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:
Jan. 02, 1990
Filed:
Nov. 22, 1988
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
Pitch that is obtained from a condensed polycyclic aromatic hydrocarbon and the content of an optically anisotropic phase in which is substantially 100% is disclosed. This mesophase pitch has a H/C atomic ratio of 0.5-1.0, contains naphthenic carbon in an amount of at least 7% of the total carbon, and has a softening point of 180.degree.-400.degree. C. Fibers melt-spun from this mesophase pitch can be converted to carbon or graphite fibers having high strength and modulus of elasticity by a heat treatment which consists of heating to a temperature of 250.degree.-300.degree. C. in an air atmosphere, then heating to 1,000.degree. C. or higher in an inert gas atmosphere. Such mesophase pitch is produced by polymerizing a condensed polycyclic aromatic hydrocarbon for 5-300 minutes at a temperature of 180.degree.-400.degree. C. and at a pressure of 5-100 atmospheres in the presence of 0.1-20 moles of HF and 0.05-1 mole of BF.sub.3 per mole of the condensed polycyclic aromatic hydrocarbon.