Lubricant composition for internal combustion engines

Abstract

A lubricant composition for internal combustion engines is provided, which comprises a lubricant base oil and a sulfonate detergent, wherein the content of the sulfonate detergent is 0.8% to 1.5% (by weight) calculated on the basis of the composition; the sulfonate detergent comprises calcium sulfonate with a ultra-high base number more than 400 mg KOH / g, calcium sulfonate with a high base number of 300 to 350 mg KOH / g and lithium sulfonate with a base number less than 150 mg KOH / g. The lubricant composition has low contents of S, P and sulfuric ash, the additives used have a low cost and are easily available, and the economical efficiency is better. The lubricant composition can not only meet the requirements for normal operation of engines but also meet the requirements for normal operation of automobile exhaust gas recirculation (EGR) systems.

Description

technical field [0001] The present invention is an internal combustion engine lubricating oil composition, specifically, a lubricating oil composition for gasoline and diesel engines. Background technique [0002] With the increase of the number of automobiles in our country, automobile exhaust emission has become the main factor of polluting the environment. The exhaust gas contains substances that seriously pollute the air such as carbon monoxide, hydrocarbons and nitrogen oxides. Therefore, it is very necessary to filter and absorb vehicle exhaust. The current method of treating automobile exhaust is to install an exhaust converter, and the three-way catalyst in the converter oxidizes carbon monoxide and hydrocarbons in the exhaust to carbon dioxide and water, and nitrogen oxides are reduced to nitrogen and oxygen. [0003] Three-way catalysts are very sensitive to sulfur, phosphorus and ash in engine lubricating oil. Excessive sulfur content will lead to an increase in...

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Problems solved by technology

However, the preparation process of alkyl salicylate is complex and the product cost is high

[0022] Calcium sulfonate and alkyl salicylate are compounded to prepare lubricating oil composition. Although the advantages of both are combined, the additives are prone to turbidity or precipitation during the storage and use of the oil, which affects its further use.

[0023] Generally, a small amount of additives such as overbasic magnesium sulfonate, overbasic sodium sulfonate or overbasic potassium sulfonate will be introduced into compositions using overbasic calcium sulfonate as a metal detergent. The introduction of overbasic magnesium salt It has a certain impact on the high-temperature detergency of the composition, and the introduction of high-basic sodium sulfonate or potassium will reduce the anti-wear performance of the lubricating oil composition. At the same time, due to the high-basicity sodium or potassium salt anti-oxidation properties Due to the limitations, more antioxidants need to be introduced, which affects the economy of the formula

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