Lubricating oil composition, and sliding mechanism using lubricating oil composition

A sliding mechanism comprising:

• two sliding members that slide to each other, each sliding member having a sliding surface;
• and
• a lubricating oil composition, which is sandwiched between the sliding surfaces of the two sliding members,
• wherein at least one sliding surface of the two sliding members is formed from a diamond-like carbon film comprising hydrogen in an amount of 5 to 50 atom %, and the other sliding surface of the sliding material is formed from a DLC material, an iron base, or an aluminum alloy material, and
• wherein the lubricating oil composition comprises a lubricant base oil, wherein the lubricant base oil comprises, based on the total amount of the composition:
• (A) an organic zinc dithiophosphate in an amount of from 0.005% to 0.10% by mass in terms of the phosphorus concentration therein;
• (B) an amine-based friction-reducing agent in an amount of from 0.1% to 3.0% by mass, wherein the amine-based friction-reducing agent is an adduct of a primary amine having an aliphatic hydrocarbon group having from 16 to 24 carbon atoms with an ethylene oxide;
• (C) a calcium salicylate-based detergent and/or a calcium sulfonate-based detergent in an amount of from 0.1% to 0.25% by mass in terms of the alkaline earth metal concentration therein;
• and
• (D) an ashless dispersant comprising a succinic acid imide, a boron-containing succinic acid imide, or mixture thereof,
• wherein the organic zinc dithiophosphate (A) comprises, based on the total amount of the composition, a zinc primary dialkyldithiophosphate in an amount of from 0.005% to 0.05% by mass in terms of the phosphorus concentration therein.