Glazing with hydrophobic properties achieved through the gaseous release of hydrophobic compounds contained in an emitter

Abstract

The present invention relates to glazing comprising a transparent substrate, characterized in that it includes, at the periphery of the substrate, at least one emitter of hydrophobic compounds via gaseous means. The present invention also relates to the use of glazing such as described above as rainproof glazing, said rainproof glazing being suitable for use as glazing in buildings, land vehicles, aircraft, or watercraft, or in street furniture, preferably as cockpit glazing in aircraft.

Description

Title of the invention: Glazing with hydrophobic properties by gaseous release of hydrophobic compounds contained in an emitter

[0001] The present invention relates to glazing comprising a transparent substrate, in particular a glass article, the external surface of which has been rendered hydrophobic by the gaseous release of hydrophobic compounds contained in an emitter located on the periphery of said substrate. The invention relates in particular to rainproof glazing for buildings, land, air or water vehicles, or street furniture.

[0002] Hydrophobic properties are desirable for windows and windshields in the transportation sector, particularly for motor vehicles and aircraft, as well as for glazing in the building sector. For transportation applications, rain-repellent properties are required, as water collected by the glazing and the areas upstream of the vehicle must easily flow off the glass as drops or rivulets, for example, while moving under the influence of air and wind. This is done to improve visibility and, consequently, safety, or to facilitate cleaning and the easy removal of frost.

[0003] To this end, a contact angle of a water droplet with the substrate greater than 60° or 70°, and preferably greater than 90°, is sought. The water droplet must not flatten or spread to the point of forming continuous films. Indeed, glazing is considered functional as long as this angle is greater than 60° for aeronautics and 70° for automobiles. To make a glass substrate hydrophobic, it is known to deposit hydrophobic compounds of the fluorinated silane type onto its external surface, as described in US patent application 4,983,459.It is also known to coat the glass with a mineral layer serving as a primer in order to graft the aforementioned fluorinated silane molecules. This mineral layer can be a dense silica layer like that described in patent EP 0545201, a sol-gel silica layer like that described in patent EP 799873, or an activated silicon layer like that described in patent application WO 2005 / 084943. However, these hydrophobic coatings created by grafting fluorinated silanes onto the external surface of a glass substrate present health and environmental risks due to the fluorinated compounds, which are also subject to regulatory restrictions. Furthermore, these coatings tend to degrade over time due to the constant stresses to which glazing is subjected, such as hydrolysis, photodegradation, sensitivity to atmospheric dust impacts, and sensitivity to electrostatic discharge.Thus, these hydrophobic coatings of silanes. Fluorinated coatings have short lifespans, especially in flight, for example, around six months when applied to the windshield of a short-haul commercial aircraft. Increasing the thickness of the hydrophobic coating on the surface of the glazing could extend its lifespan. This strategy is already implemented for hydrophobic varnishes. However, these coatings are susceptible to scratches, which would also limit their lifespan and degrade the overall optical quality of the glazing. Furthermore, these visible scratches are generally not repairable and may necessitate replacing the glazing. Therefore, thick functionalized coatings (>100 nm) are not a viable solution to the aforementioned problems.

[0004] Furthermore, the performance loss of hydrophobic coatings of the fluorinated silane type is difficult to predict since, as stated above, it is highly dependent on climatic and atmospheric conditions (exposure to dust, events causing surface electrostatic discharges, saline environment, etc.). In particular, fluorinated silane-based solutions used on aircraft glazing present significant regeneration complexity. Indeed, maintenance of such glazing requires intervention under cover from rain with good access to the glazing, as well as good lighting to guarantee good final optical quality, and heating systems to improve the adhesion of the fluorinated silanes. This also requires the availability of a hangar and often results in the temporary grounding of an aircraft.Furthermore, the chemicals are used by specially trained operators, and the short lifespan of the reagents they prepare makes the processes sensitive to deposition variations and ambient temperatures. In other words, poor control of deposition conditions can lead to a shortened lifespan of the hydrophobic functionalization of the regenerated fluorinated silanes.

[0005] In conclusion, these fluorinated silane solutions degrade easily over time and generate maintenance costs, logistical complexities and degradations in commercial aircraft availability for airlines.

[0006] The inventors therefore sought to develop glazing comprising a transparent substrate, preferably glazing for aircraft such as airplanes, having continuous hydrophobic properties and whose hydrophobic properties can be easily regenerated. Advantageously, the inventors sought to provide glazing with improved hydrophobic properties, particularly in their durability and predictability, while retaining other properties such as resistance to mechanical stresses (resistance to friction, abrasion, and wiping, etc.); resistance to climatic stresses (resistance to UVA and UVB rays, neutral salt spray, acid rain, etc.); and the preservation of optical properties, particularly when the glazing is a glass article. Even more preferably, the inventors sought to use volatile hydrophobic compounds such that they can be continuously applied to the external surface of the transparent substrate of a glazing, without maintenance intervention, in other words by a continuous regeneration of the hydrophobic functions on the surface of said substrate.

[0007] The inventors have thus proposed that hydrophobic compounds be transported by gaseous means directly from an emitter located at the periphery of the transparent substrate of a glazing to the external surface of said substrate. Therefore, the object of the present invention is to provide glazing (1) comprising a transparent substrate (S), said glazing comprising, at the periphery of the substrate, at least one emitter (2) of hydrophobic compounds by gaseous means.

[0008] Indeed, the inventors have surprisingly found that the gaseous release of hydrophobic compounds contained in at least one emitter located on the periphery of a transparent glazing substrate renders the external surface of said substrate hydrophobic. It has also been observed that this hydrophobic performance is maintained over time, as long as the balance of hydrophobic compound fluxes—between those arriving at the surface from the emitter or the environment and those leaving for various reasons already mentioned (such as hydrolysis, evaporation, erosion, etc.)—allows for the persistence of a sufficient quantity of hydrophobic compounds, which can be approximated by a fraction of a molecular monolayer of hydrophobic compounds.The maintenance of a sufficient quantity of hydrophobic compounds on the surface of the transparent substrate is thus improved according to the invention, either by generating a flow of hydrophobic compounds emitted by the emitter, which is added to the natural flows, and / or by a specifically strong affinity between the substrate surface and the hydrophobic compounds. Through this mechanism, the emitters associated with the airflows on the surface of the transparent substrate continuously regenerate the surface with hydrophobic compounds and thus improve the hydrophobic performance of the substrate. If necessary, regeneration of the emitters may be required either by replacing them or by recharging them with hydrophobic compounds.

[0009] The invention is illustrated by means of the following non-limiting figures: - Fig. 1 (Fig. 1) schematically represents a glazing (1) according to the invention; - Figures 2 ([Fig.2]) and 3 ([Fig.3]) schematically represent a glazing (1) according to the invention, each comprising an example of a substrate (S) and an emitter (2), the emitter (2) comprising in both figures at least one reservoir (20) in the form of a solid serving as an emitting surface; - Figure 4 (Fig. 4) schematically represents a glazing unit (1) according to the invention in which the emitter (2) comprises a reservoir (20') and an emitting surface (21); - Figures 5a ([Fig.5a]) and 5b ([Fig.5b]) schematically represent a glazing (1) comprising an emitter (2) which includes a reservoir (20') and an emitting surface (21) in the form of a membrane (210) or a plate provided with at least one opening (212) respectively; - Fig. 6 (Fig. 6) schematically represents an example of glazing (1) according to the invention; - Figures 7 ([Fig.7]) and 8 ([Fig.8]) schematically represent a glazing (1) according to the invention comprising a frame (3) in which the transparent substrate (S) is mounted, and the emitter (2) is arranged at the level of the frame (3).

[0010] The transparent substrate (S) of a glazing (1) according to the invention may comprise: - a ply of a material selected from the list including glass, glass-ceramic, polymer, as shown in [Fig. 2], or - a laminated assembly of at least two plies (S1,S2), said plies being of the same or different material, said material being chosen from the list including glass, glass-ceramic, polymer, as represented in [Fig.3].

[0011] According to the invention, "glass" means mineral glass, in particular of the soda-lime silico-borosilicate or aluminosilicate type. The polymer can be chosen from polycarbonate (PC), poly(methyl methacrylate) (PMMA), polyurethane (PU) and poly(ethylene terephthalate (PET).

[0012] In the case of a laminated assembly, the plies (S1, S2) are laminated or bonded by means of an interlayer (S3). This interlayer (S3) may comprise one or more adhesive layers made of a polymeric material. This polymeric material is preferably selected from thermoplastic polyurethane (TPU), polyvinyl butyral (PVB), polyethylene vinyl acetate (EVA), silicones, and ionomer resins. Several adhesive layers of different types may be used on the same glazing between two successive or different pairs of plies and between the same pair of successive plies.

[0013] In a preferred embodiment, the glazing (1) is a laminated glazing whose substrate (S) comprises at least two layers (S1,S2) of glass bonded or assembled by means of interlayer adhesive layers (S3) of the thermoplastic polyurethane, poly(vinyl butyral) or poly(ethylene-vinyl acetate) type.

[0014] In another preferred embodiment, the glazing is a laminated glazing whose substrate comprises at least one ply of poly(methyl methacrylate) (PMMA), preferably at least two PMMA plies bonded or assembled via intercalary adhesive layers as mentioned above.

[0015] In yet another preferred embodiment, the glazing is laminated glazing whose substrate comprises at least one polycarbonate (PC) ply, preferably at least two PC plies glued or assembled by means of intercalary adhesive layers as mentioned above.

[0016] But other embodiments are possible such as a glazing comprising at least one layer of poly(ethylene terephthalate (PET) and an adhesive layer of thermoplastic polyurethane (TPU) or poly(vinyl butyral) (PVB).

[0017] In the present invention, the glazing (1) comprises a transparent substrate (S) and at least one emitter (2) of hydrophobic compounds via gaseous emission, which is positioned at the periphery of said transparent substrate, as can be seen in Figures 1 and 2. In this application, "periphery" means the area corresponding to the bond or interface between the transparent substrate and the structure on which the substrate is placed, either on the substrate side or on the structure side, and preferably upstream of the airflow. It is also possible to move away from this area (boundary) while being limited by the visibility zone on the substrate side and to extend even further upstream of the airflow on the structure side. Nevertheless, positioning very close to the transparent substrate, particularly in the lower part of the glazing, is preferred.This positioning is particularly advantageous when the structure is that of a vehicle, as it improves the efficiency of using hydrophobic compounds by taking advantage of the airflow over the surface of the substrate (most often induced by the vehicle's speed) to sweep the surface with air charged with hydrophobic compounds.

[0018] More particularly, in the case of glazing of an aircraft, the emitter is positioned in the glazing-aircraft interface zone, either on the glazing side, or on the aircraft side and upstream of the airflows sweeping the glazing in flight conditions.

[0019] In a first configuration of the invention, the glazing includes an emitter which extends over the entire periphery of the substrate.

[0020] In a second configuration of the invention, the glazing comprises at least two emitters arranged to extend over the entire periphery of the substrate.

[0021] In a third configuration of the invention, the glazing comprises one or at least two emitters on the periphery of said substrate but which do not extend over the entire periphery of the substrate.

[0022] The emitter according to the invention may have a linear geometry, for example in the form of a strip or a slit or be made up of several point emission sites for example in the form of holes.

[0023] In a first embodiment, said emitter (2) according to the invention comprises at least one reservoir (20) in the form of a solid serving as an emitting surface, as can be seen in Figures 2 and 3.

[0024] Said reservoir (20) may then be flush with and / or not flush with the surface of the transparent substrate of the glazing, and may comprise: - According to a first variant, at least one pure hydrophobic compound or several hydrophobic compounds in a mixture, preferably in solid form. According to this variant, the emission of the hydrophobic compounds occurs by sublimation on the external surface of the substrate, i.e., on the surface of the substrate exposed to air, the emission potentially being amplified by air convection; or - According to a second variant, at least one hydrophobic compound solubilized and / or dispersed in a polymeric matrix. The polymeric matrix may comprise a polymer selected from polysulfides, epoxies, polyurethanes, silicones, and rubbers. According to this variant, the hydrophobic compound(s) solubilized and / or dispersed in said polymeric matrix are in the form of solid grains or droplets that diffuse within said matrix, and the hydrophobic compounds are then desorbed and emitted in the gaseous phase onto the external surface of the substrate.The polymer matrix protects hydrophobic compounds which, without encapsulation by said matrix, could, at least under certain conditions of use, flow when in liquid form at high operating temperatures. The polymer matrix also protects hydrophobic compounds from dissolution by certain fluids, erosion, rain, or dust. - According to a third variant, at least one hydrophobic compound is integrated into a porous matrix; in other words, the hydrophobic compound(s) fill the pores of the porous matrix. The porous matrix can be metallic, ceramic, or sintered glass. Alternatively, the porous matrix can be essentially composed of a polymer and take the form, for example, of a sponge or a seal. This porous matrix can be open-porous. Advantageously, the pore size of this matrix is ​​between 1 µm and 0.1 mm to prevent rainwater from penetrating the tank. This open-porous matrix physically separates the tank from the outside air and allows the hydrophobic compounds to diffuse through these open pores. This is followed by desorption and then the emission of the hydrophobic compounds in the gaseous phase to the external surface of the substrate.The hydrophobic compounds filling the open pores of the matrix are in a liquid or solid state.

[0025] In a second embodiment, said emitter (2) according to the invention comprises a reservoir (20') and an emitting surface (21), said reservoir (20') being a volume communicating with said emitting surface (21), as can be seen in [Fig. 4]. In other words, in this second embodiment, the reservoir (20') and the emitting surface (21) of the emitter (2) are dissociated. The volume of said reservoir may then comprise at least one hydrophobic compound located: - in solid form, or - in liquid form, or - solubilized and / or dispersed in a polymeric matrix, or - integrated into a porous matrix.

[0026] In the specific case of a reservoir (20') comprising at least one hydrophobic compound in liquid form, said reservoir may further comprise compounds without hydrophobic properties, such as solvents or solid fillers. If necessary, elements such as fibers, powders, or porous particles may be added to the reservoir to prevent the flow of liquid compounds by capillary action. The reservoir (20') is thus designed to allow the transport of hydrophobic compounds in liquid form by direct contact to the emitting surface (21), which is flush with the outer surface of the substrate.

[0027] In particular cases where the reservoir (20') comprises at least one hydrophobic compound in solid form, solubilized and / or dispersed in a polymeric matrix, or integrated into a porous matrix, the gas-phase emissions of the hydrophobic compounds towards the external surface of the substrate are carried out by the emitting surface (21) as mentioned in the first embodiment.

[0028] The emitting surface (21), according to the invention, may comprise: - at least one membrane (210), and / or - at least one plate with at least one opening (212).

[0029] According to a first alternative, the emitting surface (21) comprises at least one membrane (210), as shown in [Fig. 5a]. The membrane according to the invention can essentially be made of at least one polymer selected from polysulfides, polyurethanes, polyvinyl chlorides, and rubbers. The membrane is advantageously solid; thus, it can be a permeation membrane. The use of a membrane as the emitting surface allows the emission of hydrophobic compounds by absorption on the side of the reservoir, then diffusion into the membrane, and finally desorption and emission of said hydrophobic compounds in the gas phase onto the surface exposed to the outside air of the substrate (called the external surface or outer surface of the substrate). This has the advantage of better controlling or regulating the release of the hydrophobic compounds in the gas phase towards the external surface of the substrate.

[0030] According to a second alternative, the emitting surface (21) comprises at least one plate having at least one opening (212), as shown in [Fig. 5b] or in [Fig. 6]. This plate may be a metal plate perforated by one or more slots or by a multitude of holes. These slots or openings may all be identical, or there may be openings or slots of different sizes and shapes.

[0031] According to a third alternative, the emitting surface (21) comprises at least one membrane (210) according to the first alternative and at least one plate (212) according to the second alternative.

[0032] Furthermore, the emitter (2) may include a protective layer for the emitting surface (21), said protective layer being made of a porous material. The porous material is a material selected from ceramics, metallic foams, sintered glasses and polymeric foams.

[0033] In the particular case where the emitting surface (21) comprises at least one membrane (210) or a membrane (210) and a plate having at least one opening (212), said porous material is placed above the membrane, which itself may, where appropriate, cover the openings in the plate. This protective layer is then intended to protect the membrane from the abrasive external environment, without hindering the gaseous transport of hydrophobic compounds.

[0034] In another specific case, when the emitting surface (21) comprises at least one plate having at least one opening (212), said porous material can cover said openings of the plate, serving as a "plug" for filling with hydrophobic compounds. Filling can be done with liquid hydrophobic compounds by pouring them directly into the porous material (which can function as a wick). The plug(s) can then be accessed without having to remove the glazing.

[0035] In a preferred embodiment of the invention, when the reservoir (20') comprises at least one hydrophobic compound in liquid form, said emitter (2) may further comprise at least one channel (22) connecting the emitting surface to the reservoir, as shown in [Fig. 8]. This allows the emitter to include a larger reservoir in order to store a greater quantity of liquid hydrophobic compounds.

[0036] According to this embodiment, the emitter may also include a diffusion means for supplying the entire emitting surface. This diffusion means may, for example, take the form of a cavity to which the entire emitting surface and the channel are connected.

[0037] According to the second embodiment, the emitting surface (21) can extend particularly over the entire periphery of the transparent substrate, and more preferably over all or part of the length of the lower frame of the glazing (1) with a width of up to 3 cm. This emitting surface can also be partially covered, up to one millionth of its surface area, by emission through a few thin holes having a diameter between 0.05 mm and 2 mm.

[0038] According to the first and second specific embodiments mentioned above, the reservoir (20) or (20') may be in the form of a profile, a bulb, a parallelepiped, or any other shape. The reservoir may be essentially made of a material chosen from among elastomers such as rubber, thermoplastic polymers such as polyvinyl chloride, or metals such as steel or aluminum.

[0039] More particularly, the emitter according to the invention also performs the function of a peripheral seal for a glazing commonly called a "droplet". The droplet is indeed known to provide the glazing with aerodynamic continuity between the glazing and the mounting structure (such as the structure of an aircraft), as well as good inertness to treatment fluids (such as aeronautical fluids, cleaning products, degreasers, glycol for ground de-icing and the like); this droplet can be made of polysulfide or equivalent.

[0040] According to the present invention, the glazing (1) may further comprise at least one heating means. The heating means(s) are preferably located in or around the emitter (2) so as to allow heating by thermal conduction of: the reservoir (20) or (20'), the emitting surface (21), and, where applicable, any elements enabling the transport of hydrophobic compounds from the reservoir to the emitting surface, such as channels (22) or tubes. The heating may be achieved by means of resistive wires or resistive layers. The heating means(s) may, in particular, be placed directly opposite the emitter. Alternatively, the heating means may be positioned in the transparent substrate (S) of the glazing (1). In the case of a laminated assembly, the heating means is placed inside the laminate, preferably in contact with the outermost glass plies.The said heating means may be in the form of a transparent conductive layer, typically based on ITO or on copper, nickel, iron and nickel alloy, or tungsten wires having a diameter between 20 pm and 40 pm.

[0041] In the case of glazing for aircraft, heating systems are very useful. Indeed, convection and low pressures during flight significantly accelerate the evaporation of hydrophobic compounds compared to ground conditions. However, conversely, the low temperatures encountered in flight significantly reduce the partial pressures of hydrophobic compounds and therefore the gaseous molecular fluxes. This is why heating systems optimize the preferential emission of hydrophobic compounds during flight phases, which tend to draw the compounds towards the glazing, compared to the emissions of hydrophobic compounds when the aircraft is on the ground.

[0042] In addition, the heating means can prevent the emitter from becoming obstructed by frost.

[0043] According to the present invention, the glazing (1) may further comprise a frame (3) in which the transparent substrate (S) is mounted. The frame (3) may be a metal profile or a polymer seal.

[0044] In the case of vehicle glazing, the frame is either an integral part of the vehicle, or the frame is, as above, an element in which the substrate is mounted, and thus the assembly formed by the frame and the transparent substrate is then mounted in the vehicle.

[0045] According to a preferred mode, the frame (3) is used for the arrangement of the emitter (2). Indeed, the frame (3) can be arranged to carry the emitter (2), as can be seen in Figures 7 and 8, or arranged so that the emitter is placed at the interface between the substrate and the frame.

[0046] As mentioned previously, the glazing (1) according to the invention comprises a transparent substrate (S) and at least one emitter (2) of hydrophobic compounds via a gaseous route positioned at the periphery of the substrate. In this application, "via a gaseous route" means that the hydrophobic compounds are transported between the emitter and the glazing in gaseous molecular form, subject to the phenomena of entrainment by airflow and diffusion in a gaseous medium.

[0047] As described above, the emitter may comprise pure hydrophobic compounds or diluted hydrophobic compounds in cases where these hydrophobic compounds are solubilized and / or dispersed in a polymeric matrix or integrated into a porous matrix. Then, said hydrophobic compounds are either directly exposed to the air (when the emitter comprises a reservoir in the form of a solid serving as an emitting surface), or transported to an emitting surface such as a membrane or a plate with openings (when the emitter comprises a reservoir and an emitting surface). Geometrically, the emitting surface of the hydrophobic compounds can therefore take a multitude of forms. In the case of continuous emission or emission in multiple emitting zones along the frame of a window, the emitting surface can be considered equivalent to an equivalent band characterized by an equivalent slit width generating the same flux of contaminants.Consequently, the emitting surface generates a flux of hydrophobic compounds equal to or less than the flux emitted by the same surface composed primarily of pure compounds. For example, an emitting surface with a 20 mm aperture used with a 10% dilution of the product is equivalent to an emitting surface with a 2 mm aperture used with a pure compound. Therefore, those skilled in the art know that the fluxes of hydrophobic compounds must be considered in relation to the emitting surface area, the dilution ratio, and other factors.

[0048] Furthermore, the emitting surface can be a strip placed on the periphery of the transparent substrate of a glazing or one or more fractions (or pieces) placed on the periphery of the substrate, which also varies the vapor pressure of the hydrophobic compounds of the emitter. Those skilled in the art will integrate this variable and adapt each case to obtain the correct partial vapor pressure enabling release the hydrophobic compounds.

[0049] Thus, the hydrophobic compounds of the emitter, according to the invention, preferably have a vapor pressure between 10⁸ Pa and 1 Pa, more preferably between 10⁸ Pa and 10⁶ Pa for emitters with a large emission surface area between 10 mm² and 30 mm², and advantageously between 10² Pa and 1 Pa for emitters with a small emission surface area between 10 µm and 3 mm². These partial pressures are defined at a temperature between 20°C and 30°C, more preferably at a temperature of 25°C. This low vapor pressure, adapted to the emission surface area, allows the hydrophobic compounds to be evaporated in a sufficiently high quantity to enable functionalization of the transparent substrate while being limited to minimize the consumption of hydrophobic compounds.

[0050] Once the hydrophobic compounds are emitted by the emitter in gaseous form, they are incorporated into the airflow that runs parallel to the transparent substrate of the glazing. In this airflow, the hydrophobic compounds can diffuse, particularly in directions normal to the surface of the glazing, with the result that some of the compounds move away from the glazing and are lost, while some are redirected towards the external surface of the transparent substrate where they can adsorb.

[0051] The hydrophobic compounds of the emitter, according to the invention, are preferably chosen from: (a) a carboxylic acid of formula (I): R-COOH in which R represents a linear, branched or cyclic, saturated or unsaturated alkyl group, in C4-C22, preferably R is an alkyl group of formula (A): CnH2n+i, in which n is between 6 and 20, or (b) a phosphate of formula (II): RO-PO(OH)2 in which R represents a linear, branched or cyclic, saturated or unsaturated alkyl group, in C4-C22, preferably R is an alkyl group of formula (A): CnH2n+i, in which n is between 6 and 20, or (c) a phosphonic acid of formula (III): R-PO(OR')(OR") in which R, R' and R'' represent a hydrogen atom, an alkyl group or an aryl group, in C4-C22, preferably R, R' and R'' are alkyl groups of formula (A): CnH2n+i, in which n is between 6 and 20, or (d) a silicone, (e) a paraffin, or (f) a mixture of these.

[0052] More preferably, the hydrophobic compounds are chosen from carboxylic acids of formula (IA): CnH2n+i-COOH, in which n is between 7 and 19. In the specific case of a large emission surface, the preferred carboxylic acid is stearic acid (n equals 17) since this hydrophobic compound has the advantage of being inexpensive, safe for health and the environment, and sufficiently volatile. And in the specific case of a small emission surface, for example, obtained by perforations in a plate with 0.1 mm diameter holes spaced a few millimeters apart and aligned parallel to the edge of the glazing, the preferred carboxylic acid is decanoic acid (n equals 9) since this hydrophobic compound has the advantage of being liquid, allowing for easy refilling of the reservoir while remaining safe and inexpensive.

[0053] Indeed, the inventors have chosen hydrophobic compounds that are: - sufficiently volatile to evaporate, vaporize, or sublimate easily, - chemically stable to avoid polymerization reactions, and

[0054] - resistant to climatic or atmospheric conditions, such as oxidation, UV, neutral salt spray...

[0055] The transparent substrate (S) of the glazing (1) may further comprise on its outer face at least one layer capable of adsorbing hydrophobic compounds. For the purposes of the present invention, the outer (or "exterior") face corresponds to the face of the transparent substrate facing outwards from a building or vehicle.

[0056] The layer capable of adsorbing hydrophobic compounds may comprise: - at least one oxide or nitride of a lanthanide, or an alloy of at least two lanthanides, the lanthanide being chosen from the list including lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), or - at least one oxide or nitride of a metal or an alloy of at least two metals, the metal being chosen from the list including scandium (Sc), yttrium (Y), titanium (Ti), zirconium (Zr), hafnium (Hf), or - at least one oxide or nitride of an alloy comprising a lanthanide and a metal chosen from the aforementioned lists.

[0057] Advantageously, the layer capable of adsorbing hydrophobic compounds is essentially made of a material selected from cerium oxide (CeOx), gadolimium oxide (Gd), yttrium oxide (YOX), titanium oxide (TiOx), zirconium oxide (ZrOx) or hafnium oxide (HfOx).

[0058] And, as an example of an alloy, the following mixed oxides can be cited, such as TiYOx, HfYOx, HfZrOx, ZrYOx or GdYOx.

[0059] Furthermore, it should be noted that the layers capable of adsorbing hydrophobic compounds according to the invention are deposited on the outer face of the transparent substrate by a physical vapor phase (PVD) or chemical vapor phase (CVD) process, such as sputtering, or by evaporation or atomic layer deposition (ALD) or alternatively by liquid sol-gel type process.

[0060] The layers suitable for adsorbing compounds may have a thickness of between 5 and 1000 nm, preferably between 6 and 200 nm, and more preferably between 7 and 30 nm.

[0061] The inventors have observed that at least one layer capable of adsorbing hydrophobic compounds placed on the external face of the substrate makes it possible to promote the adsorption of hydrophobic compounds after diffusion and transport of them by means of air flows.

[0062] The transparent substrate may further comprise on its outer face at least one additional layer that does not have the function of adsorbing volatile hydrophobic compounds. For example, said additional layer may have electrical dissipative properties. Said additional layer may be placed above or below said at least one layer capable of adsorbing hydrophobic compounds. Said additional layer is preferably made essentially of a material selected from tin oxide or indium tin oxide.

[0063] The glazing (1) according to the invention is advantageously used as rainproof glazing, and even more advantageously as glazing for buildings, land vehicles, aircraft or watercraft, or street furniture, preferably as cockpit glazing for aircraft.

Claims

Claims

1. Glazing (1) comprising a transparent substrate (S), characterized in that it comprises: - at the periphery of the substrate, at least one emitter (2) of hydrophobic compounds by gaseous means, and - on the external face of the substrate, at least one layer capable of adsorbing said hydrophobic compounds.

2. Glazing according to claim 1, characterized in that said transparent substrate (S) comprises: - a ply made of a material chosen from the list comprising glass, vitroceramic, polymer, or - a laminated assembly of at least two plies (S1, S2), said plies being made of an identical or different material, said material being chosen from the list comprising glass, vitroceramic, polymer.

3. Glazing according to claim 1 or 2, in which the layer capable of adsorbing hydrophobic compounds comprises: - at least one oxide or nitride of a lanthanide, or an alloy of at least two lanthanides, the lanthanide being chosen from the list comprising lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or - at least one oxide or nitride of a metal or an alloy of at least two metals, the metal being chosen from the list comprising scandium, yttrium, titanium, zirconium, hafnium, or - at least one oxide or nitride of an alloy comprising a lanthanide and a metal chosen from the aforementioned lists.

4. Glazing according to any one of claims 1 to 3, in which the layer capable of adsorbing hydrophobic compounds has a thickness of between 5 and 1000 nm.

5. Glazing according to any one of the preceding claims, characterized in that said emitter comprises at least one reservoir (20) in the form of a solid serving as an emitting surface, said reservoir (20) comprising: - at least one pure hydrophobic compound or several hydrophobic compounds in a mixture, or - at least one hydrophobic compound solubilized and / or dispersed in a polymer matrix, or - at least one hydrophobic compound integrated into a porous matrix.

6. Glazing according to any one of claims 1 to 4, characterized in that said emitter comprises a reservoir (20') and an emitting surface (21), said reservoir being a volume communicating with said emitting surface.

7. Glazing according to claim 6, characterized in that the volume of said reservoir (20') comprises at least one hydrophobic compound found - in solid form, or - in liquid form, or - solubilized and / or dispersed in a polymer matrix, or - integrated in a porous matrix.

8. Glazing according to any one of claims 6 or 7, characterized in that the emitting surface (21) comprises: - at least one membrane (210), and / or - at least one plate provided with at least one opening (212).

9. Glazing according to any one of claims 6 to 8, characterized in that the emitter (2) comprises a protective layer for the emitting surface (21), said protective layer being made of a porous material.

10. Glazing according to any one of claims 7 to 9, characterized in that when the reservoir (20') comprises at least one hydrophobic compound in liquid form, the emitter (2) further comprises at least one channel (22) connecting the emitting surface (21) to the reservoir (20').

11. Glazing according to claim 10, characterized in that the emitter (2) further comprises a diffusion means.

12. Glazing according to any one of the preceding claims, characterized in that it further comprises at least one means for heating the emitter.

13. Glazing according to any one of the preceding claims, characterized in that it further comprises a frame (3) in which the transparent substrate (S) is mounted.

14. Glazing according to claim 13, characterized in that said frame (3) is arranged to also carry the transmitter (2).

15. Glazing according to any one of the preceding claims, characterized in that the hydrophobic compounds of the emitter (2) have a vapor pressure of between 108 Pa and 1 Pa, at a

16.

17.

18. temperature between 20°C and 30°C. Glazing according to any one of the preceding claims, characterized in that the hydrophobic compounds of the emitter (2) are chosen from: (a) a carboxylic acid of formula (I): R-COOH in which R represents a linear, branched or cyclic, saturated or unsaturated, C4-C22 alkyl group, or (b) a phosphate of formula (II): RO-PO(OH)2 in which R represents a linear, branched or cyclic, saturated or unsaturated, C4-C22 alkyl group, or (c) a phosphonic acid of formula (III): R-PO(OR')(OR”) in which R, R' and R' ' represent a hydrogen atom, an alkyl group or an aryl group, C4-C22, or (d) a silicone, (e) a paraffin, or (f) a mixture of these. Use of a glazing (1) according to any one of the preceding claims as rain-proof glazing. Use of rain-proof glazing according to claim 17, as glazing for a building, land, air or water vehicle, or street furniture.

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