Lubricating oil composition and method for producing same

Abstract

The lubricating oil composition of the present invention is a lubricating oil composition containing a lubricating base oil, a metal-based detergent, a molybdenum dialkyldithiocarbamate compound, and a boron-containing compound, wherein the metal-based detergent contains a calcium salicylate and at least one selected from the group consisting of a calcium sulfonate and a magnesium-based detergent; the lubricating oil composition arbitrarily contains an ashless friction modifier; the content of a calcium atom is 0.12 to 0.16 mass % on the basis of the whole amount of the lubricating oil composition; the content of a molybdenum atom is 0.05 to 0.10 mass % on the basis of the whole amount of the lubricating oil composition; and a predetermined coefficient X is less than 0.050.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a lubricating oil composition, for example, a lubricating oil composition for internal combustion engine to be used in a gasoline engine.BACKGROUND OF THE INVENTION[0002]In recent years, the environmental regulation is strengthened, and fuel consumption reduction of automobile engines is required. Thus, a supercharged direct injection engine mounted with a direct injection mechanism and a supercharging mechanism is being introduced. In the supercharged direct injection engine, by increasing a torque at a low rotational speed, the displacement can be decreased while keeping a power, and therefore, the fuel consumption can be improved.[0003]Meanwhile, in engine oils that are used for automobile engines, various additives are generally blended. For example, for the purpose of decreasing an intermetal friction coefficient to improve the fuel consumption, it is known to blend a molybdenum dialkyldithiocarbamate. In addition, fo...

AI Technical Summary

Benefits of technology

[0035]The present invention provides a lubricating oil composition, in which though it contains a molybdenum dialkyldithiocarbamate compound, with the amount of a molybdenum component being a predetermined amount or more, and has a low amount of a calcium component, a low friction coefficient can be realized while ensuring high-temperature detergency.

Problems solved by technology

However, when the blending amount of molybdenum is restricted as in the examples disclosed in PTL 1, there is a case where it becomes difficult to decrease the intermetal friction coefficient.

Furthermore, in an engine oil containing a molybdenum dialkyldithiocarbamate, in which the amount of a molybdenum component is a predetermine amount or more, the high-temperature detergency is frequently worsened.

For that reason, a large amount of a detergent dispersant may be blended, but detergent dispersants often increases the friction coefficient.

That is, in an engine oil in which the amount of a molybdenum component is a predetermined amount or more, and the amount of a calcium component is reduced, it is difficult to achieve both an improvement of high-temperature detergency and a decrease of friction coefficient that are compatible with each other.

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