VOC-FREE URETHANE COPOLYMER

Abstract

The invention relates to a method for preparing a urethane copolymer using a polyalkoxylated and polyhydroxylated compound that does not contain volatile residues of alkanes, aromatic hydrocarbons, or alkenes. The copolymer according to the invention is useful as a rheology control agent in aqueous media, particularly for paint compositions, paper coating slurries, or cosmetic compositions.

Description

Title of the invention: VOC-FREE URETHANE COPOLYMER

[0001] The invention relates to a method for preparing a urethane copolymer using a polyalkoxylated and polyhydroxylated compound that does not contain volatile residues of alkanes, volatile residues of aromatic hydrocarbon compounds, or volatile residues of alkenes. The copolymer according to the invention is useful as a rheology control agent in aqueous media, particularly for paint compositions, paper coating slurries, or cosmetic compositions.

[0002] Generally, for aqueous coating compositions, and particularly for aqueous paint or varnish compositions, it is necessary to control the viscosity at both low and medium shear rates as well as at high shear rates. Indeed, during its preparation, storage, application, or drying, a paint formulation is subjected to numerous stresses requiring particularly complex rheological properties. A high viscosity of the paint formulation must be achieved at high shear rates. A lower viscosity at low and medium shear rates will also result in a good, smooth finish after application. Furthermore, to prevent runs, the paint formulation must have a high viscosity at low and medium shear rates.For the paint to have significant leveling capacity after being deposited on a surface, a reduced viscosity at low and medium shear gradients is required for the paint formulation.

[0003] Furthermore, when preparing paper coating slurries, it is also necessary to improve viscosity under low shear gradients, while simultaneously improving water retention within the aqueous composition used. These compositions must have viscosities under different shear gradients that allow them to be used effectively, particularly when applied to the surface of a sheet of paper. These compositions must have an apparent viscosity, therefore under low shear gradients, that is well-suited to efficient application.

[0004] Also, during the preparation of aqueous cosmetic compositions, rheological control is an essential property. Indeed, the viscosity of these cosmetic compositions must be controlled during their preparation, transport, and storage, but also during their application. The use of these aqueous cosmetic compositions, particularly on the skin or hair, often requires very specific rheological properties as well as a from a safety perspective.

[0005] The compatibility of the various constituents of an aqueous composition with controlled rheology is also an important property, as is the presence in small quantities, or even the absence, of certain harmful or prohibited compounds within these compositions. In particular, these aqueous compositions, or the compounds used in their preparation, should not contain volatile organic compounds, especially alkanes, aromatic hydrocarbons, or alkenes. These compounds should not be present in the ingredients used for the preparation of paint or varnish compositions or used in the preparation of paper coating slurries. In particular, rheological control agents, as well as the compounds used in their preparation, should contain only negligible or zero amounts of residual alkanes, residual aromatic hydrocarbons, or residual alkenes.In particular, the presence of such compounds must be strictly controlled to prevent their release during the preparation of paint or varnish compositions, or during the manufacture of paper or packaging, and especially during the manufacture of paper or packaging for food products.

[0006] Monitoring for the possible presence of such compounds is therefore essential to ensure the final quality of the aqueous compositions used. This monitoring should therefore be effective while also being easily achievable using widely available techniques.

[0007] There is therefore a need for a method of preparing rheological control agents which makes it possible to provide a solution to all or part of the problems encountered during the preparation of known copolymers.

[0008] The invention therefore provides a method for preparing a copolymer P comprising the polymerization reaction: a) of at least one isocyanate compound (a) chosen independently from a diisocyanate compound (a1), a polyisocyanate compound (a2) and their combinations; b) of at least one compound (b) of formula I: [chem I] HO-R in which R independently represents a group chosen from a linear C4-C40-alkyl group, a branched C4-C40-alkyl group, a C5-C40-cycloalkyl group, a C5-C40-aryl group and their combinations; (c) of at least one polyalkoxylated polyhydroxylated compound comprising an amount of at least one compound selected from alkanes, aromatic hydrocarbon compounds, alkenes and their combinations, measured by GC-MS, which is less than 0.5 ppm in compound weight (c).

[0009] The method according to the invention comprises the use of compound (a) in the polymerization reaction. Preferably, the polymerization reaction uses a single compound (a) or two or three different compounds (a). More preferably, the polymerization reaction uses a single compound (a).

[0010] Preferably according to the invention, compound (a) is a diisocyanate compound (al) is selected from: - symmetrical aromatic diisocyanate compounds, preferably: . 2,2'-diphenylmethylene diisocyanate (2,2'-MDI) and 4,4'-diphenylmethylene diisocyanate (4,4'-MDI); . 4,4'-dibenzyl diisocyanate (4,4'-DBDI); . toluene 2,6-diisocyanate (2,6-TDI); . m-xylylene diisocyanate (m-XDI); - symmetrical alicyclic diisocyanate compounds, preferably methylene bis(4-cyclohexylisocyanate) (H12MDI); - symmetrical aliphatic diisocyanate compounds, preferably hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI); - preferably dissymmetric aromatic diisocyanate compounds: . 2,4'-diphenylmethylene diisocyanate (2,4'-MDI); . 2,4'-dibenzyl diisocyanate (2,4'-DBDI); . toluene 2,4-diisocyanate (2,4-TDI); - dissymmetric alicyclic diisocyanate compounds, preferably isophorone diisocyanate (IPDI).

[0011] More preferably according to the invention, the compound (al) is chosen from IPDI, HDI, Hi2MDI and their combinations.

[0012] Also preferably according to the invention, the compound (a) is a polyisocyanate compound (a2) comprising strictly more than 2 isocyanate functions or more than 2.2 isocyanate functions or even more than 2.5 isocyanate functions. More preferably, the polyisocyanate compound (a2) comprises more than 2.6 isocyanate functions or more than 2.7 isocyanate functions or more than 3 isocyanate functions; more preferably, the polyisocyanate compound (a2) comprises from 2.2 to 6 isocyanate functions, from 2.2 to 4 isocyanate functions, from 2.2 to 3.5 isocyanate functions, from 2.5 to 6 isocyanate functions, from 2.2 to 5 isocyanate functions, from 2.5 to 4 isocyanate functions, from 2.5 to 3.5 isocyanate functions, in particular from 2.6 to 3.3 isocyanate functions.

[0013] Also preferably according to the invention, compound (a) is a polyisocyanate (a2) selected from: . triphenylmethane-4,4',4”-triisocyanate or l,r,l”-methylidynetris (4-isocyanatobenzene); Or * an isocyanurate compound, in particular an isocyanurate compound of a compound selected from: * Symmetrical aromatic diisocyanate compounds, preferably: . 2,2'-diphenylmethylene diisocyanate (2,2'-MDI) and 4,4'-diphenylmethylene diisocyanate (4,4'-MDI); . 4,4'-dibenzyl diisocyanate (4,4'-DBDI); . toluene 2,6-diisocyanate (2,6-TDI); . m-xylylene diisocyanate (m-XDI); * symmetrical alicyclic diisocyanate compounds, preferably methylene bis(4-cyclohexylisocyanate) (Hi2MDI); * symmetrical aliphatic diisocyanate compounds, preferably hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI); * asymmetrical aromatic diisocyanate compounds, preferably: . 2,4'-diphenylmethylene diisocyanate (2,4'-MDI); . 2,4'-dibenzyl diisocyanate (2,4'-DBDI); . toluene 2,4-diisocyanate (2,4-TDI); . a biurea trimer, in particular a biurea trimer of a compound selected from: * Symmetrical aromatic diisocyanate compounds, preferably: . 2,2'-diphenylmethylene diisocyanate (2,2'-MDI) and 4,4'-diphenylmethylene diisocyanate (4,4'-MDI); . 4,4'-dibenzyl diisocyanate (4,4'-DBDI); . toluene 2,6-diisocyanate (2,6-TDI); . m-xylylene diisocyanate (m-XDI); * symmetrical alicyclic diisocyanate compounds, preferably methylene bis(4-cyclohexylisocyanate) (Hi2MDI); * symmetrical aliphatic diisocyanate compounds, preferably hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI); * asymmetrical aromatic diisocyanate compounds, preferably: . 2,4'-diphenylmethylene diisocyanate (2,4'-MDI); . 2,4'-dibenzyl diisocyanate (2,4'-DBDI); . toluene 2,4-diisocyanate (2,4-TDI); * dissymmetric alicyclic diisocyanate compounds, preferably isophorone diisocyanate (IPDI).

[0014] More preferably, compound (a2) is chosen from triphenylmethane- 4,4',4”-triisocyanate, l,l',l”-methylidynetris (4-isocyanatobenzene), an isocyanurate of HDI, an isocyanurate of IPDI, an isocyanurate of PDI, a trimer of HDI biurea and a trimer of IPDI biurea, a trimer of PDI biurea.

[0015] Preferably according to the invention, compound (b) is a compound of formula I in which R independently represents a group selected from a linear C4-C40-alkyl group, a branched C4-C40-alkyl group, a C5-C40-cycloalkyl group, a C5-C40-aryl group and combinations thereof.

[0016] Preferably according to the invention, compound (b) is a compound of formula I in which R independently represents a linear C4-C36-alkyl group, a branched C4-C36-alkyl group or a C5-C36-aryl group; preferably a linear C6-C36-alkyl group, a branched C6-C36-alkyl group or a C6-C36-aryl group; more preferably a linear C6-C24-alkyl group, a branched C6-C24-alkyl group or a C6-C24-aryl group.

[0017] Preferably according to the invention, compound (c) is a compound (cl) of formula II: [Chem II] HO-U-OH in which: - L independently represents an oxyalkylene residue; - n independently represents a number ranging from 30 to 1000.

[0018] Preferably according to the invention, compound (c) is a compound (cl) of formula II in which L independently represents an oxyethylene residue or in which n independently represents a number from 50 to 400, preferably from 100 to 300.

[0019] More preferably according to the invention, compound (c) is a compound (cl) of formula II in which L independently represents an oxyethylene residue and n independently represents a number from 50 to 400, preferably from 100 to 300.

[0020] The compound (c1) can be used alone or it can be combined with one or more other compounds. In this case, the compound (c1) of formula II can be combined with a non-alkoxy compound (c2) comprising at least three hydroxyl groups. Preferably according to the invention, the compound (c2) comprises three hydroxyl groups; more preferably, the compound (c2) is selected from glycerol, pentaerythritol, and combinations thereof.

[0021] According to the invention, compound (c) can also be associated with a poly-alkoxylated compound (c3) comprising at least three hydroxyl groups. According to the invention, the poly-alkoxylated compound (c3) is different from compound (c2).

[0022] Preferably according to the invention, the polyalkoxylated compound (c3) is polyethoxylated pentaerythritol or comprises three hydroxyl groups, in a manner The most preferred compound (c3) is polyethoxylated glycerol.

[0023] The method according to the invention can implement one or more combinations of the compounds (cl), (c2) and (c3).

[0024] Essentially, according to the invention, the polyhydroxylated compound (c) is poly-alkoxylated. It therefore comprises alkoxylated groups. Preferably, the method according to the invention uses a compound (c) comprising from 10 to 150 alkoxylations, more preferably from 20 to 100 alkoxylations or from 10 to 70 alkoxylations. More preferably, the compound (c) comprises from 20 to 60 alkoxylations.

[0025] Preferably, the method according to the invention also employs a compound (c) that is polyethoxylated, or that is polyethoxylated-polypropoxylated, or that is polyethoxylated-polybutoxylated. More preferably, compound (c) is polyethoxylated.

[0026] In a particularly preferred manner, compound (c) comprises from 10 to 150 ethoxylations, more preferably from 20 to 100 ethoxylations or from 10 to 70 ethoxylations. Much more preferably, compound (c) comprises from 20 to 60 ethoxylations.

[0027] The preparation method according to the invention can utilize polyalkoxylated compounds (c), (cl), and (c3) whose molar mass (Mw) measured by CES can vary significantly. Preferably according to the invention, compounds (c), (cl), or (c3) independently have a molar mass (Mw) measured by CES ranging from 1,500 to 40,000 g / mol, preferably from 2,000 to 20,000 g / mol. More preferably according to the invention, the molar mass (Mw) of compounds (c), (cl), or (c3) independently ranges from 2,000 to 15,000 g / mol or from 2,000 to 12,000 g / mol.

[0028] According to the invention, the molar mass of compounds (c), (cl), or (c3) is determined by Size Exclusion Chromatography (SEC), also known as Gel Permeation Chromatography (GPC). This technique employs a Waters liquid chromatography system equipped with a detector. This detector is a Waters 2414 type refractometric concentration detector. This liquid chromatography system is equipped with two size exclusion columns to separate the different molecular weights of the polymers or compounds studied. The elution liquid phase is an organic phase composed of THF (HPLC grade, unstabilized).

[0029] In a first step, approximately 25 mg of the compound is solubilized in 5 mL of THF, to which 0.1 mol% water is added as an internal flow marker. The solution is then filtered to 0.2 µm. 50 pL is then injected into the chromatography apparatus (eluent: THF, HPLC grade, unstabilized).

[0030] The liquid chromatography apparatus contains an isocratic pump (“Waters” 515) with a flow rate set at 0.3 mL / min. The chromatography apparatus includes The furnace also includes a series column system: a 250 mm long, 4.6 mm diameter Agilent PLgel MiniMIX-A column followed by a 250 mm long, 4.6 mm diameter Agilent PLgel MiniMIX-B column. The detection system consists of a Waters 2414 RI refractometer. The columns are maintained at 35°C and the refractometer is also heated to 35°C.

[0031] The chromatography apparatus is calibrated using polymethyl methacrylate standards certified by the supplier "Agilent" ("EasiVial" PMMA).

[0032] According to the invention, the compound (c) can be used in various liquid or solid forms, preferably solid at a temperature above 25°C. In solid form, the compound (c) can take various forms, for example in a form selected from pellet, flake, crushed, chip, powder and combinations thereof.

[0033] Essentially, according to the invention, compound (c) has a very high degree of purity, particularly with regard to the presence of volatile organic compounds, notably residual volatile organic compounds from the processes used in its preparation. Thus, compound (c) produced according to the invention comprises zero or a particularly low amount of alkanes, aromatic hydrocarbon compounds, or alkenes.

[0034] According to the invention, the quantities of residual compounds are measured using widely available and easy-to-implement techniques. In fact, particularly advantageously according to the invention, the quantities of residual compounds are measured by gas chromatography coupled with mass spectrometry (GC-MS). The chromatograph used is equipped with a mass spectrometer as a detector. According to the invention, the GC-MS measurement comprises injecting the compound (c) to be analyzed into the chromatograph at a controlled temperature, then separating the different volatile compounds using a capillary column, followed by detecting any residual volatile compounds using a mass spectrometer and performing analytical processing of the detection peaks.

[0035] Thus, the compound (c) implemented according to the invention comprises an amount of at least one compound selected from alkanes, aromatic hydrocarbon compounds, alkenes and their combinations, measured by GC-MS, which is less than 0.5 ppm by weight of compound (c).

[0036] Preferably according to the invention, compound (c) comprises an amount of alkanes that is less than 0.5 ppm by weight of compound (c). Also preferably according to the invention, compound (c) comprises an amount of aromatic hydrocarbon compounds that is less than 0.5 ppm by weight of compound (c). Also preferably according to the invention, compound (c) comprises an amount of alkenes that is less than 0.5 ppm by weight of compound (c).

[0037] More preferably according to the invention, the compound (c) comprises an amount of alkanes less than 0.2 ppm by weight, preferably an amount less than 0.1 ppm by weight or even zero, measured by GC-MS.

[0038] Preferably, the alkanes according to the invention are chosen from among the C3-C2o-alkanes, in particular the C7-Ci4-alkanes.

[0039] Also more preferably according to the invention, the compound (c) comprises an amount of aromatic hydrocarbon compounds less than 0.2 ppm by weight, preferably an amount less than 0.1 ppm by weight or even zero, measured by GC-MS.

[0040] Also preferably, the aromatic hydrocarbon compounds according to the invention are chosen from toluene, benzene, xylene, naphthalene and their combinations.

[0041] Also more preferably according to the invention, the compound (c) comprises

[0042] an amount of alkenes less than 0.2 ppm by weight, preferably an amount less than 0.1 ppm by weight or even zero, measured by GC-MS.

[0043] Also preferably, the alkenes according to the invention are chosen from among the C7-Cu-alkenes and their combinations.

[0044] In a particularly preferred manner according to the invention, compound (c) therefore comprises no alkane or no aromatic hydrocarbon compound or no alkene. More preferably according to the invention, compound (c) comprises neither alkane, nor aromatic hydrocarbon compound, nor alkene.

[0045] According to the invention, a zero quantity of a compound, in particular a compound selected from alkanes, aromatic hydrocarbon compounds, or alkenes, characterizes both the total absence of that compound and its presence in an analytically insignificant quantity. The limits of quantification generally accepted by analytical techniques for this compound therefore characterize its absence within compound (c) implemented according to the invention.

[0046] During the preparation of the copolymer P according to the invention, the amounts of compounds (a), (b), and (c) may vary. Preferably, the method according to the invention comprises a polymerization reaction that uses 20 to 74.9 mol%, preferably 25 to 60 mol%, of compound (a) relative to the total mol% of compounds (a), (b), and (c). Also preferably, the method according to the invention comprises a polymerization reaction that uses 25 to 79.9 mol%, preferably 35 to 70 mol, of compound (b) relative to the total mol% of compounds (a), (b), and (c). Also preferably, the method according to the invention comprises a polymerization reaction which employs 0.1 to 55 mol%, preferably 5 to 40 mol%, of compound (c) relative to the total mol amount of compounds (a), (b) and (c).

[0047] Preferably, the method according to the invention comprises a polymerization reaction which implements: - from 20 to 74.9 mol% or from 25 to 60 mol% of compound (a) or - from 25 to 79.9 mol% or from 35 to 70 mol% of compound (b), or - from 0.1 to 55 mol% or from 5 to 40 mol% of compound (c), relative to the total molar amount of compounds (a), (b) and (c).

[0048] More preferably, the method according to the invention comprises a polymerization reaction which implements: - 20 to 74.9 mol%, preferably 25 to 60 mol%, of compound (a), - 25 to 79.9 mol%, preferably 35 to 70 mol%, of compound (b), and - 0.1 to 55 mol%, preferably 5 to 40 mol%, of compound (c), relative to the total molar amount of compounds (a), (b) and (c).

[0049] In addition to compounds (a), (b) and (c), the preparation method according to the invention also includes the possibility of using other compounds during the polymerization reaction.

[0050] Thus, the preparation method according to the invention may also include a polymerization reaction which also employs at least one hydrophobic compound (d) of formula III: [Chem III] R^OEVCOPVOH in which: - q and r, whether identical or different, independently represent 0 or an integer or decimal number less than 150; q is not equal to 0. - OE independently represents a CH2CH2O group, - OP independently represents a group chosen from CH(CH3)CH2O and CH2 CH(CH3)O, - R1 represents an independently chosen group from a linear C4-C 4o-alkyl group, a branched C4-C40-alkyl group, a C5-C40-cycloalkyl group, a C5-C40-aryl group and their combinations.

[0051] The invention also relates to a method of preparing a Pc copolymer comprising the polymerization reaction of at least one compound (a), at least one compound (b) and at least one compound (d).

[0052] Preferably according to the invention, compound (d) is a compound of formula III in which: - r represents 0; or - R1 represents a linear or branched C6-C40-alkyl group, a phenyl group, a polyphenyl group, preferably a C10-C30-alkyl group, linear or branched, more preferably a Ci2-C22-alkyl group, linear or branched, or a group comprising 2 to 5 phenyls or a tristyrylphenyl group or a pentastyrylcumylphenyl group.

[0053] Also preferably according to the invention, the polymerization reaction uses less than 20 mol%, preferably from 0.05 to 20 mol%, in particular from 0.1 to 10 mol%, of compound (d) relative to the total mol amount of monomers.

[0054] The preparation method according to the invention makes it possible to obtain the copolymer P. During the preparation of this copolymer, the compound (c) used comprises a small or zero amount of alkanes, aromatic hydrocarbon compounds, or alkenes. Prior to the polymerization reaction, the invention makes it possible to select the compound (c) based on the amount of alkanes, aromatic hydrocarbon compounds, or alkenes that it may contain. Thus, the invention provides a method for preparing a copolymer P according to the invention which also includes the prior selection, prior to the polymerization reaction, of the polyhydroxylated compound (c) comprising measuring by GC-MS the amount Q of at least one compound selected from alkanes, aromatic hydrocarbon compounds, alkenes, and their combinations, and then: - the implementation of compound (c) if the quantity Q is zero or - the elimination of compound (c) if the quantity Q is non-zero or if it is greater than 0.5 ppm by weight of compound (c).

[0055] The implementation of the GC-MS measurement makes it possible to determine the quantity of at least one compound selected from alkanes, aromatic hydrocarbon compounds, alkenes, and their combinations, which may be present in compound (c). The invention provides a method for selecting a polyhydroxylated compound (c) comprising measuring by GC-MS the quantity Q of at least one compound selected from alkanes, aromatic hydrocarbon compounds, alkenes, and their combinations, and then: - the implementation of compound (c) if the quantity Q is zero or - the elimination of compound (c) if the quantity Q is non-zero.

[0056] The selection method according to the invention includes an elimination step which may be total or partial, in particular depending on the quantity present within the compound (c) of the eventual compound chosen from alkanes, aromatic hydrocarbon compounds, alkenes and their combinations.

[0057] The preparation method according to the invention is particularly effective for obtaining a copolymer P comprising a reduced or zero content of alkanes, aromatic hydrocarbon compounds, or alkenes. The invention also provides a copolymer P prepared according to the preparation method of the invention. Preferably, the copolymer P according to the invention comprises an amount of at least one compound chosen from alkanes, aromatic hydrocarbon compounds, alkenes and their combinations, measured by GC-MS, which is less than 0.5 ppm by weight of compound (c), more preferably an amount less than 0.1 ppm by weight of compound (c) or even a zero amount of compound chosen from alkanes, aromatic hydrocarbon compounds, alkenes and their combinations.

[0058] The copolymer P according to the invention is particularly useful for controlling the rheology of aqueous compositions. The invention provides a method for preparing a rheology-modifying agent comprising preparing a copolymer P according to the invention and mixing the copolymer P with at least one compound selected from a solvent, in particular water or a coalescing solvent, for example glycol, butyl glycol, butyldiglycol, monopropylene glycol, ethylene glycol, ethylene-diglycol, "Dowanol" products (CAS number 34590-94-8), or "Texanol" products (CAS number 25265-77-4).

[0059] In particular within the rheology modifying agent, the copolymer P can be combined with at least one additive selected from an amphiphilic compound, in particular a surfactant compound, preferably a hydroxylated surfactant compound, for example alkyl-polyalkyleneglycol, in particular alkyl-polyethyleneglycol and alkyl-polypropyleneglycol; a polysaccharide derivative, for example cyclodextrin, cyclodextrin derivative, polyethers, alkyl-glucosides; a hydrotropic compound, an antifoaming agent, a biocidal agent and combinations thereof.

[0060] Preferably according to the invention, the rheology modifying agent comprises a copolymer P according to the invention and at least one substance of natural origin, in particular a substance selected from a naturally sourced hydroxylated surfactant compound, for example, naturally sourced alkyl-polyalkyleneglycol, in particular naturally sourced alkyl-polyethyleneglycol; a naturally sourced polysaccharide derivative, for example, naturally sourced cyclodextrin, naturally sourced cyclodextrin derivative, polyethers, naturally sourced alkyl-glucosides and their combinations.

[0061] The invention also relates to an aqueous formulation comprising: - at least one copolymer P or at least one rheology-modifying agent according to the invention and, optionally, - at least one organic or mineral pigment or organic, organometallic or mineral particles, for example calcium carbonate, talc, kaolin, mica, silicates, silica, metal oxides, in particular titanium dioxide, iron oxides; and possibly - at least one agent chosen from among a particle spacer, a dispersing agent, a steric stabilizing agent, an electrostatic stabilizing agent, an opacifying agent, a coloring agent, a solvent, a coalescing agent, an anti- foam, a preservative, a biocide, a spreading agent, a thickening agent, a film-forming copolymer and mixtures thereof.

[0062] Preferably, the aqueous formulation according to the invention is a coating formulation, in particular an ink formulation, a varnish formulation, an adhesive formulation, a paint formulation, for example decorative paint or industrial paint.

[0063] The invention also provides a concentrated aqueous pigment paste comprising at least one copolymer P according to the invention and at least one organic or mineral colored pigment.

[0064] Particularly advantageously, the rheology-modifying agent according to the invention can be used in aqueous media. The invention thus provides an aqueous composition comprising at least one copolymer P according to the invention and at least one rheology-modifying agent according to the invention. Preferably, according to the invention, this composition is a coating composition, in particular a paint or varnish, or a paper coating composition, or a cosmetic composition, or a detergent composition, or an adhesive composition.

[0065] The copolymer P prepared according to the invention possesses particularly effective rheological control properties for aqueous compositions. The invention provides a method for controlling the viscosity of an aqueous composition comprising adding to this composition at least one copolymer P according to the invention.

[0066] The advantageous, particular or preferred characteristics of the preparation method according to the invention define copolymers P, aqueous compositions, formulations, pigment pastes as well as selection methods and viscosity control methods according to the invention which are also advantageous, particular or preferred.

[0067] The following examples illustrate the different aspects of the invention. EXAMPLES

[0068] Example 1: Preparation and characterization of PI to P6 copolymers according to the invention

[0069] The compounds used are chosen from: - diisocyanate compound (a): isophorone diisocyanate (IPDI), compound (ala), - diisocyanate compound (a): 4,4'-diisocyanato dicyclohexylmethane (H12MDI), compound (alb), - compound (b): compound (ba) of formula I in which R represents a cardanyl group, ethoxylated 4 times, - compound (b): compound (bb) of formula I in which R represents a 1-hexanyl group, - compound (b): compound (bc) of formula I in which R represents an 1-ethylhexanyl group, - compound (b): compound (bd) of formula I in which R represents an 1-octanyl group, - compound (b): compound (be) of formula I in which R represents an 1-dodecanyl group, - compound (c): compound (cia) of formula II in which L represents an oxyethylene residue and n represents approximately 225 (Polyglycol 10,000 SG "Vita Clariant").

[0070] The compound (cia) is analyzed by GC-MS using a gas chromatograph (“Agilent” 7890B) comprising a headspace injector (“Agilent” 7967A) and a mass spectrometer (“Agilent” 5977B) as detector.

[0071] A 2 g sample of the compound is placed in a flask (screw cap, 2 mL headspace) and injected into the chromatograph. After detection and processing of the peaks of the compounds present in the sample, in addition to compound (cia), the presence of the compounds detailed in Table 1 is characterized.

[0072] [Table 1] Compounds | N*CAS Peak surface area acetic acid § .................. 3 917 922 l^-diexolane | 6464)6-0 8 37 994 methoxyethanol | 109-86-4 352 184 ■UA" 1 448 755 l-btikinM § 7 î-36-3 576 441 methoxyaeetone ] 5878-19-3 06 220 Mwfonnafe Glycd | 628-35-3 316 091 ethykae fbxmate | 629-15-2 616 318 ivi A ce 1 4 Acne 71-43-2 124-18-5 0 0 dcdecane U 2-40 A 0 UHntdêeane § 629-59-4 0

[0073] In a 2L reactor, 261.9g of compound (cia) and 24.8g of compound (ba) are introduced. The mixture is heated to 90°C under vacuum for 30 min, then 12.8g of compound (ala) are introduced and the heating is increased and maintained at 100°C for 45 min. The PI polymer according to the invention is obtained.

[0074] Similarly, polymers P2 to P5 are prepared according to the invention. The compounds and quantities (g) used are shown in Table 2.

[0075] [Table 2] Powders Pi po P3 P4 P5 Compound (a la) 12.8 15.0 13.7 16.7 Compound (alb) 8.8 Compound (ba) 24.8 Compound (bb) 3.7 Compound (bc) 8.8 Compound (bd) 8.0 Compound (be) 14.0 Compound (cia) 261.9 186.9 775 5 227.8 268.5

[0076] Example 2: Preparation and characterization of MRI rheology-modifying agents MR5 according to the invention

[0077] The PI polymer of Example 1 is cooled to 60°C and then mixed with 266.4g of a surfactant compound (“Simulsol” SL7G “Seppic”) and 432.9g of water to obtain the rheology modifying agent MRI according to the invention.

[0078] Similarly, the rheology modifying agent MR2 according to the invention is prepared by mixing the polymer P2 with 799.2g of water.

[0079] The rheology modifying agent MR3 according to the invention is prepared by mixing the polymer P3 with 749.2g of water.

[0080] The rheology modifying agent MR4 according to the invention is prepared by mixing the P4 polymer with 749.4g of water.

[0081] The rheology modifying agent MR5 according to the invention is prepared by mixing the P5 polymer with 266.4g of surfactant compound (“Simulsol” SL7G “Seppic”) and 432.9g of water.

[0082] For each rheology-modifying agent, the resulting low-gradient viscosity is determined: Brookfield viscosity at 100 rpm (mobile no. 6), denoted VB (mPa·s). These measurements are taken 24 hours after preparation of the agent. The agents are thermostated at 25 ± 0.5°C. The results are presented in Table 3.

[0083] [Table 3] Agent Viscosity VB (mPa.s) MRI 8700 MR2 3200 MR3 2250 MR4 4700 MR5 6400

[0084] Example 3: Preparation and characterization of aqueous coating compositions CRI to CR5 according to the invention

[0085] Each composition is prepared by mixing the different ingredients. The ingredients and quantities (in g) are detailed in Table 4.

[0086] [Table 4] Ingredients of the waterborne paint formulation Quantity (g) Ecodis P50 (dispersant Coatex) 2.00 Tego 810 (antifoam Tego) 0.51 Acticide MBS (bactericide Thor) 1.00 TiONa 568 (TiO2 Tronox) 40.01 Omyacoat 850 OG (CaCO3 Omya) 110.00 Durcal 2 AV (CaCO3 Omya) 150.29 Acronal S790 (binder BASF) 65.00 Monopropylene glycol 5.06 Texanol (coalescing agent Eastman) 5.02 NaOH (20 wt. in water) 0.41 MRI to MR5 agent (30 wt. PI P5) 4.70 Water 116.00 Total 500.00

[0087] For each composition, the resulting viscosities are determined at different velocity gradients: - at low gradient: Brookfield viscosities at 10 rpm and 100 rpm, respectively denoted VB10 and VB100 (mPa.s), - at medium gradient: Stormer viscosity (Krebs Unit, KU), - at high gradient: viscosity HERE (mPa.s).

[0088] These measurements are taken 24 hours after preparation of the formulation. The formulations are thermostated at 25 ± 0.5°C. The results are presented in Table 5.

[0089] [Table 5] Compositions Viscosities U'i'pxh metes p / BU' mn'a VBioO pnPj.:,.» HERE (mP; CRI (PH 1 ! 800 y ï H ) i 108 0.9 CR 2 <p2>2,000: QQ •"J CR3 UUî I 4ÜO 900 G CR4tl^} 2,200 1 4150: 91 •*î 'î CR^ t P51 n 200 4' SOü j XS 1.6

[0090] The copolymers according to the invention make it possible to effectively thicken a solvent-free matte paint at different shear gradients.

[0091] In the field of aqueous paints, a high viscosity at a low or medium shear gradient indicates good static behavior. This ensures a good stability during storage while avoiding sedimentation and limiting the tendency to run on vertical supports.

[0092] These paint compositions do not include VOCs from the polyhydroxylated compound used in the preparation of the copolymer according to the invention.

Claims

Demands

1. Method for preparing a copolymer P comprising the polymerization reaction: a) of at least one isocyanate compound (a) chosen independently from a diisocyanate compound (a1), a polyisocyanate compound (a2) and their combinations; b) of at least one compound (b) of formula I: [chem I] HC^R in which R independently represents a group chosen from a linear C4-C40-alkyl group, a branched C4-C40-alkyl group, a C5-C4o-cycloalkyl group, a C5-C40-aryl group and their combinations; (c) of at least one (c) polyalkoxylated polyhydroxylated compound comprising an amount of at least one compound selected from alkanes, aromatic hydrocarbon compounds, alkenes and their combinations, measured by GC-MS, which is less than 0.5 ppm by weight of compound (c).

2. Method according to claim 1 wherein: * The diisocyanate compound (al) is chosen from: - symmetrical aromatic diisocyanate compounds, preferably: ** 2,2'-diphenylmethylene diisocyanate (2,2'-MDI) and 4,4'-diphenylmethylene diisocyanate (4,4'-MDI); **4,4'-dibenzyl diisocyanate (4,4'-DBDI); **Toluene 2,6-diisocyanate (2,6-TDI); **m-xylylene diisocyanate (m-XDI); - symmetrical alicyclic diisocyanate compounds, preferably methylene bis(4-cyclohexylisocyanate) (Hi2MDI); - symmetrical aliphatic diisocyanate compounds, preferably hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI); - preferably dissymmetric aromatic diisocyanate compounds: ** 2,4'-diphenylmethylene diisocyanate (2,4'-MDI); ** 2,4'-dibenzyl diisocyanate (2,4'-DBDI); **Toluene 2,4-diisocyanate (2,4-TDI); - dissymmetric alicyclic diisocyanate compounds, preferably isophorone diisocyanate (IPDI), preferably according to the invention, the compound Al is selected from IPDI, HDI, Hi2MDI and their combinations; or * The polyisocyanate compound (a2) comprises strictly more than 2 isocyanate functions, or more than 2.2 isocyanate functions, or more than 2.5 isocyanate functions; preferably, the polyisocyanate compound A2 comprises more than 2.6 isocyanate functions, or more than 2.7 isocyanate functions, or more than 3 isocyanate functions; more preferably, the polyisocyanate compound A2 comprises from 2.2 to 6 isocyanate functions, from 2.2 to 4 isocyanate functions, from 2.2 to 3.5 isocyanate functions, from 2.5 to 6 isocyanate functions, from 2.2 to 5 isocyanate functions, from 2.5 to 4 isocyanate functions, from 2.5 to 3.5 isocyanate functions, in particular from 2.6 to 3.3 isocyanate functions; or * the polyisocyanate compound (a2) is selected from: ** triphenylmethane-4,4',4"-triisocyanate or 1,1',1"-methylidynetris (4-isocyanatobenzene); or *** an isocyanurate compound, in particular an isocyanurate compound of a compound selected from: *** symmetrical aromatic diisocyanate compounds, preferably: ** 2,2'-diphenylmethylene diisocyanate (2,2'-MDI) and 4,4'-diphenylmethylene diisocyanate (4,4'-MDI); **4,4'-dibenzyl diisocyanate (4,4'-DBDI); **Toluene 2,6-diisocyanate (2,6-TDI); **m-xylylene diisocyanate (m-XDI); *** symmetrical alicyclic diisocyanate compounds, preferably methylene bis(4-cyclohexylisocyanate) (Hi2MDI); *** symmetrical aliphatic diisocyanate compounds, preferably hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI); *** asymmetric aromatic diisocyanate compounds, preferably: ** 2,4'-diphenylmethylene diisocyanate (2,4'-MDI); ** 2,4'-dibenzyl diisocyanate (2,4'-DBDI); **Toluene 2,4-diisocyanate (2,4-TDI); ** a biurea trimer compound, in particular a biurea trimer compound of a compound selected from: *** symmetrical aromatic diisocyanate compounds, of preference : ** 2,2'-diphenylmethylene diisocyanate (2,2'-MDI) and 4,4'-diphenylmethylene diisocyanate (4,4'-MDI); **4,4'-dibenzyl diisocyanate (4,4'-DBDI); **Toluene 2,6-diisocyanate (2,6-TDI); **m-xylylene diisocyanate (m-XDI); *** symmetrical alicyclic diisocyanate compounds, preferably methylene bis(4-cyclohexylisocyanate) (Hi2MDI); *** symmetrical aliphatic diisocyanate compounds, preferably hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI); *** asymmetric aromatic diisocyanate compounds, preferably: ** 2,4'-diphenylmethylene diisocyanate (2,4'-MDI); ** 2,4'-dibenzyl diisocyanate (2,4'-DBDI); **Toluene 2,4-diisocyanate (2,4-TDI); *** dissymmetric alicyclic diisocyanate compounds, preferably isophorone diisocyanate (IPDI), preferably compound (a2) is selected from triphenylmethane-4,4',4”-triisocyanate, l,l',l”-methylidynetris (4-isocyanatobenzene), an HDI isocyanurate, an IPDI isocyanurate, a PDI isocyanurate, an HDI biurea trimer and an IPDI biurea trimer, a PDI biurea trimer.

3. A method according to any one of claims 1 or 2 wherein compound (b) is a compound of formula I in which R independently represents a linear C4-C36-alkyl group, a branched C4-C36-alkyl group or a C5-C36-aryl group; preferably a linear C6-C36-alkyl group, a branched C6-C36-alkyl group or a C6-C36-aryl group; more preferably a linear C6-C24-alkyl group, a branched C6-C24-alkyl group or a C6-C24-aryl group.

4. A method according to any one of claims 1 to 3 wherein compound (c) is selected from: * a compound (cl) of formula II: [Chem II] HO-La-OH in which: - L independently represents an oxyalkylene residue; - n independently represents a number from 30 to 1,000; * a compound (cl) of formula II associated with a non-alkoxy compound (c2) comprising at least three hydroxyl groups; * a polyalkoxy compound (c3) comprising at least three hydroxyl groups; * their combinations.

5. A method according to any one of claims 1 to 4 wherein compound (c) is selected from: * a compound (c1) of formula II: [Chem II] HO-Ln-OH in which: - L independently represents an oxyethylene residue; or - n independently represents a number from 50 to 400, preferably from 100 to 300; or in which L independently represents an oxyethylene residue and n independently represents a number from 50 to 400, preferably from 100 to 300; * a compound (c2) comprising three hydroxyl groups, preferably selected from glycerol, pentaerythritol and their combinations; * polyethoxylated pentaerythritol or a polyalkoxylated compound (c3) different from compound (c2) and comprising three hydroxyl groups, preferably a compound (c3) which is polyethoxylated glycerol.

6. A method according to any one of claims 1 to 5 wherein: * compound (c) comprises from 10 to 150 alkoxylations, preferably from 20 to 100 alkoxylations or from 10 to 70 alkoxylations, more preferably from 20 to 60 alkoxylations, or * compound (c) is polyethoxylated or is polyethoxylated-polypropoxylated or is polyethoxylated-polybutoxylated, preferably compound (c) is polyethoxylated, or * compound (c) comprises from 10 to 150 ethoxylations, preferably from 20 to 100 ethoxylations or from 10 to 70 ethoxylations, more preferably from 20 to 60 ethoxylations.

7. A method according to any one of claims 1 to 6, wherein the compounds (c), (cl) or (c3) independently have a molar mass (Mw) measured by CES ranging from 1,500 to 40,000 g / mol, preferably from 2,000 to 20,000 g / mol, more preferably from 2,000 to 15,000 g / mol or from 2,000 to 12,000 g / mol.

8. A method according to any one of claims 1 to 7 wherein compound (c) comprises * less than 0.2 ppm by weight, preferably less than 0.1 ppm by weight or even zero, measured by GC-MS, of alkanes, in particular alkanes selected from C3-C2o-alkanes and their combinations, or * less than 0.2 ppm by weight, preferably less than 0.1 ppm by weight or even zero, measured by GC-MS, of aromatic hydrocarbon compounds, in particular aromatic hydrocarbon compounds selected from toluene, benzene, xylene, naphthalene and their combinations, or * less than 0.2 ppm by weight, preferably less than 0.1 ppm by weight or even zero, measured by GC-MS, of alkenes, in particular alkenes selected from C7-Ci4-alkenes and their combinations.

9. Method according to any one of claims 1 to 8 wherein the polymerization reaction employs: - 20 to 74.9 mol%, preferably 25 to 60 mol%, of monomer (a) or - 25 to 79.9 mol%, preferably 35 to 70 mol%, of compound (b), or - 0.1 to 55 mol%, preferably 5 to 40 mol%, of monomer (c), relative to the total mol% of compounds (a), (b) and (c).

10. A method according to any one of claims 1 to 9, wherein the polymerization reaction also employs at least one hydrophobic compound (d) different from compound (b), preferably a compound of formula (III): [Chem III] R*-(OE)q-(OP)r-OH in which: - q and r, identical or different, independently represent 0 or an integer or decimal number less than 150, m or p is different from 0, - OE independently represents a CH2CH2O group, - OP independently represents a group selected from CH(CH3)CH2O and CH2CH(CH3)O, - R1 represents a linear or branched Ce-C^-alkyl group, a phenyl group, a polyphenyl group, preferably a linear or branched Cio-C3O-alkyl group, more preferably a linear or branched Ci2-C22-alkyl group, or a group comprising 2 to 5 phenyls or a tristyrylphenyl group or a pentastyrylcumylphenyl group, preferably less than 20 mol%, preferably from 0.05 to 20 mol%, in particular from 0.1 to 10 mol%, of monomer (d) relative to the total molar amount of monomers.

11. Method for selecting a polyhydroxylated compound (c) comprising measuring by GC-MS the amount Q of at least one compound selected from alkanes, aromatic hydrocarbon compounds, alkenes and their combinations, then - implementing the compound (c) if the amount Q is zero or - eliminating the compound (c) if the amount Q is non-zero or greater than 0.5 ppm by weight of compound (c).

12. Copolymer P prepared according to the preparation method according to any one of claims 1 to 10.

13. Method of preparing a rheology modifying agent comprising: - the preparation of a copolymer P according to any one of claims 1 to 10, - the mixing of the copolymer P with at least one compound selected from a solvent, in particular water or a coalescing solvent, for example glycol, butyl glycol, butyldiglycol, monopropylene glycol, ethylene-lene glycol, ethylenediglycol, "Dowanol" products (CAS number 34590-94-8), "Texanol" products (CAS number 25265-77-4) or with at least one additive selected from an amphiphilic compound, in particular a surfactant compound, preferably a hydroxylated surfactant compound, for example alkyl-polyalkylene glycol, in particular alkyl-polyethylene glycol and alkyl-polypropylene glycol; a polysaccharide derivative, for example cyclodextrin, cyclo-dextrin derivative, polyethers, alkyl-glucosides; a hydrotropic compound, an antifoaming agent, a biocidal agent and their combinations.

14. Rheology modifying agent comprising a copolymer P defined according to any one of claims 1 to 10 and at least one substance of natural origin, in particular a substance selected from a naturally sourced hydroxylated surfactant compound, for example a naturally sourced alkyl-polyalkylene glycol, in particular alkyl- polyethylene glycol of natural origin; a derivative of a polysaccharide of natural origin, for example cyclodextrin of natural origin, derivative of cyclodextrin of natural origin, polyethers, alkyl-glucosides of natural origin and their combinations.

15. Aqueous composition comprising at least one copolymer P defined according to any one of claims 1 to 10 or 11 or comprising at least one rheology modifying agent according to claim 14.

16. Composition according to claim 15 which is a coating composition, in particular of paint or varnish, or a paper coating composition or a cosmetic composition or a detergent composition or an adhesive composition.

17. Method for controlling the viscosity of an aqueous composition comprising the addition of at least one copolymer P defined according to any one of claims 1 to 10 or 11.