US 7,563,752 B2
Lubricating oil compositions
Kazuhiro Yagishita, Yokohama (Japan)
Assigned to Nippon Oil Corporation, Tokyo (Japan)
Filed on Feb. 01, 2005, as Appl. No. 11/48,441.
Application 11/048441 is a continuation of application No. PCT/JP03/09884, filed on Aug. 04, 2003.
Claims priority of application No. 2002-227484 (JP), filed on Aug. 05, 2002.
Prior Publication US 2005/0130854 A1, Jun. 16, 2005
This patent is subject to a terminal disclaimer.
Int. Cl. C10M 159/22 (2006.01)
U.S. Cl. 508—460  [508/376; 508/371] 13 Claims
 
1. A lubricating oil composition comprising a lubricating base oil, (A) an alkali metal or alkaline earth metal salicylate containing at least one type of compound selected from those represented by formula (1) below and/or an overbased or basic salt thereof in an amount of 0.005 to 5 percent by mass in terms of metal, (B) a phosphorus-containing anti-wear agent in an amount of 0.005 to 0.2 percent by mass in terms of phosphorus, and (C) an amide compound represented by formula (2) in an amount of 0.01 to 1 percent by mass and containing sulfur in a total amount of 0.3 percent by mass or less, based on the total mass of the composition:

OG Complex Work Unit Drawing
wherein R1 is a hydrocarbon group having 1 to 40 carbon atoms, R2 is hydrogen or a hydrocarbon group having 1 to 40 carbon atoms, which hydrocarbon groups may contain oxygen or nitrogen, M is an alkali metal or alkaline earth metal, and n is an integer of 1 or 2 depending on the valence of the metal; and

OG Complex Work Unit Drawing
wherein R3 is a hydrocarbon group having 6 to 40 carbon atoms, and R4 and R5 may be the same or different and are each independently hydrogen or a hydrocarbon group having 1 to 40 carbon atoms,wherein Component (B) is a zinc salt of a phosphorus compound of formula (4)

OG Complex Work Unit Drawing
wherein X4, X5, and X6 are each independently oxygen or sulfur, X7 is oxygen, at least one of X4, X5, and X6 is oxygen, and two of R8, R9, and R10 are each independently a hydrocarbon group having 1 to 30 carbon atoms and the rest hydrogen, and wherein a sulfated ash content of the lubricating oil composition is 1.0 percent by mass or less.