| abstract |
ABSTRACT OF THE DISCLOSURE A lubricating oil additive composition which imparts improved oxidation properties to crankcase lubricants comprises an antioxidant selected from aromatic or alkyl sulfides and polysulfides, sulfurized olefins, sulfurized carboxylic acid esters and sulfurized ester-olefins, and an amine of the formula R-RH2, (R1)2NH, (R2)3N, R-N-(C?)xyNH2, A R3?N-A1)y" 3-x'N?A2-OH)x' or Het N?R4)y,X y wherein each R is independently alkyl or alkenyl of at least 6 carbon atoms, each R is independently an aliphatic hydrocarbon group, each R2 is independently C3-C10 alkyl, phenyl, or phenyl substituted by 1 or 2 alkyl groups of 1-12 carbon atoms, R3 is C1-C30 alkyl, R4 is alkylene of at least 2 carbon atoms, each A is independently hydrogen or C1-C18 alkyl, each A1 and A2 is independently C2-C10 alkylene, X is hydrogen, -OH, or -NA2, Y is hydrogen, C1-C6 alkyl, or A1-OH, Het is a carbon chain forming with the N atom a 5- or 6-membered heterocyclic ring, optionally containing in place of one carbon atom an additional N or O hetero atom, x is an integer from 2 to 4, x' is 1 or 2, y is an integer from 1 to 4, y' is 0 or 1, and y" is 0, 1 ro 2, with the proviso that when y' is 0, X is hydrogen. Lubricating oil compositions containing this additive composition are also disclosed. |