Patent ID: 8937112
Filing Date: 2015-01-20
Classification: C08K,C08L,C09D

Abstract:
1. A process for reducing the fluorosurfactant content of and concentrating an aqueous fluorosurfactant-containing fluoropolymer dispersion comprising: stabilizing fluoropolymer dispersion comprising fluoropolymer particles having an average size of about 10 to about 400 nm and a solids content of about 15 to about 55 wt % with anionic polyelectrolyte dispersing agent; contacting said stabilized fluorosurfactant-containing aqueous fluoropolymer dispersion with an anion exchange resin to reduce fluorosurfactant content to a predetermined level; separating said anion exchange resin from said dispersion after the fluorosurfactant content has been reduced to produce a reduced-fluorosurfactant dispersion; and concentrating said dispersion to at least about 35% by weight using a method which produces dispersion substantially free of nonionic surfactants; wherein said concentrated reduced fluorosurfactant dispersion comprises less than about 300 ppm fluorosurfactant.