Lubricant composition containing ester, use thereof, and well water containing same

PROBLEM TO BE SOLVED: To obtain a lubricant compsn. which is used for well water, based on water, and nontoxic, does not pollute the environment, and is useful in 'works of digging, completing, and repairing a well by compounding a specified amt. of a specific ester with a specified amt. of a specific monocarboxylic acid. SOLUTION: The compsn. comprises 50-99 wt.% at least one ester obtd. by reacting a linear or branched monocarboxylic acid having 1-3 unsatd. groups with a linear or branched 2-20C polyol in a molar ratio of 1:1 to (n-n/10):1 (wherein n is the hydroxyl functionality of the polyol) (e.g. pentaerythritol monooleate) and 1-50 wt.% at least one linear or branched 8-24C monocarboxylic acid having 1-3 unsatd. groups (e.g. oleic, stearic. or linolenic acid). COPYRIGHT: (C)1996,JPO