| 摘要 |
Oil soluble viscosity index improvers-dispersants exhibiting improved cold temperature viscometric properties, and Thickening Efficiencies and Shear Stability Indexes generally similar to conventional V.I.-dispersants, comprised of the reaction products of (i) ethylene copolymer, such as copolymer of ethylene and propylene, grafted with ethylenically unsaturated carboxylic acid moieties, preferably maleic acid or anhydride moieties; (ii) polyamine having two or more primary amino groups or polyol; (iii) an amount effective to provide a V.I. improver-dispersant exhibiting improved cold temperature viscometric properties of a high functionality long chain hydrocarbyl substituted dicarboxylic acid material such as alkenyl succinic anhydride, preferably polybutene succinic anhydride, having a functionality of at least 1.2, preferably at least about 1.3, and more preferably at least 1.4; and (iv) a molecular weight stabilizing effective amount of a short chain hydrocarbyl substituted dicarboxylic acid or anhydride. |
