PRODUCTION OF CARBON FIBER

摘要

PURPOSE:To produce a carbon fiber excellent in opening properties suitable for producing prepreg with good productivity. CONSTITUTION:This method for producing carbon fiber is to continuously burn carbonized fiber yarn while applying 1.5-10kgf/mm<2> tension thereto in subjecting pitch fiber using mesophase pitch as a raw material to the oxidizing treatment in an oxidizing gas atmosphere containing nitrogen dioxide and oxygen, burning the resultant oxidized fiber at >=350 to <400 deg.C for >=10min in an inert atmosphere, then continuously carbonizing the obtained fiber at 800-1250 deg.C temperature, thereby providing carbon fiber yarn having >=15kgf/mm<2> breaking strength thereof and carrying out the graphitization of the carbonized fiber yarn so as to afford 1500 deg.C final temperature.