Laminated glazing comprising a silver-based functional coating

Abstract

The invention relates to a material comprising a transparent substrate coated with a functional coating, comprising, consecutively from the substrate, an alternation of three silver-based functional metal layers starting from the substrate referred to as first, second and third functional layers, and comprising four dielectric coatings starting from the substrate referred to as Di1, Di2, Di3 and Di4, which each have an optical thickness Eo1, Eo2, Eo3 and Eo4, each dielectric coating comprising at least one dielectric layer such that each functional metal layer is arranged between two dielectric coatings. The invention is characterised 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 thicknesses Eo2 / Eo3 is greater than 1.00.

Description

[0001] LAMINATED GLAZING INCLUDING A SILVER-BASED FUNCTIONAL COATING

[0002] The invention relates to a material comprising a transparent substrate coated with a functional coating capable of acting on solar radiation and / or infrared radiation. In the remainder of the description, the term "functional" qualifying a coating or a layer means "capable of acting on solar radiation and / or infrared radiation". The invention also relates to glazing comprising these materials as well as the use of such materials for manufacturing thermal insulation and / or solar protection glazing.

[0003] These glazings can be intended to equip vehicles or buildings, in particular to prevent excessive overheating, so-called "solar control" glazing, caused by the ever-increasing importance of glazed surfaces in vehicle interiors and buildings.

[0004] The "solar control" function or property corresponds to the ability of a glazing to let in visible light while blocking infrared radiation. The selectivity "s", the solar factor (FS or g), the total energy transmission (TTS) make it possible to evaluate this property. Selectivity corresponds to the ratio of the light transmission TL VjS in the visible of the glazing on the solar factor FS of the glazing (s = TL VjS / FS). The solar factor "FS or g" and the total energy transmission (TTS) correspond to the quantity of heat transmitted by the glass. The solar factor and the total energy transmission therefore measure the contribution of a glazing to heating the "room". The smaller the solar factor or the total energy transmission, the lower the solar gains. The solar control function therefore corresponds to a strong reduction in the total energy transmission and the solar factor (g) of the glazing associated with a small reduction in the light transmission (TL).

[0005] The invention is particularly concerned with glazing for automotive applications, in particular for automobile windshields. Glazing intended for these applications must necessarily have the following properties: high light transmission, solar control properties, a neutral or bluish aesthetic appearance in reflection and be capable of undergoing heat treatment at high temperature. Other features can be added to these properties to improve driver comfort.

[0006] Among these features, compatibility with so-called head-up display (HUD) systems is particularly sought after. To obtain clear images, a birefringent film or coating is often applied to the part of the laminated glazing where the images are intended to be projected. This part of the glazing must therefore reflect the projected images while maintaining good visibility. The application of any additional film or coating to a laminated windshield glazing, whether for HUD compatibility or the acquisition of other functions, necessarily results in a loss of light transmission. However, this is highly detrimental in the case of windshield applications because the light transmission must remain high, particularly above 70% for legal and safety reasons.

[0007] Materials comprising a substrate coated with a functional coating comprising several silver-based functional metal layers are used to provide glazing with solar control properties.

[0008] The objective of the invention is to provide a new improved material with ultra-high light transmission comprising a substrate coated with a functional coating which makes it possible to obtain, in combination, good solar control performance, a satisfactory aesthetic appearance and a capacity to be heat-treated ("heatability").

[0009] According to the invention, the term “material having a good capacity to be heat treated” means a material which, following heat treatment:

[0010] - retains its aesthetic properties or solar control performance or

[0011] - acquires its aesthetic properties or solar control performances.

[0012] According to the invention, the term “good solar control performance” means a material which gives the glazing incorporating it:

[0013] - low total energy transmission, notably less than 48.5%, and / or

[0014] - high selectivity,

[0015] - low reflection on the exterior side, notably less than 20%, preferably less than 15%.

[0016] According to the invention, the term "material or glazing having a satisfactory aesthetic appearance" means a material or glazing having uniform and pleasant colors in reflection, preferably blue or neutral, whether the material is flat or curved.

[0017] To identify functional coatings capable of exhibiting these properties, the applicant was interested in finding combinations of characteristics specific to functional coatings capable of leading to the required properties. Extensive explorations were carried out by optical simulation. These explorations made it possible to highlight a family of solutions meeting these criteria. Indeed, only specific combinations of thickness characteristics for functional layers and dielectric coatings make it possible to obtain the desired combination of characteristics.

[0018] The invention relates to a material comprising a transparent substrate coated with a functional coating comprising successively from the substrate an alternation of three silver-based functional metal layers called, starting from the substrate, first, second and third functional layers, and four dielectric coatings called, starting from the substrate, Di1, Di2, Di3 and Di4 which each have an optical thickness Eo1, Eo2, Eo3 and Eo4, each dielectric coating comprising at least one dielectric layer, so that each functional metal layer is arranged between two dielectric coatings, characterized in that:

[0019] - 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

[0020] - the ratio of optical thicknesses Eo2 / Eo3 is greater than 1.00.

[0021] The invention relates to materials comprising a substrate coated with a functional coating used in laminated glazings for automotive applications with ultra-high light transmission, in particular greater than 70%, or even 75% or 77%. The functional coating is preferably applied to side 3 or side 2 of the laminated glazing. The coated material is preferably heat-treated. The functional coating may be combined with other functionalities. This means that the functional coating may be on a part of the surface of the glazing comprising another film or coating, for example, a birefringent film or coating.

[0022] The material achieves a light transmission of over 77% in a conventional laminated glazing configuration, low exterior light reflection, while maintaining high selectivity with low energy transmission (TTS < 48.5%) and stable external reflection colors.

[0023] The material of the invention has the following advantages over previous solutions.

[0024] It allows for laminated glazing with very high light transmission while maintaining high-quality aesthetic and thermal properties. This means that the coating can be applied in combination with other films, such as a birefringent coating, for HUD applications, without the risk of lowering light transmission below legal and safety requirements.

[0025] It maintains excellent energy, thermal and aesthetic properties. The thermal properties of the functional coating correspond to a TTS equal to or less than 48.5% when the functional coating is used in a conventional laminated glazing. Conventional laminated glazing is defined as a material comprising a clear glass substrate coated with the functional coating laminated to another clear glass substrate via a PVB lamination interlayer. The functional coating is positioned on face 2 or 3 of the laminated glazing.

[0026] The material of the invention advantageously exhibits low-intensity reflection colors for a wide range of angles of incidence. The material of the invention advantageously exhibits in external reflection:

[0027] - a bluish or neutral color from all angles of observation, and / or

[0028] - a stable color between 8° and 60°, and / or

[0029] - limited RLext light reflection, in particular less than or equal to 15%.

[0030] Color stability is characterized by measuring the color variation between the two observation angles 8° and 60° and Ab*Rext = | a*Rext 60°-a*Rext 0° | . According to the invention, the colors are considered stable if Aa*Rext < 4 and Ab*Rext < 5.

[0031] The functional coating of the invention is particularly suitable for use in laminated glazing, to improve thermal comfort and the aesthetic appearance seen from the outside.

[0032] The invention therefore relates to laminated glazing comprising a material according to the invention and at least one second substrate, the material and the second substrate being bonded together by means of a lamination interlayer.

[0033] Conventionally, the faces of a glazing unit are designated from the outside by numbering the faces of the substrates from the outside to the inside of the passenger compartment or room it equips. This means that incident sunlight passes through the faces in ascending order of their number. In the case of laminated glazing, all the faces of the substrates are numbered but the faces of the lamination interlayers are not numbered.

[0034] The laminated glazing according to the invention comprises a face 1 located outside the building or vehicle it equips, faces 2 and 3 in contact with the lamination interlayer and a face 4 inside the building or vehicle. The silver-based functional coating is then positioned on face 2 or 3, that is to say on the internal face of the substrate located furthest to the outside (face 2) or on the internal face of the substrate located furthest to the inside (face 3).

[0035] The laminated glazing according to the invention may comprise curved substrates.

[0036] The invention also relates to:

[0037] - laminated glazing according to the invention mounted on a vehicle or on a building, and

[0038] - the use of laminated glazing according to the invention as glazing for buildings or vehicles,

[0039] - a building, a vehicle comprising glazing according to the invention.

[0040] The preferred characteristics which appear in the remainder of the description are applicable both to the material according to the invention and, where appropriate, to the glazing, the process, the use, the building or the vehicle according to the invention.

[0041] All the luminous characteristics described are obtained according to the principles and methods of ISO 9050, EN 410 and ISO 13837 relating to the determination of the luminous and solar characteristics of glazing used in glass for construction. According to the invention:

[0042] - light reflection corresponds to the reflection of solar radiation in the visible part of the spectrum,

[0043] - light transmission corresponds to the transmission of solar radiation in the visible part of the spectrum,

[0044] - light absorption corresponds to the absorption of solar radiation in the visible part of the spectrum.

[0045] The luminous and energy characteristics are measured according to illuminant A at 2°, perpendicular to the material mounted in laminated glazing with the functional coating positioned on face 3 (unless otherwise indicated):

[0046] - TL corresponds to the light transmission in the visible range in %,

[0047] - Rext corresponds to the external light reflection in the visible in %, observer side functional coating,

[0048] - TTS corresponds to the total energy transmission, it is measured according to convention A with a wind speed of 4 m / s.

[0049] The colorimetric characteristics are measured according to illuminant D65, observer at 10°, perpendicular to the material mounted in laminated glazing with the functional coating positioned on face 2 (unless otherwise indicated):

[0050] - a*Rext 8° and b* Rext 8° correspond to the colors in reflection a* and b* in the L*a*b* system observer functional coating side measured at an angle of 8°,

[0051] - a*Rext 60° and b* Rext 60° correspond to the colors in reflection a* and b* in the L*a*b* system observer functional coating side measured at an angle of 60°.

[0052] The material exhibits excellent energy and thermal properties. This results in total energy transmittance values ​​of less than 48.5%, measured on a laminated glazing comprising the functional coating on face 3 deposited on a clear glass substrate and laminated to a second clear glass substrate via a clear PVB polymer interlayer.

[0053] These properties are measured on ordinary clear glass. Ordinary clear glass 4 to 6 mm thick has the following luminous characteristics:

[0054] - a light transmission between 87 and 91.5%,

[0055] - a light reflection of between 7 and 9.5%,

[0056] - a light absorption of between 0.3 and 5%.

[0057] A clear PVB lamination interlayer has a light transmission greater than 80%.

[0058] Conventionally, refractive indices are measured at a wavelength of 550 nm. Unless otherwise stated, the thicknesses mentioned in this document without further details are physical, real or geometric thicknesses called Ep and are expressed in nanometers (and not optical thicknesses). The optical thickness Eo is defined as the physical thickness of the layer considered multiplied by its refractive index at the wavelength of 550 nm: Eo = n*Ep. Since the refractive index is a dimensionless value, the unit of optical thickness can be considered to be that chosen for the physical thickness.

[0059] According to the invention, a dielectric coating corresponds to a sequence of layers comprising at least one dielectric layer, located between the substrate and the first functional layer (Di1), between two functional layers (Di2 or Di3) or above the last functional layer (Di4).

[0060] If a dielectric coating is composed of several dielectric layers, the optical thickness of the dielectric coating corresponds to the sum of the optical thicknesses of the different dielectric layers constituting the dielectric coating.

[0061] If a 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, for example a metal layer, the thickness of this layer is not taken into account for the calculation of the optical thickness of the dielectric coating.

[0062] The thickness of the blocking layers is not taken into account for the calculation of the optical thickness of the dielectric coating.

[0063] For the purposes of the present invention, the terms "first", "second", "third" and "fourth" for the functional layers or dielectric coatings are defined starting from the substrate carrying the stack and referring to the layers or coatings of the same function. For example, the functional layer closest to the substrate is the first functional layer, the next one away from the substrate is the second functional layer, etc.

[0064] The functional coating is deposited by magnetic field-assisted sputtering (magnetron process). According to this advantageous embodiment, all layers of the coatings are deposited by magnetic field-assisted sputtering. Unless otherwise specifically stated, the expressions "above" and "below" do not necessarily mean that two layers and / or coatings are arranged in contact with each other. When it is specified that a layer is deposited "in contact" with another layer or coating, this means that there cannot be one (or more) layer(s) intercalated between these two layers (or layer and coating).

[0065] In this description, unless otherwise indicated, the expression "based on", used to qualify a material or a layer as to what it contains, means that the mass fraction of the constituent that it comprises is at least 50%, in particular at least 70%, preferably at least 90%.

[0066] The functional coating comprises at least three silver-based metal functional layers (F1, F2 and F3), each disposed between two dielectric coatings (Di1, Di2, Di3, Di4). Preferably, the functional coating consists of three silver-based metal functional layers (F1, F2 and F3), each disposed between two dielectric coatings (Di1, Di2, Di3, Di4).

[0067] The silver-based metal functional layers comprise at least 95.0%, preferably at least 96.5% and more preferably at least 98.0% by mass of silver relative to the mass of the functional layer. Preferably, a silver-based metal functional layer comprises less than 1.0% or less than 0.5% by mass of metals other than silver relative to the mass of the silver-based metal functional layer.

[0068] According to the invention, the third functional layer has a smaller thickness than the first functional layer or the second functional layer or the first and second functional layers. The functional layers may have the following characteristics:

[0069] - 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

[0070] - 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

[0071] - 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

[0072] - 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

[0073] - 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

[0074] - 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

[0075] - 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

[0076] - 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

[0077] - 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

[0078] - 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,

[0079] - the first silver-based functional metal layer has a thickness of between 6 and 15 nm, between 8 and 14 nm or between 9 and 13 nm, and / or or between 9 and 12 nm, and / or

[0080] - the second silver-based functional metal layer has a thickness of between 6 and 16 nm, between 8 and 14 nm, between 8 and 12 nm, and / or

[0081] - the third silver-based functional metal layer has a thickness of between 6 and 15 nm, between 6 and 11 nm, between 6 and 10 nm or between 6 and 9 nm, and / or

[0082] - 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.

[0083] The stack may further comprise at least one blocking layer located in contact with a functional metal layer. Preferably, the stack does not comprise any or only very small thicknesses.

[0084] Preferably, the sum of the thicknesses of all the blocking layers located in contact with all the silver-based functional layers is between 0 and 2 nm, preferably between 0 and 1.5 nm.

[0085] Blocking layers traditionally serve to protect the functional layers from possible degradation during the deposition of the upper anti-reflective coating and during possible high-temperature heat treatment, such as annealing, bending and / or quenching.

[0086] The blocking layers are chosen from:

[0087] - metallic layers based on a metal or a metallic alloy, metallic nitride layers, and metallic oxynitride layers of one or more elements chosen from titanium, zinc, tin, nickel, chromium and niobium,

[0088] - metal oxide layers of one or more elements chosen from titanium, nickel, chromium and niobium.

[0089] The blocking layers may in particular be layers of Ti, TiN, TiOx, Nb, NbN, Ni, NiN, Cr, CrN, NiCr, NiCrN, SnZnN. When these blocking layers are deposited in metallic, nitrided or oxynitrided form, these layers may undergo partial or total oxidation depending on their thickness and the nature of the layers surrounding them, for example, at the time of deposition of the following layer or by oxidation in contact with the underlying layer.

[0090] According to embodiments of the invention, the blocking layer(s) satisfy one or more of the following conditions:

[0091] - each silver-based functional metal layer may be located below and / or above, and possibly in contact with, a contact blocking layer chosen from a blocking sub-layer and a blocking over-layer, and / or - the blocking layer may be based on at least one element chosen from nickel, chromium, niobium, tantalum and titanium, and / or

[0092] - each functional metal layer is in contact with a blocking overlayer, and / or

[0093] - the thickness of each blocking layer is at least 0.1 nm, preferably between 0.2 and 2.0 nm.

[0094] According to the invention, the blocking layers are considered not to be part of a dielectric coating. This means that their thickness is not taken into account in the calculation of the optical or geometric thickness of the dielectric coating located in contact with them.

[0095] According to advantageous embodiments of the invention, the dielectric coatings of the functional coatings satisfy one or more of the following conditions:

[0096] - the dielectric coating Di 1 has an optical thickness Eo1 between 50 and 90 nm or between 50 and 80 nm, and / or

[0097] - the dielectric coating Di2 has an optical thickness Eo2 between 120 and 190 nm, and / or

[0098] - the dielectric coating Di3 has an optical thickness Eo3 between 110 and 160 nm, and / or

[0099] - the dielectric coating Di4 has an optical thickness Eo4 between 60 and 100 nm and / or

[0100] - the ratio of optical thicknesses Eo2 / Eo3 is greater than 1.10, and / or

[0101] - the ratio of optical thicknesses Eo2 / Eo1 is greater than 1.5, and / or

[0102] - the optical thickness ratio Eo2 / Eo1 is less than 3.0, and / or

[0103] - the optical thickness ratio Eo2 / Eo4 is greater than 1.5, and / or

[0104] - the optical thickness ratio Eo2 / Eo4 is less than 3.0, and / or

[0105] - the optical thickness ratio Eo1 / Eo3 is greater than 0.30, and / or

[0106] - the optical thickness ratio Eo1 / Eo3 is less than 0.80, and / or

[0107] - the optical thickness ratio Eo1 / Eo2 is less than 0.60, and / or

[0108] - the optical thickness ratio Eo1 / Eo4 is greater than 0.80 and / or

[0109] - the ratio of optical thicknesses Eo1 / Eo4 is less than 1.00.

[0110] By "dielectric layer" for the purposes of the present invention, it is to be understood that from the point of view of its nature, the material is "non-metallic", i.e. is not a metal. In the context of the invention, this term designates a material having an n / k ratio over the entire visible wavelength range (from 380 nm to 780 nm) equal to or greater than 5.

[0111] According to advantageous embodiments of the invention, the dielectric coatings of the functional coatings satisfy one or more of the following conditions:

[0112] - the dielectric layers are deposited by magnetic field-assisted sputtering, and / or

[0113] - the dielectric layers may be based on oxide or nitride of one or more elements chosen from silicon, zirconium, titanium, aluminum, tin, zinc, and / or

[0114] - the dielectric layers are chosen from: oxide layers of one or more elements chosen from titanium, silicon, aluminum, zirconium, iron, chromium, cobalt, manganese, tungsten, niobium, bismuth, tantalum, zinc and / or tin, nitride layers of one or more elements chosen from silicon, zirconium and aluminum, oxynitride layers of one or more elements chosen from silicon, zirconium and aluminum, metal sulfide layers such as zinc sulfide, and / or

[0115] - the dielectric layers have a thickness greater than 2 nm, preferably between 4 and 100 nm, and / or

[0116] - at least one dielectric coating comprises at least one dielectric layer with a barrier function, and / or

[0117] - each dielectric coating comprises at least one dielectric layer with a barrier function, and / or

[0118] - each dielectric coating comprises a layer comprising silicon chosen from layers based on silicon nitride and / or

[0119] - the dielectric layers with barrier function are based on silicon and / or aluminum compounds chosen from oxides such as SiC>2 and AI2O3, nitrides SisISk and AIN and oxynitrides SiO x N y and AIO x N y , based on zinc and tin oxide or based on titanium oxide,

[0120] - the dielectric layers with barrier function are based on silicon and / or aluminum compounds and optionally include at least one other element, such as aluminum, hafnium and zirconium, and / or

[0121] - each dielectric coating comprises a layer comprising silicon chosen from layers based on silicon nitride, and / or

[0122] - the sum of the physical thicknesses of all layers comprising silicon in each dielectric coating is greater than 25% of the total thickness of the dielectric coating, and / or

[0123] - at least one dielectric coating comprises at least one dielectric layer with a stabilizing function, and / or

[0124] - each dielectric coating comprises at least one dielectric layer with a stabilizing function, and / or

[0125] - the dielectric layers with a stabilizing function are preferably based on an oxide chosen from zinc oxide, tin oxide, zirconium oxide or a mixture of at least two of them, and / or

[0126] - the dielectric layers with a stabilizing function are preferably based on crystallized oxide, in particular based on zinc oxide, possibly doped with at least one other element, such as aluminum, and / or

[0127] - each functional layer is above a dielectric coating, the upper layer of which is a dielectric layer with a stabilizing function, preferably based on zinc oxide, and / or below a dielectric coating, the lower layer of which is a dielectric layer with a stabilizing function, preferably based on zinc oxide, and / or

[0128] - each dielectric coating located below a functional layer comprises a zinc oxide-based layer located below, in contact with or separated by a blocking layer, from the functional layer, and / or

[0129] - each dielectric coating located above a functional layer comprises a zinc oxide-based layer located above, in contact with or separated by a blocking layer, from the functional layer, and / or

[0130] - each dielectric coating located below a functional layer comprises a zinc and tin oxide-based layer located below and in contact with a zinc oxide-based layer.

[0131] Preferably, each dielectric coating consists of only one or more dielectric layers. Preferably, there is therefore no absorbing layer in the dielectric coatings so as not to reduce the light transmission.

[0132] Dielectric layers may have a barrier function. Dielectric layers with a barrier function (hereinafter barrier layer) are understood to mean a layer made of a material capable of acting as a barrier to the diffusion of oxygen and water at high temperature, coming from the ambient atmosphere or the transparent substrate, towards the functional layer. Such dielectric layers are chosen from the layers:

[0133] - based on silicon, aluminum and / or zirconium compounds chosen from oxides such as SiO2 and AI2O3, nitrides such as nitrides such as SisN4 and AIN, and oxynitrides such as SiO x N y , AlOxNy possibly doped with at least one other element,

[0134] - based on zinc and tin oxide,

[0135] - based on titanium oxide.

[0136] Preferably, each coating comprises at least one dielectric layer consisting of:

[0137] - of an aluminum and / or silicon nitride or oxynitride or

[0138] - a mixed oxide of zinc and tin, or

[0139] - of a titanium oxide.

[0140] These dielectric layers have a thickness:

[0141] - less than or equal to 80 nm, less than or equal to 60 nm or less than or equal to 25 nm, and / or

[0142] - greater than or equal to 5 nm, greater than or equal to 10 nm or greater than or equal to 15 nm. The functional coatings of the invention may comprise dielectric layers with a stabilizing function. For the purposes of the invention, “stabilizing” means that the nature of the layer is selected so as to stabilize the interface between the functional layer and this layer. This stabilization leads to strengthening the adhesion of the functional layer to the layers surrounding it, and in fact it will oppose the migration of its constituent material.

[0143] The dielectric layer(s) with stabilizing function may be directly in contact with a functional layer or separated by a blocking layer.

[0144] Preferably, the last dielectric layer of each dielectric coating located below a functional layer is a dielectric layer with a stabilizing function. Indeed, it is advantageous to have a layer with a stabilizing function, for example, based on zinc oxide below a functional layer, because it facilitates the adhesion and crystallization of the silver-based functional layer and increases its quality and stability at high temperature.

[0145] It is also advantageous to have a stabilizing functional layer, for example, based on zinc oxide above a functional layer, to increase its adhesion and optimally oppose diffusion on the side of the stack opposite the substrate.

[0146] The dielectric layer(s) with stabilizing function may therefore be located above and / or below at least one functional layer or each functional layer, either directly in contact with it or separated by a blocking layer.

[0147] Advantageously, each dielectric layer with barrier function is separated from a functional layer by at least one dielectric layer with stabilizing function.

[0148] The zinc oxide layer may optionally be doped with at least one other element, such as aluminum. The zinc oxide is crystallized. The zinc oxide-based layer comprises, in order of increasing preference, at least 90.0%, at least 92%, at least 95%, at least 98.0% by mass of zinc relative to the mass of elements other than oxygen in the zinc oxide-based layer.

[0149] Preferably, the dielectric coatings of the functional coatings comprise a zinc oxide-based dielectric layer located below the silver-based metal layer.

[0150] The zinc oxide layers have, in order of increasing preference, a thickness:

[0151] - at least 3.0 nm, at least 4.0 nm, at least 5.0 nm, and / or

[0152] - not more than 25 nm, not more than 10 nm, not more than 8.0 nm.

[0153] The functional coating may optionally comprise a protective top layer. The protective top layer is preferably the last layer of the stack, i.e., the layer furthest from the coated substrate of the stack. These protective top layers are considered to be included in the last dielectric coating. These layers generally have a thickness of between 2 and 10 nm, preferably 2 and 5 nm.

[0154] The protective layer may be chosen from a layer of titanium, zirconium, hafnium, zinc and / or tin, this or these metals being in metallic, oxidized or nitrided form. Advantageously, the protective layer is a layer of titanium oxide, a layer of zinc and tin oxide or a layer based on titanium and zirconium oxide.

[0155] Another particularly advantageous embodiment relates to a substrate coated with a stack defined starting from the transparent substrate comprising:

[0156] - a first dielectric coating comprising at least one layer with a barrier function and one dielectric layer with a stabilizing function,

[0157] - possibly a blocking layer,

[0158] - a first functional layer,

[0159] - possibly a blocking layer,

[0160] - a second dielectric coating comprising at least one dielectric layer with a lower stabilizing function, a layer with a barrier function and a dielectric layer with an upper stabilizing function,

[0161] - possibly a blocking layer,

[0162] - a second functional layer,

[0163] - possibly a blocking layer,

[0164] - a third dielectric coating comprising at least one dielectric layer with a lower stabilizing function, a layer with a barrier function, a dielectric layer with an upper stabilizing function,

[0165] - possibly a blocking layer,

[0166] - a third functional layer,

[0167] - possibly a blocking layer,

[0168] - a fourth dielectric coating comprising at least one dielectric layer with a stabilizing function, one layer with a barrier function,

[0169] - possibly a protective layer.

[0170] Another particularly advantageous embodiment comprises a stack which comprises, starting from the substrate:

[0171] - a first dielectric coating comprising at least one layer based on silicon nitride and one layer based on zinc oxide,

[0172] - possibly a blocking layer,

[0173] - a first functional layer,

[0174] - possibly a blocking layer,

[0175] - a second dielectric coating comprising at least three successive layers, a zinc oxide-based layer, a silicon nitride-based layer and a zinc oxide-based layer,

[0176] - possibly a blocking layer,

[0177] - a second functional layer,

[0178] - possibly a blocking layer,

[0179] - a third dielectric coating comprising at least three successive layers, a zinc oxide-based layer, a silicon nitride-based layer and a zinc oxide-based layer,

[0180] - possibly a blocking layer,

[0181] - a third functional layer,

[0182] - possibly a blocking layer,

[0183] - a fourth dielectric coating comprising at least one zinc oxide-based layer, one silicon nitride-based layer and

[0184] - possibly a protective layer.

[0185] The invention also relates to glazing comprising at least one material as defined above in the form of monolithic, laminated or multiple glazing, in particular double glazing or triple glazing.

[0186] A laminated glazing unit comprises the material as defined above and at least one second substrate, the material and the second substrate are bonded together by means of a lamination interlayer. It comprises a face 1 located outside the building or vehicle it equips, faces 2 and 3 in contact with the lamination interlayer and a face 4 inside the building or vehicle, the functional coating is positioned on face 2 or 3. It has:

[0187] - a light transmission greater than 70%, preferably greater than 75%, and / or

[0188] - a total energy transmission of less than 50%, preferably less than 48.5% and / or

[0189] - an exterior light reflection of less than 15%.

[0190] In laminated glazing configurations, the colorimetric properties are calculated with:

[0191] - materials comprising a substrate coated with a functional coating mounted in laminated glazing,

[0192] - the laminated glazing comprises a material comprising a substrate of ordinary soda-lime glass type of 1 to 2.1 mm and another substrate of soda-lime glass type of 1 to 2.1 mm, the two substrates are separated by a lamination interlayer of Polyvinyl Butyral (PVB) of 0.76 mm,

[0193] - the silver-based functional coating is preferably positioned on face 3.

[0194] The laminated glazing may further comprise a functional coating based on conductive oxide. It is preferably positioned on face 4. The conductive oxide layer is chosen from fluorine-doped tin oxide, antimony-doped tin oxide and / or indium tin oxide.

[0195] The substrates may be mineral glass or transparent polymer material substrates. The substrates are preferably mineral glass.

[0196] The mineral glass substrates that make up the glazing can be soda-lime, aluminosilicate or borosilicate glass.

[0197] The substrates can be made of transparent polymeric material which include poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyurethane or polyurea (PU) substrates.

[0198] The substrate is preferably transparent, colorless (in which case it is clear or extra-clear glass) or colored, for example blue, gray or bronze.

[0199] The substrate can be an ultra-thin glass, for example with a thickness of less than 0.7 mm.

[0200] The substrate can be (thermally) tempered glass.

[0201] The silver-based functional coating can be advantageously deposited on a clear glass substrate to allow maximum reflection of infrared radiation and thus obtain a low total energy transmission.

[0202] The silver-based functional coating can be applied to a tinted substrate to neutralize the exterior reflection appearance. However, in this case a compromise must be found between color neutralization and energy performance.

[0203] Preferably, the lamination interlayers comprise one or more sheets of organic polymers.The organic polymers are selected from polyvinyl butyral (PVB), polyurethanes (PU), polyureas, ethylene vinyl acetate (EVA), polyolefins (including polyethylene (PE), polypropylene (PP) or polyisobutylene (P-IB)), polyvinyl chloride and its derivatives (e.g. poly(vinyl dichloride) (PVDC)), styrenic polymers (e.g. polystyrene (PS), acrylostyrene butadiene (ABS), 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), polyamides (PA), fluorinated polymers such as polychlorotrifluoroethylene (PCTFE), polycarbonates (PC), aromatic polysulfones including polysulfone (PSU), polyphenylene ether (PPE), epoxy (EP) alone or as a mixture and / or copolymer of several of them. The lamination interlayer can be tinted.

[0204] Typically, interlayers have a thickness between 0.20 and 3.00 mm. An interlayer can be composed of one or more polymer sheets. The thickness range given is the total thickness of the interlayer.

[0205] The material, i.e. the substrate coated with the functional coating, may undergo a high-temperature heat treatment such as annealing, for example by flash annealing such as laser or flame annealing, quenching and / or bending. The temperature of the heat treatment is above 400°C, preferably above 450°C, and more preferably above 500°C. The substrate coated with the functional coating may therefore be curved and / or quenched.

[0206] The material of the invention is particularly suitable for use in laminated glazing for automobiles, in particular curved glazing such as roofs or windshields. The laminated glazing according to the invention is therefore preferably automotive glazing such as automotive roof glazing or a windshield.

[0207] The laminated material or glazing may also have a light transmission greater than 70%, greater than 75%, or greater than 77%. The laminated glazing according to the invention, when used in particular as a windshield or side glazing, preferably has a light transmission TL of preferably at least 70% and even at least 75% or even at least 77%.

[0208] Laminated glazing can be used as a windshield to provide a combination of solar control and another function, for example a HUD function with advantageous reflective optical properties.

[0209] Finally, the glazing of the invention is suitable for building applications, particularly when the glazing is used as a separation element with the exterior. The glazing is then indifferently in the form of single glazing, multiple glazing or laminated glazing. Multiple glazing comprises a material according to the invention and a second substrate separated by a gas layer.

[0210] The details and advantageous characteristics of the invention emerge from the following non-limiting examples.

[0211] Examples

[0212] I. Nature of layers and coatings

[0213] Functional coatings defined below are deposited on clear soda-lime glass substrates with a thickness of 1.6 mm.

[0214] The functional metal layers (F) are silver (Ag) layers. The blocking layers are nickel-chromium alloy (NiCr) metal layers. The dielectric coatings of the functional coatings include barrier layers and stabilizing layers. The barrier layers are based on aluminum-doped silicon nitride (SisN4:Al), aluminum-doped silicon zirconium nitride (SiZr17Nx), or zinc-tin mixed oxide (SnZnOx). The stabilizing layers are zinc oxide (ZnO).

[0215] The deposition conditions of the layers, which were deposited by sputtering (so-called "magnetron cathode sputtering"), are summarized in Table 1. [Table 1]

[0216] At. = atomic.

[0217] Table 2 lists the materials and physical thicknesses in nanometers (unless otherwise indicated) of each layer or coating that constitutes the coatings according to their position relative to the substrate carrying the stack (last line at the bottom of the table).

[0218] [Table 2]

[0219] Di: Dielectric coating; CF: Functional layer.

[0220] Table 3 shows the optical thicknesses and thickness ratios of the functional layers and dielectric coatings.

[0221] [Table 3]

[0222]

[0223] The substrates undergo heat treatment for several minutes at a temperature of at least 550°C

[0224] II. Laminated glazing configuration

[0225] Materials comprising a transparent substrate, one of the faces of which is coated with a functional coating, have been assembled in the form of laminated glazing.

[0226] Laminated glazing, hereinafter “L” configuration, has a structure of the type first substrate 2.1 mm / lamination interlayer / second substrate 1.6 mm.

[0227] The silver-based functional coating is positioned on face 3.

[0228] The interlayer is a clear PVB.

[0229] The second substrate is chosen from clear glass.

[0230] III. Exploratory research

[0231] Extensive explorations were carried out by optical simulation to determine the functional coatings likely to confer the desired properties.

[0232] In these simulations, all layer thicknesses were varied. The thickness ranges in which the layers varied are defined in Table 2 under RFX. The results of these Brownian explorations are shown in Figures 1, 2 and 3.

[0233] Figures 1 and 2 represent the distribution of functional coatings with the following properties:

[0234] - the points correspond to functional coatings presenting: a TL > 77% and a TTS < 48.5%,

[0235] - the squares correspond to functional coatings presenting: a TL > 77%, a TTS

[0236] < 48.5% and values ​​of a*Rext and b*Rext < 0,

[0237] - the stars correspond to functional coatings presenting: a TL > 77%, a TTS

[0238] < 48.5%, values ​​of a*Rext and b*Rext < 0 and values ​​of a*60Rext and b*60Rext < 0.

[0239] Figure 1 shows the thickness of Agl on the abscissa and the thickness of Ag2 on the ordinate. Figure 2 shows the thickness of Agl on the abscissa and the thickness of Ag3 on the ordinate. These figures highlight that:

[0240] - high light transmission values ​​can only be obtained for certain thickness ratios Ag2 / Ag1 and Ag3 / Ag1.

[0241] Figure 2 highlights a high concentration of functional coatings exhibiting all the desired properties represented by stars with Agl thicknesses both greater than 10 nm and greater than Ag3 thicknesses.

[0242] Figure 1 highlights a high concentration of functional coatings exhibiting all the desired properties represented by stars with Agl and Ag2 thicknesses such that the Ag2 / Ag1 ratio is less than or equal to 1.30.

[0243] Figure 3 shows the distribution of functional coatings with the combination of all the desired properties: TL > 77%, TTS < 48.5%, a*Rext and b*Rext values ​​< 0 and a*60Rext and b*60Rext values ​​< 0, as a function of the thickness of the following elements of the functional coatings:

[0244] - thicknesses of the functional layers Agi, Ag2 and Ag3,

[0245] - thicknesses of all the nitride layers present in a dielectric coating Di1, Di2, Di3, Di4, called respectively NDi1, NDi2, NDi3, NDi4.

[0246] For example, NDi2 includes the sum of the thicknesses of the Si3N4 and SiZrN layers in the dielectric coating Di2.

[0247] This figure highlights that the advantageous property combination is obtained with silver layers satisfying Ag1 >Ag2 and / or Ag2>Ag3 and Eo2>Eo3.

[0248] III. “Solar control” and colorimetry performances

[0249] Colorimetric performance and properties were determined by simulation [Table 4]

Claims

Claims 1. Material comprising a transparent substrate coated with a functional coating comprising successively from the substrate an alternation of three silver-based functional metal layers called, starting from the substrate, first, second and third functional layers, and four dielectric coatings called, starting from the substrate, Di1, Di2, Di3 and Di4 which each have an optical thickness Eo1, Eo2, Eo3 and Eo4, each dielectric coating comprising at least one dielectric layer, so 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 ratio of optical thicknesses Eo2 / Eo3 is greater than 1.

00.

2. 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, characterized in that the ratio of the optical thicknesses 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 between 6 and 15 nm, and / or - the second silver-based functional metal layer has a thickness of between 6 and 16 nm, and / or - the third functional metal layer based on silver has a thickness between 6 and 15 nm.

5. Material according to any one of the preceding claims, characterized in that the sum of the thicknesses of all the 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 has a light transmission greater than 70%.

7. Material according to any one of the preceding claims, characterized in that the sum of the thicknesses of all the blocking layers located in contact with all the silver-based functional layers is between 0 and 1.5 nm, the blocking layers being chosen from: - metallic layers based on a metal or a metallic alloy, metallic nitride layers, and metallic oxynitride layers of one or more elements chosen from titanium, zinc, tin, nickel, chromium and niobium, - metal oxide layers of one or more elements chosen from titanium, nickel, chromium and niobium.

8. Material according to any one of the preceding claims, characterized in that: - the dielectric coating Di1 has an optical thickness Eo1 between 50 and 90 nm, - the dielectric coating Di2 has an optical thickness Eo2 between 120 and 190 nm, - the dielectric coating Di3 has an optical thickness Eo3 between 110 and 160 nm, - the dielectric coating Di4 has an optical thickness Eo4 between 60 and 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 ratio of optical thicknesses Eo1 / Eo4 is greater than 0.80 and less than 1.

00.

10. Material according to any one of the preceding claims, characterized in that each dielectric coating comprises a layer comprising silicon chosen from layers based on silicon nitride.

11. Material according to any one of the preceding claims, characterized in that each dielectric coating located below a functional layer comprises a zinc oxide-based layer located below, in contact with or separated by a blocking layer, the functional layer.

12. Material according to any one of the preceding claims, characterized in that each dielectric coating located below a functional layer comprises a layer based on zinc and tin oxide located below and in contact with a layer based on zinc oxide.

13. Laminated glazing comprising the material according to any one of the preceding claims and at least one second substrate, the material and the second substrate are bonded together by means of a lamination interlayer.

14. Laminated glazing according to the preceding claim, characterized in that it comprises a face 1 located outside the building or vehicle which it equips, faces 2 and 3 in contact with the lamination interlayer and a face 4 inside the building or vehicle, the functional coating is positioned on face 2 or 3.

15. Laminated glazing according to claim 13 or 14 characterized in that it has: - a light transmission greater than 70%, preferably greater than 75%, and / or - a total energy transmission of less than 50%, preferably less than 48.5% and / or - an exterior light reflection of less than 15%.

Images