Lubricant composition inhibiting adsorption of alpha-olefin, and method and agent for inhibiting adsorption of alpha-olefin

Abstract

A method for inhibiting adsorption of α-olefin in a lubricant composition to a metal surface is disclosed. The lubricant composition comprises any of oils of Group III, Group IV and polyisobutylenes classified into Group V according to the API base oil classification or a mixture thereof as a base oil, and the α-olefin coexisting in an amount of 1% by mass or less based on the total amount of the composition. The method comprises adding a sarcosinic acid derivative, an aspartic acid derivative or a diethanolamine derivative, or a mixture thereof to the lubricant composition.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a lubricant composition, and more particularly, to improvement of an industrial lubricating oil such as a working oil or a compressor oil.BACKGROUND OF THE INVENTION[0002]A lubricating oil such as a working oil or a compressor oil cannot obtain good oxidation stability and rust prevention and is difficult to use stably over a long period unless an additive package including a rust inhibitor as an additive is used in the lubricant composition. Therefore, a lubricant composition having desired oxidation stability and rust prevention has been obtained by adding an additive package including a rust inhibitor to a lubricant composition used as a working oil, a compressor oil, or the like.[0003]Although adding such an additive package including a rust inhibitor can usually obtain oxidation stability and rust prevention, with certain types of lubricant compositions, it has been found that even adding a commonly used additive pack...

AI Technical Summary

Benefits of technology

The patent improves the stability and prevents rust in a lubricant by blocking a small amount of α-olefin from adsorbing into the lubricant. This results in a better quality lubricant.

Problems solved by technology

A lubricating oil such as a working oil or a compressor oil cannot obtain good oxidation stability and rust prevention and is difficult to use stably over a long period unless an additive package including a rust inhibitor as an additive is used in the lubricant composition.

Although adding such an additive package including a rust inhibitor can usually obtain oxidation stability and rust prevention, with certain types of lubricant compositions, it has been found that even adding a commonly used additive package including a rust inhibitor cannot obtain sufficient oxidation stability and rust prevention.

Alpha-olefins are highly reactive, and presumably have an ill effect on oxidation stability.

Although the present inventors considered that substances having a rust-preventing effect would generally be effective, after testing to confirm the effect of various substances with the object of inhibiting the adsorbing effect of a very small quantity of an α-olefin in a lubricant composition, they concluded that just having a rust-preventing effect did not always mean that a substance would be effective.

Because Group III and Group IV base oils are 90 mass % or more saturated hydrocarbons, the present inventors tried obtaining the desired effect by adding a large quantity of an additive having a rust-preventing effect, and found that because additives have low solubility in base oils and adding a large quantity of an additive is disadvantageous economically, an additive which has an effect by adding a small quantity had to be selected.

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