| 摘要 |
PROBLEM TO BE SOLVED: To provide a fine carbon fiber having high electrical conductivity, a carbon fiber having low metal content and methods for producing the fibers. SOLUTION: The invention provides a fine carbon fiber having a layer spacing d002 of 0.337 nm measured by X-ray diffraction method, a fiber diameter of <=1,000 nm and a compact specific resistance of <=0.02Ω.cm and a fine carbon fiber having a metal content of <=500 mass ppm. These carbon fibers can be produced by using a fine carbon fiber produced by a gaseous phase process, an arc discharge process, a laser process, etc., as a raw material and heat-treating the fiber at >=2000 deg.C in the presence of boron or a boron compound in a state separated from the carbon fiber. |
