Multifunctional viscosity index improver exhibitng improved low temperature viscometric properties

摘要

Multifunctional viscosity index improver additives for oleaginous composition comprising reaction products of (i)(a) ethylene-alpha-olefin copolymers grafted with (i)(b) carboxylic acid material, further reacted with (ii) at least one of polyamine, polyol, about C30-C400 hydrocarbyl substituted carboxylic acid component together with polyol, or said carboxylic acid component together with polyamine, wherein the copolymer (i)(a) comprises intramolecularly heterogeneous copolymer chains containing at least one crystallizable segment of methylene units and at least one low crystallinity ethylene-alpha-olefin copolymer segment, and wherein said copolymer has a molecular weight distribution characterized by at least one of a ratio of &upbar& Mw/ &upbar& Mn of less than 2 and a ratio of &upbar& Mn/ &upbar& Mw of less than 1.8.