JP3020972B2 - Conductive yarn - Google Patents

Description

The present invention relates to a conductive yarn, and more particularly, to a conductive yarn for shielding electromagnetic waves.

[Conventional technology and its problems]

In order to make a woven fabric exhibit an electromagnetic wave shielding effect and an electrostatic shielding effect, conventionally, the following various methods have been tried.

I. A method in which a woven fabric is coated with a metal or impregnated with an organic antistatic agent to make it conductive.

B. A method in which a yarn is coated with Ni or CuS, mixed with carbon black, or impregnated with an organic antistatic agent to make the yarn conductive.

C. A method of processing Cu or SUS metal fiber or carbon fiber into yarn.

However, the method of making a woven fabric conductive (above-mentioned (a)) is difficult to adjust the degree of conductivity, and a metal-coated one is difficult to decorate, and the impregnation effect of the organic antistatic agent is poor. Poor reliability. Method for making yarn conductive (b)
Have problems with Ni coating and CuS coating. Ni coating has been pointed out to have risks such as allergenicity and carcinogenicity, and is not suitable for materials of members that come into contact with the human body. CuS coatings have poor conductivity and are limited to electrostatic shielding applications. Furthermore, these metal coatings are dark in color and cannot be used for applications requiring whiteness or coloring. In addition, the mixture of carbon black is black, so its use is limited, and it is difficult to adjust the conductivity. Those impregnated with an organic antistatic agent have poor reliability because their effects are greatly affected by humidity. Further, these conductive yarns have low conductivity, and their use is limited to an electrostatic shield. On the other hand, those obtained by processing metal fibers or carbon fibers into yarn (the above-mentioned item (3)) have a problem that the spinning process is complicated and the affinity with the organic fibers is poor, which impairs the feel of the woven fabric.

[Means for Solving the Problems: Structure of the Invention]

The present inventors have studied a general-purpose conductive yarn having excellent conductivity and easy adjustment thereof, excellent in reliability and safety, and having white and coloring properties. It has been found that a desired conductive yarn can be obtained by mixing with an organic fiber having no.

According to the present invention, 30 to 90% by weight of organic fiber coated with silver by electroless plating is mixed with organic fiber not coated with silver, and the fiber is made of a spun yarn. Is provided. In a preferred embodiment, the conductive yarn is provided, wherein the silver-coated organic fiber has a silver coverage of 5 to 50% by weight.

The organic fibers used in the present invention are natural and synthetic organic fibers, that is, fibers of cotton, hemp, regenerated cellulose, polyamide, acryl, polyolefin, polyester and the like. The thickness of the organic fiber is preferably from 0.1 to 15 d (denier), and if it is smaller than 0.1 d, a large amount of silver is required, and the overall weight increases. If the thickness of the fiber is larger than 15d, the silver coverage can be reduced, but the fiber becomes hard and loses flexibility.

As a method for coating silver, an electroless plating method can be applied. In addition, among these coating methods, the electroless plating method is excellent in mass productivity. The silver coverage is preferably from 5 to 50% by weight. If the amount is less than 5% by weight, the fibers cannot be sufficiently covered, and sufficient conductivity cannot be exhibited. On the other hand, if the silver coating amount is more than 50% by weight, the overall weight becomes heavy and the conductivity also reaches a plateau.

The conductive yarn of the present invention is produced by mixing the above-mentioned silver-coated organic fiber and an organic fiber not covering silver and spinning the mixture. The mixing amount of the silver-coated organic fiber is 30 to 90% by weight. If the mixing amount is less than 30% by weight, the conductivity is greatly reduced, and the conductivity sufficient for electromagnetic wave shielding (the surface resistance when woven fabric is 10% or less).
⁽ Less than ⁰ Ω / □). On the other hand, if the content exceeds 90% by weight, the conductivity will level off, and the metallic luster due to silver coating may be undesirably increased. As a means for processing into yarn, a usual spinning method can be applied.

The bleaching or dyeing for imparting white or coloring may be performed after the spinning step, or may be bleached and dyed before mixing the organic fibers.

[Examples and Comparative Examples]

Examples of the present invention are shown below together with comparative examples. In addition, the following examples do not limit the scope of the present invention.

Acrylic fiber (1.5d × 38mm) and aromatic polyamide fiber (2d × 51mm) were coated with 30% by weight of silver by electroless plating. Specifically, the fiber is first immersed in a scouring agent, washed with water, then immersed in an aqueous solution containing 10 g of stannous chloride / 20 m / hydrochloric acid, washed with water, and provided with a catalytic property for electroless silver plating. Silver was coated using a predetermined amount of a plating solution having the following composition. Since all silver ions in the plating solution were reduced and precipitated, a plating solution containing silver ions in an amount corresponding to the coating amount was used.

The obtained silver-coated fiber was mixed with a fiber not coated with silver and processed into a 20th yarn to obtain a woven fabric. For comparison, a woven fabric was prepared in the same manner using conductive yarns prepared by other methods, and their conductivity was measured. The results are shown in Table 1 together with the color tone of the woven fabric.

[Effects of the Invention] As is clear from Table 1, according to the present invention, by mixing 30 to 90% by weight of silver-coated organic fibers with uncoated organic fibers and spinning, a high level sufficient for electromagnetic wave shielding is obtained. A conductive yarn exhibiting conductivity is obtained. This conductive yarn is extremely stable to humidity and has high reliability. Further, it is white or silvery and has excellent coloring properties. Moreover, even if it comes into contact with the human body, there is no allergy or the like, and the safety is high.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Motohiko Yoshizumi 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsui Kinzoku Co., Ltd. Central Research Laboratory (56) References JP-A-1-207473 (JP, A) JP-A-1-225776 (JP, A) JP-A-61-187261 (JP, A) JP-A-60-262846 (JP, A) JP-A-63-183284 (JP, U) JP-B-60-11401 (JP, A) , B2)

Claims (2)

(57) [Claims] (1) mixing 30 to 90% by weight of organic fibers coated with silver by an electroless plating method with organic fibers not coated with silver,
A conductive yarn for shielding electromagnetic waves, comprising a spun yarn. 2. The conductive yarn according to claim 1, wherein the silver-coated organic fiber has a silver coverage of 5 to 50% by weight.