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:
Jul. 14, 1992
Filed:
Apr. 10, 1991
Thomas Schottle, Burghausen, DE;
Herbert Weber, Burgkirchen, DE;
Werner Dostler, Mettenheim-Hart, DE;
Karl Rettenbeck, Burgkirchen, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
A process for the preparation of mixtures of chlorotetrafluoroethane and octafluorocyclobutane from the gas stream from the pyrolysis of chlorodifluoromethane at temperatures above 600.degree. C. is described in which the principal constituents tetrafluoroethylene and hexafluoropropylene as well as hydrogen chloride are removed in advance. The mixtures are obtained by withdrawal as a side fraction during the rectifying distillation of the residue remaining, a clean separation of the perfluorocyclobutenes advantageously taking place. The mixtures are used for obtaining hexafluoropropylene by pyrolysis.