PROCESS FOR THE MANUFACTURE OF CARBON FILAMENTS

摘要

1395284 Carbon filaments BAYER AG 9 March 1973 [10 March 1972] 11412/73 Heading C1A [Also in Division H5] Filaments of carbon are produced from filaments of polyacrylonitrile by first heating the acrylonitrile filament under tension at a temperature between 150‹ and 190‹ C. in an oxidizing atmosphere, then heating under tension in an intert gas atmosphere at a temperature between 250‹ and 300‹ C., then without tension at a temperature between 200‹ and 250‹ C. in an oxidizing atmosphere and finally carbonizing without tension in an inert gas atmosphere at a temperature above 900‹ C. The fibre used preferably has a denier of from 0À9 to 5À0 d tex, and a tensile strength from 1À35 to 9À0 p/d tex. The tensile stress employed in the oxidizing stage is preferably greater than that used in the inert gas treating stage. The carbon fibres obtained may be subsequently graphitized e.g. at 1600 to 2600‹ C. in an argon atmosphere. The filaments obtained may be coated and bound with resin for use as reinforcement.