| 摘要 |
PURPOSE:To obtain the titled pitch having excellent spinnability and infusibility and capable of providing a carbon fiber having excellent mechanical properties, by hydrogenating a particular fraction of a heavy distillate derived from petroleum, mixing the hydrogenation product with a recovered high-boiling oil, heat-treating the mixture under pressure and removing insoluble matter, followed by heat treatment. CONSTITUTION:A petroleum heavy distillate obtd. by steam cracking and catalytic cracking of petroleum or the like is distilled to obtain a fraction having a b.p. of 250 deg.C or above. The fraction is hydrogenated under a hydrogen pressure of 50-300kg/cm<2> at 300-550 deg.C for 10-120min in the presence of a hydrogenation catalyst. To the hydrogenated fraction is added a recovered heavy distillate. The mixture is heat-treated under pressure at 350-550 deg.C, followed by removal of insoluble solids by means of filtration or the like. The filtrate is distilled to remove the solvent and a light oil having a b.p. of 250 deg.C or below which has been produced as a by-product, thereby obtaining a fraction having a b.p.of 250 deg.C or above. The fraction is heat-treated under a reduced pressure of 5-100mmHg and/or in a stream of an inert gas at 350-550 deg.C to obtain the titled pitch having a b.p. of 220-320 deg.C and contg. 40% or less quinoline-insoluble matter and 70% or more toluene-insoluble matter. The heavy distillate which has been recovered by stripping is also circulated for reuse.
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