Detergent and dispersant systems for improved steel piston cleanliness in heavy duty lubricants
AssigneeAfton Chemical Corporation
InventorsDominic Myers, Nicholas Giles, Peter Carress, Guillaume Carpentier, Paul Ransom, Leah Donham
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Abstract
The present disclosure relates to heavy duty crankcase lubricating oil compositions achieving high piston cleanliness of steel piston pursuant to the OM471 piston cleanliness test using a detergent system of sulfonate soap and dispersant system of one or more polyisobutylene succinimide dispersants to the lubricating oil composition.
Claims20
A method of lubricating a heavy-duty diesel engine having steel pistons, the method comprising:
- lubricating the steel pistons of the heavy-duty diesel engine with a lubricating oil composition:
- wherein the lubricating oil composition includes (i) a detergent system consisting of one or more alkaline earth metal sulfonate detergents delivering from 0.3 to about 1 weight percent sulfonate soap to the lubricating oil composition and (ii) a dispersant system including one or more polyisobutylene succinimide dispersants delivering at least about 5 weight percent of the one or more dispersants to the lubricating oil composition;
- and
- wherein the one or more polyisobutylene succinimide dispersants are derived from highly reactive polyisobutylenes having a number average molecular weight of about 1,200 to about 2,500 and delivering more than 650 ppm nitrogen to the lubricating oil composition.
A heavy-duty crankcase lubricating oil composition suitable for a diesel engine having a gross vehicle weight of about 6,000 pounds or more, the heavy-duty crankcase lubricating oil composition comprising:
- one or more base oils of lubricating viscosity:
- a detergent system consisting of one or more alkaline earth metal sulfonate detergents delivering up to about 1 weight percent sulfonate soap to the lubricating oil composition:
- a dispersant system comprising one or more polyisobutylene succinimide dispersants delivering at least about 5 weight percent of the one or more dispersants to the lubricating composition;
- and
- wherein the one or more polyisobutylene succinimide dispersants are derived from highly reactive polyisobutylenes having a number average molecular weight of about 1,200 to about 2,500 and delivering more than 650 ppm nitrogen to the lubricating oil composition.
Dependencies are inferred from the claim text.