Lubricant composition

Abstract

A lubricant composition comprising lubricant base oil; (A) from 300 to 3000 ppm by weight, in terms of elemental molybdenum, of a sulphur-containing organomolybdenum complex, based on the total weight of the lubricant composition, wherein the weight ratio of sulphur to molybdenum is in the range of from 1 to 1.4; (B) a zinc dithiocarbamate wherein the amount of sulphur derived from this component relative to the amount of molybdenum derived from component (A) in terms of the weight ratio is in the range of from 0.2 to 4; and (C) one or more calcium salts of organic acids, wherein the amount of calcium derived from this component relative to the amount of molybdenum derived from component (A) in terms of the weight ratio is in the range of from 0.2 to 7.

1 . A lubricant composition comprising a lubricant base oil and: 
 (A) in the range of from 300 to 3000 ppm by weight, in terms of elemental molybdenum, of a sulphur-containing organomolybdenum complex, based on the total weight of the lubricant composition, wherein the weight ratio of sulphur to molybdenum is in the range of from 1 to 1.4;    (B) a zinc dithiocarbamate wherein the amount of sulphur derived from this component relative to the amount of molybdenum derived from component (A) in terms of the weight ratio is in the range of from 0.2 to 4; and    (C) one or more calcium salts of organic acids selected from the group consisting of alkyl phenols, alkyl salicylic acids, aliphatic sulphonic acids and aromatic sulphonic acids, wherein the amount of calcium derived from this component relative to the amount of molybdenum derived from component (A) in terms of the weight ratio is in the range of from 0.2 to 7.    
   
   
       2 . The lubricant composition according to  claim 1 , where said lubricant further comprises a component (D) selected from the group consisting of simple metallic soaps, complex metallic soaps thereof, urea compounds and combinations thereof.  
   
   
       3 . The lubricant composition according to  claim 2 , wherein said lubricant composition further comprises a compound (D) selected from the group consisting of lithium soaps, calcium soaps, sodium soaps, aluminium soaps, complex soaps thereof, urea compounds and mixtures thereof.  
   
   
       4 . The lubricant composition according to  claim 2 , wherein component (D) is present in a total amount in the range of from 2 to 30% by weight, based on the total weight of the lubricant composition.  
   
   
       5 . The lubricant composition according to  claim 1 , wherein the sulphur-containing organomolybdenum complex used as component (A) is selected from the group consisting of molybdenum dithiocarbamates, molybdenum dithiophosphates, and mixtures thereof.  
   
   
       6 . The lubricant composition according to  claim 1 , wherein the sulphur-containing organomolybdenum complex used as component (A) comprises a molybdenum dithiocarbamate complex having the general formula (I),  
     
       
         
         
             
             
         
       
     
     wherein R 1  and R 2  are each radicals independently selected from hydrocarbon groups having in the range of from 4 to 18 carbon atoms, m is an integer in the range of from 0 to 3, n is an integer in the range of from 1 to 4 and m+n=4.  
   
   
       7 . The lubricant composition according to  claim 1 , wherein the sulphur-containing organomolybdenum complex used as component (A) comprises a molybdenum dithiophosphates complex having the general formula (II),  
     
       
         
         
             
             
         
       
     
     wherein R 3  and R 4  are each radicals independently selected from hydrocarbon groups having in the range of from 4 to 18 carbon atoms, m is an integer in the range of from 0 to 3, n is an integer in the range of from 1 to 4 and m+n=4.  
   
   
       8 . The lubricant composition according to  claim 1 , wherein the zinc dithiocarbamate used as component (B) comprises a compound having the general formula (III),  
     
       
         
         
             
             
         
       
     
     wherein R 5  and R 6  are each radicals independently selected from hydrocarbon groups having in the range of from 4 to 18 carbon atoms.  
   
   
       9 . A method of reducing friction in bearings, gears or joints of mechanical devices, wherein said method comprises lubricating said bearings, gears or joints with a lubricant composition according to  claim 1 .  
   
   
       10 . Use of a lubricant composition according to  claim 1  to reduce friction in a bearing, a gear or a joint of a mechanical device.