Process for producing pitch-based carbon fiber.

摘要

There is disclosed a process for producing pitch-based carbon fiber which comprises melt spinning an optically isotropic pitch or a mesophase pitch to form pitch fiber; subjecting the pitch fiber to liquid-phase oxidative polymerization in a solvent e.g. acetic acid in the presence of an acid catalyst such as strong inorganic acids and a crosslinking selected from formalin, paraformaldehyde or tioxane agent to form infusibilized fiber; and carbonizing the infusiblized fiber. The above process enables low temperature and short time infusibilizing treatment of optically isotropic pitch fiber having a low softening point which has heretofore been difficult because of failure to preserve the original fibrous shape during infusibilization, and also efficient production of mesophase pitch-based carbon fibers as well as optically isotropic pitch-based carbon fibers each being improved in physical properties.