FR3019087A1 - COMPOSITE MATERIAL FOR SURFACE COATING - Google Patents

Abstract

The invention relates to a composite material (10) for surface coating. This material comprises a first material (1) curing at a temperature above a first threshold temperature, and at least a second material (2), hardening at a temperature above a second threshold temperature. The second threshold temperature is higher than the first threshold temperature. The second material (2) is further encapsulated in uncured form in the first material (1) at a temperature between the first and second threshold temperatures. Furthermore, the second material (2) is shaped to harden at a temperature greater than or equal to the second threshold temperature, ensuring mechanical maintenance of the coating.

Description

TECHNICAL FIELD The invention relates to the field of composite materials used as surface coatings. BACKGROUND TECHNOLOGY Surface coatings typically serve several functions. One of these functions is generally to form a protective layer of the surface against external elements. For example, applying a paint to a metal surface can protect that surface from oxidation. In a facility requiring a high degree of safety, for example a reactor building of a nuclear power station, the use of a coating in the form of paint protects a surface against the deposition of radioactive particles and thus contributes to slowing the degradation of said area. Nevertheless, a surface coating generally withstands thermal stresses badly and degrades when the temperature exceeds a certain threshold. In the example of a coating in the form of a paint, raising the temperature above a certain threshold can cause flaking which results in the formation of debris. These debris themselves are harmful to the extent that they expose a part of the surface and because they constitute a pollution. Debris resulting from a degraded coating can for example obstruct backup systems, ventilation systems, or pipes. One of the disadvantages of coatings is that they are generally resistant only in a narrow range of temperatures. In the case of a coating in the form of paint, the paint dries or polymerizes at a hardening temperature. The coating then generally retains good structural properties when the temperature typically deviates less than 30 ° Celsius from this curing temperature. This limited strength is not acceptable for surfaces susceptible to high temperatures. This concerns, for example, pipelines or installations that must withstand thermodynamic accidents such as the reactor buildings of a nuclear power station. The temperature range, limited around the curing temperature, for which the coating retains good structural properties, conditions its deposition. In particular, the deposition of a paint resistant to high temperatures, typically above 60 ° C, can not be done at room temperature.

Conversely, a paint curing at room temperature, for example suitable for a deposit at a temperature of 30 ° C, is not resistant to high temperatures. Exposure to thermal stresses degrades the coating and prevents it from fulfilling its primary protective function. Maintaining and monitoring of the coating is then necessary to evaluate the extent of degradation in the event of exposure to thermal stresses. Significant degradation may generate debris, and may require an intervention such as stripping of the surface to apply a new, undegraded coating. The implementation of such means is expensive and impractical.

In order to overcome the drawbacks enumerated above, a surface coating material which is simple to apply and which is capable of withstanding thermal stresses is desired. SUMMARY OF THE INVENTION In order to meet the problems described above, the present invention proposes a composite material for surface coating, comprising: a first material hardening at a temperature greater than a first threshold temperature, and at least one second material. curing at a temperature above a second threshold temperature, the second threshold temperature being greater than the first threshold temperature. In addition, the second material is: - encapsulated in uncured form in the first material, at a temperature between the first and second threshold temperatures, and - shaped to harden at a temperature greater than or equal to the second threshold temperature, ensuring a mechanical maintenance of the coating.

By using two materials having distinct respective cure temperatures, the invention provides a composite material having thermal resistance over an extended temperature range. Indeed, the first material may be chosen to cure at a temperature at which the composite is applied to the surface, or a temperature deviating less than 30 degrees Celsius from this first threshold temperature. The second material may be chosen to cure at a temperature corresponding to an extreme condition to which the surface is likely to be exposed. For example, in the case of a pipe, it may be the maximum temperature at which a fluid flowing through the pipe is carried in the event of an accident. In the case of a reactor building of a nuclear installation, it may be the temperature reached in the event of an accident by loss of primary refrigerant, generally close to 150 degrees Celsius. Encapsulation separates the two materials and keeps the second material in pockets within the first material. The second material may be encapsulated in the solid state or in the liquid state within the first material.

In this way, the composite material retains a solid structure for temperatures between the first and second threshold temperatures, despite the presence of the second material that can be encapsulated in the liquid state. An increase in the temperature beyond the second threshold temperature causes a hardening of the second material. Both materials are then in the solid state, and the composite has improved thermal resistance properties in two different temperature ranges corresponding to two different conditions of use.

It should be noted that the first and second materials can both be in the solid state for temperatures between the first and the second threshold temperature. It is sufficient for the second material to undergo a first solid-to-liquid transition at a temperature below the second threshold temperature, and then to undergo a second liquid-to-solid transition, corresponding to hardening, at the second threshold temperature. Whether it is initially in the solid or liquid state, the second material is therefore initially in uncured form within the first material, for temperatures between the first and second threshold temperatures. The hardening refers hereinafter to the liquid-to-solid transition occurring, for the first material, at a temperature greater than or equal to the first threshold temperature, and for the second material, at a temperature greater than or equal to the second threshold temperature. When the second material is in the liquid state within the first material, it constitutes a safety to prevent any wear of the coating in case of raising the temperature beyond the second threshold temperature. In particular, the second material in the liquid state can flow to fill a wear such as cracks in the composite material. By hardening, this second material consolidates the coating in its areas of weakness.

In this way, the structure of the coating has suitable structural properties in a temperature range centered on the first threshold temperature, and retains a suitable structure, avoiding spalling, degradation or wear, in a temperature range centered on the second temperature. threshold temperature.

According to one embodiment, the second material may be encapsulated within the first material in vesicles. Encapsulation in vesicles makes it possible to create pockets containing the second material distributed uniformly in the composite material. When a degradation of the coating causes the breakage of a vesicle, the second material that it contains flows in the liquid phase and heals the degradation of the composite.

The rise in temperature, which may be at the origin of the formation of the degradations, makes it possible to harden the second material in order to form a homogeneous solid coating. Encapsulation in vesicles therefore supports the self-healing effect of the composite material.

Moreover, the encapsulation in vesicles makes it possible to guarantee a homogeneous dispersion in the coating. In particular, it avoids the local accumulation of the second material, especially when the latter is in the liquid state, within the composite material. Such an accumulation could locally weaken the structure of the coating for temperatures lower than the second threshold temperature.

In particular, the vesicles may each comprise an envelope made of a substance that is soluble in the second material at a temperature between the first and second threshold temperatures.

By solubilizing the envelope, the composite is not polluted by a foreign substance whose envelope could be constituted. On the other hand, this soluble envelope can delay the flow of the second material to prevent leakage in case of early degradation of the coating. In this way, the self-healing effect can advantageously be exploited for temperatures close to the second threshold temperature. The vesicle casings may advantageously be solubilized at temperatures close to this second temperature. In particular, the soluble substance can participate in the hardening of the second material.

In this way, it is possible to choose the second threshold temperature as being the melting temperature of the soluble substance that comprise the vesicles. Moreover, the substance that the vesicles comprise does not modify the composition of the composite material and can not therefore be perceived as being a foreign pollutant.

According to one embodiment, the first and second materials may each comprise at least one curing component and at least one curing component.

By providing a hardening component and a hardener in each material, it is possible to control the threshold temperature above which the hardening of each material occurs. In particular, it is possible to retard the curing reaction of one of the materials by separating the hardening component from the hardener below a certain temperature. A reaction involving a hardener therefore provides greater flexibility in the choice of the first and second threshold temperatures. According to an advantageous embodiment, the hardener of the second material can be reversibly bonded to a complexing agent blocking the hardening of the second material, the bond between the complexing agent and the hardener breaking at a temperature above the first threshold temperature. and lower than the second threshold temperature. By binding the hardener to a complexing agent, it is possible to retard the hardening of the second material and thus modulate the second threshold temperature. Indeed, the second threshold temperature is greater than or equal to the temperature at which the bond between the complexing agent and the hardener is broken. Therefore, the binding of the hardener with the complexing agent defines a breaking temperature below which the second material does not cure.

Advantageously, the complexing agent may be CuBr2 copper bromide. This complexing agent is capable of forming a reversible bond with the hardener of the second material for temperatures below 130 degrees Celsius. It can therefore be quite suitable for applications involving exposure to temperatures between 100 degrees Celsius and 160 degrees Celsius. For example, copper bromide is suitable for a composite used as a coating in reactor buildings of a nuclear facility.

According to one embodiment, a component of the second material may comprise a group intended to form a chemical bond between the first and second materials. By bonding with the first material, the second material can form a single homogeneous phase in the composite material and help strengthen the coating. This reinforcement intervenes not only locally in the vicinity of a vesicle but also in the areas between the vesicles. By thus binding to the first material, and dispersing in the areas of fragility of the composite material, the second material better preserves the composite against any wear or damage that may for example be caused by a rise in temperature. According to one embodiment, the first threshold temperature can be between 0 and 30 degrees Celsius.

In this way, the composite material cures at ambient temperature. It can thus be particularly suitable for application on a surface in usual working conditions. The composite material has satisfactory thermal stress resistance in a temperature range deviating less than 30 degrees Celsius from the first threshold temperature.

Advantageously, the second threshold temperature may be greater than 60 degrees Celsius. A temperature above 60 degrees Celsius typically corresponds to temperatures encountered in an industrial environment. Temperatures between 60 ° C and 120 ° C can occur in pipes in the event of an accident, while higher temperatures between 130 ° C and 200 ° C can occur, for example, in case of loss of primary coolant in nuclear installations. According to one embodiment, at least one of the first and second materials may comprise at least one epoxide monomer intended to polymerize in the presence of a crosslinking agent. The use of epoxides is particularly suitable for applications such as paints used inter alia in industrial installations. According to one embodiment, the first material may comprise epoxide monomers chosen from compounds consisting of: DiGlycidyl Aether Bisphenol A-Polyamidoamine, DiGlycidyl Aether Bisphenol F, Novolac, Glycidyl, Aliphatic. According to another embodiment, the second material may comprise epoxide monomers chosen from compounds consisting of: DiGlycidyl Aether of Bisphenol A, DiGlycidyl Aether of Bisphenol F, Novolac, Glycidyl, Aliphatic. These epoxy monomers are suitable for use in paints or any other coating compatible with use in an industrial setting. According to one embodiment, the first material may comprise a curative component selected from compounds consisting of: polyamine, aliphatic amine, aromatic amine, amidopolyamines, polyaminidamide, aminoamide, polyamide, anhydride, imidazoline polyamines, urea-formaldehydes, melamines, Trially Cyanurate, Cyanuric Chloride, Guanamines, Dicyandiamides, Acrylamides, Imidazole, Hydrazides, Duanidines, Nitrosamines, Ethylene Imines, Thioureas, Sulfonamides, Lewis Acids, Phenolic Hardeners, Metal Salts, Non-Carboxylic Acids, Organic Acids. These hardening compounds make it possible to polymerize the epoxide monomers mentioned above. According to another embodiment, the second material may comprise a hardener component chosen from compounds reversibly complexable during a rise in temperature in the medium, consisting of: 2-methylimidazole, diethyl toluene diamine, boron trifluoride monoethylamine ( BF3.MEA), diamino cyclohexane.

These compounds have the advantage of being able to bind to complexing agents in order to delay the polymerization of the second material until a sufficiently high temperature is reached. According to one embodiment, a proportion of the second material in the composite material may represent 5% to 40% by weight of the composite material. Thus, the composite material retains satisfactory mechanical and structural properties for temperatures between the first and second threshold temperatures, when the second material is encapsulated in uncured form in the first material. Advantageously, the composite material is applied to a surface as a protective coating against contaminating substances.

This type of application of the composite material may in particular be suitable for protecting a surface against the deposition of radioactive particles, or against the deposit of germs, biological material or corrosive substances.

DESCRIPTION OF THE FIGURES The method which is the subject of the invention will be better understood on reading the following description of exemplary embodiments presented for illustrative purposes, in no way limiting, and on the observation of the following drawings in which: FIG. 1 is a schematic representation of a composite material comprising a first material in the solid state and a second material in the liquid state encapsulated in vesicles; and FIG. 2 is a schematic representation in plan view of a composite material comprising a first material in the solid state and a second solid state material filling degradations of the composite material. For the sake of clarity, the dimensions of the various elements shown in these figures are not necessarily in proportion to their actual dimensions. In the figures, identical references correspond to identical elements.

DETAILED DESCRIPTION The invention relates to a composite material for a simple surface coating to be applied and offering improved resistance to thermal stresses. The composite material of the invention consists of at least two mixed materials. FIG. 1 schematically represents an example of a composite material 10, also called a "composite", comprising a first material 1 occupying a majority proportion of the total volume of the composite 10 and a second material 2 occupying a minor proportion of the volume of the composite 10. The first material 1 may be selected so as to cure at a first threshold temperature of between 0 ° C and 30 ° C. Such temperatures are considered to be ambient temperatures, allowing the first material to cure in the open without requiring a temperature rise by heating. The second material 2 may be chosen so as to harden at a second threshold temperature higher than the first threshold temperature. For example, a second threshold temperature of 130 ° C is suitable for most common applications encountered in an industrial context. In order to separate the second material 2 from the first material 1, the invention proposes to encapsulate the second material 2 in vesicles 3. This encapsulation makes it possible to avoid a flow and a leakage of the second material 2 when the latter is at the same time. liquid state, the first material 1 after deposition having already hardened. The use of vesicles 3 to separate the two materials 1, 2 is however not essential. In some applications, the second material 2 is in the liquid state during the deposition of the composite 10 on a surface. In this case, the use of vesicles 3 or at least separation means of the two materials can be advantageous. It is also possible that the second material 2 is in the solid state at room temperature, when the composite 10 is applied to a surface. In this second embodiment, a solid to liquid transition of the second material advantageously intervenes at an intermediate temperature between the first and the second threshold temperature. For example, when the second threshold temperature is 130 ° C, the intermediate solid-to-liquid transition temperature of the second material may be 80 ° C. The use of a second solid material at room temperature has the advantage of simplifying the handling of the composite 10 during the application of the composite 10 on the surface. The use of vesicles 3 facilitates the initial production of the mixture forming the composite material 10, when the latter is in the liquid state before it is applied to a surface. The vesicles also make it possible to mix the two materials 1, 2 in order to uniformly distribute the second material 2 in the composite 10 and to prevent a local accumulation of material 2.

In FIG. 1, the vesicles 3 form reservoirs of material 2. For temperatures between the first and second threshold temperatures, the second material 2 remains in the liquid state. For temperatures deviating less than 30 ° C. from the first threshold temperature, the coating generally retains good structural properties thanks to the first material 1. Generally, a proportion of the second material 2 in the first material 1 represents between 5% and 40%. % of the total volume of the composite material, to ensure good structural integrity of the coating at room temperature despite the presence of liquid pockets in the coating. Moreover, such a proportion of second material constitutes an adequate compromise between mechanical resistance at ambient temperature and thermal resistance for temperatures higher than the second threshold temperature. Several materials can be used to produce the composite 10. The use of a bisphenol A-polyamidoamine DiGlycidyl A-type epoxy resin system, also called DGEBA-polyamidoamine, may be a particularly advantageous choice for the first material 1. This The compound cures by crosslinking at room temperature, and may be particularly suitable for use in surface forming paints. Similarly, several compounds can be envisaged for the second material 2.

In an embodiment suitable for the manufacture of a paint resistant to thermal stresses exceeding 130 ° C, the invention proposes the use of DGEBA monomers combined with a 2-methylimidazole hardener for the second material 2. The contacting DGEBA with the hardener is then a condition allowing the crosslinking of the second material. To control the second threshold temperature, at which this hardening takes place, the hardener is complexed with CuBr2 copper bromide. This complexation creates the compound of chemical formula CuBr2 (2-Melm) 4. The bonding of copper bromide with the hardener is reversible: it breaks above 130 ° C, and is reformed when the temperature drops below 130 ° C.

Thus, the crosslinking reaction of DGEBA occurs only at temperatures above that which allows the copper bromide to separate from the hardener, ie temperatures above 130 ° C. The vesicles 3 encapsulating the second material 2 can be made in different ways. In order to effectively separate the first 1 and second 2 materials, the vesicles can be made in the form of spherical microcapsules with a diameter of between 30 and 100 microns. These microspheres can easily be added in a desired quantity in a solution of the first material 1 in the liquid state, and can be mixed by mixing. The outer envelope of the vesicles 3 can be made of different materials. An advantageous embodiment consists in using formaldehyde-urea as an envelope. This substance has the advantage of not denaturing the structural properties of the coating as it is also in the form of resin. In addition, formaldehyde-urea is resistant to room temperature but becomes brittle at temperatures above 60 ° C and melts at temperatures above 100 ° C. Therefore, this envelope is an effective means for separating the second material 2 from the first material 1 at room temperature. It also allows the release of the second material 2 when the temperature rises to the second threshold temperature, at temperatures at which the first material 1 is likely to undergo damage. The formaldehyde-urea has a light shade, which contributes to not altering the visual appearance of the coating unlike for example phenoplasts, which can also be considered to form an envelope.

According to another embodiment, it is possible to use an outer envelope for the vesicles 3 which melts at a temperature between the first and second threshold temperatures. This is achievable for example by using polystyrene or PMMA as an envelope. These compounds are soluble in the resin of material 2 above 100 ° C. Thus, when the envelope of the vesicles 3 melts, the second material 2 in the liquid state remains fixed in the cavities of the first material 1 which is in the solid state. The material 2 can nevertheless be poured to fill cracks or other damage occurring in the composite material 10 in order to prevent its wear. According to another advantageous variant embodiment, the envelope of the vesicles 3 can be made from a substance which participates in the crosslinking, and thus the hardening, of the second material 2. For example, it is possible to provide polyesters. epoxides of low mass crosslinked by metal salts. It is thus conceivable to bind the molecules of the hardener of the second material 2, such as 2-methylimidazole with salts, thus achieving a complexing of the hardener likely to increase the second threshold temperature and form an envelope for vesicle 3. In this mode Advantageously, the envelope of a vesicle 3 is not an object foreign to the coating. The dissolution of the envelope occurs at a temperature below the second threshold temperature and above the first threshold temperature. As a result, the material 2 is released from its vesicles and can flow into interstices of the composite material 10 to heal any degradation experienced by the composite with the temperature rise. Then, the second material 2 solidifies, to obtain the compound shown in Figure 2, showing a top view of a healed coating by the flow of the second material 2. In this figure, the cracks 4 and other degradations 4, witnesses d wear or peeling of the coating, are filled by the second material 2. The release of the second material 2 when the envelope of the vesicles 3 bottom allows to create a continuous phase of material 2 in the material 1 by the flow Thus, there is coalescence of the second material 2, thus contributing to structurally strengthening the coating in its entirety, and not specifically in the vicinity of a vesicle 3. This reinforcement constitutes both a mechanical reinforcement and a better thermal resistance at temperatures deviating less than 30 ° C from the second threshold temperature. According to another embodiment, it is possible to functionalize the hardener of the second material 2, namely 2-methylimidazole. This functionalization can in particular allow the hardener to react, for example with the hydroxyl groups available on each of the segments of the hardening component DGEBA when the first material 1 is solidified. In this way the second material 2 can create chemical bonds with the first material 1, which further contributes to the structural reinforcement of the composite material 10. This reinforcement is mechanical insofar as the two materials can then be intimately linked to each other. a microscopic scale. It is also thermal insofar as the resistance to both ambient temperatures and temperatures in the region of 130 ° C. can be guaranteed homogeneously throughout the volume of the composite material 10.

As a variant, it is possible to provide a functionalization of one of the constituents of the first material 1 in order to create connections between the first 1 and second 2 materials. It is also possible to provide a functionalization of both of the constituents of the first material 1 and the second material 2, to ensure a coalescence linking the compounds of the first material 1 to those of the second material 2. The release of the second material 2 in the composite can be done in different ways. In the case of using an insoluble envelope to form the vesicles 3, the second material 2 can be released when a degradation of the coating breaks a vesicle. In the case of a soluble vesicle, a mechanical rupture remains possible but the solubilization guarantees a systematic disappearance of the envelope of the vesicle according to a thermal criterion. It is also possible to provide vesicles devoid of envelope. In addition to the embodiment described above, it is possible to provide compounds for the hardener and the hardener of the second material which coalesce once mixed with the first material to form microdroplets of second material 2 in the composite 10. The composite material 10 described above can be envisaged in several applications of both industrial and domestic nature.

The composite material 10 may in particular be a suitable coating in pipes. In the latter, a paint is applied at ambient temperature to protect the inside and / or the outside of the pipe against elements likely to damage it, such as, for example, corrosive fluids. The fluid flowing through the pipeline or the external environment in which the pipeline is located can sometimes reach high temperatures, exceeding 60 ° C or even 100 ° C. Therefore, the presence in the paint of a second material 2 able to heal any degradation of the coating allows to preserve the intact pipeline longer and avoid the formation of debris that can participate in the capping of the pipe.

Another advantageous application relates to reactor buildings in nuclear installations. In these installations, the protection of reactor building surfaces is of great importance for safety reasons. It is therefore advantageous to ensure that the coatings applied to protect building surfaces against radioactive particles and / or corrosion adequately withstand the stresses to which they are exposed. In particular, the reactor buildings can be subjected to sudden rises in temperature in the event of a thermodynamic accident such as the loss of primary refrigerant. Under such circumstances, the temperature can reach more than 150 ° C in a few seconds and the pressure rise to more than 5 bars. The invention makes it possible under these extreme conditions to avoid abrupt and harmful degradation of coatings such as paints by virtue of the self-healing and mechanically reinforcing action exerted by the second material 2.

In general, the invention is of interest for applications in which safety issues call for particular vigilance vis-à-vis the coating of a surface. The invention is not limited to the embodiments described above, and also extends to other variants. In particular, although only two different materials have been described, the invention may relate to more than two different materials, each having different curing threshold temperatures, to further enhance the coating and ensure its structural integrity in a range. even wider temperature range. It is also conceivable to use other compounds for the first and / or second material. For example, the DGEBA-polyamidoamine of the first material 1 and the DGEBA of the second material 2 can be replaced by the following compounds: DiGlycidyl Ether Bisphenol F, Novolac, Glycidyl, Aliphatic.

Similarly, the hardener of the second material may be chosen from: diethyltoluene diamine, boron trifluoride monoethylamine (BF3.MEA), diamino cyclohexane. The first material is also used in conjunction with a hardener to initiate crosslinking. These hardeners may be chosen from: polyamine, aliphatic amine, aromatic amine, amidopolyamines, polyaminidamide, aminoamide, polyamide, anhydride, polyamines imidazoline, urea-formaldehydes, melamines, trially cyanurate, cyanuric chloride, guanamines, dicyandiamides, acrylamides, imidazole, hydrazides, Duanidines, nitrosamines, ethylene imines, thioureas, sulfonamides, Lewis acids, phenolic hardeners, metal salts, non-carboxylic acids, organic acids. Unlike the use of thermoplastic materials which melt when the temperature rises above a melting temperature of the material, the invention proposes to define hardening steps for a coating to make it able to withstand constraints located outside a usual temperature range of use. However, it is not excluded to combine the materials of the invention with materials with thermoplastic properties to be able to melt the coating in case of exceeding a maximum temperature not to be exceeded. In addition, the invention is not limited to the first and second threshold temperatures described above. Any combination of first and second threshold temperatures can be obtained by a suitable choice of complexing agent and materials suitable for the intended applications.

Claims (17)

REVENDICATIONS1. Composite material (10) for surface coating, characterized in that it comprises: - a first material (1) curing at a temperature above a first threshold temperature, and - at least a second material (2), hardening at a a temperature greater than a second threshold temperature, said second threshold temperature being greater than said first threshold temperature, the second material (2) being: - encapsulated in uncured form in the first material (1) at a temperature between said first and second threshold temperatures; second threshold temperature, and - shaped to harden at a temperature greater than or equal to the second threshold temperature by ensuring a mechanical maintenance of the coating. 2. composite material (10) according to claim 1, characterized in that the second material (2) is encapsulated within the first material in vesicles (3). 3. composite material (10) according to claim 2, characterized in that the vesicles (3) each comprise a casing made of a substance soluble in the second material (2) at a temperature between the first and second threshold temperatures. 4. Composite material (10) according to claim 3, characterized in that said soluble substance participates in the hardening of the second material (2). Composite material (10) according to one of the preceding claims, characterized in that the first (1) and second (2) materials each comprise at least one curing component and at least one curing component. 6. composite material (10) according to claim 5, characterized in that the hardener of the second material (2) is reversibly bonded to a complexing agent blocking the hardening of the second material (2), the bond between the complexing agent and the hardener breaking at a temperature above the first threshold temperature and below the second threshold temperature. 7. composite material (10) according to claim 6, characterized in that the complexing agent is CuBr2 copper bromide. 8. composite material (10) according to one of the preceding claims, characterized in that a component of the second material (2) comprises a group for forming a chemical bond between the first (1) and second (2) materials. 9. composite material (10) according to one of the preceding claims, characterized in that the first threshold temperature is between 0 and 30 degrees Celsius. 10. composite material (10) according to one of the preceding claims, characterized in that the second threshold temperature is greater than 60 degrees Celsius. 11. composite material (10) according to one of the preceding claims, characterized in that at least one of the first (1) and second (2) materials comprises at least one epoxy monomer for polymerizing in the presence of an agent crosslinking. 12. Composite material (10) according to claim 11, characterized in that the first material (1) comprises epoxide monomers chosen from compounds consisting of: DiGlycidyl Aether Bisphenol A-Polyamidoamine, DiGlycidyl Ether Bisphenol F, Novolac, Glycidyl , Aliphatic. 13. The composite material according to claim 11, wherein the second material comprises epoxide monomers chosen from compounds consisting of: , Glycidyl, Aliphatic. 14. composite material (10) according to one of claims 11 to 13, characterized in that the first material (1) comprises a curative component selected from compounds consisting of: polyamine, aliphatic amine, aromatic amine, amidopolyamines, polyaminidamide , aminoamide, polyamide, anhydride, polyamines imidazoline, urea-formaldehydes, melamines, trially cyanurate, cyanuric chloride, guanamines, dicyandiamides, acrylamides, imidazole, hydrazides, duanidines, nitrosamines, ethylene imines, thioureas, sulfonamides, Lewis acids, phenolic hardeners, metal salts, non-carboxylic acids, organic acids. 15. composite material (10) according to one of claims 11 to 14, characterized in that the second material (2) comprises a hardener component selected from compounds reversibly complexable during a temperature rise in the medium consisting of: 2-methylimidazole, diethyl toluene diamine, boron trifluoride monoethylamine (BF3.MEA), diamino cyclohexane. 16. composite material (10) according to one of the preceding claims, characterized in that a proportion of the second material (2) in the composite material (10) represents 5% to 40% by weight of the composite material (10). 17. composite material (10) according to one of the preceding claims, characterized in that it is applied on a surface as a protective coating against contaminating substances.