Patent · US Expired

Process for the recovery of mixtures of chlorotetrafluoroethane and octafluorocyclobutane

US5129997A · kind A · utility

10Cited by

6References

5Claims

0Family size

Assignee

Hoechst GmbH · DE

Inventors

Thomas Schottle · Burghausen, DE
Herbert Weber · Backnang, DE
Werner Dostler · Mühldorf a. Inn, DE
Karl Rettenbeck · Altötting, DE

Key dates

Filing date	Apr 10, 1991
Grant date	Jul 14, 1992
Priority date	—
Expiry date	Apr 10, 2011

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10S203/20
WIPO fieldOrganic fine chemistry
WIPO sectorChemistry

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.