Material for head-up display comprising a substrate provided with a stack having thermal properties

Abstract

The present invention relates to a material comprising a transparent substrate coated on one face with a stack of thin layers, the stack of thin layers comprising, in succession from said face, an alternation of four silver-based metal functional layers and five dielectric coatings, the material being characterized in that: - the physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea2 of the second functional layer Ag2, where 0.60 < Ea1 / Ea2 < 0.90; - the physical thickness Ea1 of the first functional layer Ag1 is such that 8.00 ≤ Ea1 ≤ 13.00 nm; - the physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea3 of the third functional layer Ag3, where 0.60 < Ea1 / Ea3 < 0.90; and - the physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea4 of the fourth functional layer Ag4, where 0.60 < Ea1 / Ea4 < 0.90.

Description

[0001] The present invention relates to a material, such as a glazing, comprising a transparent substrate coated with a thin-film stack comprising a plurality of functional layers which can influence solar radiation and / or infrared radiation. The invention also relates to glazings comprising these materials and to the use of these materials for producing heat-insulating and / or solar-protective glazings.

[0002] The invention relates more particularly to such materials for producing so-called "daylight control" vehicle glazings, which allow reducing the air conditioning load and / or preventing excessive overheating in the vehicle passenger compartment while allowing a so-called "Head Up" display or HUD.

[0003] The invention relates even more particularly to a material for producing such a glazing in which the daylight control function is achieved using a stack of thin layers comprising a plurality of metallic functional layers, the stack having a low electrical resistance throughout its thickness, so that the stack can be heated by applying an electric current available at the edge of the vehicle, the current flowing transversely to the thickness of the stack.

[0004] A glazing, in particular a laminated glazing, comprising a transparent substrate coated with a thin-film stack comprising four metallic functional layers, each of which is arranged between two dielectric coatings, has been proposed to improve solar protection and to obtain a low sheet resistance while maintaining sufficient light transmittance. These stacks are generally obtained by a series of depositions by cathode sputtering, optionally assisted by a magnetic field.

[0005] Prior art materials allow sufficiently high light transmittance and low sheet resistance values ​​to be obtained. Prior art From example 16 of international patent application WO 2005 / 051858 a material is known which allows a laminated glazing having a light transmittance of 70.3% and a sheet resistance of 1.03 ohm / square to be obtained.

[0006] However, there is a need for laminated glazings that have a light transmittance of at least 70% as before but with a lower sheet resistance and, most importantly, an internal reflection that is compatible with HUD displays.

[0007] The complexity of the stack consisting of three functional layers makes it difficult to improve these properties in combination.

[0008] The inventors surprisingly found that by selecting the thicknesses of the four functional layers, a material can be obtained that exhibits the desired properties.

[0009] The present invention is based on the use of a stack having four metal functional layers (i.e., a stack having exactly four metal functional layers, no more and no less), the respective thicknesses of which, starting from the carrier substrate, are characterized in particular in that the thicknesses of the second, third and fourth functional layers are each greater than the thickness of the first layer but less than twice the thickness of the first layer.

[0010] The first subject of the present invention is the material according to claim 1. This material comprises a transparent substrate coated on one face with a stack of thin layers which, starting from said face, successively comprises the following alternation of layers:

[0011] - Four metal functional layers based on or made of silver, named the first functional layer Ag1, the second functional layer Ag2, the third functional layer Ag3 and the fourth functional layer Ag4, starting from the substrate, having physical thicknesses Ea1, Ea2, Ea3 and Ea4 respectively, and

[0012] - Five dielectric coatings, named M1, M2, M3, M4 and M5, starting from said face of the substrate, having optical thicknesses Eo1, Eo2, Eo3, Eo4 and Eo5 respectively, each dielectric coating comprising a dielectric layer or a dielectric layer assembly,

[0013] such that each metal functional layer is arranged between two dielectric coatings.

[0014] The material is notable in that:

[0015] - The physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea2 of the second functional layer Ag2, where 0.60 < Ea1 / Ea2 < 0.90, even 0.70 ≤ Ea1 / Ea2 ≤ 0.85, even 0.75 ≤ Ea1 / Ea2 ≤ 0.85;

[0016] - The physical thickness Ea1 of the first functional layer Ag1 is such that 8.00 ≤ Ea1 ≤ 13.00 nm, even such that 9.00 ≤ Ea1 ≤ 12.00 nm;

[0017] - The physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea3 of the third functional layer Ag3, where 0.60 < Ea1 / Ea3 < 0.90, even 0.70 ≤ Ea1 / Ea3 ≤ 0.85, even 0.75 ≤ Ea1 / Ea3 ≤ 0.8; and

[0018] - The physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea4 of the fourth functional layer Ag4, where 0.60 < Ea1 / Ea4 < 0.90, even 0.70 ≤ Ea1 / Ea4 ≤ 0.85, even 0.75 ≤ Ea1 / Ea4 ≤ 0.85.

[0019] Thus, this allows for the achievement of the desired optical and thermal properties, transparency, and aesthetic appearance, as previously explained.

[0020] It is a material for HUD projectors, especially for HUD projectors in s-polarization. The material reduces the reflected color intensity in s-polarization (L*(Ri65°) < 15.0); the material does not increase the reflected color intensity in p-polarization.

[0021] Some preferred but non-limiting embodiments of the present invention are given below in alternative or cumulative form:

[0022] - The geometric thickness Ea2 of the second functional layer Ag2 is between 12.0 and 15.0 nm;

[0023] - The geometric thickness Ea3 of the third functional layer Ag3 is between 13.0 and 16.0 nm;

[0024] - The geometric thickness Ea4 of the fourth functional layer Ag4 is between 13.0 and 16.0 nm;

[0025] - The cumulative geometric thickness of the four functional layers Ag1, Ag2, Ag3, and Ag4 is between 45.0 and 65.0 nm, preferably between 50.0 and 60.0 nm.

[0026] To achieve the target characteristics, it is preferred that:

[0027] - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo2 of the second dielectric coating M2, where 0.40 < Eo1 / Eo2 < 0.90, even 0.45 ≤ Eo1 / Eo2 ≤ 0.85;

[0028] - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo3 of the third dielectric coating M3, where 0.40 < Eo1 / Eo3 < 0.90, even 0.45 ≤ Eo1 / Eo3 ≤ 0.85;

[0029] - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo4 of the fourth dielectric coating M4, where 0.35 < Eo1 / Eo4 < 0.90, even 0.45 ≤ Eo1 / Eo4 ≤ 0.85; and

[0030] - The optical thickness Eo5 of the fifth dielectric coating M5 is such that 0.50 < Eo1 / Eo5 < 1.50, even 0.60 ≤ Eo1 / Eo5 ≤ 1.30.

[0031] To achieve the target characteristics, it is preferred that:

[0032] - The physical thickness Ea2 of the second functional layer Ag2 is such that 0.80 < Ea2 / Ea3 < 1.20, even 0.90 ≤ Ea2 / Ea3 ≤ 1.10, and even 0.95 ≤ Ea2 / Ea3 ≤ 1.05; and

[0033] - The physical thickness Ea2 of the second functional layer Ag2 is such that 0.80 < Ea2 / Ea4 < 1.20, even 0.90 ≤ Ea2 / Ea4 ≤ 1.10, and even 0.95 ≤ Ea2 / Ea4 ≤ 1.05.

[0034] Furthermore, the physical thickness Ea3 of the third functional layer Ag3 is preferably such that 0.80 < Ea3 / Ea4 < 1.20, even 0.90 ≤ Ea3 / Ea4 ≤ 1.10, and even 0.95 ≤ Ea3 / Ea4 ≤ 1.05.

[0035] In particular, in order to achieve the desired chromaticity characteristics, it is preferred that each of the dielectric coatings M1, M2, M3, M4, and M5 includes a high-index dielectric layer having a refractive index equal to or greater than 2.2 at a wavelength of 550 nm, and preferably includes a high-index dielectric barrier layer, each of which is based on zirconium silicon nitride.

[0036] The optical thickness of the high-index dielectric layer preferably constitutes between 20% and 75% of the optical thickness of the dielectric coating in which it is located, and even constitutes between 25% and 70% of the optical thickness of the dielectric coating in which it is located.

[0037] It may be preferred that:

[0038] - The optical thickness Eo2 of the second dielectric coating M2 is close to or the same as the optical thickness Eo3 of the third dielectric coating M3, where 0.80 < Eo2 / Eo3 < 1.20, even 0.90 ≤ Eo2 / Eo3 ≤ 1.10;

[0039] - The optical thickness Eo2 of the second dielectric coating M2 is close to or the same as the optical thickness Eo4 of the fourth dielectric coating M4, where 0.80 < Eo2 / Eo4 < 1.20, even 0.90 ≤ Eo2 / Eo4 ≤ 1.10; and

[0040] - The optical thickness Eo2 of the second dielectric coating M2 is greater than the optical thickness Eo5 of the fifth dielectric coating M5, where 1.30 < Eo2 / Eo5 < 2.00, even 1.40 ≤ Eo2 / Eo5 ≤ 1.90.

[0041] In a particular variant:

[0042] - The optical thickness Eo3 of the third dielectric coating M3 is close to or the same as the optical thickness Eo4 of the fourth dielectric coating M4, where 0.80 < Eo3 / Eo4 < 1.20, and even 0.90 ≤ Eo3 / Eo4 ≤ 1.10; and

[0043] - The optical thickness Eo3 of the third dielectric coating M3 is greater than the optical thickness Eo5 of the fifth dielectric coating M5, where 1.20 < Eo3 / Eo5 < 2.00, and even 1.30 ≤ Eo3 / Eo5 ≤ 1.90.

[0044] In a very specific variant, the optical thickness Eo4 of the fourth dielectric coating M4 is greater than the optical thickness Eo5 of the fifth dielectric coating M5, where 1.20 < Eo4 / Eo5 < 2.10, and even 1.30 ≤ Eo4 / Eo5 ≤ 1.90.

[0045] The four silver-based metal functional layers described above can be metal functional layers made of silver.

[0046] Starting from the transparent substrate, the stack can include the following layers or consist of the following layers:

[0047] - A first dielectric coating M1, which preferably includes at least one dielectric layer with a barrier function and a dielectric layer with a wetting function,

[0048] - A first functional layer Ag1,

[0049] - An optional upper barrier layer,

[0050] - A second dielectric coating M2, which preferably includes at least one dielectric layer with a barrier function and a dielectric layer with a wetting function,

[0051] - A second functional layer Ag2,

[0052] - An optional upper barrier layer,

[0053] - A third dielectric coating M3, which preferably includes at least one dielectric layer with a barrier function and a dielectric layer with a wetting function,

[0054] - A third functional layer Ag3,

[0055] - An optional upper barrier layer,

[0056] - A fourth dielectric coating M4, which preferably includes at least one dielectric layer with a barrier function and a dielectric layer with a wetting function,

[0057] - A fourth functional layer Ag4,

[0058] - An optional upper barrier layer,

[0059] - a fifth dielectric coating M5 , which preferably comprises at least one dielectric layer having a barrier function.

[0060] The invention also relates to a glazing comprising at least one material as described above. Such a glazing is preferably in the form of a laminated glazing.

[0061] A dielectric coating within the meaning of the present invention preferably does not comprise any absorber layer, metal layer or nitride layer at all.

[0062] All light properties presented in this specification are obtained according to the principles and methods described in European Standard EN 410 relating to the determination of light and daylight properties of glazing used in glazing for motor vehicle construction.

[0063] Traditionally, the refractive index is measured at a wavelength of 550 nm. L And light reflectivity R L The coefficients are measured under illuminant A with a 2° field of view or under illuminant D65 using a 10° observer according to the following instructions.

[0064] Unless otherwise stated, thicknesses mentioned in this document, without further details, are physical thicknesses or real thicknesses or geometric thicknesses, named Ep for dielectric layers and Ea for metallic functional layers, and are expressed in nanometers. The optical thickness Eo of a layer or a layer assembly is defined as the physical thickness of the layer under consideration multiplied by its refractive index (n) at a wavelength of 550 nm: Eo = n 550 ×Ep or, for this layer assembly, the sum of the optical thicknesses of these layers. Since the refractive index is a dimensionless value, the units of the optical thickness can be considered to be the same as the units chosen for the physical thickness. In this specification, unless otherwise stated, the units chosen for the thickness are nanometers. If the dielectric coating consists of a plurality of 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.

[0065] Throughout the specification, the substrate according to the invention is considered to be placed horizontally. The thin layer stack is deposited above the substrate and in contact with the substrate. The meaning of the expressions "above" and "below" and "below" and "above" will be considered relative to this orientation. Unless otherwise specified, the expressions "above" and "below" do not necessarily mean that two layers and / or coatings are 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) intervening layers between the two layers (or layer and coating).

[0066] For the purposes of the present invention, the designations "first", "second", "third", "fourth" and "fifth" 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 subsequent functional layer further away from the substrate is the second functional layer, etc.

[0067] Preferably, the multilayer is deposited by magnetic field-assisted cathode sputtering (magnetron process).According to this advantageous embodiment, all layers of the multilayer are deposited by magnetic field-assisted cathode sputtering.

[0068] Barrier layers may be present in the multilayer according to the invention. They generally have the function of protecting the functional layers from possible damage during deposition of the upper antireflection coating and / or during optional high-temperature heat treatments of the annealing, bending and / or quenching type.

[0069] The barrier layer is, for example, a metal layer based on a metal or metal alloy selected from one or more elements selected from titanium, nickel, chromium and niobium, such as Ti, TiN, TiO x , Nb, NbN, Ni, NiN, Cr, CrN, NiCr, NiCrN or NbNO x or NiCrO x .

[0070] The geometric thickness of this layer is in the order of a few nanometers, typically less than 5 nanometers, and most often about one nanometer or even less than one nanometer.

[0071] When these barrier layers are deposited in the form of metals, nitrides or oxynitrides, these layers may, depending on their thickness and the nature of the layers surrounding them, undergo partial or complete oxidation, for example, during the deposition of the next layer or due to oxidation in contact with the underlying layer.

[0072] According to an advantageous embodiment of the invention, the dielectric coating satisfies one or more of the following conditions:

[0073] - the dielectric coating comprises at least one dielectric layer based on an oxide or nitride of one or more elements selected from silicon, titanium, zirconium, aluminum, tin or zinc, and / or

[0074] - at least one dielectric coating comprises at least one dielectric layer having a barrier function, and / or

[0075] - each dielectric coating comprises at least one dielectric layer having a barrier function, and / or

[0076] - The dielectric layer with barrier function is based on silicon and / or aluminum compounds selected from oxides such as SiO2 and Al 2 O 3 or a mixture thereof, silicon nitride Si 3 N 4 and AlN or a mixture thereof and oxynitride SiO x N y and AlO x N y or a mixture thereof, and / or

[0077] - the dielectric layer having a barrier function is based on a compound of silicon and / or aluminum, which compound optionally contains at least one other element, such as aluminum, hafnium and zirconium, and / or

[0078] - at least one dielectric coating comprises at least one dielectric layer having a stabilizing function, and / or

[0079] - each dielectric coating comprises at least one dielectric layer having a stabilizing function, and / or

[0080] - 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 of them,

[0081] - the dielectric layer having a stabilizing function is preferably based on a crystalline oxide, in particular on zinc oxide, optionally doped with at least one other element such as aluminum, and / or

[0082] Each functional layer is above a dielectric coating, the upper layer of which is a dielectric layer with stabilizing functions, preferably based on zinc oxide, and / or below a dielectric coating, the lower layer of which is a dielectric layer with stabilizing functions, preferably based on zinc oxide.

[0083] Preferably, each dielectric coating consists of one or more dielectric layers only. Preferably, there are therefore no absorbing layers in the dielectric coatings, so as not to reduce light transmission.

[0084] The stack of the present invention may include a dielectric layer with a barrier function. The expression "dielectric layer with a barrier function" is understood to mean a layer made of a material capable of forming a barrier to the diffusion of water and oxygen from the ambient atmosphere or from a transparent substrate toward the functional layer at high temperatures. Therefore, the constituent materials of the dielectric layer with a barrier function must not be subjected to chemical or structural modifications at high temperatures, which will lead to modifications of their optical properties. The one or more layers with a barrier function are also preferably selected to be made of a material capable of forming a barrier to the constituent materials of the functional layer. Therefore, the dielectric layer with a barrier function allows the stack to undergo annealing, quenching or bending type heat treatments without excessive optical changes.

[0085] The stack of the invention may include a dielectric layer having a stabilizing function. For the purposes of the invention, the term "stabilizing" refers to the property of selecting a layer to stabilize the interface between the functional layer and the layer. This stabilizing effect causes an increased adhesion of the functional layer to the layers surrounding it, in fact, it will prevent the migration of its constituent materials.

[0086] The one or more dielectric layers having a stabilizing function may be in direct contact with the functional layer or separated by a barrier layer.

[0087] Preferably, the final dielectric layer of each dielectric coating located below the functional layer is a dielectric layer with stabilizing functions. In fact, it is advantageous to have a layer with stabilizing functions (e.g. based on zinc oxide) below the functional layer, since it facilitates the adhesion and crystallization of the silver-based functional layer and improves its quality and its stability at high temperatures.

[0088] It is also advantageous if a layer having a stabilizing function is present above the functional layer, for example a layer based on zinc oxide, in order to increase its adhesion and to optimally prevent diffusion on the side of the multilayer opposite to the substrate.

[0089] One or more dielectric layers having a stabilizing function may therefore be present above and / or below at least one functional layer or each functional layer, either in direct contact therewith or separated therefrom by a barrier layer.

[0090] Advantageously, each dielectric layer having a barrier function is separated from the functional layer by at least one dielectric layer having a stabilizing function.

[0091] Such a dielectric layer having a stabilizing function may have a thickness of at least 4 nm, in particular a thickness of 4 nm to 18 nm and more preferably a thickness of 8 nm to 15 nm.

[0092] The transparent substrate according to the invention is preferably made of a rigid inorganic material, for example of glass, or of an organic material based on (or made of) a polymer.

[0093] The transparent organic substrate according to the invention can also be made of polymers, rigid or flexible. Examples of suitable polymers according to the invention include in particular:

[0094] - Polyethylene;

[0095] - Polyesters, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or polyethylene naphthalate (PEN);

[0096] - polyacrylates, such as polymethyl methacrylate (PMMA);

[0097] - Polycarbonate;

[0098] - Polyurethane;

[0099] - polyamide;

[0100] - Polyimide;

[0101] - fluorinated polymers, for example fluorinated esters, such as ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE) or fluorinated ethylene propylene (FEP) copolymers;

[0102] - photocrosslinkable and / or photopolymerizable resins, for example thiophene, polyurethane, urethane-acrylate or polyester-acrylate resins; and

[0103] - Polythiourethane.

[0104] The substrate is preferably a glass sheet.

[0105] The substrate is preferably transparent, colorless (in which case it is clear or extra clear glass) or colored, for example blue, gray or bronze. The glass is preferably of the soda-lime-silica type, but can also be made of borosilicate or aluminoborosilicate type glass.

[0106] The substrate advantageously has at least one dimension greater than or equal to 1 m, even 2 m or even 3 m. The thickness of the substrate generally varies between 0.6 mm and 2.1 mm. The substrate may be flat or curved.

[0107] The material, i.e. the substrate coated with the multilayer, can be subjected to a high temperature heat treatment, such as annealing, for example by rapid annealing, such as laser or flame annealing, quenching and / or bending. The temperature of the heat treatment is higher than 400° C., preferably higher than 450° C., more preferably higher than 500° C. The substrate coated with the multilayer can thus be bent and / or quenched.

[0108] The glazing according to the invention is preferably in the form of a laminated glazing, in particular a laminated glazing for a HUD projector. The laminated glazing comprises at least one structure of the first substrate / sheet / second substrate type. The stack of thin layers is arranged on at least one face of one of the substrates. The stack may be on the face of the first substrate that is in contact with the sheet, preferably a polymer sheet.

[0109] The glazing according to the invention, when used as a laminated glazing, preferably has the following optical properties:

[0110] - light transmittance equal to or greater than 70%,

[0111] -a* T <0.0

[0112] - External and internal reflections equal to or less than 15%,

[0113] -a* Re <0.0, -12.0≤b* Re < 0.0,

[0114] -a* Ri <0.0, -15.0≤b* Ri < 0.0,

[0115] - and within the meaning of this document, L*(Ri65°)<15.0.

[0116] Details and advantageous features of the invention become apparent from the following non-limiting examples described using the accompanying drawings:

[0117] [ Figure 1 ] shows a stacked structure with four metal functional layers according to the present invention, which is deposited on a transparent glass substrate 10;

[0118] [ Figure 2 ]Combination Figure 1 The components of four embodiments are described in detail, numbered 1 to 4;

[0119] [ Figure 3 ] summarizes the specific ratio of optical thickness Eo or physical thickness Ea;

[0120] [ Figure 4 ] shows the sheet resistance and optical properties in a single structure, after annealing heat treatment;

[0121] [ Figure 5 ] shows the optical properties of the laminated structure; and

[0122] [ Figure 6 ] shows a reference white color used to convert the quantities X, Y, Z to L*, a*, b* (as a function of wavelength λ in nanometers).

[0123] exist Figure 1 The proportions between the different components are not followed for ease of reading.

[0124] exist Figure 1 The stack shown in is arranged on a substrate 10 and comprises only four metallic functional layers 40, 80, 120 and 160. Each functional layer 40, 80, 120, 160 is arranged between two dielectric coatings 20, 60, 100, 140 and 180, such that:

[0125] - a first functional layer 40 starting from the substrate 10 is arranged between the dielectric coatings 20 and 60,

[0126] - a second functional layer 80 is arranged between the dielectric coatings 60 and 100,

[0127] - a third functional layer 120 is arranged between the dielectric coatings 100 and 140, and

[0128] A fourth functional layer 160 is arranged between the dielectric coatings 140 and 180 .

[0129] Each of these dielectric coatings 20 , 60 , 100 , 140 , 180 includes at least one dielectric layer 24 , 27 , 28 ; 62 , 64 , 66 , 67 , 68 ; 102 , 104 , 106 , 107 , 108 ; 142 , 144 , 146 , 147 , 148 , 182 , 186 and 187 .

[0130] The stack may also include:

[0131] - barrier upper layers 50, 90, 130 and 170, each located above and in contact with the functional layer,

[0132] - barrier sublayers (not shown), each of which is located below and in contact with the functional layer,

[0133] - A protective layer (not shown), the last layer located above all the previous layers, for example made of TiZr or of zirconium and titanium oxides.

[0134] Example:

[0135] I. Substrate preparation: stack, deposition conditions and thermal treatment

[0136] The thin-film stack defined below was deposited on a substrate made of clear soda-lime glass with a thickness of 1.6 mm.

[0137] In an embodiment, these layers are deposited by sputtering (so-called "magnetron cathode sputtering"):

[0138] - Functional layers 40, 80, 120 and 160 are silver (Ag) layers, which are heated in a 100% argon or krypton atmosphere and 3×10 -3 Deposition from a metal target under reduced pressure of 1000 mbar,

[0139] - The barrier upper layers 50, 90, 130 and 170 are metal layers made of nickel-chromium alloy (NiCr), which are heated in a 100% argon atmosphere and 3×10 -3 Deposition was carried out from a metal target having 80 atomic % Ni and 20 atomic % Cr under reduced pressure of 100 mbar,

[0140] - The dielectric layer is:

[0141] - Medium index barrier layers 104, 144 and 187, each of which is based on silicon nitride doped with aluminum ("Si 3 N 4 ”), and from a silicon target having 92 wt % silicon and 8 wt % aluminum, in a nitrogen-argon atmosphere having 45 % nitrogen and 55 % argon and at 3.2×10 -3 The deposition was carried out under reduced pressure of 1000 mbar.

[0142] - High index barrier layers 24, 64, 106, 146 and 186, each of which is based on silicon zirconium nitride ("SiZrN") and is prepared from a silicon target having 83 atomic % silicon and 17 atomic % zirconium in a nitrogen-argon atmosphere having 45 atomic % argon and 55 atomic % argon at 3.2×10 -3 The deposition was carried out under reduced pressure of 1000 mbar.

[0143] - an ultra-high index barrier layer 66, which is based on silicon zirconium nitride ("SiZrN*") and is prepared from a silicon target having 73 atomic % silicon and 27 atomic % zirconium, in a nitrogen-argon atmosphere having 45% nitrogen and 55% argon and at 3.2×10 -3 The deposition was carried out under reduced pressure of 1000 mbar.

[0144] - Wetting layers 28, 68, 108 and 148, each of which is located below and in contact with each metal functional layer and each of which is made of zinc oxide ("ZnO"), produced from a ceramic target in a 100% argon atmosphere and at 3×10 -3 Deposition was carried out at a pressure of 100 mbar,

[0145] - smoothing layers 27, 67, 107 and 147, each of which is located between the barrier layer and the wetting layer and each of which is made of zinc-tin mixed oxide ("SnZnO"), from a metal target with 50% by weight of tin and 50% by weight of zinc, in an atmosphere with 30% argon and 70% oxygen and at 3×10 -3 The deposition was carried out under reduced pressure of 1000 mbar.

[0146] - Stabilization layers 62, 102, 142, and 182, each of which is located above and in contact with the barrier upper layer and each of which is made of zinc oxide ("ZnO") doped with aluminum, which is produced from a ceramic target in an atmosphere of 100% argon and at 3×10 -3 The deposition was carried out under reduced pressure of 100 mbar.

[0147] therefore, Figure 2 A table lists the material and physical thickness Ep of each dielectric layer, the thickness Ea of each metallic functional layer (in nanometers) and the corresponding optical thickness Eo of each dielectric coating (in nanometers) as a function of their position relative to the substrate supporting the stack (located at the bottom of the table).

[0148] Columns I1, I2 and I3 list ratios, preferred ratios and more preferred ratios, respectively, for use in the present invention.

[0149] II. "Daylight Control" and Chromaticity Performance

[0150] Figure 4 The table lists the main optical properties measured in the monomer state after annealing at 650°C for 5 minutes and cooling in ambient air (20°C).

[0151] For these monomer structures:

[0152] - TL indicates: light transmittance in the visible region, in %, measured under illuminant A at an observer angle of 2°;

[0153] -a* T and b* T Indication: Color a* and b* in transmission at normal incidence (0°) in the L*a*b* system, measured with illuminant D65 at 10° observer and perpendicular to the substrate;

[0154] -Rc indicates: light reflectance in visible light, in %, measured with light source A and one side of the stack at 10° observer;

[0155] -a* Rc and b* Rc Indication: Color a* and b* in the L*a*b* system at normal incidence (0°) in reflection, measured with illuminant D65 and 10° observer on the side of the multilayer and thus perpendicular to the substrate;

[0156] - Rg indicates: visible light reflectance, in %, measured with illuminant A, on the side opposite to the stack (below the substrate 10) with an observer at 2°;

[0157] -a* Rg and b* Rg Indication: Color a* and b* in the L*a*b* system at normal incidence (0°) in reflection, measured with illuminant D65, at 10° observer on the opposite side of the stack and thus perpendicular to the substrate;

[0158] -L*Rc(60°),a* Rc (60°) and b* Rc (60°) indicates: the intensity L* and the colors a* and b* in reflection on the layer side in the L*a*b* system, measured at an angle of incidence of 60° to the normal with a D65 illuminant and a 10° observer on the multilayer side.

[0159] Figure 5The table lists the main optical properties measured when the substrates coated with the multilayer each formed part of a laminated glazing having the following structure: 1.6 mm inner glass substrate / 0.76 mm PVB intermediate sheet / 2.1 mm outer glass substrate, the multilayer being located on the face of the inner substrate facing the intermediate sheet.

[0160] For these laminated glazings,

[0161] - TL indicates: light transmittance in the visible region, in %, measured with illuminant A and 2° observer;

[0162] -a* T and b* T Indication: Color a* and b* in transmission at normal incidence (0°) in the L*a*b* system, measured with a D65 illuminant and a 10° observer and measured perpendicular to the glass;

[0163] - Re indicates: the light reflection in visible light, in %, measured with illuminant A and with an observer at 2° on the outermost side of the window pane;

[0164] -a* Re and b* Re Indication: Color a* and b* in reflection at normal incidence (0°) in the L*a*b* system, measured with illuminant D65, with an observer at 10° to the side of the outermost face and thus perpendicular to the window pane;

[0165] - Ri indicates: light reflection in the visible region, in %, measured with a D65 illuminant and an observer at 2° on the side of the inner face of the glazing;

[0166] -a* Ri and b* Ri Indication: Color a* and b* in reflection at normal incidence (0°) in the L*a*b* system, measured with illuminant D65, with an observer at 10° on the inside face side and therefore perpendicular to the window pane;

[0167] - L*(Re60°), a*(Re60°) and b*(Re60°) denote the reflected color a* and b* in the L*a*b* system, measured with a D65 illuminant at an incidence of 60° relative to the normal, with an observer at 2° on the side of the outer face of the glass; and

[0168] - L*(Ri65°), a*(Ri65°) and b*(Ri65°) denote the reflected colors a* and b* in the L*a*b* system measured at an incidence of 65° to the normal: on laminated glazings, by measuring the colors L*(Ri65°), a*(Ri65°) and b*(Ri65°) under s-polarization and at an incidence of 65° to the normal, corresponding to the second reflection from the inner face of the glazing (the first reflection is the reflection measured directly on the innermost face). The light source used for this measurement corresponds to the HUD projector (to measure the X, Y, Z values ​​by using a reference white corresponding to the illuminant D65 and a 2° observer, which are then converted to L*, a*, b*); the light source selected is as follows Figure 6 as shown in .

[0169] The present invention simultaneously displays all target values ​​in Figure 4 and 5 In column I1 of the table.

[0170] Examples 1 and 2 are comparative examples outside the present invention. Examples 3 and 4 are examples according to the present invention.

[0171] Example 1 follows the general teaching of International Patent Application No. WO2005 / 051858 in that it includes four functional layers of substantially the same thickness, all of which are approximately 14.0 nm ± 0.5 nm. Thus, the ratio of the thickness of the first functional layer to the thickness of the other functional layers is approximately 1.00 ± 0.05, such as Figure 3 These thicknesses are not strictly the same because this Example 1 was optimized to try to achieve the highest possible light transmittance while achieving a satisfactorily low sheet resistance, i.e., on the order of 0.70 ohms per square or less.

[0172] Figure 4 The table shows that the light transmittance of this monomer structure is 73%, while Figure 5 The table shows that the light transmittance of this laminated structure is 70%, which is satisfactory.

[0173] However, Figure 5 This table shows that the color intensity in the reflection of the HUD image, expressed as L*(Ri65°), is too high. This window glass is not compatible for use with a HUD system.

[0174] Example 2 follows another general teaching and includes a very thin first functional layer and the following three substantially identical layers. The ratio of the thickness of the first functional layer to the thickness of the other functional layers is about 0.50 plus or minus 0.05, such as Figure 3This Example 2 was also the subject of optimization in order to try to achieve the highest possible light transmittance, but the sheet resistance obtained was not satisfactory: it was well above the maximum limit of 0.70 ohm / square, not allowing efficient electrical heating of the glazing through the thin-film stack.

[0175] also, Figure 5 The table shows that the light transmittance of the laminated structure is 71%, which is satisfactory, but the color intensity in the reflection of the HUD image expressed as L*(Ri65°) is also too high.

[0176] in addition, Figure 5 The table shows that the color of the internal reflection is far from the target value, where a* Ri is much higher than zero and is too positive, b* Ri is far below zero and too negative; the color in the external reflection is also far from the target value, a* Re is much higher than zero and is too positive, b* Re Well below zero and overly negative.

[0177] According to the invention, it is possible to produce a glazing comprising a multilayer having three metallic functional layers, which multilayer in laminated construction has a light transmission equal to or greater than 70%, a* T <0.0, external reflection and internal reflection are equal to or less than 15%, a* Re <0.0, -12.0≤b* Re <0.0, a* Ri <0.0, -15.0≤b* Ri <0.0 and L*(Ri65°)<15.0.

[0178] Examples 3 and 4 are therefore satisfactory. They have a pleasant and very faint coloration in transmission, preferably in the blue or blue-green range, but the intensity is very low.

Claims

1. A material comprising a transparent substrate coated on one face with a stack of thin layers, said stack of thin layers comprising in succession, from said face, an alternation of the following layers: - Four metal functional layers based on or made of silver, named the first functional layer Ag1, the second functional layer Ag2, the third functional layer Ag3 and the fourth functional layer Ag4 starting from the substrate, having physical thicknesses Ea1, Ea2, Ea3 and Ea4 respectively, - Five dielectric coatings, named M1, M2, M3, M4 and M5 starting from said face of the substrate, having optical thicknesses Eo1, Eo2, Eo3, Eo4 and Eo5 respectively, each dielectric coating comprising a dielectric layer or a dielectric layer assembly, such that each metal functional layer is disposed between two dielectric coatings, The material is characterized in that: - The physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea2 of the second functional layer Ag2, where 0.70 < Ea1 / Ea2 < 0.90; - The physical thickness Ea1 of the first functional layer Ag1 is such that 8.00 ≤ Ea1 ≤ 13.00 nm; - The physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea3 of the third functional layer Ag3, where 0.60 < Ea1 / Ea3 < 0.90; - The physical thickness Ea1 of the first functional layer Ag1 is less than the physical thickness Ea4 of the fourth functional layer Ag4, where 0.70 < Ea1 / Ea4 < 0.90; and - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo2 of the second dielectric coating M2, where 0.40 < Eo1 / Eo2 < 0.90; - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo3 of the third dielectric coating M3, where 0.40 < Eo1 / Eo3 < 0.90; - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo4 of the fourth dielectric coating M4, where 0.35 < Eo1 / Eo4 < 0.90; and - The optical thickness Eo5 of the fifth dielectric coating M5 is such that 0.50 < Eo1 / Eo5 < 1.

50.

2. The material according to claim 1, wherein: - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo2 of the second dielectric coating M2, where 0.45 ≤ Eo1 / Eo2 ≤ 0.85; - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo3 of the third dielectric coating M3, where 0.45 ≤ Eo1 / Eo3 ≤ 0.85; - The optical thickness Eo1 of the first dielectric coating M1 is less than the optical thickness Eo4 of the fourth dielectric coating M4, where 0.45 ≤ Eo1 / Eo4 ≤ 0.85; and - The optical thickness Eo5 of the fifth dielectric coating M5 is such that 0.60 ≤ Eo1 / Eo5 ≤ 1.

30.

3. The material according to claim 1 or 2, wherein: - The physical thickness Ea2 of the second functional layer Ag2 is such that 0.80 < Ea2 / Ea3 < 1.20; and - The physical thickness Ea2 of the second functional layer Ag2 is such that 0.80 < Ea2 / Ea4 < 1.

20.

4. The material according to any one of claims 1 to 2, wherein the physical thickness Ea3 of the third functional layer Ag3 is such that 0.80 < Ea3 / Ea4 < 1.

20.

5. The material according to any one of claims 1 to 2, wherein each of the dielectric coatings M1, M2, M3, M4, and M5 includes a high-index dielectric layer having a refractive index at a wavelength of 550 nm equal to or greater than 2.

2.

6. The material according to claim 5, wherein the optical thickness of the high-index dielectric layer accounts for 25% to 75% of the optical thickness of the dielectric coating in which it is located.

7. The material according to any one of claims 1 to 2, wherein - the optical thickness Eo2 of the second dielectric coating M2 is close to or the same as the optical thickness Eo3 of the third dielectric coating M3, where 0.80 < Eo2 / Eo3 < 1.20; - the optical thickness Eo2 of the second dielectric coating M2 is close to or the same as the optical thickness Eo4 of the fourth dielectric coating M4, where 0.80 < Eo2 / Eo4 < 1.20; and - the optical thickness Eo2 of the second dielectric coating M2 is greater than the optical thickness Eo5 of the fifth dielectric coating M5, where 1.30 < Eo2 / Eo5 < 2.

00.

8. The material according to any one of claims 1 to 2, wherein - the optical thickness Eo3 of the third dielectric coating M3 is close to or the same as the optical thickness Eo4 of the fourth dielectric coating M4, where 0.80 < Eo3 / Eo4 < 1.20; and - the optical thickness Eo3 of the third dielectric coating M3 is greater than the optical thickness Eo5 of the fifth dielectric coating M5, where 1.20 < Eo3 / Eo5 < 2.

00.

9. The material according to any one of claims 1 to 2, wherein - the optical thickness Eo4 of the fourth dielectric coating M4 is greater than the optical thickness Eo5 of the fifth dielectric coating M5, where 1.20 < Eo4 / Eo5 < 2.

10.

10. The material according to claim 1, wherein - 0.70 ≤ Ea1 / Ea2 ≤ 0.85; - 9.00 ≤ Ea1 ≤ 12.00 nm; - 0.70 ≤ Ea1 / Ea3 ≤ 0.85; and - 0.70 ≤ Ea1 / Ea4 ≤ 0.

85.

11. The material according to claim 3, wherein - 0.90 ≤ Ea2 / Ea3 ≤ 1.10; and - 0.90 ≤ Ea2 / Ea4 ≤ 1.

10.

12. The material according to claim 4, wherein 0.90 ≤ Ea3 / Ea4 ≤ 1.

10.

13. The material according to any one of claims 1 to 2, wherein each of the dielectric coatings M1, M2, M3, M4, and M5 includes high-index dielectric barriers (24, 64, 106, 146, 186), all of which are based on zirconium silicon nitride.

14. The material according to claim 7, wherein - 0.90 ≤ Eo2 / Eo3 ≤ 1.10; - 0.90 ≤ Eo2 / Eo4 ≤ 1.10; and - 1.40 ≤ Eo2 / Eo5 ≤ 1.

90.

15. The material according to claim 8, wherein - 0.90 < Eo3 / Eo4 < 1.10; and -1.30≤Eo3 / Eo5≤1.

90.

16. The material according to claim 9, wherein -1.30≤Eo4 / Eo5≤1.

90.

17. Glazing comprising at least one material according to any one of claims 1 to 16.

18. Glazing according to claim 17, being a laminated glazing for a HUD projector.

Images