Laminated sheet with electrically switchable mirror elements and reduced light transmittance

Abstract

The invention relates to a laminated sheet (1) for separating the interior from the exterior environment, comprising an outer sheet (2) and an inner sheet (3) which are firmly connected to each other by means of at least one thermoplastic intermediate layer (4, 4 ', 4' '), where the outer sheet (2) and the inner sheet (3) each have a surface facing the exterior environment and a surface facing the interior, where the thermoplastic intermediate layer (4, 4', 4 '') is arranged between the outer sheet (2) and the inner sheet (3), and where the thermoplastic intermediate layer (4, 4 ', 4' ') is arranged between the outer sheet (2) and the inner sheet (3). An electrically switchable mirror element (6, 13) is arranged between the outer sheet and the inner sheet, the laminated sheet being designed such that it has a light transmission of greater than 70% in a first region (7) on the side of the mirror element (6, 13) facing the outside environment and a light transmission of at most 70% in a second region (8) on the side of the mirror element (6, 13) facing the inside.

Description

Technical Field

[0001] This invention relates to the technical field of sheet (or pane) manufacturing, and specifically to a laminated sheet having an electrically switchable mirror element and reduced light transmittance. The invention further extends to the application of the laminated sheet according to the invention. Background Technology

[0002] In summer, the interiors of vehicles and buildings heat up significantly under high ambient temperatures and intense direct solar radiation. Reducing heating caused by direct solar radiation in vehicles and buildings is desirable in the context of reducing CO2 emissions, as this saves energy used for cooling the interior. In electric vehicles, this saving can also increase driving range. Infrared radiation and radiation in the visible wavelength range (light) are primarily responsible for heating the interior.

[0003] To address this issue, sheets with a reduced emissivity coating are known to be used. This coating, also known as a low-emissivity coating, has reflective properties relative to thermal radiation. At high external temperatures, the reduced emissivity coating prevents thermal radiation emitted from the heated sheet from penetrating the interior. Furthermore, a portion of infrared solar radiation is reflected. At low external temperatures, the coating reduces heat transfer from the heated interior through the sheet to the external environment. Overall, such sheets with reduced emissivity improve thermal comfort. Sheets with reduced emissivity coatings are used in the automotive field, particularly as roof sheets. Suitable reduced emissivity coatings for this purpose are known, for example, from EP2141135A1, WO2011 / 105991 A1, WO2013 / 131667 A1, and WO2018 / 206236 A1.

[0004] Silver-based layers are also used to reflect IR radiation, especially in the near-infrared range. For example, in laminated sheets, a silver-based layer is applied to the inner side surface (side II) of the outer sheet, combined with an emissivity-reducing layer applied to the inner side surface (side IV) of the inner sheet.

[0005] These measures allow IR radiation incident on the laminated sheet to be reflected and blocked, which reduces the energy input into the interior.

[0006] In addition to IR radiation, radiation in the visible wavelength range (i.e., light) also has a considerable influence on the energy input into the interior. This is often unavoidable because minimum transparency of the sheet to light may be desired or legally required. As is known in the art, approximately 44% of the energy input into the interior can be caused by visible light. To reduce light transmittance, colored thermoplastic interlayers and / or colored sheets are used. However, colored interlayers and colored sheets can heat up significantly due to solar radiation, and thus increase the energy input into the interior through the emitted thermal radiation. As has been shown in practice, colored elements can sometimes become so hot that contact with body parts can cause burns. To improve the light reflection properties of laminated sheets, electrically switchable light-reflective functional films may also be used.

[0007] Reducing emissivity coatings typically have the following drawback: they provide some light reflection to the inner side of the sheet, especially at shallow reflection angles. This can create a jarring effect. For example, the display of a navigation system or other electronic screen may be reflected off the top sheet, potentially interfering with passengers in the back seat. Similarly, this naturally applies to light-reflecting films.

[0008] DE 1596815 A1, JP 2006106343 A and JP 2006267670 A each disclose laminated sheets having electrically switchable mirror elements. Summary of the Invention

[0009] In contrast, the object of the present invention is to avoid the aforementioned disadvantages and provide an improved laminated sheet that reduces energy input into the interior and, moreover, causes less light reflection on the interior side. Furthermore, the laminated sheet should be available through a cost-effective, industrially applicable process, wherein the laminated sheet should be of high quality and long-term stability.

[0010] According to the proposal of the invention, these and other objectives are achieved by a laminated sheet having the features of the independent claims. Preferred embodiments are derived from the dependent claims.

[0011] The present invention proposes a laminated sheet that is configured to be installed in an opening in a vehicle or building and is used to separate the interior from the external environment.

[0012] The laminated sheet comprises: an outer sheet having a surface facing the external environment (side I) and a surface facing the interior (side II); and an inner sheet having a surface facing the external environment (side III) and a surface facing the interior (side VI). The outer and inner sheets are firmly connected to each other by at least one thermoplastic interlayer. Furthermore, the laminated sheet has an electrically switchable mirror element with light-reflecting properties between the outer and inner sheets, capable of reflecting light incident on the laminated sheet from the external environment, i.e., radiation in the visible wavelength range. The mirror element is also generally capable of reflecting light incident on the laminated sheet from the interior, wherein, according to the invention, light incident from the external environment is a key factor in reducing energy input into the interior. The mirror element is adapted and designed to reflect light incident on the mirror element from the external environment. In other words, the mirror element is used to reflect light incident on the mirror element from the external environment. Therefore, the subject matter of the invention relates to a laminated sheet having an electrically switchable mirror element for reflecting light incident from the external environment.

[0013] The laminated sheet can be divided by an electrically switchable mirror element into a first region comprising an outer sheet located on the externally facing side of the mirror element and a second region comprising an inner sheet located on the internally facing side of the mirror element. The designation of the two regions of the laminated sheet as "first region" and "second region" is merely for ease of distinction. The first region may also be referred to as the outer region of the laminated sheet, and the second region may be referred to as the inner region of the laminated sheet. The first region includes all components of the laminated sheet on the externally facing side of the mirror element, except for the opaque masking layer (black printing). Correspondingly, the second region includes all components of the laminated sheet on the internally facing side of the mirror element.

[0014] The laminated sheet according to the invention is generally designed such that it has a light transmittance greater than 70% in a first region and a maximum light transmittance of 70% in a second region. For this light transmittance, all components of the laminated sheet in both the first and second regions must be considered; that is, the light transmittance in the first region is the total light transmittance of all components of the laminated sheet in the first region, and the light transmittance in the second region is the total light transmittance of all components of the laminated sheet in the second region. Therefore, the laminated sheet has different light transmittances on both sides of the electrically switchable mirror element, wherein the light transmittance in the second region of the laminated sheet on the inward-facing side of the mirror element is lower than the light transmittance in the first region of the laminated sheet on the outward-facing side of the mirror element.

[0015] The means of reducing light transmittance in laminated sheets are known to those skilled in the art.

[0016] In one embodiment, the laminated sheet has a colored (colored) thermoplastic interlayer and / or a colored (colored) inner sheet in the second region and / or a (dark) transmission-reducing coating formed by deposition to reduce light transmittance. The transmission-reducing coating is preferably deposited on the inner sheet.

[0017] In one embodiment, the laminated sheet has an uncolored outer sheet and / or an uncolored thermoplastic interlayer in a first region. Advantageously, the outer sheet and / or thermoplastic interlayer in the first region is clear, i.e., uncolored or colorless. In an alternative embodiment, the laminated sheet has a colored outer sheet and / or a colored thermoplastic interlayer in the first region. The colored outer sheet and / or colored thermoplastic interlayer in the first region may, for example, have a lower tint (or colorfastness) than the inner sheet and / or thermoplastic interlayer in the second region.

[0018] This invention advantageously allows for a reduction in energy input into the interior in the visible wavelength range via electrically switchable mirror elements. Furthermore, the reduced light transmittance in a second region of the laminated sheet on the inward-facing side of the mirror element prevents unwanted light reflection on the inward side. These are significant advantages of the laminated sheet according to the invention.

[0019] In one embodiment of the invention, the laminated sheet is designed such that it has a light transmittance of greater than 80% in a first region and a maximum of 50%, preferably a maximum of 30%, and particularly preferably a maximum of 10% in a second region. On the one hand, this measure allows for particularly effective reflection of light incident from the outside; on the other hand, the significantly reduced light transmittance in the second region allows for particularly effective prevention of light reflection on the inner side.

[0020] In one embodiment of the invention, the laminated sheet is designed to have a total light transmittance (TL) of up to 65%, preferably up to 50%, particularly preferably up to 30%, and most particularly preferably up to 15%. For example, a dark-top sheet having TL = 7% + an IR reflective (Ag) layer + a low-emissivity layer on the side IV has a TTS of approximately 12-13% (no reflection in the visible range). TTS ( T otal T ransferred S Total solar energy (TEE) is a term used to describe the heat input caused by radiation at visible and non-visible wavelengths.

[0021] The electrically switchable mirror element is flat and extends over a large portion of the surface area of ​​the laminated sheet, such as at least 35%, at least 40%, at least 60%, at least 70%, at least 80%, or at least 90% of the surface area of ​​the laminated sheet.

[0022] The electrically switchable mirror element is designed to be able to switch between a non-reflective state (relative to light) and a reflective state (relative to light) 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. For the purposes of this invention, "reflective state" is also understood as a semi-reflective state, in which only a portion of the incident visible light is reflected.

[0023] Electrically switchable mirror elements are known to those skilled in the art. In one embodiment of the invention, the electrically switchable mirror element is a pre-fabricated electrically switchable functional element (uncoated) designed to be electrically switched to a non-reflective state (relative to light) or a reflective state (relative to light) by applying a corresponding operating voltage. Such electrically switchable functional elements are typically in film form and can be readily laminated into a laminated sheet. 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 as a decorative frame to avoid local height differences in the laminate and undesirable forces acting on the electrically switchable functional element. Pre-fabricated, electrically switchable liquid crystal-based functional elements in film form are commercially available (e.g., from Kent Optronics).

[0024] In one embodiment of the invention, an electrically switchable functional element in the form of a film is disposed between a thermoplastic interlayer in a first region and a thermoplastic interlayer in a second region, wherein the thermoplastic interlayer in the second region is colored. Advantageously, the thermoplastic interlayer in the first region is uncolored or has at least a lower coloration than the thermoplastic interlayer in the second region. Thus, the electrically switchable functional element is embedded between two differently colored thermoplastic interlayers, wherein the electrically switchable functional element can be additionally disposed within a frame-shaped surrounding thermoplastic interlayer. This measure has the advantage that the thermoplastic interlayer used to laminate the electrically switchable functional element in the second region simultaneously reduces the light transmittance in the second region. Additionally, the inner sheet may be colored, while the outer sheet is clear or at least has a lower coloration than the inner sheet.

[0025] In one embodiment of the invention, the electrically switchable mirror element is in the form of an electrically switchable functional coating designed to allow it to be switched to a non-reflective state (relative to light) or a reflective state (relative to light) by applying a corresponding operating voltage. Such electrically switchable functional coatings are known in the art (see, for example, AIST, Japan), and are based, for example, on a Mg-Ni alloy as the electrically switchable mirror layer.

[0026] Preferably, the electrically switchable functional coating is applied to the inner sheet by deposition, preferably onto the outer-facing surface (side III) of the inner sheet. Preferably, a (dark) transmittance reducing coating is applied to the inner side of the electrically switchable functional coating. Preferably, the electrically switchable functional coating is disposed on the transmittance reducing coating. Preferably, the transmittance reducing coating is deposited on the outer-facing surface (side III) of the inner sheet, and the electrically switchable functional coating is deposited on the transmittance reducing coating.

[0027] Transmission-reducing coatings include, for example, those based on titanium nitride and / or titanium carbide, or amorphous carbon layers.

[0028] The transmission-reducing coating is typically applied to the entire surface area of ​​the inner sheet, except for peripheral edge regions and / or other locally defined areas that may be used for data transmission, for example. Preferably, at least 90% of the surface of the inner sheet is coated.

[0029] In one embodiment, an emissivity-reducing coating is applied to the inner sheet, preferably to the inward-facing surface (side IV) of the inner sheet. This advantageously reduces the energy input into the interior caused by IR radiation. The emissivity-reducing coating can also be referred to as a heat-reflective coating or a low-emissivity coating. Emissivity is a measure of how much thermal radiation a sheet emits into the interior in its mounting position, compared to an ideal thermal emitter (i.e., a blackbody). The emissivity-reducing coating functions to prevent heat from entering the interior (the IR component of solar radiation and, in particular, thermal radiation from the laminated sheet itself) and also to prevent heat from radiating outwards from the interior. It has reflective properties relative to infrared radiation, especially relative to thermal radiation in the spectral range of 5-50 µm (see standard DIN EN 12898:2019-06).

[0030] Advantageously, the emissivity-reducing coating comprises at least one transparent conductive oxide (TCO) layer, such as 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) or antimony-doped tin oxide (ATO, SnO2:Sb).

[0031] The emissivity-reducing coating is typically applied to the entire surface area of ​​the inner sheet, except for peripheral edge regions and / or other locally defined areas, which may be used for data transmission, for example. Preferably, at least 90% of the surface of the inner sheet is coated.

[0032] Alternatively or alternatively, the IR reflective coating is preferably applied to the inward-facing surface of the outer sheet, thereby (further) reducing the energy input into the interior.

[0033] In the laminated sheet according to the invention, the light transmittance in the second region of the laminated sheet is lower than the light transmittance in the first region of the laminated sheet. "Light" is understood to mean the visible spectral range of 380 nm to 780 nm.

[0034] The total light transmittance (TL) and the reflected portion of the light from the laminated sheet are measured according to DIN ISO 5033 (old standard) or DIN EN ISO / CIE 11664 (new standard). The transmitted portion of light is determined in transmission, and the reflected portion is determined in reflection. A standard light source (e.g., light source A, D65) is used under the conditions specified in the standard, wherein the ratio of the intensity of the transmitted light to the intensity of the incident light is determined to determine the percentage value of the transmittance. In this case, the light source is arranged on one side of the laminated sheet, and the light sensor is arranged on the other side of the laminated sheet. To determine the percentage value of the reflectance, the ratio of the intensity of the reflected light to the intensity of the incident light is determined. In this case, the light source and the light sensor are arranged on the same side of the laminated sheet. The light transmittance of a first or second region of the laminated sheet is similarly determined, wherein, instead of the laminated sheet itself, the first or second region of the laminated sheet is examined separately.

[0035] The first and second sheets of the laminate can, in principle, have any chemical composition known to those skilled in the art. Both sheets preferably comprise or are composed 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 sheets comprise or are composed of clear plastic, preferably rigid clear plastic, especially polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride, and / or mixtures thereof.

[0036] In one embodiment of the invention, the laminated sheet comprises or is composed of glass. The thickness of each individual sheet of the laminated sheet can vary widely and thus can be adapted to the requirements of individual cases. Preferably, sheets with a standard thickness of 0.5 mm to 25 mm, and more preferably 0.5 mm to 5 mm, are used. The size of the sheet can vary widely and depends on its application. The laminated sheet can have any three-dimensional shape and can be planar or curved in one or more spatial directions.

[0037] Two sheets of a laminate are securely bonded to each other by at least one thermoplastic interlayer, which is created by laminating the two sheets with one or more adhesive films. Each adhesive film preferably comprises or consists 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 the adhesive film is preferably from 0.2 mm to 1 mm, for example, 0.38 mm or 0.76 mm.

[0038] Methods known per se for laminating laminated sheets can be used to laminate such sheets. Vacuum lamination is particularly well-known and common, in which lamination is carried out in a heated and vacuum-ventilated chamber, for example, for about 60 minutes at a reduced pressure of, for example, 0.01 mbar to 800 mbar, and at a temperature of, for example, 80°C to 170°C. Vacuum bag or vacuum ring methods, known per se, operate, for example, at about 200 mbar and at a temperature of, for example, 130°C to 145°C. In roll lamination, pressing is carried out in a calender between at least a pair of rolls or between a roll and a rigid support. The temperature during the pressing process is, for example, 40°C to 150°C. This is known in the art and therefore does not need to be discussed in detail here.

[0039] The invention also extends to the use of the laminated sheets according to the invention in buildings or in vehicles used for land, air or water transportation, especially in motor vehicles, for example as top sheets, rear sheets and / or side sheets.

[0040] Various embodiments of the present 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 specified combinations, but also in other combinations or individually without departing from the scope of the invention. Attached Figure Description

[0041] The invention will now be explained in more detail with reference to exemplary embodiments, wherein reference is made to the accompanying drawings. In simplified, non-total representation: Figure 1 This is a schematic cross-sectional view of a first exemplary embodiment of the laminated sheet according to the present invention. Figure 2 This is a schematic cross-sectional view of a second exemplary embodiment of the laminated sheet according to the present invention. Detailed Implementation

[0042] refer to Figure 1 and Figure 2 To explain two different exemplary embodiments of the laminated sheet according to the present invention, which are generally indicated by reference numeral 1.

[0043] First consideration Figure 1 . Figure 1 A first exemplary embodiment of laminated sheet 1 is shown in a schematic cross-sectional view, the laminated sheet being configured to be inserted into an opening in a motor vehicle or building, where it separates the internal INT (Interior Intake) from the external AMB (Exterior Environment). Laminated sheet 1 is, for example, the roof sheet of a motor vehicle.

[0044] The laminated sheet 1 comprises an outer sheet 2 and an inner sheet 3, which are firmly connected to each other by three thermoplastic interlayers 4, 4', 4''. The outer sheet 2 has a surface I facing the external environment and a surface II facing the interior. Similarly, the inner sheet 3 has a surface III facing the exterior and a surface IV facing the interior. The outer surface I of the outer sheet 2 and the inner surface IV of the inner sheet are the exposed surfaces of the laminated sheet, wherein, in the installation position, surface I faces the external environment and surface IV faces the interior of the vehicle or building. The outer sheet 2 and the inner sheet 3 are, for example, sheets made of soda-lime glass, each having a thickness of 2.1 mm. Preferably, the outer sheet 2 is uncolored. However, it is also possible for a colored outer sheet 2 to be advantageous, i.e., when the external reflection of light is not visually appealing. Although this is disadvantageous for heat input (TTS), it is a good trade-off between reflectivity and heat input. The interlayers 4, 4', 4'' are formed, for example, films made of polyvinyl butyral (PVB).

[0045] An emissivity-reducing coating 5 (low-emissivity coating) is applied to the exposed, inner-side surface IV of the inner sheet 3. The emissivity-reducing coating 5 improves thermal comfort inside the sheet by reflecting a portion of the sheet's thermal radiation and solar radiation at high external temperatures, and by reducing internal cooling at low external temperatures. The emissivity-reducing coating 5 is, for example, based on ITO.

[0046] Between the outer sheet 2 and the inner sheet 3, the laminate 1 includes an electrically switchable mirror element in the form of an electrically switchable, liquid crystal-based functional film 6, which can be switched to a non-reflective state or a reflective state relative to light by applying a suitable operating voltage. With the aid of the electrically switchable functional film 6, the laminate can be at least nominally divided into a first region 7 and a second region 8, wherein the first region 7 is located on the side of the electrically switchable functional film 6 facing the external environment, and the second region 8 is located on the side of the electrically switchable functional film 6 facing inwards.

[0047] An electrically switchable functional film 6 is embedded between the two thermoplastic interlayers 4, 4', wherein the electrically switchable functional film 6 is additionally surrounded by the thermoplastic interlayer 4'' as a decorative frame. For this purpose, the electrically switchable functional film 6 is inserted into an opening or through-hole in the surrounding interlayer 4'' (interlayer film). It is understood that the thermoplastic interlayers 4, 4', 4'' are fused together during lamination. They are typically provided in film form prior to lamination. The electrically switchable functional film 6 has two terminal electrodes (busbars) 10 through which an operating voltage for switching the functional film can be applied.

[0048] The thermoplastic interlayer 4 is located in the first region 7; the thermoplastic interlayer 4' is located in the second region 8.

[0049] Between the electrically switchable functional membrane 6 and the thermoplastic intermediate layer 4, 4', 4'', there is a sealing material 11 that prevents the diffusion process.

[0050] Furthermore, on surface II of the inner side of the outer sheet 2, the laminate 1 includes an IR reflective coating 9, which is, for example, based on silver. Areas without coating or coating are possible to allow radio signals to pass through.

[0051] The laminated sheet 1 has a maximum light transmittance of 70% in the second region 8 and a light transmittance greater than 70% in the first region 7; that is, the light transmittance in the second region 8 is lower than that in the first region 7. This is achieved through a correspondingly high coloration of the thermoplastic interlayer 4' in the second region 8. Conversely, the thermoplastic interlayer 4 in the first region 7 is uncolored (clear) or has a coloration at least lower than that of the thermoplastic interlayer 4' in the second region 8. Additionally or alternatively, the inner sheet 3 may also have a corresponding coloration. The outer sheet 2 is clear and uncolored.

[0052] Furthermore, a black print 12 is provided on the inner side surface II of the outer sheet 2 of the laminated sheet 1, which covers the connecting and sealing materials below.

[0053] Figure 2 A second exemplary embodiment of the laminated sheet 1 according to the present invention is shown in a schematic cross-sectional view. To avoid unnecessary repetition, only descriptions related to... Figure 1 The differences between the first exemplary embodiment explained above are noted, and reference is made in other respects to the explanation above.

[0054] Therefore, instead of the electrically switchable functional film 6, an electrically switchable functional coating 13 is provided on the inner sheet 3. The electrically switchable functional coating 13 is deposited on the externally facing surface III of the inner sheet 3, for example by sputtering. A transmission-reducing coating 14 is located between the electrically switchable functional coating 13 and the inner sheet 3, and is based, for example, on titanium nitride and / or titanium carbide, or an amorphous carbon layer. During production, the transmission-reducing coating 14 is first deposited on the externally facing surface III of the inner sheet 3, for example by sputtering, and then the electrically switchable functional coating 13 is deposited on the transmission-reducing coating 14, for example by sputtering. Similar to the electrically switchable functional film 6, the electrically switchable functional coating 13 can be switched to a non-reflective state or a reflective state relative to light by applying a suitable operating voltage.

[0055] exist Figure 2 In an exemplary embodiment, the outer sheet 2 and the inner sheet 3 are connected to each other only through a clear (uncolored) intermediate layer 4.

[0056] The laminated sheet 1 has a maximum light transmittance of 70% in the second region 8 and a light transmittance greater than 70% in the first region 7; that is, the light transmittance in the second region 8 is lower than that in the first region 7. This is achieved by a transmission-reducing coating 14. Alternatively or additionally, the inner sheet 3 may have a corresponding color.

[0057] Figure 1 and Figure 2 The laminated sheet 1 of the exemplary embodiment can optionally be brought to a state with light-reflective properties, wherein the first region 7 has a lower tint than the second region 8, such that a relatively large portion of the incident sunlight is reflected. By reducing the high transmittance in the second region 8, undesirable reflections on the inner side can be avoided. The total heat input (TTS) of the laminated sheet 1 in the visible and non-visible wavelength range is approximately 6%, corresponding to a reduction of approximately 50% compared to conventional top sheets.

[0058] The electrically switchable functional film 6 and the electrically switchable functional coating 13 can be formed in segments.

[0059] The foregoing statements indicate that the present invention provides a novel laminated sheet that reduces energy input into the interior of motor vehicles or buildings through strong reflection of visible light, and further avoids the adverse effects of internal side reflection. The laminated sheet can be easily produced using standard processes in the industrial production of laminated sheets. The laminated sheet can be easily, cost-effectively, and with high quality.

[0060] List of reference numerals 1. Laminated sheet 2 outer sheets 3 inner sheets 4,4',4'' Intermediate layer 5. Emissivity Reduction Coating 6. Functional membranes 7. First Area 8 Second Zone 9 IR reflective coating 10-terminal electrode 11 Sealing materials 12 Black Printing 13 Functional Coatings 14 Transmission-reducing coating INT internal AMB external environment.

Claims

1. A laminated sheet (1) for separating an internal from an external environment, comprising an outer sheet (2) and an inner sheet (3), said outer and inner sheets being securely connected to each other by at least one thermoplastic interlayer (4,4',4''), wherein, The outer sheet (2) and the inner sheet (3) each have a surface facing the external environment and a surface facing the interior, wherein an electrically switchable mirror element (6, 13) is arranged between the outer sheet (2) and the inner sheet (3), wherein the laminated sheet is designed such that it has a light transmittance greater than 70% in a first region (7) on the side of the mirror element (6, 13) facing the external environment, and a maximum light transmittance of 70% in a second region (8) on the side of the mirror element (6, 13) facing the interior.

2. The laminated sheet (1) according to claim 1, which is designed to have a light transmittance of more than 80% in the first region (7) and a light transmittance of up to 50%, up to 30% or up to 10% in the second region (8).

3. The laminated sheet (1) according to any one of claims 1 or 2, having a colored inner sheet (3), a colored thermoplastic intermediate layer (4'), and / or a transmission-reducing coating (14) in the second region (8).

4. The laminated sheet (1) according to any one of claims 1 to 3, having i) the uncolored outer sheet (2) and / or the uncolored thermoplastic intermediate layer (4) in the first region (7), or ii) The colored outer sheet (2) and / or the colored thermoplastic intermediate layer (4) in the first region (7).

5. The laminated sheet (1) according to any one of claims 1 to 4, having a total light transmittance (TL) of up to 65%, preferably up to 50%, particularly preferably up to 30%, and most particularly preferably up to 15%.

6. The laminated sheet (1) according to any one of claims 1 to 5, wherein the electrically switchable mirror element (6, 13) reflects 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.

7. The laminated sheet (1) according to any one of claims 1 to 6, wherein the electrically switchable mirror element is an electrically switchable functional film (6) capable of switching to a non-reflective state relative to light or a reflective state relative to light.

8. The laminated sheet (1) according to claim 7, wherein the electrically switchable functional film (6) is disposed between the thermoplastic interlayer (4) in the first region (7) and the thermoplastic interlayer (4') in the second region (8), wherein, The thermoplastic intermediate layer (4') in the second region (8) is colored.

9. The laminated sheet (1) according to claim 8, wherein the thermoplastic intermediate layer (4) in the first region (7) is uncolored or has a lower coloration than the thermoplastic intermediate layer (4') in the second region (8).

10. The laminated sheet (1) according to any one of claims 1 to 6, wherein the electrically switchable mirror element is an electrically switchable functional coating (13) capable of switching to a non-reflective state relative to light or a reflective state relative to light.

11. The laminated sheet (1) according to claim 10, wherein the transmission reduction coating (14) is applied to the inner side of the electrically switchable functional coating (13).

12. The laminated sheet (1) according to claim 11, wherein the electrically switchable functional coating (13) is disposed on the transmission reduction coating (14).

13. The laminated sheet (1) according to claim 11 or 12, wherein the transmission-reducing coating is based on titanium nitride and / or titanium carbide, or an amorphous carbon layer.

14. The laminated sheet (1) according to any one of claims 1 to 13, wherein an emissivity-reducing coating (5) is applied to the inward-facing surface (IV) of the inner sheet (3), and / or an IR-reflective coating is applied to the inward-facing surface (II) of the outer sheet (2).

15. The use of a laminated sheet (1) according to any one of claims 1 to 14 in buildings or in vehicles used for land, air or water transportation, especially in motor vehicles, for example as a top sheet, rear sheet and / or side sheet.

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