Method of making an aqueous dispersion of fluoropolymers
Assignee3M Innovative Properties Company
InventorsKlaus Hintzer, Gernot Löhr, Albert Killich, Werner Schwertfeger
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Abstract
The invention provides a process for removing steam-volatile fluorinated emulsifiers in their free acid form, from aqueous fluoropolymer dispersions. The process comprises adding a nonionic emulsifier, to the aqueous fluoropolymer dispersion and, at a pH-value of the aqueous fluoropolymer dispersion below 5, removing steam-volatile fluorinated emulsifier by distillation until the concentration of steam-volatile fluorinated emulsifier in the dispersion reaches the desired value.
Claims17
A process for removing steam-volatile fluorinated emulsifiers in their free acid form, from aqueous fluoropolymer dispersions, said process comprising adding a nonionic emulsifier to said aqueous fluoropolymer dispersion and, at a pH-value of said aqueous fluoropolymer dispersion below 5, removing steam-volatile fluorinated emulsifier by distillation until the concentration of steam-volatile fluorinated emulsifier in the fluoropolymer dispersion reaches the desired value.
Dependencies are inferred from the claim text.