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Abstract

A process for preparing fluoropolymer dispersions, substantially free from anionic fluorinated surfactants, and with a coagulum amount <0.1% by weight, comprising:a) step a1) addition of: a non ionic surfactant having cloud point (CP) between 40.degree. and 80.degree. C., in an amount from 1.5% to 50% by weight on the dispersion fluoropolymer; and optionally an electrolyte to bring the specific conductivity of the dispersion to values in the range 130-8,000 .mu.S/cm; optionally a buffer agent to have a pH between 2 and 12 to a fluoropolymer dispersion obtainable by an emulsion polymerization process; step a2): heating of the dispersion obtained in a1) up to a temperature T.sub.c in the range CP.+-.10.degree. C.; decantation without stirring, at the temperature T.sub.c, until obtaining the dispersion separation in two aqueous phases, of which the lower one containing the fluoropolymer is discharged; b) step b1): the dispersion obtained in step a2) is optionally additioned of an electrolyte and of a non ionic surfactant as in a1).

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First Claim