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:
Mar. 04, 1997
Filed:
Sep. 26, 1995
Applicant:
Inventor:
Rene Bertocchio, Vourles Par Vernaison, FR;
Assignee:
Elf Atochem S.A., Puteaux, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ; B01J / ; B01J / ;
U.S. Cl.
CPC ...
570179 ; 502 25 ;
Abstract
To remove the traces of chlorofluoromethane present in a difluoromethane, the difluoromethane to be purified is passed over a 13X molecular sieve at a temperature of at least 60.degree. C. The sieve can be regenerated by washing with the aid of a solution of sodium or potassium carbonate and heating to high temperature under inert atmosphere or in vacuum.