Lubricant composition containing a dispersant which is a condensation product of a copolymer, polyamine and a polycarboxylic acid

Claim 1

An oil soluble lubricating oil dispersant which is made by: (A) copolymerizing a mixture of (i) about 3-55 mole percent of a material having the formula ##STR4## wherein R is an olefinically unsaturated hydrocarbon radical of up to 25 carbon atoms in which the carboxyl group is separated from all olefinic bonds by at least two carbon atoms and R 1 is selected from the group consisting of hydrogen and alkyl radicals containing 1 to about 15 carbon atoms, (ii) about 5 to 80 mole percent of a conjugated diethylenically unsaturated aliphatic hydrocarbon of 4 to about 12 carbon atoms, and (iii) about 92 to 15 mole percent of a monoalkene of 3 to about 30 carbon atoms, said material and said monoalkene being selected such that the total number of carbon atoms in these compounds is at least 12, said copolymerization being conducted at a temperature of about 0°-50° C. to form an intermediate copolymer, (B) reacting said intermediate copolymer with at least 1.1 equivalents of a hydrocarbyl polyamine containing 2 to about 12 carbon atoms and from about 2 to about 7 amine nitrogen atoms at a temperature of about 60°-320° C. to form an amidated copolymer which contains unreacted >NH and then (C) coupling said unreacted >NH by reaction at about 100°-300° C. with about 0.01-1.5 equivalents of a polycarboxylic acid per equivalent of said >NH group, said polycarboxylic acid being selected from the group consisting of (i) aliphatic dicarboxylic acid, and (ii) aromatic polycarboxylic acid containing an aryl group of about 6-10 carbon atoms and having 2 to 3 carboxylic groups bonded to said aryl group, said aliphatic dicarboxylic acid and aromatic polycarboxylic acid including precursor compound which yield said aliphatic dicarboxylic acid and said aromatic polycarboxylic acid under reaction conditions.