Claims
- 1. An antioxidant composition comprising the reaction product of:(a) at least one N-aryl naphthylamine (PNA); (b) at least one diphenylamine (DPA); and (c) about 0.5 to about 3 moles of an organic peroxide free radical source per mole of said PNA and said DPA; said N-aryl naphthylamine having a total of from one to six and on each aryl or naphthyl ring up to three alkyl, styryl, or methyl substituted styryl groups, or combinations thereof, wherein said alkyl has from 1 to 20 carbon atoms; said diphenylamine having a total of from one to six and on each phenyl ring up to three alkyl, styryl, or methyl substituted styryl groups, or combinations thereof, each alkyl having from 1 to 20 carbon atoms; wherein the mole ratio of said diphenylamine to said N-aryl naphthylamine is from 1:1 to 10:1, wherein the reaction of (a), (b), and (c) is conducted at temperatures from about 70° C. to about 200° C., wherein the reaction product has at least 10 mole percent of said DPA in the form of homo-oligomers of DPA, and wherein the reaction product has at least 35 mole percent of said PNA and DPA in the form of cross oligomers of DPA and PNA.
- 2. The antioxidant composition according to claim 1, wherein said peroxide free radical source is present in amounts from about 0.5 to about 2 moles per mole of combined moles diphenylamine and aryl naphthylamine, and wherein said mole ratio of diphenylamine to N-aryl naphthylamine is about 1.2:1 to about 5:1.
- 3. The antioxidant composition according to claim 2, wherein said groups on the diphenylamine are independently C4 to C8 alkyl radicals or styryl or methyl substituted styryl and said groups on the N-aryl naphthylamine are independently C4 to C8 alkyl radicals or styryl or methyl substituted styryl groups, and wherein said mole ratio of diphenylamine to N-aryl naphthylamine is from 1.5:1 to 4:1.
- 4. The antioxidant composition according to claim 3, wherein said at least one N-aryl naphthylamine and said at least one diphenylamine are reacted with an organic peroxide at a temperature of about 130° C. to about 150° C. to form primarily dimers and cross oligomers of said diphenylamine.
- 5. The antioxidant composition according to claim 4, wherein the alkyl groups on said diphenylamine and N-aryl naphthylamine are t-octyl groups.
- 6. The antioxidant composition according to claim 4, wherein said organic peroxide is present in amounts of about 1 to 1.5 moles per combined moles of diphenylamine and N-aryl naphthylamine.
- 7. The antioxidant composition according to claim 6, wherein the reaction is carried out in an alkane solvent free of peresters.
- 8. The antioxidant composition according to claim 4, wherein said reaction product has at least 40 mole percent of said DPA and PNA in the form of cross oligomers of DPA and PNA.
- 9. The antioxidant composition according to claim 4, including a solvent, wherein the product has no more than 30 mole % of said diphenylamine dehydrocondensed with the solvent.
- 10. In a process for making antioxidant stabilizers from one or more mono or poly (alkyl and/or styryl and/or methyl styryl) substituted N-aryl naphthylamines (PNA) and mono or poly (alkyl and/or styryl and/or methyl styryl) substituted diphenylamines (DPA), the improvement which comprises using a mole ratio of diphenylamines to N-aryl naphthylamines of about 1:1 to about 10:1 and reacting said PNA and DPA in the presence of about 0.5 to about 3 moles of a peroxide free radical source per mole of said PNA and said DPA at a temperature from about 70° to about 200° C., and producing a reaction product having at least 10 mole percent of said DPA in the form of homo-oligomers of DPA, and wherein the reaction product has at least 35 mole percent of said PNA and DPA in the form of cross oligomers of DPA and PNA.
- 11. The process according to claim 10, wherein said alkyl groups are C4-C8 alkyl groups and said styryl groups are styryl or methyl substituted styryl; wherein said mole ratio diphenylamine to N-aryl naphthylamine is about 1.5:1 to about 4:1; wherein the free radical source has a half life of one hour at a temperature from 70° C. to 200° C.
- 12. The process according to claim 11, wherein the reaction of said PNA and DPA is conducted in an alkane solvent, said alkane having from 6 to 16 carbon atoms.
- 13. The process according to claim 11, wherein the reaction of the PNA and DPA is conducted in the presence of a synthetic ester lubricant.
- 14. The process according to claim 11, wherein the reaction is conducted in a solvent, and wherein no more than 30 mole percent of said DPA is reacted into dehydrocondensation products with said solvent.
- 15. The process according to claim 14, wherein the reaction product has less than 10 wt. % of PNA and DPA in monomeric form.
- 16. The process according to claim 15, wherein said free radical source is present at a concentration from about 1.0 to about 1.5 moles per combined moles of DPA and PNA.
- 17. An antioxidant composition comprising homo-oligomers of diphenylamine and cross oligomers of diphenylamine with N-aryl naphthylamine and optionally a solvent, wherein said diphenylamine includes substituted diphenylamine having a total of from one to six and on each phenyl ring up to three, independently, alkyl, methylstyryl or styryl groups, wherein said alkyl groups have from 1 to 20 carbon atoms; wherein said N-aryl naphthylamine has a total of from one to six and on each aryl or naphthyl ring up to three, independently alkyl, methylstyryl, or styryl groups, wherein said alkyl group has from 1 to 20 carbon atoms; wherein said homo-oligomers of diphenylamine are at least 10 mole % of the total diphenylamine units; and wherein the cross oligomers have at least 40 mole % of the total diphenylamine and N-aryl naphthylamine units.
- 18. The antioxidant composition according to claim 17, wherein the amount of said homo-oligomers of diphenylamine are about 15 to about 30 mole % and wherein said cross oligomers are at least 50 mole %.
- 19. The antioxidant composition according to claim 18, wherein said alkyl groups of said diphenylamine oligomer are t-butyl or t-octyl and said alkyl groups on said N-aryl maphthylamine are t-butyl or t-octyl.
- 20. A lubricating fluid composition stabilized against oxidative and thermal degradation which comprises:a) a lubricating fluid containing a synthetic ester fluid subject to thermal or oxidative degradation, and b) an effective stabilizing amount of an antioxidant composition of claim 1.
- 21. A composition according to claim 20, wherein the synthetic ester fluid is at least 50 weight percent of said composition.
- 22. A composition according to claim 20, wherein the mole ratio of diphenylamine to N-aryl naphthylamine in said reaction product antioxidant is about 1.2:1 to about 5:1; and wherein said reaction product contains at least 40 mole percent of said diphenylamines and N-aryl naphthylamines in the form of cross oligomers of DPA and PNA.
- 23. A lubricant composition which comprises a major amount of an ester fluid lubricant and 0.1 to 10 weight percent, based on the total weight of the lubricant composition, of an antioxidant composition comprising the reaction product of:(a) at least one N-aryl naphthylamine wherein said N-aryl naphthylamine has up to three independent alkyl and/or styryl substituent groups on each aryl ring, wherein said alkyl has from 1 to 20 carbon atoms and said styryl is styryl or methyl substituted styryl; (b) at least one diphenylamine wherein the phenyl groups are individually phenyl or phenyl having up to 3 alkyl or styryl substituent groups on each aryl ring, each alkyl having from 1 to 20 carbon atoms and the styryl being styryl or methyl substituted styryl; and (c) an organic peroxide free radical source; wherein the mole ratio of said diphenylamine to said N-aryl naphthylamine is about 1:1 to about 10:1, the reaction is conducted from about 70° C. to 200° C. and the reaction product comprises primarily a mixture of homo-oligomers of said diphenylamine and cross oligomers of said N-aryl naphthylamine and said diphenylamine.
- 24. The lubricant of claim 23 wherein the amount of the antioxidant composition is about 0.5 to about 5.0 weight percent based on the total weight of the lubricant and wherein the antioxidant composition comprises the reaction product of p,p′-di-t-octyl diphenylamine (DODPA) with N-(p-octylphenyl)-1-naphthylamine (OPNA) in a DODPA:OPNA mole ratio in the range of about 1.75:1 to about 3:1.
- 25. A lubricant composition which comprises a major amount of an ester fluid lubricant and 0.1 to 10 weight percent, based on the total weight of the lubricant composition, of an antioxidant composition comprising the reaction product of:(a) at least one N-aryl naphthylamine wherein said N-aryl naphthylamine has up to three independent alkyl groups on each aryl ring, and wherein each said alkyl group has from 1 to 20 carbon atoms; (b) at least one diphenylamine wherein the phenyl groups are individually phenyl or phenyl having up to 3 alkyl substituent groups on each phenyl ring, each alkyl having from 1 to 20 carbon atoms; and (c) an organic peroxide free radical source; wherein the mole ratio of said diphenylamine to said N-aryl naphthylamine is about 1:1 to about 10:1, the reaction is conducted from about 70° C. to 200° C. and the reaction product comprises primarily a mixture of homo-oligomers of said diphenylamine and cross oligomers of said N-aryl naphthylamine and said diphenylamine.
- 26. The lubricant of claim 1 wherein (i) the diphenylamine (DPA-H) is represented by the following general formula: wherein each R1 and R2 independently are H, or branched or straight chain C1-C20 alkyl radicals and m and n each represent 0, 1, 2 or 3 and (ii) the N-aryl naphthylamine is N-phenyl naphthylamine (PNA-H) represented by the general formula: wherein R3 and R4 are independently C1 to C20 branched or straight chain alkyl radicals and o and p represent 0, 1, 2, or 3 and the mole ratio of (DPA-H) to (PNA-H) is from 1:1 to 10:1.
- 27. The lubricant of claim 26 wherein the peroxide free radical source is present in an amount of about 0.5 to about 3 moles per mole of combined DPA-H and PNA-H and wherein the mole ratio of DPA-H to PNA-H is about 1.2:1 to about 5:1.
- 28. The lubricant of claim 27 wherein R1, R2, R3, and R4 are independently C4 to C8 alkyl radicals and m, n, o and p are 1.
- 29. The lubricant of claim 28 wherein R1, R2, R3, and R4 are t-octyl radicals.
- 30. The lubricant of claim 29 wherein the molar ratio of said organic peroxide to the combined moles of DPA-H and PNA-H is about 1:1 to about 1:5 and wherein the reaction product is substantially free of permanganate.
- 31. The lubricant of claim 28 wherein the mole ratio of DPA-H to PNA-H is about 1.75:1 to about 3:1.
- 32. The lubricant of claim 31 wherein R1, R3 and R4 are independently t-butyl or t-octyl radicals.
- 33. The lubricant of claim 32 wherein the reaction product is at least 30 wt % of oligomers containing at least one DPA unit and one PNA unit.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation in part of U.S. Ser. No. 08/166,851 filed Dec. 15, 1993, now abandoned.
US Referenced Citations (11)
Non-Patent Literature Citations (1)
Entry |
“Fate of Amine Antioxidants During Thermal Oxidative Ageing of Neopentypolyl Ester Oils”, Journal of Synthetic Lubrication, 4, pp. 179-201 (1987), Loaf Coppin Pub., Ltd.: Kent, England |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
08/166851 |
Dec 1993 |
US |
Child |
09/696617 |
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US |