Patent ID: 8344192

Claim:
A recovering method of a fluoromonomer having a sulfonic acid precursor functional group convertible to a sulfonic acid group and remaining unreacted from an aqueous fluoropolymer dispersion obtained by emulsion polymerization of the fluoromonomer, which comprises recovering the unreacted fluoromonomer from the aqueous fluoropolymer dispersion by heating so as to evaporate the unreacted fluoromonomer, the aqueous fluoropolymer dispersion having an acidic pH, and wherein the aqueous fluoropolymer dispersion is one obtained by emulsion polymerization of the fluoromonomer in an aqueous medium having a pH of not lower than 0.5 but lower than 3.0 or one obtained by emulsion polymerization during which an acidic compound is added to the polymerization system in order to lower the pH of the aqueous medium at the time of completion of the polymerization to the pH at the time of initiation of the polymerization.