Opaque vehicle roof pane with vacuum insulation

Abstract

The present invention relates to a vehicle roof pane, comprising an exterior pane (1) and an interior pane (2) which are flatly connected together, wherein the vehicle roof pane is opaque and wherein the vehicle roof pane has a vacuum insulating glazing (5) which comprises an outer pane (5a) that faces the exterior pane (1) and an inner pane (5b) that is spaced from the outer pane (5a) via spacers (5d, 5e), wherein the intermediate space (5c) between the outer pane (5a) and the inner pane (5b) is evacuated, and (i) the vacuum insulating glazing (5) is incorporated into the vehicle roof pane between the exterior pane (1) and the interior pane (2) or (ii) the interior pane (2) of the vehicle roof pane forms the inner pane (5b) of the vacuum insulating glazing (5).

Description

[0001] Opaque vehicle roof window with vacuum insulation

[0002] The invention relates to a vehicle roof window equipped with vacuum insulating glazing, as well as to a vehicle equipped therewith.

[0003] Some cars are equipped with roof windows, often simply referred to as "glass roofs." The roof window allows 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 largely on the user's personal preferences. For example, some users find the view of the surroundings through the roof and the sunlight passing through the glass roof distracting or otherwise disturbing.

[0004] As a result, vehicle manufacturers typically offer two versions of their vehicles: one with a glass roof and one without. This requires them to provide two different vehicle bodies, and in some cases, interior components, such as upper lighting, antennas, and wiring, must be adapted to the two vehicle versions.

[0005] To simplify vehicle manufacturing, it is in principle possible to provide a single vehicle body with a roof opening into which, depending on the model, a transparent or opaque vehicle roof window is inserted. The version with the opaque vehicle roof window thus effectively creates a classic vehicle "without a glass roof." The vehicle manufacturer only needs to produce a uniform body for both versions, thereby reducing production costs and eliminating the need for production lines. DE202020104733U1 proposes a non-transparent vehicle roof window with at least one frosted glass pane for such a purpose. DE112018001647T5 also discloses an opaque vehicle roof window.

[0006] Compared to a traditional sheet metal roof (metal roof) formed by the vehicle body, such an opaque vehicle roof window has disadvantages, particularly with regard to thermal comfort in the vehicle. For example, the energy input due to solar radiation is significantly higher than with a sheet metal roof. The total solar energy radiated is essentially the sum of the directly radiated energy and the indirectly radiated energy as thermal radiation after the heating of window components (emissivity). This is typically characterized as the TTS value. While an opaque vehicle roof window can essentially reduce the directly radiated energy to zero, the problem of emissivity remains.The components of the roof window can be heated up considerably by solar radiation, which can be even more pronounced if the window components are heavily tinted compared to a transparent glass roof. They, in turn, emit heat radiation into the vehicle interior. If the vehicle interior heats up too much, this must be counteracted with air conditioning, which is not conducive to energy-saving operation.

[0007] There is therefore a need for improved opaque vehicle roof windows that reduce the energy input into the vehicle interior.

[0008] Vacuum insulating glazing (VIG) consists of two spaced-apart glass panes, with the space between the panes evacuated. Such glazing is known, for example, from EP1978199A1 and W09804802A1. EP3878827A1 discloses a vehicle window constructed as vacuum insulating glazing.

[0009] Aerogels are highly porous solids known for their very low thermal conductivity and thermal insulation properties. WO2012154602A1 discloses an insulating glazing unit with an aerogel layer. US2010146880A1 discloses a building roof panel consisting of two glass panes and an aerogel layer in between. EP3381881A1 discloses a composite pane consisting of two glass panes and an intermediate thermally insulating layer, which may be formed as an aerogel layer. CN102839893A discloses a type of insulating glazing unit in which two glass panes are connected to one another via a spacer. The space between them is filled with aerogel and evacuated. CN204081872U discloses a glazing unit with two vacuum insulating glazing units with an aerogel layer arranged between them.

[0010] The present invention is based on the object of providing an improved opaque vehicle roof window that exhibits low heat input and ensures high thermal comfort in the vehicle interior. This object is achieved according to the invention by a vehicle roof window according to independent claim 1. Advantageous embodiments are evident from the subclaims.

[0011] The vehicle roof window according to the invention comprises an outer pane and an inner pane, which are joined together in a planar manner. The vehicle roof window is opaque. The vehicle roof window also features vacuum-insulated glazing.

[0012] The vacuum insulating glazing comprises an outer pane and an inner pane, which are spaced apart by spacers, forming a gap between the outer pane and the inner pane. The outer pane of the vacuum insulating glazing faces the outer pane of the vehicle roof window, while the inner pane faces away from the outer pane. The gap between the outer pane and the inner pane is evacuated.

[0013] The invention can fundamentally be implemented in two different variants. In a first variant (also referred to as "variant (i)"), the vacuum insulating glazing is embedded between the outer pane and the inner pane in the vehicle roof window. In a second variant (also referred to as "variant (ii)"), the inner pane of the vehicle roof window also forms the inner pane of the vacuum insulating glazing.

[0014] The vehicle roof window according to the invention is opaque overall and can thus replace a conventional opaque sheet metal roof, which is realized by the vehicle body itself. The vehicle manufacturer only needs to provide a vehicle body with an opening (window opening) in the roof, whereby either a transparent vehicle roof window or the opaque vehicle roof window according to the invention can be inserted into said opening. The vehicle manufacturing process is thereby simplified and the vehicle manufacturer can, in particular, save on production lines. The vacuum insulating glazing endows the opaque vehicle roof window according to the invention with thermally insulating properties, thereby reducing the energy input into the vehicle interior due to solar radiation, particularly in summer. Likewise, heat loss through the vehicle roof window is reduced, particularly in winter when outside temperatures are low.This significantly improves thermal comfort in the vehicle interior, and reduces the need for air conditioning or heating, which both saves energy and reduces noise pollution in the vehicle. These are major advantages of the present invention.

[0015] The vehicle roof window is intended to separate the interior (vehicle interior) from the outside environment in an opening (roof opening) in the roof of a vehicle or a vehicle body. In the sense of the invention, the inner window refers to the window facing the interior. The outer window refers to the window facing the outside environment. The outer window and the inner window each have an outside surface and an inside surface and a circumferential side edge surface running between them. In the sense of the invention, the outside surface refers to the main surface which is intended to face the outside environment in the installed position. In the sense of the invention, the inside surface refers to the main surface which is intended to face the interior in the installed position.The interior surface of the outer pane and the exterior surface of the inner pane face each other and are connected to each other.

[0016] When installed, the outer pane of the vacuum insulating glazing also faces the outside environment and the outer pane. The inner pane of the vacuum insulating glazing faces the interior, as does the inner pane in variant (i).

[0017] The vehicle roof window according to the invention is designed as a type of composite pane and is sometimes referred to below as a composite pane. The outer pane is connected to the vacuum insulating glazing via a (first) intermediate layer. In variant (i), the vacuum insulating glazing is connected to the inner pane via a further (second) intermediate layer. The intermediate layers each comprise at least one bonding layer.

[0018] In variant (i), the vacuum insulating glazing is embedded in the vehicle roof window between the outer pane and the inner pane. In variant (i) of the invention, the vehicle roof window comprises, in a preferred embodiment, in the order given: the outer pane, a first bonding layer, the vacuum insulating glazing, a second bonding layer, and the inner pane.

[0019] In a preferred embodiment, the vacuum insulating glazing is connected to the outer pane and the inner pane via a connecting layer.

[0020] In variant (ii) of the invention, the vehicle roof window comprises, in a preferred embodiment, in the order given:

[0021] - the outer pane,

[0022] - a (first) connection layer,

[0023] - vacuum insulating glazing.

[0024] In a preferred embodiment, the vacuum insulating glazing is connected to the outer pane via a connecting layer.

[0025] In variant (ii), the vacuum insulating glazing is an exposed element of the vehicle roof window, with the exposed inner pane of the vacuum insulating glazing also forming the inner pane of the vehicle roof window. The inner pane and the inner pane are therefore identical.

[0026] In a further development, the vehicle roof window according to the invention also comprises an aerogel layer. The aerogel layer can also be referred to as an aerogel layer. It is embedded in the vehicle roof window between the outer pane and the inner pane. The further development with an aerogel layer is applicable to both variant (i) and variant (ii). The aerogel layer further improves the thermal insulation effect of the vehicle roof window and thus the thermal comfort in the vehicle interior. The aerogel layer also has acoustically insulating properties, so that outside noise penetrates the vehicle interior to a lesser extent and the use of costly acoustically insulating thermoplastic layers can be dispensed with. The aerogel layer is very lightweight, so that the overall weight of the vehicle roof window is also comparatively low.

[0027] In a first embodiment of variant (i) with an aerogel layer, the aerogel layer is embedded in the first intermediate layer, i.e., between the outer pane and the vacuum insulating glazing. The vacuum insulating glazing is thus spaced further apart from the outer pane than the aerogel layer. The laminated pane preferably comprises, in the order given:

[0028] - the outer pane,

[0029] - the first connection layer,

[0030] - the aerogel layer,

[0031] - another connecting layer,

[0032] - vacuum insulating glazing,

[0033] - the second connection layer and

[0034] - the inner pane.

[0035] In a second embodiment of variant (i) with an aerogel layer, the aerogel layer is embedded in the second intermediate layer, i.e., between the inner pane and the vacuum insulating glazing. The vacuum insulating glazing is thus spaced closer to the outer pane than the aerogel layer. The laminated pane preferably comprises, in the order given:

[0036] - the outer pane,

[0037] - the first connection layer,

[0038] - vacuum insulating glazing,

[0039] - the second connection layer,

[0040] - the aerogel layer,

[0041] - another connecting layer and

[0042] - the inner pane.

[0043] In variant (ii) with an aerogel layer, the outer pane and the vacuum insulating glazing are bonded together via an intermediate layer, with the aerogel layer embedded in the intermediate layer. The laminated pane preferably comprises, in the order given:

[0044] - the outer pane,

[0045] - the first connection layer,

[0046] - the aerogel layer,

[0047] - another connecting layer,

[0048] - vacuum insulating glazing.

[0049] In particularly preferred embodiments of the preferred configurations described above, the vehicle roof window structurally consists only of the specified elements. The outer pane, the inner pane, the thermoplastic layer, and / or the panes of the vacuum insulating glazing can additionally be provided with conventional coatings or printing.

[0050] The vehicle roof window preferably does not include any large-area electrical units. This is advantageous in terms of a simple structure and a low overall thickness. The vehicle roof window particularly preferably does not include any photovoltaic cells.

[0051] The connecting layers serve to adhesively bond the components of the vehicle roof window between which they are arranged. The connecting layers are preferably formed as thermoplastic layers. The thermoplastic layers can also be referred to as thermoplastic layers.

[0052] The thermoplastic layers are preferably based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or polyurethane (PU), or on mixtures or copolymers or derivatives thereof, particularly preferably based on PVB. This means that the layer predominantly contains the said polymer (a proportion greater than 50 wt.%). In addition to the polymer, the layer may contain further additives, for example, plasticizers, UV absorbers, or stabilizers. Each thermoplastic layer is preferably formed from at least one thermoplastic film. The thickness of each film is preferably between 0.2 mm and 1 mm. For example, PVB films with standard thicknesses of 0.38 mm or 0.76 mm can be used.

[0053] The connecting layers can alternatively be formed as adhesive layers, for example. So-called optically clear adhesives (OCAs) are preferred. This is particularly advantageous with regard to the aesthetic appearance of the vehicle roof window. OCAs are known as such to those skilled in the art. They are characterized in particular by high optical quality. They are particularly 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 low-distortion visibility is possible. The optically clear adhesive is preferably a 2-component polyurethane adhesive, a 1-component acrylate adhesive, a 1-component silicone adhesive, or a 1-component acrylate hybrid adhesive.Since the vehicle roof window according to the invention is opaque, the optical properties of the adhesive are not critical, so optically clear adhesives may not necessarily be used. Essentially, any adhesive can be used.

[0054] In principle, a combination is also conceivable, with at least one connecting layer being designed as a thermoplastic layer and at least one other connecting layer being designed as an adhesive layer.

[0055] The outer pane and the inner pane are preferably glass panes, particularly preferably made of soda-lime glass, as is common for window panes. However, one or both of the 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 pane and the inner pane, independently of one another, are preferably between 0.5 mm and 5 mm, particularly preferably between 1 mm and 3 mm.

[0056] The outer pane and the inner pane can optionally be thermally or chemically toughened, partially toughened, or not toughened independently of each other. In variant (ii), where the inner pane of the vehicle roof window and the inner pane of the vacuum insulating glazing are identical, it is advantageous if the inner pane is toughened, preferably thermally toughened. Since the inner pane is only locally or punctually connected to the adjacent layer (the outer pane of the vacuum insulating glazing) via spacers, the toughening can increase mechanical stability and reduce the risk of glass breakage and the generation of dangerous glass shards.

[0057] According to the invention, the vehicle roof window is equipped with vacuum insulating glazing. The vacuum insulating glazing comprises an outer pane and an inner pane, which are spaced apart from each other by spacers, so that a gap is formed between the outer pane and the inner pane.

[0058] In variant (i), the outer pane and the inner pane have a thickness of, for example, 0.3 mm to 5 mm, preferably 0.3 mm to 3 mm, particularly preferably 0.5 mm to 2 mm, most preferably 0.5 mm to 1.5 mm, in particular 0.5 mm to 1 mm. The outer and inner panes are preferably thinner than the outer pane and the inner pane.

[0059] In variant (ii), the outer pane has a thickness of, for example, 0.3 mm to 5 mm, preferably 0.3 mm to 3 mm, particularly preferably 0.5 mm to 2 mm, most preferably 0.5 mm to 1.5 mm, in particular 0.5 mm to 1 mm. The inner pane is identical to the inner pane of the composite pane, and the preferred thicknesses specified above for the inner pane apply.

[0060] The outer and inner panes are preferably made of glass. Soda-lime glass can also be used. Very thin outer and inner panes (e.g., with thicknesses of 0.5 mm to 1 mm) can also be made of aluminosilicate glass, which is preferably chemically toughened.

[0061] The gap between the outer and inner panes preferably has a thickness of 0.1 mm to 1 mm, particularly preferably 0.2 mm to 0.5 mm. This achieves good thermal insulation without requiring an excessive increase in the thickness of the composite pane. The thickness of the gap corresponds to the distance between the facing surfaces of the outer and inner panes.

[0062] According to the invention, the intermediate space is evacuated, resulting in a vacuum insulating glazing unit consisting of the outer pane and the spaced-apart inner pane. This means that a negative pressure prevails in the intermediate space, i.e., a pressure that is lower than the ambient pressure. The pressure in the intermediate space is preferably at most 100 mbar, particularly preferably at most 10 mbar. The pressure can, for example, be from 0.01 mbar to 100 mbar, preferably from 0.1 mbar to 10 mbar.

[0063] Vacuum insulating glazing features spacers that ensure that the outer and inner panes do not deform despite the negative pressure between them. The distance between the outer and inner panes is preferably kept constant by the spacers, so that the outer and inner panes are arranged parallel to each other.

[0064] The spacing means preferably comprise a plurality of spacer columns. The spacer columns are distributed (preferably evenly) over the surface of the outer and inner panes. The number of spacer columns and their spacing from one another depend on the thickness of the panes and the negative pressure prevailing in the space between them. The thinner the panes (and the lower the pressure in the space between them), the more likely they are to deform, necessitating a larger number of spacer columns.

[0065] The spacer columns can be transparent or opaque. They are preferably made of glass or plastic.

[0066] The spacing means particularly preferably also comprise a circumferential spacer in an edge region between the outer pane and the inner pane. The circumferential spacer runs circumferentially in an edge region between the outer and inner panes. The evacuated space is delimited by the outer pane, the inner pane, and the circumferential spacer. The spacer is made, for example, of glass, plastic, metal, or a metal alloy.

[0067] To maintain the vacuum (or more precisely, the negative pressure) in the gap, the vacuum insulating glazing preferably has a gas-tight edge seal. The surrounding spacer (if present) can itself act as an edge seal, or the vacuum insulating glazing can be equipped with an additional edge seal, for example, made of glass, a metal or metal alloy (e.g., stainless steel, silver, or copper), or a gas-tight plastic.

[0068] The vehicle roof window according to the invention is opaque, thus preventing any visibility. The light transmittance of the vehicle roof window is preferably less than 2%, particularly preferably less than 0.5%, and in particular 0%. Light transmittance refers to the total transmittance, determined by the method specified in ECE-R 43, Annex 3, Section 9.1, for testing the light transmittance of motor vehicle windows. This is achieved by the vehicle roof window having at least one component that is opaque. This opaque component is present over the entire surface of the vehicle roof window.

[0069] In a first embodiment of the vehicle roof window, the said opaque component is at least one of the connecting layers. At least one of the connecting layers is opaque. For example, an opaque-tinted thermoplastic layer or film or an adhesive layer with opaque-tinting additives can be used. The said at least one opaque connecting layer is in particular in variant (i): the first connecting layer or the second connecting layer, in variant (ii): the (first) connecting layer, in variant (i) with an aerogel layer: the first connecting layer, the second connecting layer or the further connecting layer, in variant (ii) with an aerogel layer: the first connecting layer or the further connecting layer.

[0070] In a second embodiment of the vehicle roof window, the said opaque component is at least one of the external 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.

[0071] In a third embodiment of the vehicle roof window, the opaque component is the vacuum insulating glazing or part of the vacuum insulating glazing. 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.

[0072] It is possible for the vacuum insulating glazing to be present over the entire surface of the vehicle roof window, i.e., to extend to the side edges of the vehicle roof window. Alternatively, it is also possible for the vacuum insulating glazing to be arranged in a section of a thermoplastic layer that surrounds it in a frame-like manner (particularly in variant (i)), or for the vacuum insulating glazing to be surrounded by another polymeric encapsulation in a frame-like manner. In this case, there is no vacuum insulating glazing in the edge area of ​​the vehicle roof window and thus no thermal shielding, although this can be acceptable. The frame-like thermoplastic layer or the encapsulation should have a width of no more than 10 cm, preferably no more than 5 cm.If the opacity of the vehicle roof window is provided by the vacuum insulating glazing, the frame-like thermoplastic layer or frame-like encapsulation should also be opaque (and preferably the same color as the vacuum insulating glazing). The opaque component then comprises the vacuum insulating glazing and the thermoplastic layer or encapsulation surrounding it.

[0073] In a fourth embodiment of the vehicle roof window, the opaque component is the aerogel layer or comprises the aerogel layer, if such an aerogel layer is present. An inherently opaque aerogel can be used, or an inherently transparent or translucent aerogel that is provided with opaque-tinting additives. However, since the aerogel layer typically has less favorable optical properties than the panes or the connecting layers, which can lead to a less uniform aesthetic appearance, an opaque aerogel layer is less preferred than an opaque pane or an opaque connecting layer.

[0074] It is possible for the aerogel layer to be present over the entire surface of the vehicle roof window, i.e., to extend to the side edges of the vehicle roof window. Alternatively, it is also possible for the aerogel layer to be arranged in a section of a thermoplastic layer that surrounds it in a frame-like manner. In this case, there is no aerogel layer in the edge region of the vehicle roof window and therefore no thermal shielding, although this can 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 window is provided by the aerogel layer, in this case the frame-like thermoplastic layer should also be opaque (and preferably in the same color as the aerogel layer). The said opaque component then comprises the aerogel layer and the thermoplastic layer surrounding it in a frame-like manner.

[0075] Since the opaque component, in advantageous applications, is intended to match the exterior color of the vehicle roof window to the vehicle paintwork, it is advantageous if the opaque component is positioned as far outside as possible. This creates a particularly uniform color impression of the vehicle. In the case of an opaque window or an opaque bonding layer, it is therefore particularly preferred if the outer pane or the first bonding layer (in contact with the outer pane) is opaque.

[0076] Combinations of the configurations described above are also possible.

[0077] It is also conceivable for the opaque component to be provided in the form of a dedicated film, which is integrated into one of the intermediate layers, for example, arranged between two thermoplastic layers. The film can, for example, be a film based on polyethylene terephthalate (PET) that is opaquely tinted or colored.

[0078] In a further development of the invention, the vehicle roof window comprises an additional colored layer on the interior side of the said opaque component, which adapts the color of the roof window to the color scheme of the vehicle interior. This additional colored layer can, but does not have to, be opaque. For example, it is possible for the outer pane and / or the first connecting layer to be opaque, matching the color of the vehicle paintwork, and for the inner pane and / or the second or additional connecting layer to be colored in a color matching the vehicle interior.

[0079] In an advantageous embodiment, the interior-facing 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-reflecting coatings, low-emissivity coatings, or LowE coatings (low emissivity). Emissivity is the measure that indicates how much heat radiation the pane emits into an interior space in the installed position compared to an ideal heat radiator (a black body). Emissivity-reducing coatings prevent heat from radiating into the interior (IR components of solar radiation and, in particular, the thermal radiation of the pane itself) and also prevent heat from radiating out of the interior. They exhibit reflective properties against infrared radiation, particularly against thermal radiation in the spectral range of 5 pm - 50 pm (cf.This effectively improves thermal comfort in the interior. At high outside temperatures and in direct sunlight, the emissivity-reducing coatings can at least partially reflect the heat radiation emitted by the entire pane toward 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 increases thermal comfort in the interior.

[0080] The emissivity-reducing coating is typically a transparent stack of thin films. The emissivity-reducing coating preferably has at least one, particularly preferably precisely one, electrically conductive layer, which provides the IR-reflecting 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 interior-side surface of the inner pane.In addition to the conductive layer, the coating typically comprises dielectric layers (e.g. based on silicon oxide or nitride), which serve in particular to optimize the optical properties (e.g. light transmission) or serve as barrier layers to regulate oxygen diffusion during the deposition of the coating.

[0081] In an advantageous embodiment, the interior-side surface of the outer pane facing the intermediate layer is provided with a sun protection coating. Sun protection coatings are also known as IR-reflective coatings or Solar ConfroZ coatings. The sun protection coating has reflective properties in the near-infrared range and is suitable for reflecting infrared components of solar radiation, so that the underlying layers of the composite pane are heated to a lesser extent. 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 sun protection coating is typically a stack of thin films with at least one layer based on a metal, particularly silver.In addition, dielectric layers are usually present to optimize the optical properties of the coating (e.g., anti-reflective layers or layers that influence the structure of the metallic layer) and / or protect the metallic layer from corrosion. The dielectric layers can be based 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, for example. The solar control coating is particularly useful when the outer pane is transparent and the opaque element is, for example, one of the connecting layers.Alternatively, the sun protection coating can also be applied to a carrier film (for example made of PET) which is embedded in an intermediate layer, preferably in the first intermediate layer, for example arranged between two thermoplastic layers.

[0082] As already described, developments of the vehicle roof window according to the invention comprise an aerogel layer. The thickness of the aerogel layer can be selected according to the requirements of the specific application. In particular, the thermal conductivity of the aerogel (which in turn depends on the material, density, and porosity), the heat absorption of the composite pane (which in turn depends on the other components of the composite pane, in particular the material, thickness, and degree of tinting of the outer pane, the inner pane, and the connecting layers), and the desired heat input (i.e., the desired TTS value, the total incident solar energy) play a role. The aerogel layer preferably has a thickness in the range of 0.1 mm to 10 mm, particularly preferably 0.2 mm to 8 mm, in particular 0.5 mm to 6 mm or 0.5 mm to 5 mm. This achieves good results in typical applications.The aerogel layer is particularly preferably 1 mm to 4 mm thick. In typical applications, good thermal insulation is achieved even with such a thin aerogel layer, because the vacuum insulating glazing further improves thermal insulation. This allows for the realization of laminated panes with advantageously thin aerogel layers.

[0083] Contrary to what the name initially suggests, aerogels are not gels, but highly porous solids. The name derives from the fact that aerogels are typically made from gels, whereby the liquid component of the gel is replaced by a gas without collapsing the gel structure, for example through supercritical drying or freeze-drying. Structurally, aerogels consist of a branching of particle chains (dendritic structure) with very many interstices (pores), particularly in the form of open pores. The particle chains have contact points with one another, so that the aerogel can be thought of 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, particularly open pores. Therefore, aerogels have a very low density.The aerogel layer according to the invention is therefore lightweight, so that the weight of the laminated pane 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. Intercalations can be present in the pores, for example, to influence the mechanical, thermal, or optical properties of the aerogel layer. The pores are typically air-filled, apart from any intercalations. The aerogel layer according to the invention can also be referred to as a layer or layer made of an aerogel or based on an aerogel.

[0084] For the purposes of the invention, porosity refers to the proportion of the pore volume to the total volume of the aerogel. The aerogel layer according to the invention is preferably formed from 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 measurement gas at a temperature of 273 K.

[0085] The pore size of the aerogel is preferably between 1 nm and 50 nm, particularly preferably between 10 nm and 40 nm. This refers in particular to the diameter of the typically approximately spherical pores. The pore size can also be determined using the aforementioned gas sorption measurement.

[0086] The density of the aerogel is preferably 0.16 mg / cm 3 up to 500 mg / cm 3 , particularly preferably 10 mg / cm 3up to 300 mg / cm 3 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.

[0087] The particles that make up the network of particle chains typically have a size of 1 nm to 10 nm.

[0088] Aerogels can be formed from various materials (material of the particle chains). The aerogel of the aerogel layer according to the invention is preferably made of silicate, a polymer, carbon, cellulose, or a metal oxide. In principle, all polymers and metal oxides are suitable. Examples are 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. Strictly speaking, silicate aerosols do not have the chemical composition of a silicate, but rather SiO(OH). y (OR) z, where R is an organic residue and the parameters y and z depend on the manufacturing process. Nevertheless, they are generally referred to as such, and the term silicate is used accordingly in the context of the present invention. In English, the term "silica aerogel" is also commonly used (i.e., SiCh aerogel). Silicate aerogels, polymer aerogels, and cellulose aerogels are particularly preferred for the aerogel layer according to the invention. These aerogels are well researched and are already commercially available in large numbers.

[0089] The aerogel layer according to the invention can be structurally designed differently and integrated into the vehicle roof window, in particular

[0090] - as a so-called blanket or mat; this is understood to mean a composite material made of an aerogel (in particular silicate aerogel) and a material which influences the mechanical properties; the said material is in particular a fibre material (for example glass fibres); blankets are flexible and can be provided, for example, on rolls; such a mat can be made, for example, of an aerogel felt (in particular silicate aerogel felt);

[0091] - as a film; films are flexible and can also be provided, for example, on rolls; they can, for example, be formed from or based on a polymer aerogel, which can optionally have inclusions; an aerogel film can comprise a carrier film (for example made of PET or polyimide) on which an aerogel layer is arranged;

[0092] - as a rigid layer (“plate”);

[0093] - in the form of granules (with particle sizes in the millimeter range, for example) or particles (with particle sizes in the micrometer range, for example).

[0094] The aerogel layer may optionally have an edge seal, for example in the form of a polymeric tape or a polymeric film.

[0095] Because the aerogel layer has acoustically dampening properties, the use of so-called acoustic thermoplastic films as connecting layers can be omitted. Instead, single-layer films are preferred when the vehicle roof window is equipped with an aerogel layer, which is significantly more cost-effective. The vehicle roof window can be flat or cylindrically or spherically curved. Spherically curved composite panes are particularly common for roof windows on passenger cars.

[0096] The vehicle roof window can be coated with any desired coating, paint finish, or decoration, depending on the specific application. For example, digital printing, screen printing, or any type of color coating can be applied to the interior surface of the outer pane, facing the interlayer (before or after any bending process). This also allows the outer pane to be made opaque and in the desired color.

[0097] The vehicle roof window can be manufactured by stacking the individual layers in the specified order to form a stack and then laminating them together. Known processes can be used for this, such as autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators, or combinations thereof. The outer and inner panes are typically bonded using heat, vacuum, and / or pressure.

[0098] The invention also encompasses the use of a vehicle roof window according to the invention in means of transport for traffic on land, in the air or on water, in particular as a roof window of a passenger car or truck.

[0099] The invention further encompasses a vehicle equipped with a vehicle roof window according to the invention. The vehicle 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, particularly preferably a passenger car or truck.

[0100] To ensure a uniform appearance of the vehicle, the vehicle roof window preferably has the same color as the vehicle body or the vehicle paintwork. The color of the vehicle roof 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 light source D65 (standard illuminant D65) at an angle of 8° (angle of incidence and observation) with a 2° detector. For the purposes of the invention, the roof window and the vehicle body have the same color if the color difference AE in the Lab color space (CIELAB of the International Commission on Illumination CIE, cf. standard EN ISO 11664-4) is less than or equal to 3, preferably less than or equal to 2.

[0101] However, it may also be intentionally desired that the vehicle roof window according to the invention visually contrasts with the bodywork and therefore has a different color. The vehicle roof window does not have to be uniformly colored. It (or the opaque component) can also be multicolored. This allows, for example, patterns, symbols, or national flags to be displayed.

[0102] 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:

[0103] Fig. 1 is a plan view of an embodiment of the vehicle according to the invention

[0104] roof pane,

[0105] Fig. 2 shows a cross-section along XX' through the vehicle roof window from Figure 1,

[0106] Fig. 3 shows a cross section along XX' through a further embodiment of the vehicle roof window according to the invention,

[0107] Fig. 4 shows a cross section along XX' through a further embodiment of the vehicle roof window according to the invention,

[0108] Fig. 5 shows a cross section along XX' through a further embodiment of the vehicle roof window according to the invention and

[0109] Fig. 6 shows a cross section along XX' through a further embodiment of the vehicle roof window according to the invention.

[0110] Figures 1 and 2 each show a detail of an embodiment of the vehicle roof window according to the invention. The vehicle roof window is opaque overall, thus preventing any visibility. 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 according to the invention can be used. If this is the same color as the vehicle's paintwork, it blends unobtrusively into the vehicle's appearance.

[0111] The vehicle roof window is designed as a composite pane. It consists of an outer pane 1 and an inner pane 2 that are bonded together. 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 the installed position, the outer pane 1 faces the exterior of the vehicle, while the inner pane 2 faces the vehicle interior. To improve thermal comfort in the vehicle interior, a vacuum-insulated glazing unit 5 is embedded in the vehicle roof window between the outer pane 1 and the inner pane 2. The vacuum-insulated glazing unit 5 is bonded 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, 3b are thermoplastic layers, each made of a PVB-based film with a thickness of 0.76 mm. The first bonding layer 3a is opaque due to a strong tint or coloration, giving the vehicle roof window its opacity. The second bonding layer 3b is clear and untinted.

[0112] The vacuum insulating glazing 5 is formed from an outer pane 5a and an inner pane 5b, which are connected to one another and kept at a distance by a circumferential spacer 5d in the edge region and by spacer columns 5e evenly distributed over the surface. This creates an evacuated gap 5c between the outer pane 5a and the inner pane 5b. The outer pane 5a faces the outer pane 1 and is connected to the outer pane 1 via the first connecting layer 3a. The inner pane 5b faces the inner pane 2 and is connected to it via the second connecting layer 3b. The outer pane 5a and the inner pane 5b are each made of chemically toughened aluminosilicate glass and each have a thickness of 0.7 mm. The gap 5c has a thickness of 0.3 mm. The spacer columns 5e are made of glass or a transparent plastic.The surrounding spacer 5d is made of a plastic material. Furthermore, the surrounding spacer 5d is equipped with an edge seal (not shown) that seals the gap 5c in a gas-tight manner.

[0113] Compared to a traditional metal roof as part of the vehicle body, a vehicle roof window is significantly heated by solar radiation. It then emits thermal radiation, which reduces thermal comfort in the interior. According to the invention, this problem is addressed by vacuum insulating glazing 5. Vacuum insulating glazing 5 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.

[0114] In order 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-side surface of the outer pane 1 facing the intermediate layer and an emissivity-reducing coating 7 on the interior-side surface of the inner pane 2 facing away from the intermediate layer.

[0115] The sun protection coating 4 has IR-reflective properties in the near IR range and reflects infrared components of solar radiation. The sun protection coating 4 therefore reduces the heating of the components of the vehicle roof window located behind it (seen from the outside) - in particular also the heavily tinted first connecting layer 3a. Since the roof window is heated to a lesser extent, it can in turn emit a low level of thermal radiation. The sun protection coating 4 is a stack of thin layers, including several silver layers, which are arranged alternately with dielectric layers or layer sequences. The emissivity-reducing coating 7 has reflective properties in the mid-IR range and has a particular effect on thermal radiation. In summer, it reduces the irradiation of thermal radiation from the roof window into the vehicle interior and in winter, it reduces heat loss through the roof window.The emissivity-reducing coating 7 is also a stack of thin layers, including an ITO layer and dielectric layers.

[0116] Figure 3 shows a cross-section through a further embodiment of the vehicle roof window according to the invention. It differs from the above embodiment of Figure 2 in that the vacuum insulating glazing 5 is not arranged between the outer pane 1 and a separate inner pane 2. Instead, the inner pane 2 is part of the vacuum insulating glazing 5 and also forms its inner pane 5b.

[0117] The outer pane 1 with the sun protection coating 4 and the first connecting layer 3a are designed in the same way as in the embodiment of Figure 2.

[0118] The outer pane 5a of the vacuum insulating glazing 5 is again a chemically toughened pane made of aluminosilicate glass with a thickness of 0.7 mm. It is connected to the inner pane 2, which is also the inner pane 5b of the vacuum insulating glazing 5, via a circumferential spacer 5d and spacer columns 5e. The inner pane 2, 5b is made of thermally toughened soda-lime glass and has a thickness of 1.6 mm. The intermediate space 5c has a thickness of 0.3 mm and is evacuated. The interior-facing surface of the inner pane 2 is again provided with an emissivity-reducing coating 7.

[0119] Figure 4 shows a cross-section through a further embodiment of the vehicle roof window according to the invention. It differs from the above embodiment of Figure 2 in that the vehicle roof window comprises an aerogel layer 6 between the vacuum insulating glazing 5 and the outer pane 1.

[0120] Aerogel layer 6 further improves the thermal insulation properties of the vehicle roof window. In addition, aerogel layer 6 exhibits acoustic insulation properties, so that disturbing outside noises are less noticeable in the vehicle interior. Due to its low weight, it only slightly increases the overall weight of the vehicle roof window.

[0121] The outer pane 1 with the sun protection coating 4, the first connecting layer 3a, the vacuum insulating glazing 5, the second connecting layer 3b and the inner pane 2 with the emissivity-reducing coating 7 are designed in the same way as in the embodiment of Figure 2.

[0122] The aerogel layer 6 is connected to the outer pane 1 via the opaque first connecting layer 3a and to the vacuum insulating glazing 5 via a further connecting layer 3c. The further connecting layer 3c is also a thermoplastic layer formed from a PVB-based film with a thickness of 0.76 mm.

[0123] Aerogel layer 6, for example, has a thickness of 3 mm. It is designed as a so-called blanket, consisting of a silicate aerogel with glass fiber inserts, which provide the aerogel layer 6 with mechanical stability and flexibility.

[0124] Figure 5 shows a cross-section through a further embodiment of the vehicle roof window according to the invention. It differs from the above embodiment of Figure 4 in that the aerogel layer 6 is not arranged between the outer pane 1 and the vacuum insulating glazing 5, but rather between the vacuum insulating glazing 5 and the inner pane 2. The outer pane 1 with the sun protection coating 4, the first bonding layer 3a, the vacuum insulating glazing 5, the second bonding layer 3b, the aerogel layer 6, the further bonding layer 3c, and the inner pane 2 with the emissivity-reducing coating 7 are designed exactly as in the embodiment of Figure 4.

[0125] The aerogel layer 6 is connected to the vacuum insulating glazing 5 via the opaque second connecting layer 3b and to the inner pane 2 via the further connecting layer 3c.

[0126] Figure 6 shows a cross-section through another embodiment of the vehicle roof window according to the invention. It differs from the embodiment of Figure 3 in that the vehicle roof window comprises an aerogel layer 6 between the outer pane 1 and the vacuum insulating glazing 5.

[0127] The outer pane 1 with the sun protection coating 4, the first thermoplastic layer 3a and the vacuum insulating glazing 5, whose inner pane 5b also forms the inner pane 2 of the vehicle roof window and is provided with the emissivity-reducing coating 7, are designed in the same way as in the embodiment of Figure 3.

[0128] The aerogel layer 6 is designed in the same way as in the embodiments of Figures 4 and 5. It is connected to the outer pane 1 via the first thermoplastic layer 3a and to the vacuum insulating glazing 5, more precisely to the outer pane 3a of the vacuum insulating glazing 5, via a further thermoplastic layer 3c. The further thermoplastic layer 3c is also made of a PVB film with a thickness of 0.76 mm.

[0129] The embodiments presented here are merely examples. It is not absolutely necessary for the opacity of the vehicle roof window to be provided by the first bonding layer 3a. Alternatively, the outer pane 1, the second bonding layer 3b, the inner pane 2, or, if present, the aerogel layer 6 could also be opaque. Alternatively, at least one pane 5a, 5b of the vacuum insulating glazing 5 could also be opaque. It is also possible for several elements of the vehicle roof window to be opaque, for example, the outer pane 1 and the first bonding layer 3a. Examples

[0130] The energy input through the vehicle roof window was determined through simulations. To characterize the performance, the so-called thermal transmittance coefficient, commonly referred to as the I / L value, was determined. The lower the I / L value, the lower the thermal transmittance.

[0131] There were:

[0132] Example 1 shows a vehicle roof window according to the invention with an opaque first connecting layer 3a and a vacuum insulating glazing 5 (structure according to Figure 2);

[0133] Example 2 shows a vehicle roof window according to the invention with an opaque first connecting layer 3a, a vacuum insulating glazing 5 and a 3 mm thick aerogel layer 6 (structure according to Figure 5);

[0134] Comparative example 1 a transparent vehicle roof window without vacuum insulating glazing 5 and aerogel layer 6, the intermediate layer was formed from only a single 0.76 mm thick PVB film;

[0135] Comparative example 2: a black sheet metal roof with a thickness of 20 mm.

[0136] The roof panes of Examples 1 and 2 and Comparative Example 2 were designed analogously, with the outer pane 1, the inner pane 2, the coatings 4, 5, the possible vacuum insulating glazing 5 and the connecting layers being designed in the same way.

[0137] The simulated U-values ​​are shown in Table 1. Although the inventive examples do not quite achieve the low thermal transmittance of a conventional sheet metal roof (Comparative Example 2), a significant reduction in thermal transmittance can be achieved compared to a roof pane without vacuum insulating glazing 5 (Comparative Example 1) (Example 1). The thermal transmittance is further reduced by the additional aerogel layer 6 (Example 2). Table 1

[0138] List of reference symbols:

[0139] (1) Outer pane of the vehicle roof window

[0140] (2) Inner pane of the vehicle roof window

[0141] (3a) first connecting layer

[0142] (3b) second connecting layer

[0143] (3c) further connecting layer

[0144] (4) Sun protection coating

[0145] (5) Vacuum insulating glazing

[0146] (5a) outer pane of vacuum insulating glazing 5

[0147] (5b) inner pane of vacuum insulating glazing 5

[0148] (5c) evacuated space of the vacuum insulating glazing 5

[0149] (5d) circumferential spacer of the vacuum insulating glazing 5

[0150] (5e) Spacer columns of the vacuum insulating glazing 5

[0151] (6) Aerogel layer

[0152] (7) emissivity-reducing coating (LowE coating)

[0153] X - X' intersection line

Claims

Patent claims 1. A vehicle roof window, comprising an outer pane (1) and an inner pane (2) which are joined to one another in a planar manner, wherein the vehicle roof window is opaque and wherein the vehicle roof window has a vacuum insulating glazing (5) which comprises an outer pane (5a) facing the outer pane (1) and an inner pane (5b) spaced apart from the outer pane (5a) by spacer means (5d, 5e), wherein the intermediate space (5c) between the outer pane (5a) and the inner pane (5b) is evacuated, and wherein (i) the vacuum insulating glazing (5) is embedded in the vehicle roof window between the outer pane (1) and the inner pane (2) or (ii) the inner pane (2) of the vehicle roof window forms the inner pane (5b) of the vacuum insulating glazing (5).

2. Vehicle roof window according to claim 1 according to variant (i), which comprises in the specified order: - the outer pane (1), - a first connecting layer (3a), - vacuum insulating glazing (5), - a second connecting layer (3b) and - the inner pane (2).

3. Vehicle roof window according to claim 1 according to variant (ii), which comprises in the specified order: - the outer pane (1), - a first connecting layer (3a), - the vacuum insulating glazing (5), the inner pane (5b) of which is preferably tempered.

4. Vehicle roof window according to claim 1, which comprises an aerogel layer (6) which is embedded in the vehicle roof window between the outer pane (1) and the inner pane (2) and which preferably has a thickness of 0.1 mm to 10 mm, particularly preferably of 0.5 mm to 6 mm, most particularly preferably of 1 mm to 4 mm.

5. Vehicle roof window according to claim 4 according to variant (i), which comprises in the specified order: - the outer pane (1), - a first connecting layer (3a), - the aerogel layer (6), - another connecting layer (3c), - vacuum insulating glazing (5), - a second connecting layer (3b) and - the inner pane (2), or which comprises in the specified order: - the outer pane (1), - a first connecting layer (3a), - vacuum insulating glazing (5), - a second connecting layer (3b), - the aerogel layer (6), - another connecting layer (3c) and - the inner pane (2).

6. Vehicle window according to claim 4 according to variant (ii), which comprises in the specified order: - the outer pane (1), - a first connecting layer (3a), - the aerogel layer (6), - another connecting layer (3c), - the vacuum insulating glazing (5), the inner pane (5b) of which is preferably tempered.

7. Vehicle roof window according to one of claims 2, 3, 5 or 6, wherein at least one of the connecting layers (3a, 3b, 3c) is opaque, preferably the first connecting layer (3a).

8. Vehicle roof window according to one of claims 1 to 7, wherein the outer pane (1) and / or the inner pane (2) is opaque, preferably the outer pane (1).

9. Vehicle roof window according to one of claims 1 to 8, wherein the outer pane (5a) and / or the inner pane (5b) of the vacuum insulating glazing (5) is opaque.

10. Vehicle roof window according to one of claims 1 to 9, 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.

11. Vehicle roof window according to one of claims 1 to 10, wherein the outer pane (5a) and the inner pane (5b) are made of glass and wherein - the outer pane (5a) and the inner pane (5b) have a thickness of 0.3 mm to 3 mm, preferably 0.5 mm to 1.5 mm, if the vehicle roof window is designed according to variant (i), or - the outer pane (5a) has a thickness of 0.3 mm to 3 mm, preferably 0.5 mm to 1.5 mm, if the vehicle roof pane is designed according to variant (ii).

12. Vehicle roof window according to one of claims 1 to 11, wherein the intermediate space (5c) between the outer pane (5a) and the inner pane (5b) has a thickness of 0.1 mm to 1 mm, preferably of 0.2 mm to 0.5 mm.

13. Vehicle roof window according to one of claims 1 to 12, wherein the spacing means (5d, 5e) - a circumferential spacer (5d) in an edge region between the outer disc (5a) and the inner disc (5b) and - comprise a plurality of spacer columns (5e).

14. Vehicle equipped with a vehicle roof window according to one of claims 1 to 13.

15. The vehicle of claim 14, wherein the vehicle roof window has the same color as the vehicle paint.

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