Dispersant-viscosity improvers for lubricating oil compositions

Abstract

A polyacrylate ester, and more particularly a polymethacrylate ester based dispersant-viscosity improver for lubricating oil compositions. Specifically, the dispersant viscosity improvers of this invention are nitrogen-containing copolymers comprising units derived from (A) from about 5% to about 75% by weight of alkyl acrylate ester monomers containing from 1 to 11 carbon atoms in the alkyl group; (B) from about 25% to about 95% by weight of alkyl acrylate ester monomers containing from 12 to about 24 carbon atoms in the alkyl group; and (C) From about 0.1% to about 20% by weight of at least one nitrogen containing monomer selected from the group consisting of vinyl substituted nitrogen heterocyclic monomers, N,N-dialkylaminoalkyl acrylate monomers, N,N-dialkylaminoalkyl acrylamide monomers and tertiary-alkyl acrylamides, provided that the total equals 100%. Processes for preparing the compositions, additive concentrates and lubricating oil compositions are described.

Dependencies are inferred from the claim text.