Use Of Biodegradable Alkoxylated (Meth)Acrylate Copolymers As Crude Oil Demulsifiers

Abstract

The invention relates to the use of copolymers which can be obtained by the polymerization of monomers (A) and (B), (A) being a monomer of formula (I), wherein A represents a C 2 to C 4 alkylene group, B represents a C 2 to C 4 alkylene group different from A, R represents hydrogen or methyl, m is a number from 1 to 500, and n is a number from 1 to 500, and (B) being an ethylenically unsaturated monomer which contains an aliphatic hydrocarbon group, for demulsifying oil/water emulsions in amounts of 0.0001 to 5% by weight, based on the oil content of the emulsion to be demulsified.

1 . A process for breaking an oil/water emulsion, comprising the step of adding at least one copolymer obtainable by polymerization of monomers (A) and (B), wherein 
       (A) is a monomer of formula (I) 
       
         
           
           
               
               
           
         
       
       wherein
 A is a C 2  to C 4  alkylene group, 
 B is a C 2  to C 4  alkylene group other than A, 
 R is hydrogen or methyl, 
 m is from 1 to 500, 
 n is from 1 to 500, and 
 
       (B) is an ethylenically unsaturated monomer which contains an aliphatic hydrocarbon group, 
       in amounts of 0.0001% to 5% by weight based on the oil content of the emulsion to be broken to the emulsion to be broken. 
     
     
         2 . A process according to  claim 1 , wherein the at least one copolymer is obtainable by polymerization of monomers (A), (B) and (C) wherein (C) is an ethylenically unsaturated monomer which contains an aromatic group. 
     
     
         3 . A process according to  claim 1 , wherein the molar fraction of monomer (A) is in the range from 0.1% to 99.9% and of monomer (B) is in the range from 0.1% to 99.9% in the copolymer. 
     
     
         4 . A process according to  claim 2 , wherein the molar fraction of monomer (A) is from 1% to 80%, of monomer (B) is from 0.1% to 80% and of monomer (C) is from 0.1% to 80% in the copolymer. 
     
     
         5 . A process according to  claim 2 , wherein the molar fraction of monomer (A) is from 10% to 70%, of monomer (B) is from 10% to 60% and of monomer (C) is from 1% to 60% in the copolymer. 
     
     
         6 . A process according to  claim 1 , wherein the alkylene oxide units (A-O) m  and (B-O) n  are arranged blockwise. 
     
     
         7 . A process according to  claim 1 , wherein (A-O) m  represents a block of propylene oxide units and (B-O) n  represents a block of ethylene oxide units, or (A-O) m  represents a block of ethylene oxide units and (B-O) n  represents a block of propylene oxide units, and wherein the molar fraction of ethylene oxide units, based on the sum total of ethylene oxide and propylene oxide units, is from 50% to 98%. 
     
     
         8 . A process according to  claim 7 , wherein the molar fraction of ethylene oxide units in the copolymer is from 55% to 95%, based on the sum total of ethylene oxide and propylene oxide units. 
     
     
         9 . A process according to  claim 1 , wherein the monomer (B) is a compound of formula (II): 
       
         
           
           
               
               
           
         
       
       wherein
 R 1  is hydrogen or methyl, 
 Y is a linear, branched or cyclic aliphatic hydrocarbon radical of 1 to 30 carbon atoms, preferably 4 to 28 carbon atoms and particularly 6 to 24 carbon atoms, which may be saturated or unsaturated, and which may contain heteroatoms selected from O, N and S, 
 W a  is oxygen or the group —NH—. 
 
     
     
         10 . A process according to  claim 2 , wherein the monomer (C) is a compound of formulae (IIIa) or (IIIb) 
       
         
           
           
               
               
           
         
       
       wherein
 X a  is an aromatic or araliphatic radical of 3 to 30 carbon atoms, which may optionally contain heteroatoms selected from O, N and S, 
 Z a  is H or C 1  to C 4  alkyl, 
 Z b  is H or C 1  to C 4  alkyl, and 
 Z c  is H or C 1  to C 4  alkyl; 
 
       
         
           
           
               
               
           
         
       
       wherein
 R 2  is hydrogen or methyl, 
 X b  is an aromatic or araliphatic radical of 3 to 30 carbon atoms, which may optionally contain heteroatoms selected from O, N and S, 
 W b  is oxygen or the group —NH—. 
 
     
     
         11 . A process according to  claim 1 , wherein said monomer (B) is an alkyl ester or alkylamide of acrylic or methacrylic acid and wherein alkyl has the meaning methyl, ethyl, propyl, butyl, isobutyl, 2-ethylhexyl, 2-ethoxyethyl, myristyl, lauryl and stearyl. 
     
     
         12 . A process according to  claim 2 , wherein said monomer (C) is styrene, 1-vinylimidazole, benzyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate or phenethyl (meth)acrylate. 
     
     
         13 . A process according to  claim 1 , wherein m is from 2 to 50. 
     
     
         14 . A process according to  claim 1 , wherein n is from 2 to 50. 
     
     
         15 . A process according to  claim 10 , wherein X a  or X b  represent aromatic or araliphatic radicals of 6 to 24 carbon atoms. 
     
     
         16 . A process according to  claim 1 , wherein (n+m) is from 5 to 80. 
     
     
         17 . A process according to  claim 4 , wherein the molar fraction of monomer (A) is from 10% to 70%, of monomer (B) is from 10% to 60% and of monomer (C) is from 1% to 60% in the copolymer.