| 摘要 |
<p>The present invention relates to a lubricating oil composition comprising a mineral oil, an ethylene- alpha -olefin copolymer, a polymethacrylate and common additives, characterized in that it comprises (A) a mineral oil having a kinematic viscosity at 100 DEG C of 1 . 10<-><6> to 50 . 10<-><6> m<2>/s (1 -50 cSt) and a viscosity index of at least 60, (B) 0,5 to 20% by weight based on the total weight of the composition of an ethylene- alpha -olefin copolymer having a number average molecular weight of 800 to less than 5 000, (C) 0,05 to 20% by weight based on the total weight of the composition of polymethacrylate having a number average molecular weight of 10 000 to 250 000 or a mixture of said polymethacrylate and an olefin copolymer, having a number average molecular weight of 10 000 to 250 000 selected from the group consisting of an ethylene-propylene copolymer and an ethylene-styrene copolymer, and (D-II)0,5 to 20% by weight based on the total weight of the composition of at least one member selected from the group consisting of a extreme pressure agent, an anti-wear agent and an oiliness agent.</p> |
