Patent ID: 7105581

Claim:
An antifoam formulation comprising: (A) at least one siloxane antifoam based on siloxane composition, and (B) at least one branched polyether/polysiloxane copolymer comprising structural elements of the formula Y[—C n H 2n —(R 2 SiO) m —A p —R 2 Si—G] x (I) in which Y is a trivalent to decavalent, hydrocarbon radical optionally containing one or more hetero atoms selected from the group consisting of the oxygen, nitrogen and silicon, R are identical or different monovalent, optionally halogenated hydrocarbon radicals having 1 to 18 carbon atoms per radical, A is a radical of the formula —R 2 Si—R 2 —(R 2 SiO) m —, in which R 2 is a divalent hydrocarbon radical which has 2 to 30 carbon atoms and may be interrupted by one or more non-adjacent oxygen atoms, G is a monovalent radical of the formula —C f H 2f-2k —Z, or a divalent radical of the formula —C n H 2n — in which the second bond is to a further radical Y, Z is a radical of the formula —(R 6 ) v —(OCH 2 CH 2 ) a [OCH 2 CH(CH 3 )] b [OCH 2 CH(CH 2 CH 3 )] c —OR 3 , in which R 3 is a hydrogen atom, a hydrocarbon radical having 1 to 18 carbon atoms, or a radical of the formula R—C(O)—, R 6 is a divalent hydrocarbon radical having 1 to 10 carbon atoms, v is 0 or 1, a, b and c are 0 or an integer between 1 and 1000, with the proviso that the sum (a+b+c) has a value of from 2 to 2000, x is an integer from 3 to 10, f is an integer from 2 to 12, k is 0 or 1, n is an integer from 2 to 12, m is an integer of at least 1, and p is 0 or a positive integer, with the proviso that the branched polyether/polysiloxane copolymers (B) contain on average at least one group Z.