| abstract |
A crankcase lubricating oil composition that is compatible with fluoroelastomer engine seal materials and conforms to copper corrosion performance. A tetraalkylated phenylenediamine compound useful as an ashless TBN raw material, that is, a hydrocarbyl group (for example, an alkyl group) having 1 to 3 branched at an α carbon atom and has 3 to 12 carbon atoms. And a lubricating oil composition comprising N, N′-tetra-aliphatic hydrocarbylphenylenediamine, wherein 1 to 3 of the hydrocarbyl groups (eg, alkyl groups) are branched at the β carbon atom and have 4 to 12 carbon atoms. object. [Selection figure] None |