OSIDIC DISPERSANT AGENT

DESCRIPTION

The invention relates to the field of dispersing agents for an aqueous composition, in particular for the dispersion of an inorganic material in the form of particles. The dispersing agent according to the invention comprises a dispersing polymer combined with an osidic derivative or of saccharide origin. The invention also relates to an aqueous composition comprising this dispersing agent and an inorganic material in the form of particles, as well as the use of this agent or of this composition.

An aqueous suspension of an inorganic material is a dispersion of a solid material which is sparingly soluble or insoluble in an aqueous medium. The characteristics sought for a suspension generally depend on the destination of this suspension, in particular when the mineral material is used as filler for a composition, for example of a composition for paper coating sauce or of a coating composition.

The characteristics of an aqueous dispersion of mineral material in the form of particles can be controlled, in particular by means of a dispersing agent.

The viscosity and the stability of the aqueous dispersion are important properties.

The origin and properties of dispersing agents of inorganic material in particulate form can vary widely. In particular, this agent can be prepared from products of natural origin. The use of renewable products must therefore be able to be developed.

The compatibility of the dispersing agents, in particular with the various elements present in an aqueous dispersion of mineral material in the form of particles, is also an important property.

There are known dispersing agents for mineral material in the form of particles. However, the known agents do not make it possible to provide satisfactory solutions to the problems encountered during the dispersion of these materials in an aqueous medium.

In particular, dispersing agents do not always have degradability properties, in particular improved biodegradability properties.

The dispersing agents should also have a controlled bulk viscosity to facilitate their handling, transport or introduction into an aqueous composition.

The reduction in the amounts of adjuvants, in particular of dispersing polymers, in particular of synthetic dispersing polymers, used in aqueous compositions should also be sought.

Document EP 2044159 describes a process for manufacturing an aqueous suspension of mineral matter by means of a polymer of acrylic acid or of methacrylic acid and of maleic anhydride. Document US 4801354 discloses aqueous suspensions of pigments intended for papermaking. They contain a dispersant which is a copolymer of an ester of (meth) acrylic acid and a monohydric or dihydric alcohol as well as a carboxylic acid. Document WO 2018-109400 discloses a method for preparing particles of mineral matter by grinding in the presence of water and a polymer prepared from at least one anionic monomer and sodium hypophosphite or disodium trithiocarbonate dipropionate. WO 2015-063402 relates to the use of

The dispersing agent according to the invention makes it possible to provide a solution to all or part of the problems encountered when using the dispersing agents of the state of the art. Thus, the invention provides an aqueous dispersing agent comprising:

- at least one polymer (P) prepared by at least one radical polymerization reaction, at a temperature above 50 ° C, of ​​at least one anionic monomer (M1) comprising at least one polymerizable olefinic unsaturation and at least one acid function carboxylic acid or one of its salts, in the presence of at least one radical generating compound chosen from hydrogen peroxide, benzoyl peroxide, acetyl peroxide, lauryl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulfate, a persulfate of alkali metal, an azo compound, their combinations and their respective associations with an ion chosen from Fe °, Fe 111 , Cu 1 , Cu 11 and their combinations;

- at least one derivative (S) chosen from:

o an ose (SI) comprising from 3 to 8 carbon atoms;

o an ose oligomer (S2) comprising from 1 to 10 ose units; o a product (S3) resulting from the degradation of a saccharide.

According to the invention, the polymer (P) is prepared by at least one radical polymerization reaction in the presence of at least one compound which generates radicals. This compound can in particular be an azo compound, for example an azo compound chosen from 2,2'-azobis (2- (4,5-dihydroimidazolyl) propane, 2,2'-azobis dihydrochloride (2-

methylpropionamidine), diazo-valero-nitrile, 4,4'-azobis- (4-cyanovaleric) acid, AZDN or 2,2'-azo-bis-isobutyronitrile.

Preferably according to the invention, the compound generating radicals is chosen from hydrogen peroxide and alkali metal persulphates, in particular sodium persulphate and potassium persulphate.

In addition to a compound which generates radicals, the polymerization reaction can also implement at least one compound comprising phosphorus in oxidation degree I. Preferably, this phosphorus in oxidation degree I is a compound chosen from hypophosphorous acid. (H3PO2) and a derivative of hypophosphorous acid (H3PO2). More preferably, this compound comprises at least one hypophosphite ion (H2PO2). More preferably, this compound is chosen from sodium hypophosphite (BkPChNa), potassium hypophosphite (H2PO2K), calcium hypophosphite ([HbPC Ca) and their combinations.

According to the invention, the polymerization reaction can also be carried out in the presence of at least one compound comprising a bisulphite ion, preferably a compound chosen from ammonium bisulphite, an alkali metal bisulphite, in particular sodium bisulphite, potassium bisulfite, calcium bisulfite, magnesium bisulfite, and combinations thereof.

According to the invention, the polymerization reaction can also be carried out in the presence of at least one compound comprising phosphorus in oxidation degree III, preferably a compound chosen from phosphorous acid and an acid derivative. phosphorous. More preferably, this compound comprises at least one phosphite ion, in particular a compound chosen from sodium phosphite, calcium phosphite, potassium phosphite, ammonium phosphite and their combinations.

According to the invention, the polymerization reaction can also be carried out in the presence of 0.05 to 5% by weight, relative to the total amount of monomers, of at least one compound chosen from a xanthate derivative, a compound mercaptan and a compound of formula (I):

in which :

- X independently represents H, Na or K,

- R independently represents a C -Cs-alkyl group, preferably a methyl group.

Preferably according to the invention, the compound of formula (I) is disodium trithiocarbonate diisopropionate (DPTTC).

According to the invention, the polymerization reaction can also be carried out in the presence of at least one reducing compound, for example of a compound chosen from hydroxylamine sulfate, hydrazine hydrate and their combinations.

According to the invention, the polymerization reaction is carried out at a temperature above 50 ° C, in particular at atmospheric pressure and at a temperature ranging from 50 to 98 ° C or from 75 to 99 ° C. Preferably, the polymerization reaction is carried out at 50 to 95 ° C or 50 to 85 ° C. The polymerization reaction can also be carried out at a pressure above atmospheric pressure and at a temperature above 100 ° C, preferably below 140 ° C.

According to the invention, the polymerization reaction is carried out in water, in a solvent, alone or as a mixture with water, in particular an alcoholic solvent, in particular isopropyl alcohol. Preferably, it is carried out in water.

Preferably according to the invention, the polymer (P) is totally or partially neutralized, in particular at the end of the polymerization reaction.

More preferably, the neutralization of the polymer (P) is carried out by means of at least one derivative chosen from an alkali metal, an alkaline earth metal, an amine derivative, ammonia, ammonia and their combinations. More preferably, the neutralization of the polymer (P) is carried out by means of a derivative comprising at least one element chosen from lithium, sodium, calcium, magnesium and their combinations, for example NaOH, KOH, Ca (OH) 2, Mg ( OH) 2, an amino derivative chosen from monoisopropylamine (AMP), triethylamine, diethylamine, monoethylamine and their combinations.

Sodium, calcium and their combinations are particularly preferred. Neutralization by means of sodium and calcium can therefore be carried out using at least one compound chosen from NaOH, KOH, Ca (OH) 2, Mg (OH) 2 and their combinations. The respective proportions of sodium and calcium can vary quite widely. For example, the Na / Ca molar ratio can range from 98/2 to 30/70, preferably from 95/5 to 40/60, more preferably from 90/10 to 30/70 or from 90/10 to 40/60 , even more preferably from 70/30 to 40/60, in particular 50/50.

Preferably according to the invention, the anionic monomer (M1) comprising at least one polymerizable olefinic unsaturation comprises one or two carboxylic acid functions. More preferably, it comprises a single carboxylic acid function. Even more preferably, it is chosen from acrylic acid, methacrylic acid, a salt of acrylic acid, a salt of methacrylic acid, itaconic acid, a salt of itaconic acid and their combinations. The preferred monomer (M1) is acrylic acid.

According to the invention, the polymerization reaction can implement one or more monomers (M1). Another anionic monomer (M1) can then be chosen from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride and their combinations.

According to the invention, the polymerization reaction can implement, relative to the total amount by weight of monomers:

- 100% by weight of anionic monomer (Ml) or

- from 50% to 99.5% or from 70% to 99.5% by weight of anionic monomer (M1) and, respectively, from 0.5% to 50% or from 0.5% to 30% by weight d at least one other monomer.

Besides the monomer (M1), the polymerization reaction can therefore also implement at least one nonionic monomer (M2) comprising at least one polymerizable olefinic unsaturation, preferably at least one polymerizable ethylenic unsaturation and in particular a polymerizable vinyl function.

More preferably, the nonionic monomer (M2) is chosen from styrene, vinylcaprolactam, esters of an acid comprising at least one monocarboxylic acid function, in particular an ester of an acid chosen from acrylic acid, methacrylic acid, and their combinations. , for example hydroxyethylacrylate, hydroxypropylacrylate, hydroxyethylmethacrylate, hydroxypropylmethacrylate, alkyl acrylate, in particular C1-Cio-alkyl acrylate, preferably C1-C4-alkyl acrylate, more preferably methyl acrylate, ethyl acrylate, propyl acrylate, isobutyl acrylate, n-butyl acrylate, alkyl methacrylate, in particular Ci-Cio-alkyl methacrylate, preferably Ci-C4-alkyl methacrylate.

Even more preferably, it is chosen from methyl methacrylate, ethyl methacrylate, propyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, aryl acrylate, preferably phenylacrylate, benzylacrylate, phenoxyethylacrylate, aryl methacrylate, preferably phenylmethacrylate, benzylmethacrylate, phenoxyethylmethacrylate.

According to the invention, the polymerization reaction can also implement at least one monomer (M3) chosen from 2-acrylamido-2-methylpropane sulfonic acid, a salt of 2-acrylamido-2-methylpropane sulfonic acid, acid

2- (methacryloyloxy) ethanesulfonic acid, an acid salt

2- (methacryloyloxy) ethanesulfonic acid, sodium methallyl sulfonate, styrene sulfonate, phosphated hydroxyethyl acrylate, phosphated hydroxypropyl acrylate, phosphated hydroxyethyl methacrylate, phosphated hydroxypropyl methacrylate and their combinations and mixtures.

The preferred monomer (M3) is chosen from 2-acrylamido-2-methylpropanesulfonic acid and a salt of 2-acrylamido-2-methylpropanesulfonic acid.

According to the invention, the polymerization reaction can also implement at least one monomer (M4) of formula (II):

in which :

- R 1 and R 2 , identical or different, independently represent H or CH3,

- L 1 independently represents a group chosen from C (O), CHh,

CH 2 -CH2 and O-CH2-CH2-CH2-CH2,

- L 2 independently represents a group chosen from (CH 2 -CH 2 0) X , (CH 2 CH (CH 3 ) 0) y , (CH (CH 3 ) CH 2 0) Z and their combinations and

- x, y and z, identical or different, independently represent an integer or decimal between 0 and 150 and the sum x + y + z is between 10 and 150.

According to the invention, the polymerization reaction can also implement at least one compound (M5) of formula (III):

R 1 - (OE) m- (OP> -R 2

(III)

in which :

- m and n, which are identical or different, independently represent 0 or an integer or decimal number less than 150, m or n is different from 0,

- OE represents a CH2CH2O group,

- OP independently represents a group chosen from CH (CH 3 ) CH20 and CH CH (CH 3 ) 0,

- R 1 represents a group comprising at least one polymerizable olefinic unsaturation, preferably a group chosen from acrylate, methacrylate, acrylurethane, methacrylurethane, vinyl, allyl, methallyl and isoprenyl, more preferably a methacrylate group,

- R 2 represents a linear, branched or cyclic, saturated, unsaturated or aromatic hydrocarbon group comprising from 6 to 40 carbon atoms, preferably a linear or branched C6-C4o-alkyl group, preferably a Cs-C3o-alkyl group , linear or branched, a C6-C40-aryl group, preferably a Cs-C3o-aryl group, for example a tristyrylphenyl group.

According to the invention, the polymerization reaction can also implement at least one monomer (M6) chosen from:

- polyalkylene glycol acrylate, preferably polyethylene glycol acrylate or polyethylene polypropylene glycol acrylate,

- polyalkylene glycol methacrylate, preferably polyethylene glycol methacrylate or polyethylene polypropylene glycol methacrylate,

allylpolyalkyleneglycol, preferably allylpolyethyleneglycol or allylpolyethylenepolypropyleneglycol,

- methallylpolyalkyleneglycol, preferably methallylpolyethyleneglycol or methallylpolyethylenepolypropylene glycol,

3-methyl-3-buten-1-ylpolyalkylene glycol, preferably

3-methyl-3-buten-1-ylpolyethylene glycol or

3-methyl-3 -buten- 1 - ylpolyethylenepolypropylene glycol,

- polyalkylene glycol acrylate phosphate, preferably polyethylene glycol acrylate phosphate or polyethylene polypropylene glycol acrylate phosphate,

- polyalkylene glycol methacrylate phosphate, preferably polyethylene glycol methacrylate phosphate or polyethylene polypropylene glycol methacrylate phosphate,

allylpolyalkylene glycol phosphate, preferably allylpolyethylene glycol phosphate or allylpolyethylene polypropylene glycol phosphate,

- methallylpolyalkylene glycol phosphate, preferably methallylpolyethylene glycol phosphate or ethallylpolyethylenepolypropylene glycol phosphate,

- 3-methyl-3-buten-1-ylpolyalkylene glycol phosphate, preferably 3-methyl-3-buten-1-ylpolyethylene glycol phosphate or

3-methyl-3-buten-1-ylpolyethylenepolypropylene glycol.

According to the invention, the polymerization reaction can also implement at least one monomer (M7) chosen from a crosslinking compound and a monomer comprising at least two olefinic unsaturations.

According to the invention, in addition to one or more monomers (M1), the polymerization reaction can also implement one or more monomers (M2) to (M7) as well as their various combinations. Particularly preferred polymers according to the invention are chosen from:

- homopolymers prepared by polymerization reaction using a single monomer (M1), preferably acrylic acid or a salt of acrylic acid or alternatively itaconic acid or a salt of itaconic acid,

- Copolymers prepared by polymerization reaction using two monomers (M1), preferably acrylic acid and methacrylic acid; a salt of acrylic acid and methacrylic acid; acrylic acid and maleic acid; a salt of acrylic acid and maleic acid; acrylic acid and maleic anhydride; a salt of acrylic acid and maleic anhydride,

- Copolymers prepared by polymerization reaction using three monomers (M1), preferably acrylic acid, methacrylic acid and itaconic acid; a salt of acrylic acid, methacrylic acid and itaconic acid,

- Copolymers prepared by polymerization reaction using a monomer (M 1) and a monomer (M2); preferably acrylic acid and ethyl acrylate; a salt of acrylic acid and ethyl acrylate; acrylic acid and butyl acrylate; a salt of acrylic acid and butyl acrylate; acrylic acid and hydroxypropyl acrylate; a salt of acrylic acid and hydroxypropyl acrylate; acrylic acid and hydroxypropyl methacrylate; a salt of acrylic acid and hydroxypropyl methacrylate,

- Copolymers prepared by polymerization reaction using a monomer (M1) and two monomers (M2), preferably acrylic acid, butyl acrylate and styrene; a salt of acrylic acid, butyl acrylate and styrene,

- Copolymers prepared by polymerization reaction using two monomers (M1) and two monomers (M2), preferably acrylic acid, methacrylic acid, butyl acrylate and styrene; a salt of acrylic acid, methacrylic acid, butyl acrylate and styrene,

- Copolymers prepared by polymerization reaction using a monomer (M1) and a monomer (M3), preferably acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid; a salt of acrylic acid and 2-acrylamido- acid

2-methylpropane sulfonic acid; acrylic acid and a salt of 2-acrylamido-2-methylpropanesulfonic acid; a salt of acrylic acid and a salt of 2-acrylamido-2-methylpropanesulfonic acid,

- Copolymers prepared by polymerization reaction using a monomer (M1) and a monomer (M4), preferably acrylic acid and polyethylene polypropylene glycol methacrylate; a salt of acrylic acid and polyethylene polypropylene glycol methacrylate and

- Copolymers prepared by polymerization reaction using a monomer (M1) and a monomer (M6), preferably acrylic acid and polyethylene glycol methacrylate phosphate; a salt of acrylic acid and polyethylene glycol methacrylate phosphate.

Besides a polymer (P), the dispersing agent according to the invention comprises at least one derivative (S) chosen from an ose (SI), an oligomer of ose (S2), a product (S3) and their combinations.

According to the invention, the derivative (SI) is an ose which comprises a free hemiacetal function or else condensed between the hydroxyl of the hemiacetal function carried by the anomeric carbon with an OH group of another molecule. Preferably according to the invention, the ose (SI) is chosen from trioses (oses comprising 3 carbon atoms), tetroses (oses comprising 4 carbon atoms), pentoses (oses comprising 5 carbon atoms), hexoses and deoxyhexoses (oses comprising 6 carbon atoms), heptoses (oses comprising 7 carbon atoms), octoses (oses comprising 8 carbon atoms). More preferably, it is chosen from glyceraldehyde, dihydroxyacetone, erythrose, threose, erythrulose, deoxyribose, ribose, arabinose, xylose, lyxose, ribulose, xylulose, allose, altrose, galactose, glucose, gulose, idose, mannose, talose, fructose, psicose, sorbose, tagatose, fucose, rhamnose, sedoheptulose, mannoheptulose, heptahydroxyoctanal. Glucose used alone or as a mixture is preferred.

According to the invention, the derivative (S2) is an oligomer formed from a determined number of oses. Preferably according to the invention, the oligomer (S2) is chosen from ose dimers and ose trimers. More preferably, it is chosen from dextrose, maltose, lactose, sucrose, maltoriosis, maltotetraose, alpha-glucoheptonic acid, beta-glucoheptonic acid. Sucrose used alone or as a mixture is preferred.

According to the invention, the derivative (S3) is a product resulting from the degradation of a saccharide generally obtained from a ketose which is degraded under determined conditions, leading to a chain break at the level of the ketone function. We obtain

generally one or more carboxylic acids. Preferably according to the invention, the product (S3) is chosen from aldoses, synthetic monosaccharide derivatives, synthetic disaccharide derivatives. More preferably, it is chosen from sorbitol, mannitol, gluconic acid, citric acid, isocitric acid, lactic acid, tartaric acid and the salts of these acids. Gluconic, citric and tartaric acids are preferred, in particular gluconic acid used alone or as a mixture.

Particularly preferably according to the invention, the derivative (S) is chosen from sorbitol, mannitol, gluconic acid, citric acid, isocitric acid, lactic acid, tartaric acid, the salts of these acids, dextrose, maltose, glucose, a mixture glucose and maltose, lactose, sucrose, maltoriosis, maltotetraose, alpha-glucoheptonic acid, beta-glucoheptonic acid, salts of these acids, and combinations of these derivatives.

These various derivatives (S) are generally products available commercially, for example in crystalline form or in syrup form, such as glucose syrup or corn syrup.

According to the invention, the respective amounts of derivative (S) and of polymer (P) can vary quite significantly. Preferably according to the invention, the ratio (S / P) of the quantities by dry weight of derivative (S) and of polymer (P) ranges from 0.1 to 10 or from 0.2 to 5 or from 0.3 to 5. More preferably, this ratio ranges from 0.5 to 4 or from 0.6 to 3.

Besides a dispersing agent, the invention also relates to an aqueous composition which comprises at least one such dispersing agent and an inorganic material. Thus, the invention provides an aqueous composition comprising:

(a) at least one dispersing agent according to the invention;

(b) at least one inorganic material in the form of particles.

Numerous inorganic materials may be suitable for the composition according to the invention, in particular according to the nature or according to the form of the inorganic material.

Preferably, the particles of mineral material have an average diameter of less than 500 μm, less than 200 μm or 100 μm or else less than 50 mih or else an average diameter ranging from 0.05 μm to 50 μm or else a average diameter less than 10 μm, preferably less than 5 μm or 2 μm, also preferably less than 1 μm or less than 0.5 μm.

According to the invention, a single mineral material (a) or two or three mineral materials (a) are used. Preferably, a single mineral material or else two mineral materials are used.

Advantageously according to the invention, the mineral material (a) is synthetic or of natural origin. Preferably, it is chosen from alkaline earth metal carbonates, preferably calcium carbonate (natural calcium carbonate or precipitated calcium carbonate), strontium carbonate, magnesium carbonate, barium carbonate, dolomite, kaolin, calcined kaolin , titanium dioxide, iron oxide, talc, calcium sulfate, barium sulfate, silicas, mica, zinc oxide.

More preferably, it is chosen from calcium carbonate (natural calcium carbonate or precipitated calcium carbonate), titanium oxide, kaolin and calcined kaolin.

Besides a dispersing agent according to the invention and a mineral material, the composition according to the invention can comprise other elements, in particular according to the technical field of use of this composition.

Thus, the aqueous composition according to the invention can also comprise at least one binding agent (c) of natural or synthetic origin. According to the invention, the binding agent (c) can be a natural binding agent such as starch, carboxymethyl cellulose (CMC), hydroxyethyl celluloses, polyvinyl alcohol (PV-OH), casein, proteins, alginates. According to the invention, the binding agent (c) can also be a synthetic binding agent such as a latex, preferably chosen from a styrene-butadiene polymer, a styrene-acrylic polymer, a styrene-acetate polymer, more preferably a styrene polymer. -butadiene.

The aqueous composition according to the invention can also comprise at least one thickening agent (d) of natural or synthetic origin. Preferably, it is chosen from a polymeric emulsion, a HASE polymer, an ASE polymer, an HEUR polymer, a polyurethane polymer, a steric thickening polymer, a polyacrylamide polymer, CMC, a derivative of CMC and their combinations.

The proportions of the various elements of the aqueous composition according to the invention can vary significantly, in particular according to the technical field of use of this composition.

Preferably, the aqueous composition according to the invention comprises:

- from 0.02 to 2% dry weight of dispersing agent (a),

- from 30 to 75% dry by mass of mineral material (b),

- from 2 to 25% dry weight of binding agent (c),

- from 0.01 to 2% dry weight of thickening agent (d) and

- from 22.97 to 42.98% by mass of water.

During its use, the aqueous composition according to the invention can be used after dilution, in particular after dilution with water.

More preferably, the aqueous composition according to the invention is a composition for paper coating sauce.

The aqueous composition according to the invention can also comprise at least one adjuvant, in particular at least one adjuvant chosen from dispersing agents, anti-foaming agents, biocidal agents, coloring agents, lubricating agents and optical brightening agents.

The dispersing agent according to the invention is suitable for many uses. Preferably, the dispersing agent according to the invention is used for the preparation of an aqueous composition, preferably for the preparation of an aqueous composition according to the invention.

Thus the invention also relates to a use of a dispersing agent according to the invention which comprises the addition of the dispersing agent in an aqueous suspension of at least one inorganic material in the form of particles. This use according to the invention can also comprise the addition of at least one inorganic material in the form of particles in an aqueous composition comprising at least one dispersing agent according to the invention.

The invention also relates to the use of at least one dispersing agent according to the invention for the preparation of an aqueous composition chosen from a composition for papermaking coating sauce, preferably intended for the preparation of a primary coating layer. paper (pre-layer) or a final coating layer of paper (top-layer); a coating composition, preferably paint or varnish; an ink composition, preferably an ink composition for an inkjet printer; a care composition, preferably a body or hair care composition; a soil amendment composition. Preferably, this use relates to the preparation of a composition for papermaking coating sauce or of a coating composition.

Furthermore, the invention also provides a method of controlling the rheology of an aqueous composition comprising at least one polymer (P) defined according to the invention by adding to the composition at least one derivative (S) chosen from:

- a ose (SI) comprising from 3 to 8 carbon atoms;

- an ose oligomer (S2) comprising from 1 to 10 ose units;

- a product (S3) resulting from the degradation of a saccharide.

Preferably for this method according to the invention, the ratio (S / P) of the quantities by dry weight of derivative (S) and of polymer (P) ranges from 0.1 to 10 or from 0.2 to 5 or from 0.3 to 5. More preferably, it ranges from 0.5 to 4 or from 0.6 to 3.

More preferably according to the invention for this method according to the invention, the composition comprises at least one ingredient chosen from:

a mineral material in the form of particles, preferably a material defined according to the invention;

- a binding agent, preferably a binding agent (c) defined according to the invention;

- a thickening agent, preferably a thickening agent (d) defined according to the invention.

The examples which follow give an illustration of the various aspects of the invention.

EXAMPLES

Preparation of the polymers used according to the invention and of comparative polymers

Polymer (PI)

In a 1 L reactor fitted with mechanical stirring, an oil bath type heating and peristaltic pumps, the following are weighed: 209.7 g of water, 0.08 g of iron sulphate heptahydrate and 0.011 g of hydrated penta copper sulphate. The whole is then heated to 95 ° C and the following are added over 120 min, using peristaltic pumps: 302.5 g of acrylic acid and 13 g of water, 25.6 g of sodium hypophosphite monohydrate dissolved in 29 g of water, 20.46 g of 130V hydrogen peroxide diluted with 25 g of water. Then, it is cooked for 60 min at 95 ° C. The whole is then cooled, neutralized with 50% sodium hydroxide in water to pH 8.5 and diluted in order to obtain a dry matter content of 40%. The sodium polyacrylate polymer (PI) of Mw 4400 g / mol is then obtained.

Polymer (P2)

In a 1 L reactor fitted with mechanical stirring, oil bath type heating and peristaltic pumps, the following are weighed: 158 g of water, 0.014 g of iron sulphate heptahydrate. The whole is then heated to 80 ° C and the following reagents are simultaneously added using peristaltic pumps while maintaining the temperature at 81 +/- 1 ° C: 271 g of acrylic acid in 210 min, 3.3 g of sodium persulfate dissolved in 44 g of water in 210 min and 114.46 g of a solution of sodium bisulfite diluted to 40% by weight in water in 180 min. Then, it is cooked for 60 min at 80 ° C. Treated with 4.5 g of hydrogen peroxide at 130 V and baked again for 60 min at 80 ° C.

The whole is then cooled, neutralized with 50% sodium hydroxide in water to pH 8.5 and diluted in order to obtain a dry matter content of 40%. The sodium polyacrylate polymer (P2) is then obtained, of Mw 2800 g / mol.

Polymer (P3)

From itaconic acid partially neutralized by means of soda added slowly, with stirring and at controlled temperature, then polymerized by heating in water and with stirring in the presence of sodium hypophosphite and hydrogen peroxide, and finally partially decarboxylated by heating under reflux in water, a polymeric solution (P3) of partially decarboxylated sodium polyitaconate is prepared having a concentration of 40% by weight of polymer and a pH of 9 (method described in the examples of document WO 2015- 100412).

The polymer (P3) of Mw 2 160 g / mol is obtained.

Polymer (P4)

In a 1 L reactor fitted with mechanical stirring, oil bath type heating and peristaltic pumps, the following are weighed: 245 g of water, 0.13 g of iron sulphate heptahydrate and 0.02 g of hydrated penta copper sulfate. The whole is then heated to 95 ° C and added over 120 min, simultaneously using 3 independent pumps: a mixture of 284 g of acrylic acid and 180 g of hydroxypropyl acrylate, 37 g of 130 V hydrogen peroxide diluted with 34 g of water and 96 g of a 50% solution of sodium hypophosphite. Then, it is cooked for 60 min at 95 ° C.

The whole is then cooled, neutralized with a 28 ° ammonia solution to pH 7 and diluted to obtain a dry matter content of 44%. The polymer (P4) of Mw 2800 g / mol is then obtained.

Polymer (PS)

In a 1 L reactor fitted with mechanical stirring, oil bath type heating and peristaltic pumps, the following are weighed: 200 g of isopropanol and 1.7 g of AZDN. The whole is then heated to reflux at approximately 80 ° C. and the following are added over 120 min, using peristaltic pumps: 200 g of acrylic acid and 81 g of butyl acrylate. Then, it is cooked for 60 min at reflux. The isopropanol is then distilled and the latter is gradually replaced by water during the distillation.

The whole is then cooled, neutralized with a 50% solution of potassium hydroxide in water to pH 8 and diluted in order to obtain a dry matter content of 40%. The polymer (P5) of Mw 9000 g / mol is then obtained.

Polymer (P6)

260 g of water are weighed out in a 1 L reactor fitted with mechanical stirring, an oil bath type heating and peristaltic pumps, then heated to 65 ° C and added over 180 min, simultaneously. using 3 independent pumps: a mixture of 50 g of acrylic acid and 343 g of a poly (ethylene glycol-co-propylene glycol) methacrylate macromonomer with a molecular mass of 3000 g / mol (corresponding on average with 46 units of ethylene oxide and 15 units of propylene oxide distributed randomly) and terminated by a hydroxyl group, 3.6 g of ammonium persulfate dissolved with 80 g of water and 4.5 g of l , 8-dimercapto-3,6-dioxaoctane (DMDO). Then, cooked for 60 min by gradually adding a solution of 1 g of sodium persulfate dissolved in 10 g of water.

The whole is then cooled, neutralized with a 50% sodium hydroxide solution in water to pH 4 and diluted in order to obtain a dry matter content of 40%. The polymer (P6) of Mw 38 OOOg / mol is then obtained.

Polymer (P7)

In a 2 L reactor equipped with mechanical stirring, an oil bath type heating and peristaltic pumps, the following are weighed: 230 g of isopropanol, 230 g of water, 0.005 g of iron sulphate heptahydrate and 0.11 g of hydoxylamine sulfate. The whole is then heated to reflux at about 80 ° C and the following are added over 120 min, using three peristaltic pumps: a mixture comprising 296.8 g of acrylic acid, 164.2 g of an aqueous solution 50% by weight of sodium 2-acrylamido-2-methylpropane-sulfonate, moreover 12 g of 130 V hydrogen peroxide diluted in 50 g of water and 3.3 g of hydroxylamine sulfate dissolved in 70 g of 'water. Then, it is cooked for 60 min at reflux. The isopropanol is then distilled and the latter is gradually replaced by water during the distillation.

The whole is then cooled, neutralized with 50% sodium hydroxide in water to pH 4 and diluted in order to obtain a dry matter content of 50%. We then obtain a polymer

(P7) of Mw 5000 g / mol.

Preparation of dispersing agents according to the invention and comparative dispersing agents

A dispersing agent (Dl) according to the invention is prepared by mixing the polymer (PI) with the derivative (SI). The polymer (PI) is weighed in a beaker and then the derivative (SI) and water are added, with stirring by means of a VMI turbine engine 30 at 1000 rpm. The quantities used are presented in Table 1.

Similarly, other dispersing agents according to the invention are prepared. The following derivatives (S) were used:

- Sl-1: glucose syrup at 80% by weight of dry extract (CSweet M01658, Cargill), - S 1-2: glucose syrup at 85% by weight of dry extract (74/968, Roquette) and

- S 1-3: glucose syrup at 91% by weight of dry extract (4779, Roquette).

Table 1

The final solids extract of each dispersing agent is checked by means of a CEM microwave balance at 110 ° C. until a variation in solids content of less than 0.1% by weight after 10 seconds. The dry extract of the agents according to the invention is 42% by weight, with the exception of the dispersing agents D12, D13 and D14 which have, respectively, a dry extract of 40% by weight, 40% by weight and 44%. in weight.

Preparation of aqueous compositions of mineral materials comprising dispersing agents according to the invention or comparative dispersing agents

An aqueous composition (C1) according to the invention is prepared.

In a beaker, the dispersing agent (D2) according to the invention is weighed, then water and then an inorganic pigment (PMI) are added while stirring up to 2,500 rpm using a VMI stirrer fitted a 65 mm turbine.

Finally, 12.5% ​​by weight sodium hydroxide in water is added until the pH is controlled and stirring is maintained for 20 min. The dry extract of the composition is then measured. The respective amounts (g) and level of dispersing agent (% by dry weight relative to the amount of dry pigment) of the various ingredients as well as the characteristics of the compositions prepared are presented in Tables 2 and 3.

In an analogous manner, aqueous compositions (C2) to (C36) according to the invention are prepared according to the invention as well as comparative compositions (CCI) to (CCI 4) not comprising a derivative (S) in the dispersing agent used but only a comparative polymer. The pH of the compositions is adjusted to 8.5, with the exception of the pH of the aqueous compositions (C33), (C34), (C35) and (C36) according to the invention which is respectively 7, 7, 9 and 9 and comparative compositions (CCI 2), (CCI 3) and (CCI 4) which are respectively 9, 7 and 7. The dispersing agents (D1) to (DI 4) according to the invention were used. The following mineral pigments were used:

- PMI: kaolin (Capim DG, Imerys),

- PM2: kaolin (Amazon plus Lump, Kamin),

- PM3: calcium carbonate (Violet Label, Omya),

- PM4: precipitated calcium carbonate (SOCAL P3, Solvay),

- PM5: kaolin (Speswhite, Imerys),

- PM6: titanium dioxide (RHD2, Elementis),

- PM7: titanium dioxide (RCL 722, Cristal) and

- PM8: calcined kaolin (Hubertex, Kamin).

The viscosity (mPa.s) of the aqueous suspensions prepared is measured by means of a Brookfield RVI viscometer at 100 rpm and at 25 ° C. The results are shown in Tables 2 and 3.

Table 2

Table 3

It is observed that the compositions according to the invention have a lower viscosity than the comparative compositions while they contain a smaller amount of polymer.

Furthermore, a dilatancy effect is evaluated by measuring a shear rate (s -1 ) at 25 ° C of the aqueous suspensions prepared, using a Thermofisher RS600 coaxial rheometer, the spindle of which has a CC27 DG Ti geometry by increasing the speed (s 1 ) of the moving part until this moving part is blocked. The results are shown in Table 4.

Table 4

It is observed that the dilatancy effect of the compositions according to the invention is lower than that of the comparative composition. In fact, the compositions according to the invention make it possible to achieve a higher shear rate when the moving part is blocked.

CLAIMS

1. Aqueous dispersant comprising:

- at least one polymer (P) prepared by at least one radical polymerization reaction, at a temperature above 50 ° C, of ​​at least one anionic monomer (M1) comprising at least one polymerizable olefinic unsaturation and at least one acid function carboxylic acid or one of its salts, in the presence of at least one radical generating compound chosen from hydrogen peroxide, benzoyl peroxide, acetyl peroxide, lauryl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulfate, a persulfate of alkali metal, an azo compound, their combinations and their respective associations with an ion selected from Fe 11 , Fe 111 , Cu 1 , Cu "and their combinations;

- at least one derivative (S) chosen from:

o an ose (SI) comprising from 3 to 8 carbon atoms;

o an ose oligomer (S2) comprising from 1 to 10 ose units;

o a product (S3) resulting from the degradation of a saccharide.

2. Agent according to claim 1 for which:

- the polymerization reaction is also carried out in the presence of at least one compound comprising phosphorus at oxidation degree I, preferably a compound chosen from hypophosphorous acid (H 3 PO 2 ) and a derivative of hypophosphorous acid (H 3 PO 2 ), preferably a compound comprising at least one hypophosphite ion (H2PO2), more preferably a compound chosen from sodium hypophosphite (FkPC Na), potassium hypophosphite (H 2 PO 2 K), hypophosphite of calcium ([FhPC JiCa) and combinations thereof; Where

- the polymerization reaction is also carried out in the presence of at least one compound comprising a bisulphite ion, preferably a compound chosen from ammonium bisulphite, an alkali metal bisulphite, in particular sodium bisulphite, potassium bisulphite, bisulphite calcium, magnesium bisulphite and their combinations; Where

- the polymerization reaction is carried out in the presence of at least one compound comprising phosphorus in oxidation degree III, preferably a compound chosen from phosphorous acid and a derivative of phosphorous acid, more preferably a compound comprising at least one phosphite ion, in particular a

compound selected from sodium phosphite, calcium phosphite, potassium phosphite, ammonium phosphite and combinations thereof; Where

- the polymerization reaction is also carried out in the presence of 0.05 to 5% by weight, relative to the total amount of monomers, of at least one compound chosen from a xanthate derivative, a mercaptan compound and a compound of formula (I):

in which :

- X independently represents H, Na or K,

- R independently represents a Ci-Cs-alkyl group, preferably a methyl group; in particular a compound of formula (I) which is disodium trithiocarbonate diisopropionate (DPTTC - CAS number 6332-91-8); Where

the polymerization reaction is also carried out in the presence of at least one reducing compound, for example of a compound chosen from hydroxylamine sulphate, hydrazine hydrate and their combinations; Where

- the polymerization reaction is carried out at atmospheric pressure and at a temperature ranging from 50 to 98 ° C or from 75 to 99 ° C, preferably from 50 to 95 ° C or from 50 to 85 ° C; at a pressure above atmospheric pressure and at a temperature above 100 ° C, preferably below 140 ° C; Where

the polymerization reaction is carried out in water, in a solvent, alone or as a mixture with water, in particular an alcoholic solvent, in particular isopropyl alcohol, preferably in water; Where

- the polymer (P) is totally or partially neutralized, in particular at the end of the polymerization reaction; preferably by means of at least one derivative chosen from an alkali metal, an alkaline earth metal, an amine derivative, ammonia, ammonia and their combinations, in particular a derivative comprising at least one element chosen from lithium, sodium, calcium, magnesium and their combinations, for example NaOH, KOH, Ca (OH) 2, Mg (OH) 2, an amino derivative selected from monoisopropylamine (AMP), triethylamine, diethylamine, monoethylamine and their combinations; Where

- the polymerization reaction implements, relative to the total amount by weight of monomers:

o 100% by weight of anionic monomer (Ml) or o from 50% to 99.5% or from 70% to 99.5% by weight of anionic monomer (Ml) and, respectively, from 0.5% to 50% or from 0.5% to 30% by weight of at least one other monomer.

3. Dispersing agent according to one of claims 1 and 2 for which the anionic monomer (M1) comprising at least one polymerizable olefinic unsaturation comprises one or two carboxylic acid functions, preferably comprises a single carboxylic acid function, preferably is chosen from acrylic acid, methacrylic acid, itaconic acid, a salt of acrylic acid, a salt of methacrylic acid, a salt of itaconic acid and their combinations, more preferably acrylic acid.

4. Dispersing agent according to one of claims 1 to 3 for which the polymerization reaction also implements at least one other monomer chosen from:

- Another anionic monomer (M1), preferably a monomer chosen from acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride and their combinations;

- at least one nonionic monomer (M2) comprising at least one polymerizable olefinic unsaturation, preferably at least one polymerizable ethylenic unsaturation and in particular one polymerizable vinyl function, more preferably a nonionic monomer (M2) chosen from styrene, vinylcaprolactam, esters of an acid comprising at least one monocarboxylic acid function, in particular an ester of an acid chosen from acrylic acid, methacrylic acid, and their combinations, for example hydroxyethylacrylate, hydroxypropylacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, alkyl acrylate, in particular acrylate of Ci-Cio-alkyl, preferably Ci-C4-alkyl acrylate, more preferably methyl acrylate, ethyl acrylate, propyl acrylate, isobutyl acrylate, n-butyl acrylate,alkyl methacrylate, in particular C1-Cio-alkyl methacrylate, preferably C1-C4-alkyl methacrylate, more preferably methyl methacrylate, ethyl methacrylate, propyl methacrylate, isohutyl methacrylate, n-butyl methacrylate, aryl acrylate, preferably phenylacrylate, benzylacrylate, phenoxyethylacrylate, aryl methacrylate, preferably phenylmethacrylate, benzylmethacrylate, phenoxyethylmethacrylate;benzylmethacrylate, phenoxyethylmethacrylate;benzylmethacrylate, phenoxyethylmethacrylate;

- at least one monomer (M3) chosen from 2-acrylamido-2-methylpropanesulfonic acid, a salt of 2-acrylamido-2-methylpropanesulfonic acid, 2- (methacryloyloxy) ethanesulfonic acid, a salt of acid

2- (methacryloyloxy) ethanesulfonic acid, sodium methallyl sulfonate, styrene sulfonate, phosphated hydroxyethyl acrylate, phosphated hydroxypropyl acrylate, phosphated hydroxyethyl methacrylate, phosphated hydroxypropyl methacrylate and their combinations and mixtures;

- at least one monomer (M4) of formula (II):

in which :

- R 1 and R 2 , identical or different, independently represent H or C¾,

- L 1 independently represents a group chosen from C (O), CHh, CH2-CH2 and O-CH2-CH2-CH2-CH2,

- L 2 independently represents a group chosen from (CH 2 -CH20) X , (CH 2 CH (CH 3 ) 0) y , (CH (CH 3 ) CH 2 0) Z and their combinations and

- x, y and z, which are identical or different, independently represent an integer or decimal between 0 and 150 and the sum x + y + z is between 10 and 150;

- at least one compound (M5) of formula (III):

R i - (OE) - (OP) nR 2

(III)

in which :

- m and n, which are identical or different, independently represent 0 or an integer or decimal number less than 150, m or n is different from 0,

- OE represents a CH2CH2O group,

- OP independently represents a group chosen from CH (CH 3 ) CH20 and CH 2 CH (CH 3 ) 0,

- R 1 represents a group comprising at least one polymerizable olefinic unsaturation, preferably a group chosen from acrylate, methacrylate, acrylurethane, methacrylurethane, vinyl, allyl, methallyl and isoprenyl, more preferably a methacrylate group,

- R 2 represents a linear, branched or cyclic, saturated, unsaturated or aromatic hydrocarbon group comprising from 6 to 40 carbon atoms, preferably a linear or branched C6-C4o-alkyl group, preferably a Cs-C3o-alkyl group linear or branched, a C ô -C4o-aryl group, preferably a C8-C30-aryl group, for example a tristyrylphenyl group;

- at least one monomer (M6) chosen from:

- polyalkylene glycol acrylate, preferably polyethylene glycol acrylate or polyethylene polypropylene glycol acrylate,

- polyalkylene glycol methacrylate, preferably polyethylene glycol methacrylate or polyethylene polypropylene glycol methacrylate,

allylpolyalkyleneglycol, preferably allylpolyethyleneglycol or allylpolyethylenepolypropyleneglycol,

- methallylpolyalkyleneglycol, preferably methallylpolyethyleneglycol or methallylpolyethylenepolypropylene glycol,

- 3-methyl-3-buten-l-ylpolyalkylene glycol, preferably 3-methyl-3-buten-l-ylpolyethylene glycol or 3-methyl-3-buten-l-ylpolyethylenepolypropylene glycol,

- polyalkylene glycol acrylate phosphate, preferably polyethylene glycol acrylate phosphate or polyethylene polypropylene glycol acrylate phosphate,

- polyalkylene glycol methacrylate phosphate, preferably polyethylene glycol methacrylate phosphate or polyethylene polypropylene glycol methacrylate phosphate,

allylpolyalkylene glycol phosphate, preferably allylpolyethylene glycol phosphate or allylpolyethylene polypropylene glycol phosphate,

- methallylpolyalkylene glycol phosphate, preferably methallylpolyethylene glycol phosphate or ethallylpolyethylenepolypropylene glycol phosphate,

- 3-methyl-3-buten-1-ylpolyalkylene glycol phosphate, preferably 3-methyl-3-buten-1-ylpolyethylene glycol phosphate or 3-methyl-3-buten-1-ylpolyethylenepolypropylene glycol phosphate;

- at least one monomer (M7) chosen from a crosslinking compound and a monomer comprising at least two olefinic unsaturations.

5. Agent according to one of claims 1 to 4 for which the derivative (S) is chosen from:

- an ose (SI) chosen from trioses (oses comprising 3 carbon atoms), tetroses (oses comprising 4 carbon atoms), pentoses (oses comprising 5 carbon atoms), hexoses and deoxyhexoses (oses comprising 6 carbon atoms), heptoses (oses comprising 7 carbon atoms), octoses (oses comprising 8 carbon atoms); preferably chosen from glyceraldehyde, dihydroxyacetone, erythrose, threose, erythrulose, deoxyribose, ribose, arabinose, xylose, lyxose, ribulose, xylulose, allose, altrose, galactose, glucose, gulose, idose, mannose, talose, fructose, psicose, sorbose, tagatose, fucose, rhamnose, sedoheptulose, mannoheptulose, heptahydroxyoctanal;

- an oligomer (S2) chosen from ose dimers and ose trimers; preferably chosen from dextrose, mastose, lactose, sucrose, maltoriosis, maltotetraose, alpha-glucoheptonic acid, beta-glucoheptonic acid;

- a product (S3) chosen from aldoses, synthetic monosaccharide derivatives, synthetic disaccharide derivatives; preferably chosen from sorbitol, mannitol, gluconic acid, citric acid, isocitric acid, lactic acid, tartaric acid, the salts of these acids.

6. Agent according to one of claims 1 to 5 for which the derivative (S) is chosen from sorbitol, mannitol, gluconic acid, citric acid, isocitric acid, lactic acid, tartaric acid, the salts of these acids, dextrose, maltose , glucose, a mixture of glucose and maltose, lactose, sucrose, maltoriosis, maltotetraose, alpha-glucoheptonic acid, beta-glucoheptonic acid, salts of these acids, and combinations of these derivatives.

7. Agent according to one of claims 1 to 6 for which the ratio (S / P) of the quantities by dry weight of derivative (S) and of polymer (P) ranges from 0.1 to 10 or from 0.2 to 5 or 0.3 to 5, preferably 0.5 to 4 or 0.6 to 3.

8. Aqueous composition comprising:

(a) at least one dispersing agent defined according to one of claims 1 to 7;

(b) at least one inorganic material in the form of particles.

9. Composition according to claim 8 for which:

- the particles of mineral material have an average diameter of less than 500 μm, less than 200 μm or 100 μm or even less than 50 μm or even an average diameter ranging from 0.05 μm to 50 μm or else a lower average diameter at 10 pm, from

preferably less than 5 mih or 2 mih, also preferably less than 1 pm or less than 0.5 mih; Where

- a single mineral material (a) or two or three mineral materials (a) are used; Where

- the mineral material (a) is synthetic or of natural origin, preferably chosen from alkaline earth metal carbonates, preferably calcium carbonate (natural calcium carbonate or precipitated calcium carbonate), strontium carbonate, carbonate of magnesium, barium carbonate, dolomite, kaolin, calcined kaolin, titanium dioxide, iron oxide, talc, calcium sulfate, barium sulfate, silicas, mica, zinc oxide; more preferably calcium carbonate (natural calcium carbonate or precipitated calcium carbonate), titanium dioxide, kaolin and calcined kaolin.

10. Aqueous composition according to one of claims 8 and 9 also comprising:

- at least one binding agent (c) of natural or synthetic origin, preferably a natural binding agent such as starch, carboxymethyl cellulose (CMC), hydroxyethyl celluloses, polyvinyl alcohol (PV-OH), casein , proteins, alginates, or a synthetic binding agent such as a latex, preferably chosen from a styrene-butadiene polymer, a styrene-acrylic polymer, a styrene-acetate polymer, more preferably a styrene-butadiene polymer; Where

- at least one thickening agent (d) of natural or synthetic origin, preferably chosen from a polymeric emulsion, a HASE polymer, an ASE polymer, a HEUR polymer, a polyurethane polymer, a steric thickening polymer, a polyacrylamide polymer, CMC , a derivative of CMC and combinations thereof.

11. Aqueous composition, preferably aqueous composition for papermaking coating sauce, according to one of claims 8 to 10 comprising:

- from 0.02 to 2% dry weight of dispersing agent (a),

- from 30 to 75% dry by mass of mineral material (b),

- from 2 to 25% dry weight of binding agent (c),

- from 0.01 to 2% dry weight of thickening agent (d) and

- from 22.97 to 42.98% by mass of water.

12. Aqueous composition according to one of claims 8 to 11 also comprising at least one adjuvant, in particular at least one adjuvant chosen from dispersing agents, anti-foaming agents, biocidal agents, coloring agents, lubricating agents and optical brightening agents.

13. Use of at least one dispersing agent defined according to one of claims 1 to 7 for the preparation of an aqueous composition, preferably for the preparation of an aqueous composition defined according to one of claims 8 to 12, comprising:

- the addition of the dispersing agent in an aqueous suspension of at least one mineral material in the form of particles or else

the addition of at least one inorganic material in the form of particles in an aqueous composition comprising at least one dispersing agent.

14. Use of at least one dispersing agent defined according to one of claims 1 to 7 for the preparation of an aqueous composition chosen from a composition for papermaking coating sauce, preferably intended for the preparation of a coating layer. paper primer (pre-layer) or a final coating layer of paper (top-layer); a coating composition, preferably paint or varnish; an ink composition, preferably an ink composition for an inkjet printer; a care composition, preferably a body or hair care composition; a soil amendment composition.

15. A method of controlling the rheology of an aqueous composition comprising at least one polymer (P) defined according to one of claims 1 to 4 by addition to the composition of at least one derivative (S) chosen from:

- a ose (SI) comprising from 3 to 8 carbon atoms;

- an ose oligomer (S2) comprising from 1 to 10 ose units;

- a product (S3) resulting from the degradation of a saccharide.

16. Method according to claim 15 for which the ratio (S / P) of the quantities by dry weight of derivative (S) and of polymer (P) ranges from 0, 1 to 10 or from 0.2 to 5 or from 0, 3 to 5, preferably 0.5 to 4 or 0.6 to 3.

17. Method according to one of claims 15 and 16 for which the composition comprises at least one ingredient chosen from:

- an inorganic material in the form of particles, preferably a material defined according to claim 9;

- a binding agent, preferably a binding agent (c) defined according to one of claims 10 and 11;

- a thickening agent, preferably a thickening agent (d) defined according to one of claims 10 and 11.