Coupled Phenols for Use in Biodiesel Engines
AssigneeThe Lubrizol Corporation
InventorYanshi Zhang
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Abstract
The invention provides a lubricating composition containing an oil of lubricating viscosity and an alkylene-coupled phenol compound for use in engines operated with biodiesel fuels or fuel blends containing biodiesel components. The invention further relates to methods of lubricating an internal combustion engine fueled with biodiesel by supplying the described lubricating composition to the internal combustion engine. The invention further relates to the use of the alkylene-coupled phenol compound to reduce corrosion and oxidative instability resulting from biodiesel introduction into the lubricant.
Claims20
A lubricating oil composition containing or contaminated with at least about 0.1 wt. % of a biodiesel fuel or a decomposition product thereof, based on the total weight of the lubricating oil composition, said lubricating composition further comprising an oil of lubricating viscosity and about 0.05 to about 8 weight percent of an antioxidant which comprises an alkylene-coupled phenol, wherein the alkylene-coupled phenol comprises at least two phenol units, at least one phenol unit thereof having a hydrocarbyl substituent in the position para to the hydroxy group of said phenol unit;
- an alkyl group which is hydrocarbyl-substituted in the 1 and/or 2 position thereof, located in a position ortho to the hydroxy group of said phenol unit;
- and an alkylene linking group in the other ortho position of said phenol unit.
A method for lubricating a diesel engine fueled with a liquid fuel containing at least about 2 percent by weight of a fatty acid alkyl ester, comprising supplying to said engine a lubricant comprising an oil of lubricating viscosity and about 0.05 to about 8 weight percent of an antioxidant which comprises an alkylene-coupled phenol, wherein the alkylene-coupled phenol comprises at least two phenol units, at least one phenol unit thereof having a hydrocarbyl substituent in the position para to the hydroxy group of said phenol unit;
- an alkyl group which is hydrocarbyl-substituted in the 1 and/or 2 position thereof, located in a position ortho to the hydroxy group of said phenol unit;
- and an alkylene linking group in the other ortho position of said phenol unit.
Dependencies are inferred from the claim text.