JPH10261891A - Electromagnetic shielding body and display filter formed therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a display filter which is capable of shutting off electromagnetic waves emitted from an electromagnetic equipment such as a plasma display or the like and enhanced in electromagnetic shielding properties, light transmission properties, and environmental resistance, by a method wherein an electrode which contains metal is continuously formed on a transparent conductive layer and the periphery of a transparent laminate. SOLUTION: A transparent high-molecular film 10 is used as a transparent base, and a transparent conductive layer 20 and an electrode 30 which contains metal are formed on the transparent high-molecular film 10. When a transparent protective layer is formed, a transparent high-molecular film 10 is used as a transparent based, a transparent conductive layer 20, a transparent protective film 40 as a transparent protective layer, and an electrode 30 which contains metal are formed on the primary surface of the transparent high-molecular film 10. The electrode which contains metal is continuously formed on the transparent conductive layer and the periphery of a transparent laminate, and an electromagnetic shielding body is possessed of a light transmitting part at its center. By this setup, an electromagnetic shielding body can be enhanced in electromagnetic shielding properties without deteriorating in light transmission.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shield and a display filter using the same, and more particularly, to an electromagnetic wave shield having a light-transmitting property and an environmental resistance, which shields an electromagnetic wave having a high intensity generated by a plasma display. The present invention relates to a filter for a display using the same, which has an excellent electromagnetic wave shielding property, a light transmitting property, and environmental resistance.

[0002]

2. Description of the Related Art Optoelectronics-related components and equipment have been remarkably advanced and spread as society has become highly information-oriented. Among them, displays have become extremely popular for televisions, personal computers, etc., and their thickness and size have been reduced. 2. Description of the Related Art In recent years, plasma displays have attracted attention for use in large-sized thin televisions and thin display devices, and have already begun to appear on the market. However, plasma displays generate strong leakage electromagnetic fields due to their structural principle, and the effects of recent leakage electromagnetic fields on the human body and other devices have been investigated. It is necessary to clear the standards.

[0003] The regulated value of VCCI is indicated by the radiated electric field intensity which is an absolute value, and its unit is dBμV / m. It is 50 dBμV / m in Class I indicating the regulation value for industrial use, and 40 dBμV in Class II indicating the regulation value for home use.
V / m. The radiated electric field strength of the plasma display is within the range of 20 to 90 MHz,
0 dBμV / m, 50 dBμV / m for a diagonal type of about 40
Therefore, it cannot be used for home use as it is. Practically radiated electric field strength of 40d for home use
It is required to be not more than BμV / m, preferably not more than 35dBμV / m, more preferably not more than 30dBμV / m.
The radiation electric field intensity of the plasma display is 50 dBμV /
In the case of m, a display filter having an electromagnetic wave shielding ability having a shielding effect of 10 dB or more, preferably 15 dB or more, more preferably 20 dB or more is required. Further, when the transmittance of visible light is low, the sharpness of an image is reduced. Therefore, the visible light transmittance of the display filter is preferably as high as possible, and at least 50%.
%, Preferably 60% or more.

In order to shield a leakage electromagnetic field (electromagnetic wave), it is necessary to cover the display surface with a conductive material having high conductivity. Generally, a grounded metal mesh or a mesh of synthetic resin or metal fiber is used,
These methods have problems in that a portion that does not transmit light emitted from the display is generated, moire occurs, and cost is increased due to poor yield. Therefore, ITO (Indium)
A transparent conductive film typified by Tin Oxide) is used for the electromagnetic wave shielding layer, and the conductivity usually required is 10 ⁵ Ω / □ or less, preferably 10 ³ Ω / □ or less. Examples of the transparent conductive film include metal thin films such as gold, silver, copper, platinum, and palladium, oxide semiconductor thin films such as indium oxide, stannic oxide, and zinc oxide, and multilayer thin films in which a metal thin film and a high refractive index transparent thin film are laminated. There is. Among them, a metal thin film can have conductivity, but cannot have a high visible light transmittance due to reflection and absorption of metal over a wide wavelength range. Further, the oxide semiconductor thin film is superior in transparency to the metal thin film, but is inferior in conductivity. On the other hand, a transparent laminated body in which a metal thin film and a high-refractive-index transparent thin film are laminated has the conductivity and optical properties of a metal such as silver and the prevention of reflection of the high-refractive-index transparent thin film by a metal in a certain wavelength region. Has favorable characteristics in both conductivity and visible light transmittance. However, in order to improve the conductivity by increasing the conductivity, it is necessary to increase the thickness of the metal layer, resulting in a problem in optical characteristics such as a decrease in light transmittance.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, an object of the present invention is to provide an excellent electromagnetic wave shielding ability for blocking electromagnetic waves generated from electronic devices such as a plasma display and said to be harmful to health. An object of the present invention is to provide an electromagnetic wave shield having light-transmitting properties and environmental resistance, and a display filter using the same.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have formed an electrode (C) containing a metal on one main surface of a transparent substrate (A). Of a transparent laminate having at least a transparent conductive layer (B) formed thereon,
It has been found that by continuously forming on the transparent conductive layer (B) and on the periphery of the transparent laminate, the electromagnetic wave shielding performance is enhanced without lowering the light transmittance of the electromagnetic wave shielding body, and the present invention is completed. It has arrived.

That is, the present invention provides (1) a transparent laminate comprising at least a transparent conductive layer (B) formed on one main surface of a transparent substrate (A), wherein an electrode (C) containing a metal comprises: An electromagnetic wave shielding body continuously formed on the transparent conductive layer (B) and at a peripheral portion of the transparent laminate; (2) a metal-containing electrode (C) having a specific resistance of 1 × 10 ^-3 Ω · cm or less (1)
(3) The transparent conductive layer (B)
(1) or (2), wherein the sheet resistance of the electromagnetic wave shield is 1000Ω / □ or less.
The sheet resistance of the transparent conductive layer (B) is 3 Ω / □ or less (the electromagnetic wave shield according to (3), (5) as an optical member having a visible light transmittance of 50% or more and having a light transmitting property. The electromagnetic wave shield according to any one of (1) to (4), which is preferably used, and (6) the electromagnetic wave shield preferably used for a plasma display using the electromagnetic wave shield according to any one of (1) to (5). The present invention relates to a display filter.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The electromagnetic wave shield of the present invention is a transparent laminate comprising an electrode (C) containing a metal and at least a transparent conductive layer (B) formed on one main surface of a transparent substrate (A). It is formed continuously on the transparent conductive layer (B) of the body and at the periphery of the transparent laminate, and has excellent electromagnetic wave shielding ability without lowering light transmittance.

An example of the configuration and electrode shape of the electromagnetic wave shield of the present invention will be described with reference to the drawings, but the present invention is not limited thereto. As the simplest example, FIG. 1 shows a sectional view of the electromagnetic wave shield of the present invention. A transparent polymer film 10 is used as a transparent substrate (A), and a transparent conductive layer (B) 20 and a metal-containing electrode (B) 3 are formed on its main surface.
0 is formed. As an example of a case where a transparent protective layer is formed, a transparent polymer film 10 is used for a transparent substrate (A), and a transparent conductive layer (B) 20 is formed on the main surface of the transparent substrate (A). A transparent protective film 40 as a transparent protective layer and an electrode (C) 30 containing metal are formed. The shape of the electrode (C) containing the metal of the present invention is formed continuously on the transparent conductive layer (B) and on the periphery of the transparent laminate as described with reference to FIG. It has a light-transmitting portion at the center.

The transparent substrate (A) in the present invention includes:
Inorganic compound moldings such as glass and quartz, and transparent organic polymer moldings can be mentioned, but polymer moldings are light and hard to break, so that they can be used more suitably. The polymer molded article may be transparent in the visible wavelength range, and specific examples thereof include polyethylene terephthalate, polyether sulfone, polystyrene, polyethylene naphthalate,
Examples include, but are not limited to, polyarylate, polyetheretherketone, polycarbonate, polypropylene, polyimide, triacetylcellulose, and the like. These transparent polymer molded products may be in the form of a plate (sheet) or film as long as the main surface is smooth. When a sheet-shaped polymer molded product is used as a substrate, the substrate has excellent dimensional stability and mechanical strength, and thus a transparent laminate having excellent dimensional stability and mechanical strength is obtained. It can be used preferably when required.
In addition, since the transparent polymer film has flexibility and the transparent conductive layer can be formed continuously by a roll-to-roll method, when this is used, it is efficient and long. The ability to produce transparent laminates in large areas, and the use of film-like transparent laminates for display glass, dimmers,
Since it can be prevented from scattering when the glass is broken by being attached to the glass support of the display filter, it can also be suitably used. In this case, a film having a thickness of usually 10 to 250 μm is used. When the thickness of the film is less than 10 μm, the mechanical strength as a base material is insufficient, and when it exceeds 250 μm, the flexibility is insufficient, so that the film is not suitable for being wound on a roll and used.

These substrates are subjected to an etching process such as a sputtering process, a corona process, a flame process, an ultraviolet ray irradiation, an electron beam irradiation or the like, or an undercoating process on their surfaces, and a film layer formed thereon is adhered to the substrate. A process for improving the performance may be performed. Further, in order to enhance the adhesion between the transparent substrate and the transparent conductive layer, an arbitrary inorganic layer may be formed therebetween. The kind of the inorganic substance is not particularly limited. The thickness may be a thickness that does not impair the transparency, and is preferably about 0.02 nm to 10 nm. If the thickness is too small, a sufficient effect of improving the adhesion cannot be obtained, and if it is too large, the transparency is impaired. If the thin film layer to be formed is an oxide, part or all of the metal of the adhesion layer is actually a metal oxide, but there is no problem in its effect. Before forming the transparent conductive layer, dust-proofing treatment such as solvent cleaning or ultrasonic cleaning may be performed as necessary.

In the present invention, such a transparent substrate (A)
A transparent conductive layer (B) is formed on one of the main surfaces. Examples of the transparent conductive layer (B) include indium oxide (ITO) doped with tin and zinc oxide (AZ) doped with aluminum.
O), a thin film of zinc oxide (ATO) doped with antimony and the like, and a multilayer laminated film of a high refractive index transparent thin film layer and a metal thin film layer. The sheet resistance of these transparent conductive layers is usually preferably 1000 Ω / □ or less, but is 3 Ω / □ or less, preferably 2.5 Ω / □ or less in order to shield electromagnetic waves having a plasma display intensity.

Electromagnetic wave shielding is achieved by the effects of 1) reflection and 2) absorption of the electromagnetic wave in the electromagnetic wave shield. The electromagnetic wave shield needs to have conductivity for absorption. As described above, the electromagnetic wave shield for a plasma display requires a conductive layer having a very low resistance. Also, in order to absorb all the electromagnetic waves generated from the display, the conductive layer needs to have a certain thickness or more, but if the conductive layer, that is, the metal thin film layer is thickened, the visible light transmittance becomes low. I will. Therefore, it is also important to increase the reflection interface by multi-layer lamination of a metal thin film layer and a high-refractive-index transparent thin film layer to increase the reflection of electromagnetic waves.

Further, since the plasma display emits strong near-infrared rays and may cause malfunctions of peripheral electronic devices, it is preferable to cut off light in a wavelength range of 800 to 1000 nm, which is a near-infrared range. However, it is desirable that the electromagnetic wave shielding body itself has a near-infrared cut property in view of a demand for reducing the number of members and a limit of near-infrared absorption using a dye.

The near-infrared ray can be cut by reflection of free electrons of a metal. However, as the thickness of the metal thin film layer increases, the visible light transmittance also decreases as described above. Therefore, a laminated structure in which a metal thin film layer having a certain thickness is sandwiched between high refractive index transparent thin film layers is described as one.
By stacking more than one step, the visible light transmittance can be increased and the overall thickness of the metal thin film layer can be increased, and the visible light can be increased by controlling the number of layers and / or the thickness of each layer. The transmittance, visible light reflectance, near infrared transmittance, transmitted color, and reflected color can be changed within a certain range. If the visible light transmittance is low, the sharpness of an image is reduced when the display is installed. Therefore, the higher the visible light transmittance of the display filter, the better, at least 50%.
Or more, preferably 60% or more. If the visible light reflectance is high, the reflection of lighting equipment etc. on the screen will increase,
Visibility decreases. Here, the visible light transmittance or the visible light reflectance in the present invention is calculated according to JIS (R-3106) from the wavelength dependence of the transmittance and the reflectance. Further, since the transmission color of the filter greatly affects the contrast of the display and the like, it is necessary to control the transmission color. For this reason, a multilayer stack that is easy to design and control optically is preferable.

Therefore, as the transparent conductive layer (B) of the electromagnetic wave shield used in the plasma display, a multilayer laminated film in which a laminated structure in which a metal thin film layer is sandwiched between high refractive index transparent thin film layers is stacked one or more stages is suitable. . In this case, in order to control the optical characteristics, in consideration of the refractive index and the extinction coefficient of the transparent substrate and the thin film material, an optical design is performed using a vector method, a method using an admittance diagram, and the like, and the thin film material of each layer and Determine the number of layers, film thickness, etc. In addition, film formation can be performed by controlling the number of layers, film thickness, and the like while observing optical characteristics.

Specific examples of the material of the metal thin film in the case of multilayer lamination include silver, gold, platinum, palladium, nickel, chromium, zinc, zirconium, titanium, tungsten, tin and the like, or two or more of these materials. Alloys. Among them, silver can be preferably used because it has excellent conductivity, infrared reflectivity, and visible light transmittance when laminated with a high refractive index transparent thin film layer. However, silver lacks chemical and physical stability and is degraded by environmental pollutants, water vapor, heat, light, etc.
An alloy containing one or more environmentally stable metals such as platinum, palladium, indium, and tin is also preferably used. Here, the silver content of the alloy containing silver is not particularly limited, but it is preferable that the silver content does not largely differ from the conductivity and optical characteristics of the silver thin film, and is about 50% by weight or more and less than 100% by weight. However, when other metals are added to silver,
If possible, it is desirable to use at least one of the layers without alloying silver, because such excellent conductivity and optical characteristics are impaired. When the all-metal thin-film layer is composed of silver that is not an alloy, a transparent laminate having excellent conductivity and optical properties can be obtained, but the environmental resistance is not sufficient. Also,
When the adjacent high-refractive-index transparent thin film layer is an oxide, part of the metal of the metal thin film layer may actually be a metal oxide. There is no particular problem in film formation. Further, all metal thin film layers are not necessarily the same in thickness, and may not be the same metal or alloy.

The thickness of the metal thin-film layer is determined optically and experimentally from the viewpoint of conductivity, optical characteristics, etc., and is not particularly limited as long as the transparent laminate has the required characteristics. Since it is necessary that the thin film is in a continuous state, the thickness is preferably 4 nm or more, and if it is too thick, transparency becomes a problem. For the formation of the metal thin film layer, any of conventionally known methods such as sputtering, ion plating, vacuum deposition, plating and the like can be adopted.

The transparent thin film forming the high-refractive-index transparent thin film layer in the case of a multilayer thin film is a transparent thin film which has transparency in the visible region and has an effect of preventing light reflection in the visible region of the metal thin film layer. Although not particularly limited, a material having a high refractive index to visible light of 1.6 or more, preferably 1.7 or more is used. Specific materials for forming such a transparent thin film include oxides of indium, titanium, zirconium, bismuth, tin, zinc, antimony, tantalum, cerium, neodymium, lanthanum, thorium, magnesium, gallium and the like, or Examples include a mixture of oxides and zinc sulfide. These oxides or sulfides, even if there is a shift in the stoichiometric composition of the metal and oxygen or sulfur,
It does not matter if the optical characteristics are not largely changed. Above all, indium oxide or a mixture of indium oxide and tin oxide (ITO), in addition to transparency and refractive index,
It can be suitably used because it has a high deposition rate and good adhesion to the metal thin film layer. In addition, by using an oxide semiconductor thin film having relatively high conductivity such as ITO, the number of electromagnetic wave absorbing layers can be increased, and the conductivity of the electromagnetic wave shield can be increased. The thickness of the high-refractive-index transparent thin film layer is determined optically and experimentally from the optical properties of the transparent substrate, the thickness and optical properties of the metal thin-film layer, and the refractive index of the high-refractive-index transparent thin film layer. Although not limited, it is preferably 5 nm or more and 200 nm or less, more preferably 10 nm or more and 100 nm or less. Further, the entire high-refractive-index transparent thin film layers are not necessarily the same in thickness, and need not be the same transparent thin film material. For forming the high refractive index transparent thin film layer, any of conventionally known methods such as sputtering, ion plating, ion beam assist, vacuum deposition, and wet coating can be employed.

In particular, sputtering is suitable for controlling the film thickness and laminating a plurality of layers. The metal thin film layer and the high-refractive-index transparent thin film layer can be easily and continuously repeated. As will be described later in the examples as specific examples, a high-refractive-index transparent thin film layer mainly composed of indium oxide and a metal thin film layer composed of silver or an alloy containing silver are continuously formed by a sputtering method. The formation of the high-refractive-index transparent thin film layer mainly composed of indium oxide is performed by reactive sputtering using a metal target containing indium as a main component or a sintered body target containing indium oxide as a main component. In the reactive sputtering method, an inert gas such as argon is used as a sputtering gas and oxygen is used as a reactive gas, and a pressure of 0.1 to 20 mTorr and a direct current (DC) or high frequency (RF) magnetron sputtering method are used. it can. The oxygen gas flow rate is experimentally determined from the obtained film formation rate and the like, and is controlled so as to obtain a thin film having desired transparency. The metal thin film layer made of silver or an alloy containing silver is formed by sputtering using silver or an alloy containing silver as a target. An inert gas such as argon is used as a sputtering gas, and a direct current (DC) or high frequency (RF) magnetron sputtering method or the like can be generally used at a pressure of 0.1 to 20 mTorr.

In order to improve the environmental resistance of the metal thin film layer and the adhesion between the metal thin film layer and the high-refractive-index transparent thin film layer, the conductivity and the optical characteristics between the metal thin film layer and the high-refractive-index transparent thin film layer are improved. Any inorganic layer may be formed to such an extent as not to impair. Specific materials include copper, nickel, chromium, gold, silver, platinum, zinc, zirconium, titanium, tungsten, tin, palladium, and the like, and alloys composed of two or more of these materials. , Preferably 0.
When the thickness is about 02 nm to 2 nm, if the thickness is too thin, a sufficient effect of improving the adhesion cannot be obtained. If the high-refractive-index transparent thin film layer is an oxide, part or all of the metal of the inorganic layer is actually a metal oxide, but there is no problem in its effect.

The atomic composition of the high-refractive-index transparent thin film layer and the metal thin film layer formed by the above method can be determined by Auger electron spectroscopy (AES), inductively coupled plasma method (ICP), Rutherford backscattering method (RBS), or the like. Can be measured. Further, the layer configuration and the film thickness can be measured by depth direction observation of Auger electron spectroscopy, cross-sectional observation by a transmission electron microscope, or the like. The film thickness is controlled by clarifying the relationship between the film forming conditions and the film forming speed in advance, or by monitoring the film thickness during film forming using a quartz oscillator or the like. A compound that suppresses the deterioration of the metal thin film may be dissolved in an arbitrary solvent and applied to the surface or the end surface of the thin film forming surface of the transparent laminate of the present invention.

The above transparent substrate (A) / transparent conductive layer (B)
In order to improve the mechanical strength and environmental resistance of the transparent substrate (A), a transparent hard coat layer may be provided on a surface other than the conductive surface of the transparent substrate (A). Further, as described above, silver which can be suitably used for the metal thin film layer lacks chemical and physical stability, is deteriorated by environmental contaminants, water vapor, etc., and causes aggregation and whitening. A transparent protective layer with a gas barrier property on the outermost surface of the thin film formation surface to the extent that the conductivity and optical characteristics are not impaired so that the thin film is not exposed to pollutants and water vapor in the usage environment. It is preferred to coat with. Gas barrier properties are required, 10 g / m ² · day or less moisture permeability, ^2-preferably 5 g / m
day or less, more preferably 1 g / m ² · day or less.
In addition, since the surface on which the thin film is formed has poor scratch resistance, it is desirable to cover the surface on which the thin film is formed with a transparent protective layer having a hard coat property for imparting scratch resistance. More preferably, the transparent protective layer has both gas barrier properties and hard coat properties.

The transparent protective layer is a layer which is transparent in the visible wavelength region having the above functions such as gas barrier properties, and has a film having these functions or a transparent molded article on which a film having these functions is formed. And transparent molded articles having these functions. Even if a film having these functions is formed by chemical vapor deposition (CVD), vapor deposition, sputtering, ion plating, coating, printing, or any other conventionally known film forming method, it has these functions. A polymer film, a polymer sheet, glass, or a polymer film formed with a film having these functions, a polymer sheet may be attached via an arbitrary adhesive, an adhesive, or a member. The adhesive and the adhesive to be bonded may have these functions. There are no particular restrictions on these fabrication methods.

Specific examples of the transparent protective layer having gas barrier properties include silicon oxide, aluminum oxide, tin oxide, indium oxide, yttrium oxide, magnesium oxide and the like, or a mixture thereof, or a small amount of other elements added thereto. Metal oxide thin film, other than polyvinylidene chloride, acrylic resin, silicone resin, melamine resin, urethane resin, fluorine resin, etc.
It is not particularly limited to these. The thickness of these films is about 10 to 200 nm in the case of a metal oxide thin film and about 1 to 100 μm in the case of a resin, and may be a single layer or a multilayer, but is not particularly limited. These thin film-formed polymer films may be bonded together.
Examples of the polymer film having low moisture permeability include polyethylene, polypropylene, nylon, polyvinylidene chloride, vinylidene chloride and vinyl chloride, a copolymer of vinylidene chloride and acrylonitrile, and a fluorine-based resin. Not something. Even when the moisture permeability is relatively high, the moisture permeability decreases by increasing the thickness of the film or adding an appropriate additive. Therefore, polyethylene terephthalate, polycarbonate, polystyrene, having a thickness sufficient to achieve the above moisture permeability
Polyarylate, polyetheretherketone, polyethersulfone and the like may be used.

Examples of the film having a hard coat property include, but are not limited to, films of acrylic resin, silicon resin, melamine resin, urethane resin, fluorine resin and the like. As a method for forming a film having a hard coat property, depending on the resin used, a conventionally known method such as a printing method or a coating method can be selected and used, and its thickness is about 1 to 100 μm, and even a single layer. It may be a multilayer, but these are not particularly limited either.

The transparent protective layer may have an antireflection property and / or an anti-Newton ring property and / or an antiglare property. In this case, when it is necessary to provide these functions, there is no need to separately provide a layer having these functions, which is preferable. Conversely, the layer having these functions may have gas barrier properties and / or hard coat properties.

An arbitrary adhesive or adhesive can be used for bonding. In this case, it is important that, when the electromagnetic wave shielding body of the present invention is used as an optical member such as a display filter, the adhesive or adhesive used in the light transmitting portion is sufficiently transparent to visible light. There is a need. The adhesive or the adhesive may be a sheet or a liquid as long as it has a practical adhesive strength, and the members are laminated by laminating each member after sticking the adhesive sheet or applying the adhesive. The liquid thing is an adhesive that is cured by being left at room temperature or heated after coating and bonding, and examples of the coating method include a bar coating method, a reverse coating method, a gravure coating method, a die coating method, and a roll coating method. Consideration and selection are made based on the type, viscosity, and application amount of the adhesive. The thickness of the pressure-sensitive adhesive or adhesive layer is not particularly limited, but may be 0.5 μm
To 50 μm, preferably 1 μm to 30 μm. After bonding using an adhesive or adhesive, the air that has entered between the members at the time of bonding is defoamed or dissolved in the adhesive or adhesive to improve the adhesion between the members. It is important to perform curing under the conditions of pressurization and heating.
At this time, the pressurizing condition is about several to 20 atm or less, and the heating condition is about room temperature or more and about 80 ° C. or less, depending on the heat resistance of each member, but is not particularly limited thereto.

An electrode (C) containing a metal is continuously formed on the transparent conductive layer of the above-mentioned transparent laminate and on the periphery thereof to obtain the electromagnetic wave shield of the present invention. For devices that require an electromagnetic wave shield, a metal layer is provided inside the case of the device, or radio waves are blocked by using a conductive material for the case. When transparency is required as in a display device (display), a window-shaped optical member (filter) having a so-called transparent conductive layer is provided. Since the electromagnetic wave induces electric charge after being absorbed in the conductive layer, if the electric charge is not escaped by grounding, the electromagnetic wave shielding body again acts as an antenna and oscillates the electromagnetic wave. Therefore, it is necessary that the transparent conductive layer of the display filter provided with the electromagnetic wave shielding property is in ohmic contact with the conductive layer inside the case of the display body. Therefore, in the transparent laminate, a part of the thin film forming surface, which is a current-carrying part, is partially exposed, and the layers formed on the thin film forming surface including the above-described transparent protective layer are formed in portions other than a portion that obtains electrical contact. Need to be.

The electromagnetic wave shield of the present invention is formed by continuously forming an electrode (C) containing a metal on the transparent conductive layer of the transparent laminate and at the periphery thereof. By forming an electrode containing a metal, electrical contact is improved. Also, if the specific resistances of the transparent conductive layer (B), the electrode (C), and the conductive layer in the case are significantly different, an impedance difference occurs at these contact portions, and electromagnetic waves are emitted at those portions. Usually, the conductive layer in the case is a metal layer, and the specific resistance is 10 ^−5.
Ω · cm or less, while the specific resistance of the transparent conductive layer is 1
0 ^-5 to 10 ^-4 Ω · cm or more. Therefore, the electrode preferably has a specific resistance of 1 × 10 ⁻³ Ω · cm or less. In addition, since the electrode portion is in contact with the transparent conductive layer (B) / the electrode containing metal (C) / the conductive layer in the case, the electrode containing metal (C) is in contact with the transparent conductive layer (B) and the case. It is more preferable to have an intermediate specific resistance of the conductive layer inside.

It is important that there is no gap for leakage of electromagnetic waves between an optical member such as a display filter and a device requiring an electromagnetic wave shield. That is, it is necessary that the electrode is formed continuously on the transparent conductive layer (B) of the transparent laminate and at the peripheral portion, and there is no air layer between the metal electrode and the transparent conductive layer. This is very important. This is because the electrode also plays a role in efficiently releasing charges induced when the electromagnetic wave is absorbed by the transparent conductive layer to the conductive layer inside the case.

The material used for the electrode may be a simple substance such as silver, gold, copper, platinum, nickel, aluminum, chromium, iron, zinc, or the like, from the viewpoints of conductivity, contact resistance, and adhesion to the transparent conductive layer. An alloy composed of two or more kinds, a metal such as silver or an alloy containing silver and a synthetic resin such as polyester, or a silver paste composed of a mixture of borosilicate glass and an alloy containing silver or silver can be used. For the formation of the electrode, a conventionally known method such as a printing method or a coating method for a silver paste or the like such as a plating method, a vacuum evaporation method, or a sputtering method can be employed. The thickness of the electrode is also not particularly limited, but is about several μm to several mm.

When no electrode is formed on the electromagnetic wave shield, the transparent conductive layer, which is a current-carrying part, is exposed at a portion that is in electrode contact with the device. The thin film used for the transparent conductive layer generally has poor scratch resistance, and when a metal having poor environmental resistance such as silver is used for the transparent conductive layer, the transparent conductive layer is whitened and deteriorated. For this reason, it is important that the electrical contact portion between the electromagnetic wave shield and the device is provided with electrodes instead of exposing the transparent conductive layer. When the metal-containing electrode is sufficiently thick, the electrode serves as a protective layer of the transparent conductive layer, and can provide environmental resistance and scratch resistance. As described above, it is desirable that the entire surface on which the transparent conductive layer is formed be covered with a transparent protective layer having gas barrier properties or a metal electrode having gas barrier properties. If there is a portion where neither is formed, contaminants and water vapor in the environment enter from that portion, causing a whitening phenomenon.

When the polymer film is used for the transparent substrate (A), the electromagnetic wave shield of the present invention has strength, flatness, and the like.
From the viewpoint of the installation method, it is desirable to use the sheet by bonding it to a plate-shaped transparent molded body having a smooth main surface. The bonding is performed with an adhesive or an adhesive between the main surface of the transparent molded body and the main surface of the electromagnetic wave shield that is not the thin film forming surface. As the transparent molded body, a plastic plate that is transparent in the visible region is desirable from the viewpoint of mechanical strength, lightness, and resistance to cracking, but a glass plate can also be suitably used because of its thermal stability with little deformation due to heat. Specific examples of the plastic plate include acrylic resin including polymethyl methacrylate (PMMA), polycarbonate resin, transparent ABS resin, and the like, but are not limited to these resins. In particular, PMMA can be suitably used because of its high transparency in a wide wavelength region and high mechanical strength. The thickness of the plastic plate is not particularly limited as long as sufficient mechanical strength and rigidity for maintaining flatness without sagging are obtained, and are not particularly limited, but are usually about 1 mm to 10 mm. When a glass plate is used as a transparent molded body, it is desirable to use a semi-tempered glass plate or a tempered glass plate that has been subjected to a chemical strengthening process or an air-cooling strengthening process to add mechanical strength.

When a display filter is used with the main surface of the filter and the display surface in close contact with each other,
Since the degree of adhesion between the display surface and the display filter varies depending on the portion, a Newton ring occurs due to the gap generated thereby. Therefore, it is preferable to form an anti-Newton ring layer on the main surface of the display filter that is in close contact with the display surface. It is essential that the anti-Newton ring layer not interfere with the contact between the metal electrode and the display body.

In addition, since the display screen becomes difficult to see due to the reflection of a lighting device or the like on the display, it is necessary to suppress reflection of external light by forming an antireflection layer on the display filter or to form an antiglare layer. It is preferable to provide anti-glare properties. By forming an anti-reflection layer, the light transmittance can also be improved by reducing the reflection of the display filter.

The layers in the anti-Newton ring layer, the anti-glare layer and the anti-reflection layer are films having each function or films on which each function is formed. Even if a film having each function is applied or printed or formed by various conventionally known film forming methods, a transparent molded article having a film having each function formed thereon, or a transparent molded article having each function is coated with an optional adhesive or It may be pasted via an adhesive. There is no particular limitation on the method of making these. The type and thickness of the transparent molded product are not particularly limited.

Further, in order to add abrasion resistance to the display filter, in particular, on the human side surface of the filter,
A hard coat layer having transparency to the extent that the characteristics of the display filter including the optical characteristics are not impaired may be formed. The antiglare layer may have a hard coat property, and the antireflection layer may have a hard coat property.

Further, dust easily adheres to the surface of the display due to electrostatic charging, and may be subjected to electric shock due to discharge when a human body comes into contact with the display.
It may be necessary to perform an antistatic treatment. The antistatic ability can be solved by directly forming a conductive film on the display surface or attaching a member having the conductive film to the display surface and grounding the conductive film.
In this case, the conductive film should have a sheet resistance of about 10 ⁸ Ω / □ or less, and should not impair the transparency and resolution of the display screen.

A near-infrared absorbing dye may be used in combination with the electromagnetic shielding body of the present invention and a display filter using the same in order to impart or supplement near-infrared ray cutting ability. In addition, a dye that absorbs in the visible region may be used in combination to adjust the color tone. That is, a dye may be contained in the transparent substrate (A) or the transparent protective layer already described, or a dye may be contained in a layer or a member bonded or formed on the electromagnetic wave shield. . The type and concentration of these dyes are not particularly limited, and two or more dyes may be used in combination.

The inclusion of the dye means not only that the dye is contained inside the substrate, but also that it is applied to the surface of the substrate or that it is sandwiched between the substrates. That is, it is obvious that a dye can be applied to a substrate, a dye-containing molded product obtained by kneading a dye in a polymer can be used as a substrate, or bonded. A transparent film (U) containing a UV absorber for improving the light fastness of a dye-containing electromagnetic wave shield and a display filter using the same.
(V-cut film).

The display filter of the present invention may be subjected to arbitrary frame printing in order to prevent the mounting jig, the electrode portion, and the like from being seen by a viewer when the filter is mounted on a display. The printing shape, printing surface, printing color, and printing method are not particularly specified. Further, a process such as a hole process for mounting on a display may be performed. Further, by adding a polarizing film, a retardation film, or the like, and adding the performance of a circularly polarizing filter, the reflected light from the display side can be suppressed, and the filter becomes more excellent.

[0043]

Next, the present invention will be described in detail with reference to examples. The present invention is not limited by this. The thicknesses of the thin films shown in the following examples and comparative examples are values obtained from film forming conditions, and are not actually measured film thicknesses. [Example 1] On one main surface of a biaxially stretched polyethylene terephthalate film (thickness: 50 µm), an indium oxide / tin oxide sintered body (composition ratio In ₂ O ₃ :
SnO ₂ = 90: 10 wt%, and an argon / oxygen mixed gas (total pressure 266 mPa: oxygen partial pressure 5 mPa) as a sputtering gas
), A silver thin film as a target, a silver thin film as an argon gas (total pressure 266 mPa) as a sputtering gas, and an ITO thin film as a sputtering gas by magnetron DC sputtering.
A transparent conductive layer was formed by laminating an O thin film 40 nm, a silver thin film 10 nm, an ITO thin film 75 nm, a silver thin film 15 nm, an ITO thin film 75 nm, a silver thin film 10 nm, and an ITO thin film 40 nm in this order to form a transparent laminate. When the sheet resistance of the transparent laminate was measured using a four-probe measurement method, it was 2.2 Ω / □. The surface on which the thin film is not formed and the PMMA plate (470 mm
X 350 mm acrylic light manufactured by Mitsubishi Rayon Co., Ltd.) was adhered via an adhesive. Further, a silver paste (MSP-600F, manufactured by Mitsui Toatsu Chemicals, Inc.) is screen-printed in a shape as shown in FIGS. 1 and 3 on the thin film forming surface, that is, the conductive surface of the transparent laminate, and dried. An electrode containing a metal having a thickness of 20 μm and a width of 10 mm was formed, and an electromagnetic wave shield of the present invention was produced. The specific resistance of the electrode was 5 × 10 ⁻⁵ Ω · cm.

Comparative Example 1 An electromagnetic wave shield was produced in the same manner as in Example 1 except that no electrode containing a metal was formed.

[Comparative Example 2] Polycarbon was used as the electrode
Conductive paste dispersed in resin (resistivity 8 × 10 ^-3Ω
cm) except that the electromagnetic wave sheet was used in the same manner as in Example 1.
A gold body was prepared.

Example 2 A transparent conductive layer was formed on one main surface of a polyethylene terephthalate film in the same manner as in Example 1, and the surface on which the thin film was not formed and the air-cooled tempered glass plate having a thickness of 3 mm The main surface (470 mm × 350 mm) was bonded via an adhesive. Further, an electrode similar to that of Example 1 was formed. A magnesium fluoride thin film was formed to a thickness of 95 nm by electron beam evaporation on one main surface of a polyethylene terephthalate film (thickness: 50 μm) to produce an antireflection film. The anti-reflection film is ASTM-
When the moisture permeability was measured in accordance with E96, it was 2.7 g / m ^2.
It was day and had gas barrier properties. The other main surface of the antireflection film on which the magnesium fluoride thin film is not formed, the portion of the transparent laminate on which the metal electrode is not formed, and the other main surface of the air-cooled tempered glass plate The surfaces were bonded together via an adhesive to produce a display filter of the present invention.

The electromagnetic wave shielding body of the present invention of Example 1, the electromagnetic wave shielding bodies of Comparative Examples 1 and 2, and the electromagnetic wave shielding ability of the display filter of the present invention of Example 2 produced as described above, and Examples The visible light transmittance and environmental resistance of the display filter of No. 2 of the present invention were evaluated by the following methods. 1) Electromagnetic Wave Shielding Capability In Examples 1 and 2 and Comparative Examples 1 and 2, the electromagnetic wave shielding body and the display filter were installed on the screen of the plasma display, and the dipole antenna was positioned at a position 3 m perpendicular to the surface from the screen center position. Install and use Advantest spectrum analyzer (TP4172) 30-20
The radiated electric field intensity in the 0 MHz band was measured. At this time, the entire electrode portion of the electromagnetic wave shielding body or the display filter and the entire conductive portion (copper plating, specific resistance 2 × 10 ⁻⁶ Ω · cm) in the case of the display main body were securely brought into contact with each other. The evaluation was performed based on the radiated electric field strength at 33, 80, and 200 MHz.

2) Visible Light Transmittance (Tvis) In the display filter of Example 2, an object to be measured was cut into small pieces, and a parallel light of 300 to 1000 nm was measured by a spectrophotometer (U-3400) manufactured by Hitachi, Ltd. The transmittance was measured. Tvis was calculated from the transmittance determined here. 3) Environmental resistance (high temperature and high humidity test) In the display filter of Example 2, the temperature was 6
It was left for 48 hours in an atmosphere of 0 ° C. and a humidity of 95%, and the occurrence of whitening was examined. If whitening (white spots, whitening of the entire surface) does not occur after standing for 48 hours under these environmental conditions, it can be said that the method is practical. Table 1 shows the test results of electromagnetic wave shielding performance.

[0049]

[Table 1]

As is evident from Table 1, when the electrodes are formed as shown in FIG.
Electromagnetic wave shielding ability is improved. Further, the specific resistance of the electrode is 5
Example 1, which is × 10 ⁻⁵ , is excellent in electromagnetic wave shielding performance as compared with Comparative Example 2, in which the specific resistance is 1 × 10 ⁻³ or more. Also, Tvi of the display filter of Example 2 was used.
s was 70%, and the image was clear and the visibility was good with little reflection when placed on the screen of the plasma display. Also, in the high-temperature and high-humidity test, no whitening was observed in both the light transmitting portion and the electrode portion of the display filter.

[0051]

As described above, according to the present invention, an electrode (C) containing a metal is laminated on at least one transparent conductive layer (B) on one main surface of a transparent substrate (A). By continuously forming the body on the transparent conductive layer (B) and on the periphery of the transparent laminate, the electromagnetic wave shielding performance can be enhanced without lowering the light transmittance of the electromagnetic wave shielding body. The electromagnetic wave shield of the present invention is preferably used for an optical member having a light transmittance of 50% or more,
It can be suitably used for an optical filter for a plasma display.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example of an electromagnetic wave shield of the present invention.

FIG. 2 is a sectional view showing an example of the electromagnetic wave shield of the present invention.

FIG. 3 is a plan view showing an example of the electromagnetic wave shield of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Transparent base material (A) (transparent polymer film) 20 Transparent conductive layer (B) 30 Metal-containing electrode (C) 40 Transparent protective layer (transparent protective film) 50 Translucent part of electromagnetic wave shield

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Masato Koyama 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Mitsui Toatsu Chemicals Co., Ltd.

Claims (6)

[Claims] 1. A transparent laminate comprising at least a transparent conductive layer (B) formed on one main surface of a transparent substrate (A), wherein a metal-containing electrode (C) is provided on the transparent conductive layer (B). An electromagnetic wave shield, wherein the electromagnetic wave shield is formed continuously on an upper portion and a peripheral portion of the transparent laminate. 2. The electrode (C) containing metal has a specific resistance of 1 × 1.
Electromagnetic wave shielding member according to claim 1, characterized in that 0 ^-3 Ω · cm or less. 3. The transparent conductive layer (B) has a sheet resistance of 1000Ω.
3. The electromagnetic wave shield according to claim 1, wherein the ratio is not more than / □. 4. The electromagnetic wave shield according to claim 3, wherein the sheet resistance of the transparent conductive layer (B) is 3Ω / □ or less. 5. The electromagnetic wave shield according to claim 1, which is suitably used as an optical member having a light transmittance of 50% or more in visible light transmittance. 6. A display filter suitably used for a plasma display using the electromagnetic wave shield according to claim 1. Description: