Lubricating oil composition comprising an epoxidized ester and an aspartic acid derivative

Abstract

The present invention aims to obtain a lubricating oil composition with good corrosion resistance properties, strong sludge inhibition and also superior energy saving properties for use in all kinds of lubricating oil compositions which use highly refined base oils, in particular in machine oils, turbine oils, compressor oils, hydraulic oils, gear oils, sliding friction oils, bearing oils and calibration oils. To this end the invention provides a lubricating oil composition comprising a base oil having a sulphur content of not more than 300 ppm, an aspartic acid derivative and an epoxidised ester compound.

1 . A lubricating oil composition comprising a base oil having a sulphur content of not more than 300 ppm, an aspartic acid derivative, and an epoxidised ester compound,
 wherein the aspartic acid derivative has general formula 1   
     
       
         
         
             
             
         
       
       wherein X 1 , and X 2  are each hydrogen atoms or same or different alkyl groups or hydroxyalkyl groups having from 3 to 6 carbon atoms; 
       X 3  is an alkyl group having 1 to 30 carbon atoms, possibly containing an ether bond and/or a hydroxyalkyl group; 
       X 4  is a C 1 -C 30  saturated or unsaturated carboxylic group, alkyl group, an ethylhexyl group or hydroxyalkyl group. 
     
   
   
       2 . The lubricating oil composition according to  claim 1 , wherein the acid number of the aspartic acid derivative is from 10 to 250 mgKOH/g. 
   
   
       3 . The lubricating oil composition according to  claim 1 , wherein the epoxidised ester compound is an epoxidised fatty acid ester derived from animal oils and fats and/or vegetable oils and fats. 
   
   
       4 . The lubricating oil composition according to  claim 1 , wherein the amount of each of the aspartic acid derivative and epoxidised ester compound is from 0.01 to 5% by weight, based on the total composition. 
   
   
       5 . The lubricating oil composition according to  claim 1 , further comprising an aliphatic amine. 
   
   
       6 . The lubricating oil composition according to  claim 5 , wherein the aliphatic moiety of the fatty acid amine has from 8 to 24 carbons. 
   
   
       7 . The lubricating oil composition according to  claim 1 , wherein the base oil is a synthetic oil. 
   
   
       8 . The lubricating oil composition according to  claim 7 , wherein the base oil is a poly-α-olefin. 
   
   
       9 . The lubricating oil composition according to  claim 7 , wherein the base oil is a GTL derived base oil. 
   
   
       10 . The use of the lubricating oil composition according to  claim 1  as a machine oil, hydraulic oil, turbine oil, compressor oil, gear oil, sliding friction oil, bearing oil and calibration oil. 
   
   
       11 . (canceled)