| abstract |
This invention relates to a composition comprising at least one sulphur-containing calixarene represented by formula (I)or a metal salt of said calixarene, wherein in formula (I): Y is a divalent bridging group, at least one of said bridging groups being a sulphur atom; R3 is hydrogen, a hydrocarbyl or a hetero-substituted hydrocarbyl group; either R1 is hydroxyl and R2 and R4 are independently either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl, or R2 and R4 are hydroxyl and R1 is either hydrogen, hydrocarbyl or hetero-substituted hydrocarbyl; and n is a number having a value of at least 4. In one embodiment, the foregoing salt is an overbased salt. The invention also relates to additive compositions and finished lubricating oil compositions containing the foregoing overbased salt. The invention also relates to a process for making the foregoing overbased salt. |