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:
Aug. 25, 1998
Filed:
Oct. 21, 1996
Ronald Damian Myers, Calgary, CA;
John Brenton MacLeod, Calgary, CA;
Exxon Research and Engineering Company, Florham Park, NJ (US);
Abstract
A process for devulcanizing and functionalizing a rubber vulcanizate by desulfurization involves suspending a rubber vulcanizate crumb in a solvent which preferably swells the rubber vulcanizate before or during the devulcanization reaction and adding an alkali metal, such as sodium, to the suspension. The alkali metal cleaves mono-, di- and polysulfidic cross-linkages in the rubber vulcanizate to liberate rubber polymer having a molecular weight substantially equal to that of the rubber polymer prior to vulcanization. Functional groups derived from the solvent molecules bond to the devulcanized rubber's polymeric backbone. In addition to the functionalized devulcanized rubber polymer, carbon black may also be recovered for re-use in accordance with the process of the present invention. The functionalized devulcanized rubber may be subjected to a re-vulcanization reaction without separation of rubber polymer from the solvent by addition of an appropriate curing mixture.