FR3111631A1 - SOLAR CONTROL GLASS CONSISTING OF A TITANIUM NITRIDE BASED LAYER AND AN ITO BASED LAYER - Google Patents

Abstract

Heatable glass article with solar control properties comprising at least one glass substrate provided with a stack of layers, in which said stack comprises successively, from the surface of said substrate, two layers with infrared reflection properties, one of which comprises titanium nitride and the other comprises indium tin oxide ITO, said two layers being separated by at least one dielectric layer.

Description

SOLAR CONTROL GLAZING COMPRISING A TITANIUM NITRIDE BASED LAYER AND AN ITO BASED LAYER

The invention relates to so-called "low-e" low-emissivity insulating glazing, provided with stacks of so-called functional thin layers, that is to say acting on solar and/or thermal radiation essentially by reflection and/or absorption of near (solar) or far (thermal) infrared radiation. The application more particularly targeted by the invention is primarily vehicle glazing, such as side windows, car roofs, rear windows. Without departing from the scope of the invention, this glazing can also be used in the building sector, as solar control glazing.

“Functional” or even “active” layer is understood to mean, within the meaning of the present application, the layers of the stack which give the stack most of its thermal insulation properties. Most often, the stacks of thin layers with which the glazing unit gives it substantially improved insulation properties, very essentially through the intrinsic properties of said active layers. Said layers act on the flux of thermal infrared radiation passing through said glazing, as opposed to the other layers, generally made of dielectric material and most often mainly having the function of chemical or mechanical protection of said functional layers. By dielectric material is meant a material whose massive shape and devoid of impurities has a high resistivity, in particular a resistivity initially greater than 10 ¹⁰ ohms.meters (Ω.m) at 25°C.

Such glazing provided with stacks of thin layers act on the incident solar radiation either essentially by the absorption of the incident radiation by the functional layer or layers, or essentially by reflection by these same layers.

They are grouped under the designation of solar control glazing. They are mainly marketed and used:
- either to essentially ensure protection of the passenger compartment (car) or the dwelling from solar radiation and to avoid overheating, such glazing being qualified in the field of solar protection,
- either essentially to ensure thermal insulation of the passenger compartment or dwelling and to prevent heat loss, these glazings being qualified as insulating glazings.

By thermal insulation, is meant within the meaning of the present invention a glazing provided with at least one functional layer giving it reduced energy loss, said layer having properties of reflection of IR radiation of between 5 and 50 micrometers. The functional layers used in this function have a high IR radiation reflection coefficient and are called low-emissive (or more often low-e according to the English term). A classic parameter used in the field to assess this capacity is the normal emissivity ε _n of the glazing, as calculated in standard ISO 10292 (1994), appendix A. The lower this value, the more the stack comprising the functional layers reflect thermal IR and the better the thermal insulation provided by the glass article provided with said stack.

In addition, insulating glazing in the sense described above is currently being sought while also providing improved visual comfort, in particular in the field of automobiles (as side glazing, rear window glazing or even as glazed roof) or building and in particular a "private" comfort, that is to say that the passengers of the vehicle or the occupants of the building fitted with said glazing are not or hardly visible from the outside in daylight but can on their side see without no interference with the external environment.

To obtain such an effect, it is necessary to be able to offer glass articles incorporating stacks that reflect infrared having the following characteristics, when said stack is deposited on a clear glass substrate: low emissivity, in particular less than 30% and preferably of the order of 15% to 30%, a moderate light transmission, of the order of 20 to 60%, a strong side reflection of the surface of the uncoated glass, in particular greater than 20% associated with a weak reflection of the side of the face of the glass coated with the stack, in particular less than 10% and a difference between the exterior and interior reflections of at least 10%, or even of at least 15%.

In the present description, the surfaces of the glass article are designated as a function either of the positioning of the stack of layers, or of the positioning of the latter in the vehicle or the building which it occupies. More precisely, one can describe indifferently:

• the stacking side of the article, which corresponds to its side facing the interior of the vehicle or building and coated with said stacking and
• the glass side of the item, which corresponds to its bare side facing the outside of the vehicle or building it equips.

In general, all the luminous and thermal characteristics presented in this description are obtained according to the principles and methods described in the international standards ISO 9050 (2003) and ISO 10292 (1994), relating respectively to the determination of the luminous characteristics and energy of the glazing used in glass for construction.

The most efficient stacks currently marketed to solve the above problems and deposited by magnetron sputtering techniques incorporate a metallic layer of the Silver type operating essentially in the mode of reflection of a major part of the IR (infrared) radiation. incident. These stacks are thus mainly used as low-emissivity (or low-e) glazing for the thermal insulation of buildings. These layers are however very sensitive to humidity and are therefore exclusively used in double glazing, facing 2 or 3 of them, to be protected from humidity. The stacks according to the invention do not include such layers of the silver type, or else of the gold or platinum type or even copper. More generally, the stacks according to the invention do not contain such precious metals, or else in very negligible quantities, in particular in the form of unavoidable impurities.

The development of new stacks is made necessary to solve the technical problem previously exposed.

It has already been described in applications US2016/0002100 and WO2018/156568 a solar control glazing comprising a stack comprising above the glass surface and in this order an infrared-reflecting layer in ITO and above that- ci an absorbent layer based on titanium nitride, the two layers being separated by a layer of silicon nitride. The experiments and modeling carried out by the applicant company have shown that such glazing does not, however, make it possible to satisfactorily obtain the desired privacy effect, in particular due to too low an external light reflection, of the order of 15%. even less.

According to the results obtained by the applicant company, the previous problems have been solved by glass articles as now described:

According to a first aspect, the present invention relates to a thermally insulating glass article, comprising at least one glass substrate provided with a stack of layers, in which the stack comprises successively from the surface of said substrate:

- preferably a first module M ₁ constituted by a layer based on a dielectric material of thickness e1 or by a set of layers based on dielectric materials of cumulative thickness e ₁ ,

- a first TiN layer comprising titanium nitride, with a thickness of between 5 nanometers and 40 nanometers,

- a second module M ₂ constituted by a layer based on a dielectric material of thickness e ₂ or by a set of layers based on dielectric materials of cumulative thickness e ₂ ,

- an ITO layer comprising an oxide of indium and tin, with a thickness of between 5 nanometers and 70 nanometers,

- a third module M ₃ constituted by a layer based on a dielectric material of thickness e ₃ or by a set of layers based on dielectric materials of cumulative thickness e ₃ ,

in which e ₁ is less than 70 nanometers, preferably between 1 and 70 nm, e ₂ is between 5 nm and 100 nm and e ₃ is greater than 10 nanometers, preferably between 10 and 100 nm.

According to preferred embodiments of the present invention, which can obviously be combined if necessary with each other:

• Said dielectrics are chosen from a silicon nitride, an aluminum nitride, a tin oxide, a mixed oxide of zinc and tin, a silicon oxide, a titanium oxide, a silicon oxynitride, preferably a silicon nitride, silicon oxide or silicon oxynitride.
• The coating does not contain a layer based on silver or gold or even copper or nickel.
• M ₁ is a single layer comprising silicon nitride and preferably based on silicon nitride.
• The module M ₃ comprises and preferably consists of a layer comprising silicon oxide or silicon oxynitride and optionally an overlayer of titanium oxide, zirconium oxide or titanium and zirconium oxide.
• The module M ₂ comprises, and preferably consists of, a layer comprising silicon oxide or silicon oxynitride.
• An intermediate layer of titanium, aluminum, silicon, an alloy of at least two of these elements, or a nickel-chromium alloy is deposited between the layer comprising titanium nitride and the layer comprising a dielectric chosen from a tin oxide, a mixed oxide of zinc and tin, a silicon oxide, a titanium oxide, a silicon oxynitride, in particular a silicon oxide or a silicon oxynitride.
• M ₁ and M ₂ and preferably M ₃ comprise, or consist of, a layer comprising silicon nitride and preferably based on silicon nitride.
• Said coating comprises, and preferably consists of, the following succession of layers, starting from the surface of the substrate:
  - a layer based on silicon nitride with a thickness e ₁ preferably between 5 nm and 60 nm, preferably between 10 and 50 nm,
  - a layer comprising titanium nitride, with a thickness between 5 nm and 30 nm, preferably between 5 and 25 nm
  - a layer based on silicon nitride, with a thickness e ₂ of between 10 nm and 70 nm, preferably with a thickness of between 10 and 30 nm,
  - a layer comprising indium tin oxide, with a thickness of between 10 and 60 nanometers, preferably between 20 and 50 nm,
  - a layer M ₃ based on silicon nitride with a thickness e ₃ greater than 10 nm, preferably between 20 nm and 65 nanometers, or a set of dielectric layers M ₃ , including at least one layer based on silicon nitride silicon with a thickness greater than 10 nm, preferably between 25 nanometers and 60 nanometers,

- optionally a layer based on titanium oxide, titanium oxide and zirconium or a layer of zirconium oxide, with a thickness preferably between 1 and 10 nm.

- Said coating comprises, and preferably consists of, the following succession of layers, starting from the surface of the substrate:
- a first layer M ₁ based on silicon nitride with a thickness e ₁ preferably between 1 nm and 50 nm, preferably between 2 and 30 nm,
- a layer comprising titanium nitride, with a thickness between 5 nm and 30 nanometers, preferably between 7 and 25 nm,
- optionally an intermediate layer of titanium, aluminum, silicon, an alloy of at least two of these elements, or a nickel-chromium alloy, with a thickness between 0.5 and 7 nm, of preferably between 1 and 6 nm,

- a layer M ₂ based on silicon oxide or silicon oxynitride, with a thickness e ₂ of between 20 nm and 65 nm,
- a layer comprising indium and tin oxide, with a thickness of between 10 and 60 nanometers, preferably between 20 and 50 nm,
- a single third layer M ₃ comprising silicon oxide or silicon oxynitride with a thickness e ₃ greater than 10 nm, in particular between 20 nm and 80 nanometers, preferably between 30 and 70 nm,

- optionally a layer based on titanium oxide, titanium oxide and zirconium or a layer of zirconium oxide, with a thickness of between 1 and 10 nm.

• The stack comprises, and preferably consists of, successively from the surface of said substrate:
  - a first module M₁consisting of a layer based on a dielectric material of thicknesse ₁ or by a set of layers based on dielectric materials of cumulative thicknesse ₁ , said thicknesse ₁ being preferably between 1 and 50 nm, more preferably between 5 and 30 nm,

- a first TiN layer₁comprising titanium nitride, with a thickness of between 5 nanometers and 40 nanometers, preferably between 5 and 30 nm,
- a second module M₂consisting of a layer based on a dielectric material of thicknesse ₂ or by a set of layers based on dielectric materials of cumulative thicknesse ₂ ,said thicknesse ₂ being preferably between 10 and 80 nm, more preferably between 20 and 70 nm,
- an ITO layer comprising an oxide of indium and tin, with a thickness of between 5 nanometers and 70 nanometers, preferably between 10 and 50 nm,
- a third module M₃consisting of a layer based on a dielectric material of thicknesse ₃ or by a set of layers based on dielectric materials of cumulative thicknesse ₃ , said thicknesse ₃ being preferably between 10 and 80 nm, more preferably between 20 and 50 nm,
- a second TiN layer₂comprising titanium nitride, with a thickness of between 5 nanometers and 40 nanometers, preferably between 10 and 35 nm,

- a fourth module M ₄ constituted by a layer based on a dielectric material with a thickness e ₄ or by a set of layers based on dielectric materials with a cumulative thickness e ₄ , in which e ₄ is greater than 10 nanometers, preferably between 20 and 80 nm.

- According to this last mode, the module M ₄ comprises, and preferably consists of, a layer comprising silicon nitride, silicon oxide or silicon oxynitride and optionally an overlayer of titanium oxide, in zirconium oxide or titanium and zirconium oxide.

- The glass substrate is tempered or curved.

The invention also relates to automobile glazing, in particular a car roof for a car, comprising a glass article as described above and comprising a single glass substrate, in which said substrate is preferentially tinted in its mass, and in which said stack is preferably positioned towards the face of the glazing exposed towards the interior of the vehicle or of the building that it equips.

The invention relates in particular to automobile glazing, in particular automobile roof for automobile, comprising a first glass substrate, preferably colored in its mass, bonded by an intermediate thermoplastic sheet, in particular in PVB, to a glass article as described previously, whose substrate is preferably made of clear glass and in which the stack of layers is preferably arranged on the face exposed towards the outside of said glazing.

The invention also relates to glazing for buildings, comprising a glass article as described above. Said glazing for buildings may comprise one, two or three glass substrates in the form of single glazing or double glazing or even triple glazing for buildings, in which the successive glass substrates are separated from each other by gas blades and most often interconnected by spacers.

According to other preferred characteristics of the invention which can of course be combined with each other if necessary:

- The thickness e ₁ of the first module M ₁ is less than 60 nm, or even less than 50 nm, in particular between 1 nm and 50 nanometers, limits included.

- The thickness e ₂ of the second module M ₂ is between 10 nm and 80 nm inclusive terminals, preferably is between 20 nm and 60 nm inclusive terminals

- The thickness e ₃ of the third module M ₃ is between 20 nm and 80 nanometers, terminals included, preferably is between 25 nm and 70 nanometers, terminals included and very preferably is between 30 nm and 60 nanometers, terminals included

- The thickness e ₄ of the fourth module M ₄ is between 20 nm and 65 nanometers, terminals included, preferably is between 25 nm and 60 nanometers, terminals included and very preferably is between 30 nm and 50 nanometers, terminals included.

- The TiN thickness of the first layer based on titanium nitride below the ITO layer is between 10 nm and 40 nanometers, limits included, preferably between 15 nm and 30 nanometers, limits included.

- The TiN thickness of the second optional layer based on titanium nitride above the ITO layer is between 5 nm and 20 nanometers, limits included, preferably between 7 nm and 15 nanometers, limits included.

- The ITO-based layer comprises, in mass proportions and on the basis of simple oxides, between 70 and 95% indium oxide and 5 to 20% tin oxide. A typical proportion by mass, still on the basis of simple oxides, is about 90% by mass of indium oxide In ₂ O ₃ for about 10% by mass of SnO ₂ .

- The modules M ₁ , M ₂ and preferably M ₃ comprise silicon nitride, in the form of a single layer or a set of layers including at least one layer comprising silicon nitride.

- M ₁ comprises a layer comprising silicon nitride,

- M ₂ comprises a layer comprising silicon nitride.

- M ₃ comprises a layer comprising silicon nitride.

- M ₄ comprises a layer comprising silicon nitride.

- M ₁ and M ₂ are single layers.

- M ₁ and M ₂ and M ₃ are single layers.

- M ₁ and M ₂ are based on silicon nitride.

- M ₁ , M ₂ and M ₃ are based on silicon nitride.

- M ₁ , M ₂ , M ₃ and if necessary M ₄ are based on silicon nitride.

- M ₁ is a single layer based on silicon nitride or consists essentially of silicon nitride and is in direct contact with the layer comprising titanium nitride,

- The module(s) M ₂ and M ₃ and where appropriate M ₄ comprise and preferably are based on materials chosen from among a silicon oxide, a titanium oxide, or a silicon oxynitride, more preferably a silicon oxide or a silicon oxynitride.

- Layers based on silicon oxynitride are preferably characterized by a refractive index at 550 nm, intermediate between a non-nitrided oxide layer and a non-oxidized nitride layer. The layers based on silicon oxynitride preferably have a refractive index at 550 nm greater than 1.55, preferably greater than 1.60 or even greater than 1.70 or alternatively between 1.55 and 1.99 ; more preferably between 1.60 and 1.97; even between 1.70 and 1.95 or even between 1.70 and 1.90.

- The silicon oxynitride material according to the invention may in particular have an O/(O+N) molar ratio of between 0.94 and 0.25, more preferably between 0.87 and 0.36.

- The glass substrate on which the stack is placed is made of clear glass.

- The glass article is inserted into a laminated glazing comprising two glass substrates assembled by a thermoplastic sheet, one of which corresponds to that of the glass article previously described, in such a way that the stack of layers described above is arranged towards a outer surface of said glazing.

- The preceding glazing comprises a first glass substrate, preferably colored in its mass, bonded to a second substrate by an intermediate thermoplastic sheet, in particular of PVB, said second substrate being made of clear glass and provided with said stack of layers preferably arranged on its face exposed towards the outside of said article or glazing. By colored in its mass, it is meant that the substrate includes in its glass composition elements aimed at giving it a coloring (i.e. different from that of a so-called "clear" glass), in particular elements such as cobalt, iron , selenium, or even chromium, which can also aim to reduce light transmission.

- The said glass substrate or substrates are tempered or curved.

Preferably, the titanium nitride layers are based on titanium nitride or more preferably consist essentially of titanium nitride.

Layers based on titanium according to the invention comprise for example more than 50% by weight of titanium nitride, preferably more than 80% or even more than 90% by weight of titanium nitride.

The titanium nitride according to the invention is not necessarily stoichiometric (Ti/N atomic ratio of 1) but can be over- or under-stoichiometric. According to an advantageous mode, the N/Ti ratio is between 1 and 1.2. Also, the titanium nitride according to the invention can comprise a minor quantity of oxygen, for example between 1 and 10% molar of oxygen, in particular between 1 and 5% molar of oxygen.

According to a particularly preferred mode, the titanium nitride layers according to the invention correspond to the general formula TiN _x O _y , in which 1.00 <x <1.20 and in which 0.01 <y <0.10.

Within the meaning of the present invention, the term indium-tin oxide (or indium oxide doped with tin or ITO for the English name: Indium tin oxide) is understood to mean a mixed oxide or a mixture obtained from the oxides indium(III) (In ₂ O ₃ ) and tin (IV) (SnO ₂ ), preferably in mass proportions of between 70 and 95% for the first oxide and 5 to 20% for the second oxide. A typical mass proportion is approximately 90% by mass of In ₂ O ₃ for approximately 10% by mass of SnO ₂ .

The dielectric materials, once deposited in thin layers, can however comprise additional elements which substantially increase their electrical conductivity, useful for example for improving the yield of cathode sputtering of the precursor material constituting the magnetron target. The dielectric layers of the modules M ₁ , M ₂ and M ₃ according to the invention can be layers based on a material chosen from among a silicon nitride, an aluminum nitride, a tin oxide, a mixed oxide of zinc or tin, a silicon oxide, a titanium oxide, a silicon oxynitride. Preferably the modules M ₁ , M ₂ and M ₃ consist of a single layer. The single layer constituting the module M1 is preferably based on silicon nitride. The single layer constituting the module M ₂ is preferably based on tin oxide, mixed oxide of zinc and tin, silicon oxide, titanium oxide, silicon oxynitride. In particular, a layer based on a material consists mainly, for example for more than 50% by weight, preferably for more than 80% or even more than 90% by weight, of such a material. It may in particular contain other minority elements, in particular in substitution for the cations, in particular to promote their deposition in the form of thin layers by the usual techniques of magnetron sputtering as described previously. By way of example, the layers according to the present invention based on silicon nitride or based on silicon oxynitride, or even based on silicon oxide, in particular those deposited by magnetron, most often comprise elements of the type Al, Zr, B, etc., in proportions which can go for example up to 10 atomic % or even sometimes up to 20 atomic % or even 30 atomic %, on the basis of the total molar content of the layer in elements other than oxygen and nitrogen. Similarly, the titanium oxide layers may comprise, in substitution for titanium, other metal cations such as zirconium, without departing from the scope of the present invention.

According to an advantageous aspect of the present invention, the layers based on oxide or oxynitride as described above, when they are in the immediate vicinity of a layer comprising titanium nitride in the stack according to the invention, are separated from that by an intermediate layer based on titanium, aluminum, silicon, an alloy of at least two of these elements, or according to a less preferred alternative, a nickel-chromium alloy. Preferably this intermediate layer is based on titanium.

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

The glass article or the glazing according to the invention can be a single glazing in which the stack of thin layers being arranged on face 2 of the single glazing by numbering the faces of the substrate from the outside towards the inside of the building or the passenger compartment it equips.

According to another embodiment, in particular for use in the automotive field, the article according to the invention can be integrated into a laminated glazing, comprising two glass substrates assembled by a thermoplastic sheet, one of said substrates being provided with a stack of layers as previously described. Preferably, the stack is deposited on the face of the substrate facing the interior of the building or the passenger compartment that it equips.

The substrates and glazings described above can of course be heat-tempered and/or bent if necessary.

A method of manufacturing a glass article or a glazing according to the invention comprises for example at least the following steps:
- a glass substrate is introduced into a sputtering device,
- in a first compartment, at least one sub-layer of a dielectric material is deposited,
- in a subsequent compartment, a titanium target is sputtered by means of a plasma generated from a gas comprising nitrogen,
- in a subsequent compartment, at least one intermediate layer of a dielectric material is deposited,
- in a subsequent compartment, a tin and indium oxide target is sputtered by means of a plasma generated from a gas comprising nitrogen,
- In a subsequent compartment, at least one overlayer of a dielectric material is deposited.

The terms “above” and “below” refer to an observation point corresponding to the surface of the glass substrate.

By the terms “under-layer” and “over-layer”, reference is made in the present description to the respective position of said layers with respect to the functional layer(s) in the stack, said stack being supported by the glass substrate . In particular, when the stack contains a single underlayer and a single overlayer, the underlayer is the layer in contact with the glass substrate and the overlayer is the outermost layer of the stack, facing away from the substrate .

The term “intermediate layer” denotes the layer or layers arranged between two functional layers.

By thickness of a layer, is meant within the meaning of the present invention the actual geometric thickness of the layer, such as it can be measured in particular by the conventional techniques of electron microscopy or other.

The invention and its advantages are described in more detail, below, by means of the non-limiting examples below, according to the invention and comparative. In all examples and description, unless otherwise specified, thicknesses given are geometric.

All substrates are 2 clear glass mm thickness of the Planiclear™ type marketed by Saint-Gobain Glass France. All the layers are deposited in a known manner by sputtering assisted by a magnetic field (often called a magnetron).

In a well-known way, the various successive layers are deposited in the successive compartments of the sputtering device, each compartment being provided with a specific metal target in Si, Ti, chosen for the deposition of a specific layer of the stack.

More precisely, the silicon nitride layers are deposited in the device compartments from a metallic silicon target (doped with 8% by mass of aluminium), in a reactive atmosphere containing nitrogen. Silicon nitride layers therefore also contain aluminum.

The titanium nitride layer(s) are deposited in other compartments of the device from a pure metallic titanium target in a reactive atmosphere containing nitrogen and argon.

The ITO layers are deposited from a ceramic target comprising, on the basis of simple oxides, approximately 90% by mass of indium oxide In ₂ O ₃ for approximately 10% by mass of SnO ₂ in an argon atmosphere. containing a small proportion of oxygen.

The magnetron deposition conditions of such layers are technically well known in the field.

In example 1 according to the invention which follow, the glass substrate was thus covered successively with a stack of layers comprising a functional layer of titanium nitride (denoted for convenience TiN thereafter even if the actual stoichiometry of the layer is not necessarily this one), a functional layer of indium and tin oxide ITO and sub-layer (first layer M ₁ ), over-layer (third layer M ₃ ) and intermediate layer (second layer M ₂ ) based on silicon nitride (denoted for convenience Si ₃ N ₄ hereinafter even if the actual stoichiometry of the layer is not necessarily this) or based on silicon oxide.

In example 2 according to a particularly advantageous embodiment of the invention, a second functional layer of titanium nitride was added above the stack, separated from the ITO layer by a layer of silicon nitride .

In examples 3 to 5 according to the invention, layers based on silicon oxide were used to form the modules M ₂ and M ₃ .

Comparative Example 6 relates to a stack comprising only a single layer based on titanium nitride.

The deposition conditions were adjusted according to conventional techniques for magnetron deposition to obtain different stacks, the succession of layers and their thicknesses (in nanometers nm) of which are reported in Table 1 below.

The thermal and optical characteristics of the glass articles have been measured according to the following principles and standards:

1°) Optical properties:

The measurements of examples 1 to 6 are carried out on glass articles obtained experimentally in accordance with European standard ISO 9050 (2003). More specifically, the light transmission T _L and the light reflections on the side coated by the stack (Rc) and on the side of the surface of the uncoated glass (Rg) are measured between 380 and 780 nm depending on the illuminant D ₆₅ . The same characteristics are calculated for examples 7 to 9 according to the techniques and principles that are well known and mastered today in the field of stacks of thin layers.

2°) Thermal properties:

The thermal insulation properties of the glass articles according to Examples 1 to 6 are evaluated by determining the emissivity at normal incidence ε _n measured on the inner face of the substrate covered with the stack of layers, according to the conditions described in the ISO 10292 (1994), Annex A.

The values of light transmission T _L , of light reflection on the stack side and on the glass side and of the normal emissivity ε _n (in percentages) are measured for the substrates provided with the stacks according to Examples 1 to 6.

Examples 7 and 8 are examples modeled and corresponding to the teaching of publication WO201815658 of the prior art relating to a glazing provided with a stack first comprising a layer of ITO close to the substrate and surmounted by a layer of titanium nitride.

Example 9 is a modeled example corresponding to the teaching of publication US2016/002100 belonging to the present applicant and describing (see example 8 of US2016/002100) a glazing comprising a clear or tinted substrate in its mass on which is deposited a stack also comprising the succession firstly of an ITO layer then of a TiN layer.

Ex. Ex.1 Ex.2 Example 3 Ex.4 Example 5 Formerly 6* Formerly 7* Ex 8* Ex 9* Clear glass substrate surface s. clear glass s. tinted glass If ₃ N ₄ (M ₁ ) 20 16 13 5 5 20 - - 35 ( _SiO2 ) TiN 20 8 16 16 15 20 - - - - You - - 5 5 5 - - - - - SiO ₂ (M ₂ ) - - 15 16 15 - - - - - If ₃ N ₄ (M ₂ ) 20 60 - - - 70 - - - - IoT 30 30 40 40 32 - 33 33 120 If ₃ N ₄ (M ₃ ) 20 36 - - - - 30 2 20 SiO ₂ (M ₃ ) - - 58 44 48 - - - - TiN - 28 - - - - 20 18 20 If ₃ N ₄ (M ₄ ) - 38 - - - - 45 39 70 ( _SiO2 ) Optical and thermal properties T _L (%) 54 34 43 42 45 53 50 58 52 16 RC (%) 6 3 9 7 4 9 3 7 4 3 Rg (%) 22 25 21 26 25 24 15 15 15 5 _εn (%) 28 20 25 25 28 40 NM NM NM NM

*excluding invention; NM = Not Measured

It is observed that the glass articles according to Examples 1 to 6 in accordance with the present invention have a low light reflection on the side of the stack (R _c less than 10%) and on the contrary a high light reflection on the glass side (R _L greater than 20%) for according without however the light transmission being too high. Such characteristics make such articles suitable for use allowing unobstructed vision of the exterior of the vehicle for the occupants of the vehicle or of the building equipped with such glazing and the privacy effect described above.

Example 2 according to the invention also has the advantage of providing further improved thermal insulation with a significantly lower emissivity value.

In addition, all the examples according to the invention show a significant improvement in the normal emissivity compared with comparative example 6 comprising only a single layer of titanium nitride. A lower emissivity makes it possible to conclude that the glazing obtained from glass articles according to the invention is better thermally insulated.

Examples 7 to 9 according to the prior art have values of the external reflection (that is to say on the bare surface side of the glass) that are too low to effectively perform the function sought according to the invention (private effect).

Claims (17)

Glass article comprising at least one glass substrate provided with a stack of layers, in which the stack comprises successively from the surface of said substrate:
- preferably a first module M₁consisting of a layer based on a dielectric material of thicknesse ₁ or by a set of layers based on dielectric materials of cumulative thicknesse ₁ ,
- a first TiN layer comprising titanium nitride, with a thickness of between 5 nanometers and 40 nanometers,
- a second module M₂consisting of a layer based on a dielectric material of thicknesse ₂ or by a set of layers based on dielectric materials of cumulative thicknesse ₂ ,
- an ITO layer comprising an oxide of indium and tin, with a thickness of between 5 nanometers and 70 nanometers,
- a third module M₃consisting of a layer based on a dielectric material of thicknesse ₃ or by a set of layers based on dielectric materials of cumulative thicknesse ₃ ,
in whiche ₁ is less than 70 nanometers, preferably between 1 and 70 nm,e ₂ is between 5 nm and 100 nm ande ₃ is greater than 10 nanometers, preferably between 10 and 100 nm. Glass article according to Claim 1, in which the said dielectric materials are chosen from among a silicon nitride, an aluminum nitride, a tin oxide, a mixed oxide of zinc and tin, a silicon oxide, a titanium, silicon oxynitride, preferably silicon nitride, silicon oxide or silicon oxynitride. Glass article according to one of the preceding claims, in which the coating does not contain a layer based on silver or gold. Glass article according to one of the preceding claims, in which M ₁ is a single layer comprising silicon nitride. Glass article according to one of the preceding claims, in which the module M ₃ comprises and preferably consists of a layer comprising silicon oxide or silicon oxynitride and optionally an overlayer of titanium oxide, silicon oxide zirconium or titanium oxide and zirconium. Glass article according to one of the preceding claims, in which the module M ₂ comprises, and preferably consists of, a layer comprising silicon oxide or silicon oxynitride. Glass article according to one of Claims 5 or 6, in which an intermediate layer of titanium, aluminium, silicon, an alloy of at least two of these elements, or a nickel-chromium alloy is deposited between the layer comprising titanium nitride and the layer comprising a dielectric material chosen from a tin oxide, a mixed oxide of zinc and tin, a silicon oxide, a titanium oxide, a silicon oxynitride, in particular an oxide or an oxynitride of silicon. Glass article according to one of the preceding claims, in which M ₁ and M ₂ and preferably M ₃ comprise, or consist of, a layer comprising silicon nitride and preferably based on silicon nitride. Glass article according to the preceding claim, in which said coating comprises, and preferably consists of, the following succession of layers, starting from the surface of the substrate:
- a layer based on silicon nitride with a thickness e ₁ preferably between 5 nm and 60 nm, preferably between 10 and 50 nm,
- a layer comprising titanium nitride, with a thickness between 5 nm and 30 nm, preferably between 5 and 25 nm
- a layer based on silicon nitride, with a thickness e ₂ of between 10 nm and 70 nm, preferably with a thickness of between 10 and 30 nm,
- a layer comprising indium tin oxide, with a thickness of between 10 and 60 nanometers, preferably between 20 and 50 nm,
- a layer M ₃ based on silicon nitride with a thickness e ₃ greater than 10 nm, preferably between 20 nm and 65 nanometers, or a set of dielectric layers M ₃ , including at least one layer based on silicon nitride silicon with a thickness greater than 10 nm, preferably between 25 nanometers and 60 nanometers,
- optionally a layer based on titanium oxide, titanium oxide and zirconium or a layer of zirconium oxide, with a thickness preferably between 1 and 10 nm. Glass article according to one of Claims 1 to 7, in which the said coating comprises, and preferably consists of, the following succession of layers, starting from the surface of the substrate:
- a first layer M ₁ based on silicon nitride with a thickness e ₁ preferably between 1 nm and 50 nm, preferably between 2 and 30 nm,
- a layer comprising titanium nitride, with a thickness between 5 nm and 30 nanometers, preferably between 7 and 25 nm,
- optionally an intermediate layer of titanium, aluminum, silicon, an alloy of at least two of these elements, or a nickel-chromium alloy, with a thickness between 0.5 and 7 nm, of preferably between 1 and 6 nm,
- a layer M ₂ based on silicon oxide or silicon oxynitride, with a thickness e ₂ of between 20 nm and 65 nm,
- a layer comprising indium and tin oxide, with a thickness of between 10 and 60 nanometers, preferably between 20 and 50 nm,
- a single third layer M ₃ comprising silicon oxide or silicon oxynitride with a thickness e ₃ greater than 10 nm, in particular between 20 nm and 80 nanometers, preferably between 30 and 70 nm,
- optionally a layer based on titanium oxide, titanium oxide and zirconium or a layer of zirconium oxide, with a thickness of between 1 and 10 nm. Glass article according to one of the preceding claims, in which the stack comprises, and preferably consists of, successively from the surface of the said substrate:
- a first module M₁consisting of a layer based on a dielectric material of thicknesse ₁ or by a set of layers based on dielectric materials of cumulative thicknesse ₁ , said thicknesse ₁ being preferably between 1 and 50 nm, more preferably between 5 and 30 nm,
- a first TiN layer₁comprising titanium nitride, with a thickness between 5 nanometers and 40 nanometers, preferably between 5 and 30 nm
- a second module M₂consisting of a layer based on a dielectric material of thicknesse ₂ or by a set of layers based on dielectric materials of cumulative thicknesse ₂ ,said thicknesse ₂ being preferably between 10 and 80 nm, more preferably between 20 and 70 nm,
- an ITO layer comprising an oxide of indium and tin, with a thickness of between 5 nanometers and 70 nanometers, preferably between 10 and 50 nm,
- a third module M₃consisting of a layer based on a dielectric material of thicknesse ₃ or by a set of layers based on dielectric materials of cumulative thicknesse ₃ , said thicknesse ₃ being preferably between 10 and 80 nm, more preferably between 20 and 50 nm,
- a second TiN layer₂comprising titanium nitride, with a thickness between 5 nanometers and 40 nanometers, preferably between 10 and 35 nm
- a fourth module M₄consisting of a layer based on a dielectric material of thicknesse ₄ or by a set of layers based on dielectric materials of cumulative thicknesse ₄ , in whiche ₄ is greater than 10 nanometers, preferably between 20 and 80 nm. Glass article according to the preceding claim, in which the module M ₄ comprises, and preferably consists of, a layer comprising silicon nitride, silicon oxide or silicon oxynitride and optionally an overlayer of silicon oxide. titanium, zirconium oxide or titanium zirconium oxide. Glass article according to one of the preceding claims, in which the glass substrate is tempered or bent. Automotive glazing, in particular automotive roof, comprising a glass article according to one of the preceding claims, comprising a single glass substrate, in which said glass substrate is preferentially tinted in its mass, and in which said stack is preferentially positioned towards the side of the glazing exposed towards the interior of the vehicle that it equips. Automotive glazing, in particular a car roof for a car, comprising a first glass substrate, preferably colored in its mass, bonded by an intermediate thermoplastic sheet, in particular of PVB, to a glass article according to one of Claims 1 to 13, the substrate is preferably made of clear glass and in which the stack of layers is preferably arranged on the face exposed towards the outside of said glazing. Building glazing, comprising a glass article as described according to one of Claims 1 to 13. Building glazing according to the preceding claim, comprising one, two or three glass substrates.