Non-aqueous antifoam compositions

Claim 1

A non-aqueous antifoam composition consisting essentially of a lipophilic nonionic surface active agent having a hydrophilic-lipophilic balance value of less than 9 homogeneously dispersed in a transient siloxanate antifoam agent, wherein said siloxanate antifoam agent consists essentially of the product resulting from heating, in the absence of water, a mixture consisting essentially of a finely divided silica filler and a condensation product of a partially hydrolyzed trifunctional silane, said condensation product having a residual alkoxy content of at least about 9 percent by weight, said silane being selected from the group consisting of RSiX 3 and RSi(OR') 3 wherein R is an alkyl radical having 1 to 5 carbon atoms, R' is an alkyl radical having 1 to 4 carbon atoms and X is a halogen atom, wherein the amount ratio of said silica filler to said condensation product ranges from about 1 to about 33 parts by weight of the silica filler per 100 parts by weight of the condensation product, and wherein the amount ratio of said surface active agent to said antifoam agent ranges from about 3 to about 33 parts by weight of the surface active agent per 100 parts by weight of the antifoam agent.