JP2983989B2 - Static electricity, electromagnetic wave shielding material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to various kinds of electronic and communication devices, for example, static electricity attached to a device having a display device and the like.
It relates to an electromagnetic wave shielding material.

[Conventional technology]

Conventionally, as a shield material used as, for example, a window material in an apparatus equipped with the above display device, etc., it has a high visible light transmittance so that the inside of the display can be seen from outside, that is, excellent transparency (visibility). In addition, it is required to have a shielding property capable of shielding static electricity (high voltage) or electromagnetic waves generated from a display device or the like.

As this kind of shielding material, a material in which a mesh type carbon fiber or a metal coating fiber is bonded on a transparent member such as a glass substrate or a polycarbonate substrate, or a metal oxide thin film is directly formed on the transparent member. Are widely used.

[Problems to be solved by the invention]

However, the above-mentioned conventional shielding material, that is, the one using mesh type carbon fiber or metal coating fiber, causes an image or an object passing through the substrate to be cut at the mesh portion, or to fluctuate due to scattering due to light reflection. However, there is a problem when the metal oxide is made worse, while the production using a metal oxide requires a single operation of forming a metal oxide film on a transparent member at the time of its production. Not only is it bad and expensive,
When a glass substrate is used as described above, there are problems that the substrate itself is easily damaged at the time of work or use and that bending cannot be performed due to the properties of the substrate itself. Further, even when a plastic substrate is used, the thin film is easily scratched during the metal oxide film forming operation, and the scratch resistance is poor.

Therefore, the present invention has a high visible light transmitting ability and an excellent shielding ability capable of shielding static electricity and electromagnetic waves generated from the display device of the above-mentioned apparatus in order to solve the above-mentioned conventional problems. Another object of the present invention is to provide a static electricity and electromagnetic wave shielding material having good workability and scratch resistance at the time of its production.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve the above object, and as a result, provided a transparent conductive layer on one surface of a transparent film substrate to form a transparent conductive film, and formed a conductive layer of the transparent conductive film. A member having both functions of visible light transmitting ability, shielding property against static electricity and electromagnetic waves by providing an adhesive layer on an open surface having no adhesive and bonding another transparent substrate through the adhesive layer. Was obtained, and it was found that the workability and abrasion resistance at the time of its production were good, and the present invention was completed.

That is, the present invention provides a transparent film substrate having a thickness of 5 to 300 μm, on one surface, a transparent conductive layer made of a metal thin film or a metal oxide thin film having a thickness of 50 to 5,000 mm, and on the other surface. A transparent pressure-sensitive adhesive layer having a thickness of 5 to 500 μm is provided, and a thickness of 1 to 10
The present invention relates to an electrostatic and electromagnetic wave shielding agent obtained by bonding another transparent substrate having a thickness of mm.

[Structure and operation of the invention]

As the transparent film substrate used in the present invention, any film having transparency can be widely applied, for example, polyethylene terephthalate (PET), polyimide (PI), polyethersulfone (PES), polyetheretherketone (PEEK). ), Polycarbonate (P
C), polypropylene (PP), polyamide, acrylic,
The thickness of cellulose propione (CP) is 5-300μ
m of plastic film is preferably used.

If the thickness of the film is too thin, the mechanical strength of the film is insufficient, and if the film is too thick, the flexibility of the film is lacking, for example, the transparent conductive layer on the film surface continuously as a roll, or It becomes difficult to form an adhesive layer. In addition, since there is no flexibility, when the transparent substrates are bonded to each other, a floating phenomenon and air bubbles are easily generated between the two, which hinders the adhesion, which is not preferable.

In the present invention, the transparent conductive layer provided on one surface of the film substrate is a metal oxide thin film made of a metal oxide such as stannic oxide, indium oxide, titanium oxide, cadmium oxide or a mixture thereof. There is, or, metal indium, metal tin, gold, silver, platinum, palladium, copper, aluminum, nickel, chromium, titanium, iron, metal such as cobalt or any of these metal thin films made of alloys thereof, The thickness is 50-5,000Å
Although it is appropriately changed in the range, in consideration of the use according to the present invention, in the case of the metal oxide thin film, 80 to 5,000
Å, and in the case of the above-mentioned metal thin film, it is about 50 to 400 °.

If the thickness of the conductive layer is too thin, the shielding properties against static electricity and electromagnetic waves are reduced due to defects in the film structure. If the thickness is too large, the visible light transmittance is reduced, and neither is preferable.

The surface resistance of the conductive layer is preferably 10 ⁹ Ω / □ or less when used for electrostatic shielding, and 10 ³ Ω / □ or less when used for electromagnetic wave shielding. Such a conductive layer can be formed by a conventional technique for forming a metal thin film or a metal oxide thin film, for example, a vacuum deposition method, a sputtering method, an ion plating method, a chemical vapor deposition method, a spray pyrolysis method, a chemical plating method, an electric plating method. It can be easily formed by a known thin film forming technique such as a plating method or a combination method thereof.

In the present invention, the pressure-sensitive adhesive layer provided on one side of the film substrate having no conductive layer can be used without any particular limitation as long as it has transparency. For example, an acrylic pressure-sensitive adhesive is preferably used. The thickness of the pressure-sensitive adhesive layer is usually 5 to 500 μm.

The thickness of the pressure-sensitive adhesive layer is an important factor in the present invention. For example, when the thickness of the image adhesive of the shielding material is less than 5 μm, the pressure-sensitive adhesive layer may be attached to an apparatus having the display device or the like. In such a case, since the cushioning action of the pressure-sensitive adhesive layer in the shield material cannot be expected, if the conductive layer on the transparent film base material is easily damaged by a pressing operation or the like, it may lead to an adverse effect.
When the thickness is more than μm, the cushioning effect is maintained, but there is a problem that it is not preferable in terms of visible light transmittance, workability and cost.

The transparent substrate serving as a carrier of the film substrate provided with the conductive layer according to the present invention has a plate shape or a curved shape, for example, a glass plate having a thickness of usually about 1 to 10 mm, or a polycarbonate ( A transparent plastic plate such as PC), cellulose propione (CP), or acrylic is used.

The transparent plate may be formed by laminating the glass plate and the plastic plate. In this case, an effect of preventing the glass plate, which is relatively brittle and easily damaged, from being scattered when the glass plate is damaged is added.

FIG. 1 shows the structure of an electrostatic and electromagnetic wave shielding material according to the present invention. In FIG. 1, reference numeral 1 denotes a transparent conductive layer provided on one surface of a transparent film substrate 2, and 3 denotes the film. It is a transparent pressure-sensitive adhesive layer provided on the other surface of the substrate 2. Reference numeral 4 denotes a transparent substrate bonded to the film substrate 2 via the pressure-sensitive adhesive layer 3.

Such a shielding material is laminated so as not to contact the conductive layer 1 for the purpose of improving the electromagnetic wave shielding property, or the shielding material shown in FIG. As shown in (1), the conductive layers may be stacked so that their surfaces are in contact with each other.

In addition, the surface of the transparent substrate 4 is made uneven by anti-glare treatment, that is, molding, sand matting, coating method, etc., and the surface reflection and absorption are reduced by increasing surface scattering and absorption of light, thereby reducing glare. The visibility of the substrate 4 may be further improved by eliminating it.

〔The invention's effect〕

As described above, since the static electricity and electromagnetic wave shielding material of the present invention also has one of the functions of transmitting visible light, static electricity and electromagnetic wave shielding ability, for example, as a window material of an apparatus having a display device or the like. When applied, the transparency facilitates visual inspection inside the device, and provides a special effect of suitably shielding static electricity or electromagnetic waves generated from inside the device.

Further, since the shielding material is configured using a transparent film substrate as described above, for example, a conductive layer is continuously formed on the film substrate by using a rolled transparent film substrate, or The pressure-sensitive adhesive layer can be formed, and the film substrate on which the conductive layer and the pressure-sensitive adhesive layer are formed and the transparent substrate can be continuously bonded.

Therefore, a dramatic improvement in work efficiency and productivity can be expected.In addition, the produced shielding material has the above-mentioned excellent performance and the abrasion resistance of the conductive layer due to the cushioning effect of the pressure-sensitive adhesive layer described above. Is good, so that it can be applied to a wide range of uses as an unprecedented electrostatic and electromagnetic wave shielding material.

〔Example〕

Hereinafter, embodiments of the present invention will be described in more detail. In addition, the following characteristic test was performed by the following method.

<Surface resistance> It was measured by a four-terminal method.

<Visible light transmittance> The transmittance at a wavelength of 550 nm was measured using a spectrophotometer UV-240 (manufactured by Shimadzu Corporation).

<Electrostatic shield characteristics> Using a collector-type potential meter KS-325 (manufactured by Kasuga Electric Co., Ltd.), install a shield material (with a ground) on the surface of the CRT (CRT) of the TV, and measure the amount of static electricity ( (When the TV is ON). When no shielding material is installed, the static electricity potential is 40 to 50 kV.

Was measured <electromagnetic shielding properties> electromagnetic shielding effect measuring device TR-17301 Frequency 10 ⁷ using (manufactured by Advantest Corporation), 10 ^8, 10 ⁹ Hz field shielding effect (dB).

Example 1 A transparent conductive layer was formed on one surface of a PET film having a thickness of 75 μm as a transparent base material by a sputtering method to a thickness of about 600 μm.
A metal oxide thin film layer composed of ITO (In ₂ O ₃ : SnO ₂ = 9: 1) was formed. Then, an acrylic pressure-sensitive adhesive layer having a thickness of about 20 μm was formed on the other surface of the PET film having no conductive layer. Next, 2 mm thick through the adhesive layer of the film
Was laminated on the film to prepare a static electricity and electromagnetic wave shielding material.

Example 2 Except that a metal thin film layer of about 150 mm thick made of Au was formed as a conductive layer on one surface of the transparent base material used in Example 1 by a vacuum evaporation method, static electricity and electromagnetic waves were produced in the same manner as in Example 1. A shield material was manufactured.

Example 3 Except that a metal thin film layer made of Ag and having a thickness of about 180 ° made of Ag was formed as a conductive layer on one surface of the transparent substrate used in Example 1 by a vacuum evaporation method, static electricity and electromagnetic waves were obtained in the same manner as in Example 1. A shield material was manufactured.

Table 1 shows the characteristics of each of the shield materials manufactured in Examples 1 to 3 above.

When the shielding materials according to the above Examples 1 to 3 were attached to the front of a display such as a CRT or an LCD and a practical test was performed, good visibility was obtained, and excellent shielding properties against static electricity and electromagnetic waves were exhibited. Was confirmed.

In addition, the above-mentioned shielding material, in its manufacture, it is only necessary to bond the film substrate provided with the conductive layer to the transparent substrate via the adhesive layer of the film substrate, and the workability is good, No scratches or the like were observed even when attached to the front surface of the display, and it was proved that the scratch resistance was good.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of the electrostatic and electromagnetic shielding material of the present invention, and FIG. 2 is a sectional view showing a state in which the shielding materials of FIG. 1 are stacked. 1 ... Transparent conductive layer, 2 ... Transparent film substrate, 3 ...
... Transparent adhesive layer, 4 ... Transparent substrate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Kawaguchi 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Electric Industry Co., Ltd.

Claims (1)

(57) [Claims] 1. A transparent film substrate having a thickness of 5 to 300 .mu.m is provided with a transparent conductive layer made of a metal thin film or a metal oxide thin film having a thickness of 5 to 5,000.degree. Is provided with a transparent pressure-sensitive adhesive layer having a thickness of 5 to 500 μm, and static electricity characterized by being bonded to another transparent substrate having a thickness of 1 to 10 mm through the pressure-sensitive adhesive layer,
Electromagnetic wave shielding material.