Lubricant composition for bio-diesel fuel engine applications

Abstract

A diesel engine operating on a fuel containing from about 5 to about 100 wt. % bio-diesel components and being lubricated with a lubricating oil composition including a major amount of oil of lubricating viscosity, and a minor amount of at least one highly grafted, multi-functional olefin copolymer. The olefin copolymer is made by reacting an acylating agent with an olefin copolymer having a number average molecular weight greater than about 1,000 in the present of a free radical initiator to provide an acylated olefin copolymer having a degree of grafting (DOG) of the acylating agent on the olefin copolymer of at least 0.5 wt. %, and reacting the acylated olefin copolymer with an amine to provide the highly grafted, multi-functional olefin copolymer. As used, the highly grafted, multi-functional olefin copolymer is effective to reduce a viscosity increase in the lubricating oil composition for the engine.

Description

RELATED APPLICATION[0001]This application claims priority to provisional application No. 60 / 887,539, filed Jan. 31, 2007.TECHNICAL FIELD[0002]The disclosure relates to bio-diesel fuel engine lubrication and to improved lubricant compositions for bio-diesel fuel engine applications that provide improved properties.BACKGROUND AND SUMMARY[0003]Emission requirements for all vehicles have become increasingly more stringent. For instance, diesel engine design changes required to meet emission requirements have led to increased levels of soot in engine lubricants. An increased level of soot may cause increased wear when oils are not properly formulated due to an increase in oil viscosity and / or inability of the oil to disperse particles that may cause engine wear. In particular, with the arrival of new exhaust gas recirculation or recycle (hereinafter “EGR”) cooled engines including cooled EGR engines, a problem has developed in the ability of the conventional lubricating oils to handle th...

AI Technical Summary

Benefits of technology

[0005]In accordance with a first exemplary embodiment, the disclosure provides a diesel engine operating on a fuel containing from about 5 to about 100 percent by weight bio-diesel fuel. The engine is lubricated with a major amount of oil of lubricating viscosity, and a minor amount of at least one highly grafted, multi-functional olefin copolymer made by reacting an acylating agent with an olefin copolymer having a number average molecular weight greater than about 1,000 in the present of a free radical initiator to provide an acylated olefin copolymer having a degree of grafting (DOG) of the acylating agent on the olefin copolymer of at least 0.5 wt. %, and reacting the acylated olefin copolymer with an amine to provide the highly grafted, multi-functional olefin copolymer. In the engine, the highly grafted, multi-functional olefin copolymer is effective to reduce a viscosity increase in the lubricating oil composition for the engine to less than or equal to a viscosity increase in a lubrication oil composition for an engine operating on a fuel devoid of the bio-diesel components.

[0006]In another exemplary embodiment, the disclosure provides method for reducing a viscosity increase in a lubricating oil composition for a diesel engine operating on a fuel containing from about 5 to about 100 wt. % bio-diesel. The engine is lubricated with a lubricant composition containing a major amount of oil of lubricating viscosity, and a minor amount of at least one highly grafted, multi-functional olefin copolymer made by reacting an acylating agent with an olefin copolymer having a number average molecular weight greater than about 1,000 in the present of a free radical initiator to provide an acylated olefin copolymer having a degree of grafting (DOG) of the acylating agent on the olefin copolymer of at least 0.5 wt. %, and reacting the acylated olefin copolymer with an amine to provide the highly grafted, multi-functional olefin copolymer. The engine is operated to provide a viscosity increase as determined by a T-11 engine test in the lubricating oil composition that is less than a viscosity increase in the lubricating oil for an engine operating on a diesel fuel devoid of bio-diesel components.

[0007]Accordingly, a primary advantage of the exemplary embodiments may be an increased in oil change intervals due to a lower viscosity increase in the lubricating oil for an engine operating on a fuel containing bio-diesel components.

Problems solved by technology

For instance, diesel engine design changes required to meet emission requirements have led to increased levels of soot in engine lubricants.

An increased level of soot may cause increased wear when oils are not properly formulated due to an increase in oil viscosity and / or inability of the oil to disperse particles that may cause engine wear.

In particular, with the arrival of new exhaust gas recirculation or recycle (hereinafter “EGR”) cooled engines including cooled EGR engines, a problem has developed in the ability of the conventional lubricating oils to handle the resulting increased soot loading.

Certain diesel engines with cooled EGR may exhibit undesirable oil thickening because of the way soot and blowby generated in the engine contaminate the engine oil.

Increasing the treat rate of standard dispersants in the lubricating oils may not adequately solve the problems caused by an increased use of bio-diesel fuels in the engines.

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