Laminated glazing comprising silver-based functional coating

Abstract

The invention relates to a material comprising a transparent substrate coated with a functional coating, said functional coating comprising, in order from the substrate: three silver-based functional metal layers arranged alternately, referred to as a first functional layer, a second functional layer and a third functional layer from the substrate; and four dielectric coatings, referred to as Di1, Di2, Di3 and Di4 starting from the substrate, each dielectric coating having an optical thickness of Eo1, Eo2, Eo3 and Eo4, and each dielectric coating comprising at least one dielectric layer such that each functional metal layer is located between two dielectric coatings. Characterized in that:-the ratio of the thickness of the first functional metal layer to the thickness of the third functional metal layer, Ag1 / Ag3, is greater than 1.05, or the ratio of the thickness of the second functional metal layer to the thickness of the third functional metal layer, Ag2 / Ag3, is greater than 1.05, and-the ratio of the optical thickness, Eo2 / Eo3, is greater than 1.00.

Description

[0001] The present invention relates to materials comprising a transparent substrate coated with a functional coating capable of influencing solar and / or infrared radiation. In the following description, the term "functional" means "capable of controlling solar and / or infrared radiation." The present invention also relates to glazing comprising these materials and the use of such materials for producing thermally insulating and / or solar-protective glazing.

[0002] These glazings can be fitted to vehicles or buildings, in particular to prevent excessive overheating due to the increasing importance of glazed surfaces in vehicle interiors and buildings, so-called "solar control" glazings.

[0003] The "solar control" function or property refers to the ability of a glazing unit to allow visible light to enter while blocking infrared radiation. Selectivity "s", the solar factor (SF or g) and the total transmittance (TTS) are used to evaluate this property. Selectivity corresponds to the transmittance TL of the glazing unit in the visible range. vis Ratio to the solar factor SF of the glazing unit (s = TL vis / SF). The "SF or g" solar coefficient and the total energy transmittance (TTS) correspond to the amount of heat transmitted by the glass. They therefore measure the contribution of the glazing unit to the heating of the "space". The lower the solar coefficient or total energy transmittance, the smaller the contribution of sunlight. Therefore, the solar control function corresponds to a sharp drop in the total energy transmittance and solar coefficient (g) of the glazing, while the transmittance (TTS) increases. L ) decreased slightly.

[0004] The present invention is particularly focused on glazing for automotive applications, particularly automotive windshields. Glazing for these applications must possess the following properties: high light transmittance, solar control properties, a neutral or bluish reflective appearance, and the ability to withstand high-temperature heat treatment. Additional features can be added to these properties to enhance driver comfort.

[0005] Among these features, compatibility with head-up displays (HUDs) is particularly sought after. To achieve a clear image, a birefringent film or coating is often applied to the portion of the laminated glazing where the image is projected. Therefore, this portion of the glazing must reflect the projected image while maintaining good visibility.

[0006] Applying any additional film or coating to laminated windshield glazing, whether for HUD compatibility or other functionalities, inevitably results in a loss of light transmittance. However, this is highly detrimental in windshield applications, where light transmittance must remain high, particularly above 70%, for regulatory and safety reasons.

[0007] A material comprising a substrate coated with a functional coating comprising a plurality of silver-based functional metal layers is used to impart solar control properties to glazing.

[0008] The object of the present invention is to provide a new and improved ultra-high light transmittance material comprising a substrate coated with a functional coating, the ultra-high light transmittance material providing a combination of good solar control properties, satisfactory aesthetic appearance and heatability.

[0009] According to the present invention, a material having good heatability refers to a material which, after heat treatment: - retain its aesthetic qualities or solar control properties, or - for its aesthetic properties or solar control properties.

[0010] According to the present invention, "good solar control properties" are materials which impart to the glazing into which they are incorporated: - low total energy transmittance, in particular less than 48.5%, and / or - High selectivity, - Low external reflectivity, in particular less than 20%, preferably less than 15%.

[0011] According to the invention, an aesthetically pleasing material or glazing is understood to mean a material or glazing which has a uniform, pleasing, preferably bluish or neutral colour in reflection, regardless of whether the material is flat or curved.

[0012] To identify functional coatings that might possess these properties, the applicants focused on identifying unique combinations of properties that could achieve the desired properties. Extensive explorations were conducted using optical simulations. These explorations enabled the applicants to identify a range of solutions that met these criteria. Indeed, only specific combinations of thickness characteristics of the functional layer and dielectric coating could achieve the desired combination of properties.

[0013] The present invention relates to a material comprising a transparent substrate coated with a functional coating, the functional coating comprising, starting from the substrate, three alternating silver-based functional metal layers, referred to as the first, second and third functional layers, starting from the substrate; and four dielectric coatings, referred to as Di1, Di2, Di3 and Di4, starting from the substrate, each having an optical thickness Eo1, Eo2, Eo3 and Eo4 and each comprising at least one dielectric layer, such that each functional metal layer is arranged between two dielectric coatings, characterized in that: - the ratio of the thickness of the first functional metal layer to the thickness of the third functional metal layer Ag1 / Ag3 is greater than 1.05, and / or the ratio of the thickness of the second functional metal layer to the thickness of the third functional metal layer Ag2 / Ag3 is greater than 1.05, and - The optical thickness ratio Eo2 / Eo3 is greater than 1.00.

[0014] The present invention relates to a material comprising a substrate coated with a functional coating for use in laminated glazing for automotive applications, having an ultra-high light transmittance, in particular greater than 70%, or even 75% or 77%. The functional coating is preferably applied to face 3 or face 2 of the laminated glazing. The coated material is preferably heat-treated. The functional coating can be combined with other functionalities. This means that the functional coating can be located on a portion of the glazing surface that contains another film or coating, such as a birefringent film or coating.

[0015] The material achieves over 77% light transmittance in conventional laminated glazing configurations with low exterior light reflectance, while maintaining high selectivity, low energy transmittance (TTS < 48.5%) and stable exterior reflected color.

[0016] Compared to previous solutions, the material of the present invention offers the following advantages.

[0017] It enables laminated glazing to have very high light transmittance while maintaining high-quality aesthetic and thermal properties. This means the coating can be combined with other films, such as birefringent coatings, for HUD applications without the risk of reducing light transmittance below regulatory and safety requirements.

[0018] It retains excellent energy, thermal, and aesthetic properties. When used in conventional laminated glazing, the thermal properties of the functional coating correspond to a TTS of 48.5% or less. Conventional laminated glazing is a material comprising a transparent glass substrate coated with a functional laminate coating, which is bonded to another transparent glass substrate via a PVB laminate interlayer. The functional coating is located on either side 2 or side 3 of the laminated glazing.

[0019] The materials of the present invention advantageously exhibit color at low intensity reflection over a wide range of incident angles. The materials of the present invention advantageously exhibit in external reflection: - appear light blue or neutral in color from all viewing angles, and / or - a stable color between 8° and 60°, and / or - Limited light reflectivity RLext, in particular less than or equal to 15%.

[0020] Color stability is characterized by measuring the color change between two observation angles: Δa*Rext = |a*Rext 60° - a*Rext 0°| and Δb*Rext = |a*Rext60° - a*Rext 0°|. According to the present invention, a color is considered stable if Δa*Rext ≤ 4 and Δb*Rext ≤ 5.

[0021] The functional coating of the invention is particularly suitable for use in laminated glazing to improve thermal comfort and aesthetic appearance when viewed from the outside.

[0022] The present invention therefore relates to a laminated glazing comprising the material according to the invention and at least one second substrate, said material and said second substrate being connected to one another via a first lamination interlayer.

[0023] Typically, the faces of the substrate are numbered from the outside of the passenger compartment or the area in which it is installed toward the inside, thus designating the faces of the glazing starting from the outside. This means that incident sunlight passes through the faces in ascending numerical order. In the case of laminated glazing, all faces of the substrate are numbered, but the faces of the laminated interlayer are not.

[0024] The laminated glazing according to the invention comprises a face 1 situated on the outside of a building or vehicle equipped with the laminate, faces 2 and 3 in contact with the lamination interlayer, and a face 4 situated on the inside of the building or vehicle. A silver-based functional coating is then applied to face 2 or 3, i.e., on the inside of the outermost substrate (face 2) or on the inside of the innermost substrate (face 3).

[0025] The laminated glazing according to the invention may comprise a curved substrate.

[0026] The present invention also relates to: - a laminated glazing according to the invention mounted on a vehicle or a building, and - use of the laminated glazing according to the invention as glazing for buildings or vehicles, - A building or a vehicle comprising a glazing according to the invention.

[0027] The preferred features appearing in the remainder of the description also apply to the material according to the invention and, where appropriate, to the glazing, method, use, building or vehicle according to the invention.

[0028] All described light characteristics are obtained according to the principles and methods of ISO 9050, EN 410 and ISO 13837 standards relating to the determination of light and sunlight characteristics of glazing units in glass for use in the building industry.

[0029] According to the present invention: - light reflectance corresponds to the reflection of solar radiation in the visible part of the spectrum, - transmittance corresponds to the transmission of solar radiation in the visible part of the spectrum, - Light absorptivity corresponds to the absorption of solar radiation in the visible part of the spectrum.

[0030] Luminous and energy properties are measured using illuminant A at 2°, perpendicular to the material when installed in laminated glazing with a functional coating on face 3 (unless otherwise specified): - TL corresponds to the transmittance in the visible light range, expressed in %, - Rext corresponds to the external light reflectance in the visible range, in %, with the observer on the functional coating side, - TTS corresponds to the total energy transmittance, which is measured according to convention A at a wind speed of 4 m / s.

[0031] Colorimetric properties measured using illuminant D65, observed at 10°, perpendicular to the material when installed in laminated glazing with a functional coating on face 2 (unless otherwise stated): - a*Rext 8° and b* Rext 8° correspond to the colors a* and b* in reflection in the L*a*b* system, measured at an angle of 8° with the observer on the side of the external space, a*Rext 60° and b*Rext 60° correspond to the colors a* and b* in reflection in the L*a*b* system, measured with the observer on the side of the external space at an angle of 60°.

[0032] The material has excellent energy and thermal properties. This results in a total energy transmittance value of less than 48.5%, measured on a laminated glazing comprising a functional coating on face 3 deposited on a transparent glass substrate and laminated to a second transparent glass substrate via a transparent PVB polymer interlayer.

[0033] These properties are measured on ordinary clear glass. Ordinary clear glass with a thickness of 4 to 6 mm has the following optical properties: - 87 to 91.5% light transmittance, - 7 to 9.5% light reflectivity, - 0.3 to 5% light absorption.

[0034] The transparent PVB laminate interlayer has a light transmittance greater than 80%.

[0035] Typically, the refractive index is measured at a wavelength of 550 nm.

[0036] Unless otherwise stated, in the absence of other information, the thicknesses mentioned herein are real or geometric physical thicknesses, denoted as Ep, and are expressed in nanometers (not optical thickness). The optical thickness, Eo, is defined as the physical thickness of the layer in question multiplied by its refractive index at a wavelength of 550 nm: Eo = n*Ep. Since the refractive index is a dimensionless value, the units of optical thickness can be considered to be the same as those chosen for the physical thickness.

[0037] According to the invention, a dielectric coating corresponds to a layer sequence comprising at least one dielectric layer, which is located between the substrate and the first functional layer ( Di1 ), between two functional layers ( Di2 or Di3 ) or above the final functional layer ( Di4 ).

[0038] If the dielectric coating consists of several dielectric layers, the optical thickness of said dielectric coating corresponds to the sum of the optical thicknesses of the different dielectric layers constituting the dielectric coating.

[0039] If the dielectric coating includes an absorbing layer—for which the refractive index at 550 nm includes a non-zero (or non-negligible) imaginary part of the dielectric function—such as a metal layer, the thickness of this layer is not considered when calculating the optical thickness of the dielectric coating.

[0040] The thickness of the barrier layer is not considered when calculating the optical thickness of the dielectric coating.

[0041] In the meaning of the present invention, the terms "first", "second", "third" and "fourth" for functional layers or dielectric coatings are defined starting from the substrate carrying the stack and with reference to layers or coatings having the same function. For example, the functional layer closest to the substrate is the first functional layer, the next functional layer further away from the substrate is the second functional layer, etc.

[0042] The functional coatings are deposited by magnetic field-assisted cathode sputtering (magnetron sputtering). According to this advantageous embodiment, all coatings are deposited by magnetic field-assisted cathode sputtering. Unless otherwise specified, the expressions "above" and "below" do not necessarily mean that two layers and / or coatings are positioned in contact with each other. When a layer is deposited "in contact with" another layer or coating, this means that no layer (or layers) can be interposed between the two layers (or between a layer and a coating).

[0043] In this specification, unless otherwise stated, the expression “based on” used to characterize a material or layer with respect to the substances it contains means that it comprises a component with a mass fraction of at least 50%, in particular at least 70%, preferably at least 90%.

[0044] The functional coating comprises at least three silver-based functional metal layers (F1, F2, and F3), each disposed between two dielectric coating layers (Di1, Di2, Di3, Di4). Preferably, the functional coating comprises three silver-based functional metal layers (F1, F2, and F3), each disposed between two dielectric coating layers (Di1, Di2, Di3, Di4).

[0045] The silver-based functional metal layer contains at least 95.0% by weight, preferably at least 96.5% by weight, and more preferably at least 98.0% by weight of silver relative to the weight of the functional layer. Preferably, the silver-based functional metal layer contains less than 1.0% by weight or less than 0.5% by weight of metal other than silver relative to the weight of the silver-based functional metal layer.

[0046] According to the present invention, the thickness of the third functional layer is less than that of the first functional layer or the second functional layer or the first and second functional layers. The functional layer may have the following characteristics: - the ratio of the thickness of the first functional metal layer to the thickness of the third functional metal layer Ag1 / Ag3 is greater than 1.10, and / or - the ratio of the thickness of the first functional metal layer to the thickness of the third functional metal layer Ag1 / Ag3 is greater than 1.15, and / or - the ratio of the thickness of the first functional metal layer to the thickness of the third functional metal layer Ag1 / Ag3 is greater than 1.20, and / or - the ratio of the thickness of the first functional metal layer to the thickness of the third functional metal layer Ag1 / Ag3 is less than 1.60, and / or - the ratio of the thickness of the second functional metal layer to the thickness of the third functional metal layer Ag2 / Ag3 is greater than 1.10, and / or - the ratio of the thickness of the second functional metal layer to the thickness of the third functional metal layer Ag2 / Ag3 is greater than 1.15, and / or - the ratio of the thickness of the second functional metal layer to the thickness of the third functional metal layer Ag2 / Ag3 is greater than 1.20, and / or - the ratio of the thickness of the second functional metal layer to the thickness of the third functional metal layer Ag2 / Ag3 is less than 1.40, and / or - the ratio of the thickness of the second functional metal layer to the thickness of the first functional metal layer Ag2 / Ag1 is less than or equal to 1.30, 1.20, 1.10, 1.05, 1.00 or 1.10, and / or - the ratio of the thickness of the second functional metal layer to the thickness of the first functional metal layer Ag2 / Ag1 is greater than or equal to 0.60 or 0.70, and / or - the thickness of the first silver-based functional metal layer Ag2 is 6 to 15 nm, or 8 to 14 nm, or 9 to 13 nm, or 9 to 12 nm, and / or - the thickness of the second silver-based functional metal layer is 6 to 16 nm, or 8 to 14 nm, or 8 to 12 nm, and / or - the thickness of the third silver-based functional metal layer is 6 to 15 nm, or 6 to 11 nm, or 6 to 10 nm, or 6 to 9 nm, and / or The sum of the thicknesses of all silver-based functional layers of the functional coating is less than 32 nm, preferably less than 30 nm.

[0047] The stack may further comprise at least one barrier layer located in contact with the functional metal layer.Preferably, the stack does not comprise any barrier layer, or comprises only barrier layers of very small thickness.

[0048] Preferably, the sum of the thicknesses of all barrier layers in contact with all silver-based functional layers is from 0 to 2 nm, preferably from 0 to 1.5 nm.

[0049] The barrier layer generally has the function of protecting the functional layer from possible damage during the deposition of the upper antireflection coating and during possible high-temperature heat treatments of the annealing, bending and / or tempering type.

[0050] The barrier layer is selected from: - metal layers, metal nitride layers and metal oxynitride layers based on metals or metal alloys of one or more elements selected from titanium, zinc, tin, nickel, chromium and niobium, - a metal oxide layer of one or more elements selected from titanium, nickel, chromium and niobium.

[0051] The barrier layers may in particular be layers of Ti, TiN, TiOx, Nb, NbN, Ni, NiN, Cr, CrN, NiCr, NiCrN, SnZnN. When these barrier layers are deposited in the form of metals, nitrides or oxynitrides, they may, depending on their thickness and the nature of the layers surrounding them, undergo partial or complete oxidation, for example during the deposition of subsequent layers or through oxidation in contact with underlying layers.

[0052] According to some embodiments of the present invention, the one or more barrier layers satisfy one or more of the following conditions: - Each silver-based functional metal layer may be located below and / or above, and optionally in contact with, a contact barrier layer selected from a barrier primer and a barrier cap layer, and / or - the barrier layer may be based on at least one element selected from nickel, chromium, niobium, tantalum and titanium, and / or - Each functional metal layer is in contact with a barrier coating, and / or - The thickness of each barrier layer is at least 0.1 nm, preferably 0.2 to 2.0 nm inclusive.

[0053] According to the present invention, barrier layers are considered not to form part of the dielectric coating. This means that their thickness is not taken into account when calculating the optical or geometric thickness of the dielectric coating in contact with them.

[0054] According to an advantageous embodiment of the invention, the dielectric coating of the functional coating satisfies one or more of the following conditions: - the optical thickness Eo1 of the dielectric coating Di1 is between 50 and 90 nm or between 50 and 80 nm, and / or - the optical thickness Eo2 of the dielectric coating Di2 is between 120 and 190 nm, and / or - the optical thickness Eo3 of the dielectric coating Di3 is between 110 and 160 nm, and / or - the optical thickness Eo4 of the dielectric coating Di4 is between 60 and 100 nm, and / or - the optical thickness ratio Eo2 / Eo3 is greater than 1.10, and / or - the optical thickness ratio Eo2 / Eo1 is greater than 1.5, and / or - the optical thickness ratio Eo2 / Eo1 is less than 3.0, and / or - the optical thickness ratio Eo2 / Eo4 is greater than 1.5, and / or - The optical thickness ratio Eo2 / Eo4 is less than 3.0, and / or - the optical thickness ratio Eo1 / Eo3 is greater than 0.30, and / or - the optical thickness ratio Eo1 / Eo3 is less than 0.80, and / or - the optical thickness ratio Eo1 / Eo2 is less than 0.60, and / or - The optical thickness ratio Eo1 / Eo4 is greater than 0.80, and / or - The optical thickness ratio Eo1 / Eo4 is less than 1.00.

[0055] Within the meaning of the present invention, a "dielectric layer" is understood to mean a material that is "non-metallic" in terms of its properties, i.e., not a metal. In the context of the present invention, this term refers to a material that exhibits an n / k ratio equal to or greater than 5 over the entire wavelength range of the visible region (380 nm to 780 nm).

[0056] According to an advantageous embodiment of the invention, the dielectric coating of the functional coating satisfies one or more of the following conditions: - Dielectric coatings are deposited by magnetic field assisted cathode sputtering, and / or - The dielectric layer may be based on oxides or nitrides of one or more elements selected from silicon, zirconium, titanium, aluminum, tin, zinc, and / or - The dielectric layer is selected from: an oxide layer of one or more elements selected from titanium, silicon, aluminum, zirconium, iron, chromium, cobalt, manganese, tungsten, niobium, bismuth, tantalum, zinc and / or tin, a nitride layer of one or more elements selected from silicon, zirconium and aluminum, an oxynitride layer of one or more elements selected from silicon, zirconium and aluminum, Metal sulfide layer such as zinc sulfide, and / or - the dielectric layer has a thickness greater than 2 nm, preferably between 4 and 100 nm, and / or - at least one dielectric coating comprises at least one dielectric layer having a barrier function, and / or - each dielectric coating comprises at least one dielectric layer having a barrier function, and / or - each dielectric coating comprises a layer comprising silicon, said layer comprising silicon being selected from layers based on silicon nitride, and / or - The dielectric layer with barrier function is based on silicon and / or aluminum compounds selected from oxides such as SiO2 and Al2O3, nitrides Si3N4 and AlN, and oxynitrides SiO x N y and AlO x N y , based on zinc and tin oxides, or based on titanium oxide, - a dielectric layer with a barrier function based on a compound of silicon and / or aluminum, optionally containing at least one other element, such as aluminum, hafnium and zirconium, and / or - each dielectric coating comprises a layer comprising silicon, said layer comprising silicon being selected from layers based on silicon nitride, and / or - the sum of the physical thicknesses of all silicon-containing layers in each dielectric coating is greater than 25% of the total thickness of the dielectric coating, and / or - at least one dielectric coating comprises at least one dielectric layer having a stabilizing function, and / or - Each dielectric coating comprises at least one dielectric layer having a stabilizing function, and / or - the dielectric layer having a stabilizing function is preferably based on an oxide selected from zinc oxide, tin oxide, zirconium oxide or a mixture of at least two thereof, and / or - a dielectric layer having a stabilizing function, preferably based on a crystalline oxide, in particular on zinc oxide, optionally doped with at least one other element such as aluminum, and / or - each functional layer is above a dielectric coating, the upper layer of said dielectric coating being a dielectric layer with stabilizing functions, preferably based on zinc oxide, and / or each functional layer is below a dielectric coating, the lower layer of said dielectric coating being a dielectric layer with stabilizing functions, preferably based on zinc oxide, and / or - each dielectric coating layer below the functional layer comprises a zinc oxide-based layer below the functional layer, said zinc oxide-based layer being in contact with the functional layer or separated from the functional layer by a barrier layer; and / or - each dielectric coating layer overlying the functional layer comprises a zinc oxide-based layer overlying the functional layer, said zinc oxide-based layer being in contact with the functional layer or separated from the functional layer by a barrier layer; and / or Each dielectric coating layer below the functional layer comprises a zinc tin oxide based layer below and in contact with the zinc oxide based layer.

[0057] Preferably, each dielectric coating consists only of one or more dielectric layers. Preferably, no absorbing layers are present in the dielectric coating so as not to reduce light transmittance.

[0058] The dielectric layer may have a barrier function. A dielectric layer having a barrier function (hereinafter referred to as a barrier layer) is understood to mean a layer made of a material that forms a barrier to the diffusion of oxygen and water from the ambient atmosphere or from the transparent substrate into the functional layer at high temperatures. Such a dielectric layer is selected from the following layers: - compounds based on silicon, aluminum and / or zirconium, selected from oxides such as SiO2 and Al2O3, nitrides such as Si3N4 and AlN, and oxynitrides such as SiO x N y 、AlO x N y , optionally doped with at least one other element, - Based on zinc tin oxide, - Based on titanium oxide.

[0059] Preferably, each coating comprises at least one dielectric layer consisting of: - nitrides or oxynitrides of aluminium and / or silicon, or - mixed oxides of zinc and tin, or - Titanium oxide.

[0060] These dielectric layers have the following thicknesses: - less than or equal to 80 nm, less than or equal to 60 nm, or less than or equal to 25 nm, and / or - Greater than or equal to 5 nm, greater than or equal to 10 nm, or greater than or equal to 15 nm.

[0061] The functional coating of the present invention may include a dielectric layer with a stabilizing function. In the context of the present invention, "stabilizing" means that the properties of the layer are selected to stabilize the interface between the functional layer and the layer. This stabilization leads to an increase in the adhesion of the functional layer to the surrounding layers and actually counteracts the migration of its constituent materials.

[0062] The dielectric layer or layers having a stabilizing function may be in direct contact with the functional layer or separated by a barrier layer.

[0063] Preferably, the final dielectric layer of each dielectric coating layer located below the functional layer is a functionally stabilizing dielectric layer. This is because it is advantageous to have a functionally stabilizing layer (e.g., based on zinc oxide) below the functional layer, as it promotes adhesion and crystallization of the silver-based functional layer and improves its quality and stability at high temperatures.

[0064] It is also advantageous to have a layer with a stabilizing function (for example based on zinc oxide) above the functional layer in order to increase its adhesion and to optimally counteract diffusion of the multilayer on the side opposite the substrate.

[0065] One or more dielectric layers having a stabilizing function may thus be above and / or below at least one functional layer or each functional layer, in direct contact therewith or separated by a barrier layer.

[0066] Advantageously, each dielectric layer having a barrier function is separated from the functional layer by at least one dielectric layer having a stabilizing function.

[0067] The zinc oxide layer may optionally be doped with at least one other element, such as aluminum. Zinc oxide is crystalline. The zinc oxide-based layer preferably contains, in increasing order of preference, at least 90.0 mass%, at least 92 mass%, at least 95 mass%, and at least 98.0 mass% of zinc, relative to the mass of elements other than oxygen in the zinc oxide-based layer.

[0068] Preferably, the dielectric coating of the functional coating comprises a zinc oxide based dielectric layer underlying a silver based metal layer.

[0069] The zinc oxide layer has the following thicknesses in increasing order of preference: - at least 3.0 nm, at least 4.0 nm, at least 5.0 nm, and / or - Up to 25 nm, up to 10 nm, up to 8.0 nm.

[0070] The functional coating may optionally include an upper protective layer. The upper protective layer is preferably the last layer of the stack, i.e., the layer furthest from the substrate coated with the stack. These upper protective layers are considered to be included in the final dielectric coating. These layers typically have a thickness of 2 to 10 nm, preferably 2 to 5 nm.

[0071] The protective layer can be chosen from layers of titanium, zirconium, hafnium, zinc and / or tin, this or these metals being in the form of metals, oxides or nitrides. Advantageously, the protective layer is a titanium oxide layer, a tin zinc oxide layer or a layer based on titanium zirconium oxide.

[0072] Another particularly advantageous embodiment relates to a substrate coated with a multilayer, defined starting from a transparent substrate, said multilayer comprising: - a first dielectric coating comprising at least one layer having a barrier function and one dielectric layer having a stabilizing function, - optional barrier layer, - first functional layer, - optional barrier layer, - a second dielectric coating comprising at least a lower dielectric layer having a stabilizing function, a layer having a barrier function and an upper dielectric layer having a stabilizing function, - optional barrier layer, - Second functional layer, - optional barrier layer, - a third dielectric coating comprising at least one lower dielectric layer with a stabilizing function, a layer with a barrier function, and an upper dielectric layer with a stabilizing function, - optional barrier layer, - The third functional layer, - optional barrier layer, - a fourth dielectric coating comprising at least one dielectric layer having a stabilizing function, one layer having a barrier function, - Optional protective layer.

[0073] Another particularly advantageous embodiment comprises a stack which, starting from a substrate, comprises: - a first dielectric coating comprising at least one layer based on sodium nitride and one layer based on zinc oxide, - optional barrier layer, - first functional layer, - optional barrier layer, - a second dielectric coating comprising at least three consecutive layers, a layer based on zinc oxide, a layer based on silicon nitride and a layer based on zinc oxide, - optional barrier layer, - Second functional layer, - optional barrier layer, - a third dielectric coating comprising at least three consecutive layers, a layer based on zinc oxide, a layer based on silicon nitride and a layer based on zinc oxide, - optional barrier layer, - The third functional layer, - optional barrier layer, - a fourth dielectric coating comprising at least one layer based on zinc oxide, a layer based on silicon nitride, and - Optional protective layer.

[0074] The invention also relates to a glazing comprising at least one material as defined above, in the form of a monolithic, laminated or multi-layer glazing, in particular a double-glazing or triple-glazing.

[0075] The laminated glazing comprises a material as defined above and at least one second substrate, the material and the second substrate being interconnected by a first laminating interlayer. It comprises a face 1 located on the exterior of the building or vehicle in which it is installed, surfaces 2 and 3 in contact with the laminating interlayer, and a surface 4 located on the interior of the building or vehicle, the functional coating being located on face 2 or 3. It exhibits: - a light transmittance greater than 70%, preferably greater than 75%, and / or - a total energy transmittance of less than 50%, preferably less than 48.5%, and / or - External light reflectivity is less than 15%.

[0076] In laminated glazing configurations, the following calculated colorimetric properties are used: - materials comprising substrates coated with functional coatings for installation in laminated glazing, - Laminated glazing comprising a material comprising a substrate comprising 1 to 2.1 mm ordinary soda-lime glass and another 1 to 2.1 mm glass substrate of soda-lime glass, the two substrates being separated by a 0.76 mm polyvinyl butyral (PVB) laminate interlayer, A silver-based functional coating is preferably located on face 3 .

[0077] The laminated glazing may also comprise a functional coating based on a conductive oxide. Said functional coating based on a conductive oxide is preferably located on face 4. The conductive oxide layer is selected from fluorine-doped tin oxide, antimony-doped tin oxide and / or indium tin oxide.

[0078] The substrate can be made of mineral glass or a transparent polymer material. The substrate is preferably made of mineral glass.

[0079] The mineral glass substrate constituting the glazing may be soda-lime glass, aluminosilicate glass or borosilicate glass.

[0080] The substrate can be made of a transparent polymer material including poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyurethane, or polyurea (PU) substrates.

[0081] The substrate is preferably transparent, colorless (it is thus clear or extra-clear glass) or colored, for example blue, gray or bronze.

[0082] The substrate may be ultra-thin glass, for example having a thickness of less than 0.7 mm.

[0083] The substrate may be (heat) strengthened glass.

[0084] Silver-based functional coatings can advantageously be deposited on transparent glass substrates in order to maximize the reflection of infrared radiation and thereby achieve a low total energy transmission.

[0085] Silver-based functional coatings can be deposited on pigmented substrates to neutralize the exterior reflective appearance. However, in this case, a compromise must be found between color neutralization and energy performance.

[0086] Preferably, the laminate interlayer comprises one or more sheets of an organic polymer. The organic polymer is selected from polyvinyl butyral (PVB), polyurethane (PU), polyurea, ethylene vinyl acetate (EVA), polyolefins (including polyethylene (PE), polypropylene (PP), or polyisobutylene (P-IB)), polyvinyl chloride and its derivatives (such as polyvinyl dichloride (PVDC)), styrene polymers (such as polystyrene (PS), acrylonitrile butadiene styrene (ABS), and styrene acrylonitrile (SAN)), polyacrylics (including polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA)), polyesters (including poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT)), polyoxymethylene (POM), polyamide (PA), fluoropolymers such as polychlorotrifluoroethylene (PCTFE), polycarbonate (PC), aromatic polysulfones including polysulfone (PSU), polyphenylene ether (PPE), and epoxy resins (EP), alone or in blends and / or copolymers of several of these. The laminate interlayer may be pigmented.

[0087] The interlayer is typically 0.20 to 3.00 mm thick. The interlayer may consist of one or more polymer sheets. The thickness ranges given are for the total thickness of the interlayer.

[0088] The material, that is, the substrate coated with the functional coating, can undergo high-temperature heat treatment, such as annealing (e.g., by flash annealing, such as laser or flame annealing), tempering, and / or bending. The heat treatment temperature is greater than 400°C, preferably greater than 450°C, and more preferably greater than 500°C. The functionally coated substrate can thus be bent and / or tempered.

[0089] The material of the invention is particularly suitable for laminated automotive glazing, in particular curved glazing such as roof glazing or windshield glazing. The laminated glazing according to the invention is therefore preferably an automotive glazing, such as an automotive roof glazing or windshield glazing.

[0090] The material or laminated glazing may also have a light transmittance of more than 70%, more than 75% or more than 77%. The laminated glazing according to the invention, when used in particular as a windshield or side glazing, preferably has a light transmittance TL of at least 70% and even at least 75% or even at least 77%.

[0091] Laminated glazing can be used as windshields to provide combined solar control with additional functionality, such as HUD, having advantageous optical reflective properties.

[0092] Finally, the glazing according to the invention is suitable for architectural applications, in particular when the glazing is used as a partition element from the outside. The glazing can be single-glazed, multi-glazed or laminated. Multi-glazing comprises the material according to the invention and a second substrate, separated by a gas layer.

[0093] Details and advantageous features of the invention emerge from the following non-limiting examples. Example

[0094] I. Properties of Layers and Coatings The functional coating defined below was deposited on a substrate made of transparent soda-lime glass with a thickness of 1.6 mm.

[0095] The functional metal layer (FL) is a silver (Ag) layer. The barrier layer is a metal layer made of nickel-chromium alloy (NiCr). The dielectric coating of the functional coating comprises a barrier layer and a stabilization layer. The barrier layer is based on silicon nitride doped with aluminum (Si3N4:Al), silicon and aluminum-doped zirconium nitride (SiZr 17 N x ) or based on mixed zinc tin oxide (SnZnO x ). The stabilization layer is made of zinc oxide (ZnO).

[0096] The deposition conditions for the layers deposited by sputtering (“magnetron cathode” sputtering) are summarized in Table 1.

[0097] [Table 1] At. = Atom Table 2 lists the materials and the physical thickness in nm (unless otherwise stated) of each layer or coating forming the coating as a function of their position relative to the substrate carrying the stack (last row at the bottom of the table).

[0098] [Table 2] Di: dielectric coating; FL: functional layer Table 3 shows the optical thickness and thickness ratio of the functional layers and dielectric coatings.

[0099] [Table 3] .

[0100] The substrate is heat treated at a temperature of at least 550°C for several minutes.

[0101] II. Laminated Glazing Configuration Materials comprising a transparent substrate, one side of which is coated with a functional coating, have been assembled in the form of laminated glazings.

[0102] The laminated glazing, hereinafter referred to as "L." configuration, had a structure of first substrate 2.1 mm / laminated interlayer / second substrate 1.6 mm.

[0103] A silver-based functional coating is located on face 3 .

[0104] The barrier is transparent PVB.

[0105] The second substrate is selected from transparent glass.

[0106] III. Exploratory Research Extensive studies were conducted using optical simulations to identify functional coatings that might provide desirable properties.

[0107] In these simulations, all layer thicknesses were varied. The range of thickness variations for each layer is defined as RFX in Table 2. The results of these Brownian studies are shown in Figure 1 、 2 and 3.

[0108] Figure 1 and 2 The distribution of functional coatings with the following properties is shown: - Points corresponding to functional coatings with TL > 77% and TTS < 48.5%, - Squares correspond to functional coatings with TL>77%, TTS<48.5%, and a*Rext and b*Rext<0, - Stars correspond to functional coatings with TL>77%, TTS<48.5%, a*Rext and b*Rext<0, and a*60Rext and b*60Rext<0.

[0109] FIG. 1 shows the thickness of Ag1 on the x-axis and the thickness of Ag2 on the y-axis.

[0110] FIG. 2 shows the thickness of Ag1 on the x-axis and the thickness of Ag3 on the y-axis.

[0111] These figures show that: - Only with certain thickness ratios of Ag2 / Ag1 and Ag3 / Ag1 can higher transmittance be obtained.

[0112] Figure 2 shows a high concentration functional coating with all the desired properties, represented by a star with Ag1 thickness greater than 10 nm and greater than Ag3 thickness.

[0113] Figure 1 shows a high concentration functional coating with all the desired properties, represented by a star with Ag1 and Ag2 thicknesses such that the ratio Ag2 / Ag1 is less than or equal to 1.30.

[0114] Figure 3 The distribution of functional coatings having a combination of all desirable properties is shown: TL>77%, TTS<48.5%, values ​​of a*Rext and b*Rext<0, and values ​​of a*60Rext and b*60Rext<0, as a function of the thickness of the following elements of the functional coating: - Thickness of functional layers Ag1, Ag2 and Ag3, - the thickness of all nitride layers present in the dielectric coatings Di1 , Di2, Di3, Di4, said nitride layers being respectively referred to as NDi1 , NDi2, NDi3, NDi4.

[0115] For example, NDi2 contains the sum of the thicknesses of the Si3N4 and SiZrN layers in the Di2 dielectric coating.

[0116] The figure shows that a favourable combination of properties is achieved with silver layers satisfying Ag1>Ag2 and / or Ag2>Ag3 and Eo2>Eo3.

[0117] III. "Sunlight Control" and Chromaticity Performance Performance and colorimetric properties were determined by simulation.

[0118] [Table 4] .

Claims

1. A material comprising a transparent substrate coated with a functional coating, wherein the functional coating comprises, starting from the substrate: Three alternating silver-based functional metal layers, referred to as the first, second, and third functional layers starting from the substrate; and four dielectric coatings, referred to as Di1, Di2, Di3 and Di4 starting from the substrate, each having an optical thickness Eo1, Eo2, Eo3 and Eo4, each dielectric coating comprising at least one dielectric layer, such that each functional metal layer is located between two dielectric coatings, characterized in that: - the ratio of the thickness of the first functional metal layer to the thickness of the third functional metal layer Ag1 / Ag3 is greater than 1.05 and / or the ratio of the thickness of the second functional metal layer to the thickness of the third functional metal layer Ag2 / Ag3 is greater than 1.05, and - The optical thickness ratio Eo2 / Eo3 is greater than 1.

00.

2. The material according to claim 1, characterized in that The ratio of the thickness of the second functional metal layer to the thickness of the first functional metal layer Ag2 / Ag1 is less than or equal to 1.

30.

3. Material according to any one of the preceding claims, characterised in that The optical thickness ratio Eo2 / Eo3 is greater than 1.

10.

4. Material according to any one of the preceding claims, characterized in that: - the first silver-based functional metal layer has a thickness of 6 to 15 nm, and / or - the second silver-based functional metal layer has a thickness of 6 to 16 nm, and / or - The third silver-based functional metal layer has a thickness of 6 to 15 nm.

5. Material according to any one of the preceding claims, characterized in that The total thickness of all silver-based functional layers of the functional coating is less than 32 nm.

6. Material according to any one of the preceding claims, characterized in that It exhibits a light transmittance greater than 70%.

7. Material according to any one of the preceding claims, characterized in that The sum of the thicknesses of all barrier layers located in contact with all silver-based functional layers is 0 to 1.5 nm, said barrier layers being selected from: - metal layers based on metals or metal alloys, metal nitride layers and metal oxynitride layers of one or more elements selected from titanium, zinc, tin, nickel, chromium and niobium; - a metal oxide layer of one or more elements selected from titanium, nickel, chromium and niobium.

8. Material according to any one of the preceding claims, characterised in that: - the dielectric coating Di1 has an optical thickness Eo1 of 50 to 90 nm, - the dielectric coating Di2 has an optical thickness Eo2 of 120 to 190 nm, - the dielectric coating Di3 has an optical thickness Eo3 of 110 to 160 nm, - The dielectric coating Di4 has an optical thickness Eo4 of 60 to 100 nm.

9. Material according to the preceding claim, characterized in that: - The optical thickness ratio Eo2 / Eo1 is greater than 1.5 and less than 3.0, - The optical thickness ratio Eo2 / Eo4 is greater than 1.5 and less than 3.0, - The optical thickness ratio Eo1 / Eo3 is greater than 0.30 and less than 0.80, - The optical thickness ratio Eo1 / Eo4 is greater than 0.80 and less than 1.

00.

10. Material according to any one of the preceding claims, characterised in that Each dielectric coating comprises a silicon-containing layer selected from silicon nitride-based layers.

11. Material according to any one of the preceding claims, characterised in that Each dielectric coating layer underlying the functional layer includes a zinc oxide-based layer underlying the functional layer, in contact with the functional layer, or separated from the functional layer by a barrier layer.

12. Material according to any one of the preceding claims, characterised in that Each dielectric coating layer overlying the functional layer includes a zinc tin oxide-based layer underlying and in contact with the zinc oxide-based layer.

13. Laminated glazing comprising a material according to any one of the preceding claims and at least one second substrate, the material and the second substrate being connected to each other via a lamination interlayer.

14. Laminated glazing according to the preceding claim, characterized in that It comprises a face 1 on the outside of a building or vehicle equipped with the laminated glazing, faces 2 and 3 in contact with the laminate interlayer, and a face 4 on the inside of the building or vehicle, the functional coating being located on face 2 or face 3 .

15. Laminated glazing according to claim 13 or 14, characterized in that It shows: - a light transmittance greater than 70%, preferably greater than 75%, and / or - a total energy transmittance of less than 50%, preferably less than 48.5%, and / or - External light reflectivity is less than 15%.

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