POLYITACONIC COMPOSITION

Abstract

The invention relates to an aqueous polymeric composition comprising a water-soluble sulfonated polymer which is prepared by a radical polymerization reaction in water in the presence of a compound comprising sulfur in oxidation state IV. The invention also relates to this method of preparation as well as to a dispersing or grinding agent comprising the composition according to the invention.

Description

Title of the invention: POLYITACONIC COMPOSITION

[0001] The invention relates to an aqueous polymeric composition comprising a water-soluble sulfonated polymer which is prepared by a radical polymerization reaction in water in the presence of a compound comprising sulfur in oxidation state IV. The invention also relates to this method of preparation as well as a dispersing or grinding agent comprising the composition according to the invention.

[0002] Many technical fields require the use of polymers chosen for their particular properties. In particular, the field of treatment of mineral materials, in particular the dispersion or grinding of mineral material, uses dispersing agents or grinding aids. Also, the fields of water treatment and detergents use polymers capable of developing interactions with mineral materials.

[0003] The methods of preparation of these polymers play an essential role for their effectiveness but also for their conditions of implementation, in particular when it comes to limiting or banning the use of polluting substances or dangerous substances.

[0004] The methods for preparing these polymers also play an essential role when they allow the use of compounds of renewable or non-fossil origin, in particular compounds of natural origin. These preparation methods should not use volatile organic compounds, in particular alkanes, aromatic hydrocarbon compounds or alkenes. In particular, the presence of such compounds should be controlled in order to avoid their release during the use of these polymers.

[0005] Furthermore, these polymers should be able to be prepared in the absence of a compound that could be considered harmful from an environmental point of view or in the absence of a compound whose use is restricted by regulatory provisions. In particular, the preparation of these polymers in the absence of a compound comprising phosphorus should be preferred, in particular in the absence of phosphorus in oxidation state I, III or V.

[0006] The general economy of the methods for preparing these polymers also plays a very important role, both with regard to the yield of the polymerization reaction or the conversion rate of the reactants and with regard to the control of the quantities of by-products formed. In particular, these methods should make it possible to control or reduce the quantities of by-products which are detrimental to the properties of the polymers formed. Preferably, these methods should make it possible to control or reduce the quantities of oligomers formed. They should also to reduce the quantities of residual monomers present at the end of the polymerization reaction.

[0007] Thus, there is a significant need to have available polymers that are effective and can be prepared by improved methods. Control of the molecular mass and the polymolecularity index of polymers is also sought. State-of-the-art polymers and their preparation methods are not always satisfactory in providing a solution to all or part of the problems encountered.

[0008] Thus, the invention provides an aqueous polymeric composition C comprising at least one water-soluble sulfonated polymer P, of molecular mass Mw, measured by CES, ranging from 1,500 g / mol to 50,000 g / mol and prepared by a radical polymerization reaction in water of at least one compound Ml chosen from itaconic anhydride, itaconic acid, sodium itaconate, potassium itaconate, lithium itaconate, ammonium itaconate, calcium itaconate, magnesium itaconate and combinations thereof, in the presence of at least one initiator compound and at least one sulfur compound T comprising sulfur in oxidation state IV (sulfur IV or SIV).

[0009] Generally, the composition C according to the invention comprises a quantity by weight of water which is less than 70%, preferably less than 65% or 60%, more preferably less than 55% or 50%, relative to the quantity by weight of all the other compounds present, in particular relative to the quantity by weight of polymer P.

[0010] Essentially according to the invention, the polymer P is prepared by a radical polymerization reaction in the presence of the sulfur compound T which comprises sulfur at oxidation state IV (sulfur IV or SIV). Thus, the polymer P according to the invention is a sulfonated or sulfoitaconic polymer. Preferably according to the invention, the polymer P is a sulfo-polyitaconic polymer. Also preferably according to the invention, the polymer P is an α-co-sulfonated polyitaconic polymer.

[0011] Preferably, the composition C according to the invention comprises a polymer P which has a molecular mass Mw, measured by CES, ranging from 2,000 g / mol to 50,000 g / mol or from 1,500 g / mol to 40,000 g / mol, preferably from 2,000 g / mol to 25,000 g / mol or from 1,500 g / mol to 20,000 g / mol. More preferably, the polymer P has a molecular weight Mw ranging from 2,000 g / mol to 20,000 g / mol, even more preferably from 2,000 g / mol to 15,000 g / mol, much more preferably from 3,000 g / mol to 13,000 g / mol or from 2,500 g / mol to 15,000 g / mol, particularly preferably from 3,500 g / mol to 20,000 g / mol or from 3,000 g / mol to 15,000 g / mol, most preferably from 3,500 g / mol to 15,000 g / mol or from 3,500 g / mol to 13,000 g / mol, and much more preferably from 3,500 g / mol to 10,000 g / mol or from 3,500 g / mol to 8,000 g / mol or from 3,500 g / mol to 6,500 g / mol or from 3,500 g / mol to 5,500 g / mol.

[0012] According to the invention, the molecular weight or mass of the polymer P as well as the polymolecularity index are determined by Size Exclusion Chromatography (SEC). A test sample of the polymer dispersion corresponding to 90 mg of dry matter is introduced into a 10 mL flask. 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% by mass.The CES chain is composed of a "Waters" 510 isocratic pump, whose flow rate is set at 0.8 mL / min, a "Waters" 717+ sample changer, an oven containing a "Guard Column Ultrahydrogel Waters" precolumn of 6 cm length and 40 mm inner diameter, followed by a linear column of "Ultrahydrogel Waters" of 30 cm length and 7.8 mm inner diameter. Detection is ensured by means of a differential refractometer of "RI Waters" 410 type. The oven is brought to the temperature of 60°C and the refractometer is brought to the temperature of 45°C. The CES device is calibrated with a series of sodium polyacrylate standards supplied by "Polymer Standard Service" with peak molecular weights between 900 g / mol and 2,250,000 g / mol and polydispersity index 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 chromatogram obtained is integrated into the area corresponding to molecular weights greater than 250 g / mol.

[0013] The method for preparing composition C according to the invention is particularly effective, in particular for controlling the properties of polymer P. Thus, preferably, composition C according to the invention comprises a polymer P whose polymolecularity index (Ip), measured by CES, is less than 5.5, preferably less than 4.5 or less than 4. More preferably, the polymolecularity index of polymer P is less than 3. Also preferably according to the invention, the polymolecularity index of polymer P ranges from 1.6 to 5.5, more preferably from 1.6 to 4.5 or ranging from 1.6 to 4, much more preferably from 1.6 to 3.

[0014] Preferably according to the invention, the polymer P is totally or partially neutralized. More preferably, the polymer P is neutralized by means of an ion chosen from a monovalent ion, a divalent ion and their combinations, much more preferably by means of an ion chosen from K+, Na+, Li+, NH4+, Mg2+, Ca2+ and their combinations. Also preferably, the polymer P is totally or partially neutralized by means of at least one compound chosen from LiOH, NaOH, KOH, Zn(OH)2, Mg(OH)2, Ca(OH)2, ZnO, MgO, CaO, ammonium derivatives, ammonia, aqueous ammonia, amine bases, for example triethanolamine, aminomethylpropanol or 2-amino-2-methyl-propanol (AMP), and combinations thereof. Preferred compounds according to the invention are selected from NaOH, Ca(OH)2, CaO and combinations thereof.

[0015] Essentially according to the invention, the polymer P is prepared using the compound Ml. Preferably, the compound Ml is chosen from itaconic acid, sodium itaconate, potassium itaconate, lithium itaconate, ammonium itaconate and combinations thereof. More preferably, the compound Ml is chosen from itaconic acid, sodium itaconate and combinations thereof. More preferably according to the invention, the polymer P is a homopolymer.

[0016] According to the invention, the polymer P can also be prepared using at least one other compound different from the compound M1. Then, the polymer P is prepared using a combination of compound M1 and another different compound. Preferably, the polymer P is then prepared using 0.5% by weight to 30% by weight of another compound relative to the total amount by weight of monomers.

[0017] Also preferably according to the invention, the polymer P can be prepared by means of another compound chosen from a compound M2 chosen from acrylic acid, methacrylic acid, an oligomer of acrylic acid, an oligomer of methacrylic acid, an acrylic acid salt, a salt of methacrylic acid, an oligomer salt of acrylic acid, a salt of oligomer of methacrylic acid, maleic acid, maleic anhydride, crotonic acid, 2-acrylamido-2-methylpropane sulfonic acid, a salt of 2-acrylamido-2-methylpropane sulfonic acid, ethoxymethacrylate sulfonic acid, sodium methallyl sulfonate, styrene sulfonate, phosphated hydroxyethylacrylate, phosphated hydroxyethylmethacrylate, phosphated hydroxypropylacrylate, phosphated hydroxypropylmethacrylate, hydroxybutylacrylate phosphated, hydroxybutyl methacrylate phosphated and combinations thereof.Preferably, compound M2 is selected from acrylic acid, methacrylic acid, an acrylic acid oligomer, a methacrylic acid oligomer, an acrylic acid salt, a methacrylic acid salt, an acrylic acid oligomer salt, a methacrylic acid oligomer salt, maleic acid, maleic anhydride, 2-acrylamido-2-methylpropane sulfonic acid, a 2-acrylamido-2-methylpropane sulfonic acid salt and combinations thereof.

[0018] Also preferably according to the invention, the polymer P can be prepared by means of another compound chosen from a compound M3 independently chosen from C1-C12 esters of methacrylic acid, C1-C12 esters of acrylic acid, acrylamide, styrene, t-Bu-acrylamide, alkylacrylamides, N-methylolacrylamide, acrylonitrile, vinyl-lactam, N-vinylpyrrolidone, ureidomethacrylate, hydroxyethylacrylate, hydroxyethylmethacrylate, hydroxypropylacrylate, hydroxypropylmethacrylate, hy- droxybutyl methacrylate, hydroxybutyl acrylate, caprolactone methacrylate, caprolactone acrylate, polycaprolactone methacrylate, polycaprolactone acrylate, lactam methacrylate, lactam acrylate, polycaprolactam methacrylate, polycaprolactam acrylate, vinyl acetate and combinations thereof; preferably Cr-C8 esters of methacrylic acid, Cr-C8 esters of acrylic acid and combinations thereof; preferably styrene, t-Bu-acrylamide, methylmethacrylate, ethylmethacrylate, propylmethacrylate, butylmethacrylate, methylacrylate, ethylacrylate, pro-pylacrylate, butylacrylate, more preferably, methylmethacrylate, methylacrylate, ethylacrylate, butylacrylate and combinations thereof. According to the invention, the preferred M3 compounds are chosen from t-Bu-acrylamide, ethylacrylate and combinations thereof.

[0019] Preferably according to the invention, the polymer P is not decarboxylated, in particular by the release of carbon dioxide. Also preferably according to the invention, the polymer P is prepared in the absence of a phosphorus compound, in particular in the absence of a compound comprising phosphorus I or in the absence of a compound comprising phosphorus III, in particular in the absence of hypophosphorous acid, a compound comprising hypophosphite, phosphorous acid or a compound comprising phosphite.

[0020] Essentially according to the invention, the polymer P is prepared in the presence of at least one sulfur compound T comprising sulfur in oxidation state IV (sulfur IV or SIV). Preferably according to the invention, the compound T is chosen from lithium hydrogen sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, ammonium hydrogen sulfite, calcium di(hydrogen sulfite), magnesium di(hydrogen sulfite) and combinations thereof. The preferred compound T is sodium hydrogen sulfite.

[0021] During the preparation of the polymer P according to the invention, the amount of compound T can vary. Preferably according to the invention, the compound T is used in an amount of 0.5% by weight to 15% by weight, preferably of 1% by weight to 10% by weight, more preferably of 1.5% by weight to 8% by weight, relative to the total amount by dry weight of monomers used during the polymerization reaction.

[0022] According to the invention, the polymerization reaction is preferably carried out at a temperature above 30°C and below 100°C, preferably below 90°C, more preferably below 80°C or 75°C.

[0023] Essentially according to the invention, the polymer P is prepared in the presence of at least one initiator compound. Preferably according to the invention, the initiator compound is chosen from a peroxide (for example hydrogen peroxide, tert-butyl hydroperoxide), a persulfate (for example sodium persulfate, persulfate ammonium, potassium persulfate), their combinations and their associations with a metal salt, preferably a metal salt chosen from an iron salt (for example Fe11 or Fe111), a copper salt (for example Cu1 or Cu11) and their combinations.

[0024] The preferred initiator compound is chosen from a peroxide, in particular hydrogen peroxide, tert-butyl hydroperoxide and their combinations and their associations with a metal salt, preferably a metal salt chosen from an iron salt (for example Fe11 or Fe111), a copper salt (for example Cu1 or Cu11) and their combinations.

[0025] Preferably, during the polymerization reaction according to the invention, the compound M1 is used in a particular manner in order to obtain the polymer P. In a particularly preferred manner, during the preparation of the composition C according to the invention, the compound M1 is present during the polymerization reaction in an amount by weight greater than 30%, much more preferably greater than 35% or 40%, relative to all the compounds present in the reaction medium. More preferably, according to the invention, the compound M1 is present during the polymerization reaction in an amount by weight greater than 45% or 50%, relative to all the compounds present in the reaction medium.

[0026] The preparation of composition C according to the invention comprises several steps. In particular, the preparation of composition C according to the invention comprises a step of preparing the reaction medium which comprises compound M1, in particular the preparation of the bottom of the tank when a radical polymerization reactor is used. Preferably according to the invention, the reactor is chosen from a tubular reactor and a stirred tank. The preparation method also comprises a step of introducing the initiator compound and a step of introducing compound T and heating the reaction medium.

[0027] During the different stages, the presence and quantities of the different compounds may vary. Preferably, during the preparation of composition C according to the invention, the polymerization reaction comprises: - the preparation of a reaction medium comprising at least one compound Ml in an amount by weight greater than 35%, preferably greater than 50% or 60%, more preferably greater than 65% or 70%, relative to all the reagents of this reaction medium, then - the addition of the initiator compound, of the compound T, and possibly of the compound Ml and - heating the reaction medium.

[0028] The polymer P according to the invention is prepared according to particular reaction conditions which make it possible to obtain a composition C with particularly advantageous properties, in particular to obtain a composition C comprising a limited quantity of oligomers of compound M1 or oligomers of compound M1 and at least a compound M2 or M3. Preferably according to the invention, the composition C according to the invention comprises small quantities of such oligomers whose molecular mass Mw, measured by CES, is less than 1,000 g / mol.

[0029] More preferably according to the invention, composition C comprises less than 30% by weight, preferably less than 25% by weight or less than 20% by weight, of oligomers of compound Ml having a molecular mass Mw, measured by CES, of less than 1000 g / mol relative to the quantity of polymer P.

[0030] Also more preferably according to the invention, composition C comprises less than 30% by weight, preferably less than 25% by weight or less than 20% by weight, of oligomers of compound M1 and of at least one compound M2 or M3, and having a molecular mass Mw, measured by CES, of less than 1000 g / mol relative to the quantity of polymer P.

[0031] The invention also relates to the method for preparing composition C according to the invention. Preferably, the method for preparing a composition C according to the invention comprises: - the preparation of a reaction medium comprising at least one compound Ml in an amount by weight greater than 35%, preferably greater than 50% or 60%, more preferably greater than 65% or 70%, relative to all the reagents of the reaction medium, then - the addition of the initiator compound, of the compound T, and possibly of the compound Ml and - heating the reaction medium.

[0032] The preparation method according to the invention is particularly effective for the preparation of a water-soluble sulfonated polymer P. In particular, this preparation method makes it possible to obtain a composition C in which the quantities of residual monomers, in particular of residual monomer M1, are low. According to the invention, the quantities of residual monomers are measured at the end of the polymerization reaction by high-performance liquid chromatography (HPLC) and expressed in % by weight (dry / dry) relative to the quantity of reagents used during the polymerization reaction.Preferably according to the invention, the aqueous composition C comprises less than 5% by weight, more preferably less than 3% by weight or less than 2% by weight, more preferably less than 1.5% by weight or less than 1% by weight, measured by HPLC, of residual monomers, preferably of monomer M1 and optionally of monomers M2 and M3, relative to the quantity of reagents used during the polymerization reaction.

[0033] The preparation method according to the invention makes it possible to obtain a composition C which has particularly interesting properties in different fields. Thus, the invention also provides a dispersing or grinding agent comprising at at least one composition C according to the invention. The dispersing or grinding agent according to the invention may also comprise at least one liquid or solid support or at least one additive.

[0034] The advantageous, particular or preferred characteristics of composition C according to the invention define methods of preparation and dispersing or grinding agents which are also advantageous, particular or preferred.

[0035] The various aspects of the invention can be illustrated by examples.

[0036] EXAMPLES

[0037] Preparation of a composition Cl according to the invention comprising the polymer PI

[0038] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, 127.38 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 97°C + / - 2°C and then 0.04 g of iron sulfate heptahydrate and 10 g of deionized water are introduced.

[0039] In a first beaker, 27.3 g of hydrogen peroxide in a 35% mass solution and 27 g of deionized water are weighed. In a second beaker, 25 g of sodium bisulfite in an aqueous solution at 40% mass are weighed.

[0040] The reagents from the 2 beakers are introduced in parallel into the reactor for 2 hours and the temperature is maintained at 97°C+ / -2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C1 is obtained, comprising the copolymer PI according to the invention at 50.6% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0041] Preparation of a composition C2 according to the invention comprising the polymer P2

[0042] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, 127.39 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 97°C + / -2°C and then 0.04 g of iron sulfate heptahydrate and 10 g of deionized water are introduced.

[0043] In a first beaker, 40.95 g of hydrogen peroxide in solution at 35% by mass and 27 g of deionized water are weighed. In a second beaker, 25 g of sodium bisulfite in aqueous solution at 40% by mass are weighed.

[0044] The reagents from the 2 beakers are introduced in parallel into the reactor for 2 hours and the temperature is maintained at 97°C + / - 2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C2 is obtained comprising the copolymer P2 according to the invention at 50.2% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0045] Preparation of a composition C3 according to the invention comprising the polymer P3

[0046] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, 127.39 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 97°C + / -2°C and then 0.04 g of iron sulfate heptahydrate and 10 g of deionized water.

[0047] In a first beaker, 40.95 g of hydrogen peroxide in solution at 35% by mass and 27 g of deionized water are weighed. In a second beaker, 15 g of sodium bisulfite in aqueous solution at 40% by mass are weighed.

[0048] The reagents from the 2 beakers are introduced in parallel into the reactor for 2 hours and the temperature is maintained at 97°C + / - 2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C3 is obtained comprising the copolymer P3 according to the invention at 50.4% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0049] Preparation of a composition C4 according to the invention comprising the polymer P4

[0050] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, and 127.39 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 90°C + / -2°C.

[0051] In a first beaker, 27.3 g of hydrogen peroxide in a 35% mass solution and 27 g of deionized water are weighed. In a second beaker, 25 g of sodium bisulfite in an aqueous solution at 40% mass are weighed.

[0052] The reagents from the 2 beakers are introduced in parallel into the reactor for 2 hours and the temperature is maintained at 90°C+ / -2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C4 is obtained comprising the copolymer P4 according to the invention at 51.5% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0053] Preparation of a composition C5 according to the invention comprising the polymer P5

[0054] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, 127.38 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 90°C + / -2°C and then 0.02 g of iron sulfate heptahydrate and 10 g of deionized water are introduced.

[0055] In a first beaker, 27.3 g of hydrogen peroxide in a 35% mass solution and 27 g of deionized water are weighed. In a second beaker, 25 g of sodium bisulfite in an aqueous solution at 40% mass are weighed.

[0056] The reagents from the 2 beakers are introduced in parallel into the reactor for 2 hours and the temperature is maintained at 90°C+ / -2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C5 is obtained comprising the copolymer P5 according to the invention at 50.6% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0057] Preparation of a composition C6 according to the invention comprising the polymer P6

[0058] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, and 127.38 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 90°C + / -2°C.

[0059] In a first beaker, 10.35 g of sodium persulfate and 27 g of deionized water are weighed. In a second beaker, 25 g of sodium bisulfite in aqueous solution at 40% by mass are weighed.

[0060] The reagents from the 2 beakers are introduced in parallel into the reactor for 2 hours and the temperature is maintained at 90°C+ / -2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C6 is obtained comprising the copolymer P6 according to the invention at 53.2% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0061] Preparation of a composition C7 according to the invention comprising the polymer P7

[0062] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, 127.39 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 97°C + / -2°C and then 0.0159 g of iron sulfate heptahydrate, 0.0186 g of copper sulfate pentahydrate and 10 g of deionized water are introduced.

[0063] In a first beaker, 27.3 g of hydrogen peroxide in a 35% mass solution and 27 g of deionized water are weighed. In a second beaker, 25 g of sodium bisulfite in an aqueous solution at 40% mass are weighed.

[0064] The reagents from the 2 beakers are introduced into the reactor for 2 hours and the temperature is maintained at 97°C + / - 2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C7 is obtained comprising the copolymer P7 according to the invention at 53.1% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0065] Preparation of a composition C8 according to the invention comprising the polymer P8

[0066] 207 g of itaconic acid (compound Ml) are introduced into a glass reactor, 127.38 g of a 50% by mass aqueous sodium hydroxide solution are added. The reaction is exothermic, the reactor temperature is maintained at 97°C + / -2°C and then 0.02 g of iron sulfate heptahydrate and 10 g of deionized water are introduced.

[0067] In a first beaker, 27.3 g of hydrogen peroxide in a 35% mass solution and 27 g of deionized water are weighed. In a second beaker, 25 g of sodium bisulfite in an aqueous solution at 40% mass are weighed.

[0068] The reagents from the 2 beakers are introduced in parallel into the reactor for 2 hours and the temperature is maintained at 97°C + / - 2°C. Then, 150 g of deionized water are added and the medium is allowed to cool to room temperature. Composition C8 is obtained comprising the copolymer P8 according to the invention at 50.6% by weight of dry extract, the composition and characteristics of which are detailed in Table 1.

[0069] [Tab 1] PI ri P 3 W P5 P6 P7 PS Residual Ml (%) 0.023 0.005 0.008 0.038 0.037 0.620 0.013 0.036 Mw (g / mol) 4,260 3,730 3,845 12,545 6,395 12,255 2 400 5 155 Ip 2.4 T'y O 5.2 2.9 5.4 1.9 ? s Oligomers (%) 15.3 15.9 15.1 11.5 P 1 LS 24.1 13.3

[0070] The invention makes it possible to obtain, in a particularly efficient manner and with very good conversion rates, compositions C of polymers P of itaconic acid which comprise very small quantities of residual monomers or unwanted oligomers.

Claims

Claims

1. Aqueous polymeric composition C comprising at least one water-soluble sulfonated polymer P, of molecular mass Mw, measured by CES, ranging from 1,500 g / mol to 50,000 g / mol and prepared by a radical polymerization reaction in water of at least one compound Ml chosen from itaconic anhydride, itaconic acid, sodium itaconate, potassium itaconate, lithium itaconate, ammonium itaconate, calcium itaconate, magnesium itaconate and combinations thereof, in the presence of at least one initiator compound and at least one sulfur compound T comprising sulfur in oxidation state IV (sulfur IV or S

2. h Composition C according to claim 1 for which the polymer P has a molecular mass Mw, measured by CES, ranging from 2,000 g / mol to 50,000 g / mol or from 1,500 g / mol to 40,000 g / mol, preferably from 2,000 g / mol to 25,000 g / mol or from 1,500 g / mol to 20,000 g / mol, more preferably from 2,000 g / mol to 20,000 g / mol, even more preferably from 2,000 g / mol to 15,000 g / mol, much more preferably from 3,000 g / mol to 13,000 g / mol or from 2,500 g / mol to 15,000 g / mol, particularly preferably from 3,500 g / mol to 20,000 g / mol. 000 g / mol or from 3,000 g / mol to 15,000 g / mol, most preferably from 3,500 g / mol to 15,000 g / mol or from 3,500 g / mol to 13,000 g / mol, and much more preferably from 3,500 g / mol to 10,000 g / mol or from 3,500 g / mol to 8,000 g / mol or from 3,500 g / mol to 6,500 g / mol or from 3,500 g / mol to 5,500 g / mol.

3. Composition C according to one of claims 1 or 2 for which: - the polymer P has a polymolecularity index (Ip), measured by CES, of less than 5.5, preferably less than 4.5 or less than 4, more preferably less than 3; or - the polymer P has a polymolecularity index, measured by CES, ranging from 1.6 to 5.5, preferably ranging from 1.6 to 4.5 or ranging from 1.6 to 4, more preferably ranging from 1.6 to 3; or - the polymer P is totally or partially neutralized, preferably by means of an ion chosen from a monovalent ion, a divalent ion and their combinations, more preferably by means of an ion chosen from K+, Na+, Li+, NH4+, Mg2+, Ca2+ and their combinations; also preferably, the polymer P is totally or partially neutralized by means of at least one compound chosen from LiOH, NaOH,

4. KOH, Zn(OH)2, Mg(OH)2, Ca(OH)2, ZnO, MgO, CaO, ammonium derivatives, ammonia, aqueous ammonia, amine bases, for example triethanolamine, aminomethylpropanol or 2-amino-2-methylpropanol (AMP), and combinations thereof, more preferably NaOH, Ca(OH)2, CaO and combinations thereof. Composition C according to one of claims 1 to 3 for which: - the polymer P is also prepared using at least one other compound different from the compound M1, preferably from 0.5% by weight to 30% by weight of another compound relative to the total quantity by weight of monomers; or - the polymer P is also prepared using another compound chosen from: * a compound M2 selected from acrylic acid, methacrylic acid, an acrylic acid oligomer, a methacrylic acid oligomer, an acrylic acid salt, a methacrylic acid salt, an acrylic acid oligomer salt, a methacrylic acid oligomer salt, maleic acid, maleic anhydride, crotonic acid, 2-acrylamido-2-methylpropane sulfonic acid, a 2-acrylamido-2-methylpropane sulfonic acid salt, ethoxymethacrylate sulfonic acid, sodium methallyl sulfonate, styrene sulfonate, phosphated hydroxyethylacrylate, phosphated hydroxyethylmethacrylate, phosphated hydroxypropylacrylate, phosphated hydroxypropylmethacrylate, phosphated hydroxybutylacrylate, phosphated hydroxybutylmethacrylate and combinations thereof; or * a compound M3 independently selected from CrCi2 esters of methacrylic acid, CrCi2 esters of acrylic acid, acrylamide, styrene, t-Bu-acrylamide, alkylacrylamides, N-methylolacrylamide, acrylonitrile, vinyl lactam, N-vinylpyrrolidone, ureidomethacrylate, hydroxyethylacrylate, hydroxyethylmethacrylate, hydroxypropylacrylate, hydroxypropylmethacrylate, hydroxybutylmethacrylate, hydroxybutylacrylate, caprolactone methacrylate, caprolactone acrylate, polycaprolactone methacrylate, polyca-prolactone acrylate, lactam methacrylate, lactam acrylate, polycaprolactam methacrylate, polycaprolactam acrylate, vinyl acetate and combinations thereof; preferably CrC8 esters of methacrylic acid, CrC8 esters of acrylic acid and combinations thereof; preferably styrene, t-Bu-acrylamide, methylmethacrylate, ethylmethacrylate, propylmethacrylate, butylmethacrylate, methylacrylate, ethyl- acrylate, propylacrylate, butylacrylate, more preferably, methyl methacrylate, methylacrylate, ethylacrylate, butylacrylate and combinations thereof.

5. Composition C according to one of claims 1 to 4 for which: - the compound T is chosen from lithium hydrogen sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, ammonium hydrogen sulfite, calcium di(hydrogen sulfite), magnesium di(hydrogen sulfite) and combinations thereof; or - the initiator compound is chosen from a peroxide (for example hydrogen peroxide, tert-butyl hydroperoxide), a persulfate (for example sodium persulfate, ammonium persulfate, potassium persulfate), combinations thereof and associations thereof with a metal salt, preferably a metal salt chosen from an iron salt (for example Fe11 or Fe111), a copper salt (for example Cu1 or Cu11) and combinations thereof;or - compound T is used in an amount of 0.5% by weight to 15% by weight, preferably 1% by weight to 10% by weight, more preferably 1.5% by weight to 8% by weight, relative to the total dry weight amount of monomers used during the polymerization reaction.;

6. Composition C according to one of claims 1 to 5 for which: - the compound Ml is present during the polymerization reaction in an amount by weight greater than 30%, preferably greater than 35% or 40%, more preferably greater than 45% or 50%, relative to all the compounds present in the reaction medium; or for which: - the polymerization reaction comprises: * the preparation of a reaction medium comprising at least one compound Ml in an amount by weight greater than 35%, preferably greater than 50% or 60%, more preferably greater than 65% or 70%, relative to all the reactants of this reaction medium, then * the addition of the initiator compound, of the compound T, and optionally of the compound Ml and * the heating of the reaction medium.

7. Composition C according to one of claims 1 to 6 comprising: - less than 5% by weight, preferably less than 3% by weight or less than 2% by weight, more preferably less than 1.5% by weight or less than 1% by weight, measured by HPLC, of residual monomers, preferably monomer M1 and optionally monomers M2 and M3, relative to the quantity of reagents used during the polymerization reaction; or comprising: - less than 30% by weight, preferably less than 25% by weight or less than 20% by weight, of oligomers of compound Ml having a molecular mass Mw, measured by CES, of less than 1000 g / mol relative to the quantity of polymer P; or comprising: - less than 30% by weight, preferably less than 25% by weight or less than 20% by weight, of oligomers of compound Ml and of at least one compound M2 or M3, and having a molecular mass Mw, measured by CES, less than 1000 g / mol relative to the quantity of polymer P.

8. Method for preparing a composition C according to one of claims 1 to 7 comprising: - the preparation of a reaction medium comprising at least one compound Ml in an amount by weight greater than 35%, preferably greater than 50% or 60%, more preferably greater than 65% or 70%, relative to all the reagents of the reaction medium, then - the addition of the initiator compound, of the compound T, and possibly of the compound Ml and - heating the reaction medium.

9. Dispersing or grinding agent comprising at least one composition C according to one of claims 1 to 7.