Patent ID: 8198480

Claim:
A method of producing a fluoropolymer, wherein a fluoroalkylcarboxylic acid derivative which is represented by the general formula (ii): Rf 1 (OCH 2 CF 2 CF 2 ) n1 OCHX 1 CF 2 (Rf 2 ) n2 COOM (ii) wherein Rf 1 represents a straight or branched fluoroalkyl group containing 1 to 20 carbon atoms, said fluoroalkyl group may optionally contain 1 to 5 oxygen atoms in the principal chain thereof, Rf 2 represents a straight or branched fluoroalkylene group containing 1 to 25 carbon atoms, said fluoroalkylene group may optionally contain 1 to 5 oxygen atoms in the principal chain thereof, n1 represents an integer of 0 to 3, n2 represents an integer of 0 or 1, X 1 represents hydrogen atom or fluorine atom, and M represents NH 4 or a monovalent metal element, is used as a surfactant in carrying out a polymerization in an aqueous medium.