Lubricant composition with improved non-Newtonian viscosimetric properties

摘要

A lubricant additive for use in a lubricant composition that has improved non-Newtonian viscosimetric properties and that has a Brookfield viscosity of less than 20,000 mPa · s measured at -40 ° C according to ASTM D2983, said lubricant additive comprising: C. from 10 80 percent by weight of a diluent oil based on the total weight of said lubricant additive; and D. 30 to 80 percent by weight of a random copolymer viscosity index improver based on a total weight of said lubricant additive, said viscosity index improver being the free radical polymerization product of at least: ( i) 5 to 15 percent by weight of methyl methacrylate based on a total weight of said viscosity index improver, and (ii) 5 to 95 percent by weight of 2-propylheptyl methacrylate based on a total weight of said viscosity index improver, wherein said viscosity index improver has a number average molecular weight of 10,000 to 200,000 g / mol and a weight average molecular weight of 20,000 to 500,000 g / mol.