Compositions comprising anionic ionomeric polyurethanes crosslinkable in a wide temperature range, said composition comprising the following components:

I) an aqueous dispersion of a linear crosslinkable ionomeric polyurethane, containing carboxylic groups and having a perfluoropolyether structure;

II) a crosslinking agent, the ratio between the equivalents of the functional groups of the crosslinking agent and of the carboxylic groups of component I) being at least 0.7 up to 1.5, preferably 0.9-1.2, said crosslinking agent being dispersible or soluble in the dispersion component I).