BE1029530B1 - Process for obtaining a coating - Google Patents

Abstract

A process for obtaining a coating in which a polyol, a polyisocyanate, an SMP polymer and a first molecule comprising a hydrolyzable silane derivative with a silanol group and a residue capable of forming a covalent bond with the polyisocyanate. Coating obtained by this process and uses of this coating for its biocidal properties or to reinforce the mechanical resistance of a substrate.

Description

Process for obtaining a coating Technical field The present invention relates to a process for obtaining a coating with multiple polymeric components.

The present invention further relates to such a coating where the components are nested.

The present invention also relates to a method for obtaining a coating on a substrate.

The present invention finally relates to the use of the coating, in particular to a biocidal and/or durable use.

PRIOR ART A coating created from epoxy resin, corresponding to a thermosetting liquid polymer is known.

When the epoxy resin is cured, often in the presence of a catalyst, it can be shaped to suit the needs of the user.

For example, it can be smoothed, cut or perforated.

It works in liquid form and is applicable in many areas such as jewelry, furniture or even flooring.

Unfortunately, this resin has the disadvantage of requiring several days of drying to be hardened and the hardness depends on the temperature or the time of treatment or the presence of catalysts.

Another disadvantage of this resin lies in the fact that it degrades over time.

For example, patent US8158191 discloses a two-step process: a first layer of polyurethane is applied to a surface of a polycarbonate or polyamide substrate, then an abrasion-resistant silane-type coating is applied to the first layer of polyurethane. .

US4345053 discloses a moisture-curable sealant composition for application to non-porous substrates. The sealing composition comprises a silicon-terminated polymer which is obtained by reaction between a polyurethane, polyether or polyethylene prepolymer carrying two OH (or amine) functions with a polyisocyanate. When the polyisocyanate is no longer detectable, an organosilane carrying an isocyanate group is then added. The process is therefore carried out in several stages.

Patent EP2785801 discloses a process for obtaining a hardenable film-forming composition applied to the substrate to attenuate the accumulation of ice on the substrate. This composition includes two layers that are applied one after the other.

Patent EP3209739 discloses a composition for obtaining a two-component coating. The coating, as a product, does not contain isocyanate which has not reacted during the production process, which is an essential characteristic of this document. Unreacted isocyanates are removed from the mixture by an additional step. Cross-linking takes place via epoxy or acrylate residues.

Thus, the methods of the prior art are carried out in two stages, each being well controlled.

Quaternary ammoniums coupled to an aliphatic chain have been used as a bactericidal agent for the development of antibacterial coatings, in particular those in the form of an organosilane, such as 3-(trinydroxysilyl)propyldimethyloctadecyl-ammonium chloride. Indeed, several scientific studies show that quaternary ammoniums prevent the growth of bacteria and certain viruses on solid supports.

EP1863865 discloses a process for the preparation of a quaternary ammonium antibacterial agent containing silica combined with other polymers.

Document EP2285857 presents an antibacterial coating in the form of an interconnected polyurethane-silica network with quaternary ammoniums used as an antibacterial agent. The process is carried out in two stages, the first stage consists in preparing a polyurethane functionalized by a siloxane function and a second stage where the siloxane functions carried by the polyurethane react with the siloxanes carrying quaternary ammoniums at temperatures between the temperature ambient and 100°C. The advantage of a two-step process is that there is good control of the different reactions, that any excess reagents can be neutralized. Also, catalysts or other compounds that are not desired in the coating are easily removed.

However, the reactions between the siloxane functions are not very rapid at room temperature and require an additional baking step at a temperature above 100° C. to ensure the chemical bonds between the quaternary ammonium and the polyurethane network. Another disadvantage of this type of coating is that once applied to a solid support, it has a limitation in terms of mechanical resistance when subjected to external stresses.

Brief summary of the invention The present invention aims to solve the drawbacks of the state of the art, in particular to provide a process for obtaining an easy, fast and economical coating, the coating being biocidal and having mechanical resistance. reinforced.

It was only after much trial-and-error that the inventors had the intuition of the 'one-pot' process according to the present invention. They were very surprised at the simplicity of the solution, which seemed unachievable to them.

Thus, a first object of the present invention consists of a process for obtaining a coating in which one mixes in a single container: a polyol (or several polyols) in aqueous phase or in an aqueous-organic biphasic system, a aliphatic polyisocyanate (or more polyisocyanates) in the organic phase, said polyisocyanate being hydrophilic and/or dispersible in an aqueous solution, one (or more) SMP polymer(s) carrying silane groups, said silane groups being hydrolysable to form silanol derivatives, and a first molecule comprising (i) a silane derivative which can be hydrolyzed with a silanol group and (ii) a residue (eg alkyl amine, alkyl thiol) capable of forming a covalent bond with the polyisocyanate.

The components are then allowed to react with stirring so that: this polyol and this polyisocyanate form a first network; this polyisocyanate and this first molecule form a second network and this first molecule and this SMP polymer form a third network via their silanol groups. Other molecules comprising a silane derivative which can be hydrolyzed into a silanol group and an alkyl residue, but devoid of the residue (eg amine, thiol) capable of forming a covalent bond with the polyisocyanate can optionally be incorporated into the reaction mixture.

This process allows a simplified reaction system, easily applicable to a substrate (glass, metal, paper, etc.) and which, after polymerization (crosslinking), becomes very resistant.

Preferably, this process further comprises the (preliminary) step of adding to the reaction mixture a second molecule comprising a silane derivative and further comprising an ammonium group (a quaternary amine, one of the derivatives of which is a long-chain alkyl), this silane derivative being hydrolysable into a slanol group, so that, during the reaction phase, this silanol group of this silane derivative of this second molecule can form an Si-O-Si bond with the silanol group of the first molecule and/or with the silane group of the SMP.

Preferably, when this molecule carrying an ammonium group is added, this polyol in aqueous phase or the aqueous-organic biphasic system used in this process is cationic or neutral or, in any case, does not have too high a negative charge density. and/or the absence of aggregate between the SMP polymer and the second molecule has been tested beforehand, as has the compatibility between the polyol and the second molecule.

Indeed, the inventors have noticed that polyols having too high a density of negative charges, for example a polyol of acrylate structure, interacted with ammonium, which negatively affected the reaction.

A second particularly preferred molecule is dimethyloctadecyl[3(trimeethoxysilyl)propyl] ammonium (CAS: 27668-52-6) or a similar molecule whose hydrophobic tail, instead of being Cis, is C1s OR C7. It is important that the second molecule is soluble before its incorporation into the reaction mixture and does not form aggregates.

Indeed, the inventors have noticed that the presence of aggregates of the second molecule, for example when the second molecule is not well dissolved, induces strong heterogeneities for the coating, which reduces its mechanical strength and even the persistence of its biocidal property.

The inventors surprisingly noticed that the second molecule could advantageously be in solution in a C1-C4 alcohol, despite the presence at the level of the 'one pot' reaction mixture with the isocyanates, which involves secondary reactions which were considered parasites.

On the contrary, surprisingly and advantageously, the inventors have noticed that the incorporation of the second molecule, even dissolved in a C1-C4 alcohol, increases the mechanical properties, including the mechanical resistance of the coating, instead of reduce it.

This addition ensures a durable biocidal property to the coating.

In the context of the present invention, the term "polyol" should be understood broadly. However, the preferred polyols have neither too high nor too low a content of -OH residues.

Polyols having an -OH residue content of between 20 and 100 mg KOH/g of polyol, preferably between 30 and 55 mg KOH/g of polyol, preferably between 40 and 50 mg KOH/g of polyol, are preferred, even very preferred.

The inventors have noticed that this range of values provides both a well-controlled reaction and a particularly solid coating.

In the context of the present invention, the -OH content of the polyol is preferably measured by acidification with acetic acid, followed by neutralization with KOH. Standards such as JIS K 1557-1:2007, ISO 14900:2017 or JIS K 0070-1992 can be used for this purpose.

Some flexibility in quantity ratios is allowed. However, the inventors have noticed that the polyol gains from being incorporated at a content of between 3 and 20% (weight of the polyol: total weight of the reaction mixture) in the reaction mixture, preferably between 5 and 15%, more preferably between 8 and 12%, for example about 11% (by weight).

Alternatively (or additionally), the polyol content can be expressed relative to the other constituents forming the triple polymeric network. According to this method of calculation, the polyol is preferably incorporated at a content of between 25% and 75% (weight of the polyol: weight of all the compounds intended to form the polymer, such as the polyol (the first, seconds and SMP) molecules having a group having a hydrolyzable function in Si-OH and the polyisocyanate), preferably between 30 and 70%, preferably between 35 and 65%, preferably between 40 and 60%, preferably between 45 and 55 %.

The polyol content and the choice of a polyol with a specific -OH value is also advantageously determined by the polyisocyanate content (see below).

A preferred polyol has one or more halogen residues, preferably fluorine. The inventors have noticed that this type of polyol reacts more quickly and more completely with the polyisocyanate, even at room temperature. In this process, preferably the polyol is present in the form of an emulsion, and/or in the form of a dispersion in water. Preferably, the polyisocyanate is added to the reaction mixture at a content by weight of between 1 and 10%, preferably between 2 and 7%, preferably between 3 and 5%. Alternatively (or in addition), the polyisocyanate is preferably added to the reaction mixture in a content relative to the other constituents forming the triple polymeric network.

According to this method of calculation, the polyisocyanate is preferably incorporated at a content of between 2% and 30% (weight of the polyisocyanate: weight of all the compounds intended to form the polymer, such as the polyol the groups having a hydrolysable function to Si—OH and the polyisocyanate), preferably between 5 and 25%, preferably between and 20%, preferably between 14 and 18%. A third way of determining the polyisocyanate content is to ensure a (slight) excess with respect to the - 10 OH functions of the polyol and to the functions likely to react with the polyisocyanate carried by the molecules having Si derivatives hydrolysable to Si-OH , in particular the first molecule.

A preferred polyisocyanate has an NCO content (% by mass) between 15 and 20 (% by mass), preferably between 16 and 19.5 (% by mass), preferably between 17 and 19 (% by mass). The NCO content (% by mass) is advantageously determined according to standard ISO 11909 (2007). In practice, advantageously, the total content of isocyanate residues (NCO) present on the polyisocyanates is higher by 5, 10, 15, 20, 25, 30, 40, 50, or even up to 100% (preferably up to at 90%, 80%, 70%, 60%) relative to the total content in the mixture of —OH residues present on the polyol(s). An excess of isocyanate residues of 20 to 50% relative to the content of -OH residues present on the polyol is preferred.

By "excess" is preferably meant the number of isocyanate equivalents carried by the polyisocyanate (or by the polyisocyanates if an example is used) which is greater than the number of -OH equivalents carried by the polyol (or the polyols if a mixture of polyols is used).

In the context of the present invention, the polyisocyanate(s) is (are) hydrophilic and/or dispersible in an aqueous solution, which means, preferably, that in the reaction mixture which comprises water and an organic solvent, the polyisocyanate is completely soluble or forms aggregates only of faults (diameter) less than 1 μm, preferably less than 500 nm, preferably less than 300 nm. In the context of the present invention, if the aggregate is not spherical, the term “diameter” will preferably mean the equivalent diameter of the particle, that is to say that the volume of the particle is related to that of a sphere of the same volume.

The absence of aggregates, or at least the absence of aggregates with a diameter greater than 1 um (or 300 nm) allows thin, resistant and transparent coatings.

The organic solvent is advantageously also chosen according to the size of the isocyanate aggregates. For example, the inventors have noticed that acetate is not a good solvent from this point of view. Ketone type solvents are preferred, although acetone is less preferred as a solvent than other ketones.

The first and second molecules carrying a hydrolyzable group in Si—OH preferably have a mass of less than 10,000 Da, preferably a mass of less than 5,000 Da, preferably less than 1,000 Da, or even less than 500 Da and even (slightly ) less than 200 Da (first molecule only) or 400 Da (second molecule). Preferably, the molecules carrying a hydrolyzable group in Si—OH have less than 5 hydrolyzable residues in Si—OH per molecule, preferably less than 4, exactly 3, less than 3, or a single Si—OH residue. Thus, by way of example, preferably,

for the calculation of the content of this first or second molecule bearing a hydrolyzable Si—OH group, the content of SMP polymer is not taken into account.

In this process, preferably, the first molecule is a tri alkyloxysilyl amine, preferably an alkyl amine, or an alkyl thiol, of tri alkyloxysilyl, such as 3 (trmethoxysilyl)-propylamine (CAS Number 13822-56-5 ). Alternatively, the above methoxy groups can be substituted by other alkoxy groups (eg ethoxy).

These first and second molecules bearing a hydrolyzable group to Si-OH (preferably those described above) are preferably incorporated into the reaction mixture at a fraction of between 2% and 20% (weight of molecules with hydrolyzable group to Si—OH: weight of the reaction mixture), preferably between 3% and 15%, preferably between 4% and 10%, such as between 5% and 7%.

Alternatively (or in addition), these first and second molecules carrying a hydrolyzable group in Si—OH (preferably those described two paragraphs above) are incorporated in a content relative to the other constituents forming the triple polymeric network. According to this method of calculation, this molecule comprising an Si is preferably incorporated at a content of between 4% and 50% (weight of the Molecule-Si: weight of all the compounds intended to form the polymer, such as the polyol, the groups having a hydrolysable function to Si—OH and the polyisocyanate), preferably between 7 and 40%, preferably between 10 and 35%, preferably between 13 and 30%, preferably between 15 and 25%.

The SMP polymers, first and (optionally) second molecules, are preferably incorporated in contents which ensure

A Si content in the coating of between 0.5 and 10% (Si weight: coating weight), preferably between 1 and 7% (Si weight: coating weight), such as between 1.5% and 6% (weight of Si:weight of coating), preferably between 2% and 5% (weight of Si:weight of coating).

In the context of the present invention, by molecule bearing a hydrolyzable group in Si-OH, is preferably meant an organosilane (therefore an Si-C- bond) having at least one, preferably the 3 remaining bonds, bond(s) S-O-R, in which R is an organic derivative, preferably methyl or ethyl. Thus a particularly preferred molecule carrying a hydrolysable group to Si—OH contains a trimethoxysilyl group.

Such a group (S-OR, Si(OR]3, trimethoxysilyl, etc.) is therefore found at the level of the first molecule, of the second molecule and also of the SMP polymer (this is the SMP function).

Advantageously, the first and second molecules both comprise a trialkoxysilyl group (preferably trimethoxysilyl or triethoxysilyl), the fourth bond preferably being a C1-C6 alkane, preferably C:3, derivatized with a terminal amine ( therefore for example a propylamine group), primary or quaternary. The SMP polymer is advantageously derivatized with one or more trialkoxysilyl-propylcarbamate.

Preferably, in this process, the mass ratio between the SMP polymer and the first molecule (preferably 3(trimethoxysilyl)-propylamine) is between 2 and 20%, preferably between 5 and 15%, preferably between 8 and 12%.

The SMP polymer is preferably incorporated into the reaction mixture at a content (by weight) of between 1.5 and 10%, preferably between 2 and 5%, preferably between 3 and 4%.

Alternatively (or in addition), the SMP polymer is preferably added to the reaction mixture in a content relative to the other constituents forming the triple polymeric network. According to this method of calculation, the SMP polymer is preferably incorporated at a content of between 2% and 30% (weight of the SMP polymer: weight of all the compounds intended to form the polymer, such as the polyol, the groups having a hydrolysable function to Si—OH and the polyisocyanate), preferably between 5 and 25%, preferably between 10 and 20%, preferably between 13 and 17%.

A preferred SMP polymer is a polyester, polyether or polyurethane, preferably polyurethane.

Although the invention could have been designed without the SMP polymer, for example by adapting the amounts of polyol, polyisocyanate and first and second molecule, the inventors have noticed that such formulations result in a less homogeneous coating, in particular when the second molecule is present, which reduces the mechanical strength of the coating.

Preferably a surfactant, preferably a nonionic surfactant such as a polyoxyethylene alkyl ether is added to the reaction mixture. This allows a good homogenization of the different components. An advantageous ratio of the surfactant is 2 to 10% based on the weight of the polyol, preferably 3 to 7%.

Preferably, in this process, the organic phase for the SMP polymer and/or for the polyisocyanate and/or, optionally for the two-phase system of the polyol and/or for the first molecule and/or for the second molecule is a derivative liquid ketone at room temperature and partially soluble in water, preferably methyl-ethyl-ketone (MEK).

Preferably, the aqueous component is more abundant (weight of aqueous component: weight of all solvents) than the organic component.

Very preferably, the relative contents of water and of organic solvent are such that the mixture of the solvents results in the formation of a single phase, and not in a two-phase water:organic solvent system. Conversely, an organic solvent in water very preferably has sufficient solubility in water.

Furthermore, as described above, a very preferred organic solvent ensures that the isocyanate remains soluble in the reaction mixture or, at the very least, forms aggregates only of small size (diameter <1 um, even <300 nm).

In this process, preferably, between 50 and 85% of the reaction mixture consists of solvents (weight of solvents: total weight of the reaction mixture), preferably between 60%, or even 70% and 80%.

A reaction mixture that is too concentrated has the disadvantage of not allowing a completely transparent coating and also of being incompatible with thin coatings.

A key aspect of the present invention relates to the coating obtainable by the above process.

Preferably, this coating has a thickness of between 1 and 40 μm, preferably between 2 and 20 μm, more particularly between 5 and 10 μm.

Another related aspect of the present invention is a method of applying this coating to a substrate comprising the following steps: - Mixing (according to the invention) in a single container of a polyol (according to the invention) dispersed in water, of a polyisocyanate (according to the invention), of an SMP polymer (according to the invention), of a first molecule (according to the invention) comprising a hydrolyzable group in SI-OH and in addition a group capable of forming a covalent bond with the polyisocyanate and a second molecule (according to the invention) comprising at least one hydrolysable group to SI-OH and in addition an ammonium group, in an organic phase, - Stirring at room temperature for an interval predetermined time of between 1 and 45 minutes, preferably between 2 and 15 minutes, more particularly between 5 and 10 minutes, - Application (by spraying) of at least one layer of the coating obtained by the method according to the invention on at least least one area of the support, and - Drying at room temperature, preferably between 15 and 35°C, for a predetermined time interval, preferably between 30 minutes and 48 hours, preferably between 4 and 24 hours, more particularly between 8 and 12 hours.

Another aspect of the present invention relates to the use of the coating described above to increase the mechanical strength of a substrate, such as plastic, glass, paper, paint or metal.

Detailed description of an embodiment of the invention Other characteristics and advantages of the present invention will be drawn from the non-limiting description which follows, and with reference to the examples.

Examples.- Example 1: One-pot process for obtaining a coating The mixture containing a first component, being a fluoropolyol in emulsion in water, the particles have a diameter of between 0.1 and 0.2 μm .

It is a polyol with a hydroxyl value of 49 mg KOH/g of polymer, the emulsion is stabilized by a non-ionic surfactant; A second component comprising 8 g of methyl ethyl ketone (MEK); 3.6 g of an SMP being a polyurethane functionalized with trimethoxysilane functions (contains between 5 and 10% of methoxy functions); 0.4 g of 3-[Trimethoxysilyl)propylamine; 35 g of dimethyloctadecyl(3-(trimethoxysilyl)propyl)ammonium chloride and 0.9g of (3-chloropropyl)trimethoxysilane) dissolved in 0.6g of methanol; A third component comprising 3g of MEK and 4g of aliphatic polyisocyanate having an NCO content of approximately 18%

measured according to method M105-ISO 11909. The molecular mass is approximately 230. These three components are mixed and the mixture is stirred in a single container for 5 minutes at room temperature to obtain a final mixture ready to be applied. The final mix is spray applied onto PVC substrates. The coating is hardened by a drying step at room temperature for 24 to 48 hours.

The final coating has very good abrasion resistance (no scratch marks after the abrasion test) and antibacterial activity (determined according to ISO 22196).

The inventors have tested other polyols with good results. However, the use of a halogenated polyol made it possible to increase the mechanical resistance of the coating (see below).

On the other hand, other polyols that were too strongly anionic, where OH groups were grafted to a polyacrylate-like structure, caused interference when the silane having a quaternary ammonium was added.

Other SMPs can be used, however, when quaternary ammonium is present in the mixture, there is a risk of formation of aggregates. Thus, the usable SMPs benefit from being tested beforehand.

Example 2: Antibacterial effectiveness of the coating deposited on PVC surfaces:

The antibacterial activity of the coating deposited on PVC is determined according to the ISO 22196 standard. 3 types of surfaces were tested (with a surface of 5 x 5 cm) - A series of negative references in PVC, without treatment - A reference series Positive stainless steel coated with AgOX - A series of PVC plates covered with the antibacterial coating according to the invention.

Each surface was tested in triplicate, on two different strains of bacteria (Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 8739) and two different contact times (1h and 24h).

The two strains of bacteria were cultured up to an OD of 0.88 for E. coli 8739 and 0.53 for S. aureus and diluted respectively 200 times and 50 times in order to obtain approximately 5*105 bacteria/ml for the inoculum departure. This inoculum was evaluated and it was approximately 2*106 for E. coli and 4*106 for S. aureus.

Each surface was inoculated with 800! of the starting inoculum. These surfaces are placed in a humid atmosphere in an oven at 37° C. to be incubated for 1 hour or 24 hours.

After the necessary incubation time, the inoculum from these surfaces is recovered in 20 ml of LB500. The bacteria present in this solution are listed by dilutions of 100 to 105 by spreading 3 times 10 μl per box of peri.

For E. coli, 1.6*106 bacteria were inoculated per area, i.e. 6.4*104 bacteria/cm2 For S. aureus, 3.2*106 bacteria were inoculated per area, i.e. 1.3*105 bacteria/cm?

Results of the tests: The biocidal coating according to the invention provides the same efficacy as the AgOX control, with reductions of 5 to 7 Log10, as shown below or Table 1, even after only 1 hour of contact. 1 hour contact 24 hour contact Reduction % Reduction % E.coli |S.Aur |E-coli |s. Aur [E.coli |S. Aur |E.coli_|S. Au | stainless steel coating- positive 5.036 6.39 |>99.99/>99.99]| 7.27 7.48 |>99.99|>99 ‚99 AgOX INOX- Negative (untreated Example 3: Virucidal activity The coating was used to test for possible virucidal activity against Coronavirus hCOV-229E, a virus of the same family as SARS-Covid19, according to ISO 21702.

Under the experimental conditions (8 h, 20° C.; relative humidity 55%), the inventors measured a reduction of 2.3 Log10 in the viral load, which means a reduction of 99.3% in the virus content. The surfaces used were non-porous, 4.5 X 4 cm. Even coatings subjected to aging tests (see Example 4) retained the strong virucidal activity.

Additionally, a cytotoxicity assay was performed using MRC5 cells (ATCC CCL-171) and the inventors did not notice any cytotoxicity associated with the coating of the invention.

Example 4: Resistance to abrasion The same formulation described in Example 1 is deposited on a wallpaper substrate.

The abrasion resistance test is carried out using a 2803 linear abraser with a weight of 100 g and a speed of 50 cycles/minute. To have an abrasive effect, a microfiber cloth is stuck on the axis of the abraser. Abrasion is carried out in a humid environment (permanent presence of water on the surface of the coating).

Figure 1 shows the 4 conditions, wallpaper without coating or with coating and without or after 1000 abrasion cycles. We immediately notice that the uncoated wallpaper is damaged by the abrasive treatment, unlike the wallpaper that has been covered.

The same formulation described in example 1 is deposited on a gyproc substrate with an acrylic paint on the surface.

The abrasion test is carried out under the same conditions described above for wallpaper.

Figure 2 shows similar results: untreated Gyproc is damaged by the abrasive treatment, unlike treated Gyproc.

The same formulation described in example 1 was deposited on a wooden substrate, on a polypropylene substrate and on a PVC substrate.

The abrasion tests are carried out under the same conditions described above for the wallpaper and lead to the same results: the formulation of Example 1 protects the various substrates very effectively.

Thus, the coating described in Example 1 and deposited on the various substrates has a resistance to abrasion which is very high. After 1000 abrasion cycles with a weight of 100g, the coating shows no visible degradation. These are severe aging conditions.

Functionalization test: To verify the presence of quaternary ammonium functions on the surface of the coating after the abrasion tests, the inventors used the immersion test in a bromothymol blue solution. In the event of the presence of quaternary ammonium functions on the surface, an ion exchange takes place between the bromothymol blue anion (aromatic anions of blue color) with the ammonium chloride anion. This ionic exchange results in a lasting blue coloration of the surface.

For this coloring test, the inventors used the gyproc-acrylic plates+coating of the example above (before and after abrasion test).

The blue coloration decreases only slightly after 1000 abrasion cycles, which is a remarkable result. This test thus makes it possible to confirm the presence of quaternary ammoniums even after 1000 abrasion cycles. In other words, the coating has a durability greater than 1000 abrasion cycles, including for its biocidal properties.

| It is clearly understood that the present invention is in no way limited to the embodiments described above and that many modifications can be made thereto without departing from the scope of the appended claims.

Claims (17)

Claims MCE DES 1. A process for obtaining a coating in which is mixed in a single container: - A polyol in aqueous phase or in an aqueous-organic biphasic system, said polyol having an -OH residue content of between 20 and 60 mg KOH/g of polyol, preferably between 30 and 55 mg KOH/g of polyol, preferably between 40 and 50 mg KOH/g of polyol, said polyol comprising one or more halogen residues, - an aliphatic polyisocyanate in organic phase said polyisocyanate being hydrophilic and/or dispersible in an aqueous solution, - Uun SMP polymer bearing silane groups, said siane groups being hydrolyzable into silanol derivatives, - a first molecule comprising a silane derivative hydrolyzable into silanol group and a residue capable of forming a bond covalent with the polyisocyanate, - a second molecule comprising a silane derivative and further comprising an ammonium group, said silane derivative being hydrolyzable into a silanol group, of man st that, during the reaction phase, said silanol group of said silane derivative of said second molecule can form an Si-O-Si bond with the silanol group of said first molecule and/or with the silanol group of SMP, - then the components are allowed to react with stirring so that: said polyol and said polyisocyanate form a first network; said polyisocyanate and said first molecule form a second network and said first molecule and said SMP polymer form a third network via their silanol groups. 2. The process according to claim 1, in which the polyol in aqueous phase or in the two-phase aqueous-organic system of claim 1 is cationic or neutral and/or in which, preferably 7921/5498 the absence of aggregate between the SMP polymer and/or the polyol, and the second molecule has been tested beforehand. 3. The process according to claim 1 or 2, wherein a surfactant, preferably a non-ionic surfactant such as a polyoxyethylene alkyl ether is added to the reaction mixture. 4. The process according to any one of the preceding claims, in which the polyol comprises one or more halogen residues being fluorine. 5. The process according to any preceding claim, wherein the SMP polymer is a polyester, polyether or polyurethane. 6. The process according to any one of the preceding claims, in which the organic phase for the SMP polymer and/or for the polyisocyanate and/or, optionally for the two-phase system of the polyol and/or for the first molecule and/or for the second molecule is a ketone derivative that is liquid at room temperature, preferably methyl-ethyl-ketone. 7. The process according to any one of the preceding claims, in which the polyol is present in the form of an emulsion, and/or in the form of a dispersion in water. 8. The process according to any one of the preceding claims, in which the first molecule is an alkyl amine, or an alkyl thiol, of trialkyloxysilyl, preferably 3(trimethoxysilyl)-propylamine (CAS Number 13822-56-5), and/ or wherein the second molecule is dimethyloctadecyl(3-(trimethoxysilyl)propyl)ammonium chloride. 9. The process according to any one of the preceding claims, in which the mass ratio between the SMP polymer and the first molecule is between 2 and 20%, preferably between 5 and 15%, preferably between 8 and 12%. 10. The process according to any one of the preceding claims, in which the content of isocyanate residues (total of isocyanate equivalents) of the polyisocyanate is in excess with respect to the content of -OH residues of the polyol (total of -OH equivalents of the polyol). 11. Coating obtainable by the method according to any one of claims 1 to 10. 12. The coating according to claim 11, characterized in that it has a thickness of between 1 and 40 μm, preferably between 2 and 20 μm, more particularly between 5 and 10 μm. 13. Support covered by the coating according to claim 11 or 12, said support preferably being wood, metal, glass or paper. 14. Method for obtaining the coating according to one of claims 11 to 12 applied to a substrate comprising the following steps: - Mixing in a single container of a polyol in dispersion in water, of a polyisocyanate, of an SMP polymer, of a first molecule further comprising a residue capable of forming a covalent bond with the polyisocyanate and a second molecule comprising an ammonium group, in an organic phase, - Stirring at room temperature for a predetermined time interval between 5 and 6 minutes, - Application of at least one layer of the coating obtained by the process according to any one of Claims 1 to 10 on at least one surface of the support, and - Drying at ambient temperature. 15. Use of the coating according to any one of claims 11 to 12 to increase the mechanical strength of a substrate. 16. Use of the coating according to claim 15, wherein the substrate is interior or exterior, such as plastic, glass, paper, paint or metal. 17. Biocidal, bactericidal, virucidal and/or fungicidal use of the coating according to any one of claims 11 to 12.