Sulfur-containing organophosphorus compounds

Abstract

New sulfur-containing organophosphorus compounds of general formulae (I) and (II) and processes for producing the same; additives for lubricating oils, which contain the sulfur-containing organophosphorus compounds; and lubricating oil compositions satisfying requirements of extreme-pressure lubrication and abrasion resistance under severe conditions of high loads imposed, on automatic or continuously variable transmissions or the like. In said formulae, R1 is a hydrocarbon group having 6 to 20 carbon atoms; R2 is a divalent hydrocarbon group having 1 to 6 carbon atoms; n is an integer of 1 to 3; p is an integer of 0 to 2; and q is an integer of 0 or 1, with the proviso that p and q cannot be 0 at the same time.

1 . At least one sulfur-containing organophosphorus compound selected from compounds of a general formula (I): 
       (R 1 —S—R 2 —O) n —P—(OH) 3−n   (I) 
       wherein R 1  represents a hydrocarbon group having from 6 to 20 carbon atoms; R 2  represents a divalent hydrocarbon group having from 1 to 6 carbon atoms; and n indicates an integer of from 1 to 3,  
       and a general formula (II):  
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  have the same meanings as above; p indicates an integer of from 0 to 2, and q indicates an integer of 0 or 1, with the proviso that p and q cannot be 0 at the same time.  
     
     
         2 . At least one sulfur-containing organophosphorus compound selected from compounds of formulae (I) and (II) wherein n=1, those wherein n=2, those wherein p=1 and q=0, those wherein p=1 and q=1, and those wherein p=2 and q=0.  
     
     
         3 . A method for producing sulfur-containing organophosphorus compounds of  claim 1  or  2 , which comprises reacting an alkylthioalkyl alcohol of a general formula (III): 
       R 1 —S—R 2 —OH  (III) 
       wherein R 1  and R 2  have the same meanings as above, with phosphorus trichloride in the absence of a catalyst or in the presence of a base.  
     
     
         4 . Additives for lubricating oils, which contain at least one sulfur-containing organophosphorus compound selected from compounds of a general formula (IV): 
       [R 1 —(X—R 2 ) m —Y] n —P—(OH) 3−n   (IV) 
       wherein R 1  and R 2  have the same meanings as above; X and Y each represent S (sulfur) or O (oxygen), and either one of X and Y is S; m indicates an integer of from 0 to 4 (provided that, when n=3, m is an integer of from 1 to 4); and n has the same meaning as above,  
       and a general formula (V):  
       
         
           
           
               
               
           
         
       
       wherein m indicates an integer of from 0 to 4; and X, Y, R 1 , R 2 , p and q have the same meanings as above.  
     
     
         5 . Additives for lubricating oils, which contain at least one sulfur-containing organophosphorus compound selected from compounds of a general formula (VI): 
       (R 1 —S—R 2 —Y) n —P—(OH) 3−n   (VI) 
       wherein R 1 , R 2 , Y and n have the same meanings as above, and a general formula (VII):  
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , Y, p and q have the same meanings as above.  
     
     
         6 . Additives for lubricating oils, which contain at least one sulfur-containing organophosphorus compound selected from compounds of the following general formulae (VIII), (IX), (X), (XI) and (XII): 
       R 1 —S—R 2 —O—P—(OH) 2   (VIII)(R 1 —S—R 2 —O) 2 —P—OH  (IX)                    
       wherein R 1  and R 2  have the same meanings as above.  
     
     
         7 . Lubricating oil compositions comprising base oil and an effective amount of the sulfur-containing organophosphorus compound of any one of  claims 4  to  6 .