Process for preparing a dispersant/VI improver.

摘要

Dispersant/VI improver luboil additives are produced by reacting a star polymer with an alpha, beta unsaturated carboxylic acid or derivative to form an activated star polymer, which is then reacted with (a) at least one compound of general formula RO(AO)nH wherein R is a C4-20 alkyl group, any A moiety is independently an ethylene or propylene moiety, and n is 0 to 5, optionally followed by reaction with (b) an alkyl carboxylic acid and/or (c) an alkylamine or alkane polyol, or with the preformed product of reactants (b) and (c), optionally followed by esterifying any residual acid groups with a C1-6 alkanol.