JPH0762311B2 - Method for producing metal-coated fiber - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a metal-coated fiber.

(Prior Art) Conventionally, when plating a fiber, it is preferable to previously activate the fiber surface, and a means for attaching a noble metal is commonly used. For example, a carbon material is immersed in an aqueous solution of an inorganic salt of palladium or silver. JP-A-60-208495 for performing electroplating after treatment or JP-A-61-63780 for performing chemical plating after impregnating a water-absorbent fiber such as cellulose with a surfactant-stabilized palladium hydrosol Is mentioned.

(Problems to be Solved by the Invention) Certainly, the fiber surface is activated by the means for adhering the noble metal described in each of the above publications and the subsequent plating reaction is promoted, but those noble metals are expensive. In addition, since it has a high catalytic ability and a high plating rate, problems such as insufficient adhesion of the metal film and uneven plating accompanying the formation of a sparse film are derived.

That is, the object of the present invention is to increase the plating speed moderately,
A final object is to provide a means for industrially advantageously producing a metal-coated fiber having excellent adhesion and uniformity.

(Means for Solving the Problems) The above-mentioned object of the present invention is to use fibers as a salt of one or more metals selected from copper, nickel, cobalt, iron, zinc, cadmium, tin, lead and chromium. Is treated with a colloid formed by reduction with sodium borohydride or dimethylamine borane, and then plated.

Here, the types of fibers to be treated include conductive inorganic fibers made of metal or carbon; non-conductive inorganic fibers such as glass and asbestos; natural fibers such as wool, cotton and silk; rayon, cupra,
Regenerated or semi-synthetic fibers such as acetate; polyvinyl alcohol-based, polyamide-based, acrylic-based synthetic fibers and the like can be mentioned. Among them, carbon fibers and acrylic fibers are preferable. In addition, as the form of the fiber, short fiber, long fiber,
Examples thereof include sliver, papermaking sheet, non-woven fabric and knitted fabric.

The activation metal is copper, nickel, cobalt,
One or more metals selected from iron, zinc, cadmium, tin, lead and chromium, and salts of the metals used as the metal source include inorganic salts such as hydrochlorides, sulfates, nitrates and acetates. It is a salt or an organic salt. The solution of the metal salt is usually an aqueous solution, but a mixed solvent solution of water and an organic solvent miscible with water or an organic solvent solution may be used.

The metal colloid can be obtained by subjecting the above metal salt solution to a reduction treatment with sodium borohydride and dimethylamine borane. Fortunately, in the combination of the above metal species and the boron compound, the reduction effect of the boron compound is strong, and the metal is deposited all at once. Therefore, a very large number of fine particles form a colloid. If the reducing agent is also weak for the above-mentioned metal species, the metal particles that are slowly deposited are associated with each other one after another, and become agglomerated particles having a large coarse structure. This difference affects the adhesion and uniformity of the final plating.

Among the above activation treatment methods, copper (although copper is the main component,
A colloid (which may contain other metals as long as the effect is not lost) is industrially preferable in terms of uniform adhesion, activation effect, handleability, and the like.

The fibers treated by the above method are then subjected to a metal coating by a conventional method such as chemical plating, electroplating, chemical plating, and then electroplating. Above all, a good metal film is formed by plating nickel and copper.

(Effects of the Invention) By the method of the present invention, the plating rate can be appropriately increased, and finally the metal-coated fiber having excellent adhesion and uniformity can be industrially advantageously produced. The obtained metal-coated fiber is used alone or in a mixture with other fibers to form fibers having excellent conductivity or antistatic property for clothes, papermaking, and dispersed in a matrix of resin or metal. Thus, it can be widely used for applications such as an electromagnetic wave shielding material, a heating element, a conductive molded product, an electrode plate for an alkaline storage battery, and an acoustic diaphragm.

(Example) In order to facilitate understanding of the present invention, an example will be shown below.

Example 1 Pitch-based carbon fiber manufactured by Osaka Gas Co., Ltd. (trade name: DONACAR)
BOS-2000) is dipped in NaBH ₄ 1% aqueous solution for 10 minutes, dehydrated to a water content of 10% with a centrifugal dehydrator, and then dipped in CuSO ₄ 2% aqueous solution to deposit copper colloidal fine particles on the fiber surface. It was

Next, electroplating was performed for 10 minutes using the Watt bath under the following conditions.

When the plated state was observed with a scanning electron microscope, the entire surface of the carbon fiber under test was uniformly plated.

Example 2 After the activation treatment was carried out in the same manner as in Example 1 except that acrylic fiber (manufactured by Japan Exlan Industrial Co., Ltd .: K type 3d × 6 mm) was used in place of the carbon fiber, a Rochelle salt bath was used and the following conditions Electroless plating was performed.

Bath composition Copper sulfate 12 g / Rochelle salt 45 〃 Paraformaldehyde 15 〃 pH (adjusted with NaOH) 12, 25 Temperature 20 ℃ Stirring with air blowing Plating condition is good and volume resistivity is 4.5 × 10 ^-5
Ω · cm showed good conductivity.

When outside using NiSO ₄ 2% aqueous solution in place of Example 3 CuSO ₄ 2% aqueous solution was conducted in the same manner as in Example 1, the fibers of favorable plating condition was obtained.

Claims (1)

[Claims] 1. A fiber is prepared by reducing a salt of one or more metals selected from copper, nickel, cobalt, iron, zinc, cadmium, tin, lead and chromium with sodium borohydride or dimethylamine borane. A method for producing a metal-coated fiber, which comprises plating with a colloid prepared as described above and then plating.