GB837764A - Process for the manufacture of unsaturated perfluorochloro-paraffins of low molecular weight - Google Patents

Abstract

Unsaturated perfluorochloroparaffins of low molecular weight are made by polymerizing a perfluorochlorolefin with the aid of a catalyst and in the presence of sulphuryl chloride as chain transfer agent and perchlorethylene as a solvent wherein after the polymerization the excess sulphuryl chloride is hydrolysed by injecting steam into the reaction mixture. As catalysts there may be used organic or inorganic peroxides, e.g. benzoyl peroxide, which may be mixed with a reducing agent and a heavy metal compound such as a compound of iron, cobalt or copper, or alternatively azo-catalysts such as azo-isobutyronitrile may be used. The process may be carried out by batch or continuous operation and the latter may be carried out in two stages: a fast initial reaction and a slower after-reaction. The perfluorochlorolefin, such as trifluorochlorethylene, may be polymerized alone or copolymerized with second or third components such as tetrafluorethylene, trifluorethylene vinylidene fluoride, 1 : 1-difluoro-2 : 2-dichlorethylene, 1 : 2-difluoro-1 : 2-dichlorethyethylene, vinyl methyl ether or perfluoropropylene.