Abstract: Mixture comprising, on the one hand, an aqueous dispersion of a copolymer (A) containing in interpolymerized form:1. 30% to 99% by weight of one or more monomers of the formula: ##STR1## in which Rf represents a perfluoro chain, straight or branched, containing 1 to 20, preferably 2 to 10 carbon atoms, a is a whole number between 2 and 20 inclusive, preferably equal to 2 or 4, R represents a hydrogen atom or an alkyl group containing 1 to 10 carbon atoms, a cycloalkyl group containing 5 to 12 carbon atoms, an hydroxyalkyl group containing 2 to 4 carbon atoms or an aryl group possibly substituted by an alkyl radical containing 1 to 6 carbon atoms, R', R", X and X' may be the same or different and represent hydrogen atoms or alkyl groups containing 1 to 4 carbon atoms, b is a whole number between 1 and 4 inclusive, preferably equal to 1 or 2, and Y represents the residue of an alkene-mono- or -di-carboxylic acid or a monoalkyl ester of such a dicarboxylic acid;2.