| 摘要 |
An additive concentrate composition having a TBN greater than 300 suitable for incorporation into a finished lubricating oil composition comprising:- (I') a first alkaline earth metal sulphurised hydrocarbyl phenate, and (II') a lubricating oil, the first alkaline earth metal sulphurised hydrocarbyl phenate (I') being obtained by overbasing a second alkaline earth metal sulphurised hydrocarbyl phenate containing at least 4% by weight sulphur, or its precursors, in the presence of the lubricating oil (II'), the amount of the lubricating oil (II') being such that the ratio of the weight of the additive concentrate to the weight of the second alkaline earth metal sulphurised hydrocarbyl phenate, or its precursors, is at least 3.0. |
