Patent ID: 7026429

Claim:
Hydrophilic polyurethane (PU) prepolymers comprising a polymer backbone with structural units of formula (I), in which R 1 and R 2 independently of one another represent the radicals H, C 1 –C 20 -(cyclo)alkyl, C 6 –C 24 -aryl, C 1 –C 20 -(cyclo)alkyl ester or amide, C 6 –C 24 -aryl ester or amide, mixed aliphatic/aromatic radicals having 1 to 24 carbon atoms, which may also be part of a 4- to 8-membered ring, and X is an electron-withdrawing group, n is an integer from 0 to 5, and also having structural units of polymeric polyols with a number average molecular weight range from 400 to 6000, the polymer backbone possessing ionic or potentially ionic and/or nonionically hydrophilizing groups.