| abstract |
A lubricating oil composition having a total base number of more than 15 mg KOH/g, as determined by ASTM D2896, and including at least 40 mass % of an oil of lubricating viscosity; at least one detergent; and at least one compound of the formula (I) and/or formula (II): n n n n n n n n n n In formula (I), each Ar independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, aryloxy, aryloxyalkyl, hydroxy, hydroxyalkyl, halo and combinations thereof; each L is independently a linking moiety comprising a carbon-carbon single bond or a linking group; each Y is independently —OR 1″ or a moiety of the formula H(O(CR 1 2 ) n ) y X—, wherein X is selected from the group consisting of (CR 1′ 2 ) z , O and S; R 1 and R 1′ are each independently selected from H, C 1 to C 6 alkyl and aryl; R 1″ is selected from C 1 to C 100 alkyl and aryl; z is 1 to 10; n is 0 to 10 when X is (CR 1′ 2 ) z , and 2 to 10 when X is O or S; and y is 1 to 30; each a is independently 0 to 3, with the proviso that at least one Ar moiety bears at least one group Y; and m is 1 to 100. In formula (II), each Ar′ independently represents an aromatic moiety having 0 to 3 substituents selected from the group consisting of alkyl, alkoxy, alkoxyalkyl, hydroxy, hydroxyalkyl, acyloxy, acyloxyalkyl, aryloxy, aryloxy alkyl, halo and combinations thereof; each L′ is independently a linking moiety comprising a carbon-carbon single bond or a linking group; each Y′ is independently a moiety of the formula Z(O(CR 2 2 ) n′ ) y′ X′—, wherein X′ is selected from the group consisting of (CR 2′ 2 ) z′ , O and S; R 2 and R 2′ are each independently selected from H, C 1 to C 6 alkyl and aryl; z′ is 1 to 10; n′ is 0 to 10 when X′ is (CR 2′ 2 ) z′ , and 2 to 10 when X′ is O or S; y′ is 1 to 30; Z is H, an acyl group, an alkyl group or an aryl group; each a′ is independently 0 to 3, with the proviso that at least one Ar′ moiety bears at least one group Y′ in which Z is not H; and m′ is 1 to 100. |