Process for reducing the amount of fluorinated surfactant in aqueous fluoropolymer dispersions

摘要

The present invention provides a process of reducing the amount of fluorinated emulsifier in an aqueous fluoropolymer dispersion by contacting the aqueous fluoropolymer dispersion with an anion exchange resin in a non-fixed resin bed, the process comprising:(a) mixing the aqueous fluoropolymer dispersion with an effective amount of a surfactant so as to stabilize the fluoropolymer dispersion while being contacted with the anion exchange resin;(b) contacting the aqueous fluoropolyrner dispersion with an anion exchange resin by agitating the aqueous fluoropolymer dispersion with an effective amount of anion exchange resin for a time of less than 4 hours to reduce the amount of fluorinated emulsifier in the aqueous fluoropolymer dispersion to a desired level; and(c) separating the anion exchange resin from the aqueous fluoropolymer dispersion.