Method for controlling the stability or the droplets size of simple water-in-oil emulsions, and stabilized simple water-in-oil emulsions

Abstract

The invention concerns a process for controlling the stability or the droplets sized of simple water-in-oil emulsions, wherein a diblock or tri-block copolymer is used. A block is a hydrophilic block, the other block is a hydrophobic block. The invention concerns also a stabilized water-in-oil emulsion.

1 . A method for controlling the stability or the droplets size of a simple water-in-oil emulsion comprising droplets of an aqueous phase dispersed in a hydrophobic phase, said method comprising the step of using in the emulsion: 
 a block copolymer selected from the group consisting of: 
 (block A)-(block B) di-block copolymers,  
 (block A)-(block B)-(block A) tri-block copolymers, and  
 (block B)-(block A)-(block B) tri-block copolymers,  
 wherein  
 block A is a hydrophilic block,  
 block B is a hydrophobic block, and  
 block A or block B comprises units deriving from mono-alpha-ethylenically-unsaturated monomers, and  
   optionally, an emulsifier, different from the block copolymer.    
     
     
         2 . A method according to  claim 1 , wherein block B and block A comprise units deriving from mono-alpha-ethylenically-unsaturated monomers.  
     
     
         3 . A method according to  claim 1 , wherein an emulsifier is used, being a surfactant.  
     
     
         4 . A method according to  claim 1 , wherein the amount of aqueous phase is of from 10 to 99 weight %, relative to the weight of the hydrophobic phase, block copolymer, optional emulsifier, and aqueous phase.  
     
     
         5 . A method according to  claim 4 , wherein the amount of aqueous phase is of from 50 to 95 weight %.  
     
     
         6 . A method according to  claim 1 , wherein the amount of block copolymer and optional emulsifier is of from 0.1 to 10 weight % of the amount of aqueous phase.  
     
     
         7 . A method according to  claim 6 , wherein the amount of block copolymer and optional emulsifier is of from 0.5 to 5 weight %.  
     
     
         8 . A method according to  claim 1 , wherein block B comprises repeating units deriving from monomers selected from the group consisting of: 
 dialkylsiloxane,    alkylesters of an alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acid,    vinyl Versatate,    vinyl acetate,    acrylonitrile,    vinyl nitriles, comprising from 3 to 12 carbon atoms,    vinylamine amides, and    vinylaromatic compounds.    
     
     
         9 . A method according to  claim 8 , wherein block B comprises repeating units deriving from monomers selected from the group consisting of: 
 methylacrylate, ethylacrylate, n-propylacrylate, n-butylacrylate, methylmethacrylate, ethylmethacrylate, n-propylmethacrylate, n-butylmethacrylate, and 2-ethyl-hexyl acrylate, 2-ethyl-hexyl methacrylate, isooctyl acrylate, isooctyl methacrylate, lauryl acrylate, lauryl methacrylate, and    styrene.    
     
     
         10 . A method according to  claim 1 , wherein block A comprises repeating units deriving from monomers selected from the group consisting of: 
 ethylene oxide,    vinyl alcohol,    vinyl pyrrolidone,    acrylamide, methacrylamide,    polyethylene oxide (meth)acrylate,    hydroxyalkylesters of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acids,    hydroxyalkylamides of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acids,    dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, ditertiobutylaminoethyl (meth)acrylate, dimethylaminomethyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide;    ethylenimine, vinylamine, 2-vinylpyridine, 4- vinylpyridine;    trimethylammonium ethyl (meth)acrylate chloride, trimethylammonium ethyl (meth)acrylate methyl sulphate, dimethylammonium ethyl (meth)acrylate benzyl chloride, 4-benzoylbenzyl dimethylammonium ethyl acrylate chloride, trimethyl ammonium ethyl (meth)acrylamido (also called 2-(acryloxy)ethyltrimethylammonium, TMAEAMS) chloride, trimethylammonium ethyl (meth)acrylate (also called 2-(acryloxy)ethyltrimethylammonium, TMAEAMS) methyl sulphate, trimethyl ammonium propyl (meth)acrylamido chloride, vinylbenzyl trimethyl ammonium chloride,    diallyidimethyl ammonium chloride,    monomers having the following formula:                          wherein 
 R 1  is a hydrogen atom or a methyl or ethyl group;  
 R 2 , R 3 , R 4 , R 5  and R 6 , which are identical or different, are linear or branched C 1 -C 6 , preferably C 1 -C 4 , alkyl, hydroxyalkyl or aminoalkyl groups;  
 m is an integer from 1 to 10, for example 1;  
 n is an integer from 1 to 6, preferably 2 to 4;  
 Z represents a —C(O)O— or —C(O)NH— group or an oxygen atom;  
 A represents a (CH 2 ) p  group, p being an integer from 1 to 6, preferably from 2 to 4;  
 B represents a linear or branched C 2 -C 12 , advantageously C 3 -C 6 , polymethylene chain optionally interrupted by one or more heteroatoms or heterogroups, in particular O or NH, and optionally substituted by one or more hydroxyl or amino groups, preferably hydroxyl groups;  
 X, which are identical or different, represent counterions,  
   alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monomers comprising a phosphate or phosphonate group,    alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acids,    monoalkylesters of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, dicarboxylic acids,    monoalkylamides of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, dicarboxylic acids,    alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, compounds comprising a sulphonic acid group, and salts of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, compounds comprising a sulphonic acid group.    
     
     
         11 . A method according to  claim 10 , wherein block A comprises repeating units deriving from monomers selected from the group consisting of: 
 2-hydroxyethylacrylate,    acrylic acid, methacrylic acid,    vinyl sulphonic acid, salts of vinyl sulfonic acid, vinylbenzene sulphonic acid, salts of vinylbenzene sulphonic acid, alpha-acrylamidomethylpropanesulphonic acid, salts of alpha-acrylamidomethylpropanesulphonic acid 2-sulphoethyl methacrylate, salts of 2-sulphoethyl methacrylate, acrylamido-2-methylpropanesulphonic acid (AMPS), salts of acrylamido-2-methylpropanesulphonic acid, and styrenesulfonate (SS).    
     
     
         12 . A method according to  claim 1 , wherein, in the block copolymer, the weight ratio between block B and block A is of from 40/60 to 95/5.  
     
     
         13 . A method according to  claim 2 , wherein the mixture of the block copolymer and the emulsifier has a HLB of lower than or equal to 10.  
     
     
         14 . A method according to  claim 1 , wherein the emulsion is an explosive emulsion, the hydrophilic phase comprising an oxygen-donating compound.  
     
     
         15 . A method according to  claim 2 , Wherein the emulsifier is a polyisobutene succinic anhydride, optionally modified, and wherein the hydrophilic phase comprises ammonium nitrate.  
     
     
         16 . A method according to  claim 1 , wherein the hydrophobic phase comprises an organic, vegetal or mineral oil, or a wax.  
     
     
         17 . A simple water-in-oil emulsion comprising 
 droplets of an aqueous phase dispersed in a hydrophobic phase,    a block copolymer selected from the group consisting of: 
 (block A)-(block B) di-block copolymers,  
 (block A)-(block B)-(block A) tri-block copolymers, and  
 (block B)-(block A)-(block B) tri-block copolymers,  
 wherein  
 block A is a hydrophilic block,  
 block B is a hydrophobic block, and  
 block A or block B comprises units deriving from mono-alpha-ethylenically-unsaturated monomers, and  
   optionally, an emulsifier, different from the block copolymer.    
     
     
         18 . An emulsion according to  claim 17 , wherein block B and block A comprise units deriving from mono-alpha-ethylenically-unsaturated monomers.  
     
     
         19 . An emulsion according to  claim 17 , comprising the emulsifier, said emulsifier being a surfactant.  
     
     
         20 . An emulsion according to  claim 17 , wherein the amount of aqueous phase is of from 10 to 99 weight %, relative to the weight of the hydrophobic phase, block copolymer, optional emulsifier, and aqueous phase.  
     
     
         21 . An emulsion according to  claim 17 , wherein the amount of aqueous phase is of from 50 to 95 weight %.  
     
     
         22 . An emulsion according to  claim 17 , wherein the amount of block copolymer and optional emulsifier is of from 0.1 to 10 weight % of the amount of aqueous phase.  
     
     
         23 . An emulsion according to  claim 22 , wherein the amount of block copolymer and optional emulsifier is of from 0.5 to 5 weight %.  
     
     
         24 . An emulsion according to  claim 17 , wherein block B comprises repeating units deriving from monomers selected from the group consisting of: 
 dialkylsiloxane,    alkylesters of an alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acid,    vinyl Versatate,    vinyl acetate,    acrylonitrile,    vinyl nitriles, comprising from 3 to 12 carbon atoms,    vinylamine amides, and    vinylaromatic compounds.    
     
     
         25 . An emulsion according to  claim 24 , wherein block B comprises repeating units deriving from monomers selected from the group consisting of: 
 methylacrylate, ethylacrylate, n-propylacrylate, n-butylacrylate, methylmethacrylate, ethylmethacrylate, n-propylmethacrylate, n-butylmethacrylate, and 2-ethyl-hexyl acrylate, 2-ethyl-hexyl methacrylate, isooctyl acrylate, isooctyl methacrylate, lauryl acrylate, lauryl methacrylate, and    styrene.    
     
     
         26 . An emulsion according to  claim 17 , wherein block A comprises repeating units deriving from monomers selected from the group consisting of: 
 ethylene oxide,    vinyl alcohol,    vinyl pyrrolidone,    acrylamide, methacrylamide,    polyethylene oxide (meth)acrylate,    hydroxyalkylesters of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acids,    hydroxyalkylamides of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acids,    dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, ditertiobutylaminoethyl (meth)acrylate, dimethylaminomethyl (meth)acrylamide, dimethylaminopropyl (meth)acrylamide;    ethylenimine, vinylamine, 2-vinylpyridine, 4-vinylpyridine;    trimethylammonium ethyl (meth)acrylate chloride, trimethylammonium ethyl (meth)acrylate methyl sulphate, dimethylammonium ethyl (meth)acrylate benzyl chloride, 4-benzoylbenzyl dimethylammonium ethyl acrylate chloride, trimethyl ammonium ethyl (meth)acrylamido (also called 2-(acryloxy)ethyltrimethylammonium, TMAEAMS) chloride, trimethylammonium ethyl (meth)acrylate (also called 2-(acryloxy)ethyltrimethylammonium, TMAEAMS) methyl sulphate, trimethyl ammonium propyl (meth)acrylamido chloride, vinylbenzyl trimethyl ammonium chloride,    diallyldimethyl ammonium chloride,    monomers having the following formula:                          wherein 
 R 1  is a hydrogen atom or a methyl or ethyl group;  
 R 2 , R 3 , R 4 , R 5  and R 6 , which are identical or different, are linear or branched C 1 -C 6 , preferably C 1 -C 4 , alkyl, hydroxyalkyl or aminoalkyl groups;  
 m is an integer from 1 to 10, for example 1;  
 n is an integer from 1 to 6, preferably 2 to 4;  
 Z represents a —C(O)O— or —C(O)NH— group or an oxygen atom;  
 A represents a (CH 2 ) p  group, p being an integer from 1 to 6, preferably from 2 to 4;  
 B represents a linear or branched C 2 -C 12 , advantageously C 3 -C 6 , polymethylene chain optionally interrupted by one or more heteroatoms or heterogroups, in particular O or NH, and optionally substituted by one or more hydroxyl or amino groups, preferably hydroxyl groups;  
 X, which are identical or different, represent counterions,  
   alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monomers comprising a phosphate or phosphonate group,    alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, monocarboxylic acids,    monoalkylesters of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, dicarboxylic acids,    monoalkylamides of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, dicarboxylic acids,    alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, compounds comprising a sulphonic acid group, and salts of alpha-ethylenically-unsaturated, preferably mono-alpha-ethylenically-unsaturated, compounds comprising a sulphonic acid group.    
     
     
         27 . An emulsion according to  claim 26 , wherein block A comprises repeating units deriving from monomers selected from the group consisting of: 
 2-hydroxyethylacrylate,    acrylic acid, methacrylic acid,    vinyl sulphonic acid, salts of vinyl sulfonic acid, vinylbenzene sulphonic acid, salts of vinylbenzene sulphonic acid, alpha-acrylamidomethylpropanesulphonic acid, salts of alpha-acrylamidomethylpropanesulphonic acid 2-sulphoethyl methacrylate, salts of 2-sulphoethyl methacrylate, acrylamido-2-methylpropanesulphonic acid (AMPS), salts of acrylamido-2-methylpropanesulphonic acid, and styrenesulfonate (SS).    
     
     
         28 . An emulsion according to  claim 17 , wherein, in the block copolymer, the weight ratio between block B and block A is of from 40/60 to 95/5.  
     
     
         29 . An emulsion according to  claim 18 , wherein the mixture of the block copolymer and the emulsifier has a HLB of lower than or equal to 10.  
     
     
         30 . An emulsion according to  claim 17 , wherein the emulsion is an explosive emulsion, the hydrophilic phase comprising an oxygen-donating compound.  
     
     
         31 . An emulsion according to  claim 17 , wherein the emulsifier is a polyisobutene succinic anhydride, optionally modified, and wherein the hydrophilic phase comprises ammonium nitrate.  
     
     
         32 . An emulsion according to  claim 18 , wherein the hydrophobic phase comprises an organic, vegetal or mineral oil, or a wax.