JP2000208984A - Electromagnetic wave shielding material and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic shielding material which has superior shielding performance and conductivity, and which is superior in bending resistance and wear resistance, and a method of manufacturing thereof. SOLUTION: This electromagnetic shielding material comprises a metal- contained resin coating layer formed on the whole surface or a part of the surface of a fiber base material. The shielding material has an electromagnetic shielding performance of 20 dB or more in the electric field content of an electromagnetic wave in a region of 100 MHz-1 GHz and has a surface resistance of 5 Ω/sq or lower. In a method of manufacturing of this electromagnetic shielding material, the fiber base material is subject to a heat treatment, after the hole surface or a part of the surface of the fiber base material is applied with a metal-contained resin fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shielding material having a metal-containing resin coating layer and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the progress of electronics technology,
Many electronic devices, home appliances, and personal wireless communication devices are used. Although such electronic devices have greatly contributed to social life, on the other hand, the effects of electromagnetic waves generated from these electronic devices have become a problem, and various companies have been studying to solve this problem. It is a fact. For example, many methods have been proposed for forming a metal layer on the surface of a fiber or cloth, particularly a non-woven fabric, by vacuum evaporation, ion plating, or sputtering. However, although the fabrics obtained by these methods are excellent in a lightweight surface, it is difficult to obtain a sufficient electromagnetic wave shielding property because there is a limit in a film thickness, and when the conductive effect is lowered due to cracking easily caused by bending. There is a problem to say. On the other hand, JP-A-62-238698 and JP-A-63-26
Japanese Patent Publication No. 2900 proposes an electromagnetic wave shielding material made of a nonwoven fabric by an electroless metal plating method. Although the electromagnetic wave shielding is considerably improved by these methods, the bending resistance and the abrasion resistance are still not sufficient as in the case of the above proposal, and at present, the conductivity is reduced by bending or abrasion. Further, methods such as the vacuum evaporation method and the electroless metal plating method are troublesome and have a processing problem that the cost is increased.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the conventional electromagnetic wave shielding material, the present invention provides an electromagnetic wave shield having excellent electromagnetic wave shielding performance and conductivity, and excellent bending resistance and wear resistance. Materials and a method for producing the same.

[0004]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the electromagnetic wave shielding material of the present invention is an electromagnetic wave shielding material in which a metal-containing resin coating layer is formed on the entire surface or a part of the surface of the fiber base material, and has a frequency of 100 MHz or less.
In the electric field component of the electromagnetic wave in the 1GHZ range, it has the electromagnetic wave shielding performance of 20dB or more and the surface resistance is 5Ω / s.
q It is characterized by the following.

[0005] Further, the method of manufacturing an electromagnetic wave shielding material of the present invention is characterized in that a metal-containing resin liquid is applied to the entire surface or a part of the surface of a fiber base material, and then heat treatment is performed.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The present invention addresses this problem, namely,
This is based on the fact that the metal-containing resin coating layer is formed on the entire surface or a part of the surface of the fiber base material, and the present invention cannot be achieved without this.

The fiber base material of the present invention includes nylon 6.6, nylon 6, nylon 12, nylon 4.6.
Copolymerization of nylon 6 with nylon 6.6, polyamide fiber obtained by copolymerizing nylon 6 with polyalkylene glycol, dicarboxylic acid, amine, etc., homopolyester such as polyethylene terephthalate, polybutylene terephthalate, and acid constituting polyester repeating unit Polyester fiber obtained by copolymerizing aliphatic dicarboxylic acid such as isophthalic acid, 5-sodium sulfoisophthalic acid or adipic acid, aramid fiber represented by copolymerization with paraphenylene terephthalamide and aromatic ether, polyacrylonitrile Fiber, rayon fiber,
It refers to a fiber substrate composed of a polymer fiber having a sea-island structure mainly composed of sulfone fibers, ultrahigh molecular weight polyethylene fibers and the above-mentioned synthetic fibers. Usually, a fiber fabric such as a woven fabric, a knitted fabric, or a non-woven fabric is appropriately used, and among these fiber fabrics, a woven fabric is preferably used in terms of lightness, flexibility, and strength. In addition, a mesh-like woven fabric can be used as appropriate. Such fibers may contain various additives that are commonly used for improving productivity or characteristics in the production or processing steps of the raw yarn. For example, heat stabilizers, antioxidants, light stabilizers, leveling agents, antistatic agents,
A plasticizer, a thickener, a pigment, a flame retardant and the like can be contained.

The thickness of the fibrous base material is not particularly limited, but is, for example, 0.01 to 0.01 in terms of lightness and flexibility.
The thickness is preferably about 5.000 mm, preferably about 0.050 to 1.000 mm.

On the other hand, the metal component of the metal-containing resin for forming the metal-containing resin coating layer of the present invention includes metals such as aluminum, copper, nickel, gold, silver, zinc, platinum, titanium, cobalt, beryllium, and palladium. Also, conductive materials such as alloys containing these metals are used, but gold, silver, copper, aluminum and nickel are particularly preferably used. Further, those metals having a scale-like shape and an average particle diameter of 0.1 to 20.0 μm are particularly preferable because they exhibit an effect. As the resin component, polyurethane, polyester, polyamide, acrylic, silicone, polyfluorine, polyethylene,
Synthetic resins such as styrene-butadiene and nitrile-butadiene are used, but are not limited thereto. As the synthetic resin, a solvent-based, water-based, or water-dispersed resin can be used as appropriate. The content of the metal component constituting the metal-containing resin coating layer is preferably 10 to 95% by weight, and 50 to 90% by weight.
% By weight is more preferred. Although this region varies depending on the type of metal, if the amount is more than necessary, the flexibility, that is, the bending resistance is impaired. If the amount is too small, the electromagnetic wave shielding property is not sufficiently exhibited. The thickness of the metal-containing resin coating layer is not particularly limited, but is preferably 100 μm or less in terms of flexibility. If it is thicker than necessary, it becomes coarse and hard, and is not suitable for applications requiring flexibility.

The electromagnetic wave shielding material referred to in the present invention is:
It is composed of a cloth layer formed from the above-mentioned fiber cloth and a coating layer formed from the above-mentioned metal-containing resin.
It is indispensable to have an electromagnetic wave shielding performance of 20 dB or more in the electric field component of the electromagnetic wave in the Z region and a surface resistance of 5 Ω / sq or less.

On the other hand, as a method of applying a metal-containing resin to the fiber base material, a usual impregnation treatment or coating process can be applied. For example, in the case of impregnation, a device including a dipping tank and a mangle for uniform impregnation is applied, and in the case of coating,
Knife coating, comma coating, gravure coating and the like are applied. In addition, a metal-containing resin can be applied to the fiber base material by applying a spray method, a printing method, or the like. When a coating process or the like is applied, it may be applied to one side or both sides of the fiber base material. As the heat treatment, after applying the synthetic resin,
A heat treatment at 200 ° C. is preferable, and may be appropriately set depending on the type of resin and the processing time. In this heat treatment,
After drying at 30 to 150 ° C., by applying a heat and pressure treatment at 30 to 200 ° C., such as calendering,
It is possible to provide one having more excellent electromagnetic wave shielding properties. When the metal-containing resin is applied to the surface of a woven fabric or the like, it may be applied to any of the greige, scouring, drying, or heat setting.

Such an electromagnetic wave shielding material can be used for applications such as a housing and a gasket of electronic equipment, a wall material, a curtain, and a blinder.

A feature of the electromagnetic wave shielding material of the present invention is that it has excellent electromagnetic wave shielding properties and conductivity, and can maintain bending resistance and wear resistance in a suitable range.

[0014]

Next, the present invention will be described in more detail by way of examples.

The characteristics in the examples were determined by the following methods.

Weight: JIS L1096 (6.
4.2 Method).

Thickness: JIS L1096 (6.
5 method).

Electromagnetic wave shielding properties: Measured in the range of 100 to 1000 MHz by the KEC method (electric field).

Surface resistance: Measured with Loresta GP (manufactured by Mitsubishi Chemical Corporation).

Flex resistance: JIS P8115 (MIT
(Folding strength test method using a shape tester).

Abrasion resistance: JIS L1096 (6.1
7.1 Method A-2).

Example 1 The total fineness was 40 deniers, 34 filaments, and the strength was 5.
A filament yarn made of nylon 6.6 fiber having an elongation of 63.5 g / d and 43.5% was used.
A woven fabric having book / in flat texture was obtained. Next, the woven fabric was scoured with a nonionic surfactant and heat set at 180 ° C. for 1 minute. Thereafter, one side of the woven fabric was coated with a silver-containing fluororesin liquid composed of 43% by weight of scaly silver particles (average major axis: 6 μm, average minor axis: 2 μm), 15% by weight of a fluororesin, and 42% by weight of an acetate-based solvent. Knife coating to a thickness of 30 μm, heat treatment at 120 ° C. for 3 minutes,
An electromagnetic wave shielding material was obtained. Table 1 shows the characteristics of the obtained electromagnetic wave shielding material.

[0023]

[Table 1] As is clear from Table 1, the electromagnetic wave shielding material of Example 1 had excellent electromagnetic wave shielding properties, and was excellent in bending resistance and wear resistance.

COMPARATIVE EXAMPLES 1 AND 2 A flat-textile woven fabric composed of the same filament yarns of nylon 6.6 fibers as in Example 1 was used, and an aluminum thin film layer (Comparative Example 1) and a silver thin film layer (Comparative Example 1) were formed on one side. Example 2)
Was formed to a thickness of 100 nm by a vacuum evaporation method to obtain an electromagnetic wave shielding material.

Table 2 shows the characteristics of the obtained electromagnetic wave shielding material. As is clear from Table 2, the electromagnetic wave shielding materials of Comparative Examples 1 and 2 exhibited electromagnetic wave shielding properties, but were inferior in bending resistance and abrasion resistance, were complicated in processing, and were expensive. There was a problem of becoming.

Example 2 Nylon 6 • having a total fineness of 420 denier, 72 filaments, a strength of 9.6 g / d and an elongation of 23.5%
Using a filament yarn composed of 6 fibers, the weaving density of warp and weft is 4
5 / inch flat fabric was obtained. Next, the woven fabric was scoured with a nonionic surfactant and heat set at 180 ° C. for 1 minute. Thereafter, one side of the woven fabric was coated with a silver-containing silicone resin liquid composed of 45% by weight of scaly copper particles (average major axis: 8 μm, average minor axis: 3 μm), 35% by weight of a silicone resin, and 20% by weight of toluene, to a thickness of 45 μm. And heat-treated at 130 ° C. for 3 minutes, and then heated and pressed with a calender roll at 100 ° C. for 15 seconds to obtain an electromagnetic wave shielding material.

Table 2 shows the characteristics of the obtained electromagnetic wave shielding material. As is clear from Table 2, the electromagnetic wave shielding material of Example 2 had excellent electromagnetic wave shielding properties, and was excellent in bending resistance and wear resistance.

Comparative Example 3 Copper having a solid content of 35 g / m ² in terms of solid content was applied to a flat-textured woven fabric composed of the same filament yarn of nylon 6.6 fiber as in Example 2 by an electroless plating method. The coating was uniformly applied to obtain an electromagnetic wave shielding material.

Table 2 shows the characteristics of the obtained electromagnetic wave shielding material. As is clear from Table 2, although the electromagnetic wave shielding material of Comparative Example 3 was recognized as having an electromagnetic wave shielding property, it was inferior in bending resistance and abrasion resistance, was complicated in processing, and had a problem of high cost. there were.

Example 3 The total fineness was 50 denier, 36 filaments, and the strength was 5.
5 g / d, using a filament yarn made of polyester fiber having an elongation of 19.5%, in a rapier room,
A woven fabric having a flat texture of 155 yarns / inch was obtained for both the warp and weft yarns.

Next, the woven fabric was scoured with a nonionic surfactant and heat set at 180 ° C. for 1 minute. Thereafter, one side of the woven fabric was coated with a silver-containing urethane resin liquid composed of 45% by weight of acicular silver particles (average major axis: 8 μm, average minor axis: 3 μm), 35% by weight of a polyester resin, and 20% by weight of methyl ethyl ketone. And heat-treated at 130 ° C. for 3 minutes to obtain an electromagnetic wave shielding material. Table 2 shows the characteristics of the obtained electromagnetic wave shielding material.

As apparent from Table 2, the electromagnetic wave shielding material of Example 3 had excellent electromagnetic wave shielding properties, and was excellent in bending resistance and abrasion resistance.

Comparative Example 4 Silver having a solid content of 30 g / m ² in terms of solid content was uniformly adhered to a flat-textured woven fabric composed of the same polyester fiber filament yarn as in Example 3 by an electroless plating method. At least
An electromagnetic wave shielding material was obtained.

Table 2 shows the characteristics of the obtained electromagnetic wave shielding material. As is clear from Table 2, although the electromagnetic wave shielding material of Comparative Example 4 was recognized as having an electromagnetic wave shielding property, it was inferior in bending resistance and abrasion resistance, and had a problem that processing was complicated and cost was increased. there were.

[0035]

[Table 2]

[0036]

According to the present invention, it is possible to provide an electromagnetic wave shielding material having excellent electromagnetic wave shielding properties and conductivity, and maintaining bending resistance and abrasion resistance in a suitable range. Since it can be applied, it is possible to provide an inexpensive electromagnetic wave shielding material which is excellent in productivity as compared with the conventional vacuum evaporation method and electroless plating method.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L031 AB32 AB33 AB34 BA04 CA06 DA00 5E321 AA03 AA44 BB32 BB41 BB44 GG05

Claims (14)

[Claims] An electromagnetic wave shielding material comprising a metal-containing resin coating layer formed on the entire surface or a part of the surface of a fiber base material, and having an electromagnetic wave shielding of 20 dB or more in an electric field component of an electromagnetic wave in the range of 100 MHz to 1 GHz. Has performance,
An electromagnetic wave shielding material having a surface resistance of 5Ω / sq or less. 2. The electromagnetic wave shielding material according to claim 1, wherein said surface resistance is 1 Ω / sq or less. 3. The electromagnetic wave shielding material according to claim 1, wherein the metal-containing resin is a resin containing at least one metal selected from gold, silver, copper, and nickel. 4. The electromagnetic wave shielding material according to claim 1, wherein said metal-containing resin coating layer contains 10 to 95% by weight of a metal. 5. The electromagnetic wave shielding material according to claim 1, wherein said metal-containing resin coating layer contains 50 to 90% by weight of a metal. Material. 6. The electromagnetic wave shielding material according to claim 1, wherein said metal-containing resin coating layer has a thickness of 100 μm or less. 7. The metal according to claim 1, wherein said metal is in the form of scale.
7. The electromagnetic wave shielding material according to any one of 6. 8. The metal having an average particle diameter of 0.1 to 20.0.
The electromagnetic wave shielding material according to any one of claims 1 to 7, which has a size of µm. 9. The electromagnetic wave shielding material according to claim 1, wherein said fiber base material is at least one selected from a woven fabric, a knitted fabric and a nonwoven fabric. 10. A method for producing an electromagnetic wave shielding material, comprising applying a metal-containing resin solution to the entire surface or a part of the surface of a fiber base material and then performing a heat treatment. 11. The method according to claim 10, wherein said applying is a coating method. 12. The method for producing an electromagnetic wave shielding material according to claim 10, wherein said applying is a method of squeezing with a mangle after immersion. 13. The method for producing an electromagnetic wave sealing material according to claim 10, wherein said heat treatment is performed under a temperature condition of 30 to 200 ° C. 14. The method for producing an electromagnetic wave sealing material according to claim 10, wherein the heat treatment is performed by heating at 30 to 200 ° C. after drying at 30 to 150 ° C.