Patent ID: 7981847

Claim:
A lubricating oil composition comprising: (1) a base oil; and (2) as a dispersant viscosity index improver, a graft copolymer produced by (A) providing an acylating agent having at least one point of ethylenic unsaturation; (B) providing an amine selected from the group consisting of primary amines and secondary amines; (C) combining the acylating agent and the amine; (D) heating the acylating agent and the amine to form a reaction product comprising a graftable monomer; (E) providing a graftable polyolefin and an initiator; (F) dissolving said polyolefin in a solvent, forming a solution; (G) combining said reaction product with said solution; (H) combining said initiator with said solution; and, (I) heating said solution to at least the initiation temperature of said initiator; thereby forming a graft copolymer of said monomer and said polyolefin, without recovering the monomer from the reaction product before carrying out the grafting reaction; wherein the dispersant viscosity index improver is present in the amount sufficient to raise the viscosity index of said base oil by at least about 5 points.