EP4077457A1

EP4077457A1 - Heat-stabilizing agent

Info

Publication number: EP4077457A1
Application number: EP20841968.9A
Authority: EP
Inventors: Benoit Magny; Yves MATTER; Denis Ruhlmann; Jean Marc Suau
Original assignee: Coatex SAS
Current assignee: Coatex SAS
Priority date: 2019-12-16
Filing date: 2020-12-02
Publication date: 2022-10-26
Also published as: KR20220117250A; FR3104587B1; CN114787228A; FR3104587A1; CN114787228B; US20230025556A1; WO2021123513A1

Abstract

The invention relates to a specific polyurethane heat-stabilizing agent (P) and to the preparation of an aqueous composition which is resistant to temperature changes due to the use of said agent (P). The invention also relates to the thermal stabilization of the viscosity of an aqueous composition in a wide temperature range and for many shear gradient values.

Description

THERMO-STABILIZING AGENT

The invention relates to a particular heat-stabilizing agent (P) polyurethane as well as the preparation of an aqueous composition resistant to temperature variations thanks to the use of the agent (P). It also relates to the thermostabilization of the viscosity of an aqueous composition over a wide temperature range and for many shear gradient values.

Many technical fields require the use of aqueous compositions. In particular, there are known aqueous hydraulic binder compositions, aqueous adhesive compositions, aqueous detergent compositions, aqueous cosmetic compositions, aqueous ink compositions, aqueous paper coating compositions, aqueous coating compositions, in particular water-based coating compositions. aqueous varnish compositions or aqueous paint compositions, in particular aqueous decorative paint compositions or aqueous industrial paint compositions.

In addition to their functional properties, these aqueous compositions must have a texture suitable for their use or their storage. In particular, they must have a viscosity suitable for their use or their storage.

In addition, these aqueous compositions should be usable under conditions which can vary widely. In particular, these aqueous compositions should be used under varying temperature conditions. In fact, the properties of these aqueous compositions can vary or deteriorate when the temperature varies, both for upward temperature variations and for downward temperature variations.

In particular, the viscosity of these aqueous compositions can vary or deteriorate as the temperature varies. The functional properties of these aqueous compositions can therefore be altered in the event of variation or degradation of their viscosity during variations in temperature. Such variations or degradations are particularly detrimental or damaging for aqueous hydraulic binder compositions, for aqueous adhesive compositions, for aqueous detergent compositions, for aqueous ink compositions, for aqueous paper coating compositions, for aqueous cosmetic compositions, for aqueous coating compositions, in particular for aqueous varnish compositions or for aqueous paint compositions. Document JP 2016 065151 discloses a composition for preparing a thermosetting polyurethane elastomer. Document US 2017 0326060 describes a cosmetic composition in the form of an oil-in-water emulsion thickened by means of a hydrophobically modified polyether urethane. There is therefore a need to be able to have available aqueous compositions which do not exhibit such drawbacks or aqueous compositions which do not lead to such problems.

In particular, it is particularly useful to be able to have available aqueous coating compositions, in particular aqueous varnish compositions or aqueous paint compositions, the viscosity of which is thermally stable. Such aqueous compositions, the viscosity of which varies little or not, when the temperature at the time of their use is greater than 5 ° C. or when this temperature is less than 50 ° C., are particularly desirable. These properties are also sought after for intermediate temperature ranges which correspond to frequently encountered conditions of use, for example from 5 to 15 ° C, from 15 to 35 ° C or from 30 to 50 ° C.

On the other hand, maintaining the viscosity and limiting the loss of viscosity of these aqueous compositions should be possible for wide ranges of shear gradient, for example from 0.1 to 1000 s ¹ , from 0.1 to 100. s ¹ , from 1 to 100 s ¹ or from 0.1 to 1 s ¹ .

There is therefore a need for improved aqueous compositions. The invention allows the preparation of an aqueous composition which provides a solution to all or part of the problems of aqueous compositions of the state of the art.

Thus, the invention provides a heat-stabilizing agent (P) chosen from:

* a polyurethane (PI) prepared by reaction:

- from 0.1 to 28% by weight of at least one isocyanate compound (A) chosen independently from a diisocyanate compound (Al), a polyisocyanate compound (A2) and their combinations;

- from 2 to 99.5% by weight of at least one polyhydroxy compound (B); and

- from 0.4 to 70% by weight of at least one compound (C) chosen independently from a monoisocyanate compound (Cl) of formula I, a monohydroxylated compound (C2) of formula II, a compound (C3) of formula III and their combinations

T ⁵ -NCO

(i) in which T ¹ independently represents a linear C28-C40-alkyl group or a branched C28-C40-alkyl group;

T ² -OH

(P) in which T ² independently represents a linear C28-C40-alkyl group or a branched C28-C40-alkyl group;

R ^l - (OE) r (OPV ^ ² ^' (III) in which:

- a and b, identical or different, independently represent 0 or an integer or decimal less than 150, a or b is different from 0,

- EO independently represents a CH2CH2O group,

- OP independently represents a combination of at least one CH2CH2O group with at least one group selected from CH (CH3) CH20 and CH2CH (CH3) 0,

- R ¹ represents a group comprising at least one labile hydrogen atom and

- R ² independently represents a linear C28-C40-alkyl group or a branched C28-C40-alkyl group;

* a polyurethane (P2) prepared in the absence of any diisocyanate compound, by reaction:

- from 0.1 to 28% by weight of at least one polyisocyanate compound (A2);

- from 2 to 99.5% by weight of at least one polyhydroxy compound (B); and

- from 0.4 to 70% by weight of at least one compound (C) chosen independently from a monoisocyanate compound (Cl) of formula I, a monohydroxylated compound (C2) of formula II, a compound (C3) of formula III and their combinations. Preferably, the agent (P) is a nonionic compound, for example an alkoxylated nonionic compound. Also preferably, the agent (P) is an associative compound, for example an alkoxylated associative compound. Also preferably, the agent (P) is a nonionic associative compound, for example an alkoxylated nonionic associative compound.

Preferably according to the invention, the agent (P) is an associative compound. An associative compound makes it possible to produce associative bonds during the implementation of the composition according to the invention. These associative bonds generally develop between chemical groups of the same nature, in particular between hydrophobic groups.

The agent (P) can be polyalkoxylated and comprise at least one C2-C4 alkoxyl group, in particular at least one ethoxyl group or a propoxyl group. Preferably, the polyalkoxylated agent (P) comprises ethoxylated groups alone or in combination with propoxylated groups. Also preferably, the agent (P) comprises from 10 to 2000 C2-C4 alkoxylated groups, in particular from 100 to 1500 ethoxylated or propoxylated groups. More preferably, the alkoxylated agent (P) comprises from 100 to 1500 ethoxylated groups. Even more preferably, the alkoxylated agent (P) comprises from 250 to 1,500 ethoxylated groups.

According to the invention, the heat-stabilizing agent (P) is chosen from a polyurethane (PI) and a polyurethane (P2).

For the preparation of the heat-stabilizing agent (P), the diisocyanate compound (Al) comprises two isocyanate functions. Preferably according to the invention, the diisocyanate compound (Al) is independently chosen from:

- symmetrical aromatic diisocyanate compounds, preferably:

Diphenylmethylene 2,2'-diisocyanate (2,2'-MDI) and diphenylmethylene 4,4'-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);

- unsymmetrical 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 trimeric biuret compound, in particular a trimeric biuret compound of a compound chosen from:

- symmetrical aromatic diisocyanate compounds, preferably:

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);

2,4'-dibenzyl diisocyanate (2,4'-DBDI);

Toluene 2,4-diisocyanate (2,4-TDI);

- dissymmetric alicyclic diisocyanate compounds, preferably isophorone diisocyanate (IPDI);

- unsymmetrical aromatic diisocyanate compounds, preferably diphenylmethylene 2,4'-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 polyisocyanate compound (A2) comprises more than 2 isocyanate functions or more than 2.2 isocyanate functions or even 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.

Also preferably according to the invention, the polyisocyanate compound (A2) is independently chosen from:

- triphenylmethane-4,4 ", 4" -triisocyanate;

- l, r, l ”-methylidynetris (4-isocyanatobenzene);

- an isocyanurate compound, in particular an isocyanurate compound of a compound chosen from:

- symmetrical aromatic diisocyanate compounds, preferably:

4,4'-dibenzyl diisocyanate (4,4'-DBDI);

Toluene 2,6-diisocyanate (2,6-TDI); m-xylylene diisocyanate (m-XDI);

2,4'-dibenzyl diisocyanate (2,4'-DBDI);

Toluene 2,4-diisocyanate (2,4-TDI);

- symmetrical aromatic diisocyanate compounds, preferably:

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);

2,4'-dibenzyl diisocyanate (2,4'-DBDI);

Toluene 2,4-diisocyanate (2,4-TDI);

Also preferably according to the invention, the polyhydroxy compound (B) is chosen from:

* a compound (B1) of formula IV

(HO) -L _a - (OH) _(iv) in which:

- L independently represents a poly (alkylene glycol) residue;

- n independently represents a number ranging from 30 to 1000;

* a compound (B1) of formula IV associated with a non-alkoxylated compound (B2) comprising at least three hydroxyl groups;

* a polyalkoxylated compound (B3) comprising at least three hydroxyl groups;

* a compound (B4) of formula V:

HG (OA) _p N (Q) - (OA) _q -OH

(V) in which:

- Q independently represents a linear C28-C40-alkyl group or a branched C28-C40-alkyl group; preferably a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group;

- OA independently represents an ethoxylated group or a combination of ethoxylated groups (-CH2CH2O-) and propoxylated groups (-CH ₂ C (CH ₃ ) 0-);

- p and q independently represent a number ranging from 50 to 200;

* their combinations. Particularly preferably according to the invention, the polyhydroxy compound (B) is chosen from:

* a compound (B1) of formula IV:

(HO) -L _s - (OH) in which :

- L independently represents a poly (ethylene glycol) residue; or

- n independently represents a number ranging from 50 to 400, preferably from 100 to 300; or

- L independently represents a poly (ethylene glycol) residue and n independently represents a number ranging from 50 to 400, preferably from 100 to 300;

* a compound (B2) comprising three hydroxyl groups, preferably chosen from glycerol, pentaerythritol and their combinations;

* a compound (B3) comprising three hydroxyl groups, preferably a compound (B3) chosen from polyethoxylated glycerol, polyethoxylated pentaerythritol and their combinations;

* a compound (B4) of formula V in which Q independently represents a branched C30-C36-alkyl group or a linear C3o-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group.

More particularly preferably according to the invention, the polyhydroxy compound (B) is a compound (B1) of formula IV: in which L independently represents a poly (ethylene glycol) residue and n independently represents a number ranging from 50 to 400, preferably from 100 to 300.

Also preferably according to the invention, the compounds (B), (B1), (B3) and (B4) independently have a molar mass (Mw) measured by CES ranging from 1,500 to 40,000 g / mol, preferably of 2,000 to 20,000 g / mol, more preferably from 4,000 to 15,000 g / mol or from 5,000 to 12,000 g / mol. According to the invention, the molar mass is calculated from the hydroxyl number determined according to standard DIN 53240-1, now DIN EN ISO 4629-1 standard, applying the formula: (56,100 x functionality in OH groups) / hydroxyl number.

The Steric Exclusion Chromatography (CES) or in English “Steric Exclusion Chromatography” (SEC) is a technique which implements a Waters brand liquid chromatography apparatus equipped with a detector. This detector is a Waters brand refractometric concentration detector. This liquid chromatography apparatus is fitted with a steric exclusion column in order to separate the different molecular weights of the copolymers studied. The liquid elution phase is an aqueous phase adjusted to pH 9.00 by means of 1 N sodium hydroxide containing 0.05 M of NaHCOH, 0.1 M of NaNCE, 0.02 M of triethanolamine and 0.03% of NaN3 .

According to a first step, the copolymer solution is diluted to 0.9% dryness in the solvent for solubilizing the CES, which corresponds to the liquid phase for eluting the CES to which 0.04% of dimethylformamide is added, which plays the role of flow marker or internal standard. Then, it is filtered at 0.2 µm. 100 μL are then injected into the chromatography apparatus (eluent: an aqueous phase adjusted to pH 9.00 with IN sodium hydroxide containing 0.05 M of NaHCOH, 0.1 M of NaNCE, 0.02 M of triethanolamine and 0.03% NaN ₃ ).

The liquid chromatography apparatus contains an isocratic pump (Waters 515) whose flow rate is set at 0.8 mL / min. The chromatography apparatus also includes an oven which itself comprises the following column system as standard: a Guard Column Ultrahydrogel Waters type precolumn 6 cm in length and 40 mm in internal diameter and a linear column of Waters Ultrahydrogel type 30cm in length and 7.8mm inside diameter. The detection system consists of an RI Waters 410 type refractometric detector. The oven is brought to a temperature of 60 ° C and the refractometer is brought to a temperature of 45 ° C. Molecular masses are assessed by dynamic light scattering detection using a Viscotek Dual 270 detector whereby the molecular mass is determined from the hydrodynamic volume of the copolymer.

More preferably according to the invention, the polyhydroxy compound (B) is a compound (B1) of formula IV in which L independently represents a poly (ethylene glycol) residue, n independently represents a number ranging from 30 to 1000 and of molar mass (Mw) measured by CES ranging from 2000 to 20,000 g / mol, preferably from 4000 to 15000 g / mol or from 5000 to 12000 g / mol.

Much more preferably according to the invention, the polyhydroxy compound (B) is a compound (B1) of formula IV in which L independently represents a poly (alkylene glycol) residue, preferably a poly (ethylene glycol) residue, and n independently represents a number ranging from 30 to 1000, preferably from 40 to 500 or from 80 to 400, more preferably from 100 to 300.

Also preferably, the compound (C) is chosen from:

* a monoisocyanate compound (Cl) of formula I in which T ¹ independently represents a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group;

* a monoisocyanate compound (Cl) comprising a single isocyanate function, preferably a monoisocyanate compound (Cl) prepared by a separate reaction:

- at least one compound comprising at least one labile hydrogen atom and

- at least one diisocyanate compound, preferably an unsymmetrical diisocyanate compound, at least one polyisocyanate compound, and combinations thereof;

* a monohydroxylated compound (C2) of formula II in which T ² independently represents a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group;

* a compound (C3) of formula III in which a represents an integer or decimal ranging from 5 to 100, b represents 0, R ¹ represents a group comprising at least one labile hydrogen atom and R ² represents a C30- group Linear C36-alkyl or a branched C30-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group.

According to the invention, the compounds comprising at least one labile hydrogen atom comprise at least one hydrogen atom which is reactive with a compound comprising at least one isocyanate function (-N = C = 0). Preferably, the compounds comprising at at least one labile hydrogen atom are chosen from a compound comprising at least one hydroxyl group (-OH); a compound comprising a primary amine function (-NH2) or a secondary amine function (-N (H) -); preferably a compound comprising a hydroxyl group, in particular a monoalcohol, for example a monoalcohol in C28-C40-linear alkyl or a monoalcohol in C28-C40-branched alkyl; preferably a branched C30-C36-alkyl monoalcohol; more preferably a branched C32-alkyl monoalcohol.

Particularly preferably, the agent (P) according to the invention is a compound prepared by reaction:

- at least one diisocyanate compound (Al);

- at least one compound (B1) of formula IV in which L independently represents a poly (ethylene glycol) residue, n independently represents a number ranging from 30 to 1000 and of molar mass (Mw) measured by CES ranging from 2000 to 20,000 g / mol, preferably 4,000 to 15,000 g / mol or 5,000 to 12,000 g / mol; and

- at least one monohydroxylated compound (C2) of formula II in which T ² independently represents a linear C28-C40-alkyl group or a branched C28-C40-alkyl group, preferably a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group.

Also preferably, the agent (P) according to the invention is a compound prepared by reaction:

- at least one diisocyanate compound (Al);

- at least one compound (C3) of formula III in which a represents an integer or decimal ranging from 5 to 100, b represents 0, R ¹ represents a hydroxyl group and R ² represents a linear C28-C40-alkyl group or a branched C28-C40-alkyl group, preferably a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group. The agent (P) can be prepared by preparation methods analogous to the methods of preparing urethane compounds of the state of the art. During the preparation of the agent (P) according to the invention, the amounts of reagents used may vary.

According to the invention, the agent (P) is prepared by at least one polymerization reaction:

- from 0.1 to 28% by weight of monomer (A),

- from 2 to 99.5% by weight of monomer (B),

- From 0.4 to 70% by weight of monomer (C), relative to the total amount by weight of monomers.

Preferably according to the invention, the agent (P) is prepared by at least one polymerization reaction:

- from 0.2 to 26% by weight of monomer (A),

- from 6 to 99.3% by weight of monomer (B),

- from 0.5 to 68% by weight of monomer (C), relative to the total amount by weight of monomers.

Also more preferably according to the invention, the agent (P) is prepared by at least one polymerization reaction:

- from 1 to 20% by weight of monomer (A),

- from 25 to 94% by weight of monomer (B),

- from 5 to 55% by weight of monomer (C) relative to the total amount by weight of monomers.

- from 1 to 15% by weight of monomer (A),

- from 40 to 94% by weight of monomer (B),

- from 5 to 45% by weight of monomer (C), relative to the total amount by weight of monomers.

According to the invention, the heat-stabilizing agent (P) can be prepared by polymerization reaction of at least one isocyanate compound (A), of at least one polyhydroxy compound (B) and of at least one compound ( VS). The heat-stabilizing agent (P) can therefore be prepared by polymerization reaction of only compounds (A), (B) and (C). Preferably according to the invention, the condensation of compounds (A), (B) and (C) is carried out in the presence of a catalyst. This catalyst can be chosen from acetic acid, an amine, preferably l, 8-diazabicyclo [5.4.0] undec-7-ene (DBU), a derivative of a metal chosen from Al, Bi, Sn, Hg, Pb, Mn, Zn, Zr, Ti. Traces of water can also participate in the catalysis of the reaction. As examples of metal derivatives, preferred is a derivative selected from dibutyl bismuth dilaurate, dibutyl bismuth diacetate, dibutyl bismuth oxide, bismuth carboxylate, dibutyl tin dilaurate, dibutyl tin diacetate, dibutyl tin oxide, a mercury derivative. , a derivative of lead, zinc salts, manganese salts, a compound comprising chelated zirconium, a compound comprising chelated aluminum. The preferred metal derivative is chosen from a derivative of B i and a derivative of Sn.

Advantageously, the urethane compound according to the invention is a compound having a hydrophilic character. The agent (P) can be used directly or else in a co-formulated form, preferably in the form of an aqueous formulation, for example an aqueous formulation combining at least one agent (P) and at least one compound. anionic surfactant or at least one nonionic surfactant compound or else a compound chosen from cyclodextrin, alkyl-glucosides, osides, solvents.

The invention also provides a method of preparing an aqueous composition which is heat-resistant to temperature variations comprising the addition to the aqueous composition of at least one heat-stabilizing agent (P) defined according to the invention.

Depending on the invention, the amounts of agent (P) used may vary. The invention also provides such an aqueous composition. Preferably, the aqueous composition prepared according to the invention comprises from 0.05 to 5% by weight, preferably from 0.1 to 2% by weight, of agent (P) relative to the total weight of the composition. According to the invention, the amounts of agent (P) used are expressed for the agent (P) as such, therefore dry.

Also preferably, the aqueous composition according to the invention is chosen from a hydraulic binder composition, an adhesive composition, a detergent composition, a cosmetic composition, an ink composition, an aqueous paper coating composition, a composition of coating. Preferably according to the invention, the aqueous composition is a varnish composition or a composition of paint or a decorative paint composition or an industrial paint composition.

The implementation of the heat-stabilizing agent (P) of the invention provides a heat-resistant function or a function of resistance to temperature variations to the aqueous composition. These functions can be advantageously implemented when the aqueous composition is subjected to an increase in temperature or else when the aqueous composition is subjected to a decrease in temperature. In addition to its action on the thermal resistance or resistance to temperature variations of the aqueous composition according to the invention, the use of the agent (P) according to the invention makes it possible to influence the viscosity of the composition according to the invention. In particular, the agent (P) makes it possible to obtain an aqueous composition whose viscosity is thermostable at a low shear gradient or at a medium shear gradient, optionally at a high shear gradient.

According to the invention, the effectiveness of the heat-stabilizing agent (P) is evaluated by measurements of viscosity and the evolution of this viscosity. Then, the agent (P) is implemented in an aqueous formulation for which the viscosity is evaluated after 24 hours by measuring flow curves for different shear gradients (Thermo Scientific Mars III rheometer using a cone-plane geometry of 60 mm in diameter and 1 ° angle) and at different temperatures. According to the invention, the initial viscosity is the viscosity measured at a particular shear gradient before changing the temperature in a determined temperature range. The change in viscosity can then be evaluated by comparing a particular viscosity value with the initial viscosity.

Preferably, the change in viscosity is evaluated for temperature variations ranging from 5 to 50 ° C or ranging from 30 to 50 ° C or ranging from 15 to 35 ° C or even ranging from 5 to 15 ° C. For these temperature ranges, the initial viscosity is the viscosity measured respectively at 5 ° C, at 30 ° C, at 15 ° C and at 5 ° C.

The effectiveness of the heat-stabilizing agent (P) according to the invention can be evaluated by comparison with similar formulations which do not include a heat-stabilizing agent (P) but a comparative polymer. Essentially according to the invention, the heat-stabilizing agent (P) makes it possible to maintain the viscosity of the aqueous composition at high values for wide ranges of temperature. Also, the heat-stabilizing agent (P) makes it possible to maintain the viscosity of the aqueous composition at high values for many values of shear gradient, preferably for wide ranges of temperature. Thus, preferably according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 30%. and 98%, preferably between 44% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ and for a temperature variation ranging from 30 to 50 ° C, between 50% and 98%, preferably between 65% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ and for a temperature variation ranging from 15 to 35 ° C, between 50% and 98%, preferably between 68% and 98%, the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ and for a temperature variation ranging from 5 to 15 ° C, between 70% and 98%, preferably between 81% and 98%, of the initial viscosity value of the aqueous composition.

Also preferably according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 30% and 98. %, preferably between 44% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ and for a temperature variation ranging from 30 to 50 ° C, ranging between 50% and 98%, of preferably between 68% and 98%, of the initial viscosity value of the aqueous composition. Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ and for a temperature variation ranging from 15 to 35 ° C, ranging between 50% and 98%, of preferably between 66% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ and for a temperature variation ranging from 5 to 15 ° C, ranging between 70% and 98%, of preferably between 81% and 98%, of the initial viscosity value of the aqueous composition.

Also preferably according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 1 to 100 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 30% and 98%, preferably between 44% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 1 to 100 s ¹ and for a temperature variation ranging from 30 to 50 ° C, between 50% and 98%, preferably between 67% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 1 to 100 s ¹ and for a temperature variation ranging from 15 to 35 ° C, between 70% and 98%, preferably between 84% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 1 to 100 s ¹ and for a temperature variation ranging from 5 to 15 ° C, between 70% and 98%, preferably between 81% and 98%, of the initial viscosity value of the aqueous composition.

Also preferably according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 40% and 98. %, preferably between 56% and 98%, of the initial viscosity value of the aqueous composition. Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ and for a temperature variation ranging from 30 to 50 ° C, ranging between 40% and 98%, of preferably between 67% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ and for a temperature variation ranging from 15 to 35 ° C, ranging between 70% and 98%, of preferably between 84% and 98%, of the initial viscosity value of the aqueous composition.

Also according to the invention, the aqueous composition has a viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ and for a temperature variation ranging from 5 to 15 ° C, ranging between 80% and 98%, of preferably between 95% and 98%, of the initial viscosity value of the aqueous composition.

In addition to maintaining the viscosity, the heat-stabilizing agent (P) also advantageously makes it possible to heat-stabilize the viscosity of the aqueous composition for numerous values of shear gradient and for wide ranges of temperature relative to the temperature. initial viscosity of the aqueous composition. Thus, the agent (P) makes it possible to limit the loss of viscosity of the aqueous composition subjected to a temperature variation. The agent (P) used according to the invention makes it possible to limit the loss of viscosity for different values of the shear gradient applied to the aqueous composition, therefore for different conditions of use of this composition. The invention therefore also relates to a method of thermostabilizing the viscosity of an aqueous composition which is particularly advantageous during temperature variations at the time of preparation or else at the time of transport or storage, and even more at the time of storage. the application or use of the aqueous composition according to the invention. Preferably, the thermostabilization method according to the invention makes it possible to limit or even avoid the reduction in the viscosity of the aqueous composition according to the invention during temperature variations at the time of application or use of G. the aqueous composition according to the invention. Preferably, the thermostabilization method according to the invention makes it possible to limit or even avoid the reduction in the viscosity of the aqueous composition according to the invention for variations temperature ranging from 5 to 50 ° C or ranging from 30 to 50 ° C or ranging from 15 to 35 ° C or even ranging from 5 to 15 ° C.

Thus, the invention provides a method of thermostabilizing the viscosity of an aqueous composition comprising the addition to the aqueous composition of at least one agent (P) according to the invention.

Particularly advantageously, the thermostabilization method according to the invention makes it possible to limit or even avoid the reduction in the viscosity of the aqueous composition according to the invention during temperature variations.

Preferably, the method of thermostabilizing the viscosity of an aqueous composition comprises the addition of at least one thermostabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a gradient of shear ranging from 0.1 to 1000 s ¹ is less than 70%, preferably less than 56%, for a temperature range of 5 to 50 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermostabilizing the viscosity of an aqueous composition comprises the addition of at least one thermostabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ is less than 50%, preferably less than 35%, for a temperature range of 30 to 50 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermostabilizing the viscosity of an aqueous composition comprises the addition of at least one thermostabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ is less than 50%, preferably less than 32%, for a temperature range of 15 to 35 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermostabilization of the viscosity of an aqueous composition comprises the addition of at least one thermostabilizer (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ is less than 30%, preferably less than 19%, for a temperature range ranging from 5 to 15 ° C, relative to the initial viscosity of the aqueous composition.

Also preferably, the method of thermostabilizing the viscosity of an aqueous composition comprises the addition of at least one thermostabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a gradient shear rate ranging from 0.1 to 100 s ¹ is less than 70%, preferably less than 56%, for a temperature range of 5 to 50 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ is less than 50%, preferably less than 32%, for a temperature range ranging from 30 to 50 ° C, relative to the initial viscosity of the aqueous composition. Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ is less than 50%, preferably less than 34%, for a temperature range of 15 to 35 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ is less than 30%, preferably less than 19%, for a temperature range of 5 to 15 ° C, relative to the initial viscosity of the aqueous composition. Also preferably, the method of thermostabilizing the viscosity of an aqueous composition comprises the addition of at least one thermostabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a gradient shear rate ranging from 1 to 100 s ¹ is less than 70%, preferably less than 56%, for a temperature range of 5 to 50 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 1 to 100 s ¹ is less than 50%, preferably less than 33%, for a temperature range ranging from 30 to 50 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 1 to 100 s ¹ is less than 30%, preferably less than 16%, for a temperature range of 15 to 35 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 1 to 100 s ¹ is less than 30%, preferably less than 19%, for a temperature range of 5 to 15 ° C, relative to the initial viscosity of the aqueous composition.

Also preferably, the method of thermostabilizing the viscosity of an aqueous composition comprises the addition of at least one thermostabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a gradient shear rate ranging from 0.1 to 1 s ¹ is less than 60%, preferably less than 44%, for a temperature range of 5 to 50 ° C, relative to the initial viscosity of the aqueous composition. Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ is less than 50%, preferably less than 33%, for a temperature range ranging from 30 to 50 ° C, relative to the initial viscosity of the aqueous composition.

Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ is less than 30%, preferably less than 16%, for a temperature range of 15 to 35 ° C, relative to the initial viscosity of the aqueous composition. Also according to the invention, the method of thermo-stabilization of the viscosity of an aqueous composition comprises the addition of at least one thermo-stabilizing agent (P) in the aqueous composition for which the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ is less than 20%, preferably less than 5%, for a temperature range of 5 to 15 ° C, relative to the initial viscosity of the aqueous composition.

Preferably for the thermo-stabilization method according to the invention, there is added to the aqueous composition from 0.05 to 5% by weight, preferably from 0.1 to 2% by weight, of agent (P) per relative to the total weight of the composition.

The invention also provides a method of improving the resistance to temperature variations of an aqueous composition comprising the addition to the aqueous composition of at least one heat-stabilizing agent (P) defined according to the invention. In a particularly advantageous manner, the method of improving the resistance to temperature variations according to the invention makes it possible to limit or even avoid the reduction in the viscosity of the aqueous composition, preferably during temperature variations at the time of preparation. or else at the time of transport or storage or else at the time of application or use of the aqueous composition according to the invention. Preferably according to the invention, the method of improving the resistance to temperature variations of an aqueous composition is implemented at a temperature ranging from 5 to 50 ° C or ranging from 30 to 50 ° C or ranging from 15 to 35 ° C or even ranging from 5 to 15 ° C.

Preferably, for the method of improving resistance to temperature variations according to the invention, 0.05 to 5% by weight, preferably 0.1 to 2% by weight, is added to the aqueous composition, d agent (P) relative to the total weight of the composition.

The aqueous composition according to the invention can be used in several technical fields. Preferably, the aqueous composition according to the invention is used in the field of materials, in particular in the form of a hydraulic binder composition or of an adhesive composition, in the field of detergents, in particular in the form of a detergent composition, in the field of cosmetics, in particular in the form of a cosmetic composition, in the field of printing, in particular in the form of an ink composition, in the field of papermaking, in particular in the form of an aqueous paper coating composition, in the field of coatings, for example in the fields of varnishes or paints, in particular in the form of a coating composition, in particular a varnish composition or a paint composition, or else a decorative paint composition or an industrial paint composition.

The invention therefore provides a formulation F comprising at least one aqueous composition according to the invention in combination with at least one functional substance useful in the field of use of the formulation.

Preferably, the formulation according to the invention is a coating composition, in particular a varnish composition or a paint composition. The formulation according to the invention then combines at least one aqueous composition according to the invention and at least one substance chosen from an organic or inorganic pigment, organic particles, organo-metallic particles, mineral particles, for example calcium carbonate, talc, kaolin, mica, silicates, silica, metal oxides, especially titanium dioxide, iron oxides. The formulation according to the invention can also comprise at least one agent selected from a particle spacer, a dispersing agent, a steric stabilizing agent, an electrostatic stabilizing agent, an opacifying agent, a solvent, a coalescing agent, an antifoaming agent, a preservative, an agent biocide, a spreading agent, a thickening agent, a film-forming copolymer and mixtures thereof.

Furthermore, the formulation according to the invention can be a concentrated aqueous pigment paste comprising at least one aqueous composition according to the invention and at least one organic or inorganic colored pigment.

The following examples illustrate the various aspects of the invention.

Example 1: preparation of urethane compounds (PI a) and (Pib) according to the invention and of a comparative urethane compound (PCI) In a 3 L glass reactor (vessel 1) equipped with mechanical stirring, a vacuum pump, with a nitrogen inlet and heated by means of a double jacket in which oil circulates, 357 g of compound (B) (polyethylene glycol of molecular mass (M _w ) 8000 or PEG 8000) which is heated to 90 ° C under an inert atmosphere. 139.8 g of dotriacontane alcohol (monoalcohol comprising a branched C32-alkyl group which is ethoxylated with 25 equivalents of ethylene oxide as compound (C3) of formula III in which a represents 25, EO represents a group CH2CH2O, R ¹ represents OH and R ² represents a branched C32-alkyl group This mixture is subjected to vacuum / inert atmosphere cycles until the water level reaches or is less than 1500 ppm.

29.7 g of isophorone diisocyanate (IPDI) are then rapidly added as compound (Al) and containing 0.3 g of a catalyst of bismuth carboxylate type. After complete addition, the reaction mixture is left under stirring for 60 minutes at 90 ° C ± 1 ° C. Then, it is checked that the level of isocyanate is zero by a back assay. 1 g of the reaction medium is taken to which an excess of dibutylamine (1 molar for example) which reacts with the isocyanate functions potentially present in the medium is added. The dibutylamine which may not have reacted is then determined with hydrochloric acid (1 N for example). The quantity of isocyanate functions present in the reaction medium can then be deduced therefrom. If this is not zero, the reaction is prolonged by a period of 15 minutes until the reaction is complete. The heat-stabilizing agent (Pla) according to the invention is obtained.

Similarly, a heat-stabilizing agent (Pib) according to the invention is prepared using 382.1 g of PEG 8000 as compound (B), 55.7 g of dotriacontane alcohol (monoalcohol comprising a branched C32-alkyl group ) non-ethoxylated as compound (C2) of formula II in which T ² represents a C32-branched alkyl group and 26.5 g of IPDI as compound (Al). The heat-stabilizing agent (Pib) according to the invention is obtained. Analogously, a comparative urethane compound (PCI) is prepared using

437.8 g of PEG 8000, 165 g of tristyrylphenolic alcohol (monoalcohol comprising a tristyrylphenolyl group) which is ethoxylated with 25 equivalents of ethylene oxide and

36.8 g of IPDI as compound (Al). The comparative urethane compound (PCla) is obtained.

Example 2: preparation and evaluation of aqueous formulations comprising a heat-stabilizing agent according to the invention or a comparative urethane compound

Pour 400 mL of bipermuted water into a 500 mL beaker and heat to 60 ° C. With mechanical stirring, 8.16 g of heat stabilizer (Pla) are added. This addition is made slowly in order to allow a gradual homogenization of the mixture. A gelled formulation F1 is obtained according to the invention.

Similarly, a gelled formulation F2 is prepared according to the invention by replacing the heat-stabilizing agent (PI) with 21.05 g of heat-stabilizing agent (Pib). Also in an analogous manner, a gelled FC1 formulation according to the invention is prepared by replacing the heat-stabilizing agent (Pla) with 44.04 g of comparative compound (PCI). The amount of water in formulations F2 and FC1 is adjusted so that these formulations have starting viscosities comparable to that of formulation F1 for a shear gradient of 10 s ¹ .

The thickening efficiency of the formulations is evaluated after 24 hours by measuring flow curves at different shear gradients (Thermo Scientific Mars III rheometer using a cone-plane geometry 60 mm in diameter and 1 ° angle) and for different temperatures. The thermal stability of the formulation is then evaluated by calculating the change in viscosity as a function of the change in temperature for the different applied shear gradients. The change in viscosity is calculated in a standardized manner with respect to the viscosity measured at 4.9 ° C, for each measured viscosity value, the ratio R is calculated (viscosity measured at a certain temperature / viscosity measured at 4.9 ° C) corresponding to the residual viscosity of each formulation evaluated.

The results of viscosity values and R ratios for formulation F1 comprising the agent (PI) according to the invention are presented in Table 1.

[Table 1]

The results for a formulation F2 comprising the agent (Pib) according to the invention are presented in Table 2. [Table 2]

The results for the comparative formulation FC1 comprising the comparative polymer (PCI) are shown in Table 3. [Table 3]

For different shear gradient values, the change in viscosity of formulations comprising an agent according to the invention or a comparative polymer is compared for different temperature ranges by calculating the loss of viscosity.

The viscosity loss results are shown in Table 4. [Table 4]

For many temperature ranges, it is found that the heat stabilizing agents according to the invention make it possible to limit the loss of viscosity to a much greater extent than the comparative polymer. This thermostabilization of the viscosity is possible for shear gradient values corresponding to many conditions of use or application of aqueous compositions.

Claims

I. Heat-stabilizing agent (P) chosen from: * a polyurethane (PI) prepared by reaction:

- from 2 to 99.5% by weight of at least one polyhydroxy compound (B); and - 0.4 to 70% by weight of at least one compound (C) chosen independently from a monoisocyanate compound (Cl) of formula I, a monohydroxy compound (C2) of formula

II, a compound (C3) of formula III and their combinations

TP-NCQ

T - OH

R ¹ - (OE) ₃ - (OP) _b -R ²

(III) in which:

- EO independently represents a CH2CH2O group,

- OP independently represents a combination of at least one CH2CH2O group with at least one group selected from OH (ϋ¾) OH2q and CH2CH (CH3) 0,

- R ¹ represents a group comprising at least one labile hydrogen atom and - R ² independently represents a linear C28-C40-alkyl group or a group

Branched C28-C40-alkyl; * a polyurethane (P2) prepared in the absence of any diisocyanate compound, by reaction:

- from 0.1 to 28% by weight of at least one polyisocyanate compound (A2);

- from 2 to 99.5% by weight of at least one polyhydroxy compound (B); and

- 0.4 to 70% by weight of at least one compound (C) chosen independently from a monoisocyanate compound (Cl) of formula I, a monohydroxyl compound (C2) of formula II, a compound (C3) of formula III and their combinations.

2. Agent (P) according to claim 1 for which the polyisocyanate compound (A2) comprises more than 2 isocyanate functions or more than 2.2 isocyanate functions or even 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.

3. Agent (P) according to one of claims 1 or 2 for which the polyhydroxy compound (B) is chosen from:

* a compound (B1) of formula IV: in which :

- L independently represents a poly (alkylene glycol) residue;

- n independently represents a number ranging from 30 to 1000;

* a polyalkoxylated compound (B3) comprising at least three hydroxyl groups;

* a compound (B4) of formula V:

HO- (OA) _p N (Q) - (OA) _q -OH

(V) in which: - Q independently represents a linear C28-C40-alkyl group or a branched C28-C40-alkyl group; preferably a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group;

- OA independently represents an ethoxylated group or a combination of ethoxylated groups (-CH2CH2O-) and propoxylated groups _{(-0H 2} 0 (ϋ¾) 0-);

- p and q independently represent a number ranging from 50 to 200;

* their combinations.

4. Agent (P) according to one of claims 1 to 3 for which the compound (B) is chosen from:

* a compound (B1) of formula IV:

[chem IV] in which :

- L independently represents a poly (ethylene glycol) residue; or

5. Agent (P) according to one of claims 1 to 4 for which the compounds (B), (B1), (B3) and (B4) independently have a molar mass (Mw) measured by CES ranging from 1500 to 40,000 g / mol, preferably from 2000 to 20,000 g / mol, more preferably from 4,000 to 15,000 g / mol or from 5,000 to 12,000 g / mol.

6. Agent (P) according to one of claims 1 to 5 for which:

* the monoisocyanate compound (Cl) is a compound of formula I in which T ¹ independently represents a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; preferably C30-C36-branched alkyl; more preferably a branched C32-alkyl group; or

* the monoisocyanate compound (Cl) is prepared by a separate reaction:

- at least one compound comprising at least one labile hydrogen atom, preferably an alcohol comprising a linear C28-C40-alkyl group or an alcohol comprising a branched C28-C40-alkyl group, for example a C28- monoalcohol Linear C40-alkyl or a branched C28-C40-alkyl monoalcohol, more preferably a branched C32-alkyl monoalcohol and

- at least one diisocyanate compound, preferably an unsymmetrical diisocyanate compound, at least one polyisocyanate compound, and combinations thereof; or

* the monohydroxylated compound (C2) is a compound of formula II in which T ² independently represents a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group or

* the compound (C3) is a compound of formula III in which a represents an integer or decimal ranging from 5 to 100, b represents 0, R ¹ represents a group comprising at least one labile hydrogen atom and R ² represents a linear C30-C36-alkyl group or a branched C30-C36-alkyl group; preferably a branched C30-C36-alkyl group; more preferably a branched C32-alkyl group.

7. Agent (P) according to one of claims 1 to 6 prepared by at least one polymerization reaction:

- from 0.2 to 26% by weight, preferably from 1 to 20% by weight or from 1 to 15% by weight, of monomer (A), - from 6 to 99.3% by weight, preferably from 25 to 94% by weight or from 40 to 94% by weight, of monomer (B), and

- From 0.5 to 68% by weight, preferably from 5 to 55% by weight or from 5 to 45% by weight, of monomer (C), relative to the total amount by weight of monomers.

8. A method of preparing an aqueous composition which is heat-resistant to temperature variations comprising the addition to the aqueous composition of at least one heat-stabilizing agent (P) defined according to one of claims 1 to 7.

9. Method according to claim 8 for which the aqueous composition comprises from 0.05 to 5% by weight, preferably from 0.1 to 2% by weight, of agent (P) relative to the total weight of the composition.

10. Method according to one of claims 8 or 9 for which the aqueous composition

- has a viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 30% and 98%, preferably between 44% and 98% , the initial viscosity value of the aqueous composition, or

- has a viscosity measured for a shear gradient ranging from 0.1 to 100 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 30% and 98%, preferably between 44% and 98%, the initial viscosity value of the aqueous composition, or

- has a viscosity measured for a shear gradient ranging from 1 to 100 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 30% and 98%, preferably between 44% and 98%, of the initial viscosity value of the aqueous composition, or

- has a viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ and for a temperature variation ranging from 5 to 50 ° C, between 40% and 98%, preferably between 56% and 98%, of the initial viscosity value of the aqueous composition.

11. Aqueous composition according to one of claims 8 to 10.

12. An aqueous composition according to claim 11 selected from a hydraulic binder composition, an adhesive composition, a detergent composition, a cosmetic composition, an ink composition, an aqueous paper coating composition, a coating composition. Preferably according to the invention, the aqueous composition is a varnish composition or a paint composition or else a decorative paint composition or an industrial paint composition.

13. A method of thermostabilizing the viscosity of an aqueous composition comprising the addition of at least one agent (P) defined according to one of claims 1 to 7 in the aqueous composition, for which:

- the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1000 s ¹ is less than 70%, preferably less than 56%, for a temperature range ranging from 5 to 50 ° C, relative to to the initial viscosity of the aqueous composition, or - the decrease in viscosity measured for a shear gradient ranging from 0.1 to

100 s ¹ is less than 70%, preferably less than 56%, for a temperature range from 5 to 50 ° C, relative to the initial viscosity of the aqueous composition, or

- the decrease in viscosity measured for a shear gradient ranging from 1 to 100 s ¹ is less than 70%, preferably less than 56%, for a temperature range ranging from 5 to 50 ° C, relative to the viscosity initial aqueous composition, or

- the decrease in viscosity measured for a shear gradient ranging from 0.1 to 1 s ¹ is less than 60%, preferably less than 44%, for a temperature range ranging from 5 to 50 ° C, relative to the initial viscosity of the aqueous composition.

14. A method of thermostabilization according to claim 13 for which is added to the aqueous composition from 0.05 to 5% by weight, preferably from 0.1 to 2% by weight, of agent (P) relative to the total weight of the composition.

15. A method of improving the resistance to temperature variations of an aqueous composition comprising the addition to the aqueous composition of at least one heat-stabilizing agent (P) defined according to one of claims 1 to 7.