Grease composition

Abstract

A grease composition includes a base oil, a thickener, and an additive. The base oil is at least one selected from the group consisting of polyoxyalkylene, ether derivatives of polyoxyalkylene, and mixtures thereof. The additive includes polytetrafluoroethylene as a first solid lubricant and at least one selected from the group consisting of melamine cyanurate, tricalcium phosphate, and sodium sebacate as a second solid lubricant. The content of the second solid lubricant is 0.5% by mass or more based on the total mass of the composition.

What is claimed is: 
     
         1 . A grease composition comprising a base oil, a thickener, and an additive, wherein
 the base oil is at least one selected from the group consisting of polyoxyalkylene, ether derivatives of polyoxyalkylene, and mixtures thereof,   the additive comprises polytetrafluoroethylene as a first solid lubricant and at least one selected from the group consisting of melamine cyanurate, tricalcium phosphate, and sodium sebacate as a second solid lubricant, and   a content of the second solid lubricant is 0.5% by mass or more based on a total mass of the composition.   
     
     
         2 . The grease composition according to  claim 1 , wherein a content of the first solid lubricant is 0.5 to 20% by mass based on the total mass of the composition. 
     
     
         3 . The grease composition according to  claim 1 , wherein a content of the second solid lubricant is 0.5 to 10% by mass based on the total mass of the composition. 
     
     
         4 . The grease composition according to  claim 1 , wherein the second solid lubricant is melamine cyanurate. 
     
     
         5 . The grease composition according to  claim 1 , wherein the first and second solid lubricants are contained in a ratio of 3 to 5% by mass of the second solid lubricant to 10% by mass of the first solid lubricant. 
     
     
         6 . A mechanical part to which the grease composition according to  claim 1  is applied.