Prepn. of charge-transfer mesophase from coal tar or coal tar pitch - by reacting isotropic aromatic mixt. having raised electron-acceptor or electron-donor potential, with electron donor or electron acceptor

摘要

In prepn. of charge-transfer (CT) mesophases from purified coal tar, coal tar pitch or similar mixts. of polycyclic aromatics, isotropic aromatic mixts. with raised electron-acceptor potential are mixed, in the melt or in soln., with electron donors, the mixt. is treated, opt. at raised temp., and the mesophase formed from the CT-complexes is sepd. in known way, e.g. by decanting, from the isotropic phase. Opt., the isotropic aromatic mixt. has raised electron-donor potential, and is mixed with electron acceptors. The mixt. of modified aromatic and electron acceptor or donor, as inductor, is heated at above 350 deg.C until a liq. mesophase formed of CT complexes is formed by polycondensation, and is sepd. in known way from the isotropic phase. The aromatic mixt. with raised acceptor potential is obtd. from the isotropic aromatic mixt. by nitration or introduction of quinoid functions, and the raised electron donor potential is obtd. by introduction of amine, OH or S functions. The mesophase contg.. NO2 gps. may be reduced, or the mesophase contg. quinone gps. may be reacted with N cpds. Pptn. of the CT-mesophases may be in several stages, opt. with different inductors or inductor mixts., with the mesophases obtd. in each stage being sepd. USE/ADVANTAGE - Mesophases low in solids and with low flow temp. are obtd. The mesophases can be processed, e.g. to graphite fibres or films, or to C mouldings.