| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing carbon fiber having increased strength and increased elongation. SOLUTION: The method for producing carbon fiber comprises a step for spinning a copolymer provided by polymerizing acrylonitrile with itaconic acid to obtain a thread having 1.22-1.33 single fiber fineness, drying and compactifying at 70-150°C, treating by moist heat-drawing under conditions of 100-130°C and 3.0-5.0 times draw ratio and obtaining precursor fiber adjusted to have 25-50 mass% moisture with water having≤1μS/cm ionic conductivity, a step for flameproofing to obtain flameproof fiber on the condition of 250-260°C and 1.01-1.10 times draw ratio in the first chamber of the flameproofing furnace or on the condition of temperature in the first chamber or more but <280°C and 0.95-1.00 time draw ratio in the second and later chambers, and a step for precarbonizing flameproof fiber in an inert gas at 300-800°C and carbonizing in an inert gas at 300-1,420°C. COPYRIGHT: (C)2008,JPO&INPIT
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