Patent ID: 7625847
Filing Date: 2009-12-01
Classification: C10M,C10N

Abstract:
1. A lubricating oil composition comprising a lubricating base oil, (A) an alkali metal or alkaline earth metal salicylate represented by formula (1) below and/or an overbased or basic salt thereof in an amount of 0.005 to 0.4 percent by mass in terms of metal and (B) a phosphorus-containing anti-wear agent in an amount of 0.005 to 0.2 percent by mass in terms of phosphorus and containing sulfur in a total amount of 0.3 percent by mass or less, based on the total mass of the composition, the salicylate being any of salicylates fulfilling at least one of requirements selected from (I) through (IV) or a mixture of the salicylates: wherein R 1 is a hydrocarbon group having 1 to 40 carbon atoms, R 2 is hydrogen or a hydrocarbon group having 1 to 40 carbon atoms, which hydrocarbon groups may contain oxygen or nitrogen, M is an alkali metal or alkaline earth metal, and n is an integer of 1 or 2 depending on the valence of the metal; (I) either one of R (II) the component ratio of a salicylate represented by formula (1) wherein R (III) the component ratio of a salicylate having one hydrocarbon group having 20 to 40 carbon atoms is 85 percent by mol or more wherein the component ratio of a salicylate represented by formula (1) wherein R (IV) the component ratio of a salicylate having one hydrocarbon group having 10 to 19 carbon atoms is 85 percent by mol or more wherein the component ratio is a salicylate represented by formula (1) wherein R