US 12,110,468 B1
Antiwear systems for improved wear in medium and/or heavy duty diesel engines
Leah Donham, Henrico, VA (US); and Abaigeal Ritzenthaler, Richmond, VA (US)
Assigned to Afton Chemical Corporation, Richmond, VA (US)
Filed by Afton Chemical Corporation, Richmond, VA (US)
Filed on Mar. 22, 2023, as Appl. No. 18/187,932.
Int. Cl. C10M 137/10 (2006.01); C10M 113/02 (2006.01); C10M 169/04 (2006.01); C10N 10/04 (2006.01); C10N 20/02 (2006.01); C10N 30/00 (2006.01); C10N 30/06 (2006.01); C10N 40/25 (2006.01)
CPC C10M 137/10 (2013.01) [C10M 113/02 (2013.01); C10M 169/04 (2013.01); C10M 2201/041 (2013.01); C10M 2223/045 (2013.01); C10N 2010/04 (2013.01); C10N 2020/02 (2013.01); C10N 2030/06 (2013.01); C10N 2030/40 (2020.05); C10N 2040/252 (2020.05)] 20 Claims
 
1. A medium or heavy duty diesel engine crankcase lubricant to reduce valve train wear, the lubricant comprising:
one or more base oils of lubricating viscosity;
an antiwear system providing about 200 to about 500 ppm of phosphorus and/or about 200 to about 500 ppm of zinc from one or more overbased zinc dihydrocarbyl dithiophosphate compounds including hydrocarbyl groups bonded to a phosphorus atom through an oxygen linker;
wherein the hydrocarbyl groups of the antiwear system are provided from secondary alcohols or combinations of secondary and primary alcohols, wherein the hydrocarbyl groups have an average degree of branching of about 0.2 to about 0.72 and at least about 50 weight percent of the hydrocarbyl groups are derived secondary alcohols, and wherein the hydrocarbyl groups of the antiwear system have an average chain length of 5 to 7 total carbons;
wherein the one or more overbased zinc dihydrocarbyl dithiophosphate compounds of the antiwear system herein have a zinc to phosphorous ratio of about 1.0:1 to about 1.12:1; and
wherein, when tested according to the Cummins ISB Engine Test (ASTM D7484-21b), the lubricant results in an Average Cam Shaft Wear (ACSW) of 55 μm or lower and/or an Average Tappet Mass Loss (ATWL) of 100 mg or lower.