Grease composition and bearing

Abstract

A grease composition which is suitable for a ball bearing exposed to high temperatures and exhibits stable lubricity for a prolonged period of time, and a bearing which encapsulates the grease composition are provided. A grease composition comprising (a) a base oil, (b) a thickener, (c) a compound having alkylthiocarbamoyl group of the general formula (1), and an amine-ketone condensate-based antioxidant. A grease composition further comprising (e) a metal inactivator. (wherein R 1 , R 2 , R 3 , R 4 are independently C 1 -C 20 alkyl, and X is S, S—S, S—CH 2 —S, S—CH 2 CH 2 —S, or S—CH 2 CH 2 CH 2 —S)

1 . A grease composition comprising (a) a base oil, (b) a thickener, (c) a compound having alkylthiocarbamoyl group of the general formula (1), and an amine-ketone condensate-based antioxidant. 
     
       
         
         
             
             
         
       
       (wherein R 1 , R 2 , R 3 , R 4  are independently C 1 -C 20  alkyl, and X is S, S—S, S—CH 2 —S, S—CH 2 CH 2 —S, or S—CH 2 CH 2 CH 2 —S) 
     
   
   
       2 . The grease composition according to  claim 1 , wherein said thickener is at least one selected from the group consisting of lithium soaps and lithium complex soaps. 
   
   
       3 . The grease composition according to  claim 1 , further comprising (e) a metal inactivator. 
   
   
       4 . The grease composition according to  claim 2 , further comprising (e) a metal inactivator. 
   
   
       5 . The grease composition according to  claim 1 , which comprises (a) 50 or more percent by mass of said base oil, (b) 1-30 percent by mass of said thickener, (c) 0.1-10 percent by mass of said compound having alkylthiocarbamoyl group of the general formula (1), and (d) 0.1-10 percent by mass of said amine-ketone condensate-based antioxidant based on the entire grease composition. 
   
   
       6 . The grease composition according to  claim 2 , which comprises (a) 50 or more percent by mass of said base oil, (b) 1-30 percent by mass of said thickener, (c) 0.1-10 percent by mass of said compound having alkylthiocarbamoyl group of the general formula (1), and (d) 0.1-10 percent by mass of said amine-ketone condensate-based antioxidant based on the entire grease composition. 
   
   
       7 . The grease composition according to  claim 5 , comprising (e) 0.1-10 percent by mass of said metal inactivator. 
   
   
       8 . The grease composition according to  claim 6 , comprising (e) 0.1-10 percent by mass of said metal inactivator. 
   
   
       9 . A bearing comprising said grease composition according to  claim 1  encapsulated therein.