based, squarylium-based, polymethine-based, azomethine -Based, azo-based, polyazo-based, diimonium-based, aminium-based, and anthraquinone-based dyes, and cyanine-based dyes or squarylium-based dyes are particularly preferable. These dyes can be used alone or in appropriate combination.

  Further, the near-infrared absorbing layer 6 may have a color tone adjusting function by providing an absorbing function of neon light emission. For this purpose, a neon-emission absorbing layer may be provided separately, but a neon-emission selective absorption dye may be contained in the near-infrared absorption layer to exert both functions.

  Examples of the selective absorption dye for neon emission include cyanine dyes, squarylium dyes, anthraquinone dyes, phthalocyanine dyes, polymethine dyes, polyazo dyes, azurenium dyes, diphenylmethane dyes, and triphenylmethane dyes. Such a selective absorption dye has a selective absorption of neon emission at around 585 nm and needs to have a small absorption at other visible light wavelengths. Therefore, the absorption maximum wavelength is 575 to 595 nm. Those having a spectrum half width of 40 nm or less are preferably used.

  Also, when combining multiple types of near-infrared or neon luminescent absorbing dyes, if there is a problem with the solubility of the dye, if there is a reaction between the dyes due to mixing, if there is a decline in heat resistance or moisture resistance, etc. In the present invention, it is not necessary to contain all the near-infrared absorbing dyes in the same layer, and they can be contained in another layer. As long as the optical properties are not greatly affected, coloring pigments, ultraviolet absorbers, antioxidants and the like may be further added.

  As a near-infrared absorption characteristic in the filter of the present invention, it is preferable that the transmittance in the wavelength region of 850 to 1000 nm is 20% or less, and further 15%. Further, as the selective absorption of neon light emission, the transmittance at a wavelength of 585 nm is preferably 50% or less. The former has the effect of reducing the transmittance in the wavelength region where malfunction of peripheral devices such as remote controllers has been pointed out, and for the latter, orange having a peak at a wavelength of 575 to 595 nm deteriorates color reproducibility. Because it is the cause, there is an effect of absorbing this orange wavelength, and thereby, the redness can be increased and the color reproducibility can be improved.

  The thickness of the near infrared absorbing layer 6 is preferably about 0.5 to 50 μm.

  A transparent adhesive layer 7 for adhering the filter of the present invention to the display can be formed on the near infrared absorbing layer 6. As the transparent pressure-sensitive adhesive layer 7, any resin may be used as long as it has an adhesive function. For example, an acrylic pressure-sensitive adhesive formed from butyl acrylate, a rubber pressure-sensitive adhesive, SEBS (styrene / ethylene / TPE pressure-sensitive adhesives and adhesives mainly composed of a thermoplastic elastomer (TPE) such as butylene / styrene and SBS (styrene / butadiene / styrene) can be used. The thickness of the transparent adhesive layer 7 is usually in the range of 5 to 500 μm, particularly 10 to 100 μm. The filter of the present invention can be mounted by thermocompression bonding the transparent adhesive layer 7 to a glass plate of a display.

  When EVA is used as the material for the transparent pressure-sensitive adhesive layer 7, a material having a vinyl acetate content of 5 to 50% by weight, particularly 15 to 40% by weight, can be suitably used as the EVA. When the vinyl acetate content is less than 5% by weight, there is a problem in transparency. On the other hand, when it exceeds 40% by weight, the mechanical properties are remarkably deteriorated and film formation becomes difficult and mutual film blocking is likely to occur.

  In addition, an organic peroxide is suitable as a crosslinking agent when EVA is heated and crosslinked, and is selected in consideration of sheet processing temperature, crosslinking temperature, storage stability, and the like. Examples of usable organic peroxides include 2,5-dimethylhexane-2,5-dihydroperoxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane-3; Di-t-butyl peroxide; t-butylcumyl peroxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; dicumyl peroxide; α, α'-bis (t-butyl Peroxyisopropyl) benzene; n-butyl-4,4-bis (t-butylperoxy) valerate; 2,2-bis (t-butylperoxy) butane; 1,1-bis (t-butylperoxy) Cyclohexane; 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane; t-butylperoxybenzoate; benzoyl peroxide; 3-butylperoxyacetate; 2,5-dimethyl-2,5-bis (tertiarybutylperoxy) hexyne-3; 1,1-bis (tertiarybutylperoxy) -3,3,5-trimethylcyclohexane; 1,1-bis (tert-butylperoxy) cyclohexane; methyl ethyl ketone peroxide; 2,5-dimethylhexyl-2,5-bisperoxybenzoate; tert-butyl hydroperoxide; p-menthane hydroperoxide; p- Examples thereof include chlorobenzoyl peroxide; tert-butyl peroxyisobutyrate; hydroxyheptyl peroxide; chlorhexanone peroxide. These organic peroxides are used singly or in appropriate combination of two or more, and usually 5 parts by mass or less, preferably 0.5 to 5.0 parts by mass with respect to 100 parts by weight of EVA. used. Such an organic oxide is usually kneaded with EVA using an extruder, a roll mill or the like, but may be dissolved in an organic solvent, a plasticizer, a vinyl monomer or the like and added to the EVA film by an impregnation method. Good.

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

  Examples thereof include polyfunctional esters such as trimethylolpropane, pentaerythritol, glycerin and other acrylic or methacrylic acid esters, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl isophthalate, diallyl maleate, and the like. Examples include allyl group-containing compounds, which are used alone or in combination of two or more, and are usually 0.1 to 2 parts by weight, preferably 0.5 to 5 parts by weight with respect to 100 parts by weight of EVA. Used in

  When EVA is crosslinked by light, a photosensitizer can be used in place of the organic peroxide, and the amount added is usually 5 parts by mass or less, preferably 0 with respect to 100 parts by mass of EVA. .1 to 3.0 parts by mass. Usable photosensitizers include, for example, benzoin, benzophenone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, dibenzyl, 5-nitroacenaphthene, hexachlorocyclopentadiene, p-nitrodiphenyl, p -Nitroaniline, 2,4,6-trinitroaniline, 1,2-benzanthraquinone, 3-methyl-1,3-diaza-1,9-benzanthrone, and the like, Alternatively, two or more kinds can be appropriately mixed and used.

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

  The silane coupling agent is usually used in an amount of 0.001 to 10 parts by mass, preferably 0.001 to 5 parts by mass with respect to 100 parts by mass of EVA, and one kind or two or more kinds may be appropriately mixed and used. it can.

  In addition, the transparent adhesive layer 7 may contain a small amount of an ultraviolet absorber, an infrared absorber, an anti-aging agent, a coating processing aid, a colorant, etc., and in some cases, carbon black, hydrophobic silica, A small amount of a filler such as calcium carbonate may be included.

  The transparent pressure-sensitive adhesive layer 7 is, for example, a mixture of EVA and the above-mentioned additives, kneaded with an extruder, roll, etc., and then sheeted into a predetermined shape by a film forming method such as calendar, roll, T-die extrusion, inflation, etc. It can be manufactured by molding.

  Further, a release sheet can be provided on the transparent pressure-sensitive adhesive layer 7, and the material of the release sheet is preferably a transparent polymer having a glass transition temperature of 50 ° C. or higher. Examples of such a material include PET, Polyester resins such as polycyclohexylene terephthalate and polyethylene naphthalate (PEN), nylon resins such as nylon 46, modified nylon 6T, nylon MXD6 and polyphthalamide, ketone resins such as polyphenylene sulfide and polythioether sulfone, polysulfone In addition to sulfone-based resins such as polyethersulfone, polymers such as polyethernitrile, polyarylate, polyetherimide, polyamideimide, PC, PMMA, triacetylcellulose, polystyrene, and polyvinyl chloride are the main components. That the resin can be used. Among these, PC, PMMA, polyvinyl chloride, polystyrene, and PET can be suitably used. As thickness, about 10-200 micrometers is preferable and 30-100 micrometers is more preferable.

  As a method for producing the filter of the present invention, after the electromagnetic wave shielding material 2 and the functional coating layers 3 and 4 are sequentially formed on the base film 1, a predetermined position, for example, in the example shown in FIG. What is necessary is just to let the electroconductive member 5 penetrate by the method suitably in several places along a pair of edge part 11 which a filter opposes, and, thereby, conduction | electrical_connection with the electromagnetic wave shielding material 2 is securable.

  The filter of the present invention is particularly advantageous in that it can be produced by a continuous process. Specifically, for example, as shown in FIG. 6, an electromagnetic wave shielding material is sequentially formed on a long base film 1. 2 (A), the functional coating layers 3 and 4 are formed (B), and the conductive member 5 is formed at a plurality of locations along the portion of the electromagnetic wave shielding material 2 that becomes the filter edge portion 11 that is not exposed. Manufacturing can be performed by a series of these steps (C). In this case, these steps (A) to (D) can be performed continuously by a so-called roll-to-roll method, and then a product filter can be obtained by cutting according to the final filter size. .

  FIG. 7 shows a schematic cross-sectional view of a state in which the filter of the present invention is incorporated in a PDP apparatus. As shown in the drawing, the filter 10 of the present invention is disposed on the front surface of the PDP panel 20 and accommodated in the housing 30, and is electrically connected to the electromagnetic shielding material 2 in the filter 10. By bringing the conductive surface 31 into contact, a good electromagnetic wave shielding effect can be obtained.

(A) of the filter for display panels which concerns on one suitable embodiment of this invention is a width direction sectional drawing which follows the AA line, (b) is a top view, (c) is a BB line. It is length direction sectional drawing which follows. (A), (b) is a schematic plan view of the filter for display panels which concerns on other suitable embodiment of this invention. It is a schematic plan view of a filter for a display panel according to still another preferred embodiment of the present invention. It is a schematic plan view of a filter for a display panel according to still another preferred embodiment of the present invention. It is a schematic plan view of a filter for a display panel according to still another preferred embodiment of the present invention. It is a schematic explanatory drawing which shows the manufacturing method of the filter for display panels of this invention. It is a schematic sectional drawing which shows the state which incorporated the filter for display panels of this invention in the PDP apparatus.

Explanation of symbols

1 Base film 2 Electromagnetic wave shielding material 3 Hard coat layer (functional coating layer)
4 Antireflection layer (functional coating layer)
5, 5A, 5B, 5C Conductive member 6 Near-infrared absorbing layer 7 Transparent adhesive layer 10 Display panel filter 11 Edge portion 20 PDP panel 30 Housing 31 Conductive surface

Claims (4)

In a display panel filter comprising an electromagnetic wave shielding material and at least one functional coating layer on a base film,
A filter for a display panel, wherein a conductive member formed by penetrating the filter is provided at a plurality of locations along at least a pair of opposite edge portions of the filter.   The display panel filter according to claim 1, wherein the functional coating layer includes at least one non-conductive layer.   The display panel filter according to claim 1, wherein a conductive member formed by penetrating the filter is provided at a plurality of locations along two opposing edge portions of the filter.   The filter for display panels as described in any one of Claims 1-3 in which the said electroconductive member is provided in the substantially equal interval along the edge part.

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