WO2024110400A1

WO2024110400A1 - Solar control glazing with high external reflection

Info

Publication number: WO2024110400A1
Application number: PCT/EP2023/082421
Authority: WO
Inventors: Sacha ABADIE; Vincent Reymond
Original assignee: Saint-Gobain Glass France
Priority date: 2022-11-24
Filing date: 2023-11-20
Publication date: 2024-05-30
Also published as: FR3142471A1

Abstract

The invention relates to a transparent glass item for solar control glazing, comprising at least one glass substrate, at least one of the faces of which is provided with a coating comprising the following series of layers, starting from the surface of said substrate: - a layer comprising a nitride of at least one element chosen from Si, Al, said nitride optionally comprising Zr, having a physical thickness of between 1 and 25 nm; - an infrared-absorbing layer consisting of a material comprising niobium or of a material comprising nickel and chromium, having a physical thickness of between 1 and 20 nm; - a layer of which the optical thickness is between 60 and 100 nm, comprising a nitride of at least one element chosen from Si, Al, said nitride further comprising Zr, in contact with the infrared-absorbing layer, having a refractive index at 550 nm of greater than 2.2, or an assembly of layers of which the total optical thickness is between 60 and 100 nm, said assembly comprising or consisting of a) a layer comprising a nitride of at least one element chosen from Si, Al, said nitride optionally comprising Zr, in contact with the infrared-absorbing layer, and b) a layer of a dielectric material having a refractive index at 550 nm of greater than 2.2, having a physical thickness of greater than or equal to 15 nm.

Description

DESCRIPTION

TITLE: Anti-solar glazing with strong external reflection

The invention relates to insulating glazing called solar control, provided with stacks of thin layers of which at least one is absorbent, that is to say it acts on solar and/or thermal radiation essentially by absorption. at least part of the near (solar) or far (thermal) infrared radiation. The present invention relates more particularly to layer(s) glazing, in particular those intended mainly for the thermal insulation of buildings.

Such glazing provided with stacks of thin layers acts on the incident solar radiation by absorbing said radiation and/or by reflecting this radiation.

They are grouped under the designation of solar control glazing. They are marketed and used mainly to protect the home from solar radiation and prevent overheating.

By anti-solar, we therefore mean in the sense of the present invention the ability of the glazing to limit the energy flow, in particular the solar infrared radiation (1RS) passing through it from the outside towards the inside of the home or passenger compartment. .

To fulfill the anti-solar function, such glazing advantageously comprises at least one absorbent layer, that is to say a layer absorbing part of the solar radiation and in particular solar infrared.

To measure the solar control properties of glazing, the solar factor denoted FS or g is used in the field.

In a known manner, the solar factor g is equal to the ratio of the energy passing through the glazing (that is to say entering the room) and the incident solar energy. More particularly, it corresponds to the sum of the flow transmitted directly through the glazing and the flow absorbed by the glazing (including the stacks of layers possibly present on one of its surfaces) and re-emitted towards the interior (the room ). We are currently looking for glazing with the lowest possible g factor and at most equal to 50% (0.5).

Another important factor taken into account is the TL light transmittance which describes the percentage of visible light (between 380 and 780 nm) that passes through the glazing. The TL values can however vary greatly from one anti-solar glazing to another depending on the level of sunshine in the country concerned but also the wishes of architects and other project managers. Typically it can be estimated that the required light transmission can vary between 20 and 80%, depending on requests.

The most efficient stacks currently marketed to achieve such performances incorporate at least one silver-type metallic layer operating essentially in the mode of reflecting a majority of the incident IR (infrared) radiation. These stacks can be used mainly as low-emission glazing (or low-e in English) or as solar protection glazing. However, these layers are very sensitive to humidity and oxidation. They are therefore exclusively used in double glazing, on side 2 or 3 thereof, to be protected from humidity. For applications in the building or automotive sectors, it is not possible to deposit such layers on single glazing. The stacks according to the present invention do not include such layers based on silver, or even based on gold or platinum, or in very negligible quantities, in particular in the form of inevitable impurities.

We also know stacks with low emissive or anti-solar properties but based on absorbent layers of transparent conductive oxides (TCO) such as mixed oxides of tin and indium, such as for example the stacks described in publication US2009320824. However, to obtain glazing with a solar factor of less than 50%, it is necessary to deposit layer thicknesses of at least 100 nm. The deposition of such layers by magnetron-assisted sputtering techniques is therefore long and expensive. Advantageously, the stacks according to the present invention do not include such layers.

Other stacks with anti-solar function have also been disclosed in the field, comprising absorbent layers of the metallic Nb or nitrided niobium NbN type, as described for example in application W001/21540 or even in application W02009/1 12759. within such layers based on niobium, and in particular based on nitrided niobium, the solar radiation is this time mainly absorbed in a non-selective manner by the absorbing layer, that is to say that the IR radiation (i.e. i.e. whose wavelength is between approximately 780 nm and 2500 nm) and visible radiation (whose wavelength is between approximately 380 and 780 nm) are absorbed indiscriminately by the active layer. As indicated in these publications, the use of niobium-based layers does not make it possible to achieve a high external reflection (greater than 25%) for a light transmission greater than 35%.

A key aspect to consider is the exterior aesthetics of the building, which should be highly reflective and neutral or blue in color. According to another aspect of the present invention, this involves minimizing reflection on the interior side of the building, for the comfort reasons described below.

Also, an essential factor lies in the visual comfort of the occupants of the building or the passenger compartment equipped with the glazing. In particular, the vision through the glazing must be as clear as possible and the color perceived must be pleasant.

A light transmission of around 50% is therefore preferable, in order to guarantee good illumination of the interior of the building without excessive heating of the building.

We also distinguish, in this respect:

- the exterior light reflection Ri_ext, that is to say the light reflection measured on the face of the glazing exposed to the exterior of the building or the passenger compartment, and

- the interior light reflection Runt, that is to say the light reflection measured on the side of the glazing facing inwards.

Generally speaking, all the light characteristics presented in this description, in particular, the light transmission TL and the light reflections RL, as well as the g factor, are obtained according to the principles and methods described in standard NF EN 410 ( 2011) relating to the determination of the light and energy characteristics of glazing used in glass for construction.

In a glazing according to the invention, the so-called solar control stack can be arranged on the face of the glazing facing the interior of the building or the passenger compartment which it equips and in particular on face 2 of a single glazing, the faces being conventionally numbered from the outside to the inside.

In other words, the Rünt interior light reflection is measured on the side provided with the stack of layers (also called the layer side) while the Riext exterior light reflection is measured on the bare side of the glazing (also called the glass side). For the good comfort of the occupants of the building or the passenger compartment, it is first of all necessary that the interior reflection Runt be minimized, in particular less than 20%, so as to avoid a "mirror" effect of the glazing, this that is to say a reflected image of the interior of the building to the detriment of the exterior view, particularly in oblique vision (that is to say with a non-zero angle compared to the normal to the glazing).

For the purposes of the present invention, we are therefore looking for glazing whose difference ARL = Riext - Runt is close to or greater than 6%.

Ideally, an obscuring effect is sought, this time from inside the building, by observers from the outside. Such a property this time requires a sufficiently high external reflection, for example of the order of 30%, while nevertheless remaining significantly lower than the light transmission, for example at least 10%.

However, with such a level of external reflection (exterior side), the colorimetric aspect becomes critical for the general aesthetics of the building. It is particularly desired that such glazing have a neutral or slightly bluish coloring.

To obtain such a property, it is necessary that the values of a* and b*, and in particular of b*, in the system L, a*, b* (typically under a viewing angle of 2° and under the illuminant Des), are precisely adjusted. Values of a* and b* sought are notably less than 0, as indicated in the remainder of the description.

Not only do the glazings comprising a single absorbent layer based on niobium, as described in application W001/21540, have suitable colorimetry (negative a* and b*) but external reflection levels that are too low (less than 20%) . In addition, they mostly exhibit high internal reflection and low external reflection.

The present invention aims to meet the objectives described above and relates to glass articles presenting the majority and most often all of the following criteria:

- a light transmission greater than or equal to 35%, preferably greater than 40%, and for example less than 70%, advantageously between 40 and 65%, - A solar factor substantially equal to or less than the value of light transmission, in percentage,

- an internal light reflection Runt (that is to say on the face of the substrate on which the stack of layers is deposited) less than or equal to 25%, preferably less than 20%,

- a light reflection Ri_ext (that is to say on the face of the substrate opposite to which the stack of layers is deposited) greater than the Runt and in particular greater than or equal to 25%, preferably greater than or equal to 30%,

- parameters a* and b* in negative external reflection in the colorimetric system L, a*, b* and in particular a parameter a* _ex t between 0 (excluded) and -3.5 and a parameter b* _ex t less than 0 and preferably less than -5,

- preferably a difference between the exterior reflection and the interior reflection (ARL = Riext - Runt) of at least 6%, or even at least 7% or even at least 10%.

According to the invention, the parameters L, a* and b* are measured according to the CIE LAB criteria, under the illuminant D65, 2°.

By stack side, as indicated previously, we mean the face of the glazing on which the stack is placed. By glass side we mean the side of the glazing opposite to that on which the stack is placed, in principle not covered. For the purposes of the present invention, the terms “exterior face” (or “external”) and “interior face” or (“internal”) refer to the position of the glazing when it equips the building or vehicle to which it is installed. destined.

Furthermore, the glass and glazing articles according to the invention have solar control properties conforming to those required in the field, in particular a solar factor g close to and preferably less than 50%, or even less than 45% or even less than 40 % in certain configurations.

More specifically, the present invention relates to a transparent glass article for anti-solar glazing, comprising at least one glass substrate provided on at least one of its faces with a coating constituted by a stack of layers, said stack comprising the succession of layers following, from the surface of said substrate:

- a first layer comprising a nitride of at least one element chosen from Si, Al, said nitride optionally comprising Zr, with a physical thickness of between 1 and 25 nm, preferably between 5 and 20 nm, - a second infrared absorbing layer, consisting of a material comprising niobium or a material comprising nickel and chromium, with a physical thickness of between 1 and 20 nm, preferably between 5 and 15 nm,

- a third layer whose optical thickness is between 60 and 100 nm, preferably between 65 and 95 nm, comprising a nitride of at least one element chosen from Si, Al, said nitride further comprising Zr, in contact with the infrared absorbing layer, with a refractive index at 550 nm greater than 2.2 or a set of third layers whose total optical thickness is between 60 and 100 nm, preferably between 65 and 95 nm, said set comprising or preferably consisting of a) a layer comprising a nitride of at least one element chosen from Si, Al, said nitride optionally comprising Zr, in contact with the infrared absorbing layer and b) a layer of a dielectric material of refractive index at 550 nm greater than 2.2, of physical thickness greater than or equal to 15 nm, preferably of physical thickness greater than or equal to 20 nm,

- preferably a layer of a dielectric material with a refractive index at 550 nm of less than 1.6, with a physical thickness of between 1 and 25 nm, preferably between 5 and 20 nm,

- optionally a protective layer of a titanium oxide, a zirconium oxide or a titanium and zirconium oxide, with a physical thickness of between 1 and 5 nm, preferably between 1 and 3 nm.

According to particular and preferred embodiments of the present invention, which can be combined if necessary:

- The stack only includes one IR absorbing layer.

- The succession of layers comprises said layer of a dielectric material with a refractive index at 550 nm less than 1.6,

- Said nitride layer with a refractive index at 550 nm greater than 2.2 or said layer of a dielectric material with a refractive index at 550 nm greater than 2.2 has a physical thickness preferably at least 1.5 times greater than said layer of a dielectric material with a refractive index at 550 nm less than 1.6.

- Said layer of a dielectric material with a refractive index at 550 nm greater than 2.2, with a physical thickness greater than 15 nm and the layer of a dielectric material with a refractive index at 550 nm less than 1, 6 of said set of layers have a total cumulative physical thickness of between 25 and 50 nm, preferably between 25 and 35 nm.

- The layers comprising a nitride of at least one element chosen from Si, Al, and optionally comprising Zr, are in contact with the absorbent layer.

- The first layer of the stack comprising a nitride of at least one element chosen from Si, Al and optionally comprising Zr is in contact with the surface of the substrate and preferably is in contact with the absorbent layer.

- The first layer of the stack comprising a nitride of at least one element chosen from Si, Al and optionally comprising Zr is a silicon nitride or a silicon and aluminum nitride. Preferably in the layers according to the invention comprising silicon nitride or silicon aluminum nitride, the silicon nitride preferably represents at least 50% of the weight of said layers, on the basis of a SisN4 formulation, and preferably more than 80% or even more than 90% by weight of said layers, based on the SisN4 formulation. More preferably, said layers are based on silicon nitride, but can also include another metal such as aluminum. For example, aluminum is used in a well-known manner, in proportions of up to 10 atomic% or more, in silicon targets used for the deposition by cathode sputtering assisted by a magnetic field (magnetron) of layers containing silicon, in particular layers based on silicon nitride.

- The dielectric material with a refractive index at 550 nm greater than 2.2 in said set of layers comprises, preferably for more than 80% of its weight, an oxide of at least one element chosen from titanium, niobium , zirconium or their mixture, in particular comprises titanium oxide, niobium oxide, zirconium oxide, or a nitride of silicon and zirconium or a nitride of silicon, aluminum and zirconium.

- The dielectric material with a refractive index at 550 nm less than 1.6 comprises silicon oxide or a silicon oxynitride, preferably a silicon oxide. Preferably said material comprises more than 80% by weight of said oxides, and preferably consists of said oxides.

- The material constituting the absorbent layer is chosen from a material comprising niobium or niobium nitride, preferably niobium nitride. Preferably said material comprises more than 80% by weight of niobium or niobium nitride, and preferably consists of niobium or niobium nitride.

- The material constituting the absorbent layer is chosen from niobium or an alloy of niobium with at least one other metal such as Zr or Ti, the niobium representing at least 50% of the metal atoms present in said material, preferably representing at least 80 % of metal atoms present in said material.

- The material constituting the absorbent layer comprises a niobium nitride or a niobium nitride and at least one other metal such as Zr or Ti, the niobium representing at least 50% of the metal atoms present in said material, preferably representing at least least 80% of the metal atoms present in said material.

- The material constituting the absorbent layer comprises a nickel and chromium alloy or a nitride of a nickel and chromium alloy, an alloy in which the Ni/Cr atomic ratio varies between 2 and 9, preferably between 3 and 5.

- The third layer comprising a nitride of at least one element chosen from Si, Al, and comprising Zr, with a refractive index at 550 nm greater than 2.2 and a silicon nitride or a silicon and aluminum nitride in which the Si/Zr ratio is between 1.5 and 6.0, preferably between 2.0 and 5.5, or even between 3.5 and 5.0.

- The stack is only made up of the layers described previously.

- The stack comprises or is constituted by the succession of the following layers, each layer being in direct contact with the next, from the surface of said substrate:

SiN/CA/SiN/TiO/ preferably Si 0/ optionally TiO, ZrO or TiZrO in which SiN designates layers comprising silicon nitride, CA designates the absorbent layer, in particular a layer of niobium nitride or niobium, SiO denotes a layer comprising silicon oxide, TiO denotes a layer comprising titanium oxide, ZrO denotes a layer comprising zirconium oxide and TiZrO denotes a layer comprising titanium and zirconium oxide.

- The stack comprises or is constituted by the succession of the following layers, each layer being in direct contact with the next, from the surface of said substrate: SiN/CA/SiN/NbO/ preferably SiO /optionally TiO, ZrO or TiZrO, in which SiN designates layers comprising silicon nitride, CA designates the absorbent layer, in particular a layer of niobium nitride or niobium, SiO designates a layer comprising silicon oxide, NbO designates a layer comprising niobium oxide, TiO designates a layer comprising titanium oxide, ZrO designates a layer comprising zirconium oxide and TiZrO designates a layer comprising an oxide titanium and zirconium.

- The stack comprises or preferably consists of the succession of the following layers, each layer being in direct contact with the next and from the surface of said substrate:

SiN/CA/SiNZ SiZrN/ preferably SiO/optionally TiO, ZrO or TiZrO in which SiN designates layers comprising silicon nitride, CA designates the absorbent layer, in particular a layer of niobium nitride or niobium, SiO designates a layer comprising silicon oxide, SiZrN designates a layer comprising silicon and zirconium nitride, TiO designates a layer comprising titanium oxide, ZrO designates a layer comprising zirconium oxide and TiZrO designates a layer comprising silicon oxide titanium and zirconium.

SiN/CA/ SiZrN/ preferably SiO/optionally TiO, ZrO or TiZrO in which SiN designates layers comprising silicon nitride, CA designates the absorbent layer, in particular a layer of niobium nitride or niobium, SiO designates a layer comprising silicon oxide, SiZrN designates a layer comprising silicon and zirconium nitride, TiO designates a layer comprising titanium oxide, ZrO designates a layer comprising zirconium oxide and TiZrO designates a layer comprising titanium oxide and zirconium.

- The stack does not include layers based on Ag, Au, Pt, Cu, Ni or stainless steel.

- The item is thermally tempered and/or curved. - The article has a light transmission greater than or equal to 35%, in particular greater than or equal to 40%.

- The article has an internal light reflection Runt (i.e. on the face of the substrate on which the stack of layers is deposited) less than or equal to 20%.

- The article has a light reflection Ri_ext (that is to say on the face of the substrate opposite to which the stack of layers is deposited) greater than or equal to 25%, preferably greater than or equal to 30 %.

- The article presents a difference between external reflection and internal reflection (ARL = Ri_ext - Runt) of at least 6%, or even at least 8% or even at least 10%.

- The article presents in internal reflection at least one parameter b*, and preferably parameters a* and b*, negative, in the colorimetric system L, a*, b* and under the illuminant D65 2°, in particular a parameter a* _ex t between 0 (0 excluded) and - 3.5 and a parameter b* _ex t less than 0 and preferably less than -5.

- The item is anti-solar glazing comprising only a single glass substrate.

- The item is a multiple glazing comprising several glass substrates.

- The article is a laminated glazing comprising a combination of at least two glass substrates linked by a thermoplastic sheet, in particular polyvinyl butyral (PVB).

Throughout the description, unless otherwise indicated, the thicknesses are physical (geometric) thicknesses.

The optical thickness of a layer is obtained in a conventional manner by multiplying its physical thickness by the refractive index at 550 nm of the material which constitutes it. For example, the optical thickness of a layer of silicon oxide (refractive index at 550 nm equal to 1.45) whose physical thickness is 10 nm is equal to 10 x 1.45 = 14, 5nm.

By infrared absorbing layer is meant a layer consisting of a material absorbing at least partially infrared, in particular infrared from solar radiation between 780 nm and 3000 nm. By the term “absorbing IR”, we do not exclude within the meaning of the present invention that said layer can also reflect another portion. A dielectric material is for example a material whose massive form, devoid of impurities, has a high resistivity, in particular a resistivity greater than 10 ¹⁰ ohms. meters (Q. m) at ambient temperature (25°C).

A layer comprising silicon nitride according to the invention may also comprise the elements aluminum and zirconium.

The absorbent layer according to the invention is selected in order to obtain a relatively high light transmission value of the substrate, allowing vision from the inside to the outside without discomfort, while maintaining a significant effect of controlling thermal input.

Preferably the absorbent layer according to the invention comprises niobium and in particular niobium nitride.

In the layers according to the invention comprising niobium nitride, the niobium nitride NbN preferably represents at least 50% by weight of said layers, and preferably more than 80% or even more than 90% of said layers. In a niobium nitride according to the invention, the N/Nb ratio can vary for example between 0 and 1.2, preferably is of the order of 1, that is to say corresponds substantially to a stoichiometric NbiNi formulation . According to a possible embodiment of the present invention, the layers comprising niobium nitride or niobium may also comprise another element, for example chosen from zirconium, titanium, in a minority quantity compared to niobium.

The formulation of the layers can be obtained conventionally by XPS photoelectron spectrometry, according to techniques well known in the field of materials. According to a preferred embodiment of the invention, said layers are preferably made up essentially of niobium nitride, or even are made up of niobium nitride, apart from inevitable impurities.

The layer comprising niobium nitride or niobium may further comprise a small quantity of oxygen, for example such that the O/Nb atomic ratio is less than 0.2, preferably less than 0.1. According to a preferred embodiment, however, the layers comprising niobium nitride or niobium do not include oxygen other than in the form of inevitable impurities.

In the layers according to the invention comprising silicon oxide, the silicon oxide preferably represents at least 50% of the weight of said layers, on the basis of a SiC>2 formulation, and preferably more than 80% or even more than 90% of said layers, based on the SiCh formulation. Preferably still, said layers consist essentially of silicon oxide, but can also include aluminum. Aluminum is used in a well-known manner, in proportions of up to 10 atomic% or more based on the sum of the elements Si and Al, in silicon targets used for sputtering deposition assisted by a magnetic field (magnetron) of layers containing silicon, in particular layers based on silicon oxide.

In the layers according to the invention comprising niobium oxide, the niobium oxide preferably represents at least 50% of the weight of said layers, on the basis of an Nb20s formulation, and preferably more than 80% or even more than 90% of said layers, based on the Nb2Û5 formulation. More preferably, said layers consist essentially of niobium oxide.

In the layers according to the invention comprising titanium oxide, the titanium oxide preferably represents at least 50% of the weight of said layers, on the basis of a TiCh formulation, and preferably more than 80% or even more than 90% of said layers, based on the TiCh formulation. More preferably, said layers consist essentially of titanium oxide.

In the layers according to the invention with a refractive index at 550 nm greater than 2.2 comprising silicon and zirconium nitride, the silicon and zirconium nitride preferably represents at least 70% of the weight of said layers, on the based on a Si _x Zr _y N formulation, and preferably more than 80% or even more than 90% of the weight of said layers, based on said formulation.

In a layer comprising silicon and zirconium nitride according to the invention, the Si/Zr atomic ratio is between 1.5 and 6.0, and preferably is between 2.0 and 5.5, or even included between 2.5 and 5.0. More preferably, said layers consist essentially of silicon nitride and zirconium, but may also include aluminum. Aluminum is used in a well-known manner, in proportions of up to 10 atomic%, based on the sum of the elements Si Zr and Al, or even more and preferably between 1 and 8 atomic%, on the basis of the sum of the elements Si Zr and Al, in the silicon targets used for the deposition of layers by cathodic sputtering assisted by a magnetic field (magnetron).

The coatings according to the invention are conventionally deposited by field-assisted vacuum spraying type deposition techniques. magnetic of a cathode of the material or of a precursor of the material to be deposited, often called magnetron sputtering technique in the field. Such a technique is now conventionally used, particularly when the coating to be deposited consists of a complex stack of successive layers with thicknesses of a few nanometers or a few tens of nanometers.

By the terms “underlayer” and “overlayer”, reference is made in the present description to the respective position of said layers relative to the absorbent layer comprising niobium nitride in the stack, said stack being supported by the glass substrate taken as a reference.

In particular, the underlayer is generally the layer in contact with the glass substrate and the overlayer is the outermost layer of the stack, facing away from the substrate.

The terms “above” or “below”, unless otherwise stated, are understood to refer to the surface of the substrate on which the stack is placed.

If the application more particularly targeted by the invention is glazing for buildings, it is clear that other applications are possible, in particular in vehicle glazing (apart from the windshield where very high high light transmission), such as side windows, car roof, rear window. The invention and its advantages are described in more detail below, using the non-limiting examples below, according to the invention and comparative. In all examples and description, the thicknesses given are physical.

All substrates are 6 mm thick clear glass of the Planiclear® type marketed by the company Saint-Gobain Glass France.

All layers are deposited in a known manner by magnetic field-assisted cathode sputtering (often called magnetron).

In a well-known manner, the different successive layers are deposited in the successive compartments of the cathode sputtering device, each compartment being provided with a specific metallic target (for example in Si, or Nb) chosen for the deposition of a specific layer of stacking.

More precisely, the layers based on silicon nitride are deposited in a first compartment of the device from a metallic silicon target (doped with 8% by mass of aluminum), in a reactive atmosphere containing nitrogen ( 40% Ar and 60% N2). The silicon nitride layers, denoted SisN4 by convenience, therefore also contain aluminum. These layers are subsequently designated according to the classic general formulation Si3N4, even if the deposited layer does not necessarily meet this assumed stoichiometry.

The layers based on silicon nitride and zirconium are deposited in a first compartment of the device from a target of silicon and zirconium whose Si/Zr ratio is equal to 4.9 and further comprising 8% by mass of aluminum, in a reactive atmosphere containing nitrogen (40% Ar and 60% N2). The silicon and zirconium nitride layers, denoted SiZrN for convenience, therefore also contain aluminum.

The NbN niobium nitride layers are obtained by sputtering a metallic niobium target in an atmosphere comprising a mixture of nitrogen and argon, according to the conditions described in publication W001/21540 or even in publication W02009/112759.

The silicon oxide layers are obtained using an aluminum-doped silicon target identical to that previously described according to a sputtering process in an atmosphere this time comprising oxygen and argon, according to well-known techniques. of a person skilled in the art.

The titanium oxide layers are obtained by means of a titanium oxide target according to a sputtering process in an atmosphere this time comprising essentially argon and a little oxygen and, according to the well-known techniques of the skilled person.

In the examples 1 to 3 according to the invention which follow, the glass substrate is successively covered, according to current magnetron-assisted cathode sputtering deposition techniques, with a stack successively comprising a layer of niobium nitride surrounded by layers of silicon nitride with a refractive index of 2.0, then layers of titanium oxide, with a refractive index of around 2.4 and silicon oxide, with a refractive index of around 2.4 of 1.45. Niobium nitride is substantially stoichiometric, based on an NbiNi formulation.

A first stack according to example 1 is constituted by the succession of the following layers:

Glass/Si ₃ N ₄ (10 nm) / NbN (7 nm) / Si ₃ N ₄ (11 nm) /TiO ₂ (21 nm) /S iO ₂ (8 nm) The cumulative optical thickness of all of the two layers of Si ₃ N ₄ and TiO ₂ is equal to 72 nm (11 *2+21 x2.4).

A second stack according to example 2 is constituted by the succession of the following layers:

Glass/Si ₃ N ₄ (10 nm) / NbN (7 nm) / Si ₃ N ₄ (10 nm) /TiO ₂ (25nm) /SiO ₂ (10 nm) The cumulative optical thickness of all of the two layers of Si ₃ N ₄ and TiO ₂ is equal to 80 nm.

A third stack according to example 3 is constituted by the succession of the following layers:

Glass/Si ₃ N ₄ (10 nm) /NbN (9 nm) / Si ₃ N ₄ (9 nm) ZTiO ₂ (21 nm) /SiO ₂ (8 nm) The cumulative optical thickness of all of the two layers of Si ₃ N ₄ and TiO ₂ is equal to 68 nm.

Example 4:

In this example, the glass substrate is successively covered, according to current magnetron-assisted cathode sputtering deposition techniques described previously, with a stack successively comprising a layer of silicon nitride with a refractive index of 2.0, a layer of niobium nitride, a layer of silicon nitride and zirconium obtained from the metallic target SiZr previously described and with a refractive index of the order of 2.3 and a layer of silicon oxide, refractive index of the order of 1.45. Niobium nitride is substantially stoichiometric, based on an NbiNi formulation.

The fourth stack according to the invention is therefore constituted by the succession of the following layers:

Glass/Si ₃ N ₄ (10 nm) /NbN (7 nm) / SiZrN (30 nm) / SiO ₂ (8 nm) The optical thickness of the SiZrN layer is equal to 69 nm (30x2.3). The light transmission values TL and external and internal light reflections R _ex t and Rint are measured in the range 380 nm to 780 nm according to the methods described in standard NF EN 410 (2011). The solar factor is measured according to this same standard, between 300 and 2500 nm.

The results obtained are grouped in table 2 which follows, in percentages: [Table 2]

The results reported in Table 2 above show that the glazing obtained from examples 1 to 3 according to the invention have a solar factor less than or close to 50% (0.5), which guarantees good thermal insulation of the building. or the passenger compartment.

It can be seen on the basis of Table 2 that the glazing according to the invention all has a blue color in external reflection.

Finally, we can also see that all the glazing according to the invention, unlike the comparative examples, presents not only a reduced internal reflection but also a difference AR between the exterior reflection and the significantly increased interior reflection. Such a property ensures, as indicated previously, the visual comfort of the occupants of the building or of the passenger compartment equipped by the glazing, in daytime vision as well as in night vision.

Examples 5 and 6:

In example 5, according to another embodiment of the invention, the following stack is described:

Glass/Si3N4 (10 nm) /Nb (4nm) / Si ₃ N4 (12 nm) /TiO ₂ (30nm) /SiO2 (8 nm)

The cumulative optical thickness of all of the two layers of Si ₃ N4 and TiO ₂ is equal to 96 nm.

In example 6, according to another embodiment of the invention, the following stack is described:

Glass/Si ₃ N ₄ (20 nm) /NiCr (5 nm) / Si ₃ N ₄ (8 nm) /TiO ₂ (27nm) /SiO ₂ (8 nm)

The cumulative optical thickness of all of the two layers of Si ₃ N4 and TiO ₂ is equal to 81 nm.

The results obtained are grouped in table 3 below, in percentages: [Table 3]

The results reported in Table 3 above show that the glazing obtained from examples 5 and 6 according to the invention have a solar factor less than or close to 50% (0.5), which guarantees good thermal insulation of the building or the passenger compartment.

It can be seen on the basis of Table 3 that the glazing according to the invention all has a blue color in external reflection.

Finally, we can also see that the glazing according to examples 5 and 6 according to the invention, unlike the comparative examples, present not only a reduced internal reflection but also a difference AR between the exterior reflection and the significantly increased interior reflection.

Examples according to prior art:

We can compare the properties of the stacks of application WO 01/21540 cited above.

Example 4 of application W001/21540 describes a succession of layers in the stack:

Glass / SisN4 (10nm) / Nb (12 nm) / SisN4 (17 nm)

In the table on page 18 of this publication, for a light transmission of 32.3%, it is indicated that the light reflection Ri_ext is 14.4% and the light reflection Runt is 25.3%.

The value of the interior reflection appears too high and greater than that of the exterior reflection, contrary to the objectives sought by the present invention, as described previously.

Likewise, example 6 of application W001/21540 describes a succession of layers in the stack:

Glass / SisN4 (10nm) / NbN (10nm) / SisN4 (15nm)

In the table on page 18 of this publication, the reported values of Ri_ext and Runt are respectively equal to 17.9% and 27.8%. As with the previous stack, we can see that the interior reflection is also much higher for this configuration and the exterior reflection is much too low for the objective sought according to the present invention.

Claims

1. Transparent glass article for anti-solar glazing, comprising at least one glass substrate provided on at least one of its faces with a coating constituted by a stack of layers, said stack comprising the succession of following layers, from the surface of said substrate:

- a layer comprising a nitride of at least one element chosen from Si, Al, said nitride optionally comprising Zr, with a physical thickness of between 1 and 25 nm, preferably between 5 and 20 nm,

- an infrared absorbing layer, constituted by a material comprising niobium or by a material comprising nickel and chromium, with a physical thickness of between 1 and 20 nm, preferably between 5 and 15 nm,

- a layer whose optical thickness is between 60 and 100 nm, preferably between 65 and 95 nm, comprising a nitride of at least one element chosen from Si, Al, said nitride further comprising Zr, in contact with the infrared absorbing layer, with a refractive index at 550 nm greater than 2.2 or a set of layers whose total optical thickness is between 60 and 100 nm, preferably between 65 and 95 nm, said set comprising or being constituted by a layer comprising a nitride of at least one element chosen from Si, Al, said nitride optionally comprising Zr, in contact with the infrared absorbing layer and by a layer of a dielectric material with a refractive index at 550 nm greater than 2.2, with a physical thickness greater than 15 nm.

2. Glass article according to claim 1, in which the stack only comprises an IR absorbing layer.

3. Glass article according to one of the preceding claims, in which the succession of layers comprises said layer of a dielectric material with a refractive index at 550 nm less than 1.6, and in which said layer of a dielectric material of refractive index at 550 nm greater than 2.2 has a thickness physical preferably at least 1.5 times greater than said layer of a dielectric material with a refractive index at 550 nm less than 1.6.

4. Article according to one of the preceding claims, in which the layer of a dielectric material with a refractive index at 550 nm greater than 2.2, of thickness greater than 15 nm and the layer of a dielectric material of refractive index at 550 nm less than 1.6 have a total cumulative physical thickness of between 25 and 50 nm, preferably between 25 and 35 nm.

5. Article according to one of the preceding claims in which the layers comprising a nitride of at least one element chosen from Si, Al, and optionally comprising Zr, are in contact with the absorbent layer.

6. Article according to one of the preceding claims in which the dielectric material with a refractive index at 550 nm greater than 2.2 in said set of layers comprises an oxide of at least one element chosen from titanium, niobium, zirconium or their mixture, in particular comprises titanium oxide, niobium oxide, zirconium oxide, or a silicon and zirconium nitride or a silicon, aluminum and zirconium nitride .

7. Article according to one of the preceding claims in which the dielectric material with a refractive index at 550 nm less than 1.6 comprises silicon oxide or a silicon oxynitride, preferably silicon oxide.

8. Article according to one of the preceding claims in which the material constituting the absorbent layer is chosen from a material comprising, and preferably consisting essentially of, niobium or niobium nitride, preferably niobium nitride.

9. Article according to one of the preceding claims in which the material constituting the absorbent layer is chosen from niobium or an alloy of niobium with at least one other metal, the niobium representing at least 50% of the metal atoms present in said material, preferably representing at least 80% of the metal atoms present in said material.

10. Article according to one of claims 1 to 8 in which the material constituting the absorbent layer comprises a niobium nitride or a niobium nitride and at least one other metal, the niobium representing at least 50% of the atoms metals present in said material, preferably representing at least 80% of the metal atoms present in said material.

11. Article according to one of claims 1 to 7 in which the material constituting the absorbent layer comprises a nickel and chromium alloy or a nitride of a nickel and chromium alloy, in which the Ni/Cr atomic ratio varies between 2 and 9, preferably between 3 and 5.

12. Article according to one of the preceding claims in which the stack consists solely of the layers described in said claims.

13. Article according to one of the preceding claims, in which the stack comprises or is constituted by the succession of the following layers, each layer being in direct contact with the next, from the surface of said substrate:

SiN/CA/SiN/TiO/ preferably SiO/ optionally TiO, ZrO or TiZrO in which SiN designates layers comprising silicon nitride, CA designates the absorbent layer, in particular a layer of niobium nitride or niobium, SiO designates a layer comprising silicon oxide, TiO designates a layer comprising titanium oxide, ZrO designates a layer comprising zirconium oxide and TiZrO designates a layer comprising titanium and zirconium oxide.

14. Article according to one of claims 1 to 12, in which the stack comprises or is constituted by the succession of the following layers, each layer being in direct contact with the next, from the surface of said substrate:

SiN/CA/SiN/NbO/ preferably SiO /optionally TiO, ZrO or TiZrO, in which SiN designates layers comprising silicon nitride, CA designates the absorbent layer, in particular a layer of niobium nitride or niobium, SiO designates a layer comprising silicon oxide, NbO designates a layer comprising niobium oxide, TiO designates a layer comprising a titanium oxide, ZrO designates a layer comprising a zirconium oxide and TiZrO designates a layer comprising an oxide titanium and zirconium.

15. Article according to one of claims 1 to 12, in which the stack comprises or preferably is constituted by the succession of the following layers, each layer being in direct contact with the next and from the surface of said substrate:

SiN/CA/SiNZ SiZrN/ preferably SiO/optionally TiO, ZrO or TiZrO in which SiN designates layers comprising silicon nitride, CA designates the absorbent layer, in particular a layer of niobium nitride or niobium, SiO designates a layer comprising silicon oxide, SiZrN designates a layer comprising silicon and zirconium nitride, TiO designates a layer comprising titanium oxide, ZrO designates a layer comprising zirconium oxide and TiZrO designates a layer comprising a titanium and zirconium oxide.

16. Article according to one of claims 1 to 12, in which the stack comprises or preferably is constituted by the succession of the following layers, each layer being in direct contact with the next and from the surface of said substrate:

17. Article according to one of the preceding claims, characterized in that the stack does not include layers based on Ag, Au, Pt, Cu, Ni or stainless steel.

18. Article according to one of the preceding claims, in which the layer of a dielectric material with a refractive index at 550 nm greater than 2.2 has a physical thickness greater than or equal to 20 nm.