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:
Mar. 11, 1986
Filed:
Aug. 28, 1984
Applicant:
Inventors:
Kozo Yudate, Chiba, JP;
Ken Nagasawa, Chiba, JP;
Assignee:
Kawasaki Steel Corporation, Kobe, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C10C / ; C10C / ; D01F / ;
U.S. Cl.
CPC ...
208 45 ; 208 40 ; 208 44 ; 4234471 ; 4234474 ;
Abstract
Precursor pitch to be used for formation of carbon fiber is produced by heating a coal tar soft or middle pitch at a temperature of 350.degree.-500.degree. C. at a first stage to form mesophase, extracting the thus treated pitch with a solvent, separating and removing the solvent insoluble portion including mesophase to obtain a pitch containing no free carbon and further at the second stage heat-treating the pitch containing no free carbon in an inert gas atmosphere under atmospheric pressure or a reduced pressure under the following condition