BIODEGRADABLE LUBRICANT BASE OIL AND LUBRICANT COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a lubricant base oil and a lubricant composition excellent in biodegradability and good in thermal stability. SOLUTION: This biodegradable lubricant base oil comprises an oil and fat derivative obtained by using an oil and fat, a poly-functional alcohol and 5-150mol alkylene oxide based on 1mol oil and fat as raw materials and performing both an addition reaction of the alkylene oxide and an ester- exchange reaction in a mixed state thereof. Alternatively, the objective base oil comprises the oil and fat derivative obtained by using the oil and fat, an aliphatic acid and the alkylene oxide as raw materials and performing both the addition reaction of the alkylene oxide and an ester-exchange reaction in a mixed state thereof. Further alternatively, the base oil is obtained by an esterification of a part or all of end groups of the oil and fat with the aliphatic carboxylic acid or its ester derivative.