Claims
- 1. A method for controlling the stability of an emulsion comprising a hydrophobic phase dispersed in an aqueous phase, or an aqueous phase dispersed in a hydrophobic phase, and less than 4% by weight of a surfactant, said process 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 comprises units deriving from mono-alpha-ethylenically-unsaturated monomers.
- 2. A method according to claim 1, wherein block B comprises units deriving from mono-alpha-ethylenically-unsaturated monomers.
- 3. A method according to claim 1, wherein the emulsion comprises a hydrophobic phase dispersed in an aqueous phase, and both block A and block B comprise units deriving from a mono-alpha-ethylenically-unsaturated monomers.
- 4. A method according to claim 1, wherein the emulsion comprises less than 1% by weight of surfactant.
- 5. A method according to claim 4, wherein the emulsion comprises less than 0.1% by weight of surfactant.
- 6. A method according to claim 1, wherein the weight ratio between the amount of the block polymer and the amount of the surfactant together with the block copolymer is comprised between 50% and 1%.
- 7. A method according to claim 1, wherein the emulsion comprises less than 0.1% by weight of the block copolymer.
- 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, acrylonitrile, vinyl nitriles, comprising from 3 to 12 carbon atoms, vinylamine amides, and vinylaromatic compounds such as styrene.
- 9. A method according to claim 8, wherein block B comprises units deriving from monomers selected from the 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:
vinyl alcohol, vinyl pyrrolidone, polyethylene oxide (meth)acrylate (i.e. polyethoxylated (meth)acrylic acid), alpha ethylenically unsaturated monomers comprising a phosphate or phosphonate group, alpha ethylenically unsaturated monocarboxylic acids, amides of alpha ethylenically unsaturated monomers comprising a carboxylic group, alpha ethylenically unsaturated compounds comprising a sulphonic acid group, salts of alpha ethylenically unsaturated compounds comprising a sulphonic acid group, 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 chloride, trimethyl ammonium propyl (meth)acrylamido chloride, vinylbenzyl trimethyl ammonium chloride, diallyldimethyl ammonium chloride, monomers having the following formula: 5wherein
R1 is a hydrogen atom or a methyl or ethyl group; R2, R3, R4, R5 and R8, which are identical or different, are linear or branched C1-C6, preferably C1-C4, 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 (CH2)p group, p being an integer from 1 to 6, preferably from 2 to 4; B represents a linear or branched C2-C12, advantageously C3-C6, 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, and X, which are identical or different, represent counterions, and their mixtures, and macromonomers deriving therefrom.
- 10. A method according to claim 9, wherein block A comprises units deriving from monomers selected from the group consisting of:
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 chloride, trimethylammonium ethyl (meth)acrylate methyl sulphate, trimethyl ammonium propyl (meth)acrylamido chloride, vinylbenzyl trimethyl ammonium chloride, diallyidimethyl ammonium chloride, 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 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 the block copolymer is a di-block copolymer, block A being a poly(acrylic acid) block, or a salt thereof, and block B being a poly (butylacrylate) block.
- 13. A method according to claim 1, wherein the surfactant is a nonionic, anionic, cationic, or amphoteric surfactant.
- 14. A method according to claim 13, wherein block A is polyanionic in the pH conditions of the emulsion, and wherein the surfactant is not cationic in the pH conditions of the emulsion.
- 15. A method according to claim 1, wherein the emulsion comprises a hydrophobic phase dispersed in an aqueous phase, the hydrophobic phase comprising ethylenically-unsaturated monomers.
- 16. A method according to claim 15, wherein the ethylenically unsaturated monomers are selected from the group consisting of alkylacrylates, alkylmethacrylates, vinylacetate, styrene, butadiene, derivatives thereof, and mixtures thereof.
- 17. A method according to claim 15, wherein the hydrophobic phase comprises a mixture of monomers comprising ethyl-hexyl acrylate, vinyl acetate, and acrylic acid oligomers comprising at least one ethylenically unsaturated group.
- 18. A stabilized pre-emulsion, used for latex polymerization, of a latex monomer phase in a water phase, comprising:
less than 4% by weight of a surfactant, and 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 comprises units deriving from a mono-alpha-ethylenically-unsaturated monomers.
- 19. A stabilized pre-emulsion according to claim 18, wherein both block A and block B comprise units deriving from mono-alpha-ethylenically-unsaturated monomers.
- 20. A stabilized pre-emulsion according to claim 18, wherein the latex monomers comprise monomers selected from the group consisting of alkylacrylates, alkylmethacrylates, vinylacetate, styrene, butadiene, derivatives thereof, and mixtures thereof.
- 21. A stabilized pre-emulsion according to claim 18, wherein the latex monomers comprise a mixture comprising ethyl-hexyl acrylate, vinyl acetate, and acrylic acid oligomers comprising at least one ethylenically unsaturated group.
- 22. A stabilized pre-emulsion according to claim 18, wherein the block copolymer is a di-block copolymer, block A being a poly(acrylic acid) block, or a salt thereof, and block B being a poly(butylacrylate) block.
- 23. A stabilized pre-emulsion according to claim 18, wherein the ratio between the weight-average molecular weight of the hydrophilic block(s) and the weight-average molecular weight of the hydrophobic block is of from 2.33 to 9, and the weight-average molecular weight of the copolymer is comprised between 2000 g/mol and 15000 g/mol.
CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the priority under 35 U.S.C. 119 and/or 365 to 60/356,066 filed in the United States on Feb. 11, 2002, the entire content of which is hereby incorporated by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60356066 |
Feb 2002 |
US |