| 摘要 |
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° and 80° 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 muS/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 </SUB>in the range CP±10° C.; decantation without stirring, at the temperature T<SUB>c</SUB>, 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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