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. 22, 1995
Filed:
Oct. 15, 1992
Hiromoto Ohno, Kawasaki, JP;
Toshio Ohi, Kawasaki, JP;
Hidetoshi Nakayama, Kawasaki, JP;
Kazuo Muramaki, Kawasaki, JP;
Showa Denko Kabushiki Kaisha, Tokyo, JP;
Abstract
In the production of 1,1,1,2-tetrafluoroethane by reacting trichloroethylene with hydrogen fluoride, crude 1,1,1,2-tetrafluoroethane is highly purified by a method comprising subjecting the crude 1,1,1,2-tetrafluoroethane to preliminary purification to remove hydrogen chloride to a concentration of not higher than 2%, and bring the preliminarily purified 1,1,1,2-tetrafluoroethane containing one or more unsaturated impurities and hydrogen fluoride in an amount at least equimolar to the unsaturated impurities into contact with a fluorination catalyst in a vapor phase to decrease the content of the unsaturated impurities.