Process for producing fluorocopolymer

Abstract

A process for preparing a fluorine containing copolymer by an emulsion polymerization method in the presence of aqueous ammonia as a pH modifier, and a molded article obtainable by melt molding or crosslinking molding the fluorine containing copolymer are disclosed. In preparing the fluorine containing copolymer by coagulation of the fluorine containing copolymer contained in a fluorine containing copolymer dispersed aqueous solution, it is preferred to use a cationic surfactant and a water soluble organic solvent as a coagulating agent used for the above coagulation. The surfactant is preferably represented by the formula (R4N+)X− wherein R is an alkyl group of 1 to 22 carbon atoms, a fluoroalkyl group obtainable by fluorine substituting at least a part of hydrogen atoms present in the above alkyl group or hydrogen, four R's may be the same or different provided that they are not hydrogen atoms simultaneously, and X is a halogen atom. The process for preparing a fluorine containing copolymer provides a decrease in a concentration of metal elements, which act as an impurity source, for example, having a metal element concentration of not more than 1 ppm.

Dependencies are inferred from the claim text.