To provide a lubricating oil composition having decreased foaming tendency in spite of the use of a base oil having high aromatic content and low sulfur content or a base oil free from aromatic component and sulfur component.
The lubricating oil composition is produced by adding 1-20 mass ppm of a silicone oil containing a perfluoroalkyl group to at least one kind of base oil selected from the group consisting of a mineral oil-based base oil having a saturated component content of 90 mass%, a sulfur content of 0.03 mass% and a viscosity index of 80 and a poly--olefin. Preferably, the base oil has a kinematic viscosity of 7-150 mm2/s at 40C, a sulfur content of 30 mass ppm and a %CA of 3 determined by n-d-M ring analysis, and the silicone oil containing a perfluoroalkyl group preferably has a kinematic viscosity of 1,000-5,000 mm2/s at 25C.
SHIDARA YUJI
| JP2000087065A | 2000-03-28 | |||
| JPH09118892A | 1997-05-06 | |||
| JPH0657276A | 1994-03-01 | |||
| JPS59105091A | 1984-06-18 | |||
| JP2005154760A | 2005-06-16 | |||
| JPH01153792A | 1989-06-15 | |||
| JP2000087069A | 2000-03-28 | |||
| JP2005247995A | 2005-09-15 |
Shiro Fujitani
Kiyoshi Kuruma
Kazuyuki Tomita