| abstract |
A lubricating oil, grease or fuel composition contains an antioxidant amount of a Mannich base reaction product of an N-hydrocarbyl-substituted-phenylenediamine or an N,N'-dihydrocarbyl-substituted phenylenediamine such as N,N'-di-sec-butyl-para-phenylenediamine, an aldehyde or ketone and a hindered phenol such as 2,6-di-tert-butylphenol. |