Polyurethane dispersions having improved film forming properties

Preparation of aqueous N-methylpyrrolidone- and solventfree polyurethane- dispersion coating agent, comprises: reacting isocyanate-prepolymer solution (66-98 wt.%) in a normal pressure boiling point of below 100[deg]C with e.g. one or more polyisocyanate, dispersing the mixture in water, chain elongation with one or more polyamine with M n of 500, and removing the solvent completely by distillating; an ethylene- or propylene glycol ether (1-7 wt.%); and further lacquer additives, where by mixing the component to form polyurethane dispersion. Preparation of aqueous N-methylpyrrolidone- and solventfree polyurethane- dispersion coating agent, comprises: reacting isocyanate-prepolymer solution (66-98 wt.%) in a normal pressure boiling point of below 100[deg]C with one or more polyisocyanate, polyol with average molecular weight (M n) of 500-6000, another polyol with M n of 62-500, ionic group compound or developed ionic group, dispersing the mixture in water, when dispersing or after dispersing results in partial neutralization of ionic group, chain elongation with one or more polyamine with M n of 500, and removing the solvent completely by distillating; an ethylene- or propylene glycol ether (1-7 wt.%); and further lacquer additives, where by mixing the component to form polyurethane dispersion. An independent claim is included for an aqueous N-methylpyrrolidone- and solventfree polyurethane- dispersion coating agent, is obtained by the process.