Laminated glazing panel for head-up display

Abstract

The invention relates to a laminated glazing panel (1000) comprising a first glass sheet (1001); a second glass sheet (1002); a lamination interlayer (1003) in adhesive contact with the first outer glass sheet (1001) and the second inner glass sheet (1002); a functional coating (1004) of thin layers arranged on the second glass sheet (1002) and comprising, starting from the second glass sheet (1002), a first dielectric module (2001), a functional metal layer (2002) and a second dielectric module (2003), said functional metal layer (2002) being located between the first dielectric module (2001) and the second dielectric module (2003). The first dielectric module (2001) and / or the second dielectric module (2003) comprise a layer of tungsten oxide (2004a, 2004b) which is in the form of pure substoichiometric tungsten oxide, WOx, where x is preferably between 2.55 and 2.98, or in the form of doped tungsten oxide comprising at least one dopant element selected from group 1 elements according to IUPAC nomenclature.

Description

Laminated glass for head-up display

[0001] The invention relates to laminated glazing for a head-up display. Technical background

[0002] Modern vehicles are now equipped with display systems or devices known as "head-up displays", also called Head-Up Display (HUD) in English.

[0003] These systems or devices include a projector, typically located near the vehicle's dashboard, configured to project an image onto an area of ​​the vehicle's windshield. The projected image appears to the vehicle's driver as a virtual image located behind the windshield, and allows information such as vehicle speed or navigation or warning indications to be displayed directly in their field of vision. The driver then no longer looks away from the road to view this information, and remains alert to events taking place outside the vehicle. HUD systems or devices thus contribute to improving road safety.

[0004] Most HUD devices rely on the emission of polarized electromagnetic radiation with an s-type polarization and an angle of incidence of approximately 65° relative to the normal to the windshield. This angle is close to the Brewster angle for a glass-air interface, which is approximately 56.5° for soda-lime glass. The projected image is then reflected by the two main external surfaces of the windshield. In addition to the main image, a secondary image also appears, more or less offset and more or less partially covering the main image. This secondary image is called a "ghost image", "double image" or "ghost image" in English.

[0005] To mitigate this parasitic ghost image phenomenon, it is common to arrange the main surfaces of the windshield at different angles by inserting a lamination interlayer of varying thickness so as to cause the ghost image and the main image to overlap. This type of glazing is generally known as "wedge glazing" or "wedge windshield".

[0006] For example, EP 0 420 228 A2 [HUGHES AIRCRAFT CO [US]] 03.04.1991 describes a windshield comprising a lamination interlayer whose thickness gradually decreases between a first and a second side of the windshield so that the two sheets of glass in adhesive contact with said interlayer have two different angles of inclination relative to the headlight.

[0007] This type of glazing is, however, expensive to manufacture, limited to certain viewing angles of the projected image and does not prevent the formation of a ghost image when the glazing includes a functional coating.

[0008] It is common alternative practice to use HUD devices whose implementation is based on the emission of electromagnetic radiation polarized according to a p-type polarization and on a windshield comprising a functional coating adapted to the formation of a new reflective interface within said windshield for this type of radiation.

[0009] Since p-polarized electromagnetic radiation is emitted towards the windshield at an angle of incidence close to the Brewster angle, it is not reflected by the glass-air interfaces. Reflection occurs only at the reflective interface formed by the functional coating. Different types of functional coating can be used.

[0010] WO 2005 / 017600 A1 [3M INNOVATIVE PROPERTIES CO [US]] 24.02.2005 describes a polarizing optical film comprising a plurality of individual layers having different optical refractive indices. The film is intended to be laminated in a laminated glazing so as to form a windshield for a head-up display comprising a zone reflecting predominantly visible light polarized according to a p-polarization. The film can also reflect infrared radiation in order to reduce greenhouse effects in a vehicle.

[0011] DE 102014220189 A1 [CONTINENTAL AUTOMOTIVE GMBH [DE]] 07.04.2016 describes a laminated glazing comprising a metallic layer based on silver or aluminum and having a thickness between 5 nm and 9 nm. The metallic layer allows the reflection of visible light polarized according to a p polarization.

[0012] WO 2016 / 058474 A2 [FUYAO GLASS IND GROUP CO LTD [CN]] 21.04.2016, WO 2021 / 104800 A1 [SAINT GOBAIN [FR]] 03.06.2021, WO 2019 / 046157 A1 [VITRO FLAT GLASS LLC [US]] 07.03.2019, WO 2020 / 094422 A1 [SAINT GOBAIN [FR]] 14.05.2020 describe laminated glazing for head-up displays provided with a functional coating comprising one or more metallic functional layers, in particular based on silver, allowing the reflection of visible light polarized according to a polarization p. The functional coating may also comprise dielectric layers which, optionally combined with the metallic functional layers, provide other properties such as solar control properties and / or color neutralization of the coating in transmission and / or reflection.

[0013] Among the glazings, laminated or not, called "solar control", there are also glazings equipped with stacks of thin layers without metallic functional layers in order to guarantee a certain transparency to radio frequencies for on-board telecommunications systems. Instead of metallic functional layers, functional layers absorbing infrared radiation are generally used. They can be based on oxides and / or nitrides.

[0014] JP H0812378 A [NISSAN MOTOR] 16.01.1996 describes a "solar control" functional stack comprising a tungsten oxide layer disposed between two dielectric layers. The stack makes it possible to reduce the surface electrical resistance and increase the transparency to radio waves compared to stacks comprising a metallic functional layer, in particular based on silver.

[0015] JP 2010180449 A [SUMITOMO METAL MINING CO [JP]] 19.08.2010 discloses a tungsten oxide-based layer deposited by sputtering using a tungsten oxide target comprising chemical elements selected from hydrogen, alkali, alkaline earth, and rare earth. The layer has a "solar control" function due to its strong absorption of near-infrared radiation.

[0016] EP 3686312 A1 [SUMITOMO METAL MINING CO [JP]] 29.07.2020 describes a layer based on cesium-doped tungsten oxide, and a method for depositing such a layer by cathode sputtering. The layer has transparency to radio waves and a "solar control" function thanks, in particular, to its strong absorption of infrared radiation.

[0017] For certain applications in the automotive sector, in addition to solar control functions, the glazing must include a heating function to enable, for example, defrosting and / or demisting.

[0018] Whether these glazings are in the form of windshields, quarter windows, windows, sun visors, and / or glass roofs, the heating function is generally provided by the solar control stack itself. Thanks to the metal layers it contains, the stack is an electrical conductor. When powered by electricity from the vehicle's alternator and / or battery, it can release heat through the Joule effect.

[0019] For obvious safety reasons, vehicle alternators and / or batteries generally deliver a low electrical voltage to their terminals, typically between 12 V and 48 V, often around 14 V. Also, in order for the quantity of heat released to be sufficient for effective demisting and / or defrosting, the surface resistivity of the stack must be sufficiently low to accentuate the Joule effect at low voltage.

[0020] EP 0726232 A2, EP 1614325 A1 and US 2015229030A1 describe examples of solar-controlled heated windshields in which an electrically conductive stack simultaneously provides solar control and heating functions.

[0021] There is a need for laminated glazings that have "solar control" properties, are suitable for head-up display applications, and provide a heating function. Such glazing must meet five requirements: a low solar factor, high light transmission, color neutrality in reflection and / or transmission, strong reflection of p-polarized electromagnetic radiation in the visible spectrum, and low surface electrical resistance. Solution to the technical problem

[0022] A first aspect of the invention relates to a laminated glazing as described in claim 1, the dependent claims being advantageous embodiments. The laminated glazing comprises:- a first glass sheet;- a second glass sheet;- a lamination interlayer in adhesive contact with the first glass sheet and the second glass sheet;- a functional coating of thin layers arranged on the second glass sheet and comprising, starting from the second glass sheet, a first dielectric module, a metallic functional layer and a second dielectric module, said metallic functional layer being located between the first dielectric module and the second dielectric module;said glazing being remarkable in that:- the first dielectric module and / or the second dielectric module comprises (or comprise) a layer of tungsten oxide and in that:- said layer of tungsten oxide is made of pure sub-stoichiometric tungsten oxide, WOx, with x preferably between 2.55 and 2.98, or- said layer of tungsten oxide is made of doped tungsten oxide and comprises at least one doping element selected from the chemical elements of group 1 according to the IUPAC nomenclature.;

[0023] Other advantageous embodiments are described in the detailed description.

[0024] Preferably, said first glass sheet is an outer glass sheet and said second glass sheet is an inner glass sheet.

[0025] Said metallic functional layer may be the only metallic functional layer of said functional coating.

[0026] According to a second aspect of the invention, there is provided a projection device for a head-up display comprising laminated glazing according to the first aspect of the invention.

[0027] According to a third aspect of the invention, there is provided a method of manufacturing laminated glazing according to the first aspect of the invention. Advantages of the invention

[0028] The remarkable advantage of the glazing according to the invention is that it has a low solar factor, high light transmission, color neutrality in reflection and / or transmission, strong reflection of electromagnetic radiation polarized according to a p polarization in the visible spectrum, and low surface electrical resistance.

[0029] More specifically, the glazing according to the invention has a selectivity greater than 1.3, or even 1.35 for a light transmission greater than 70%. It also has color neutrality in transmission and reflection.

[0030] In “head-up” application, the glazing according to the invention has a level of reflection of electromagnetic radiation in p-type polarization at 65° greater than 16%, or even 18%, or even 19% for certain embodiments.

[0031] The glazing according to the invention also has a surface electrical resistance of less than 3.5 Ω / □, in particular less than 2.5 or even 2.4 for certain embodiments. These electrical resistance values ​​are advantageous for electric heating applications.

[0032] a schematic representation of laminated glazing according to the invention.

[0033] a detailed schematic representation of the functional covering of the.

[0034] is a schematic representation of a head-up display projection device.

[0035] is a graphical representation of the light transmission and direct solar transmittance for the examples according to the invention and two counterexamples.

[0036] is a graphical representation of the light transmission and the total solar transmission for the examples according to the invention and two counter-examples. Detailed description of the embodiments

[0037] It uses the following definitions and conventions.

[0038] The term "above" or "below" respectively, qualifying the position of a layer or set of layers and defined relative to the position of another layer or set, means that said layer or set of layers is closer to, or further away from, the substrate.

[0039] These two terms, "above" and "below", do not in any way imply that the layer or set of layers they describe and the other layer or set in relation to which they are defined are in contact. They do not exclude the presence of other intermediate layers between these two layers. The expression "in contact" is explicitly used to indicate that no other layer is arranged between them.

[0040] Without any precision or qualification, the term "thickness" used for a layer corresponds to the physical, real or geometric thickness of said layer. It is expressed in nanometers.

[0041] The terms "layers" or "thin layers" mean a layer of material as commonly defined in the technical field. Generally, it is a thin layer with a thickness of less than 1 µm, or even less than 500 nm, typically less than 100 nm.

[0042] The expression "dielectric module" designates one or more layers in contact with each other forming a set of globally dielectric layers, that is to say that it does not have the functions of a metallic functional layer. If the dielectric module comprises several layers, these may themselves be dielectric. The physical, real or geometric thickness of a dielectric module of layers corresponds to the sum of the physical, real or geometric thicknesses of each of the layers that constitute it.

[0043] In the present description, the expressions "a layer of" or "a layer based on", used to qualify a material or a layer as to what it contains, are used equivalently. They mean that the mass fraction of the constituent that it comprises is at least 50%, in particular at least 70%, preferably at least 90%. In particular, the presence of minority or doping elements is not excluded.

[0044] By the term "transparent", used to describe a sheet of glass, means that the sheet of glass is preferably colorless, non-opaque and non-translucent in order to minimize light absorption and thus maintain maximum light transmission in the visible electromagnetic spectrum.

[0045] By "light transmission", TL, is meant the light transmission, denoted TL, as defined and measured and / or calculated in the ISO 13837:2021 standard.

[0046] By "direct solar transmittance", TE, is meant the direct solar transmittance as defined and calculated according to ISO 13837:2021.

[0047] By "solar factor", TTS (or T TS ), it is understood to mean the total solar transmission as defined according to ISO 13837:2021. – convention A. It is equal to the sum of the direct solar transmittance, TE, and the secondary heat flux, qi.

[0048] By "selectivity", s, is meant the ratio of light transmission, TL, to the solar factor TTS.

[0049] According to the IUPAC nomenclature, group 1 of chemical elements includes hydrogen and the alkali elements, i.e., lithium, sodium, potassium, rubidium, cesium and francium

[0050] The expression "optical refractive index" means the optical refractive index, n, as defined in the technical field, in particular according to the Forouhi & Bloomer model described in the work Forouhi & Bloomer, Handbook of Optical Constants of Solids II, Palik, ED (ed.), Academic Press, 1991, Chapter 7.

[0051] According to a first aspect of the invention, with reference to the set, there is provided a laminated glazing 1000 comprising - a first sheet 1001 of glass; - a second sheet 1002 of glass; - a lamination interlayer 1003 in adhesive contact with the first sheet 1001 of glass, which is here an outer sheet of glass, and the second sheet 1002 of glass, which is here an inner sheet of glass; - a functional coating 1004 of thin layers arranged on the second sheet 1002 of glass and comprising, starting from the second sheet (1002) of glass, a first dielectric module 2001, a metal functional layer 2002 and a second dielectric module 2003, said metal functional layer 2002 being located between the first dielectric module 2001 and the second dielectric module 2003.

[0052] Said glazing is remarkable in that- the first dielectric module 2001 and / or the second dielectric module 2003 comprise a layer of tungsten oxide 2004a, 2004b and in that:- the tungsten oxide is pure sub-stoichiometric tungsten oxide, WOx, with x preferably between 2.55 and 2.98, or- the tungsten oxide comprises at least one doping element selected from the chemical elements of group 1 according to the IUPAC nomenclature.

[0053] The glass sheets 1001, 1002 may be mineral or glass-ceramic glass sheets. The glass may preferably be a soda-lime-silica, borosilicate, aluminosilicate or alumino-borosilicate type glass. According to a preferred embodiment of the invention, the glass sheets 1001, 1002 are soda-lime-silica mineral glass sheets.

[0054] According to certain embodiments, the first sheet 1001 of glass and / or the second sheet 1002 of glass may be a thin sheet of glass, in particular with a thickness of between 0.4 and 1.1 mm, in particular between 0.4 and 0.7 mm.

[0055] According to preferred embodiments, the glass sheets 1001, 1002 are transparent glass sheets.

[0056] According to certain embodiments, one of the two glass sheets 1001, 1002 may be a mass-tinted mineral glass. The mass-tinting or coloring of a mineral glass is known and extensively detailed in the technical literature. Coloring can generally be obtained by the addition of coloring oxides to the glass chemical composition. Examples of coloring oxides may be iron II oxide, copper oxide, chromium oxide, nickel oxide, gold oxide, manganese oxide, cobalt oxide, uranium oxide, neodymium oxide, and erbium oxide. Mixtures of oxides such as copper and tin oxide, or ionic complexes, such as iron-sulfur or cadmium-sulfur complex, may also be used.

[0057] The lamination interlayer 1003 may be comprised of one or more layers of thermoplastic material. Examples of thermoplastic material are polyurethane, polycarbonate, polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), ethylene vinyl acetate (EA), or an ionomer resin.

[0058] The lamination interlayer 1003 may be in the form of a multi-layer film. It may also have special features such as, for example, acoustic or anti-UV properties.

[0059] Typically, the lamination interlayer 1003 comprises at least one layer of PVB. Its thickness is between 50 µm and 4 mm. In general, it is less than 1 mm.

[0060] The metal functional layer 2002 has the function of reflecting infrared radiation and / or part of the solar radiation. It can be made of any suitable metal, for example gold-based or silver-based. The thickness of the metal functional layer 1003 can typically be between 2 nm and 25 nm, preferably between 10 nm and 20 nm.

[0061] According to preferred embodiments, the metal functional layer 2002 is a silver-based or silver-based layer.

[0062] According to certain preferred embodiments, the laminated glazing 1000, when used as glazing for a motor vehicle, for example as a windshield, is such that the second sheet 1002 of glass is located inside the vehicle. In other words, the functional coating 1004 is placed on face 3 of the glazing from the second sheet 1002 of glass inside the vehicle, face 4 being the face facing inwards; or on face 2 of the glazing from the first sheet 1001 of glass outside the vehicle, face 1 being the face facing outwards.

[0063] According to the first aspect of the invention, the first dielectric module 2001 and / or the second dielectric module 2003 comprise a tungsten oxide layer 2004a, 2004b. Thus, according to a first embodiment variant, only the first dielectric module 2001 comprises a tungsten oxide layer 2004a. According to a second embodiment variant, only the second dielectric module 2002 comprises a tungsten oxide layer 2004b. According to a third embodiment variant, each of the dielectric modules 2001, 2002 comprises a tungsten oxide layer 2004a, 2004b.

[0064] When the first dielectric module and the second dielectric module each comprise a tungsten oxide layer, the tungsten oxide of the two tungsten oxide layers may be of different composition.

[0065] According to other preferred embodiments, the optical refractive index of the tungsten oxide layer 2004a, 2004b decreases monotonically with wavelength from a maximum value greater than 2.4 at 350 nm to a minimum value between 600 nm and 1400 nm such that the difference between the maximum value and the minimum value is greater than 0.8, preferably greater than 1.0, or even greater than 1.4.

[0066] In other words, the value of the optical refractive index decreases monotonically by at least 0.8, preferably by at least 1.0, or even at least 1.4 between a maximum value greater than 2.4 at 350 nm and a minimum value between 600 nm and 1400 nm. For example, the optical refractive index value may decrease monotonically by at least 0.8, preferably by at least 1.0, or even at least 1.4 between a maximum value greater than 2.4 at 350 nm and a minimum value less than 2.3 between 600 nm and 1400 nm, in particular between 800 nm and 1100 nm.

[0067] Although not particularly required to achieve the effects of the present invention, these optical refractive index values ​​may nevertheless be advantageous for improving color neutrality in transmission and reflection.

[0068] According to certain additional preferred embodiments, the optical extinction coefficient of the tungsten oxide layer 2004a, 2004b may be less than 0.2 or even 0.1 at 500 nm and less than 2.0 or even less than 1.5 at 1200 nm. The selectivity may thus be favorably further increased.

[0069] The tungsten oxide of the tungsten oxide layer(s) 2004a, 2004b, may be pure substoichiometric tungsten oxide, WO x , with x preferably between 2.55 and 2.98, or even between 2.6 and 2.95. A value of x between 2.98 and 3.02 will be considered as generating a pure stoichiometric tungsten oxide, WO3. These characteristics, combined with the presence of a metallic functional layer, have a synergistic effect on increasing selectivity.

[0070] Surprisingly, a tungsten oxide layer of pure substoichiometric tungsten oxide, WO x, exhibits unexpected optical characteristics, particularly in terms of the evolution of the optical extinction coefficient and refractive index as a function of the wavelength of electromagnetic radiation. These characteristics, combined with the presence of a metallic functional layer, have a synergistic effect on increasing selectivity.

[0071] Surprisingly, a layer of tungsten oxide 2004a, 2004b, comprising a doping element chosen from the group 1 elements according to the IUPAC nomenclature, exhibits unexpected optical characteristics, particularly in terms of the evolution of the optical extinction coefficient and refractive index as a function of the wavelength of the electromagnetic radiation.

[0072] The optical extinction coefficient and the optical diffraction index can vary according to:- the substoichiometry or- the nature and quantity of the doping element(s) selected from the elements of group 1 according to the IUPAC nomenclature.

[0073] However, it is currently difficult to establish a general behavior law for the optical extinction coefficient and the refractive index according to, on the one hand, the sub-stoichiometry or, on the other hand, the nature and / or quantity of the doping element(s).

[0074] According to certain particular embodiments, the tungsten oxide layer 2004a, 2004b, made of doped tungsten oxide, comprises the doping element X or the doping elements X1, X2,… in a proportion such that the molar ratio, X / W of said element on the tungsten, W, or the sum of the molar ratios of each element on the tungsten (X1+X2+…) / W is between 0.01 and 0.4, preferably between 0.01 and 0.2, or even between 0.01 and 0.1.

[0075] It has been found that these molar ratio values ​​can advantageously achieve the optical extinction coefficient and refractive index values ​​described in the preceding embodiments while limiting the amount of doping elements. In addition, a saving on the exploitation of mineral resources for doping elements may possibly result, as well as a reduction in costs.

[0076] In some embodiments, the tungsten oxide layer 2004a, 2004b of doped tungsten oxide comprises at least one doping element selected from hydrogen, lithium, sodium, potassium and cesium. Among the group 1 elements, these particular elements can make it possible to obtain the most optimal optical extinction coefficient and refractive index values ​​for the desired technical effects.

[0077] In particularly preferred embodiments, the tungsten oxide layer 2004a, 2004b of doped tungsten oxide comprises cesium as a doping element, and the molar ratio of cesium to tungsten is between 0.01 and 0.4, preferably between 0.01 and 0.2. These embodiments provide the best performance in terms of increased selectivity, preservation of neutral colors, and cost savings.

[0078] According to certain advantageous embodiments, the physical thickness of the tungsten oxide layer(s) 2004a, 2004b may be between 2 nm and 50 nm, in particular between 5 nm and 30 nm, preferably between 5 nm and 20 nm. These thickness ranges are sufficient to obtain the remarkable advantages of the first aspect of the invention.

[0079] According to embodiments, the first dielectric module 2001 and / or the second dielectric module 2002 may comprise one or more layers with a refractive index of less than 2.45 at 550 nm.

[0080] The layer(s) with a refractive index of less than 2.45 at 550 nm are preferably based on silicon, zirconium, titanium, or tin and zinc oxide or nitride. For example, they may be based on silicon nitride, silicon oxide, zirconium nitride, or zinc and tin oxide.

[0081] According to embodiments, the functional coating 1004 of thin layers may further comprise a blocking metal overlayer, preferably based on a nickel and chromium alloy, located above and in contact with the metal functional layer and / or a blocking metal underlayer, preferably based on a nickel and chromium alloy, located below and in contact with the metal functional layer.

[0082] The presence of a blocking metal overlayer and / or a blocking metal underlayer makes it possible to advantageously increase the durability of the stack, for example in terms of mechanical resistance to brushing or scratching. It also makes it possible to avoid deterioration, for example oxidation, of the metal functional layer 2002 during the deposition of subsequent layers and / or during heat treatments, in particular by limiting the diffusion of certain chemical elements from the adjacent layers and / or the diffusion of oxygen.

[0083] According to advantageous embodiments, the first dielectric module 2001 and / or the second dielectric module 2002 may comprise a layer based on mixed indium and tin oxide, mixed indium and zinc oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, antimony-doped tin oxide and / or niobium-doped titanium oxide.

[0084] It has been surprisingly found that the combination of one of these layers with a doped tungsten oxide layer as described in the present invention makes it possible to advantageously reduce the solar factor, TTS, thanks to a stronger absorption of infrared radiation without prejudice to color neutrality and transmission.

[0085] Preferably, the thickness of the layer based on mixed indium and tin oxide, mixed indium and zinc oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, antimony-doped tin oxide and / or niobium-doped titanium oxide is between 50 and 100 nm.

[0086] Said layer is to be distinguished from any wetting layers, also called crystallization layers, located under and in contact with the metallic functional layers, which are generally based on aluminum-doped zinc oxide and have a thickness generally less than 15 nm.

[0087] In preferred embodiments, the first dielectric module 2001 and / or the second dielectric module 2002 may comprise a layer based on mixed indium and tin oxide with a thickness between 50 nm and 100 nm.

[0088] According to a second aspect of the invention, with reference to the, there is provided a projection device 3000 for head-up display comprising:- a laminated glazing 1000 according to the first aspect of the invention;- a head-up projector 3001 configured to emit electromagnetic radiation 3002 onto at least one zone 3003 of the laminated glazing 1000, the electromagnetic radiation being at least partially polarized according to a polarization p.

[0089] In operation, the head-up projector 3001 projects an image into the area 3003 of the laminated glazing which behaves like a screen. The image is perceived by a user 3004, in this case a driver, as a virtual image when he looks into the solid angle of observation 3005 adapted to the perception of said image in the area 3003 of the laminated glazing 1000.

[0090] Laminated glazing manufacturing processes are well known in the glass industry. For example, a laminated glazing manufacturing process may be a process of laminating a lamination interlayer between two glass sheets. The glass sheets may be pre-shaped, for example, in a curved manner using a bending process. They may also be coated with one or more thin-film coatings using any suitable type of thin-film deposition process.

[0091] The processes for depositing thin layers on substrates, in particular glass sheets, are well-known processes in the industry. For example, the deposition of a stack of thin layers on a glass substrate is carried out by successively depositing each thin layer of said stack by passing the glass substrate through a succession of deposition cells adapted to deposit a given thin layer.

[0092] Deposition cells can use deposition methods such as magnetic field-assisted sputtering (also called magnetron sputtering), ion beam-assisted deposition (IBAD), evaporation, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), low-pressure chemical vapor deposition (LPCVD), etc.

[0093] The magnetic field-assisted sputtering deposition process is particularly used. The conditions for deposition of layers are widely documented in the literature, for example in patent applications WO2012 / 093238 A1 and WO2017 / 00602 A1.

[0094] When a pure tungsten metal target or a pure tungsten oxide target is used, it can allow the deposition of a pure substoichiometric tungsten oxide layer, WO x , with x preferably between 2.55 and 2.98.

[0095] An advantage of using a ceramic target (i.e., with oxygen) over a metal target, especially for rotating targets, is that the ceramic target is lighter; thus, it is easier to control the process using this ceramic target.

[0096] When a ceramic or metallic target is used, it may in particular contain one or more doping elements in a proportion as described for the doped tungsten oxide layer in certain embodiments of the first aspect of the invention.

[0097] According to a third aspect of the invention, a method of manufacturing a laminated glazing 1000 according to the first aspect of the invention is provided, such that the tungsten oxide layer 2004a, 2004b of doped tungsten oxide is deposited by a magnetron cathode sputtering method using a tungsten oxide target doped with a chemical element chosen from the chemical elements of group 1 according to the IUPAC nomenclature.

[0098] The tungsten oxide target may in particular contain one or more doping elements in a proportion as described for the doped tungsten oxide layer in certain embodiments of the first aspect of the invention.

[0099] In particularly preferred embodiments, the tungsten oxide layer comprises cesium as a doping element, and the molar ratio of cesium to tungsten is between 0.01 and 0.2, preferably between 0.01 and 0.1. These embodiments provide the best performance in terms of increased selectivity, preservation of neutral colors, and cost savings.

[0100] What is most important in the context of the invention is that the absorption in the visible range of the material of the tungsten oxide layer(s) is as low as possible in the visible range (wavelength of 380 to 780 nm) in order to maximize the gain in selectivity.

[0101] The tungsten oxide layer can be deposited by sputtering using the above-mentioned target under a deposition atmosphere composed of 60-100% argon and 0-40% dioxygen, preferably 70-85% argon and 15-30% dioxygen.

[0102] The tungsten oxide layer can be deposited under a pressure of between 1 and 15 mTorr, preferably 3 to 10 mTorr.

[0103] Preferably, the deposition can be carried out cold, that is to say at a temperature below 100°C, in particular between 20°C and 60°C, for the substrate.

[0104] The deposition can also be carried out hot, in particular at a temperature between 100°C and 400°C.

[0105] According to particular embodiments, the glass sheet 1002, after deposition of the stack 1004, may undergo an annealing heat treatment. The annealing temperature may be between 450°C and 800°C, in particular between 550°C and 750°C, or even between 600°C and 700°C. The annealing time may be between 5 min and 30 min, in particular between 5 min and 20 min, or even between 5 min and 10 min.

[0106] The laminated glazing 1000 according to the first aspect is particularly suitable for head-up display applications in a land, sea or air vehicle, preferably in a motor vehicle, a railway vehicle, an airplane or a boat, in particular a passenger car or a truck.

[0107] All the embodiments described, whether they relate to the first or second aspect of the invention, can be combined with each other without any particular modification or adaptation. In the event that technical incompatibilities appear during the implementation of one of these combinations, it is within the reach of those skilled in the art to be able to resolve them using their knowledge without this requiring undue effort, in particular by implementing a research program. Examples

[0108] The characteristics and advantages of the invention are illustrated by the examples and counter-examples described below.

[0109] Three examples, E1-E3, in accordance with the invention, and two counter-examples, CE1 and CE2, not in accordance with the invention, are described in Table 1 which indicates the composition and thickness of the glass sheets 1001, 1002, of the lamination interlayer 1003 and of the different thin layers of the functional coating 1004. The thickness of the thin layers of the functional coating 1004 are expressed in nanometers. The numbers in the first two columns correspond to the references of the figures.

[0110] In examples E1 to E3, the layer, denoted CWO, of tungsten oxide 1005 is a layer of cesium-doped tungsten oxide. It has a refractive index of approximately 2.4 at 550 nm.

[0111] The molar ratio of cesium to tungsten in the layer is about 0.05-0.06.

[0112] Tab. 1 E1 E2 E3 CE1 CE21001glass1.6mm1.6mm1.6mm1.6mm1.6mm1003PVB0.76mm0.76mm0.76mm0.76mm0.76mm10042003SiN 3SnZnO SiZrN16211132CWO2120TiOxZnO 5555NiCr11112002Ag 13,413,613,714,02001ZnO 5555SiZrN34224332CWO830ITO91661002 glass 2.1mm 2.1mm 2.1mm 2.1mm 2.1mm

[0113] In example E1, the tungsten oxide layer is in the first module 2001 starting from the glass sheet 1002. In example E2, the tungsten oxide layer is in the second module 2003 starting from the glass sheet 1002. Example E3 differs from examples E1 and E2 in that it includes a doped tungsten oxide, CWO, layer in each of the two dielectric modules 2002, 2003 and an indium tin oxide (ITO) layer in the first dielectric module 2001 starting from the glass sheet 1002.

[0114] An example E4 according to the invention, similar to example E3, is presented in Table 2.Tab. 1 E4 1001glass1.6mm1003PVB0.76mm10042003SiN 11WO x40SiZrN3ZnO 5NiCr12002Ag 11.92001ZnO 5WO x 17SiN51002 glass 2.1mm

[0115] Example E4 differs from Example E3 in that it includes a layer of substoichiometric pure tungsten oxide, WO x in each of the two dielectric modules 2002, 2003 and a layer of silicon nitride (SiN) in the first dielectric module 2001 starting from the glass sheet 1002.

[0116] Counterexample CE1 corresponds to examples E1 and E2. It differs from them by the absence of a tungsten oxide layer. Counterexample CE2 corresponds to examples E3 and E4. It differs from them by the absence of a tungsten oxide layer.

[0117] The thin layers of the functional coatings 1004 of examples E1 to E4 and of counter-examples CE1 and CE2 were deposited by cathodic sputtering assisted by a magnetic field (magnetron process) whose characteristics are widely documented in the literature, for example in patent applications WO2012 / 093238 and WO2017 / 00602.

[0118] The nature of the targets used and the deposition conditions of examples E1 to E4 and counter-examples CE1 and CE2 are described in Table 3.

[0119] The functional coatings are deposited directly onto the 1002 glass sheet. This 1002 glass sheet is a 2.1 mm thick soda-lime-silica mineral glass sheet. Immediately after deposition, the functional coatings were heat treated at 650°C for 10 minutes.

[0120] Tab. 3 Target Pressure (µbar) Ar (sccm) O2 (sccm) N2 (sccm) Power (W) TiOxTiOx210202000SnZnOSn60Zn40274401000SiN Si:Al at 92:8% by weight570142000SiZrNSi:Zr 27% by weight weight2150151000NiCrNiCr at 80:20% at.2200070Ag Ag84000210ZnOZnO:Al 2% by weight240201300CWOCWO: Cs / W 0.3-0.44-1030-402-1001300WO x W pur12406001300

[0121] at. = atomic

[0122] The WO layer x was deposited from a tungsten metal target, under an atmosphere comprising 60% oxygen and at a pressure of 12 mTorr. The WO layer x is thus a layer of pure substoichiometric tungsten oxide, WO x , with an x ​​of about 2.9. It has a refractive index of about 2.2 at 550 nm.

[0123] Once the deposition and heat treatment are complete, each of the glass sheets 1002 provided with a functional coating 1004 is laminated with a lamination interlayer 1003 made of PVB with a thickness of 0.76 mm and a second glass sheet 1001 made of soda-lime-silica mineral glass with a thickness of 1.6 mm in order to form a laminated glazing according to the diagram of the.

[0124] Light transmission, TL, “direct solar transmittance”, TE, and “solar factor”, TTS (or T TS ) have measured and / or calculated according to ISO 13837:2021 Convention A for each example and counterexample.

[0125] The “selectivity”, s, defined as the ratio, TL / TTS, of the light transmission, TL, to the solar factor TTS, and the “solar selectivity”, SE, defined as the ratio, TL / TE, of the light transmission TL to the direct solar transmittance, TE, were calculated for each example and counter-example from the previously measured and / or calculated parameters.

[0126] For each example and counter-example, the colorimetric parameters a* and b* were measured and / or calculated in transmission (a*T, b*T) and in reflection with respect to the first glass sheet 1001 (a*R1_65, b*R1_65) and with respect to the second glass sheet 1001 (a*R2_65, b*R2_65) in the CIE 1976 L*a*b* color space according to ISO 11664-4:2019 with a D65 illuminant and a visual field of 2° or 10° for the reference observer.

[0127] In color space, the characteristic a* is the color position on a green-red axis (between -500 and 500), and b* the color position on a blue-yellow axis (between -200 and 200).

[0128] Also, for each example and counter-example, the colorimetric parameters a* and b* were measured and / or calculated in transmission in reflection with respect to the second sheet of glass 1001 (a*R2_65_p, b*R2_65_p) in the L*a*b* CIE 1976 color space according to the ISO 11664-4:2019 standard with a D65 illuminant under p-polarized light and a visual field of 2° or 10° for the reference observer.

[0129] The chroma index, noted Chroma_R2_p, was calculated from the colorimetric parameters a*R2_65_p, b*R2_65_p obtained in reflection with respect to the second sheet of glass 1002. This index expresses the degree of purity of the color, which is an important parameter for “head-up” windshield applications.

[0130] The surface electrical resistance, denoted R², was evaluated using the 4-point measurement method as described in the article Measurement of Sheet Resistivities with the Four-Point Probe, FM Smits, Bell Syst. Tech. J., 711 (1958) or in the ASTM F390-11 standard. The measurements were acquired using a Napson RT70V 4-point ohmmeter.

[0131] All measured and / or calculated properties are grouped in Table 4.

[0132] Tab. 4CE1CE2E1E2E3E4TTS57.152.153.454.452.352.7TE51.946.347.747.945.547.4TL72.572.572.572.572.572.5s1.271.391.361.331.391.38 a*T-2.8-3.0-4.6-2.5-4.5-2.5b*T4.03.92.73.84.04.1R1_6529.829 .029.928.527.629.1a*R1_650.10.81.1-0.51.0-0.3b*R1_650.72.51. 4-1.80.7-0.3R222.418.617.521.318.322.7R2_p18.717.115.818.91 6.917.1a*R2_p2.32.42.42.40.82.5b*R2_65_p1.0-0.5-0.5-0.72.10. 2Chroma_R2_p2.52.52.52.52.22.5R2_6531.328.227.630.928.331.0 a*R2_65-0.10.7-0.3-0.2-0.7-1.0b*R2_651.7-0.9-1.0-0.21.21.3R² (Ω)2.562.352.502.452.442.95

[0133] For comparison purposes, in Table 4, the examples and counterexamples have the same light transmission value.

[0134] The luminous transmittance, TL, and direct solar transmittance, TE, values ​​for the examples (filled circles) and counterexamples (open circles) are shown in the figure. Also shown are the "solar selectivity" thresholds, SE, defined as the ratio, TL / TE, of luminous transmittance TL to direct solar transmittance TE, as guides for the eyes.

[0135] Compared to counterexample CE1, examples E1 and E2 have lower direct solar transmittance and therefore higher solar selectivity value. Examples E3 and E4 both have direct solar transmittance and solar selectivity value equivalent to counterexample CE2.

[0136] The luminous transmittance, TL, and total solar transmittance, TTS, values ​​for the examples (filled circles) and counterexamples (open circles) are shown in the figure. Also shown are the "selectivity" thresholds, s, defined as the ratio, TL / TTS, of the luminous transmittance TL to the total solar transmittance, TTS, as guides for the eyes.

[0137] Compared to counterexample CE1, examples E1 and E2 have a total solar transmittance, TTS, approximately 3 to 5% lower and therefore a higher solar selectivity value. Examples E3 and E4 have a total solar transmittance and solar selectivity value equivalent to counterexample CE2.

[0138] All examples E1 to E4 have a reflectance under p-polarized light greater than 15.5% and a neutral color with a chroma index of at most 2.5. These values ​​are suitable for head-up display applications.

[0139] All examples E1 to E4 also have a surface electrical resistance of less than 2.5 Ω, compatible with heating applications.

[0140] These examples very clearly illustrate the advantages of laminated glazing of the invention, namely that they have higher selectivity and have a color compatible with windshield type applications in "head-up" display and heating function.

Claims

Laminated glazing (1000) comprising: - a first sheet (1001) of glass; - a second sheet (1002) of glass; - a lamination interlayer (1003) in adhesive contact with the first sheet (1001) of glass, and the second sheet (1002) of glass; - a functional coating (1004) of thin films disposed on the second sheet (1002) of glass and comprising, starting from the second sheet (1002) of glass, a first dielectric module (2001), a metallic functional layer (2002) and a second dielectric module (2003), said metallic functional layer (2002) being located between the first dielectric module (2001) and the second dielectric module (2003);characterized in that - the first dielectric module (2001) and / or the second dielectric module (2003) comprises (or comprise) a tungsten oxide layer (2004a, 2004b) and in that: - said tungsten oxide layer (2004a, 2004b) is of pure substoichiometric tungsten oxide, WOx, with x preferably between 2.55 and 2.98, or - said tungsten oxide layer (2004a, 2004b) is of doped tungsten oxide and comprises at least one doping element selected from the chemical elements of group 1 according to the IUPAC nomenclature.; Laminated glazing according to claim 1, wherein the optical refractive index of the tungsten oxide layer (2004a, 2004b) is monotonically decreasing with wavelength from a maximum value greater than 2.4 at 350 nm to a minimum value between 600 nm and 1400 nm such that the difference between the maximum value and the minimum value is greater than 0.8, preferably 1.0, or even 1.

4. Laminated glazing according to any one of claims 1 to 2, wherein the optical extinction coefficient of the tungsten oxide layer (2004a, 2004b) is less than 0.2, or even 0.1 at 500 nm and less than 2.0, or even less than 1.5 at 1200 nm. Laminated glazing according to any one of claims 1 to 3, wherein the tungsten oxide layer (2004a, 2004b) of doped tungsten oxide comprises the doping element or several doping elements in proportions such that the molar ratio of said element to tungsten or the sum of the molar ratios of each element to tungsten is between 0.01 and 0.4, preferably between 0.01 and 0.2, or even between 0.01 and 0.

1. Laminated glazing according to any one of claims 1 to 4, wherein the tungsten oxide layer (2004a, 2004b) of doped tungsten oxide comprises at least one dopant element selected from hydrogen, lithium, sodium, potassium and cesium. Laminated glazing according to claim 5, wherein the tungsten oxide layer (2004a, 2004b) in doped tungsten oxide comprises cesium as a dopant element, and the molar ratio of cesium to tungsten is between 0.01 and 0.4, preferably between 0.01 and 0.

2. Laminated glazing according to any one of claims 1 to 6, wherein the physical thickness of the tungsten oxide layer (2004a, 2004b) is between 2 nm and 50 nm, in particular between 5 nm and 30 nm, preferably between 5 nm and 20 nm. Laminated glazing according to any one of claims 1 to 7, wherein the first dielectric module (2001) and / or the second dielectric module (2002) comprises (or comprise) one or more layers with a refractive index of less than 2.45 at 550 nm. Laminated glazing according to any one of claims 1 to 8, wherein the functional coating (1004) of thin films further comprises a metallic blocking overlayer, preferably based on a nickel and chromium alloy, located above and in contact with the metallic functional layer and / or a metallic blocking underlayer, preferably based on a nickel and chromium alloy, located below and in contact with the metallic functional layer. Laminated glazing according to any one of claims 1 to 9, wherein the first dielectric module (2001) and / or the second dielectric module (2002) comprises (or comprise) a layer based on mixed indium tin oxide, mixed indium zinc oxide, fluorine-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, antimony-doped tin oxide and / or niobium-doped titanium oxide. Glazing according to claim 10, wherein the thickness of said layer is between 50 nm and 100 nm. Laminated glazing according to any one of claims 1 to 11, wherein the metallic functional layer (2002) is silver-based. Head-up display projection device (3000) comprising: - a laminated glass (1000) according to any one of claims 1 to 12; - a head-up projector (3001) configured to emit electromagnetic radiation (3002) on at least one area (3003) of the laminated glass (1001), the electromagnetic radiation being at least partially polarized according to a p polarization. Use of laminated glazing (1000) according to any one of claims 1 to 12 for a head-up display in a land, sea or air vehicle, preferably in a motor vehicle, a railway vehicle, an aircraft or a boat, in particular a passenger car or a truck. Method of manufacturing laminated glazing (1000) according to any one of claims 1 to 12, wherein the tungsten oxide layer (2004a, 2004b) of doped tungsten oxide is deposited by a magnetron sputtering method using a target of tungsten oxide doped with a chemical element selected from the chemical elements of group 1 according to the IUPAC nomenclature.

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