Grease composition

Abstract

A grease composition comprising a lubricating base oil combined with (A) 2-30 wt % of a thickener and (B) 0.1-10 wt % of at least one type of compound selected from the group consisting of phosphorus compounds represented by general formulas (1) and (2) below and their metal salts or amine salts, based on the total weight of the composition.  [wherein X 1 , X 2 and X 3 each represent an oxygen atom or sulfur atom, with at least two from among X 1 , X 2 and X 3 being oxygen atoms, and R 1 , R 2 and R 3 each represent hydrogen or a C1-30 hydrocarbon group]  [wherein X 4 , X 5 , X 6 and X 7 each represent an oxygen atom or sulfur atom, with at least three from among X 4 , X 5 , X 6 and X 7 being oxygen atoms, and R 4 , R 5 and R 6 each represent hydrogen or a C1-30 hydrocarbon group].

1 . A grease composition comprising a lubricating base oil combined with 
 (A) 2-30 wt % of a thickener and    (B) 0.1-10 wt % of at least one type of compound selected from the group consisting of phosphorus compounds represented by general formulas (1) and (2) below and their metal salts or amine salts, based on the total weight of the composition.                           [wherein X 1 , X 2  and X 3  may be the same or different and each represents an oxygen atom or sulfur atom, with at least two from among X 1 , X 2  and X 3  being oxygen atoms, and R 1 , R 2  and R 3  may be the same or different and each represents hydrogen or a C1-30 hydrocarbon group]                          [wherein X 4 , X 5 , X 6  and X 7  may be the same or different and each represents an oxygen atom or sulfur atom, with at least three from among X 4 , X 5 , X 6  and X 7  being oxygen atoms, and R 4 , R 5  and R 6  may be the same or different and each represents hydrogen or a C1-30 hydrocarbon group].    
     
     
         2 . A grease composition according to  claim 1 , which further comprises an organic molybdenum compound.  
     
     
         3 . A grease composition according to  claim 1 , wherein said thickener is a lithium soap.  
     
     
         4 . A grease composition according to  claim 1 , wherein said thickener is a urea-based thickener.  
     
     
         5 . A grease composition according to  claim 1 , wherein said thickener is a urea-based thickener represented by the following general formula (3).  
         A-CONH—R 7 —NHCO—B (3)  
       [wherein A and B may be the same or different and each is a group represented by —NHR 8 , —NR 9 R 10  or —OR 11  (where R 8 , R 9 , R 10  and R 11  may be the same or different and each represents a C6-20 hydrocarbon group), and R 7  is a divalent hydrocarbon group].  
     
     
         6 . A grease composition according to  claim 1 , which comprises at least one compound selected from among compounds represented by general formula (1) wherein X 1 , X 2  and X 3  are all oxygen atoms and compounds represented by general formula (2) wherein X 4 , X 5 , X 6  and X 7  are all oxygen atoms.