| abstract |
A lubricating oil composition comprising a di-block copolymer of poly(monovinyl aromatic hydrocarbon) and hydrogenated poly(conjugated diene) as a dispersant additive is described. The said di-block copolymer preferably comprises poly(monovinyl aromatic hydrocarbon) in the molecular weight range 8,000 - 30,000. The diblock copolymers are useful as dispersant additives in lubricant oils, reduce heavy metal corrosion, reduce degradation of elastomeric seals and are less sensitive to the presence of over-based detergents. |