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:
Sep. 30, 1997
Filed:
Jul. 05, 1996
Richard Dickinson Chambers, Durham, GB;
Andrew Keith Joel, Preston, GB;
BNFL Fluorochemicals Ltd., , GB;
Abstract
A process for the preparation of a perfluoropolyether having a general formula: ##STR1## as defined hereinbefore, which process includes the direct fluorination with elemental fluorine of a polyether having a general formula: ##STR2## as defined hereinbefore, wherein the fluorination is carried out in the presence of a solvent which is an ether having at least one substituent R.sub.F, wherein R.sub.F is a fluorinated hydrocarbon group. The said solvent ether is preferably a fluorinated volatile ether. The said solvent ether preferably has at least two groups R.sub.F which may be the same or different groups. Each group R.sub.F preferably has from two to four carbon atoms and at least two fluorine atoms. The said solvent ether may be an alicyclic ether having from 3 to 5 carbon atoms in its alicyclic ring. The intermediate polyether of formula (2) may be prepared by a process in which an appropriate straight-chained or cyclic polyether is reacted with an appropriate fluoroalkene in the presence of a sensitising medium and ultra-violet radiation is applied to energise the medium and promote multiple fluorination.