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. 28, 2001
Filed:
Apr. 01, 1999
Mario Joseph Nappa, Newark, DE (US);
V. N. Mallikarjuna Rao, Wilmington, DE (US);
Allen Capron Sievert, Elkton, MD (US);
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A process is disclosed for the manufacture of CF,CHFCF,containing less than 0.01 ppm (CF,),C═CF,. The process involves (a) contacting hexafluoropropene in the vapor phase at a temperature of less than about 260° C. with hydrogen fluoride in the presence of a selected fluorination catalyst or produce a product containing less than 10 parts (CF,),C═CF,per million parts of CF,CHFCF,; and (b) treating the product of (a) as necessary to remove excess (CF,),C═CF,. Suitable catalysts include: (i) an activated carbon treated to contain from about 0.1 to about 10 weight % added alkali or alkaline earth metals, (ii) three dimensional matrix porous carbonaceous materials, (iii) supported metal catalysts comprising trivalent chromium, and (iv) unsupported chrome oxide prepared by the pyrolysis of (NH,),Cr,O,.