| 摘要 |
PURPOSE:To prepare pitch material for carbon fiber having good heat stability, and excellent spinnability and infusibility, and giving a high carbonization yield, by thermally treating ashless coal liquefaction pitch obtd. by the hot extraction of coal with a solvent. CONSTITUTION:Coal is depolymerized and hydrotreated in a hydrogen donating solvent such as creosote oil or anthracene oil at a high temp. and high press. in an atmosphere of hydrogen, and is removed from an ash-contg., solvent-insoluble component and then from the solvent, to form coal liquefaction pitch. A low-molecular weight component in the pitch is removed by keeping the pitch at 300-400 deg.C for more than 30min in vacuum or inert gas atmosphere, to prepare hard pitch of softening temp. >=about 200 deg.C.
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