Corrosion protection for lubricants

Abstract

The present invention relates to compositions comprising at least one triazole-containing species and at least one thiadiazole-containing species, which in embodiments are suitable for manual transmission oils.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application claims the benefit of Provisional Application No. 60 / 673,858 filed Apr. 22, 2005, the disclosure of which is incorporated by reference.FIELD OF THE INVENTION [0002] The invention relates to lubricating compositions and other functional fluids. The compositions comprise at least one triazole-containing species and at least one thiadiazole-containing species. In preferred lubricating compositions, at least one extreme pressure (EP) component and at least one phosphorus-containing antiwear component are also present. In preferred embodiments the compositions are particularly useful in manual transmission oils. BACKGROUND OF THE INVENTION [0003] Emerging industry requirements for manual transmission fluids in the areas of micropitting and corrosion protection have created a need for new lubricant compositions. In order to meet these requirements, new additive systems suitable for blending with appropriate base stocks are nee...

AI Technical Summary

Benefits of technology

[0015] The lubricant composition of the invention comprises a combination of at least one triazole-containing species and at least one species selected from a thiadiazole-containing species. In embodiments the invention provides improved corrosion protection for manual transmissions.

[0017] In even more preferred embodiments, lubricant compositions comprising alkyl polysulfides and alkyl phosphate esters, in combination with a triazole-containing corrosion inhibitor, such as tolyl triazole and dimercaptothiadizole, have been found particularly effective in avoiding corrosion of copper.

[0021] It is another object of the invention to provide a lubricant formulation based on S, P chemistry that provides high temperature copper corrosion resistance.

Problems solved by technology

However, corrosion may be seen in the field with the use of S, P-based lubricants, particularly when copper-containing components, e.g. coolers, are employed.

Consequently, OEMs are issuing specifications which make it difficult for formulators to use S, P-containing additives.

Therefore, many have stopped using S, P-containing additive systems because of corrosion issues.

New demands with respect to micropitting, corrosion protection and durability are placing severe demands even on MTOs not using S, P chemistry.

Conventional S, P packages struggle to meet a satisfactory level of performance.

Given the enormous number of ingredients proposed for additive packages, it is a formidable task to find the right combination capable of meeting the number of new requirements desired in driveline fluids such as MTOs while maintaining traditional performance standards in other areas.