Lubricating composition with improved cold thickening properties

Abstract

The present application relates to the use of a comb polymer comprising repeating units that can be obtained by polymerisation of monomers (a) of formula (I): in which: R 1 is a hydrogen atom or a methyl group, X 1 is a group chosen from: —O—, —O(AO) m , or —NH—, each group A being independently a C 2 -C 4 alkylene group and m being an integer ranging from 0 to 10, R 2 is polybutylene group, and p is equal to 0 or 1, for improving the cold thickening properties of a lubricating composition having a grade (X)W—(Y) according to the standard SAEJ 300 in which x=0, 5 or 10 and y=8, 16, 20, 30 or 40, comprising at least one base oil, the lubricating composition thus obtained having a Gelation Index according to the standard ASTM D5133 of less than 6.

1 - 5 . (canceled) 
     
     
         6 . A method for improving the cold thickening properties of a lubricating composition of Grade (X)W—(Y) according to standard SAEJ 300 in which x=0, 5 or 10 and y=8, 16, 20, 30 or 40, comprising at least one base oil, said method comprising the addition to said lubricating composition of at least one comb polymer comprising repeating units able to be obtained by polymerisation of monomers (a) of formula (I): 
       
         
           
           
               
               
           
         
         in which: 
         R 1  is a hydrogen atom or a methyl group, 
         X 1  is a group chosen from among: —O—, —O(AO) m , or —NH—, each group A independently being a C 2 -C 4  alkylene group and m being an integer ranging from 0 to 10, 
         R 2  is a polybutylene group, and 
         p is equal to 0 or 1, 
         the lubricating composition thus obtained having a Gelation Index according to standard ASTM D5133 of less than 6. 
       
     
     
         7 . The method according to  claim 6 , wherein the polymer further comprises units derived from monomers (b) of formula (II): 
       
         
           
           
               
               
           
         
         in which: 
         R 3  is a hydrogen atom or a methyl group, 
         X 2  is a group —O— or —NH—, 
         groups R 4  are each independently a C 2 -C 4  alkylene group, 
         R 5  is a C 1 -C 8  alkyl group, and 
         g is an integer ranging from 1 to 20. 
       
     
     
         8 . A lubricating composition of Grade (X)W—(Y) according to standard SAEJ 300 in which x=0, 5 or 10 and y=8, 16, 20, 30 or 40, comprising at least one base oil, a calcium-based detergent and a magnesium-based detergent, and at least one polymer comprising repeating units able to be obtained by polymerisation of monomers (a) of formula (I): 
       
         
           
           
               
               
           
         
         in which: 
         R 1  is a hydrogen atom or a methyl group, 
         X 1  is a group chosen from: —O—, —O(AO) m , or —NH—, each group A independently being a C 2 -C 4  alkylene group and m being an integer ranging from 0 to 10, 
         R 2  is a polybutylene group, and 
         p is equal to 0 or 1, 
         said lubricating composition having a Gelation Index of less than 6. 
       
     
     
         9 . The composition according to  claim 8 , wherein the polymer further comprises units derived from monomers (b) of formula (II): 
       
         
           
           
               
               
           
         
         in which: 
         R 3  is a hydrogen atom or a methyl group, 
         X 2  is a group —O— or —NH—, 
         groups R 4  are each independently a C 2 -C 4  alkylene group, 
         R 5  is a C 1 -C 8  alkyl group, and 
         g is an integer ranging from 1 to 20. 
       
     
     
         10 . The method according to  claim 6 , wherein the polymer is used in an amount of between 1 and 20% by weight relative to the total weight of the lubricating composition. 
     
     
         11 . The method according to  claim 6 , wherein the lubricating composition comprises at least one calcium-based detergent and at least one magnesium-based detergent. 
     
     
         12 . The method according to  claim 6 , wherein the polymer is used in an amount of between 4 and 16% by weight relative to the total weight of the lubricating composition. 
     
     
         13 . The method according to  claim 6 , for mitigating pre-ignition. 
     
     
         14 . The lubricating composition according to  claim 8 , wherein the polymer is used in an amount of between 1 and 20% by weight relative to the total weight of the lubricating composition. 
     
     
         15 . The lubricating composition according to  claim 8 , wherein the lubricating composition comprises at least one calcium-based detergent and at least one magnesium-based detergent. 
     
     
         16 . The lubricating composition according to  claim 8 , wherein the polymer is used in an amount of between 4 and 16% by weight relative to the total weight of the lubricating composition.