Lubricating oil composition

Abstract

A lubricant composition is disclosed which can largely reduce abrasion, can exhibit a low friction coefficient steadily, and has a high corrosion resistance in the lubrication of an iron-based sliding member. The lubricant composition includes a lubricant base oil, a 3,4,5-trihydroxybenzoic acid ester in an amount of 0.01 to 10 mass % relative to the total amount of the lubricant composition, and a detergent dispersant in an amount of 0.1 to 20 mass % relative to the total amount of the lubricant composition.

Description

TECHNICAL FIELD[0001]The present invention relates to a lubricating oil composition. In particular, the invention relates to a lubricating oil composition that is used as a lubricating oil for an internal combustion engine, as a lubricating oil for a driving system, or as a hydraulic oil.BACKGROUND ART[0002]In recent years, reduction in environmental load has become desirable in various fields. In particular, reduction of carbon dioxide (CO2) emission is a task of pressing urgency, and efforts to conserve energy have been made in various domestic industries and transport industries including automobile transportation, as well as in general public consumption.[0003]For example, in the automotive industry, the efficiency of gasoline engine has been improved by adopting lean-burn technology, direct-injection technology or the like in order to improve on fuel consumption and to reduce CO2 emissions. On the other hand, use of a low-friction material for sliding members, or adoption of fu...

AI Technical Summary

Benefits of technology

[0019]Since the lubricating oil composition according to the invention comprises a lubricating oil base oil, a 3,4,5-trihydroxybenzoic acid ester, and a detergent dispersant, it significantly reduces wear, stably exhibits low friction coefficient, and has an excellent rust prevention effect on iron sliding members. Therefore, the lubricating oil composition of the invention can be suitable for a long-term use, and exhibit a significant effect for energy conservation due to the low and stable friction coefficient.

[0020]A lubricating oil composition according to the invention contains a 3,4,5-trihydroxybenzoic acid ester in an amount of 0.01 to 10 mass %, and a detergent dispersant in an amount of 0.1 to 20 mass %, in addition to a lubricating oil base oil. Since a 3,4,5-trihydroxybenzoic acid ester exhibits low solubility in a mineral base oil or in a hydrocarbon base oil not containing a polar group such as ester, ether or the like, the 3,4,5-trihydroxybenzoic acid ester alone cannot be added to the effective concentration at which the improved lubricity is achieved. However, the 3,4,5-trihydroxybenzoic acid ester can be used at the effective concentration at which the improved lubricity is achieved if it is used in combination with a detergent dispersant.

[0021]Mineral oil, synthetic oil, animal/pla

Problems solved by technology

However, a reduction of phosphorus content in the lubricating oil could cause the problem of poor wear resistance, seizure, or the like.

However, a decrease in wear resistance of sliding members, seizure of sliding members, and so on, have been the problems associated with the lower viscosity.

Ideal characteristics of a lubricating oil is tha