LUBRICATING OIL COMPOSITION AND AUTOMOTIVE TRANSMISSION OIL USING SAME

摘要

An object of the present invention is to provide a lubricating oil composition having a low viscosity and an extremely high viscosity index as well as an excellent shearing stability. The present invention relates to a lubricating oil composition including the following components (A) to (C):;(A) a low-viscosity synthetic oil including a compound containing an ether bond in a molecule thereof and having a kinematic viscosity of less than 10 mm2/s as measured at 40° C., in which a ratio of the number of oxygen atoms to the number of carbon atoms as constituents of the compound (O/C ratio) and the kinematic viscosity (mm2/s) of the compound as measured at 40° C. satisfy the following formula (1):;Kinematic Viscosity at 40° C.≦12−[(O/C ratio)×30]  (1);;(B) a high-viscosity synthetic oil as a hydrocarbon-based synthetic oil having a kinematic viscosity of 40 mm2/s or more as measured at 100° C. which includes at least one compound selected from the group consisting of an α-olefin oligomer or a hydrogenated product of the α-olefin oligomer, and an ethylene-propylene co-oligomer; and;(C) a polymethacrylate having a weight-average molecular weight of 50,000 or less.

主权项

1. A lubricating oil composition comprising the following components (A) to (C):
(A) a low-viscosity synthetic oil comprising a compound containing an ether bond in a molecule thereof and having a kinematic viscosity of less than 10 mm2/s as measured at 40° C., in which a ratio of number of oxygen atoms to number of carbon atoms as constituents of the compound (0/C ratio) and the kinematic viscosity (mm2/s) of the compound as measured at 40° C. satisfy the following formula (1):
Kinematic Viscosity at 40° C.≦12−[(O/C ratio)×30]  (1); (B) a high-viscosity synthetic oil as a hydrocarbon-based synthetic oil having a kinematic viscosity of 40 mm2/s or more as measured at 100° C. which comprises at least one compound selected from the group consisting of an α-olefin oligomer, a hydrogenated product of an α-olefin oligomer and an ethylene-propylene co-oligomer; and (C) a polymethacrylate having a weight-average molecular weight of 50,000 or less.