| 摘要 |
PROBLEM TO BE SOLVED: To provide a synthetic lubricating oil composition having desirable physical properties and performance required as a lubricating oil and excellent particularly in oxidation stability by using a specified alkylnaphthalate compound as the base oil and a specified organic amine compound as the essential constituent. SOLUTION: The alkylnaphthalene compound used comprises, e.g. an alkylmethylnaphthalene compound having one methyl and one 6-24C alkyl as the substituents on the naphthalene ring (e.g. 1-methyl-decylnaphthalene), or a dialkylmethylnaphthalene compound having one methyl and two 6-24C alkyls. The organic amine compound used comprises one represented by formula I [wherein X is a group represented by, e.g. formula II (wherein R<1> to R<4> are each H, a 1-20C alkyl, cycloalkyl, aryl, aralkyl or alkylaryl)]. An example of the suitable compound is one represented by formula III (wherein R<13> to R<16> are each H or a 1-20C alkyl), which has good solubility in the base oil and is readily available. This compound is blended in an amount of 0.01-3.0 pts.wt. with 100 pts.wt. base oil. |
