Lubricant composition comprising traction coefficient additive

Abstract

The present invention relates to a lubricant composition suitable for use in an electric vehicle. The lubricant composition comprises a traction coefficient additive and wherein the traction coefficient additive is an ester, said ester being the reaction product of at least one saturated branched-chain aliphatic monohydric alcohol having between 12 and 32 carbon atoms and at least one aliphatic carboxylic acid having between 6 and 32 carbon atoms. The lubricant composition as described herein provides an electric vehicle gear oil and imparts desirable coefficient of traction properties when in use.

1 . A lubricant composition, comprising a traction coefficient additive and wherein the traction coefficient additive is an ester, said ester being the reaction product of:
 i) at least one saturated branched-chain aliphatic monohydric alcohol selected from the group consisting of a C12 Guerbet alcohol, C14 Guerbet alcohol, C16 Guerbet alcohol, C18 Guerbet alcohol, C20 Guerbet alcohol, C24 Guerbet alcohol, and mixtures thereof and,   ii) at least one saturated aliphatic carboxylic acid having between 6 and 32 carbon atoms.   
     
     
         2 . (canceled) 
     
     
         3 . The lubricant composition of  claim 1 , wherein said at least one aliphatic carboxylic acid is a monocarboxylic acid or dicarboxylic acid, such that said ester is a monoester or a diester. 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . The lubricant composition of  claim 3 , wherein said traction coefficient additive has a thermal conductivity of higher than 0.131 W/mK at 40° C. 
     
     
         9 . (canceled) 
     
     
         10 . The lubricant composition of  claim 3 , wherein said traction coefficient additive has a kinematic viscosity at 100° ° C. of not more than 3.3 cSt. 
     
     
         11 . The lubricant composition of  claim 10 , wherein said traction coefficient additive has a kinematic viscosity at 40° C. of not more than 30 cSt. 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The lubricant composition of  claim 3 , wherein said lubricant composition comprises up to 50 wt % of said traction coefficient additive. 
     
     
         16 . The lubricant composition of  claim 3 , wherein said lubricant composition comprises at least 3 wt % of said traction coefficient additive. 
     
     
         17 . (canceled) 
     
     
         18 . The lubricant composition of  claim 3 , wherein said lubricant composition comprises at least one base oil selected from a Group I to Group IV base oil, or mixtures of two or more thereof. 
     
     
         19 . The lubricant composition of  claim 18 , comprising at least one of a Group III or Group IV base oil. 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . A gear oil comprising a lubricant composition in accordance with  claim 1 . 
     
     
         25 . A method of improving energy efficiency in an electric vehicle, the method comprising using a lubricant composition in accordance with  claim 1 . 
     
     
         26 . The method of  claim 25 , where in the lubricant composition is used in at least one system within the electric vehicles power train, said system selected from axels, differentials, transmissions, battery pack and power electronics. 
     
     
         27 . The method of  claim 26 , wherein the lubricant composition is used in the electric vehicle's gearbox. 
     
     
         28 . (canceled) 
     
     
         29 . (canceled) 
     
     
         30 . The lubricant composition of  claim 3 , which is a monoester and is selected from the group consisting of C16 Guerbet heptanoate, a C20 Guerbet hepanoate, and mixtures thereof. 
     
     
         31 . A gear oil comprising a lubricant composition in accordance with  claim 30 . 
     
     
         32 . A method of improving energy efficiency in an electric vehicle, the method comprising using a lubricant composition in accordance with  claim 30 .