Hydrocarbon oil compositions containing polymers to control viscosity temperature relationship

Claim 1

A liquid composition exhibiting reversible solution/emulsion phase transition to provide a constant viscosity/temperature dependence, said composition comprising a lubricating oil and a minor amount of an interpolymer of at least one hydrocarbon monomer, selected from the group consisting of styrene and alpha methyl styrene, an oil solubilizing monomer selected from the group consisting of nuclear alkylated styrene wherein the alkyl group contains up to about eight carbon atoms and alkyl methacrylates having from 12 to 18 carbon atoms and oxyalkylmethacrylates having from 12 to 18 carbon atoms and at least one dispersant monomer having an oil soluble pendant moiety and selected from the group consisting of vinyl silicones and vinyl benzyl ethers having the formula: ##STR8## wherein R is hydrogen or methyl, m is about 10 to 100 and R 1 is an alkyl, alkaryl, or aralkyl group of 10 to about 22 carbon atoms, said interpolymer being soluble in said oil above a characteristic temperature and said dispersant monomer being present in said interpolymer in sufficient amount to maintain any insolubilized interpolymer below said characteristic temperature in stable colloidal dispersion.