WO2013093317A1

WO2013093317A1 - Process for obtaining, via the sol-gel process, a durable functional coating for supports, especially textiles, and coating thus obtained

Info

Publication number: WO2013093317A1
Application number: PCT/FR2012/052961
Authority: WO
Inventors: Isabelle Ferreira; Rahime Merve KARABULUT; Hélène BLAS
Original assignee: Institut Francais Textile & Habillement
Priority date: 2011-12-20
Filing date: 2012-12-17
Publication date: 2013-06-27
Also published as: FR2984343B1; FR2984343A1

Abstract

The present invention relates to a composition for coating a support comprising: -an aqueous solvent; -a polycarboxylic acid; -a catalyst for the formation of an anhydrous acid intermediate starting from polycarboxylic acid; -a sol-gel precursor, all the groups of which are hydrolysable, with functional particles and/or a sol-gel precursor comprising at least one non-hydrolysable functional group; or a sol-gel precursor comprising at least one non-hydrolysable functional group, and optionally functional particles, the use thereof for coating a support and the coating thus obtained.

Description

PROCESS FOR THE SOL-GEL PRODUCTION OF A SUSTAINABLE FUNCTIONAL COATING FOR SUBSTRATES, IN PARTICULAR TEXTILES, AND COATING THUS OBTAINED

FIELD OF THE INVENTION

The present invention relates to the coating of supports, in particular textile, to durably give them desired properties (hydrophobicity, oleophobia, wrinkle-proofing, coloring, etc.). More precisely, the invention aims at a composition that can be used in a process for synthesizing a soil in one step, making it possible to coat different types of supports and to make them functional or even multifunctional in a sustainable manner.

PRIOR STATE OF THE ART

In the field of textiles, a sector in full development is that of technical and functional (or multifunctional) textiles. These textiles are high performance products, with specific properties adapted to certain uses. These textiles can be woven, knitted or non-woven and the fields of application are very varied: clothing, medical field, transport .... The properties conferred to these textiles are also very diverse: high resistance, anti-fire, antimicrobial , water repellency, anti-UV,

Moreover, a constant concern with functional textiles is to improve the persistence over time (or durability) of the particular properties presented by these textiles, in other words to ensure their resistance to use, the resistance to washes and the non-release of the assets conferring these properties, for example provided in the form of particles. Various techniques have been explored to provide a textile support with a functional and possibly durable coating. Thus, and for some years, sol-gel treatments have been applied to textiles by impregnation, for example to give them abrasion resistance properties or to incorporate medical treatments therein. In known manner, the sol-gel chemistry relies on hydrolysis and condensation reactions of alkoxysilane precursors in a water / ethanol solvent, catalyzed by acids or bases. These reactions initially lead to the formation of a sol consisting of small oligomers in solution. Following the continuation of the condensation, these reactions make it possible to obtain an inorganic network inflated with solvent, called gel. The solvent is then removed from the gel by various operations to form a material (sol-gel), for example a film or coating.

Thus, it has been described the provision of durable hydrophobic functions to cellulosic textiles using formulations of silicon alkoxides and polyacids, used in a sol-gel process.

Specifically, the documents Huang et al. from 2010 and 2011 (Wenqi Huang, Yanjun Xing and Dai jinjin, "Durable Cellulosic Hydrophobic Fabric Prepared with Polyacid Acid Catalyze Silica Soil", Ind Eng., Chem Res 2010, 49, 9135-9142, Wenqi Huang, Yanjun Xing, yunyi Yu, Songmin Shang, Jinjin Dai, "Applied Surface Science 257 (2011) 4443-4448) report a 2-step treatment on desensitized cotton fabrics: formation of a tetraethoxysilane-based sol and a polyacid, which is impregnated on cotton fabrics, then application of a solution based hexadecyltrimethoxysilane in ethanol as a hydrophobic treatment.

In practice, the coating of the textile with a hydrophobic layer is as follows:

In a first step, an aqueous composition is prepared, containing TEOS, a polycarboxylic acid such as BTCA (butanetetracarboxylic acid) and a catalyst for the formation of an anhydrous acid from the polycarboxylic acid, for example sodium hypophosphite (NaH ₂ PO ₂ ). The composition is mixed and stirred to obtain an SiO ₂ sol. Cellulosic fabric is impregnated by immersion then dried. Alternatively, it is the cellulosic fabric which is immersed in the presence of the polycarboxylic acid and the catalyst and, after drying, is immersed in a soil of SiO ₂ (hydrolysed TEOS). In a second step, a non-aqueous composition (for example in ethanol) is prepared, containing a siloxane alkyl, for example HDTMS, to form a solution in which this precursor is not pre-hydrolysed. The tissue obtained at the end of the first step is immersed in this composition and then dried. According to this treatment, HDTMS, whose hexadecyl chain confers hydrophobicity, would therefore be grafted onto the surface of the sol-gel layer, said layer being itself bound to the cellulose support via the polycarboxylic acid.

Even if data relating to washing durability could be reported for these hydrophobic coatings, the methods of obtaining these coatings have limitations: They are long and tedious and require many manipulations (2 steps; drying, ...). Furthermore, their feasibility has been demonstrated only in relation to cellulosic textile supports and for the integration of a hydrophobicity function. Finally, the absence of hydrolysis / controlled condensation of HDTMS does not allow its optimal incorporation, especially homogeneous, in the coating.

There is therefore a clear need for new processes to provide supports, including textiles, a durable functional coating, giving them properties of interest.

SUMMARY OF THE INVENTION

The present invention is based on the demonstration by the Applicant that flexible supports, especially textile, could be coated with the composition or sol-gel formulation subject of the present invention. This coating makes it possible to confer at least one feature, or even more, in a sustainable manner to said support. Thus, according to a first aspect, the present invention relates to a composition for coating a support comprising:

an aqueous solvent;

a polycarboxylic acid;

a catalyst for the formation of an anhydrous acid intermediate from the polycarboxylic acid;

a sol-gel precursor, all the groups of which are hydrolysable, with functional particles and / or a sol-gel precursor comprising at least one non-hydrolyzable functional group; or a sol-gel precursor comprising at least one non-hydrolysable functional group, and optionally functional particles.

Characteristically, the composition according to the invention thus comprises:

a sol-gel precursor, all the groups of which are hydrolysable, associated with functional particles and / or a sol-gel precursor comprising at least one non-hydrolysable functional group; or

a sol-gel precursor comprising at least one non-hydrolysable functional group, and optionally functional particles. In other words, it can contain:

a sol-gel precursor, all the groups of which are hydrolyzable, and functional particles; or

a sol-gel precursor, all of whose groups are hydrolyzable, and a sol-gel precursor comprising at least one non-hydrolyzable functional group; or

a sol-gel precursor, all of whose groups are hydrolyzable, a sol-gel precursor comprising at least one non-hydrolyzable functional group and functional particles; or

a sol-gel precursor comprising at least one non-hydrolyzable functional group; or

a sol-gel precursor comprising at least one non-hydrolyzable functional group and functional particles. According to a first embodiment, the composition or formulation according to the invention therefore contains a first sol-gel precursor intended to form the matrix or the sol-gel network. Advantageously, this sol-gel precursor is characterized in that all its groups are hydrolyzable.

Typically, this sol-gel precursor is a metal alkoxide, a semi-metal alkoxide, or a metal salt thereof. Typically, it is a silicon alkoxide or sodium silicate.

In the case of a silicon alkoxide or alkoxysilane, a sol-gel precursor in which all the groups are hydrolyzable thus has the following formula:

rOR ₃

Thus, the hydrolysis results in the formation of S1OH ₄ + R ₁ -OH + R ₂ -OH + R ₃ -OH + R ₄ -OH. After condensation, an SiO ₂ gel is obtained. As such, this precursor may be called "sol-gel precursor matrix".

R 1, R ₂ , R 3 and R ₄ may be of any kind, but are advantageously short linear alkyl chains (Ci to C ₅ ). Advantageously, the sol-gel precursor in which all the groups are hydrolysable is tetraethoxysilane or TEOS, of formula Si- (O-C ₂ H ₅ ) ₄ .

To fulfill its function as a sol-gel precursor, this precursor is typically present in the composition according to the invention in an amount of from 0.1 to 30 mol%, advantageously from 0.1 to 3 mol%.

As already said, this sol-gel precursor serves essentially to establish the matrix network constituting the coating of the support. It is in this matrix network that the second essential component of the composition according to the invention will be integrated, intended to give the coating the desired properties. This second component may be a second sol-gel precursor or particles, or a mixture of both. According to a first case, it is therefore a second sol-gel precursor, different from that described above in that all its groups are not hydrolyzable. Indeed, it is characterized by the presence of at least one non-hydrolysable group carrying the desired functionality or property, hereinafter referred to as the "functional group".

Again, this precursor may be a metal alkoxide or a semi-metal alkoxide. Typically, it is a silicon alkoxide.

This precursor is therefore characterized by the presence of at least one non-hydrolysable functional group. It can, of course, comprise several non-hydrolyzable functional groups, of the same nature or different. However, and preferably, it comprises at least one hydrolysable group so as to be integrated into the sol-gel formulation. Thus, via its hydrolysable groups, this second precursor can in fact participate in the formation of the sol-gel. However, it carries at least one group that is not hydrolysed and persists in the gel, thus conferring a property of interest. Because of this dual role, this precursor may be called a "hybrid sol-gel precursor". In the case of a silicon alkoxide or alkoxysilane, a sol-gel precursor comprising at least one non-hydrolysable functional group may have the following formula:

rOR ₃

LOR4 In this case, the group R ₂ is a non-hydrolyzable group, while the groups R 1, R ₃ and R ₄ are capable of being hydrolysed. Thus, the hydrolysis of this precursor results in the formation of R ₂ -Si-OH ₃ + R ₁ -OH + R ₃ -OH + R ₄ -OH. The group R ₂ , by its nature, determines the additional property conferred on the sol-gel coating obtained. Thus, and by way of example, if this precursor is hexadecyltrimethoxysilane (HDTMS) of formula Ci ₆ H ₃₃ -Si - (O-CH ₃ ) ₃ , the only nonhydrolyzable group is the hexadecyl group which, by the length of its carbon chain, confers hydrophobicity.

More generally, the non-hydrolysable functional group may be very varied in nature depending on the desired property: long carbon chain to confer hydrophobicity; the presence of heteroatoms, in particular fluorine, to confer oleophobicity; presence of a group colored in the UV; presence of a group ensuring compatibilization with the medium; ...

Advantageously, the sol-gel precursor comprising at least one non-hydrolysable functional group is a silicon alkoxide, advantageously chosen from the group comprising hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, bistriethoxysilylethane, vinyltetraethoxysilane, phenyltetraethoxysilane, and methyltetraethoxysilane

Since it is potentially less "efficient" in the formation of sol-gel and potentially more expensive, the sol-gel precursor comprising at least one non-hydrolysable functional group is advantageously present in the composition in a molar proportion of less than or equal to that of the sol-gel precursor, all the groups of which are hydrolysable (molar ratio less than or equal to 1).

In practice, it advantageously represents from 0.1 to 30 mol% of the composition, still more advantageously from 0.1 to 3 mol% of the composition. Alternatively, the desired properties are conferred by particles which will be called later in the description "functional particles". Thus and by way of example, if the particle is a pigment, the coating is colored. Moreover, it is known under the terminology "lotus effect" that a nanoscale roughness caused by the presence of nanoparticles confers superhydrophobia.

In practice, the functional particles used in the context of the invention may therefore be pigments, inorganic or organic microparticles, inorganic or organic nanoparticles, possibly porous, particles carrying chemical functions known for their specific property (for example, a long aliphatic chain for imparting hydrophobicity), structured particles, microcapsules containing an active ingredient. Different types of particles can be combined. Spherical silica microparticles may for example be used to impart hydrophobicity. Alternatively, raspberry-shaped particles, namely agglomerates of spheres of different sizes, can be used.

In order to obtain a stable coating and in particular to ensure the durable maintenance of the particles in the coating, these particles are advantageously functionalized using a compatibilizing group intended to ensure the binding of these particles to the support and / or the coating. In practice, these particles have a function capable of reacting with the polycarboxylic acid present in the composition according to the invention, advantageously an epoxide functional group capable of forming an ester bond with the polycarboxylic acid. By way of example, it is possible to graft glycidyloxypropyltrimethoxysilane. Alternatively, it is an amine function capable of forming an amide bond with the polycarboxylic acid. By way of example, it is possible to graft aminopropyltriethoxysilane. In this case, there is therefore a real attachment of the particles and not a simple integration to the coating.

Suitably, the functional particles represent from 0.1 to 30% by weight of the composition, advantageously from 0.1 to 15% by weight. As already stated and according to another embodiment, the composition comprises a sol-gel precursor comprising at least one non-hydrolysable functional group and optionally functional particles, these two entities being defined as above.

A sol-gel precursor comprising at least one non-hydrolysable functional group particularly suitable for this case is, for example, methyltriethoxysilane (MTEOS) or bistriethoxysilylethane. Advantageously, the desired properties that can be provided by the sol-gel precursor or the particles are: hydrophobicity, superhydrophobicity, oleophobicity, hydrophilicity, ease of maintenance, wrinkle-proofing, abrasion resistance, UV (Ultra Violet) staining, IR (Infra Red) or visible, photocatalytic properties, binding and / or reinforcing properties.

Of course, the same functional sol-gel precursor or the same functional particle can provide several properties. If several properties are desired, one or more types of precursor and / or particles may be combined.

Typically in a sol-gel route, the solvent in the presence is an aqueous solvent.

According to a particular embodiment, the solvent is solely composed of water, which advantageously represents from 40 to 99 mol% of the composition.

Alternatively, the aqueous solvent may also contain an alcohol. Advantageously, it is a linear alcohol having from 1 to 5 carbon atoms (C1-C5) such as methanol, ethanol, propan-1-ol, or mixtures thereof. It is preferentially ethanol. The alcohol advantageously represents from 0.1 to 60 mol% of the composition. While a strong acid is commonly employed in a sol-gel formulation, the composition according to the invention advantageously comprises a polycarboxylic acid, intended to promote the bridging between the support and the sol-gel and / or the functional particles.

Advantageously, the polycarboxylic acid is maleic acid, succinic acid, tartaric acid, citric acid, or 1,2,3,4-butanetetracarboxylic acid (BCTA). . Suitably, the polycarboxylic acid is from 0.05 to 10 mol% of the composition.

The composition according to the invention further comprises a catalyst for the formation of an acid anhydride intermediate from the polycarboxylic acid. Thus, and by way of example, in the case of a dicarboxylic acid of formula HO-CO-R-CO-OH, the catalyst promotes the formation of an acid anhydride intermediate of formula - (- O-CO- R-CO-O-CO-R-CO-O -) -.

Thus, the catalyst ensures in particular the grafting of the polyacid on the support, catalyzing the formation of an acid anhydride which then forms an ester function with the free alcohol functions on the surface of the support.

It is advantageously a phosphorus catalyst, for example sodium hypophosphite.

Advantageously, the catalyst represents from 0.05 to 20 mol% of the composition.

Optionally, the composition may further contain a strong inorganic acid such as hydrochloric acid. It then advantageously represents from 0.01 to 0.1 mol% of the composition. Remarkably, such a composition containing all the ingredients in the same mixture is stable and can be stored and stored as it is, for example for several days at moderate temperature (5 to 15 ° C). Alternatively, all the ingredients are mixed with the exception of the optional sol-gel precursor comprising at least one non-hydrolyzable functional group and / or functional particles. Thus, the sol-gel precursor comprising at least one non-hydrolyzable functional group can be added extemporaneously, just before the formation of the soil. It is the same for the functional particles, which can also be added directly to the support, before application of the composition.

Classically, the various ingredients are mixed at room temperature, advantageously with magnetic stirring or ultrasound to promote good homogenization. According to another aspect, the present invention relates to the use of such a composition for coating a support. The support may be of varied nature and is preferably a flexible support. Advantageously, the support is chosen from a textile, fibers, paper and related soft materials, of organic or inorganic origin, films for example fabrics, knits, braids, nonwovens, fibers, filaments and their assemblies. The textile supports are advantageously cellulosic textiles, such as cotton, or non-cellulosic, such as polyamide or polyester.

In other words, the present invention also relates to a method of coating a support consisting of applying the composition according to the invention, then if necessary to remove the excess composition, and finally to dry the support.

Typically, the application of the composition to the support, which corresponds to an impregnation step, can be carried out in full bath, by spraying, or by squeezing on the headscarf. The drying of the support is conventionally carried out at a temperature of between 20 and 200 ° C., preferably between 120 and 180 ° C. in order to ensure the condensation of the sol-gel precursors, the elimination of solvents, and the condensation reaction of the anhydrides. of acids catalyzed by sodium hypophosphite

At the end of this process, a coating in the form of a sol-gel is thus obtained, comprising a condensed precursor of which at least the functional group has not been hydrolysed and optionally a condensed precursor of which all the groups have been hydrolyzed, and possibly functional particles. Remarkably, the condensed precursors are integrated in the sol-gel network and have bonds to the support. The functional particles are incorporated in the sol-gel network and may have bonds to the support and / or sol-gel.

As already stated, another aspect of the invention relates to the use of a composition according to the invention for conferring on a carrier at least one property chosen from the following group: hydrophobicity, superhydrophobia, oleophobicity, hydrophilicity, ease of maintenance , crease resistance, abrasion resistance, UV, IR or visible coloration, photocatalytic properties, binding and / or reinforcing properties. As is apparent from the present application, the composition and the coating method according to the invention have several originalities and advantages:

the preparation of the composition takes place in one step ("one pot"), thus minimizing the manipulations, the material and the costs.

it gives rise to the formation of a hybrid sol: the composition contains a sol-gel precursor intended to form the matrix of the sol-gel coating and contains a second component allowing the functionalization of the sol-gel, in the form of a second precursor sol-gel or particles. Unlike the prior art where the second sol-gel precursor was only grafted on the sol-gel layer, in the context of the present invention, it also undergoes hydrolysis and condensation and is therefore integrated into the soil. strictly speaking. The durability of the coating obtained is thus improved, especially with respect to abrasion and washes.

the invention allows a particle deposition in a durable manner on a support. the composition or sol-gel formulation according to the invention is stable and can be preserved as it is.

the coating process can be applied to any flexible support, in particular on different textile supports, and not only on cotton or cellulosic fibers.

it is flexible, thus providing a support of various interesting properties, even to achieve a multifunctionality.

According to the invention, all the constituents of the composition are adapted to ensure their good adhesion to the support. The coatings obtained are homogeneous and uniform, show optimized properties such as flexibility and especially increased durability, which is the result of a limitation of the tearing of the coating during use, by abrasion or washing, or by mechanical stress . BRIEF DESCRIPTION OF THE FIGURES

The manner in which the invention can be realized and the advantages which result therefrom will emerge more clearly from the exemplary embodiment which follows, given by way of indication and not limitation, in support of the appended figure:

Figure 1 shows Scanning Electron Microscopy (SEM) pictures:

(a) raw cotton before abrasion;

(b) hydrophobic cotton after abrasion;

(c) non-washed hydrophobic cotton prior to abrasion;

(d) non-washed hydrophobic cotton after abrasion;

(e) hydrophobic cotton washed before abrasion; and

(f) hydrophobic cotton washed after abrasion.

EMBODIMENTS OF THE INVENTION: 1 / Method of Preparation: Generally: the reactants are mixed at room temperature in a suitable container, with magnetic stirring or ultrasonic agitation to promote good homogenization of the mixture.

for optimized formulations, the mixtures can be stored for several days at moderate temperature (5-15 ° C).

the impregnation of the textile can be carried out in full bath, by spraying, or by squeezing on the headscarf.

Protocol:

5.4 g of succinic acid (polycarboxylic acid) and 5.35 g of sodium hypophosphite (catalyst) are introduced into a flask in 71.8 ml of deionized water (aqueous solvent), with magnetic stirring and at room temperature. room. Then, 6.7 g of tetraethoxysilane (TEOS, fully hydrolysable sol-gel precursor) and 11.1 g of hexadecyltrimethoxysilane (HDTMS, functional sol-gel precursor) are added to the mixture and the reaction mixture is shaken under ultrasound for 60 minutes. at 25 ° C.

A sample of cotton fabric, 11 cm x 15 cm (115 g / m ² ), is impregnated with the mixture under ultrasound for 5 minutes, then the excess formulation is expressed using a padding, under a pressure of 1 bar and a speed of 1 m / min. The sample is dried at 80 ° C for 1 hour and then at 170 ° C for 2.5 min.

To note :

similar treatment was applied to fabric samples of polyamide (PA) and polyethylene terephthalate (PE or polyester) of equivalent weight. similar experiments have been carried out using maleic acid (MA) or 1,2,3,4-butanetetracarboxylic acid (BTCA) as the polycarboxylic acid in place of succinic acid (AS), a functional sol-gel precursor of different nature may be chosen to confer other properties of interest on the treated support, such as a coloration (UV or visible), oleophobia, ... Characterization of the textile support obtained:

2-1 / Characterization of water-repellent properties: measure of contact angle Θ

A drop of water of 10 microliters is deposited on the treated textile support using a micro-syringe and a suitable device. A micro-camera makes it possible to photograph the drop formed.

It is found that the drop remains in pearl form and forms a contact angle (AC) Θ between 124 ° and 145 ° with the support, depending on the experimental conditions and the support used. These values are characteristic of a good water repellency property.

2-2 / Durability at washings:

The washes were carried out under real conditions in a domestic machine, in the presence of 3 kg of fillers (cotton + polyester), using an ECE detergent with phosphate whose composition is given in the standard NF EN ISO-105-C06 (1994). ). The detergent is used at a concentration of 0.5 g / l. This household cycle lasts 65 minutes and ends with a spin at 800 rpm.

After 1 washing, the contact angle measured is 132 ° <Θ <139 °, depending on the experimental conditions and the support used. After thermal reactivation by ironing at 200 ° C, the contact angle measured is 131 <Θ <141 °. Finally, after 20 household washes with washing and then ironing, the contact angle varies between 127 and 144 °. These results demonstrate good durability at washings.

2-3 / Multifunctionality:

The samples treated with the sol-gel formulation described above have other interesting properties such as:

an improvement in their abrasion resistance properties;

- an ability to wrinkle (NF EN 22313 ISO 2313) and a good general appearance after washing (NF G07-137-1); good test spray behavior, testifying to the good resistance to washings of the coating.

Abrasion resistance (Martindal test):

The abrasion resistance tests were carried out according to standard NF EN 530 (October 2010).

Operating conditions:

number of abrasion cycles = 3000 turns with abrasive wool fabric;

- applied pressure: 9kPa.

At the end of the abrasion, no textile tear is observed. Following the abrasion test, the state of the surface of the sample is compared with the control surface and SEM (Scanning Electron Microscopy) is taken on the used fabric and the control for comparison to the microscopic scale. The electron micrographs reveal that the raw cotton fibers are deteriorated by abrasion, while the fibers of the hydrophobic cotton are intact (Figure 1). It is also observed that the treated cotton surface has been protected by the sol-gel coating.

Test spray behavior (NF EN ISO):

The quotation of the hydrophobic cotton before abrasion is ISO 5 (100), which means that "neither adhesion nor wetting of the upper surface" is observed. The quotation of the hydrophobic cotton after abrasion is ISO 4 (90), which means that a "slight adhesion or a slight scattered wetting of the upper surface" is obtained. In practice, these ratings show that a small loss of coating is observed following the abrasion test.

Determination of self-bleeding by the measurement of remanent angles (NF EN 22313 ISO 2113. December 1992):

The treatment tends to improve the self-crumper properties (better residual angle index) of the sample of a treated cotton compared to a sample of untreated cotton, and makes the treated cotton easier to iron. The improvement of the self-crease is preserved, even after 10 successive household washes.

The values below give an average indication of the values of the remanent angles of the treated and untreated cotton samples:

General appearance of the samples: the treated samples have fewer folds before or after repeated washing compared to an untreated cotton sample. No apparent change in sample touch or color change.

3 / Addition of microparticles:

Spherical silica microparticles are added to the reaction medium described above. In order to ensure sustainable grafting, these particles are functionalized with a compatible function (capable of reacting with an acid), for example an amine function, and therefore by grafting aminopropyltriethoxysilane.

Contact angles between 130 and 145 ° are obtained for the samples treated with such a composition, showing good water repellency properties.

Claims

A composition for coating a support comprising:

an aqueous solvent;

a polycarboxylic acid;

a sol-gel precursor, all the groups of which are hydrolysable, with functional particles and / or a sol-gel precursor comprising at least one non-hydrolyzable functional group; or a sol-gel precursor comprising at least one non-hydrolyzable functional group, optionally combined with functional particles.

2. Composition according to claim 1, characterized in that the sol-gel precursor is a metal alkoxide or a semi-metal alkoxide.

3. Composition according to claim 2, characterized in that the sol-gel precursor, all of whose groups are hydrolyzable, consists of tetraethoxysilane (TEOS).

4. Composition according to one of the preceding claims, characterized in that the sol-gel precursor, all groups are hydrolyzable, is from 0.1 to 30 mol% of the composition, preferably from 0.1 to 3% . 5. Composition according to one of the preceding claims, characterized in that the sol-gel precursor comprising at least one non-hydrolysable functional group is a silicon alkoxide, advantageously chosen from the group comprising: hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, perfluorooctyltrimethoxysilane, perfluorooctyltriethoxysilane, bistriethoxysilylethane, vinyltetraethoxysilane, phenyltetraethoxysilane, and methyltetraethoxysilane. Composition according to one of the preceding claims, characterized in that the sol-gel precursor comprising at least one non-hydrolyzable functional group represents from 0.1 to 30 mol% of the composition, advantageously from 0.1 to 3 mol% of the composition.

Composition according to one of the preceding claims, characterized in that the functional particles are chosen from the group comprising pigments, inorganic or organic nanoparticles or nanoparticles, optionally porous, particles carrying chemical functions known for their specific property. , structured particles, and microcapsules containing an active ingredient.

8. Composition according to one of the preceding claims, characterized in that the functional particles have a function capable of reacting with the polycarboxylic acid, preferably an epoxide or amine function.

9. Composition according to one of the preceding claims, characterized in that the functional particles represent from 0.1 to 30% by weight of the composition, preferably 0.1 to 15%.

10. Composition according to one of the preceding claims, characterized in that the solvent consists of water which advantageously represents from 40 to 99 mol% of the composition. 11. Composition according to one of claims 1 to 9, characterized in that the solvent is a mixture of water and alcohol, the alcohol preferably being a linear alcohol C 1 -C 5, preferably selected from methanol, l. ethanol, propan-1-ol, or mixtures thereof, still more advantageously ethanol, said alcohol being able to represent from 0.1 to 60 mol% of the composition.

12. Composition according to one of the preceding claims, characterized in that the polycarboxylic acid is advantageously chosen from the group comprising maleic acid, succinic acid, tartaric acid, citric acid, or acid. butanetetracarboxylic, and in that it represents from 0.05 to 10 mol% of the composition.

13. Composition according to one of the preceding claims, characterized in that the catalyst is advantageously constituted by a phosphorus compound, still more advantageously sodium hypophosphite, and in that it represents from 0.05 to 20% by weight. moles of the composition.

14. Composition according to one of the preceding claims, characterized in that it further comprises a strong inorganic acid, such as hydrochloric acid, preferably representing from 0.01 to 0.1 mol% of the composition.

15. Use of a composition according to one of claims 1 to 14 for coating a support, said support being advantageously chosen from the group comprising textiles, paper and flexible films, being even more advantageously a textile of cotton, polyamide or polyester.

16. Use of a composition according to one of claims 1 to 14 to give a carrier at least one property selected from the group comprising hydrophobicity, superhydrophobia, oleophobia, hydrophilicity, ease of maintenance. , crease resistance, abrasion resistance, UV, IR or visible coloration, photocatalytic properties, and binding and / or reinforcing properties.

17. A method of coating a support, comprising the following steps:

applying the composition according to one of claims 1 to 14 on the support, preferably by dipping bath, by spraying or by squeezing the headscarf;

possibly eliminate the surplus composition;

dry the support.

18. Sol-gel coating obtained using the process according to claim 17.