JP3070467U - Metal coated fiber material - Google Patents

Abstract

(57) [Abstract] [Object] To obtain a conductive fiber material used as a conductive material such as an electromagnetic wave shielding material and a grounding material that maintains high shielding performance over a wide band without impairing the inherent flexibility of the fiber. A conductive fiber material comprising a metal-coated coated fabric using a thermoplastic synthetic fiber multifilament yarn having a non-circular cross section having an average aspect ratio of 1.5 to 5.

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive fiber material having a metal film formed on a synthetic fiber surface and used as a conductive material such as an electromagnetic wave shielding material and a grounding material.

[0002]

2. Description of the Related Art Conductive fabrics are often used to prevent leakage of electromagnetic waves from electronic devices. Among these materials, synthetic fiber fabrics made of polymer materials such as polyester and nylon are coated with metal and have both the flexibility of fibers themselves and the electromagnetic wave shielding properties of metals. It is built in. In recent years, as electronic devices have become smaller and higher in frequency, conductive materials such as electromagnetic shielding materials and grounding materials have also become thinner, and high shielding performance in high frequency ranges has been required. In terms of thinness and high shielding properties, there are materials that have been coated with metal foil or polymer film by vapor deposition or sputtering, but the durability, flexibility and flexibility required for electromagnetic wave shielding materials and conductive materials Lack.

Japanese Utility Model Application Laid-Open No. 64-30899 describes an electromagnetic wave shielding sheet made of a nonwoven fabric in which a metal-plated fiber having a flat cross section and a heat-fused binder fiber are integrally joined by fusion of the binder fiber. Have been. However, the heat-compression bonding is carried out using a heat-fusible binder fiber to improve the shielding property, so that the flexibility of the fabric is impaired. In addition, the number of manufacturing steps increases, and the cost becomes high. Japanese Patent Application Laid-Open No. 8-291432 discloses a flexible and flexible electromagnetic wave shielding property using a composite yarn obtained by spirally winding a metal monofilament having a flat non-circular cross section around a core yarn composed of 10 or more fibers. Woven fabrics are introduced. However, in order to obtain shielding properties, the content of the metal monofilament must be increased, which not only impairs the flexibility of the fiber itself but also increases the cost.

[0004]

[Problems to be solved by the present invention] The present invention has been made in view of such circumstances, and an electromagnetic wave shielding material or a group that maintains high shielding performance over a wide band without impairing the inherent flexibility and flexibility of fibers. The purpose is to obtain a conductive fiber material used as a conductive material such as a landing material.

[0005]

Means for Solving the Problems The invention for which a utility model registration is requested in the present application is as follows. (1) A conductive fiber material characterized in that a metal coating is formed on a fabric using a thermoplastic synthetic fiber multifilament yarn having a non-circular cross section having an average flatness of 1.5 to 5. (2) The conductive fiber material according to (1), wherein the fabric is a woven fabric. (3) The conductive fiber material according to (1) or (2), wherein the thermoplastic synthetic fiber is polyester. (4) The conductive fiber material according to (2) or (3), wherein the woven fabric has a cover factor of 1,000 to 3,000.

[0006] The flatness of a thermoplastic synthetic fiber multifilament yarn having a non-circular cross section used in the conductive fiber material of the present invention refers to the flatness of a single yarn constituting a multifilament yarn as shown in FIG. When a rectangle circumscribing the cross section is drawn, it refers to a value obtained by dividing the long side L of the rectangle by the short side H, and the average aspect ratio is 1.5 to 5, preferably 2 to 4. If the aspect ratio is more than 5, the yarn formability and the weaving property are impaired, and if it is 1.5 or less, the flexibility of the conductive material is impaired. For this purpose, the long side L of the rectangle circumscribing the non-circular cross-section yarn has a range of 10 to 50 μm, preferably 20 to 40 μm. The short side H of the rectangle circumscribing the non-circular cross-section yarn has a range of 2 to 30 μm, and preferably 6 to 20 μm. The fineness of the single yarn is 1 to 10 denier (hereinafter referred to as d), and preferably 2 to 5 d. If it is less than 1d, it is easily broken, making the manufacturing process difficult. If it exceeds 10d, the fabric becomes hard, and it may be difficult to obtain flexibility. The total fineness of the multifilament yarn comprising the non-circular cross-section yarn of the present invention is in the range of 10 to 100d, preferably 20 to 80d.

The flat shape of the cross section of the single yarn is not particularly limited, such as an ellipse, a rectangle, a W shape, and a gourd shape, but it is preferable that the flat shape is such that the single yarns easily overlap each other, such as a W shape or a gourd shape. . By overlapping, the surface smoothness of the fabric is enhanced, the flexibility is improved, and a high electromagnetic wave shielding effect is easily obtained.

[0008] The fabric using a multifilament yarn having such a non-circular cross-section yarn is not particularly limited, such as a woven fabric, a knitted fabric, or a nonwoven fabric. Woven fabrics are preferred from the viewpoint of ease of obtaining and processability. When weaving a woven fabric, a non-circular cross-section yarn may be used for a warp alone, a weft alone, or both a warp and a weft. The weaving structure is not particularly limited, such as plain weaving, twill weaving, satin weaving, and those applying these weaving methods. Is preferred. The fabric using the multifilament yarn comprising the non-circular cross-section yarn of the present invention can provide excellent effects when used as a high-density fabric.

The thermoplastic synthetic fiber used for the conductive fiber material of the present invention is not particularly limited, such as polyester, polyamide, and acryl. However, polyester is preferable from the viewpoint of processability and durability.

The method for producing the non-circular cross-section yarn of the present invention includes a calendering method and a melt spinning method. The melt spinning method is preferable for obtaining a uniform non-circular cross-section yarn.

When using the conductive fiber material of the present invention in which a metal film is formed on a woven fabric substrate, the woven fabric has a cover factor of 1000 to 3000, preferably 1500 to 2500. If the cover factor is 1000 or less, the number of voids in the fabric increases, and it becomes difficult to obtain high shielding properties. On the other hand, if it exceeds 3,000, the weaving property is deteriorated, the flexibility is impaired, and the plating solution is hardly permeated into the fabric, which adversely affects the plating processability and the durability of the plating film. The cover factor of the woven fabric referred to here is the total fineness of the warp as D1, the density of the warp as N1, the total fineness of the weft as D2, and the density of the weft as N2. (D1) ^1/2 × N1 + (D2) ^{1 /} It is represented by ² × N2. (Yarn fineness is denier, yarn density is book / inch)

In order to metal-cover a fabric using the multifilament yarn having a non-circular cross-section yarn of the present invention, a conventionally known method such as sputtering, vacuum deposition, electroplating, and electroless plating can be used. Although it is possible, a method using electroless plating is preferred from the viewpoint of forming a metal film at the intersection of the yarns. Electroless plating is generally performed by a known method, and includes a sensitization treatment, an activation treatment, and a chemical plating treatment. The purpose of the sensitization treatment and the activation treatment is to attach the catalytic noble metal before the chemical plating treatment, and to determine the uniformity of the plating. In the catalyst application step, after sensitization with a tin chloride solution, activation with a palladium chloride solution and a one-part catalyst with a tin-palladium colloid are applied, and then tin ions on the colloid surface layer are removed to form a catalyst. There is a method of exposing effective palladium, but there is no particular limitation. The chemical plating bath and the processing conditions in the chemical plating may be performed under conventionally known conditions. The chemical plating bath comprises a metal salt, a reducing agent, a buffer, a pH adjuster and the like. The conductive metal includes silver, copper, nickel, cobalt, tin and the like, and is not particularly limited, but is preferably selected from copper and nickel in view of the stability of the plating bath and the ease of operation. The thickness of the metal plating film layer to be formed is preferably in the range of 0.1 to 10 μm. If it is smaller than 0.1 μm, sufficient surface conductivity cannot be obtained, and if it is larger than 10 μm, the surface conduction effect is no longer improved, and the texture of the fiber material is impaired in flexibility. Further, when the object to be plated is a cloth made of a multifilament yarn, the degree of metal coating is often expressed by the amount of precipitation per unit area or surface resistance rather than the thickness. In this case, the metal deposition amount is in the range of 5 to 50 g / m ² , preferably 10 to 30 g / m ² , and the surface resistance is 0.001 to 1 Ω / □, preferably 0.01 to 0.1 Ω / □. Range is good.

[0013]

The conductive fiber material of the present invention will be described below with reference to examples, but the present invention is not limited to these examples.

【Evaluation methods】

 1. The surface conductivity was measured by a four-terminal four-probe measurement method (JIS-K-7194) using a resistance value measuring device (Lorester MP, manufactured by Mitsubishi Chemical Corporation). The unit is Ω / □. 2. The measurement method of the electromagnetic wave shielding property is similar to that of the measurement cell invented by Ikoma Radio Measurement Center of Kansai Electronics Industry Promotion Center. The sample was received by the cell receiver and measured by a spectrum analyzer. The unit is dB. 3. Metal film adhesion The adhesion of the metal film formed on the fabric surface was evaluated according to JIS-H-8504. ○ Good △ Somewhat bad × Bad 4. Soft Flexibility The soft flexibility of the fabric was evaluated according to the JIS-L-1096A method (45 ° C. cantilever method). The unit is mm.

[0014]

Example 1 A regular polyester multifilament yarn of 50 denier (hereinafter referred to as d) -24 filament (hereinafter referred to as f) for the warp, and a W-shaped cross-section yarn of 35 μm long side and 15 μm short side for the weft (Asahi Kasei Kogyo Co., Ltd.) Plain woven fabric consisting of 75d-30f polyester multifilament yarns made of Techno Fine Co., Ltd. was refined and pre-set, and then subjected to a 10% weight reduction process by alkali hydrolysis to give a warp density of 124 threads / inch and a weft density of 85 threads / An inch fabric having a cover factor of 1530 was obtained. Further, after performing conditioning, catalyzing, and accelerating treatment, a copper / nickel metal coating layer was formed by copper 20 g / m ² and nickel 5 g / m ² by an electroless plating method to obtain a target metal coating material. . Table 1 shows the evaluation results.

[0015]

Example 2 A 30d-18f polyester multifilament yarn composed of a W-shaped cross-section yarn (Technofine manufactured by Asahi Kasei Kogyo Co., Ltd.) having a long side of 35 μm and a short side of 15 μm for the warp, and a long side of 35 μm and a short side of 15 μm for the weft. A plain woven fabric using a 50d-30f polyester multifilament yarn composed of W-shaped irregular cross-section yarn (Technofine manufactured by Asahi Kasei Kogyo Co., Ltd.) is subjected to a 10% weight reduction treatment by alkali hydrolysis after scouring presetting, and a warp density of 135. A fabric having a weft density of 120 fibers / inch and a cover factor of 1506 was obtained. Furthermore, conditioning, catalyzing, after an accelerated rate processing, copper 20 g / m 2 of copper-nickel metallization film layer by an electroless plating ^method, the metal coating material of interest was nickel 5 g / m ² is formed Obtained. Table 1 shows the evaluation results.

[0016]

[Comparative Example 1] A plain woven fabric using regular polyester multifilament yarns of 50d-36f for the warp and the weft was subjected to scouring presetting and then subjected to a 10% weight reduction process by alkali hydrolysis to give a warp density of 164 yarns / inch and a weft density of 164. 104 / inch, a cover factor of 1798 was obtained. Further, after performing conditioning, catalyzing, and accelerating treatment, a copper / nickel metal coating layer was formed by copper 20 g / m ² and nickel 5 g / m ² by an electroless plating method to obtain a target metal coating material. . Table 1 shows the evaluation results.

[Table 1]

[0017]

[Effect of the Invention] As described above, a fabric using a thermoplastic synthetic fiber multifilament yarn having a structure in which filaments having a non-circular cross section having an average flatness of 1.5 to 5 are closely overlapped with each other is used. The conductive fiber material formed with the coating has a dense, uniform and smooth metal coating layer on the surface, is thin and has high electromagnetic wave shielding performance over a wide frequency range without impairing the inherent flexibility of the fiber. Show.

[Brief description of the drawings]

FIG. 1 is an example of a conceptual diagram for calculating an oblateness.

FIG. 2 is a photograph of a surface of a woven fabric according to an embodiment of the present invention.

FIG. 3 is a cross-sectional photograph of an embodiment of the present invention.

[Explanation of symbols]

 1: Single yarn

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hidemasa Shinke 1-10-1 Kiya, Fukui City, Fukui Prefecture

Claims (4)

[Utility model registration claims] 1. A conductive fiber material, wherein a metal coating is formed on a fabric using a thermoplastic synthetic fiber multifilament yarn having a non-circular cross section having an average flatness of 1.5 to 5. 2. The conductive fiber material according to claim 1, wherein the fabric is a woven fabric. 3. The electromagnetic wave shielding material according to claim 1, wherein the thermoplastic synthetic fiber is polyester. 4. A fabric having a cover factor of 1000 to 30.
4. The conductive fiber material according to claim 2, wherein