Patent ID: 6858663

Claim:
A method for defoaming aqueous media which comprises adding to the aqueous media an organopolysiloxane derivative of the general average formula (I) where the radicals R 1 are alky radicals or aryl radicals, but at least 80% of the radicals R 1 are methyl radicals, R 2 in the molecule are identical or different and have the following definitions: in which R 3 is a hydrogen or alkyl radical, R 4 is a hydrogen, alkyl or carboxyl radical, c is a number from 1 to 20, d is a number from 0 to 50, e is a number from 0 to 50 or (b) —(CH 2 —) f OR 5 , in which R 5 is a hydrogen, alkyl or carboxyl radical or a dimethylol propane radical containing ether groups if desired, and f is a number from 2 to 20 or c) —(CH 2 —) g (OC 2 H 4 —) h (OC 3 H 6 —) i (OC 4 H 8 ) j (OCH 2 CH(C 6 H 5 )) k OK 6 in which R 6 is a hydrogen, alkyl or carboxyl radical, g is a number from 2 to 6, h is a number from 0 to 20, i is a number from 1 to 50, j is a number form 0 to 10, k is a number from 0 to 10 or (d) correspond to the radical R 1 , with the proviso that in the average molecule at least one radical R 2 has the definition (a), a is a number from 1 to 500, b is a number from 0 to 10. and wherein the water solubility of the organopolysiloxane is such that it forms a clear solution in water in an amount not more than 20 g/l at 25° C.