| 摘要 |
1304340 Carbon and graphite filaments CELANESE CORP 15 June 1971 27914/71 Heading C1A Continuous lengths of carbonized filamentary material are produced by first stabilizing, i.e. heating at least in part in an oxygen containing atmosphere, whilst retaining the filamentary structure until the filaments are non-combustible in a match flame, continuous filaments of acrylonitrile, either as a homopolymer or a copolymer, and then passing the stabilized filaments continuously into and through a heater which has an inlet temperature not higher than 650‹ C. and a zone where the temperature rises from 900‹ to 1600‹ C. in the direction of travel of the filament or filaments, the feed rate of the material to the heater being such that it reaches said zone in from 3 sees. to 10 mins., and passes through said zone in from 3 sees. to 5 mins. Preferably the material reaches the zone in from 3 sees. to 5 mins. and passes through that part having a temperature of from 1400‹ to 1600‹ C. in from 3 to 70 seconds. The carbonization is preferably performed in an atmos. of nitrogen. The carbonized filaments may subsequently be graphitized by heating at 2400‹ to 3100‹ C. in an inert atmosphere. The graphitization may be effected by passing through a zone in which the filament is heated to 2700‹ to 3000‹ C. in from 30 sees. to 2 mins. If desired, the process may be completed in a heater having two zones, the first having a temperature rising from 900- 1600‹ C. and the second from 2700‹ to at least 2900‹ C., the material travelling from the low to the high temperature zone in from 2-30 secs. |
