CPC B01D 19/0409 (2013.01) [C11D 3/0026 (2013.01); C11D 3/373 (2013.01); D21C 3/28 (2013.01); D21H 17/59 (2013.01); D21H 21/12 (2013.01); C08K 2003/329 (2013.01)] | 17 Claims |
1. A defoamer formulation, comprising:
(1) organopolysiloxane(s) containing per molecule at least one structural unit of formula
O1/2R2Si—Y—SiRO2/2 (I)
and at least 2 units of formula
R1R2 SiO1/2 (II)
and units of general formula
R2SiO2/2 (III),
wherein
R each is identical or different and represents a monovalent SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms which may contain one or more nonadjacent oxygen atoms and which is free from aliphatic carbon-carbon multiple bonds and
R1 each is R or an alkenyl radical having 2 to 30 carbon atoms, wherein at least one alkenyl radical per molecule is present,
Y each individually represents a divalent hydrocarbon radical having 2 to 30 carbon atoms, with the proviso that the organopolysiloxane contains a structural element of formula
R2Y2SiO—(SiR2O)x1—SiRY1O—(SiR2O)x2—SiR2R1 (IV),
wherein
R and R1 are as defined above,
Y1 each individually represents a divalent hydrocarbon radical having 2 to 30 carbon atoms which is bonded to a group having the formula SiR2O1/2,
Y2 each individually represents a divalent hydrocarbon radical having 2 to 30 carbon atoms which is bonded to a group having the formula SiRO2/2, and
x1 and x2 is 0 or a positive integer,
with the proviso that the sum of x1+x2 is x,
wherein x is on average more than 5, and less than 100,
(2) fillers,
(3) organopolysiloxane resin(s) composed of units of formula
R2e(R3O)fSiO(4-e-f)/2 (V),
wherein
R2 each is identical or different and represents a hydrogen atom or a monovalent, optionally substituted, SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms,
R3 each is identical or different and represents a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 4 carbon atoms,
e is 0, 1, 2 or 3 and
f is 0, 1, 2, or 3,
with the proviso that the sum of e+f is not more than 3 and that the sum of e+f is 2 in less than 50% of all units of formula (V) in the organopolysiloxane resin,
(4) silanol-containing organopolysiloxane(s) of the formula
XSiR42O—(SiR42O)n—SiR42X (VI)
wherein
R4 each is identical or different and represents a monovalent SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms, which may contain one or more nonadjacent oxygen atoms, and
X each is a hydrogen atom, an optionally substituted C1-C18-hydrocarbon radical, a C1-C18-alkoxy group or a hydroxyl group —OH,
n has integral values between 0 and 1000,
with the proviso that on average 30 to 60 mol %, of the groups X correspond to hydroxyl groups —OH,
wherein the silanol-containing organopolysiloxanes may also contain small proportions of branchings, as T units (R4SiO3/2) and/or Q units (SiO2), wherein small proportions signify 0 to 1 mol %, based on the sum of all siloxane units in the organopolysiloxane, and
(5) at least one inorganic or organic acid.
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