(57) The present invention is directed to improved oil soluble dispersant materials which
comprise members selected from the group consisting of oil soluble salts, amides,
imides, oxazolines, or mixtures thereof, of polyolefin-substituted mono and dicarboxylic
acids or their anhydrides covered as per claim 1 wherein the polyolefin is characterized
by number average molecular weight of from about 1,500 to 2,500 and a molecular weight
distribution of less than about 3.0, and wherein the dispersant additive contains
within its structure an average of from 0.7 to 1.3 mono- or dicarboxylic acid producing
moieties (preferably acid or anhydride moieties) covered as per claim 1 per polyolefin
molecule, and wherein the dispersant material contains from 0.5 to 4 equivalents of
secondary amine groups per equivalent of the mono- or dicarboxylic acid producing
moieties per molecule, with the proviso that the dispersant material is further characterized
by a Z factor of from 4,000 to ,6,000, wherein the Z factor is determined by the expression:
wherein [N] is the total nitrogen content of the dispersant material expressed in
wt% and Mn is the polyolefin number average molecular weight.
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