Laminated glass

Abstract

The invention relates to a laminated glass comprising a first substrate (SI) and a second substrate (S2) connected to one another via a first polymer interlayer (11), and optionally a third substrate (S3) connected to the second substrate (S2) via a second polymer interlayer (I2), the substrates (S1, S2, S3) being made of chemically strengthened glass. The glass comprises: • - a solar control coating (R2) comprising at least one functional silver-based metal layer and at least two dielectric coatings, each dielectric coating comprising at least one dielectric layer, such that each functional metal layer is arranged between two dielectric coatings and • - a heating coating (RI) comprising a conductive oxide layer located on one surface of a substrate that does not comprise the solar control coating, the solar control coating (R2) and the heating coating (RI) being located on the surface 2 or on the surface 3, each on two different substrates.

Description

[0001] Title: LAMINATED GLAZING

[0002] The present invention relates to the field of glazing, and relates more particularly to laminated glazing intended for aeronautics, in particular cockpit glazing.

[0003] Cockpit glazing is a complex system that fulfills multiple roles. It provides physical, acoustic, and thermal protection from the external environment.

[0004] For this purpose, these glazings are laminated glazings. Laminated glazing comprises two or more glass substrates bonded together by polymer interlayers, also called lamination interlayers. Glazings for aeronautics preferably comprise at least three substrates.

[0005] Conventionally, the faces of a glazing unit are designated from the outside by numbering the faces of the substrates from the outside to the inside of the passenger compartment or room it equips. This means that incident sunlight passes through the faces in ascending order of their number.

[0006] In the case of laminated glazing, all the faces of the substrates are numbered but the faces of the lamination interlayers are not numbered. Face 1 is on the outside of the building or vehicle and therefore constitutes the outer wall of the glazing. Faces 2 and 3 are in contact with the lamination interlayer.

[0007] In the case of laminated glazing comprising two substrates, face 4 is inside the building or vehicle and therefore constitutes the inner wall of the glazing.

[0008] In the case of laminated glazing comprising three substrates, faces 4 and 5 are in contact with the second lamination interlayer and face 6 is inside the building or vehicle and therefore constitutes the inner wall of the glazing.

[0009] Laminated glazing for aeronautics preferably has a structure of the first substrate / first polymer interlayer / second substrate / second polymer interlayer / third substrate type.

[0010] For these applications, the substrates are curved and chemically toughened glass substrates. The substrates are made of chemically toughened glass, meaning they include a superficial compressive zone obtained by ion exchange. This superficial compressive zone is obtained by the superficial substitution of an ion of the glass substrate (usually an alkali ion such as sodium or lithium) by an ion of larger ionic radius (usually an alkali ion, such as potassium or sodium). This allows compressive stresses to be created on the surface of the glass substrate, up to a certain depth. These superficial compressive stresses are in fact balanced by the presence of a central tension zone. There is therefore a certain depth at which the transition between compression and tension occurs, a depth called the surface exchange depth.These laminated glazings may further comprise coatings providing additional functionalities. For example, at least one of the substrates may be coated with a heating coating with a defrosting function comprising an electrically conductive layer. These electrically conductive layers may be based on an oxide such as indium tin oxide (ITO).

[0011] Due to the intended application, these glazings must necessarily have high light transmission and low light absorption. However, while these "substrates", "interlayers" and "solar control coatings" constituting the glazings allow the visible part of the solar spectrum to pass into the cockpit, they also allow most of the infrared radiation to pass through. This results in excessive heating of the cockpit and an increase in its temperature, which must be compensated for by an energy-intensive air conditioning system.

[0012] To overcome this problem, it is possible to introduce, into these cockpit windows, an element with a solar control (or protection) function.

[0013] The "solar control" function or property corresponds to the ability of a glazing to let in visible light while blocking infrared radiation. The selectivity "S" and the solar factor (FS or g) are used to evaluate this property. Selectivity corresponds to the ratio of light transmission TL VjS in the visible of the glazing on the solar factor FS of the glazing (S = TL VjS / FS). The solar factor "FS or g" corresponds to the ratio in % between the total energy entering the room through the glazing and the incident solar energy. The solar factor therefore measures the contribution of a glazing to heating the "room". The smaller the solar factor, the lower the solar gain. Energy transmission corresponds to the percentage of the solar energy flow transmitted directly through the glazed wall.

[0014] The solar control function therefore corresponds to a strong reduction in the energy transmission (TE) and the solar factor (g) of the glazing associated with a slight reduction in the light transmission (TL).

[0015] The purpose of adding a solar control element is to prevent excessive overheating. However, the addition of this element should not be at the expense of light transmission and light absorption.

[0016] To provide this solar protection function, different types of elements can be considered. It is known to use lamination interlayers with a solar control function. For example, we can cite the Saflex® Solar interlayers made of polyvinyl butyral "PVB" of the SH and SG types. These interlayers have a high light transmission and absorb infrared (IR) rays. Laminated glazing for cockpits containing such solar control interlayers is not satisfactory. Indeed, they are not selective enough.

[0017] To overcome these drawbacks, the applicant has developed a laminated glazing having a configuration particularly suitable for use as cockpit glazing comprising a solar control coating. The particular structure of the invention makes it possible to obtain an excellent compromise between low light absorption and high light transmission and selectivity. The invention makes it possible in particular to obtain high selectivity which is not accessible by other technologies.

[0018] The invention therefore relates to a laminated glazing comprising a first substrate (S1) and a second substrate (S2) bonded together via a first polymer interlayer, and optionally a third substrate (S3) bonded to the second substrate (S2) via a second polymer interlayer, the substrates being made of chemically toughened glass, characterized in that it comprises

[0019] - a solar control coating comprising at least one silver-based functional metal layer and at least two dielectric coatings, each dielectric coating comprising at least one dielectric layer, such that each functional metal layer is disposed between two dielectric coatings and

[0020] - a heating coating comprising a conductive oxide layer located on one side of a substrate not comprising the solar control coating, the solar control coating and the heating coating are located on side 2 or on side 3, each on two different substrates.

[0021] One of the features of the invention is that the substrates are chemically toughened. These chemically toughened glass substrates can be defined as follows:

[0022] - they include a surface area in compression obtained by ion exchange, and / or

[0023] - they have a surface exchange depth greater than 50 pm and / or

[0024] - they have surface compression stresses greater than 100 MPa.

[0025] Chemical hardening processes are well known. Reference may be made in particular to patent application WO1994008910.

[0026] The solar control coating and the heating coating are necessarily deposited after the chemical reinforcement step. These coatings do not normally undergo a heat treatment step after deposition. They must therefore preferably have acquired their final properties directly after deposition.

[0027] According to the invention, the solar control coating comprises at least one silver-based functional metal layer and at least two dielectric coatings, each dielectric coating comprising at least one dielectric layer, such that each functional metal layer is arranged between two dielectric coatings.

[0028] According to one embodiment, the solar control coating comprises a single silver-based functional layer. Such coatings make it possible to obtain a good compromise between a significant reduction in the solar factor and a minimal reduction in light transmission. Only coatings with a single silver layer make it possible to obtain high light transmissions. It is not possible to obtain such high light transmissions with coatings with several silver layers, in particular with two silver-based layers, because the silver layers necessarily generate a minimal absorption which is unavoidable. The applicant has discovered that it is very difficult to obtain sufficiently low absorption with solar control coatings with several silver-based functional layers. For example, the absorption on clear glass of a solar control coating with two silver-based functional layers is generally greater than 12%.This is notably due to the presence of at least four “metal / dielectric” interfaces, each of which necessarily generates absorption. The invention is therefore, according to one embodiment, deliberately limited to coatings comprising a single silver-based functional layer because they are likely to have visible light absorption values ​​of less than 10% when deposited on clear glass. According to this embodiment, the solar control coating does not comprise other layers whose main function is to reflect infrared radiation.

[0029] In applications where achieving maximum light transmission is not the primary criterion, a solar control coating comprising at least two silver-based functional layers may be used. In another embodiment, the solar control coating comprises at least two silver-based functional layers. Such coatings achieve higher selectivity but require a greater reduction in light transmission.

[0030] The particular structure based on at least three substrates linked together by two polymer interlayers is particularly suitable for aeronautical applications. In the case of an air vehicle, the first substrate is not held by a vehicle connection system. Only the other two substrates, called structural, are held.

[0031] The first substrate constitutes the outer part of the glazing. It is not structurally fixed to the vehicle or building it is fitted to. It is simply held to the second substrate by the polymer interlayer.

[0032] The second and third substrates are mechanically fixed in the building or vehicle. These two substrates provide protection for people inside the vehicle. The assembly formed by the second substrate, the second polymer interlayer and the third substrate must therefore have excellent impact resistance.

[0033] As a result, the edge of the first substrate may be set back relative to that of the second substrate to prevent delamination phenomena due to deformations of the glazing subjected to the pressure of the aircraft or to the mechanisms of tearing and / or peripheral shearing of the external substrate.

[0034] The first polymer interlayer is preferably polyurethane-based. The specific choice of this material for this polymer interlayer is justified because it is less hygroscopic, i.e. it has less tendency to absorb and / or retain water than other polymer interlayers, for example PVB. This first interlayer keeps the substrate furthest outward and therefore most likely to be subjected to extreme climatic conditions. The second polymer interlayer is preferably polyvinylbutadiene-based. The specific choice of this material for this polymer interlayer is justified because it has better mechanical properties, particularly impact resistance. In addition, due to its "inner" position, its chemical durability is less critical than that of the first polymer interlayer.

[0035] The glazing according to the invention may have the following characteristics alone or in combination:

[0036] - the solar control coating comprises a single functional silver-based metal layer,

[0037] - the solar control coating comprises a single functional silver-based metal layer,

[0038] - the solar control coating comprises at least two silver-based functional metal layers,

[0039] - it has a selectivity greater than 1.4,

[0040] - each dielectric coating of the solar control coating comprises oxide-based layers and the sum of the thicknesses of all the oxide layers of each dielectric coating represents at least 50% of the total thickness of the dielectric coating considered,

[0041] - the conductive oxide layer is a layer of indium tin oxide (ITO),

[0042] - the conductive oxide layer has a thickness of at least 50 nm, at least 100 nm, at least 200 nm,

[0043] - the conductive oxide layer has at least two zones of different thickness, the ratio between the thickness of these two zones is greater than 2, 3, 4 or 6,

[0044] - the polymer interlayers are chosen from polyurethane (PU) and polyvinyl butadiene (PVB) sheets,

[0045] - the first polymer interlayer is chosen from polyurethane (PU) sheets,

[0046] - the second polymer interlayer is chosen from polyvinyl butadiene (PVB) sheets,

[0047] - the thickness of the first polymer interlayer is between 3 and 10 mm, preferably 4 and 8 mm,

[0048] - the thickness of the second polymer interlayer is between 0.5 and 4 mm, between 0.5 and 2 mm,

[0049] - the thickness of the first substrate is between 2 and 4 mm and the thickness of the second substrate is between 4 and 8 mm or between 5 and 7 mm.

[0050] The invention also relates to:

[0051] - a laminated glazing according to the invention mounted on a vehicle or on a building, and - the method for preparing a laminated glazing according to the invention,

[0052] - the use of laminated glazing according to the invention as solar control glazing for buildings or vehicles,

[0053] - a building, a vehicle comprising glazing according to the invention.

[0054] The invention relates in particular to:

[0055] - the use of laminated glazing according to the invention as cockpit glazing for an air vehicle,

[0056] - an airplane or helicopter characterized in that it is equipped with the glazing according to the invention, as side or front glazing for the cockpit.

[0057] The preferred characteristics which appear in the remainder of the description are applicable both to the material according to the invention, to the glazing, and, where appropriate, to the method, to the use, to the building or to the vehicle according to the invention.

[0058] All the luminous characteristics described are obtained according to the principles and methods of the ISO 9050 standard relating to the determination of the luminous and solar characteristics of glazing used in glass for construction.

[0059] Conventionally, refractive indices are measured at a wavelength of 550 nm.

[0060] Unless otherwise stated, the thicknesses mentioned in this document without further details are physical, real or geometric thicknesses called Ep and are expressed in nanometers (and not optical thicknesses). The optical thickness Eo is defined as the physical thickness of the layer considered multiplied by its refractive index at the wavelength of 550 nm: Eo = n*Ep. Since the refractive index is a dimensionless value, the unit of optical thickness can be considered to be that chosen for the physical thickness.

[0061] For the purposes of the present invention, the qualifications "first", "second", "third" and "fourth" for functional layers or dielectric coatings are defined starting from the substrate carrying the solar control coating and referring to layers or coatings of the same function. For example, the functional layer closest to the substrate is the first functional layer, the next one away from the substrate is the second functional layer, etc.

[0062] The solar control coating is deposited by magnetic field-assisted sputtering (magnetron process). In this advantageous embodiment, all layers of the coatings are deposited by magnetic field-assisted sputtering.

[0063] In the absence of a specific stipulation, the expressions "above" and "below" do not necessarily mean that two layers and / or coatings are placed in contact with each other. When it is specified that a layer is deposited "in contact" with another layer or coating, this means that there cannot be one (or more) layer(s) interposed between these two layers (or layer and coating).

[0064] In this description, unless otherwise indicated, the expression "based on", used to qualify a material or a layer as to what it contains, means that the mass fraction of the constituent that it comprises is at least 50%, in particular at least 70%, preferably at least 90%.

[0065] According to the invention:

[0066] - light reflection corresponds to the reflection of solar radiation in the visible part of the spectrum,

[0067] - light transmission corresponds to the transmission of solar radiation in the visible part of the spectrum,

[0068] - light absorption corresponds to the absorption of solar radiation in the visible part of the spectrum.

[0069] Ordinary clear glass 4-6 mm thick has the following light characteristics:

[0070] - a light transmission between 85 and 91.5%,

[0071] - a light reflection of between 7 and 9.5%,

[0072] - a light absorption of between 0.3 and 5%.

[0073] The silver-based metal functional layers comprise at least 95.0%, preferably at least 96.5% and more preferably at least 98.0% by mass of silver relative to the mass of the functional layer. Preferably, a silver-based metal functional layer comprises less than 1.0% by mass of metals other than silver relative to the mass of the silver-based metal functional layer.

[0074] The silver-based metal functional layers have a thickness:

[0075] - greater than 5 nm, 6 nm, 7 nm, 8 nm or 9 nm, and / or

[0076] - less than 25 nm, 22 nm, 20 nm, 18 nm, 16 nm, 15 nm, 14 nm or 13 nm.

[0077] The solar control coating may comprise one or more blocking layers located in contact below and / or above one or more functional layers.

[0078] Blocking layers traditionally serve to protect the functional layers from possible degradation during deposition of the upper anti-reflective coating and during possible high-temperature heat treatment.

[0079] The blocking layers are chosen from:

[0080] - metallic layers based on a metal or a metallic alloy, metallic nitride layers, and metallic oxynitride layers of one or more elements chosen from titanium, zinc, tin, nickel, chromium and niobium,

[0081] - metal oxide layers of one or more elements chosen from titanium, nickel, chromium and niobium. The blocking layers may in particular be layers of Ti, TiN, TiOx, Nb, NbN, Ni, NiN, Cr, CrN, NiCr, NiCrN, NiCrOx, SnZnN. When these blocking layers are deposited in metallic, nitrided or oxynitrided form, these layers may undergo partial or total oxidation depending on their thickness and the nature of the layers surrounding them, for example, at the time of deposition of the next layer or by oxidation in contact with the underlying layer.

[0082] Preferably, the blocking layers are titanium layers, i.e. these layers have been deposited in the form of metallic titanium.

[0083] According to advantageous embodiments of the invention, the blocking layer(s) satisfy one or more of the following conditions:

[0084] - each functional metal layer is in contact with a blocking overlayer, and / or

[0085] - the blocking layers are layers of titanium deposited in metallic form, and / or

[0086] - the thickness of each blocking layer is at least 0.05 nm, or between 0.08 and 2.00 nm, between 0.10 and 1.00 nm or between 0.05 and 0.50 nm.

[0087] The sum of the thicknesses of all blocking layers may be less than 2.0 nm, less than 1.5 nm, less than 1.0 nm or less than 0.5 nm.

[0088] By "dielectric layer" for the purposes of the present invention, it is to be understood that from the point of view of its nature, the material is "non-metallic", i.e. is not a metal. In the context of the invention, this term designates a material having an n / k ratio over the entire visible wavelength range (from 380 nm to 780 nm) equal to or greater than 5.

[0089] Preferably, each dielectric coating consists of only one or more dielectric layers. Preferably, there is therefore no absorbing layer in the dielectric coatings so as not to reduce the light transmission.

[0090] Improving properties such as selectivity results from the precise control of optical interference effects between the different layers making up the coating. This control is achieved by choosing the nature, thickness and sequences of dielectric layers constituting the dielectric coatings.

[0091] The dielectric layers of the coatings have the following characteristics alone or in combination:

[0092] - they are deposited by magnetic field-assisted cathode sputtering,

[0093] - they have a thickness greater than 2 nm, preferably between 4 and 200 nm.

[0094] The dielectric layers are conventionally chosen from oxide-based, nitride-based or oxynitride-based layers. The oxide-based layers of one or more elements comprise essentially oxygen and very little nitrogen. The oxide-based layers comprise in particular at least 90% by atomic percentage of oxygen relative to the oxygen and nitrogen in said layer. The nitride-based layers comprise essentially nitrogen and very little oxygen. The nitride-based layers comprise at least 90% by atomic percentage of nitrogen relative to the oxygen and nitrogen in said layer. The oxynitride-based layers comprise a mixture of oxygen and nitrogen. The silicon oxynitride-based layers comprise 10 to 90% (limits excluded) by atomic percentage of nitrogen relative to the oxygen and nitrogen in said layer.

[0095] The amounts of oxygen and nitrogen in a layer are determined as atomic percentages relative to the total amounts of oxygen and nitrogen in the layer under consideration.

[0096] The dielectric layers are classically chosen from:

[0097] - layers comprising silicon, aluminum and / or zirconium, optionally doped with at least one other element,

[0098] - layers based on zinc and tin oxide,

[0099] - layers based on titanium oxide,

[0100] - zinc oxide-based layers.

[0101] Dielectric layers, in addition to their optical function, can have various other functions. Examples include stabilizing layers, smoothing layers, and barrier layers.

[0102] Dielectric layers with a barrier function (hereinafter barrier layer) are understood to mean a layer made of a material capable of acting as a barrier to the diffusion of oxygen and water at high temperature, coming from the ambient atmosphere or from the transparent substrate, towards the functional layer. Such dielectric layers are chosen from:

[0103] - layers comprising silicon such as layers chosen from oxides such as SiO2 and AI2O3, nitrides such as SisN4 and AIN, and oxynitrides such as SiO x N y , AlOxNy possibly doped with at least one other element,

[0104] - layers containing aluminum,

[0105] - layers based on zinc and tin oxide,

[0106] - layers based on titanium oxide.

[0107] The layers comprising silicon comprise at least 50% by mass of silicon relative to the mass of all elements constituting the layer comprising silicon other than nitrogen and oxygen.

[0108] The layers comprising silicon may be selected from oxide-based, nitride-based or oxynitride-based layers such as silicon oxide-based layers, silicon nitride-based layers and silicon oxynitride-based layers.

[0109] The silicon oxide-based layers comprise at least 90 atomic percent oxygen relative to the oxygen and nitrogen in the silicon oxide-based layer. The silicon nitride-based layers comprise at least 90 atomic percent nitrogen relative to the oxygen and nitrogen in the silicon nitride-based layer. The silicon oxynitride-based layers comprise 10 to 90 atomic percent nitrogen relative to the oxygen and nitrogen in the silicon oxide-based layer. Preferably, the silicon oxide-based layers are characterized by a refractive index at 550 nm of less than or equal to 1.55. Preferably, the silicon nitride-based layers are characterized by a refractive index at 550 nm of greater than or equal to 1.95.

[0110] The layers comprising silicon may comprise or consist of elements other than silicon, oxygen and nitrogen. These elements may be selected from aluminum, boron, titanium, and zirconium. The layers comprising silicon may comprise at least 2%, at least 5% or at least 8% by mass of aluminum relative to the mass of all elements constituting the layer comprising silicon other than oxygen and nitrogen.

[0111] The layers comprising aluminum may be chosen from oxide-based, nitride-based or oxynitride-based layers such as aluminum oxide-based layers such as AI2O3, aluminum nitride-based layers such as AIN and aluminum oxynitride-based layers such as AlOxNy.

[0112] Preferably, the barrier layers are layers chosen from layers comprising silicon, layers based on titanium oxide and layers based on zinc and tin oxide.

[0113] The dielectric layers may be so-called stabilizing layers. For the purposes of the invention, "stabilizing" means that the nature of the layer is selected so as to stabilize the interface between the functional layer and this layer. This stabilization leads to strengthening the adhesion of the functional layer to the layers surrounding it. The stabilizing layers are preferably layers based on zinc oxide, optionally doped, for example, with aluminum. The zinc oxide is crystallized. The zinc oxide-based layer comprises, in increasing order of preference, at least 90.0%, at least 92%, at least 95%, at least 98.0% by mass of zinc relative to the mass of elements other than oxygen in the zinc oxide-based layer.

[0114] The stabilizing dielectric layer(s) may be directly in contact with a functional layer or separated by a blocking layer.

[0115] Preferably, the last dielectric layer of each dielectric coating located below a functional layer is a stabilizing dielectric layer. Indeed, it is advantageous to have a stabilizing layer, for example, based on zinc oxide below a functional layer, because it facilitates the adhesion and crystallization of the silver-based functional layer and increases its quality and stability.

[0116] It is also advantageous to have a stabilizing layer, for example, based on zinc oxide above a functional layer, to increase its adhesion and optimally oppose diffusion on the side of the stack opposite the substrate. The stabilizing dielectric layer(s) may therefore be located above and / or below at least one functional layer or each functional layer, either directly in contact with it or separated by a blocking layer.

[0117] Advantageously, each dielectric layer with barrier function is separated from a functional layer by at least one dielectric layer with stabilizing function.

[0118] The zinc oxide layers have, in order of increasing preference, a thickness:

[0119] - at least 3.0 nm, at least 4.0 nm, at least 5.0 nm, and / or

[0120] - not more than 15 nm, not more than 10 nm, not more than 8.0 nm.

[0121] The sum of the physical thicknesses of all layers comprising silicon in each dielectric coating is greater than 50%, 60% or 70% of the total thickness of the dielectric coating in question.

[0122] According to one embodiment, the sum of the physical thicknesses of all oxide layers of each dielectric coating is greater than 50%, 60%, 70%, 80%, 90%, 95% or 99% of the total thickness of the dielectric coating.

[0123] A particularly advantageous embodiment relates to a substrate coated with a coating comprising, starting from the substrate:

[0124] - a first dielectric coating comprising at least one layer with a barrier function and one dielectric layer with a stabilizing function,

[0125] - a first functional layer,

[0126] - possibly a blocking layer,

[0127] - a second dielectric coating comprising at least one dielectric layer with a stabilizing function and a layer with a barrier function.

[0128] A particularly advantageous embodiment relates to a substrate coated with a coating comprising, starting from the substrate:

[0129] - a first dielectric coating comprising at least one layer with a barrier function and one dielectric layer with a stabilizing function,

[0130] - a first functional layer,

[0131] - possibly a blocking layer,

[0132] - a second dielectric coating comprising at least a first dielectric layer with a stabilizing function, a layer with a barrier function and a second dielectric layer with a stabilizing function,

[0133] - a second functional layer,

[0134] - possibly a blocking layer,

[0135] - a third dielectric coating comprising at least one dielectric layer with a stabilizing function and a layer with a barrier function. The heating coatings suitable according to the invention are described in particular in application WO 2020 / 120879. The heating coating comprises at least one electrically conductive layer which is a transparent conductive oxide layer.

[0136] Heating is achieved by the Joule effect. The heating layer is powered by energized electrodes. Uniform heating of a non-rectangular or square shape is impossible with a layer of uniform electrical conductivity.

[0137] To homogenize heating on complex surfaces, the electrically conductive layer can have an electrical conductivity gradient. This gradient can be achieved by a thickness gradient. Large variations in layer thickness can limit the current density in certain parts of the heating surface.

[0138] To homogenize the heating, the electrically conductive layer may also include ablation lines, called flux separation lines or more commonly flux lines as described in patent EP1897412-B1, which guide the flow of electric current.

[0139] These two strategies can be used in combination.

[0140] The conductive oxide layer (electroconductive layer) has one or more of the following characteristics:

[0141] - it is located on the inward-facing face of the first substrate or on the outward-facing face of the second substrate, and / or

[0142] - it comprises a conductive oxide layer based on doped metal oxide such as tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (SnO2:F), and / or

[0143] - it has a thickness of 2 to 1600 nm, preferably 25 to 500 nm or 50 to 300 nm, and / or

[0144] - it has a thickness greater than 50 nm, greater than 100 nm, greater than 150 nm, this means that it has this thickness on at least part of the surface of the substrate, and / or

[0145] - it has a thickness gradient, i.e. a variation in its thickness, this is reflected for example by the existence of at least two zones of different thickness and a thickness ratio between these two zones greater than 2, 3, 4 or 6, and / or

[0146] - it has flux lines to guide the electric current preferably having a width between 5 and 1000 pm.

[0147] The thickness ratio between these two zones of different thicknesses therefore corresponds to the ratio of the thickness of the thicker layer to the thickness of the thinner layer.

[0148] Preferably, the mineral glass substrates that constitute the glazing are made of soda-lime, aluminosilicate or borosilicate glass. Preferably, the lamination interlayers comprise one or more sheets of organic polymers.The organic polymers are selected from polyvinyl butyral (PVB), polyurethanes (PU), polyureas, ethylene vinyl acetate (EVA), polyolefins (including polyethylene (PE), polypropylene (PP) or polyisobutylene (P-IB)), polyvinyl chloride and its derivatives (e.g. poly(vinyl dichloride) (PVDC)), styrenic polymers (e.g. polystyrene (PS), acrylostyrene butadiene (ABS), styrene acrylonitrile (SAN)), polyacrylics (including polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA)), polyesters (including poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT)), polyoxymethylene (POM), polyamides (PA), fluorinated polymers such as polychlorotrifluoroethylene (PCTFE), polycarbonates (PC), aromatic polysulfones including polysulfone (PSU), polyphenylene ethers (PPE), epoxies (EP) alone or as a mixture and / or copolymer of several of them.

[0149] According to preferred characteristics of the laminated glazing of the invention:

[0150] - the laminated glazing comprises a third sheet of glass connected to the second sheet of glass by a second interlayer, and / or

[0151] - the first glass substrate has a thickness of between 0.5 and 5 mm, preferably between 2 and 4 mm, and / or

[0152] - the second glass substrate, and where applicable the third glass substrate, are made of glass with a thickness of between 4 and 10 mm, and / or

[0153] - said interlayers are made of polyurethane (PU), polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) or equivalent, and / or

[0154] - the first interlayer is made of polyurethane, and / or

[0155] - the second interlayer is made of polyvinyl butyral (PVB), and / or

[0156] - the thickness of the first interlayer is between 2 and 10, preferably 4 and 8 mm, and / or

[0157] - the thickness of the second interlayer is between 0.5 and 4, preferably at most equal to 2 mm, and / or

[0158] - it has a selectivity greater than 1.4 or 1.5, and / or

[0159] - it has a light transmission of at least 65% or at least 68%.

[0160] Another object of the invention consists of the use of the laminated glazing described above as glazing for buildings, land, air or water vehicles, or for street furniture, in particular as glazing for the cockpit of an air vehicle.

[0161] Figure 1 schematically represents a cross-sectional view of an embodiment of the laminated glazing of the invention for a cockpit. A laminated glazing according to the invention therefore comprises:

[0162] - a first glass substrate S1 constituting an outer face of the curved and chemically toughened glazing, for example 3 mm thick,

[0163] - a first interlayer 11 of polyurethane (PU), for example 5 mm thick, - a second substrate of curved and chemically toughened S2 glass, for example 6 mm thick,

[0164] - a second interlayer 12 of polyvinyl butyral (PVB) 1.1 mm thick,

[0165] - a third substrate of curved and chemically toughened glass, for example 6 mm thick,

[0166] - two R1 and R2 coatings including a heating coating and a solar control coating.

[0167] Preferably, the entire peripheral edge of the laminated glazing is covered by a seal (J). This includes the edge of the first glass substrate, the edge of the first interlayer, a portion of the surface of the second glass substrate extending beyond the first glass substrate, the edge of the second glass substrate, the edge of the second interlayer and the edge of the third glass substrate.

[0168] Laminated glazing also includes:

[0169] - a heating coating,

[0170] - a solar control coating comprising at least one silver-based layer, the heating coating and the solar control coating are each in contact with the first lamination interlayer, on one face of the first substrate and on one face of the second substrate.

[0171] Examples

[0172] I. Materials and coatings

[0173] 1. General information

[0174] In these examples, the glass substrates are chemically toughened and curved aluminosilicate glass substrates.

[0175] The first lamination interlayers are 6.5 mm polyurethane interlayers. The second interlayers are 1.1 mm thick PVB interlayers.

[0176] For the comparative example, a solar control PVB interlayer was used. This is the Saflex® solar SH41 product with the following characteristics according to ISO 9050:

[0177] - Solar transmission: 51%, Solar reflection: 5%, Solar absorption: 43%,

[0178] - Light transmission: 83% and light reflection: 7%.

[0179] 2. Heating coatings

[0180] The ITO14 heating coating consists of a 140 nm layer of indium tin oxide. This layer was deposited by magnetron sputtering on a 3 mm glass substrate. It has a sheet resistance of 14 Q / n measured by induction.

[0181] The ITO11 heating coating consists of a 180 nm layer of indium tin oxide. This layer is deposited by magnetron sputtering on a 3 mm glass substrate. It has a sheet resistance of 11 Q / n measured by induction.

[0182] 3. Solar control coatings

[0183] The functional metal layers (F) are silver (Ag) layers. The blocking layers are titanium (Ti) metal layers. The dielectric coatings include barrier layers and stabilizing layers. The barrier layers are based on titanium oxide and zinc tin oxide. The stabilizing layers are based on zinc oxide (ZnO).

[0184] The deposition conditions of the layers, which were deposited by sputtering (so-called “magnetron cathode sputtering”), are summarized in Table 1.

[0185] [Table 1]

[0186] Pds: Weight; at: Atomic

[0187] Solar control coatings defined below are deposited on 6 mm thick glass substrates.

[0188] Table 2 lists the materials and physical thicknesses in nanometers (unless otherwise indicated) of each layer or coating that constitutes the coatings according to their position relative to the substrate carrying the stack (last line at the bottom of the table).

[0189]

[0190] CB: Blocking layer; CF: Functional layer; RD: Dielectric coating.

[0191] II. Configurations: glazing for aeronautics

[0192] The laminated glazings have the following configuration: a first glass substrate S1 of 3 or 6 mm thickness possibly coated on face 2 with a coating / a first polyurethane (PU) interlayer / a second glass substrate S2 of 3 or 6 mm thickness possibly coated with a coating on face 3 / a second polyvinyl butyral (PVB) interlayer / a third substrate of 6 mm thickness.

[0193] The reference glazing does not include solar control coating.

[0194] The glazings according to the invention comprise a solar control coating and a heating coating on face 2 or 3 of the glazing.

[0195] Comp.1 glazing includes a solar control PVB as a second interlayer.

[0196] The table below lists the different configurations tested.

[0197]

[0198] 1. First tests

[0199] The performances on Ref.1, lnv.1, lnv.2 and lnv.3 glazing were obtained by simulation.

[0200] As (%) compared to the reference

[0201] 2. Second attempts

[0202] The glazings Ref.2, comp.1 and lnv.4 and lnv.5 are physical samples.

[0203] The invention makes it possible to obtain laminated glazing that is very satisfactory for aeronautics.

[0204] The invention allows a significant improvement in selectivity compared to glazing without solar control coating (comparison of the glazings of the invention and Ref). The glazings of the invention have a selectivity of at least 1.40.

[0205] Comparing the "first tests" with the "second tests", a decrease in selectivity is observed. This is partly due to the fact that the ITO11 heating coating is less transparent than the ITO14 heating coating. To obtain glazing with high light transmission, less absorbent functional coatings were used.

[0206] For a single-layer silver glazing, high light transmission and improved selectivity (lnv.1 and lnv.4) are obtained. The use of a two-layer silver coating also allows high selectivity to be obtained but at the expense of light transmission (reduction of several TL points compared to the single-layer silver coating).

[0207] The addition of a low-absorbency solar control coating according to the invention allows a drastic reduction in energy transmission, in particular at least 16 percentage points for a single-layer silver coating (lnv.4 vs Ref.2) and at least 20 percentage points for a two-layer silver coating (lnv.5 vs Ref.2).

[0208] It also allows a drastic reduction of the solar factor.

[0209] Comp.1 glazing does not allow for effects as advantageous as those of the invention.

[0210] The glazing according to the invention offers a good compromise between light transmission and high selectivity and low solar factor.

[0211] Figures 2 and 3 represent for examples Ref.2, Comp.1, lnv.4 and lnv.5, respectively the transmission and reflection as a function of the wavelength.

[0212] It is clear from Figure 2 that the examples according to the invention lnv.4 and lnv.5 and example comp.1 both have similar transmission spectra. They all allow infrared radiation to be filtered better and visible radiation to pass through compared to the reference example.

[0213] On the other hand, we see in Figure 3 that the reflection spectra are very different. This explains the significant differences for the solar factor.

[0214] The glazings according to the invention have a high light transmission and selectivity pair.

Claims

Demands 1. Laminated glazing comprising a first substrate (S1) and a second substrate (S2) bonded together via a first polymer interlayer, and optionally a third substrate (S3) bonded to the second substrate (S2) via a second polymer interlayer, the substrates being made of chemically tempered glass, characterized in that it comprises - a solar control coating comprising at least one silver-based functional metallic layer and at least two dielectric coatings, each dielectric coating comprising at least one dielectric layer, such that each functional metallic layer is disposed between two dielectric coatings and - a heating coating comprising a conductive oxide layer located on one face of a substrate not comprising the solar control coating, the solar control coating and the heating coating are located on face 2 or face 3, each on two different substrates.

2. Laminated glazing according to claim 1 characterized in that the solar control coating comprises a single functional silver-based metallic layer.

3. Glazing according to claim 1, characterized in that the solar control coating comprises at least two functional silver-based metallic layers.

4. Laminated glazing according to any one of the preceding claims, characterized in that it has a selectivity greater than 1.

4.

5. Laminated glazing according to any one of the preceding claims, characterized in that each dielectric coating of the solar control coating comprises oxide-based layers and the sum of the thicknesses of all the oxide layers of each dielectric coating represents at least 50% of the total thickness of the dielectric coating considered.

6. Laminated glazing according to any one of the preceding claims, characterized in that the conductive oxide layer is a layer of indium tin oxide (ITO).

7. Glazing according to any one of the preceding claims, characterized in that the conductive oxide layer has a thickness of at least 50 nm.

8. Laminated glazing according to any one of the preceding claims, characterized in that the conductive oxide layer has at least two zones of different thickness, the ratio between the thickness of these two zones is greater than 2, 3, 4 or 6.

9. Laminated glazing according to any one of the preceding claims, characterized in that the polymer interlayers are selected from polyurethane (PU) and polyvinyl butadiene (PVB) sheets.

10. Laminated glazing according to any one of the preceding claims, characterized in that the first polymer interlayer is selected from polyurethane (PU) sheets.

11. Laminated glazing according to any one of the preceding claims, characterized in that the second polymer interlayer is selected from polyvinyl butadiene (PVB) sheets.

12. Laminated glazing according to any one of the preceding claims, characterized in that the thickness of the first polymer interlayer is between 3 and 10 mm and in that the thickness of the second polymer interlayer is between 0.5 and 4 mm.

13. Laminated glazing according to any one of the preceding claims, characterized in that the thickness of the first substrate is between 2 and 4 mm and the thickness of the second substrate is between 4 and 8 mm or between 5 and 7 mm.

14. Use of laminated glazing according to any one of claims 1 to 13 as cockpit glazing for aircraft.

15. Aircraft or helicopter characterized in that it is equipped with glazing according to one of the preceding claims, as side or front glazing for cockpit.

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