Multifunctional viscosity index improver-dispersant antioxidant

Abstract

Oleaginous compositions, particularly lubricating oil compositions, exhibiting improved antioxidant properties containing a viscosity index improving amount of a viscosity index improver-dispersant comprised of the reaction products of: (a) an oil soluble ethylene copolymer comprising from about 15 to 90 wt. % ethylene and from about 10 to 85 wt. % of at least one C.sub.3 to C.sub.28 alpha-olefin, having a number average molecular weight of from about 5,000 to 500,000, grafted with an ethylenically unsaturated carboxylic acid material having 1 or 2 acid or anhydride moieties; (b) an organic polyamine having at least two primary amino groups; (c) an aldehyde; (d) a heterocyclic nitrogen reactant having at least one --N(H)-- group in the heterocyclic ring; and, optionally, (e) an amount effective to provide a V.I. improver-dispersant exhibiting improved low temperature viscometric properties of high functionality long chain hydrocarbyl substituted dicarboxylic acid material having a functionality of at least 1.2.

Dependencies are inferred from the claim text.