JPH10284875A - Light transmitting electromagnetic wave shielding panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance electromagnetic wave shielding effect and antireflection performance of external light by providing a transparent conductive film including a conductive layer having a specified surface resistance at least on one side of a transparent resin sheet, specifying the total beam transmittance and forming an earth electrode at least on a part of the conductive layer. SOLUTION: A transparent sheet 1 is applied, on one side thereof, with an anti-glare film 2 and, on the other side thereof, with a transparent conductive film 3. The transparent conductive film 3 comprises a conductive layer having surface resistance of 30 Ω/square or less formed on a basic material of a transparent resin film. An earth electrode 4 is formed at least on a part of the conductive layer of the transparent conductive film 3 in order to shield electromagnetic wave and an earth wire 6 is led out from the earth electrode 4. Total beam transmittance of the light transmitting electromagnetic wave shielding panel is set at 60% or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-transmitting electromagnetic wave shielding panel which can be suitably used on the front of an image display panel of a display, and more particularly to a television, an automobile navigation system, a display for a fish finder, and a portable device. The present invention relates to a light-transmitting electromagnetic wave shielding panel installed on the front of a video display section of various devices such as mobile communication devices such as telephones and portable terminals, AV devices, OA devices, word processors, personal computers, game machines, and plasma displays.

[0002]

2. Description of the Related Art A display panel for video equipment typified by a color television is a device in which an external light such as an indoor lamp, a fluorescent lamp or sunlight is reflected on a surface of the panel toward an observer, and a reproduced image, Since it becomes difficult for an observer to see an image, improvement in prevention of external light reflection is desired.

As a method of preventing external light reflection, a method of forming a multilayer vapor-deposited film utilizing irregular reflection of light and interference of light has been proposed. For example, Japanese Unexamined Patent Publication No. 5-29237 discloses a method of forming an antireflection film directly on a panel surface by coating or the like using ultrafine particles such as silicon dioxide having an average particle diameter of not more than the wavelength of visible light. 307104,
JP-A-8-144048 discloses that a cured film is formed on the upper surface of a transparent plastic film, an aluminum oxide layer is formed thereon by a sputtering method, and a magnesium fluoride layer is further formed thereon by an evaporation method to form an antireflection film. Filter, JP-A-6-160982, JP-A-7-1680
03, JP-A-7-28169, JP-A-8-
No. 48935 discloses a method of forming a low refractive index layer on a resin substrate, and the like.

On the other hand, with the diversification of video equipment and the increase of electronic equipment, microwaves and radio waves are transmitted from the surface of a display due to structural factors of a light source serving as an image signal source, a discharge part, or each pixel part forming an image. Such harmful electromagnetic waves of non-ionizing radiation are generated in large quantities, and health problems are pointed out, and problems such as flickering of the screen and malfunctions of the devices due to the electromagnetic waves have become problems. In particular, there is high interest in electromagnetic waves emitted from the display surface, and VCCI
Regulations of the Voluntary Control Council for Electromagnetic Interference such as Information Processing Equipment are becoming stricter year by year, and strict electromagnetic wave shielding measures are desired.

Conventionally, various improved methods have been proposed for removing electromagnetic interference. There are many proposals for this electromagnetic wave shielding technology, such as various electromagnetic wave shielding materials in which a transparent conductive layer made of an oxide thin film such as indium-tin is formed on a transparent plastic substrate. For example, JP-A-62-14
These techniques are disclosed in JP-A-7799, JP-A-2-221493, and JP-A-5-323101.

However, since the above-mentioned conventional electromagnetic wave shielding material is a transparent conductive layer made of an oxide film, it has a problem that the resistance value is high and the electromagnetic wave shielding effect is insufficient. Further, when the thickness of the transparent conductive layer is increased in order to enhance the shielding effect, the light transmittance is reduced, the light reflectance is increased, the contrast of the display screen is reduced, and the display is difficult to see.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a light-transmitting electromagnetic wave shielding panel having high light transmittance and electromagnetic wave shielding effect, and at the same time, having an external light reflection preventing performance.

[0008]

Means for Solving the Problems The inventors of the present invention have studied diligently to solve the above-mentioned problems, and have an antiglare film having an anti-reflection property for external light on one side of a transparent resin sheet and a transparent conductive film having a low resistance value on the other side. The above object was achieved by satisfactorily laminating the conductive films, and the present invention was completed.

That is, the present invention provides a transparent conductive film having at least one surface of a transparent resin sheet having an anti-glare treatment film and another surface having a conductive layer having a surface resistance of 30 Ω / □ or less on one side of the transparent resin film. Having a total light transmittance of 60
% Or more, wherein at least a part of the conductive layer has a ground electrode.

Further, by laminating and laminating an antiglare-treated film and a transparent conductive film on a transparent resin sheet via an adhesive layer, a more preferable light-transmitting electromagnetic wave shielding panel can be obtained.

The present invention can be more preferably achieved when the antiglare film has an antistatic layer and an antireflection layer on one surface of the transparent resin film substrate.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a representative example of a light-transmitting electromagnetic wave shielding panel according to the present invention. In the drawing, 1 is a transparent resin sheet, 2 is an anti-glare treatment film, 3 is a transparent conductive film, and the anti-glare treatment film 2 has a transparent conductive film so that the anti-glare treatment surface faces in the opposite direction to the image generation surface. The film 3 is arranged so that the surface having the conductive layer faces the image generating surface or the direction opposite to the image generating surface. Transparent conductive film 3
A ground electrode 4 is formed on at least a part of the conductive layer for shielding electromagnetic waves, and a ground wire 6 is drawn from the ground electrode 4.

Further, the exposed portion of the conductive layer is guarded or masked, and a light-transmitting electromagnetic wave shielding panel in which a transparent protective film 5 is further laminated on the exposed portion to protect the conductive layer as necessary is provided. I do not care.

The total light transmittance of the light-transmitting electromagnetic wave shielding panel is 6 in order not to greatly reduce the original luminance of the video equipment.
It is necessary to be 0% or more, preferably 60 to 90%.

In the present invention, the total light transmittance is measured by:
The light-transmitting electromagnetic wave shielding panel can be formed on a sheet-shaped article having a thickness of 1 to 20 mm, more preferably 2 to 10 mm, using a commercially available measuring instrument according to the JIS K-7105 method.

The transparent resin sheet 1 used in the present invention needs to have a small loss of light amount due to scattering and diffusion of light, and has a haze of 1 measured according to JIS K-7105.
It is defined as a sheet that is 0% or less.

Specific examples include sheets of methacrylic resin, polycarbonate resin, polystyrene resin, styrene-butadiene resin, polyvinyl chloride resin and the like. Particularly preferred is a methacrylic resin sheet.

The methacrylic resin is a resin mainly composed of methyl methacrylate, and is a homopolymer or a mixture of methyl methacrylate and methyl acrylate, ethyl acrylate, n-methacrylate.
Propyl acrylate, isopropyl acrylate, butyl acrylate, acrylonitrile, acrylic acid, methacrylic acid, vinyl pyridine, vinyl morpholine, vinyl pyridone tetrahydrofurfuryl acrylate, N,
Any one of copolymerizable monomers such as N-dimethylaminoethyl acrylate, N, N-dimethylacrylamide, 2-hydroxyacrylate, ethylene glycol monoacrylate, glycerin monoacrylate, maleic anhydride, styrene or α-methylstyrene The above-mentioned copolymer, a heat-resistant acrylic resin, a low-moisture-absorbing acrylic resin, and the like are included, and they may be used alone or in a blend.

In order to maintain transparency and simultaneously provide impact resistance, an impact-resistant acrylic resin is used, and its rubber elastic material is disclosed in JP-A-53-55854 and JP-A-55-94.
Nos. 917 and 61-32346. Briefly, it is a multi-stage polymer produced by a multi-stage sequential polymerization method in which an elastic layer and an inelastic layer are alternately formed around an acrylic polymer core material.

The thickness of the transparent resin sheet 1 is 1.0 to 20.
mm is preferred. In particular, 2.0 to 10 mm is the most preferable thickness. When the thickness of the transparent resin sheet 1 is 1.0 mm or more, rigidity as a front panel is obtained, and
If it is 0 mm or less, the front panel becomes light in weight, which is preferable.

The method for forming the transparent resin sheet 1 is not particularly limited, but can be easily obtained by using, for example, an extruded sheet forming method using a T-die. The sheet may be subjected to secondary processing by vacuum forming, pressure forming, or stampable forming.

Further, other components such as a reinforcing agent, a filler, and the like, as long as the optical characteristics and the mechanical and thermal characteristics are not impaired.
A release agent, a heat stabilizer, an antioxidant, a nucleating agent, a light stabilizer, an ultraviolet absorber, a plasticizer, and the like can be contained in any process such as at the time of sheet molding.

Anti-glare treatment film 2 used in the present invention
Is obtained by using a transparent resin film as a base material and subjecting one surface thereof to an antiglare treatment.

The transparent resin film substrate is preferably such that polyethylene terephthalate (refractive index: 1.65), which has a small loss of light amount due to scattering and diffusion of light and has a large refractive index, is easily available. Polyester, polycarbonate (refractive index: 1.58), triacetyl cellulose (refractive index: 1.52), polymethyl methacrylate (refractive index: 1.49), polystyrene (refractive index: 1.6)
0), polyvinyl chloride (refractive index: 1.53) and the like are preferably mentioned as suitable examples.

The thickness of the transparent resin film substrate is 25 to 2
00 μm is preferred. In particular, 50 to 150 μm is the most preferable thickness. The thickness of the transparent resin film substrate is 25
If the thickness is at least μm, the strength is sufficient, and if it is at most 200 μm, the rigidity of the film is high and there is no problem that the secondary workability on the surface of the transparent resin sheet 1 is inferior.

The anti-glare treatment is not particularly limited, and any processing method can be selected. For example, a method of reducing luminous reflectance by irregularly reflecting external light, that is, applying light to a surface of the transparent resin film substrate by applying silicon dioxide or the like, which is an ultrafine particle having a particle size equal to or smaller than the wavelength of visible light, on one surface of the transparent resin film substrate. A method of forming an antireflection film in which irregular reflection occurs, or forming a cured film having a high refractive index on one surface of a transparent resin film substrate,
A method of forming a thin film of a magnesium fluoride layer thereon by a vapor deposition method, or a method of forming a low-refractive index layer of a thin film on one or both surfaces of a transparent resin film substrate, and the like are known. Available.

Among them, a low refractive index layer of a thin film is formed,
A simple and effective method is to reduce the reflectivity by interference of light between the surface reflected light of the low refractive index layer and the refracted reflected light at the interface. That is, when an antireflection layer having a lower refractive index than the transparent resin film substrate is formed as the outermost layer with a film thickness of 1/4 of the wavelength of visible light, the upper surface reflected light and the lower surface reflected light cancel each other out, so that the surface reflection occurs. Can be reduced.

The refractive index of the antireflection layer is preferably lower than the refractive index of the transparent resin film substrate, and the total light reflectance is preferably less than 7%. The low-refractive-index transparent resin forming the anti-reflection layer is not particularly limited, but is most preferably an amorphous transparent fluorinated polymer, and has a refractive index of 1.28 to 1.44. Is more preferred.

Examples of such a noncrystalline transparent fluoropolymer include perfluorooctane, CF ₃ (C
F ₂ ) nCH = CH ₂ (n: 5 to 11), CF ₃ (CF ₂ )
Polymers soluble in a specific fluorine-based solvent such as mCH ₂ CH ₃ (m: 5 to 11), a fluorinated alkyl ester polymer of acrylic acid or a fluorinated alkyl ester polymer of methacrylic acid, trade name “CYTOP” ( Asahi Glass Co., Ltd.), trade name "Teflon AF" (DuPont) and the like.

The antireflection layer is coated on a transparent resin film substrate by a spray coating method, a spin coating method, a dip coating method, a roll coating method, a gravure coating method, a die coating method or the like. These coating methods enable continuous processing and are excellent in productivity. In order to enhance the adhesion of the antireflection layer to the transparent resin film substrate surface, an active energy ray treatment such as a corona discharge treatment or an ultraviolet treatment, or a primer treatment may be applied.

Commercially available anti-reflective transparent resin films include “Arc Top” (trade name, manufactured by Asahi Glass Co., Ltd.) and “Real-Look” (trade name, manufactured by NOF Corporation).

The thickness of the antireflection layer is 0.05 to 0.25
The range of μm is preferable because the antireflection performance is sufficient. In order to reduce reflection in the visible light wavelength range when observing a video screen, a thickness of 0.1 to 0.2 μm is more preferable.

It is more preferable to have an antistatic treatment layer between the transparent resin film substrate and the antiglare treatment layer. In the antistatic treatment, a metal oxide such as tin oxide, a surfactant, and a transparent conductive layer are applied by coating or the like, and the surface resistance is desirably 10 ¹⁰ Ω or less.

The transparent conductive film 3 used in the present invention
Has a conductive layer having a surface resistance of 30 Ω / □ or less, preferably 15 Ω / □ or less on one surface thereof, using a transparent resin film as a base material. Light loss due to diffusion is small, and the light transmittance at 550 nm is desirably 70% or more. Further, those having an electromagnetic wave attenuation effect of 50% or more at a frequency of 100 MHz are preferable.

The transparent resin film substrate is generally made of polyester such as polyethylene terephthalate, which is easily available.
Suitable examples include polycarbonate, triacetyl cellulose, and polymethyl methacrylate.

The thickness of the transparent resin film substrate is 25 to 2
00 μm is preferred. In particular, 50 to 100 μm is the most preferable thickness. The thickness of the transparent resin film substrate is 25
If the thickness is at least μm, the strength will be sufficient, and if it is at most 200 μm, the rigidity of the film will be high and the secondary workability to the surface of the transparent resin sheet 1 will not deteriorate, which is preferable.

Examples of the conductive layer include metal layers such as a noble metal thin film layer and a metal oxide thin film layer. Examples of the noble metal forming the noble metal thin film layer include gold, silver, palladium, and alloys thereof, and are preferably silver and an alloy of silver and gold. For alloys, the silver content is 6
0% by weight or more is preferred. Examples of the metal oxide forming the metal oxide thin film layer include a composite oxide of indium oxide and zinc oxide, indium oxide, and the like.

It is preferable to laminate a transparent dielectric layer in order to reinforce the metal layer, protect it, prevent oxidative deterioration, and increase the transmittance in the visible light range. Examples of the transparent dielectric layer include thin films of oxides of divalent to tetravalent metals, zirconium oxide, titanium oxide, magnesium oxide, silicon oxide, aluminum oxide, and metal alkoxide compounds. When the transparent dielectric layer is provided on both the surface side and the substrate side of the metal layer, both may be the same substance or may be different.

Further, in order to protect the conductive layer, a transparent protective film 5 is preferably laminated.

Examples of the transparent protective film 5 include a polyethylene film, a transparent film of polyester, polycarbonate, and triacetyl cellulose. Further, the above-described antiglare film may be used as the transparent protective film 5.

The structure of the conductive layer is, for example, when the transparent resin film substrate is (A), the metal layer is (B), the transparent dielectric layer is (C), and the transparent protective film 5 is (D). ,
(A) / (B) / (C) / (B) or (A) / (B)
It is particularly preferable that the metal layer (B) and the transparent dielectric layer (C) are further laminated in multiple layers in the order of / (C) / (B) / (D).

The thickness of the metal layer is preferably 50 to 300 angstroms. If it is 50 Å or more, the electromagnetic wave shielding effect is sufficient. When the thickness is 300 Å or less, the light transmittance can be 70% or more, which is preferable.

The thickness of the transparent dielectric layer is 200 to 3000
Angstrom is preferred. Within this range, a high transmittance can be obtained in the visible light range, which is preferable. Preferably, 40
0 to 1000 angstroms.

The method for forming the metal layer and the transparent dielectric film layer is not particularly limited, and an arbitrary processing method can be selected. For example, electron beam evaporation, vacuum evaporation,
Any conventionally known method such as a cathode sputtering method and an ion plating method can be used.

Examples of commercially available transparent conductive films include “IDIXO” (trade name; manufactured by Idemitsu Kosan Co., Ltd.) having an oxide thin film layer of a composite oxide of indium oxide and zinc oxide and a metal oxide composed of indium oxide. No.

The light-transmitting electromagnetic wave shielding panel of the present invention needs to be grounded to shield electromagnetic waves. This can be achieved by providing a ground electrode 4 on at least a part of the conductive layer of the transparent conductive film 3 and pulling a ground wire 6 from the ground electrode 4 to directly connect the ground to a main body housing of a display or the like.

The ground electrode 4 may be formed on the periphery of the panel and on a part or all of a portion covered by an outer frame cover of the display or the like so as not to disturb the display of images or characters from the display or the like. Preferably, the surface is grounded.

The method of forming the ground electrode 4 is not particularly limited, but may be suitably applied, for example, a method of forming a conductive silver paste as a main component by a printing method, a method of attaching a copper tape, and the like.

Further, by connecting and fixing the ground wire 6 to a main body ground portion such as a main body conductive chassis, it is possible to effectively exhibit electromagnetic wave shielding. It is also preferable to use metal packing in this connection.

The method of laminating the anti-glare treatment film 2 and the transparent conductive film 3 used in the present invention on the transparent resin sheet 1 is not particularly limited. A method is preferable in which the antiglare-treated surface of the material or the surface opposite to the conductive layer surface is bonded and laminated to the transparent resin sheet 1 via an adhesive layer. There is no particular limitation on the method of laminating to the transparent resin sheet surface, and a method such as visco-compression bonding or heat fusion is appropriately selected.

As the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer, those usually used for pressure-sensitive adhesive sheets and films can be suitably used. Among them, acrylates using polybutyl acrylate, 2-ethylhexyl polyacrylate, polyisobutylene, SB having a glass transition temperature of a main component resin in a range of −50 ° C. to −130 ° C., and SB
R type, rubber type such as natural rubber, urethane-acrylate type, epoxy-acrylate type, silicone rubber type, vinyl chloride type or ethylene vinyl acetate type having a vinyl acetate content of 20 to 40% are preferable.

Examples of the tackifier include rosin, rosin ester and its derivatives, terpene resin, phenol resin,
Coumarone-indene resin, hydrocarbon resin, etc. are used,
Further, fatty acid esters, animal and vegetable fats and oils, waxes, and heavy petroleum fractions are used as softeners, and are appropriately selected based on their compatibility with the transparent main component resin.

The thickness of the adhesive layer is preferably in the range of 5 to 200 μm because of high transparency. When the thickness of the adhesive layer is 5 μm or more, it is easy to form the adhesive layer uniformly,
When the thickness is not more than μm, for example, it is preferable because there is no problem that defects such as wrinkles easily occur during lamination and integration on a display panel surface or the like under a high temperature in summer. A more preferred thickness of the adhesive layer is 10 to 50 μm.

The pressure-sensitive adhesive layer is formed by applying the pressure-sensitive adhesive by a commonly used coating method such as transfer printing, a knife coater, a roll coater, or a gravure coater, and dried by heating with infrared rays, hot air, steam, or the like. On one side.

The shape of the panel and the method of forming the panel are not particularly limited. For example, if an extruded sheet forming method using a T-die is used, a smooth, corrugated, prism-shaped sheet-shaped panel formed body can be obtained. The sheet-shaped panel molded body may be subjected to secondary processing by vacuum forming and pressure forming. When the panel shape of the video equipment is complicated, a molded article having a desired shape can be obtained by irregular extrusion molding, blow molding, injection molding, compression molding, or the like using an annular die.

In order to obtain a panel having a multilayer structure, a coextrusion molding method in which two or more types of resin compositions are simultaneously melt-extruded, and one of the two types of resin compositions is molded in advance while extruding a single layer. There are a method of laminating the other, a method of forming two kinds of resin compositions in advance and pressing and thermocompression bonding, a method of continuously overlapping and bonding, a method of laminating at the time of vacuum forming and pressure forming, and the like.

As a preferred method, the transparent resin sheet 1
Is extruded into a sheet shape using a T-die, the antiglare-treated film 2 is coated on one side, the transparent conductive film 3 is formed on the other side, and the temperature of the transparent resin sheet 1 before lamination is 20.
~ 100 ° C and tension of the film is 1 ~ 10k
g / m (per roll length) is continuously supplied under tension and roll pressure is 0.5 to 4 ton / m. This is a method of laminating. It is convenient. According to this method, continuous production is easy, the process is simple, and mass productivity is excellent, which is preferable. Furthermore,
It is preferable to use a roll of an expander roll or a spiral roll type as the tension roll because it is possible to prevent wrinkles of the film at the time of lamination.

The temperature of the transparent resin sheet 1 before lamination is 20 ° C.
If it is more than the above, lamination unevenness is hardly generated and the film is hardly peeled off, which is preferable. When the temperature of the transparent resin sheet 1 before lamination is 100 ° C. or less, it is preferable because there is no problem that the temperature is too high and the polyethylene-based protective film is disadvantageous. The temperature of the transparent resin sheet 1 at the time of lamination is most preferably 30 to 70 ° C. because the lamination adhesive strength is high.

When the tension at the time of laminating the anti-glare treatment film 2 and the transparent conductive film 3 is 1 kg / m or more, there is no problem that the polyethylene-based protective film is not smoothly removed and the tension is uneven. preferable. Further, when the tension is 10 kg / m or less, there is no problem that the tensile stress of the film remains and causes the warpage of the panel, which is preferable.

When the roll pressure is 0.5 ton / m or more, it is difficult to entrain the air, and when the roll pressure is 4 ton / m or less, it is preferable because no optical distortion occurs.

[0062]

The present invention will be described in more detail with reference to the following examples.

The measurement, evaluation and test methods used in each of the examples and comparative examples are as follows.

(1) Total light transmittance: JIS K-710
The measurement is performed using a 1001-DP type haze meter manufactured by Nippon Denshoku Industries Co.

(2) Spectral reflectance: 400 to 700 using a self-recording spectrophotometer (model 330) manufactured by Hitachi, Ltd.
The spectral reflectance of 5 ° reflectance was measured in the wavelength range of
The reflectance at 0 nm was defined as the external light reflectance.

(3) Antistatic property: The test piece was set on a super insulation meter SME-8310 manufactured by Toa Denpa Co., Ltd., and the surface resistance of the antireflection surface for external light was measured.

(4) Surface resistance value: The resistance value is measured by using a digital multimeter 7541 manufactured by Yokogawa Electric Corporation with the terminals separated by 10 cm.

(5) Electromagnetic wave attenuation effect: The electromagnetic wave shielding measurement method (KEC method) by Kansai Electronics Industry Promotion Center
The electromagnetic wave attenuation effect was measured, and the electric field wave attenuation effect (dB) at 100 MHz was compared.

Example 1 A methacrylic resin (trade name: Del Powder 70H, manufactured by Asahi Kasei Kogyo Co., Ltd.) was used to extrude a vented extruder 50.
Extrusion sheet molding was performed using a unit consisting of mmφ (L / D = 32, single axis), a multi-manifold die, and three polishing rolls. The width was 300 mm and the thickness was 3 mm.
To form a single-layer transparent resin sheet.

At the time of extrusion molding of the transparent resin sheet, a roll of the anti-glare treatment film is prepared on the upper surface of the extruded sheet, and a roll of the transparent conductive layer film is prepared on the lower surface. The sheet is continuously supplied with a tension of 2 kg / m through a feeding roll and a tension roll so as to be positioned on the surface of the extruded sheet, and the sheet surface temperature becomes 6
When it was at 0 ° C., it was laminated with a pressure roll.

The antiglare film has a thickness of 80 μm.
Anti-glare anti-reflection film "Japan", which uses triacetyl cellulose as a transparent resin film substrate, performs anti-static treatment, forms an anti-reflection layer of fluororesin on it, and provides an adhesive layer on the opposite surface Oil / Fat Co., Ltd. product name: Rialuk "was used. As the transparent conductive layer film, a 100 μm-thick polyethylene terephthalate is used as a transparent resin film base material, a silver-deposited surface mainly composed of silver having a surface resistance of 10Ω / □ is used as a conductive layer, and an adhesive layer is formed on the opposite surface. The applied transparent conductive film “Tefijin Corporation, trade name: Reftel WR02” was used.

Further, a corner outer frame portion of the exposed surface of the silver-deposited conductive layer of the transparent conductive film of the laminate (the peripheral portion of the edge was 5 m in width).
(Around m), a conductive silver paste was used to apply a ground to the surface by a printing method to obtain a light-transmitting electromagnetic wave shielding panel shown in FIG.

Using the obtained panel as a test piece, the total light transmittance is measured, and evaluations (2) to (5) are performed by the test method. Table 1 shows the results.

It is preferable because it has excellent external light reflectivity and electromagnetic wave attenuation effect.

(Example 2) A continuous long thickness of 100 μm
m on one side of a methacrylic resin film, a primer (manufactured by Asahi Glass; trade name: CT-P10) was diluted to 0.5% of component,
It was applied continuously by a gravure coating method, dried, and subjected to a primer treatment.

Next, a non-crystalline transparent fluoropolymer (manufactured by Asahi Glass Co., Ltd .; trade name: CYTOP CTL-102)
A)) is continuously applied by a gravure coating method using a coater having a roll film transport system, dried, a uniform 0.13 μm thin film is laminated, an antireflection layer is formed, and a polyethylene protective film is formed thereon. Was used for masking.

On the opposite side of the anti-reflection treated surface, a transparent pressure-sensitive adhesive containing an acrylic ester copolymer as a pressure-sensitive adhesive and containing rosin and an antioxidant was laminated to a thickness of about 20 μm by a gravure coating method. The top was masked with a 50 μm thick polyethylene terephthalate film releasable protective film to give an antiglare film.

The above film was used as an antiglare film.
A light was obtained in the same manner as in Example 1 except that a transparent conductive film having a surface resistance value of 2Ω / □ and a transparent conductive layer having a surface resistance value of 2Ω / □ was used as the transparent conductive film. A transmissive electromagnetic wave shielding panel was obtained. Table 1 shows the evaluation results.
Shown in

The anti-reflection property of external light and the effect of attenuating electromagnetic waves are excellent and preferable.

(Comparative Example 1) A transparent acrylic resin plate (manufactured by Asahi Kasei Kogyo; trade name "Delaglass A") was used as a panel for evaluation. Table 1 shows the results.

[0086] The display panel had no external light reflection preventing property and no electromagnetic wave attenuation effect, and was not desirable as a display panel.

(Comparative Example 2) A surface on which a transparent conductive film made of an oxide film of a mixture of indium oxide and tin oxide was formed by sputtering using a transparent resin film substrate of polyethylene terephthalate having a thickness of 100 μm as a transparent conductive film. A light-transmitting electromagnetic wave shielding panel was obtained in the same manner as in Example 1 except that a transparent conductive film having a resistance value of 200 Ω / □ was used. Table 1 shows the evaluation results.

The light transmittance was greatly reduced, and the anti-reflection property of external light and the effect of attenuating electromagnetic waves were inferior.

[0084]

[Table 1]

[0085]

According to the present invention, there is provided a light-transmitting electromagnetic wave shielding panel which has high image quality transparency, and has both an external light reflection preventing property and an electromagnetic wave shielding property.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of a light-transmitting electromagnetic wave shielding panel of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent resin sheet 2 Anti-glare treatment film 3 Transparent conductive film 4 Earth electrode 5 Transparent protective film 6 Earth wire

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29K 105: 32 B29L 9:00

Claims (3)

[Claims] At least one surface of a transparent resin sheet has an antiglare treatment film, and the other surface has a transparent conductive film having a conductive layer having a surface resistance of 30 Ω / □ or less on one surface of the transparent resin film, A light-transmitting electromagnetic wave shielding panel, wherein the panel has a total light transmittance of 60% or more, and has a ground electrode on at least a part of the conductive layer. 2. The light-transmitting electromagnetic wave shielding panel according to claim 1, wherein the anti-glare treatment film and the transparent conductive film are laminated on a transparent resin sheet via an adhesive layer. 3. The light-transmitting electromagnetic wave shielding panel according to claim 1, wherein the antiglare film has an antistatic layer and an antireflection layer on one surface of the transparent resin film substrate.