JP2002189420A - Filter for plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding filter having a high transmittance in the visible light region and excellent in antireflection performance. SOLUTION: In the filter for a plasma display, the surface resistance of a transparent electrically conductive sheet with a transparent electrically conductive film layer is 3-10 Ω/sq. and the transparent electrically conductive film layer is brought into contact with an adhesive or sticky resin containing >=0.05 wt.% metal deactivator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter disposed in front of a plasma display (PDP), and more particularly, to a shielding function using a transparent conductive film to prevent leakage of electromagnetic waves generated from the PDP. The present invention relates to a plasma display filter provided with a filter.

[0002]

2. Description of the Related Art Conventionally, display has been CR
T (Cathode Ray Tube) was the mainstream, but recently FPD (Flat Panel Di)
spray) has been developed and commercialized. However,
LCD (Liquid Crystal Di), which is expanding its market by utilizing functions such as thinness, light weight, and low power consumption
Spray is widely used, but PDP (Plasma Display) which is thin and is applied to a large screen.
y Panel) is attracting attention.

[0003] Since a PDP utilizes a light emission phenomenon accompanying gas discharge, a large current flows and a magnetic field is generated.
For this reason, there is a concern that the electromagnetic waves generated from the PDP may affect the human body and other electronic devices. For this reason,
Attachment of an electromagnetic wave shielding filter to a PDP has been studied.

The basic structure of a DC type PDP is to selectively discharge and emit phosphors in a large number of display cells separated between two glass plates, and a partition is provided between a front glass and a rear glass. A display cell, an auxiliary cell, and the like are arranged, and a red phosphor, a green phosphor, and a blue phosphor are provided in a film on the inner wall of each display cell. These phosphors emit light when discharged by the voltage applied to the cathode, display anode, and auxiliary anode. For this reason, it is inevitable that electromagnetic waves of several kHz to several GHz are generated from the front surface of the PDP due to voltage application, discharge, light emission, and the like, and it is necessary to shield the electromagnetic waves.

For this reason, conventionally, a transparent filter having an electromagnetic wave shielding function is disposed on the front surface of the PDP in order to shield electromagnetic waves from the PDP. That is, the filter used to prevent the leakage of the electromagnetic waves has a configuration in which a conductive mesh material such as a wire mesh is interposed between transparent substrates such as an acrylic plate to be integrated.

However, in terms of simplifying the manufacturing process, reducing the manufacturing cost, and improving the production efficiency, it is more advantageous to use a transparent conductive film than to use a conductive mesh as an electromagnetic wave shielding material. The use of a conductive mesh is not necessary as long as it is a multilayer film in which a certain kind of transparent oxide conductive film and a metal thin film are alternately laminated.

[0007] For example, Japanese Patent Application Laid-Open No. 10-217380 proposes a plasma display filter using a transparent conductive film. However, the filter proposed here has a drawback that the transparent conductive film has a sheet resistance of 3Ω / □ or less, and therefore has a low visible light transmittance and a high reflectance.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, has electromagnetic wave shielding properties,
Moreover, an object of the present invention is to provide an electromagnetic wave shielding filter having high transmittance in a visible light region and excellent antireflection performance.

[0009]

According to the present invention, a transparent conductive sheet having a transparent conductive layer has a sheet resistance of 3 to 10 Ω / □, and the transparent conductive layer is in contact with an adhesive resin or an adhesive resin. The adhesive resin or the adhesive resin is 0.0%
The present invention relates to a plasma display filter comprising 5% by weight or more of a metal deactivator, and more specifically, a transparent conductive film layer is formed on a transparent resin substrate,
This is a plasma display filter in which an antireflection film is laminated on this film with an adhesive or a pressure-sensitive adhesive containing a metal deactivator.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the recently developed plasma display, the control circuit and the luminous efficiency have been improved, and the amount of electromagnetic waves radiated from the plasma display light-emitting panel has been reduced. Because the sheet resistance of the sheet is a transparent conductive film larger than 3Ω / □,
While having electromagnetic wave shielding properties, high visible transmittance,
The reflectivity can be reduced.

As the transparent conductive film to be used, a thin film of silver (or silver alloy), copper, gold, platinum or the like and a metal oxide (tin oxide, indium oxide, titanium oxide, zinc oxide, indium-tin alloy) are usually used. Oxides and the like are alternately laminated. As a transparent conductive film formed of a thin film stack, for example, a known method is proposed as proposed in US Pat. No. 4,799,745. Since such a thin film laminate shields near-infrared light by interference, it is possible to prevent leakage of near-infrared light emitted from the plasma display light-emitting panel. These transparent conductive films can be easily formed on a base film by a sputtering method, a vacuum evaporation method, an ion plating method, a CVD method, or the like.

In the present invention, if the resistance value of the transparent conductive sheet exceeds 3 Ω / □, the transmittance of near infrared rays of 800 to 1000 nm increases, so that it is preferably 10 Ω / □ or less.

Since the silver (or silver alloy) thin film constituting the transparent conductive film is easily oxidized relatively early, in the present invention, for example, a metal deactivator such as benzotriazole is used as an adhesive or a tackifier. The amount is 0.01% by weight or more, preferably 0.05% by weight.
That is all.

In order to reduce the leakage of electromagnetic waves, it is desirable to install metal electrodes along the four sides of the filter and make electrical contact with the conductive surface of the transparent conductive film. However, this electrode is not necessary in the case of a plasma display light-emitting panel that generates a small amount of electromagnetic waves. Even in such a case, since the transparent conductive film may be charged by the capacitor effect, it is preferable to ground at least one place from the transparent conductive film.

In order to further reduce the transmittance of near-infrared rays, a known near-infrared absorbing dye can be laminated by coating or kneading. Further, various dyes can be mixed in the transparent conductive film or an adhesive or a pressure-sensitive adhesive described later in order to correct the transmission color or the reflection color. In particular, for the purpose of correcting the emission color of the plasma display, it is preferable to mix a dye that selectively absorbs and blocks only light of a specific wavelength. Among them, color reproducibility is particularly improved by using a dye having a maximum absorption at 570 to 595 nm.

The filter of the present invention is usually made of PET, P
C, a transparent conductive film layer is formed on a substrate typified by PMMA, and an antireflection film is further laminated on this film with an adhesive or a pressure-sensitive adhesive containing a metal deactivator. Then, it can be directly adhered to the surface of a display, for example, the surface of a light emitting panel of a plasma display with an adhesive or an adhesive, and of course, can be fixed to the front surface of a PDP.

The adhesive is preferably a transparent and elastic one. Specifically, ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer, and ethylene-methyl (meth) acrylate are preferred. Ethylene copolymers such as a polymer, a carboxylethylene-vinyl acetate copolymer, and an ethylene-vinyl acetate- (meth) acrylate copolymer are exemplified. In addition, polyvinyl butyral (PVB) resin, acrylic resin, silicon resin, urethane resin, and the like can also be used.

As the pressure-sensitive adhesive, a transparent and elastic one is preferable. For example, as the rubber-based pressure-sensitive adhesive, NR,
A resin such as rosin, terpene, styrene, etc. is blended with IR, SBR, etc., and a softening agent, an antioxidant, a crosslinking agent, etc. are added thereto. An adhesive can also be used.

[0019]

EXAMPLES A transparent conductive sheet of the present invention and a sheet as a comparative example were produced. That is, a PET with a thickness of 100 microns
On the film, the thin films shown in Table 1 were formed by magnetron sputtering. The numerical values in the table are the thickness of each layer, and the unit is angstrom.

The conductivity of the obtained film was measured with a four-terminal resistance meter. The measuring instrument used is a LORESTA sheet resistance measuring device manufactured by Dia Instruments. The measurement results are shown in Table 1.

Further, this PET film is adhered to a glass plate (thickness: 2.8 mm) so that the film is formed on the outside, and an anti-reflection film (manufactured by Nippon Oil & Fat Co., Ltd., Rialuk) is coated on the outside with an acrylic pressure-sensitive adhesive (Soken). (Manufactured by Kagaku). To this acrylic pressure-sensitive adhesive was added 0.2% by weight of a benzotriazole-based metal deactivator. that time,
The anti-reflection film is made smaller than glass so that the underlying thin film is exposed along the four sides, and a conductive paste (Fujikura Kasei Co., Dotite) is applied to the exposed portion of the thin film, dried and cured. Was. The conductive paste is based on an acrylic resin, and is a mixture of silver and copper powder.

The transmittance and the reflectance were measured with a spectrophotometer. The measuring method conformed to JIS R 3106. Table 1 shows the measurement results.

[0023]

The films of the examples have excellent properties as a filter for PDP having a high transmittance and a low reflectance.

[0024]

[Table 1]

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G02B 1/11 H04N 5/66 101A 5G435 H01J 11/02 G02B 1/10 Z H04N 5/66 101 A F term (reference) 2K009 AA02 DD01 EE03 4F100 AB17C AB17H AB24C AB24H AH03H AK25B AK25C AK42D AR00B AR00C AR00D BA03 BA04 BA07 BA10B BA10C BA10D CA21C CA30B DE01C DE01H EH66A GB41 GB56 JG01A JG04A JL11B JL13B JN01 JN01A JN01C JN06 JN06D JN08 YY00A YY00B 4J040 DA051 DA061 DD071 DE031 DF001 DF041 EF001 EK001 GA07 HC25 LA09 LA10 MA10 NA17 NA19 5C040 FA01 FA04 GB03 GB14 GH10 MA08 5C058 AA11 AB05 BA35 5G435 AA03 AA04 BB06 CC09 GG11 GG33 HH03

Claims (2)

[Claims] 1. A transparent conductive sheet having a transparent conductive film layer has a sheet resistance of 3 to 10 Ω / □, and the transparent conductive film layer is in contact with an adhesive resin or an adhesive resin. Alternatively, a filter for plasma display, wherein the adhesive resin contains 0.05% by weight or more of a metal deactivator. 2. A plasma display, wherein a transparent conductive film layer is formed on a transparent resin substrate, and an antireflection film is laminated on the film with an adhesive or a pressure-sensitive adhesive containing a metal deactivator. filter.