Novel polymers having acid functionality

Claim 1

A polymerization process for the preparation of polymers from ethylenically unsaturated monomers wherein at least one monomer of a first group is selected from tetrafluoroethylene, trifluoromonochloroethylene, trifluoroethylene, vinylidene fluoride, l,l-difluoro-2,2--dichloroethylene, l,l-difluoro-2-chloroethylene, hexafluoropropylene, 1,1,1,3,3-pentafluoropropylene, octafluoroisobutylene ethylene, vinylchloride, trifluoronitrosomethane, perfluoronitrosoethane and alkyl vinyl ether; the improvement which comprises employing as a co-monomer at least one monomer selected from a second group represented by the general formula: where: Y is an acid group or a group easily convertible to an acid group; a is zero or an integer greater than zero; b is zero or an integer greater than zero; c is 0 or 1; a + b + c # 0; X is Cl, Br, F, or mixtures thereof when n > 1; n is zero or an integer greater than zero; and R f and R' f are independently selected from the group consisting of F, Cl, perfluoroalkyl radical and fluorochloro- alkyl radical; and employing at least one monomer selected from a third group of monomers represented by the general formula: where: Y' is Cl or Br; a' is zero or an integer greater than zero; b' is zero or an integer greater than zero; c' is zero or one; a' + b l + c'≠ 0; X' is F, Cl, Br, or mixtures thereof when n' > 1; n' is zero or an integer greater than zero; and R f and are independently selected from the group consisting of F, Cl, a perfluoroalkyl radical and a chloroperfluoro alkyl radical; provided that when Y is a carboxylic acid group or a group easily convertible to a carboxylic acid group, n is one or an integer greater than one and X is F, n' must be one or an integer greater than one.