Patent ID: 8461213

Claim:
A thickener comprising an aqueous preparation of a nonionic water-dispersible or water-soluble polyurethane, prepared by the process comprising the step of reacting a mixture comprising: (a) one or more hydrophilic polyols which contain, per molecule, at least two OH groups and at least two functional groups selected from the group consisting of —O— (ether groups) and —COO— (ester groups), wherein the molecular weight of these hydrophilic compounds is at least 300, (b) one or more compounds of the formula (I) wherein R is a C 15 H 31 , group, and wherein m has a value of 0, 2, 4 or 6, Y is hydrogen or a methyl group and n is a number in the range from 0 to 10, and (c) one or more difunctional isocyanates, wherein the compounds (a), (b) and (c) are reacted with one another in the equivalent ratios OH (a) :OH (b) :NCO (c) of 1:(1+x):2(1+y), and wherein: x is a number in the range from 0.05 to 1.2, y is a number in the range from (0.2 to 1.05) x , and equivalent ratio NCO (c) >(OH a) +OH b) ).