PURPOSE: To obtain carbon yarn having high strength and high modulus of elasticity, by purifying and distilling coal tar pitch, fractionating it in to mesophase pitch and distillate, treating the distillate under specific conditions to improve it, remixing the treated distillate with the mesophase pitch, spinning the mixture.
CONSTITUTION: A large amount of coal tar (pitch) prepared as a by-product during carbonization of coal is extracted with an aromatic solvent such as toluene, etc., and heat-treated to give purified pitch. The purified pitch is then distilled under reduced pressure to fractionate it into mesophase pitch and distillate, the distillate is further treated with molecular hydrogen in an aliphatic hydrocarbon such as n-pentane, etc. in the presence of extremely strong acid such as hydrobromic acid, etc. as a catalyst to improve it. The treated distillate is blended with the mesophase pitch, and heat-treated, to give spinning pitch. Then, the spinning pitch is spun, made infusible, and carbonized, to give the desired carbon yarn.
| JP3861899 | CARBON FIBER |
| JPH01282323 | CALCINATION OF PITCH FIBER |
OKADA TOSHIHIKO
MATSUBARA KENJI
