Preparation of hydrophilic coating

Claim 1

A process for placing on a polymer surface a hydrophilic coating which has a low coefficient of friction when wetted with a water-based liquid, which consists essentially of applying to the polymer surface a solution which consists essentially of an organic solvent and between 0.05 to 40% (weight to volume) of an isocyanate monomer having at least two unreacted isocyanate groups per molecule, or an isocyanate pre-polymer thereof having up to 5 monomer units, or a mixture of such monomers and pre-polymers, evaporating the solvent, applying a second solution consisting essentially of a solvent between 0.5 to 10% (weight to volume) of polyvinylpyrrolidone containing an amine catalyst in an amount between 0.1 and 50% by weight to the thus treated polymer surface and then evaporating the solvent of the second solution, and curing the coating in the presence of a water-containing gas at elevated temperature; and, wherein said polymer is selected from the group consisting of rubber, latex rubber, vinylpolymers, polyesters, and polyacrylates.