[1] Industrial Lubricant Business Div, Yushiro Chemical Industry Co, Ltd., 1580, Tabata, Samukawa-machi. Koza-gun, Kanagawa,253-0913, Japan
[2] Lubricants Research Laboratory, Idemitsu Kosan Co, Ltd., 24-4, Anesakikaigan, Ichihara-shi, Chiba,299-0107, Japan
[3] Research and Development Division, Tokyo Metropolitan Industrial Technology Research Institute, 4-10, Aomi 2-chome, Koto-ku, Tokyo,135-0064, Japan