Patent ID: 8623957

Claim:
Method of making fluoropolymers by emulsion polymerization of one or more fluorinated monomers in an aqueous phase in the presence of a fluorinated emulsifier, said method comprises adding a doping agent in a weight ratio with respect to the emulsifier of from about 1:2 to about 1:20, said doping agent has a melting point of equal or less than 30° C. and a boiling point of at least about 100° C. and is selected from the group consisting of (iii) fluorinated alkenes of the formula F 3 C—C(R d f )═C(R e f )(R f f ) (II), (iv) fluorinated polyoxyalkanes of the formula R g f —O—R h f —O—R i f (III), wherein R d f and R e f are independently fluorinated alkyl groups of 1 to 6 C-atoms, R f f is F or a fluorinated alkyl group of 1 to 6 C-atoms, R g f and R i f are independently fluorinated alkyl groups of 2 to 5 C-atoms and R h f is a branched perfluorinated alkylene group of 2 to 4 C-atoms.