JPH03213567A - Production of brass-coated fiber - Google Patents

Abstract

PURPOSE:To obtain the subject uniform fiber without using harmful chemicals by contacting a copper-coated fiber with hot zinc vapor in a reactor under the flow of an inert gas and a reducing gas, thereby alloying copper and zinc to form a brass-coating layer on the fiber. CONSTITUTION:A copper-coated fiber 1 is introduced into a reactor having a reaction tube 3 containing a flow of a mixture of an inert gas and a reducing gas introduced through a gas inlet port 4. Zinc vapor of 400-1050 deg.C generated from metallic zinc 9 filled in a boat 10 in the reactor is transferred with a carrier gas introduced through a carrier gas introduction port 8 and made to contact with the copper-coated fiber 1. Zinc is diffused into the copper coating layer to alloy the zinc and the copper. A brass-coating layer is formed on the fiber surface to obtain the objective brass-coated fiber.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention can be used as a molding material for fiber-reinforced brass, or as a decorative wrap for sports equipment such as fishing rods, golf shafts, and tennis rackets made of fiber-reinforced plastic. The present invention relates to a method for producing brass-coated fibers suitable for improving the design effects of brass-coated fibers.

<Prior art> The most common method of forming a brass coating on fibers is
This is an electrolytic plating method. In this method, the fibers are passed through a plating bath consisting of copper cyanide and zinc cyanide to be plated with brass. However, since this method uses toxic cyanide, there are not only safety and health problems, but also the problem that the treatment of the plating waste liquid is troublesome.

Also, this is a problem common to plating methods, but it is very difficult to maintain a constant composition of the plating bath, i.e. the ratio of copper to zinc, and the concentration of the plating solution, making it difficult to form a brass coating with a constant composition. The problem is that it is difficult to

Other methods include thermal spraying using gas or plasma, and vacuum evaporation. However, the former method tends to cause the problem of so-called one-sided coating, in which brass adheres only to the side facing the gas or plasma source, and it is difficult to form a -like coating. In addition, the latter method has the problem that the so-called dezincing phenomenon, in which the zinc in the brass vaporizes and evaporates, easily occurs, making it difficult to maintain a constant composition of the brass.

On the other hand, the invention of JP-A No. 60-119266 by the inventors involves contacting copper-coated fibers with zinc vapor at a temperature of 400 to 1050°C in a reactor in which an inert gas is flowed.
Zinc is diffused into the copper coating to alloy the copper and zinc to form a brass coating on the fibers. Unlike the above-mentioned method, this method does not use harmful cyanide, so it does not cause safety and health problems. Also, there is no problem caused by the so-called dezincing phenomenon.

However, on the other hand, oxygen in the oxide film formed on the surface of the copper-coated fibers, oxygen in the atmosphere that is taken into the copper-coated fibers and enters the reactor, and oxygen that accompanies the copper-coated fibers and enters the reactor. There are problems in that the brass coating becomes uneven in color due to the oxidation film created by the oxygen in the atmosphere that enters the interior, and that the unique luster of brass decreases. These oxygen-induced oxide films can be removed by treating the obtained brass-coated fibers with a chemical solution or heat-treating them in a reducing atmosphere, but doing so will increase the manufacturing cost due to the additional manufacturing steps. It becomes a problem.

<Problems to be Solved by the Invention> The purpose of the present invention is to solve the problems of the above-mentioned conventional methods, especially the method of the invention of JP-A No. 60-119266, and to solve The formation of an oxide film due to oxygen in the film, atmospheric oxygen that is taken into the copper-coated fibers and enters the reactor, and atmospheric oxygen that enters the reactor along with the copper-coated fibers. To provide a method for producing a fiber having a brass coating that can prevent color unevenness, has almost no color unevenness, and has excellent gloss.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides copper-coated fibers in a reactor in which a mixed gas of an inert gas and a reducing gas is flown. Provided is a method for producing a brass-coated fiber, characterized in that copper and zinc are alloyed by contacting with zinc vapor at 1-050° C. to diffuse zinc into the copper coating to form a brass coating on the fiber. do.

To explain the present invention in detail, in the present invention, first, a fiber coated with copper is prepared.

The above-mentioned fibers are fibers that can withstand temperatures of 400° C. or higher, such as carbon fibers, flame-resistant fibers, graphite fibers, glass fibers, alumina fibers, alumina-silica fibers, and silicon carbide fibers. These fibers are usually used in the form of fiber bundles (multifilaments), that is, continuous fibers, but they may also be in the form of monofilaments, or in the form of strings, textiles,
It may be in the form of a tape or the like.

Copper coatings can be formed by known methods. For example, when the fibers are conductive carbon fibers or graphite fibers, electrolytic plating can be used. Furthermore, in the case of non-conductive fibers such as glass fibers and alumina fibers, an electroless plating method can be used. The thickness of the copper coating may be arbitrary, but it is about 0.1 to 4 μm when electrolytically plated, and about 0.1 to 2 μm when electroless plating is used. In addition, when the fibers are in an aggregate form such as a fiber bundle, the copper coating may be applied to each fiber (single fiber) forming the aggregate, or it may be applied around the aggregate. . Coating around the copper-coated fibers may improve the flexibility of the copper-coated fibers compared to coating each fiber individually, which is preferable in some cases.

Now, in this invention, the copper-coated fiber is brought into contact with zinc vapor at 400 to 1050° C. in a reaction device in which a mixed gas of an inert gas and a reducing gas is flowing. To explain this situation using a drawing, in the drawing, the copper coated fiber 1 is heated to 400 to 1000
The mixture is passed through reaction tube 3 which is heated to 050°C. Reaction tube 3
is made of a heat-resistant material such as quartz, and the copper-coated fiber 1
A gas port 4 and a gas outlet 5 are provided on the inlet side, and a gas port 6 is provided on the outlet side.Inert gas such as argon gas and nitrogen gas is introduced from the gas port 4, and from the gas port 6, the above gas is introduced. A mixed gas of an inert gas and a reducing gas such as hydrogen gas is introduced and flows toward the gas outlet 5, respectively. This isolates the inside of the reaction tube 3 from the atmosphere and replaces it with the mixed gas.

On the other hand, a carrier gas introduction pipe 8 is inserted into the reaction tube 3 through a flange 7 and is detachably connected to a carrier gas supply source (not shown). In this carrier gas introduction pipe 8, a boat 10 containing granular or lumpy metal zinc 9 is placed. As the carrier gas, the above-mentioned inert gas is used.

Now, while the copper-coated fiber 1 is running inside the reaction tube 3, it comes into contact with zinc vapor generated from the metal zinc 9 and carried by the carrier gas. Then, zinc diffuses into the copper coating and becomes alloyed with copper.

That is, a brass coating is formed.

In this invention, the inside of the reaction tube is replaced with a mixed gas of an inert gas and a reducing gas. The oxygen in the air that enters the reaction tube along with the copper-coated fibers is reduced and removed, and the oxidized film caused by the oxygen causes uneven color on the brass coating. This is to prevent the unique luster of brass from deteriorating. The concentration of reducing gas such as hydrogen gas is 1 to 40% by volume. If it is less than 1% by volume, a sufficient reducing effect may not be obtained.

Moreover, if it exceeds 40% by volume, the reducing effect will become saturated, and if hydrogen gas or the like is used, there will be a risk of explosion. Note that since the interior of the reaction tube is not in a vacuum state, the so-called dezincing phenomenon observed in the above-mentioned vacuum evaporation method does not occur.

In addition, maintaining the inside of the reaction tube at 400 to 1050°C is
Zinc does not vaporize below 400℃, and below 1050℃
This is because if it exceeds this, the copper coating tends to peel off, making it impossible to produce brass-coated fibers in either case. The preferred atmospheric temperature is 419-800°C, more preferably 450-700°C.

The composition of the brass forming the coating depends on the thickness of the copper coating,
It is affected by the traveling speed of the copper-coated fiber, the length and heating temperature of the reaction tube, the flow rate of the carrier gas, etc. In other words, a brass coating of any composition can be obtained by changing these conditions. Incidentally, according to experiments conducted by the inventors, by appropriately selecting the above-mentioned conditions, brass coatings having an extremely wide range of compositions can be obtained, with the amount of zinc ranging from a few percent by weight to more than 50 percent by weight. Note that the running speed of the copper-coated fibers varies depending on the length of the reaction tube, heating temperature, flow rate of carrier gas, etc., but is usually 0.2
Select within the range of ~5 m/min.

The brass-coated fiber produced by the method of this invention is
It can be used for various purposes.

For example, if brass-coated carbon fibers are arranged in a die and hot pressed, a carbon fiber-reinforced tool can be manufactured. That is, it can be used as a molding material for fiber-reinforced appliances. Such materials, especially carbon fibers and graphite fibers, are used in, for example, sliding parts such as bearings, vanes, and brake shoes, parts of machinery and equipment that require corrosion resistance such as boilers and seawater equipment, and other parts. It is useful as a constituent material for parts of general machinery and equipment. Further, the brass-coated fiber according to the present invention can be combined with a resin or the like to constitute a speaker diaphragm, a radio wave shielding material, an antistatic material, an antenna, etc. Additionally, it can be used as a tire cord.

Furthermore, in the brass-coated fiber according to the present invention, the amount of zinc can be controlled almost freely as described above, and the color tone of the coating can be varied. For example, the coating is almost copper-colored with low amounts of zinc, becomes golden yellow with increasing amounts of zinc, and becomes yellow with further increases.

Therefore, if it is used as a decoration for sporting goods such as fishing rods, golf shafts, and tennis rackets made of fiber-reinforced plastic, it can give a decorative effect to them.

<Examples> Example 1 Torayka T300 carbon fiber manufactured by Toshi Co., Ltd. with an average single fiber diameter of 7 μm and 3,000 filaments each was coated with copper by an electrolytic plating method using a copper sulfate solution as the plating liquid. Copper coating is applied to almost each single fiber, and its average thickness is approximately 0.
．． It was 2 μm.

Next, using the apparatus shown in the drawing, the copper-coated carbon fibers were continuously introduced into the reaction tube 03 at a speed of 2 m/min to diffuse zinc into the copper coating and alloy it. .

At this time, the temperature of the reaction tube 3 was maintained at about 650°C. In addition, argon gas is flowed from gas population 4, and gas population 6
From there, argon gas containing 5% by volume of hydrogen gas was flowed.
Boat 10 contained 50 g of granular metallic zinc.

The obtained brass-coated carbon fiber has an average coating thickness of about 0. At 5 μm, the coating contained about 30% by weight of zinc and was mostly yellow in color.

Example 2 The carbon fiber used in Example 1 above was coated with copper by electroless plating. As the plating liquid, "Chemiplate Process" Cu manufactured by Kizai Co., Ltd. was used. The copper coating is applied mostly to each single fiber, and its average thickness is approximately 0.
It was 2 μm.

Next, a brass coating was formed in the same manner as in Example 1.

However, the running speed of copper-coated carbon fiber is approximately 0.2 m/min,
The temperature of the reaction tube was about 550°C.

In addition, as a mixed gas, hydrogen gas is 30% by volume 1 argon gas was used.

The obtained brass-coated carbon fiber has a thickness of about 0. having a coating thickness of 3 μm, the coating containing approximately 15% by weight zinc;
It had a golden color.

<Effects of the Invention> In this invention, a mixed gas of an inert gas and a reducing gas is caused to flow in the reaction device, so that the reducing gas causes oxygen in the oxide film formed on the surface of the copper-coated fiber. It is possible to reduce and remove the oxygen in the air that is taken into the copper-coated fibers and enters the reaction tube, and the oxygen in the air that enters the reaction tube accompanied by the copper-coated fibers. It becomes possible to prevent color unevenness on the brass coating and deterioration of the unique luster of brass due to the oxide film. Moreover, unlike conventional methods, there is no need to use harmful cyanide, and there is no need to worry about safety and health problems, and there is no need to pay attention to waste liquid treatment. Since there is no need to worry about the so-called dezincing phenomenon that occurs in the case of evaporation or vapor deposition, it becomes possible to easily obtain fibers having a -like composition and a uniform brass coating.

[Brief explanation of drawings]

The drawing is a schematic partial side view of a reaction apparatus showing how the method of the present invention is carried out. 1: Copper coated fiber 2: Electric furnace 3: Reaction tube 4: Gas inlet 5: Gas outlet 6: Gas inlet A: Flange 8: Carrier gas introduction tube 9: Metal zinc 10: Boat

Claims (1)

[Claims] Copper-coated fibers are heated at 400 to 1050°C in a reactor where a mixed gas of inert gas and reducing gas is flowing.
A method for producing a brass-coated fiber, comprising alloying copper and zinc by contacting the fiber with zinc vapor and diffusing the zinc into the copper coating to form a brass coating on the fiber.