Patent ID: 8575390

Claim:
A process for forming a dispersant compound comprising: (i) reacting a polycarbonyl compound of formula I having at least three carbonyl functions with a primary amine moiety of a polyamine of formula II to form a polyamine polyamide intermediate; and (ii) reacting the polyamine polyamide intermediate with a hydrocarbyl carbonyl compound of formula IV, wherein formula I is: where n ranges from 0 to 4, and where R 1 , R 2 , R 3 , R 4 and R 5 are independently chosen from a hydrogen atom and C 1 to C 10 linear or branched alkyl groups, wherein formula II is: wherein R 6 is a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, m is an integer ranging from 1 to 3, and n is an integer ranging from 2 to 10, wherein a mole ratio of polycarbonyl compound to polyamine of formula II ranges from about 1:3 to about 1:5 to provide the polyamine polyamide dispersant intermediate compound of formula III, where n ranges from 0 to 4, and R 9 , R 10 , R 11 , R 12 and R 13 are independently chosen from OH, a polyamine group, or a amine salt of the polyamine group, with the proviso that at least three of R 9 , R 10 ,R 12 and R 13 are polyamine groups, and wherein formula IV is: wherein R 14 is a hydrocarbyl group.