| abstract |
Aqueous dispersions of polyurethanes which are crosslinkable by the action of high energy radiation contain (a) a polyisocyanate, (b) a polyol having a molecular weight of from 400 to 6,000 g/mol, (c) if required, a polyol having a molecular weight of from 62 to 399 g/mol, (d) if required, a polyamine having two or more amino groups which are reactive to isocyanate, (e) if required, an aminoalcohol having one or more amino groups which are reactive to isocyanate, (f) a compound containing ionic groups or groups which can be converted into ionic groups and one or more hydroxyl or amino groups which are reactive to isocyanate (g) if required, a monofunctional polyetheral and (h) a compound having one or more ethylenically unsaturated groups and one or more hydroxyl groups. The compound having an ethylenically unsaturated group (h) is used in amounts corresponding to 0.02-0.08 gram equivalent, based on the polyisocyanate (a), of OH, and the polyurethane, dissolved in dimethylformamide, has a Fikentscher K value greater than 40 or is insoluble in dimethylformamide. |