The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 29, 1991
Filed:
Apr. 27, 1990
Nippon Oil Company, Limited, Tokyo, JP;
Abstract
A pitch-based carbon fiber having a high strength is produced by (a) treating a heavy oil at a temperature of 370.degree. to 480.degree. C. and a pressure of 2 to 50 kg/cm.sup.2 ; (b) separating and removing insoluble solids from the heat-treated oil so that the insoluble solids content is not higher than 50 ppm; (c) subjecting the oil to thin film distillation at a temperature of 250.degree. to 450.degree. C., a pressure of not higher than 100 mm Hg and a film thickness of not larger than 5 mm; (d) heat-treating the resulting pitch at a temperature of 340.degree. to 450.degree. C. while passing an inert gas at atmospheric or reduced pressure to obtain an optically anisotropic pitch having a softening point of 260.degree. to 300.degree. C., a quinoline insolubles content of not higher than 40 wt % and an optically anisotropic phase content of 60 to 100 vol %; (e) melt-spinning said optically anesotropic pitch in a melt-spinning apparatus having a nozzle with a vertically longer molded product disposed therein, at a temperature of 280.degree. to 360.degree. C. and a spinning viscosity of 300 to 3,000 poise; (f) rendering the resulting pitch fiber infusible and (g) calcining the infusibilized fiber in an inert gas atmosphere, initially at a temperature of 650.degree. to 850.degree. C. and subsequently conducting calcination at a temperature of 1,200.degree. to 3,000.degree. C.