Lubricant compositions

Abstract

A lubricant composition for a high load carrying oil comprises a synergistic mixture of a neutral alkyl phosphorus compound and a sulphur carrier. The neutral alkyl phosphorus compound is selected from neutral alkyl and alkoxyalkyl phosphates, phosphonates, phosphinates and phosphites. Preferred neutral alkyl phosphorus compounds are triisobutyl phosphate, tributoxyethyl phosphate and dioctyl octyl phosphonate. Preferred sulphur carriers are sulphurised fatty acid esters and dialkyl polysulphides. High load carrying oils containing the lubricant composition of the invention include metal working fluids, gear oils, extreme pressure turbine oils and hydraulic oils.

1 . A lubricant composition for a high load carrying oil, said lubricant composition comprising: 
 (a) a neutral alkyl phosphorus compound selected from the group consisting of    (i) a neutral alkyl phosphate of the general formula I                           wherein R 1 , R 2  and R 3  are the same or different and are alkyl groups of 1 to 18 carbon atoms;    (ii) a neutral alkoxyalkyl phosphate of the general formula IV                           wherein R 4 , R 6  and R 8  are —C 2 H 4  or C 3 H 8  and R 5 , R 7  and R 9  are the same or different and are alkyl groups of 1 to 8 carbon atoms and n is 1 to 6; and    (iii) a neutral dialkylalkoxyalkyl phosphate of the general formula XI                           wherein R 2  and R 3  are the same as in formula I above and R 4  and R 5  are the same as in formula IV above and mixtures thereof; and    (b) a sulphur carrier containing active or inactive sulphur and which is selected from the group consisting of sulphurised synthetic esters, sulphurised vegetable oils and fats, metal sulphonates, dialkylpolysulphides and mixtures thereof.    
   
   
       2 . The lubricant composition according to  claim 1  wherein the neutral alkyl phosphorus compound and the sulphur carrier are present in a weight ratio of P to S content from 1:50 to 1:1.  
   
   
       3 . The lubricant composition according to  claim 2  wherein the neutral alkyl phosphorus compound and the sulphur carrier are present in a weight ratio of P to S content from 1:1 to 1:30.  
   
   
       4 . The lubricant composition according to  claim 1  wherein the phosphorus compound is selected from the group consisting of triisobutyl phosphate, tri-n-butyl phosphate, triisopropyl phosphate, triocyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, butoxyethyldioctyl phosphate and mixtures thereof.  
   
   
       5 . The lubricant composition according to  claim 1  wherein the sulphur carrier is selected from the group consisting of a sulphurised fatty acid, a dialkylpentasulphide and mixtures thereof.  
   
   
       6 . (Canceled)  
   
   
       7 . The lubricant composition according to  claim 1  which is a metal working fluid, a gear oil, an extreme pressure turbine oil or a hydraulic oil.  
   
   
       8 . (Canceled)  
   
   
       9 . The lubricant composition according to  claim 1  wherein the phosphorus compound is selected from the group consisting of triisobutyl phosphate, tri-n-butyl phosphate, triisopropyl phosphate, triocyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, butoxyethyldioctyl phosphate and mixtures thereof and the sulphur carrier is selected from the group consisting of a sulphurised fatty acid, a dialkylpentasulphide and mixtures thereof.  
   
   
       10 . The lubricant composition according to  claim 1  further comprising one or more additional components selected from the group consisting of surfactants, non-ionic alcohols and mixtures thereof.  
   
   
       11 . A method for working metal comprising (a) contacting a metal workpiece with a metal working fluid comprising an effective amount of a lubricant composition and (b) working the metal workpiece, wherein the lubricant composition comprises (i) a neutral alkyl phosphorus compound selected from the group consisting of a neutral alkyl phosphate of the general formula I  
     
       
         
         
             
             
         
       
        wherein R 1 , R 2  and R 3  are the same or different and are alkyl groups of 1 to 18 carbon atoms;  
       a neutral alkoxyalkyl phosphate of the general formula IV  
       
         
           
           
               
               
           
         
       
        wherein R 4 , R 6  and R 8  are —C 2 H 4  or C 3 H 8  and R 5 , R 7  and R 9  are the same or different and are alkyl groups of 1 to 8 carbon atoms and n is 1 to 6; (iii) a neutral dialkylalkoxyalkyl phosphate of the general formula XI  
       
         
           
           
               
               
           
         
       
        wherein R 2  and R 3  are the same as in formula I above and R 4  and R 5  are the same as in formula IV above and mixtures thereof, and (ii) a sulphur carrier containing active or inactive sulphur and which is selected from the group consisting of sulphurised synthetic esters, sulphurised vegetable oils and fats, metal sulphonates, dialkylpolysulphides and mixtures thereof.  
     
   
   
       12 . The method according to  claim 11  wherein the neutral alkyl phosphorus compound and the sulphur carrier of the lubricant composition are present in a weight ratio of P to S content from 1:50 to 1:1.  
   
   
       13 . The method according to  claim 11  wherein the neutral alkyl phosphorus compound and the sulphur carrier of the lubricant composition are present in a weight ratio of P to S content from 1:1 to 1:30.  
   
   
       14 . The method according to  claim 11  wherein the phosphorus compound of the lubricant composition is selected from the group consisting of triisobutyl phosphate, tri-n-butyl phosphate, triisopropyl phosphate, triocyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, butoxyethyldioctyl phosphate and mixtures thereof.  
   
   
       15 . The method according to  claim 11  wherein the sulphur carrier of the lubricant composition is selected from the group consisting of a sulphurised fatty acid, a dialkylpentasulphide and mixtures thereof.  
   
   
       16 . The method according to  claim 11  wherein the lubricant composition is a metal working fluid, a gear oil, an extreme pressure turbine oil or a hydraulic oil.