Patent ID: 8362168

Claim:
An aqueous fluoropolymer dispersion comprising a dispersed fluoropolymer particle with an average primary particle diameter of 50 to 400 nm, a surface layer of the dispersed fluoropolymer particle being obtained by emulsion polymerization of a tetrafluoroethylene-containing monomer composition in the presence of a chain transfer agent, a fluorinated surfactant content being not higher than 50 ppm, a fluoropolymer content being 20 to 75% by mass, and a nonfluorinated nonionic surfactant content is 2 to 15% by mass relative to 100% by mass of the fluoropolymer, wherein the dispersed fluoropolymer particle has a core-shell structure, the shell is obtained by emulsion polymerization of the tetrafluoroethylene-containing monomer composition in the presence of the chain transfer agent, and the core and the shell are obtained from one and the same monomer composition and are different in number average molecular weight, or the core and the shell are obtained from different monomer compositions and are different in number average molecular weight.