Ether-Based Lubricant Compositions, Methods and Uses

Abstract

The present invention provides a lubricant composition comprising a base oil of lubricating viscosity, wherein the base oil comprises an ether base stock of formula (A) where: R a and R b are aliphatic hydrocarbyl groups and may be the different; the lubricant composition further comprising from 0.5 to 7% of total dispersant additive, by weight of the lubricant composition. In some embodiments, the ether base stock has the formula (1) where: R 1 , R 2 , R 3 , R 4 , R 5 and R 6 are as defined herein. The lubricant composition may be used for lubricating a surface in an internal combustion engine as well as for improving the fuel economy performance and/or piston cleanliness performance of an engine and/or a vehicle, such as an automotive vehicle associated with an internal combustion engine.

1 . A lubricant composition comprising a base oil of lubricating viscosity,
 wherein the base oil comprises an ether base stock of formula (A):   
       
         
           
           
               
               
           
         
         where: R a  and R b  are aliphatic hydrocarbyl groups and may be the same or different;
 the lubricant composition further comprising from 0.5 to 7% of total dispersant additive, by weight of the lubricant composition. 
 
       
     
     
         2 . The lubricant composition of  claim 1 , wherein at least one of R a  and R b  is branched-chain alkyl, alkoxy-substituted-alkyl or cycloalkyl-substituted-alkyl. 
     
     
         3 . The lubricant composition of  claim 2 , wherein R a  and R b  are independently selected from alkyl, alkoxy-substituted-alkyl and cycloalkyl-substituted-alkyl, provided that where R a  and R b  are both alkyl at least one of R a  and R b  is/are branched-chain alkyl. 
     
     
         4 . The lubricant composition of  claim 1 , wherein R a  contains more carbon atoms than R b . 
     
     
         5 . The lubricant composition of  claim 1 , wherein R a  contains from 12 to 30 carbon atoms, and/or R b  contains from 2 to 20 carbon atoms. 
     
     
         6 . The lubricant composition of  claim 1 , wherein the ether base stock is of formula (1): 
       
         
           
           
               
               
           
         
         where: R 1  and R 2  are alkyl or, together with the carbon atom to which they are attached, cycloalkyl;
 R 3 , R 4  and R 5  are H or alkyl; 
 R 6  is alkyl or 
 
       
       
         
           
           
               
               
           
         
         where: R 7  and R 8  are H, alkyl or, together with the carbon atom to which they are attached, cycloalkyl;
 R 9  is H or alkyl; 
 X is alkylene or is absent; and 
 p is 0, 1, 2 or 3; and 
 m and n are 0, 1, 2 or 3, wherein m is 0 when R 4  and R 5  are H. 
 
       
     
     
         7 . The lubricant composition of  claim 6 , wherein R 1  and R 2  are C 1-15  alkyl or, together with the carbon atom to which they are attached, C 5-30  cycloalkyl, and/or wherein R 3 , R 4  and R 5  are H or C 1-15  alkyl. 
     
     
         8 . The lubricant composition of  claim 6 , wherein m and n are 0, 1 or 2. 
     
     
         9 . The lubricant composition of  claim 6 , wherein the ether base stock has the formula (4): 
       
         
           
           
               
               
           
         
         where: R 1  and R 4  are alkyl;
 R 3  and R 5  are H or alkyl. 
 
       
     
     
         10 . The lubricant composition of  claim 6 , wherein the ether base stock has the formula (7): 
       
         
           
           
               
               
           
         
         where: R 1  and R 2  are alkyl or, together with the carbon to which they are attached, cycloalkyl;
 R 3 , R 4  and R 5  are H or alkyl; and 
 R 6  is alkyl. 
 
       
     
     
         11 . The lubricant composition of  claim 1 , wherein the ether base stock contains a total number of carbons atoms of from 20 to 50. 
     
     
         12 . The lubricant composition of  claim 1 , wherein the ether base stock is prepared from bio-derived feedstock containing greater than 50% by weight of biobased carbon. 
     
     
         13 . The lubricant composition of  claim 1 , wherein the base oil of the lubricant composition comprises greater than 10% by weight of the ether base stock and/or wherein the lubricant composition comprises greater than 50% by weight of the base oil. 
     
     
         14 . The lubricant composition of  claim 13 , wherein the base oil of the lubricant composition further comprises a base stock selected from Group I, Group II, Group III, Group IV and Group V base stocks and mixtures thereof. 
     
     
         15 . The lubricant composition of  claim 1 , wherein the lubricant composition has at least one of:
 a kinematic viscosity at 40° C. of less than 60 cSt;   a kinematic viscosity at 100° C. of less than 12 cSt;   a viscosity index of greater than 100;   a viscosity at 150° C. and a shear rate of 10 6  s −1  of no greater than 3 cP; and   a Noack volatility of less than 25% by weight.   
     
     
         16 . The lubricant composition of  claim 1 , wherein the lubricant composition has at least one of:
 an oxidative stability performance on a CEC-L-088-02 test indicated by an absolute viscosity increase at 40° C. of no more than 45 cSt;   a fuel economy performance on a CEC-L-054-96 test of at least 2.5%; and   a piston cleanliness performance on a CEC-L-088-02 test indicated by an overall piston merit of at least 8.5.   
     
     
         17 . The lubricant composition of  claim 1 , wherein the total amount of dispersant additive present in the lubricant composition is from 1.0 to 7.0% by weight of the lubricant composition. 
     
     
         18 . The lubricant composition of  claim 1 , wherein the dispersant additive is selected from oil soluble salts, esters, amino-esters, amides, imides and oxazolines of long chain hydrocarbon-substituted mono- and polycarboxylic acids or anhydrides thereof; thiocarboxylate derivatives of long chain hydrocarbons; long chain aliphatic hydrocarbons containing polyamine moieties attached directly thereto; Mannich condensation products formed by condensing a long chain substituted phenol with formaldehyde and polyalkylene polyamine; and Koch reaction products. 
     
     
         19 . The lubricant composition of  claim 1 , wherein the dispersant additive is selected from those having a molecular weight of from 500 to 15,000 g/mol. 
     
     
         20 . The lubricant composition of  claim 18 , wherein the dispersant additive is selected from nitrogen-containing dispersants. 
     
     
         21 . The lubricant composition of  claim 1 , wherein the amount of phosphorus contained in the lubricant composition is less than 0.5 wt % based on the total weight of the lubricant composition. 
     
     
         22 . A method of preparing a lubricant composition, said method comprising providing a base oil as defined in  claim 1  and blending the base oil with 0.5 to 7% of total dispersant additive by weight of the lubricant composition, and optionally one or more additional lubricant additives in order to prepare the lubricant composition. 
     
     
         23 . A method of lubricating a surface, said method comprising supplying a lubricant composition according to  claim 1  to said surface, such as wherein the lubricant composition is supplied to a surface in an internal combustion engine. 
     
     
         24 . (canceled) 
     
     
         25 . A method of improving the dispersancy properties and/or viscosity profile of a lubricant composition comprising the step of providing or supplying to the lubricant composition at least one of the ether base stocks defined in  claim 1 . 
     
     
         26 . (canceled) 
     
     
         27 . A method of improving the fuel economy performance and/or piston cleanliness performance of an engine and/or a vehicle, comprising the step of providing the engine and/or the vehicle with a lubricant composition according to  claim 1 . 
     
     
         28 . (canceled)