A viscosity index improver, a process for making a viscosity index improver, and a lubricating oil composition containing the same

摘要

Lubricating oil dispersant viscosity index improvers may be made by grafting, for example, maleic anhydride to an ethylene/α-olefin copolymer in a hydrogen-treated mineral oil solvent using a free radical and then reacting the grafted intermediate with an amine having the structurewherein R is an aliphatic hydrocarbon group containing from 12 to 33 carbon atoms and n is an integer from 1 to 3. Use of hydrogen-treated mineral oil increases the effectiveness of the viscosity index improver.;The invention includes a lubricating oil composition containing a viscosity index improver made as above.