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AssigneeGeneral Motors Corporation
InventorsReuben Sarkar, Brent D. Calcut, Thomas J. Chapaton, Marie-Christine G. Jones
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Antifoam compositions for functional fluids contain antifoam agents comprising perfluoropolyether compounds (PFPE). An automatic transmission fluid is provided containing the antifoam composition in a lubricating base oil, along with conventional additives such as antiwear agents. Automobile transmissions are provided that contain an automatic transmission fluid containing the new antifoam compositions. In a further embodiment, methods are provided for reducing foam in an engine oil or unwanted noise in an automobile transmission during operation, comprising lubricating the engine or transmission with a lubricating fluid containing the antifoam compositions of the invention.
A method for reducing noise during operation of an automobile automatic transmission, comprising
A method of reducing foam in an engine oil during operation of the engine, comprising
A method of treating an automatic transmission, the transmission comprising a housing defining a lubricant sump, wherein the sump contains a lubricating composition, the method comprising contacting the lubricating composition in the sump with a rubber composition, wherein the rubber composition comprises an elastomer and an antifoam composition, wherein the antifoam composition comprises a perfluoropolyether compound.
A method of treating an engine comprising a crankcase defining a lubricant sump, wherein the sump contains a lubricating composition, the method comprising contacting the lubricating composition in the sump with a rubber composition, wherein the rubber composition comprises an elastomer and an antifoam composition, wherein the antifoam composition comprises a perfluoropolyether compound.
Dependencies are inferred from the claim text.