Use Of Polytetrahydrofurans In Lubricating Oil Compositions

Abstract

An axle lubricating oil composition includes a polyalphaolefin having a kinematic viscosity at 100° C. of from 2 to 40 cSt when measured in accordance with ASTM D445. The axle lubricating oil composition also includes an alkoxylated polytetrahydrofuran of general formula (II). The alkoxylated polytetrahydrofuran of general formula (II) is present in an amount of from 10 to 40 parts by weight based on 100 parts by weight of the axle lubricating oil composition.

1 . An axle lubricating oil composition comprising:
 (i) a polyalphaolefin having a kinematic viscosity at 100° C. of from 2 to 40 cSt when measured in accordance with ASTM D445, with said polyalphaolefin being present in an amount of from 20 to 60 parts by weight based on 100 parts by weight of said axle lubricating oil composition; and   (ii) an alkoxylated polytetrahydrofuran of general formula (II) present in an amount of from 10 to 40 parts by weight based on 100 parts by weight of said axle lubricating oil composition   
       
         
           
           
               
               
           
         
         wherein,
 m is an integer in the range of ≧1 to ≦50, 
 m′ is an integer in the range of ≧1 to ≦50, 
 (m+m′) is an integer in the range of ≧1 to ≦90, 
 n is an integer in the range of ≧0 to ≦75, 
 n′ is an integer in the range of ≧0 to ≦75, 
 p is an integer in the range of ≧0 to ≦75, 
 p′ is an integer in the range of ≧0 to ≦75, 
 k is an integer in the range of ≧2 to ≦30, 
 R 1  denotes an unsubstituted, linear or branched, alkyl radical having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 carbon atoms, 
 R 2  denotes —CH 2 —CH 3 , 
 R 3  is identical or different and denotes a hydrogen atom or —CH 3 , and 
 
         wherein the concatenations denoted by k are distributed to form a block polymeric structure and the concatenations denoted by p, p′, n, n′, m and m′ are distributed to form a block polymeric structure or a random polymeric structure. 
       
     
     
         2 . The axle lubricating oil composition according to  claim 1  wherein said polyalphaolefin has a kinematic viscosity at 100° C. of from 2 to 10 cSt when measured in accordance with ASTM D445, with said polyalphaolefin being present in an amount of from 40 to 50 parts by weight based on 100 parts by weight of said axle lubricating oil composition. 
     
     
         3 . The axle lubricating oil composition according to  claim 2  further comprising a carboxylic acid ester in an amount of from 5 to 20 parts by weight based on 100 parts by weight of said axle lubricating oil composition. 
     
     
         4 . The axle lubricating oil composition according to  claim 1  wherein k is an integer in the range of ≧3 to ≦25. 
     
     
         5 . The axle lubricating oil composition according to  claim 1  wherein k is an integer in the range of ≧5 to ≦20, and wherein (m+m′) is in the range of ≧3 to ≦65. 
     
     
         6 . The axle lubricating oil composition according to  claim 1 , wherein the alkoxylated polytetrahydrofuran has a weight average molecular weight in the range of 4000 to 7000 g/mol determined according to DIN 55672-1 (polystyrene calibration standard), and wherein the ratio of (m+m′) to k is in the range of 0.3:1 to 6:1. 
     
     
         7 . The axle lubricating oil composition according to  claim 3  having a KRL Shear loss after 200 hours of less than 8% when measured in accordance with CEC L-45-A-99. 
     
     
         8 . The axle lubricating oil composition according to  claim 1  wherein R 1  denotes an unsubstituted, linear alkyl radical having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms. 
     
     
         9 . The axle lubricating oil composition according to  claim 1 , wherein;
 m is an integer in the range of ≧1 to ≦30,   m′ is an integer in the range of ≧1 to ≦30,   (m+m′) is an integer in the range of ≧3 to ≦50,   n is an integer in the range of ≧0 to ≦45,   n′ is an integer in the range of ≧0 to ≦45,   p is an integer in the range of ≧3 to ≦45,   p′ is an integer in the range of ≧3 to ≦45,   (p+p′) is an integer in the range of ≧6 to ≦90,   k is an integer in the range of ≧3 to ≦25,   R 1  denotes an unsubstituted, linear alkyl radical having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms,   R 2  denotes —CH 2 —CH 3 , and   R 3  denotes —CH 3 .   
     
     
         10 . An axle lubricating oil composition comprising:
 (i) a polyalphaolefin having a kinematic viscosity at 100° C. of from 2 to 40 cSt when measured in accordance with ASTM D445; and   (ii) an alkoxylated polytetrahydrofuran of general formula (II)   
       
         
           
           
               
               
           
         
         
           wherein, 
           m is an integer in the range of ≧1 to ≦50, 
           m′ is an integer in the range of ≧1 to ≦50, 
           (m+m′) is an integer in the range of ≧1 to ≦90, 
           n is an integer in the range of ≧0 to ≦75, 
           n′ is an integer in the range of ≧0 to ≦75, 
           p is an integer in the range of ≧0 to ≦75, 
           p′ is an integer in the range of ≧0 to ≦75, 
           k is an integer in the range of ≧2 to ≦30, 
           R 1  denotes an unsubstituted, linear or branched, alkyl radical having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 carbon atoms, 
           R 2  denotes —CH 2 —CH 3 , 
           R 3  is identical or different and denotes a hydrogen atom or —CH 3 , and 
           wherein the concatenations denoted by k are distributed to form a block polymeric structure and the concatenations denoted by p, p′, n, n′, m and m′ are distributed to form a block polymeric structure or a random polymeric structure; and 
         
         wherein said axle lubricating oil composition has a KRL Shear loss after 200 hours of less than 8% when measured in accordance with CEC L-45-A-99. 
       
     
     
         11 . The axle lubricating oil composition according to  claim 10  wherein said polyalphaolefin has a kinematic viscosity at 100° C. of from 2 to 10 cSt when measured in accordance with ASTM D445, with said polyalphaolefin being present in an amount of from 40 to 50 parts by weight based on 100 parts by weight of said axle lubricating oil composition. 
     
     
         12 . The axle lubricating oil composition according to  claim 11  further comprising a carboxylic acid ester base stock in an amount of from 5 to 20 parts by weight based on 100 parts by weight of said axle lubricating oil composition. 
     
     
         13 . The axle lubricating oil composition according to  claim 10  wherein k is an integer in the range of ≧3 to ≦25. 
     
     
         14 . The axle lubricating oil composition according to  claim 10  wherein k is an integer in the range of ≧5 to ≦20, and wherein (m+m′) is in the range of ≧3 to ≦65. 
     
     
         15 . The axle lubricating oil composition according to  claim 10 , wherein the alkoxylated polytetrahydrofuran has a weight average molecular weight in the range of 4000 to 7000 g/mol determined according to DIN 55672-1 (polystyrene calibration standard), and wherein the ratio of (m+m′) to k is in the range of 0.3:1 to 6:1. 
     
     
         16 . The axle lubricating oil composition according to  claim 12  having a KRL Shear loss after 200 hours of less than 8% when measured in accordance with CEC L-45-A-99. 
     
     
         17 . The axle lubricating oil composition according to  claim 10  wherein R 1  denotes an unsubstituted, linear alkyl radical having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms. 
     
     
         18 . The axle lubricating oil composition according to  claim 10 , wherein;
 m is an integer in the range of ≧1 to ≦30,   m′ is an integer in the range of ≧1 to ≦30,   (m+m′) is an integer in the range of ≧3 to ≦50,   n is an integer in the range of ≧0 to ≦45,   n′ is an integer in the range of ≧0 to ≦45,   p is an integer in the range of ≧3 to ≦45,   p′ is an integer in the range of ≧3 to ≦45,   (p+p′) is an integer in the range of ≧6 to ≦90,   k is an integer in the range of ≧3 to ≦25,   R 1  denotes an unsubstituted, linear alkyl radical having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms,   R 2  denotes —CH 2 —CH 3 , and   R 3  denotes —CH 3 .   
     
     
         19 . A method of lubricating an axle of a vehicle for increasing the fuel efficiency of the vehicle, said method comprising:
 providing an axle lubricating oil composition comprising;
 (i) a polyalphaolefin having a kinematic viscosity at 40° C. of from 2 to 40 cSt when measured in accordance with ASTM D445, with said polyalphaolefin being present in an amount of from 30 to 60 parts by weight based on 100 parts by weight of said axle lubricating oil composition; and 
 (ii) an alkoxylated polytetrahydrofuran of general formula (II) present in an amount of from 20 to 40 parts by weight based on 100 parts by weight of said axle lubricating oil composition 
   
       
         
           
           
               
               
           
         
         
           
             wherein, 
             m is an integer in the range of ≧1 to ≦50, 
             m′ is an integer in the range of ≧1 to ≦50, 
             (m+m′) is an integer in the range of ≧1 to ≦90, 
             n is an integer in the range of ≧0 to ≦75, 
             n′ is an integer in the range of ≧0 to ≦75, 
             p is an integer in the range of ≧0 to ≦75, 
             p′ is an integer in the range of ≧0 to ≦75, 
             k is an integer in the range of ≧2 to ≦30, 
             R 1  denotes an unsubstituted, linear or branched, alkyl radical having 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 or 28 carbon atoms, 
             R 2  denotes —CH 2 —CH 3 , 
             R 3  is identical or different and denotes a hydrogen atom or —CH 3 , and 
             wherein the concatenations denoted by k are distributed to form a block polymeric structure and the concatenations denoted by p, p′, n, n′, m and m′ are distributed to form a block polymeric structure or a random polymeric structure; and 
           
         
         contacting the axle lubricating oil composition and the axle of the vehicle to lubricate the axle and increase the fuel efficiency of the vehicle. 
       
     
     
         20 . The method as set forth in  claim 19  wherein the axle lubricating oil composition has a KRL Shear loss after 200 hours of less than 8% when measured in accordance with CEC L-45-A-99.