Use of a diester in a cooling and/or lubricating composition for an electric or hybrid vehicle

Abstract

Use of a diester in a composition for cooling and/or lubrication of an electric or hybrid vehicle The present invention relates to the use, for cooling and/or lubricating a propulsion system of an electric or hybrid vehicle, of a composition comprising one or a plurality of diesters, each of said diesters being formed between a diol containing from 3 to 12 carbon atoms and two monocarboxylic acids, identical or different, including a linear or branched hydrocarbon chain having from 4 to 10 carbon atoms.

1 . A method for cooling and/or lubricating at least one part of a propulsion system of an electric or hybrid vehicle, said method comprising at least one step of bringing said at least one part into contact with a composition comprising one or a plurality of diesters, each of said diesters being formed between a diol containing from 3 to 12 carbon atoms and two monocarboxylic acids, identical or different, including a linear or branched hydrocarbon chain having from 4 to 10 carbon atoms, said hydrocarbon chain optionally being interrupted by one or a plurality of heteroatoms. 
     
     
         2 . The method according to  claim 1 , wherein the linear or branched hydrocarbon chain having from 4 to 10 carbon atoms is a linear or branched, saturated or unsaturated alkyl or alkylene chain consisting of carbon and hydrogen atoms. 
     
     
         3 . The method according to  claim 1 , wherein the composition comprises at least 5% by weight of said diester(s), relative to the total weight of the composition. 
     
     
         4 . The method according to  claim 1  wherein the composition comprises:
 from 5 to 95% by weight of the diester or diesters, and 
 from 5 to 95% by weight of one or a plurality of base oils different from said diesters, 
 
       with respect to the total weight of the diester(s) and base oils different from the diesters. 
     
     
         5 . The method according to  claim 1 , wherein the at least one part of a propulsion system of an electric or hybrid vehicle comprises the battery and/or the power electronic components of an electric or hybrid vehicle. 
     
     
         6 . The method according to  claim 1 , wherein said diester has from 13 to 25 carbon atoms, preferably from 15 to 24 carbon atoms. 
     
     
         7 . The method according to  claim 1 , wherein the diester or the diesters correspond to the formula (I): 
       
         
           
           
               
               
           
         
       
       wherein:
 R 1  represents a linear or branched, saturated or unsaturated hydrocarbon chain having from 3 to 9 carbon atoms, preferably from 4 to 8 carbon atoms, preferably from 5 to 7 carbon atoms, said hydrocarbon chain optionally being interrupted by one or a plurality of heteroatoms; and 
 R 2  represents a linear or branched, saturated or unsaturated hydrocarbon chain having from 4 to 9 carbon atoms, said hydrocarbon chain optionally being interrupted by one or a plurality of heteroatoms; and 
 R 3  represents a linear or branched, saturated or unsaturated hydrocarbon chain having from 3 to 10 carbon atoms, said hydrocarbon chain optionally being interrupted by one or a plurality of heteroatoms. 
 
     
     
         8 . The method according to  claim 1 , wherein said diester has a kinematic viscosity at 100° C. ranging from 1 to 6 mm 2 /s. 
     
     
         9 . The method according to  claim 1 , wherein at least one of the two hydroxyl functions of the diol is supported by a primary carbon atom. 
     
     
         10 . The method according to  claim 1 , wherein the diol is chosen from 1,2-propanediol, 1,2-decanediol and 1,3-alkanediols including from 3 to 10 carbon atoms. 
     
     
         11 . The method according to  claim 1 , wherein the diol is chosen from 1,2-propanediol and 1,3-propanediol. 
     
     
         12 . The method according to  claim 1 , wherein said monocarboxylic acids, either identical or different, include a linear hydrocarbon chain having from 4 to 10 carbon atoms. 
     
     
         13 . The method according to  claim 1 , wherein the diester(s) is (are) chosen from:
 one or a plurality of diesters formed between: a diol chosen from 1,2 decanediol and 1,3 propanediol, and two monocarboxylic acids, identical or different, including a linear or branched hydrocarbon chain having from 4 to 10 carbon atoms,   a diester formed from 1,2-propanediol and two heptanoic acids,   a diester formed from 1,2-propanediol and two octanoic acids,   a diester formed from 1,2-propanediol and two decanoic acids,   a diester formed from 1,2-propanediol and an octanoic acid and a decanoic acid, and mixtures thereof.   
     
     
         14 . The method according to  claim 1 , wherein the diester or diesters are chosen from:
 a diester formed from 1,2-decanediol and two heptanoic acids,   a diester formed from 1,2-decanediol and two pentanoic acids,   a diester formed from 1,2-propanediol and two heptanoic acids,   a diester formed from 1,2-propanediol and two nonanoic acids,   a diester formed from 1,3-propanediol and two heptanoic acids,   a diester formed from 1,2-propanediol and two octanoic acids,   a diester formed from 1,2-propanediol and two decanoic acids,   a diester formed from 1,2-propanediol and an octanoic acid and a decanoic acid, and mixtures thereof.   
     
     
         15 . The method according to  claim 1 , characterized in that said composition comprises, in addition to said diester(s), at least one additive chosen from antioxidants, pour point depressants, anti-foam agents, anticorrosion agents, anti-wear and/or extreme-pressure additives, friction modifiers, detergents, dispersants and mixtures thereof. 
     
     
         16 . The method according to  claim 5 , wherein the battery is a lithium-ion or nickel-cadmium battery. 
     
     
         17 . The method according to  claim 1 , wherein the diester or the diesters have a kinematic viscosity at 100° C. ranging from 1 to 4 mm 2 /s.