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US 10,870,071 B2Granted
Defoaming formulations containing organopolysiloxanes
AssigneeWacker Chemie AG
InventorsChristof Brehm, Willibald Burger, Wolfgang Ziche
Life of this patent
Estimating the term…
Abstract
Defoamer compositions containing a plurality of defined organopolysiloxanes exhibit very short initial foam collapse and yet exhibit long lasting defoaming activity when added to aqueous media prone to foaming.
Claims22
A defoamer formulation, comprising:
- (1) at least one organopolysiloxane containing per molecule at least one structural unit of formula
- O1/2R2Si—Y-SiRO2/2 (I)
- at least 2 units of formula
- R1R2SiO1/2 (II)
- and units of formula
- R2SiO2/2 (III),
- wherein
- R each is identical or different and is a monovalent SiC-bonded hydrocarbon radical having
- 1 to 30 carbon atoms which optionally contains one or more nonadjacent O-atoms and which is free from aliphatic carbon-carbon multiple bonds and
- R1 each is identical or different and is R or an alkenyl radical having 2 to 30 carbon atoms, wherein at least one alkenyl radical per molecule is present,
- Y each is an identical or different divalent hydrocarbon radical having 2 to 30 carbon atoms,
- with the proviso that the at least one organopolysiloxane contains a structural element of formula
- R2Y2SiO—(SiR2O)x1—SiRY1O—(SiR2O)x2—SiR2R1 (IV),
- wherein
- R and R1 are as defined above,
- Y1 is a divalent hydrocarbon radical having 2 to 30 carbon atoms which is bonded to a group having the formula SiR2O1/2,
- Y2 is 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 are, independently, 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, and
- (3) organopolysiloxane resins comprising units of formula
- R2e(R3O)fSiO(4-e-f)/2 (V),
- wherein
- R2 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 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.
26 more elements
Dependencies are inferred from the claim text.