Epoxidized ester additives for reducing lead corrosion in lubricants and fuels

Abstract

Fuels, especially hydrocarbon fuels, and lubricants, especially lubricating oils, contain a class of anti-corrosion, anti-fatigue, and anti-wear additives that are derived epoxidized esters of fatty acids. Epoxidized 2-ethylhexyl tallate is particularly effective.

Description

[0001] I claim the benefit under Title 35, United States Code, § 120 of U.S. Provisional Application No. 60 / 623,036, filed Oct. 29, 2004, entitled EPOXIDIZED ESTER ADDITIVES FOR REDUCING LEAD CORROSION IN LUBRICANTS AND FUELS.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention is related to fuels, especially hydrocarbon fuels, and lubricants, especially lubricating oils, and, more particularly, to a class of anti-corrosion additives that are derived from epoxidized esters for such fuels and lubricants. [0004] 2. Description of Related Art [0005] In developing lubricating oils, there have been many attempts to provide additives that protect metal engine parts from corrosion. Metal corrosion may variously result from the corrosivity of the lubricant itself or, more frequently, from corrosive additives that are added to the lubricant formulation to impart other desired properties, such as anti-wear and extreme pressure protection. Corrosion may als...

AI Technical Summary

Benefits of technology

[0041] It has now been found that epoxidized esters, epoxidized diesters, and epoxidized triesters (hereinafter collectively termed “epoxidized esters”) are useful as lubricant additives, imparting anti-corrosive properties to the lubricant that protect lead and copper from corrosion. The epoxidized ester additives impart protection to the lubricated system against the corrosive tendencies of other additives that might otherwise be desirable to add to the lubricant, such as glycerol mono-oleate, which is useful as a phosphorus-free friction modifier and anti-wear agent.

Problems solved by technology

Corrosion may also be due to contaminants, such as water and combustion by-products, that are normally present in the engine.

Engine bearings are particularly prone to corrosion, especially copper-lead bearings.

It is important to protect these bearings from corrosion, as bearing corrosion can lead to wear, increased friction, lost fuel economy, and, ultimately, catastrophic engine failure.

Lead that is leached from the bearings by corrosion contaminates the oil and poses additional environmental problems from particulate emissions and toxic waste pollution.

Very little can be done, however, to protect against materials that are corrosive to lead.

The known lead anti-corrosion additives are not satisfactory.

Many of these additives are expensive, being prepared by multi-step processes from costly starting materials.

Others contain phosphorus, which is undesirable in its own right, as phosphorus is suspected of limiting the service life of the catalytic converters that are used on cars to reduce pollution.

However, zinc dialkyldithiophosphates give rise to ash, which contributes to particulate matter in automotive exhaust emissions, and regulatory agencies are seeking to reduce emissions of zinc into the environment.

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