JP2005175217A - Electromagnetic-wave shielding transparent film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain the facilitation of the method of the flowing of a resin layer by a pressing through a film on a conductive metal on which a geometric pattern is formed, and the method or the like of the coating of a resin for a coating even after the formation of the geometric pattern and the reduction of a manufacturing cost, although the methods have been conducted because a light is scattered on an irregular surface and an electromagnetic-wave shielding film is made opaque, since the roughened surface of a conductive metallic foil is transferred on the resin layer on a transparent base material and the irregular surface is formed when the geometric pattern composed of the conductive metal is formed on the transparent base material. <P>SOLUTION: In a manufacturing method for the electromagnetic-wave shielding transparent film, the conductive metallic foil is laminated to a plastic supporter through the resin layer using the smooth surface of the metallic foil as the resin layer side, and a part of the metallic foil is removed so that an opening ratio reaches 50% or more and the geometric pattern is formed. It is preferable that the surface roughness Rz of the smooth surface of the metallic foil is 1.5 μm or less. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing an electromagnetic wave shielding transparent film having shielding properties against electromagnetic waves generated from the front surface of a display such as CRT, PDP (plasma), liquid crystal, and EL, and an electromagnetic wave shielding body and a display using the film.

As a method for shielding electromagnetic noise generated from the front surface of a display such as a CRT or PDP, a method of forming a thin film conductive layer by depositing a metal or metal oxide on a transparent substrate (JP-A-1-278800, JP-A-5). -323101) is proposed. On the other hand, an electromagnetic shielding material (see JP-A-5-327274 and JP-A-5-269912) in which good conductive fibers are embedded in a transparent substrate, or a conductive resin containing metal powder or the like is directly applied on the transparent substrate. A printed electromagnetic shielding material (see JP-A-62-257297 and JP-A-2-52499), and further, a transparent resin layer is formed on a transparent substrate such as polycarbonate, and an electroless plating method is formed thereon. An electromagnetic shielding material (see Japanese Patent Application Laid-Open No. 5-283889) in which a copper mesh pattern is formed is proposed.
JP-A-1-278800 JP-A-5-323101 JP-A-5-327274 Japanese Patent Laid-Open No. 5-269912 JP 62-57297 A JP-A-2-52499 Japanese Patent Laid-Open No. 5-288989

  As a method for achieving both electromagnetic shielding properties and transparency, a thin film conductive layer is formed by depositing a metal or metal oxide on a transparent substrate disclosed in JP-A-1-278800 and JP-A-5-323101. In the method of forming the film, the surface resistance of the conductive layer becomes too large when the film thickness is such that transparency can be achieved (several hundreds to 2,000 mm). Therefore, 30 dB or more, preferably 50 dB or more required from 30 MHz to 1 GHz. It was insufficient with less than 30 dB for the shielding effect. In the electromagnetic shielding material (Japanese Patent Laid-Open No. 5-327274 and Japanese Patent Laid-Open No. 5-269912) in which the highly conductive fibers are embedded in the transparent base material, the electromagnetic shielding effect of 30 MHz to 1 GHz is 40 to 50 dB. When the fiber diameter is 25 μm, there is no problem, the pitch required for regularly arranging the conductive fibers is 50 μm or less, the aperture ratio is lowered and the transparency is impaired, and it is not suitable for display applications. . Similarly, in the case of an electromagnetic shielding material obtained by printing a conductive resin containing the metal powder of JP-A-62-257297 or JP-A-2-52499 directly on a transparent substrate by a screen printing method or the like, From the limit of printing accuracy, the line width was around 50 to 100 μm, and the transparency was lowered and the visibility of the line was developed. Therefore, it was not suitable as a front filter. On the other hand, in the method of forming a conductive metal geometric figure on a transparent substrate by photolithography, the roughened surface of the conductive metal foil is transferred to the resin layer on the transparent substrate to form an uneven surface. Therefore, light is scattered on the surface, and the electromagnetic wave shielding film becomes opaque. In order to solve the problem, until now, a resin is applied on a conductive metal on which a geometric figure is formed (Patent No. 3388682), or pressure is applied through a film to flow the resin layer (Patent) It was made transparent by a method such as No. 3386743). Therefore, simplification or omission of these methods is desired.

  About the shielding property of the electromagnetic wave generated from the front of the display, in addition to the electromagnetic shielding function of 30 dB or more, preferably 50 dB or more in 30 MHz to 1 GHz, not only good visible light transmittance and further visible light transmittance, but also shielding Non-visibility, which is a characteristic that the presence of the material cannot be confirmed with the naked eye, is also required. As an electromagnetic shielding transparent film having both electromagnetic shielding properties, transparency and non-visibility characteristics, the electromagnetic shielding transparent film having electromagnetic shielding properties and transparency / non-visibility, and the film, taking into consideration even mass production It is intended to provide a manufacturing method for stably mass-producing an electromagnetic shielding body and a display using the above.

The present invention relates to the following.
1. A conductive metal foil is laminated on a plastic support through a resin layer with the smooth side facing the resin layer, and part of the conductive metal foil is removed so that the aperture ratio is 50% or more. The manufacturing method of the electromagnetic shielding transparent film characterized by forming a figure.
2. Item 2. The method for producing an electromagnetic wave shielding transparent film according to Item 1, wherein the conductive metal foil having a smooth surface roughness Rz of 2.0 µm or less is used.
3. Item 3. The method for producing an electromagnetic wave shielding transparent film according to Item 1 or 2, wherein the smooth surface of the conductive metal foil is a surface on the rust-proof side.
4). Item 4. The method for producing an electromagnetic wave shielding transparent film according to Item 3, wherein the rust-proofing treatment uses nickel, tin, zinc, chromium, molybdenum, cobalt, or an alloy thereof.
5). Item 5. The method for producing an electromagnetic wave shielding transparent film according to any one of Items 1 to 4, wherein the smooth surface of the conductive metal foil is the surface on the side subjected to the chromate treatment.
6). Item 6. The method for producing an electromagnetic wave shielding transparent film according to any one of Items 1 to 5, wherein the smooth surface of the conductive metal foil is a surface treated with a silane coupling agent.
7). Item 6. The method for producing an electromagnetic wave shielding transparent film according to Item 5, wherein the silane coupling agent chemically reacts with the resin layer by heating.
8). Item 8. The method for producing an electromagnetic wave shielding transparent film according to Item 6 or 7, wherein the silane coupling agent is an amino-functional silane.
9. Item 10. The electromagnetic wave shielding transparent film according to any one of Items 1 to 8, wherein a line width of a geometric figure drawn with a conductive metal foil is 1 to 40 μm, a line interval is 50 to 500 μm, and a line thickness is 1 to 40 μm. Manufacturing method.
10. Item 10. The method for producing an electromagnetic wave shielding transparent film according to any one of Items 1 to 9, wherein the method of forming a geometric figure by partially removing the conductive metal foil so that the aperture ratio is 50% or more is a photolithographic method. Method.
11. Item 11. An electromagnetic wave shielding transparent film produced by the method for producing an electromagnetic wave shielding transparent film according to any one of Items 1 to 10.
12 Item 12. An electromagnetic wave shielding body comprising the electromagnetic wave shielding transparent film according to Item 11 and a transparent substrate.
13. Item 13. A display using the electromagnetic wave shielding transparent film according to Item 11 or the electromagnetic wave shielding material according to Item 12.

According to this invention, since the geometrical figure of electroconductive metal foil can be formed with sufficient precision, an electromagnetic wave shield film is obtained. Moreover, the adhesiveness to a resin layer can be improved because the smooth surface of electroconductive metal foil is the surface which carried out the antirust process, the surface which carried out the chromate treatment, or the surface processed with the silane coupling agent. Further, the geometric figure is a geometric figure drawn with conductive metal foil having a line width of 1 to 40 μm, a line interval of 50 to 500 μm, and a line thickness of 1 to 40 μm. The property is surely excellent. Furthermore, by using a photolithographic method as a method for forming a geometric figure, the geometric figure is formed with high accuracy, and it is easy as a method for producing an electromagnetic wave shielding film.
In addition, an electromagnetic shielding body excellent in non-visibility, electromagnetic shielding ability and transparency that can be applied to a high-definition display using such an electromagnetic shielding film is obtained, and such an electromagnetic shielding transparent film or electromagnetic shielding body is obtained. By using it, a display having excellent electromagnetic shielding properties and excellent visibility can be obtained.

  When an electromagnetic shielding transparent film is used for the display, the visible light transmittance is large and the invisibility is good, so that a clear image can be comfortably displayed under almost the same conditions as normal without increasing the display brightness. You can appreciate it. The electromagnetic wave shielding transparent film and the electromagnetic wave shielding body of the present invention are excellent in electromagnetic wave shielding properties and transparency. Therefore, in addition to the display, the electromagnetic wave is generated or protected from electromagnetic waves. It can be used by being provided in a portion such as a window or a case that looks inside, particularly a window that requires transparency.

The metal foil used in the present invention has a smooth surface on at least one side, and the degree of smoothness is preferably such that the 10-point average roughness (Rz) shown in JIS B 0601 is 2.0 μm or less. As long as Rz of the smooth surface of the conductive metal foil is 2.0 μm or less, either the glossy side or the rough side of the conductive metal foil may be used. Rz is particularly preferably 1.5 μm or less.
Ordinary metal foils are subjected to roughening treatment by oxidation treatment, reduction treatment, etching and the like, but those subjected to the roughening treatment generally have an Rz larger than 2.0 μm.

Examples of the conductive metal foil material include copper, aluminum, nickel, iron, gold, silver, platinum, tungsten, chromium, titanium, tin, lead, and palladium, and a combination of one or more of them. Alloys such as stainless steel and solder can also be used. Silver, copper or nickel is suitable in terms of conductivity and price. On the other hand, when a paramagnetic metal such as iron, nickel, or cobalt is used as the conductive metal foil, it is possible to improve the shielding property of the magnetic field in addition to the electric field. When the conductive metal foil is in the state of a foil, it is preferable because it is easy to continuously produce a structure in which a plastic support, a resin layer, and a conductive metal foil are sequentially laminated. The thickness of the conductive metal foil is preferably 40 μm or less.
For example, in the case of a copper sulfate bath, the production conditions of the copper foil are sulfuric acid 50-100 g / L, copper 30-100 g / L, liquid temperature 20 ° C.-80 ° C., current density 0.5-100 A / dm ² , In the case of a copper pyrophosphate bath, the conditions of potassium pyrophosphate 100-700 g / L, copper 10-50 g / L, liquid temperature 30 ° C.-60 ° C., pH 8-12, current density 1-10 A / dm ² are generally good. In some cases, various additives are added in consideration of the physical properties and smoothness of copper.

A peelable type metal foil having a thickness of 0.5 to 10.0 μm and a rough metal foil surface roughness Rz of 1.5 μm or less may be used. Here, the peelable type metal foil is a metal foil having a carrier, which is a metal foil that can be peeled off by the carrier. For example, in the case of a peelable type ultra-thin copper foil, a metal oxide or organic layer to be a release layer is formed on a carrier foil having a thickness of 10 to 50 μm, and a sulfuric acid 50 to 100 g / h is used on the copper sulfate bath. L, copper 30-100 g / L, liquid temperature 20 ° C.-80 ° C., current density 0.5-100 A / dm ² condition, potassium pyrophosphate bath 100-700 g / L potassium pyrophosphate, copper 10-50 g / L, a liquid temperature of 30 ° C. to 60 ° C., a pH of 8 to 12, and a current density of 1 to 10 A / dm ² are produced by forming a metal foil having a thickness of 0.5 to 10.0 μm.
By using a thin metal foil, the degree of over-etching can be minimized, so that the accuracy of circuit processing is greatly improved. At this time, in the metal foil that has not been subjected to the roughening treatment, the roughened copper foil is less likely to sink into the resin, so that the circuit processing accuracy is also greatly improved in this respect. However, if the thickness of the metal foil is too small, the electromagnetic wave shielding property tends to be lowered. Therefore, the thickness is preferably 0.5 μm or more, and particularly preferably 3 μm or more.

As a conductive metal foil, when using a material that easily rusts, for example, copper, aluminum, iron, etc., at least the smooth surface of the rust prevention treatment, any of nickel, tin, zinc, chromium, molybdenum, cobalt, Or it can carry out by forming the layer of those alloys on the surface of metal foil. For this purpose, a method of forming a thin film on a metal foil by sputtering, electroplating or electroless plating is preferable from the viewpoint of cost. Specifically, plating is performed using a plating layer containing one or more metal salts of nickel, tin, zinc, chromium, molybdenum, and cobalt. In order to facilitate the precipitation of metal ions, a complexing agent such as citrate, tartrate or sulfamic acid can be added in the required amount. The plating solution is usually used in an acidic region and is performed at a temperature of room temperature to 80 ° C. The plating is appropriately selected from a range of usually a current density of 0.1 to 10 Å / dm ² , an energization time of 1 to 60 seconds, preferably 1 to 30 seconds. The amount of the rust-proofing metal varies depending on the type of metal, but is preferably 10 to 2,000 μg / dm ^{2 in} total. If the rust preventive treatment is too thick, it may cause etching inhibition and deterioration of electrical characteristics, and if it is too thin, it may cause a reduction in peel strength with the resin. In addition, if metal foil is the same as these rust-proof metal, it is not necessary to give a rust-proof process.
When the conductive metal foil that is easily rusted is oxidized, the adhesiveness with the resin layer is lowered.

Furthermore, the smooth surface of the conductive metal foil may be chromated. This chromate treatment may be performed on the above rust prevention treatment. If the smooth surface of the conductive metal foil is chromated, it is useful because the adhesive strength (for example, peel strength) with the resin layer can be improved (at least the reduction can be suppressed). Specifically, it is performed using an aqueous solution containing hexavalent chromium ions. The chromate treatment can be performed by a simple immersion treatment, but is preferably performed by a cathode treatment. Cathodic treatment can be performed by connecting a metal foil to the cathode and conducting electricity in an aqueous solution containing hexavalent chromium ions. For example, sodium dichromate 0.1-50 g / L, pH 1-13, bath temperature 0-60 ° C., current density 0.1-5 A / dm ² , electrolysis time 0.1-100 seconds. good. It can also carry out using chromic acid or potassium dichromate instead of sodium dichromate. The chromate treatment is preferably performed in advance on the rust-proof metal foil before use.

In the present invention, the smooth surface of the conductive metal foil is preferably treated with a silane coupling agent. The silane coupling agent treatment can be performed on the above rust prevention treatment or chromate treatment. By this treatment, the titan coupling agent is adsorbed on the smooth surface, and the adhesion with the resin layer can be improved. Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, epoxy-functional silanes such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N- Amino-functional silanes such as 2- (aminoethyl) 3-aminopropyltrimethoxysilane and N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, vinyltrimethoxysilane, vinylphenyltrimethoxysilane, vinyltris (2 Olefin functional silanes such as -methoxyethoxy) silane, acrylic functional silanes such as 3-acryloxypropyltrimethoxysilane, methacryl functional silanes such as 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysila And mercapto-functional silanes and the like are used. These may be used alone or in combination. These coupling agents are dissolved in a solvent such as water at a concentration of 0.1 to 15 g / L and applied to a metal foil at a temperature of room temperature to 50 ° C. or electrodeposited to be adsorbed. These silane coupling agents form a film by condensation bonding with a hydroxyl group of a rust-preventing metal on the surface of the metal foil. After the silane coupling treatment, a stable bond is formed by heating, ultraviolet irradiation or the like. If it is heating, it is dried at a temperature of 100 to 200 ° C. for 2 to 60 seconds. In the case of ultraviolet irradiation, it is performed in the range of 200 to 400 nm and 200 to 2500 mJ / cm ² .

  The combination of the resin layer and the silane coupling agent is preferably selected so that the functional group of the resin present in the resin layer and the functional group of the silane coupling agent chemically react by heating. For example, when an epoxy group is contained in the resin, an amino functional silane (amino group such as amino group, alkylamino group, dialkylamino group or the like, or one or two of its hydrogen atoms is a substituent as a silane coupling agent. When a silane compound containing a substituted amino group is selected, the effect is more remarkably exhibited. This is because the epoxy group and amino group easily form a strong chemical bond by heat, and this bond is extremely stable against heat and moisture. As a combination for forming a chemical bond in this manner, epoxy group-amino group, epoxy group-epoxy group, epoxy group-mercapto group, epoxy group-hydroxyl group, epoxy group-carboxyl group, epoxy group-cyanato group, amino group-hydroxyl group , Amino group-carboxyl group, amino group-cyanato group and the like.

  Typical examples of the resin layer for bonding the plastic support and the conductive metal foil and the resin layer for covering the geometrical figure drawn with the conductive metal include the following thermoplastic resins. For example, natural rubber (n = 1.52: n represents a refractive index, the same applies hereinafter), polyisoprene (n = 1.521), poly-1,2-butadiene (n = 1.50), polyisobutene (n = 1.505 to 1.51), polybutene (n = 1.513), poly-2-heptyl-1,3-butadiene (n = 1.50), poly-2-t-butyl-1,3-butadiene (Di) enes such as (n = 1.506), poly-1,3-butadiene (n = 1.515), polyoxyethylene (n = 1.456), polyoxypropylene (n = 1.450) ), Polyethers such as polyvinyl ethyl ether (n = 1.454), polyvinyl hexyl ether (n = 1.659), polyvinyl butyl ether (n = 1.456), polyvinyl acetate (n = 1.467), poly Polyesters such as nilpropionate (n = 1.467), polyvinyl butyral resin (n = 1.52), EVA resin (n = 1.48-1.49), polyvinyl acetate resin (n = 1. 5), polyurethane (n = 1.5 to 1.6), polyester polyurethane (n == 1.5 to 1.6), ethyl cellulose (n = 1.479), polyvinyl chloride (n = 1.54 to 1.55), polyacrylonitrile (n = 1.52), polymethacrylonitrile (n = 1.52), polysulfone (n = 1.633), polysulfide (n = 1.6), phenoxy resin (n = 1.5-1.6), polyethyl acrylate (n = 1.469), polybutyl acrylate (n = 1.466), poly-2-ethylhexyl acrylate (n = 1.463), poly-t- Tyl acrylate (n = 1.464), poly-3-ethoxypropyl acrylate (n = 1.465), polyoxycarbonyltetramethacrylate (n = 1.465), polymethyl acrylate (n = 1.472-1. 480), polyisopropyl methacrylate (n = 1.473), polydodecyl methacrylate (n = 1.474), polytetradecyl methacrylate (n = 1.475), poly-n-propyl methacrylate (n = 1.484) Poly-3,3,5-trimethylcyclohexyl methacrylate (n = 1.484), polyethyl methacrylate (n = 1.485), poly-2-nitro-2-methylpropyl methacrylate (n = 1.487), Poly-1,1-diethylpropyl methacrylate (n = 1.490), polymer Poly (meth) acrylic acid esters such as til methacrylate (n = 1.490) can be used. Two or more kinds of these acrylic polymers may be copolymerized as required, or two or more kinds may be blended and used.

Furthermore, as the reactive resin, epoxy acrylate (n = 1.48 to 1.60), urethane acrylate (n = 1.5 to 1.6), polyether acrylate (n = 1.48 to 1.49), Polyester acrylate (n = 1.48 to 1.54) or the like can also be used. In particular, urethane acrylate, epoxy acrylate, and polyether acrylate are excellent from the viewpoint of adhesiveness. As the epoxy acrylate, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, allyl alcohol diglycidyl ether, resorcinol (Meth) acrylic such as diglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, polyethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, sorbitol tetraglycidyl ether An acid adduct is mentioned. A polymer which reacts like an epoxy acrylate or originally has a hydroxyl group in the molecule is effective for improving the adhesion. These reactive resins can be used in combination of two or more as required.
As the resin having an epoxy group reactive with the amino-functional silane, those having an epoxy group can be used.
It is preferable that a curing agent is used in combination with the reactive resin. Such curing agents include amines such as triethylenetetramine, xylenediamine, N-aminotetramine, diaminodiphenylmethane, phthalic anhydride, maleic anhydride, dodecyl succinic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, etc. Acid anhydride, diaminodiphenylsulfone, tris (dimethylaminomethyl) phenol, polyamide resin, dicyandiamide, ethylmethylimidazole, and the like can be used. These may be used alone or in combination of two or more. The addition amount of these curing agents is preferably 0.1 to 50 parts by weight, particularly 1 to 30 parts by weight, based on 100 parts by weight of the reactive resin.
The reactive resin can be used in combination with the thermoplastic resin.

  For the resin used in the present invention, an infrared absorber, an ultraviolet absorber, a filler, a tackifier dispersant, a thixotropy imparting agent, an antifoaming agent, a leveling agent, a diluent, a plasticizer, and an oxidation, if necessary. You may mix | blend additives, such as an inhibitor, a metal deactivator, a coupling agent, and a filler. These resins or resin compositions can be dissolved in an ordinary general-purpose solvent or used without a solvent.

The softening temperature of the resin composition containing these resins or additives is preferably 200 ° C. or less and more preferably 150 ° C. or less from the viewpoint of handleability. 80 to 120 ° C. is most preferable from the viewpoint of manufacturing a structure in which a plastic support, a resin layer, and a conductive metal foil are sequentially laminated, and workability in the case of covering from a geometric figure. The reactive resin is preferably softened or fluidized at such a temperature before curing. The softening temperature is a temperature at which the viscosity becomes 10 ¹² poises or less, and normally, the flow is recognized within a time of about 1 to 10 seconds at that temperature.
The resin layer is preferably one that flows and exhibits an adhesive function by exhibiting fluidity by heating or pressurization (for example, heating at 200 ° C. or lower or pressurization at 1 Kgf / cm ² or higher).

As a refractive index of the resin layer used by this invention, it is preferable to use the thing of the range of 1.35-1.70. This is because when the refractive index of the plastic support and the resin layer used in the present invention is different, the visible light transmittance is lowered. When the refractive index is 1.35 to 1.70, the visible light transmittance is lowered. The refractive index of the above-mentioned polymer which is small and good is within this range.
The coating resin layer used in the present invention preferably has a refractive index in the range of 1.35 to 1.70. This is because the visible light transmittance is reduced when the refractive index of the plastic support or resin layer used in the present invention is different from the refractive index of the coating resin layer, and the refractive index is 1.35 to 1.70. The refractive index of the above-described polymer, which is good with little reduction in visible light transmittance, is within this range.

  Examples of the plastic support used in the present invention include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefins such as polyethylene, polypropylene, polystyrene, and ethylene-vinyl acetate copolymer (EVA), polyvinyl chloride, A film made of plastic such as vinyl resin such as polyvinylidene chloride, polysulfone, polyethersulfone, polycarbonate, polyamide, polyimide, acrylic resin, etc. It has a total visible light transmittance of 70% or more, including colorless or colored, and a thickness of 1 mm. The following are preferred. These can be used as a single layer, but may be used as a multilayer film in which two or more layers are combined. Among these, a polyethylene terephthalate film or a polycarbonate film is preferable from the viewpoint of transparency, heat resistance, ease of handling, and price. As for the thickness of a plastic film, 5-500 micrometers is more preferable. When the thickness is less than 5 μm, the handleability deteriorates, and when the thickness exceeds 500 μm, the visible light transmittance decreases. 10-200 micrometers is further more preferable. On the other side of the plastic support, gold, silver, copper, aluminum, nickel, iron, cobalt, chromium, tin, titanium, etc. can be used by methods such as vacuum deposition, sputtering, CVD, spraying, and printing. A conductive thin film layer may be formed using these alloys, or indium oxide, tin oxide and a mixture thereof (hereinafter referred to as ITO), titanium oxide, stannic oxide, cadmium oxide or a mixture thereof. Good.

  In order to improve the adhesion between the resin layer and the plastic support, the plastic support can be subjected to various surface treatments. As the surface treatment, a primer coating treatment, a plasma treatment, a corona discharge treatment or the like is effective. With these treatments, the critical surface tension of the plastic support after treatment is preferably 35 dyn / cm or more, more preferably 40 dyn / cm or more. When the critical surface tension is less than 35 dyn / cm, the adhesiveness with the resin layer tends to decrease.

In order to adhere the plastic support and the conductive metal foil, the resin or the resin composition is applied to the plastic support or the conductive metal foil, or the film-like resin or the resin composition is laminated. There is a method in which a layer is formed and both are bonded through a resin layer. In this case, the resin layer may be formed on both the plastic support or the conductive metal foil, and the bonding surface or the resin layer forming surface of the conductive metal foil is the smooth surface described above.
As a method for applying the resin or the resin composition, there is a method in which a varnish obtained by dissolving or dispersing the resin or the resin composition in a solvent is applied using a kiss coater, a roll coater, a comma coater or the like. Thereafter, heating and drying are performed, and it is appropriate that the temperature is from room temperature to 200 ° C. (more preferably, 50 ° C. or more) for 1 to 30 minutes. The amount of residual solvent in the resin composition after heating and drying Is suitably about 0.2 to 10%. In addition, when reactive resin is used, it is preferable to make it a semi-hardened state, without making it harden | cure completely.
As the conditions for the pressure bonding, a temperature of 50 to 150 ° C., a pressure of 0.1 to 5 MPa, a reduced pressure or an atmospheric pressure are appropriate. The thickness of the resin layer is preferably about 10 to 300 μm.

  It is preferable that a resin layer is a layer (photosensitive resin layer) hardened | cured by irradiating an active energy ray. Active energy rays include radiation such as ultraviolet rays and electron beams. The photosensitive resin layer is preferably a geometric figure drawn with a conductive metal for a structure in which a plastic support, a resin layer and a conductive metal foil are sequentially laminated. After forming, it is desirable to cure by irradiating with active energy rays. After that, the photosensitive resin layer may be cured by irradiating an active energy ray after constituting an electromagnetic wave shielding body or display which is an adherend of the electromagnetic wave shielding adhesive film. It is also possible to slightly advance the degree of curing in advance by irradiation before adhering to the adherend. In this case, the melt viscosity of the resin layer after progressing the degree of curing is a numerical value measured with a rotational viscometer at 200 ° C. and is preferably 10000 poise or less. This is because the fluidity of the resin layer is secured in order to enable processing such as adhesion by pasting even after the degree of curing of the resin layer has been advanced. Any adhesive layer may be used as long as the adhesive layer can exhibit fluidity and adhesiveness even in a completely cured state.

  As the material of the resin layer that is cured by ultraviolet rays, electron beams, etc., which are active energy rays used in the present invention, an acrylic resin, epoxy resin, polyester resin, urethane resin, etc. are used as the base polymer, and each is radically polymerizable or cationically polymerized. Examples thereof include materials provided with a functional functional group. As radically polymerizable functional groups, there are carbon-carbon double bonds such as acrylic group (acryloyl group), methacryl group (methacryloyl group), vinyl group, allyl group, etc., and highly reactive acrylic group (acryloyl group) is suitable. Used for. As the cationically polymerizable functional group, an epoxy group (glycidyl ether group, glycidylamine group) is representative, and a highly reactive alicyclic epoxy group is preferably used. Specific materials include acrylic urethane, epoxy (meth) acrylate, epoxy-modified polybutadiene, epoxy-modified polyester, polybutadiene (meth) acrylate, and acrylic-modified polyester.

  When the active energy ray is ultraviolet, photosensitizers or photoinitiators added at the time of ultraviolet curing include known materials such as benzophenone, anthraquinone, benzoin, sulfonium salt, diazonium salt, onium salt, and halonium salt. Can be used.

  As a method used when drawing a geometric figure in the present invention, a microlithographic method that is effective in terms of the accuracy of processing a circuit corresponding to the geometric figure and the efficiency of processing the circuit can be used. At this time, there is a pattern forming process using a mask material for etching such as a photoresist. This includes a method including a photo resist layer forming process, an exposure process and a pattern forming process by etching, and an ink that is a mask material for etching. A printing method using a resist (for example, a letterpress reverse offset printing method, a screen printing method, a planographic offset printing method, an intaglio offset printing method, etc.) can be used. The photolithographic method is excellent because it is excellent in line formation with high accuracy of 50 μm or less. The relief reversal offset method is a method in which an ink resist is filled in a concave portion of a plate, the ink resist is once transferred to a blanket, and then printed on a conductive metal foil.

  Examples of the microlithographic method include a photolithographic method, an X-ray lithographic method, an electron beam lithographic method, and an ion beam lithographic method. Among these, the photolithographic method is the most efficient in terms of its simplicity and mass productivity. Of these, the photolithographic method using the chemical etching method is most preferable from the viewpoint of its simplicity, economy, and circuit processing accuracy. In the photolithographic method, in addition to the chemical etching method using an etchant solution, a conductive circuit is formed on the resist pattern by electroless plating or electroplating on the resist pattern, or conductive by electroless plating or electroplating. It is also possible to combine the method of forming a circuit with the chemical etching method.

  When the printing method is used, an ink resist is used as a mask material for etching. Examples of the binder polymer include those shown below. Natural rubber, polyisoprene, poly-1,2-butadiene, polyisobutene, polybutene, poly-2-heptyl-1,3-butadiene, poly-2-t-butyl-1,3-butadiene, poly-1,3- (Di) enes such as butadiene, polyoxyethylene, polyoxypropylene, polyvinyl ethyl ether, polyvinyl hexyl ether, polyethers such as polyvinyl butyl ether, polyesters such as polyvinyl acetate and polyvinyl propionate, polyurethane, ethyl cellulose, poly Vinyl chloride, polyacrylonitrile, polymethacrylonitrile, polysulfone, polysulfide, polyethyl acrylate, polybutyl acrylate, poly-2-ethylhexyl acrylate, poly-t-butyl acrylate, poly-3- Toxipropyl acrylate, polyoxycarbonyl tetramethacrylate, polymethyl acrylate, polyisopropyl methacrylate, polydodecyl methacrylate, polytetradecyl methacrylate, poly-n-propyl methacrylate, poly-3,3,5-trimethylcyclohexyl methacrylate, polyethyl methacrylate, Poly (meth) acrylic acid esters such as poly-2-nitro-2-methylpropyl methacrylate, poly-1,1-diethylpropyl methacrylate, and polymethyl methacrylate can be used. Furthermore, epoxy acrylate, urethane acrylate, polyether acrylate, polyester acrylate, or the like can be used as a copolymerizable monomer other than acrylic resin and acrylic. In particular, urethane acrylate, epoxy acrylate, and polyether acrylate are excellent in terms of wettability to conductive metal foil. As epoxy acrylate, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, allyl Alcohol diglycidyl ether, resorcinol diglycidyl ether, adipic acid diglycidyl ester, phthalic acid diglycidyl ester, polyethylene glycol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, sorbitol tetraglycidyl ether (Meth) acrylic acid adducts such as A polymer which reacts like an epoxy acrylate or originally has a hydroxyl group in the molecule is effective for improving wettability and adhesion. These copolymer resins can be used in combination of two or more as required. In addition to these, thermosetting resins such as phenol resins, melamine resins, epoxy resins, xylene resins, etc. are applicable, and these polymers may be copolymerized in two or more types, if necessary. Two or more kinds can be blended and used. These binder polymers can usually be used by dissolving in a general-purpose solvent or stirring and mixing with the following additives without solvent. In addition to the binder polymer, the ink resist used in the present invention includes a dispersant, a thixotropic agent, an antifoaming agent, a leveling agent, a diluent, a plasticizer, an antioxidant, and a metal deactivator as necessary. You may mix | blend additives, such as an agent, a coupling agent, a filler, and electroconductive particle. As the ink resist, it is preferable to use an ink that is cured by ultraviolet rays (UV) or heat because it is advantageous in handling the resist, chemical resistance during chemical etching, and when using the resist. The composition of a photosensitive resin or a conductive paste used in the printed wiring board field can be modified and applied.

  According to the relief reversal offset printing method, which is one of the methods for forming a pattern (resist pattern) using the mask material described above, the ink resist is formed on a roll-shaped rotating cylinder by utilizing the capillarity of the cap coater. After being supplied and applied to the mold release surface (blanket) and dried for several minutes, the roll-shaped or flat relief is pressed to transfer and remove unnecessary ink resist. The ink resist remaining on the conductive surface (the blanket) is transferred to the conductive metal foil of the structure composed of the conductive metal foil, the resin layer, and the plastic support. As a result, a desired resist pattern is formed.

  Geometric figures of conductive metal foil include triangles such as regular triangles, isosceles triangles, right triangles, squares such as squares, rectangles, rhombuses, parallelograms, trapezoids, (positive) hexagons, (positive) octagons , (Regular) dodecagons, (positive) n-decagons such as (decorative) dodecagons, circles, ellipses, star shapes, etc., these units can be repeated alone or in combination of two or more It is also possible to use it. From the viewpoint of electromagnetic shielding properties, the triangle is the most effective, but from the point of view of visible light transmittance, the aperture ratio increases as the n number of (positive) n-gons increases with the same line width. In view of this, the aperture ratio needs to be 50% or more, and more preferably 60% or more. The aperture ratio is a percentage of the ratio of the area obtained by subtracting the area of the conductive metal foil of the geometric figure drawn with the conductive metal foil from the effective area with respect to the effective area of the electromagnetic wave shielding transparent film. When the area of the display screen is the effective area of the electromagnetic shielding transparent film, the screen is visible.

  Such a geometric figure preferably has a line width of 40 μm or less, a line interval of 100 μm or more, and a line thickness of 40 μm or less. The line width is more preferably 25 μm or less from the viewpoint of non-visibility of the geometric figure, and the line interval is more preferably 120 μm or more and the line thickness is 18 μm or less from the viewpoint of visible light transmittance. The line thickness is preferably 0.5 μm or more because the resistance increases and the shielding performance decreases as the line thickness decreases. The larger the line interval, the better the aperture ratio and the visible light transmittance, but the electromagnetic wave shielding property is lowered. Therefore, the line width is preferably 1 mm or less. If the line spacing is too large, the electromagnetic wave shielding property tends to be lowered, and therefore it is preferably 500 μm or less. When the line interval is complicated by a combination of geometric figures or the like, the area is converted into a square area with the repetition unit as a reference, and the length of one side is set as the line interval.

  The electromagnetic wave shielding property can be further improved by performing metal plating on the conductive metal foil used in the present invention. As a method of performing metal plating, any method such as electrolytic plating or electroless plating by a conventional method is possible. The type of plating metal can be gold, silver, copper, nickel, aluminum, etc., but copper or nickel is preferable from the viewpoint of conductivity and cost. The range of the plating thickness is suitably from 0.1 to 100 μm, and if it is less than 0.1 μm, the conductivity is insufficient, so that sufficient shielding properties may not be exhibited. On the other hand, if the plating thickness exceeds 100 μm, the viewing angle becomes narrow, which is not preferable. More preferably, it is 0.5-50 micrometers. It is preferable that the conductive metal foil is a blackened conductive metal foil because the surface of the geometric figure formed later is black and the contrast is high. Further, it can be prevented from being oxidized and fading over time. Further, the blackening process can be performed after the geometric figure is formed. For example, the blackening treatment can be performed using a method performed in the printed wiring board field. When the conductive metal foil is copper, sodium chlorite (31 g / l), sodium hydroxide (15 g / L) and a treatment in an aqueous solution of trisodium phosphate (12 g / l) at 95 ° C. for 2 minutes.

  A conductive metal foil is laminated on a plastic support through a resin layer with the smooth side facing the resin layer, and part of the conductive metal foil is removed so that the aperture ratio is 50% or more. When forming a figure, or after that, it is preferable to form the earth | ground part which is connected with this geometric figure in the shape of a frame around it. The frame portion is preferably formed as a part of the geometric figure, but the frame part may be separately formed on the plastic support or the resin layer so as to connect to the geometric figure. The frame portion can be formed by plating a conductive metal, attaching a conductive metal foil, applying a conductive conductive paint, or the like.

  A conductive metal foil is laminated on a plastic support through a resin layer with the smooth side facing the resin layer, and part of the conductive metal foil is removed so that the aperture ratio is 50% or more. After forming the figure, a resin layer may be further laminated. This resin layer is the same as the resin layer described above, and the formation method can be the same as described above. Thereby, the transparency of the electromagnetic wave shielding film can be made excellent. In this invention, since the conductive metal foil which has a smooth surface is used, even if this is stuck to the said resin layer and an unnecessary part is removed, the transparency of the part (as an electromagnetic shielding film) The transparency of the metal foil is not greatly impaired, but the transparency lost during the lamination and removal process of the metal foil can be recovered by laminating a resin layer thereon.

  In the electromagnetic wave shielding transparent film of the present invention, an antireflection layer, a near infrared shielding layer, and the like may be laminated. The plastic support or the resin layer (or coating resin layer) itself may also serve as an antireflection layer and a near infrared shielding layer. When laminating an antireflection layer, near-infrared shielding layer, etc. separately from the plastic support or resin layer (or coating resin layer), the laminating position is the opposite side of the surface of the plastic support where the conductive metal foil is present. Plane. It is optional between the plastic support and the resin layer, or on the coating resin layer. The formation method of these layers can be performed similarly to the said resin layer.

In order to make a near-infrared shielding layer, a near-infrared absorber is contained in the layer. Near-infrared absorbers include metal oxides such as iron oxide, cerium oxide, tin oxide and antimony oxide, or indium-tin oxide (hereinafter referred to as ITO), tungsten hexachloride, tin chloride, cupric sulfide, chromium-cobalt. Complex salt, thiol-nickel complex or aminium compound, diimonium compound (trade name, manufactured by Nippon Kayaku Co., Ltd.) or anthraquinone (SIR-114), metal complex (SIR-128, SIR-130, SIR-132, SIR-159) , SIR-152, SIR-162), organic compounds such as phthalocyanine (SIR-103) (trade name, manufactured by Mitsui Toatsu Chemical Co., Ltd.), and the like. Among these near-infrared absorbing compounds, those that are most effective in absorbing infrared rays are near-infrared absorbers such as cupric sulfide, ITO, aminium compounds, diimonium compounds, and metal complex systems. In the case of infrared absorbers other than organic infrared absorbers, it is necessary to pay attention to the particle size of the primary particles of these compounds.
When the particle size is too larger than the wavelength of infrared rays, the shielding efficiency is improved, but irregular reflection occurs on the particle surface and haze increases, so that the transparency is lowered. On the other hand, if the particle size is too short compared to the infrared wavelength, the shielding effect is reduced. The preferred particle size is 0.01-5 μm, more preferably 0.1-3 μm.

Near infrared absorption is used by dissolving or dispersing in a binder resin. As the binder resin, the resin for the resin layer described above can be used, and the above-described photosensitive resin may be used.
Specific examples of binder resins for near infrared absorbers include epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and novolak type epoxy resin, polyisoprene, poly-1,2-butadiene, polyisobutene, polybutene, and the like. Polyene acrylate copolymer consisting of diene resin, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, t-butyl acrylate, etc., polyester resins such as polyvinyl acetate, polyvinyl propionate, polyethylene, polypropylene, polystyrene, EVA It is uniformly dispersed in a binder resin such as a polyolefin resin. The optimum amount of the compound is 0.01 to 10 parts by weight of the infrared absorber with respect to 100 parts by weight of the binder resin, and more preferably 0.1 to 5 parts by weight. If it is less than 0.01 part by weight, the infrared shielding effect is small, and if it exceeds 10 parts by weight, the transparency is impaired.

The transparent substrate used in the electromagnetic wave shielding body of the present invention is a plate made of glass or plastic. As the glass, glass such as soda glass, non-alkali glass, and tempered glass can be used. Plastics include polystyrene resin, acrylic resin, polymethyl methacrylate resin, polycarbonate resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyethylene resin, polypropylene resin, polyamide resin, polyamideimide resin, polyetherimide resin, polyetheretherketone Resin, polyarylate resin, polyacetal resin, polybutylene terephthalate resin, thermoplastic polyester resin such as polyethylene terephthalate resin, cellulose acetate resin, fluororesin, polysulfone resin, polyethersulfone resin, polymethylpentene resin, polyurethane resin, diallyl phthalate Examples thereof include thermoplastic resins such as resins and thermosetting resins. Among these, polystyrene resins, acrylic resins, polymethyl methacrylate resins, polycarbonate resins, and polyvinyl chloride resins that are excellent in transparency are preferably used.
The thickness of the transparent substrate used in the present invention is preferably 0.5 mm to 5 mm in view of display protection, strength, and handleability.

  The electromagnetic wave shielding body is composed of the above transparent base material and an electromagnetic wave shielding transparent film, and any surface of the electromagnetic wave shielding transparent film is laminated on at least one surface of the transparent base material. In this case, an adhesive layer may be laminated on the surface of the electromagnetic wave shielding transparent film and laminated via this adhesive layer. As the adhesive layer, any of the resin layers described above may be used as a resin layer made of an adhesive layer. As the layer having adhesiveness, a layer having adhesiveness or tackiness can be selected from the above-described resin layers and used. The adhesive layer is preferably one that flows by pressure or heating itself, or one that flows by pressure or heating (preferably heated to 80 to 200 ° C.) in the resin layer. It can be performed in the same manner as the method for laminating the adhesive layer, the method for applying the resin or resin composition, and the method for laminating the film-like resin or resin composition. The method for laminating the transparent substrate and the electromagnetic wave shielding transparent film can be performed in the same manner as the above-described pressure bonding method.

  The surface on which the geometrical figure of the electromagnetic wave shielding film is formed can be overlapped with a transparent substrate, and both can be bonded by pressing, laminating or the like.

  The electromagnetic wave shielding transparent film can be directly attached to the screen of the display. In this case, it can carry out according to the manufacturing method of an electromagnetic wave shielding body. In addition, the electromagnetic shielding body can be attached to the front surface of the display. In this case, the electromagnetic wave shielding body can be fixed to the attachment frame and attached to the front surface of the display.

Using a polyethylene terephthalate (PET) film (product name: A-4100, manufactured by Toyobo Co., Ltd.) having a thickness of 50 μm, a primer (trade name, manufactured by Hitachi Chemical Co., Ltd., HP-1, coating thickness: 1 μm) is applied to the surface. Further, a polyvinyl butyral resin (trade name, # 6000PE, softening point 72 ° C., molecular weight 2,400, n = 1.52) manufactured by Denki Kagaku Kogyo Co., Ltd. is applied as a resin layer thereon to a dry coating thickness of 20 μm. It was applied as follows. On the other hand, nickel plating is applied to one side of an electrolytic copper foil (product name: NDGE, manufactured by Nihon Electrolytic Co., Ltd.) with a glossy surface (surface roughness Rz = 1.5 μm) on both sides with a thickness of 9 μm by a conventional method. The surface (rust-proof surface) side and the resin surface were bonded together. Then, a photosensitive resist film (made by Hitachi Chemical Co., Ltd., trade name FOTEC) is bonded to the surface of the copper foil, and a high-pressure mercury lamp is applied on the mask having a shielding pattern corresponding to the reverse pattern of the following lattice pattern. The conductive metal foil lattice pattern (line) is formed through the process of irradiating (exposing) ultraviolet light 90 mJ / cm ² , developing the photosensitive resist film, chemically etching the copper foil, and peeling off the remaining resist film. An electromagnetic shielding transparent film having a width of 15 μm and a line interval (pitch) of 250 μm was produced. The aperture ratio of this film was 88%, and the visible light transmittance was 70%.

A 25 μm thick polyethylene terephthalate (PET) film (trade name A-4100, manufactured by Toyobo Co., Ltd.) was used, and a primer (trade name, HP-1, manufactured by Hitachi Chemical Co., Ltd., coating thickness 1 μm) was applied to the surface. Furthermore, a polyvinyl acetate resin (trade name, SN-10, softening point 55 ° C., polymerization degree 1200 to 1500, n = 1.5) manufactured by Denki Kagaku Kogyo Co., Ltd. is applied as a resin layer on the resin layer. It apply | coated so that it might become 30 micrometers. On the other hand, nickel plating is applied to one side of an electrolytic copper foil (trade name NDGE, manufactured by Nippon Electrolytic Co., Ltd.) with a glossy surface (surface roughness Rz = 1.0 μm) on both sides with a thickness of 5 μm, and chromate. After processing, the processing surface side and the resin surface were bonded together. Thereafter, an ink resist (trade name PHOTO FINER, manufactured by Taiyo Ink Co., Ltd.) is formed on the glossy surface of the copper foil in a lattice pattern (line width: 10 μm, line interval (pitch): 300 μm) by using a letterpress reverse offset method. After pre-baking at 15 ° C. for 15 minutes, ultraviolet rays were irradiated at 70 mJ / cm ² with a high-pressure mercury lamp. Then, the electromagnetic wave shielding transparent film was produced through the chemical etching process of copper foil, and the ink resist peeling process. A copper plating layer having a thickness of 3 μm was formed on the resulting copper lattice pattern by electrolytic copper plating by a conventional method. The aperture ratio of this film was 90%, and the visible light transmittance was 74%. Furthermore, the following resin composition was apply | coated to the surface where the conductor of this film is exposed, and it hardened | cured for 30 minutes at 100 degreeC after drying for 10 minutes at 90 degreeC, and coat | covered the copper lattice pattern. The visible light transmittance of this film was 85%.
(Resin composition used for coating)
(1) YD-812 (trade name, manufactured by Toto Kasei Co., Ltd .; bisphenol A type epoxy resin, Mw = 300,000) 100 parts by weight,
(2) IPDI (manufactured by Hitachi Chemical Co., Ltd .; 12.5 parts by weight of mask isophorone diisocyanate,
(3) 0.3 part by weight of 2-ethyl-4-methylimidazole,
(4) 330 parts by weight of methyl ethyl ketone,
And (5) containing 15 parts by weight of cyclohexanone.

Polyester polyurethane resin (trade name, manufactured by Toyobo Co., Ltd., manufactured by Toyobo Co., Ltd.) was used as a resin layer on the corona discharge treated surface (critical surface tension 54 dyn / cm) using a polycarbonate film (trade name, Lexan, manufactured by Asahi Glass Co., Ltd.) having a thickness of 50 μm. UR-1400, softening point 83 ° C., average molecular weight 40,000, n = 1.5) was applied so that the dry coating thickness was 25 μm. On the other hand, nickel plating is applied to one side of an electrolytic copper foil (trade name NDGE, manufactured by Nippon Electrolytic Co., Ltd.) with a glossy surface (surface roughness Rz = 1.0 μm) on both sides with a thickness of 5 μm, and chromate. After processing, the processing surface side and the resin surface were bonded together. After that, a photosensitive resist film (made by Hitachi Chemical Co., Ltd., trade name FOTEC) is bonded to the surface of the copper foil, and a high-pressure mercury lamp is applied from above the mask having a shielding pattern corresponding to the reverse pattern of the following lattice pattern. An electromagnetic wave having a copper foil lattice pattern (line width 10 μm, line interval (pitch) 127 μm) through a process of irradiating 70 mJ / cm ^{2 with} ultraviolet rays, developing, chemically etching the copper foil, and peeling off the remaining resist film. A shielding transparent film was prepared. The aperture ratio of this film was 85%, and the visible light transmittance was 72%. Further, the following photosensitive resin composition was applied to the surface of the film where the conductor was exposed, laminated with a PET film, and then irradiated with UV light at 700 mJ / cm ² with a high-pressure mercury lamp. The visible light transmittance of this film was 81%.
(Composition of photosensitive resin)
(1) 2,2-bis (4- (4-N-maleimidylphenoxy) phenyl) propane 30 parts by weight,
(2) 45 parts by weight of an acid-modified epoxy resin obtained by reacting 1 equivalent of tetrahydrophthalic anhydride with bisphenol A type epoxy resin having an epoxy equivalent of 500 in a nitrogen atmosphere at 150 ° C. for 10 hours,
(3) Acrylonitrile butadiene rubber (PNR-1H, trade name, manufactured by Nippon Synthetic Rubber Co., Ltd.) 20 parts by weight,
(4) 1,7-di-9-acridinylheptane (5 parts by weight) and (5) aluminum hydroxide (10 parts by weight) were dissolved in cyclohexanone / methyl ethyl ketone (1/1, weight ratio) to obtain a 45% by weight varnish. thing.

Using a 50 μm thick PET film (trade name, A-4100, manufactured by Toyobo Co., Ltd.), a primer (trade name, manufactured by Hitachi Chemical Co., Ltd., HP-1, coating thickness: 1 μm) was applied to the surface, and further Acrylic resin (trade name, HTR-811, softening point -43 ° C., average molecular weight 420,000, n = 1.52) manufactured by Teikoku Chemical Sangyo Co., Ltd. was applied as a resin layer to a dry coating thickness of 20 μm. did. On the other hand, nickel plating is applied to one side of an electrolytic copper foil (trade name JTC, manufactured by Japan Energy Co., Ltd.) with a glossy surface (surface roughness Rz = 1.5 μm) on both sides with a thickness of 9 μm, followed by chromate treatment. Then, using 3-aminopropyltrimethoxysilane (manufactured by Dow Corning Toray Co., Ltd.), a silane coupling agent treatment was performed, and the treated surface side and the resin surface were bonded together. After that, a lattice pattern (line width 20 μm, line interval (pitch) 250 μm) is formed on the glossy surface of the copper foil using a letterpress inversion offset method, prebaked at 80 ° C. for 15 minutes, and then irradiated with ultraviolet light with a high-pressure mercury lamp to 100 mJ / Cm ² irradiation. Then, the electromagnetic wave shielding transparent film was produced through the copper foil chemical etching process. The aperture ratio of this film was 84%, and the visible light transmittance was 74%. Furthermore, the following resin composition was apply | coated to the surface where the conductor of this film is exposed, and it was made to harden | cure at 100 degreeC for 30 minutes after drying at 90 degreeC for 10 minutes. The visible light transmittance of this film was 81%.
(Resin composition used for coating)
(1) YD-812 (trade name, manufactured by Toto Kasei Co., Ltd .; bisphenol A type epoxy resin, Mw = 300,000) 100 parts by weight,
(2) IPDI (manufactured by Hitachi Chemical Co., Ltd .; 12.5 parts by weight of mask isophorone diisocyanate,
(3) 0.3 part by weight of 2-ethyl-4-methylimidazole,
(4) A substance containing 330 parts by weight of methyl ethyl ketone and (5) 15 parts by weight of cyclohexanone.

Using a PET film having a thickness of 100 μm (trade name, manufactured by Toyobo Co., Ltd., A-4100), a primer (trade name, manufactured by Hitachi Chemical Co., Ltd., HP-1, coating thickness of 1 μm) was applied to the surface. A polyvinyl butyral resin (trade name, # 6000EP, softening point 72 ° C., molecular weight 2,400, n = 1.52) manufactured by Denki Kagaku Kogyo Co., Ltd. was applied as a resin layer so that the dry coating thickness was 20 μm. . On the other hand, nickel plating is applied to one side of an electrolytic copper foil (trade name SQ-VLP, manufactured by Mitsui Kinzoku Co., Ltd.) having a glossy surface (surface roughness Rz = 1.5 μm) on both sides with a thickness of 5 μm by a conventional method. After the chromate treatment, silane coupling agent treatment was performed using 3-aminopropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd.), and the treated surface side and the resin surface were bonded together. After that, a photosensitive resist film (made by Hitachi Chemical Co., Ltd., trade name FOTEC) is bonded to the surface of the copper foil, and a high-pressure mercury lamp is applied from above the mask having a shielding pattern corresponding to the reverse pattern of the following lattice pattern. A copper foil lattice pattern (line width 20 μm, line interval (pitch) 250 μm) was formed through a process of irradiating 70 mJ / cm ^{2 with} ultraviolet light, developing, chemically etching the copper foil, and peeling off the remaining resist film. . The finished copper lattice pattern was subjected to electroless copper plating by 1 μm by a conventional method, and further subjected to blackening treatment on the electroless copper plating in the same manner as in Example 3. The aperture ratio of this film was 84%, and the visible light transmittance was 73%. Furthermore, a UV curable resin (trade name, Hitachito 7983A, manufactured by Hitachi Chemical Co., Ltd., coating thickness 20 μm) is applied to the surface of the film where the conductor is exposed, laminated with a PET film, and then UV irradiated with a high-pressure mercury lamp. Was irradiated at 1000 mJ / cm ² . The visible light transmittance of this film was 79%.

Commercially available acrylic plate (Kuraray Co., Ltd., trade name, 3 mm thickness) or commercially available soda lime glass having a thickness of 3 mm with the electromagnetic shielding transparent film obtained in Example 1 having a lattice pattern inside. In each of the above, through an adhesive film (Sekisui Chemical Co., Ltd., trade name, ESREC, thickness 250 μm) or without an adhesive film, 110 ° C., 20 Kgf / cm ² , 15 minutes with a hot press machine Was subjected to thermocompression bonding to obtain four types of electromagnetic wave shielding bodies (Table 1 shows characteristics when an adhesive film is used and an acrylic plate is used).

The electromagnetic shielding transparent film obtained as described above, the aperture ratio of the geometric figure of the electromagnetic shielding body, the presence or absence of pattern abnormality, the electromagnetic shielding properties (300 MHz), the visible light transmittance before and after the resin coating, and the invisibility The adhesion to the glass plate was measured. The measurement results are shown in Table 1. The aperture ratio of the geometric figure drawn with the conductive metal foil was measured based on a micrograph. The electromagnetic wave shielding property was measured at a frequency of 300 MHz by the Advantest method. The visible light transmittance was measured using an average value of transmittance of 400 to 700 nm using a double beam spectrophotometer (trade name, manufactured by Hitachi, Ltd., model 200-10). Presence / absence of pattern abnormality and invisibility were determined by visual observation. The non-visibility was determined as NG when the electromagnetic wave shielding transparent film was observed from a place 0.5 m away, and those that could not recognize the geometric figure formed of the conductive material were good and could be recognized. For the adhesion of the electromagnetic wave shielding transparent film to glass, the sample was adhered to the glass at 110 ° C. and 10 kgf / cm ² for 10 minutes, and the adhesive force was measured (except for Example 6).

  As shown in the examples, when a conductive metal foil that has not been roughened is used, the degree of surface scattering on the resin can be minimized, so that the visible light transmittance can be achieved even after the lattice pattern is formed. Is big enough. Since the visible light transmittance can be easily improved by covering with a resin after forming the lattice pattern, it can be provided at low cost. In addition, by using a thin foil, the degree of over-etching can be minimized, so that the accuracy of circuit processing is greatly improved. At this time, in the metal foil that has not been subjected to the roughening treatment, the roughened copper foil is less likely to sink into the resin, so that the circuit processing accuracy is also greatly improved in this respect.

When a copper foil having a roughened surface (surface roughness Rz = 5.5 μm or Rz = 5.0 μm was used, line width unevenness was likely to occur. In addition, in order to completely eliminate disconnection The copper foil was preferably rust-proofed.

Claims (13)

A conductive metal foil is laminated on a plastic support through a resin layer with the smooth side facing the resin layer, and part of the conductive metal foil is removed so that the aperture ratio is 50% or more. The manufacturing method of the electromagnetic shielding transparent film characterized by forming a figure. 2. The method for producing an electromagnetic wave shielding transparent film according to claim 1, wherein a conductive metal foil having a smooth surface of the conductive metal foil having a surface roughness Rz of 2.0 μm or less is used. The method for producing an electromagnetic wave shielding transparent film according to claim 1 or 2, wherein the smooth surface of the conductive metal foil is the surface on the rust-proof side. The method for producing an electromagnetic wave shielding transparent film according to claim 3, wherein the rust-proofing treatment uses nickel, tin, zinc, chromium, molybdenum, cobalt, or an alloy thereof. The method for producing an electromagnetic wave shielding transparent film according to any one of claims 1 to 4, wherein the smooth surface of the conductive metal foil is a surface on the side subjected to the chromate treatment. The method for producing an electromagnetic wave shielding transparent film according to any one of claims 1 to 5, wherein the smooth surface of the conductive metal foil is a surface treated with a silane coupling agent. The method for producing an electromagnetic wave shielding transparent film according to claim 5, wherein the silane coupling agent chemically reacts with the resin layer by heating. The method for producing an electromagnetic wave shielding transparent film according to claim 6 or 7, wherein the silane coupling agent is an amino-functional silane. The electromagnetic wave shielding transparent according to any one of claims 1 to 8, wherein a line width of a geometric figure drawn with a conductive metal foil is 1 to 40 µm, a line interval is 50 to 500 µm, and a line thickness is 1 to 40 µm. A method for producing a film. The electromagnetic shielding transparent film according to any one of claims 1 to 9, wherein a method of forming a geometric figure by removing a part of the conductive metal foil so that the aperture ratio is 50% or more is a photolithographic method. Production method. The electromagnetic shielding transparent film produced by the manufacturing method of the electromagnetic shielding transparent film in any one of Claims 1-10. The electromagnetic wave shielding body comprised from the electromagnetic wave shielding transparent film of Claim 11, and a transparent base material. A display using the electromagnetic wave shielding transparent film according to claim 11 or the electromagnetic wave shielding body according to claim 12.