PURPOSE: To obtain a pitch, having a high mesophase content, good in spinning properties and useful as a raw material, etc., for carbon fiber by adding a nitro compound to a hydrogenated heavy oil or pitch and then heat-treating the resultant mixture at a high temperature while blowing an inert gas thereinto.
CONSTITUTION: Coal tar is subjected to filtration treatment to remove solid substances. The obtained filtrate is then distilled under reduced pressure to take out low-boiling substances and afford a pitch. Previously hydrogenated anthracene oil as a hydrogenating oil is mixed with the resultant pitch and heat-treated at 400°C reactional temperature under 20kg/cm2G reactional pressure in a nitrogen atmosphere for 30min and then subjected to vacuum distillation to remove low-boiling substances. Thereby, a coal tar-based hydrogenated pitch is obtained and a nitro compound such as dinitronaphthalene is added thereto. An autoclave is then charged with the obtained mixture, which is subsequently heat-treated at 300-500°C under stirred conditions while blowing an inert gas such as nitrogen gas to provide a mesophase pitch having 200-310°C softening point. As a result, the objective pitch excellent in spinning properties is obtained.
MIZUTORI SHIGEJI
MORINO GUNJI
SO SHIYOMEI
