LUBRICATING OIL COMPOSITION, AND SLIDING MECHANISM USING LUBRICATING OIL COMPOSITION

摘要

A lubricating oil composition for a low-friction sliding material, wherein the lubricating oil composition is used interposed between sliding surfaces of a sliding mechanism and at least one of the sliding surfaces has a DLC film containing hydrogen in the amount of 5 atom% to 50 atom% formed thereon. The lubricating oil composition is characterized by containing in a lubricant base oil, based on the total amount of the composition, (A) 0.005 mass% to 0.12 mass% of organic zinc dithiophosphate in phosphorus concentration equivalent, (B) 0.05 mass% to 5.0 mass% of an amine-based friction-reducing agent, and (C) 0.05 mass% to 0.5 mass% of an alkaline-earth metal salicylate-based cleaning agent and/or an alkaline-earth metal sulfonate-based cleaning agent in alkaline-earth metal concentration equivalent. Component (A) contains, based on the total amount of the composition, 0.005 mass% to 0.05 mass% of primary dialkyl zinc dithiophosphate in phosphorous concentration equivalent .