| 摘要 |
PURPOSE:When carbonaceous pitch fibers are preoxidized, then carbonized to produce carbon fibers, the preoxidized fibers are treated with dimethyl polysiloxane of a specific viscosity to prevent the fibers from fusing with one another in the carbonization process, thus improving filament separating properties. CONSTITUTION:Carbonaceous pitch, preverably petroleum pitch softening at 260-300 deg.C, containing 5-100% of meso phase is melted, e.g., at a temperature 30-80 deg.C higher than the softening point, extruded through nozzles of 0.1- 0.5mm. diameter and wound up at a speed of 100-2,000m/min. The resultant fibers are preoxidized, preferably in an oxidative atmosphere at 200-350 deg.C. Then, dimethyl polysiloxane of the formula having a viscosity of 12,000-1,000,000 cSt at 25 deg.C is applied to the fibers, preferably by 0.1-10wt%. Then, the carbonization is effected at 800-2,000 deg.C, when needed, further graphitization is conducted to give the objective fibers. |
