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:
Apr. 06, 1993
Filed:
Aug. 21, 1991
Applicant:
Inventors:
Pravin K Dattani, Hockessin, DE (US);
John D Scott, Cheshire, GB;
Barry W Farrant, Lancashire, GB;
Charles J Shields, Cheshire, GB;
Assignee:
Imperial Chemical Industries PLC, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
570178 ; 203 64 ;
Abstract
Method for separating 1,1,1,2-tetrafluoroethane from a mixture thereof with chlorine-containing halogenated hydrocarbons such as HCFC's 1122, 124, 114, 114a and 133a which comprises adding an extraction agent to the mixture and extractively distilling the mixture in an extractive distillation zone from which HFA 134a containing less than 10 ppm of chlorinated contaminants is recovered. Suitable extraction agents include trichloroethylene, perchloroethylene, alpha-pinene and cyclohexane.