Ethylene copolymer viscosity index improver - dispersant additive useful in oil compositions

Abstract From the Canadian patent

Oil-soluble viscosity index-improving ethylene copolymers, such as copolymers of ethylene and propylene; and ethylene, propylene and diolefin; etc. are reacted or grafted with ethylenically unsaturated carboxylic acid moieties, preferably maleic anhydride, and reacted with polyamines having two or more primary amine groups and a carboxylic acid component, preferably alkylene polyamine and alkenyl succinic anhydride, such as polyisobutenyl succinic anhydride; or the grafted ethylene copolymer can be reacted with already formed salts, amides, imides etc. of said, polyamine and acid component preferably imides of alkylene, polyamine and alkenyl succinic anhydride. These reactions can permit …