Patent ID: 9714307
Date: 2017-07-25
CPC Classifications: C08F,C08L

Claim:
1. A method of making a partially fluorinated polymer dispersion comprising: polymerizing vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene in an aqueous emulsion polymerization in the presence of a polymerizable fluorinated emulsifier to form the partially fluorinated polymer, wherein the polymerizable fluorinated emulsifier has the formula: where X is independently selected from H, F, or CF 3 ; Y is COOM or SO 3 M where M is H, an alkali metal or NH 4 ; m is 0 to 5, n is 0 to 5, p is at least 1, q is 0 to 5, r is 0 to 5, s is 0 to 5, t is 0 to 5, u is 0 to 5, v is 0 to 5, w is 0 or 1, and z is 0 to 5; wherein at least one of m, n, q, s, t, u, v, and z is at least 1; wherein the polymerizable fluorinated emulsifier (a) comprises at least 1 fluorine atom; and (b) is less than 1 wt % based on the total weight of monomers used; and wherein the partially fluorinated polymer comprises less than 30% by weight of vinylidene fluoride, at most 60% by weight of tetrafluoroethylene, and at most 55% by weight of hexafluoropropylene based on the total weight of the partially fluorinated polymers.