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:
Dec. 23, 2008
Filed:
Aug. 09, 2004
Hiromoto Ohno, Kawasaki, JP;
Tatsuharu Arai, Kawasaki, JP;
Hiromoto Ohno, Kawasaki, JP;
Tatsuharu Arai, Kawasaki, JP;
Show A Denko K.K., Tokyo, JP;
Abstract
A process for producing hexafluoroethane, comprising a step of distilling a crude hexafluoroethane containing chlorine compounds each having two carbon atoms to distill out hexafluoroethane as a top flow from the top of a distillation column and separate a hexafluoroethane mixture containing the chlorine compounds as a bottom flow from the bottom, and a step of contacting the bottom flow with hydrogen fluoride in the gas phase at a temperature of 300 to 500° C. in the presence of a fluorination catalyst to fluorinate the chlorine compounds. This process provides hexafluoroethane which can be used mainly as a cleaning gas in the production process of a semiconductor device.