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:
May. 28, 2002
Filed:
Jul. 03, 1997
Applicant:
Inventors:
Bernard Cheminal, Brignais, FR;
Andre Lantz, Vernaison, FR;
Assignee:
Elf Atochem, S.A., Puteaux, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 1/708 ;
U.S. Cl.
CPC ...
C07C 1/708 ;
Abstract
In order to remove the impurities (in particular 1-chloro-2,2-difluoroethylene) present in crude 1,1,1,2-tetrafluoroethane (F134a), a gaseous mixture of crude F134a and hydrofluoric acid is treated in the gas phase, in the presence of a fluorination catalyst, at a temperature of between 200 and 380° C. and under a pressure between atmospheric pressure and 2.5 MPa, the HF/F134a molar ratio being between 0.05 and 0.5.