摘要 |
PURPOSE:To provide a method for producing a pitch-based carbon fiber, capable of preventing the fusion of fibers during the infusibilization process and of improving both the flexibility and the bundlability. CONSTITUTION:1. In relation to the method for producing a carbon fiber by melt-spinning an optically anisotropic pitch, doubling the resultant pitch fibers, subsequently infusibilizing it, preliminarily carbonizing it and carbonizing or graphitizing it, this method for producing a pitch-based carbon fiber is characterized by doubling of spun pitch fibers into a bundle of 500 to 10000 filaments using a heat-resistant doubling agent, infusibilizing the resultant doubled pitch fibers in an oxygen-containing atmosphere, subsequently adhering an aqueous oxidant thereto, secondly infusibilizing by heating up to 150 to 300 deg.C in an oxygen-containing atmosphere, subsequently carrying out preliminary carbonization in an inert atmosphere followed by carbonization or graphitization. 2. A method for producing a pitch-based carbon fiber, described in the item 1 is that the concentration of the aqueous oxidant is 0.5 to 10wt.%. |