Lubricating oil ashless dispersant and lubricating oils containing same

Claim 1

An ashless dispersant suitable for use in lubricating oil, said dispersant being made by a process comprising (1) heating a mixture of reactants consisting essentially of 100 parts by weight of a Bright Stock mineral oil, about 1-25 parts by weight of a C 1-20 alkyl acrylate or methacrylate and about 1-25 parts by weight of maleic anhydride in the presence of a free radical-generating catalyst at a temperature high enough to form free radicals up to about 250° C. to form a succinic grafted intermediate, and (2) reacting said intermediate with an amine containing 1-30 carbon atoms and 1-6 amine groups, at least one of said amine groups being a primary or secondary amine group, the amount of said amine being sufficient to provide at least one primary or secondary amine group for each grafted succinic group at a temperature high enough to cause the formation of succinamide or succinimide groups up to about 250° C.