JP2012047779A - Filter for display - Google Patents

Abstract

【Task】
Disclosed is a display filter which has excellent antistatic properties, good gloss and transparency on the surface, and low cost.
[Solution]
A display filter in which a base film, a mesh-like conductive layer, and a surface layer composed of one or more layers are laminated in this order, and the layer A adjacent to the mesh-like conductive layer in the surface layer is a metal oxide The fine particles are contained in an amount of 1% by mass to less than 18% by mass with respect to 100% by mass of the total solid content of the layer A, the surface layer has an average thickness from the surface of the mesh conductive layer of more than 1 μm and less than 7 μm, A filter for display, wherein the center line average roughness Ra of the layer surface is 20 nm or more and less than 60 nm.
[Selection] Figure 2

Description

  The present invention relates to a display filter mounted on the front surface of a display such as a CRT, a liquid crystal display, a plasma display, or an organic EL display. More specifically, the present invention relates to a display filter having excellent antistatic properties, good gloss and transparency on the surface, and low cost, and particularly to a display filter suitable for a plasma display.

  A display such as a CRT, a liquid crystal display, a plasma display, and an organic EL display is usually provided with a display filter having a function such as antireflection, electromagnetic shielding, or near infrared shielding on the front surface. In particular, since a strong electromagnetic wave is generated in a plasma display, a display filter having an electromagnetic wave shielding function is usually used.

  In addition, the display filter is generally provided with an antireflection function for preventing reflection of external light such as a fluorescent lamp and a hard coat function for preventing the display filter from being damaged. Yes.

  Conventionally, as a filter for a display, an electromagnetic wave shielding film having an electromagnetic wave shielding function (a film obtained by laminating an electromagnetic wave shielding layer on a base film) and an optical film having an antireflection property or a hard coat property (an antireflection layer on the base film) In general, a display filter in which an adhesive layer and a film on which a hard coat layer is laminated) is laminated is used.

  In recent years, the price of display filters has been inevitably reduced as the price of displays has been reduced. For the display filter composed of a plurality of films as described above, a surface layer such as an antireflection layer or a hard coat layer is directly laminated on the electromagnetic wave shielding layer (mesh-like conductive layer) of the electromagnetic wave shielding film. As a result, the number of substrate films is reduced and the cost is reduced.

  It has been proposed to laminate a surface layer such as a hard coat layer or an antireflection layer directly on the mesh-like conductive layer (for example, Patent Documents 1 to 4). These patent documents also describe that the hard coat layer contains metal oxide fine particles.

JP 2008-216734 A JP 2009-37237 A JP 2009-271393 A International Publication No. 2009/096124 Pamphlet

  In order to increase the refractive index of the hard coat layer or to improve the antistatic property of the hard coat layer, it is generally known that the hard coat layer contains metal oxide fine particles. When the hard coat layer containing metal oxide fine particles is directly laminated on the mesh-like conductive layer as in ~ 4, the swell of the hard coat layer increases on the fine line portion of the mesh-like conductive layer, and the hard coat layer surface Inconvenience that the glossiness and the transparency of the film are lowered may occur.

  Further, if the content of the metal oxide fine particles in the hard coat layer is reduced in order to avoid the inconvenience, there arises a problem that the antistatic property is lowered.

  Accordingly, an object of the present invention is to provide a display filter that has excellent antistatic properties, good surface glossiness and transparency, and low cost, and also has good surface scratch resistance. An object of the present invention is to provide a display filter in which the generation of interference fringes is suppressed.

The above object of the present invention has been achieved by the following invention.
1) A display filter in which a base film, a mesh-like conductive layer, and a surface layer composed of one or more layers are laminated in this order, and the layer A adjacent to the mesh-like conductive layer in the surface layer is a metal The oxide fine particles are contained in an amount of 1% by mass or more and less than 18% by mass with respect to 100% by mass of the total solid content of the layer A, the average thickness of the surface layer from the surface of the mesh-like conductive layer is more than 1 μm and less than 7 μm, and The display filter, wherein a center line average roughness Ra of the surface layer surface is 20 nm or more and less than 60 nm.
2) The display filter according to 1), wherein the metal oxide fine particles are conductive metal oxides.
3) The display filter according to 1) or 2), wherein the number average particle diameter of the metal oxide fine particles is less than 150 nm.
4) The display filter according to any one of 1) to 3), wherein the mesh-shaped conductive layer has a thickness of 0.3 μm or more and less than 8 μm.
5) The display filter according to any one of 1) to 4), wherein the surface layer includes at least a hard coat layer.
6) The display filter according to any one of 1) to 5), wherein the surface resistivity on the surface layer side is less than 1 × 10 ¹² Ω / □.
7) The display filter according to any one of 1) to 6), wherein an average thickness of the surface layer from the surface of the base film is less than 12 μm.
8) The display filter according to any one of 1) to 7) above, wherein the substrate film has a layer having a near-infrared shielding function on a surface opposite to the surface on which the mesh conductive layer is laminated.
9) The display filter according to 8), wherein the layer having a near-infrared shielding function is an adhesive layer.

  According to the present invention, it is possible to provide a low-cost display filter having excellent antistatic properties, good surface glossiness, transparency, and scratch resistance, and suppressed generation of interference fringes. .

The partial model top view by the side of the surface layer which shows an example of the filter for displays of this invention. FIG. 2 is a partial schematic cross-sectional view taken along a straight line Y in FIG. 1.

  The display filter of the present invention is obtained by sequentially laminating a base film, a mesh-like conductive layer, and a surface layer composed of one or more layers. The layer A adjacent to the mesh-like conductive layer in the surface layer contains 1% by mass or more and less than 18% by mass of metal oxide fine particles with respect to 100% by mass of the total solid content of the layer A.

  The layer A has been found to improve the antistatic property due to the synergistic effect with the mesh-like conductive layer only by containing metal oxide fine particles in a relatively small amount of 1% by mass or more and less than 18% by mass as described above. The present invention has been accomplished.

  That is, when the average thickness of the surface layer from the surface of the mesh-like conductive layer is more than 1 μm and less than 7 μm, a synergistic effect between the metal oxide fine particles in the layer A and the mesh-like conductive layer is expressed, and the metal in the layer A It has been found that the antistatic property is improved even when the content of the oxide fine particles is relatively small as described above.

The effect of antistatic properties can be measured by measuring the surface resistivity on the surface layer side. That is, in the display filter of the present invention, the surface resistivity on the surface layer side is preferably less than 1 × 10 ¹² Ω / □, and more preferably less than 1 × 10 ¹¹ Ω / □. The lower limit of the surface resistivity is about 1 × 10 ³ Ω / □.

  In addition to improving the gloss and transparency of the surface layer surface by setting the center line average roughness Ra of the surface layer surface to 20 nm or more and less than 60 nm, the surface layer surface is more effective in preventing static electricity. I found.

  The display filter of the present invention is preferably supplied by a long roll. When this long roll is processed into a sheet of a predetermined size, the long roll is unwound and cut, but static electricity is generated at the time of unwinding, and there is an inconvenience that dust in the air and cutting waste at the time of cutting adhere. May occur. In addition, static electricity may be generated when separating the overlapping sheets in which a plurality of sheets cut into a predetermined size sheet are stacked one by one, and there is a disadvantage that dust in the air adheres. May occur.

  These disadvantages are that the layer A contains metal oxide fine particles in an amount of 1% by mass or more and less than 18% by mass with respect to the total solid content of the layer A of 100% by mass, and from the surface of the mesh-like conductive layer of the surface layer. In addition to making the average thickness of more than 1 μm and less than 7 μm, the center line average roughness Ra of the surface layer surface is further improved to 20 nm or more and less than 60 nm.

(Surface layer)
The surface layer concerning this invention is a layer used as the outermost surface on the opposite side to the display side, when the display filter of this invention is mounted | worn with a display. That is, it is the layer that becomes the outermost surface on the viewer side. The surface layer is preferably laminated directly on the mesh conductive layer by coating.

  The surface layer of the present invention comprises one or more layers. The surface layer may be composed of a single layer or may be composed of a plurality of layers. When the surface layer is composed of a single layer, only the layer A is laminated on the mesh-shaped conductive layer, and when the surface layer is composed of a plurality of layers, the layer A and others are disposed on the mesh-shaped conductive layer. These layers are sequentially stacked.

  The surface layer preferably includes at least a hard coat layer. And it is preferable that the said hard-coat layer is arrange | positioned in the position adjacent to a mesh-shaped electroconductive layer. That is, the layer A is preferably a hard coat layer.

  As an aspect in which the surface layer is composed of a plurality of layers, a laminated structure of a hard coat layer and an antireflection layer can be mentioned.

  The average thickness of the surface layer from the surface of the mesh-like conductive layer is more than 1 μm and less than 7 μm. Here, the average thickness from the surface of the mesh-like conductive layer of the surface layer will be described with reference to FIGS.

  FIG. 1 is a partial schematic plan view on the surface layer side showing an example of the display filter of the present invention, and FIG. 2 is a partial schematic cross-sectional view taken along a straight line Y in FIG. The display filter of the present invention has a mesh-like conductive layer 2 on a base film 1, and a surface layer 3 is further laminated. The mesh-like conductive layer has a fine line part and an opening surrounded by the fine line part. Reference numeral 2 in FIGS. 1 and 2 means both a mesh-like conductive layer and a thin line portion for convenience of explanation. The opening of the mesh-like conductive layer is a region surrounded by the fine wire portion 2 and the fine wire portion 2.

  In FIG. 1, the surface layer outermost surface point A corresponding to the center of gravity of a certain opening is cut by a straight line Y connecting the surface layer outermost surface point C corresponding to the center of gravity of the opening adjacent to the opening. FIG. 2 is a cross-sectional view at this time. In FIG. 2, the vertical distance L between the vertex B of the surface layer on the fine wire portion 2 of the mesh-like conductive layer and the surface of the fine wire portion 2 is the thickness of the surface layer from the surface of the mesh-like conductive layer, and is arbitrarily selected 5 The average thickness from the surface of the mesh-like conductive layer of the surface layer is obtained by averaging the vertical distances L for one location.

  When the average thickness from the surface of the mesh-like conductive layer of the surface layer is 7 μm or more, the antistatic property is lowered. On the other hand, when the average thickness is 1 μm or less, the scratch resistance of the surface layer is lowered, and scratches and the like are likely to occur. The average thickness of the surface layer from the mesh-like conductive layer surface is preferably less than 6 μm, more preferably less than 5.5 μm, and particularly preferably less than 5 μm from the viewpoint of antistatic properties. On the other hand, from the viewpoint of ensuring the scratch resistance of the surface layer, it is preferably 1.5 μm or more, more preferably 2 μm or more, and particularly preferably 3 μm or more.

  In the present invention, the average thickness of the surface layer from the surface of the base film is also important from the viewpoint of curling the display filter. The average thickness of the surface layer from the substrate film surface is preferably less than 12 μm, more preferably less than 10 μm, and particularly preferably less than 9 μm. The lower limit is preferably 2 μm or more, and more preferably 3 μm or more. When the average thickness of the surface layer from the surface of the base film is 12 μm or more, the display filter is easily curled.

  The thickness of the surface layer from the surface of the base film is the vertical distance M between the point A on the outermost surface layer corresponding to the center of gravity of the opening of the mesh-like conductive layer in FIG. The average thickness from the surface of the base film of the surface layer is obtained by averaging the vertical distances M obtained from the five openings.

  In the present invention, the center line average roughness Ra of the surface layer surface is in the range of 20 nm or more and less than 60 nm. When the center line average roughness Ra of the surface layer surface is 60 nm or more, the glossiness and transparency of the surface layer are lowered. On the other hand, when the center line average roughness Ra of the surface layer surface is less than 20 nm, interference fringes are likely to occur, and the antistatic effect tends to decrease.

  The lower limit of the center line average roughness Ra on the surface layer surface is preferably 25 nm or more, and more preferably 28 nm or more. The upper limit is preferably less than 55 nm, more preferably less than 50 nm, and particularly preferably less than 45 nm.

  The surface layer having the above-described center line average roughness Ra (range of 20 nm or more and less than 60 nm) can be realized by forming an appropriate bulge on the fine line portion of the mesh-like conductive layer. The bulge of the surface layer can be formed by adjusting the coating amount, viscosity, composition, and the like when the surface layer is applied directly onto the mesh-like conductive layer. For example, the coating amount of the surface layer is adjusted so that the thickness of the surface layer finally formed by coating is in the range of 150 to 700% with respect to 100% of the thickness of the mesh-like conductive layer. Alternatively, by adjusting the viscosity of the surface layer coating liquid to a range of 2 to 50 mPa · s, an appropriate bulge can be formed on the fine line portion of the mesh-like conductive layer.

  Moreover, although mentioned later in detail, since it becomes easy to form a swell by making a surface layer contain metal oxide microparticles | fine-particles, it is important to adjust content.

  The surface layer of the present invention preferably forms an appropriate bulge only on the fine line portion of the mesh-like conductive layer. If the surface layer is raised other than on the fine line portion of the mesh-like conductive layer, that is, if the surface layer is raised at the opening of the mesh-like conductive layer, glossiness and transparency may be lowered, which is not preferable. Therefore, it is preferable that none of the layers constituting the surface layer contain relatively large particles that form the bulge of the surface layer in the openings of the mesh-like conductive layer.

(Layer A)
Layer A (a layer adjacent to the mesh-like conductive layer in the surface layer) contains metal oxide fine particles in an amount of 1% by mass to less than 18% by mass with respect to 100% by mass of the total solid content of layer A.
As described above, the layer A is preferably a hard coat layer, and the layer A will be described below taking the hard coat layer as an example. However, in the present invention, the layer A is not limited to the hard coat layer.

(Hard coat layer)
The hard coat layer has a pencil hardness defined by JIS K5600-5-4 (1999) of preferably H or higher, more preferably 2H or higher. The upper limit is about 9H.

In the hard coat layer, a thermosetting resin or an active energy ray curable resin is preferably used as the resin, and an active energy ray curable resin is particularly preferably used.
Examples of the thermosetting resin include an acrylic resin, a polyester resin, a polyurethane resin, a polycarbonate resin, a polystyrene resin, a polyolefin resin, a fluorine resin, and a polyimide resin that are polymerized or crosslinked by heat. .

  The active energy ray-curable resin is a composition in which monomers, oligomers, and prepolymers having an ethylenically unsaturated group such as a vinyl group, an allyl group, a (meth) acryloyl group, and a (meth) acryloyloxy group are appropriately mixed. Can be used.

  Examples of monomers include styrene, methyl (meth) acrylate, lauryl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate , Monofunctional acrylates such as isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxy (meth) acrylate, and neopentyl glycol di (meth) acrylate 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol Ritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol tri (meth) acrylate Polyfunctional acrylate such as tripentaerythritol hexa (meth) triacrylate, trimethylolpropane (meth) acrylic acid benzoate, trimethylolpropane benzoate, glycerin di (meth) acrylate hexamethylene diisocyanate, pentaerythritol tri (meth) ) Urethane acrylates such as acrylate hexamethylene diisocyanate.

  As oligomers and prepolymers, polyester (meth) acrylate, polyurethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, alkit (meth) acrylate, melamine (meth) acrylate, silicone (meth) acrylate, etc. Can be mentioned.

  The monomers, oligomers and prepolymers described above may be used alone or in combination, but it is preferable to use a trifunctional or higher polyfunctional monomer.

  In order to initiate the polymerization of the monomer, oligomer and prepolymer described above, it is preferable to contain a photopolymerization initiator. Specific examples of such photopolymerization initiators include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4′-dichlorobenzophenone, 4 , 4'-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methyl benzoyl formate, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, 2,2 -Carbonyl compounds such as dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone, tetramethylthiuram monosulfide, tetramethyl Sulfur compounds such as ruthiuram disulfide, thioxanthone, 2-chlorothioxanthone, and 2-methylthioxanthone can be used. These photopolymerization initiators may be used alone or in combination of two or more.

  The hard coat layer contains metal oxide fine particles in an amount of 1% by mass to less than 18% by mass with respect to 100% by mass of the total solid content of the hard coat layer. When the content of the metal oxide fine particles is 18% by mass or more, the swell on the fine line portion of the mesh-like conductive layer increases, and it becomes difficult to adjust the center line average roughness Ra of the surface layer surface to less than 60 nm. . On the other hand, when the content of the metal oxide fine particles is less than 1% by mass, good antistatic properties cannot be obtained.

  The content of the metal oxide fine particles in the hard coat layer is less than 17% by mass with respect to the total solid content of 100% by mass of the hard coat layer from the viewpoint of adjusting the center line average roughness Ra of the surface layer surface to less than 60 nm. Is preferable, less than 16 mass% is more preferable, and especially less than 15 mass% is preferable. On the other hand, from the viewpoint of ensuring good antistatic properties, the content of the metal oxide fine particles in the hard coat layer is preferably 2% by mass or more with respect to 100% by mass of the solid content of the hard coat layer, and is preferably 4% by mass. The above is more preferable, and particularly 6% by mass or more is preferable.

  The metal oxide fine particles are preferably conductive metal oxide fine particles, and examples include conductive metal oxide particles such as zinc, tin, antimony, aluminum, iron, and indium. Specific examples of the metal oxide fine particles include, for example, zinc oxide, tin oxide, antimony oxide, iron oxide, zinc antimonate, tin oxide-doped indium oxide (ITO), antimony-doped tin oxide (ATO), phosphorus-doped tin oxide, Examples thereof include aluminum-doped zinc oxide, gallium-doped zinc oxide, and fluorine-doped tin oxide. These metal oxide fine particles may be used alone or in combination.

  The number average particle diameter of the metal oxide fine particles is preferably less than 150 nm, more preferably less than 120 nm, further preferably less than 80 nm, and particularly preferably less than 50 nm. The lower limit number average particle diameter of the metal oxide fine particles is about 1 nm. The number average particle diameter of the metal oxide fine particles is a number average particle diameter determined by observation with a transmission electron microscope. When the number average particle diameter of the metal oxide fine particles is 150 nm or more, the haze value of the surface layer is increased and the transparency may be lowered. From the viewpoint of antistatic properties, the metal oxide fine particles preferably have a smaller number average particle size.

  Moreover, it is preferable that a hard-coat layer contains surfactant further. This improves the scratch resistance of the surface layer. As such a surfactant, a fluorine-based surfactant and a silicone-based surfactant are preferably used. The content of the surfactant in the hard coat layer is preferably in the range of 0.05 to 3% by mass and more preferably in the range of 0.1 to 2% by mass with respect to 100% by mass of the total solid content of the hard coat layer. In particular, the range of 0.2 to 1% by mass is preferable.

  The refractive index of the hard coat layer is preferably less than 1.57, more preferably less than 1.55, and particularly preferably less than 1.54. The lower limit refractive index of the hard coat layer is about 1.47. In order to set the refractive index of the hard coat layer to 1.57 or more, it is necessary to contain the above-mentioned metal oxide fine particles in a relatively large amount, and the center line average roughness Ra of the surface layer surface is adjusted to less than 60 nm. Becomes difficult. Further, when a polyester resin film (particularly polyethylene terephthalate film) is used as the base film and only the hard coat layer is laminated as the surface layer, the refractive index of the hard coat layer is less than 1.57, preferably less than 1.55. More preferably, it is preferably less than 1.54 because the reflectance decreases.

(Antireflection layer)
In the case where the surface layer has a laminated structure of a plurality of layers, a laminated structure of a hard coat layer and an antireflection layer can be mentioned. In the above laminated structure, the hard coat layer is layer A (a layer adjacent to the mesh-like conductive layer in the surface layer). Examples of the antireflection layer include a single layer having only a low refractive index layer, and a laminated structure of a high refractive index layer (hard coat layer side) and a low refractive index layer. In the present invention, when an antireflection layer is provided on the hard coat layer, the antireflection layer is preferably a single layer consisting of only a low refractive index layer.

  The refractive index of the low refractive index layer is preferably in the range of 1.30 to 1.44, more preferably in the range of 1.33 to 1.43, and particularly preferably in the range of 1.35 to 1.43. The refractive index of the high refractive index layer is preferably in the range of 1.55 to 1.80, more preferably in the range of 1.58 to 1.75, and particularly preferably in the range of 1.60 to 1.70.

(Low refractive index layer)
The low refractive index layer is a layer containing an active energy ray-curable resin that is cured by active energy rays such as ultraviolet rays and electron beams, and low refractive index inorganic particles and / or fluorine-containing compounds as a low refractive index material. preferable.

  Since the same active energy ray-curable resin as that used for the hard coat layer is used, the description thereof is omitted here. Moreover, since the same photoinitiator that can be used in combination with the active energy ray-curable resin is the same as that used for the hard coat layer, the description thereof is omitted here.

  As the low refractive index inorganic particles, inorganic particles such as silica and magnesium fluoride are preferably used. Further, these inorganic fine particles are preferably hollow or porous. The refractive index of the inorganic particles is preferably in the range of 1.2 to 1.4, more preferably in the range of 1.2 to 1.35.

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

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

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

  The thickness of the low refractive index layer is suitably in the range of 0.05 to 0.15 μm, and preferably in the range of 0.08 to 0.12 μm.

(High refractive index layer)
The high refractive index layer is preferably a layer containing an active energy ray-curable resin that is cured by active energy rays such as ultraviolet rays and electron beams, and metal oxide fine particles as a high refractive index material.

  Since the same active energy ray-curable resin as that used for the hard coat layer is used, the description thereof is omitted here. Moreover, since the same photoinitiator that can be used in combination with the active energy ray-curable resin is the same as that used for the hard coat layer, the description thereof is omitted here.

  As the metal oxide fine particles, those having a refractive index of 1.6 or more are preferable, and those having a refractive index of 1.7 to 2.8 are particularly preferably used. Examples of the metal oxide fine particles include metal oxide particles such as titanium, zirconium, zinc, tin, antimony, cerium, iron, and indium. Specific examples of the metal oxide fine particles include, for example, titanium oxide, zirconium oxide, zinc oxide, tin oxide, antimony oxide, cerium oxide, iron oxide, zinc antimonate, tin oxide-doped indium oxide (ITO), and antimony-doped tin oxide. (ATO), phosphorus-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, fluorine-doped tin oxide and the like. These metal oxide fine particles may be used alone or in combination.

  The number average particle diameter of the metal oxide fine particles is preferably in the range of 1 to 200 nm. The number average particle size of the metal oxide fine particles is a number average particle size obtained by observation with a transmission electron microscope.

  The content of the metal oxide fine particles is preferably in the range of 20 to 90% by mass, more preferably in the range of 30 to 85% by mass, particularly 40 to 80% by mass with respect to 100% by mass of the total solid content of the high refractive index layer. The range of is preferable.

  The thickness of the high refractive index layer is preferably in the range of 0.05 to 0.2 μm, and more preferably in the range of 0.08 to 0.15 μm.

(Mesh-like conductive layer)
The mesh-like conductive layer has a role of shielding electromagnetic waves generated from the display. In that sense, the surface resistivity of the mesh conductive layer is preferably low. Specifically, the surface resistivity of the mesh conductive layer is preferably 3Ω / □ or less, more preferably 1Ω / □ or less, and particularly preferably 0.5Ω / □ or less. A practical lower limit of the surface resistivity of the mesh conductive layer is about 0.01Ω / □.

  Even when the thickness of the surface layer laminated on the mesh-like conductive layer is relatively small (the thickness of the surface layer from the surface of the mesh-like conductive layer is more than 1 μm and less than 7 μm) From the viewpoint of controlling the center line average roughness Ra of the layer surface to be 20 nm or more and less than 60 nm, a smaller one is preferable. Specifically, the thickness of the mesh-like conductive layer is preferably less than 8 μm, more preferably less than 6 μm, further preferably less than 5 μm, and particularly preferably less than 3 μm.

  When the thickness of the mesh-like conductive layer is 8 μm or more, unless the thickness of the surface layer laminated thereon (average thickness of the surface layer from the mesh-like conductive layer surface) is 7 μm or more, the center line average of the surface layer surface It becomes difficult to control the roughness Ra to 20 nm or more and less than 60 nm, and when the thickness of the surface layer is 7 μm or more, the antistatic property is lowered.

  On the other hand, from the viewpoint of ensuring good electromagnetic wave shielding properties, the thickness of the mesh conductive layer is preferably 0.3 μm or more, more preferably 0.5 μm or more, further preferably 0.8 μm or more, and particularly preferably 1 μm or more. .

  The line width of the mesh conductive layer is suitably about 3 to 50 μm, preferably 5 to 40 μm, more preferably 6 to 30 μm, and particularly preferably 8 to 25 μm. The pitch of the mesh-like conductive layer (distance between adjacent fine line portions) is suitably in the range of 50 to 500 μm, preferably in the range of 75 to 450 nm, and more preferably in the range of 100 to 350 μm.

  The shape of the mesh pattern of the mesh-like conductive layer (opening shape) is, for example, a lattice mesh pattern made of a quadrangle such as a square, a rectangle, or a rhombus, a triangle, a pentagon, a hexagon, an octagon, or a dodecagon. Examples thereof include a mesh pattern consisting of a simple polygon, a mesh pattern consisting of a circle and an ellipse, a mesh pattern consisting of the composite shape, and a random mesh pattern. Among these, a lattice mesh pattern made of a tetragon and a mesh pattern made of a hexagon are preferable, and a regular mesh pattern is more preferably used.

  As a method for producing the mesh-like conductive layer, a known method can be used, but a production method in which the mesh-like conductive layer is formed and laminated without interposing an adhesive on the base film is preferable. As such a production method, 1) a method of forming a metal thin film on a base film by a vapor deposition method and / or a plating method, and then performing an etching process to form a mesh pattern, 2) a mesh formed on the base film A method of applying electroless plating to the patterned electroless plating catalyst layer is preferably used.

  The production method 1) is a method in which a metal thin film is formed on a base film by a vapor deposition method and / or a plating method, followed by etching to form a mesh pattern. In this method, a metal thin film is formed on the metal thin film by a vapor deposition method and / or a plating method, a resist pattern is formed on the metal thin film, and then the metal thin film is etched.

  As a method for forming a metal thin film on a base film, either a vapor deposition method or a plating method, or a method using a vapor deposition method and a plating method in combination can be used. It is preferable to form the metal thin film only by the film method. By forming a metal thin film by a vapor deposition method, a mesh-like conductive layer having a low surface resistivity can be formed as a thin film.

  Examples of the vapor deposition method include sputtering, ion plating, electron beam vapor deposition, vacuum vapor deposition, chemical vapor deposition, and the like, and these one method or a combination of two or more 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 multilayer of one or more of metals such as copper, aluminum, nickel, iron, gold, silver, stainless steel, chromium and titanium is used. can do. Among these, copper is preferably used from the viewpoints of obtaining good electromagnetic shielding properties, easy mesh pattern processing, and low cost.

  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 0.005-0.1 micrometer between a base film and a copper thin film. That is, when copper is used as the metal of the metal thin film, it is preferable to have a laminated structure of a nickel thin film and a copper thin film. Thereby, the adhesiveness of a base film and a copper thin film improves.

  Further, a metal compound such as a metal oxide, metal nitride, or metal sulfide can be laminated on the surface of the metal thin film by a vapor deposition method. Since the reflection color of the metal thin film can be adjusted by laminating the metal compound, it is effective for suppressing interference fringes. Examples of such metal compounds include gold, platinum, silver, mercury, copper, aluminum, nickel, chromium, iron, tin, zinc, indium, palladium, iridium, cobalt, tantalum, antimony, titanium, and other metal oxides, nitriding Or sulfide.

  The thickness of the metal compound is preferably in the range of 0.005 to 0.1 μm, and more preferably in the range of 0.01 to 0.1 μm. This metal compound layer constitutes a part of the metal thin film and further constitutes a part of the mesh-like conductive layer. Providing a metal compound layer on the surface of the mesh-like conductive layer is preferable from the viewpoint of reducing interference fringes.

  A resist pattern is formed on the metal thin film. As a method for forming such a resist pattern, there are a photolithographic method and a printing method.

  The photolithographic method is a method of forming a resist pattern by laminating a photoresist layer on a metal thin film, exposing through a photomask of a desired pattern, or directly scanning and exposing with a laser, and developing. As a method of laminating a photoresist layer on a metal thin film, for example, a method of attaching a resist film on a metal thin film or a method of applying a liquid resist is used.

  A method for forming a resist pattern on a metal thin film by a printing method is a method in which an ink containing a resin curable with ultraviolet rays or an electron beam and an alkali-soluble resin is printed by a printing method such as a gravure printing method, a screen printing method, or an offset printing method. In this method, a resist pattern is formed on a metal thin film. Among the above printing methods, gravure printing is preferably used because a mesh pattern can be formed continuously with high productivity and high definition.

  As described above, after forming a resist pattern on the metal thin film, the metal thin film is etched to form a mesh-like conductive layer. Finally, the resist pattern remaining on the mesh-like conductive layer is peeled off and a mesh-like conductive layer is formed on the base film.

  Next, the production method 2), which is one of the preferred production methods for the mesh-like conductive layer, will be described. This manufacturing method is a method in which electroless plating is performed on an electroless plating catalyst layer having a mesh pattern formed on a base film. In this method, first, a mesh pattern electroless plating catalyst layer is formed on a substrate film.

  As a method of forming a mesh pattern electroless plating catalyst layer on a base film, a) a pattern printing method using an electroless plating catalyst ink on the base film, and b) a reducing agent on the base film A pattern printing is performed with an ink to form a reducing agent-containing pattern layer, and then a reducing agent-containing pattern layer is coated with a metal ion solution containing metal ions that can become an electroless plating catalyst by reduction, and the reducing agent and In this method, the metal ions are reduced by contact with metal ions to form an electroless plating catalyst layer.

  Examples of the electroless plating catalyst ink used in the method a) include inks containing an electroless plating catalyst, a binder resin, and an organic solvent. As electroless plating catalysts, high catalytic activity can be obtained, such as chlorides, hydroxides, oxides, sulfates and ammonium salts of metal atoms such as palladium, silver, platinum, and gold, etc. Used. In particular, a palladium compound is preferable and palladium chloride is more preferable.

Examples of the ink containing a reducing agent used in the method b) include inks containing a reducing agent, a binder resin, and a solvent. The reducing agent is not particularly limited as long as it is a substance capable of causing an oxidation reaction by itself by reducing the metal ion to a metal by contact with a metal ion that can be an electroless plating catalyst. For example, particles of metal that are electrochemically lower than catalytic metals such as Pb, Sn, Ni, Co, Zn, Ti, and Cu, and salts of Sn (II) and Fe (II), and the like can be given. Among these, a metal salt selected from the group consisting of Sn (II) and Fe (II) is preferable, and a salt of Sn (II) is preferably used. Examples of the metal salts include chlorides, sulfates, oxalates, acetates, and the like, and more preferably chlorides or sulfates. As a particularly preferred metal salt, a metal salt selected from the group consisting of SnCl ₂ and SnSO ₄ is used.

After the ink containing the reducing agent is pattern-printed on the substrate film, a metal ion solution containing metal ions that can become an electroless plating catalyst by reduction is applied on the reducing agent-containing pattern layer, and the reduction is performed. The metal ions are reduced by contact between the agent and the metal ions to form an electroless plating catalyst layer. Examples of metal ions contained in the metal ion solution include ions of metals such as Ag, Au, Pd, Pt, and Rh. Among these, Pd (II) ions and Ag (I) ions are preferably used. The solution containing the metal ions can be obtained by dissolving a metal salt in the solution. Examples of the metal salt used include chloride, bromide, acetate, nitrate, citrate and the like. Specific examples include Pd (II) salts such as PdCl ₂ , PdBr ₂ and Pd (CH ₃ COO) ₂ , Ag (I) salts such as CH ₃ COOAg, AgNO ₃ and silver citrate (I). It is done.

  Examples of the printing method used for the pattern printing of a) and b) include known printing methods such as gravure printing, flexographic printing, gravure offset printing, screen printing, inkjet printing, and electrostatic printing. Among these, gravure printing is preferably used because a mesh pattern can be formed continuously with high productivity and high definition.

  The method b) is described in, for example, JP-A-2009-123408, and can be used in the present invention.

  After the electroless plating catalyst layer having a mesh pattern is formed on the base film by the method a) or b), electroless plating is performed. Examples of the metal used for electroless plating include copper, nickel, gold, silver, tin, zinc, or alloys thereof. Among these, copper is preferably used. A mesh-like conductive layer is formed on the base film by this electroless plating. Furthermore, electrolytic copper plating can be performed on the mesh-like conductive layer formed as described above, and in order to blacken the surface of the mesh-like conductive layer, a black alloy (zinc-nickel alloy, nickel-tin alloy, etc.) Can be plated. The black alloy plating is preferable from the viewpoint of reducing interference fringes.

  The mesh-like conductive layer according to the present invention needs to have a mesh pattern other than a portion that becomes a light-transmitting portion when installed on a display, that is, a portion other than an image display area or a portion hidden in frame printing. Alternatively, these portions may be unpatterned, for example, a solid metal. However, it is preferable that a mesh pattern is continuously formed on the mesh-like conductive layer from the viewpoint of uniformly coating the surface layer on the mesh-like conductive layer with good productivity.

  That the mesh pattern is continuously formed means that, for example, the mesh pattern of the mesh-like conductive layer is continuously formed in the longitudinal direction of the long base film without interruption.

(Base film)
As a base film used for the display filter of the present invention, a plastic film is preferable. Examples of the resin constituting the plastic film include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as triacetyl cellulose, polyolefin resins such as polyethylene, polypropylene, and polybutylene, acrylic resins, polycarbonate resins, arton resins, and epoxy resins. , Polyimide resin, polyetherimide resin, polyamide resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, and the like. Among these, polyester resins, polyolefin resins, and cellulose resins are preferable, polyester resins are particularly preferably used, and polyethylene terephthalate is more preferably used. The base film may be a laminated plastic film in which two or more layers made of the above resin are laminated.

  The thickness of the substrate film is suitably in the range of 50 to 300 μm, but is preferably in the range of 90 to 250 μm from the viewpoint of securing cost and rigidity of the display filter.

  The base film used in the present invention is a plastic having an easy-adhesion layer (primer layer) for enhancing adhesion (adhesion strength) with the above-described surface layer, mesh-like conductive layer, or near-infrared shielding layer described later. A film is preferred.

  The display filter according to the present invention is preferably composed of only one base film.

(Near-infrared shielding layer)
It is preferable to have a near-infrared shielding layer on the surface opposite to the surface on which the mesh-like conductive layer of the base film is laminated. The near-infrared shielding layer is preferably adjusted so that the average transmittance in the wavelength range of 800 to 1100 nm is 20% or less.

  The near-infrared shielding layer may be a resin layer containing a near-infrared absorber or a pressure-sensitive adhesive layer containing a near-infrared absorber. Near-infrared absorbers include organic near-infrared absorbers such as phthalocyanine compounds, anthraquinone compounds, dithiol compounds, diimonium compounds, or titanium oxide, zinc oxide, indium oxide, tin oxide, zinc sulfide, cesium-containing oxides An inorganic near infrared absorber such as tungsten can be used.

  As the resin binder, polyester resins, (meth) acrylic resins, (meth) acrylic urethane resins, polycarbonate resins, and the like are preferably used, and (meth) acrylic resins are particularly preferable.

  As the pressure-sensitive adhesive, an acrylic, silicone-based, urethane-based, polyvinyl butyral, or ethylene-vinyl acetate-based pressure-sensitive adhesive layer can be used. An acrylic adhesive is particularly preferable.

  The near-infrared shielding layer preferably further contains a dye having a maximum absorption at 570 to 610 nm, for example, a tetraazaporphyrin-based dye. The transmittance at the absorption maximum wavelength is preferably adjusted to be 30% or less.

  The near-infrared shielding layer can be provided with a color correction function by containing a dye having absorption in the vicinity of 500 nm and 550 nm.

(Adhesive layer)
The display filter of the present invention preferably has an adhesive layer on the outermost surface on the side opposite to the mesh-like conductive layer with respect to the base film. The pressure-sensitive adhesive layer has a function of attaching the display filter of the present invention directly to the display or indirectly through a high-rigidity transparent substrate such as a glass plate or an acrylic plate. The display filter of the present invention is preferably attached directly to the display filter.

  Moreover, when a near-infrared shielding layer is an adhesive layer, this adhesive layer can serve as the above-mentioned adhesive layer for sticking.

(Configuration of display filter)
The display filter according to the present invention is preferably a single substrate filter composed of only one substrate film. Although the preferable structural example of this single substrate filter is illustrated below, this invention is not limited to these.
1) Adhesive layer / Near-infrared shielding layer / Base film / Mesh-like conductive layer / Surface layer (hard coat layer)
2) Adhesive layer / Near-infrared shielding layer / Base film / Mesh-like conductive layer / Surface layer (hard coat layer / low refractive index layer)
3) Pressure-sensitive adhesive layer having a near-infrared shielding function / base film / mesh-like conductive layer / surface layer (hard coat layer)
4) Adhesive layer having a near-infrared shielding function / base film / mesh-like conductive layer / surface layer (hard coat layer / low refractive index layer)

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(Evaluation methods)
(1) Measurement of center line average roughness Ra of surface layer surface Based on JIS B0601 (1982), it measured using surface roughness measuring instrument SE-3400 (made by Kosaka Laboratory). It measured about five places of the sample, the average value was calculated | required, and it was set as centerline average roughness Ra of the surface layer surface. In addition, in the case of the measurement, what stuck the adhesive layer side of the sample to the glass plate of thickness 2.5mm was used. In the above measurement, the measuring needle was moved in the direction parallel to the fine wire portion of the mesh-like conductive layer and passed through the approximate center of the opening of the mesh-like conductive layer.
<Measurement conditions>
Feeding speed: 0.5mm / S
Cut-off value λc; 0.25 mm
Evaluation length: 8 mm.

(2) Measurement of the thickness of the mesh-like conductive layer and the surface layer As shown in FIG. 1, the sample cross section is cut out with a microtome according to the line segment Y passing through the center of gravity of the opening of the mesh-like conductive layer, and the cross section is electrolytically scanned. Observed with an electron microscope (Hitachi S-800, acceleration voltage 26 kV, observation magnification 3000 times), the thickness of the mesh-like conductive layer, the thickness of the surface layer from the mesh-like conductive layer surface (L), and The thickness (M) of the surface layer from the base film was measured. About each Example and the comparative example, it measured and averaged each of arbitrary 5 places from one sample of 20 cm x 20 cm size.

(3) Measurement of line width and pitch of mesh-like conductive layer Surface observation was performed at a magnification of 450 times using a Keyence digital microscope (VHX-200). Using the length measurement function, the line width and pitch of the lattice mesh conductive layer were measured. About each Example and the comparative example, it measured and averaged five arbitrary places from one sample of 20 cm x 20 cm size.

(4) Evaluation of glossiness <Preparation of sample for evaluation>
The adhesive layer side of each sample is attached to a glass plate, and black tape (Nitto Denko No. 21 Tokoku (Nitto Denko Corporation) is attached to the opposite side of the glass plate (the side opposite to the side on which the display filter sample is attached). BC)) was affixed to produce a sample for evaluation.
<Evaluation>
In a dark room, install a three-wavelength fluorescent lamp (National Parrook, three-wavelength daylight white (FL 15EX-N 15W)) at a location 50 cm directly above the surface of the display filter side of the sample for evaluation. The display filter side outermost surface of the evaluation sample is visually observed from a distance of 30 cm in front, and the sharpness of the contour of the fluorescent lamp image reflected on the display filter side outermost surface is evaluated according to the following criteria.
・ The outline of the reflected image is clearly visible: ○
・ The outline of the reflected image is slightly blurred: △
・ The outline of the reflected image is unclear: ×.

(5) Evaluation of transparency When the transparency on the surface layer side of the display filter is reduced, the black image viewed through the display filter appears whitish. It was evaluated with.
An evaluation sample is prepared in the same manner as in (4) above. This evaluation sample is placed on a desk in a general office work room (illuminance is about 500 lux under fluorescent lamp) so that the display filter side of the evaluation sample is on the top, and the evaluation sample is inclined from a 45 ° angle. It was observed visually, and how much whitish black of the black tape on the back of the evaluation sample looked was evaluated according to the following criteria.
・ Black does not look white at all: ○
・ Black looks a little whitish: △
・ Black looks quite whitish: ×.

(6) Evaluation of scratch resistance; steel wool hardness evaluation The scratch resistance is 10 reciprocations at a stroke width of 10 cm and a speed of 30 mm / sec by applying a load of 250 g to # 0000 steel wool on the surface layer surface of the display filter. After rubbing, the surface was visually observed, and the scratching was evaluated in the following five stages.
5th grade: No scratches 4th grade: 1 or more and 5 or less scratches 3rd grade: 6 or more and 10 or less scratches 2nd grade: 11 or more scratches 1st grade: Countless scratches on the entire surface In the above evaluation, If it is any of the third grade, the fourth grade, and the fifth grade, it is a pass level (◯), and the first grade and the second grade are impossible levels (×).

(7) Evaluation of interference fringes An evaluation sample is produced in the same manner as in (4) above. In a dark room, install a three-wavelength fluorescent lamp (National Parrook, three-wavelength daylight white (FL 15EX-N 15W)) at a location 50 cm directly above the surface of the display filter side of the sample for evaluation. The display filter outermost surface of the sample for evaluation is visually observed from a distance of 30 cm in front, and the degree of occurrence of interference fringes is evaluated according to the following criteria.
-Almost no interference fringes are observed: ○
-Generation of interference fringes is observed: x.

(8) Surface resistivity and antistatic property on the surface layer side According to JIS K6911 (1995), the surface resistivity on the surface layer side is a high resistivity meter (“Hiresta (registered trademark) -UPMCP manufactured by Mitsubishi Chemical Corporation). -HT450 "). However, instead of forming the back electrode with conductive rubber or conductive paint, a sample was placed on a metal plate, and the measurement atmosphere was a temperature of 20 ° C. and a humidity of 30% RH. The sample was measured before the pressure-sensitive adhesive layer was formed on the side opposite to the surface layer, or after the pressure-sensitive adhesive layer was peeled off, and a metal plate instead of the back electrode was adhered to the base film surface. The applied voltage was 500 V, and 1000 V when the surface resistivity was 1 × 10 ¹³ Ω / □ or more. The measurement results were evaluated according to the following criteria.
A: The surface resistivity is less than 1 × 10 ¹¹ Ω / □, and the antistatic property is excellent.
○: The surface resistivity is 1 × 10 ¹¹ Ω / □ or more and less than 1 × 10 ¹² Ω / □, and the antistatic property is good.
X: The surface resistivity is 1 × 10 ¹² Ω / □ or more and the antistatic property is poor.

(9) Measurement of number average particle diameter of metal oxide fine particles The number average particle diameter of metal oxide fine particles is measured by using a transmission electron microscope (H-7100FA type manufactured by Hitachi, Ltd.) to disperse inorganic fine particles. In a photographic projection obtained by photographing an object at a magnification of 100,000 to 500,000, the maximum diameter of each of 50 arbitrary particles is measured and averaged. The photographing magnification is appropriately selected according to the number average particle diameter of the metal oxide fine particles.

(10) Measurement of refractive index of surface layer A coating material of a layer to be measured is applied onto a silicon wafer using a spin coater so that the dry film thickness is 1.5 μm. Next, using an inert oven INH-21CD (manufactured by Koyo Thermo System Co., Ltd.), a film is formed by heat curing at 130 ° C. for 1 minute. About this film, the refractive index in 633 nm was measured with the phase difference measuring apparatus (Nikon Co., Ltd. product: NPDM-1000).

Example 1
A display filter was prepared as follows.
<Preparation of mesh conductive layer>
On one side of a polyethylene terephthalate film (thickness 100 μm) with an easy adhesion layer laminated on both sides, a nickel layer (thickness 0.01 μm) by sputtering, a copper layer (thickness 1.5 μm) by vacuum deposition, and by sputtering A copper nitride layer (thickness 0.03 μm) was formed in this order. Subsequently, a resist layer (alkali developing negative resist film) is laminated on the surface of the copper nitride layer, the resist layer is exposed and developed through a square lattice mesh pattern mask, and then subjected to an etching treatment. Finally, the resist layer was peeled and removed to produce a mesh-like conductive layer. This mesh-shaped conductive layer had a square lattice pattern with openings, a thickness of 1.5 μm, a line width of 20 μm, and a pitch of 300 μm.

<Formation of surface layer>
The following hard coat layer was laminated as a surface layer on the mesh conductive layer.
<Hard coat layer>
46 parts by mass of dipentaerythritol hexaacrylate, 40 parts by mass of urethane acrylate, 10 parts by mass of phosphorus-doped tin oxide (number average particle diameter 15 nm) as metal oxide fine particles, photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) 3.5 parts by mass of “Irgacure (registered trademark) 184”) and 0.5 parts by mass of a fluorosurfactant (DIC Corporation “Defenser (registered trademark) MCF-350-SF”) , A mixed solvent of methyl ethyl ketone and methyl isobutyl ketone) to prepare a coating material having a solid content concentration of 45 mass%.
The coating material prepared as described above was applied with a gravure coater, dried at 100 ° C., and then cured by irradiation with ultraviolet rays to form a hard coat layer. The thickness of the hard coat layer (thickness after drying and curing) was applied such that the thickness M from the surface of the base film of the surface layer in FIG. 2 was about 6 μm. The refractive index of this hard coat layer was 1.52.

<Preparation of display filter>
A display-use filter was prepared by laminating a pressure-sensitive adhesive layer having the following near-infrared shielding function on the surface opposite to the surface on which the mesh-like conductive layer and surface layer of the polyethylene terephthalate film were formed.
<Lamination of pressure-sensitive adhesive layer having a near-infrared shielding function>
200 parts by mass of acrylic pressure-sensitive adhesive (as an amount converted to the pressure-sensitive adhesive component) has 3 parts by weight of diimonium-based near infrared absorbing dye, 1 part by weight of phthalocyanine-based near infrared absorbing dye, and has a maximum absorption wavelength at 570 to 610 nm. A release PET film (thickness: 38 μm) prepared by mixing 0.3 part by mass of tetraazaporphyrin (trade name “PD-320”, manufactured by Mitsui Chemicals, Inc.) as a neon light cut pigment so that the dry thickness is 25 μm. ) Coated with a slot die coater and dried to form an adhesive layer. Next, the pressure-sensitive adhesive layer applied to the release PET film was laminated on the surface opposite to the surface on which the mesh-like conductive layer and the surface layer of the polyethylene terephthalate film were formed.

(Example 2)
A display filter was produced in the same manner as in Example 1 except that the hard coat layer was changed to the following.
<Hard coat layer>
46 parts by mass of dipentaerythritol hexaacrylate, 45 parts by mass of urethane acrylate, 5 parts by mass of phosphorus-doped tin oxide (number average particle diameter 15 nm) as metal oxide fine particles, photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) 3.5 parts by mass of “Irgacure (registered trademark) 184”) and 0.5 parts by mass of a fluorosurfactant (DIC Corporation “Defenser (registered trademark) MCF-350-SF”) And a coating solution having a solid content concentration of 45% by mass was prepared by dissolving and dispersing in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone, and the refractive index of the hard coat layer was 1.51.

(Example 3)
A display filter was produced in the same manner as in Example 1 except that the hard coat layer was changed to the following.
<Hard coat layer>
46 parts by mass of dipentaerythritol hexaacrylate, 35 parts by mass of urethane acrylate, 15 parts by mass of phosphorus-doped tin oxide (number average particle size 15 nm) as fine metal oxide particles, photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) 3.5 parts by mass of “Irgacure (registered trademark) 184”) and 0.5 parts by mass of a fluorosurfactant (DIC Corporation “Defenser (registered trademark) MCF-350-SF”) And a coating solution having a solid content concentration of 45% by mass was dissolved and dispersed in a mixed solvent of methyl ethyl ketone and methyl isobutyl ketone, and the refractive index of the hard coat layer was 1.53.

Example 4
In Example 1, the display filter was prepared in the same manner as in Example 1 except that the hard coat layer was coated so that the thickness of the hard coat layer (the thickness M from the surface of the base film of FIG. 2) was about 4 μm. Produced.

(Example 5)
In Example 1, the display filter was prepared in the same manner as in Example 1 except that coating was performed so that the thickness of the hard coat layer (the thickness M of the surface layer of FIG. 2 from the substrate film surface) was about 7 μm. Produced.

(Example 6)
A display filter was produced in the same manner as in Example 1 except that the hard coat layer was changed to the following.
<Hard coat layer>
46 parts by mass of dipentaerythritol hexaacrylate, 40 parts by mass of urethane acrylate, 10 parts by mass of antimony-doped tin oxide (number average particle diameter 30 nm) as metal oxide fine particles, photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) ) "Irgacure (registered trademark) 184") 3.5 parts by mass, fluorosurfactant (DIC Corporation "Defenser (registered trademark) MCF-350-SF" 0.5 parts by mass, organic solvent ( A paint having a solid content concentration of 45% by mass was prepared by dissolving and dispersing in a mixed solvent of propanol, methyl ethyl ketone, and methyl isobutyl ketone, and the refractive index of the hard coat layer was 1.52.

(Comparative Example 1)
In Example 1, a display filter was prepared in the same manner as in Example 1 except that the hard coat layer was coated so that the thickness of the hard coat layer (the thickness M of the surface layer from FIG. 2) was about 9 μm. Produced.

(Comparative Example 2)
A display filter was produced in the same manner as in Example 1 except that the hard coat layer was changed to the following.
<Hard coat layer>
46 parts by mass of dipentaerythritol hexaacrylate, 40 parts by mass of urethane acrylate, 3.5 parts by mass of photopolymerization initiator (“Irgacure (registered trademark) 184” manufactured by Ciba Specialty Chemicals), fluorine-based interface 0.5 parts by mass of an activator (DIC Corporation “Defenser (registered trademark) MCF-350-SF”) is dissolved and dispersed in an organic solvent (a mixed solvent of propanol, methyl ethyl ketone, and methyl isobutyl ketone) to obtain a solid content concentration. A paint of 45% by mass was prepared, and the refractive index of this hard coat layer was 1.50.

(Comparative Example 3)
A display filter was produced in the same manner as in Example 1 except that the hard coat layer was changed to the following.
<Hard coat layer>
36 parts by mass of dipentaerythritol hexaacrylate, 35 parts by mass of urethane acrylate, 25 parts by mass of phosphorus-doped tin oxide (number average particle diameter 15 nm) as metal oxide fine particles, photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) 3.5 parts by mass of “Irgacure (registered trademark) 184”) and 0.5 parts by mass of a fluorosurfactant (DIC Corporation “Defenser (registered trademark) MCF-350-SF”) , A mixed solvent of methyl ethyl ketone and methyl isobutyl ketone) to prepare a paint having a solid content concentration of 45% by mass, and the refractive index of this hard coat layer was 1.54.

(Comparative Example 4)
In Comparative Example 2, the display filter was prepared in the same manner as in Example 1 except that the hard coat layer was coated so that the thickness (the thickness M of the surface layer of FIG. 2 from the surface of the base film) was about 2 μm. Produced.

(Example 7)
A display filter was prepared as follows.
<Preparation of mesh conductive layer>
<Formation of mesh pattern electroless plating catalyst layer>
On one surface of a polyethylene terephthalate film (thickness: 100 μm) having an easy adhesion layer laminated on both sides, an electroless plating catalyst ink containing 10% by mass of an electroless plating catalyst (palladium chloride) with respect to the polyester resin. Gravure printing was performed on the mesh pattern, and heating drying was performed to form a mesh pattern electroless plating catalyst layer. The mesh pattern-shaped electroless plating catalyst layer had a square lattice pattern with openings, a line width of 20 μm, and a pitch of 300 μm.
<Copper plating>
The electroless plating catalyst layer was degreased with 5% sulfuric acid and then subjected to electroless copper plating to form an electroless copper plating layer on the electroless plating catalyst layer. Subsequently, electrolytic copper plating was performed on the electroless copper plating layer to form electrolytic copper plating. The total thickness of the electroless copper plating layer and the electrolytic copper plating layer was 1.8 μm.
<Formation of blackened layer>
On the electrolytic copper plating layer, nickel-zinc alloy plating was further applied to prepare a mesh-like conductive layer having a blackened layer. This mesh conductive layer had a thickness of 4.3 μm, a line width of 23 μm, and a pitch of 297 μm.
<Formation of surface layer>
The same hard coat layer as in Example 1 was applied on the mesh-shaped conductive layer so that the thickness of the hard coat layer (the thickness M of the surface layer of FIG. 2 from the surface of the base film) was about 10 μm. A display filter was produced in the same manner as in Example 1 except that.

(Comparative Example 5)
A display filter was produced in the same manner as in Example 7 except that the hard coat layer of Example 7 was changed to the following hard coat layer.
<Hard coat layer>
41 parts by mass of dipentaerythritol hexaacrylate, 35 parts by mass of urethane acrylate, 20 parts by mass of tin-doped indium oxide (number average particle diameter 150 nm) as metal oxide fine particles, photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) ) "Irgacure (registered trademark) 184") 3.5 parts by mass, fluorosurfactant (DIC Corporation "Defenser (registered trademark) MCF-350-SF" 0.5 parts by mass, organic solvent ( A mixed solvent of propanol, methyl ethyl ketone, and methyl isobutyl ketone) was dissolved and dispersed to prepare a coating material having a solid content concentration of 45% by mass.
The coating material prepared as described above was applied with a gravure coater, dried at 100 ° C., and then cured by irradiation with ultraviolet rays to form a hard coat layer. The thickness of the hard coat layer (thickness after drying and curing) was applied such that the thickness M from the surface of the base film of the surface layer in FIG. 2 was about 14 μm. The refractive index of this hard coat layer was 1.52.

(Example 8)
A display filter was produced in the same manner as in Example 1 except that the following antireflection layer (only the low refractive index layer) was laminated on the hard coat layer of Example 1.
<Antireflection layer (low refractive index layer)>
50 parts by mass of hollow silica, 50 parts by mass of an ultraviolet curable acrylic resin (dipentaerythritol triacrylate), 2 parts by mass of a photopolymerization initiator (“Irgacure (registered trademark) 184” manufactured by Ciba Specialty Chemicals) A low refractive index layer-forming coating solution (solid content concentration 3% by mass) prepared by dissolving and dispersing in a mixed solvent of methyl ethyl ketone and isopropyl alcohol is applied with a gravure coater so that the dry thickness becomes 0.1 μm, and dried. Then, the low refractive index layer (refractive index 1.35) was formed by irradiating with ultraviolet rays and curing.

(Evaluation)
About each sample of the Example produced above and a comparative example, the average thickness (L) from the mesh-like conductive layer surface of the surface layer, the average thickness (M) from the substrate film surface of the surface layer, the surface layer surface The center line average roughness Ra, the surface resistivity (antistatic property) on the surface layer side, glossiness, transparency, scratch resistance and interference fringes were measured and evaluated. The results are shown in Table 1.

  From the results shown in Table 1, all of the examples of the present invention have low surface resistivity on the surface layer side, excellent antistatic properties, good gloss, transparency and scratch resistance, and the occurrence of interference fringes is also suppressed. I understand that

  On the other hand, in Comparative Example 1, the average thickness (L) from the surface of the mesh-like conductive layer of the surface layer is 7 μm or more, and the surface resistivity is high and the antistatic property is inferior. In Comparative Example 1, the center line average roughness Ra of the surface layer surface was less than 20 nm, and the occurrence of interference fringes was observed.

  In Comparative Example 2, since the metal oxide fine particles are not contained in the hard coat layer, the surface resistivity is high and the antistatic property is inferior. In Comparative Example 2, the center line average roughness Ra of the surface layer surface was less than 20 nm, and the occurrence of interference fringes was observed.

  In Comparative Example 3, since the hard coat layer contains 18% by mass or more of metal oxide fine particles, the center line average roughness Ra of the surface layer surface is 60 nm or more, and glossiness and transparency are deteriorated.

  In Comparative Example 4, since the hard coat layer is laminated with an extremely thin film, the average thickness (L) from the surface of the mesh-like conductive layer of the surface layer is 1 μm or less, and the scratch resistance of the surface layer is inferior. In addition, since the hard coat layer does not contain metal oxide fine particles, the surface resistivity is high and the antistatic property is poor.

  In Comparative Example 5, since the hard coat layer contains 18% by mass or more of relatively large metal oxide fine particles having a number average particle diameter of 150 nm, the transparency is lowered. Moreover, since the average thickness (M) from the base film surface of a surface layer was large in the comparative example 5, generation | occurrence | production of the curl was recognized.

DESCRIPTION OF SYMBOLS 1 Base film 2 Mesh-like conductive layer / fine wire part 3 Surface layer

Claims (9)

  A display filter in which a base film, a mesh-like conductive layer, and a surface layer composed of one or more layers are laminated in this order, and the layer A adjacent to the mesh-like conductive layer in the surface layer is a metal oxide The fine particles are contained in an amount of 1% by mass to less than 18% by mass with respect to 100% by mass of the total solid content of the layer A, the average thickness of the surface layer from the surface of the mesh-like conductive layer is more than 1 μm and less than 7 μm, and the surface A filter for display, wherein the center line average roughness Ra of the layer surface is 20 nm or more and less than 60 nm.   The display filter according to claim 1, wherein the metal oxide fine particles are oxides of conductive metals.   The display filter according to claim 1 or 2, wherein the metal oxide fine particles have a number average particle diameter of less than 150 nm.   The display filter according to claim 1, wherein a thickness of the mesh conductive layer is 0.3 μm or more and less than 8 μm.   The display filter according to claim 1, wherein the surface layer includes at least a hard coat layer. The display filter according to claim 1, wherein the surface resistivity on the surface layer side is less than 1 × 10 ¹² Ω / □.   The display filter according to claim 1, wherein the average thickness of the surface layer from the surface of the base film is less than 12 μm.   The display filter according to any one of claims 1 to 7, further comprising a layer having a near-infrared shielding function on a surface opposite to a surface on which the mesh conductive layer of the base film is laminated.   The display filter according to claim 8, wherein the layer having a near-infrared shielding function is an adhesive layer.

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