US 8,048,833 B2 · Catalytic antioxidants

Abstract

The present invention is directed to lubricating oils exhibiting improved resistance to oxidation and deposit/sludge formation comprising a lubricant base oil and catalytic antioxidants comprising an effective amount of a) one or more polymetal organometallic compound; and, b) effective amounts of one or more substituted N,N′-diaryl-o-phenylenediamine compounds or c) one or more hindered phenol compounds or both, to a method for improving the antioxidancy and the resistance to deposit/sludge formation of formulated lubricating oil compositions by the addition thereto of an effective amount of the aforementioned catalytic antioxidants, and to an additive concentrate containing the aforementioned catalytic antioxidants.

Claims30

Dependent claims

A lubricating oil exhibiting improved resistance to oxidation and deposit/sludge formation comprising a major amount of lubricant base oil and catalytic antioxidants comprising

(a) an effective amount of one or more oil soluble dimanganese compounds having the formula [Mnn(Ligand)]2, where n is the oxidation state and Ligand is an organic moiety complexing the manganese;
and, effective amounts of
(b) one or more substituted N,N′-diaryl-o-phenylenediamine compounds having Formula I
where R1, R2, R3 and R4 are independently H or C1 to C12 alkyl;
or,
(c) one or more hindered phenol compound having Formula II
where R5 is OH and R6 is C1 to C8 alkyl;
or a combination of both (b) and (c).

5 more elements

Dependencies are inferred from the claim text.

Catalytic antioxidants

Life of this patent

Catalytic antioxidants

Life of this patent

Abstract

Claims30