Defoaming compositions for detergents

Defoamer powders, comprising:

• (A) 100 parts by weight of a defoamer formulation comprising
• (Aa) a polysiloxane containing units of formula (I)
• wherein R1 may be identical or different and is a monovalent, optionally branched, SiC-bonded hydrocarbon radical having 1 to 5 carbon atoms, and
• wherein R2 may be identical or different and is a monovalent, optionally branched, SiC-bonded hydrocarbon radical having 6 to 30 carbon atoms,
• (Ab) a filler,
• (Ac) an organopolysiloxane resin composed of units of the general formula
• wherein R3 may be identical or different and is a monovalent, optionally substituted, SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms,
• wherein R4 may be identical or different and is a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 4 carbon atoms,
• wherein a is 0, 1, 2 or 3,
• wherein b is 0, 1, 2 or 3, and
• wherein the sum total of a+b is ≤3 and in less than 50% of all units of formula (II) in the organopolysiloxane resin the sum total of a+b=2,
• (Ad) optionally a further organopolysiloxane consisting of units of formula (III) and (IV)
• wherein R1 has the definition as described above,
• wherein R5 may be identical or different and may be R1 or —OR6,
• wherein R6 is a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 25 carbon atoms,
• (Ae) optionally water-insoluble organic compounds,
• (Af) optionally an alkaline or acidic catalyst or the reaction product thereof with components (Aa) to (Ad);
• (B) 10 to 45 parts by weight, based on 100 parts by weight of the defoamer formulation (A), of a waxy additive containing a monoester (B′) of glycerol and a fatty acid that is free of a polysiloxane-containing additive and that contains less than 5% by weight of a triester (B″) of glycerol and a fatty acid;
• (C) 10 to 50 parts by weight, based on 100 parts by weight of the defoamer formulation (A), of a polycarboxylate binder that has a pH of 3 or less when it is dissolved in water;
• and
• (D) 120 to 5000 parts by weight, based on 100 parts by weight of the defoamer formulation (A), of at least one pulverulent carrier material, with the proviso that the carrier material contains less than 50% by weight of alkaline carrier material, preferably less than 40% by weight of alkaline carrier material, more preferably less than 25% by weight of alkaline carrier material.

A process for producing defoamer powders, comprising:

• a premix, preferably in the form of a dispersion, of defoamer formulation (A), waxy additive (B) and binder (C) is produced,
• wherein (A) is 100 parts by weight of a defoamer formulation comprising
• (Aa) a polysiloxane containing units of formula (I)
• wherein R1 may be identical or different and is a monovalent, optionally branched, SiC-bonded hydrocarbon radical having 1 to 5 carbon atoms, and
• wherein R2 may be identical or different and is a monovalent, optionally branched, SiC-bonded hydrocarbon radical having 6 to 30 carbon atoms,
• (Ab) a filler,
• (Ac) an organopolysiloxane resin composed of units of the general formula
• wherein R3 may be identical or different and is a monovalent, optionally substituted, SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms,
• wherein R4 may be identical or different and is a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 4 carbon atoms,
• wherein a is 0, 1, 2 or 3,
• wherein b is 0, 1, 2 or 3, and
• wherein the sum total of a+b is ≤3 and in less than 50% of all units of formula (II) in the organopolysiloxane resin the sum total of a+b=2,
• (Ad) optionally a further organopolysiloxane consisting of units of formula (III) and (IV)
• wherein R1 has the definition as described above,
• wherein R5 may be identical or different and may be R1 or —OR6,
• wherein R6 is a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 25 carbon atoms,
• (Ae) optionally water-insoluble organic compounds,
• (Af) optionally an alkaline or acidic catalyst or the reaction product thereof with components (Aa) to (Ad),
• wherein (B) is 10 to 45 parts by weight, based on 100 parts by weight of the defoamer formulation (A), of a waxy additive containing a monoester (B′) of glycerol and a fatty acid that is free of a polysiloxane-containing additive and that contains less than 5% by weight of a triester (B″) of glycerol and a fatty acid,
• wherein (C) is 10 to 50 parts by weight, based on 100 parts by weight of the defoamer formulation (A), of a polycarboxylate binder that has a pH of 3 or less when it is dissolved in water, and
• wherein (D) is 120 to 5000 parts by weight, based on 100 parts by weight of the defoamer formulation (A), of at least one pulverulent carrier material, with the proviso that the carrier material contains less than 50% by weight of alkaline carrier material, preferably less than 40% by weight of alkaline carrier material, more preferably less than 25% by weight of alkaline carrier material;
• and
• mixing the premix with the pulverulent carrier material.