Abstract: An interpolymer composition comprising monomer-derived units of (i) at least one of an aliphatic olefin containing from 2 to 30 carbon atoms and a vinyl aromatic monomer, and (ii) at least one alpha, beta-unsaturated acylating agent; wherein a portion of said acylating agent monomers is esterified and wherein a portion of said acylating agent monomers is condensed with at least one aromatic amine, provides good viscosity modification and dispersancy performance.

Abstract: The invention provides a composition comprising: (a) a star polymer comprising: (i) a core portion comprising a polyvalent (meth)acrylic monomer, oligomer or polymer thereof or a polyvalent divinyl non-acrylic monomer, oligomer or polymer thereof; and (ii) at least two arms of polymerized alkyl(meth)acrylate ester; and (b) an oil of lubricating viscosity, wherein the core portion further comprises a functional group of formula (I): —CH2—C(R1)(C(?O)A)-Y—??(I) wherein R1 is hydrogen, a linear or branched alkyl group containing 1 to 5 carbon atoms; A is nitrogen or oxygen; and Y is a free radical leaving group selected from the group consisting of one or more atoms or groups of atoms which may be transferred by a radical mechanism under the polymerisation conditions, a halogen, an —O—N? group and an —S—C(?S)— group. The invention further provides the use of the composition in an oil of lubricating viscosity as a dispersant, a viscosity modifier or a precursor to a dispersant viscosity modifier.

Abstract: This invention relates to a method comprising (a) employing a composition comprising (i) an oil of lubricating viscosity; and (ii) a salt of a nitrogen containing poly(meth)acrylate and a phosphorus acid ester; and (b) lubricating a gear with such composition resulting in control of gear fatigue.

Abstract: The present invention provides a composition containing: (a) an oil of lubricating viscosity; (b) an amine salt of a phosphorus compound; (c) a compound selected from the group consisting of: 1) a polymeric dispersant viscosity modifier wherein the polymeric dispersant viscosity modifier excludes copolymers derived from (a) a nitrogen containing monomer; and (b) methacrylic acid esters containing from about 9 to about 25 carbon atoms in the ester group; 2) a polymeric dispersant viscosity modifier, a borated dispersant; and a sulphurised olefin; and 3) mixtures thereof. The invention further provides a process for preparing the composition and a method for improving oxidation cleanliness of surface.