| abstract |
This invention is directed to a nitrogen-containing mixed ester of a carboxy-interpolymer having a reduced specific viscosity of from about 0.05 to 2.0. The carboxy-interpolymers, from which the mixed esters are obtained, are derived from at least one monomer selected from the class consisting of aliphatic olefins and styrene and at least one monomer comprising an unsaturated carboxylic acid, the anhydride or ester thereof. The nitrogen-containing mixed ester may be characterized as having in the polymeric structure carboxylic-ester groups derived from high molecular weight alcohols at least 7 aliphatic carbon atoms and low molecular weight alcohols having from 1 to 6 aliphatic carbon atoms and carbonyl-polyamino groups derived from hydrazine or a hydrocarbon-substituted hydrazine. The nitrogen-containing mixed esters are particularly useful either alone or in combination with other known additives in small but effective amounts in various oleaginous materials including lubricants and fuels. |