Composite pane comprising an electrically switchable mirror element and an IR-reflective film

Abstract

The invention relates to a composite pane (1) for separating an interior from an exterior. The composite pane comprises an outer pane (2) and an inner pane (3) which are firmly bonded to one another by at least one thermoplastic interlayer (4', 4', 4''). An electrically switchable mirror element (6, 13) is arranged between the outer pane (2) and the inner pane (3), an IR-reflective film (15) being arranged on the exterior-side of the mirror element (6, 13). The IR-reflective film (15) has a light transmission of between 30% and 90%.

Description

[0001] SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0002] 1

[0003] Composite pane with electrically switchable mirror element and IR reflective film

[0004] The present invention lies in the technical field of disc manufacturing and relates to a composite disc with an electrically switchable mirror element and an IR reflective film. The invention further extends to the use of the composite disc according to the invention.

[0005] The interior of a vehicle or building can heat up considerably in summer when ambient temperatures are high and there is intense direct sunlight. With CO2 emissions in mind, reducing heat buildup from direct sunlight in a vehicle or building is desirable, as this saves energy needed for cooling the interior. In electric vehicles, saving on cooling energy can also increase the vehicle's range. Infrared radiation and radiation in the visible wavelength range (light) are primarily responsible for heating the interior.

[0006] To address this problem, panes with emissivity-reducing coatings, also known as low-E coatings, are used. These coatings have reflective properties against thermal radiation. In particular, when a pane heats up significantly at high outside temperatures, the emissivity-reducing coating prevents the heat radiation emitted by the heated pane from entering the interior. It also reflects some of the sun's infrared radiation. At low outside temperatures, the coating reduces heat transfer from the heated interior through the pane to the outside environment. Overall, thermal comfort is improved by such a pane with reduced emissivity. Panes with emissivity-reducing coatings are used in the automotive sector, especially as roof panes.Suitable emissivity-reducing coatings for this purpose are known, for example, from EP2141135A1 , WO2011 / 105991 A1 , WO2013 / 131667 A1 and WO2018 / 206236 A1 .

[0007] Silver-based coatings are also used for the reflection of IR radiation, particularly in the near-infrared range. For example, in laminated glass panes, silver-based coatings are applied to the inner surface (side II) of the outer pane and emissivity-reducing coatings are applied in combination to the inner surface (side IV) of the inner pane. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0008] 2

[0009] These measures allow infrared radiation striking the laminated glass to be reflected and blocked, thus reducing the energy input into the interior. However, the complex manufacturing process for laminated glass with silver-based layers is problematic.

[0010] Besides infrared radiation, radiation in the visible wavelength range (i.e., visible light) also has a significant impact on the energy input into the interior. This is often unavoidable, as a minimum transparency of the glazing may be desirable or legally required. As is well known, approximately 44% of the energy input into an interior space can be caused by visible light. To reduce light transmission, tinted thermoplastic interlayers and / or tinted glass are used. However, tinted interlayers and tinted glass can heat up considerably through the absorption of sunlight, thus increasing the energy input into an interior space through the heat radiation they emit. As practical experience has shown, tinted elements can sometimes become so hot that contact with them can cause burns.To improve the light-reflecting properties of laminated glass, the use of electrically switchable, light-reflecting functional films would also be possible.

[0011] In general, light-reflecting coatings have the fundamental disadvantage of causing a certain degree of light reflection on the glass, both from the outside and / or inside, especially at shallow angles of reflection. This can lead to disruptive effects. For example, when a laminated glass is used as a roof window in a vehicle, the display of the navigation system or other electronic displays can be reflected on the roof window from the inside, which can be distracting for passengers in the back seat. From the outside, light reflections can obstruct, distract, or irritate other road users, which can negatively impact road safety.

[0012] DE 1596815 A1 , JP 2006106343 A, WO 2023 / 213621 A1 and JP 2006267670 A each show a composite disc with an electrically switchable mirror element.

[0013] In contrast, the object of the present invention is to avoid the aforementioned disadvantages and to provide an improved laminated glass pane that reduces energy input into the interior and also results in lower light reflection on the exterior, and optionally also on the interior. Furthermore, the laminated glass pane is to be made of SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0014] 3. A cost-effective, industrially applicable process can be provided, whereby the composite disc should be of high quality and stable over the long term.

[0015] These and other problems are solved according to the invention by a composite disk and the use of a composite disk as defined in the independent claims. Preferred embodiments are described in the dependent claims.

[0016] The invention relates to a composite pane designed for installation in an opening of a vehicle or building and serving to separate an interior space from an exterior space – also referred to as the external environment. The composite pane comprises an outer pane with a surface facing the exterior (side I) and a surface facing the interior (side II), as well as an inner pane with a surface facing the exterior (side III) and a surface facing the interior (side IV).

[0017] As described above, the outer pane and the inner pane each have an outer surface, i.e., an outer face, and an inner surface, i.e., an inner face, and a circumferential side edge running between them. For the purposes of the invention, the term "outer surface" refers to the main surface intended to face the outside (the external environment) when installed. For the purposes of the invention, the term "inner surface" refers to the main surface intended to face the interior when installed. In the composite pane according to the invention, the inner surface of the outer pane and the outer surface of the inner pane face each other. The radiation that enters the interior from the outside through the composite pane during the intended use of the invention consists predominantly of solar radiation.

[0018] The outer and inner panes are firmly bonded together by at least one thermoplastic interlayer. Furthermore, the laminated pane has an electrically switchable mirror element with light-reflecting properties between the outer and inner panes. This mirror element reflects light incident on or into the laminated pane from the external environment (i.e., light incident on or entering the laminated pane from the outside through the outer surface of the outer pane), i.e., radiation in the visible wavelength range. The electrically switchable mirror element can be used for this purpose between a light- SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0019] 4. The reflective state and a non-reflective state can be electrically switched, for example by applying a corresponding operating voltage.

[0020] The mirror element can typically also reflect light incident on the laminated pane from the interior, whereby, according to the invention, the light incident from the external environment is essential for reducing the energy input into the interior. The mirror element is suitable and designed to reflect light incident on it from the external environment. In other words, the mirror element serves to reflect light incident on it from the external environment. The electrically switchable mirror element advantageously reduces the energy input into the interior from light in the visible wavelength range. This reduces the energy required to cool the interior separated by the laminated pane.

[0021] The laminated glass pane can be divided by the electrically switchable mirror element into a first region containing the outer pane on the side of the mirror element facing the outside, and a second region containing the inner pane on the side facing the inside. The designation of the two regions of the laminated glass as "first region" and "second region" serves only for ease of distinction. The first region can also be referred to as the outer region, and the second region as the inner region of the laminated glass. The first region comprises all components of the laminated glass on the side of the mirror element facing the outside environment, with the exception of an opaque masking layer (black print). Similarly, the second region comprises all components of the laminated glass on the side of the mirror element facing the inside.

[0022] On the exterior side facing the mirror element, i.e., in the first area of ​​the laminated glass, an IR reflective film is arranged, which has a light transmission between 30% and 90%. In other words, the IR reflective film is arranged on the exterior side facing the electrically switchable mirror element. This film has a light transmission between 30% and 90% for light incident on the laminated glass from the exterior. The IR reflective film is also referred to as an IR-reflective film. The IR reflective film is at least partially reflective for IR radiation, in particular for IR radiation incident on the IR reflective film from the exterior. The IR reflective film can, for example, have a light transmission of more than 10%, more than 20%, more than 30%, more than 40%, more than 50%, more than 60%, more than 70%, SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0023] 5. Reflect more than 80% or more than 90% of the incoming IR radiation from the outside. The specified reflectance values ​​may refer to near-infrared or the entire infrared range.

[0024] At the same time, the IR reflective film is partially transparent to visible light, so that some of the light incident on the laminated glass from the outside (in the visible wavelength range) is reflected by the switchable mirror element after passing through the IR reflective film, when the mirror element is in the reflective state. This reflection at the mirror element directs the visible light towards the outside of the laminated glass. After passing through the IR reflective film again, the visible light exits the laminated glass into the outside. However, the IR reflective film is only partially transparent to light; that is, as it passes through the IR reflective film, some of the light is absorbed and / or reflected.

[0025] In the composite disc according to the invention, the light transmission of the IR reflective film is in the range of 30% to 90%. "Light" or "visible light" is understood to mean the visible spectral range from 380 nm to 780 nm.

[0026] The specified values ​​for the visible light transmission through the IR reflective film refer to light incident on the laminated glass or the IR reflective film from the outside. The total light transmission (TL) of the laminated glass, of a single pane of the laminated glass, or of the IR reflective film, as well as the reflected light fraction, are measured according to DIN ISO 5033 (old standard) or DIN EN ISO / CIE 11664 (new standard). The transmitted light fraction is determined in transmitted light, while the reflected light fraction is determined in reflected light. A standard light source (e.g., light source A, D65) is used under the conditions specified in the standard. The percentage of transmission is determined by calculating the ratio of the intensity of the transmitted light to the intensity of the incident light.In this method, the light source is positioned on one side of the laminated glass / disc / film, and a light sensor is placed on the other side. To determine the percentage of reflection, the ratio of the intensity of the reflected light to the intensity of the incident light is calculated. In this case, the light source and the light sensor are positioned on the same side of the laminated glass / disc / film. This allows for the determination of the light transmission or reflectivity of areas of the laminated glass, for example, SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT.

[0027] The first area or the second area of ​​the composite disk is examined in an analogous manner, whereby the area of ​​the composite disk is examined separately instead of the composite disk itself.

[0028] The IR reflective film is not completely transparent to visible light because its light transmission ranges from 30% to 90%. A portion of the visible light is therefore absorbed by the IR reflective film, thus at least partially preventing external light reflections caused by the visible light reflected from the mirror element. This eliminates, for example, a potential source of disturbance for people outside, i.e., reduces unwanted visual impairment for those outside (e.g., other road users in the case of a composite windshield, see below).

[0029] At the same time, however, the IR reflective film should not absorb too much light, because the absorbed energy, unlike the light reflected by the mirror element, leads to heating of the glass and thus generates additional energy input into the interior. The specified range for the light transmission of the IR reflective film represents a good compromise, ensuring sufficient reflection of light by the mirror element to reduce energy input into the interior and sufficient absorption of light by the IR reflective film to reduce reflections from the outside.

[0030] The fact that visible light passes through the IR reflective film twice—once before reflection by the mirror element from the outside towards the interior, and again after reflection by the mirror element from the inside towards the outside—enhances the reflection-reducing effect of the IR-reflective film. This reduces external light reflections, which can be distracting for other road users. As a positive side effect, the reduction in light reflections improves the vehicle's external appearance.

[0031] IR reflective films are commercially available. The IR reflective film can, for example, be an XIR® film. The IR reflective film—especially if it is an XIR® film—can have at least a partially transparent carrier film, which acts as a substrate for a spectrally selective coating applied to one or both sides. The coating can, for example, contain metal and / or ceramic particles that reflect IR radiation. The at least partially transparent carrier film of the IR reflective film can be SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0032] 7. For example, it could be a PET film. Of course, the carrier film can also consist of other materials, especially plastics.

[0033] As mentioned at the outset, laminated glass units often use an IR-reflective coating, typically applied to the inner surface of the outer pane. If a black print is also required on this same surface, a special pretreatment of the IR-reflective coating or the glass itself can be performed to prevent the coating from reacting with the black print. This necessary pretreatment, which can involve removing the IR-reflective coating (also called stripping) and then printing and drying the black print, represents an additional, complex, and difficult-to-control step in the manufacturing process of a laminated glass unit, making its production both complex and expensive.

[0034] In other embodiments, a special black ink is used, which is formed from a printing ink that has corrosive properties towards the IR-reflective coating. However, this pretreatment weakens the structure of the disc, negatively impacting the stability and durability of the laminated disc and limiting the achievable bending geometries. Furthermore, the temperature during the application of the black ink must be kept within tight limits, complicating the manufacturing process of the laminated disc.

[0035] The printing ink with decomposing properties preferably contains at least one pigment and glass frits suspended in a liquid phase. The decomposing properties of the printing ink towards the IR-reflective coating can be achieved by the appropriate selection of the glass frits. These are preferably based on bismuth-zinc borate. To achieve the decomposing properties, the bismuth content and / or the boron content is preferably higher than in conventional glass frits. In a further embodiment, a black print made from a decomposing printing ink, known from WO 2014 / 133929 A2, can also be used.

[0036] Regardless of the specific method used to apply the black print, simultaneously providing a black print and an IR-reflective coating in a laminated glass panel is therefore associated with significant disadvantages. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0037] 8

[0038] If an IR reflective film is used in a laminated glass pane to reflect IR radiation instead of an IR-reflective coating, these disadvantages can be avoided. The IR reflective film can, for example, be attached to the outer pane and / or the mirror element by means of a thermoplastic interlayer. This simplifies the manufacturing process and improves the durability of the laminated glass because the structure of the outer pane is not weakened by a black print that could dissolve the coating.

[0039] In one embodiment of the invention, the light transmission of the IR reflective film is at least 60%, preferably at least 65%, particularly preferably at least 70%, and most preferably at least 75% or at least 80%. Additionally or alternatively, the light transmission of the IR reflective film is at most 85%, preferably at most 80%, particularly preferably at most 77.5%, and most preferably at most 75% or at most 70%. It has been shown that external light reflections are effectively reduced when the light transmission of the IR reflective film is within the specified range. Simultaneously, sufficient reflection of IR radiation by the IR reflective film and sufficient reflection of visible light by the switchable mirror element are maintained, so that the energy input into the interior is effectively reduced.

[0040] In one embodiment of the invention, the IR reflective film is arranged between the mirror element and the outer pane. Consequently, the IR reflective film faces the mirror element on the outside and the outer pane on the inside. This arrangement protects the IR reflective film from weathering and mechanical wear, resulting in a longer service life for the IR reflective film. This also improves the overall durability of the laminated glass unit.

[0041] In one embodiment of the invention, the electrically switchable mirror element is firmly connected to the IR reflective film by a thermoplastic intermediate layer. This intermediate layer secures the IR reflective film to the switchable mirror element, thereby providing it with additional stability. Because the IR reflective film is located adjacent to the mirror element, the optical properties of the IR reflective film and the mirror element can be precisely matched, taking into account the properties of the intervening thermoplastic intermediate layer. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0042] 9

[0043] Preferably, the IR reflective film is embedded between two thermoplastic interlayers, such that one thermoplastic interlayer faces the IR reflective film on the inside and the other faces the IR reflective film on the outside. This makes it particularly easy to integrate the IR reflective film into the laminated glass unit, for example by lamination.

[0044] In one embodiment of the invention, the composite pane is designed such that it has a light transmission of between 70% and 90% in the first region, i.e., on the outer side of the mirror element, and a light transmission of a maximum of 70% in the second region, i.e., on the inner side of the mirror element. For the light transmission, all components of the composite pane in the first region and the second region must be taken into account; that is, the light transmission in the first region is the total light transmission of all components of the composite pane in the first region, and the light transmission in the second region is the total light transmission of all components of the composite pane in the second region.Accordingly, the laminated pane can have different light transmissions on both sides of the electrically switchable mirror element, with the light transmission preferably being lower in the second region of the laminated pane on the interior-facing side of the mirror element than in the first region of the laminated pane on the exterior-facing side of the mirror element. The reduced light transmission in the second region of the laminated pane on the interior-facing side of the mirror element reduces unwanted interior light reflections.

[0045] Means for reducing light transmission in a laminated glass pane are known to those skilled in the art.

[0046] In one embodiment of the invention, the composite pane has, in the second area, a tinted (colored) thermoplastic intermediate layer and / or a tinted (colored) inner pane and / or a (dark) transmission-reducing coating produced by deposition to reduce light transmission. The transmission-reducing coating is preferably deposited on the inner pane.

[0047] In one embodiment of the invention, the composite pane has in the first region an untinted outer pane and / or an untinted thermoplastic intermediate layer. Advantageously, the outer pane and / or a thermoplastic intermediate layer in the first region are SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0048] 10

[0049] The first area is clear, i.e., untinted or uncolored. In an alternative embodiment, the laminated glass has a tinted outer pane and / or a tinted thermoplastic interlayer in the first area. The tinted outer pane and / or the tinted thermoplastic interlayer in the first area can, for example, have a lighter tint than the inner pane and / or the thermoplastic interlayer in the second area.

[0050] The invention advantageously reduces energy input into the interior in the visible wavelength range by means of the electrically switchable mirror element. Furthermore, the IR reflective film, which is not completely transparent to light in the visible wavelength range, reduces unwanted external light reflections. These are significant advantages of the composite glass according to the invention.

[0051] In one embodiment of the invention, the composite pane is designed such that it has a light transmission of a maximum of 50%, preferably a maximum of 30%, and particularly preferably a maximum of 10% in the second area. This measure allows, on the one hand, particularly effective reflection of light incident from the outside by means of the mirror element, and on the other hand, the significantly reduced light transmission in the second area allows for a particularly effective reduction of interior light reflections, which can, for example, prevent any impairment of the well-being of vehicle passengers.

[0052] The electrically switchable mirror element is preferably planar and extends over a substantial portion of the surface of the composite pane, for example, at least 35%, at least 40%, at least 60%, at least 70%, at least 80%, or at least 90% of the surface of the composite pane. The electrically switchable mirror element can be formed in one piece, i.e., as a single, extended element. Alternatively, the electrically switchable mirror element can be formed by a plurality of electrically switchable mirror element segments. The mirror element segments can be distributed along the surface of the composite pane. Adjacent mirror element segments can be spaced apart from one another and / or abutting one another. Some adjacent mirror element segments can be abutting one another, while other adjacent mirror element segments are spaced apart from one another.SAI NT-GOBAI N SECURIT FRANCE 2024292-WO-PCT.

[0053] 1 1

[0054] The electrically switchable mirror element is preferably designed such that it can be switched between a non-reflective (light) state and a reflective (light) state by applying a corresponding operating voltage. Advantageously, the electrically switchable mirror element is designed such that at least 35%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the incident (visible) light is reflected when the mirror element is switched to the reflective (light) state. For the purposes of the present invention, a "reflective state" is also understood to mean a semi-reflective state in which only a portion of the incident visible light is reflected.The switching of the mirror element between the non-reflective and the reflective state can be done discretely, for example when a certain threshold for the operating voltage is exceeded, or continuously, for example when the reflectance of the mirror element changes in a certain ratio to the operating voltage.

[0055] Preferably, the electrically switchable mirror element is in a reflective state when no or a low operating voltage is applied and switches to the non-reflective state when a suitable operating voltage is applied. This has the advantage that the mirror element does not require any electrical energy to reflect light. Especially in summer, when a large amount of light strikes a vehicle or building, the energy required for cooling the interior is particularly high. Because no energy is required to operate the mirror element in its reflective state, the already high energy requirement for cooling is not further increased by the energy needed to operate the mirror element. On the contrary, the energy requirement is actually reduced, since reflecting light in the visible wavelength range reduces the energy input into the interior and thus also reduces the energy required for cooling the interior.

[0056] Electrically switchable mirror elements are known per se to those skilled in the art. In one embodiment of the invention, the electrically switchable mirror element is a prefabricated electrically switchable functional element, i.e., not a coating, which is designed such that it can be electrically switched to a non-reflective (light) state or a reflective (light) state by applying a corresponding operating voltage. Such electrically switchable functional elements are typically in film form and can be readily laminated into a composite panel. The electrically switchable functional element or functional film can, for example, be arranged in a thermoplastic film that surrounds the functional element in a frame-like manner, similar to a passe-partout, to achieve local SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0057] 12

[0058] To avoid height differences in the laminate and unwanted forces acting on the electrically switchable functional element. This design can also be referred to as picture frame technology. Prefabricated, electrically switchable functional elements based on liquid crystals in foil form are commercially available (e.g., from Kent Optronics).

[0059] In one embodiment of the invention, the electrically switchable functional element is arranged in film form between a thermoplastic intermediate layer in the first region and a thermoplastic intermediate layer in the second region, wherein the thermoplastic intermediate layer in the second region preferably has a tint. Preferably, the thermoplastic intermediate layer in the first region has no tint or at least a lesser tint than the thermoplastic intermediate layer in the second region. Thus, the electrically switchable functional element is embedded between two thermoplastic intermediate layers of different tints, and the electrically switchable functional element can additionally be arranged in a frame-shaped surrounding thermoplastic intermediate layer.This measure has the advantage that the thermoplastic intermediate layer used to laminate the electrically switchable functional element in the second area simultaneously reduces light transmission in that area. Additionally, the inner pane can be tinted, while the outer pane is clear or at least has a lighter tint than the inner pane.

[0060] In one embodiment of the invention, the electrically switchable mirror element is in the form of an electrically switchable functional coating, which is designed such that it can be switched to a non-reflective (light) state or a reflective (light) state by applying a corresponding operating voltage. Such electrically switchable functional coatings are known in the trade (see, e.g., AIST, Japan) and are based, for example, on a Mg-Ni alloy as the electrically switchable mirror layer.

[0061] Preferably, the electrically switchable functional coating is applied to the inner pane by deposition, preferably to the surface of the inner pane facing the outside (side III). Preferably, a (dark) transmission-reducing coating is applied to the inner side of the electrically switchable functional coating. Preferably, the electrically switchable functional coating is arranged on the transmission-reducing coating. Preferably, the transmission-reducing coating is on the surface facing the outside (side SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0062] 13

[0063] III) the inner disc is deposited and the electrically switchable functional coating is deposited on the transmission-reducing coating.

[0064] The transmission-reducing coating is based, for example, on titanium nitride and / or titanium carbide, or is an amorphous carbon layer.

[0065] The transmission-reducing coating is typically applied to the entire surface of the inner pane, possibly with the exception of a circumferential edge area and / or other locally limited areas that may, for example, serve for data transmission. The coated area of ​​the inner pane's surface is preferably at least 90%.

[0066] In one embodiment, an emissivity-reducing coating is applied to the inner pane, preferably to the surface of the inner pane facing the interior (side IV). This advantageously further reduces the energy input into the interior from IR radiation. The emissivity-reducing coating can also be referred to as a heat-radiation-reflecting coating or a low-E coating. Emissivity is the measure that indicates how much heat radiation the pane emits into an interior space in its installed position compared to an ideal heat radiator (i.e., a black body). The emissivity-reducing coating serves to prevent heat radiation from entering the interior space (IR components of solar radiation and, in particular, the thermal radiation of the laminated pane itself) and also from radiating heat out of the interior space.It exhibits reflective properties towards infrared radiation, especially towards thermal radiation in the spectral range of 5 - 50 pm (see standard DIN EN 12898:2019-06).

[0067] Advantageously, the emissivity-reducing coating contains at least one layer of a transparent conductive oxide (TCO), for example based on indium tin oxide (ITO), indium zinc mixed oxide (IZO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), fluorine-doped tin oxide (FTO, SnO2:F), antimony-doped tin oxide (ATO, SnO2:Sb) or titanium nitride (TiN).

[0068] The emissivity-reducing coating is typically applied to the entire surface of the inner pane, possibly with the exception of a circumferential edge area and / or other locally limited areas that may, for example, serve for data transmission. The coated area of ​​the inner pane's surface is preferably at least 90%. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0069] 14

[0070] Additionally or alternatively, an IR-reflective coating can be applied to the surface of the outer pane facing the interior, which can (further) reduce the energy input into the interior.

[0071] The panes of the laminated glass unit (outer pane and / or inner pane) can, in principle, have any chemical composition known to a person skilled in the art. The two panes preferably contain or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, or aluminosilicate glass. It is also conceivable that the two panes contain or consist of a clear plastic, preferably a rigid clear plastic, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride, and / or mixtures thereof.

[0072] In one embodiment of the invention, the laminated glass pane contains or consists of glass. The thickness of each individual pane of the laminated glass pane can vary widely and be adapted to the requirements of the specific application. Preferably, panes with standard thicknesses of 0.5 mm to 25 mm and more preferably from 0.5 mm to 5 mm are used. The size of the panes can vary widely and depends on their intended use. The laminated glass pane can have any three-dimensional shape and be planar or curved in one or more directions in space.

[0073] The two panes of the laminated glass are firmly bonded together by at least one thermoplastic interlayer, which is formed by laminating the two panes with one or more adhesive films. Each adhesive film can contain or consist of polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), thermoplastic polyurethane (TPU), polyethylene terephthalate (PET), or mixtures, copolymers, or derivatives thereof, particularly preferably PVB. The thickness of an adhesive film is preferably from 0.2 mm to 1 mm, for example, 0.38 mm or 0.76 mm.

[0074] For laminating the composite pane, methods known per se for the lamination of composite panes can be used. Vacuum lamination is particularly well-known and common, in which lamination takes place in a heated and evacuated chamber within, for example, about 60 minutes at a reduced pressure of, for example, 0.01 mbar to 800 mbar and temperatures of, for example, 80°C to 170°C. Vacuum bag or SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0075] 15

[0076] Vacuum ring processes, for example, operate at approximately 200 mbar and temperatures between 130 °C and 145 °C. In roller lamination, pressing takes place in a calender between at least one pair of rollers or a single roller and a solid base. The temperature during the pressing process is, for example, between 40 °C and 150 °C. This is well-known in the field, so it does not require further discussion here. Lamination of the composite disc in an autoclave under overpressure conditions is also possible.

[0077] The invention also extends to the use of the composite disc according to the invention in buildings or in means of transport for traffic on land, in the air or on water, in particular in motor vehicles, for example as a roof disc, rear disc and / or side disc.

[0078] The various embodiments of the invention can be implemented individually or in any combination. In particular, the features mentioned above and explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention.

[0079] The invention is explained in more detail below with reference to exemplary embodiments, with reference to the accompanying figures. These show, in a simplified representation not to scale:

[0080] Fig. 1 shows a schematic cross-sectional view of a first embodiment of the composite disc according to the invention.

[0081] Fig. 2 shows a schematic cross-sectional view of a second embodiment of the composite disc according to the invention, and

[0082] Fig. 3 shows a spectral diagram of the reflectance and transmittance for an IR reflection film of an embodiment of a composite disc according to the invention.

[0083] With reference to Figures 1 and 2, two different embodiments of the composite disc according to the invention, which is collectively designated by the reference numeral 1, are explained. To improve readability, similar or identical elements of a composite disc 1 SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0084] 16 are numbered with the same reference numbers, regardless of which embodiment the elements are assigned to.

[0085] Let us first consider Figure 1. Figure 1 illustrates, by means of a schematic cross-sectional view, a first embodiment of the composite pane 1, which is intended to be inserted into an opening of a motor vehicle or building, where it separates an interior space INT from an exterior space AMB. The composite pane 1 is, for example, the roof pane of a motor vehicle.

[0086] The laminated glass 1 comprises an outer pane 2 and an inner pane 3, which are bonded together by four thermoplastic interlayers 4, 4', 4", 4''. The outer pane 2 has a surface I facing the outside AMB and a surface II facing the inside INT. Similarly, the inner pane 3 has a surface III facing the outside AMB and a surface IV facing the inside INT. The outer surface I of the outer pane 2 and the inner surface IV of the inner pane 3 are the exposed surfaces of the laminated glass 1, with surface I facing the outside environment / the outside AMB in the installed position and surface IV facing the inside INT of the vehicle or building. The outer pane 2 and the inner pane 3 are, for example, panes of soda-lime glass, each with a thickness of 2.1 mm. Preferably, the outer pane 2 is not tinted.The intermediate layers 4, 4', 4", 4'' are formed, for example, by films made of polyvinyl butyral (PVB).

[0087] The laminated glass pane 1 contains an electrically switchable mirror element between the outer pane 2 and the inner pane 3. This mirror element is in the form of an electrically switchable functional film 6 based on liquid crystals, which can be switched to a non-reflective or a reflective state by applying a suitable operating voltage. Preferably, the electrically switchable functional film 6 is in a reflective state in its initial state and can be switched to a non-reflective state by applying a suitable operating voltage. The laminated glass pane 1 can be conceptually divided, at least theoretically, into a first region 7 and a second region 8 by means of the electrically switchable functional film 6. The first region 7 is located on the side of the electrically switchable functional film 6 facing the outside AMB, and the second region 8 is located on the side of the electrically switchable functional film 6 facing the inside INT.SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT.

[0088] 17

[0089] The electrically switchable functional film 6 is embedded between the two thermoplastic intermediate layers 4, 4', and is additionally surrounded by a thermoplastic intermediate layer 4" in the manner of a passe-partout or frame. For this purpose, the electrically switchable functional film 6 is inserted into an opening or perforation in the surrounding intermediate layer 4" (intermediate film). It is understood that the thermoplastic intermediate layers 4, 4', 4" fuse together during lamination. These are provided in film form prior to lamination in the usual manner. The electrically switchable functional film 6 has two connecting electrodes (busbars) 10 through which an operating voltage can be applied to switch the functional film 6.

[0090] The thermoplastic intermediate layer 4 is located in the first area 7, the thermoplastic intermediate layer 4' in the second area 8. Between the electrically switchable functional film 6 and the material of the thermoplastic intermediate layers 4, 4', 4" is sealing material 11, which prevents diffusion processes.

[0091] The switchable mirror element, designed here as functional film 6, is configured to reflect incident light in the visible wavelength range while in its reflective state. This prevents light from the exterior space 6 from entering the interior space INT, thus preventing it from entering the laminated glass pane 1.

[0092] The laminated glass pane 1 also includes an IR reflective film 15 (also called IR-reflective film 15), which is arranged in the first region 7, i.e., on the outside side of the functional film 6, in particular between the functional film 6 and the outer pane 2. The IR reflective film 15 reflects IR radiation incident on the laminated glass pane from the outside AMB, thus preventing it from entering the second region 8 of the laminated glass pane 1 or the interior INT of the vehicle or building.

[0093] In combination, the switchable mirror element reduces the amount of visible light entering the interior space INT, while the IR reflective film 15 prevents IR radiation from entering the interior space INT. This reduces the energy entering the interior space INT from solar radiation and light. Consequently, the energy required to cool the interior space INT at high outside temperatures is also reduced.

[0094] At the same time, the IR reflective film 15 is not completely transparent to light. For example, the light transmission (TL) of the film 15 can be in the range of 30% to 90%. Preferably SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0095] For example, the TL of the IR reflective foil 15 could be 70%, 75%, or 80%. Because the light reflected by the mirror element passes through the IR reflective foil 15 both before and after reflection by the mirror element, external light reflections are reduced. This at least partially eliminates a potential source of disturbance for people in the outdoor area.

[0096] The IR reflection film 15 is arranged between two thermoplastic intermediate layers 4"' and 4, by means of which it is held in position and mechanically stabilized.

[0097] Optionally, the laminated pane 1 can have an IR-reflective coating 9 on the interior surface II of the outer pane 2, which is, for example, silver-based. Areas without coating or uncoated areas are possible to allow the transmission of radio signals.

[0098] An optional emissivity-reducing coating 5 (low-E coating) is applied to the exposed, interior-facing surface IV of the inner pane 3. The emissivity-reducing coating 5 improves thermal comfort in the interior INT by reflecting heat radiation from the pane and portions of solar radiation at high outside temperatures, and by reducing heat loss from the interior INT at low outside temperatures. The emissivity-reducing coating 5 is based, for example, on ITO.

[0099] In the embodiment shown in Figure 1, the interior-facing second region 8 of the laminated glass 1 is configured such that the laminated glass in the second region 8 has a light transmission of a maximum of 70%. Preferably, the light transmission in the second region 8 is lower than the light transmission in the first region 7. One way to achieve the low light transmission in the second region 8 is to tint the thermoplastic interlayer 4' in the second region 8 to a correspondingly high degree. The thermoplastic interlayers 4, 4''' in the first region 7, on the other hand, are either untinted (clear) or have at least a lower tint than the thermoplastic interlayer 4' in the second region 8. It would also be possible for the inner pane 3 to have a corresponding tint, either additionally or alternatively. The outer pane 2 is clear and has no tint.

[0100] In the embodiment shown in Figure 1, the composite pane 1 is further provided with a black print 12 on the inner surface II of the outer pane 2, which conceals underlying connections, sealing material 11, and the like. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0101] 19

[0102] The thermoplastic intermediate layer 4'' structurally separates the outer pane 2, or the black print 12 attached to it, and the IR reflective film 15. This also offers the advantage that, if the laminated pane 1 only has an IR reflective film 15 and no IR-reflective coating 9, the manufacturing of the laminated pane 1 is simplified, since no additional manufacturing steps for pretreating the outer pane 2 are required when applying the black print 12, nor is the structure of the outer pane 2 weakened by a black print that degrades the IR-reflective coating.

[0103] Figure 2 illustrates a second embodiment of the composite disk 1 according to the invention by means of a schematic cross-sectional view. To avoid unnecessary repetition, only the differences from the first embodiment explained in connection with Figure 1 are described; otherwise, reference is made to the above explanations.

[0104] Accordingly, instead of the electrically switchable functional film 6, an electrically switchable functional coating 13 is provided for the inner pane 3. The electrically switchable functional coating 13 is deposited on the surface III of the inner pane 3 facing the outer space AMB, for example by sputtering. Between the electrically switchable functional coating 13 and the inner pane 3 is a transmission-reducing coating 14, which is based, for example, on titanium nitride and / or titanium carbide or is an amorphous carbon layer. During manufacturing, the transmission-reducing coating 14 is first deposited on the surface III of the inner pane 3 facing the outer space AMB, for example by sputtering, followed by the deposition of the electrically switchable functional coating 13 onto the transmission-reducing coating 14, for example by sputtering.Analogous to the electrically switchable functional film 6, the electrically switchable functional coating 13 can be switched into a light-non-reflective state or into a light-reflecting state by applying a suitable operating voltage.

[0105] In the embodiment shown in Figure 2, the outer pane 2 and the inner pane 3 are connected to each other only by a clear (untinted) intermediate layer 4 and a clear (untinted) intermediate layer 4'''. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0106] 20

[0107] An IR reflective film 15 is arranged between the intermediate layers 4 and 4'', which can, for example, have the features described in connection with the first embodiment. The IR reflective film 15 has several film segments. The segments of the IR reflective film 15 can, for example, be arranged such that—as shown in the figure—IR radiation incident on the laminated pane 1 from the outside space AMB is reflected either by the IR reflective film 15 or by an IR-reflective coating 9 provided on the inner surface II of the outer pane 2. However, a different arrangement of the film segments 15 can also be chosen, and it is not absolutely necessary for an IR-reflective coating 9 to be present in the laminated pane 1.

[0108] The foil segments are enclosed by the intermediate layers 4 and 4''', thus fixing their position within the laminated sheet 1. Segmented application and arrangement of the IR-reflective foil 15 offers the advantage of reducing the overall consumption of IR-reflective foil 15 compared to full-surface application. Furthermore, it allows for the definition of zones within the laminated sheet 1 where the laminated sheet 1 exhibits IR-reflective properties, and other zones that are transparent to IR radiation. The same applies to the local adjustment of the transmission of the laminated sheet 1.

[0109] In the embodiment shown in Figure 2, the composite pane 1 has a maximum light transmission of 70% in the second area 8. This is achieved by the transmission-reducing coating 14. Alternatively or additionally, the inner pane 3 can have a corresponding tint.

[0110] The composite pane 1 of the embodiments shown in Figures 1 and 2 can be made to have light-reflecting properties, so that a relatively large proportion of the incident sunlight is reflected. Undesired interior reflections can be reduced by the significant transmission reduction in the second area 8. Exterior reflections are reduced by the transmission reduction provided by the IR-reflective film 15. The total heat gain from radiation in the visible and non-visible wavelength range (TTS) of the composite pane 1 can, for example, be approximately 6%, which corresponds to a reduction of approximately 50% compared to conventional roof windows. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT

[0111] 21

[0112] The electrically switchable functional film 6 and the electrically switchable functional coating 13 can be segmented. This simplifies the production of the composite disc 1, improves the mechanical stability, and allows for simpler cable routing when connecting the mirror element segments of the switchable functional film 6 and the electrically switchable functional coating 13.

[0113] Figure 3 illustrates the dependence of the transmittance and reflectance of an IR reflective foil 15 on the wavelength of the incident radiation (especially light and IR radiation). The wavelength of the radiation in nm is plotted on the abscissa of the diagram. Percentage values ​​for the reflectance and transmittance are plotted on the ordinate of the diagram. The solid curve, marked with crosses, shows how the transmittance of the foil 15 changes with wavelength. The dashed curve shows how the reflectance changes when radiation with a different wavelength strikes the IR reflective foil 15.

[0114] The diagram shows that the IR reflective foil 15 has a transmission between 70% and 85% for light in the visible wavelength spectrum, i.e., from approximately 380 nm to 780 nm. At the same time, only a small proportion of the visible light is reflected, for example, less than 10%. For IR rays with a wavelength > 780 nm, especially in the near-infrared spectrum, the IR reflective foil 15 is almost fully reflective; for example, the foil 15 exhibits a reflection for near-infrared radiation in the range between 90% and 98%.

[0115] From the above, it follows that the invention provides a novel laminated glass panel 1 which reduces the energy input into the interior INT of a motor vehicle or building through the reflection of visible light and infrared radiation, and also reduces adverse effects with regard to external reflections and optionally also with regard to internal reflections. The laminated glass panel 1 can be easily manufactured using standard methods in the industrial mass production of laminated glass panels 1. The laminated glass panel 1 can be produced simply, cost-effectively, and with high quality. SAINT-GOBAIN SEKURIT FRANCE 2024292-WO-PCT

[0116] 22

[0117] Reference symbol list

[0118] 1 composite disc

[0119] 2 Outer pane

[0120] 3 inner disc

[0121] 4, 4', 4", 4"' Intermediate layer

[0122] 5 emissivity-reducing coating

[0123] 6 Functional slide

[0124] 7 first area

[0125] 8 second area

[0126] 9 IR-reflective coating

[0127] 10 Connecting electrode

[0128] 11 Sealing material

[0129] 12 Black print

[0130] 13 Functional coating

[0131] 14 transmission-reducing coating

[0132] 15 IR reflective foil

[0133] I Surface of the outer pane facing the outside AMB 2

[0134] II Surface of the outer pane facing the interior INT 2

[0135] III Surface of the inner pane facing the outside AMB 3

[0136] IV Surface of the inner pane facing the interior INT 3

[0137] INT Interior

[0138] AMB outdoor area

Claims

SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT 23 Patent claims 1. Composite pane (1) for separating an interior space (INT) from an exterior space (AMB), comprising an outer pane (2) and an inner pane (3) which are firmly connected to each other by at least one thermoplastic intermediate layer (4, 4', 4", 4''), wherein an electrically switchable mirror element (6, 13) is arranged between the outer pane (2) and the inner pane (3), wherein an IR reflective film (15) is arranged on the exterior side of the electrically switchable mirror element (6, 13) and the IR reflective film (15) has a light transmission between 30% and 90%.

2. Composite disc (1) according to claim 1, wherein the light transmission of the IR reflective film (15) is at least 60%, preferably at least 65%, particularly preferably at least 70%, and / or the light transmission of the IR reflective film (15) is at most 85%, preferably at most 80%, particularly preferably at most 77.5%, and most preferably at most 75%.

3. Composite disc (1) according to one of the preceding claims, wherein the IR reflective film (15) is arranged between the electrically switchable mirror element (6, 13) and the outer disc (2).

4. Composite disc (1) according to one of the preceding claims, wherein the electrically switchable mirror element (6, 13) is firmly connected to the IR reflection film (15) by a thermoplastic intermediate layer (4).

5. Composite pane (1) according to one of the preceding claims, wherein the composite pane (1) is designed such that in a first area (7) on the side of the electrically switchable mirror element (6, 13) facing the outside space (AMB) it has a light transmission between 70% and 90% and in a second area (8) on the side of the electrically switchable mirror element (6, 13) facing the inside space (INT) it has a light transmission of a maximum of 70%, preferably a maximum of 50%, particularly preferably a maximum of 30%, most preferably a maximum of 10%. SAI NT-GOBAI N SEKURIT FRANCE 2024292-WO-PCT 24 6. Composite disc (1) according to claim 5, which in the second area (8) has a tinted inner disc (3), a tinted thermoplastic intermediate layer (4') and / or a transmission-reducing coating (14).

7. Composite pane (1) according to one of the preceding claims, wherein the outer pane (2) and / or a thermoplastic intermediate layer (4, 4'') arranged between the outer pane (2) and the electrically switchable mirror element (6, 13) is not tinted.

8. Composite disc (1) according to one of the preceding claims, wherein at least 35%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, or at least 90% of the incident light is reflectable by means of the electrically switchable mirror element (6, 13).

9. Composite disc (1) according to one of the preceding claims, wherein the electrically switchable mirror element (6, 13) is an electrically switchable functional film (6) which can be switched to a non-light-reflecting state or to a light-reflecting state.

10. Composite disc (1) according to claim 9, wherein the electrically switchable functional film (6) is arranged between an outer-side thermoplastic intermediate layer (4) and an inner-side thermoplastic intermediate layer (4'), wherein the inner-side thermoplastic intermediate layer (4') has a tint.

11. Composite disc (1) according to one of claims 1 to 8, wherein the electrically switchable mirror element (6, 13) is an electrically switchable functional coating (13) which can be switched to a non-light-reflecting state or to a light-reflecting state.

12. Composite disc (1) according to claim 11, wherein a transmission-reducing coating (14) is applied on the interior side of the electrically switchable functional coating (13).

13. Composite disc (1) according to claim 12, wherein the electrically switchable functional coating (13) is on the transmission-reducing coating (14) SAINT-GOBAIN SEKURIT FRANCE 2024292-WO-PCT 25 is arranged, which is preferably based on titanium nitride and / or titanium carbide or is an amorphous carbon layer.

14. Composite pane (1) according to one of the preceding claims, wherein the outer pane (2) and the inner pane (3) each have a surface facing the outside (AMB) and a surface facing the interior (INT), wherein an emissivity-reducing coating (5) is applied to the surface (IV) of the inner pane (3) facing the interior (INT) and / or an IR-reflecting coating is applied to the surface (II) of the outer pane (2) facing the interior (INT).

15. Use of the composite window (1) according to any of the preceding claims in buildings or in means of transport for traffic on land, in the air or on water, in particular in motor vehicles, for example as a roof window, rear window and / or side window.

Images