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US 7,704,930 B2Granted
Mixed TBN detergents and lubricating oil compositions containing such detergents
AssigneeExxonMobil Research and Engineering Company
InventorsDouglas E. Deckman, Mark D. Winemiller, William L. Maxwell, William H. Buck, David J. Baillargeon
Life of this patent
Estimating the term…
Abstract
The present invention concerns a detergent additive for lubricating oil compositions comprising at least two of low, medium, and high TBN detergents. Preferably the detergent is a calcium salicylate. The present invention also concerns lubricating oil compositions comprising such detergents, and at least one of Group II base stock, Group III base stock, or wax isomerate base stock.
Claims13
A method to improve piston cleanliness and coefficient of friction in an internal combustion engine comprising
- (a) obtaining a lubricating oil composition comprising a first calcium salicylate detergent having a TBN of over about 200, present in an amount of about 0.2 to about 4 weight percent of the lubricating oil composition on an active ingredient basis, a second calcium salicylate detergent having a TBN between about 100 and 200, present in an amount of about 0.2 to about 4 weight percent of the lubricating oil composition on an active ingredient basis, and a third calcium salicylate detergent having a TBN less than about 100, present in an amount of about 0.2 to about 4 weight percent of the lubricating oil composition on an active ingredient basis, and any combination thereof,
- (b) lubricating the internal combustion engine, and
- (c) maintaining in the internal combustion engine a coefficient of friction less than 0.1 between 100 and 180° C. and a film cleanliness less than 10% between 100° C. and 180° C.
Dependencies are inferred from the claim text.