| abstract |
A lubricant composition for internal combustion engines of the present invention contains: a base oil; a sulfur-containing heterocyclic compound represented by general formula (I); and an amino alcohol compound which has one or more amino groups and one or more hydroxyl groups in each molecule. This lubricant composition for internal combustion engines is configured such that the phosphorus content (P mass%) and the sulfuric acid ash content (M mass%) based on the total amount of the composition satisfy one of the conditions A-C described below. Consequently, this lubricant composition for internal combustion engines can be significantly reduced in the amounts of additives containing phosphorus or metal-based detergents, while maintaining high-temperature cleaning properties and wear resistance.nCondition A: P < 0.03 and M < 0.3nCondition B: P < 0.03 and 0.3 ≤ M ≤ 0.6nCondition C: 0.03 ≤ P ≤ 0.06 and M < 0.3n(In general formula (I), As represents a sulfur-containing heterocyclic ring; each of R 1 and R 2 independently represents a hydrogen atom, an amino group or a hydrocarbon group having 1-50 carbon atoms, said hydrocarbon group being selected from among an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group and an aryl group; or in cases where R 1 and R 2 are hydrocarbon groups, each of R 1 and R 2 represents a heteroatom-containing group having 1-50 carbon atoms, said heteroatom-containing group containing an atom that is selected from among an oxygen atom, a nitrogen atom and a sulfur atom in the hydrocarbon group; and each of k, l, m and n independently represents an integer of from 0 to 5 (inclusive).) |