Solar control window glass comprising a titanium nitride layer

Abstract

A glass article having anti-sunlight properties and comprising at least one glass substrate, the glass substrate being provided with a layer stack, wherein the stack successively comprises, starting from the surface of the substrate: - a first module M1, which consists of a layer based on a dielectric material or a layer assembly based on a material having a thickness e 1 ; - a layer TN1, which contains titanium nitride and is preferably based on titanium nitride, having a thickness of 2 nanometers to 80 nanometers; - a second module M2, which consists of a layer based on a dielectric material having a thickness e 2 or a layer assembly based on a dielectric material having a cumulative thickness e 2 , and an intermediate layer, which contains at least one element selected from silicon, aluminum, titanium or a mixture of at least two of these elements, is deposited between the layer TN1 and the first module M1 and / or between the layer TN1 and the second module M2, and the one or more intermediate layers have a thickness of 0.2 nm - 6 nm.

Description

[0001] The present invention relates to a "solar control" insulating glazing provided with a "functional" thin layer stack, which acts on solar and / or thermal radiation substantially by reflection and / or absorption of near (solar) or far (thermal) infrared radiation. The applications to which the present invention particularly pertains are mainly in the building field, as solar control glazing. Without departing from the scope of the present invention, the glazing of the present invention can also be used for vehicle glazing, such as side windows, roofs and rear windows.

[0002] The term "glazing" is understood in the sense of the present invention to mean any glass product consisting of one or more glass substrates, in particular single glazing, double glazing, triple glazing, etc.

[0003] In the sense of the present application, a "functional" or "active" layer is understood to mean a layer that confers most of its heat insulation properties in the stack. Most commonly, the thin layer stack equipped on the glazing provides significantly improved insulation properties mainly through the inherent properties of the active layer. Contrary to other layers, which are usually made of dielectric materials and most commonly mainly have the function of chemically or mechanically protecting the functional layer, this layer acts on the flow of thermal infrared radiation passing through the glazing. The term "dielectric material" should be understood as a material that, in solid form, contains no impurities or dopants and has a high resistivity, particularly greater than 10 10 ohm.meters (Ω.m) at room temperature (300K).

[0004] Such glazing provided with a thin layer stack acts on the incident IR radiation substantially by absorption of the radiation by the functional layer or substantially by reflection of these same layers.

[0005] They are classified as solar control glazing. They are sold and used mainly for:

[0006] - mainly to protect a dwelling or a passenger compartment (vehicle) from solar radiation and prevent overheating, and such glazing is known in the art as sun protection glazing;

[0007] - or mainly to insulate a dwelling and prevent heat loss, and these glazing are then known as insulating glazing.

[0008] Thus, in the sense of the present invention, the expression "anti-solar" is understood as the ability of the glazing to limit the energy flux, particularly the ability to limit solar infrared radiation (SIR) passing from the outside through it to the interior of a dwelling or a passenger compartment.

[0009] The expression "heat-insulating" is understood to mean a window glass fitted with at least one functional layer which provides it with reduced energy losses, said layer having the reflective property of reflecting thermal IR radiation between 5 and 50 microns. The functional layer used in this function has a high IR reflection coefficient and is referred to as low-emissivity (or the English term is low-e).

[0010] In certain countries, standards require that window glass simultaneously have anti-solar performance and heat-insulating properties for the window glass of a building.

[0011] The expression "low-emissivity" is understood to mean a window glass provided with at least one functional layer which gives it a normal emissivity ε of less than 50%, preferably less than 45%, and even less than 40% n (or the total emissivity when the incidence is perpendicular), the emissivity being defined by the following formula:

[0012] ε n = 1 - R n ,

[0013] where R n is the normal reflection coefficient of the window glass (according to Appendix A of the international standard ISO 10292 (1994)).

[0014] The concept of low-emissivity window glass is described in particular in the reference article in "Techniques De l'Ingénieur": "Vitrages à isolation thermique renforcée", C3635 (1999).

[0015] Generally, all the energy characteristics present in this specification are obtained according to the principles and methods described in the international standard ISO 10292 (1994) for determining the energy insulation characteristics of window glass used in building glass.

[0016] For the simplest cases, these coatings are generally deposited by deposition techniques of the CVD type, or currently most often by vacuum sputtering deposition techniques (commonly referred to as magnetron sputtering in the art), particularly when the coating consists of a stack of continuous layers with a complex thickness not exceeding a few nanometers or a few tens of nanometers.

[0017] Most commonly, the thin layer stack has solar control properties, mainly through the inherent properties of one or more active layers (referred to herein as functional layers). The "active" or "functional" layer is thus understood to mean a layer that has a significant effect on the solar radiation flux passing through the window glass. Such an active layer can operate mainly in a reflection mode of incident infrared radiation or mainly in an absorption mode of said infrared radiation in a known manner. Most commonly, these anti-sunlight layers act partly by reflection and partly by absorption, as explained previously.

[0018] In particular, the most effective stacks currently on the market include at least one metal functional layer of the silver type, which mainly acts by reflecting most of the incident IR (infrared) radiation. Its normal emissivity does not exceed a few percent. These stacks are thus mainly used as low-emissivity (or low-e in English) type window glasses for building insulation. However, these layers are sensitive to moisture and are therefore specifically used on the second or third side of double glazing to prevent moisture ingress. The stack according to the invention does not include such silver type layers, or gold or platinum type layers, or is present in a very negligible amount, particularly in the form of inevitable impurities.

[0019] Other metal layers with anti-sunlight functions have also been reported in the art, which include functional layers of the Nb, Ta or W type or nitride layers of these metals, as described, for example, in WO01 / 21540. In such layers, the solar radiation is this time mostly non-selectively absorbed by the one or more functional layers, i.e., the IR radiation (i.e., its wavelength is between approximately 780 nm - 2500 nm) and the visible radiation (its wavelength is between approximately 380 nm - 780 nm) are absorbed / reflected without distinction. In such window glasses, the normal emissivity ε n value is usually relatively high. A relatively low emissivity value can only be obtained when the functional layer is relatively thick, particularly at least 20 nm for niobium metal. Due to the non-selective absorption of this layer, the light transmittance coefficient of such window glasses is necessarily very low, generally less than 30%. Finally, considering these characteristics, it seems impossible to obtain such a solar control window glass from such a stack that combines a relatively low normal emissivity, usually less than 50%, particularly approximately 40% or even 35%, while maintaining a sufficiently high light transmittance, i.e., usually higher than 30%.

[0020] The optical characteristics, in particular the light transmittance, are measured according to the invention in accordance with the principles described in NF EN410 (2011).

[0021] In other publications, the use of a titanium nitride (TiN)-based material as a functional layer has been proposed, which also has low emissivity properties and is less susceptible to corrosion than a silver-based layer. In particular, DE102014114330, DE102013112990 or JPH05124839 may be mentioned. The object of the present invention relates to a solar control window glass comprising a stack containing such a layer, and more particularly aims to improve its performance, more particularly the combined performance of high light transmittance and low emissivity of such a window glass.

[0022] Accordingly, an object of the present invention is to provide a window glass comprising a layer stack that imparts to them the solar control properties as described above, while having a light transmittance T that is generally greater than 30%, preferably greater than or equal to 40%, or even greater than or equal to 50%. L , and a lower normal emissivity ε n , that is, less than 50%, even less than 45% or even less than 40%, and the stack is durable over time, especially when it is directly disposed on the surface of a window glass exposed to the interior or even the exterior of a building or a passenger compartment without any special precautions.

[0023] In the sense of the present invention, therefore, what is sought is a window glass having a maximum T L / ε n ratio, that is, its selectivity is improved; thus, a window glass in the meaning of the present invention allows most of the light in the visible light range to pass through, while reflecting most of the near-IR radiation after heat treatments such as quenching, bending, annealing, etc.

[0024] Accordingly, the present invention enables the obtaining of a sun protection window glass that can withstand heat treatments such as quenching, bending or more generally heat treatments at temperatures above 500 °C, which can in particular improve its optical and energy properties, particularly its selectivity.

[0025] The window glass according to the present invention also makes it possible to select the radiation passing through it by more precisely favoring the transmission of light waves, that is, light waves having a wavelength between approximately 380 - 780 nm, and by limiting the passage of infrared radiation having a wavelength greater than 780 nm.

[0026] According to the present invention, it is thus possible to maintain strong illumination in the room or passenger compartment protected by the window glass while minimizing the heat entering therein.

[0027] According to another aspect, the window glass according to the present invention also has heat insulation properties due to the low emissivity properties of the layers used, which makes it possible to limit the heat exchange between the interior and the exterior of a building.

[0028] According to another advantage of the invention, compared with other known window glasses having anti-sunlight properties, especially those window glasses comprising a silver-based stack, the window glass provided with the stack according to the invention is easy to produce.

[0029] In addition, they are also moisture-resistant, scratch-resistant and resistant to acid erosion. In particular, in the sense that their initial thermal insulation or solar insulation properties vary only very slightly under the chemical erosion they are subjected to during their intended use, the window glasses according to the invention have an improved lifespan.

[0030] Therefore, they can be advantageously used as simple window glasses (only one glass substrate), with the stack preferably facing the inner face of the building or the passenger compartment to be protected.

[0031] More particularly, the invention relates to a glass article having anti-sunlight properties, which comprises at least one glass substrate provided with a layer stack, wherein the stack comprises the following and preferably consists of the following: starting from the surface of the substrate in sequence:

[0032] - A first module M1, which consists of a layer based on a dielectric material having a thickness e1 or a layer assembly based on a dielectric material having a cumulative thickness e1, where e1 is from 1 to 100 nm,

[0033] - A layer TN1, which contains titanium nitride, preferably based on titanium nitride, or even consists essentially of titanium nitride, with a thickness of 2 to 80 nm, preferably 4 to 70 nm, more preferably 10 to 50 nm,

[0034] - A second module M2, which consists of a layer based on a dielectric material having a thickness e2 or a layer assembly based on a dielectric material having a cumulative thickness e2 ， where e2 is from 1 to 100 nm,

[0035] - An optional protective layer, which contains or is preferably based on titanium oxide, zirconium oxide or titanium-zirconium oxide.

[0036] According to the invention, the stack further comprises an intermediate layer, which contains and preferably consists essentially of or consists only of at least one element selected from silicon, aluminum, titanium or a mixture of at least two of these elements, and the intermediate layer is deposited between the layer TN1 and the first module M1 and / or between the layer TN1 and the second module M2, and the intermediate layer has a thickness of 0.2 nm - 6 nm, preferably 0.5 nm - 5 nm, more preferably 1 - 4 nm.

[0037] According to the preferred embodiments of the invention, these embodiments can of course be combined with each other if necessary:

[0038] - The element deposited to form the intermediate layer is substantially aluminum. According to this embodiment, a layer consisting essentially of aluminum or consisting only of aluminum is thus deposited between the layer TN1 and the first module M1 and / or the second module M2 to form the intermediate layer (in particular by magnetron-assisted cathodic sputtering of an aluminum target in an atmosphere of a neutral gas such as argon).

[0039] - The element deposited to form the intermediate layer is substantially silicon. According to this embodiment, a layer consisting essentially of silicon or consisting only of silicon is thus deposited between the layer TN1 and the first module M1 and / or the second module M2 to form the intermediate layer (in particular by magnetron-assisted cathodic sputtering of a silicon target in an atmosphere of a neutral gas such as argon).

[0040] - The element deposited to form the intermediate layer is substantially titanium. According to this embodiment, a layer consisting essentially or only of titanium is thus deposited between the layer TN1 and the first module M1 and / or the second module M2 to form the intermediate layer (in particular by magnetron-assisted cathodic sputtering of a titanium target in an atmosphere of a neutral gas such as argon). Preferably, titanium is deposited at least between the layer TN1 and the second module M2 to form the intermediate layer. According to another embodiment, a titanium layer is deposited between the layer TN1 and the first module M1 and a titanium layer is deposited between the layer TN1 and the second module M2 to form two intermediate layers on either side of the layer TN1.

[0041] - The element deposited to form the intermediate layer is a mixture of aluminum and silicon. According to this embodiment, a layer consisting essentially or only of aluminum and silicon is thus deposited between the layer TN1 and the first module M1 and / or the second module M2 to form the intermediate layer (in particular by magnetron-assisted cathodic sputtering of a silicon target in an atmosphere of a neutral gas such as argon). According to this embodiment, the Si / Al mass ratio can vary between 99 / 1 and 1 / 99. In particular, it can be between 97 / 3 and 75 / 25, especially between 95 / 5 and 80 / 20.

[0042] - The elements deposited to form the intermediate layer are silicon and titanium. According to this embodiment, a mixture consisting essentially of silicon and titanium is thus deposited between the layer TN1 and the first module M1 and / or the second module M2 to form the intermediate layer (in particular by magnetron-assisted cathodic sputtering of a target containing a mixture of silicon and titanium in an atmosphere of a neutral gas such as argon). According to this embodiment, the Si / Ti mass ratio can vary between 99 / 1 and 1 / 99. In particular, it can be 97 / 3 to 75 / 25, especially 95 / 5 to 80 / 20.

[0043] - The elements deposited to form the intermediate layer are aluminum and titanium. According to this embodiment, a mixture consisting essentially of aluminum and titanium is thus deposited between the layer TN1 and the first module M1 and / or the second module M2 to form the intermediate layer (in particular by magnetron-assisted cathodic sputtering of a target containing a mixture of aluminum and titanium in an atmosphere of a neutral gas such as argon). According to this embodiment, the Al / Ti mass ratio can vary between 99 / 1 and 1 / 99. In particular, it can be from 97 / 3 to 75 / 25, and in particular from 95 / 5 to 80 / 20.

[0044] - The dielectric material-based layers constituting the layer assembly having a cumulative thickness e 1 are deposited continuously and are in contact with each other.

[0045] - The dielectric material-based layers constituting the layer assembly having a cumulative thickness e 2 are deposited continuously and are in contact with each other.

[0046] - The layer TN1 and the one or more intermediate layers are in contact with each other.

[0047] - The module M1, the layer TN1, the module M2, and the one or more intermediate layers are deposited successively and are in contact with each other.

[0048] - The modules M1, M2 comprise and preferably are based on a material selected from silicon nitride, aluminum nitride, aluminum silicon nitride, tin oxide, a mixed oxide of zinc and tin, silicon oxide, titanium oxide, silicon oxynitride, aluminum oxynitride, or aluminum silicon oxynitride. More preferably, the one or more modules M1, M2 are based on a material selected from silicon nitride, aluminum silicon nitride, silicon oxynitride, or aluminum silicon oxynitride.

[0049] - The first module M1 comprises and preferably consists of a layer containing silicon nitride or aluminum silicon nitride, and the layer containing silicon nitride or aluminum silicon nitride preferably remains in contact with the intermediate layer.

[0050] - The second module M2 comprises and preferably consists of a layer containing silicon nitride or aluminum silicon nitride, and the layer containing silicon nitride or aluminum silicon nitride preferably remains in contact with the intermediate layer.

[0051] - At least one of M1 or M2 comprises or consists of a layer containing silicon oxynitride and / or aluminum oxynitride and preferably consists of it, and the layer containing silicon oxynitride and / or aluminum oxynitride preferably is in contact with the intermediate layer.

[0052] - The refractive index of the silicon oxynitride and / or aluminum oxynitride at 550 nm is between 1.60 and 1.99, preferably between 1.70 and 1.95. The index can be adjusted in particular according to the N / O ratio in the material.

[0053] - The stack comprises and preferably consists of the following layer sequence, starting from the substrate surface: a layer based on silicon nitride or silicon oxynitride (optionally also containing aluminium), an intermediate layer containing at least one element selected from silicon, aluminium, titanium or a mixture of at least two of these elements, the layer TN1, an optional second intermediate layer containing at least one element selected from silicon, aluminium, titanium or a mixture of at least two of these elements, a layer based on silicon nitride or silicon oxynitride (optionally also containing aluminium), and an optional protective layer, the protective layer being in particular selected from oxides of titanium, zirconium or a mixture of titanium and zirconium.

[0054] - The stack comprises and preferably consists of the following layer sequence, starting from the substrate surface: a layer based on silicon nitride or silicon oxynitride (optionally also containing aluminium), an optional further intermediate layer containing at least one element selected from silicon, aluminium, titanium or a mixture of at least two of these elements, the layer TN1, the intermediate layer containing at least one element selected from silicon, aluminium, titanium or a mixture of at least two of these elements, a layer based on silicon nitride or silicon oxynitride (optionally also containing aluminium), and an optional protective layer, the protective layer being in particular selected from oxides of titanium, zirconium or a mixture of titanium and zirconium.

[0055] - The stack comprises, starting from the substrate surface, the following layer sequence, each layer being in contact successively with the next layer:

[0056] SiN x or SiON / Al, Si or Ti or SiAl / TiN x / optionally Al, Si, Ti or SiAl / SiN x or SiON,

[0057] or

[0058] SiN x or SiON / optionally Al, Si or Ti or SiAl / TiN x / Al, Si, Ti or SiAl / SiN x or SiON,

[0059] where

[0060] - SiN x is a layer containing or based on silicon nitride,

[0061] - SiON is a layer containing or based on silicon oxynitride,

[0062] - Al, Si or AlSi are layers obtained by depositing aluminium, silicon or a mixture of aluminium and silicon respectively,

[0063] - TiNx is a layer TN1 that contains or is based on titanium nitride.

[0064] - The stack includes a plurality of layers TN1, TN2,... containing titanium nitride, in particular two layers containing titanium nitride (TN1 and TN2), and each layer containing titanium nitride is separated from the next layer in the stack by: a layer based on a dielectric material or a layer assembly of a layer based on a dielectric material and an optional intermediate layer composed of an element containing at least one selected from silicon, aluminum, titanium, and mixtures thereof.

[0065] - The stack does not contain any layer based on silver, platinum, gold, or copper.

[0066] - The glass substrate is made of translucent glass. Without departing from the scope of the present invention, the stack can also be deposited on a substrate made of glass, which is colored or tinted in its body. The expression "colored in its body" is understood to mean that the substrate contains elements in its glass composition intended to give it a color (i.e., different from those of so-called "transparent" glass), in particular elements such as cobalt, iron, selenium, or chromium, which may also be used to reduce its light transmittance.

[0067] - The glass substrate provided with the stack is heat-treated after the deposition of the stack, in particular by quenching, annealing, or bending.

[0068] The thickness of the first module M1 e 1 is between 1 nm and 100 nm, including the endpoints, in particular between 10 nm and 70 nm, including the endpoints.

[0069] The thickness of the second module M2 e 2 is between 5 nm and 100 nm, including the endpoints, in particular between 20 nm and 70 nm, including the endpoints.

[0070] - The glass article includes two glass substrates assembled by a thermoplastic sheet, in particular a polyvinyl butyral PVB sheet, and at least one of the substrates is provided with the layer stack, and the stack is preferably arranged on the face of the substrate facing the inside of the window glass or in contact with the thermoplastic sheet.

[0071] Preferably, the functional layer according to the present invention is based on titanium nitride or preferably consists essentially of titanium nitride.

[0072] The layer based on titanium nitride (or other material) includes, for example, at least 50% by weight of titanium nitride (or the other material), or more than 60% by weight of titanium nitride (or the other material), or even more than 80% by weight of titanium nitride (or the other material), or even more than 90% by weight of titanium nitride (or the other material).

[0073] The titanium nitride according to the present invention does not necessarily have to be stoichiometric (Ti / N atomic ratio of 1), but can be superstoichiometric or substoichiometric. According to an advantageous embodiment, the N / Ti ratio is between 1 and 1.2. In addition, the titanium nitride according to the present invention may contain a small amount of oxygen, for example 1 - 10 mol% of oxygen, particularly 1 - 5 mol% of oxygen.

[0074] According to a particularly preferred embodiment, the titanium nitride layer according to the present invention corresponds to the general formula TiN x O y , where 1.00 < x < 1.20 and where 0.01 < y < 0.10.

[0075] However, the dielectric material, once deposited in the form of a thin layer, may contain additional elements that significantly increase its electrical conductivity and can be used, for example, to improve the cathode sputtering efficiency of the precursor material constituting the magnetron target. The dielectric layers of the modules M1, M2 according to the present invention can be layers based on materials selected from silicon nitride, aluminum nitride, tin oxide, mixed oxides of zinc or tin, silicon oxide, titanium oxide, and silicon oxynitride. Preferably, the modules M1 and M2 are composed of a single layer and this layer is based on silicon nitride. Materials based on silicon nitride, tin oxide, mixed oxides of zinc and tin, silicon oxide, titanium oxide, or silicon oxynitride are, for example, materials that mainly and preferably consist essentially of such compounds but may also contain other minor elements, particularly as substitutes for cations, for example in order to enable their deposition in the form of a thin layer by promoting the conventional magnetron sputtering techniques as described above. For example, the silicon nitride layer or silicon oxynitride layer or silicon oxide layer according to the present invention, particularly a layer deposited by magnetron, most commonly contains elements of the type Al, Zr, B, etc., in a proportion of, for example, up to 10 atomic% and even sometimes up to 20 atomic%, based on the silicon content of the layer. Similarly, the titanium oxide layer may contain other minor metal cations, such as zirconium as a substitute for titanium, without departing from the scope of the present invention.

[0076] The window glass according to the present invention can be a simple window glass, where by numbering the faces of the substrate from the outside to the inside of the building or passenger compartment in which it is installed, the thin layer stack is preferably arranged on face 2 of the simple window glass.

[0077] The intermediate layer according to the present invention deposited from a metal target composed of Ti, Si, Al, or a mixture of at least two of these elements may include nitrogen, and even oxygen, even before any heat treatment.

[0078] Thus, SIMS (Secondary Ion Mass Spectrometry) analysis has shown that such heteroatoms are contained in small amounts in the layer, even when there is no nitrogen or oxidizing gas during their deposition by sputtering, especially in an atmosphere of 100% argon, but the exact amount in the layer in question cannot be determined by currently available techniques. This is also true for the glass articles according to the invention.

[0079] According to another embodiment, the window glass according to the invention can be a laminated window glass, which comprises two glass substrates assembled by a thermoplastic sheet, in particular a polyvinyl butyral or PVB sheet, and the window glass is provided with a layer stack as described above. Preferably, the stack is deposited on the face of the substrate facing the inside of the laminated structure, in particular on face 2 of the window glass, and more preferably it is in contact with the thermoplastic sheet. Alternatively, it can be deposited on the inner face of the laminated window glass, i.e., on face 4 of the window glass, and these faces are generally numbered from 1 to 4 from the outside to the inside of the window glass.

[0080] Of course, the above-mentioned substrate can be thermally quenched and / or bent after the deposition of the stack according to the invention.

[0081] The method for producing an article according to the invention includes, for example, at least the following steps:

[0082] - Introducing a glass substrate into a cathodic sputtering device,

[0083] - Depositing at least one lower dielectric material layer in one or more first compartments,

[0084] - In another compartment, sputtering a titanium target by a plasma generated from a nitrogen-containing gas (preferably mixed with a noble gas such as argon) under conditions for obtaining a titanium nitride layer,

[0085] - Depositing at least one upper dielectric material layer in one or more additional compartments.

[0086] According to the invention, in a compartment comprising a target composed of aluminum, silicon, titanium or at least two of these elements, in particular a mixture of silicon and aluminum, which compartment is immediately before and / or after the compartment equipped with a titanium target, a thin layer of 1 to 6 nm of aluminum, silicon, titanium or at least two of these elements, in particular a mixture of silicon and aluminum, is deposited by sputtering the target material in the presence of a neutral gas, such as only argon.

[0087] The term "upper layer" in this specification refers to the respective position of the layer relative to one or more functional layers in the stack, which stack is supported by a glass substrate. In particular, the upper layer is the outermost layer of the stack, facing away from the substrate.

[0088] Within the meaning of the present invention, the "thickness of a layer" is understood to mean the actual geometric thickness of the layer, which can in particular be measured by means of conventional electron microscopy or other techniques.

[0089] The present invention and its advantages are described in more detail below by means of the following non-limiting examples according to the present invention. In all examples and in the description, unless otherwise stated, the thicknesses given are geometric thicknesses.

[0090] The properties and advantages of the window glass according to the present invention are illustrated by the following examples:

[0091] In a manner known per se, in the following examples, the different successive layers are deposited in successive dedicated compartments of a cathodic sputtering device, each compartment being provided with a specific metal target made of Si, Ti, Al, Al - Si, which are chosen for depositing the specific layers of the stack, and being fed with a specific gas composition having the desired composition for each layer.

[0092] More precisely, the silicon nitride - based layer is deposited in a compartment of the device from a silicon metal target (containing 8 wt% of aluminium) in a reactive atmosphere containing argon and nitrogen according to a known technique. The silicon nitride layer thus also contains aluminium.

[0093] The silicon oxynitride - based layer is deposited in a compartment of the device from a silicon metal target (containing 8 wt% of aluminium) in a reactive atmosphere containing argon, nitrogen and oxygen. The respective flow rates of the gases introduced into the compartment are 20 sccm (standard cubic centimetres per minute) of Ar, 5 sccm of O2 and 100 sccm of N2. The refractive index measured at 550 nm for this material is 1.88.

[0094] The titanium nitride layer is deposited in another compartment of the device from a pure titanium metal target in a reactive atmosphere containing nitrogen and argon.

[0095] The aluminium layer or the aluminium - silicon alloy layer is deposited by sputtering a target having the same composition in a neutral argon atmosphere.

[0096] The titanium layer is deposited from a pure titanium metal target in a neutral argon atmosphere.

[0097] The deposition conditions of such layers by means of a magnetron, in particular the conditions for obtaining the desired thickness of each layer of the stack, are technically well - known in the art.

[0098] Example 1:

[0099] According to Example 1, preferably, the glass substrate is coated successively with a stack comprising a lower layer (layer M1) based on silicon nitride (referred to as Si3N4 hereinafter for the sake of convenience, even if the actual stoichiometry of the layer is not necessarily Si3N4), a functional layer based on titanium nitride, and an upper layer (layer M2) also based on silicon nitride (referred to as Si3N4 hereinafter for the sake of convenience, even if the actual stoichiometry of the layer is not necessarily Si3N4).

[0100] Examples 2 and 3:

[0101] According to Examples 2 and 3 of the present invention, an intermediate layer of aluminum (Example 2) or a silicon-aluminum alloy layer containing 8 wt% aluminum (Example 3) is deposited above the titanium nitride layer (i.e., between the TiN layer and the Si3N4 upper layer) in the stack of Reference Example 1.

[0102] Example 4:

[0103] According to Example 4 of the present invention, a two-nanometer titanium metal intermediate layer is deposited between the TiN layer and the Si3N4 lower layer in the stack of Reference Example 1.

[0104] Example 5:

[0105] According to Example 5 of the present invention, a one-nanometer titanium metal intermediate layer is deposited between the TiN layer and the Si3N4 upper layer, and another one-nanometer titanium metal layer is inserted between the TiN layer and the Si3N4 lower layer.

[0106] Example 6:

[0107] According to Comparative Example 6, a nickel-chromium intermediate layer (80 wt% nickel, 20 wt% chromium) is deposited between the TiN layer and the Si3N4 upper layer in the stack of Reference Example 1.

[0108] Example 7:

[0109] According to Comparative Example 7, a 2-nm-thick niobium nitride intermediate layer is inserted between the TiN layer and the Si3N4 upper layer in the stack of Reference Example 1.

[0110] Example 8:

[0111] In this example, the silicon nitride upper layer constituting module M2 in Example 2 is replaced with a silicon oxynitride layer having a refractive index of 1.88 at 550 nm.

[0112] All substrates are made of 4-mm-thick transparent Planiclear® glass sold by Saint-Gobain Glass France. All layers are deposited in a known manner by magnetic field-assisted anion sputtering (commonly referred to as magnetron sputtering).

[0113] The deposition conditions were adjusted according to conventional techniques for magnetron deposition to obtain different stacks. The layer sequences and the thicknesses of the layers (in nanometers, nm) of the stacks are reported in Table 1 below:

[0114] Table 1

[0115] <![CDATA[Si3N4(M1)]]> CI* <![CDATA[TiN(TN1)]]> CI* <![CDATA[Si3N4(M2)]]> CI sediment material type Example 1 (reference) 30 - 20 - 30 - Example 2 (invention) 30 - 20 2 30 Al Example 3 (invention) 30 - 20 2 30 Si-Al Example 4 (invention) 30 2 20 - 30 Ti Example 5 (invention) 30 1 20 1 30 Ti Example 6 (comparison) 30 - 20 2 30 NiCr Example 7 (comparison) 30 - 20 2 30 NbN Example 8 (invention) 30 - 20 3 30** Al

[0116] *CI: Intermediate layer

[0117] **Silicon oxynitride SiON with a refractive index of 1.88 at 550 nm.

[0118] All the window glasses thus obtained according to Examples 1 to 8 were then heat-treated at 650 °C for 10 minutes.

[0119] A - Measuring the properties of the window glasses

[0120] The thermal and optical properties of the window glasses before and after quenching were measured according to the following principles and criteria:

[0121] 1°) Optical properties:

[0122] The measurement was carried out according to the above-mentioned standard NF EN410 (2011). More precisely, the light transmittance T L was measured according to D 65 for a light source between 380 - 780 nm.

[0123] 2°) Thermal properties:

[0124] The normal emissivity ε n was measured according to the above-mentioned standard ISO 10292.

[0125] B - Results

[0126] The results obtained for the monolithic window glasses according to the above-mentioned examples are summarized in Table 2 below:

[0127] Table 2

[0128] Example <![CDATA[After quenching, T L ]]> <![CDATA[After quenching, ε n ]]> <![CDATA[T after quenching L / ε n ]]> 1 (reference) 54.1 40.6 1.33 2 (invention) 54.5 37.9 1.44 3 (invention) 55.5 38.0 1.46 4 (invention) 52.7 34.8 1.51 5 (invention) 50.7 32.6 1.56 6 (comparison) 48.5 35.8 1.35 7 (comparison) 52.5 49 1.07 8 (invention) 53.5 34.9 1.53

[0129] Examples 2 and 3 are examples according to the present invention. For these two examples, after quenching, a light transmittance of approximately 55% was observed, which is surprisingly higher than that of the same stack without the aluminum intermediate layer or the Si - Al alloy intermediate layer according to the present invention. According to an advantageous feature, the emissivity at normal incidence was also significantly reduced compared to reference Example 1.

[0130] Examples 4 and 5 according to the present invention showed a slight decrease in light transmittance, but the emissivity was also significantly reduced compared to the reference stack.

[0131] Finally, the use of the intermediate layer in the stack according to the invention makes it possible to obtain a light transmittance equal to or substantially equivalent to that of the reference stack, while improving the thermal properties of the window glass.

[0132] Finally, it was observed that the selectivity of the window glass measured by the T L / ε n ratio is significantly improved for the window glass according to the invention, especially after quenching.

[0133] The comparative window glass according to Example 6, including an intermediate layer made of NiCr alloy, has a significantly reduced light transmittance compared to the reference example and the examples according to the invention, and finally has a selectivity substantially equal to that of the reference window glass.

[0134] The comparative window glass according to Example 7, including a NbN intermediate layer, has a reduced selectivity compared to the reference example.

[0135] The window glass according to Example 8, in which a silicon (and aluminum) oxynitride layer in contact with the intermediate layer is used, also has an improved selectivity compared to the reference example.

[0136] If the T L / ε n selectivity of the window glasses according to Examples 1 to 8 as reported in Table 2 is considered, it can finally be seen that the window glasses according to the invention have the best selectivity after undergoing heat treatment.

[0137] According to other supplementary examples, an attempt was made to determine what thickness of aluminum for constituting the intermediate layer is optimal for selectivity by changing the thickness in the stack described in Example 2 above. The results obtained are summarized in Table 3 below:

[0138] Table 3

[0139] Example Al layer thickness (nm) <![CDATA[After quenching, T L ]]> <![CDATA[After quenching, ε n ]]> <![CDATA[T after quenching L / ε n ]]> 1 (reference) 0 54.1 40.6 1.33 2 2 54.5 37.9 1.44 2a 1 54.7 40.1 1.44 2b 3 54.9 34.1 1.61 2c 4 52.9 32.8 1.61 2d 5 51.3 32.9 1.56

[0140] Analysis of the data reported in Table 3 shows that when the thickness of the aluminum intermediate layer is between 2 - 4 nm, the best results and a compromise are obtained.

Claims

1. A glass article having anti-sunlight properties and comprising at least one glass substrate, the glass substrate being provided with a layer stack, wherein the stack successively comprises, starting from the surface of the substrate: - A first module M1, which consists of a dielectric material-based layer having a thickness e1 or a dielectric material-based layer assembly having an accumulated thickness e1, the thickness e1 being 1 - 100 nm, - A layer TN1, which contains titanium nitride and has a thickness of 2 - 80 nm, - A second module M2, which consists of a dielectric material-based layer having a thickness e2 or a dielectric material-based layer assembly having an accumulated thickness e2, the thickness being 5 - 100 nm, And wherein an intermediate layer is deposited between the layer TN1 and the first module M1 and / or between the layer TN1 and the second module M2, the intermediate layer containing at least one element selected from silicon, aluminum, titanium or a mixture of at least two of these elements, the one or more intermediate layers having a thickness of 0.2 nm - 6 nm, Wherein the stack does not contain a layer based on silver, platinum or gold.

2. The glass article according to claim 1, wherein the element deposited to form the one or more intermediate layers is aluminum.

3. The glass article according to claim 1, wherein the element deposited to form the one or more intermediate layers is silicon.

4. The glass article according to claim 1, wherein the element deposited to form the one or more intermediate layers is silicon and aluminum.

5. The glass article according to claim 1, wherein the element deposited to form the one or more intermediate layers is titanium.

6. The glass article according to any one of the preceding claims 1 to 5, wherein the modules M1, M2 contain materials selected from silicon nitride, aluminum nitride, aluminum silicon nitride, tin oxide, a mixed oxide of zinc and tin, silicon oxide, titanium oxide and silicon oxynitride.

7. The glass article according to any one of the preceding claims 1 to 5, wherein the first module M1 includes a layer containing silicon nitride or aluminum silicon nitride, and the layer containing silicon nitride or aluminum silicon nitride is in contact with the intermediate layer.

8. The glass article according to any one of the preceding claims 1 to 5, wherein the second module M2 includes a layer containing silicon nitride or aluminum silicon nitride, and the layer containing silicon nitride or aluminum silicon nitride is in contact with the intermediate layer.

9. The glass article according to any one of the preceding claims 1 to 5, wherein at least one of the modules M1 or M2 includes a layer containing silicon oxynitride and / or aluminum oxynitride and the silicon oxynitride and / or aluminum oxynitride layer is in contact with the intermediate layer.

10. The glass article according to any one of the preceding claims 1 to 5, wherein the stack includes the following layer sequence, starting from the substrate surface: a layer based on silicon nitride or silicon oxynitride, the intermediate layer including at least one element selected from silicon, aluminum, titanium or a mixture of at least two of these elements, the layer TN1, an optional second intermediate layer containing at least one element selected from silicon, aluminum, titanium or a mixture of at least two of these elements, a layer based on silicon nitride or silicon oxynitride, and an optional protective layer.

11. The glass article according to any one of claims 1 to 5, wherein the stack comprises the following layer sequence, starting from the substrate surface: a layer based on silicon nitride or silicon oxynitride, titanium, or a mixture of at least two of these elements, an optional further intermediate layer comprising at least one element selected from silicon, aluminium, titanium or a mixture of at least two of these elements, the layer TN1, the intermediate layer comprising at least one element selected from silicon, aluminium, a layer based on silicon nitride or a layer based on silicon oxynitride, and an optional protective layer.

12. The glass article according to any one of the preceding claims 1 to 5, wherein the stack comprises a plurality of layers containing titanium nitride, each layer containing titanium nitride being separated from another layer containing titanium nitride in the stack by a layer based on a dielectric material or by a combination of a layer based on a dielectric material and an optional intermediate layer containing at least one element selected from silicon and / or aluminium.

13. The glass article according to any one of the preceding claims 1 to 5, wherein the glass substrate is made of transparent glass.

14. The glass article according to any one of the preceding claims 1 to 5, wherein one or more of the glass substrates provided with the stack are quenched or bent.

15. The glass article according to any one of the preceding claims 1 to 5, wherein module M1, layer TN1, module M2 and the one or more intermediate layers are deposited continuously and are in contact with each other.

16. The glass article according to claim 1, wherein the thickness e1 is 5 - 80 nm.

17. The glass article according to claim 1, wherein the thickness e1 is 10 nm - 70 nm.

18. The glass article according to claim 1, wherein the layer TN l is based on titanium nitride.

19. The glass article according to claim 1, wherein the layer TN1 has a thickness of 4 - 70 nm.

20. The glass article according to claim 1, wherein the layer TN1 has a thickness of 10 - 50 nm.

21. The glass article according to claim 1, wherein the thickness e2 is 20 - 70 nm.

22. The glass article according to claim 1, wherein the one or more intermediate layers have a thickness of 0.5 nm - 5 nm.

23. The glass article according to claim 1, wherein the one or more intermediate layers have a thickness of 1 - 4 nm.