Lubricant composition containing an ionic liquid

Abstract

A lubricant composition, including 20 to 99.5 wt. %, based on a total weight of the lubricant composition, of a base oil, the base oil having a solubility for ionic liquid methyltrioctylammonium-bis(fluorosulfonyl)imide of at least 3 wt. % at a room temperature of 20° C. The base oil contains a base stock A in a proportion of at least 50 wt. %, based on a total weight of the base oil, the base stock A having a solubility for the ionic liquid methyltrioctylammonium-bis(fluorosulfonyl)imide of at least 3 wt. % at a room temperature of 20° C. The lubricant composition further includes 0.5 to 80% wt. %, based on the total weight of the lubricant composition, of an ionic liquid whose anion is bis(fluorosulfonyl)imide.

1 : A lubricant composition, comprising:
 20 to 99.5 wt. %, based on a total weight of the lubricant composition, of a base oil, the base oil having a solubility for ionic liquid methyltrioctylammonium-bis(fluorosulfonyl)imide of at least 3 wt. % at a room temperature of 20° C., and the base oil containing a base stock A in a proportion of at least 50 wt. %, based on a total weight of the base oil, the base stock A having a solubility for the ionic liquid methyltrioctylammonium-bis(fluorosulfonyl)imide of at least 3 wt. % at a room temperature of 20° C.; and   0.5 to 80% wt. %, based on the total weight of the lubricant composition, of an ionic liquid whose anion is bis(fluorosulfonyl)imide.   
     
     
         2 : The lubricant composition as recited in  claim 1 , wherein the base stock A is present in a proportion of 50 to 100 wt %. 
     
     
         3 : The lubricant composition as recited in  claim 1 , wherein a proportion of the base oil, based on the total weight of the lubricant composition, is 40 wt. % to 95 wt. %. 
     
     
         4 : The lubricant composition as recited  claim 1 , wherein the proportion of the base stock A, based on the total weight of the lubricant composition, is 10 wt. % to 99.5 wt. %. 
     
     
         5 : The lubricant composition as recited in  claim 1 , wherein the base stock A is an ester and/or a polyglycol containing unsubstituted ethylene units as a carbon group in a repeating unit. 
     
     
         6 : The lubricant composition as recited in  claim 5 , wherein the ester has an oxygen/carbon weight ratio of more than 0.1, and/or the polyglycol has an oxygen/carbon weight ratio of more than 0.44. 
     
     
         7 : The lubricant composition as recited in  claim 5 , wherein the polyglycol is selected from homopolymers of ethylene oxide as a sole monomer and/or copolymers with unsubstituted ethyl groups and 1-methylethyl groups as carbon groups in a repeating unit. 
     
     
         8 : The lubricant composition as recited in  claim 5 , wherein the ester is selected from carboxylic acid esters and mixtures thereof. 
     
     
         9 : The lubricant composition as recited in  claim 5 , wherein the ester is selected from the group consisting of aliphatic ester of aliphatic monocarboxylic acids with a carbon number of C 5 to C 22 with an aliphatic tri-, tetra-, hexa-alcohol with a carbon number of C 3 to C 10, present singly or in mixtures, in particular trimethylolpropane, pentaerythritol, and/or dipentaerythritol, and/or aliphatic ester of aliphatic dicarboxylic acids with a carbon number of C6 to C20, with an aliphatic mono-alcohol and/or di-alcohol with a carbon number of C6 to C22, present singly or in mixtures, estolides, aromatic ester of aromatic tri- and tetra-carboxylic acids with one or a mixture of aliphatic C7 to C22 alcohols, and mixtures thereof. 
     
     
         10 : The lubricant composition as recited  claim 1 , wherein the base oil contains the base stock A in a mixture with a base stock B, the base stock B having a solubility for the ionic liquid methyltrioctylammonium-bis(fluorosulfonyl)imide of less than 3 wt. % at a room temperature of 20° C. 
     
     
         11 : The lubricant composition as recited in  claim 10 , wherein the base stock B is a base stock B1 having an oxygen/carbon weight ratio of at most 0.1 and/or the base stock B is a base stock B2 having a halogen content and/or silicon content of more than 5 wt. %, based on the total weight of the base stock B2. 
     
     
         12 : The lubricant composition as recited in  claim 10 , wherein the base stock B is selected from a group consisting of group I, II, II+, III, IV base stocks and group V base stocks according to the classification of the American Petroleum Institute (API) [NLGI Spokesman, N. Samman, Volume 70, Number 11, pp. 14ff], polyalkylene glycols having ethylene units substituted with aliphatic or aromatic alkyl groups, a percentage by weight of unsubstituted ethylene units in the polyalkylene glycols being less than 20 wt. %, based on a total weight of the polyalkylene glycol, and aliphatic esters of aliphatic dicarboxylic acids with a carbon number of C 22 to C40, with an aliphatic mono-alcohol and/or di-alcohol with a carbon number of 6 to 22, present singly or in mixtures, aliphatic esters of aliphatic tricarboxylic acids with a carbon number of C33 to C60, with an aliphatic mono-alcohol and/or di-alcohol with a carbon number of 6 to 22, present singly or in mixtures, and mixtures thereof. 
     
     
         13 : The lubricant composition as recited in  claim 10 , wherein a proportion of the base stock B is at most 48 wt. % based on the total weight of the lubricant composition, and/or a weight ratio between the base stock A and the base stock B is at least 50:50. 
     
     
         14 : The lubricant composition as recited in  claim 10 , wherein a weight ratio between the base stock A and the base stock B is from 50:50 to 60:40, and a proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5 to 10 wt. %, based on the total weight of the lubricant composition, and/or the weight ratio between the base stock A and the base stock B is from 60:40 to 70:30, and the proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5% to 15 wt. %, based on the total weight of the lubricant composition, and/or the weight ratio between the base stock A and the base stock B is from 70:30 to 90:10, and the proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5% to 40 wt. %, based on the total weight of the lubricant composition, and/or at the weight ratio between the base stock A and the base stock B is from 80:20 to 90:10, and the proportion of the ionic liquid whose anion is bis(fluorosulfonyl)imide is 0.5% to 80 wt. %, based on the total weight of the lubricant composition. 
     
     
         15 : The lubricant composition as recited in  claim 1 , wherein the lubricant composition has a kinematic viscosity at 40° C. of from 20 mm 2 /sec to 1500 mm 2 /sec. 
     
     
         16 : The lubricant composition as recited in  claim 1 , wherein the ionic liquid has a cation selected from a group consisting of symmetrical ammonium ions, unsymmetrical ammonium ions, NR1R2R3R4+, and phosphonium ions PR1R2R3R4+,
 wherein the substituents R1 to R4 are independently branched or unbranched, substituted or unsubstituted C1 to C24.   
     
     
         17 : The lubricant composition as recited in  claim 1 , wherein the lubricant composition contains no ionic liquid whose anion is not bis(fluorosulfonyl)imide, or ionic liquids whose anion is not bis(fluorosulfonyl)imide in a proportion of no more than 0.5 wt %, based on the total weight of the lubricant composition. 
     
     
         18 : The lubricant composition as recited in  claim 1 , wherein the lubricant composition contains no ionic liquid containing perfluoroalkyl groups or ionic liquids containing perfluoroalkyl groups in a proportion of no more than 0.5% wt %, based on the total weight of the lubricant composition. 
     
     
         19 : The lubricant composition as recited in  claim 1 , wherein the ionic liquid whose anion is bis(fluorosulfonyl)imide is selected from a group consisting of: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       and mixtures thereof. 
     
     
         20 : The lubricant composition as recited in  claim 1 , the lubricant composition contains a thickening agent in a proportion of from 3 to 35 wt. %, based on the total weight of the lubricant composition, the thickening agent being selected from urea, aluminum complex soaps, simple metal soaps of the elements of the 1st and 2nd main groups of the periodic table, simple lithium soaps, complex metal soaps of the elements of the 1st and 2nd main groups of the periodic table, lithium complex soaps, bentonite, sulfonate, silicate, polyimide, and mixtures thereof. 
     
     
         21 : The lubricant composition as recited in  claim 20 , wherein the thickening agent is a urea with an amine or diamine of a general formula (H2N)xR, where x=1 or 2, and R is an aryl, alkyl, cycloalkyl or alkylene radical having 2 to 22 carbon atoms. 
     
     
         22 : The lubricant composition as recited in  claim 20 , wherein the thickening agent is a diurea containing aliphatic, cycloaliphatic/aliphatic and/or cycloaliphatic ureas, and the diurea is represented by the formula A, 
       
         
           
           
               
               
           
         
         where R2 is a divalent aromatic C6-15 hydrocarbon radical; and R 1 and R3 are independently a C6-20 cycloalkyl radical, cyclohexyl radical, or a straight-chain or branched C8-20 alkyl radical. 
       
     
     
         23 : The lubricant composition as recited in  claim 20 , wherein the thickening agent is a lithium complex soap, prepared starting from C4-C36 dicarboxylic acids and/or starting from higher functional carboxylic acids with 3 or more, wherein a number of carbon groups is 6 to 60, and/or starting from ester compounds, in each case combined with one or more monocarboxylic acids and/or combined with sebacic acid monostearylamide and/or terephthalic acid monostearylamide. 
     
     
         24 : The lubricant composition as recited in  claim 1 , the lubricant composition contains, as an additive, an aromatic amine in a proportion of 0.5 to 23 wt. % based on the total weight of the lubricant composition. 
     
     
         25 : The lubricant composition as recited in  claim 1 , wherein the lubricant composition has a lower service temperature of no greater than −30° C. according to IP 186, Edition 2015, and/or an upper service temperature of at least +160° C. according to DIN 51821 1+2, Edition 2016-07. 
     
     
         26 : A method for lubricating drive elements, comprising, comprising:
 providing the lubricant composition according to  claim 1 ; and   applying the lubricant composition to the drive elements.   
     
     
         27 : The method as recited in  claim 26 , wherein the drive elements are selected from a group of elements consisting of pulley bearings, fan bearings, vacuum pump bearings, rolling-element bearings of electric motors of hybrid and electric vehicles, generators of electric vehicles and rail vehicles, wind turbines, industrial motors, auxiliary units in vehicles, and joints of vehicles. 
     
     
         28 : The method as recited in  claim 26 , wherein the lubricant composition is lubricates drive elements which require a lower service temperature of the lubricant composition of no greater than −30° C. according to IP 186, Edition 2015, and/or an upper service temperature of at least +160° C. determined according DIN 51821 1+2, Edition 2016-07.