| abstract |
An esterification product obtained by reacting ethylene oxide/propylene oxide block copolymer with a long-chain monocarboxylic acid, when employed as a supplemental rust inhibitor in lubricating oils for internal combustion engines, has been found to furnish excellent rust inhibition in the engines and to be compatible with other components in the lubricating oils. A lubricating oil composition containing such product may be used to inhibit rust formation in an internal combustion engine. |