JPH02271697A - Electrostatic and electromagnetic wave shielding material - Google Patents

Abstract

PURPOSE:To improve operability, scratch resistance and durability at the time of use by providing a transparent adhesive layer on a conductive layer, and adhering other transparent substrate through the adhesive layer to provide high visible light ray transmission performance and excellent shielding performance. CONSTITUTION:A transparent conductive layer 2 provided on one surface of a transparent film base material 1, a transparent adhesive layer 3 provided on the layer 2, and a transparent substrate 4 to be adhered to the material 2 through the layer 3. A both-side adhesive tape 5 of a ground leading structure, and a conductive tape 6 are provided. Since it has all visible light ray transmission performance, electrostatic and electromagnetic shielding performance, the interior can be easily visually observed due to its transparency, and static electricity and electromagnetic wave generated from the interior can be effectively shielded. Thus, operating efficiency, productivity are improved, and scratch resistance and durability of the conductive layer are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention is directed to the prevention of static electricity and
Regarding electromagnetic shielding materials.

[Prior Art] Conventionally, shielding materials used, for example, as window materials in devices equipped with display devices, etc., have a high visible light transmittance that allows the inside of the display to be viewed from the outside, that is, excellent transparency. (Visibility)
In addition, it is desired that the display device has excellent shielding characteristics capable of shielding static electricity (high voltage) or electromagnetic waves generated from display devices and the like.

This type of shielding material includes mesh-type carbon fibers or metal-coated fibers bonded onto a transparent member such as a glass substrate or polycarbonate substrate, or a metal oxide thin film formed on the same transparent member as above. is widely used.

[Problem to be solved by the invention]

However, among the above-mentioned conventional shielding materials, those in which mesh-type carbon fibers or metal-coated fibers are bonded together may cause images or objects that pass through the substrate to be cut at the mesh portion, or cause fluctuations due to scattering due to light reflection.
There was a problem of poor visibility.

Further, in the case of forming a metal oxide thin film, a single operation for forming the thin film on a transparent member must be repeated, resulting in poor productivity and high cost. In addition, in the case of glass substrates, there are problems in that they are easily damaged during work or use due to the nature of the substrate itself, and cannot be bent.On the other hand, even in the case of plastic substrates, the thin film is easily damaged during film formation work. In addition to the problem of poor abrasion resistance, there was also a problem of durability in that the resistance of the thin film changed significantly under conditions of use such as outdoors, resulting in a significant drop in shielding properties.

In view of the above-mentioned conventional problems, this invention has high visible light transmittance, excellent shielding ability that can effectively shield static electricity and electromagnetic waves generated from display devices, etc., and also reduces work during manufacturing. The purpose of this invention is to provide a static electricity and electromagnetic shielding material that has excellent hardness, scratch resistance, and durability during use.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the inventors constructed a transparent conductive film by providing a transparent conductive layer on one side of a transparent film base material, and also constructed a transparent conductive film on the conductive layer of this film. By further providing an adhesive layer and bonding it to a transparent substrate via this adhesive layer, it has the ability to transmit visible light and shield against static electricity and electromagnetic waves. This invention was completed based on the knowledge that a shielding material with excellent properties such as hardness, scratch resistance, and durability during use can be obtained.

That is, the present invention provides a transparent conductive layer on one side of a transparent film base material, a transparent adhesive layer on this conductive layer, and attaches another transparent substrate via this adhesive layer. This invention relates to a static electricity and electromagnetic shielding material that is characterized by:

[Structure and operation of the invention]

The transparent film substrate used in this invention can be widely applied as long as it has transparency, such as polyethylene terephthalate, polyimide, polyether sulfone, polyether ether ketone, polycarbonate, polypropylene, polyamide, acrylic,
Plastic films such as cellulose propionate are preferably used.

The thickness of such a film base material is not particularly limited, but is generally preferably about 5 to 300 μm. If it becomes too thin, the film will lack mechanical strength, and if it becomes too thick, it will lack flexibility, making it difficult to continuously form a conductive layer or an adhesive layer on the surface of the film, for example, in roll form. Furthermore, when bonding the transparent substrates together, floating phenomena and bubbles tend to occur between the two, which may impair adhesion, which is not preferable.

In this invention, the transparent conductive layer provided on one side of the above film base material includes stannic oxide, indium oxide, titanium oxide, cadmium oxide, metallic indium, metallic tin, gold, silver, platinum, palladium, Examples include copper, aluminum, nickel, chromium, titanium, iron, cobalt, copper iodide, and mixtures or alloys thereof.

The thickness of this conductive layer can be changed as appropriate depending on the purpose, but for example, when the conductive layer is made of an oxide or a mixture thereof, it is usually 8.
The number of participants is preferably 0 to 5,000, and when the conductive layer is made of metal or alloy, the number is usually 50 to 400. If it becomes too thin, the shielding property against static electricity and electromagnetic waves will deteriorate due to defects in the film structure, and if it becomes too thick, the visible light transmittance will decrease, which are both undesirable.

Generally, the surface resistance of this transparent conductive layer is preferably 10 9 Ω/or less for electrostatic shielding, and 10 3 Ω/or less for electromagnetic shielding.

Such a transparent conductive layer can be formed by, for example, a vacuum deposition method, a sputtering method, an ion blasting method, a chemical vapor deposition method,
It can be easily formed by a known thin film forming technique such as a spray pyrolysis method, a chemical plating method, an electroplating method, or a combination thereof.

In this invention, the adhesive layer provided on the conductive layer can be widely applied as long as it has transparency and does not corrode the conductive layer. Among known adhesives, acrylic adhesives are particularly preferred. The thickness of this adhesive layer is preferably 2 μm or more, usually 5 to 500 μm.

In this invention, a film base material provided with a transparent conductive layer and an adhesive layer as described above is laminated to a transparent substrate via the adhesive layer to constitute a static electricity and electromagnetic shielding material.

The transparent substrate used here includes a glass plate with a thickness of about 1 to 10 mm, a transparent plastic plate made of polycarbonate, cellulose propionate, acrylic, etc., and its shape can be any shape such as a flat plate or a curved shape. It may be in the shape of

Note that a transparent substrate made by laminating a glass plate and a plastic plate may be used, and in this case, the glass plate, which is relatively brittle and easily broken, has an added effect of preventing scattering when broken.

FIG. 1 shows an example of the structure of the static electricity and electromagnetic wave shielding material of the present invention. A transparent adhesive layer 4 provided on the conductive layer 2 is a transparent substrate bonded to the film base material 2 via the adhesive layer 3. In addition, 5.6 shows a ground extraction structure, 5 is a double-sided adhesive tape, and 6 is a conductive tape.

In the shield material configured in this way, the transparent substrate 4
The visibility may be further improved by applying anti-glare treatment to the surface. Further, the exposed surface of the film base material 1, that is, the surface opposite to the surface on which the conductive layer and the adhesive layer are provided, may be subjected to a hard coat treatment for the purpose of improving scratch resistance.

〔Effect of the invention〕

As described above, the electrostatic and electromagnetic silt material of this invention is
Because it has both the ability to transmit visible light and the ability to shield static electricity and electromagnetic waves, if it is applied as a window material for equipment equipped with display devices, etc., its transparency will allow visual inspection of the inside of the equipment. Not only is this easy, but it also has the special effect of effectively shielding static electricity and electromagnetic waves generated from inside the device.

Furthermore, since the shielding material is constructed using a transparent film base material, it is possible to continuously form a conductive layer and an adhesive layer on the surface of this base material by rolling this film base material, and also to form a conductive layer and an adhesive layer on the surface of the base material. The film base material with the layer formed thereon and the transparent substrate can be successively bonded together.

Therefore, a dramatic improvement in work efficiency and productivity can be expected, and in addition to the above-mentioned excellent performance, the fabricated shielding material has good scratch resistance and durability of the conductive layer, which is unprecedented. It can be used in a wide range of applications as a static electricity and electromagnetic shielding material.

〔Example〕

EXAMPLES Below, examples of the present invention will be described in more detail. In addition, the following characteristic tests were conducted using the method of GG.

<Surface resistance> Measured using the 4-terminal method. Measurements were performed on the film before lamination.

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

<Static electricity shielding characteristics> Using a current collector type potential measuring device KS-325 model (manufactured by Kasuga Denki Co., Ltd.), a shielding material was installed (grounded) on the surface of a cathode ray tube (CRT) of a television, and the amount of static electricity on the surface of the shielding material (
(when the TV was on) was measured.

In addition, if no shielding material is installed, the voltage will be 40 to 50 kV.
It has an electrostatic potential of .

<Electromagnetic shielding characteristics> Using an electromagnetic shielding effect measuring device TR-17301 (manufactured by Atopan Test Co., Ltd.), a frequency of 10'10'10 was measured.
The electric field shielding effect (dB) at 9 Hz was measured.

<Scratch Resistance> The surface of the transparent film base material in the shielding material was strongly rubbed with gauze, and the conductive layer surface was evaluated as × if the surface was markedly scratched by this operation, and ○ if it was not.

Resistance to outdoor exposure〉 A durability test was conducted in which the shielding material was left outdoors for one month.
The initial resistance value (R) before performing this test.

) The change in resistance value (R) after the test (R/R0) was measured. The smaller this change (R/R,) is, the better the durability is. In addition, in the shield material of the example, a non-adhesive part was made in a part of the conductive layer, and the resistance was measured using that part.

Example 1 A transparent conductive layer with a thickness of approximately 600 μm was formed on one side of a 75 μm thick polyethylene terephthalate (hereinafter referred to as PET) film as a transparent base material by sputtering.
A thin oxide film layer made of human ITO (In2off:SnO□=11 (weight ratio)) was formed.Then, a transparent acrylic adhesive layer with a thickness of about 20 μm was interposed on this conductive layer, and then a film with a thickness of 2 mm was formed. A static electricity and electromagnetic shielding material was created by pasting together transparent acrylic plates.

Comparative Example 1 A static electricity and electromagnetic shielding material was produced in the same manner as in Example 1, except that a conductive layer was provided on one side of the PET film and an adhesive layer was provided on the other side, and this was bonded to an acrylic plate. did.

Example 2 A transparent conductive layer was formed with a thickness of about 120 mm by vacuum evaporation method.
A static electricity and electromagnetic shielding material was produced in the same manner as in Example 1, except that a thin metal Ag thin film layer was formed.

Comparative Example 2 A static electricity and electromagnetic shielding material was produced in the same manner as in Example 2, except that a conductive layer was provided on one side of the PET film, an adhesive layer was provided on the other side, and the acrylic plate was bonded to prevent this. did.

The results of examining the characteristics of each shielding material according to Examples 1 and 2 and Comparative Examples 1.2 above are as shown in Table 1 below.

There was no damage to Table 1, and it was confirmed that the durability characteristics were very good.

[Brief explanation of drawings]

The drawing is a sectional view showing an example of the electrostatic and electromagnetic shielding material of the present invention.

Claims (1)

[Claims] (1) A transparent conductive layer is provided on one side of a transparent film base material, and a transparent adhesive layer is further provided on this conductive layer, and another transparent substrate is bonded to the transparent film base via this adhesive layer. Static electricity and electromagnetic shielding material.