Grease composition

Abstract

A grease composition includes at least one mineral-based or synthetic-based oil, individually or in a mixture; at least one fatty acid simple or complex metal soap as thickener; at least one molybdenum dithiocarbamate; and graphite. The grease can be used for constant velocity joints of a motor vehicle transmission.

1 . A grease composition comprising:
 a) one or several mineral or synthetic base oils, either alone or as a mixture;   b) one or several simple or complex fatty acid metal soaps as a thickener;   c) at least one molybdenum dithiocarbamate; and   d) graphite.   
     
     
         2 - 22 . (canceled) 
     
     
         23 . The grease composition according to  claim 1 , having a molybdenum content comprised between 1,000 and 2,800 ppm. 
     
     
         24 . The grease composition according to  claim 1 , comprising between 0.5 and 3.0% by mass of graphite. 
     
     
         25 . The grease composition according to  claim 1 , wherein the Mo/[graphite] ratio, between the molybdenum content in ppm and the mass percentage of graphite in the composition, is comprised between 1,250 and 1,550. 
     
     
         26 . The grease composition according to  claim 1 , free of MoS 2  solid lubricant. 
     
     
         27 . The grease composition according to  claim 1 , free of polytetrafluorethylene solid lubricant. 
     
     
         28 . The grease composition according to  claim 1 , exclusively comprising one or several simple or complex fatty acid metal soaps as a thickener. 
     
     
         29 . The grease composition according  claim 1 , comprising as a thickener, at least one simple or complex soap of lithium, sodium, calcium, barium, or titanium, either alone or as a mixture. 
     
     
         30 . The grease composition according to  claim 1 , comprising one or several simple or complex lithium soaps as a thickener. 
     
     
         31 . The grease composition according to  claim 1 , wherein the oils comprise the mineral base oil and the synthetic base oil. 
     
     
         32 . The grease composition according to  claim 1 , further comprising a polymer. 
     
     
         33 . The grease composition according to  claim 1 , further comprising one or several anti-wear and/or extreme pressure additives containing phosphorus and sulfur. 
     
     
         34 . The grease composition according to  claim 33 , wherein the phosphorous content is comprised between 300 and 1,200 ppm. 
     
     
         35 . The grease composition according to  claim 33 , wherein the anti-wear and/or extreme pressure additives containing phosphorus and sulfur is zinc dithiophosphates and wherein the zinc content is comprised between 500 and 1,400 ppm. 
     
     
         36 . The grease composition according to  claim 1 , comprising:
 from 70 to 94% of base oils (a);   from 5 to 25% of thickener (b); and   from 1 to 5% of the mixture of MoDTC (c) and graphite (d).   
     
     
         37 . The grease composition according to  claim 32 , comprising:
 from 70 to 94% of base oils (a);   from 5 to 25% of thickener (b);   from 1 to 5% of the mixture of MoDTC (c) and graphite (d); and   the possible remainder consisting of one or several polymers selected from polyisobutenes, olefin copolymers, polymethacrylates, and polyalphaolefins.   
     
     
         38 . The grease composition according to  claim 32 , comprising:
 from 70 to 93.9% of base oils (a);   from 5 to 23.5% of thickener (b);   from 1 to 5% of the mixture of MoDTC (c) and graphite (d); and   from 0.1 to 1.5% of one or several anti-wear and/or extreme pressure additives containing phosphorus and sulfur, selected from zinc dithiophosphates.   
     
     
         39 . The grease composition according to  claim 32 , comprising:
 from 70 to 93.9% of base oils (a);   from 5 to 23.5% of thickener (b);   from 1 to 5% of the mixture of MoDTC (c) and graphite (d);   from 0.1 to 1.5% of one or several anti-wear and/or extreme pressure additives containing phosphorus or containing phosphorus and sulfur; and   the possible remainder consisting of one or several polymers selected from polyisobutenes, olefin copolymers, polymethacrylates, and polyalphaolefins.   
     
     
         40 . A method for the lubrication of constant velocity joints of automobile vehicle transmissions with a grease composition, the method comprising contacting the grease composition with the constant velocity joints of automobile vehicle transmissions, the grease composition comprising:
 a) one or several mineral or synthetic base oils, either alone or as a mixture;   b) one or several simple or complex fatty acid metal soaps as a thickener;   c) at least one molybdenum dithiocarbamate; and   d) graphite.   
     
     
         41 . A constant velocity joint filled with a grease comprising:
 a) one or several mineral or synthetic base oils, either alone or as a mixture;   b) one or several simple or complex fatty acid metal soaps as a thickener;   c) at least one molybdenum dithiocarbamate; and   d) graphite.