摘要 |
The invention provides an oil composition comprising a major amount of an oil and, as viscosity index improver a minor amount of a selectively hydrogenated carboxyl functionalised polymer of general formula B-A-B, wherein each B, prior to hydrogenation, is a conjugated diolefin polymer block and A is a monoalkenyl aromatic hydrocarbon polymer block, said polymer being carboxyl functionalised in the aromatic hydrocarbon polymer block thereof. |