| 摘要 |
PURPOSE:To provide the subject composition good in the heat resistance, suitable for heat-resistant bearing oils, etc., and long in the shelf life by adding a specific amount of an ester such as a polycarboxylic acid ester or polyolester to a hydrocarbon lubricant oil base oil containing an antioxidant. CONSTITUTION:A base oil of a mineral or synthetic hydrocarbon series lubricant oil is compounded with a thiobis-hindered-phenol compound (e.g. 2,2'- thiodiethylbis-[3,5-di-t-butyl-4-hydroxyphenyl) propionate]} as an antioxidant and further with an ester compound such as a polycarboxylic acid ester or polyolester (e.g. triethyl trimellitate) in an amount of 5-40 pts.wt. per 100 pts.wt. of the base oil of the hydrocarbon series lubricant oil, and then with an alkylphenylphosphate in an amount of 0.1-5 pts.wt. per 100 pts.wt. of the base oil to obtain the objective lubricant oil composition excellent in the heat resistance and useful for heat-resistant bearing oils, etc. |
