Dihydrocarbyl substituted phenylenediamine-derived phenolic products as antioxidants

A lubricant composiion comprising a major amount of a lubricant and an amount sufficient to impart antioxidant and anticorrosion properties to the lubricant of a reaction product of a phenylenediamine which is selected from the group consisting of N,N'-di-sec-butyl-p-phenylenediamine and N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine, a carbonyl compound having the following structural formula:

• R.sub.3 R.sub.4 C.dbd.
• wherein R.sub.3 and R.sub.4 are the same or different, hydrogen atom, hydrocarbyl containing 1 to 60 carbon atoms or at least one heteroatom such as oxygen, sulfur or nitrogen and a dihydrocarbyl-substituted hindered phenol compound whereby the reaction product has improved lubricant solubility properties.

A method of making a lubricant composition comprising blending a major amount of a lubricant and a minor additive maount of a reaction product having antioxidant properties comprising a reaction product of a hydrocarbyl-sbustituted phenylenediamine compound in which the hydrocarbyl substitutent contains 4 to 60 carbon atoms, a carbonyl compound and a di-hydrocarbyl-substituted hindered phenol whreeby the lubricant has improved solubility properties.