Process for preparing a urea grease

Abstract

The invention provides for a process for preparing urea grease. The process is carried out in the presence of a base oil and avoids the use of diisocyanate reagents.

1 . A process for preparing a urea grease comprising one or more steps in which a compound of formula (I), a compound of formula (II) and a compound of formula (III) are reacted: 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are chosen from hydrocarbyl having from 1 to 30 carbon atoms, or R 1  and R 2  are linked and form a hydrocarbylene group having from 1 to 30 carbon atoms, R 3  is chosen from hydrocarbyl comprising from 2 to 30 carbon atoms and R 4  is hydrocarbylene comprising from 2 to 30 carbon atoms; 
         wherein at least one of the reaction steps is carried out in the presence of a base oil. 
       
     
     
         2 . A process for preparing a urea grease according to  claim 1 , comprising steps of:
 (a1) reacting a compound of formula (I) with a compound of formula (II):   
       
         
           
           
               
               
           
         
         and 
         (b1) reacting the product of step (a1) with a compound of formula (III):
   H 2 N—R 4 —NH 2    (III)
 
 
         wherein step (b1) is carried out in the presence of a base oil. 
       
     
     
         3 . A process for preparing a urea grease according to  claim 1  comprising steps of:
 (a2) reacting a compound of formula (I) with a compound of formula (III): 
 
       
         
           
           
               
               
           
         
         and 
         (b2) reacting the product of step (a2) with a compound of formula (II):
   R 3 —NH 2    (II)
 
 
         wherein step (b2) is carried out in the presence of a base oil. 
       
     
     
         4 . A process according to  claim 2 , wherein a catalyst is present in step (a1), step (b1), or both. 
     
     
         5 . A process according to  claim 2 , wherein the reaction product of step (b1) is heated to at least 170° C. and then cooled. 
     
     
         6 . A process according to  claim 1 , wherein the urea grease comprises a weight percent of urea based on the total weight of urea grease in a range of from 2 weight percent to 25 weight percent. 
     
     
         7 . A process according to  claim 1 , wherein the grease is subjected to one or more finishing procedures chosen from homogenisation, filtration and de-aeration. 
     
     
         8 . A process according to  claim 1 , wherein one or more additives are added to the grease. 
     
     
         9 . A process according to  claim 3 , wherein a catalyst is present in step (a2), step (b2), or both. 
     
     
         10 . A process according to  claim 3  wherein the reaction product of step (b2) is heated to at least 170° C. and then cooled. 
     
     
         11 . A process according to  claim 4  wherein the reaction product of step (b1) is heated to at least 170° C. and then cooled. 
     
     
         12 . A process according to  claim 9  wherein the reaction product of step (b2) is heated to at least 170° C. and then cooled. 
     
     
         13 . A process according to  claim 2 , wherein the urea grease comprises a weight percent of urea based on the total weight of urea grease in a range of from 2 weight percent to 25 weight percent. 
     
     
         14 . A process according to  claim 3 , wherein the urea grease comprises a weight percent of urea based on the total weight of urea grease in a range of from 2 weight percent to 25 weight percent. 
     
     
         15 . A process according to  claim 2 , wherein the grease is subjected to one or more finishing procedures chosen from homogenisation, filtration and de-aeration. 
     
     
         16 . A process according to  claim 3 , wherein the grease is subjected to one or more finishing procedures chosen from homogenisation, filtration and de-aeration.