Copolymers of hexafluoropropylene vinylidene fluoride and aliphatic, chain transfer agents

Claim 2

COPOLYMERS COMPRISING (A) -CH2-CF2- UNITS,

Claim 3

THE PROCESS FOR PREPARING A COPOLYMER HAVING AN INHERENT VISCOSITY RANGING FROM ABOUT 0.025 TO 0.25 AT 30*C. WHEN DISSOLVED IN AN ANHYDROUS SOLVENT CONSISTING OF 86.1 PERCENT BY WEIGHT, OF TETRAHYDROFURAN AND 13.9 PERCENT BY WEIGHT OF DIMETHYLFORMAMIDE AT A CONCENTRATION OF 0.1 PERCENT BY WEIGHT, WHICH COMPRISES HEATING, AT A TEMPERATURE OF FROM ABOUT 100*C. TO ABOUT 250*C. UNDER AUTOGENOUS PRESURE, A MIXTURE OF (A) VINYLIDENE FLUORIDE, (B) HEAXFLUOROPROPENE AND (C) A CHAIN TRANSFER AGAENT IN CONTACT WITH A NON-METALLIC ORGANIC PEROXIDE, SAID CHAIN TRANSFER AGENT BEING A HALOGEN-FREE, SATURATED ACYCLIC COMPOUND CONTAINING UP TO 8 CARBON ATOMS, SAID ACYCLIC COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF ALCOHOLS, KETONES AND CARBOXYLIC ACID ESTERS.

Claim 4

THE PROCESS FOR PREPARING A COPOLYMER HAVING AN INHERENT VISCOSITY RANGING FROM ABOUT 0.025 TO 0.25 AT 30*C. WHEN DISSOLVED IN AN ANHYDROUS SOLVENT CONSISTING OF 86.1 PERCENT BY WEIGHT, OF TETRAHYDROFURAN AND 13.9 PERCENT BY WEIGHT OF DIMETHYLFORMAMIDE AT A CONCENTRATION OF 0.1 PERCENT BY WEIGHT, WHICH COMPRISES HEATING, AT A TEMPERATURE OF FROM ABOUT 100*C. TO ABOUT 250*C. UNDER AUTOGENOUS PRESURE, A MIXTURE OF (A) VINYLIDENE FLUORIDE, (B) HEAXFLUOROPROPENE AND (C) A CHAIN TRANSFER AGAENT IN CONTACT WITH A NON-METALLIC ORGANIC PEROXIDE, SAID CHAIN TRANSFER AGENT BEING A HALOGEN-FREE, SATURATED ACYCLIC COMPOUND CONTAINING UP TO 8 CARBON ATOMS, SAID ACYCLIC COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF ALCOHOLS, KETONES AND CARBOXYLIC ACID ESTERS.