| 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 fromn (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. |