Copolymer for dispersing mineral particles

Abstract

The invention relates to an aqueous composition of particles of a mineral pigment which are dispersed by means of a copolymer prepared by radical polymerisation of a carboxylic monomer, a styrene monomer and a hydrophobic polyalkoxylated ester or a hydrophobic polyalkoxylated amide. The invention also relates to this copolymer and to the use thereof as a dispersant for mineral particles, in particular in a coating composition.

Description

[0001] MINERAL PARTICLE DISPERSING COPOLYMER

[0002] 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.

[0003] Many technical fields use mineral materials in the form of particles which are generally suspended in aqueous compositions, for example for their transport, storage or use in coating compositions, particularly in paint or plaster compositions, or in paper coating compositions.

[0004] Particle size and the various rheological components of these suspensions must be controlled, particularly at high mineral concentrations. These properties are difficult to control, especially when several minerals are combined, due to the fact that these minerals possess different particle size distributions, morphologies, or rheological properties.

[0005] Methods for preparing aqueous compositions of mineral matter, particularly pigments or mineral fillers, are known. Specifically, methods are known that employ additives at various stages of preparation, notably additives to control rheology or particle size. It is important to have methods for preparing aqueous compositions of mineral matter that remain stable not only shortly after preparation but also several hours or even days later. Viscosity drift must be controlled, as it can lead to gelation of the prepared suspensions, making them difficult or even impossible to handle. Similarly, particle sedimentation must be avoided or significantly slowed.In addition to stability control, viscosity control of aqueous suspensions of mineral matter particles is also essential.

[0006] It is also important to be able to prepare aqueous suspensions of mineral particles with a high dry extract. A high dry extract in these aqueous suspensions of mineral particles allows, in particular, for increased productivity of methods that use these suspensions, as well as reducing the costs and resources required for their transport.

[0007] Document WO 2023098621 describes a pigment binder in the form of a polymeric dispersion prepared by radical polymerization in the absence of a chain transfer agent. Document WO 2020010509 describes a multiphase copolymer whose terminal methyl group is derived from a methoxy-polyethylene glycol-methacrylate monomer. Document WO 2022248318 describes the preparation in an alcoholic solvent of a dispersing copolymer for paint composition whose terminal methyl group is also derived from a methoxy-polyethylene glycol-methacrylate monomer.

[0008] Therefore, there is a need for improved methods of preparing aqueous suspensions of mineral matter. The invention provides a solution to all or part of the problems with prior art methods. Thus, the invention provides an aqueous composition C comprising:

[0009] • at least one water-soluble copolymer P obtained by a polymerization reaction, in aqueous medium and in the presence of at least one chain transfer agent and at least one initiating compound T, relative to the total weight quantity of monomers:

[0010] (a) from 25% by weight to 80% by weight of 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,

[0011] (b) from 15% by weight to less than 45% by weight of at least one non-ionic hydrocarbon compound (b) arylvinyl,

[0012] (c) from 5% by weight to less than 30% by weight of at least one compound (c) of formula I: in which:

[0013] - R 1 represents independently H or CH3,

[0014] - R 2 independently represents H or a hydrophobic hydrocarbon group,

[0015] - L 1independently represents a group chosen from C(O)O, C(O)N(H) and CH2O, - L 2 independently represents a grouping chosen from (CLLŒLO , (CH2CH(CHa)O)y , (CH(CH3)CH2O) Z and their combinations and

[0016] - 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

[0017] • particles of at least one mineral pigment Q.

[0018] Preferably for composition C according to the invention, compound (a) is selected from acrylic acid, methacrylic acid, a salt of acrylic acid, a salt of methacrylic acid, an oligomer of acrylic acid, an oligomer of methacrylic acid, a salt of an acrylic acid oligomer, a salt of a methacrylic acid oligomer, and combinations thereof. Methacrylic acid, a salt of methacrylic acid, an oligomer of methacrylic acid, a salt of a methacrylic acid oligomer, and combinations thereof are the preferred compounds (a). Methacrylic acid is the most preferred.

[0019] Preferably for composition C according to the invention, compound (b) is selected from styrene, alpha-methyl styrene, p-methyl styrene, o-vinyltoluene, p-vinyltoluene, p-acetoxystyrene, p-bromostyrene, p- / c / 7-butyl styrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, dopamine methacrylamide, dopamine acrylamide, allyl catechol, and combinations thereof. Styrene is the preferred compound (b).

[0020] Preferably for composition C according to the invention, compound (c) is a compound of formula I in which:

[0021] - R 1 represents CI; or

[0022] - R 2represents 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; or

[0023] - L 2 independently represents a group (CLL-CLLO) or a combination of groups (CH2-CH2O) X , (CH2CH(CH3)O)y and (CH(CH3)CH2O)z ; or

[0024] - x, y, and z, whether identical or different, independently represent 0 or an integer or decimal number between 1 and 140, and the sum x+y+z is between 10 and 140. More preferably, for composition C according to the invention, compound (c) is a compound of formula I in which:

[0025] - R 1 represents CH3,

[0026] - R 2represents 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,

[0027] - L 2 independently represents a group (CH2-CH2O) X or a combination of groups (CH2-CH2O) X , (CH2CH(CH3)O)y and (CH(CH3)CH2O) Z x independently represents an integer or decimal number between 10 and 140 and

[0028] - y and z represent 0 or: x represents an integer or decimal number between 20 and 140 and the sum y+z is between 20 and 140.

[0029] More preferably for composition C according to the invention, compound (c) is a compound of formula I in which R1 represents CH3.

[0030] Also, more preferably according to the invention, R 2 represents H or a CH3 group or a linear or branched C-C4o-alkyl group or a Ce-C4o-aryl group; much more preferably, a linear or branched Cs-C32-alkyl group or a Ce-C4o-aryl group; even more preferably, a linear Cs-C32-alkyl group or a linear Cs-C24-alkyl group or a C-C4o-aryl group, for example a styryl group, a cardanyl group, a tri(styryl)phenyl group. Much more preferably, R 2 represents H, CH3, a branched Ci6-alkyl group from a Guerbet alcohol or a tri(styryl)phenyl group.

[0031] Essentially for the invention, the copolymer P is obtained by a polymerization reaction that uses a significant total weight amount of anionic compound (a) compared to the weight amounts of the nonionic arylvinyl hydrocarbon compound (b) and the compound (c) of formula I. Preferably, the polymerization reaction for obtaining polymer P uses:

[0032] - from 35% by weight to 75% by weight of compound (a),

[0033] - from 20% by weight to 40% by weight of compound (b),

[0034] - from 5% by weight to 25% by weight of compound (c), relative to the total quantity by weight of monomers.

[0035] Preferably, this polymerization reaction also involves:

[0036] - from more than 50% by weight to 80% by weight of compound (a),

[0037] - from 15% by weight to 25% by weight of compound (b),

[0038] - from 5% by weight to less than 25% by weight of compound (c), relative to the total quantity by weight of monomers.

[0039] Preferably, this polymerization reaction also involves:

[0040] - from 55% by weight to 80% by weight of compound (a),

[0041] - from 15% by weight to 25% by weight of compound (b),

[0042] - from 5% by weight to 20% by weight of compound (c), relative to the total quantity by weight of monomers.

[0043] Essentially, according to the invention, composition C comprises a copolymer P prepared by polymerizing compounds (a), (b), and (c), alone or combined with one or more other monomers. Advantageously, according to the invention, the polymerization reaction may also involve at least one other compound selected from:

[0044] - another anionic compound (d) different from compound (a), preferably a compound (d) chosen from itaconic acid, maleic acid, maleic anhydride and their combinations;

[0045] - 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;

[0046] - 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 Ci-Cio-alkyl acrylate or Cs-Cio-alkyl acrylate, Ci-Cio-alkyl methacrylate or Cs-Cio-alkyl methacrylate, for example methyl acrylate, ethyl acrylate, I-propyl acrylate, isopropyl acrylate, acrylate isobutyl, α-butyl acrylate, alkyl methacrylate, methyl methacrylate,ethyl methacrylate, α-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, α-butyl methacrylate, aryl acrylate; 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 (f) relative to the total amount by weight of monomers;

[0047] - 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.

[0048] Preferably according to the invention, the polymerization reaction does not involve a non-ionic compound (f) selected from Ci-C4-alkyl acrylate and Ci-C4-alkyl methacrylate, in particular methyl acrylate, ethyl acrylate, I-propyl acrylate, isopropyl acrylate, isobutyl acrylate, I-butyl acrylate, methyl methacrylate, ethyl methacrylate, I-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, I-butyl methacrylate. Preferably according to the invention, the non-ionic compound (f) is selected from vinylcaprolactam, hydroxyethylacrylate, hydroxypropylacrylate, hydroxyethylmethacrylate, hydroxypropylmethacrylate, Cs-Cio-alkyl acrylate, preferably Cs-Cs-alkyl acrylate, Cs-Cio-alkyl methacrylate, preferably Cs-Cs-alkyl methacrylate, aryl acrylate, phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, aryl methacrylate, phenyl methacrylate, benzyl methacrylate, phenoxyethyl methacrylate.

[0049] Preferably according to the invention, the copolymer P is prepared in the absence of a crosslinking compound and in the absence of a compound comprising at least two olefinic unsaturations.

[0050] Also preferably according to the invention, the polymerization reaction can also utilize styrene sulfonate.

[0051] Preferably according to the invention, polymer P is prepared solely using polymerizable compounds (a), (b), and (c), and optionally one or more of polymerizable compounds (d), (e), (f), and (g). More preferably according to the invention, polymer P is prepared solely using polymerizable compounds (a), (b), and (c). Also preferably according to the invention, copolymer P is prepared in the absence of acrylamide. Copolymer P according to the invention is prepared by a radical polymerization reaction carried out in the presence of an initiating compound T. Preferably according to the invention, the initiating compound T is selected from peroxides, hydroperoxides, persulfates, azo compounds, and their respective combinations or associations with an ion selected from Fe 11 Fe 111 Cu 1 Cu 11Preferably, the initiating compound T is 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 (ACP A), 4,4'-azobis(4-cyanovaleric acid) (CAS No. 2638-94-0), 2,2'-azobis(2-methylpropionamidine) dihydrochloride (CAS No. 2997-92-4), azo-bis-isobutyronitrile (AZDN or AIBN) and their combinations. Preferably, the initiating compound T is chosen from sodium persulfate and hydrogen peroxide associated with an Fe ion. 11 .

[0052] Preferably according to the invention, the polymerization reaction is carried out in water, alone or combined with at least one polar, protic solvent, preferably an alcohol, preferably isopropanol. More preferably, the polymerization reaction is carried out in water alone.

[0053] According to the invention, the polymerization reaction is 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 total amount by weight of monomers.

[0054] Also preferably, the chain transfer agent may be selected from primary thiols, mercaptans and their combinations, preferably selected from δ-dodecyl mercaptan, δ-dodecyl mercaptan, δ-nonyl mercaptan, thiolactic acid, mercaptopropionic acid, mercaptoethanol, thioglycolic acid, δ,8-dimercapto-3,6-dioxaoctane (DMDO - CAS No. 14970-87-7), a compound comprising P 1 , a compound containing P 111 , a compound containing S IV; 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 / / -dodecyl mercaptan, phosphorous acid, sodium phosphite, hypophosphorous acid, sodium hypophosphite, sodium hydrogen sulfite; much more preferably a chain transfer agent selected from sodium hypophosphite and sodium hydrogen sulfite.

[0055] Preferably according to the invention, the copolymer P is obtained by a polymerization reaction carried out in the absence of a surfactant compound. The copolymer P according to the invention is neither an emulsion nor a latex.

[0056] Preferably, according to the invention, the copolymer P according to the invention has a well-defined weight molar mass Mw. More preferably, the copolymer P according to the invention has a weight molar mass Mw, measured by size-exclusion chromatography (SEC), that is less than 60,000 g / mol. Also preferably, the molar mass Mw of the copolymer P according to the invention is greater than 2,000 g / mol. Even more preferably, the molar mass Mw of the copolymer P according to the invention ranges from 5,000 g / mol to 50,000 g / mol, and much more preferably from 10,000 g / mol to 30,000 g / mol or from 15,000 g / mol to 25,000 g / mol.

[0057] Preferably, according to the invention, the copolymer P has a well-defined polymolecularity index (PMI). More preferably, the copolymer P has a PMI, measured by size-exclusion chromatography (SEC), that is less than 6. Generally, the PMI of the copolymer P is greater than 1.2. Preferably, the PMI of the copolymer P ranges from 2 to 6 or from 2.5 to 6.

[0058] According to the invention, the molar mass Mw of polymer P and its polymolecularity index Ip are determined by Size Exclusion Chromatography (SEC). A test portion of the polymer dispersion, corresponding to 90 mg of dry matter, is introduced into a 10 mL bottle. Mobile phase, supplemented with 0.04% dimethylformamide (DMF), is added up to a total mass of 10 g. The composition of this mobile phase is as follows: NaHCO3: 0.05 mol / L, NaNO3: 0.1 mol / L, triethanolamine: 0.02 mol / L, NaN3: 0.03 wt%.The CES system consists of a Waters 510 isocratic pump with a flow rate set at 0.8 mL / min, a Waters 717+ autosampler, and a furnace containing a 6 cm long, 40 mm internal diameter Waters Guard Column Ultrahydrogel pre-column, followed by a 30 cm long, 7.8 mm internal diameter Waters Ultrahydrogel linear column. Detection is performed using a Waters 410 RI differential refractometer. The furnace is heated to 60°C and the refractometer to 45°C. The CES device is calibrated with a series of sodium polyacrylate standards supplied by "Polymer Standard Service" with peak molar weights between 900 and 2250,000 g / mol and polymolecularity indices between 1.4 and 1.7. The calibration curve is linear and takes into account the correction obtained using the flow marker: dimethylformamide (DMF).The acquisition and processing of the chromatogram are carried out using the software "PSS WinGPC Scientific" v 4.02. The resulting chromatogram is integrated into the area corresponding to molar weights greater than 250 g / mol.

[0059] According to the invention, the polymerization reaction generally leads to an aqueous dispersion of polymer P. Preferably, the polymer P is obtained in the form of particles. More preferably, the polymer P particles have an average size, measured using a particle size analyzer, of less than 500 nm, preferably less than 300 nm. Also preferably, the polymer P particles have an average size ranging from 10 nm to 500 nm or from 10 nm to 300 nm.

[0060] Essentially, the aqueous composition C according to the invention comprises the copolymer P and the mineral pigment Q. Preferably according to the invention, the mineral pigment Q is a natural pigment or a synthetic pigment. More preferably, the pigment Q is 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, and a hydraulic binder compound.

[0061] Most advantageously, composition C according to the invention may comprise calcium carbonate alone or in combination, preferably combined with titanium dioxide.

[0062] Composition C according to the invention comprises water. It may also combine water with at least one polar, protic solvent, preferably an alcohol, most commonly isopropanol. Preferably, composition C according to the invention comprises water and no other solvent. Within the aqueous composition C according to the invention, the proportions of the different ingredients may vary. Preferably, the aqueous composition C according to the invention comprises: from 0.05% by dry weight to 5% by dry weight of copolymer P and from 95% by dry weight to 99.95% by dry weight of mineral pigment Q, relative to the dry weight amounts of ingredients P and Q.

[0063] Advantageously, the use of copolymer P in the aqueous composition C according to the invention allows for effective control of its viscosity; in particular, its Brookfield viscosity measured at 25°C and 100 rpm for a relative dry weight quantity of polymer P compared to the dry weight quantity of pigment Q, which is less than 1%, preferably less than 0.5%, more preferably less than 0.45% or less than 0.4%. Thus, preferably, the aqueous composition C according to the invention has a Brookfield viscosity measured at 25°C and 100 rpm that is less than 1500 mPa·s, preferably less than 1200 mPa·s, for a relative dry weight quantity of polymer P compared to the dry weight quantity of pigment Q, which is less than 1%, preferably less than 0.5%, more preferably less than 0.45% or less than 0.4%.

[0064] The invention also relates to the preparation of the aqueous composition C according to the invention. Thus, the invention provides a method for preparing an aqueous composition C according to the invention comprising mixing in water at least one copolymer P and particles of at least one mineral pigment Q defined according to the invention.

[0065] In the preparation of composition C according to the invention, the mineral pigment Q is preferably a natural or synthetic pigment, more 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.Generally according to the invention, the hydraulic binder compound is a compound capable of hydrating in the presence of water to provide a solid with mechanical characteristics suitable for construction, preferably a compound selected from a cement according to standard EN 197-1 of 2012, in particular a CEM I type cement, a CEM II type cement, a CEM III type cement, a CEM IV type cement, a CEM V type cement.

[0066] Essentially, composition C according to the invention comprises at least one copolymer P. The invention also relates to a water-soluble copolymer P according to the invention obtained by a polymerization reaction in aqueous medium and in the presence of at least one chain transfer agent and at least one initiating compound T, preferably carried out at a temperature below 100°C, more preferably at a temperature ranging from 20°C to 95°C, and with respect to the total weight quantity of monomers:

[0067] (a) from 25% by weight to 80% by weight of 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,

[0068] (b) from 15% by weight to less than 45% by weight of at least one non-ionic hydrocarbon compound (b) arylvinyl,

[0069] (c) from 5% by weight to less than 30% by weight of at least one compound (c) of formula I: in which:

[0070] - R 1 represents independently H or CH3,

[0071] - R 2 independently represents H or a hydrophobic hydrocarbon group,

[0072] - L 1 independently represents a group chosen from C(O)O, C(O)N(H) and CH2O,

[0073] - L 2 independently represents a grouping chosen from (CLLŒLO , (CH2CH(CHa)O)y , (CH(CH3)CH2O) Z and their combinations and

[0074] - 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.

[0075] The copolymer P according to the invention can be used directly. It can also be used within the composition C according to the invention. It can also be combined with a support, in particular a liquid or solid support. Thus, the invention also provides a dispersing agent A comprising at least one copolymer P according to the invention and a liquid support.

[0076] The P copolymer has particularly interesting properties, including dispersing properties of mineral pigment particles, which are very useful in many technical fields.Thus, the invention provides a 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 mixing the pigment Q under stirring with at least one composition C according to the invention or with at least one copolymer P according to the invention or with at least one dispersing agent A according to the invention.

[0077] The copolymer P thus allows the preparation of various compositions comprising mineral pigments and optionally other substances, including a substance for binding the mineral pigment particles to a substrate. The invention therefore provides a coating composition R comprising the copolymer P or the agent A according to the invention in combination with mineral pigment particles Q and at least one binding compound L. Preferably, the coating composition R according to the invention is selected from:

[0078] - a coating composition RI comprising at least one binder compound L and at least one composition C according to the invention,

[0079] - a coating composition R2 comprising at least one binder compound L, particles of at least one mineral pigment Q according to the invention and at least one copolymer P according to the invention,

[0080] - a coating composition R3 comprising at least one binder compound L, particles of at least one mineral pigment Q according to the invention and at least one dispersing agent A according to the invention.

[0081] Preferably, according to the invention, the binder L is selected from a natural binding agent such as starch, carboxymethyl cellulose (CMC), hydroxyethyl celluloses, casein, proteins, alginates, or a synthetic binding agent such as latex. More preferably, the binder L can be selected from a styrene-butadiene polymer, a styrene-acrylic polymer, a styrene-acetate polymer, a vinyl acetate polymer, a vinyl acetate homopolymer, a vinyl acetate copolymer, a vinyl versatate homopolymer, a vinyl versatate copolymer, and combinations thereof. In particular, the binder L can be selected from:

[0082] - a vinyl acetate homopolymer; - a copolymer comprising at least vinyl acetate and ethylene, a vinyl acetate and acrylate copolymer, a vinyl acetate and methacrylate copolymer, a vinyl acetate, ethylene and acrylate copolymer, a vinyl acetate, ethylene and methacrylate copolymer, a vinyl acetate, acrylate and methacrylate copolymer;

[0083] - a vinyl versatate homopolymer;

[0084] - a copolymer of vinyl versatate and ethylene, a copolymer of vinyl versatate and acrylate, a copolymer of vinyl versatate and methacrylate, a copolymer of vinyl versatate, ethylene and acrylate, a copolymer of vinyl versatate, ethylene and methacrylate, a copolymer of vinyl versatate, acrylate and methacrylate;

[0085] - a copolymer of vinyl acetate and vinyl versatate, a copolymer of vinyl acetate, vinyl versatate and ethylene, a copolymer of vinyl acetate, vinyl versatate and acrylate, a copolymer of vinyl acetate, vinyl versatate and methacrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene and acrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene and methacrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene, acrylate and methacrylate and their combinations.

[0086] Within the composition R according to the invention, the proportions of the different ingredients may vary. Preferably, the composition R according to the invention comprises: from 0.2% by dry weight to 6% by dry weight of copolymer P, from 60% by dry weight to 90% by dry weight of mineral pigment Q and from 2% by dry weight to 20% by dry weight of binding agent L, relative to the quantities by dry weight of ingredients P, Q and L.

[0087] The RI, R2 and R3 coating compositions according to the invention can be prepared by mixing, in particular by mixing in water and preferably under agitation, their different ingredients, where applicable composition C, mineral pigment particles Q, binder L and composition C, agent A or copolymer P.

[0088] The advantageous, particular, or preferred characteristics of composition C according to the invention define methods for preparing this composition, copolymers P, dispersing agents A, as well as dispersion methods and coating compositions R according to the invention that are also advantageous, particular, or preferred. The various aspects of the invention can be illustrated by examples.

[0089] EXAMPLES

[0090] Preparation and characterization of PI to P5 polymers according to the invention

[0091] In a 2 L reactor, 261 g of water and 15 g of 29% sodium lauryl sulfate in water are introduced and heated to a temperature of 85°C. In a beaker, 4.9 g of 29% sodium lauryl sulfate in water, 137 g of water, 73 g of methacrylic acid, 71 g of styrene, 15 g of dodecyl mercaptan, and 28 g of compound Ml (compound c of formula I in which R 1represents CH3, R 2 represents H, L 1 represents a C(O)O, L group 2 represents a combination of (CH2CH2O), (CH2CH(CH3)O), and (CH(CH3)CH2O) groups, where y+z represents 10 and x represents approximately 30. 0.6 g of initiator compound (ammonium persulfate) and 0.06 g of sodium bisulfite are introduced into the reactor, and the reagent mixture is added over 2 hours while maintaining a temperature of 85°C. Heating is continued for 1 hour. The mixture is neutralized with 99 g of 50% potassium hydroxide in water to obtain a pH of 10 and diluted with 179 g of water to obtain a 25% dry extract.

[0092] Similarly, polymers P2 to P5 are prepared by replacing compound M1 with the following compounds respectively:

[0093] - M2: compound c of formula I in which R 1 represents CH3, R 2 represents CH3, L 1 represents a C(O)O, L group 2represents a grouping (CFLCFLOjx and x represents 120,

[0094] - M3: compound c of formula I in which R 1 represents CH3, R 2 represents a branched Ci6-alkyl group derived from a Guerbet alcohol, L 1 represents a C(O)O, L group 2 represents a grouping (CFLCFLOjx and x represents 25,

[0095] - M4: compound c of formula I in which R 1 represents CH3, R 2 represents CH3, L 1 represents a C(O)N(H) group, L 2 represents a combination of groups (CH2CH2O), (CELCH^CLhjO) and (CH^CLhjCLLO), y+z represents 10 and x represents 30,

[0096] - M5: compound c of formula I in which R 1 represents CH3, R 2 represents a tristyrylphenyl group, L 1 represents a C(O)O, L group 2 represents a grouping (CF CFLOjx and x represents 25.

[0097] The viscosity at 100 rpm of the PI polymers at P5 was then measured at 25°C using a Brookfield viscometer equipped with a spindle. The polymer particle sizes were measured using a Zetasizer Malvem instrument. The characteristics of the PI polymers at P5 are presented in Table 1.

[0098] Table 1

[0099] Preparation and characterization of aqueous compositions of titanium dioxide Cl to C5 according to the invention

[0100] In a beaker and under stirring, an aqueous composition Cl according to the invention is prepared having a dry extract of 74% by weight and comprising titanium dioxide (“Huntsman” Tioxide R-HD2) and the polymer PI according to the invention which is introduced in an amount enabling a Brookfield viscosity, measured at 25°C and at 100 rpm by means of a viscometer equipped with a spindle 5, which is less than 2000 mPa.s.

[0101] Similarly, compositions C2 to C5 are prepared by replacing polymer PI respectively with polymers P2 to P5 according to the invention.

[0102] The relative quantities by dry weight of polymer compared to the quantity by dry weight of titanium dioxide and the results of the viscosity measurements are presented in Table 2.

[0103] Table 2

[0104] Preparation and characterization of an aqueous C6 calcium carbonate composition according to the invention

[0105] In a beaker and under stirring, an aqueous composition C6 according to the invention is prepared having a dry extract of 60% by weight and comprising calcium carbonate (Socal P3 "Imerys") and the polymer P5 according to the invention which is introduced in an amount enabling a Brookfield viscosity, measured at 25°C and at 10 rpm by means of a viscometer equipped with a spindle 5, which is less than 1000 mPa.s.

[0106] The relative quantity by dry weight of polymer P5 compared to the quantity by dry weight of calcium carbonate is 0.4%.

[0107] The polymers according to the invention make it possible to effectively control the viscosity of aqueous compositions of various highly concentrated mineral materials.

Claims

DEMANDS 1. Aqueous composition C comprising: • at least one water-soluble copolymer P obtained by a polymerization reaction, in aqueous medium and in the presence of at least one chain transfer agent and at least one initiating compound T, relative to the total weight quantity of monomers: (a) from 25% by weight to 80% by weight of 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) from 15% by weight to less than 45% by weight of at least one non-ionic hydrocarbon compound (b) arylvinyl, (c) from 5% by weight to less than 30% by weight of at least one compound (c) of formula I: in which: - R 1 represents independently H or CH3, - R 2 independently represents H or a hydrophobic hydrocarbon group, - L 1independently represents a group chosen from C(O)O, C(O)N(H) and CH2O, - L 2 independently represents a grouping chosen from (CHiCTbO (CH2CH(CHa)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, an oligomer of methacrylic acid, a salt of an acrylic acid oligomer, a salt of a methacrylic acid oligomer, and their combinations; preferably chosen from methacrylic acid, a salt of methacrylic acid, an oligomer of methacrylic acid, a salt of an oligomer of methacrylic acid 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-methyl styrene, p-methyl styrene, o-vinyltoluene, p-vinyltoluene, p-acetoxystyrene, p-bromostyrene, p- / c / 7-butyl styrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, dopamine-methacrylamide, dopamine-acrylamide, allyl-catechol and combinations thereof.

4. Composition according to any one of claims 1 to 3, wherein compound (c) is a compound of formula I in which: - R 1 represents CH3; or - R 2represents 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 Co-C4o-alkyl group or a C6-C4o-aryl group; much more preferably, a linear or branched Cs-C32-alkyl group or a Ce-C4o-aryl group; even more preferably, a linear Cs-C32-alkyl group or a linear Cs-C24-alkyl group or a Co-C40-aryl group, for example, a styryl group, a cardanyl group, a tri(styryl)phenyl group; or - L 2 independently represents a group (Œb-ŒbO) 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 10 and 140, preferably between 20 and 140.

5. Composition according to any one of claims 1 to 4 wherein the polymerization reaction involves: from 35% by weight to 75% by weight of compound (a), from 20% by weight to 40% by weight of compound (b), from 5% by weight to 25% by weight of compound (c), or from more than 50% by weight to 80% by weight of compound (a), from 15% by weight to 25% by weight of compound (b), from 5% by weight to less than 25% by weight of compound (c), or from 55% by weight to 80% by weight of compound (a), from 15% by weight to 25% by weight of compound (b), from 5% by weight to 20% by weight of compound (c), relative to the total amount by weight of monomers.

6. Composition according to any one of claims 1 to 5 wherein the polymerization reaction also involves at least one other compound selected from: - another anionic compound (d) different from compound (a), preferably a compound (d) chosen 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 Ci-Cio-alkyl acrylate or Cs-Cio-alkyl acrylate, Ci-Cio-alkyl methacrylate or Cs-Cio-alkyl methacrylate, for example methyl acrylate, ethyl acrylate, w-propyl acrylate, isopropyl acrylate, acrylate isobutyl, α-butyl acrylate, alkyl methacrylate, methyl methacrylate,ethyl methacrylate, / / -propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, / / -butyl methacrylate, aryl acrylate; preferably vinylcaprolactam, hydroxyethylacrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, Cs-Cio-alkyl acrylate, preferably Cs-Cs-alkyl acrylate, Cs-Cio-alkyl methacrylate, preferably Cs-Cs-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% by weight, of compound (f) in relation to the total amount by weight 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.

7. Composition according to any one of claims 1 to 6, wherein: the initiating compound T is selected from peroxides, hydroperoxides, persulfates, azo compounds and their respective combinations or associations with an ion selected from Fe 11 Fe 111 Cu 1 Cu 11, preferably an initiator 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 (ACP A), 4,4'-azobis(4-cyanovaleric acid) (CAS No. 2638-94-0), 2,2'-azobis(2-methylpropionamidine) dihydrochloride (CAS No. 2997-92-4), azo-bis-isobutyronitrile (AZDN or AIBN) and combinations thereof; 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 further carried out in the presence of at least one chain transfer agent; preferably a chain transfer agent used at a concentration ranging from 0.1 wt% to 10 wt%, preferably from 0.5 wt% to 8 wt% or from 1 wt% to 6 wt%, relative to the total weight of monomers; also preferably a chain transfer agent selected from primary thiols, mercaptans and their combinations, preferably selected from α-dodecyl mercaptan, α-dodecyl mercaptan, α-nonyl mercaptan, thiolactic acid, mercaptopropionic acid, mercaptoethanol, thioglycolic acid, α,8-dimercapto-3,6-dioxaoctane (DMDO - CAS No. 14970-87-7), a compound comprising P 1 , a compound containing P 111 , a compound containing S IV; 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 / / -dodecyl mercaptan, phosphorous acid, sodium phosphite, hypophosphorous acid, sodium hypophosphite, sodium hydrogen sulfite.

8. Composition according to any one of claims 1 to 7 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.

9. Method of preparing an aqueous composition C according to any one of claims 1 to 8 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 8, 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.

10. Water-soluble copolymer P defined according to any one of claims 1 to 9 or obtained by a polymerization reaction in aqueous medium and in the presence of at least one chain transfer agent and at least one initiator compound T, preferably carried out at a temperature below 100°C, more preferably at a temperature ranging from 20°C to 95°C, and with respect to the total weight quantity of monomers: (a) from 25% by weight to 80% by weight of 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) from 15% by weight to less than 45% by weight of at least one non-ionic hydrocarbon compound (b) arylvinyl, (c) from 5% by weight to less than 30% by weight of at least one compound (c) of formula I: in which: - R 1 represents independently H or CH3, - R 2independently represents H or a hydrophobic hydrocarbon group, - L 1 independently represents a group chosen from C(O)O, C(O)N(H) and CH2O, - L 2 independently represents a grouping chosen from (CEECEEO , (CH2CH(CHa)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.

11. Water-soluble copolymer P according to claim 10 having: - a molar mass by weight Mw, measured by size exclusion chromatography (SEC), that is less than 60,000 g / mol; preferably, a molar mass Mw greater than 2,000 g / mol; more preferably, a molar mass Mw from 5,000 g / mol to 50,000 g / mol; much more preferably from 10,000 g / mol to 30,000 g / mol or from 15,000 g / mol to 25,000 g / mol; or - a polymolecularity index Ip, measured by size exclusion chromatography (SEC), which is less than 6; more preferably ranging from 2 to 6 or from 2.5 to 6.

12. Dispersive agent A comprising at least one copolymer P defined according to any one of claims 1 to 8 and 10 and 11 and a liquid support.

13. Coating composition R chosen 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 8, - 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 8 and 10 and 11, - a coating composition R3 comprising at least one binder compound L, particles of at least one mineral pigment Q defined according to one of claims 8 and 9 and at least one dispersing agent A according to claim 12.

14. 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 mixing the pigment Q with at least one composition C according to any one of claims 1 to 8 or with at least one copolymer P according to claim 9 or with at least one dispersing agent A according to claim 12.

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