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:
Dec. 26, 1978
Filed:
Mar. 23, 1977
Akira Nagasaka, Chiba, JP;
Hidetomo Ashitaka, Ichihara, JP;
Yoshihiro Kusuki, Ichihara, JP;
Denichi Oda, Ichihara, JP;
Toshimune Yoshinaga, Fukuoka, JP;
Ube Industries, Inc., Ube, JP;
Abstract
Carbon fibers having excellent modulus of elasticity and tensile strength are produced in a high yield by a process wherein polybutadiene fibers are prepared by melt-spinning polybutadiene having at least 85% of vinyl structure, a melting point of at least 100.degree. C and a reduced viscosity of 0.3 to 1.2 dl/g; the fibers are then treated in a solution or suspension of a Lewis acid in an inert organic liquid, whereby the pollybutadiene is cyclized and cross-linked; the polybutadiene fibers treated as mentioned above are further treated in a melted sulphur or a sulphur-containing solution at a temperature of 170 to 300.degree. C, whereby the cyclized and cross-linked polybutadiene is dehydrogenated and aromatized; and the fibers treated as mentioned above are carbonized by raising the temperature thereof to 750.degree. C to 3000.degree. C to form carbon fibers or graphite fibers. If so desired, the ordinary carbon fibers which have been produced at 750 to 1500.degree. C, can be converted to graphite fibers by heating them to a temperature of 1500 to 3000.degree. C.