Composition for preparing a coating

Abstract

The invention relates to an aqueous composition for preparing a coating, comprising a rheological control agent comprising urethane polymers. This agent is prepared discontinuously by a polymerization reaction of a diisocyanate compound and a polyhydroxylated compound, followed by the termination reaction of the prepolymer of these compounds with a monoalcohol. It mainly comprises urethane polymers comprising strictly more than three groups of the polyhydroxylated compound.

Description

[0001] COATING PREPARATION COMPOSITION

[0002] The invention relates to an aqueous coating preparation composition comprising a rheological control agent comprising urethane polymers. This agent is prepared discontinuously by a polymerization reaction of a diisocyanate compound and a polyhydroxylated compound, followed by the termination reaction of the prepolymer of these compounds with a monoalcohol. It mainly comprises urethane polymers comprising strictly more than 3 residues of the polyhydroxylated compound. Many technical fields require the use of aqueous compositions. In particular, aqueous ink compositions, aqueous coating compositions, in particular aqueous varnish compositions or aqueous paint compositions, for example aqueous decorative paint compositions or aqueous industrial paint compositions, are known.In addition to their functional properties, these aqueous compositions must have a texture suitable for their use or storage. In particular, they must have a suitable viscosity. In addition, these aqueous compositions must be able to be used under conditions that can vary widely. In particular, the viscosity of these aqueous compositions may vary or degrade. The functional properties of these aqueous compositions may therefore be altered if their rheological behavior is not suitable, for example to prevent sedimentation or phase separation phenomena during storage time, which may also manifest themselves by viscosity variations. Such variations or degradations are particularly detrimental or damaging for aqueous ink compositions, for aqueous coating compositions, in particular for aqueous varnish or paint compositions.

[0003] There is therefore a need to be able to have aqueous compositions which do not have such disadvantages or aqueous compositions which do not lead to such problems.

[0004] In particular, it is particularly useful to have available aqueous coating compositions, in particular aqueous varnish or paint compositions, whose viscosity is adapted to allow the maintenance of their homogeneity as well as the integrity of their functional properties. Maintaining the viscosity and limiting the loss of viscosity of these aqueous compositions should be possible for wide ranges of shear rates. Therefore, many aqueous coating compositions use rheology modifying polymers. These polymers should make it possible to give the aqueous compositions the desired rheological properties for wide ranges of shear rates.These polymers should also improve the shear thinning of these aqueous compositions by giving them sufficient pseudo-plasticity, ensuring their stability and homogeneity during their storage life, facilitating their transfer to application tools and helping to limit the appearance of drips once applied. The compatibility of the different constituents of an aqueous coating composition must also be taken into account. In particular, it is important that the thickening copolymers, pigments and binders used have good compatibility.

[0005] There is a need for rheological control agents that can provide solutions to all or some of the rheological control agents of the state of the art. Polyurethanes or urethane-functional polymers are widely used in many technical fields, particularly for the preparation of coating compositions.

[0006] The preparation of polyurethanes uses two essential reagents to form the polymer chain. The units or residues of these reagents are ultimately present within the structure of the resulting polymer. The ends of the polymer chain can be obtained using a third reagent. The ends of the polymer can notably be formed from hydrophobic groups, in particular alkyl or alkylene groups, often derived from a monoalcohol, while the polymer chain originates from a polyhydroxylated compound, in particular a polyalkylene glycol, combined with a polyisocyanate monomer, in particular a diisocyanate compound.

[0007] The preparation of these polyurethanes is carried out by step-by-step polymerization according to a mechanism of independent steps which is based on the reactivity of functional groups which react together to form a new group which will chemically link the respective chain ends by poly additions. The monomers, at least bifunctional, in particular diisocyanates and diols, react and form prepolymers which can then react with a compound carrying the terminal group, for example a monoalcohol. Controlling the conditions of the reactions for preparing the prepolymer and then for reacting the monoalcohol is important and must make it possible to obtain urethane polymers with properties adapted to the different fields of use.In particular, it is useful to be able to control the respective quantities of the different urethane polymers resulting from these preparation methods, in particular to be able to promote the production of certain polyurethanes, notably depending on the high proportion of diol residues present within the polymer.

[0008] It is also very useful to be able to control the production of urethane polymers comprising a high relative quantity of urethane functions compared to the molecular mass of the polyurethane obtained. The density of urethane functions in the polymer can therefore be increased.

[0009] The polyisocyanate monomer comprising a hydrocarbon chain, the urethane polymer can then also comprise a significant proportion of hydrocarbon residues within the polymer chain.

[0010] In addition to the advantages directly linked to their preparation, particularly in terms of yield or orientation towards preferred urethane polymers, better control of the conditions for preparing polyurethanes should also make it possible to promote the desired properties, particularly for the preparation of coating compositions.

[0011] Documents EP 2444432 and EP 1940978 describe the preparation of polyurethanes from triisocyanate compounds or triols.

[0012] Polymers known as thickening agents do not always provide a satisfactory solution to these various problems. There is therefore a need for improved rheology-modifying copolymers. The copolymer according to the invention provides a solution to all or part of the problems of prior-art polymers.

[0013] Thus, the invention provides an aqueous coating preparation composition T comprising:

[0014] • at least one rheological control agent G comprising urethane polymers and prepared discontinuously:

[0015] - by a polymerization reaction, in the absence of a monohydroxylated compound:

[0016] ■ of at least one diisocyanate compound (a),

[0017] ■ of at least one polyhydroxylated compound (b), followed by:

[0018] - of the termination reaction of the prepolymer of compounds (a) and (b) with at least one compound (c) of formula I:

[0019] HO-R

[0020] (I) in which R independently represents a group chosen from a linear C1-C40-alkyl group, a branched C3-C40-alkyl group, a Cs-C40-cycloalkyl group, a linear C3-C40-alkylene group, a branched C3-C40-alkylene group, a C5-C40-aryl group and combinations thereof; in which the urethane polymers comprising strictly more than 3 residues of compound (b) are in the majority in number measured by CES;

[0021] • 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

[0022] • at least one binding agent B.

[0023] During the preparation of agent G according to the invention, the difunctional compounds (a) and (b) react, by addition of the isocyanate functions of compound (a) and the hydroxyl functions of compound (b), to form prepolymers comprising chemical residues or chemical units derived from these 2 compounds. Several compounds (a) can react with several compounds (b) to form prepolymers comprising several urethane functions. The termination reaction of these prepolymers with compound (c) leads to the presence of 2 residues of compound (c) in the urethane polymers of agent G according to the invention.

[0024] Finally, for 2 residues of compound (c), the urethane polymers according to the invention comprising a number 2N of residues of compound (b) comprise a number N+1 of hydrocarbon residues of compound (a) and a number 2N+2 urethane functions. According to the invention, the value of N is greater than 3.

[0025] Preferably according to the invention, the urethane polymers of agent G comprising strictly more than 3 residues of compound (b) represent at least 40% by number, preferably at least 50% by number or at least 55% by number, more preferably at least 60% by number or at least 65% by number or at least 70% by number, of all the urethane polymers of agent G.

[0026] According to the invention, the distribution of the polymeric entities present in the urethane polymers of agent G according to the invention, in particular the number proportions of the residues of compound (b) present in the polymers, is determined by high-performance size exclusion chromatography (SEC), preferably using a high-performance size exclusion chromatograph (“Acquity” Advanced Polymer Chromatography APC, “Waters”) with refractometric detector and column system consisting of three “Waters” columns in series: “Acquity” APC XT 900 2.5 pm 4.6 mm x 15 0mm, “Acquity” APC XT 450 2.5 pm 4.6 mm x 150mm and “Acquity” APC XT 125 2.5 pm 4.6 mm x 150 mm. The solvent used for the mobile phase is tetrahydrofuran (THF HPLC grade). The calibration is carried out with polymethyl methacrylate (PMMA) standards with a molecular mass of up to 2,200,000 g / mol; the samples of agent G according to the invention being solubilized in THF.

[0027] Also preferably according to the invention, the urethane polymers have an average molar mass Mw, measured by CES, greater than 10,000 g / mol, preferably greater than 20,000 g / mol or 30,000 g / mol, or an average molar mass Mw less than 500,000 g / mol, preferably less than 300,000 g / mol. More preferably according to the invention, the urethane polymers have an average molar mass Mw, measured by CES, ranging from 10,000 g / mol to 500,000 g / mol, preferably from 20,000 g / mol to 300,000 g / mol.

[0028] Also preferably according to the invention, the urethane polymers have a polymolecularity index Ip, measured by CES, of less than 4 or less than 3. More preferably according to the invention, this polymolecularity index is less than 2. Also preferably according to the invention, the urethane polymers have a polymolecularity index Ip greater than 1.3.

[0029] According to the invention, the molecular weight or mass Mw as well as the polymolecularity index Ip are determined by Size Exclusion Chromatography (SEC). A test sample of the compound solution 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: NaHCOs: 0.05 mol / L, NaNOs: 0.1 mol / L, triethanolamine: 0.02 mol / L, NaNs 0.03% by mass.The CES chain is composed of a “Waters” 510 isocratic pump, with a flow rate set at 0.8 mL / min, a “Waters” 717+ autosampler, an oven containing a “Waters” Guard Column Ultrahydrogel precolumn 6 cm long and 40 mm inner diameter, followed by a “Waters” Ultrahydrogel linear column 30 cm long and 7.8 mm inner diameter. Detection is ensured by means of a “Waters” RI 410 differential refractometer. The oven is heated to a temperature of 60°C and the refractometer is heated to a temperature of 45°C. The CES device is calibrated with a series of sodium polyacrylate standards supplied by Polymer Standards Service with peak molecular weights between 900 g / mol and 2,250,000 g / mol and polydispersity indexes 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.

[0030] Preferably for agent G according to the invention, the diisocyanate compound (a) is chosen from:

[0031] • symmetrical aromatic diisocyanate compounds, preferably:

[0032] ■ 2,2'-diphenylmethylene diisocyanate (2,2'-MDI) and 4,4'-diphenylmethylene diisocyanate (4,4'-MDI);

[0033] ■ 4,4'-dibenzyl diisocyanate (4,4'-DBDI);

[0034] ■ toluene 2,6-diisocyanate (2,6-TDI);

[0035] ■ m-xylylene diisocyanate (m-XDI);

[0036] • symmetrical alicyclic diisocyanate compounds, preferably methylene bis(4-cyclohexylisocyanate) (H12MDI);

[0037] • symmetrical aliphatic diisocyanate compounds, preferably hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI);

[0038] • asymmetric aromatic diisocyanate compounds, preferably:

[0039] ■ 2,4'-diphenylmethylene diisocyanate (2,4'-MDI);

[0040] ■ 2,4'-dibenzyl diisocyanate (2,4'-DBDI);

[0041] ■ toluene 2,4-diisocyanate (2,4-TDI);

[0042] • asymmetric alicyclic diisocyanate compounds, preferably isophorone diisocyanate (IPDI).

[0043] More preferably, compound (a) is selected from IPDI, HDI, H12MDI and combinations thereof.

[0044] Also preferably according to the invention, the rheological control agent G does not comprise urethane polymers prepared in the presence of a branched polyisocyanate compound comprising at least 3 isocyanate groups. In particular, the rheological control agent G does not comprise urethane polymers prepared in the presence of a cyanurate trimer compound or a biuret trimer, in particular in the absence of an HDI isocyanurate trimer or an IPDI isocyanurate trimer.

[0045] Preferably for agent G according to the invention, compound (b) is a dihydroxylated compound, more preferably a diol. Preferably for agent G according to the invention, the polyhydroxylated compound (b) is a compound of formula II:

[0046] HO-Ln-OH in which:

[0047] - L independently represents an oxyalkylene residue;

[0048] - n independently represents a number ranging from 1 to 500.

[0049] Preferably for agent G according to the invention, the polyhydroxylated compound (b) is a compound of formula II in which L independently represents an oxyethylene residue.

[0050] Also preferably for the agent G according to the invention, the polyhydroxylated compound (b) is a compound of formula II in which n independently represents a number ranging from 10 to 400, preferably from 20 to 300. More preferably for the agent G according to the invention, the polyhydroxylated compound (b) is a compound of formula II for which L independently represents an oxyethylene residue and n independently represents a number ranging from 20 to 400, preferably from 25 to 300.

[0051] Also preferably for agent G according to the invention, compound (b) has an average molar mass (Mw), measured by CES, ranging from 500 to 15,000 g / mol, preferably from 800 g / mol to 12,000 g / mol or from 800 g / mol to 10,000 g / mol. More preferably, compound (b) has an average molar mass Mw ranging from 1,000 g / mol to 8,000 g / mol or from 1,000 g / mol to 6,000 g / mol.

[0052] Preferably for agent G according to the invention, compound (c) is a compound of formula I in which R independently represents a group chosen from a linear C1-C32-alkyl group, a branched C3-C32-alkyl group, a C5-C32-cycloalkyl group, a linear C3-C32-alkylene group, a branched C3-C32-alkylene group, a Cs-C32-aryl group and combinations thereof.

[0053] More preferably for agent G according to the invention, compound (c) is a compound of formula I in which R independently represents a group chosen from a linear C1-C24-alkyl group or a linear C3-C24-alkylene group, preferably a linear C4-C20-alkyl group or a linear C4-C20-alkylene group, more preferably a linear C6-Cis-alkyl group or a linear C6-Cis-alkylene group, much more preferably a linear C6-Ci6-alkyl group or a linear C6-Ci6-alkylene group.

[0054] According to the invention, compound (c) may be different from n-decanol, a branched C12-C13 primary alcohol, a branched C14-C15 primary alcohol, 2-octyldodecanol.

[0055] Advantageously, during the preparation of the urethane polymers according to the invention, the respective quantities of compounds (a), (b) and (c) used can vary. Preferably for agent G according to the invention, the polymerization reaction uses: from 10 to 79.9 mol% or from 10 to 74.5 mol%, preferably from 10 to 68 mol% or from 10 to 60 mol%, of monomer (a) or from 20 to 89.9 mol% or from 25 to 89.5 mol%, preferably from 30 to 88 mol% or from 35 to 85 mol%, of monomer (b), or from 0.1 to 70 mol% or from 0.5 to 65 mol%, preferably from 2 to 60 mol% or from 5 to 55 mol%, of monomer (c), relative to the total molar quantity of monomers (a), (b) and (c).

[0056] More preferably for agent G according to the polymerization reaction uses: from 10 to 79.9 mol% or from 10 to 74.5 mol%, preferably from 10 to 68 mol% or from 10 to 60 mol%, of monomer (a), from 20 to 89.9 mol% or from 25 to 89.5 mol%, preferably from 30 to 88 mol% or from 35 to 85 mol%, of monomer (b), and from 0.1 to 70 mol% or from 0.5 to 65 mol%, preferably from 2 to 60 mol% or from 5 to 55 mol%, of monomer (c), relative to the total molar quantity of monomers (a), (b) and (c).

[0057] When preparing the urethane polymers according to the invention, the relative amounts of compounds (a) and (b) used can vary. Preferably for agent G according to the invention, the polymerization reaction uses molar amounts of diisocyanate compound (a) and polyhydroxylated compound (b) in a molar ratio a / b ranging from 1.05 to 3.

[0058] More preferably for the agent G according to the invention, the polymerization reaction uses molar amounts of diisocyanate compound (a) and polyhydroxylated compound (b) in a molar ratio a / b ranging from 1.1 to 2 or from 1.1 to 1.5. Much more preferably, this molar ratio a / b ranges from 1.1 to 1.45 or from 1.1 to 1.4. Essentially according to the invention, the agent G comprises urethane polymers which strictly comprise more than 3 residues of the compound (b) and which are in the majority in number measured by CES. Preferably for the agent G according to the invention, the urethane polymers strictly comprising more than 4 residues, preferably more than 5 residues or more than 6 residues, of the compound (b) are in the majority in number measured by CES. Essentially according to the invention, the composition T comprises an agent G, a pigment or particles and at least one binding agent B. Preferably according to the invention,the composition T according to the invention comprises a binding agent B which is a sterically modified binding compound. Preferably according to the invention, the binding agent B is chosen from a vinyl acetate homopolymer; a vinyl acetate copolymer; a vinyl versatate homopolymer; a vinyl versatate copolymer and combinations thereof. More preferably according to the invention, the binding agent B is chosen from: a vinyl acetate homopolymer; a copolymer comprising at least vinyl acetate and ethylene, a copolymer of vinyl acetate and acrylate, a copolymer of vinyl acetate and methacrylate, a copolymer of vinyl acetate, ethylene and acrylate, a copolymer of vinyl acetate, ethylene and methacrylate, a copolymer of vinyl acetate, acrylate and methacrylate; a vinyl versatate homopolymer; a copolymer of vinyl versatate and ethylene, a copolymer of vinyl versatate and acrylate,a copolymer of vinyl versatate and methacrylate, a copolymer of vinyl versatate, ethylene and acrylate, a copolymer of vinyl versatate, ethylene and methacrylate, a copolymer of vinyl versatate, acrylate and methacrylate; a copolymer of vinyl acetate and vinyl versatate, a copolymer of vinyl acetate, vinyl versatate and ethylene, a copolymer of vinyl acetate, vinyl versatate and acrylate, a copolymer of vinyl acetate, vinyl versatate and methacrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene and acrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene and methacrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene, acrylate and methacrylate and combinations thereof. Preferably according to the invention, the composition T is an ink composition, a varnish composition, an adhesive composition,a paint composition, for example decorative paint or industrial paint.,

[0059] The quantities of the ingredients of the composition T according to the invention may vary. Preferably according to the invention, the composition T according to the invention comprises: from 0.1 to 4% by dry weight of rheological control agent G, from 3 to 15% by dry weight of pigments or particles, from 5 to 20% by dry weight of binding agent B, from 64.9 to 71.9% by weight of water.

[0060] Advantageously according to the invention, the composition T may also comprise at least one agent chosen from a particle spacing agent, a dispersing agent, a steric stabilizing agent, an electrostatic stabilizing agent, an opacifying agent, a coloring agent, a solvent, a coalescing agent, an anti-foaming agent, a preservative, a biocidal agent, a spreading agent, a thickening agent, a film-forming copolymer and mixtures thereof.

[0061] The properties of the rheological agent G according to the invention are particularly effective. Thus, in addition to a coating composition, the invention also provides a concentrated aqueous pigment paste comprising at least one rheological control agent G according to the invention and at least one organic or mineral colored pigment.

[0062] Essentially according to the invention, the agent G according to the invention is prepared according to a method comprising a polymerization reaction, in the absence of a monohydroxylated compound, then a termination reaction. Thus, the invention provides a method for the batchwise preparation of a rheological control agent G according to the invention comprising:

[0063] • a polymerization reaction, in the absence of a monohydroxylated compound:

[0064] ■ of at least one diisocyanate compound (a),

[0065] ■ of at least one polyhydroxylated compound (b), followed by:

[0066] • of the termination reaction of the prepolymer of compounds (a) and (b) with at least one compound (c) of formula I:

[0067] HO R in which R independently represents a group chosen from a linear C1-C40-alkyl group, a branched C3-C40-alkyl group, a C5-C40-cycloalkyl group, a linear C3-C40-alkylene group, a branched C3-C40-alkylene group, a C5-C40-aryl group and combinations thereof; in which the urethane polymers comprising strictly more than 3 residues of compound (b) are in the majority in number measured by CES.

[0068] Preferably for the preparation method according to the invention, the polymerization reaction is carried out in the polyhydroxylated compound (b), preferably in the molten medium of the compound (b). In particular, the polymerization reaction is carried out in the absence of organic solvent, preferably in the absence of organic hydrocarbon solvent such as xylene or toluene.

[0069] Also preferably for the preparation method according to the invention, the polymerization reaction uses molar amounts of diisocyanate compound (a) and polyhydroxylated compound (b) in a molar ratio a / b ranging from 1.05 to 3. More preferably, this molar ratio a / b ranges from 1.1 to 2 or from 1.1 to 1.5. Much more preferably, this molar ratio a / b ranges from 1.1 to 1.45 or from 1.1 to 1.4.

[0070] Also preferably for the preparation method according to the invention, the polymerization reaction is carried out for 10 minutes to 60 minutes, more preferably 10 minutes to 30 minutes.

[0071] The preparation method according to the invention makes it possible to prepare particular urethane polymers present in the agent G according to the invention. Thus, the invention provides a rheological control agent G defined according to the invention. The rheological control agent G according to the invention can be obtained according to the preparation method according to the invention.

[0072] The rheological control agent G according to the invention can be treated in an acidic manner leading to a pH lower than 8, preferably to a pH lower than 6, for example by means of an acid, in particular for example a carboxylic acid such as acetic acid or lactic acid.

[0073] Agent G according to the invention may also comprise at least one solvent, in particular water or a coalescence solvent, for example glycol, butyl glycol, butyl diglycol, monopropylene glycol, ethylene glycol, ethylene diglycol, “Dowanol” products with CAS number 34590-94-8, “Texanol” products with CAS number 25265-77-4; or combined with at least one additive chosen 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, cyclodextrin derivative, polyethers, alkyl-glucosides; a hydrotropic compound, an antifoaming agent, a biocidal agent and combinations thereof.

[0074] The preparation method according to the invention makes it possible to prepare particular urethane polymers. Thus, the invention provides a urethane polymer P prepared according to the method defined according to the invention and which comprises strictly more than 3, preferably strictly more than 4 or strictly more than 5, more preferably strictly more than 6, residues of compound (b) measured by CES.

[0075] The properties of the polymer P according to the invention and of the rheological agent G according to the invention are particularly useful and effective and allow use in numerous applications. Thus, the invention also provides a method for controlling the viscosity of an aqueous composition comprising the addition of at least one rheological control agent G according to the invention or at least one polymer P according to the invention to this composition.

[0076] The advantageous, particular or preferred characteristics of the composition T according to the invention define rheological control agents G, urethane polymers P, methods of preparation or manufacture according to the invention which are also advantageous, particular or preferred.

[0077] The various aspects of the invention may be illustrated by examples.

[0078] EXAMPLES

[0079] Preparation and characterization of rheological agents G1 to G8 according to the invention

[0080] For the preparation of urethane polymers, the following compounds a, b and c are used: compound a1: diisocyanate H12MDI, compound a2: diisocyanate HDI, compound a3: diisocyanate IPDI, compound b1: polyethylene glycol with a molecular weight of 2,000 g / mol, compound b2: polyethylene glycol with a molecular weight of 4,000 g / mol, compound b3: polyethylene glycol with a molecular weight of 5,500 g / mol, compound b4: polyethylene glycol with a molecular weight of 8,000 g / mol, compound b5: polyethylene glycol with a molecular weight of 10,000 g / mol, compound c1: hydrophobic monoalcohol of formula I in which R represents a linear C6-alkyl group, compound c2: hydrophobic monoalcohol of formula I in which R represents a linear C12-alkyl group, compound c3: hydrophobic monoalcohol of formula I in which R represents branched C24-C26 alkyl groups derived from a Guerbet alcohol (" Isofol” 2426S from “Sasol”).

[0081] Agents G1 to G8 according to the invention

[0082] In a 2 L reactor equipped with mechanical stirring, compound (bl) (polyethylene glycol - molecular mass 2000 g / mol) (163.9 g) is introduced and heated to 90°C. 0.20 g of a bismuth catalyst (K-KAT XC-B221 “King Industries”) is added and then a diisocyanate compound (al) (H12MDI) (25.8 g) is introduced. The reaction medium is kept stirring for 30 minutes (reaction time, RT) at 95°C for the formation of the prepolymer. Then, compound (cl) is added. The reaction is continued at 95°C for 30 minutes with stirring.

[0083] In a manner analogous to the preparation of agent G1, agents G2 to G8 are prepared according to the invention. The compounds and quantities (g) used as well as the reaction times TR are presented in Table 1.

[0084] Table 1

[0085] The agents G1 to G8 according to the invention are characterized by high-performance size exclusion chromatography. The measurements of the molecular masses of the mixtures of methane polymers present in the agents G1 to G8 according to the invention are carried out using a high-performance size exclusion chromatograph (“Acquity Advanced Polymer Chromatography APC, “Waters”) with a refractometric detector. The column system used consists of 3 “Waters” columns in series:

[0086] “Acquity” APC XT 900 2.5pm 4.6 mm x 15 0mm, “Acquity” APC

[0087] “Acquity” APC XT 125 2.5pm 4.6mm x 150mm.

[0088] The solvent used for the mobile phase is tetrahydrofuran (THF HPLC grade). Calibration is carried out with polymethyl methacrylate (PMMA) standards with a molecular mass of up to 2,200,000 g / mol. The samples of polymers P according to the invention are solubilized in THF.

[0089] The analysis makes it possible to determine the number-average molecular masses Mn and mass-average molecular masses Mw (g / mol) of the methane polymers of the compositions according to the invention. The polymolecularity Ip and the degree of polymerization are also evaluated by discriminating the molecular weights of the different polymeric entities present in the samples of compositions according to the invention. The distribution of the polymeric entities is quantified in each sample, in particular the number proportions of PEG residues present in the polymers. The results obtained for the samples of urethane polymers present in agents G1 to G8 according to the invention are presented in Table 2.

[0090] Table 2

[0091] Agents G1 to G8 according to the invention mainly comprise urethane polymers comprising strictly more than 3 PEG residues.

[0092] Furthermore, agent G1 comprising urethane polymers according to the invention is formulated by mixing it in water at a concentration of 20% by mass and 80% by mass of water. In the same way, aqueous formulations are prepared with agents G2 to G8 according to the invention. Agent G8 according to the invention is formulated (17.5% by mass) in water (69.2% by mass) in the presence of a surfactant compound (“Emulan” HE51 “Basf”, polyethoxylated alcohol, 13.3% by mass).

[0093] Using an analog viscometer equipped with a spindle, the Brookfield viscosity (mPa.s) at 10 rpm was measured after storage for 24 hours at 25°C of these aqueous formulations comprising agents G1 to G8. The results obtained are presented in Table 3.

[0094] Table 3

[0095] The agents according to the invention G1 to G8, in which the methane polymers comprising strictly more than 3 PEG residues are in the majority in number, make it possible to effectively control the viscosity of aqueous compositions.

[0096] Furthermore, an aqueous formulation is prepared comprising 70% by weight of a latex as binding agent B comprising an emulsion of acrylic polymer in water ("Encor" 662 Arkema, acrylic copolymer with 50 + / - 1% by weight of dry extract and pH of 8.5 + / - 0.5) into which 2.09% by dry weight of agent G2 according to the invention is added. The pH value is adjusted to 8.5-8.8 by means of an aqueous solution of ammonium hydroxide at 28% by weight. In a similar manner, an aqueous formulation is prepared using the rheological agent G3 according to the invention.

[0097] Using a rheometer ("Haake Mars 60"), the rheological profile of the formulations is determined by measuring their viscosity (Pa.s) at 25°C using a cone-plate mobile (CP60) under a speed gradient (s 1 ) imposed. The results are presented in Table 4.

[0098] Table 4

[0099] The rheological agents according to the invention exhibit good interaction with the binder latex and make it possible to control the viscosity of binder formulations in aqueous emulsion. They make it possible to obtain good Newtonian behavior. Preparation of aqueous paint composition T according to the invention

[0100] An aqueous paint composition may be prepared comprising calcium carbonate as a filler, a water-borne polymer emulsion as a binder, a dispersing agent and a titanium dioxide pigment to which a rheological control agent G according to the invention is added. The ingredients and quantities are shown in Table 5.

[0101] Table 5

[0102] The rheological control agent according to the invention makes it possible to obtain a paint composition according to the invention.

Claims

CLAIMS 1. Aqueous composition T for coating preparation comprising: • at least one rheological control agent G comprising urethane polymers and prepared discontinuously: by a polymerization reaction, in the absence of a monohydroxylated compound: ■ of at least one diisocyanate compound (a), ■ of at least one polyhydroxylated compound (b), followed by: the termination reaction of the prepolymer of compounds (a) and (b) with at least one compound (c) of formula I: HO-R in which R independently represents a group chosen from a linear C1-C40-alkyl group, a branched C3-C40-alkyl group, a Cs-C40-cycloalkyl group, a linear C3-C40-alkylene group, a branched C3-C40-alkylene group, a C5-C40-aryl group and combinations thereof; in which the urethane polymers comprising strictly more than 3 residues of compound (b) are in the majority in number measured by CES; • 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 • at least one binding agent B.

2. Composition T according to claim 1 in which: the urethane polymers of agent G comprising strictly more than 3 residues of compound (b) represent at least 40% by number, preferably at least 50% by number or at least 55% by number, more preferably at least 60% by number or at least 65% by number or at least 70% by number, of all the urethane polymers of agent G; or for which: the urethane polymers have an average molar mass Mw, measured by CES, greater than 10000 g / mol, preferably greater than 20000 g / mol or 30000 g / mol, or an average molar mass Mw of less than 500,000 g / mol, preferably less than 300,000 g / mol; or for which: the urethane polymers have an average molar mass Mw, measured by CES, ranging from 10,000 g / mol to 500,000 g / mol, preferably from 20,000 g / mol to 300,000 g / mol; or for which: the urethane polymers have a polydispersity index Ip, measured by CES, of less than 4 or less than 3, preferably less than 2; or have a polydispersity index Ip greater than 1.

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3. Composition T according to one of claims 1 or 2 for which the diisocyanate compound (a) 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) (H12MDI); • 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); • asymmetric alicyclic diisocyanate compounds, preferably isophorone diisocyanate (IPDI), more preferably, compound (a) is chosen from IPDI, HDI, H12MDI and combinations thereof.

4. Composition T according to one of claims 1 to 3 for which the polyhydroxylated compound (b) is a compound of formula II: HO-U-OH (II) in which: L independently represents an oxyalkylene residue; n independently represents a number ranging from 1 to 500; preferably wherein: L independently represents an oxyethylene residue; or n independently represents a number ranging from 10 to 400, preferably from 20 to 300; or L independently represents an oxyethylene residue and n independently represents a number ranging from 20 to 400, preferably from 25 to 300.

5. Composition T according to one of claims 1 to 4 for which the compound (b) has an average molar mass (Mw), measured by CES, ranging from 500 to 15,000 g / mol, preferably from 800 g / mol to 12,000 g / mol or from 800 g / mol to 10,000 g / mol, more preferably from 1,000 g / mol to 8,000 g / mol or from 1,000 g / mol to 6,000 g / mol.

6. Composition T according to one of claims 1 to 5 for which compound (c) is a compound of formula I in which: R independently represents a group selected from a linear C1-C32-alkyl group, a branched C3-C32-alkyl group, a C5-C32-cycloalkyl group, a linear C3-C32-alkylene group, a branched C3-C32-alkylene group, a Cs-C32-aryl group and combinations thereof; or R independently represents a group selected from a linear C1-C24-alkyl group or a linear C3-C24-alkylene group, preferably a linear C4-C20-alkyl group or a linear C4-C20-alkylene group, more preferably a linear C6-Cis-alkyl group or a linear C6-Cis-alkylene group, much more preferably a linear C6-Ci6-alkyl group or a linear C6-Ci6-alkylene group.

7. Composition T according to one of claims 1 to 6 for which: the polymerization reaction involves: • from 10 to 79.9 mol% or from 10 to 74.5 mol%, preferably from 10 to 68 mol% or from 10 to 60 mol%, of monomer (a) or • from 20 to 89.9 mol% or from 25 to 89.5 mol%, preferably from 30 to 88 mol% or from 35 to 85 mol%, of monomer (b), or • from 0.1 to 70 mol% or from 0.5 to 65 mol%, preferably from 2 to 60 mol% or from 5 to 55 mol%, of monomer (c), relative to the total molar quantity of monomers (a), (b) and (c); or for which: the polymerization reaction uses molar quantities of diisocyanate compound (a) and polyhydroxylated compound (b) in a molar ratio a / b ranging from 1.05 to 3, preferably from 1.1 to 2 or from 1.1 to 1.5, more preferably from 1.1 to 1.45 or from 1.1 to 1.

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8. Composition T according to one of claims 1 to 7 in which the urethane polymers comprising strictly more than 4 residues, preferably more than 5 residues or more than 6 residues, of compound (b) are in the majority in number measured by CES.

9. Composition T according to one of claims 1 to 8 for which the binding agent B is a sterically modified binding compound, preferably a binding agent B chosen from a vinyl acetate homopolymer; a vinyl acetate copolymer; a vinyl versatate homopolymer; a vinyl versatate copolymer and combinations thereof; more preferably a binding agent B chosen from: a vinyl acetate homopolymer; a copolymer comprising at least vinyl acetate and ethylene, a vinyl acetate and acrylate copolymer, a vinyl acetate and methacrylate copolymer, a vinyl acetate, ethylene and acrylate copolymer, a vinyl acetate, ethylene and methacrylate copolymer, a vinyl acetate, acrylate and methacrylate copolymer; a vinyl versatate homopolymer;a copolymer of vinyl versatate and ethylene, a copolymer of vinyl versatate and acrylate, a copolymer of vinyl versatate and methacrylate, a copolymer of vinyl versatate, ethylene and acrylate, a copolymer of vinyl versatate, ethylene and methacrylate, a copolymer of vinyl versatate, acrylate and methacrylate; a copolymer of vinyl acetate and vinyl versatate, a copolymer of vinyl acetate, vinyl versatate and ethylene, a copolymer of vinyl acetate, vinyl versatate and acrylate, a copolymer of vinyl acetate, vinyl versatate and methacrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene and acrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene and methacrylate, a copolymer of vinyl acetate, vinyl versatate, ethylene, acrylate and methacrylate and combinations thereof.

10. Composition T according to one of claims 1 to 9, preferably ink composition, varnish composition, adhesive composition, paint composition, for example decorative paint or industrial paint, comprising: from 0.1 to 4% by dry weight of rheological control agent G, from 3 to 15% by dry weight of pigments or particles, from 5 to 20% by dry weight of binding agent B, from 64.9 to 71.9% by weight of water; and optionally comprising at least one agent chosen from 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 antifoaming agent, a preservative, a biocidal agent, a spreading agent, a thickening agent, a film-forming copolymer and mixtures thereof.

11. Method for the discontinuous preparation of a rheological control agent G according to one of claims 1 to 10 comprising: • a polymerization reaction, in the absence of a monohydroxylated compound: ■ of at least one diisocyanate compound (a), ■ of at least one polyhydroxylated compound (b), followed by: • of the termination reaction of the prepolymer of compounds (a) and (b) with at least one compound (c) of formula I: HO R in which R independently represents a group chosen from a linear C1-C40-alkyl group, a branched C3-C40-alkyl group, a C5-C40-cycloalkyl group, a linear C3-C40-alkylene group, a branched C3-C40-alkylene group, a C5-C40-aryl group and combinations thereof; in which the urethane polymers comprising strictly more than 3 residues of compound (b) are in the majority in number measured by CES.

12. Method according to claim 11, wherein: the polymerization reaction is carried out in the polyhydroxylated compound (b), preferably in a molten medium of the compound (b); or the polymerization reaction uses molar quantities of diisocyanate compound (a) and polyhydroxylated compound (b) in a molar ratio a / b ranging from 1.05 to 3, preferably from 1.1 to 2 or from 1.1 to 1.5, more preferably from 1.1 to 1.45 or from 1.1 to 1.4; or the polymerization reaction is carried out for 10 minutes to 60 minutes, preferably 10 minutes to 30 minutes.

13. Rheological control agent G defined according to one of claims 1 to 10 or obtained according to the preparation method according to one of claims 11 or 12, optionally treated in an acidic manner leading to a pH lower than 8, preferably to a pH lower than 6, for example by means of an acid, in particular for example a carboxylic acid such as acetic acid or lactic acid.

14. Agent G according to claim 13 also comprising at least one solvent, in particular water or a coalescing solvent, for example glycol, butyl glycol, butyl diglycol, monopropylene glycol, ethylene glycol, ethylene diglycol, “Dowanol” products whose CAS number is 34590-94-8, “Texanol” products whose CAS number is 25265-77-4; or combined with at least one additive chosen 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, cyclodextrin derivative, poly ethers, alkyl-gluco sides; a hydrotropic compound, an antifoaming agent, a biocidal agent and combinations thereof.

15. Urethane polymer P prepared according to the method defined according to one of the claims 11 or 12 comprising strictly more than 3, preferably strictly more than 4 or strictly more than 5, more preferably strictly more than 6, residues of compound (b) measured by CES.

16. Concentrated aqueous pigment paste comprising at least one rheological control agent G according to one of claims 13 or 14 and at least one organic or mineral colored pigment.

17. Method for controlling the viscosity of an aqueous composition comprising the addition of at least one rheological control agent G according to one of claims 13 or 14 or at least one polymer P according to claim 15 in this composition.

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