High efficiency antifoam compositions and process for reducing foaming
AssigneeUnion Carbide Corporation
InventorsRavindra D. Kulkarni, Bernard Kanner, Errol D. Goddard
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Abstract
Antifoam compositions containing high viscosity polydiorganosiloxane oils, finely divided hydrophobic solids, and siloxanepolyoxyalkylene block copolymer surfactants, which can be used per se or in the form of emulsions.
Claims12
An antifoam composition which comprises a polydimethylsiloxane oil, 1-20 parts by weight per 100 parts by weight of the oil of a finely divided hydrophobic silica having a surface area of at least 50 square meters per gram, and 1-20 parts by weight per 100 parts by weight of the oil and solid together of a siloxane-oxyalkylene block copolymer surfactant having a hydrophilic-lipophilic balance in the range of 4 to 14 wherein the improvement comprises the polydimethylsiloxane oil having a viscosity in the range of 5,000 to 30,000 centistokes at 25.degree. C.
An antifoam composition in which 1-20 weight % of a siloxane-oxyalkylene block copolymer having a hydrophilic-lipophilic balance in the range of 4-14 has been blended with a homogeneous mixture of 1-20 weight % of a finely divided hydrophobic silica having a surface area of from 50 to 1,000 square meters per gram and 99-80 weight % of a polydimethylsiloxane oil having a viscosity in the range of 5,000 to 30,000 centistokes at 25.degree. C.
Dependencies are inferred from the claim text.