POLYMERIC DISPERSANT VISCOSITY MODIFIER COMPOSITION

摘要

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.