| 摘要 |
PROBLEM TO BE SOLVED: To obtain a fluid excellent in power transmission capability by using a naphthene-ring-containing compound. SOLUTION: This fluid comprises a compound of the formula (wherein R1 is an alkyl group optionally containing a naphthene ring; and R2 to R8 are each H or R1) and is excellent also in low-temperature fluidity, i.e., in capability as a fluid for hydraulic control and, moreover, for wet clutch control, Further incorporation of a mineral oil, and/or a synthetic oil having a mol.wt. of 150-800, and/or a viscosity index improver preferably comprising a (hydrogenated) ethylene-α-olefin copolymer having a number average mol.wt. of 800-150,000, and/or an ashless dispersant and a phosphorus-based additive, and/or a friction modifier having at least one 6-30C alkyl or alkenyl group and not having a 31C or higher hydrocarbon group, and/or a metal-based detergent having a total base value of 20-450 mgKOH/g into the fluid is preferable. The fluid is suitable for the use in automotive nonstep variable speed gears. |
