Fluorinated graft cation exchange copolymers

Claim 2

An ion exchanger which comprises a water-insoluble copolymer prepared by post-polymerizing at least one fluoroolefin monomer selected from the group consisting of tetrafluoroethylene, trifluoroethylene, trifluorochloroethylene, hexafluoropropylene, vinylidene fluoride and vinyl fluoride to a perfluorovinylacetic acid-vinylidene fluoride copolymer containing not less than 25% by mole of the perfluorovinylacetic acid unit in an aqueous solution of said perfluorovinylacetic acid-vinylidene fluoride copolymer in the presence of an organic or inorganic peroxide polymerization initiator wherein the proportion of the post-polymerized fluoroolefin monomer is from 5 to 60% by weight based on the weight of said perfluorovinylacetic acid-vinylidine fluoride copolymer.

Claim 3

The ion exchanger of claim 1, wherein said perfluorovinylacetic acid-vinylidene fluoride copolymer contains 25 to 50% by mole of the perfluorovinylacetic acid unit.

Claim 4

The ion exchanger of claim 1, wherein the post-polymerization is carried out at a temperature of 0° to 150° C. under an autogeneous pressure of said monomer or a pressure of less than the autogeneous pressure.

Claim 5

The ion exchanger of claim 1, wherein said proportion is from 20 to 40% by weight.

Claim 6

The ion exchanger of claim 1, wherein said perfluorovinylacetic acid-vinylidene fluoride copolymer containing not less than 25% by mole of the perfluorovinylacetic acid unit is prepared by copolymerizing vinylidene fluoride and perfluorovinylacetic acid in the presence of an organic or inorganic peroxide polymerization initiator at a temperature of 0° to 150° C. under an autogeneous pressure of vinylidene fluoride or a pressure of less than the autogeneous pressure.

Claim 7

The ion exchanger of claim 5, wherein the copolymerization is carried out in the presence of a small amount of an iodine-containing saturated or unsaturated halogenated hydrocarbon.

Claim 8

The ion exchanger of claim 6, wherein said iodine-containing saturated or unsaturated halogenated hydrocarbon is a member selected from the group consisting of 4-iodo-5-chloroperfluoropentene-1, 1-iodoperfluoropropane and 1-iodoperfluorobutane.

Claim 9

A process for preparing an ion exchanger which comprises after-polymerizing at least one fluoroolefin monomer selected from the group consisting of tetrafluoroethylene, trifluoroethylene, trifluorochloroethylene, hexafluoropropylene, vinylidene fluoride and vinyl fluoride to a perfluorovinylacetic acid-vinylidene fluoride copolymer containing not less than 25% by mole of the perfluorovinylacetic acid unit in an aqueous solution of said perfluorovinylacetic acid-vinylidene fluoride copolymer in the presence of an organic or inorganic peroxide polymerization initiator at a temperature of 0° to 150° C. under an autogeneous pressure of said monomer or a pressure of less than the autogeneous pressure, the proportion of the post-polymerized monomer being from 5 to 60% by weight based on the weight of said perfluorovinylacetic acid-vinylidene fluoride copolymer.

Claim 10

A process for preparing an ion exchanger which comprises after-polymerizing at least one fluoroolefin monomer selected from the group consisting of tetrafluoroethylene, trifluoroethylene, trifluorochloroethylene, hexafluoropropylene, vinylidene fluoride and vinyl fluoride to a perfluorovinylacetic acid-vinylidene fluoride copolymer containing not less than 25% by mole of the perfluorovinylacetic acid unit in an aqueous solution of said perfluorovinylacetic acid-vinylidene fluoride copolymer in the presence of an organic or inorganic peroxide polymerization initiator at a temperature of 0° to 150° C. under an autogeneous pressure of said monomer or a pressure of less than the autogeneous pressure, the proportion of the post-polymerized monomer being from 5 to 60% by weight based on the weight of said perfluorovinylacetic acid-vinylidene fluoride copolymer.

Claim 11

The process of claim 8, wherein said perfluorovinylacetic acid-vinylidene fluoride copolymer is prepared by copolymerizing vinylidene fluoride and perfluorovinylacetic acid in the presence of an organic or inorganic peroxide polymerization initiator at a temperature of 0° to 150° C. under an autogeneous pressure of vinylidene fluoride or a pressure of less than the autogeneous pressure.

Claim 12

The process of claim 9, wherein the copolymerization is carried out in the presence of a small amount of an iodine-containing saturated or unsaturated halogenated hydrocarbon selected from the group consisting of 4-iodo-5-chloroplerfluoropentene-1, 1-iodoperfluoropropane and 1-iodoperfluorobutane.