MINERAL PARTICLE DISPERSING COPOLYMER

Abstract

The invention provides an aqueous composition of mineral pigment particles dispersed by means of a copolymer prepared by radical polymerization of a carboxylic monomer, a styrenic monomer, and a hydrophobic polyalkoxylated ester or a hydrophobic polyalkoxylated amide. The invention also relates to this copolymer and its use as a dispersant for mineral particles, particularly in a coating composition.

Claims

Demands

1. Aqueous composition C comprising: * at least one copolymer P obtained by a polymerization reaction, in aqueous medium and in the presence of at least one initiating compound T, of: (a) at least one anionic compound (a) comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or one of its salts, (b) at least one nonionic hydrocarbon compound (b) arylvinyl, (c) at least one compound (c) of formula I: [Chem I] R' in which: - R1 independently represents H or CH3, - R2 independently represents H or a hydrophobic hydrocarbon group, - L1 independently represents a group selected from C(O)O, C(O)N(H) and CH2O, - L2 independently represents a group selected from (CH2 CH2O)x, (CH2CH(CH3)O)y, (CH(CH3)CH2O)z and their combinations and - x, y and z, whether identical or different, independently represent 0 or an integer or decimal number between 1 and 150, and the sum x + y + z is between 2 and 150,and * particles of at least one mineral pigment Q.,

2. Composition according to claim 1 wherein compound (a) is selected from acrylic acid, methacrylic acid, a salt of acrylic acid, a salt of methacrylic acid, an oligomer of acrylic acid, a methacrylic acid oligomer, a salt of an acrylic acid oligomer, a salt of a methacrylic acid oligomer and combinations thereof; preferably selected from methacrylic acid, a salt of methacrylic acid, a methacrylic acid oligomer, a salt of an acrylic acid oligomer methacrylic and their combinations; more preferably methacrylic acid.

3. Composition according to any one of claims 1 or 2 wherein compound (b) is selected from styrene, alpha-methylstyrene, p-methylstyrene, o-vinyltoluene, p-vinyltoluene, p-acetoxystyrene, p-bromostyrene, p-tert-butylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, dopamine-methacrylamide, dopamine-acrylamide, allyl-catechol and combinations thereof.

4. 4. Composition according to any one of claims 1 to 3 wherein compound (c) is a compound of formula I in which: - R1 represents CH3; or - R2 represents H or a CH3 group or a hydrophobic hydrocarbon group comprising from 4 to 40 carbon atoms; preferably, a linear, branched or cyclic hydrocarbon group, saturated, unsaturated or aromatic; more preferably, a linear, branched or cyclic hydrocarbon group, saturated, unsaturated or aromatic comprising from 4 to 40 carbon atoms; more preferably, a linear or branched C6-C40-alkyl group or a C6-C4o-aryl group; much more preferably, a linear or branched C8-C32-alkyl group or a C6-C40-aryl group; even more preferentially, a linear C8-C32-alkyl group or a linear C8-C24-alkyl group or a C6-C4 O-aryl group, for example a styryl group, a cardanyl group, a tri(styryl)phenyl group;or - L2 independently represents a grouping (CH2-CH2O)X or a combination of groups (CH2-CH2O)X, (CH2CH(CH3)O)y and (CH(CH3)CH2O)z; or - x, y and z, identical or different, independently represent 0 or an integer or decimal number between 1 and 140 and the sum x +y+z is between 2 and 140.;

5. 5. Composition according to any one of claims 1 to 4 wherein the polymerization reaction also employs at least one other compound selected from: - another anionic compound (d) different from compound (a), preferably a compound (d) selected from itaconic acid, maleic acid, maleic anhydride and their combinations; - a sulfur compound (e), preferably a compound (e) selected from 2-acrylamido-2-methylpropane sulfonic acid, a salt of 2-acrylamido-2-methylpropane sulfonic acid, 2-(methacryloyloxy)ethanesulfonic acid, a salt of 2-(methacryloyloxy)ethanesulfonic acid, sodium methallyl sulfonate, sodium vinyl sulfonate, styrene sulfonate and their combinations, preferably styrene sulfonate; - a non-ionic compound (f) comprising at least one polymerizable olefinic unsaturation and different from compound (b), preferably at least one polymerizable ethylenic unsaturation, and in particular a non-ionic compound (f) comprising a polymerizable vinyl function, more preferably a non-ionic compound (f) selected from vinylcaprolactam, esters of an acid comprising at least one monocarboxylic acid function, in particular an ester of an acid selected from acrylic acid, methacrylic acid and their combinations, for example hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, alkyl acrylate, in particular C-Cio-alkyl acrylate or C5-CiO-alkyl acrylate, C-Cio-alkyl methacrylate or C5-CiO-alkyl methacrylate, for example methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, acrylate isobutyl, n-butyl acrylate, alkyl methacrylate, methyl methacrylate,ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, aryl acrylate; preferably vinylcaprolactam, hydroxyethylacrylate, hydroxypropylacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, C5-C10-alkyl acrylate, preferably C5-C8-alkyl acrylate, C5-C10-alkyl methacrylate, preferably C5-C8-alkyl methacrylate, aryl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, aryl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate; preferably in an amount of less than 5% by weight, also preferably from 0.01% by weight to 4% by weight, in particular from 0.02% by weight to 4% by weight or from 0.02% by weight to 2% by weight, in particular from 0.02% by weight to 1%,

6. in weight, of compound (f) relative to the total weight quantity of monomers; - a crosslinking compound (g) or a compound (g) comprising at least two olefinic unsaturations; preferably in an amount of less than 5% by weight, also preferably from 0.01% by weight to 4% by weight, in particular from 0.02% by weight to 4% by weight or from 0.02% by weight to 2% by weight, in particular from 0.02% by weight to 1% by weight, of compound (g) relative to the total amount by weight of monomers. A composition according to any one of claims 1 to 5, wherein: - the initiating compound T is selected from peroxides, hydroperoxides, persulfates, azo compounds and their respective combinations or associations with an ion selected from Fe11, Fe111, Cu1, Cu11, preferably an initiating compound T selected from hydrogen peroxide, tert-butyl hydroperoxide, benzoyl peroxide, acetyl peroxide, lauryl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulfate, an alkali metal persulfate and in particular sodium persulfate, potassium persulfate, 4,4'-azobis-4-cyanopentanoic acid (ACPA), 4,4'-azobis(4-cyanovaleric acid) (CAS No. 2638-94-0), 2,2'-azobis(2-methylpropionamidine) dihydrochloride (CAS No. 2997-92-4), azo-bisisobutyronitrile (AZDN or AIBN) and their combinations; or - the polymerization reaction is carried out in water, alone or combined with at least one polar, protic solvent, preferably an alcohol, more preferably isopropanol; preferably the polymerization reaction is carried out in water alone; or - the polymerization reaction is, in addition, carried out in the presence of at least one chain transfer agent; preferably a chain transfer agent used in a concentration ranging from 0.1% by weight to 10% by weight, preferably from 0.5% by weight to 8% by weight or from 1% by weight to 6% by weight, relative to the amount by weight of monomers; also preferably a chain transfer agent selected from primary thiols, mercaptans and their combinations, preferably selected from n-dodecyl mercaptan, tert-dodecyl mercaptan, tert-nonyl mercaptan, thiolactic acid, mercaptopropionic acid, mercaptoethanol, thioglycolic acid, l,8-dhnercapto-3,6-dioxaoctane (DMDO - CAS No. 14970-87-7), a compound comprising P1, a compound comprising P111, a compound comprising SIV; preferably a chain transfer agent selected from a mercaptan, a compound comprising phosphite, a compound comprising hypophosphite, a compound comprising hydrogen sulfite; more preferably a chain transfer agent selected from n-dodecyl mercaptan, phosphorous acid, sodium phosphite, hypophosphorous acid, sodium hypophosphite, sodium hydrogen sulfite.

7. Composition according to any one of claims 1 to 6 wherein the mineral pigment Q is a natural pigment or a synthetic pigment, preferably a pigment Q selected from alkaline earth metal carbonates, preferably calcium carbonate (natural calcium carbonate or precipitated calcium carbonate), strontium carbonate, magnesium carbonate, barium carbonate, dolomite, kaolin, titanium dioxide, talc, lime, calcium sulfate, barium sulfate, magnesium carbonate, magnesium silicate, calcium silicate, calcium phosphate, a hydraulic binder compound.

8. Method of preparing an aqueous composition C according to any one of claims 1 to 7 comprising mixing in water at least one copolymer P and particles of at least one mineral pigment Q defined according to any one of claims 1 to 7, preferably a natural or synthetic mineral pigment Q, preferably a pigment Q selected from alkaline earth metal carbonates, preferably calcium carbonate (natural calcium carbonate or precipitated calcium carbonate), strontium carbonate, magnesium carbonate, barium carbonate, dolomite, kaolin, titanium dioxide, talc, lime, calcium sulfate, barium sulfate, magnesium carbonate, magnesium silicate, calcium silicate, calcium phosphate, a hydraulic binder compound.

9. Copolymer P defined according to any one of claims 1 to 8 or obtained by a polymerization reaction in aqueous medium and in the presence of at least one initiating compound T, preferably carried out at a temperature below 100°C, more preferably at a temperature from 20°C to 95°C, of: (a) at least one anionic compound (a) comprising at least one polymerizable olefinic unsaturation and at least one carboxylic acid function or one of its salts, (b) of at least one non-ionic (b) arylvinyl hydrocarbon compound, (c) of at least one compound (c) of formula I: [Chem I] R1 in which: - R1 independently represents H or CH3, - R2 independently represents H or a hydrophobic hydrocarbon group, - L1 independently represents a group chosen from C(O)O, C(O)N(H) and CH2O, - L2 independently represents a group chosen from (CH2 CH2O)x, (CH2CH(CH3)O)y, (CH(CH3)CH2O)z and their combinations and - x, y and z, identical or different, independently represent 0 or an integer or decimal number between 1 and 150 and the sum x +y+z is between 2 and 150.

10. 10. Dispersive agent A comprising at least one copolymer P defined according to any one of claims 1 to 7 and 9 and a liquid support.

11. 11. Coating composition R selected from: - a coating composition RI comprising at least one binder compound L and at least one composition C according to any one of claims 1 to 7, - a coating composition R2 comprising at least one binder compound L, particles of at least one mineral pigment Q defined according to claim 8 and at least one copolymer P defined according to any one of claims 1 to 7 and 9, - a coating composition R3 comprising at least one binder compound L, particles of at least one mineral pigment Q defined according to claim 8 and at least one dispersing agent A according to claim 10.

12. 12. Method for dispersing particles of at least one mineral pigment Q selected from a natural or synthetic mineral pigment Q, preferably a pigment Q selected from alkaline earth metal carbonates, more preferably calcium carbonate (natural calcium carbonate or precipitated calcium carbonate), strontium carbonate, magnesium carbonate, barium carbonate, dolomite, kaolin, titanium dioxide, talc, lime, calcium sulfate, barium sulfate, magnesium carbonate, magnesium silicate, calcium silicate, calcium phosphate, a hydraulic binding compound, comprising the stirred mixture of pigment Q with at least one composition C according to any one of claims 1 to 7 or with at least one copolymer P according to claim 9 or with at least one dispersing agent A according to claim 10.