| 摘要 |
A viscosity index improver additive composition comprising from 1 to 25% by weight of a hydrogenated alkenylarene/conjugated diene interpolymer having a number average molecular weight greater than 20,000, from 30 to 72% by weight of a synthetic ester lubricating oil comprising an alkyl ester of a saturated aliphatic carboxylic acid and from 15 to 50% by weight of a non-synthetic mineral lubricating oil, all percentages by weight being expressed in terms of the total weight of the composition. In a modification of the invention the proportion of mineral lubricating oil is decreased and the proportion of ester lubricating oil is increased by the addition of, for example, either an ethylene copolymer or a polybutene in an amount of from 1 to 25% by weight. |
