| 摘要 |
PROBLEM TO BE SOLVED: To provide a carbon fiber having a hollow part in the interior of the fiber, having low apparent specific gravity and having high strength in horizontal direction when formed as a composite. SOLUTION: The carbon fiber has a hollow part and has low specific gravity of≤1.60 and has an uniform and specific structure in which the ratio of maximum diameter R1 of the hollow part to minimum diameter of the hollow part satisfies the formula 0≤R2≤R1<0.9. The carbon fiber can be produced by heat treatment of a flame-resistant fiber obtained by fiberizing a flame-resistant polymer, having≤40% degree of orientation and modified with an amine-based compound, at the rate of heating of≥200°C at a maximum temperature between≥300°C and <2,000°C under inert atmosphere. COPYRIGHT: (C)2008,JPO&INPIT
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