Thiophosphate esters as antiwear additives for lubricants
AssigneeAfton Chemical Corporation
InventorDarryl Williams
Life of this patent
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Abstract
The present disclosure relates to the discovery of certain ashless antiwear additives in the form of dialkyl dithiophosphate triester compounds having specific oxygen ester moieties and a specific sulfur ester moiety that combine to provide an antiwear additive that achieves performance in lubricants without the need for (or with reduced levels of) metals provided by more traditional metal-based antiwear additives. Thus, the ashless antiwear additives of the present disclosure can supplement and/or replace traditional ZDDP additives used in lubricants and still achieve desired wear and durability performance targets in all types of automotive engines.
Claims26
An ashless antiwear additive comprising:
- a triester of a dithiophosphate having two oxygen ester moieties and a sulfur ester moiety;
- each oxygen ester moiety, independently, includes at least 2 or more β-hydrogens on a linear or branched hydrocarbyl group;
- the sulfur ester moiety includes one or more heteroatoms selected from oxygen or nitrogen and having up to 4 carbon atoms linking at least one of the heteroatoms to the sulfur atom of the sulfur ester;
- and
- a molecular weight of at least about 490 g/mol.
A passenger car motor oil comprising:
- one or more base oils of lubricating viscosity;
- and
- a triester of a dithiophosphate antiwear additive including (i) two oxygen ester moieties with each moiety having at least 2 or more β-hydrogens on a linear or branched hydrocarbyl group;
- (ii) a sulfur ester moiety including one or more heteroatoms selected from oxygen or nitrogen and having up to 4 carbon atoms linking at least one of the heteroatoms to the sulfur atom of the sulfur ester;
- and (iii) a molecular weight of at least about 490 g/mol.
Dependencies are inferred from the claim text.