Abstract: A gear or transmission lubricant composition, comprising a major portion of mineral base oil, containing added thereto (A) a phosphorus-containing metal-free organic compound, such as a phosphate ester or amine salt thereof, and (B) an oil-soluble copolymer of (a) an alkyl (meth)acrylate and (b) a N,N-dialkylaminoalkyl (meth)acrylate, shows improved sludge dispersibility, and is useful as automatic transmission fluid.

Abstract: A polymer composition or concentrate comprising:(A) an olefinic copolymer,(B) a copolymer of an olefin with a (meth)acrylate,(C) a poly(meth)acrylate, and(D) a surfactant, which is poor solvent for both components (A) and (C), which acts as a solubilizer or phase-stabilizer for the components (A) and (C), and which in combination with component (B), which has surface active properties, functions as a phase-stabilizer. The composition has a relatively low viscosity even at high polymer contents and is useful as a lubricating oil additive which improves the viscosity index of a lubricating oil formulation.