Vehicle with an opaque roof window with an aerogel layer

Abstract

Vehicle equipped with a vehicle roof window comprising an outer pane (1) and an inner pane (2) which are connected to each other over a surface via an intermediate layer (3), where the vehicle roof window is opaque and wherein an aerogel layer (6) is embedded in the intermediate layer (3), the vehicle's roof window is the same color as the vehicle's paintwork.

Description

[0001] The invention relates to a vehicle equipped with a vehicle roof window that is fitted with an aerogel layer.

[0002] Some cars are equipped with roof windows, often simply referred to as "glass roofs." These allow sunlight to enter the vehicle from above, creating a pleasant atmosphere inside and a feeling of openness. However, the decision for or against a glass roof depends heavily on the user's personal preferences. Some users find the view of the surroundings through the roof and the sunlight passing through the glass distracting or otherwise bothersome.

[0003] As a consequence, vehicle manufacturers typically offer vehicles in two versions: one with a glass roof and one without. This requires providing two different vehicle bodies, and in some cases, interior components of the two versions also need to be adapted, such as overhead lighting, antennas, and wiring.

[0004] To simplify vehicle manufacturing, it is theoretically possible to provide only a single vehicle body with a roof opening into which, depending on the model, a transparent or opaque roof panel is inserted. The version with the opaque roof panel thus effectively creates a classic vehicle "without a glass roof." The vehicle manufacturer only needs to produce one uniform body for both versions, thereby reducing production costs and eliminating the need for production lines. For this purpose, German patent DE202020104733U1 proposes a non-transparent roof panel with at least one frosted glass pane.

[0005] Compared to a conventional metal roof integrated into the vehicle body, such an opaque roof panel has disadvantages, particularly regarding thermal comfort inside the vehicle. The energy input from solar radiation is significantly higher than with a metal roof. Essentially, the total solar energy received consists of direct energy and indirect energy received as heat radiation after the glass components have been heated (emissivity). This is typically characterized by the TTS value. While an opaque roof panel can essentially reduce direct energy input to zero, the problem of emissivity remains.The components of the roof panel can be heated considerably by solar radiation, a phenomenon that can be even more pronounced with a heavy tint compared to a transparent glass roof, and these components then emit heat radiation into the vehicle interior. If the vehicle interior heats up too much, the air conditioning must be used to counteract this, which is not conducive to energy-efficient operation.

[0006] Therefore, there is a need for improved opaque vehicle roof windows that reduce the energy entering the vehicle interior.

[0007] Aerogels are highly porous solids known for their very low thermal conductivity and heat-insulating properties. WO2012154602A1 discloses an insulating glass unit with an aerogel layer. US2010146880A1 discloses a building roof panel consisting of two glass panes and an aerogel layer between them. EP3381881A1 discloses a laminated glass unit consisting of two glass panes and a thermally insulating layer between them, which may be an aerogel layer.

[0008] The present invention is based on the objective of providing a vehicle with an improved opaque vehicle roof window which has low heat input and ensures high thermal comfort in the vehicle interior.

[0009] The problem is solved according to the invention by a vehicle according to independent claim 1. Advantageous embodiments are set forth in the dependent claims.

[0010] The vehicle according to the invention is equipped with a vehicle roof window comprising an outer window and an inner window, which are connected to each other over a surface via an intermediate layer. where the vehicle roof window is opaque and wherein an aerogel layer is embedded in the intermediate layer, the vehicle's roof window is the same color as the vehicle's paintwork.

[0011] The vehicle roof window is designed as a composite window. It comprises an outer window and an inner window, which are bonded together over a surface area via an intermediate layer. The roof window is opaque. According to the invention, an aerogel layer is embedded in the intermediate layer.

[0012] The vehicle roof panel is completely opaque and can therefore replace a traditional opaque metal roof integrated into the vehicle body itself. The vehicle manufacturer only needs to provide a vehicle body with an opening (window opening) in the roof, into which either a transparent or the opaque vehicle roof panel can be installed. This simplifies the vehicle manufacturing process and allows the manufacturer to save on production lines. The aerogel layer gives the opaque vehicle roof panel thermally insulating properties, reducing the amount of solar heat entering the vehicle interior, especially in summer. Similarly, it reduces heat loss through the vehicle roof panel, particularly in winter at low outside temperatures.This significantly improves thermal comfort in the vehicle interior, reducing the need for air conditioning or heating, which saves energy and lowers noise levels inside the vehicle. The aerogel layer also possesses acoustic insulating properties, minimizing the amount of external noise entering the vehicle interior and eliminating the need for costly acoustically insulating thermoplastic layers. Furthermore, the aerogel layer is very lightweight, resulting in a comparatively low overall weight for the vehicle's roof window. These are significant advantages of the present invention.

[0013] The vehicle roof window is designed to separate the interior (vehicle interior) from the external environment through an opening (roof opening) in the roof of a vehicle or vehicle body. For the purposes of this invention, the term "inner window" refers to the window facing the interior. The term "outer window" refers to the window facing the external environment. Both the outer and inner windows have an outer and an inner surface, and a circumferential side edge surface extending between them. For the purposes of this invention, the term "outer surface" refers to the main surface intended to face the external environment when installed. For the purposes of this invention, the term "inner surface" refers to the main surface intended to face the interior when installed.The inner surface of the outer pane and the outer surface of the inner pane face each other and are connected via the intermediate layer.

[0014] The outer and inner panes are preferably made of glass, particularly preferably of soda-lime glass, as is common for window panes. However, one or both panes can also be made of other types of glass, such as quartz glass, borosilicate glass, or aluminosilicate glass, or of rigid, clear plastics, such as polycarbonate or polymethyl methacrylate. The thicknesses of the outer and inner panes are preferably from 0.5 mm to 5 mm, and particularly preferably from 1 mm to 3 mm, and are independent of each other. The outer and inner panes can optionally be thermally or chemically tempered, partially tempered, or not tempered, independently of each other.

[0015] The aerogel layer is embedded between the outer and inner panes of the vehicle roof window or its intermediate layer. The aerogel layer is preferably connected to both the outer and inner panes via a bonding layer. The vehicle roof window then comprises, in the specified order: - the outer pane, - a bonding layer, - the aerogel layer, - a bonding layer, - the inner pane.

[0016] In a preferred embodiment, the vehicle roof window consists structurally only of the elements specified. The outer pane, the inner pane, and / or the connecting layers may additionally be equipped with standard coatings or imprints.

[0017] The vehicle roof window preferably does not include large-area electrical or other structural heat-insulating units. This is advantageous with regard to a simple design and low overall thickness. The vehicle roof window particularly preferably does not include photovoltaic cells, insulating glass units, or vacuum insulating glass units.

[0018] The bonding layers serve to adhesively connect the components of the vehicle roof panel between which they are positioned. These bonding layers are preferably designed as thermoplastic layers. Alternatively, these thermoplastic layers can also be referred to as thermoplastic coatings.

[0019] The thermoplastic layers are preferably based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or polyurethane (PU), or on mixtures, copolymers, or derivatives thereof, particularly preferably on PVB. This means that the layer contains the said polymer to a large extent (proportion greater than 50 wt%). In addition to the polymer, the layer may contain other additives, such as plasticizers, UV absorbers, or stabilizers. Each thermoplastic layer is preferably formed from at least one thermoplastic film. The thickness of each film is preferably from 0.2 mm to 1 mm. For example, PVB films with standard thicknesses of 0.38 mm or 0.76 mm can be used.

[0020] Since the aerogel layer has acoustic damping properties, the use of so-called acoustic thermoplastic films can be avoided. Instead, single-layer films can be used, which is significantly more cost-effective.

[0021] The bonding layers can alternatively be designed as adhesive layers. Optically clear adhesives (OCAs) are preferred. This is particularly advantageous with regard to the aesthetic appearance of the vehicle roof window. OCAs are well known to those skilled in the art. They are characterized in particular by their high optical quality. They are especially common where high optical quality is necessary so that the adhesive layer is virtually invisible, for example, in displays or touch panels. Optically clear adhesives are characterized in particular by high light transmission and the fact that distortion-free visibility is possible. The optically clear adhesive is preferably a two-component polyurethane adhesive, a one-component acrylate adhesive, a one-component silicone adhesive, or a one-component acrylate hybrid adhesive.Since the vehicle's roof window is opaque, the optical properties of the adhesive are not crucial, meaning that optically clear adhesives are not necessarily required. Basically, any adhesive can be used.

[0022] In principle, a combination is also conceivable, whereby one of the bonding layers is designed as a thermoplastic layer and the other bonding layer as an adhesive layer.

[0023] The vehicle's roof window is opaque, meaning it does not allow any visibility through it. The light transmission of the vehicle's roof window is preferably less than 2%, and particularly 0%. Light transmission here refers to the total transmission, determined by the procedure for testing the light transmittance of motor vehicle windows as specified in ECE-R 43, Annex 3, Section 9.1. This is achieved by the vehicle's roof window having at least one opaque component. This opaque component covers the entire surface of the vehicle's roof window.

[0024] In an initial embodiment of the vehicle roof window, the aforementioned opaque component is at least one of the bonding layers. The first bonding layer and / or the second bonding layer is / are opaque. For example, an opaque-tinted thermoplastic layer or film can be used, or an adhesive layer with opaque-tinting additives.

[0025] In a second embodiment of the vehicle roof window, the aforementioned opaque component is at least one of the panes. The outer pane and / or the inner pane is / are opaque. For example, an opaque-tinted glass pane can be used. Alternatively, the glass pane in question can have an opaque coating.

[0026] In a third embodiment of the vehicle roof window, the opaque component is the aerogel layer, or rather, it comprises the aerogel layer. An inherently opaque aerogel can be used, or an inherently transparent or translucent aerogel containing opaque additives. However, since the aerogel layer typically exhibits less desirable optical properties than the glass panes or the bonding layers, potentially resulting in a less uniform aesthetic appearance, an opaque aerogel layer is less preferred over an opaque glass pane or bonding layer.

[0027] It is possible for the aerogel layer to cover the entire surface of the vehicle roof panel, extending to its side edges. Alternatively, the aerogel layer can be arranged within a section of a thermoplastic layer, which surrounds it like a frame. In this case, there is no aerogel layer at the edge of the vehicle roof panel, and therefore no thermal shielding, which may be acceptable. The frame-like thermoplastic layer should have a width of no more than 10 cm, preferably no more than 5 cm. If the opacity of the vehicle roof panel is provided by the aerogel layer, then the frame-like thermoplastic layer should also be opaque (and preferably the same color as the aerogel layer). This opaque component then comprises the aerogel layer and the thermoplastic layer surrounding it like a frame.

[0028] Since the opaque component in advantageous applications is intended to match the outer color of the vehicle's roof window to the vehicle's paintwork, it is advantageous for the opaque component to be positioned as far to the outside as possible. This creates a particularly uniform color impression of the vehicle. Therefore, in the case of an opaque window or an opaque bonding layer, it is especially preferred if the outer window or the first bonding layer is opaque.

[0029] Combinations of the above-described configurations are also possible. For example, - at least one of the bonding layers and at least one of the disks, preferably outer disk and first bonding layer - at least one of the bonding layers (preferably the first bonding layer) and the aerogel layer, - at least one of the panes (preferably the outer pane) and the aerogel layer or - at least one of the bonding layers, at least one of the disks (preferably outer disk and first bonding layer) and the aerogel layer opaque must be formed.

[0030] It is also conceivable that the opaque component is provided in the form of a specially designed film, which is integrated into one of the bonding layers, for example, positioned between two thermoplastic layers. The film could, for instance, be a polyethylene terephthalate (PET)-based film that is opaquely tinted or colored.

[0031] In a further development of the invention, the vehicle roof window comprises, on the interior side of the aforementioned opaque component, an additional colored layer which adapts the interior color of the roof window to the color scheme of the vehicle interior. This additional colored layer can be, but need not be, opaque. For example, it is possible that the outer pane and / or the first bonding layer are opaque with the color of the vehicle paintwork, and the inner pane and / or the second bonding layer are colored with a color adapted to the vehicle interior.

[0032] The thickness of the aerogel layer can be selected according to the requirements of the specific application. Factors particularly important include the thermal conductivity of the aerogel (which in turn depends on the material, density, and porosity), the heat absorption of the laminated glass (which in turn depends on the other components of the laminated glass, especially the material, thickness, and tint of the outer pane, the inner pane, and the bonding layers), and the desired heat input (i.e., the desired TTS value, the total solar energy transmitted). Preferably, the aerogel layer has a thickness in the range of 0.1 mm to 10 mm, more preferably from 0.2 mm to 8 mm, and particularly from 0.5 mm to 6 mm. This achieves good results in typical applications.

[0033] The aerogel layer can optionally have an edge seal, for example in the form of a polymeric band or a polymeric film.

[0034] Contrary to what the name might suggest, aerogels are not gels, but highly porous solids. The name derives from the fact that aerogels are typically produced from gels, with the liquid component of the gel being replaced by a gas without the gel structure collapsing, for example, through supercritical drying or freeze-drying. Structurally, aerogels consist of a branching network of particle chains (dendritic structure) with numerous spaces (pores), particularly in the form of open pores. The particle chains have contact points with each other, so the aerogel can be described as a stable, sponge-like network. The particle chains themselves often result from the fusion of, for example, spherical particles. A very high volume fraction of aerogels consists of pores, especially open pores. Therefore, aerogels have a very low density.The aerogel layer is therefore lightweight, so the weight of the laminated glass is not significantly increased even by comparatively thick aerogel layers. Aerogels can also exhibit high optical transparency, which can be particularly advantageous for glazing applications. Aerogels can be produced, for example, using sol-gel processes.

[0035] The pores may contain inclusions, for example, to influence the mechanical, thermal, or optical properties of the aerogel layer. The pores are typically air-filled, apart from any inclusions. The aerogel layer can also be referred to as an aerogel layer or a layer made of or based on an aerogel.

[0036] For the purposes of this invention, porosity is defined as the proportion of the pore volume to the total volume of the aerogel. The aerogel layer is preferably composed of, or based on, an aerogel having a porosity of 50% to 99.98%, particularly preferably 80% to 99%, and most preferably 85% to 98%. The porosity can be determined by gas sorption measurement, in particular using carbon dioxide (CO2) as the measuring gas at a temperature of 273 K.

[0037] The pore size of the aerogel is preferably from 1 nm to 50 nm, particularly preferably from 10 nm to 40 nm. This refers specifically to the diameter of the typically approximately spherical pores. The pore size can also be determined using the aforementioned gas sorption measurement.

[0038] The density of the aerogel is preferably 0.16 mg / cm³. 3 up to 500 mg / cm² 3 , particularly preferably of 10 mg / cm² 3 up to 300 mg / cm²3 This refers to the bulk density based on the volume including the pore spaces, whereby the air in the pores is not included in the mass.

[0039] The particles that make up the network of particle chains typically have a size of 1 nm to 10 nm.

[0040] Aerogels can be formed from various materials (material of the particle chains). The aerogel layer is preferably composed of silicate, a polymer, carbon, cellulose, or a metal oxide. In principle, all polymers and metal oxides are suitable. Examples include polyimide for a polymer and aluminum oxide, titanium oxide, zirconium oxide (all transparent and white or bluish), iron oxide (opaque, red or yellow), chromium oxide (opaque, green or blue), and vanadium oxide (opaque, olive green) for metal oxides.

[0041] Strictly speaking, silicate aerosols do not have the chemical composition of a silicate, but rather something like SiO(OH)₂. y (OR) z , where R is an organic residue and the parameters y and z depend on the manufacturing process. They are nevertheless generally referred to as such, and the term silicate is also used accordingly within the scope of the present invention. In English, the term "silica aerogel" (i.e., SiO2 aerogel) is also common. Silicate aerogels, polymer aerogels, and cellulose aerogels are particularly preferred for the aerogel layer. These aerogels are well-researched and already commercially available in large numbers.

[0042] The aerogel layer can have different structural designs and can be integrated into the vehicle's roof window, in particular - as a so-called blanket or mat; this refers to a composite material made of an aerogel (especially silicate aerogel) and a material that influences the mechanical properties; said material is in particular a fiber material (for example, glass fibers); blankets are flexible and can be supplied on rolls, for example; such a mat can, for example, be made of an aerogel felt (especially silicate aerogel felt); - as a film; films are flexible and can also be supplied, for example, on rolls; they can be made, for example, from or based on a polymer aerogel, which may optionally contain inclusions; an aerogel film can comprise a carrier film (for example, made of PET or polyimide) on which an aerogel layer is arranged; - as a rigid layer ("plate"); - in the form of granules (with particle sizes, for example, in the millimeter range) or particles (with particle sizes, for example, in the micrometer range).

[0043] The vehicle roof panel can, in principle, have several layers of aerogel. However, for reasons of simple construction and low overall thickness, it is preferred that the vehicle roof panel has only one layer of aerogel.

[0044] In an advantageous embodiment, the interior surface of the inner pane, facing away from the intermediate layer, is provided with an emissivity-reducing coating. Emissivity-reducing coatings are also known as heat-radiation-reflecting coatings, low-emissivity coatings, or LowE (low emissivity) coatings. Emissivity is the measure that indicates how much heat radiation the pane, in its installed position, emits into an interior space compared to an ideal heat radiator (a black body). Emissivity-reducing coatings serve to prevent heat radiation from entering the interior space (IR components of solar radiation and, in particular, the thermal radiation of the pane itself) and also from radiating heat out of the interior space. They exhibit reflective properties with respect to infrared radiation, especially heat radiation in the spectral range of 5 µm to 50 µm (see [reference]).(also standard DIN EN 12898:2019-06). This effectively improves thermal comfort in the interior. At high outside temperatures and with strong sunlight, the emissivity-reducing coatings can at least partially reflect the heat radiation emitted from the entire pane towards the interior. At low outside temperatures, they can reflect the heat radiation emitted from the interior, thus reducing the effect of the cold pane as a heat sink. The emissivity-reducing coating further enhances thermal comfort in the interior.

[0045] The emissivity-reducing coating is typically a transparent stack of thin films. The emissivity-reducing coating preferably comprises at least one, and more preferably exactly one, electrically conductive layer, which provides the IR-reflective properties. The conductive layer is preferably based on a transparent conductive oxide (TCO), in particular indium tin oxide (ITO), alternatively indium zinc mixed oxide (IZO), gallium-doped tin oxide (GZO), fluorine-doped tin oxide (FTO, SnO₂:F), antimony-doped tin oxide (ATO, SnO₂:Sb), or niobium-doped titanium oxide (TiO₂:Nb). Unlike metals, TCOs are not susceptible to corrosion, so they can be used on the exposed inner surface of the inner disc.In addition to the conductive layer, the coating typically has dielectric layers (for example, based on silicon oxide or nitride), which serve in particular to optimize the optical properties (for example, light transmission) or to act as barrier layers to regulate oxygen diffusion during the deposition of the coating.

[0046] In an advantageous embodiment, the interior surface of the outer pane facing the intermediate layer is provided with a solar control coating. Solar control coatings are also known as IR-reflective coatings or solar control coatings. The solar control coating exhibits reflective properties in the near-infrared range and is suitable for reflecting infrared components of solar radiation, thus reducing the heating of the underlying layers of the laminated glass. This, in turn, has a beneficial effect on the low emissivity of the vehicle roof window, which heats up less and therefore emits less thermal radiation. The solar control coating is typically a stack of thin films with at least one layer based on a metal, particularly silver.Furthermore, dielectric layers are usually present, which optimize the optical properties of the coating (for example, anti-reflective layers or layers to influence the structure of the metallic layer) and / or protect the metallic layer from corrosion. The dielectric layers can be based, for example, on silicon nitride, zinc oxide, tin-zinc oxide, silicon-metal mixed nitrides such as silicon-zirconium nitride, zirconium oxide, niobium oxide, hafnium oxide, tantalum oxide, tungsten oxide, or silicon carbide. Alternatively, the solar control coating can also be applied to a carrier film (for example, made of PET) which is embedded in the intermediate layer, preferably in the first bonding layer, for example, arranged between two thermoplastic layers.

[0047] The vehicle roof window can be flat, cylindrical, or spherically curved. Spherically curved laminated glass is particularly common in the roof windows of passenger cars.

[0048] The vehicle roof window can have any coatings, paint finishes, or decorations to suit the specific application. For example, a digital print, screen print, or any type of colored coating can be applied to the interior surface of the outer window, facing the intermediate layer (before or after any bending process). This also allows the outer window to be made opaque and the desired color.

[0049] The vehicle roof panel can be manufactured by stacking the individual layers in the specified sequence and then laminating them together. This can be achieved using well-known methods, such as autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators, or combinations thereof. The bonding of the outer and inner panels is typically achieved under the influence of heat, vacuum, and / or pressure.

[0050] The invention comprises a vehicle equipped with a roof window as described above. The roof window is installed in an opening in the vehicle body in the roof area. The vehicle can, in principle, be any land, air, or water vehicle. The vehicle is preferably a motor vehicle or rail vehicle, and particularly preferably a passenger car or truck.

[0051] To ensure a uniform appearance of the vehicle, the vehicle roof window, according to the invention, has the same color as the vehicle body or the vehicle paintwork. The color of the laminated window is typically determined essentially by the color of the opaque component, which therefore preferably has the same color as the vehicle paintwork. The color of the roof window and the vehicle body can be assessed as the external reflection color, measured with a standard D65 light source (standard illuminant D65) at an angle of 8° (incident and observation angle) using a 2° detector. According to the invention, the roof window and the vehicle body have the same color when the color difference ΔE in the Lab color space (CIELAB of the International Commission on Illumination CIE, see standard EN ISO 11664-4) is less than or equal to 3, preferably less than or equal to 2.

[0052] The invention is explained in more detail with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way. It shows: Fig. 1 a top view of an embodiment of the vehicle roof window of a vehicle according to the invention and Fig. 2 a cross-section along XX' through the vehicle roof window Fig. 1.

[0053] Fig. 1 and Fig.Figure 2 shows a detail of an embodiment of the vehicle roof window of a vehicle according to the invention. The vehicle roof window is completely opaque, thus preventing any view through it. Such a vehicle roof window can simplify the vehicle manufacturing process. The vehicle manufacturer only needs to produce a single type of vehicle body with a roof opening. For models with a "glass roof," a transparent roof window can be inserted into this roof opening. For models without a "glass roof," the opaque roof window can be used. If it has the same color as the vehicle paintwork, it blends in unobtrusively into the vehicle's appearance.

[0054] The vehicle roof window is designed as a laminated glass unit. It consists of an outer pane 1 and an inner pane 2, which are bonded together by an intermediate layer 3. The outer pane 1 and the inner pane 2 are made of untinted soda-lime glass, with the outer pane 1 having a thickness of, for example, 2.1 mm and the inner pane 2 having a thickness of, for example, 1.6 mm. In its installed position, the outer pane 1 faces the vehicle's external environment, and the inner pane 2 faces the vehicle's interior.

[0055] To improve thermal comfort in the vehicle interior, an aerogel layer 6 is embedded in the intermediate layer 3. The aerogel layer 6 is connected to the outer pane 1 via a first bonding layer 3a and to the inner pane 2 via a second bonding layer 3b. The bonding layers 3a and 3b are thermoplastic layers, each consisting of a 0.76 mm thick PVB-based film. The first bonding layer 3a is opaque due to a strong tint or coloring, giving the vehicle roof window its opacity. The second bonding film 3b is clear and untinted.

[0056] Aerogel layer 6, for example, has a thickness of 2 mm. It is designed, for example, as a flexible film made of a transparent or translucent polymer aerogel.

[0057] Compared to a conventional metal roof as part of the vehicle body, a vehicle roof window is significantly heated by solar radiation. It then emits its own heat radiation, which reduces thermal comfort in the interior. According to the invention, this problem is addressed by the aerogel layer 6. The aerogel layer 6 has thermally insulating properties, thus reducing the energy input into the vehicle interior. Conversely, at low outside temperatures, heat loss through the roof window is reduced. Furthermore, the aerogel layer 6 has acoustically insulating properties, thus better shielding against outside noise. The aerogel layer 6 is very lightweight, so the overall weight of the vehicle roof window is not significantly increased.

[0058] To further reduce the energy input into the vehicle interior, the vehicle roof window has two coatings: a sun protection coating 4 on the interior-facing surface of the outer pane 1 facing the intermediate layer 3 and an emissivity-reducing coating 5 on the interior-facing surface of the inner pane 2 facing away from the intermediate layer.

[0059] The solar control coating 4 exhibits near-infrared (IR) reflective properties and reflects infrared components of solar radiation. Therefore, the solar control coating 4 reduces the heating of the components of the vehicle's roof window located behind it (as seen from the outside) – in particular, the heavily tinted first bonding layer 3a. Since the roof window heats up less, it can, in turn, emit a small amount of heat radiation. The solar control coating 4 is a stack of thin layers, including several silver layers, arranged alternately with dielectric layers or sequences of layers. The emissivity-reducing coating 5 exhibits reflective properties in the mid-infrared (MI) range and is particularly effective against heat radiation. In summer, it reduces the amount of heat radiation from the roof window entering the vehicle interior, and in winter, it reduces heat loss through the roof window.The emissivity-reducing coating 5 is also a stack of thin layers, including an ITO layer and dielectric layers.

[0060] The configuration shown here is merely an example. It is not mandatory that the opacity of the vehicle roof panel be provided by the first bonding layer 3a. Alternatively, the outer pane 1, the aerogel layer 6, the second bonding layer 3b, or the inner pane 2 could also be opaque. It is also possible for several elements of the vehicle roof panel to be opaque, for example, the outer pane 1 and the first bonding layer 3a, or the first bonding layer 3a and the aerogel layer 6. Examples

[0061] The energy input through the vehicle's roof window was determined through simulations. To characterize this, the so-called heat transfer coefficient, usually referred to as the U-value, was calculated. The lower the U-value, the lower the heat transfer.

[0062] There were: Example 1 a vehicle roof window with an opaque first bonding layer 3a and a 5 mm thick aerogel layer 6; Example 2 a vehicle roof window with an opaque first bonding layer 3a and a 3 mm thick aerogel layer 6; Comparative example 1 a transparent vehicle roof window without aerogel layer 6, the intermediate layer was formed from only a single 0.76 mm thick PVB film; Comparative example 2 a black sheet metal roof with a thickness of 20 mm.

[0063] The roof panes of examples 1 and 2 and of the comparative example 2 were designed analogously, with the outer pane 1, the inner pane 2, the coatings 4, 5, the material of the possible aerogel layer 6 and the connecting layers 3a, 3b being designed in the same way.

[0064] The simulated U-values ​​are shown in Table 1. In the examples according to the invention, the low thermal transmittance of the classic sheet metal roof is not quite achieved (comparative example 2), but a significant reduction in thermal transmittance can be achieved compared to a roof panel without an aerogel layer 6. Table 1 Example 1 Example 2 Comparative example 1 Comparative example 2 U-value 1,5 W / (m 2 K) 2,0 W / (m 2 K) 4,0 W / (m 2 K) 0,6 W / (m 2 K) Reference symbol list: 1 Outer pane of the composite pane 2 Inner pane of the composite pane 3 Intermediate layer 3a first bonding layer of the intermediate layer 3 3b second bonding layer of the intermediate layer 3 4 Sun protection coating 5. Emissivity-reducing coating (LowE coating) 6 aerogel layers X - X' Intersection line QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 202020104733U1

[0004] WO 2012154602A1

[0007] US 2010146880A1

[0007] EP 3381881A1

[0007] Cited non-patent literature

[0000] DIN EN 12898:2019-06

[0044] Standard EN ISO 11664-4

[0051]

Claims

[1] Vehicle equipped with a vehicle roof window comprising an outer pane (1) and an inner pane (2) which are connected to each other over a surface via an intermediate layer (3), where the vehicle roof window is opaque and wherein an aerogel layer (6) is embedded in the intermediate layer (3), the vehicle's roof window is the same color as the vehicle's paintwork. [2] Vehicle according to claim 1, wherein the vehicle roof window comprises in the specified order: - the outer pane (1), - a bonding layer (3a), - the aerogel layer (6), - a bonding layer (3b), - the inner disc (2). [3] Vehicle according to claim 2, wherein the first compound layer (3a) and / or the second compound layer (3b) is opaque, preferably the first compound layer (3a). [4] Vehicle according to claim 1 or 2, wherein the outer pane (1) and / or the inner pane (2) is opaque, preferably the outer pane (1). [5] Vehicle according to claim 1 or 2, wherein the aerogel layer (6) is opaque. [6] Vehicle according to any one of claims 1 to 5, wherein the aerogel layer (6) has a thickness of 0.1 mm to 10 mm, particularly preferably 0.2 mm to 8 mm, most preferably 0.5 mm to 6 mm. [7] Vehicle according to any one of claims 1 to 6, wherein the aerogel layer (6) is based on a silicate aerogel, polymer aerogel or cellulose aerogel. [8] Vehicle according to any one of claims 1 to 7, wherein the aerogel layer (6) is based on an aerogel having a porosity of 50% to 99.98%, preferably 80% to 99%. [9] Vehicle according to claim 2 or any of claims 3 to 8, if referring back to claim 2, wherein the first bonding layer (3a) and the second bonding layer (3b) are formed as thermoplastic layers, preferably each consisting of at least one film based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) or polyurethane (PU). [10] Vehicle according to claim 2 or any one of claims 3 to 8, if referring back to claim 2, wherein the first bonding layer (3a) and the second bonding layer (3b) are formed as adhesive layers, preferably made of an optically clear adhesive (OCA). [11] Vehicle according to any one of claims 1 to 10, wherein the outer pane (1) and the inner pane (2) are made of soda-lime glass and preferably have a thickness of 1 mm to 3 mm. [12] Vehicle according to one of claims 1 to 11, wherein the surface of the inner disc (2) facing away from the intermediate layer (3) is provided with an emissivity-reducing coating (6). [13] Vehicle according to one of claims 1 to 12, wherein the surface of the outer window (1) facing the intermediate layer (3) is provided with a sun protection coating (4).

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