| 摘要 |
PURPOSE:To obtain 100% mesophase pitch for spinning carbon fiber having high strength and modulus of filament and for matrix of composite at a low cost, by removing low volatile component having a specific low molecular weight in petroleum based pitch which is a raw material in a production process. CONSTITUTION:A petroleum based pitch produced as a by-product in thermal cracking of desulfur reduced pressure light oil is distilled under reduced pressure and the distillate is subjected to heat treatment under a nonoxidating atmosphere to provide a pitch containing 5-15% mesophase, which is then subjected to heat and aging under nonoxidating atmosphere and divided into (A) nonmesophase pitch of upper layer and (B) mesophase pitch of lower layer. Then (C) raffinate nonmesophase pitch obtained by subjecting component (A) to solvent extraction treatment is blended with (D) nonmesophase pitch mentioned hereunder and the blend is subjected to heat treatment and then heat aging under nonoxidating atmosphere to separate and purify (D) nonmesophase pitch of upper layer and (E) 100% mesophase pitch of lower layer. Further, component (E) is subjected to solvent extraction treatment to provide 100% mesophase pitch of raffinate.
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