| 摘要 |
PROBLEM TO BE SOLVED: To obtain a lubricating oil composition, capable of manifesting positive friction characteristics, having a specific friction coefficient, capable of suppressing a stick-slip phenomenon, excellent in durability and suitable for variable speed units, etc. SOLUTION: This lubricating oil composition is obtained by blending (A) 100 pts.wt. mineral oil or synthetic oil with (B) one or more of a sulfurized ester in an amount of 0.1-0.15 pt.wt. expressed in terms of the sulfur content, a metallic salt-based cleaning agent in an amount of 0.005-1.0 pt.wt. expressed in terms of the metallic content, a zinc dialkyl dithiophosphate in an amount of 0.05-0.3 pt.wt. expressed in terms of the zinc content, a phosphoric ester in an amount of 0.03-0.1 pt.wt. expressed in terms of the phosphorus content and an imide compound in an amount of 0.01-0.1 pt.wt. expressed in terms of the nitrogen content and (C) 1-10 pts.wt. poly(meth)acrylates in order to improve the low-temperature fluidity. The composition is capable of manifesting positive frictional characteristics in which the friction coefficient measured from a frictional force at each sliding velocity by changing the sliding velocity within the range of 0-100cm/sec under 200lb vertical load shows an increase in frictional coefficient with increasing sliding velocity and has the friction coefficient at <=2.5cm sliding velocity within the range of 0.12-0.14. |
