Foam control composition

Claim 1

A composition which consists essentially of (1) 65 to 98.4 percent by weight of a base oil selected from the group consisting of polyoxypropylene polymers and polyoxypropylene-polyoxyethylene copolymers having molecular weights in the range of 500 to 6000, and siloxane glycol copolymers having the general formulae (a) RaSi[(OSiMe2)n(OSiMeG)bOSiMe2G]4-a, (b) RaSi[(OSiMe2)n(OSiMeG)cOSiMe3]4-a, (c) GMe2Si(OSiMe2)n(OSiMeG)bOSiMe2G, and (d) Me3Si(OSiMe2)n(OSiMeG)cOSiMe3 in which formulae R is a hydrocarbon radical free of aliphatic unsaturation and contains from 1 to 10 carbon atoms, Me is a methyl radical, G is a radical Or the structure -D(OR')mA wherein D is an alkylene radical containing from from 1 to 30 carbon atoms, R' is an alkylene radical containing from from 2 to 10 carbon atoms, and A is a capping group, a has a value of 0 or 1, n has a value of at least 1, b has a value of 0 to 50, and c has a value of 1 to 50, (2) 1 to 20 percent by weight of mineral oil, (3) 0.5 to 5 percent by weight of a material selected from the group consisting of silica and a resin composed of SiO2 and (CH3)3SiO1/2 units in which resin the ratio of the SiO2 units to the (CH3)3SiO1/2 units is in the range of 1:0.4 to 1:1.2, and (4) 0.1 to 10 percent by weight of a dispersing agent which maintains (2) dispersed in (1) and which is a siloxane copolymer selected from the group consisting of (i) copolymers consisting essentially of SiO2 units, (CH3)3SiOi/2 units and Q(CH3)2SiO1/2 units wherein Q is a polyoxypropylene polymer or a poly-oxypropylene-polyoxyethylene copolymer radical having a molecular weight in the range of 500 to 6000, Q being attached to the silicon atom via a silicon-carbon bond, the ratio of the SiO2 units to the total (CH3)3SiO1/2 and Q(CH3)2SiO1/2 units being in the range of 1:0.4 to 1:1.2, and (ii) copolymers which are the reaction products derived from heating a mixture of a siloxane copolymer consisting essentially of SiO2 units and (CH3)3SiO1/2 units in which the ratio of SiO2 units to the (CH3)3SiO1/2 units is in the range of 1:0.4 to 1:1.2, and a hydroxylated polyoxypropylene polymer or a hydroxylated polyoxypropylene-polyoxyethylene copolymer having molecular weights in the range of 500 to 6000.