Lubricating compositions for preventing or reducing pre-ignition in an engine

Abstract

Disclosed is a lubricating composition including at least one base oil and at least one organomolybdenum compound selected from the molybdenum dithiophosphate compounds or the sulphur-free molybdenum complexes, for preventing or reducing pre-ignition in an engine, preferably in a vehicle engine.

1 - 11 . (canceled) 
     
     
         12 . Method of prevention or reduction of pre-ignition in a vehicle engine, wherein the method comprises at least one step of contacting a mechanical part of the engine with a lubricating composition comprising at least one base oil and at least one organomolybdenum compound wherein the organomolybdenum compound is selected from among sulfur-free molybdenum complexes. 
     
     
         13 . Method according to  claim 12 , wherein the organomolybdenum compound is a sulfur-free molybdenum complex selected from among organic complexes of molybdenum with ligands of amide type and prepared via reaction of a molybdenum source, an amine derivative and fatty acids. 
     
     
         14 . Method according to  claim 12 , wherein the organomolybdenum compound is a sulfur-free molybdenum complex and comprising at least one compound selected from among:
 compounds of formula (A):   
       
         
           
           
               
               
           
         
         where:
 X 1  is an oxygen atom or nitrogen atom; 
 X 2  is an oxygen atom or nitrogen atom; 
 n is 1 when X 1  is an oxygen atom and m is 1 when X 2  is an oxygen atom; 
 n is 2 when X 1  is a nitrogen atom and m is 2 when X 2  is a nitrogen atom;
 R 1  is an alkyl group, linear or branched, saturated or unsaturated, comprising from 3 to 30 carbon atoms; 
 
 
         compounds of formula (B) 
       
       
         
           
           
               
               
           
         
         where:
 X 1  is an oxygen atom or nitrogen atom; 
 X 2  is an oxygen atom or nitrogen atom; 
 n is 1 when X 1  is an oxygen atom and m is 1 when X 2  is an oxygen atom; 
 n is 2 when X 1  is a nitrogen atom and m is 2 when X 2  is a nitrogen atom;
 R 1  is a an alkyl group, linear or branched, saturated or unsaturated, comprising from 3 to 30 carbon atoms; 
 R 2  is an alkyl group, linear or branched, saturated or unsaturated, comprising from 3 to 30 carbon atoms, 
 
 
         a mixture of at least one compound of formula (A) and at least one compound of formula (B). 
       
     
     
         15 . Method according to  claim 12 , wherein the organomolybdenum compound is a sulfur-free molybdenum complex and comprising at least one compound of formula (A1): 
       
         
           
           
               
               
           
         
         where R 1  is an alkyl group, linear or branched, saturated or unsaturated, comprising from 3 to 30 carbon atoms. 
       
     
     
         16 . Method according to  claim 15 , wherein the organomolybdenum compound is a sulfur-free molybdenum complex and comprising a compound of formula (A1) where R 1  is an alkyl group comprising 11 carbon atoms. 
     
     
         17 . Method according to  claim 12 , wherein the organomolybdenum compound is a sulfur-free molybdenum complex and comprising at least one compound of formula (A2) 
       
         
           
           
               
               
           
         
         where R1 is a alkyl group, linear or branched, saturated or unsaturated, comprising from 3 to 30 carbon atoms. 
       
     
     
         18 . Method according to  claim 12 , wherein the weight content of organomolybdenum compound relative to the total weight of the lubricating composition ranges from 0.05 to 3%. 
     
     
         19 . Method according to  claim 12 , wherein the lubricating composition further comprises an additional additive selected from among friction modifiers with the exception of sulfur-free molybdenum complexes, detergents, anti-wear additives, extreme pressure additives, viscosity index improvers, dispersants, antioxidants, pour point depressants, defoamers, thickeners and mixtures thereof. 
     
     
         20 . Method according to  claim 12  to prevent or reduce pre-ignition in a motor vehicle. 
     
     
         21 . Method according to  claim 12  to prevent or reduce Low Speed Pre-Ignition (LSPI) in an engine.