Compositions and Methods for Improved Friction Durability in Power Transmission Fluids

Abstract

The present invention discloses friction modifier compositions, methods for incorporating an alkoxylated alcohol component in power transmission fluids, and methods for measuring friction performance. These formulations and methods provide improved overall friction and improved friction durability, yielding effective fluids that are stable with age. Benefits in friction modification may also be achieved when the alkoxylated alcohol component is heated with an ashless dispersant prior to its incorporation into a transmission fluid.

1 - 51 . (canceled)  
     
     
         52 . A method of increasing the duration of friction-modifying capabilities of a power transmission fluid, said method comprising adding to and operating in a power transmission a fluid comprising: 
 (a) a major amount of a base oil; and    (b) a minor amount of at least one alkoxylated alcohol.    
     
     
         53 . The method of  claim 52 , wherein the alkoxylated alcohol comprises the formula:  
         R—[O—(CH 2 ) X ] Y —OH  wherein R is an aliphatic hydrocarbon group having from about 1 to about 50 carbon atoms, X is from about 1 to about 10, and Y is from about 1 to about 10.    
     
     
         54 . The method of  claim 53 , wherein R is a hydrocarbon group having from about 8 to about 18 carbon atoms, X is from about 2 to about 4, and Y is from about 1 to about 6.  
     
     
         55 . The method of  claim 53 , wherein the aliphatic hydrocarbon is a linear, branched, or cyclic hydrocarbon and is a saturated or unsaturated hydrocarbon.  
     
     
         56 . The method of  claim 52 , wherein the amount of alkoxylated alcohol in the fluid is from about 0.01 wt % to about 20 wt %.  
     
     
         57 . The method of  claim 52 , wherein the amount of alkoxylated alcohol in the fluid is from about 0.05 wt % to about 6 wt %.  
     
     
         58 . The method of  claim 52 , wherein the fluid is suitable for use in a transmission employing one or more of a slipping torque converter, a lock-up torque converter, a starting clutch, and one or more shifting clutches.  
     
     
         59 . The method of  claim 52 , wherein the fluid is suitable for use in a belt-type, chain-type, or disk-type continuously variable transmission (CVT).  
     
     
         60 . The method of  claim 52 , further comprising a dispersant, wherein the dispersant comprises one or more of a hydrocarbyl succinimide, a hydrocarbyl succinamide, a mixture of an ester and an amide of a hydrocarbyl-substituted succinic acid, a hydroxyester of a hydrocarbyl-substituted succinic acid, and a Mannich condensation product of a hydrocarbyl-substituted phenol, a formaldehyde, and an amine.  
     
     
         61 . The method of  claim 60 , wherein the concentration of the dispersant in the fluid is from about 0.01 wt % to about 15 wt %.  
     
     
         62 . The method of  claim 52 , wherein the improved friction properties comprise improved friction durability and/or improved resistance to oxidative and thermal degradation relative to a fluid free of an alkoxylated alcohol.  
     
     
         63 . A method of making a power transmission fluid comprising: 
 combining at temperatures of from about 20° C. to about 200° C., an alkoxylated alcohol with a dispersant and forming a mixture; and    adding the mixture to a base oil.    
     
     
         64 . A method of lubricating a power transmission, comprising adding to, and operating in, a power transmission a fluid comprising: 
 (a) a major amount of a base oil; and    (b) a minor amount of at least one alkoxylated alcohol.