Abstract: A mixture of unique organopolysiloxane, filler, and additional components are effective defoamers and may be used neat, or in the form of a powder or emulsion.

Abstract: A mixture of unique organopolysiloxane, filler, and additional components are effective defoamers and may be used neat, or in the form of a powder or emulsion.

Abstract: (A) Siloxane-based antifoams and (B) silicone polyethers prepared by reacting organopolysiloxanes (1) containing 0.05% to 1.6% by weight of Si-bonded hydrogen atoms with unsaturated polyethers (3) of the formulae: CH2?CR1—(CH2)aO(C2H4O)bR1??(Ia) CH2?CR1—(CH2)aO(C2H4O)b(C3H6O)cR1??(Ib) CH2?CR1—(CH2)aO(C3H6O)cR1??(Ic), where R1 is a hydrogen or a C1-6 hydrocarbon radical, a is 0 to 16, b is 1 to 50, and c is 1 to 50, wherein the sum b+c is ?10 and at least two different polyethers (Ia), (Ib) and (Ic) are used, and optionally further reacting the reaction product with organopolysiloxanes (2) containing from 0.01% to 0.5% by weight of Si-bonded hydrogen atoms, wherein the first and second step reactions take place with a hydrosilylation catalyst, and the weight ratio of Si-bonded hydrogen in organopolysiloxane (1) to Si-bonded hydrogen in organopolysiloxane (2) is at least 1.5.

Abstract: (A) Siloxane-based antifoams and (B) silicone polyethers prepared by reacting organopolysiloxanes (1) containing 0.05% to 1.6% by weight of Si-bonded hydrogen atoms with unsaturated polyethers (3) of the formulae: CH2?CR1—(CH2)aO(C2H4O)bR1??(Ia) CH2?CR1—(CH2)aO(C2H4O)b(C3H6O)cR1??(Ib) CH2?CR1—(CH2)aO(C3H6O)cR1??(Ic), where R1 is a hydrogen or a C1-6 hydrocarbon radical, a is 0 to 16, b is 1 to 50, and c is 1 to 50, wherein the sum b+c is ?10 and at least two different polyethers (Ia), (Ib) and (Ic) are used, and optionally further reacting the reaction product with organopolysiloxanes (2) containing from 0.01% to 0.5% by weight of Si-bonded hydrogen atoms, wherein the first and second step reactions take place with a hydrosilylation catalyst, and the weight ratio of Si-bonded hydrogen in organopolysiloxane (1) to Si-bonded hydrogen in organopolysiloxane (2) is at least 1.5.

Abstract: Crosslinkable silicone coating compositions are prepared from (1) organopolysiloxanes containing alkenyl groups and containing per molecule at least one unit O3-n/2RnSi—Y(SiRnO3-n/2)a ??(I), at least 2 units R1RbSiO(3-b)/2 ??(II), and units RcSiO(4-c)/2 ??(III), where R is a monovalent, SiC-bonded organic radical having 1 to 30 C atoms free from aliphatic carbon-carbon multiple bonds, R1 is an alkenyl radical having 2 to 4 C atoms, and Y is a divalent or trivalent organic radical having 1 to 30 C atoms, with the proviso that the organopolysiloxanes (1) contain units (II) in amounts wherein the concentration of alkenyl radicals R1 is less than 2 meq/g, (2) organopolysiloxanes containing Si-bonded hydrogen atoms, (3) a hydrosilylation catalyst, and (4) optionally, inhibitors. The compositions cure rapidly with few extractables and are very useful in preparing release coatings.

Abstract: ?-ketocarbonyl-functional organosilicon compounds are prepared by reacting amino organo-functional organosilicon compounds with a diketene in the presence of a compound which inhibits the reaction of amine groups with ?-ketocarbonyl compounds.