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:
Feb. 14, 1978
Filed:
Jun. 05, 1975
Ilmar L Kalnin, Millington, NJ (US);
Celanese Corporation, New York, NY (US);
Abstract
The internal structure of carbon fibers (as defined) is modified to yield a fibrous product having a bound oxygen content of about 3 to 30 percent by weight which exhibits substantially different bulk properties than that of the starting material. The carbon fiber precursor is contacted with a strong acid medium comprising nitric acid and optionally sulfuric acid and water (as defined) under conditions found capable of producing the desired internal chemical modification. In a preferred embodiment of the process the strong acid medium is formed by a combination (as defined) of fuming nitric acid and fuming sulfuric acid. The fibrous product exhibits, inter alia, reduced electrical and thermal conductivities, and particularly is suited for use as an ablative reinforcing medium.