Claims
- 1. An additive composition for use in crankcase lubricating oils comprising:
- (1) an oil-soluble antioxidant selected from aromatic and alkyl sulfides and polysulfides, sulfurized olefins, sulfurized carboxylic acid esters, and sulfurized ester-olefins, and
- (2) an oil-soluble secondary amine of the formula: ##STR6## wherein R and R' are aliphatic radicals.
- 2. The composition of claim 1 wherein the weight ratio of the antioxidant to the secondary amine is 1:0.001-21, and R and R' each contain from 6 to 30 carbon atoms.
- 3. A lubricating oil composition comprising a major amount an oil of lubricating viscosity and an antioxidant amount of the composition of claim 1.
- 4. A lubricating oil composition comprising a major amount an oil of lubricating viscosity and an antioxidant amount of the composition of claim 2.
- 5. The composition of claim 4 comprising an oil of lubricating viscosity, from 0.25 to 10% weight of said antioxidant, and from 0.001 to 5% weight of said secondary amine.
- 6. The composition of claim 5 which contains an antioxidant-antiwear amount of an oil-soluble zinc dihydrocarbyldithiophosphate salt, and wherein the antioxidant is a wax sulfide or polysulfide.
- 7. The composition of claim 6 which contains from 2 to 40 mmols of zinc per kilogram of composition, present as the oil-soluble zinc salt, from 0.25 to 2% weight of a paraffin wax thiomer antioxidant, and from 0.01 to 0.3% weight of the secondary amine.
- 8. The composition of claim 5 wherein R and R' are each alkyl of 6 to 18 carbon atoms.
- 9. The composition of claim 7 wherein the secondary amine is dicocoamine and the zinc salt is zinc dihydrocarbyl dithiophosphate.
- 10. The composition of claim 9 wherein said zinc salt is a zinc dialkyldithiophosphate wherein each alkyl group contains from 4 to 8 carbon atoms.
- 11. The composition of claim 5 wherein the antioxidant is a sulfurized cracked wax olefin and the secondary amine is dicocoamine.
- 12. A lubricating oil additive concentrate which comprises from 90-10% weight of an oil of lubricating viscosity and from 10-90% weight of the composition of claim 1.
- 13. A method for preparing the lubricating oil composition of claim 3 which comprises admixing an oil of lubricating viscosity with (1) an oil-soluble antioxidant selected from aromatic and alkyl sulfides and polysulfides, sulfurized olefins, sulfurized carboxylic acid esters and sulfurized ester-olefins, and (2) an oil-soluble secondary amine of the formula ##STR7## wherein R and R' are aliphatic radicals, wherein the weight ratio of the antioxidant to the secondary amine is 1:0.001-21.
- 14. A method for inhibiting the oxidation of a lubricating oil which comprises adding to said lubricating oil from 0.25 to 10% weight of (1) an oil-soluble antioxidant selected from aromatic and alkyl sulfides and polysulfides, sulfurized olefins, sulfurized carboxylic acid esters and sulfurized ester-olefins, and (2) from 0.001 to 5% weight of an oil-soluble secondary amine of the formula ##STR8## wherein R and R' are aliphatic radicals.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of copending application Ser. No. 672,805, filed Apr. 4, 1976 now U.S. Pat. No. 4,102,796, the entire disclosure of which is incorporated herein by reference.
US Referenced Citations (7)
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
672805 |
Apr 1976 |
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