Composite panes containing solar-shielding coatings

Abstract

To provide a further improved composite pane having a sun-shading function.SOLUTION: A composite pane 100 includes an outer pane 1, an inner pane 2, and a thermoplastic intermediate layer 3, and has at least one sun-shading coating 4 between the outer pane 1 and the inner pane 2. The sun-shading coating 4 comprises, starting from the outer pane 1 toward the inner pane 2, a layer sequence "a first dielectric module (M1) / a first silver layer (Ag1) / a second dielectric module (M2) / a second silver layer (Ag2) / a third dielectric module (M3) / a third silver layer (Ag3) / a fourth dielectric module (M4)". The silver layers (Ag1, Ag2, Ag3) have, relative to one another, geometrical layer thickness of 0.4<Ag1 / Ag3<1.7, and Ag3 or Ag2 is the thickest silver layer. The dielectric modules (M1, M2, M3, M4) have, relative to one another, an optical layer thickness of M2 / M1≥1.9, M2 / M3≥0.8, and M2 / M4≥1.6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composite pane having an improved solar shading coating and uses thereof. [Background technology]

[0002] German Patent No. 19927683 discloses a general-purpose composite pane comprising at least two glass panes joined together by a transparent interlayer and further comprising a solar shading layer that substantially reflects solar radiation, in particular infrared radiation outside the visible spectrum of solar radiation, in particular infrared radiation, where the composite glass pane is further provided on its surface facing the interior space with another transparent coating (also called a low-E layer) that substantially reflects thermal radiation and is spatially separated from the solar shading layer.

[0003] WO 2013 / 127563 discloses another generic composite pane with a solar-shielding layer between glass panes and a low-E coating on its inner surface, where the heat-radiation-reflecting coating (low-E coating) is based on niobium, tantalum, molybdenum, or zirconium.

[0004] WO 2019 / 110172 discloses a composite glass pane comprising an outer pane having an outer surface and an inner surface, an inner pane having an outer surface and an inner surface, and a thermoplastic interlayer bonding the inner surface of the outer pane to the outer surface of the inner pane. The composite pane further comprises at least one solar shading coating between the outer pane and the inner pane that substantially reflects or absorbs light outside the visible spectrum of solar radiation, particularly infrared radiation. The composite glass pane also comprises a thermal radiation reflective coating on the inner surface of the inner pane. The composite pane has a transmittance index A of 0.02 to 0.08, where the transmittance index A is determined as follows:

number

[0005] TL is the light transmittance level and TE is the energy transmittance, each measured according to ISO 9050. VSG refers to the light transmittance through the composite pane, while TL LOWE represents only the light transmittance through the inner pane in conjunction with the infrared-reflecting, low-E glass coating. The TL value can be appropriately adjusted by selecting the tint of the composite pane's components, i.e., the inner pane, the outer pane, and the interlayer. The TE value is similarly determined by the selection of the tint of the composite pane's components, as well as by the properties of the solar-blocking coating and the thermal-radiation-reflecting coating. With such composite panes, low TTS values ​​of less than 50% could be achieved in combination with low light transmittances of 1-12%.

[0006] German Utility Model No. 202020100793 discloses a vehicle roof panel with an interference coating for preventing reflections in a display device. The interference coating includes multiple conductive silver layers, with dielectric layer structures positioned between, above, and below the silver layers. Each of the dielectric layer structures includes n optically low refractive index layers with a refractive index less than 1.8, and (n+1) optically high refractive index layers, where n is an integer greater than or equal to 1.

[0007] WO 2020 / 094423 describes a projection device for a head-up display (HUD), which includes a composite pane having a conductive coating and a projector, where the conductive coating includes at least three conductive layers, where the total thickness of all conductive layers is at most 30 nm, and where the conductive layers have a thickness of 5 nm to 10 nm. Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to provide a further improved composite pane with solar shading functionality, wherein the energy, thermal and optical properties of the composite pane should be further improved and a reflected color that is visually appealing and as independent as possible from the viewing angle should be achieved.

[0009] This problem is solved according to the invention by a composite pane according to independent claim 1. Advantageous embodiments of the invention are evident from the dependent claims. DETAILED DESCRIPTION OF THE INVENTION

[0010] The composite pane of the present invention includes an outer pane having an outer surface (Side I) and an inner surface (Side II), an inner pane having an outer surface (Side III) and an inner surface (Side IV), and a thermoplastic intermediate layer bonding the inner surface of the outer pane to the outer surface of the inner pane; wherein the composite pane has at least one solar shading coating between the outer pane and the inner pane that substantially reflects or absorbs light rays outside the visible spectrum of solar radiation, in particular infrared radiation; wherein the solar shielding coating comprises, viewed in the direction of the outer pane, the following layer sequence: a first dielectric module (M1), - a first silver layer (Ag1), - a second dielectric module (M2), - a second silver layer (Ag2), - a third dielectric module (M3), - the third silver layer (Ag3), -Fourth dielectric module (M4)

[0011] The silver layers (Ag1, Ag2, Ag3) of the solar radiation shielding coating according to the present invention have a geometric layer thickness such that 0.4 < Ag1 / Ag3 < 1.7 with respect to each other. Here, Ag3 or Ag2 is the thickest silver layer, and here, the thicknesses of the silver layers Ag3 and Ag2 can also be made the same. The dielectric modules (M1, M2, M3, M4) have an optical layer thickness such that M2 / M1 ≥ 1.9, M2 / M3 ≥ 0.8, and M2 / M4 ≥ 1.6 with respect to each other. All dielectric layers of the dielectric modules (M1, M2, M3, M4) have a refractive index greater than 1.8.

[0012] The structure of the layer arrangement of the solar radiation shielding coating according to the present invention is viewed starting from the direction of the outer pane. This means that the first dielectric module is the layer closest to the inner surface (second surface) of the outer pane of the solar radiation shielding coating, followed in this order by the first silver layer (Ag1), the second dielectric module (M2), the second silver layer (Ag2), the third dielectric module (M3), the third silver layer (Ag3), and the fourth dielectric module (M4). Thus, the fourth dielectric module is the layer of the solar radiation shielding coating that is farthest from the inner surface of the outer pane and closest to the outer surface (third surface) of the inner pane. The silver layers are, in each case, arranged between the dielectric modules, i.e., between the dielectric layers or layer arrangements. The solar radiation shielding coating is arranged between the inner surface (second surface) of the outer pane and the outer surface (third surface) of the inner pane and can, for example, be applied to one of the surfaces of the pane or integrated into a thermoplastic intermediate layer.

[0013] In other words, according to the present invention, the thickness of the first silver layer (Ag1) of the solar shading coating is smaller than the respective thicknesses of one or both of the two other silver layers Ag2 and Ag3 that follow. These silver layers are arranged above the first silver layer in the layer sequence of the solar shading coating and are therefore arranged further from the outer pane. Therefore, at least two of the silver layers Ag1, Ag2, and Ag3 have different thicknesses. In this context, "different from each other" means that the thicknesses of at least two of the three silver layers differ from each other, preferably by at least 5%, particularly preferably by at least 10%, and in particular by at least 15%. Furthermore, the thickness of the second dielectric module M2 is in each case greater than the thicknesses of the other dielectric modules M1 and M4. The second dielectric module M2 or the third dielectric module M3 is the module with the largest thickness; it is also possible that both modules M2 and M3 have the same thickness.

[0014] Surprisingly, it has been shown that such composite glass panes according to the invention have significantly improved energy properties compared to known composite glass panes with solar-shading coatings, while at the same time possessing good optical and aesthetic properties; in particular, undesirable color tones in the reflection of the composite pane can be minimized or even avoided. In addition to the visually appealing reflected color itself, the smallest possible angle-dependent change in the reflected color is also important for increasing customer satisfaction. The composite panes according to the invention exhibit only a slight angle-dependence of the reflected color.

[0015] A composite pane comprises an outer pane and an inner pane bonded together via a thermoplastic interlayer. The composite pane is intended to separate the interior of a window opening, particularly a vehicle window opening, from the exterior environment. In the context of the present invention, "inner pane" refers to the pane of the composite pane facing the interior (particularly the interior of a vehicle). "Outer pane" refers to the pane facing the exterior environment.

[0016] A composite pane has an upper edge, a lower edge, and two side edges extending therebetween. The term "upper edge" refers to the edge intended to face upward in the installed position. The term "lower edge" refers to the edge intended to face downward in the installed position. In the case of a windshield, the upper edge is also called the "roof edge" and the lower edge is called the "engine edge." When a composite pane is used as a roof panel of an automobile, the two side edges extend substantially parallel to each other above the side doors of the vehicle, respectively. Thus, the upper or lower edge of the composite pane faces the windshield, and the remaining upper or lower edge faces the rear window.

[0017] The outer pane and the inner pane each have an outer side surface and an inner side surface and a peripheral side edge extending therebetween. In the context of the present invention, the "outer side surface" refers to the main surface intended to face the external environment in the installed position. In the context of the present invention, the "inner side surface" refers to the main surface intended to face the interior in the installed position. The inner side surface of the outer pane and the outer side surface of the inner pane face each other and are joined to each other by a thermoplastic intermediate layer.

[0018] The solar-shading coating of the composite pane according to the present invention is preferably applied to one of the two pane surfaces facing the intermediate layer, i.e., the inner surface of the outer pane or the outer surface of the inner pane. Alternatively, the solar-shading coating can be disposed within the thermoplastic intermediate layer, for example, on a carrier film disposed between two thermoplastic bonding films. The solar-shading coating is preferably provided as an IR-reflective coating. In particular, the coating is applied to the entire surface of the pane, except for a peripheral region and optionally localized regions. These regions are intended to ensure the transmission of electromagnetic radiation through the composite pane as a communication, sensor, or camera window and therefore are free of coating. The uncoated peripheral region has a width of, for example, up to 20 cm. This prevents the coating from direct contact with the ambient atmosphere, thereby protecting the coating from corrosion and damage within the composite pane.

[0019] When the composite pane is a windshield, the solar-shading coating must be implemented as a transparent coating. A coating is considered to be a "transparent coating" when it has an average transmittance of at least 70%, preferably at least 75%, in the visible spectral range, i.e., it does not substantially restrict vision through the pane.

[0020] Preferably, at least 80% of the surface of the pane is provided with a coating according to the invention.

[0021] When a first layer is placed above a second layer, this means, in the context of the present invention, that the first layer is placed further from the outer pane than the second layer. When a first layer is placed below a second, this means, in the context of the present invention, that the second layer is placed further from the outer pane than the first layer.

[0022] When the layer is based on a material, it consists largely of, in particular essentially of, this material in addition to any impurities or dopants.

[0023] A solar shading coating is a stack of layers or layer sequences, in particular composed of thin layers, including several silver layers. Each silver layer is in each case arranged between two dielectric layers or layer sequences. These dielectric layers or layer sequences are called dielectric modules. The term "dielectric module" therefore refers to a dielectric layer that can be formed from a single ply, i.e., a single dielectric layer, or from several plies of dielectric layers. The coating is therefore a stack of thin layers with n silver layers and (n+1) dielectric layers or layer sequences, where n is a natural number and the silver layers and dielectric layers or layer sequences alternate with the underlying dielectric layer or layer sequence.

[0024] The solar shading coating is a stack of thin layers, i.e., a layer sequence of thin individual layers, and preferably comprises at least four dielectric modules (M1, M2, M3, and M4), i.e., at least four dielectric layers. Each functional silver layer is arranged between two dielectric layers or layer sequences. The functional layers or layer sequences and dielectric layers are arranged as follows: at least one dielectric layer is in each case arranged between two adjacent functional silver layers, with no other functional silver layers arranged between them, and at least one other dielectric layer is arranged above the top functional layer; and at least one other dielectric layer is arranged below the bottom functional layer.

[0025] The solar-shading coating according to the present invention has at least three silver layers, so that the natural number n is at least 3. The coating comprises at least the following layers or layer sequences, which are arranged in the order shown starting from the outer pane towards the inner pane: - a first dielectric layer or layer arrangement as module M1, - the first silver layer Ag1, - a second dielectric layer or layer arrangement as module M2, - The second silver layer Ag2, - The third dielectric layer or layer sequence as module M3, - The third silver layer Ag3, and - The fourth dielectric layer or layer sequence as module M4.

[0026] The coating according to the invention can comprise a further silver layer and a dielectric module arranged on top of the fourth dielectric module M4 (n > 3). However, in a particularly preferred embodiment, the natural number is precisely 3. In principle, a more complex layer structure is not necessary to obtain the essential specifications of the coating. However, in addition to the silver layers, other metal-containing layers can be present, which do not contribute much to the solar radiation shielding properties of the coating but serve another purpose. This particularly applies to metal blocking layers having a geometric thickness of less than 1 nm. These metal blocking layers are preferably arranged between the silver layer and the dielectric module.

[0027] The silver layer gives the solar radiation shielding coating a basic IR reflection effect. In this context, the term "silver layer" refers to a layer formed based on silver. The silver layer is based on silver. The silver layer preferably contains at least 90% by mass of silver, particularly preferably at least 99% by mass of silver, and most particularly preferably at least 99.9% by mass of silver. The silver layer can have dopants such as palladium, gold, copper, or aluminum.

[0028] In a preferred embodiment of the solar radiation shielding coating according to the invention, the first silver layer Ag1 and the third silver layer Ag3 have a geometric layer thickness of 0.6 < Ag1 / Ag3 < 1.7 relative to each other, while the second silver layer Ag2 is the thickest silver layer. The dielectric modules M1, M2, M3, and M4 have an optical layer thickness relative to each other of M2 / M1 ≥ 2, M2 / M3 > 1, and M2 / M4 ≥ 2, and the second dielectric module M2 is the dielectric module with the thickest layer thickness. This embodiment has proven to be particularly advantageous in that the angular-dependent change in the reflection color of the composite pane is further improved.

[0029] The optical thickness is the product of the geometric thickness and the refractive index (at 550 nm). The optical thickness of the layer sequence is calculated as the sum of the optical thicknesses of the individual layers.

[0030] In another preferred embodiment of the solar radiation shielding coating according to the present invention, the third silver layer is the silver layer having the largest layer thickness, and the first silver layer Ag1, the second silver layer Ag2, and the third silver layer Ag3 have geometric layer thicknesses such that 0.4 < Ag1 / Ag3 < 0.9 and 0.5 < Ag2 / Ag3 < 1.0 with respect to each other. In this case, the first dielectric module M1, the second dielectric module M2, the third dielectric module M3, and the fourth dielectric module M4 have optical layer thicknesses such that M2 / M1 ≥ 1.9, M2 / M3 ≥ 0.8, and M2 / M4 ≥ 1.6 with respect to each other. The composite pane provided with the solar radiation shielding coating of this configuration exhibits further improved energy reflection.

[0031] According to the present invention, all dielectric layers have a refractive index greater than 1.8, preferably greater than 1.9. In other words, all dielectric layers or layer sequences of the dielectric module are formed only by dielectric layers having a refractive index greater than 1.8. In this way, good results are obtained. The dielectric layer can be based on, for example, silicon nitride, mixed silicon metal nitride (e.g., silicon-zirconium nitride (SiZrN), mixed silicon-aluminum nitride, mixed silicon-hafnium nitride, or mixed silicon-titanium nitride), aluminum nitride (AlN), tin oxide (SnO), manganese oxide (MnO), tungsten oxide (WO3), niobium oxide (Nb2O5), bismuth oxide (Bi2O3), titanium dioxide (TiO2), zinc oxide (ZnO), or mixed tin zinc oxide (SnZnO).

[0032] In the context of the present invention, the refractive index is generally indicated with respect to a wavelength of 550 nm. The refractive index can be determined, for example, by ellipsometry. Ellipsometers are commercially available, for example, from Sentech. The refractive index of a dielectric layer is preferably determined by first depositing it as a monolayer on a substrate and then measuring the refractive index by ellipsometry. To determine the refractive index of a dielectric layer sequence, each layer of the layer sequence is in each case deposited alone as a monolayer on a substrate, and the refractive index is then determined by ellipsometry. According to the present invention, a refractive index of at least 1.8 must be obtained for each of these individual layers. Dielectric layers with a refractive index of at least 1.8 and their deposition methods are known to those skilled in the art of thin films. Preferably, physical vapor deposition, in particular magnetron sputtering, is used.

[0033] The materials described herein can be deposited stoichiometrically, substoichiometrically, or superstoichiometrically. The materials can have dopants, particularly aluminum, boron, zirconium, or titanium. The dopants can impart a specific electrical conductivity to an essentially dielectric material. Nevertheless, those skilled in the art will identify them as dielectric layers by function, as is customary in the field of thin layers. The materials for the dielectric layers are preferably 10 -4 The material of the silver layer preferably has an electrical conductivity (the reciprocal of the resistivity) of less than 10 S / m. 4 It has electrical conductivity greater than S / m.

[0034] Preferably, the first dielectric module, the second dielectric module, the third dielectric module, and / or the fourth dielectric module include a dielectric layer that functions as an antireflection layer. In an advantageous embodiment, each dielectric module includes a dielectric layer as an antireflection layer. The antireflection layer reduces the reflection of visible light and thus increases the transparency of the coated pane. The antireflection layer is based, for example, on silicon nitride (Si3N4), silicon oxide (SiO2), silicon oxynitride, mixed silicon metal nitrides such as silicon zirconium nitride (SiZrN), aluminum nitride (AlN), or tin oxide (SnO). Furthermore, the antireflection layer can contain dopants. The antireflection layer preferably has a geometric thickness of 5 nm to 100 nm, particularly preferably 10 nm to 60 nm. Silicon nitride is particularly preferred as an antireflection layer because it has a high refractive index compared to oxides, resulting in a relatively small required silicon nitride layer thickness. Furthermore, good color properties of the coating are obtained.

[0035] In an advantageous embodiment, one or more dielectric modules have a first matching layer, and preferably, at least each dielectric module arranged below the silver layer has a first matching layer. The first matching layer is preferably arranged above the anti-reflection layer. The first matching layer is preferably arranged directly below the first silver layer so as to be in direct contact with the respective silver layer. This is particularly advantageous in terms of the crystallinity of the silver layer. In an advantageous embodiment, one or more dielectric modules, and preferably each dielectric module, have a second matching layer arranged above the silver layer. The second matching layer is preferably arranged below the anti-reflection layer.

[0036] The first and / or second matching layer preferably comprises zinc oxide (ZnO). The first and / or second matching layer also preferably comprises a dopant. The first and / or second matching layer may comprise, for example, aluminum-doped zinc oxide (ZnO:Al). The zinc oxide is preferably deposited substoichiometrically with respect to oxygen, thereby avoiding reaction of excess oxygen with the silver-containing layer. The geometric layer thickness of the first and second matching layers is preferably 5 nm to 20 nm, particularly preferably 8 nm to 20 nm. Zinc oxide has proven to be a preferred material for the matching layer due to its good smoothing properties, by which means a high conductivity of the adjacent silver layer can be advantageously obtained.

[0037] In an advantageous embodiment, one or more dielectric modules have at least one dielectric layer as a smoothing layer. Preferably, each dielectric module disposed between two silver layers has at least one dielectric layer as a smoothing layer. Particularly preferably, the first, bottommost dielectric module also has at least one dielectric layer as a smoothing layer. The at least one smoothing layer is disposed below the first matching layer, preferably between the antireflection layer and the first matching layer, if such a first matching layer is present. Particularly preferably, the smoothing layer is in direct contact with the first matching layer. The smoothing layer has the effect of optimizing, particularly smoothing, the surface for the silver layer subsequently applied thereon. A silver layer deposited on a smoother surface has a relatively high transmittance and a relatively low sheet resistance. The geometric thickness of the smoothing layer is preferably 5 nm to 20 nm, particularly preferably 5 nm to 12 nm. The smoothing layer preferably has a refractive index of less than 2.2.

[0038] The smoothing layer comprises at least one amorphous oxide. The oxide can be amorphous or partially amorphous (and therefore partially crystalline), but not completely crystallized. Amorphous smoothing layers have low roughness and therefore form an advantageously smooth surface for layers applied thereon. Amorphous smoothing layers also provide an improved surface structure for layers deposited directly thereon, preferably the deposited layer being a first matching layer. The smoothing layer can comprise at least one oxide of one or more of the elements tin, silicon, titanium, zirconium, hafnium, zinc, gallium, and indium, for example. The smoothing layer preferably comprises an amorphous composite oxide. Most particularly preferably, the smoothing layer comprises mixed tin-zinc oxide (ZnSnO). The mixed oxide can comprise a dopant. The smoothing layer can comprise, for example, antimony-doped mixed tin-zinc oxide. The mixed oxide preferably has a substoichiometric oxygen content.

[0039] In an advantageous embodiment, the solar-shielding coating comprises one or more blocking layers. Preferably, at least one blocking layer is associated with at least one silver layer, particularly preferably with each silver layer. The blocking layer is in direct contact with the silver layer and is located immediately above or below the silver layer. That is, no other layers are located between the silver layer and the associated blocking layer. The blocking layer can also be located immediately above and below the silver layer in each case. The blocking layer preferably comprises niobium, titanium, nickel, chromium, and / or alloys thereof, particularly preferably nickel-chromium alloys. The geometric layer thickness of the blocking layer is preferably 0.1 nm to 1.5 nm, particularly preferably 0.1 nm to 1.0 nm. The blocking layer located immediately below the silver layer serves, in particular, to stabilize the silver layer during temperature treatment, improving the optical quality of the solar-shielding coating. The blocking layer immediately above the silver layer prevents the delicate silver layer from contacting an oxidizing reactive atmosphere during deposition of the next layer by reactive cathode sputtering, for example during deposition of a second conformal layer.

[0040] If the layer is based on a material, it consists mostly of this material, in addition to impurities or dopants. If a first layer is arranged above a second layer, this means, in the context of the present invention, that the first layer is arranged further from the substrate to which the coating is applied than the second layer. If a first layer is arranged below a second layer, this means, in the context of the present invention, that the second layer is arranged further from the substrate than the first layer. If a first layer is arranged above or below a second layer, this does not necessarily mean, in the context of the present invention, that the first and second layers are located in direct contact with each other. Unless explicitly excluded, one or more other layers may be arranged between the first and second layers.

[0041] In an advantageous embodiment, a dielectric module is arranged, which in each case comprises between two adjacent silver layers the following dielectric layer sequence:

[0042] antireflection layers based on silicon nitride, mixed silicon-metal nitrides such as silicon-zirconium nitride, aluminum nitride, and / or tin oxide:

[0043] smoothing layers based on oxides of one or more of the elements tin, silicon, titanium, zirconium, hafnium, zinc, gallium and indium:

[0044] - a first matching layer and a second matching layer based on zinc oxide; and -Optionally, a blocking layer based on niobium, titanium, nickel, chromium, and / or alloys thereof. No particular order of layers is required. Anti-reflection and matching layers based on the preferred materials listed above are preferably disposed below the bottom silver layer and above the top silver layer.

[0045] According to the invention, the dielectric module preferably has a geometric thickness of in each case 10 to 100 nm, particularly preferably 20 to 90 nm, for example between 70 and 85 nm. The optical thickness of the module is obtained by multiplying the geometric thickness of the dielectric module by the refractive index of each layer. The optical thickness of the dielectric module is 40 to 240 nm, preferably 50 to 200 nm.

[0046] The geometric thickness of each functional silver layer of the solar-shielding coating is preferably 5 nm to 25 nm, particularly preferably 8 nm to 20 nm. The total geometric thickness of all functional silver layers of the solar-shielding coating is preferably 20 nm to 80 nm, particularly preferably 30 nm to 60 nm. Within these ranges for the thickness of the functional layers and the total thickness of all functional silver layers, particularly good results are obtained in terms of solar-shielding function and transparency.

[0047] The solar shading coating according to the present invention has IR-reflecting properties so that it functions as a solar shading coating that reflects thermal radiation and thereby reduces heating inside a vehicle. The TTS value of the coated composite pane is preferably less than 50%, particularly preferably less than 45%. The TTS value refers to the total solar energy transmitted, measured according to ISO 13837. It is a measure of thermal comfort. The coating can also be used as a heating coating when electrically contacted so that an electric current flows through it, thereby heating the coating.

[0048] The outer and inner panes are preferably made of glass, in particular soda-lime glass, which is common for window panes. However, the panes may in principle also be made of other types of glass (e.g., borosilicate glass, quartz glass, aluminosilicate glass, etc.) or transparent plastics (e.g., polymethyl methacrylate or polycarbonate). The thickness of the outer and inner panes may vary widely. Preferably, panes having a thickness in the range of 0.8 mm to 5 mm, preferably 1.4 mm to 2.9 mm, are used, for example, with standard thicknesses of 1.6 mm or 2.1 mm.

[0049] The outer pane, inner pane, and thermoplastic interlayer may be transparent and colorless, but may also be tinted or pigmented. The tinting of the outer pane, inner pane, and thermoplastic interlayer is selected depending on the desired use of the composite pane. When the composite pane is used as a windshield, high transmittance in the visible range of the light spectrum is desired, and dark tinting of the components is not used. In one embodiment as an automobile windshield, the total transmittance through the composite glass is greater than 70% based on Illuminant A. The term "total transmittance" is based on the process for testing the light transmission of automobile windows specified by ECE-R 43, Annex 3, §9.1. The outer pane and inner pane may be unprestressed, partially prestressed, or prestressed independently of each other. If at least one of the panes is prestressed, this may be thermal or chemical prestressing.

[0050] In a preferred embodiment, the composite pane is intended as a roof panel for an automobile, where at least the thermoplastic interlayer and the inner pane are tinted, preferably dark tinted, in particular grey tinted.

[0051] Suitable glass panes include Saint-Gobain glass panes known under the trade names Planiclear® and Planilux® (in each case clear glass), VG10, VG20, VG40 or TSANx, TSA3+, TSA4+, where the VG series glasses are gray-colored glasses and the TSA series glasses are green-colored glasses. To further improve the transparency TL of the composite pane in the visible light range, glass panes with particularly high transparency can also be used.

[0052] The composite pane is preferably curved in one or more spatial directions, as is customary for automobile panes, with typical radii of curvature in the range of about 10 cm to 40 m, although the composite pane can also be flat, for example when intended as a pane for a bus, train, or tractor.

[0053] The inner surface of the outer pane and the outer surface of the inner pane face each other and are bonded to each other by a thermoplastic intermediate layer. The thermoplastic intermediate layer is formed by one or more thermoplastic films. In the resulting composite pane, the individual films in the resulting intermediate layer may no longer be distinguishable from each other. The thermoplastic film preferably contains polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU), and / or mixtures thereof and / or copolymers thereof, particularly preferably polyvinyl butyral. The film is preferably based on the above-mentioned materials, but may contain other components, such as plasticizers, colorants, and IR or UV absorbers.

[0054] The thermoplastic interlayer contains at least one thermoplastic polymer, preferably ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or a mixture, copolymer, or derivative thereof, particularly preferably PVB. The thickness of the interlayer is preferably 0.2 mm to 2 mm, particularly preferably 0.3 mm to 1 mm. The individual polymer films of the interlayer, particularly the PVB films, preferably have a thickness of about 0.2 mm to 1 mm, for example, 0.38 mm, 0.76 mm, or 0.81 mm. Other properties of the composite glass pane can be affected by the film thickness. For example, a thicker PVB film, especially when it contains an acoustically active core, improves sound absorption, increases the penetration resistance of the composite glass pane, and also improves protection against ultraviolet rays (UV protection).

[0055] According to the present invention, the solar-shading coating is disposed between the outer and inner panes. In a preferred embodiment, the solar-shading coating is applied to the inner surface (side II) of the outer pane. In this way, the solar-shading coating is protected from the effects of weathering within the laminate of the composite pane. It is advantageous, particularly for good solar-shading effect, to position the solar-shading coating as far outward as possible, i.e., as close as possible to the outer surface of the outer pane. This is further optimized by using a transparent, untinted outer pane.

[0056] In another possible embodiment, the solar-shading coating is embedded in a thermoplastic interlayer. The solar-shading coating can be applied onto a thermoplastic film. In a preferred embodiment, the solar-shading coating is applied to a carrier film that is arranged in the manufacture of the composite pane, for example, between two thermoplastic films that serve to form the interlayer. The integration of the solar-shading coating via the carrier film is advantageous in terms of simple prefabrication and the provision of a carrier film with a solar-shading coating. The thermoplastic interlayer film arranged between the solar-shading coating and the outer pane is preferably transparent and colorless. The thermoplastic interlayer of the composite pane comprises a carrier film with a solar-shading coating thereon, i.e., on the surface facing the outer pane. The carrier film preferably comprises or is made of polyethylene terephthalate (PET) and has a thickness of 20 μm to 100 μm, for example approximately 50 μm. However, the carrier film may also be made of other suitable plastics.

[0057] In another preferred embodiment, the solar shielding coating is applied to the exterior surface III of the inner pane, in which case the outer pane and the thermoplastic interlayer are preferably clear and untinted.

[0058] In a preferred embodiment, the composite pane can have a heat radiation reflective coating, also known as a low-E coating, on the interior surface (side IV) of the inner pane. Such a low-E coating is particularly advantageous on the inner surface of the inner pane, since in this way the heat transfer reduction layer is directly adjacent to the interior of the vehicle. Thus, according to the present invention, the composite pane can have a particularly low total transmitted thermal radiation (TTS) of less than 14% (measured according to ISO 13837), while at the same time achieving an optimal aesthetic appearance without introducing undesirable color tones in the composite pane's reflection. In particular, undesirable red and yellow reflections or haze in the composite pane can be avoided.

[0059] Such coatings are known, for example, from WO 2013 / 131667. Thermal radiation-reflecting coatings can also be called thermal protection coatings, low-emissivity coatings, emissivity-reducing coatings, low-E coatings, or low-E layers. They have the function of reflecting thermal radiation, i.e., IR radiation, particularly those with wavelengths longer than the IR component of solar radiation. When the outside temperature is low, the low-E coating reflects heat to the inside, reducing interior cooling. When the outside temperature is high, the low-E coating, in addition to the solar-shading coating, reflects the thermal radiation of a heated composite pane to the outside, reducing interior heating. In combination with the solar-shading coating according to the present invention, the low-E coating effectively reduces the emission of thermal radiation from the pane in summer and reduces the emission of heat to the external environment in winter.

[0060] According to the invention, the heat radiation reflective coatings with low emissivity known to date, for example from WO 2013 / 127563 or WO 2019 / 110172, are suitable for use in composite panes according to the invention. By combining the solar shading coating according to the invention and the low emissivity coating for composite panes, it is possible to achieve a light transmittance (TL) for visible light of 1 to 12%, preferably 5 to 10%, with improved energy values ​​(TTS<14%).

[0061] The thermal radiation reflective coating of the composite pane preferably comprises a functional layer containing a transparent conductive oxide (TCO), preferably indium tin oxide (ITO) or tin oxide (SnO2), which is arranged between dielectric layers, which may be formed from a dielectric oxide or nitride, such as ZnO, SnZnO, AlN, TiO2, SiO2 or Si3N4, among others.

[0062] However, the functional layer of the low-E coating can also contain other conductive oxides, such as fluorine-doped tin oxide (SnO-2:F), antimony-doped tin oxide (SnO2:Sb), mixed indium zinc oxide (IZO), gallium- or aluminum-doped zinc oxide, niobium-doped titanium oxide, cadmium stannate, and / or zinc stannate, etc. Particularly good results are therefore achieved with regard to the emissivity and bendability of the coating.

[0063] In one embodiment of the present invention, the low-E coating has an emissivity of at most 50%, preferably at most 30%. In other words, the interior emissivity of the composite pane according to the present invention is preferably 50% or less, particularly preferably 10% to 50%, most particularly preferably 20% to 35%, for example 30% or less. "Interior emissivity" refers to a measure of how much heat radiation a pane provided with a low-E coating emits in its installed position, for example, into the interior of a building or vehicle, compared to an ideal heat sink (blackbody). In the context of the present invention, "emissivity" refers to the normal emissivity at 283 K according to standard EN 12898.

[0064] According to the invention, the composite glass pane has an external energy reflection RE>36%, preferably RE>39%. The calculation of the energy value RE is carried out in accordance with the ISO 9050 standard.

[0065] In one embodiment of the composite glass pane according to the invention, when using a standardized A emitter at an angle of incidence of 2°, RL ext External reflectance (visible external reflectance RL) of >8%, preferably 10% to 22% ext ) Optical value RL ext The calculation is carried out according to the EN410 standard with illuminant A. Here, the external reflectance represents the reflected portion of incident visible radiation from the external environment.

[0066] The invention further relates to a method for manufacturing a composite pane according to the invention having a solar-shielding coating, said method comprising the following steps: a) applying a solar-shading coating to the inner surface (II) of the outer pane or to the outer surface (III) of the inner pane or incorporating a solar-shading coating into the thermoplastic interlayer; b) producing a stack of layers including at least an outer pane, a thermoplastic intermediate layer, and an inner pane, in that order; and c) bonding the stack of layers comprising at least an outer pane, a thermoplastic intermediate layer, and an inner pane to form a composite pane.

[0067] In a preferred embodiment of this method, the application of a thermal protective coating onto the inner surface (IV) of the inner pane is provided as a further step.

[0068] The solar-shading coating may be applied before, after, or simultaneously with the application of the thermal radiation-reflective coating. The outer and inner panes are bonded to form composite glass, preferably after both the solar-shading coating and the thermal protection coating have been applied.

[0069] Both the solar shading coating and the thermal protection coating are able to withstand high thermal loads and therefore can withstand temperature treatment or bending of the pane, typically at temperatures above 600° C., without damage.

[0070] The individual layers of the solar-shielding coating and the heat-radiation-reflecting coating can be deposited by methods known per se, preferably by magnetron-enhanced cathodic sputtering, and can be constructed in suitable layer thicknesses and layer sequences. Cathodic sputtering can be carried out in a protective gas atmosphere, for example in an argon protective gas atmosphere, or in a reactive gas atmosphere, for example with the addition of oxygen or nitrogen. However, the individual layers can also be applied by other suitable methods known to those skilled in the art, for example by vapor deposition or chemical vapor deposition.

[0071] The thermoplastic interlayer may be provided in the form of a thermoplastic film. However, the thermoplastic interlayer may also be provided in the form of multiple films, e.g., two or more thermoplastic films, optionally with an additional carrier film. Applying the solar-shading coating onto the thermoplastic interlayer only involves applying the solar-shading coating to one of the films, e.g., the carrier film. When joining the panes to form the composite glass, the carrier film with the solar-shading coating disposed thereon is preferably positioned between two thermoplastic films, with the surface of the solar-shading coating facing the outer pane.

[0072] The joining of the outer and inner panes via the thermoplastic interlayer to form the composite pane is preferably carried out by lamination under the action of heat, vacuum, and / or pressure. Methods known per se for producing composite panes may be used. During the lamination process, a heated, flowable thermoplastic material flows around the solar-shading coating, establishing a stable bond and encapsulating the solar-shading coating within the interlayer, protecting it from damage and environmental influences.

[0073] For example, the so-called autoclave process can be carried out at a high pressure of about 10 to 15 bar and a temperature of 130 to 145°C for about 2 hours. The vacuum bag or vacuum ring process, known per se, operates, for example, at about 200 mbar and 80 to 110°C. The outer pane, the thermoplastic intermediate layer, and the inner pane can also be pressed between at least one pair of rollers in a calender, thereby forming the pane. This type of system is known for the production of panes and usually has at least one heating tunnel upstream of the pressing unit. The temperature during the pressing operation is, for example, in the range of 40 to 150°C. The combination of calendering and the autoclave process has proven particularly effective in practice. Alternatively, vacuum laminators can be used. These consist of one or more heatable and evacuable chambers in which the panes are laminated, for example, within about 60 minutes, under reduced pressure of 0.01 to 800 mbar and at a temperature of 80 to 170°C.

[0074] The invention further includes the use of composite panes according to the invention having a solar-shading coating and optionally a low-E coating in land, air or water transport vehicles, in particular in motor vehicles, for example as windshields, rear windows, side windows and / or roof panels, and as functional individual components, and in buildings.

[0075] All standards mentioned refer to the versions in effect on the filing date.

[0076] The various embodiments of the invention may be implemented individually or in any combination. In particular, the features described above and below may be used not only in the combination shown, but also in other combinations or alone, without departing from the scope of the invention, unless the exemplary embodiments and / or their features are expressly mentioned only as alternatives or are mutually exclusive.

[0077] The present invention will be described in more detail below with reference to the drawings. It should be noted that various aspects are described and can be used individually or in combination. In other words, any aspect can be used with various embodiments of the present invention unless expressly presented as a pure alternative.

[0078] The drawings are simplified, schematic, and not to scale and are not intended to limit the invention. [Brief explanation of the drawings]

[0079]

Figure 1

[0080]

Figure 2

[0081]

Figure 3

[0082]

Figure 4

[0083]

Figure 5

[0084] Figure 1 shows a cross-sectional view of an embodiment of a composite pane 100 according to the present invention, having a solar radiation shielding coating 4 and a low-E coating 5. The composite pane 100 includes an outer pane 1 and an inner pane 2 bonded to each other via a thermoplastic interlayer 3. The composite pane 100 can be provided, for example, as a roof panel of a passenger car, with the outer pane 1 facing the external environment and the inner pane 2 facing the interior of the vehicle. The outer pane 1 has an outer side surface (I) and an inner side surface (II). The inner pane 2 has an outer side surface (III) and an inner side surface (IV). The outer side surfaces (I) and (III) face the external environment; the inner side surfaces (II) and (IV) face the interior of the vehicle. The inner side surface (II) of the outer pane 1 and the outer side surface (III) of the inner pane 2 face each other. In this embodiment, the solar radiation shielding coating 4 according to the present invention is disposed on the inner side surface (II) of the outer pane 1. The solar radiation shielding coating 4 preferably extends over the entire inner side surface (II) except for a region without a circumferential frame-shaped coating, for example, a region without a circumferential frame-shaped coating having a width of 8 mm. The region without the coating can then be hermetically sealed by bonding to the thermoplastic interlayer 3. Thus, the solar radiation shielding coating 4 is advantageously protected from damage and corrosion. According to the present invention, the solar radiation shielding coating 4 includes at least three functional silver layers, each having a layer thickness between 5 nm and 20 nm, and each functional silver layer is disposed between dielectric modules, for example, layers of silicon nitride. The silver layers (Ag1, Ag2, Ag3) of the solar radiation shielding coating according to the present invention have a geometric layer thickness of 0.4 < Ag1 / Ag3 < 1.7 with respect to each other, and Ag2 or Ag3 is the thickest silver layer, and the dielectric modules (M1, M2, M3, M4) have an optical layer thickness of M2 / M1 ≧ 1.9, M2 / M3 ≧ 0.8, and M2 / M4 ≧ 1.6 with respect to each other. The structure of the solar radiation shielding coating 4 according to the present invention will be described in more detail below using Figure 4 and the examples and comparative examples described therein. The solar radiation shielding coating 4 reduces the heating of the interior of the vehicle and the inner pane 2 by reflection of infrared radiation. According to the present invention, an energy reflection RE > 36%, preferably > 39% can be achieved.In addition to the favorable improvement in thermal comfort compared to conventional systems, the solar shading coating 4 according to the present invention simultaneously achieves favorable optical and aesthetic properties for the composite pane 100. A thermal protection coating 5 is optionally disposed on the inner surface (IV) of the inner pane 2. In this preferred embodiment, the composite pane not only has a favorable energy reflection RE>40%, but also a low total transmitted thermal emissivity, particularly TTS<14%. On the one hand, the thermal protection coating 5 reduces the emission of thermal radiation into the interior of the vehicle through the composite pane 100, especially when the outside temperature is high. On the other hand, the thermal protection coating 5 can reduce the emission of thermal radiation from the interior of the vehicle when the outside temperature is low. Furthermore, the thermal protection coating 5 can reduce the transmission of visible light into the interior of the vehicle. These are major advantages of the composite pane according to the present invention, since the interior environment of the vehicle is significantly improved and the need for the use of an air conditioning system is reduced. From the viewpoint of energy properties, it is preferred according to the invention to apply the solar shading coating 4 onto the transparent, untinted glass pane (inner surface II of outer pane 1) in order to particularly achieve an energy reflection RE>36 and the lowest possible TTS value of the resulting composite pane 100. On the other hand, it may be useful, optionally, to apply the solar shading coating 4 onto the tinted glass pane (outer pane 1) in order to neutralize or improve the appearance of the composite pane 100. Such a configuration of the composite pane according to the invention, having a transparent, untinted outer pane, a tinted thermoplastic interlayer, and a tinted inner pane, is particularly suitable as a roof panel for vehicles.

[0085] FIG. 2 shows a cross-sectional view of another embodiment of a composite pane 100 according to the invention, comprising a solar-shading coating and a thermal protection coating 4, 5. In contrast to FIG. 1 , the solar-shading coating 4 is not arranged on the inner surface (II) of the outer pane 1, but on a carrier film 6 in the intermediate layer 3. The solar-shading coating 4 can be arranged optionally on the surface of the carrier film facing the inner pane 2 or the outer pane 1, in either case according to the layer thickness ratio according to the invention. The carrier film 6 preferably comprises or is made of polyethylene terephthalate (PET) and has a thickness of, for example, 50 μm. The solar-shading layer 4 according to the invention comprises a layer structure, which will be explained in more detail with reference to FIG. 4 . The carrier film 6 with the solar-shading coating 4 is arranged between a first thermoplastic film 3 a and a second thermoplastic film 3 b. In the resulting composite pane, the thermoplastic films 3 a and 3 b and the carrier film 6 form the thermoplastic intermediate layer 3. The thermoplastic films 3a and 3b preferably contain or are made of PVB and have a layer thickness of, for example, 0.38 mm. The carrier film 6 is somewhat smaller than the outer pane 1, the inner pane 2, and the thermoplastic films 3a and 3b. The carrier film 6 is arranged within the composite so that it does not extend to the lateral edges of the composite glass. As a result, the carrier film 6 is peripherally surrounded by the thermoplastic films 3a and 3b in the edge regions of the composite pane, for example, to a width of about 8 mm. The solar shading coating 4 on the carrier film 6 is therefore advantageously protected from damage, in particular corrosion. The heat protection coating 5 on the inner surface (IV) of the inner pane 2 is designed as shown in Figure 1.

[0086] Figure 3 shows a cross-sectional view of another embodiment of the composite pane 100 according to the invention, having a solar radiation shielding coating and a thermal protection coating 5, 4. In contrast to FIG. 1, the solar radiation shielding coating 4 is arranged on the outer side surface (III) of the inner pane 2, rather than on the inner side surface (II) of the outer pane 1. The peripheral region of the outer side surface (III) is not provided with the solar radiation shielding coating 4. Also in this embodiment, the solar radiation shielding coating 4 is advantageously protected from damage and corrosion. Otherwise, this embodiment corresponds to the design shown in FIG. 1.

[0087] Figure 4 shows a schematic structure of the solar radiation shielding layer 4 according to the invention. In the illustrated embodiment, the solar radiation shielding coating 4 is applied on the inner surface II of the outer pane 1 as a substrate. The illustrated solar radiation shielding coating 4 includes three transparent functional silver layers Ag1, Ag2, and Ag3, which are particularly infrared reflective layers. According to the invention, these functional silver layers have a certain thickness relative to each other; specifically, in accordance with the invention, they are made to have the following with respect to the relative geometric layer thickness: 0.4 < Ag1 / Ag3 < 1.7 and Ag3 or Ag2 being the thickest silver layer. In other words, the layer thickness of the first silver layer Ag1, which is arranged closest to the outer pane 1, is thinner than the second silver layer Ag2 or the third silver layer Ag3 that follows Ag1 in the layer arrangement. The silver layers can be deposited, for example, by cathodic sputtering in an argon atmosphere.

[0088] Dielectric modules M1, M2, M3, and M4, each containing a dielectric layer, are arranged above, below, and between the silver layers Ag1, Ag2, and Ag3, respectively. According to the present invention, these dielectric modules (M1, M2, M3, M4) have optical layer thicknesses M2 / M1≧1.9, M2 / M3≧0.8, and M2 / M4≧1.6 relative to one another. Thus, the dielectric module M1 is arranged directly on the inner surface II of the outer pane 1, below the first silver layer Ag1; the second dielectric module M2 is arranged on top of the first silver layer Ag1. The first dielectric module M1 can be structured, for example, starting from the outer pane 1, as a layer sequence of silicon nitride, ZnSnOx, and ZnO layers. The silicon nitride layer can be deposited from silicon nitride in a nitrogen-containing atmosphere; the zinc oxide layer can be deposited from zinc oxide in an oxygen-containing atmosphere.

[0089] The solar-shielding coating 4 includes at least one blocking layer; particularly preferably, each functional silver layer Ag1, Ag2, Ag3 is located in direct contact with at least one blocking layer B1, B2, and B3, as shown. According to the invention, the blocking layers preferably contain or are made of at least nickel, chromium, or alloys thereof, and / or titanium chromium. Blocking layer B (B1, B2, B3) is preferably arranged between the at least one functional silver layer and the at least one dielectric layer. Blocking layer B protects the functional layers during heating, especially during the production of the composite pane according to the invention.

[0090] The present invention will now be described with reference to the following examples according to the invention and comparative examples not according to the invention.

[0091] Example

[0092] All optical, aesthetic, and energy properties of the composite panes according to the examples and comparative examples were measured in the laminated state. In the examples and comparative examples, a solar shading coating 4 was applied to the inner surface II of a transparent outer pane 1 (example Planiclear) according to Figure 4 and laminated with a thermoplastic intermediate layer 3 and an inner pane 2 according to the structure of Figure 1. A tinted PVB film was used in the intermediate layer. A low-E coating was applied to the inner surface IV of the dark-tinted inner pane 2 (example VG10). The low-E coating had an emissivity of 30%. The low-E coating was applied to a dielectric layer (Si3N4, SiO x The examples and comparative examples have the same basic structure described, but differ in the solar shielding coating used.

[0093] Examples 1 to 10 according to the invention and a comparative example not according to the invention were manufactured as composite panes (vehicle windshields) having the indicated solar-shading coatings.

[0094] For each example and comparative example, the stack structure (layers and layer thicknesses) of the solar shading coating and the optical properties of the coating in the finished composite pane are given.

[0095] The layer arrangements and layer thicknesses of the solar shielding coatings according to Examples 1 to 10 according to the invention are shown in Table 1a. For comparison, Comparative Examples 1 to 4, which are not according to the invention, are listed in Table 1b. The relative layer thicknesses of the silver layers and the dielectric modules, as well as the values ​​of the optical and energy properties, are reported in Table 2a for Examples 1 to 10 according to the invention and in Table 2b for Comparative Examples 1 to 4, which are not according to the invention. All layer thicknesses of the silver layers and the layers of the modules are shown as geometric layer thicknesses. The relative layer thicknesses of the silver layers, shown as thickness ratios Ag2 / Ag1, Ag2 / Ag3, and Ag1 / Ag3, refer to the geometric layer thicknesses. For the relative layer thicknesses of the dielectric modules, shown as thickness ratios M2 / M1, M2 / M3, and M2 / M4, the optical thicknesses were used.

[0096] Abbreviation RE Energy Reflection [%] TL Visible light transmittance [%] TTS Total transmitted thermal radiation [%] TE Total transmitted energy [%] RL 8° Visible reflection at 8° viewing angle [%] a * , b * Color coordinates in the CIE color space (International Commission on Illumination), measured in reflection at an angle of 60° and an angle of 8°, respectively Δa * , Δb * Difference in color coordinates when measured in reflection at 60° and at 8° Color R * In each case, the color impression of the external reflected color as perceived by the observer of the composite pane at 60° and at 8° reflection

[0097] Light transmittance (TL) and reflectance (RL) values ​​are based on illuminant A, i.e., the visible part of sunlight at wavelengths from 380 nm to 780 nm.

[0098] [Table 1]

[0099] [Table 2]

[0100] [Table 3]

[0101] [Table 4]

[0102] According to the present invention, a composite pane having a solar radiation shielding coating configured in accordance with the present invention is provided, which is well improved and further optimized with respect to energy characteristics, thermal and visual comfort, and at the same time with respect to aesthetic appearance, compared to known composite panes having a solar radiation shielding coating. An energy reflection of RE > 41%, preferably RE > 39% is achieved. When using the solar radiation shielding coating according to the present invention, a composite pane can be provided in combination with a heat radiation reflecting coating, and the pane can further have a particularly low total transmitted heat radiation (TTS) of less than 14%. On the other hand, at the same time, in the reflection of the composite pane, an optimal aesthetic appearance without an undesirable color tone is achieved. In particular, the undesirable red and yellow reflections or haze of the composite pane can be avoided. According to the present invention, a substantially constant desirable color reflection of the composite pane can be obtained regardless of the viewing angle.

[0103] Examples 1 to 5 according to the present invention have silver layers Ag1, Ag2, and Ag3 with relative geometric layer thicknesses of 0.4 < Ag1 / Ag3 < 0.9 and 0.5 < Ag2 / Ag3 < 1.0, where Ag3 is the thickest silver layer, and the dielectric modules (M1, M2, M3, M4) have optical layer thicknesses of M2 / M1 ≧ 1.9, M2 / M3 ≧ 0.8, and M2 / M4 ≧ 1.6 with respect to each other. Examples 1 to 5 improved the energy reflection.

[0104] Regarding Examples 6 to 10 according to the present invention, for the silver layers Ag1, Ag2, and Ag3, the relative geometric layer thickness is 0.6 < Ag1 / Ag3 < 1.7, where Ag2 is the thickest silver layer, and the dielectric modules (M1, M2, M3, M4) have relative optical layer thicknesses of M2 / M1 ≧ 2, M2 / M3 > 1, and M2 / M4 ≧ 2. These composite panes are particularly advantageous in that the angular-dependent color deviation Δa in reflection is minimized.

[0105] FIG. 5 shows an exemplary embodiment of a method according to the present invention, referring to a flowchart including the following steps. I. Providing an outer pane 1, an inner pane 2, and at least one thermoplastic film (to form a thermoplastic intermediate layer 3); II. applying the solar protection coating 4 according to the invention to the inner surface II of the outer pane 1 or to the outer surface III of the inner pane 2, for example by cathode sputtering; III optionally applying a thermal protective coating 5 to the inner surface IV of the inner pane 2; IV. Bonding the inner surface II of the outer pane 1 and the outer surface III of the inner pane 2 via a thermoplastic intermediate layer 3 to form a composite pane 100.

[0106] In one embodiment, glass panes are used as the outer pane 1 and the inner pane 2. In a preferred embodiment of this method, a solar-shading coating 4, comprising at least three functional silver layers Ag1, Ag2, and Ag3 and at least four dielectric modules M1, M2, M3, and M4, is applied to the inner surface II of the outer pane 1. This is preferably applied by magnetron-enhanced cathode sputtering. Temporally, the solar-shading coating 4 can be applied before, after, or simultaneously with the optional application of a heat-radiation-reflecting coating 5 on the inner surface IV of the inner pane 2. The bonding of the outer pane 1 and the inner pane 2 via the interlayer 3 to form the composite glass preferably occurs after both the solar-shading coating 4 and the optional heat-protective coating have been applied. The present disclosure includes the following aspects. <Aspect 1> A composite pane (100) comprising an outer pane (1) having an outer side surface (I) and an inner side surface (II), an inner pane (2) having an outer side surface (III) and an inner side surface (IV), and a thermoplastic intermediate layer (3), wherein the thermoplastic intermediate layer (3) bonds the inner side surface (II) of the outer pane (1) to the outer side surface (III) of the inner pane (2), the composite pane (100) has at least one solar radiation shielding coating (4) between the outer pane (1) and the inner pane (2), the solar radiation shielding coating (4) has the following layer arrangement starting from the outer pane (1) and facing the inner pane (2) - a first dielectric module (M1), - a first silver layer (Ag1), - a second dielectric module (M2), - a second silver layer (Ag2), - a third dielectric module (M3), - a third silver layer (Ag3), - a fourth dielectric module (M4), and includes, the silver layers (Ag1, Ag2, Ag3) have a geometric layer thickness of 0.4 < Ag1 / Ag3 < 1.7 with respect to each other; Ag3 or Ag2 is the thickest silver layer; the dielectric modules (M1, M2, M3, M4) have an optical layer thickness of M2 / M1 ≥ 1.9, M2 / M3 ≥ 0.8, and M2 / M4 ≥ 1.6 with respect to each other, and all dielectric layers of the dielectric modules (M1, M2, M3, M4) have a refractive index greater than 1.8, composite pane (100). <Aspect 2> The silver layers (Ag1, Ag2, Ag3) of the solar radiation shielding coating have a geometric layer thickness of 0.6 < Ag1 / Ag3 < 1.7 with respect to each other; Ag2 is the thickest silver layer; the dielectric modules (M1, M2, M3, M4) have an optical layer thickness of M2 / M1 ≥ 2, M2 / M3 > 1, and M2 / M4 ≥ 2 with respect to each other, the composite pane (100) according to Aspect 1. <Aspect 3> The silver layers (Ag1, Ag2, Ag3) of the solar radiation shielding coating have a geometric layer thickness of 0.4 < Ag1 / Ag3 < 0.9 and 0.5 < Ag2 / Ag3 < 1.0 with respect to each other; Ag3 is the thickest silver layer; the dielectric modules (M1, M2, M3, M4) have an optical layer thickness of M2 / M1 ≥ 1.9, M2 / M3 ≥ 0.8, and M2 / M4 ≥ 1.6 with respect to each other, the composite pane (100) according to Aspect 1. <Aspect 4> A composite pane (100) according to any one of aspects 1 to 3, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3), and / or the fourth dielectric module (M4) have at least one dielectric layer based on silicon nitride. <Aspect 5> 5. The composite pane (100) of any one of aspects 1 to 4, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3), and / or the fourth dielectric module (M4) comprise at least one first dielectric layer based on silicon nitride and at least one second dielectric layer based on zinc oxide. <Aspect 6> 6. The composite pane (100) of any one of aspects 1 to 5, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3), and / or the fourth dielectric module (M4) comprise at least one first dielectric layer based on silicon nitride, at least one second dielectric layer based on zinc oxide, and at least one third dielectric layer based on mixed tin-zinc oxide. <Aspect 7> 7. The composite pane according to any of aspects 1 to 6, wherein the solar shielding coating (4) comprises at least one metal blocking layer (B1, B2, B3) above and / or below the silver layer (Ag1, Ag2, Ag3), respectively, having a geometric thickness of less than 1 nm. <Aspect 8> 8. The composite pane of any of aspects 1 to 7, wherein the first silver layer (Ag1), the second silver layer (Ag2), and the third silver layer (Ag3) each have a geometric thickness of 5 nm to 25 nm, preferably 8 nm to 20 nm. <Aspect 9> A composite pane according to any one of aspects 1 to 8, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3), and the fourth dielectric module (M4) each have a geometric thickness of 10 nm to 100 nm, preferably 20 nm to 90 nm, and particularly preferably 70 nm to 85 nm. <Aspect 10> A composite pane according to any of the preceding aspects, wherein the solar shielding coating (4) is applied to the inner surface (II) of the outer pane (2). <Aspect 11> A composite pane according to any of aspects 1 to 10, wherein a thermal radiation reflective coating (5) is applied to the interior surface (IV) of the inner pane (2). <Aspect 12> The heat radiation reflective coating (5) is an indium tin oxide layer (ITO) or a tin oxide layer (SnO 2 12. The composite pane of claim 11, further comprising a functional layer based on an indium tin oxide or tin oxide film, wherein the indium tin oxide layer or the tin oxide layer is disposed between two dielectric layers. <Aspect 13> at least, (a) applying a solar shading coating (4) to the inner surface (II) of the outer pane (1) or the outer surface (III) of the inner pane (2) or incorporating a solar shading coating (4) in a thermoplastic intermediate layer (3); (b) producing a stack of layers comprising at least the outer pane (1), the thermoplastic intermediate layer (3), and the inner pane (2), in that order; and (c) bonding a stack of layers comprising at least the outer pane (1), the thermoplastic intermediate layer (3), and the inner pane (2) to form a composite pane (100); A method for manufacturing the composite pane (100) according to any one of the first to twelfth aspects. <Aspect 14> A method for manufacturing a composite pane (100) according to aspect 13, characterized in that a thermal radiation reflective coating (5) is applied to the interior surface (IV) of the inner pane (2). <Aspect 15> Use of a composite pane (100) according to any of the aspects 1 to 12 in a motor vehicle, preferably as a windshield, rear window, side window and / or roof panel, particularly preferably as a roof panel of a motor vehicle. [Explanation of symbols]

[0107] 1 outer pane, 2 inner pane, 3 thermoplastic intermediate layer, 3a first thermoplastic film, 3b second thermoplastic film, 4 solar shielding coating, 5 heat protection coating, 6 carrier film, I outer surface of 1, II inner surface of 1, III outer surface of 2, IV inner surface of 2, Ag1 first silver layer, Ag2 second silver layer, Ag3 third silver layer, M1 first dielectric module, M2 second dielectric module, M3 third dielectric module, M4 fourth dielectric module, B blocking layer, B1 first blocking layer, B2 second blocking layer, B3 third blocking layer

Claims

1. A composite pane (100) comprising an outer pane (1) having an outer surface (I) and an inner surface (II), an inner pane (2) having an outer surface (III) and an inner surface (IV), and a thermoplastic intermediate layer (3), the thermoplastic intermediate layer (3) connects the inner surface (II) of the outer pane (1) to the outer surface (III) of the inner pane (2); The composite pane (100) has at least one solar shading coating (4) between the outer pane (1) and the inner pane (2), The solar shielding coating (4) comprises the following layer sequence starting from the outer pane (1) towards the inner pane (2): a first dielectric module (M1), a first silver layer (Ag1), a second dielectric module (M2), - a second silver layer (Ag2), - a third dielectric module (M3), - a third silver layer (Ag3), - a fourth dielectric module (M4), Including, all dielectric layers of said dielectric modules (M1, M2, M3, M4) have a refractive index greater than 1.8; the silver layers (Ag1, Ag2, Ag3) of the solar shielding coating have relative geometric layer thicknesses of 0.6<Ag1 / Ag3<1.7; Ag2 is the thickest silver layer and has a geometric thickness of 10.2 nm to 25 nm; the dielectric modules (M1, M2, M3, M4) have relative optical layer thicknesses of M2 / M1≧2, M2 / M3>1, and M2 / M4≧2; A composite pane (100) wherein the layer thicknesses of at least two of said three silver layers differ from one another by at least 10%.

2. 2. The composite pane (100) of claim 1, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3), and / or the fourth dielectric module (M4) have at least one dielectric layer based on silicon nitride.

3. 3. The composite pane (100) of claim 1 or 2, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3), and / or the fourth dielectric module (M4) comprise at least one first dielectric layer based on silicon nitride and at least one second dielectric layer based on zinc oxide.

4. 4. The composite pane (100) of claim 1, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3), and / or the fourth dielectric module (M4) comprise at least one first dielectric layer based on silicon nitride, at least one second dielectric layer based on zinc oxide, and at least one third dielectric layer based on mixed tin-zinc oxide.

5. 5. A composite pane according to any one of claims 1 to 4, wherein the solar shielding coating (4) comprises at least one metal blocking layer (B1, B2, B3) above and / or below the silver layer (Ag1, Ag2, Ag3), respectively, having a geometric thickness of less than 1 nm.

6. 6. Composite pane according to any one of claims 1 to 5, wherein the first silver layer (Ag1) and the third silver layer (Ag3) each have a geometric thickness of 5 nm to 25 nm, preferably 8 nm to 20 nm.

7. 7. A composite pane according to any one of claims 1 to 6, wherein the first dielectric module (M1), the second dielectric module (M2), the third dielectric module (M3) and the fourth dielectric module (M4) each have a geometric thickness of 10 nm to 100 nm, preferably 20 nm to 90 nm, particularly preferably 70 nm to 85 nm.

8. A composite pane according to any one of claims 1 to 7, wherein the solar shielding coating (4) is applied to the inner surface (II) of the outer pane (2).

9. A composite pane according to any one of claims 1 to 8, wherein a heat radiation reflective coating (5) is applied to the inner surface (IV) of the inner pane (2).

10. The heat radiation reflective coating (5) is an indium tin oxide (ITO) layer or a tin oxide (SnO ２ 10. The composite pane of claim 9, further comprising a functional layer based on indium tin oxide or tin oxide, the functional layer being disposed between two dielectric layers.

11. at least, (a) applying a solar shading coating (4) to the inner surface (II) of the outer pane (1) or the outer surface (III) of the inner pane (2) or incorporating a solar shading coating (4) in a thermoplastic intermediate layer (3); (b) manufacturing a stack of layers comprising at least the outer pane (1), the thermoplastic intermediate layer (3), and the inner pane (2), in that order; and (c) bonding a stack of layers comprising at least the outer pane (1), the thermoplastic intermediate layer (3), and the inner pane (2) to form a composite pane (100); The steps include: A method for manufacturing a composite pane (100) according to any one of claims 1 to 10.

12. A method for manufacturing a composite pane (100) according to claim 11, characterized in that a heat radiation reflective coating (5) is applied to the inner surface (IV) of the inner pane (2).

13. Use of a composite pane (100) according to any one of claims 1 to 10 in a motor vehicle, preferably as a windscreen, rear window, side window and / or roof panel, particularly preferably as a roof panel of a motor vehicle.

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