Transparent substrate provided with a functional stack of thin layers

Abstract

Transparent substrate (10) provided with a functional stack (14) of thin layers on at least one of its faces (11), said functional stack (14) comprising, starting from the substrate (10), three metallic functional layers (140, 180, 220) placed between two thin-layer dielectric modules (120, 160, 200, 240), wherein at least one Zr-based nitride-hardened absorbent layer (120a, 240a) is located in the first dielectric module (120) and / or in the last dielectric module (240).

Description

Description TRANSPARENT SUBSTRATE WITH A FUNCTIONAL STACK OF THIN LAYERS Technical field

[0001] The invention relates to a transparent glass substrate provided with a functional stack of thin layers with several metallic functional layers. Technical background

[0002] Functional stacks of thin layers are commonly used to provide thermal insulation and / or solar protection functions to glazing. These glazings can be used in buildings or vehicles. Their primary benefit is that they reduce air conditioning efforts by preventing excessive overheating (so-called "solar control" glazing) and / or by reducing the amount of energy dissipated to the outside (so-called "low-emissivity" glazing).

[0003] A particularly used type of functional stack of thin layers comprises a metallic functional layer, in particular based on silver, allowing the reflection of part of the electromagnetic radiation, in particular infrared radiation.

[0004] The metallic functional layer is generally arranged between two dielectric assemblies, also called dielectric modules, in order to neutralize the optical effects of reflection and refraction in the visible range. These dielectric modules may comprise one or more thin dielectric layers of the nitride type, for example silicon or aluminum nitride, and / or of the oxide type, for example silicon, zinc, tin oxide.

[0005] Solar control features are required for glazing that is likely to be exposed to high levels of sunlight. The ability of a glazing to limit the amount of light energy transmitted is defined by the solar factor, g, which is the ratio of the total energy transmitted through the glazed surface or glazing to the interior to the incident solar energy. The lower the value of the solar factor, g, the better the protection against solar radiation.

[0006] For certain applications, for example in the building and construction markets, it is desirable for glazing incorporating a substrate carrying a functional stack to have a low visible light transmission, TL, of the order of 50%, in order to ensure adequate natural illumination of the interior space.

[0007] A functional stack is considered suitable for such applications when it meets a triple requirement: adequate light transmission, a low solar factor value and a high selectivity value. A functional stack is therefore suitable when it has a high selectivity value, s, defined as the ratio of light transmission to solar factor, and a low solar factor, for a given light transmission.

[0008] International patent application No. WO 2020 / 089545 describes “solar control” functional stacks comprising three metallic functional layers. Table 3 of this document shows that a selectivity of at least 1.8 is targeted, for a light transmission of around 50% when the substrate coated with the stack is integrated on face number two of a double glazing unit. The examples achieve a selectivity of around 1.8 or 1.9, but always less than 2.0.

[0009] International patent application No. WO 2020 / 079373 also describes “solar control” functional stacks comprising three metallic functional layers.

[0010] In both of these patent applications, a layer of silicon zirconium nitride is used in certain dielectric module(s). This layer is presented as being dielectric and, due to its "dielectric" nature, it is not an absorbent layer.

[0011] Usually, by "dielectric layer" it is meant that from the point of view of its nature, the material is "non-metallic", i.e. it is not a metal. Usually, this term "dielectric" means a material having an n / k ratio at the usual value of wavelength in the visible of 550 nm which is equal to or greater than 5.0.

[0012] Usually, by "absorbent layer" it is meant that the material constituting an absorbent layer is a material having a n / k ratio to the usual value of wavelength in the visible of 550 nm which is between 0.0 and 5.0 excluding these values ​​and excluding that this material constituting the absorbing layer considered is based on silver (because the layer considered cannot be a metallic functional layer in the usual sense).

[0013] It is recalled that n denotes the real refractive index of the material at a given wavelength and k represents the imaginary part of the refractive index at a given wavelength; the ratio n / k is calculated here at the given wavelength identical for n and for k of 550 nm.

[0014] International patent application No. WO 2014 / 125083 describes in particular in its table 2 “solar control” functional stacks comprising two metallic functional layers and an absorbent layer in the first dielectric module. The aim pursued in this document is to obtain good stability to heat treatment of the quenching and / or bending type because the data in table 7 of this document are variations in heat treatment and data after heat treatment. Table 8 of this document presents solar factor, energy absorption and selectivity data after integration in double glazing, but, strangely, not for examples 9 and 10 which include a ZrN layer in the first dielectric module.

[0015] Tests were carried out to try to estimate what the insertion of an 11 nm layer of ZrN could bring in the first dielectric module of a two-layer silver stack in accordance with the teaching of these two examples.

[0016] An example E9c was made, with the aim of achieving a monolithic light transmission similar to that of example 9 of this document, i.e., approximately 65%. Even though this example 9 of this document underwent a toughening heat treatment, as this document argues that toughening heat treatment changes the properties little, example E9c, which is presented below, aims at a monolithic light transmission of approximately 65% ​​without heat treatment. Then, an example E9c' was made by introducing 11 nm of ZrN into the first dielectric module and seeking to optimize all the other layers to achieve comparable optical data. The table below summarizes the deposited layers, starting from the substrate (the deposition conditions of these layers are the same as those of the examples presented below in the detailed description of this document):

[0017] It was found that the introduction of 11 nm of ZrN in the first dielectric module has no significant effect on the solar factor and on the selectivity (the conditions for measuring the properties in double glazing just below are the same as those of the examples presented below in the detailed description of this document):

[0018] It was thus found that the insertion of a ZrN absorbing layer in the first dielectric module of a stack with two silver functional layers had almost no influence on the solar factor, g, and even caused a degradation of the selectivity, s.

[0019] Furthermore, the transmission color according to a* is too high for both examples (a*T < -4.0) and the transmission color according to b* of example E9c' is too high and positive (towards yellow), whereas a negative (towards blue) and low value is expected (similar to that of example E9c).

[0020] In monolithic, the light transmission of example E9c is 66% and that of example E9c' is 64%. Summary of the invention Technical problem

[0021] State-of-the-art solutions consisting of using only infrared radiation-absorbing layers as functional layers in the functional stack are not suitable because they have too low a light transmission or too low a selectivity, incompatible for example with applications in the residential market.

[0022] There therefore remains a need for a functional stack suitable for “solar control” applications in a residential market, i.e. presenting a very high selectivity, of at least 2.20 and suitable overall energy performance, in particular concerning a very high neutrality of colors in transmission (in particular a*T > -4.0).

[0023] There also remains a need for the substrate coated with a functional stack to be able to undergo a heat treatment aimed at modifying the properties of the substrate (bending, quenching), without modifying the optical and thermal properties of the stack (so-called "quenchable" stack); or for the substrate coated with a functional stack to be able to undergo a heat treatment aimed at modifying the properties of the substrate (bending, quenching), and with the aim of achieving the optical and thermal properties of the stack (so-called “quenching” stack). Solution to the technical problem

[0024] According to a first aspect of the invention, a glass substrate is provided, provided with a functional stack of thin layers on at least one of its faces, said functional stack comprising, starting from the substrate, at least three metallic functional layers, preferably each based on silver, each located between two dielectric modules of thin layers and forming a succession comprising a first dielectric module, a first metallic functional layer, a second dielectric module, a second metallic functional layer, a third dielectric module, a third metallic functional layer and a last dielectric module, and in which at least one nitrided absorbent layer based on Zr is located in said first dielectric module and / or in said last dielectric module,and preferably no Zr-based nitrided absorbing layer is located in a dielectric module itself located between two metallic functional layers in said functional stack.,

[0025] An absorbing layer, by nature, is not a dielectric layer; moreover, generally, if a coating or dielectric module of a complete stack comprises an absorbing layer for which the refractive index at 550 nm includes an imaginary part of the non-zero (or non-negligible) dielectric function, for example a metallic layer, the thickness of this layer is not taken into account for the calculation of the optical thickness of this dielectric module.

[0026] Said functional stack may comprise a single Zr-based nitrided absorbing layer which is located in said first dielectric module or in said last dielectric module. Said functional stack may comprise only two Zr-based nitrided absorbing layers which are located, one in said first dielectric module and the other in said last dielectric module.

[0027] The selectivity is slightly higher when a Zr-based nitrided absorber is located in the latter dielectric module.

[0028] Preferably, no absorbing layer, whether metallic or nitrided, is located in a dielectric module itself located between two metallic functional layers in said stack in order to maintain adequate light transmission.

[0029] Said stack may comprise only three metal functional layers, preferably each based on silver. Even if a stack configuration with several metal functional layers is more complex to design and costs more than a stack configuration with a single metal functional layer, these disadvantages are offset by the surprising effects obtained, in particular such high selectivity and such low solar factor.

[0030] Depending on the configurations, said nitrided absorbent layer based on Zr may comprise at least 60% of Zr in atomic proportion of the reactive elements, or even at least 80% of Zr in atomic proportion of the reactive elements, or even 100% of Zr in atomic proportion of the reactive elements; or - said nitrided absorbent layer based on Zr may comprise at least 60% of Zr in atomic proportion of the reactive elements, or even at least 80% of Zr in atomic proportion of the reactive elements, or even are 100% of Zr in atomic proportion of the reactive elements; or - each nitrided absorbent layer based on Zr may comprise at least 60% of Zr in atomic proportion of the reactive elements, or even at least 80% of Zr in atomic proportion of the reactive elements, or even 100% of Zr in atomic proportion of the reactive elements.

[0031] Depending on the configurations, said nitrided absorbent layer based on Zr may comprise between 60% and 100% of Zr in atomic proportion of the reactive elements, or even between 80% and 100% of Zr in atomic proportion of the reactive elements, or even is 100% of Zr in atomic proportion of the reactive elements; or - said nitrided absorbent layer based on Zr may comprise between 60% and 100% of Zr in atomic proportion of the reactive elements, or even between 80% and 100% of Zr in atomic proportion of the reactive elements, or even are 100% of Zr in atomic proportion of the reactive elements; or - each nitrided absorbent layer based on Zr may comprise between 60% and 100% of Zr in atomic proportion of the reactive elements, or even between 80% and 100% of Zr in atomic proportion of the reactive elements, or even is 100% of Zr in atomic proportion of the reactive elements.

[0032] Reactive elements are the elements that make up the layer and that react with nitrogen to form the nitrided absorbing layer.

[0033] Said Zr-based nitrided absorbent layer(s) preferably does not contain oxygen because this element reduces the absorption capacity.

[0034] Depending on the configurations, to provide adequate absorption capacity, said Zr-based nitrided absorbing layer may have an optical extinction coefficient, k, decreasing with increasing wavelength over the range of 350 to 600 nm, starting from a value greater than 0.5 at the wavelength of 350 nm; or - said Zr-based nitrided absorbing layer may have an optical extinction coefficient, k, decreasing with increasing wavelength over the range of 350 to 600 nm, starting from a value greater than 0.5 at the wavelength of 350 nm; or - each Zr-based nitrided absorbing layer may have an optical extinction coefficient, k, decreasing with increasing wavelength over the range 350 to 600 nm, starting from a value greater than 0.5 at the wavelength of 350 nm.

[0035] Depending on the configurations, said Zr-based nitrided absorbing layer may have a physical thickness which is between 0.5 nm and 25.0 nm, in particular between 2.0 nm and 15.0 nm, preferably between 3.0 nm and 10.0 nm; or - said Zr-based nitrided absorbent layer may have a physical thickness which is between 0.5 nm and 25.0 nm, in particular between 2.0 nm and 15.0 nm, preferably between 3.0 nm and 10.0 nm; or - each Zr-based nitrided absorbent layer may have a physical thickness which is between 0.5 nm and 25.0 nm, in particularly between 2.0 nm and 15.0 nm, preferably between 3.0 nm and 10.0 nm.

[0036] In particular, said Zr-based nitrided absorbing layer located in said first dielectric module may have a physical thickness which is between 0.5 nm and 25.0 nm, in particular between 2.0 nm and 15.0 nm, preferably between 3.0 nm and 10.0 nm.

[0037] In particular, said Zr-based nitrided absorbing layer, when located in said first dielectric module and made of ZrN, may have a physical thickness which is between 0.5 nm and 10.0 nm, in particular between 2.0 nm and 10.0 nm, preferably between 3.0 nm and 10.0 nm. A relatively low thickness of Zr-based nitrided absorbing layer in said first dielectric module contributes to obtaining favorable transmission colors (in particular -4.0 < a*T < 0.0; or even further 0.0 < b*T < +4.0).

[0038] In particular, said Zr-based nitrided absorbing layer located in said last dielectric module may have a physical thickness which is between 0.5 nm and 25.0 nm, in particular between 2.0 nm and 15.0 nm, preferably between 3.0 nm and 10.0 nm.

[0039] Depending on the configurations, in order to have an adequate absorption capacity, said Zr-based nitrided absorbing layer may have a relatively high optical extinction coefficient, k, at the wavelength of 500 nm, of 0.35.

[0040] In a particular variant, only said first dielectric module comprises a NiCr-based metallic absorbing layer, preferably having a physical thickness of between 0.5 and 5.0 nm and in which no other dielectric module comprises a NiCr-based metallic absorbing layer. This NiCr-based metallic absorbing layer is preferably located, in contact, between two nitrided dielectric layers, preferably between two silicon-based nitrided dielectric layers. Preferably, the other dielectric modules of the functional stack do not comprise a metallic absorbing layer.

[0041] In a particular variant, at least one nitrided dielectric layer based on SiZr is located in said first dielectric module and / or in said last dielectric module and preferably only in said first dielectric module and / or in said last dielectric module for the entire functional stack.

[0042] Said functional stack of layers preferably further comprises at least one blocking overlayer, preferably based on a nickel and chromium alloy, located above and in contact with a metallic functional layer and / or at least one metallic blocking underlayer, preferably based on a nickel and chromium alloy, located below and in contact with a metallic functional layer.

[0043] Said functional stack of layers may comprise at least one blocking overlayer located above and in contact with a metallic functional layer based on titanium oxide TiOx; Said functional stack of layers may in particular comprise a blocking overlayer based on titanium oxide TiOx located above and in contact with the last metallic functional layer starting from the substrate.

[0044] Said functional stack of layers may comprise at least one blocking overlayer, preferably based on a nickel and chromium alloy, located above and in contact with each metallic functional layer and / or at least one blocking metallic underlayer, preferably based on a nickel and chromium alloy, located below and in contact with each metallic functional layer.

[0045] A nitrided dielectric layer, preferably based on Si, may be located on said Zr-based nitrided absorbing layer, in contact with it. This nitrided dielectric layer then protects said Zr-based nitrided absorbing layer.

[0046] A nitrided dielectric layer, preferably based on Si, may be located under said Zr-based nitrided absorbing layer, in contact with it. This nitrided dielectric layer then protects said Zr-based nitrided absorbing layer.

[0047] Said nitrided absorbent layer based on Zr may be in contact on each of its two faces with a nitrided dielectric layer, preferably based on Si.

[0048] The functional stack of layers may comprise a dielectric layer with a refractive index greater than 2.15 at 550 nm, said layer being comprised in the first dielectric module and / or in the last dielectric module.

[0049] According to a second aspect of the invention, there is provided a glazing comprising a transparent substrate according to the first aspect of the invention.

[0050] This glazing comprises at least two transparent substrates, one of the substrates being according to the first aspect of the invention and being arranged so that the functional stack of layers is located on face two and / or face three of said glazing. It may be double glazing. Alternatively, it may be triple glazing. Advantages of the invention

[0051] A first advantage of the invention is that it provides a suitable "solar control" functional stack, particularly for applications in the building and construction markets. The functional stack satisfies the triple requirement of adequate light transmission, a low solar factor value and high selectivity.

[0052] The presence of a nitrided absorbent layer based on Zr in said first dielectric module and / or in said last dielectric module makes it possible to increase the quantity of metal in at least one of the three functional layers (by thickening it) and thus to reduce the solar factor, while retaining adequate optical properties.

[0053] It is possible to achieve a selectivity of at least 2,200 with double glazing incorporating a stack according to the invention having an adequate light transmission, between 45.0% and 54.9%, or even between 47.0% and 52.9% and comprising only three metallic functional layers and at least one nitrided absorbent layer based on Zr is located in said first dielectric module and / or in said last dielectric module.

[0054] As examples, a transparent substrate provided with a functional stack in accordance with the first aspect of the invention may, compared to a conventional functional stack, have a lower solar factor value of at least 2%, or even at least 4%, and a equivalent light transmission, or even higher by at least 1%, or even at least 2%.

[0055] A second advantage is that the Zr-based nitrided absorbing layer(s) has (have) a favorable influence on the transmission color of the substrate coated with the functional stack compared to a conventional functional stack. A favorable transmission color can be an a*T value equal to or greater than - 4.0, in the L*a*b* system. The color specifications are thus met when such a layer is introduced into an existing functional stack according to the conditions of this document.

[0056] Another advantage of the invention is that the Zr-based nitrided absorbent layer(s) can be deposited by a magnetron sputtering method, in particular using a metal target containing zirconium, said target being sputtered in an atmosphere comprising nitrogen. Since functional stacks of thin layers are generally deposited by a magnetron sputtering method, existing methods can be more easily adapted. Brief description of the drawings

[0057] [Fig. 1] is a schematic representation of a first embodiment of the first aspect of the invention; [Fig. 2] is a schematic representation of a second embodiment of the first aspect of the invention; [Fig. 3] is a schematic representation of a third embodiment of the first aspect of the invention; [Fig. 4] is a schematic representation of a fourth embodiment of the first aspect of the invention; [Fig. 5] is a representation of the evolution of the refractive index, n, as a function of the wavelength W, in nanometers, of several different layers of SiN, SiZr27N, SiZr43N, SiZr60N and ZrN according to the terminology of this document; [Fig. 6] is a representation of the evolution of the optical extinction coefficient, k, as a function of the wavelength W, in nanometers, of several different layers of SiN, SiZr27N, SiZr43N, SiZr60N and ZrN according to the terminology of this document; [Fig.7] is a schematic representation of a first embodiment of a glazing unit according to the second aspect of the invention; and [Fig.8] is a schematic representation of a second embodiment of a glazing unit according to the second aspect of the invention. Detailed description of embodiments

[0058] It uses the following definitions and conventions.

[0059] 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. These two terms, "above" and "below", do not mean that the layer or set of layers that they qualify 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.

[0060] Without any precision or qualification, the term "thickness" used for a layer corresponds to the physical, real or geometric thickness, e, of said layer. It is expressed in nanometers.

[0061] 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.

[0062] In the present description, the term "dielectric" to qualify a layer excludes that this layer is "absorbent"; this excludes that the layer material has an absorption coefficient greater than 0.1 at the wavelength of 550 nm.

[0063] In the present description, the term "absorbent" to qualify a layer means that the material constituting the absorbent layer is a material having a ratio n / k at the usual value of wavelength in the visible of 550 nm which is between 0.0 and 5.0 excluding these values.

[0064] 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 atomic 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.

[0065] By the term "transparent", used to describe a substrate, means that the substrate 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.

[0066] The luminous transmission, TL, in the visible spectrum, the solar factor, g, and the selectivity, s, the internal reflection, Rint, and the external reflection, Rext, in the visible spectrum, as well as their methods of measurement and / or calculation are defined in the standards EN 410, ISO 9050 and ISO 10292.

[0067] The expressions "optical refractive index" and "optical extinction coefficient" mean the optical refractive index, n, and the optical extinction coefficient, k, 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.

[0068] According to a first aspect of the invention, with reference to Fig. 1, a transparent glass substrate 10 is provided, having two opposite main faces 9 and 11 and provided with a functional stack 14 of thin layers on at least one of its faces (here the face 11). This functional stack 14 comprises, starting from the substrate 10: three metallic functional layers 140, 180, 220 each placed between two dielectric modules, respectively 120, 160, 200, 240 of thin layers, and in which the first dielectric module 120 and / or in the last dielectric module 240 comprises at least one nitrided absorbent layer based on Zr 120a, 240a; and preferably no nitrided absorbent layer based on Zr is located in a dielectric module itself located between two metallic functional layers in the functional stack.

[0069] Surprisingly, a Zr 120a-based nitrided absorber layer in the first dielectric module 120 and / or a Zr 240a-based nitrided absorber layer in the last dielectric module 240, combined with the presence of three metal functional layers, has a synergistic effect on increasing selectivity.

[0070] This effect is particularly marked when the Zr-based nitrided absorber layer has a relatively thin physical thickness, which is between 3.0 nm and 10.0 nm.

[0071] The nitrided absorbent layer based on Zr 120a, 240a preferably comprises at least 60% Zr in atomic proportion of the reactive elements, or even at least 80% Zr in atomic proportion of the reactive elements, or even is 100% Zr in atomic proportion of the reactive elements. The reactive elements are elements from the periodic table that react with nitrogen to form the nitrided absorbent layer. The reactive elements reacting with nitrogen to form the nitrided absorbent layer, in addition to zirconium, are preferably silicon and / or aluminum.

[0072] As illustrative and explanatory examples, to which however the present invention should not be considered as inextricably linked, the evolutions of the optical refractive index, n, and of the optical extinction coefficient, k, are represented in Fig. 5 and Fig. 6 respectively: - for a layer called “SiN”, that is to say in silicon nitride doped with aluminum, SisN^AI; - for a layer called “SiZr27N”, that is to say in SixZr y N z with y / (y + x) = 0.27; - for a layer called “SiZr43N”, that is to say in SixZr y N z with y / (y + x) = 0.43; - for a layer called “SiZr60N”, that is to say in SixZr y N z with y / (y + x) = 0.60; and - for a layer called “ZrN”, that is to say zirconium nitride.

[0073] The extinction coefficient and refractive index were calculated by modeling from experimental measurements. The measurements were obtained using a Perkin Elmer Lambda 900 spectrophotometer and a VASE M-2000XI JA Wollam ellisopmeter.

[0074] In these [Fig. 5] and [Fig. 6], the layers were deposited on a 6 mm thick soda-lime-silica glass substrate. These figures illustrate the evolution of the optical refractive index, n, and the optical extinction coefficient, k, of the layers made of Si, Zr and N as a function of the quantity of Zr, starting from a layer without Zr (here called "SiN") to a layer without Si (here called "ZrN").

[0075] Over the entire spectrum shown, for a given wavelength, as the amount of Zr increases, both the optical refractive index, n, and the optical extinction coefficient, k, increase. More precisely, for a given wavelength, as the amount of Zr increases the optical extinction coefficient, k, increases sharply below 600 nm and even below 550 nm.

[0076] The nitrided absorbing layer based on Zr 120a, 240a preferably has an optical extinction coefficient, k, decreasing with increasing wavelength over the range of 350 to 600 nm, starting from a value greater than 0.5 at the wavelength of 350 nm.

[0077] When the nitrided absorbing layer based on Zr 120a, 240a comprises silicon at less than 50 atomic % in atomic proportion of the reactive elements of the layer, it has an optical extinction coefficient, k, decreasing with increasing wavelength over the range of 350 to 750 nm, starting from a value greater than 0.5 at the wavelength of 350 nm.

[0078] When the nitrided absorbing layer based on Zr 120a, 240a contains only zirconium as a reactive element, it has an optical extinction coefficient, k, decreasing with increasing wavelength over the range of 350 to 600 nm, starting from a value greater than 0.5 at the wavelength of 350 nm; its optical extinction coefficient has a constant value over the range 600-650 nm then, for wavelengths above 650 nm, a slight increasing then decreasing variation.

[0079] The Zr-free layer ("SiN") has an optical extinction coefficient, k, of zero over the range 300 to 1500 nm.

[0080] Although not particularly required to achieve the effects of the present invention, these optical refractive index and optical extinction coefficient values ​​may nevertheless be advantageous in meeting color specifications for applications in the building and construction markets. In particular, they allow neutral colors to be obtained.

[0081] What is most important in the context of the invention is that the absorption in the visible at less than 550 nm of the material of the absorbing layer(s) is relatively high in order to maximize the obtaining of the neutral color. It is also preferable that the absorbing layer(s) is / are present without being too thick.

[0082] The nitrided absorbing layer based on Zr 120a, 240a preferably has a physical thickness which is between 0.5 nm and 25.0 nm, in particular between 2.0 nm and 15.0 nm, preferably between 3.0 nm and 10.0 nm.

[0083] The transparent substrate 10 may preferably be flat and may be of an organic or inorganic nature, rigid or flexible. In particular, it may be a mineral glass, for example a soda-lime-silica glass.

[0084] Examples of organic substrates that can be advantageously used for implementing the invention may be polymeric materials such as polyethylenes, polyesters, polyacrylates, polycarbonates, polyurethanes, polyamides. These polymers may be fluorinated polymers.

[0085] Examples of mineral substrates that can be advantageously used in the invention may be mineral or glass-ceramic sheets. The glass may preferably be a soda-lime-silica, borosilicate, aluminosilicate or even alumino-boro- silicate. According to a preferred embodiment of the invention, the substrate 10 is a sheet of soda-lime-silica mineral glass.

[0086] [Fig. 1] illustrates a structure of a stack 14 with several functional layers according to the invention deposited on a face 11 of a transparent glass substrate 10. This diagram illustrates the positions of different layers relative to each other when these layers are present.

[0087] In this structure, the functional layers 140, 180, 220 are in particular based on silver or a metal alloy containing silver, and are each arranged between two anti-reflective modules: - the anti-reflective module 120, underlying, located below the first functional layer 140 in the direction of the substrate 10, - the first intermediate anti-reflective module 160, arranged above the first functional layer 140 opposite the substrate 10 and under the second functional layer 180, - the second intermediate anti-reflective module 200, arranged above the second functional layer 180 opposite the substrate 10 and under the third functional layer 220, and - the overlying anti-reflective module 240 is arranged above the third functional layer 220 opposite the substrate 10.

[0088] These anti-reflective modules 120, 160, 200 and 240 each comprise at least one dielectric layer 124, 126, 127, 129; 162, 164, 168, 169; 202, 204, 208, 209, 242, 243, 244.

[0089] A terminal protective layer 300, furthest from the face 11, can complete the stack.

[0090] The functional stack here further comprises a blocking overlayer 150, 190, 230, preferably based on a nickel and chromium alloy, located above and in contact, respectively, with each metallic functional layer 140, 180, 220 and at least one metallic blocking underlayer 130, 170, 210, preferably based on a nickel and chromium alloy, located below and in contact, respectively, with each metallic functional layer 140, 180, 220. These blocking layers have the function of protecting the metallic functional layers.

[0091] Each metallic functional layer 140, 180, 220 has the function of reflecting infrared radiation and / or part of the radiation solar. It can be of any suitable metal, for example gold-based or silver-based. The thickness of each metal functional layer 140, 180, 220 can typically be between 2 nm and 25 nm, preferably between 10 nm and 20 nm.

[0092] According to preferred embodiments, each metal functional layer 140, 180, 220 is a silver-based layer.

[0093] The dielectric modules may comprise one or more layers of oxides and / or nitrides of metallic elements and / or metallic alloys, such as, for example, zinc oxide, mixed zinc and tin oxide, silicon nitride, silicon oxide, zirconium nitride, titanium oxide, tin oxide, and silicon oxynitride.

[0094] The methods for depositing thin layers on substrates, in particular glass substrates, are well-known methods 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.

[0095] 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.

[0096] 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.

[0097] A second aspect of the invention relates to glazing, in particular single, double or triple glazing, comprising a transparent substrate according to any of the embodiments described.

[0098] A monolithic glazing unit comprises a single substrate, in particular a sheet of mineral glass. It may be a single glazing unit. When the substrate according to the invention is used as a monolithic glazing unit, the functional stack of thin layers is preferably deposited on the face of the substrate facing the interior of the room of the building on the walls of which the glazing is installed. In such a configuration, it may be advantageous to protect the first layer and possibly the stack of thin layers against physical or chemical degradation using a suitable means.

[0099] A multiple glazing unit comprises at least two substrates, in particular mineral glass sheets, parallel and separated by a layer of insulating gas. Most multiple glazing units are double or triple glazing units, i.e. they comprise two or three panes respectively. When the substrate according to the invention is used as an element of a multiple glazing unit, the functional stack of thin layers is preferably deposited on the face of the glass sheet facing inwards in contact with the insulating gas. This arrangement has the advantage of protecting the stack from chemical or physical damage from the external environment.

[0100] Such a functional stack of thin layers 14 can be used in a laminated glass pane providing a separation between an exterior space and an interior space. This laminated glass pane is made up of two glass substrates, which are held together by an interlayer sheet of plastic material.

[0101] Such a functional stack of thin layers 14 can also be used in a multiple glazing 100 providing a separation between an exterior space ES and an interior space IS; this glazing can have a double glazing structure, as illustrated in [Fig. 7] or [Fig. 8]: this glazing is then made up of two glass substrates 10, 30, which are held together by a frame structure 90 and which are separated from each other by an interposed gas layer 15.

[0102] In [Fig. 7] and [Fig. 8], the incident direction of sunlight entering the building is illustrated by the double arrow, top or left.

[0103] According to a first embodiment, illustrated in [Fig. 7], the functional stack 14 of thin layers is positioned on face 2 (on the outermost sheet of the building considering the incident direction of the sunlight entering the building and on its face facing the gas blade), that is to say on an inner face 11 of the substrate 10 in contact with the interposed gas blade 15, the other face 9 of the substrate 10 being in contact with the external space ES. The substrate 30, not carrying a stack in [Fig. 7], has a face 29 in contact with the interposed gas blade 15, the other face 31 of the substrate 30 being in contact with the internal space IS; this substrate 30 may comprise a stack of thin layers on one of its faces or both of its faces.

[0104] According to a second embodiment, illustrated in [Fig. 8], the functional stack 14 of thin layers is positioned on face 3 (on the innermost sheet of the building considering the incident direction of the sunlight entering the building and on its face facing the gas blade), that is to say on an inner face 11 of the substrate 10 in contact with the interposed gas blade 15, the other face 9 of the substrate 10 being in contact with the inner space IS. The substrate 30, not carrying a stack, has a face 29 in contact with the interposed gas blade 15, the other face 31 of the substrate 30 being in contact with the outer space ES.

[0105] However, it can also be considered that in this double glazing structure, one of the substrates has a laminated structure.

[0106] It is possible to integrate the substrate according to the first aspect of the invention into a triple glazing structure.

[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] In the following examples, the functional metal layers 140,180,220 are silver (Ag) layers. The blocking layers 130, 150, 170, 190, 210, 230 are metal layers made of nickel and chromium alloy (NiCr). The dielectric modules 120, 160, 200, 240 comprise barrier layers, smoothing layers or wetting layers. The barrier layers are based on silicon nitride, doped with aluminum (SisN^AI), based on silicon nitride and zirconium. The smoothing layers are based on mixed oxide of zinc and tin (SnZnOx). The wetting layers are made of zinc oxide (ZnO).

[0110] [Table 1]

[0111] The deposition conditions of the layers, which were deposited by sputtering (so-called “magnetron cathode sputtering”), are summarized in Table 2.

[0112] [Table 2] 00113] at. = atomic

[0114] In the following odd-numbered example composition presentation tables, the first two columns indicate the layer or module number, with reference to [Fig. 1] to [Fig. 4] and the third column indicates the material for these layers. For these examples, the tables detail the complete contents of the stacks starting from surface 11 of substrate 10, with a thickness of 6 mm, in the order indicated (the materials and physical thicknesses are in nanometers and the substrate carrying the stack, made of clear glass, is in the last line, at the bottom of the tables). In the following, the two letters "CE" preceding a number designate a counter-example and the letter preceding a number designates an example. In each series of example or counter-example, the same number indicates a proximity of structure.

[0115] In a first series of examples, presented in tables 3 and 4 below, in connection with [Fig. 1], the presence of a nitrided absorbent layer in SiZr60N is tested: - only in the first dielectric module 120 for examples E1 and E4a, and - only in the first dielectric module 120 and in the last dielectric module 240 for examples E2a and E3.

[0116] These four examples further have a metal absorbing layer 125 which is inserted into a dielectric module, in this case the first dielectric module 120.

[0117] These examples are compared to three counter-examples CE1, CE2 and CE3 without any nitrided absorbing layer, nor any metallic absorbing layer, inserted in a dielectric module.

[0118] [Table 3]

[0119]

[0120] In the tables presenting the properties of the examples and counter-examples below, bearing even numbers, the solar factor, g, the selectivity, s, the light transmission, TL, the light reflection on the inner face, Rint, and on the outer face, Rext, as well as the color in transmission, in reflection on the inner face and in reflection on the outer face, were measured for each substrate of the examples and counter-examples assembled in a double glazing, as illustrated in [Fig. 7], The second glass substrate 30 is a soda-calcium silico mineral glass with a thickness of 4 mm. The thickness of the interlayer blade 15 composed of air with 90% argon is 16 mm. The stack 14 is arranged on face 2, i.e. on face 11 of the substrate 10.

[0121] The term "color", used to describe a transparent substrate with a stack, means the color as defined in the CIE 1976 L*a*b* color space according to ISO 11664, in particular with a D65 illuminant and a visual field of 2° or 10° for the reference observer. It is measured in accordance with said standard. The measurements of the color parameters a* and b*, in transmission (a*T, b*T), in external reflection (a*Rext, b*Rext) and in internal reflection (a*Rint, b*Rint) are grouped together.

[0122] The luminous transmission in the visible spectrum, TL, the solar factor, g, and the selectivity, s, and the internal reflection, Rint, and the external reflection, Rext, in the visible spectrum are defined, measured and calculated in accordance with the standards EN 410, ISO 9050 and / or ISO 10292.

[0123] [Table 4]

[0124] [Tab. 4] shows that the four examples E1, E2a, E3 and E4a according to the invention have a light transmission TL similar to that of, respectively, the counter-examples CE1, CE2 and CE3 and a solar factor, g, better (lower) than those of the counter-examples CE1, CE2 and CE3.

[0125] [Tab. 4] shows that the four examples E1, E2a, E3 and E4a according to the invention allow a gain (increase) in selectivity, s, compared, respectively, to the counter-examples CE1, CE2 and CE3. This gain illustrates the synergistic effect of the presence of the absorbent layer 240a, or even in addition, of that of the absorbent layer 120a.

[0126] External and internal reflections are also low; they are less than 20%.

[0127] The last two lines of [Tab. 4] show the stability of the color according to a* and b*, in external reflection at 60°.

[0128] In a second series of examples, examples E2b, E4b, E4c and E4d of substrate according to the first aspect of the invention are compared with examples E2a and E4a already presented and these examples are compared with two counter-examples CE4 and CE5. Different natures of SiZrXN nitrided absorbent layer are tested: - examples E4b and E2b use one, respectively two, nitrided absorbent layer(s) in ZrN; - example E4c uses a nitrided absorbing layer in SiZr43N; and - the CE5 counterexample uses a nitrided absorbing layer in SiZr27N.

[0129] [Table 5]

[0130] Table 6 presents properties of these examples and this counterexample.

[0131] [Table 6]

[0132] [Tab. 6] shows that the five examples E2a, E2b, E4a, E4b and E4c according to the invention have a light transmission TL similar to that of the counter-examples CE4 and CE5 respectively and a better (lower) solar factor, g.

[0133] [Tab. 6] shows that the five examples E2a, E2b, E4a, E4b and E4c according to the invention allow a gain (increase) in selectivity, s, compared, respectively, to the counter-examples CE4 and CE5. This gain illustrates the synergistic effect of the combination of the Zr-based nitrided absorbent layer(s).

[0134] External and internal reflections are also low; they are less than 20%.

[0135] The last two lines of [Tab. 6] show the stability of the color according to a* and b*, in external reflection at 60°.

[0136] In a third series of examples, examples E4a2, E4b2, E3a2, of substrate according to the first aspect of the invention are compared with examples E4a, E4b and E3 already presented. Different natures of SiZrXN nitrided absorbent layer are tested: - examples E4b and E4b2 use a single nitrided absorbing layer, in ZrN, in the last dielectric module; - examples E4a, E4a2, use a single nitrided absorbing layer, in SiZr60N, in the last dielectric module; and - examples E3 and E3a2, use two nitrided absorbing layers in SiZr60N, in the first and last dielectric module.

[0137] [Table 7]

[0138] Table 8 presents properties of these examples and compares them to the preceding counterexamples.

[0139] [Table 8]

[0140] [Tab. 8] shows that the six examples E4a2, E4b2, E3a2, E4a, E4b and E3 according to the invention have a light transmission TL similar to that of the other examples and counterexamples and a solar factor, g, better (lower) than those of the counterexamples.

[0141] External and internal reflections are also low; they are less than 20%.

[0142] The last two lines of [Tab. 8] show the stability of the color according to a* and b*, in external reflection at 60°.

[0143] In a fourth series of examples, two examples E4b3 and E4b4 of substrate according to the first aspect of the invention test the presence of a nitrided ZrN absorbent layer in the first dielectric module 120 without a nitrided absorbent layer in the last dielectric module 240. These examples are compared to the same examples E4b and E4b2 as previously.

[0144] [Table 9]

[0145] Table 10 presents properties of these examples.

[0146] [Table 10]

[0147] [Tab. 10] shows that the solar factor of both examples E4b3 and E4b4 is slightly higher and the selectivity, s is slightly lower than that of example E4b.

[0148] External and internal reflections are also low; they are less than 20%.

[0149] The last two lines of [Tab. 10] show the stability of the color according to a* and b* in external reflection at 60°.

[0150] These examples very clearly illustrate the advantages of the substrates of the invention, namely that they have a reduced solar factor, higher selectivity, and have a neutral color, both in transmission and for reflections.

Claims

Claims Claim 1. Substrate (10), glass, provided with a functional stack (14) of thin layers on at least one of its faces (11), said functional stack (14) comprising, starting from the substrate (10) at least three metallic functional layers (140, 180, 220), preferably each based on silver, each located between two dielectric modules (120, 160, 200;240) of thin layers and forming a succession comprising a first dielectric module (120), a first metallic functional layer (140), a second dielectric module (160), a second metallic functional layer (180), a third dielectric module (200), a third metallic functional layer (220) and a last dielectric module (240), characterized in that at least one Zr-based nitrided absorbent layer (120a, 240a) is located in said first dielectric module (120) and / or in said last dielectric module (240), and preferably no Zr-based nitrided absorbent layer is located in a dielectric module itself located between two metallic functional layers in said functional stack.; Claim 2. Substrate (10) according to claim 1, wherein said Zr-based nitrided absorbent layer (120a, 240a) comprises at least 60% Zr in atomic proportion of the reactive elements, or even at least 80% Zr in atomic proportion of the reactive elements, or even is 100% Zr in atomic proportion of the reactive elements. Claim 3. A substrate (10) according to claim 1 or 2, such that said Zr-based nitrided absorbing layer (120a, 240a) has an optical extinction coefficient, k, decreasing with increasing wavelength over the range of 350 to 600 nm, starting from a value greater than 0.5 at the wavelength of 350 nm. Claim 4. Substrate (10) according to any one of claims 1 to 3, such that said Zr-based nitrided absorbent layer (120a, 240a) has a physical thickness which is between 0.5 nm and 25.0 nm, in particular between 2.0 nm and 15.0 nm, preferably between 3.0 nm and 10.0 nm. Claim 5. Substrate (10) according to any one of claims 1 to 4, such that only said first dielectric module (120) comprises a metallic absorbing layer (125) based on NiCr, preferably having a physical thickness between 0.5 and 5.0 nm and wherein no other dielectric module comprises a NiCr-based absorbing layer. Claim 6. Substrate (10) according to claim 5, such that said metallic absorbing layer (125) based on NiCr is located, in contact, between two nitrided dielectric layers, preferably between two nitrided dielectric layers based on silicon (124, 126). Claim 7. Substrate (10) according to any one of claims 1 to 6, such that at least one SiZr-based nitrided dielectric layer (127, 243) is located in said first dielectric module (120) and / or in said last dielectric module (240) and preferably only in said first dielectric module (120) and / or in said last dielectric module (240) for the entire functional stack. Claim 8. Substrate (10) according to any one of claims 1 to 7, such that said functional stack (14) of layers further comprises at least one blocking overlayer (150, 190, 230), preferably based on a nickel and chromium alloy, located above and in contact with a metallic functional layer (140, 180, 220) and / or at least one metallic blocking underlayer (130, 170, 210), preferably based on a nickel and chromium alloy, located below and in contact with a metallic functional layer (140, 180, 220). Claim 9. Substrate (10) according to any one of claims 1 to 8, such that a nitrided dielectric layer, preferably based on Si, is located on said nitrided absorbing layer based on Zr (120a, 240a), in contact with the latter. Claim 10. Substrate (10) according to any one of claims 1 to 9, such that the functional stack (14) of layers comprises a dielectric layer with a refractive index greater than 2.15 at 550 nm, said layer being included in the first dielectric module (120) and / or in the last dielectric module (240). Claim 11. Glazing comprising at least two transparent substrates, one of the substrates being a substrate according to any one of claims 1 to 10 arranged so that the functional stack of layers is located on face two and / or on face three of said glazing.

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