摘要 |
A new Mannich base, prepared by condensing tetrapropenylphenol, formaldehyde and diethylenetriamine wherein the molar ratio of reactants is 1 mol tetrapropenylphenol to 0.5 to 0.85 mols formaldehyde to at least 0.3 mols of diethylenetriamine, and the calcium salt thereof are useful as dispersant additives for lubricating oils, particularly for use in marine cylinder lubricating oils. |