Lubricating oil composition

Abstract

Lubricating oil composition comprising β-dithiophosphorylated propionic acid (A), triaryl phosphate (B) and base oil comprising mineral oil and/or synthetic oil.

1 . Lubricating oil composition, comprising β-dithiophosphorylated propionic acid (A), triaryl phosphate (B) and base oil comprising mineral oil and/or synthetic oil.  
     
     
         2 . Lubricating oil composition according to  claim 1 , wherein the β-dithiophosphorylated propionic acid (A) is represented by the general formula (1) below: 
       S═P(—OR 1 ) 2 SCH 2 CH(R 2 )COOH  (1) 
       wherein R 1 , which may be identical or different, represents a branched alkyl group of from 3 to 8 carbon atoms and R 2  represents a hydrogen atom or alkyl group of from 1 to 4 carbon atoms.  
     
     
         3 . Lubricating oil composition according to  claim 2 , where R 2  is a methyl group, ethyl group or hydrogen group.  
     
     
         4 . Lubricating oil composition according to any one of  claims 1  to  3 , wherein the β-dithiophosphorylated propionic acid (A) is selected from 3-(O,O-diisopropyldithiophosphoryl)propionic acid, 3-(O,O-diisopropyldithiophosphoryl)-2-methyl-propionic acid, 3-(O,O-diisobutyldithiophosphoryl)-propionic acid and 3-(O,O-diisobutyldithiophosphoryl)-2-methyl-propionic acid.  
     
     
         5 . Lubricating oil composition according to any one of  claims 1  to  4 , in which from 0.001 to 1.0% by weight of β-dithiophosphorylated propionic acid (A) is incorporated therein, with respect to the total amount of lubricating oil composition.  
     
     
         6 . Lubricating oil composition according to any one of  claims 1  to  5 , in which from 0.001 to 0.5% by weight of β-dithiophosphorylated propionic acid (A) is incorporated therein, with respect to the total amount of lubricating oil composition.  
     
     
         7 . Lubricating oil composition according to any one of  claims 1  to  6 , wherein the triaryl phosphate (B) is represented by the general formula (2) below: 
       O═P(—O—R 3 ) 3   (2) 
       wherein each R 3  is, independently, a phenyl group or a phenyl group having alkyl group(s) of from 1 to 9 carbon atoms.  
     
     
         8 . Lubricating oil composition according to any one of  claims 1  to  7 , in which from 0.05 to 10% by weight of triaryl phosphate (B) is incorporated therein, with respect to the total amount of lubricating oil composition.  
     
     
         9 . Lubricating oil composition according to any one of  claims 1  to  8 , in which from 0.05 to 5% by weight of triaryl phosphate (B) is incorporated therein, with respect to the total amount of lubricating oil composition.  
     
     
         10 . Use of a lubricating oil composition according to any of  claims 1  to  9 , in a hydraulic machine, a compressor, a turbine, a bearing and/or a gear.