| abstract |
An antifoam formulations comprise n (A) antifoam agent based on siloxanes and n (B) branched polyether/polysiloxane copolymers comprising structural units of the formula n Y[—C n H 2n —(R 2 SiO) m —A p —R 2 Si—G] x (I) n in which Y is a multivalent, optionally heteroatom-containing hydrocarbon radical, R are monovalent optionally halogenated hydrocarbon radicals, A is a radical —R 2 Si—R 2 —(R 2 SiO)m—, G is a monovalent radical —C f H 2f-2k —Z or a divalent radical —C n H 2n — bonded to a radical Y, Z n —(R 6 ) v —(OCH 2 CH 2 ) a [OCH 2 CH(CH 3 )] b [OCH 2 CH(CH 2 CH 3 )] c —OR 3 , n in which R 3 is hydrogen, a hydrocarbon radical, or a radical R—C(O)—, R 6 is a divalent hydrocarbon radical, v is 0 or 1, a, b and c are 0 or an integer between 1 and 1000, the sum (a+b+c) being from 2 to 2000, x is 3 to 10, f is 2 to 12, k is 0 or 1, n is 2 to 12, m is at least 1, and p is 0 or a positive integer, the branched polyether/polysiloxane copolymers (B) containing on average at least one group Z. |