GB918153A - Process for polymerizing fluorine-containing olefines - Google Patents

Abstract

The suspension polymerization of fluorine containing olefines is carried out in the absence of oxygen and in the presence of 0,004 to 0,0001% by weight of the liquor of at least one anionic surface-active perfluoro- or perfluorochlorocarboxylic acid and/or a water-soluble salt or mixture thereof. The process is applicable to the homopolymerization of tetrafluoroethylene or trifluorochloroethylene and to their copolymerization with each other or with vinylidene fluoride and may be effected continuously or discontinuously. The final ratio of liquor to polymer is preferably between 1 and 6 to 1. The pH of the liquor may be between 2,5 and 12, preferably just over 7, and may be adjusted by ammonia, a phosphate or borax as buffer. Suitable catalysts are organic and inorganic peroxidic compounds, e.g. persulphates, percarbonate, perborates, hydroperoxides such as t-butyl or t-aryl-hydroperoxide, or peracteates such as butyl peracetate in amounts of 0,001 to 5 wt. per cent of the monomer; redox catalysts such as bisulphites and thiosulphates; and multivalent metals, e.g. iron or copper or their water-soluble salts, e.g. iron sulphate, citrate or tartate and copper sulphate or chloride. Preferred reaction conditions are 2 to 100 atmospheres gauge and 10 DEG to 150 DEG C. Specification 795,513 is referred to.