| abstract |
Graft copolymers, particularly useful as dispersant viscosity index improvers in lubricating oil compositions have a polymer backbone selected from the group consisting of olefin polymers, diene polymers, vinyl polymers and vinylidene polymers, which is grafted with an amine selected from N-p-diphenylamine,1,2,3,6-tetrahydrophthalimide; 4-anilinophenyl methacrylamide; 4-anilinophenyl maleimide; 4-anilinophenyl itaconamide; acrylate and methacrylate esters of 4-hydroxydiphenylamine; the reaction product of p-aminodiphenylamine or p-alkylaminodiphenylamine with glycidyl methacrylate; the reaction product of p-aminodiphenylamine with isobutyraldehyde, derivatives of p-hydroxydiphenylamine; derivatives of phenothiazine; vinylogous derivatives of diphenylamine; and mixtures thereof and may be prepared in a single step process using solution or bulk grafting conditions. |