Patent ID: 6861466

Claim:
Fluoropolymer dispersion comprising fluoropolymer particles having an average particle size of 10 to 400 nm dispersed in water, said dispersion having a solids content between 35 and 70% by weight, said dispersion being free of fluorinated surfactant having a molecular weight of less than 1000 g/mol or containing said fluorinated surfactant having a molecular weight of less than 1000 g/mol in an amount of not more than 0.05% by weight based on the total weight solids of said dispersion, said dispersion further comprising a non-ionic non-fluorinated surfactant or mixture of non-ionic non-fluorinated surfactants and one or more non-fluorinated anionic surfactants, characterized in that the amount and nature of said non-ionic non-fluorinated surfactant or mixture of non-ionic non-fluorinated surfactants is selected such that the Viscosity Transition Temperature (VTT) of said fluoropolymer dispersion is at least 26° C. and that the fluoropolymer dispersion is essentially free of aromatic group containing non-ionic surfactants.