Cyclic thioamides as additives for lubricating oils

Abstract

A composition comprising: (a) from 0.1% to 20% of at least one cyclic thioamide of formula I: wherein X is CR 5 R 6 , CR 5 R 6 NR 7 or CR 5 R 6 CR 8 R 9 ; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 and R 9 are independently hydrogen, alkyl, alkenyl, aryl or aralkyl; or R 1 and R 2 , or R 3 and R 4 , combine with the carbon atom to which they are attached to form an alkyl or alkenyl ring; and (b) a lubricating oil.

1 . A composition comprising: 
 (a) from 0.1% to 20% of at least one cyclic thioamide of formula I:                           wherein X is CR 5 R 6 , CR 5 R 6 NR 7  or CR 5 R 6 CR 8 R 9 ; R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8  and R 9  are independently hydrogen, alkyl, alkenyl, aryl or aralkyl; or R 1  and R 2 , or R 3  and R 4 , combine with the carbon atom to which they are attached to form an alkyl or alkenyl ring; and    (b) a lubricating oil.    
     
     
         2 . The composition of  claim 1  in which X is CR 5 R 6 , and at least one of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  is alkyl, alkenyl, aryl or aralkyl, or R 1  and R 2 , or R 3  and R 4 , combine with the carbon atom to which they are attached to form a C 5 -C 8  alkyl or alkenyl ring.  
     
     
         3 . The composition of  claim 2  in which R 4  is R 10 NH, and R 10  is alkyl, alkenyl, aryl or aralkyl.  
     
     
         4 . The composition of  claim 1  in which X is CR 5 R 6 CR 8 R 9 , and at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 8  and R 9  is alkyl, alkenyl, aryl or aralkyl, or R 1  and R 2 , or R 3  and R 4 , combine with the carbon atom to which they are attached to form a C 5 -C 8  alkyl or alkenyl ring.  
     
     
         5 . The composition of  claim 4  in which R 4  is R 10 NH, and R 10  is alkyl, alkenyl, aryl or aralkyl.  
     
     
         6 . The composition of  claim 1  in which X is CR 5 R 6 NR 7 , and at least one of R 1 , R 2 , R 3 , R 4 , R 5  and R 6  is alkyl, alkenyl, aryl or aralkyl, or R 1  and R 2 , or R 3  and R 4 , combine with the carbon atom to which they are attached to form a C 5 -C 8  alkyl or alkenyl ring.  
     
     
         7 . The composition of  claim 6  in which R 7  is hydrogen, and at least one of R 3  and R 4  is alkyl, alkenyl, aryl or aralkyl.  
     
     
         8 . The composition of  claim 1  in which at least one of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8  and R 9  is aryl, aralkyl, C 4 -C 22  alkyl or C 4 -C 22  alkenyl.  
     
     
         9 . The composition of  claim 1  which comprises at least two cyclic thioamide compounds of formula (I).  
     
     
         10 . The method of  claim 9  in which said at least two cyclic thioamide compounds are present in a total amount from 0.2% to 5%.