Additive for oil-based lubricants having improved extreme pressure properties

Abstract

The present invention relates to a novel additive for oil-based lubricants having improved extreme-pressure properties, to a method for producing said novel additive, to oil-based lubricants containing said novel additive and to uses of said novel additive.

1 . A process for producing a lubricant additive, wherein
 a)
 i) a dimeric thiadiazole compound, especially a bis(2-alkyl-1,3,4-thiadiazolyl) 5,5′-disulfide derivative of the formula (I) 
   
       
         
           
           
               
               
           
         
         
           
             and/or a dimeric 2,5-dimercapto-1,3,4-thiadiazolethiol derivative of the formula (II) 
           
         
       
       
         
           
           
               
               
           
         
         
           
             where n in the formulae (I) and (II) is 1 or 2 and 
             R1 and R2 are each independently hydrogen, linear or branched alkyl groups having 1 to 12 carbon atoms, especially thioalkyl groups having 1 to 12 carbon atoms, aromatic radicals or heteroaromatic radicals, 
           
           ii) is dissolved in a polyamine or polyamine derivative of the formula (III)
   R1-(CH2-CH2-NH) n -CH2-CH2-R2  (III)
 
 where n in formula (III) is an integer from 1 to 15, especially an integer from 3 to 8, and 
 R1 and R2 are each independently hydrogen, —NH2, linear or branched alkyl groups having 1 to 12 carbon atoms or a modified or unmodified succinimide group, and 
 
           iii) a compound of the formula (IV) 
         
       
       
         
           
           
               
               
           
         
         
           
             in which n is an integer from 1 to 8, especially an integer from 3 to 8, preferably 6, is added to the solution obtained, 
           
         
         or 
         b)
 i) a dimeric thiadiazole compound, especially a bis(2-alkyl-1,3,4-thiadiazolyl) 5,5′-disulfide derivative of the formula (I) 
 
       
       
         
           
           
               
               
           
         
         
           
             and/or a dimeric 2,5-dimercapto-1,3,4-thiadiazolethiol derivative of the formula (II) 
           
         
       
       
         
           
           
               
               
           
         
         
           
             where n in the formulae (I) and (II) is 1 or 2 and 
             R1 and R2 are each independently hydrogen, linear or branched alkyl groups having 1 to 12 carbon atoms, especially thioalkyl groups (—SR) having 1 to 12 carbon atoms, aromatic radicals or heteroaromatic radicals, 
           
           ii) is dissolved in a polyol, especially a polyether polyol having a high propylene oxide content and/or a triglyceride having a hydroxy fatty acid component, and 
           iii) a hydrophobic phenol derivative and/or unsaturated fatty alcohol is added to the solution obtained. 
         
       
     
     
         2 . The process as claimed in  claim 1 , wherein
 in alternative a), the dimeric thiadiazole compound used is 5,5′-dithiobis(1,3,5-thiadiazole-2-thiol), and/or   in alternative a), the polyamine or polyamine derivative of the formula (III) used is the mono-succinimide derivative of the formula (V) or the bissuccinimide derivative of the formula (VI), and/or   in alternative a), the compound of the formula (IV) used is farnesene, lycopene or squalene.   
     
     
         3 . The process as claimed in  claim 1 , wherein
 in alternative b), the dimeric thiadiazole compound used is 5,5′-dithiobis(1,3,5-thiadiazole-2-thiol), and/or   in alternative b), the polyol used is a hydrophobic polyether polyol of the formula (VII), and/or   in alternative b), the triglyceride having a hydroxy fatty acid component used is castor oil or ricinoleic acid, and/or   in alternative b), the hydrophobic phenol derivative used is cardol, cardanol or anacardic acid, and/or   in alternative b), the unsaturated fatty alcohol used is hexadecenol or octadecenol.   
     
     
         4 . The process as claimed in  claim 1 , wherein
 the compounds of the formulae (I) and (II) in alternative a) are used with a proportion by weight of 4% to 13%, preferably 8% to 10%, and   the compounds of the formula (III) in alternative a) are used with a proportion by weight of 30% to 95%, preferably 40% to 60%, and   the compounds of the formula (IV) in alternative a) are used with a proportion by weight of 10% to 60%, preferably 30% to 50%, or   the compounds of the formulae (I) or (II) in alternative b) are used with a proportion by weight of 3% to 6%, preferably 4% to 5%, and   the polyols and/or triglycerides with a hydroxy fatty acid component in alternative b) are used with a proportion by weight of 40% to 96%, preferably 50% to 80%, and   the hydrophobic phenol derivatives and/or unsaturated fatty alcohols in alternative b) are used with a proportion by weight of 40% to 96%, preferably 50% to 80%.   
     
     
         5 . The lubricant additive obtainable according to  claim 1 . 
     
     
         6 . A lubricant additive comprising
 I. a dimeric thiadiazole compound, especially a bis(2-alkyl-1,3,4-thiadiazolyl) 5,5′-disulfide derivative of the formula (I)   
       
         
           
           
               
               
           
         
         
           and/or a dimeric 2,5-dimercapto-1,3,4-thiadiazolethiol derivative of the formula (II) 
         
       
       
         
           
           
               
               
           
         
         
           where n in the formulae (I) and (II) is 1 or 2 and 
           R1 and R2 are each independently hydrogen, linear or branched alkyl groups having 1 to 12 carbon atoms, especially thioalkyl groups having 1 to 12 carbon atoms, aromatic radicals or heteroaromatic radicals, 
         
         II. a polyamine or polyamine derivative of the formula (III)
   R1-(CH2-CH2-NH) n -CH2-CH2-R2  (III)
 
 where n in formula (III) is an integer from 1 to 15, especially an integer from 3 to 8, and 
 R1 and R2 are each independently hydrogen, —NH2, linear or branched alkyl groups having 1 to 12 carbon atoms or a modified or unmodified succinimide group, and 
 
         III. a compound of the formula (IV) 
       
       
         
           
           
               
               
           
         
         
           in which n is an integer from 1 to 8, especially an integer from 3 to 8, preferably 6. 
         
       
     
     
         7 . A lubricant additive comprising
 I. a dimeric thiadiazole compound, especially a bis(2-alkyl-1,3,4-thiadiazolyl) 5,5′-disulfide derivative of the formula (I)   
       
         
           
           
               
               
           
         
         
           and/or a dimeric 2,5-dimercapto-1,3,4-thiadiazolethiol derivative of the formula (II) 
         
       
       
         
           
           
               
               
           
         
         
           where n in the formulae (I) and (II) is 1 or 2 and 
           R1 and R2 are each independently hydrogen, linear or branched alkyl groups having 1 to 12 carbon atoms, especially thioalkyl groups having 1 to 12 carbon atoms, aromatic radicals or heteroaromatic radicals, 
         
         II. a polyol, especially a polyether polyol having a high propylene oxide content, i.e. having a low ethyl oxide/propylene oxide ratio, and/or a triglyceride having a hydroxy fatty acid component, and 
         III. a hydrophobic phenol derivative and/or unsaturated fatty alcohol. 
       
     
     
         8 . The lubricant, especially lubricant oil, comprising a lubricant additive as claimed in  claim 5 , preferably in a concentration of 0.2% by weight to 10% by weight. 
     
     
         9 . The use of a lubricant additive wherein in  claim 5  in lubricants and especially lubricant oils, more preferably in mineral oil-free forming lubricants.