Grease composition, rolling bearing, and motor

Abstract

A grease composition according to an embodiment includes a base oil, a thickener and 0.5% by weight or more of a dispersing agent, the dispersing agent including at least one of a carboxylic acid metal salt, a metal salt of a polycarboxylic acid and a copolymer of a carboxylic acid metal salt and a hydrocarbon compound.

What is claimed is: 
     
         1 . A grease composition including:
 a base oil;   a thickener; and   0.5% by weight or more of a dispersing agent,   the dispersing agent including at least one of a carboxylic acid metal salt, a metal salt of a polycarboxylic acid and a copolymer of a carboxylic acid metal salt and a hydrocarbon compound.   
     
     
         2 . The grease composition according to  claim 1 , wherein at least one of the carboxylic acid metal salt and the metal salt of the polycarboxylic acid is an alkali metal salt or an alkaline earth metal salt, the alkali metal salt including at least one of a sodium salt, a lithium salt, and a potassium salt, the alkaline earth metal salt including at least one of a magnesium salt and a calcium salt. 
     
     
         3 . The grease composition according to  claim 1 , wherein the carboxylic acid metal salt forming the copolymer of the carboxylic acid metal salt and the hydrocarbon compound is an alkali metal salt or an alkali earth metal salt, the alkali metal salt including at least one of a sodium salt, a lithium salt, and a potassium salt, the alkaline earth metal salt including at least one of a magnesium salt and a calcium salt. 
     
     
         4 . The grease composition according to  claim 1 , wherein a content of the dispersing agent is 10% by weight or less. 
     
     
         5 . The grease composition according to  claim 1 , wherein the thickener comprises a diurea compound represented by Formula (1):
   R 1 —NHCONH—R 2 —NHCONH—R 3   (1)
   
       where R 1 , R 2 , and R 3  are hydrocarbon groups selected from aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. 
     
     
         6 . A rolling bearing comprising the grease composition according to  claim 1 . 
     
     
         7 . A motor comprising the rolling bearing according to  claim 6 . 
     
     
         8 . A grease composition comprising:
 a base oil;   a thickener comprising a diurea compound represented by Formula (1):
   R 1 —NHCONH—R 2 —NHCONH—R 3   (1)
 
   
       where R 1 , R 2 , and R 3  are hydrocarbon groups selected from aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups; and
 0.5% by weight or more and 10% by weight or less of a dispersing agent, 
 the dispersing agent including at least one of a sodium salt of sebacic acid, a sodium salt of polyacrylic acid and a copolymer of maleic acid sodium salt and isobutylene. 
 
     
     
         9 . A rolling bearing comprising the grease composition according to  claim 8 . 
     
     
         10 . A motor comprising the rolling bearing according to  claim 9 .