Patent ID: 8308827
Filing Date: 2012-11-13
Classification: C10L

Abstract:
1. A method for improving the drain interval of a diesel engine oil in a diesel engine comprising supplying to the diesel engine a diesel fuel composition comprising (a) a major amount of a diesel fuel and (b) an effective amount of a soot dispersant additive capable of being delivered to the diesel engine oil, wherein the soot dispersant additive is a copolymer of ethylene and a C 3 -C 10 alpha-monoolefin having a number average molecular weight ranging from about 5,500 to about 60,000 on which has been grafted an ethylenically unsaturated carboxylic acid and/or anhydride thereof in the ratio of at least about 1.8 molecules of a carboxylic acid function per molecule of said copolymer which is then further derivatized with at least one amino-aromatic polyamine compound selected from the group consisting of: (a) N-arylphenylenediamine of the formula: wherein Ar is aromatic and R 1 is H or —NHaryl, —NHarylalkyl, a branched or straight chain radical having from 4 to about 24 carbon atoms that is alkyl, alkenyl, alkoxyl, aralkyl alkaryl, hydroxyalkyl or aminoalkyl; R 2 is —NH 2 , —[NH(CH 2 ) n —] m —NH 2 , —CH 2 —(CH 2 ) n —NH 2 , —CH 2 -aryl-NH 2 -aryl-NH 2 in which n and m each independently has a value of from 1 to about 10; and, R 3 is H or an alkyl, alkenyl, alkoxy, aralkyl or alkaryl radical having from 4 to about 24 carbon atoms, (b) aminocarbazole of the formula: wherein R and R 1 each independently represents H or an alkyl or alkenyl radical having from 1 to about 14 carbon atoms, (c) aminoindole of the formula: wherein R represents H or an alkyl radical having from 1 to about 14 atoms, (d) amino-indazolinone of the formula: wherein R is H or an alkyl radical having from 1 to about 14 carbon atoms, and (e) aminoperimidine of the formula: wherein R represents H or an alkyl radical having from 1 to about 14 atoms.