PROCESS FOR PRODUCING PITCH FOR THE MANUFACTURE OF HIGH-PERFORMANCE CARBON FIBERS TOGETHER WITH PITCH FOR THE MANUFACTURE OF GENERAL-PURPOSE CARBON FIBERS

摘要

AbstractPROCESS FOR PRODUCING PITCH FOR THE MANUFACTUREOF HIGH PERFORMANCE CARBON FIBERS TOGETHER WITHPITCH FOR THE MANUFACTURE OF GENERAL PURPOSECARBON FIBERSA process for co-production of a pitch for themanufacture of HP carbon fibers and a pitch for themanufacture of GP carbon fibers is proposed. The pitch forthe manufacture of GP carbon fibers is prepared from the spentfraction not used in the production of an opticallyanisotropic pitch suitable for the manufacture of HP carbonfibers. The spent fraction has hitherto been discarded as avalueless material. According to the present process, a pitchfor the manufacture of so-called ultra HP carbon fibrs withtensile strength of over 400 Kg/mm2 and modulus of elasticityof over 60 ton/mm2 and a pitch for the manufacture of GPcarbon fibers can be produced simulteneously. Both pitcheshave very excellent spinnability and when they are spun, theycause no fiber cut-off even at a high spinning rate of, forexample, 500 m/min or 700 m/min. One important merit of theprocess is that the production ratio of ultra HP carbon fibersand GP carbon fibers can easily be changed to accommodate tomarket's demand. Accordingly, the process has wideflexibility in operation. Of course, the effectiveutilization of valueless spent fraction can reduce theproduction costs of not only ultra HP carbon fibers but alsoGP carbon fibers.