| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide lubricating oil for internal combustion engines, which is highly effective in reduction of friction and corrosion-prevention and is in accordance with environmental regulations. <P>SOLUTION: A lubricating oil composition comprises, in base oil, (a) 0.5-1.5 mass% of a mono- or diester of glycerin and a fatty acid having a 6-20C linear or branched saturated hydrocarbyl group, (b) 0.2-0.5 mass% of a triazole derivative represented by general formula (1), and (c) 0.01-0.2 mass% of a mixture of primary zinc dialkyldithiophosphate in which the alkyl group is a primary hydrocarbyl group and secondary zinc hydrocarbyl dithiophosphate in which the alkyl group is a secondary hydrocarbyl group, in terms of the amount of phosphorus, wherein the ratio of the component (a) to the component (b) is 1.5-8 (in the formula, R<SB POS="POST">1</SB>denotes hydrogen or a 1-3C hydrocarbyl group, R<SB POS="POST">2</SB>and R<SB POS="POST">3</SB>each independently denotes a 1-20C hydrocarbyl group that may contain a hydrogen atom or an oxygen atom, or a sulfur atom or a nitrogen atom. R<SB POS="POST">2</SB>and R<SB POS="POST">3</SB>may be the same or may differ from each other). <P>COPYRIGHT: (C)2013,JPO&INPIT |
