Lubricating compositions with enhanced deposit performance

Abstract

A lubricant composition includes a lubricating base oil, a controlled release friction modifier, a dispersant, a viscosity modifier and a cleanliness booster. The controlled release friction modifier is an ashless, dispersant-stabilized, borated controlled release friction modifier including an ionic tetrahedral borate compound including a cation and a tetrahedral borate anion, wherein the tetrahedral borate anion includes a boron atom having two bidentate di-oxo ligands of C₁₈ tartrimide.

Description

[0001]This nonprovisional application claims priority to U.S. Provisional Application No. 62 / 535,527, which was filed on Jul. 21, 2017, and is herein incorporated by reference.BACKGROUND OF THE INVENTIONField of the Invention[0002]The present invention relates to a lubricant composition, in particular, a lubricant composition, suitable for use in, for example, internal combustion engines, which reduces deposit formation and friction in an engine.Description of the Background Art[0003]Engine oils are formulated for the purpose of reducing friction in the engine, engine cleanliness (e.g., deposit control), control of wear, corrosion and rust in the engine. To accomplish this goal, engine oils contain numerous and various additives including friction modifiers, detergents, dispersants, viscosity modifiers and antioxidants.[0004]Of significant concern is the reduction of friction in engines so as to improve fuel economy necessitating the use of lower viscosity lubricating base stocks wh...

AI Technical Summary

Benefits of technology

[0015]Accordingly, the claimed invention includes a dispersant-stabilized, borated CRFM that provides a much larger amount of friction modifier in the lubricating oil composition, which results in improved overall fuel economy. Additionally, the CRFM is a low-ash composition, which reduces potential damage from ash to ash particulate filters.

[0016]Adding the above CRFM to a lubricating oil composition offers a number of challenges, including CRFM deposit formation. The composition of the present invention has surprisingly mitigated the formation of deposits from the CRFM by also including a combination of additives that include a synergistic use of dispersant, viscosity modifier and cleanliness booster. Thus, the present invention provides a lubricating oil composition that not only improves overall fuel economy but does so while meeting other performance specifications that require the VW TDi2 (CEC L-78-99).

Problems solved by technology

Because there are many requirements, the chemistry used to formulate engine oils is complex.

Often a particular additive that can improve one aspect of a lubricant's performance works against the performance enabled by other additives.

Such oils are highly non-polar and, as a result, have a limited amount of solubility for polar additives.

Additionally, the use of highly paraffinic base oils can increase the amount of unwanted deposit formation.

Specifically, most fuel economy additives, including the friction modifiers detailed above, are highly polar and, as such, are challenged to remain soluble in the lubricating oil.

With limited solubility and availability of the additives, improvements in fuel economy are similarly limited.

In addition, many of the additives degrade or are consumed in service with the result that fuel economy is more difficult to maintain for extended times. Additionally, conventional friction modifiers typically cause increased deposit formation as they have limited solubility and are rapidly oxidized in-service.

These documents, however, do not describe compositions that have been formulated to provide increased fuel economy while also reducing deposit formation and friction in an engine.

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