Alkylated alkoxydiarylamine antioxidants
Alkylated diaryl amines further substituted by an alkoxy group on one or more aryl carbon atoms exhibit excellent antioxidant activity in lubricant compositions.
1. A lubricating oil composition comprising
a) a lubricating oil, and
b) one or more alkylated alkoxydiarylamine of formula III:
wherein x is 0, 1 or 2 and y is 1, 2 or 3;
R′ is C 1-12 alkyl or C 1-12 alkyl substituted by one or more hydroxyl or alkoxy;
each R is independently C 4-24 alkyl, C 7-18 aralkyl, or C 4-24 alkyl substituted by one or more hydroxyl and/or interrupted by one or more oxygen atom;
wherein the total number of carbon atoms of the combined groups R is 12 or higher, and wherein at least one carbon atom adjacent to the amine nitrogen is unsubstituted.
2. The lubricating oil composition according to claim 1 wherein b) is present in an amount of about 0.1 to about 5.0 wt%, based on the weight of the lubricating oil composition.
3. The lubricating oil composition according to claim 1 wherein b) is present in an amount of greater than 5 wt%, up to about 50 wt%, based on the weight of the lubricating oil composition.
4. The lubricating oil composition according to claim 1 further comprising one or more alkylated diarylamine not substituted by an alkoxy group.
5. The lubricating oil composition according to claim 1 wherein in the alkylated alkoxydiarylamine of the formula III x is 0 or 1 and y is 1.
6. The lubricating oil composition according to claim 1 wherein the alkoxy group of the alkoxydiarylamine is at the 3-position relative to the nitrogen according to formula V:
7. The lubricating oil composition according to claim 1 wherein the total number of carbon atoms of the combined groups R is 16 or higher.
8. The lubricating oil composition according to claim 6 wherein in the alkylated alkoxydiarylamine of the formula V x is 0 or 1 and y is 1.
9. The lubricating oil composition according to claim 6 wherein in the alkylated alkoxydiarylamine of the formula V x is 1 and y is 1.
10. The lubricating oil composition according to claim 1 , wherein the alkoxy group R′O is on the phenyl ring at the 2- or 3-position relative to the nitrogen atom.
11. The lubricating oil composition according to claim 1 , wherein x is 1 and y is 1.
12. The lubricating oil composition according to claim 1 , wherein both aryl groups in the formula III are alkylated.
13. The lubricating oil composition according to claim 1 wherein x is 0, y is 1, R′ is methyl or ethyl, and R is selected from dodecyl, octadecyl, and icosane.
14. The lubricating oil composition according to claim 1 wherein x is 1, y is 1, R′ is methyl or ethyl, and R is selected from hexyl, octyl, nonyl, decyl, and dodecyl.
15. The lubricating oil composition according to claim 1 wherein x is 1, y is 1, R′ is methyl or ethyl, and one R is n-butyl, sec-butyl, tert-butyl or hexyl and the other R is t-octyl, nonyl, dodecyl, hexadecyl or octadecyl.
16. The lubricating oil composition according to claim 1 wherein x is 1, y is 1, R′ is butyl or hexyl, and R is selected from n-butyl, sec-butyl, iso-amyl, hexyl, octyl, nonyl, and dodecyl.
17. The lubricating oil composition according to claim 1 , wherein the lubricating oil comprises one or more hydrocarbon base stocks.
18. The lubricating oil composition according to claim 1 wherein x is 0 or 1 and y is 1 or 2.
19. The lubricating oil composition according to claim 1 wherein R′ is C 1-12 alkyl.
20. The lubricating oil composition according to claim 1 wherein each R is independently C 4-24 alkyl.
21. The lubricating oil composition according to claim 20 wherein R′ is C 1-6 .
22. The lubricating oil composition according to claim 21 wherein x is 0 or 1 and y is 1 or 2.