Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3613—Coatings of type glass/inorganic compound/metal/inorganic compound/metal/other
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/001—General methods for coating; Devices therefor
  • C03C17/002—General methods for coating; Devices therefor for flat glass, e.g. float glass
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/06—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/06—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals
  • C03C17/10—Surface treatment of glass, not in the form of fibres or filaments, by coating with metals by deposition from the liquid phase
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3626—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3634—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer one layer at least containing carbon, a carbide or oxycarbide
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3649—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer made of metals other than silver
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3652—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3657—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having optical properties
  • C03C17/366—Low-emissivity or solar control coatings
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3657—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having optical properties
  • C03C17/3663—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having optical properties specially adapted for use as mirrors
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
  • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
  • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
  • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
  • C03C17/3694—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer one layer having a composition gradient through its thickness
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/25—Metals
  • C03C2217/251—Al, Cu, Mg or noble metals
  • C03C2217/252—Al
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/25—Metals
  • C03C2217/269—Non-specific enumeration
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/20—Materials for coating a single layer on glass
  • C03C2217/25—Metals
  • C03C2217/27—Mixtures of metals, alloys
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2217/00—Coatings on glass
  • C03C2217/70—Properties of coatings
  • C03C2217/73—Anti-reflective coatings with specific characteristics
  • C03C2217/734—Anti-reflective coatings with specific characteristics comprising an alternation of high and low refractive indexes
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2218/00—Methods for coating glass
  • C03C2218/10—Deposition methods
  • C03C2218/13—Deposition methods from melts
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C2218/00—Methods for coating glass
  • C03C2218/10—Deposition methods
  • C03C2218/17—Deposition methods from a solid phase

Definitions

• the invention relates to the method of depositing on glass a reflective layer, especially a metallic layer.
• a metal layer can in fact confer on a glass substrate intended to become a glazing different properties: at relatively small thickness, it plays the role of a protective coating against solar and / or low-emissivity radiation. With a greater thickness, it allows to obtain a real mirror with very strong light reflection.
• the most common example is silver: we know how to deposit it in a thin layer, in particular of interference thickness, by vacuum techniques of the sputtering type, or in a thicker layer for making mirrors, for example by the technique wet classic with a silver line.
• silver is a material of limited durability in a thin layer when it is exposed to a chemically aggressive medium, and the deposit techniques mentioned above are only carried out on, and discontinuously on, glass trays once cut from the glass ribbon from a float production line.
• the object of the invention is therefore to develop a new continuous manufacturing process on a ribbon of float glass with a metallic reflective layer which overcomes the aforementioned drawbacks, and which in particular allows obtaining layers of high quality compatible with the requirements of industrial glazing production.
• the subject of the invention is a method of depositing, in particular continuously, on a glass ribbon of a float line, a reflective layer based on metal, the melting temperature of which is less than or equal to the temperature where the ribbon of glass acquires dimensional stability. It consists in depositing in a controlled, inert or reducing atmosphere, when the glass ribbon has already acquired this dimensional stability, by bringing the surface of the ribbon into contact with the metal in question in powder or molten form, the temperature of the ribbon when brought into contact being chosen so that the powder melts and coalesces, or the molten metal coats, on the surface of the ribbon, leaving a solid continuous layer when the temperature of the ribbon decreases during the process of forming flat glass up to a temperature less than or equal to the melting temperature of the metal.
• metal is understood to mean a material with electrical behavior essentially of the conductive type. It is an essentially metallic material, either based on at least two metals, for example in the form of an intermetallic compound, an alloy, or even a eutectic compound.
• the “metal” according to the invention is based on at least one of the materials belonging to the group comprising aluminum, zinc, tin, cadmium. It can also optionally include silicon or another metal (in particular in a concentration of less than 15 atomic%).
• this material there may be mentioned aluminum, aluminum-tin alloys, aluminum-zinc, aluminum-silicon compounds, and in particular the aluminum-silicon eutectic compound comprising 12 atomic% of silicon and having a melting temperature of about 575 ° C.
• the term “continuous” layer also includes a layer which can be deposited on the glass ribbon so as to cover most, if not all, of its surface. But this also includes the layers which are deposited for example in the form of parallel strips, and therefore which only partially, but in a desired and controlled manner, cover the surface of the glass, for example for decorative purposes.
• the term “ribbon surface” includes not only the surface of the bare glass, but also the surface of the glass which may have been previously treated / covered with at least one given coating.
• the invention preferably applies to a glass ribbon of a float line. It goes without saying, however, that it is not limited thereto and that it can also apply to a glass ribbon which is not from a float line or to a non-continuous glass substrate such as a glass tray.
• the metal is only used in the solid or liquid phase, and not in the gas phase, as in the aforementioned patent FR-2 01 1 563.
• the implementation of the process is greatly facilitated, because it is easier to control the distribution of powder or liquid than vapor on the surface of the glass.
• this is a primary advantage for making it possible to manufacture layers of relatively large thicknesses, in particular of sufficient thicknesses to transform the glass into a mirror.
• the method according to the invention involves either a fusion of a metal powder, or a "coating" of a metal previously melted on the surface of the glass. It is therefore not a pyrolysis in the usual sense of the term, whether in the solid, liquid or gas phase (then also called under the term CVD or Chemical Vapor Deposition). Pyrolysis in fact involves, on the contrary, a chemical reaction step of decomposition of precursors of the organometallic derivative type in contact with hot glass.
• the layers according to the invention tend to be more adherent, denser, less “rough” than pyrolyzed layers, because they result from the fusion of elemental metal. They also tend to crystallize better, because in the invention, crystallization is carried out during the solidification of the layer at the speed corresponding to the cooling speed of the glass ribbon along its course on the float line.
• the crystallization, at least partially, of a pyrolyzed layer generally takes place in a much more “brutal” manner, during the decomposition of the precursors, and is often accompanied by mechanical stresses
• the layers according to the invention also tend to be purer, since there is little risk of impurities being incorporated into the layers.
• layers in formation which is not the case with pyrolyzed layers, which may contain, for example, a certain level of residual carbon originating from the decomposition of organic precursors in the glass
• the reflective layer is deposited when the glass ribbon is at a temperature greater than or equal to the melting temperature of the metal: this ensures the melting of the metal particles arriving on the glass, and / or good distribution of the molten metal on its surface
• the contacting of the metal in powder form with the surface of the glass can be carried out according to two different embodiments.
• the first embodiment consists in spraying said metallic powder in suspension in an inert or reducing carrier gas, in order to avoid its oxidation, in particular using a dispensing nozzle.
• a dispensing nozzle may be a static nozzle, which is arranged above the glass and substantially transversely to its axis of travel, over all or part of the width of said strip.
• It can also be a movable nozzle, which is moved back and forth along an axis substantially transverse to the axis of travel of the glass ribbon.
• the powder is made only of grains of said metal.
• the powder is preferably a mixture of powders of each of the components of the final coating, a mixture the proportions of which can be adjusted as required, or a powder directly produced from the alloy.
• the particle size of the powder or mixture of powders is advantageously between 0.1 ⁇ m and 100 ⁇ m and in particular between 1.0 and 50 micrometers, for example between 5 and 1 0 micrometers. In such a range of particle sizes, the “grains” of powder will be able to melt and coalesce optimally on the glass.
• the second embodiment consists in generating “in situ” the metal in pulverulent form above the glass ribbon, from at least one metallic derivative, in particular gaseous, which is caused to decompose into metal by thermal activation and / or bringing them into contact with derivatives capable of reacting together.
• This is another way of ensuring that the metal, formed in the inert or reducing atmosphere prevailing above the glass, is not oxidized.
• CVD gas phase pyrolysis technology
• metal powder "in situ” is done from metal derivative (s) chosen from metal alkyls, metal hydrides, mixed hydride and metal alkyl compounds. complexed with ammonia or an amine, in particular alanes in the case of aluminum: either a single type of "precursor” is chosen, or different types of precursors, in particular when the layer to be obtained is made of an alloy.
• metal derivative chosen from metal alkyls, metal hydrides, mixed hydride and metal alkyl compounds.
• ammonia or an amine, in particular alanes in the case of aluminum either a single type of "precursor” is chosen, or different types of precursors, in particular when the layer to be obtained is made of an alloy.
• Their metal decomposition temperature is generally between 50 ° C and 600 ° C, in particular between 1 00 ° C and 450 ° C. It can therefore be seen that such a range of temperatures does not coincide with the temperature that the glass ribbon has when depositing the layer: there is, unlike a gas phase pyrolysis, decorrelation between the decomposition temperature of the derivative metal chosen and the temperature of the glass at the time of deposition, and we therefore have much more freedom to optimize each of them independently of the other, and to select the appropriate metal derivative (s) ( s).
• the metal derivatives are therefore introduced above the glass ribbon in gaseous form, advantageously using a device whose walls define a guide channel for the powder generated.
• the walls of this cavity are preferably substantially vertical, possibly divergent or, on the contrary, convergent in the direction of the glass ribbon, and over at least part of its height, an appropriate "thermal gradient” is created.
• the term “thermal gradient” is understood to mean precise control of the temperature which, relatively gradually, is preferably chosen to increase in the direction of the glass.
• the method consists in injecting the metallic derivatives into the upper part of the cavity of the device, and in extracting the effluents resulting from their decomposition by lateral evacuation means provided in the walls of the cavity, extraction carried out preferably at or near the level where the metallic powder is formed and where it reaches a sufficient particle size.
• the cavity being at least partially in the inert and / or reducing atmosphere prevailing above the glass, it is designed so as to be itself filled with such an atmosphere.
• the gaseous metal derivatives are introduced in suspension in a carrier gas, the latter will of course also be chosen preferably of an inert and / or reducing nature.
• metal powder is sprayed directly or from metal derivatives, it should be understood in the invention that it liquefies or fuses either in contact with the glass, or near the glass but slightly above it, under the glass. effect of the heat emitted at a short distance from the glass ribbon. It can then arrive in a rain of droplets on the glass.
• Another possibility according to the invention is not to start from a metal powder or gaseous metal derivatives, but from the already molten metal, which can be distributed on the surface of the glass using a nozzle. static distribution arranged above the glass and transversely to its axis of travel, which delivers a "curtain" of molten metal on the glass.
• a movable nozzle driven in a transverse reciprocating movement above the glass, of the spray gun type.
• the reflective layers according to the invention have two very advantageous characteristics:
• these layers contain little or no impurities, while carbon, oxygen or nitrogen type impurities tend to increase the absorption and / or transmission of the layer at the expense of its light reflection.
• This low level of impurities therefore combines with a high density to achieve a maximum mirror effect at a given thickness.
• the maximum impurity values vary slightly as a function of the process according to the invention chosen: if one “starts” with the materials constituting the layer, in pulverulent or molten form, without involving decomposition of precursors at least partially organic, the layer can be extremely pure.
• impurities such as 0 or C
• impurities possibly being incorporated into the layer during its formation, for example by atmospheric pollution or being present in the starting powder.
• the level of impurities is less than 1 atomic% and remains below the detectability threshold of the measuring devices, in this case a scanning electron microprobe.
• the reflective layers remain very pure, but possibly with a slightly higher level of impurities than in the previous case, in particular at most 2 to 3 atomic%. It may be carbon, oxygen or nitrogen, in particular when starting from compounds of the alane type.
• the metal may be advantageous to treat the surface of the glass before the deposition of the metal layer proper.
• it may aim to facilitate wetting / bonding of the layer on the glass.
• it can also aim to inhibit a parasitic reaction at the glass / metal interface which would tend to form, from the metal and the silicon oxide contained in the glass, the metal oxide corresponding to the metal and silicon.
• the gas may, for example, be titanium tetrachloride TiCI 4 .
• the pretreatment can also include the deposition of at least one so-called “intermediate” layer before the deposition of the layer.
• the intermediate layer or layers can be advantageously chosen based on at least one of the materials belonging to the following group: silicon, oxides such as silicon oxide, oxycarbide or oxynitride, titanium oxide Ti0 2 , cerium oxide, aluminum oxide Al 2 0 3 , zirconium oxide Zr0 2 , zinc oxide ZnO, nitrides such as aluminum nitride AIN, silicon nitride Si 3 N 4 , titanium nitride TiN, zirconium nitride, boron oxide, ytt ⁇ um oxide, magnesium oxide, mixed AI and Si oxide, fluorinated aluminum oxide , magnesium fluoride MgF 2 .
• This intermediate layer preferably has a maximum refractive index of 1.8 and a light absorption at most equal to 3%. Its optical thickness may be between 40 and 120 nm and preferably between 70 and 100 nm.
• the chemical role of this intermediate layer is therefore the protection of the thin metallic reflective layer, either at the end of the production of the mirror, at the outlet of the enclosure of the float bath, or subsequently during a subsequent heat treatment of the mirror or even over time, during the lifetime of the mirror in normal use situation, in a bathroom for example.
• the additional layer or layers may in particular be chosen based on nitride, such as aluminum nitride, silicon nitride or titanium nitride. However, they can also be based on oxide (s), in particular comprising at least one oxide belonging to the following group: titanium oxide Ti0 2 , tin Sn0 2 , zirconium Zr0 2 , zinc, niobium, tungsten , antimony, bismuth, tantalum, Yt ⁇ um, aluminum nitride or silcium, or fluorinated tin oxide or "diamond-like carbon" (DLC), aluminum oxide Al 2 0 3 , in oxide, oxycarbide and / or silicon oxynitride, vanadium oxide.
• oxide (s) in particular comprising at least one oxide belonging to the following group: titanium oxide Ti0 2 , tin Sn0 2 , zirconium Zr0 2 , zinc, niobium, tungsten , anti
• the reflective metallic layer with an oxygen-containing compound
• the deposits of additional layer (s) are preferably produced by gas phase pyrolysis.
• the additional layer covering the reflective metallic layer can have a gradient in chemical composition and / or refractive index in its thickness. It can in particular be a gradient of increasing or decreasing index, in particular by deposition of a material with low refractive index (for example between 1, 45 and 1, 60), gradually increasing as and as the layer is formed from a material with a higher refractive index, in particular greater than 2 or vice versa.
• a chemical composition gradient very advantageously allows to give two properties to a single layer, and to optimize them in parallel without sacrificing one for the benefit of the other, in particular with regard to the adhesion of the layer to the layer (or layers) with which (which ) it is in contact as well as its mechanical / chemical durability ...
• This index gradient and / or this chemical composition gradient can be obtained by gas phase pyrolysis, using a distribution nozzle using two injection slots, one for each of the gaseous precursors necessary for obtaining the two materials with low and high index, and by configuring it so as to cause, along the glass, a partial and progressive mixture between the two gaseous veins coming from two slots of injection
• a layer based on silicon oxide is used which is gradually enriched with titanium oxide: if a thin layer of “sacrificial” silicon is placed on the reflective layer , an excellent adhesion Si / Si0 2 or S ⁇ / SiO x C v is thus obtained on the side of the reflective layer, and the stack is "completed” with titanium oxide which, if it is well crystallized , has very interesting anti-soiling and / or anti-fogging characteristics, due to its known photocatalytic properties.
• the metallic reflecting layer with at least one sequence of layers with low and high indices, for example a sequence Si0 2 / Ti0 2 .
• Each additional layer preferably has a geometric thickness of at least 10 nm, and in particular between 20 and 150 nm, in particular between 50 and 120 nm. More generally, as regards the nature of the materials constituting the additional “external” and additional “internal” intermediate layers, these are chosen so as to “interfere” optically as little as possible with the reflective layer.
• they are therefore chosen on the basis of material or mixture of transparent material (s) in the wavelengths belonging to the visible range.
• oxides can thus be based on oxide (s), oxycarbide (s) or oxyn ⁇ tride (s) of the elements of group 2a, 3b, 4b, 3a, 4a and lanthanides of the table of Mendeleief's periodic classification, in particular the oxides, oxycarbons or oxynitrides of magnesium Mg, calcium Ca, yttrium Y, titanium Ti, zirconium Zr, hafnium Hf, cerium Ce (Ce0 2 or Ce 2 0 3 ) , aluminum Al, silicon Si or tin Sn.
• doped metal oxides such as fluorine-doped tin oxide.
• the oxides which have a standard free enthalpy value of formation ⁇ G ° per mole of oxygen at high temperature, in particular around 500 to 600 ° C, which is less than or equal to that of metal of which the reflective layer is made, referring for example to the diagram mentioning the free enthalpies of oxide formation as a function of the temperature, also known as the Ellingham diagram.
• the oxidation of the metal of the reflective layer is not favored, and this therefore limits to the maximum any risk of oxidation or deterioration of the reflective layer when it is deposited which, if it is carried out on the float glass ribbon, is actually carried out around 450 to 700 ° C.
• the reflective layer when the reflective layer is chosen based on aluminum, it is advantageous to choose as external and / or internal complementary layers layers based on aluminum oxides, zirconium, magnesium or lanthanum.
• These oxide layers can in particular be deposited by pyrolysis techniques in solid, liquid or gaseous phase. If the deposit takes place in the enclosure of the float bath, it will rather be pyrolysis in the CVD gas phase. Outside the float enclosure, CVD techniques and solid or liquid pyrolysis techniques can be used.
• CVD oxide layers such as silicon oxide or oxycarbide from gaseous precursors of the silane and ethylene type, as described in patent EP-0 51 8 755.
• the Ti0 layers 2 can be deposited by CVD from an alcoholate such as titanium tetra-isopropylate, and tin oxide, still by CVD from tin monobutyltrichloride or tin dibutyldiacetate.
• Aluminum oxide layers can be deposited by liquid or gas pyrolysis from organometallic precursors such as acetylacetonate or aluminum hexafluoroacetonate.
• the transparent complementary layers can also be chosen based on nitride or a mixture of nitrides of at least one of the elements of group 3a of the periodic table, such as aluminum nitride.
• AIN gallium GaN x or boron BN X.
• the layers of AIN can be deposited, for example by CVD, in a known manner, from alkyl or aluminum hydride precursors associated with nitrogenous precursors of ammonia and / or amine type.
• Silicon nitride Si 3 N 4 can also be used as transparent nitride. Silicon nitride Si 3 N 4 is indeed also a very effective material for protecting the reflective layer from oxidation. It can be deposited by CVD from silane and ammonia and / or amine.
• At least one of the complementary layers, and more particularly the outer layer can also be chosen based on a transparent material of the diamond or “Diamond-like Carbon” (DLC) type, this type of material having a high hardness and thus protecting very effectively stacking the underlying layers of mechanical abrasions if necessary (this is also true, to a lesser extent, for titanium oxide).
• DLC Diamond-like Carbon
• At least one of the “internal” and “external” complementary layers can also be chosen not based on transparent materials in the visible, but on the contrary based on more or less absorbent material (s) in the visible , different from those which could also constitute the reflective layer.
• this type of complementary layers may be transition metal nitrides such as tungsten nitride W, zirconium Zr, hafnium Hf, niobium Nb, titanium Ti or even carbon nitride. It can also be semiconductor materials such as silicon.
• the materials are then chosen according to their affinity with respect to the glass and / or the material of the reflective layer and their chemical inertness. vis-à-vis the latter.
• Silicon can be deposited by CVD from SiH 4 .
• At least one of the complementary layers may also have a chemical composition gradient in its thickness, which very advantageously makes it possible to confer a double property on a single layer.
• the external complementary layer may also have a chemical composition gradient based on the oxide of the metal of the reflecting layer such as AI 2 0 3 or based on SiO x C y , gradually enriched with titanium oxide, the oxide of type Al 2 0 3 having good affinity and high chemical inertness with respect to aluminum when it is this type of material which constitutes the reflective layer, Ti0 2 in turn being able to improve mechanical durability of the stack and possibly give it interesting anti-fog / anti-fouling properties, as described in patent FR95 / 1 0839 filed on September 1, 1995.
• These chemical composition gradients can be obtained by gas phase pyrolysis, using a distribution nozzle using two injection slots, one for each of the gas precursors necessary for obtaining the two materials, and by configuring it so as to cause , along the glass, a partial and progressive mixing between the two gas streams coming from two injection slots, as is for example described in application PCT / FR96 / 01 073 filed on July 10, 1 996.
• the internal and external complementary layers generally have geometric thicknesses between 1 and 200 nm, in particular between 30 and
• the thicknesses of the complementary layers are to be modulated as a function of many parameters, including the very nature of these layers, that of the reflective layer, and the type of attacks that the stacking of layers will have to undergo.
• the reflective layer is
• the invention also provides for the application of a glass substrate as previously described and the outer layer of which is in T ⁇ 0 2 (or ends with T ⁇ 0 2 in the case of a composition gradient layer) for the production of a glazing or an anti-fouling and / or anti-fog mirror, as well as the application of this substrate, the external complementary layer of which is harder than the reflecting layer and in particular based on diamond or “diamond like carbon” , to the production of abrasion-resistant mirrors.
• the subject of the invention is also all the products obtained, in particular those obtained after cutting the float glass ribbon, preferably from the process defined above, or by any other process making it possible to obtain similar characteristics, in particular in terms of density. and low levels (or even zero or almost zero rates) of impurities at the level, in particular, of the reflective layers.
• Two applications are particularly targeted: firstly, it is a question of using these products as glazing, both for the building and for the automobile, the reflective layer of metal, in particular aluminum, giving them a sun protection function.
• the thickness of the reflective layer is then usually limited to at most 30 nm, in order to keep a sufficient level of light transmission.
• the coated glass substrate according to the invention has very diverse applications, and can be used in reflecting or semi-reflecting mirrors, including the bottom mirrors of photovoltaic cell, the bottom mirrors and the mirrors photocopier, solar protection glazing for buildings or any vehicle (of the low-emissivity or anti-solar type), electromagnetic radiation glazing (radar waves, or radio waves), mirrors, glass elements for furnishing, interior walls of the aquarium or swimming pool type, as interior partitions, decorative glass.
• the substrate according to the invention can also be used by using the reflective layer as a conductive electrode, for example in electrochemically active glazing such as electrochromic glazing, viologen, liquid crystal glazing or glass with optical valve.
• the invention also relates to the process for manufacturing the stack of layers with which the glass substrate is coated, in particular by hot deposition of the reflective layer from molten powder metal according to the “DPM” process previously mentioned.
• the complementary layer (s) are preferably deposited by pyrolytic deposition in the gas, liquid or solid phase.
• the preferred manufacturing method consists of depositing all of the layers hot, on the ribbon of a float glass, preferably depositing at least the first two layers in the enclosure of the float bath.
• the deposits are made in continuous with a gain in terms of time and significant production cost compared to deposition techniques of sputtering, sol-gel or immersion in a silver plating bath, with in addition solidity and adhesion to the substrate characteristics of the layers deposited at high temperature.
• An exemplary embodiment of products according to the invention can also be a glass substrate, mirror or glazing, which contains the aluminum / aluminum nitride sequence, or alternatively aluminum / silicon / oxide, or alummium / aluminum nitride.
• O Figure 1 a cross section of a coated glass substrate according to the invention
• O Figure 2 a cross section of the portion of the enclosure of the float bath where the metallic reflective layer according to the invention is deposited.
• glass substrates provided with a stack of layers in the following manner: the substrate 1 is coated with an optional first layer 2 known as silicon intermediate, itself covered by the reflective metal layer 3.
• the reflective layer 3 is made of aluminum, and is deposited on the glass ribbon by a process explained using FIG. 2.
• the portion of glass ribbon 10 as shown in this figure is located in the enclosure of the float bath: the ribbon 1 0 floats on the surface of a bath of molten tin 1 1 inside an enclosure not shown containing the tin bath and filled with a controlled atmosphere composed of a mixture of nitrogen and hydrogen.
• the glass pours onto the tin bath 1 1 from a glass melting furnace, not shown, located to the left of FIG. 2, spreads there to form a ribbon, which is extracted from the bath at a constant speed in the direction of the arrow by extractor means mounted at the outlet of the bath, on the right side of the figure.
• a device 12 arranged entirely inside the enclosure of the float bath. This is in the form of a gas distribution nozzle, above the glass ribbon 10, arranged transversely to its axis of travel and over its entire width.
• the device 1 2 defines a cavity 1 5 of approximately parallelepiped shape using internal lateral walls 1 4 and upper 14 ′, including walls 1 4 transverse to the axis of the glass which are substantially vertical or slightly convergent or divergent in direction of the glass. These walls end, in the lower part, very close to the surface of the glass, for example at a distance d of less than 20 millimeters from the surface of the glass. In these walls are made different openings: • openings in the upper wall 14 'and / or in the side walls 1 4 ensuring a passage of the gas mixture N 2 + H 2 from the enclosure of the float bath inside the cavity 1 5;
• the internal walls 14, 14 'and external 21 of the device 1 2 there are arranged means capable of controlling and regulating the temperature of the cavity 1 5 along its height h, in particular associated heat / heat means cooling means, the operation of which is dependent on temperature measurements inside the cavity carried out regularly by suitable sensors: this is created either by manual adjustments to said heat insulation / cooling means, or by automatic regulation electronics / computing, a temperature profile along the height h of the cavity, so as to have an increasing temperature gradient towards the glass ribbon 1 0, which starts at around 30 to 100 ° C in the upper part nearby openings 1 6 up to more than 600 ° C near the glass.
• the device 1 2 operates in the following manner: one injects permanently through the openings 1 6 of the aluminum derivative vapor in suspension in an inert gas such as nitrogen; it is the mixture x mentioned above.
• This derivative can be in particular AI (CH 3 ) 3 , AI (C 2 H 5 ) 3 , AIH 3 (NH 3 ) or AIH 3 (amino).
• AI (CH 3 ) 3 AI (C 2 H 5 ) 3
• it is more precisely dimethylmonoethylamine alane, hydride stabilized by an amine decomposing into metallic aluminum at approximately 1 80 to 200 ° C, and whose formula is AIH 3 (N (C 2 H 5 ) (CH 3 ) 2 )
• the temperature is around 40 ° C.
• the mixture x is projected into the cavity substantially perpendicular to the plane defined by the glass ribbon 1 0.
• the temperature in the cavity increases as and as we get closer to the glass, the alane decomposes to form powdered aluminum 22 in an area h ! of the cavity 1 5 where its decomposition temperature is reached, an area located approximately in the upper half of the cavity: the aluminum grains are then entrained by simple gravity in contact with the glass, while the effluents from the decomposition of the alane, are extracted through the openings 1 8, in this hi area of powder formation.
• the parameters of the decomposition reaction of the alane are adjusted, in particular to obtain a powder of grains of sufficiently large diameter so that the effluent can be extracted without entraining the powder 22 formed in the extraction conduits and also to prevent the effluents from reacting at higher temperatures with the aluminum grains according to an undesired chemical mechanism.
• the powder "arrives" on the glass ribbon when the latter is at a temperature of 660 to 700 ° C., in particular of approximately 680 ° C., that is to say at a temperature which is situated between the temperature maximum at which the glass is dimensionally stable (700-750 ° C) and the melting temperature of aluminum (approximately 650-660 ° C).
• the aluminum grains in contact with the glass, instantly melt and the droplets coalesce to leave a continuous molten aluminum film, which will gradually solidify as the temperature of the glass decreases to drop below the aluminum melting temperature.
• the final thickness of the aluminum layer thus deposited can be modulated as required by adjusting different deposition parameters, in particular the concentration of alane in the gaseous mixture x, the flow rate of said mixture, etc.
• the layer 3 of aluminum is therefore deposited using the device 1 2 which has just been described.
• a thin layer 2 of pure silicon from silane is deposited by CVD, in a known manner, for example as described in French patent FR-2 382 51 1, using a nozzle disposed just upstream of the device 1 2, when the glass ribbon has already acquired its dimensional stability, that is to say when it is at about 700 ° C.
• one or more additional layers are deposited, the sequences of which will be given in detail in the following examples .
• These are layers of aluminum nitride, which are deposited by CVD in a known manner from alkyl precursors or aluminum hydride with ammonia or amine, and / or layers of oxide such as oxide.
• silicon oxycarbide which is deposited in a known manner by CVD from silane and ethylene, as described in patent EP-0 518 755, or also from tin oxide deposited by CVD in known manner from gaseous precursors such as tin monobutyltrichoride or tin dibutyldiacetate, or titanium oxide deposited by CVD in known manner from gaseous precursors such as a titanium alcoholate of the titanium tretopropylate type.
• oxide layer of Sn0 2 or of Ti0 2 it is equally possible to use silicon oxide layers deposited by CVD from gaseous precursors such as tetraethoxysilane . It could also be layers of aluminum oxide, deposited by CVD from gaseous precursors such as acetylacetonate or aluminum hexafluoroacetonate. It is also possible to choose a layer of vanadium oxide, which can be deposited by CVD from gaseous precursors of vanadium alcoholate type such as vanadium tetraethylate, or halide type such as VCI 5 or oxychloride type such as VOCI 3 .
• a layer of silicon nitride which can be obtained by CVD from a gaseous mixture of silane and ammonia and / or amine.
• a thin layer 3 of silicon is interposed, deposited by CVD like the layer 1 previously mentioned.
• the glass ribbon usually “leaving” the enclosure of the float bath at a temperature of around 580 ° C.
• the following layer sequence is deposited on the surface of the glass ribbon 10 (the geometric thicknesses are specified under each of the layers, expressed in nanometers): glass' 11 / Al , 31 / AIN ( 5 > 50 nm 1 30 nm EXAMPLE 2
• the sequence is as follows glass (1) / Al (3 > / / SS.i ' (44)) / (gradient layer S ⁇ 0 2 / Ti0 2 )' 5I 60 nm 5 nm 1 20nm
• the Si0 2 / Ti0 2 gradient layer is a layer obtained by CVD, it has a composition containing at least 80% by weight of Si0 2 at the interface with the underlying silicon layer (4) up to at least 80% by weight of Ti0 2 at the interface with air. It is obtained according to the technique set out in patent application FR-95/08421 of July 1, 1,995, in particular in example 9, from precursors of silicon oxide and titanium oxide pre-mentioned. .
• the glass ribbon is then, in each of these 6 examples, cut and then the light reflection value R L in percentage according to Illuminant D 65 is measured on each of the 6 glass plates. The following results are obtained:
• each of these 6 trays can be advantageously used as so-called “face 1” mirrors, that is to say mirrors where the observer looks at the glass substrate from the side where it is provided with the layer reflective 3.
• face 1 that is to say mirrors where the observer looks at the glass substrate from the side where it is provided with the layer reflective 3.
• the invention also makes it possible to manufacture so-called “face 2” mirrors, that is to say mirrors. where the observer looks at the substrate on the side opposite to that provided with the reflective layer.
• the substrates provided with aluminum layers 3 thus produced, but a little thinner, for example of the order of 10 to 20 nm, can be used as sun protection glazing very satisfactorily. It can be seen that it is however important to protect the aluminum layer as well as possible from the risks of oxidation, both on the line, as soon as it leaves the float bath enclosure, and to preserve it during oxidative heat treatments of the bending or quenching type.
• the additional layers 5 according to the invention do this effectively.
• the intermediate silicon layer 2 is optional, it facilitates the adhesion of aluminum to glass, inhibits the reaction tending to manufacture at the glass / aluminum interface of alumina.
• the invention has therefore perfected the manufacture of mirrors or glazing for sun protection continuously, on the float line, a very advantageous yield and cost.
• the aluminum layer thus deposited is of high quality, it is in particular very dense, very pure and particularly adherent to glass (or to the layer which is underlying it).

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• 1997
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