Grease composition and rolling device

Abstract

As a grease composition maintaining a low torque over a wide temperature range and further hardly inducing white texture flaking, the present invention provides a grease composition comprising a base oil having a dynamic viscosity at 40° C. of 20 to 50 mm 2 /s, a urea compound as a thickening agent in an amount of 8 to 30% by weight with respect to total weight of the grease, at least one antirust additive selected from carboxylic acids, carboxylate salts, and ester-based antirust additives in an amount of 0.1 to 10% by weight per single additive with respect to total weight of the grease and in an amount of 0.1 to 15% by weight in total of the additive with respect to total weight of the grease, and a rolling device comprising the grease composition which works with a low torque, hardly induces white texture flaking, and is excellent in durability.

1 . A grease composition comprising: 
 a base oil having a dynamic viscosity at 40° C. of 20 to 50 mm 2 /S;    a urea compound as a thickening agent in an amount of 8 to 30% by weight with respect to total weight of the grease;    at least one antirust additive selected from carboxylic acids, carboxylate salts, and ester-based antirust additives in an amount of 0.1 to 10% by weight per single additive with respect to total weight of the grease and in an amount of 0.1 to 15% by weight in total of the additive with respect to total weight of the grease.    
   
   
       2 . The grease composition according to  claim 1 , wherein the antirust additive is at least one selected from naphthenate salts and succinic acid derivatives.  
   
   
       3 . The grease composition according to  claim 1 , wherein the thickening agent is a mixture of diurea compounds represented by the following general formulae (1) to (3):  
     
       
         
         
             
             
         
       
       wherein R 1  is a cyclohexyl group or an alkylcyclohexyl group having 7 to 12 carbon atoms,  
       R 2  is a divalent aromatic ring-containing hydrocarbon group having 6 to 15 carbon atoms, and  
       R 3  is an alkyl group having 8 to 20 carbon atoms,  
       wherein a ratio of [number of moles of R 1 /(number of moles of R 1 +number of moles of R 3 )] is from 0.1 to 1.0.  
     
   
   
       4 . The grease composition according to  claim 1 , wherein the grease composition further comprising at least one selected from DTC or DTP-base additives and ashless dithiocarbamates in amount of 0.1 to 10 by weight with respect to total weight of the grease.  
   
   
       5 . A rolling device into which the grease composition according to  claim 1  is charged.