Power transmission fluids having extended durability

Abstract

A power transmission fluid composition comprising a succinimide, a borated dispersant, and a phosphorus-containing antiwear component.

Description

FIELD The present disclosure relates to a power transmission fluid having improved and / or extended durability. The present disclosure may comprise a fluid suitable for power transmitting fluids, such as an automatic transmission fluid (ATF) and / or a manual transmission fluid. Power transmitting fluids of the present disclosure may comprise a friction modifier, a borated dispersant, and a phosphorus-containing antiwear component. BACKGROUND Automotive power transmission fluids are called upon to provide specific frictional properties under very demanding conditions of temperature and pressure. Changes in a fluid's frictional properties as a function of relative sliding speed, temperature, or pressure as a result of these conditions may cause performance degradation immediately noticeable to the vehicle operator. Such effects may include unacceptably long or short gear shifts, vehicle shudder or vibration, noise, and / or harsh shifts (“gear change shock”). Thus, there is a need for t...

AI Technical Summary

Benefits of technology

Power transmission fluids formulated according to the present disclosure provide improved friction durability and provide improved performance for smooth engagement of torque converter and shifting clutches and minimized shudder, vibration and / or noise, and / or improved fuel economy. Further, embodiments disclosed herein may contain dispersants that are free of phosphorus and / or contain low amounts of boron, thereby improving thermal stability and improving friction performance.

Problems solved by technology

Changes in a fluid's frictional properties as a function of relative sliding speed, temperature, or pressure as a result of these conditions may cause performance degradation immediately noticeable to the vehicle operator.

Such effects may include unacceptably long or short gear shifts, vehicle shudder or vibration, noise, and / or harsh shifts (“gear change shock”).

A disadvantage of conventional transmission fluids that include nitrogen-containing dispersants that have been allowed to react with high amounts of phosphorylating and / or boronating species (e.g., phosphorus- and boron-based acids and their esters) is that they may degrade in thermally stressful environments such as modem automatic transmissions.

This degradation may take the form of adverse friction performance, such as increased static-to-dynamic friction ratio, or in undesirable physical phenomena, such as precipitation of decomposition products or glazing of clutch friction material.

Many conventional organic friction modifiers, however, are thermally unstable.

Upon prolonged exposure to heat, these additives decompose, and the benefits they confer on clutch performance are lost.

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