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:
Sep. 21, 1999
Filed:
Jun. 02, 1995
Paul S Furmanek, Newark, DE (US);
David A Glasscock, Bear, DE (US);
Michael Keane, Jr, Wilmington, DE (US);
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A process for producing difluoromethane is disclosed which includes the step of contacting a gaseous mixture containing CH.sub.2 Cl.sub.2 and hydrogen fluoride with a catalyst containing a catalytically effective amount of trivalent chromium supported on a carbon having an ash content of less than 0.5 percent by weight, at a temperature of from about 180.degree. C. to about 375.degree. C. The catalyst and temperature conditions of this process allow the concurrent reaction CCl.sub.3 CF.sub.3 with HF to form CCl.sub.2 FCF.sub.3. CH.sub.2 ClF and unreacted CH.sub.2 Cl.sub.2, each of which may be recovered as an azeotrope with HF, may be recycled.