Lubricants containing amine antioxidants

Abstract

Lubricants containing a mixture of p,p'-dioctyldiphenylamine and substituted naphthylamines have improved antioxidant properties.

I claim: 
     
       1. A lubricant composition comprising a major proportion of a lubricant and an antioxidant amount of a mixture comprising p,p'-dioctyldiphenylamine and a substituted naphthylamine of .[.the formula.]. .Iadd.one of the formulas .Iaddend. ##SPC5## ##SPC6## ##SPC7## wherein R is .[.NO 2  or.]. an alkyl of from 4 to 20 carbon atoms, Ar is phenyl or naphthyl, R' is hydrogen or phenylazo, .[.R' being only hydrogen when R is nitro,.]. .Iadd.R" is phenylazo .Iaddend.and x is 1 or 2.   
     
     
       2. The composition of claim 1 wherein the p,p'-dioctyldiphenylamine is present therein to the extent of from about 0.001% to about 5% by weight. 
     
     
       3. The composition of claim 1 wherein the substituted naphthylamine is present therein to the extent of from about 0.001% to about 5% by weight. 
     
     
       4. The composition of claim 1 wherein the mixture comprises from about 0.002% to about 10% by weight thereof. 
     
     
       5. The composition of claim 1 wherein the lubricant is a lubricating oil or grease. 
     
     
       6. The composition of claim 5 wherein the lubricating oil is a synthetic ester lubricating oil. 
     
     
       7. The composition of claim 1 wherein the substituted naphthylamine is N-2,4-dinitrophenyl-1-naphthylamine.  .[.8. The composition of claim 1 wherein the substituted naphthylamine is 
     
     
        N-tert-octylphenyl-1-naphthylamine..]. 9. The composition of claim 1 wherein the substituted naphthylamine is 
     
     
        N-(4-tert-octylphenyl)-4-phenylazo-1-naphthylamine. 10. .[.The composition of claim 1 wherein the substituted naphthylamine is.]. .Iadd.A lubricant comprising a major proportion of a lubricant and an antioxidant amount of a mixture comprising p,p'-dioctyldiphenylamine and .Iaddend.1,1'-dinaphthylamine.