Sulfurized phenolic antioxidant composition, method of preparing same, and petroleum products containing same
AssigneeEthyl Corporation
InventorsWilliam Y. Lam, Vincent J. Gatto
Life of this patent
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Abstract
The present invention relates generally to substantially liquid, chlorine-free, sulfur-bridged phenols useful as antioxidants and more specifically to the preparation of a substantially liquid, chlorine-free, sulfur-bridged, hindered phenol compositions which are effective antioxidant(s) in lubricating oils without causing excessive copper corrosion. The invention also includes lubricating oils containing an antioxidant additive of the present invention, as well as a method of reducing oxidation in the lubricating oil used in a machine such as an internal combustion engine.
Claims16
An antioxidant composition comprising at least one thiophenol, wherein said antioxidant composition is prepared by a process comprising
- (a) preparing a mixture of:
- (i) at least two different chlorine-free reactive hindered phenols, wherein said reactive hindered phenols comprise a mixture of at least one dialkyl substituted phenol and at least one monoalkyl substituted phenol;
- (ii) a chlorine-free sulfur source;
- and
- (iii) at least one alkali metal hydroxide promoter;
- in a polar solvent;
- and
- (b) causing components (i), (ii) and (iii) to react for sufficient time and at sufficient temperature so as to form an antioxidant composition, said antioxidant composition being substantially free of chlorine, and said antioxidant composition being in a substantially liquid form.
An additive composition comprising:
- A) from about 30% to about 95% by weight of an antioxidant composition prepared by a process comprising
- (a) preparing a mixture of:
- (i) at least two different chlorine-free reactive hindered phenols, wherein said reactive hindered phenols comprise a mixture of at least one dialkyl substituted phenol and at least one monoalkyl substituted phenol;
- (ii) a chlorine-free sulfur source;
- and
- (iii) at least one alkali metal hydroxide promoter;
- in a polar solvent;
- and
- (b) causing components (i), (ii) and (iii) to react for sufficient time and at sufficient temperature so as to form an antioxidant composition, said antioxidant composition being substantially free of chlorine, and said antioxidant composition being in a substantially liquid form;
- and
- B) the balance of said additive composition comprising at least one mineral or synthetic lubricant oil.
A method of reducing the oxidative environment in a petroleum composition selected from the group consisting of lubricating compositions and liquid organic fuels, said method comprising adding to said petroleum composition an effective amount of an antioxidant composition wherein said antioxidant composition is prepared by a process comprising
- (a) preparing a mixture of:
- (i) at least two different chlorine-free reactive hindered phenols, wherein said reactive hindered phenols comprise a mixture of at least one dialkyl substituted phenol and at least one monoalkyl substituted phenol;
- (ii) a chlorine-free sulfur source;
- and
- (iii) at least one alkali metal hydroxide promoter;
- in a polar solvent;
- and
- (b) causing components (i), (ii) and (iii) to react for sufficient time and at sufficient temperature so as to form an antioxidant composition, said antioxidant composition being substantially free of chlorine, and said antioxidant composition being in a substantially liquid form.
Dependencies are inferred from the claim text.