WO2007037329A1 - Electromagnetic wave shield filter - Google Patents

Abstract

It is possible to provide an electromagnetic wave shield filter having blackened surface having a sufficient blackening degree and an excellent light reflection prevention even when used in a configuration exhibiting a wet color. The electromagnetic wave shield filter has at least a conductive mesh layer on a transparent substrate. At least one of the front surface and the rear surface of the conductive mesh layer is subjected to blackening treatment. The blackened surface has a total light ray reflectivity (RSCI) 12% or below when measured based on JIS Z8722 and a ratio (RSCE/RSCI) of a diffused light ray reflectivity (RSCE) against the total light ray reflectivity (RSCI) 0.8 or above.

Description

 Specification

 Electromagnetic shield filter

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to an electromagnetic wave shielding filter having light transmissivity, which shields (shields) electromagnetic waves generated from display cameras such as CRT and PDP.

 Background art

 [0002] In recent years, with the sophistication and increasing use of electrical and electronic equipment, electromagnetic noise interference (EMI) has increased, and cathode ray tubes (CRTs) and plasma display panels (PDPs! Electromagnetic waves are also generated on displays such as In order to shield this electromagnetic wave, an electromagnetic wave shielding filter disposed on the front surface of the display is known. The electromagnetic wave shielding filter used for such applications requires light transmission as well as electromagnetic wave shielding performance. Therefore, an electromagnetic wave shielding shield filter in which a transparent base material such as a resin film or a glass plate is used as a base material, and a mesh layer having conductivity is formed on the transparent base material by etching a metal foil or metal plating. Are known.

 [0003] As described above, when a mesh layer is formed using a copper foil or a copper plating layer, unnecessary light such as external light is reflected by the mesh layer, and the reflected metallic luster is the bright room contrast of the fluoroscopic image. Is lowered. Therefore, usually, the mesh layer has a blackened surface that has a black appearance such as a structure in which the surface is covered with a black-colored layer to prevent light reflection (Patent Document 1, Patent Document 2). ). At that time, it is said that the surface roughness of the blackened surface should be specified in terms of the high blackening degree and the improved light reflection preventing performance. For example, in Patent Document 1, the surface roughness Ra is defined as 0.1 to 10: L 00 m force. Patent Document 2 defines the arithmetic average roughness Ra defined in JIS B0601 within the range of 0.02-1.00 m.

 [0004] Patent Document 1: Japanese Unexamined Patent Publication No. 2000-286594

 Patent Document 2: Japanese Patent Laid-Open No. 2003-318596

 Disclosure of the invention

 Problems to be solved by the invention

[0005] An electromagnetic shielding filter rarely has a structure in which a mesh layer is directly exposed to air. In general, a transparent resin layer is often provided to cover the mesh layer in order to protect the mesh layer and add an optical filter function. Therefore, the blackened surface of the mesh layer on the side of the transparent resin layer is in a state where the transparent resin layer is closely adhered and wetted by the transparent resin layer. For this reason, the blackened surface has an appearance different from that when exposed to air (this is referred to as “wet color” following the color when the surface is wet with liquid). The phenomenon that looks like a wet color is the same in a configuration in which a mesh layer having the transparent substrate side as a blackened surface is laminated on the transparent substrate.

 Therefore, in the configuration that is normally used, the appearance of the black wrinkled surface is directly affected by this wet color, and if the arithmetic surface roughness Ra is specified as in the prior art, the blackened surface is In some cases, it was not possible to get enough blackness.

[0006] The present invention has been made to solve the above problems, and even when used in a configuration that exhibits a wet color, the blackness is sufficient and the light reflection preventing effect is excellent. An object of the present invention is to provide an electromagnetic wave shielding filter having a black surface.

 Means for solving the problem

[0007] An electromagnetic wave shielding filter according to the present invention that solves the above problems is an electromagnetic wave shielding filter having at least a conductive mesh layer on a transparent substrate, and at least the front and back surfaces of the conductive mesh layer. Any one or more of the above surfaces are blackened, and the total light reflectance (R) measured in accordance with JIS Z8722 of the blackened surface is 14% or less.

 SCI

 Diffuse light reflectivity (R) vs. light reflectivity (R)

 SCE ratio (R / R)

 SCI SCE SCI is not less than 0.8.

 The electromagnetic wave shielding filter according to the present invention has the above-mentioned specific range for the total reflectance and the ratio of the diffuse reflectance to the total reflectance for the blackened surface of the conductive mesh layer that has been blackened. Even when it is used in a configuration that exhibits a wet color, it can have a blackened surface with sufficient blackness and excellent anti-reflection effect, and display image visibility is good Can be.

In the electromagnetic wave shielding filter according to the present invention, when the blackened surface has minute irregularities, and a roughness curve is adopted as the contour curve of the minute irregularities, the roughness curve is sufficiently The point average roughness R¾ [IS (JIS B0601 (1994))] In view of being able to have a blackened surface having an excellent light reflection preventing effect and improving visibility, it is preferable.

[0009] The electromagnetic shielding filter according to the present invention has a configuration in which a transparent resin layer is laminated on the blackened surface of the conductive mesh layer having the blackened surface. It ’s okay. In the case of such a configuration, the blackened surface under the transparent resin layer can be protected from corrosion and scratches by the transparent resin layer. Furthermore, the blackened surface of the mesh layer under the transparent resin layer becomes wet when contacted with the transparent resin layer. However, according to the present invention, light is also applied to the blackened surface that has become wet. This is because it is excellent in terms of antireflection.

 The invention's effect

 [0010] The electromagnetic wave shielding filter according to the present invention has the total reflectance and the ratio of the diffuse reflectance to the total reflectance on the blackened surface of the blackened conductive mesh layer within the specific range. As a result, even when used in a configuration exhibiting a wet color, it is possible to have a blackened surface with sufficient blackness and an excellent antireflection effect. As a result, according to the electromagnetic wave shielding filter according to the present invention, the reflection of light is reduced, and the visibility of the image on the display can be improved by giving a contrast feeling.

 Brief Description of Drawings

 FIG. 1 is a cross-sectional view showing an example of an electromagnetic wave shielding filter according to the present invention.

 FIG. 2 is a cross-sectional view showing an example of a combination of blackened surfaces in a mesh layer of an electromagnetic wave shielding filter according to the present invention.

 [Fig. 3] (A) is the contour curve (roughness curve R), (B) is the probability density function ADF and load curve BAC, and (C) is (B) so that the probability density is positive on the vertical axis. FIG.

 [Fig.4] Probability density function ADF is shown by smoothing (probability density) curve Adc. An example of an upwardly convex curve shape suitable for the present invention is (A), and an example of a downwardly convex curve shape is (B ).

 Explanation of symbols

[0012] 1 Transparent substrate

 2 mesh layers

 21 Mesh conductor layer

22 Blackening layer 3 Transparent resin layer

 4 Substrate

 10 Electromagnetic shield filter

 ADF probability density function

 Adc probability density curve

 BAC load curve

 ML average line

 R roughness curve

 Rp (Roughness curve) maximum peak height

 Rv (roughness curve) maximum valley depth

 BEST MODE FOR CARRYING OUT THE INVENTION

[0013] An electromagnetic wave shielding filter according to the present invention that solves the above problems is an electromagnetic wave shielding filter having at least a conductive mesh layer on a transparent substrate, and at least the front and back surfaces of the conductive mesh layer. Any one or more of the above surfaces are blackened, and the total light reflectance (R) measured in accordance with JIS Z8722 of the blackened surface is 14% or less.

 SCI

 Light reflectivity (R)

 Diffuse light reflectivity (R) for SCI

 SCE ratio (R / R)

 SCE SCI is 0.8 or more.

[0014] In the present invention, the black wrinkle-treated surface is provided at least on the side where the observer views the electromagnetic wave shielding filter in the form in which the electromagnetic wave shielding filter is used for a display. In addition, the total light reflectance (R) measured in accordance with JIS Z8722 of the blackened surface in the present invention is a spectrocolorimeter (for example, co-camino) in accordance with JIS Z8722.

 SCI

 (Luta Sensing Co., Ltd., CM-3600d) is set to the reflection mode, the light source is the standard light D65, and the field of view is 2 °, and the detector is used for both diffuse reflection and specular reflection. The Y value (tristimulus value Υ Υ) was measured in the SCI (Specular Compenent Include) mode that measures the (integral) intensity of the total reflected light. Also, the diffused light reflectance (R) measured in accordance with JIS 228722 on the blackened surface is the same.

 SCE

Using a spectrocolorimeter, the light source and field of view are the same as described above, and the detector measures the (integrated) intensity of only the diffuse reflected light of the reflected light. This is a measurement of the Y value (tristimulus value Υ Υ) set to elude) mode.

[0015] The electromagnetic wave shielding filter according to the present invention optimizes the blackened surface so as to have the specific reflection characteristics as described above, so that it looks black even in wet color and becomes blackish. Further, the black level of the fluoroscopic image is prevented from being reduced by reflection of external light on the surface of the conductive mesh layer, and the black level can be improved. Therefore, when the electromagnetic wave shielding filter according to the present invention is provided, the visibility of the image on the display can be improved by providing a bright room contrast feeling of the fluoroscopic image.

[Layer structure]

 FIG. 1 is a cross-sectional view illustrating a basic form of an electromagnetic wave shielding filter 10 according to the present invention.

 FIG. 1 (Α) shows a configuration in which a conductive mesh layer 2 (hereinafter also simply referred to as “mesh layer”) is laminated on a transparent substrate 1. FIG. 1 (1) shows a configuration in which a conductive mesh layer 2 is laminated on the transparent substrate 1, and a transparent resin layer 3 is laminated on the conductive mesh layer 2. Further, the adherend layer 4 may be laminated on the transparent resin layer 3 as shown in FIG. 1 (C), or the transparent substrate 1 side may be attached as shown in FIG. 1 (D). The body layer 4 may be laminated. Further, in FIG. 1, the conductive mesh layer 2 is composed of a mesh-like conductor layer 21 and a blackish black layer 22, and the blackened surface of the mesh layer is black formed on the surface of the mesh-like conductor layer. It is formed as the surface of the chemical layer 22. FIG. 1 is an explanatory diagram in which the blackened surface is formed on the surface (upper side of the drawing) and both side surfaces of the line portion (line portion) of the conductor mesh layer 2. The blackened surface is provided on at least one of the front and back surfaces of the conductive mesh layer, and there are various combinations of treated surfaces as described later in FIG. The adherend layer 4 is, for example, a sheet-like, plate-like, or coating-like, various optical filters such as an antireflection filter and a near infrared absorption filter, a protective film, or a configuration of the display itself. This is a layer that has any function, such as the front substrate, which is a component.

[0017] Note that, as an electromagnetic wave shielding filter, other layers may be provided as necessary. For example, various layers and treatments in a conventionally known electromagnetic wave shielding filter, such as coating with a protective layer when there is a concern about wrinkles of the conductive mesh layer, are within a range that does not depart from the purpose and effect of the present invention. You can add it. [0018] Here, in the present invention, "front side" and "surface" refer to the side on which the conductive mesh layer is formed with respect to the transparent substrate as "front side" (also the side facing upward in the drawing) The surface (also the upper surface in the drawing) that faces in the same direction as the side on which the conductive mesh layer is formed is called “surface”. "Back side" and "back side" refer to the side (also the side facing the lower side of the drawing) or the side (also the lower side of the drawing) opposite to the above "front side" and "front side".

 [0019] In addition, when applied to a display application or the like, the surface on the observer side may be a back surface that is not the surface defined in the present invention.

 The above examples are not intended to limit the mode of the electromagnetic wave shielding filter of the present invention! /. Any device that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same function and effect is included in the technical scope of the present invention. The

 Hereinafter, the electromagnetic wave shielding filter of the present invention will be described in order from the transparent substrate for each layer.

 [Transparent substrate]

 The transparent substrate 1 is a layer for reinforcing a copper mesh layer having a low mechanical strength. Therefore, as long as it has light transmittance as well as mechanical strength, it may be selected and used depending on the application, taking into account heat resistance, insulation, etc. as appropriate. Specific examples of the transparent substrate include, for example, a plate and sheet (or a film, the same applies hereinafter) having an organic material strength such as transparent resin, and a plate having an inorganic material strength such as glass.

[0021] Examples of the transparent resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, terephthalic acid-cyclohexane dimethanol, ethylene glycol copolymer, and the like. Polyester resin such as nylon 6, polyamide resin such as nylon 6, polyolefin resin such as polypropylene and polymethylpentene, acrylic resin such as polymethyl methacrylate, styrene such as polystyrene and styrene-acrylonitrile copolymer Examples thereof include cellulosic resin, cellulose-based resin such as triacetyl cellulose, imide-based resin, and polycarbonate resin.

[0022] In addition, these fats may be used alone or in combination with a plurality of types of mixed fats (polymers). In addition, it is used as a single layer or a laminate of two or more layers. In the case of a resin sheet, a uniaxially stretched or biaxially stretched sheet is more preferable in terms of mechanical strength.

 In addition, additives such as ultraviolet absorbers, fillers, plasticizers, and antistatic agents may be appropriately added to these resins as needed.

 [0023] Examples of the glass include quartz glass, borosilicate glass, and soda lime glass. More preferably, the glass has a low thermal expansion coefficient, excellent dimensional stability and workability in high-temperature heat treatment, and an alkali component in the glass. Non-alkali glass that does not contain any of them, and can also be used as an electrode substrate for a display front substrate or the like.

 [0024] The thickness of the transparent substrate may be determined according to the application, and when it is made of a transparent resin with no particular limitation, it is usually 12 to: a force of about LOOO μm, preferably 50 to 500 μm. On the other hand, when the transparent substrate is a glass plate, usually about 1 to 5 mm is suitable. In any material, if the thickness is less than the above, the mechanical strength is insufficient and warping, sagging, breakage, etc. occur. If the thickness exceeds the above, the cost becomes high due to excessive performance, and it is difficult to reduce the thickness.

 [0025] Further, the transparent base material may be used also as a front substrate which is a constituent element of the display main body V. However, in the embodiment in which the electromagnetic wave shielding filter is used as a front filter disposed in front of the front substrate, the transparent base material is thin. The sheet is superior to the plate in terms of lightness, and the resin sheet is superior to the glass plate in terms of not being broken.

 [0026] In this respect, a resin sheet is preferred as the transparent substrate, and the material is a material, but among the resin sheets, polyester-based resin sheets such as polyethylene terephthalate and polyethylene naphthalate are particularly preferable. A biaxially stretched polyethylene terephthalate sheet is most preferable from the viewpoint of transparency, heat resistance, cost, and the like. The higher the transparency of the transparent substrate, the better. However, it is preferable that the light transmittance is preferably 80% or more in terms of visible light transmittance.

[0027] It should be noted that a transparent substrate such as a resin sheet is appropriately coated on its surface with corona discharge treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, pre-heat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, You may perform well-known easy-adhesion processing, such as.

The transparent substrate may be colored with a pigment or the like. Near infrared absorption, neon light by coloring Absorption, color adjustment, prevention of external light reflection, etc. can be achieved. For example, to a transparent substrate of rosin, various conventionally known dyes such as a near-infrared absorber, a neon light absorber, a color adjusting dye, and an external light antireflection dye may be added!

 [0028] [Conductive mesh layer]

 The conductive mesh layer 2 is a layer responsible for an electromagnetic wave shielding function, and is itself opaque, but by providing an opening in a mesh shape, both electromagnetic wave shielding performance and light transmittance are achieved. Is a layer. The conductive mesh layer in the present invention has at least one of the front and back surfaces as a blackened surface by blackening treatment, and the total light reflection measured in accordance with JIS Z 8722 of the blackened surface. Rate (R) is 14% or less, more preferably 12% or less

 SCI

 And the ratio of diffuse light reflectivity (R) to total light reflectivity (R) (R / R)

 SCI SCE SCE SCI

 Is more than 0.8. In the present invention, in order to give the above-mentioned specific reflection characteristics to the blackened surface, a necessary surface of the conductive mesh-like conductor layer 21 usually formed from a metal foil or the like as the main body of the conductive mesh layer. Then, the blackening layer 22 is formed by the blackening treatment, and the exposed surface of the blackening layer is used as the blackening treatment surface. In addition to the blackening layer, other layers such as a fender layer described later may be provided as a constituent layer of the conductive mesh layer as appropriate in that the mesh shape, which is a geometric feature of the mesh layer, is maintained. . When an electromagnetic wave shielding filter is used in a display, when other layers such as the anti-glare layer are formed on the outermost surface on the side where the observer views the electromagnetic wave shielding filter, the outermost layer Should be the blackened surface and have the above specific reflection characteristics.

[0029] (Mesh-like conductor layer)

The mesh-like conductor layer 21 is typically formed by etching a metal foil, but other layers are also significant in electromagnetic shielding performance. Therefore, in the present invention, the material and forming method of the mesh-like conductor layer are not particularly limited, and various mesh-like conductor layers in a conventionally known light-transmitting electromagnetic wave shielding filter are appropriately adopted. It can be done. For example, a mesh-like conductor layer is formed from the beginning on a transparent substrate using a printing method or a mating method, or the entire surface is initially formed on a transparent substrate by a plating method. After forming the conductor layer, it may be a mesh-like conductor layer formed by etching or the like to form a mesh-like conductor layer. [0030] For example, when the mesh shape of the mesh-like conductor layer is formed by etching, it can be formed by patterning the metal layer laminated on the transparent base material by etching to form an opening and forming a mesh shape. To laminate a metal layer on a transparent substrate, the metal layer prepared as a metal foil is laminated to the transparent substrate with an adhesive, or the metal layer is deposited, sputtered, plated, etc. without using an adhesive for laminating. It can also be laminated on a transparent substrate using one or more physical or chemical forming methods. Note that the mesh-like conductor layer by etching can be formed into a mesh-like mesh-like conductor layer by patterning a metal foil alone before being laminated on a transparent substrate by etching. This single-layer mesh conductor layer is laminated on a transparent substrate with an adhesive or the like. Among these, the metal foil is transparent with an adhesive because the mesh conductor layer with weak mechanical strength is easy to handle and excellent in productivity, and a commercially available metal foil can be used. A mesh-like conductor layer that is formed into a mesh-like shape by etching after being laminated on a material and laminated on a transparent substrate via an adhesive is typical. As the adhesive in this case, a known adhesive such as a non-sticky adhesive or an adhesive (adhesive layer) may be employed.

 [0031] The mesh-like conductor layer is not particularly limited as long as it is a substance having sufficient conductivity to exhibit electromagnetic wave shielding performance, but usually a metal layer is preferable because of its good conductivity. As described above, the metal layer can be formed by vapor deposition, plating, metal foil lamination, or the like. Examples of the metal material of the metal layer or the metal foil include gold, silver, copper, iron, nickel, and chromium. The metal of the metal layer may be an alloy, and the metal layer may be a single layer or multiple layers. For example, in the case of iron, low carbon rimmed steel is preferably low carbon steel such as low carbon aluminum killed steel, Ni—Fe alloy, Invar alloy, and the like. On the other hand, when the metal is copper, the metal material is copper or copper alloy, and there are rolled copper foil and electrolytic copper foil as the copper foil, but the thinness and uniformity, adhesion to the blackened layer, etc. From the viewpoint, electrolytic copper foil is preferable.

 [0032] The thickness of the mesh-like conductor layer made of the metal layer is about 1 to about LOO / zm, preferably 2 to 20 μm. If the thickness is too thin, it will be difficult to obtain sufficient electromagnetic shielding performance due to an increase in electrical resistance, and if the thickness is too thick, it will be difficult to obtain a high-definition mesh shape and the mesh shape will be less uniform. .

[0033] In addition, the front and back surfaces of the metal layer serving as the mesh-like conductor layer are bonded and laminated to the transparent substrate. When it is necessary to improve the adhesion with an adjacent layer such as a transparent adhesive layer, the surface is preferably a rough surface.

 In addition, the surface of the metal layer that becomes the mesh-like conductor layer may have the desired micro unevenness and low reflection characteristics even when the blackening layer is thinner when a blackened layer is additionally formed on the surface. From the point that it is easy to obtain, when the roughness curve is adopted as the contour curve of the surface of the metal layer as the mesh-like conductor layer, the surface roughness is the ten-point average roughness R¾ [IS CiIS B060K 1994 It is preferable that the year version)) is as described above.

[0034] (Blackening treatment)

 Blackening treatment is for preventing light reflection on the surface of the conductive mesh layer. The blackening treatment surface formed by the blackening treatment causes the black of the fluoroscopic image due to reflection of external light on the surface of the conductive mesh layer. By preventing the level from being lowered, the black level is improved, and the visibility of the image on the display is improved by giving a bright room contrast feeling of the fluoroscopic image. It is preferable to provide the black surface processing surface on all surfaces of the line portion (striated portion) of the conductive mesh layer. 1S In the present invention, at least one of the front and back surfaces is at least one surface and the black surface processing surface. To do. In the electromagnetic wave shielding filter according to the present invention, the side having the blackened surface is installed on the front surface of the display as the side on which the observer sees.

[0035] The blackened surface may be the surface of a single conductive mesh layer. In other words, if the conductive mesh layer is a single layer and the surface of the single layer has the above-mentioned specific reflection characteristics, the surface does not require additional blackening treatment. In the present invention, even if such additional blackening treatment is not performed, if the surface has the above-mentioned specific reflection characteristics, the resulting surface has the same physical properties. Is included in the present invention.

However, usually, a conductive layer such as a metal layer is employed for the conductive mesh layer in terms of conductivity necessary for the electromagnetic wave shielding function, and such a conductive layer usually has a surface color. Is often a metal color or the like, which is not a black surface in the present invention, which is not black. Therefore, in such a case, a blackening treatment such as forming a blackening layer to be described later is performed on the surface, and a blackened surface is realized on the surface of the formed blackening layer. To do. Also, providing a black layer on the surface means that the layer (mesh-like conductor layer, etc.) constituting the surface has a mesh. In addition to providing with a key or the like, the layer constituting the surface itself may be changed to a blackish layer from the surface to the inside by etching or the like. Therefore, the conductor mesh layer 2 is usually composed of a mesh-like conductor layer 21 having an electromagnetic wave shielding function due to conductivity, and a layer provided with a black layer 22 on at least one of the front and back surfaces. (See Figure 2).

 Therefore, when the target surface of the blackened surface having specific reflection characteristics according to the present invention is exemplified by the surface on which the blackened layer 22 is formed, both front and back surfaces of the line portion of the conductive mesh layer 2 (FIG. 2). (A)), front side only (Fig. 2 (B)), back side only (Fig. 2 (C)), front side and side (both sides or one side) only, back side and side (both sides or one side), entire surface (front and back side (Both sides) (Fig. 2 (D)). However, this is shown for the blackish-treated surface having the specific reflection characteristics. In addition to the blackish-treated surface shown above, the blackish-treated surface is usually included in the category of the blackened-treated surface. It may have a blackened surface that does not have the reflection characteristics. For example, the entire surface normally falls within the category of a blackened surface, but only the surface is a blackened surface having a desired reflection characteristic defined in the present invention.

 [0038] (Blackening surface)

 The blackish blue-treated surface of the conductive mesh layer in the present invention exhibits black or a color close to black (brown, dark blue, dark green, etc., including black) and conforms to JIS Z8722. The total light reflectance (R) measured by the method is 14% or less, preferably 12% or less, and the total light reflection is

 SCI

 Emissivity (R)

 Diffuse light reflectance for SCI (R)

 SCE ratio (R / R

 SCE SCI) has an optical property of 0.8 or more.

 [0039] By optimizing the black wrinkle-treated surface so as to have the specific reflection characteristics as described above, external light on the surface of the conductive mesh layer that looks black even in wet color and does not shine black The black level of the fluoroscopic image is prevented from being reduced due to reflection, and the black level can be improved. These can be achieved even in a wet color in which a transparent resin layer is further laminated on the blackish treated surface. When the electromagnetic wave shielding filter according to the present invention is provided, the image of the display is obtained by providing a bright room contrast feeling of a fluoroscopic image. Visibility can be improved.

[0040] The total light reflectance of the black wrinkle-treated surface in the present invention is a force of 14% or less, preferably 12% or less, and more preferably 8% or less. The lower the total reflectance, the more preferable is the point power that makes it appear black even in wet color. From technical difficulties The total reflectance of the blackened surface is usually 0.1% or more.

 Further, diffused light reflection with respect to the total light reflectance (R) of the blackened surface in the present invention.

 SCI

 The ratio (R / R) of the ratio (R) is 0.8 or more, preferably 0.9 or more, more preferably

SCE SCE SCI

 Or 0.95 or higher. Ratio of diffuse light reflectivity (R) to total light reflectivity (R)

 SCI SCE

 (R / R)

 Since SCE SCI is closer to 1, the diffuse reflection component in total reflection increases and the specular reflection component decreases, so that the black level without so-called black light can be improved.

 [0041] In order to make the reflection characteristics of the blackened surface according to the present invention the above-mentioned specific reflection characteristics, it is possible to adjust the blackening color and the shape of the micro unevenness by appropriately adjusting the conditions of the blackening process. I like it.

 As an aspect for setting the reflection characteristics of the blackened surface according to the present invention to the above-mentioned specific reflective characteristics, it is preferable that the blackened surface has fine irregularities in order to increase the diffuse reflection component. The specific reflection characteristics depend on various characteristics of the micro unevenness on the blackened surface.

 [0042] Among the minute irregularities, as one form of a preferable shape for obtaining the specific reflection characteristic, when a roughness curve is adopted as the contour curve of the blackened surface, the contour curve is used. Ten-point average roughness of the line R¾ [IS (JIS B0601 (1994 version)) force Sl / zm or more, more preferably 2 m or more. Here, there are a cross-sectional curve, a roughness curve, and a waviness curve as the contour curve of the black wrinkle treatment surface. In the present invention, a roughness curve R obtained by subtracting the waviness curve and the cross-sectional curve force is adopted. When the black wrinkle-treated surface has a 10-point average roughness R¾ [IS QIS B0601 (1994 version)) of 2 m or more, as described above, the specific reflection characteristics are likely to be obtained. The ten-point average roughness R¾ [IS CiIS B0601 (1994 version)) of the contour curve is more preferably 2 to 5 / ζ πι. From the viewpoint of ensuring the strength of the conductive mesh layer and the electromagnetic wave shielding property, it is preferable that the value of R¾ [IS is about half or less the thickness of the conductive mesh layer.

[0043] In addition, among the minute irregularities, as a preferred shape for obtaining the specific reflection characteristic, the probability density function CFIS of the contour curve when a roughness curve is adopted as the contour curve of the minute irregularity B0601 (2001 edition) regulation], the shape near the peak of probability density Force When the probability density is plotted on the vertical axis and taken upward (the horizontal axis is the amplitude value of the unevenness of the roughness curve), the curve becomes a convex curve. Are listed. Note that the upwardly convex “up” is the top when the probability density is taken on the vertical axis and the upward direction is a positive value of the probability density.

 In FIG. 3, FIG. 3 (A) shows a roughness curve R as a contour curve, and in the figure, the symbol ML is an average line. In addition, although there exist a cross-sectional curve, a roughness curve, and a waviness curve as a contour curve, the roughness curve R which subtracted the waviness curve from the cross-sectional curve force is adopted in the present invention. Fig. 3 (B) shows the probability density function ADF of the roughness curve and the load curve BAC (cumulative curve) of the roughness curve, in which the contour curve force of the roughness curve R of Fig. 3 (A) is also calculated. . In the figure, Rp is the maximum peak height of the roughness curve, and Rv is the maximum valley depth of the roughness curve. Fig. 3 (C) is a graph obtained by rotating Fig. 3 (B) 90 degrees in the counterclockwise direction so that the probability density becomes the vertical axis in the positive direction on the upper side of the drawing. In Fig. 3 (C), the horizontal axis between Rp and Rv and the vertical axis of probability density are true scales and not logarithmic scales. The shape shown by the probability density function ADF is fine and uneven as shown in Fig. 3 (C), so the probability density curve A dc is a smooth curve as shown in Fig. 4 (A). . The probability density function ADF obtained by measuring the surface becomes a jagged graph such as a bar graph as shown in Fig. 3 (B) and (C), and this is converted into a sliding force probability density curve by the least square method. , Capture the features of micro unevenness on the measurement surface. Note that a smooth curve of the probability density function means that if the surface measurement is repeated an infinite number of times, the jagged graph will be averaged and eventually the probability density function will approach a smooth curve. This corresponds to approximating the resultant force of a curve once or a small number of measurements. Then, like the probability density curve Adc shown in Fig. 4 (A), the blackened surface with a convex curve shape force on the shape force near the peak of the probability density curve is as shown in Fig. 4 (B). A blackening process in which the shape of the shape near the peak is pointed and has a cusp, and the curves located on the left and right of the straight line passing through the peak apex and parallel to the vertical axis are convex downward. Provides better antireflection performance than surface.

 The curve shape of the probability density function as described above is often obtained when, for example, the fine unevenness is rough and fine unevenness is superimposed on the unevenness.

In order to make the minute unevenness on the black wrinkle treated surface into the specific minute unevenness as described above, it will be described later. The conditions of the blackening process when forming such a blackened layer are adjusted as appropriate, or the fine unevenness of the surface of the target surface to be blackened, that is, the surface of the black ground surface is adjusted. In addition, when the base surface has a minute uneven surface rather than a mirror surface, when a blackened layer is additionally formed, it is easier to have the desired minute unevenness and reflection characteristics even if it is thinner. Yes. A preferable shape as the minute unevenness of the lower ground is as described above. The preferable conditions for the blackening process when forming the blackened layer will be described later.

 [0045] Further, the preferable black density of the blackened surface is 0.6 or more. The black density measurement method was set to the density standard A NSIT as an observation viewing angle of 10 degrees, observation light source D50, and illumination type using GRETAG SPM100-11 (trade name, manufactured by Kimoto) of COLOR CONTROL SYSTEM. After the white calibration, the test piece is measured.

 [0046] (Blackening layer)

 The black wrinkle layer 22 is a layer provided to give the black wrinkle treatment surface described above, and any known black may be used as long as it exhibits a dark color such as black and satisfies basic physical properties such as adhesion.匕 得 る 层 can be adopted as appropriate.

 Therefore, an inorganic material such as a metal or an organic material such as a black colored resin can be used for the blackening layer. For example, the inorganic material includes a metal such as a metal, an alloy, a metal oxide, or a metal sulfide. It is formed as a metal-based layer such as a compound. As a method for forming the metal-based layer, various conventionally known black spot treatment methods can be appropriately employed. Of these, blackening treatment by plating is preferable in terms of adhesion, uniformity, and ease. As a material for the plating method, for example, a metal such as copper, cobalt, nickel, zinc, molybdenum, tin, or chromium, or a metal compound is used. These are superior to the case of cadmium or the like in terms of adhesion and blackness.

[0047] When the mesh-like conductor layer is made of copper, such as a copper foil, a preferable plating method for the blackening treatment for forming the blackened layer includes a mesh-like conductor layer made of copper (mesh-like conductor layer). Cathodic electrodeposition method in which the conductive layer in front of the cathode layer is subjected to cathodic electrolysis in an electrolyte composed of sulfuric acid, copper sulfate, cobalt sulfate, etc. There is. According to this method, the rough surface can be obtained simultaneously with the black color by the adhesion of the cationic particles. Copper particles and copper alloy particles can be adopted as the cationic particles. The copper alloy particles are preferably copper-cobalt alloy particles, and the average particle size is preferably 0.001 to 1 / ζ πι. Yes. The copper-cobalt alloy particles can provide a black-coal layer that has a copper-cobalt alloy particle force. The cathodic electrodeposition method is also preferable in that the average particle diameter of the cationic particles to be adhered is adjusted to 0.001-1 m. When the average particle diameter is beyond the above range, the density of the adhered particles is reduced, blackness is reduced and unevenness occurs, and the particles are likely to fall off (powder falling). On the other hand, even if the average particle diameter is less than the above range, the blackness is lowered. In the cathodic electrodeposition method, when the treatment is performed at a high current density, the treated surface becomes cathodic and activated by the generation of reducing hydrogen, and the adhesion between the copper surface and the cationic particles is remarkably improved.

 [0048] Further, black chrome, black nickel, nickel alloy and the like are also preferred as the blackening layer. Examples of the nickel alloy include nickel-zinc alloy, nickel-tin alloy, and nickel-tin-copper alloy. In particular, the nickel alloy has a good degree of blackness and conductivity, and can also provide a blackening layer with a fouling function (becomes a black and white layer), and the fouling layer can be omitted. In addition, the particles in the black glazing layer are usually needle-like, and the external appearance is likely to change due to external force. However, the appearance of the black glazing layer made of nickel alloy is difficult to deform in the post-processing process. There are also advantages that are difficult to achieve. As the black alloy layer, the nickel alloy may be formed after nickel plating is performed by a known electrolytic or electroless plating method.

 Alternatively, when the mesh-like conductor layer is copper, there is a method in which the copper oxide fine particles are easily precipitated by reacting with an alkaline solution and oxidizing it. For example, as described in JP-A-2002-9484, a method of immersing a copper mesh layer in a mixed solution of a copper pyrophosphate aqueous solution, a potassium pyrophosphate aqueous solution, and an ammonia aqueous solution can be used.

 [0050] In the present invention, in order to make the blackened surface particularly have the above-mentioned reflection characteristics, a method for forming the blackened layer is appropriately selected depending on the surface state of the mesh-like conductor layer. To do. For example, when the surface roughness of the mesh-like conductor layer made of copper is relatively large, R¾ [IS is 1 μm or more, it is preferable to form a blackish silver layer by black nickel plating. In addition, when the surface roughness of the mesh-like conductor layer is relatively small, R¾ [When IS is less than 1 m, the force using copper particles or copper cobalt alloy particles with an average particle diameter of about lnm to l μm It is preferable to form a black soot layer by a soda electrodeposition method or by forming copper oxide fine particles having an average particle diameter of about 1 nm with an alkaline solution.

[0051] (Mesh shape) Note that the shape of the mesh layer 2 as a mesh shape is not particularly limited, but a square shape is typical as the shape of the mesh opening. The shape of the opening in plan view is, for example, a triangle such as a regular triangle, a square such as a square, a rectangle, a rhombus or a trapezoid, a polygon such as a hexagon, a circle or an ellipse. The mesh has a plurality of opening portions that also have these shape forces, and the openings are usually line-shaped line portions having a uniform width. Usually, the opening portions and the line portions have the same shape and the same size on the entire surface. As an example of the specific size, the width of the line portion between the openings is preferably 5 to 25 μm from the viewpoint of the aperture ratio and the invisibility of the mesh. The size of the opening is [line interval or line pitch]-[line width]. In terms of [line interval or line pitch], the opening size is 150 m to 500 m, and the opening ratio (the surface of the opening). The total product (total area of the Z mesh part) is preferably 80 to 95% in terms of compatibility between light transmittance and electromagnetic wave shielding! /.

 Note that the bias angle (the angle formed between the mesh line portion and the outer periphery of the electromagnetic wave shielding filter) may be appropriately set to an angle at which moire is difficult to occur in consideration of the pixel pitch of the display and the light emission characteristics.

 [0052] The mesh layer 2 may have a mesh shape over the entire surface of the electromagnetic wave shielding filter. The portion that requires light transmission is defined as a mesh-shaped mesh portion, and other portions (for example, all four sides are frame-shaped). It is also possible to use a non-mesh part. The non-mesh portion is a portion other than the mesh portion, and is a region where light transmittance is not required as a surface. Usually, a non-mesh part is provided on the outer periphery of the mesh part. Non-mesh parts are usually used for grounding. The non-mesh part used for grounding is usually framed around all four sides. In addition, the frame-like non-mesh portion enhances the appearance of the image seen through the mesh portion such as a display image by surrounding the image with a frame shape (for example, as a black frame) to enhance the image. It can also be used as an outer frame. When the non-mesh portion is grounded, it is preferable to expose the conductor layer at least at a part thereof.

 The specific size of the non-mesh part depends on how it is used, but when the frame is grounded or framed, the frame width should be about 15 ~: LOOmm, especially 30 ~ 40mm. Is.

[0053] (Protective layer) As the mesh layer 2, other layers may be appropriately formed or treated as necessary. For example, when durability against rust is insufficient, a fender layer may be provided. The protective layer is also the blackened layer described above. However, as long as it maintains the mesh shape, which is a geometric feature of the mesh layer, the protective layer is used as a constituent layer of the mesh layer in the present invention. Catch.

 The surface of the mesh layer may be easily applied to the surface of the mesh layer, but if it is applied on the blackened surface, the blackened surface after application (actually the surface of the protective layer) However, in the present invention, at least one of the front and back surfaces is a surface having desired reflection characteristics. The covering surface of the mesh layer by the fender layer is only the front surface, only the back surface, both front and back surfaces, only the side surface (both sides or one side), the front surface and both side surfaces, the back surface and both side surfaces, the front and back both surfaces and both side surfaces, and the like.

 [0054] The anti-corrosion layer is not particularly limited as compared with the mesh-like conductor layer covered with the anti-corrosion layer, and as long as it is an inorganic material such as a metal, an organic material such as a resin, or a combination of these, It is not a thing. In some cases, the black layer is also covered with a protective layer, so that the blackened layer can be prevented from falling off and deformed, and the black layer can be increased in blackness. In this regard, when the mesh-like conductor layer is formed of a metal foil, when the blackened layer is provided on the metal foil on the transparent substrate by the blackening treatment, the blackened layer is prevented from falling off or being altered. In this sense, it is preferably provided before the transparent substrate and the metal foil are stacked.

 [0055] For the fender layer, a conventionally known one may be used as appropriate, for example, a metal or alloy such as chromium, zinc, nickel, tin, copper, or a metal compound layer of metal oxide. is there. These can be formed by a known plating method or the like. Here, if it shows an example of a preferable antifouling layer in terms of antifouling effect and adhesion, a chromium compound layer obtained by chromate treatment after zinc plating can be mentioned.

 [0056] In the case of chromium, chromate (chromate) treatment or the like is also possible! The chromate treatment is performed by bringing the chromate treatment solution into contact with the treated surface.

 Further, the chromate treatment is preferable from the viewpoint of adhesion to zinc and the anti-mold effect before the treatment. In addition, a key compound such as a silane coupling agent may be contained in the fender layer for improving acid resistance during etching or acid cleaning.

The thickness of the fender layer is usually about 0.001 to 2111, preferably 0.01 to 1111. [0057] [Transparent resin layer]

 As illustrated in the cross-sectional view of FIG. 1B, the transparent resin layer 3 is covered on the mesh layer side by filling the surface unevenness by the conductive mesh layer 2 and flattening the surface on the mesh layer side. This is a layer provided as necessary to prevent air entrapment and to protect the mesh layer from external forces when laminating the adherend and adhesive. In terms of protection, the transparent resin layer is also a surface protective layer. In addition, as shown in FIG. 1C, the transparent resin layer 3 can be used as an adhesive layer that is interposed between the adherend 4 and the conductive mesh layer 2 and adheres both. Such a transparent resin layer 3 can be formed by applying a liquid composition containing a resin to the uneven surface of the conductive mesh layer 2 laminated on the transparent substrate 1 by coating or the like. The liquid composition is not particularly limited as long as it contains a transparent resin, and a known resin may be used as appropriate. For example, thermoplastic resin, thermosetting resin, ionizing radiation curable resin, and the like. Examples of thermoplastic resins include acrylic resin, polyester resin, thermoplastic urethane resin, and acetic acid resin resin, and thermosetting resins include thermosetting urethane resin, epoxy resin, and the like. Examples of the resin include thermosetting acrylic resin and ionizing radiation-curable resin. Of these, ionizing radiation curable resin, which can be formed in a solvent-free or nearly solvent-free state, is preferred because it can easily fill the unevenness caused by the mesh layer.

 [0058] It should be noted that, for the purpose of planarization, the transparent resin layer is sufficient to fill only the opening of the conductive mesh layer, as shown in Fig. 1 (B), including the portion directly above the line portion of the mesh layer. May be. When a transparent resin layer is provided including directly above the line part, when the surface of the mesh layer in contact with the transparent resin layer is a blackened surface, the transparent resin layer gives a wet color. In particular, in the present invention, even in the case of the wet color, since the light reflection preventing effect is high, the configuration in which the transparent resin layer including the line portion is formed is one of the preferable configurations.

 [Other layers: adherend, optical filter layer, surface protective layer, transparent adhesive layer, etc.]

The adherend is, for example, an optical filter layer (film, sheet, plate), a surface protective layer (film, sheet, plate) or the like. The optical filter function of the optical filter layer includes near infrared absorption, antireflection (including antiglare), color tone adjustment (neon light absorption, improved color reproducibility), and external light antireflection. Further, the functions of the surface protective layer are contamination prevention, scratch resistance, and the like. These may be appropriately selected from conventionally known ones. Also, the optical filter layer and the surface protective layer should be formed on the mesh layer, the transparent resin layer, or in the case of the optical filter layer on another optical filter layer by coating, etc., as an adherend of the transparent resin layer. You can also.

 [0060] Further, the adherend 4 may be laminated on the transparent substrate 1 side as shown in Fig. 1 (D), contrary to Fig. 1 (C). When the transparent substrate and the adherend are not adhesive to each other, they are appropriately laminated with a transparent adhesive layer interposed therebetween. As the transparent adhesive layer, a known adhesive such as a non-sticky adhesive or a pressure-sensitive adhesive (pressure-sensitive adhesive layer) may be employed. The transparent adhesive layer can be said to be one form of a transparent resin layer. Further, the adherend may be laminated on both the front and back surfaces of the electromagnetic wave shielding filter for display. In that case, the type (function) of the adherend can be used properly on the front and back.

 [0061] [Others]

 In addition, in the resin constituting the electromagnetic shielding filter such as a transparent substrate, a transparent resin layer, a transparent adhesive layer, and an adherend, an external light reflection preventing dye, a neon light absorber, and a color adjusting dye. In the electromagnetic wave shielding filter such as, etc., a known pigment may be added as appropriate.

[0062] Fig. 1 for explaining the details of the mesh layer and Fig. 2 for explaining the blackened surface are examples, and do not limit the form of the electromagnetic wave shielding filter of the present invention. Any device having substantially the same configuration as the technical idea described in the claims of the present invention and having the same effect can be included in the technical scope of the present invention. The Example

 Hereinafter, the present invention will be specifically described with reference to examples. These descriptions do not limit the present invention. In the examples, parts represent parts by weight unless otherwise specified. <Example 1>

 First, as a transparent substrate 1, an electrolytic copper foil with a thickness of 10 m is applied to the front side of a continuous belt-like uncolored transparent biaxially stretched polyethylene terephthalate film (thickness 100 m). Dry lamination was performed using a urethane-resin adhesive to produce a continuous belt-like copper-clad laminate sheet.

Next, the copper foil of the copper-clad laminate sheet was etched into a mesh shape by etching using a photolithography method, and the mesh-shaped conductor layer 21 was formed on the transparent substrate 1. A mesh laminated sheet was prepared.

 Next, the surface of the conductive mesh layer 2 (the surface of the conductive mesh layer 2 is subjected to a black color treatment for forming a black color layer 22 by black-packet plating on the surface of the mesh laminate sheet of the mesh laminated sheet. In addition, an electromagnetic wave shielding filter 10 as shown in FIG. 1 (A) having a blackened surface having the reflection characteristics shown in Table 1 on both sides was prepared. The formed mesh has a square opening, a line width of 25 m, and a line pitch of 150 m. In addition, the entire circumference of the four sides of the mesh part was a frame-like non-mesh part.

[0064] Further, the non-mesh portion of the acrylic resin coating liquid is partially exposed as a transparent resin layer 3 that also serves as an adhesive layer on the surface of the electromagnetic wave shielding filter 10 on the mesh layer side. As shown in the drawing, intermittent coating was performed on the mesh layer by an intermittent die coating method including a part of the inner periphery. Next, an 80 m-thick triacetyl cellulose film is used as the substrate for the coating after the solvent of the coating solution is dried, and a fluorine-based low refractive index layer is used as an antireflection layer on the surface. The antireflection film is laminated so that it faces the base layer side cache layer (the antireflection layer is exposed on the outermost surface), and a desired electromagnetic wave shielding filter with antireflection function is formed. Produced.

 <Examples 2 to 5>

 Except for changing each of the electrolytic copper foils in Example 1, the electromagnetic shielding filter 10 as shown in FIG. did. Next, an electromagnetic wave shielding filter with an antireflection function was produced in the same manner as in Example 1.

 <Example 6>

 Instead of changing the electrolytic copper foil in Example 1 and forming the black plating layer 22 by black nickel plating, the copper particles with an average particle diameter of lnm are attached and blackened by the cathodic electrodeposition method. Except that the layer 22 was formed, an electromagnetic wave shielding filter 10 as shown in FIG. 1 (A) having a blackened surface having the reflection characteristics shown in Table 1 was produced in the same manner as in Example 1. Next, in the same manner as in Example 1, an electromagnetic wave shielding filter with an antireflection function was produced.

 <Example 7>

In Example 1, the electrolytic copper foil was changed, and further, a black plating layer 22 by black nickel plating was added. Instead of forming, black cathodic layer 22 was formed by adhering copper-cobalt alloy particles having an average particle size of 0.1 μm by the cathodic electrodeposition method, as in Example 1. Thus, an electromagnetic wave shielding filter 10 as shown in FIG. 1 (A) having a blackened surface with reflection characteristics shown in Table 1 was produced. Next, in the same manner as in Example 1, an electromagnetic wave shield filter with an antireflection function was produced.

 <Example 8>

 Instead of changing the electrolytic copper foil in Example 1 and forming the black plating layer 22 by black nickel plating, the copper-cobalt alloy particles having an average particle diameter of 0 are attached by the cathodic electrodeposition method. In the same manner as in Example 1, except that the black layer 22 was formed, an electromagnetic shielding filter 10 as shown in Fig. 1 (A) having a blackened surface having the reflection characteristics shown in Table 1 was manufactured. did. Next, in the same manner as in Example 1, an electromagnetic wave shield filter with an antireflection function was produced.

 [0069] <Example 9>

 Instead of changing the electrolytic copper foil in Example 1 and forming the black plating layer 22 by black nickel plating, copper particles having an average particle diameter of 1 μm were deposited by the cathodic electrodeposition method, and then Further, the electromagnetic shielding filter as shown in FIG. 1 (A) having the blackened surface having the reflection characteristics shown in Table 1 was used in the same manner as in Example 1 except that the black plating layer 22 was formed by performing cobalt plating. 10 was produced. Next, in the same manner as in Example 1, an electromagnetic wave shield filter with an antireflection function was produced.

 <Example 10>

First, as a transparent substrate 1, a continuous strip-shaped uncolored transparent biaxially stretched polyethylene terephthalate film having a thickness of 100 m and having a polyester resin-based primer layer formed on one side was prepared. On the primer layer of the transparent substrate, a nickel-chromium alloy layer having a thickness of 0.1 μm and a copper layer having a thickness of 0.2 m were sequentially provided by sputtering to form a conductive treatment layer. On the surface of the conductive treatment layer, a copper plating layer having a thickness of 2.0 m is provided by an electrolytic plating method using a copper sulfate bath, and the conductive layer composed of the conductive treatment layer and the copper plating layer is formed on the transparent substrate. A copper-clad laminate sheet was produced which was directly formed without an adhesive layer in between. Next, the copper foil of the copper-clad laminate sheet is subjected to etching using a photolithographic method to give a mesh shape. Then, a mesh laminated sheet in which the mesh-like conductor layer 21 was formed on the transparent substrate 1 was prepared. Next, an average particle diameter of 0 .: L m is applied to the surface of the mesh laminated sheet on the mesh-like conductor layer side by an acid solution using a mixed solution of copper pyrophosphate aqueous solution, potassium pyrophosphate aqueous solution, and aqueous ammonia. The surface of the conductive mesh layer 2 (and both sides) has a blackened surface with the reflection characteristics shown in Table 1 and deposited on the surface of the conductive mesh layer 2 as shown in 01 (A). An electromagnetic wave shielding filter 10 was produced. Other than that, an electromagnetic wave shielding filter with an antireflection function was produced in the same manner as in Example 1.

 <Comparative Example 1, Comparative Example 2>

 An electromagnetic wave shield filter was produced in the same manner as in Example 1 except that the electrolytic copper foil was changed in Example 1.

 [0072] [Performance evaluation]

 First, Table 1 shows the characteristics of the blackened surface and the performance evaluation results for the electromagnetic wave shielding filters of Examples and Comparative Examples.

 The reflection characteristics and minute irregularities of the blackened surface were evaluated on the blackened surface of the mesh layer surface of the non-mesh part on the outer periphery of the mesh part of the mesh layer. In addition, the anti-reflection performance can also eliminate the influence of the opening of the mesh part, so that the non-mesh part (however, the inner peripheral part where the anti-reflection film is laminated through the transparent resin layer and becomes a wet color) went.

[0073] (1) Reflection characteristics of the blackened surface

 The total light reflectance (%) measured in accordance with JIS Z8722 on the blackened surface is determined by setting the spectrophotometer (for example, CM-3600d, manufactured by Co-Camino Norta Sensing Co., Ltd.) to the reflection mode. Uses standard light D65, 2 ° field of view, and puts the detector into SCI mode that measures the (integrated) intensity of the total reflected light, which is the sum of both diffuse and specular reflected light. Set and measure the Y value (Y of tristimulus values XYZ). Also, the diffused light reflectance (%) according to JIS Z8722 on the blackened surface is similarly measured by using a spectrocolorimeter, with the same light source and field of view, and absorbing and blocking the specular reflected light with an optical trap. The detector was set to SCE mode in which the (integral) intensity of only the diffuse reflected light out of the reflected light was set, and the Y value (Y of tristimulus values XYZ) was measured.

[0074] (2) Anti-reflection performance The evaluation of the antireflection performance of the electromagnetic wave shielding filter is based on the total light reflectivity (%) on the blackened surface side in the state of wet color after laminating the transparent resin layer and the antireflection film. Anti-reflection fill side force was also measured (“AR” in the table). The total light reflectance measurement method was the same as the total light reflectance measurement method in (1). When the total light reflectance (AR) in the wet color state is smaller, the total light reflectance is less than 5%.

[0075] (3) Ten-point average roughness of black wrinkle treated surface R¾ [IS, Ra

 The micro unevenness of the blackened surface is determined by the ten-point average roughness R¾ [IS QIS B0601 (1994 version), unit μm) of the contour curve when the roughness curve is adopted as the contour curve of the micro unevenness. evaluated. Further, as a reference value, the center line average roughness Ra QIS B0601 of the fine irregularities and the unit was μm) were also measured.

[0076] (4) Probability density curve

 Concerning the micro unevenness of the black and white processed surface, the probability density peak (top) of the probability density function CFIS B0601 (2001 edition) of the contour curve when the roughness curve is adopted for the contour curve of the micro unevenness ) When the shape of the vicinity is a curve with a smoothed probability density function and the probability density is taken on the vertical axis and taken upward (the horizontal axis is the amplitude value of the unevenness of the roughness curve), We looked at whether or not it would be a shape with curved force. Then, as shown in Fig. 4 (A), when the shape near the peak also has an upward convex curve force, it is `` convex upward '', and as shown in Fig. 4 (B), the shape near the peak is sharp. A curve that has a cusp and is located on the left and right with respect to a straight line that passes through the peak vertex and is parallel to the vertical axis.

Β§ίί to yourself.

[0077] [Table 1] table 1 ·

 -; Not measured

<Summary of results>

 As shown in Table 1, the total light reflectance (R) measured in accordance with JIS Z8722 on the blackened surface is 14% or less, and the diffused light reflectance (R) relative to the total light reflectance (R) is ratio

SCI SCI SCE

 All of the examples in which (R / R) is 0.8 or more do not satisfy these reflection characteristics.

SCE SCI

Compared to the comparative examples, the total light reflectance (AR) in the wet color state was small, and a superior antireflection performance was obtained. In Examples and Comparative Examples other than Examples 8 to 10, the arithmetic average roughness Ra of the surface is within the range of 0.2 to 1. O / zm, and the range that has been considered good in the past. However, it was found that there was a difference in performance depending on the reflection characteristics. In addition, Examples 8 to 10 reveal that good antireflection performance can be obtained even outside the range of the arithmetic average roughness Ra, which has been considered to be good in the past.

Claims

The scope of the claims  In an electromagnetic wave shielding filter having at least a conductive mesh layer on a transparent substrate, at least one of the front and back surfaces of the conductive mesh layer is blackened, and the blackened surface of the JIS The total light reflectance (R) measured according to Z8722 is 14  SCI  % And total light reflectance (R  Diffuse light reflectivity (R) for SCI)  SCE) ratio (R /  SCE  R) is an electromagnetic wave shielding filter characterized by being 0.8 or more.  SCI  The black wrinkle-treated surface has minute irregularities, and when a roughness curve is adopted as the contour curve of the minute irregularities, the ten-point average roughness R¾ [IS (JIS B0601 (1994 edition)) The electromagnetic wave shielding filter according to claim 1, wherein: The electromagnetic wave sheet according to claim 1 or 2, wherein a transparent resin layer is laminated on the blackened surface of the conductive mesh layer having the blackened surface. Filter.