METHOD OF MANUFACTURING CARBON FIBER Russian patent published in 1999 - IPC

FIELD: artificial fibers. SUBSTANCE: invention relates to carbon fiber that can be applied as fillers in production of sports- and industrial-destination products from carbon plastics and as starting materials in production of aircraft brake systems, composite fillers, and also as heat-resistant, filtration and sorption-active materials in chemical industry, mechanical engineering, and aircraft industry. Textile-destination fibers from acrylonitrile copolymer, containing at least 93 wt % of acrylonitrile and also methacrylate and methyl sulfonate or sodium styrenesulfonate, are first oxidized at 235-260 C for 35-60 min with spindle draft 20-30% and then at 230-260 C for 85-140 min with spindle draft from -5 to 5%. Fibers are then carbonized under nitrogen atmosphere for 10 min at temperature from 350 to 1500 C in pulled state. Wet-formation polyacrylonitrile fiber can also be used. Tensile strength of fibers containing at least 94 wt % carbon is up to 210 kg/sq. mm with density 1.73-1.78 g/cu.cm. EFFECT: reduced cost and widened resource of raw materials. 2 cl, 4 ex