JPH0748121A - Fiber containing boron, carbon and/or nitrogen as main components and its production - Google Patents

Abstract

PURPOSE:To provide a fiber containing boron, carbon and/or nitrogen as main components and useful as a heat-resistant, corrosion-resistant material, a conductive corrosion-resistant material, etc. CONSTITUTION:A fiber contains boron, carbon and/or nitrogen as substantially main components and has a diameter of 1-100mum. A method for producing the fiber comprises reacting a pitch fiber, regenerated cellulose fiber, vinylon fiber, lignin poval fiber, furfuryl alcohol fiber, polyacrylonitrile (PAN) fiber, polyimide fiber or polyamide fiber with a boron halide gas at 150-500 deg.C and subsequently thermally treating the obtained fiber at 500-3000 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber containing boron, carbon and / or nitrogen as a main component which is useful as a high temperature corrosion resistant material, a conductive corrosion resistant material and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, various materials have been known in which various base materials matrix and fiber materials are mixed to strengthen or give a composite function. As the fiber materials, glass fiber and carbon fiber are used. , Various ceramic fibers, etc. Of these, silicon carbide, silicon nitride, and the like are known as ceramic fibers, and carbon fibers have characteristics such as high strength and high elasticity, and products using these are made. Fibers containing boron, carbon, and nitrogen as main components have various characteristics such as oxidation resistance, heat resistance, chemical stability, chemical resistance, conductivity, and semiconductivity. It is useful as a material, a semiconductive functional material, and an electrode material, but in reality, it is a chemical vapor deposition method (JP-A-1-
No. 252520), but the fiber length is short, and the yield obtained as fibers is extremely low.

[0003]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have found that pitch-based fibers, polyacrylonitrile (PA) are used as carbon sources and carbon-nitrogen sources.
The present invention has arrived at the present invention by finding a fiber excellent as a high temperature corrosion resistant material, a conductive corrosion resistant material, a semiconductive functional material, and an electrode material by reacting N) -based fiber and the like with a boron halide gas as a boron source.

That is, the present invention is essentially based on boron, carbon or / and nitrogen and has a fiber diameter of 1-10.
Fibers characterized by being in the range of 0 μm, such as pitch-based fibers, regenerated cellulose fibers, vinylon fibers, lignin-povar fibers, furfuryl alcohol-based fibers as carbon sources or polyacrylonitrile (P
(AN) type fibers, polyimide fibers, polyamide fibers and boron halide gas as a boron source in the reaction vessel 15
The method for producing the fiber according to claim 1, wherein the reaction is carried out at 0 to 500 ° C., and the fiber obtained by the method is 50
The method for producing a fiber according to claim 1, wherein the heat treatment is performed in a temperature range of 0 to 3000 ° C.

In the present invention, the pitch-based fibers as the carbon source include polyvinyl chloride (PVC) pitch, petroleum asphalt, coal tar pitch, crude oil decomposition pitch,
Examples include oil sludge. In addition, examples of the carbon source include regenerated cellulose fiber, vinylon fiber, lignin-poval fiber, and furfuryl alcohol fiber. Further, as the polyacrylonitrile (PAN) fiber as a carbon-nitrogen source, polyacrylonitrile, A
Examples thereof include BS [copolymer of acrylonitrile, butadiene and styrene (composition ratio 30:20:50)], AS [copolymer of acrylonitrile and styrene (the above-mentioned ABS related product)] and the like. Other examples of the carbon-nitrogen source include polyimide fiber and polyamide fiber.

On the other hand, the boron source is preferably a boron halide gas such as BCl ₃ , BBr ₃ and BF ₃ . All reactions were carried out in a quartz reaction tube (inner diameter: 45
Place the raw material fiber in the center of
It was reacted with boron halide gas at 500 ° C. If the temperature is lower than 150 ° C, the reaction does not proceed sufficiently, which is not preferable. Further, even if the temperature exceeds 500 ° C, the reaction is already completed, which is not economically preferable.

The obtained fibers all had a black color,
No change in shape was observed. By-products such as HCl remained in the product, and in order to remove them, heat treatment was performed in a nitrogen stream at a temperature range of 500 to 3000 ° C. After the heat treatment, the shape of the fiber did not change. Heat treatment temperature is 5
If the temperature is lower than 00 ° C, residual halogen cannot be completely removed, which is not preferable. Further, even if it exceeds 3000 ° C., it is completely graphitized, which is not economically preferable.

The product thus obtained was analyzed for structure, shape and surface condition by X-ray diffraction measurement and SEM observation. The composition of the product was determined by combustion method for C, H, N, and alkali melting for B, followed by quantitative analysis by ICP.

[0009]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1 5 g of PAN fiber (fiber diameter: 13 to 15 μm, fiber length: 5 cm) was placed on a graphite sheet and placed in the center of a quartz reaction tube (45φ). The central part of the reaction tube was heated to 400 ° C. at 100 ° C./Hr while introducing BCl ₃ and N ₂ gas. The respective gas flow rates were as follows.

BCl₃ 50 cc / min N₂ The furnace pressure was 50 cc / min under atmospheric pressure. Completely black after the reaction
A colored, fibrous product was obtained. By-product in the product
HCl and other unreacted components remain as products
Therefore, heat treatment was performed at 1000 ° C. in a nitrogen stream. Obtained
The product yield is calculated by theoretical composition BC₃About 80 based on N
%Met. Figure shows the X-ray diffraction pattern of the product after heat treatment.
Shown in 1. Broad at 2θ = 24 °, 43.5 °
Peak appears and has a structure similar to graphite.
I found out that As a result of SEM observation, the fiber diameter is 10 to 13.
μm and fiber diameter became slightly thin, but in other shapes
There was no change. The elemental analysis results are shown in Table 1. This conclusion
As a result, the composition of the product is almost BC ₃NH_1.7Met.

[0012]

[Table 1]

Example 2 The conditions are the same as in Example 1 except that PVC pitch is used as the matrix of the fiber raw material. When the X-ray diffraction measurement of the obtained product was performed, the diffraction pattern was almost the same as in Example 1. The results of elemental analysis of this product are shown in Table 1. The resulting product composition was BC ₇ H ₅ .

[0014]

INDUSTRIAL APPLICABILITY In the present invention, unlike a gas phase reaction such as a chemical vapor deposition method, a polymer fiber is used as a matrix of a fiber raw material, so that the reaction rate is fast and a high yield can be obtained. It becomes possible to continuously manufacture long fibers to which many functions such as oxidation resistance, heat resistance, chemical stability, high conductivity, and semiconductivity are added.

[Brief description of drawings]

1 is an X-ray diffraction pattern of the fiber of Example 1 heat-treated at 1000 ° C.

Claims (3)

[Claims] 1. A fiber which is essentially based on boron, carbon or / and nitrogen and has a fiber diameter in the range of 1 to 100 μm. 2. A pitch-based fiber, a regenerated cellulose fiber, a vinylon fiber, a lignin-poval fiber, a furfuryl alcohol-based fiber as a carbon source or a polyacrylonitrile (PAN) -based fiber as a carbon-nitrogen source, a polyimide fiber,
The method for producing a fiber according to claim 1, wherein the polyamide fiber and a boron halide gas as a boron source are reacted in a reaction vessel at 150 to 500 ° C. 3. A fiber obtained by the method according to claim 2,
The method for producing a fiber according to claim 1, wherein the heat treatment is performed in a temperature range of 500 to 3000 ° C.