| 摘要 |
PROBLEM TO BE SOLVED: To provide a lubricant composition which is sufficiently improved in both high viscosity index and low-temperature fluidity.SOLUTION: A lubricant composition comprises a lubricant base oil which has a kinematic viscosity at 100°C of 3.5-4.5 mm/s, a viscosity index of 145 or greater and a urea adduct value of 2-7 mass% and a poly(meth)acrylate type pour-point depressant containing structural units of formula (1). In the formula (1), Ris hydrogen or a methyl group, and Ris an alkyl group. The ratio of structural units with Rbeing methyl groups is 0-10 mol%, and the ratio of structural units with Rbeing 12C or higher alkyl groups is 90-100 mol%, and the average number of carbons of the 12C or higher alkyl groups is 13-16. The poly(meth)acrylate type pour-point depressant has a weight average molecular weight of 10,000-200,000. |
