Bisdithiophosphoric acid derivatives as lubricant additives

Abstract

There are disclosed compounds of formula I wherein R 1 and R 2 are each independently of the other C 3 -C 18 alkyl, C 5 -C 12 cycloalkyl, C 5 -C 6 cycloalkylmethyl, C 9 -C 10 bicycloalkylmethyl, C 9 -C 10 tricycloalkylmethyl, phenyl, C 7 -C 24 alkylphenyl or, taken together, are R 3 is C 2 -C 18 alkylene which is interrupted by -O-, -S-, or -NR 4 -, or is a group of formula R 4 is hydrogen, C 1 -C 18 alkyl, phenyl-C 1 -C 4 alkyl, phenyl or C 1 -C 6 alkyl-substituted phenyl, R 5 is hydrogen or methyl. These compounds are particularly suitable for use as additives for lubricant compositions, hydraulic fluids and machining fluids.

1 . A compound of formula  
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  are each independently of the other C 3 -C 18 alkyl, C 5 -C 12 cycloalkyl, C 5 -C 6 cycloalkylmethyl, C 9 -C 10 bicycloalkylmethyl, C 9 -C 10 tricycloalkylmethyl, phenyl, C 7 -C 24 alkylphenyl or, taken together, are  
       
         
           
           
               
               
           
         
       
       R 3  is (-CH 2 -) b , C 4 -C 40 alkylene which is interrupted by -O-, -S-, or -NR 4 -, or is a group of formula  
       
         
           
           
               
               
           
         
       
       R 4  is hydrogen, C 1 -C 18 alkyl, phenyl-C 1 -C 4 alkyl, phenyl or C 1 -C 6 alkyl-substituted phenyl, R 5  is hydrogen or methyl, and b is an integer from 3 to 18.  
     
     
         2 . A compound according to  claim 1 , wherein R 1  and R 2  are each independently of the other C 3 -C 10 alkyl, C 5 -C 6 cycloalkyl, C 5 -C 6 cycloalkylmethyl, C 9 -C 10 bicycloalkylmethyl, C 9 -C 10 tricycloalkylmethyl, phenyl, C 7 -C 18 alkylphenyl or, taken together, are  
       
         
           
           
               
               
           
         
       
       and R 3  is (-CH 2 -) b , C 4 -C 20 alkylene which is interrupted by -O- or NR 4 , or is a group of formula  
       
         
           
           
               
               
           
         
       
       R 4  is hydrogen or C 1 -C 4 alkyl, and b is an integer firom 3 to 10.  
     
     
         3 . A compound according to  claim 1 , wherein R 3  is (-CH 2 -) b , C 4 -C 12 alkylene which is interrupted by -O- or NR 4,  or is  
       
         
           
           
               
               
           
         
       
       R 4  is C 1 -C 4 alkyl and b is an integer from 3 to 6.  
     
     
         4 . A compound according to  claim 1 , wherein R 1  and R 2  are C 3 -C 6 alkyl.  
     
     
         5 . A compound according to  claim 1 , wherein R 5  is hydrogen.  
     
     
         6 . A composition comprising 
 a) a lubricant, a machining fluid or hydraulic fluid, and    b) at least one compound of formula I according to  claim 1 .    
     
     
         7 . A composition according to  claim 6 , wherein R 1  and R 2  are each independently of the other C 3 -C 10 alkyl, C 5 -C 6 cycloalkyl, C 5 -C 6 cycloalkylmethyl, C 9 -C 10 bicycloalkylmethyl, C 9 -C 10 tricycloalkylmethyl, phenyl, C 7 -C 18 alkylphenyl or, taken together, are  
       
         
           
           
               
               
           
         
       
       R 3  is (-CH 2 -) b , C 4 -C 20 alkylene which is interrupted by -O- or NR 4,  or is a group of formula  
       
         
           
           
               
               
           
         
       
       R 4  is hydrogen or C 1 -C 4 alkyl, and b is an integer from 3 to 10.  
     
     
         8 . A composition according to  claim 6 , wherein R 3  is (-CH 2 -) b , C 4 -C 12 alkylene which is interrupted by -O- or NR 4,  or is  
       
         
           
           
               
               
           
         
       
       R 4  is C 1 -C 4 alkyl and b is an integer from 3 to 6.  
     
     
         9 . A composition according to  claim 6 , wherein R 5  is hydrogen.  
     
     
         10 . A composition according to  claim 6 , wherein component a) is a lubricant.  
     
     
         11 . A composition according to  claim 10 , wherein the lubricant is an engine oil.  
     
     
         12 . A composition according to  claim 6 , which additionally comprises further stabilisers selected from the group consisting of antioxidants, metal deactivators, further extreme-pressure and antiwear additives and pour-point depressants.  
     
     
         13 . A process for enhancing the performance properties of lubricant compositions, hydraulic fluids and machining fluids, which comprises adding thereto at least one compound of formula I as claimed in  claim 1.