Antioxidants and methods of making antioxidants
View Patent ↗Antioxidants for industrial, automotive, and aviation lubricants and methods of making the same are provided. A process using alkylated diphenylamines; alkylated phenyl-α-naphthyl amines; and a metal catalyst to form oxidates is provided. The metal catalyst is a combination of a cation and an organic anion, for example, a metal acetylacetone. The reaction takes place in the presence of oxygen to form an antioxidant comprising oligomers of the alkylated diphenylamine and the alkylated phenyl-α-naphthyl amine, and a metal component of the catalyst.
1. A process comprising:
providing an alkylated diphenylamine;
providing an alkylated phenyl-α-naphthyl amine;
providing a catalyst that comprises a cation and an organic anion;
mixing the alkylated diphenylamine, the alkylated phenyl-α-naphthyl amine, and the catalyst to form a reaction mixture; and
flowing an oxygen-containing gas through the reaction mixture to form an antioxidant comprising oligomers of the alkylated diphenylamine and the alkylated phenyl-α-naphthyl amine, and the cation.
2. The process of claim 1 , wherein the catalyst is substantially oil-soluble.
3. The process of claim 1 , wherein the catalyst comprises a metal acetylacetoneate.
4. The process of claim 3 , wherein the metal acetylacetoneate is substantially oil-soluble.
5. The process of claim 1 , wherein the reaction occurs at a temperature of less than or equal to approximately 200° C.
6. The process of claim 1 , wherein the reaction occurs at a temperature of less than or equal to approximately 155° C.
7. The process of claim 1 , further comprising providing a base lubricant and mixing the reaction mixture with the base lubricant.
8. The process of claim 1 , further comprising blending the antioxidant, an additive package, and an ester to form a lubricant formulation.
9. The process of claim 1 , wherein a molar ratio of the cation to nitrogen in the reaction mixture is less than or equal to approximately 0.05:1.
10. The process of claim 9 , wherein the molar ratio is less than or equal to approximately 0.025:1.
11. The process of claim 1 , wherein the cation comprises Co (III), Co (II), Mn (II), or combinations thereof.
12. The process of claim 3 , wherein a metal of the metal acetylacetoneate comprises Co (III), Co (II), Mn (II), or combinations thereof.
13. The process of claim 1 , further comprising treating the antioxidant to reduce an amount of the cation.
14. The process of claim 1 , further comprising filtering the antioxidant.
15. The process of claim 13 , wherein the amount of the cation is less than or equal to approximately 1 ppm.
16. The process of claim 1 , wherein a molar ratio of alkylated diphenylamine to alkylated phenyl-α-naphthyl amine is from approximately 1:1 to approximately 5:1 before the reaction.
17. The process of claim 16 , wherein the molar ratio is approximately 3:1.
18. An antioxidant composition produced from a process of
providing an alkylated diphenylamine;
providing an alkylated phenyl-α-naphthyl amine;
providing a metal acetylacetoneate;
mixing the alkylated diphenylamine, the alkylated phenyl-α-naphthyl amine, and the metal acetylacetoneate to form a reaction mixture; and
flowing an oxygen-containing gas through the reaction mixture;
wherein the antioxidant composition comprises oligomers of the alkylated diphenylamine and the alkylated phenyl-α-naphthyl amine, and a metal component of the metal acetylacetoneate.
19. The composition of claim 18 , wherein an amount of the metal component is less than approximately 100 ppm.
20. A method of providing an antioxidant for industrial, automotive and aviation lubricants comprising providing to said lubricants an antioxidant comprising oligomers of an alkylated diphenylamine and an alkylated phenyl-α-naphthyl amine, and a metal component of a metal acetylacetoneate.