Patent ID: 7807725

Claim:
A method of suppressing a foam in a liquid medium, the method comprising adding at least one cationic poly(ether-urethane) to the liquid medium to suppress the foam in the liquid medium, wherein the at least one cationic poly(ether-urethane) comprises monomer units of a) 50 to 90% by weight of at least one polyetherol, as component A; b) 1 to 10% by weight of at least one quaternary amine-comprising, tertiary amine-comprising and/or ammonium-comprising diol, as component B; c) 9 to 25% by weight of at least one diisocyanate as component C; and d) 0.1 to 10% by weight of at least one short-stopper, as component D; wherein the total sum of components A, B, C, and D is 100% by weight, wherein the cationic poly(ether-urethane) has an amine number of from 5 to 40 and a K-value according to Fikentscher of from 15 to 40; wherein the liquid medium comprises at least one anionic surfactant, and optionally, further auxiliaries and additives, and wherein, when only the tertiary amine-comprising diol is employed as the component B, after incorporating components A-D as monomers in a polymer, the tertiary amine in the tertiary amine-comprising diol monomer is either protonated or quaternized to form the at least one cationic poly(ether-urethane).