| abstract |
A lubricating oil composition comprising a major portion of a lubricating oil and a minor amount of an additive. The additive is prepared by reacting a polyamine with an alkenyl succinic acid anhydride having a number average molecular weight of about 500 to about 10,000 at a temperature of 60 DEG C.-120 DEG C. to form mono-alkenyl succinimide, bis-alkenyl succinimide or a mixture of mono- and bis-alkenyl succinimide. 2-pyrrolidone-5-carboxylic acid is then added to form an acylated mono-alkenyl succinimide, bis-alkenyl succinimide or mixture of mono- and bis-alkenyl succinimide. The acylated mono-alkenyl succinimide, bis-alkenyl succinimide or mixture of mono- and bis-alkenyl succinimide is acylated with an acylating compound selected from the group consisting of glycolic acid, oxalic acid, lactic acid, 2-hydroxymethyl-propionic acid and 2,2-bis(hydroxymethyl) propionic acid at a temperature of about 150 DEG C. to about 185 DEG C., to form a mixed acylated mono-alkenyl succinimide, bis-alkenyl succinimide or mixture of mono- and bis-alkenyl succinimide and the mixed acylated mono-alkenyl succinimide, bis-alkenyl succinimide or mixture of mono- and bis-alkenyl succinimide is recovered. |