Patent ID: 7550514

Claim:
A defoamer composition comprising: (A) at least one organosilicon compound comprising units of the formula R a (R 1 O) b R 2 c SiO (4-a-b-c)/2 (I) in which R each, independently denotes hydrogen or a monovalent, optionally substituted, SiC-bonded linear aliphatic hydrocarbon radical, R 1 each, independently denotes hydrogen or a monovalent, optionally substituted hydrocarbon radical, R 2 each, independently denotes a monovalent, SiC-bonded, optionally substituted, aliphatic cyclic or aliphatic branched hydrocarbon radical having at least 3 carbon atoms, a is 0, 1, 2 or 3, b is 0, 1, 2 or 3, c is 0, 1 or 2 with the proviso that the sum a+b+c≦3, the organosilicon compound has at least one unit of the formula (I) with c other than 0, and in at least 50% of all of the units of the formula (I) in the organosilicon compound the sum a+b+c is 2; (B) at least one additive (B1) and/or (B2): (B1) filler particles, (B2) organopolysiloxane resin(s) comprising units of the formula R 3 d (R 4 O) e SiO (4-d-e)/2 (II) in which R 3 each, independently denotes hydrogen or a monovalent, optionally substituted, SiC-bonded hydrocarbon radical, R 4 each, independently denotes hydrogen or a monovalent, optionally substituted hydrocarbon radical d is 0, 1, 2 or 3 and e is 0, 1, 2 or 3, with the proviso that the sum d+e≦3 and in less than 50% of all of the units of the formula (II) in the organopolysiloxane resin the sum d+e is 2, and (C) optionally, one ore more organosilicon compound(s) comprising units of the formula R 5 g (R 6 O) h SiO (4-g-h)/2 (III) in which R 5 each, independently denotes hydrogen or a monovalent, optionally substituted, SiC-bonded aromatic or linear aliphatic hydrocarbon radical, R 6 each, independently denotes hydrogen or a monovalent, optionally substituted hydrocarbon radical, g is 0,1, 2 or 3 and h is 0, 1, 2 or 3, with the proviso that the sum g+h≦3 and in at least 50% of all of the units of the formula (III) in the organosilicon compound the sum g+h is 2.