| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject composition capable of maintaining its stability to oxidation during service for a long time at high temperatures by incorporating a specific mixed oil as the base material with an antioxidant, a metal-based cleaning agent, an ashless-type dispersant, an extreme-pressure agent and a defoaming agent. SOLUTION: This gas engine lubricating composition is obtained by incorporating, as the base material, a mixed oil composed of a poly-α-olefin and an aromatic ester formed pref. by reaction between phthalic acid and an aliphatic straight-chain alcohol or aliphatic branched alcohol or a mixture thereof with an antioxidant, a metal-based cleaning agent, an ashless-type dispersant, an extreme-pressure agent and a defoaming agent; wherein the weight ratio of the poly-α-olefin to the aromatic ester is pref. (90:10) to (50:50). |
