Pitch with reduced tendency to smoke during spinning and a process for the production of said pitch

摘要

Mesophase pitch that has a softening point of no more than 250 DEG C, a pyridine-insolubles content of no more than 50% and a n-heptane solubles content of 3 - 10%, with the n-heptane solubles experiencing a weight loss of no more than 15% at 450 DEG C as measured by thermogravimetry is produced by polymerizing a condensed polycyclic aromatic hydrocarbon or a substance containing it in the presence of HF and BF3. This mesophase pitch is suppressed satisfactorily in its tendency to smoke during spinning and, additionally, it has a low enough softening point to exhibit outstanding spinnability. Hence, the pitch allows for high-volume spinning to be performed continuously for a prolonged time without causing extensive fouling of the surface of spinning nozzles.