ENGINE LUBRICANT COMPOSITION

摘要

The present invention relates to lubricant compositions comprising: (a) one or more polyalkylene glycol base oils obtained by polymerization or copolymerization of alkylene oxides comprising from 3 to 8 carbon atoms, including at least one butylene oxide and (b) at least one detergent chosen from salicylates or phenates. The present invention also relates to the use of a lubricant composition according to the invention as engine oil, preferably as oil for the engines of petrol or diesel motor vehicles. The present invention also relates to the use of a group of additives for an engine lubricant comprising polyalkylene glycol bases obtained by polymerization or copolymerization of alkylene oxides comprising from 3 to 8 carbon atoms. The present invention also relates to the use of at least one additive chosen from salicylates, phenates, dithiocarbamates, amine-based or phenol-based antioxidants, preferably from salicylates or phenates, for reducing the Noack volatility of the base oils of polyalkylene glycol type, obtained from alkylene oxides comprising from 3 to 8 carbon atoms.