EP4136502A1

EP4136502A1 - Functional element having electrically controllable optical properties

Info

Publication number: EP4136502A1
Application number: EP21717117.2A
Authority: EP
Inventors: Robin SPANJERS; Francois HERMANGE
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Priority date: 2020-04-16
Filing date: 2021-04-14
Publication date: 2023-02-22
Also published as: CN114072281B; CN114072281A; JP7455230B2; JP2023523567A; WO2021209474A1; US20230103913A1; US11820227B2; KR20220165757A

Abstract

The present invention relates to a functional element (5) having electrically controllable optical properties, having a plurality of side edges (4.1, 4.2, 4.3, 4.4), and at least comprising a stacking order consisting of a first carrier film (14), a first planar electrode (12) which is divided into at least two segments (17) by means of at least one isolation line (16), an active layer (11), a second planar electrode (13), and a second carrier film (15), wherein, on a first side edge (4.1) in a first region, the second carrier film (15), the second planar electrode (13) and the active layer (11) have a first offset (20) and, in a second region, the first carrier film (14), the first planar electrode (12) and the active layer (11) have a second offset (21), a group of first busbars (18) electrically conductively contacts the first planar electrode (12) and each segment (17) of the first planar electrode (12) is electrically conductively contacted by a busbar from the group of the first busbars (12), at least a second busbar (19) electrically conductively contacts the second planar electrode (13), the first busbars (18), in a through-view, are situated in the region of the first offset (20) on the first planar electrode (12) so as to be adjacent to one another in a row, wherein the first busbars (18) are electrically isolated from one another by the at least one isolation line (16), and the at least one second busbar (19), in a through-view, is situated in the region of the second offset (21) on the second planar electrode (13).

Description

Functional element with electrically controllable optical properties

The invention relates to a functional element with electrically controllable optical properties, a method for producing such a functional element, and a composite pane with such a functional element.

In the vehicle sector and in the construction sector, composite panes with electrically controllable functional elements are often used for sun protection or privacy protection.

For example, windshields are known in which a sun visor in the form of a functional element with electrically controllable optical properties is integrated. In particular, the transmission or the scattering behavior of electromagnetic radiation in the visible range can be controlled electrically. The functional elements are usually film-like and are laminated into a composite pane or glued to it. In the case of windshields, the driver can control the transmission behavior of the window with respect to solar radiation. This means that there is no need for a conventional mechanical sun visor. This allows the weight of the vehicle to be reduced and space is gained in the roof area. In addition, electrically controlling the sun visor is more convenient for the driver than manually lowering the mechanical sun visor.

Windshields with such electrically controllable sun visors are known, for example, from WO 2014/086555 A1, WO 2017/157626 A1, DE 102013001334 A1, DE 102005049081 B3, DE 102005007427 A1 and

DE 102007027296 A1.

Electrically controllable sun visors are also used in the glass roofs of motor vehicles. In the case of large panoramic glass panes in particular, there is a need to variably control the transmission of the pane. Depending on the position of the sun, it is only necessary to mask out parts of the window or to make the entire area non-transparent as a privacy screen in the parked vehicle.

Typical electrically controllable functional elements contain electrochromic layer structures or Suspended Particle Device (SPD) films, for example from the US 2005/227061 A1 is known. Further possible functional elements for realizing an electrically controllable sun protection are so-called PDLC functional elements (polymer dispersed liquid crystal), as is known, for example, from DE 20 2018 102520 U1. Their active layer contains liquid crystals which are embedded in a polymer matrix.

The electrical contacting of electrically controllable functional elements is usually made via bus bars (also referred to as “bus bars”), which are applied to the surface electrodes in the edge area of the functional element and make electrically conductive contact with them. By connecting the busbars to an external voltage source, for example via flat conductors attached to the busbars, a voltage is applied to the flat electrodes and the active layer of the functional element is switched.

US 2015/109651 A1 discloses a composite pane with a switchable optical filter.

WO 2017/157626 A1 discloses a windshield with a PDLC functional element, the PDLC functional element being switchable in segments.

WO 2020/083562 A1 discloses a composite pane with an electrically controllable functional element that can be switched in segments, the functional element comprising a first surface electrode and a second surface electrode arranged flat one above the other, between which an active layer is arranged flat, the first flat electrode into several segments by means of at least one dividing line is subdivided, a group of first busbars makes electrically conductive contact with the first surface electrode, at least one second busbar makes electrically conductive contact with the second surface electrode, and each segment of the first surface electrode is electrically conductively contacted by at least two busbars from the group of first busbars.

In the case of PDLC functional elements that can be switched in segments according to the prior art, the busbars arranged on the individual segments are generally connected individually to a voltage source by means of flat conductors.

The present invention is based on the object of providing a functional element with electrically controllable optical properties, which can be switched in segments and enables the busbars to be connected to a voltage source in an improved manner. The object of the present invention is achieved by a functional element with electrically controllable optical properties according to independent claim 1. Preferred embodiments emerge from the subclaims.

Further aspects of the invention include improved composite panes with functional elements according to the invention as well as methods for producing the functional element, methods for producing the composite panes and their uses.

A functional element according to the invention with electrically controllable optical properties comprises at least: a stacking sequence of a first carrier film, a first surface electrode, an active layer, a second surface electrode and a second carrier film.

In the functional element, the active layer is arranged between the first surface electrode and the second surface electrode. The flat electrodes and the active layer are arranged flat one above the other. The active layer has the controllable optical properties, which can be controlled via the voltage applied to the surface electrodes. The surface electrodes are connected in an electrically conductive manner to bus bars, via which the functional element can be connected to an external voltage source. In order to be able to switch the functional element in sections, in the form of individual segments, these must be individually electrically controllable. For this purpose, the first surface electrode is divided into at least two segments by means of at least one isolation line. The isolation line can also be referred to as an isolation line and effects an electrical separation of the individual segments of the first surface electrode from one another. A group of first busbars is used to make electrically conductive contact with the first surface electrode, each segment of the first surface electrode being contacted by a busbar from the group of first busbars. The second surface electrode is contacted in an electrically conductive manner by at least one second busbar.

The functional element has several side edges, particularly preferably four side edges. However, the functional element can also comprise more than four side edges. Opposite side edges of a functional element can run parallel to one another or not parallel to one another. The side edges do not have to be straight, they have to be often have a bend. The length of opposite side edges can differ from one another. For example, the functional element can have a trapezoidal outline. In a preferred embodiment, the functional element has several side edges, for example four side edges, two of which are arranged opposite one another.

According to the invention, the second carrier film, the second surface electrode and the active layer have a first cutback on a first side edge in a first region and the first carrier film, the first surface electrode and the active layer have a second cutback in a second region on the first side edge . The cutbacks enable the group of first busbars to be attached to the first surface electrode for electrically conductive contacting thereof and the at least one second busbar to be attached to the second surface electrode for electrically conductive contacting thereof.

The first busbars are arranged in a row adjacent to one another in a row through the functional element according to the invention in the region of the first cutback on the first surface electrode, the first busbars being electrically separated from one another by the at least one insulation line. The at least one second bus bar is arranged in the region of the second cut-back on the second flat electrode in a view through the functional element according to the invention.

If the functional element has two or more second busbars, these are also arranged adjacent to one another in a row.

In one embodiment, the first cutback and the second cutback are arranged directly adjacent to one another.

As stated above, the second carrier film, the second surface electrode and the active layer have a first cut back on a first side edge in a first region. The first cutback is therefore only present in a first area on the first side edge and does not extend completely along the first side edge. Consequently, the first cutback can also be referred to as a local first cutback or a first local notch. The first cut back at the first side edge consequently does not extend as far as a side edge opposite the first side edge. In addition, as stated above, the first carrier film, the first surface electrode and the active layer have a second cut back in a second area on the first side edge. The second cutback is therefore only present in a second area on the first side edge and does not extend completely along the first side edge. Consequently, the second cutback can also be referred to as a local second cutback or a second local notch. The second cutback at the first side edge consequently does not extend to a side edge opposite the first side edge.

Neither the first cut back nor the second cut back are therefore cuts which extend along the entire first side edge or extend as far as a side edge opposite the first side edge.

In the context of the invention, an isolation line is to be understood as a linear region within the surface electrode which is not electrically conductive and which extends over the entire thickness of the surface electrode.

In one embodiment, the at least one isolation line is divided, starting from the first side edge, into at least one vertical section that runs essentially perpendicular to the first side edge, and into at least one horizontal section that runs essentially parallel to the first side edge.

In a preferred embodiment, the at least one isolation line is divided into two vertical sections, which run essentially perpendicular to the first side edge, and two horizontal sections, which run essentially parallel to the first side edge, the vertical sections and the horizontal sections alternate. In this embodiment too, the at least one isolation line begins with a vertical section starting from the first side edge of the functional element.

It goes without saying that vertical sections of the at least one isolation line are sections that run perpendicular to the first side edge and horizontal sections of the at least one isolation line are sections that run parallel to the first side edge. Each of the first busbars is assigned to exactly one segment and is electrically isolated from all other segments, with the exception of the segment assigned to this first busbar, via a section of the isolation line. The maximum length of the busbar is selected depending on the distance between the insulation lines in the area of the respective flat electrode in which the respective busbar is arranged.

The first flat electrode is contacted via the group of first busbars by means of a first flat conductor with one pole of the voltage source and the second flat electrode is contacted via the at least one second busbar by means of a second flat conductor with the opposite pole of the voltage source. The voltage source can be configured as an AC voltage source or a DC voltage source, depending on the type of functional element.

The first flat conductor is a so-called flexible printed circuit (FPC), i.e. a flexible printed circuit.

The structure of the functional element according to the invention enables the active layer to be selectively switched in sections, the selectively switchable areas of the active layer corresponding to a projection of the segments of the first surface electrode onto the active layer. For targeted control of the segments, the opposing poles of a voltage source are connected to the bus conductors of the first surface electrode and the second surface electrode, depending on the desired circuit diagram of the active layer. A first pole of the voltage source is connected to the second busbar (s) of the second surface electrode, while the opposite pole of the voltage source is connected to the first busbars, which are contacted in the area of the segments of the first surface electrode to be controlled. An electrical potential difference between the surface electrodes is therefore only present in the areas of the functional element in which the corresponding segments of the first surface electrode are connected to the voltage source. Accordingly, the active layer of the functional element is only switched in these areas. The isolation line between the individual segments of the first surface electrode ensures that no current flows through other segments of the coating. The targeted control of the segments of the first flat electrode to which a voltage is to be applied can be done, for example, via the first flat conductor in the form of a flexible printed circuit. The arrangement according to the invention enables an improved connection of the bus bars to a voltage source. In particular, because of their arrangement on the first side edge in a row, the first busbars can be connected to the pole of a voltage source by a single flat conductor in the form of a flexible printed circuit. Contacting all segments directly with a single flat conductor in the form of a flexible printed circuit avoids having wires inserted between the connector and the segments.

The predominant surface portions of the segments of the first surface electrode are arranged essentially parallel to one another.

The number of segments within the first surface electrode can vary depending on the field of application of the glazing and is generally between 2 and 20, preferably between 3 and 10.

In a particularly preferred embodiment, only a second busbar is attached to the second surface electrode, via which the entire second surface electrode is electrically conductively contacted.

The electrical regulation of the functional element takes place, for example, by means of buttons, rotary controls or slide controls, which are integrated, for example, in the dashboard of a vehicle. However, a control button can also be integrated in the composite pane, for example a capacitive button. Alternatively, the functional element can also be controlled by non-contact methods, for example by recognizing gestures, or as a function of the pupil or eyelid state determined by a camera and suitable evaluation electronics.

The at least one isolation line is introduced into the surface electrodes in such a way that the segments of the first surface electrode are electrically isolated from one another. The individual segments are connected to the voltage source independently of one another so that they can be controlled separately. In this way, different areas of the functional element can be switched independently. The predominant surface portions of the segments are particularly preferably arranged horizontally in the installed position. In this way, the height of the non-transparent area of the functional element can be regulated by the user. The term “horizontal” is to be interpreted broadly here and denotes a Direction of propagation that runs between the side edges of the composite pane, for example the side edges of a roof pane or a windshield. The isolation lines do not necessarily have to be straight, but can also be slightly curved, preferably adapted to a possible bend of the closest pane edge, in particular essentially parallel to the front roof edge of a roof pane or a windshield.

The isolation lines have, for example, a width of 5 pm (micrometers) to 500 pm, in particular 20 pm to 200 pm. The width of the segments can be suitably selected by the person skilled in the art in accordance with the requirements in the individual case.

The isolation lines can be introduced by laser ablation during the production of the functional element. Preference is given to segmenting multilayer films that have already been laminated subsequently by means of laser ablation.

Laser ablation methods for use in the production of functional elements are described in WO 2016/171312 A1 and WO 2019/104488 A1.

The first busbars and the second busbars comprise an electrically conductive structure, preferably containing silver, and have a thickness of 5 μm to 40 μm.

The bus bars are intended to be connected to an external voltage source, so that there is an electrical potential difference between the first surface electrode and the second surface electrode.

In a preferred embodiment, the bus bars are designed as a printed and burned-in conductive structure. The printed busbars contain at least one metal, preferably silver. The electrical conductivity is preferably realized via metal particles contained in the bus bar, particularly preferably via silver particles. The metal particles can be in an organic and / or inorganic matrix such as pastes or inks, preferably as a burned screen printing paste with glass frits. The layer thickness of the printed busbars is preferably from 5 μm to 40 μm, particularly preferably from 8 μm to 20 μm and very particularly preferably from 10 μm to 15 μm. Printed busbars with these thicknesses are technically easy to implement and have an advantageous current-carrying capacity. Alternatively, the bus bars are designed as strips of an electrically conductive film. The busbars then contain, for example, at least aluminum, copper, tinned copper, gold, silver, zinc, tungsten and / or tin or alloys thereof. The strip preferably has a thickness of 10 μm to 500 μm, particularly preferably 30 μm to 300 μm. Bus bars made of electrically conductive foils with these thicknesses are technically easy to implement and have an advantageous current-carrying capacity. The strip can be connected to the surface electrode in an electrically conductive manner, for example by means of a solder mass, an electrically conductive adhesive or an electrically conductive adhesive tape, or by direct application. To improve the conductive connection, a paste containing silver, for example, can be arranged between the flat electrode and the busbar.

The collector conductors are each attached flatly on the first surface electrode and the second surface electrode. This is advantageous in terms of a simple application of the bus bars. In addition, with regard to its mechanical stability, planar contacting is preferable to contacting via the surface cross-section. The busbars run in the vicinity of a first side edge of the functional element and are each applied flatly to the surface electrode to be contacted. The busbars are preferably each at a distance of 1 mm to 50 mm, particularly preferably 1 mm to 5 mm, to the nearest side edge, i.e. to the first side edge, of the functional element.

The flat electrodes are preferably designed as transparent, electrically conductive layers. The surface electrodes preferably contain at least one metal, a metal alloy or a transparent conductive oxide (transparent conducting oxide, TCO). The flat electrodes can contain, for example, silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium-doped or aluminum-doped zinc oxide and / or fluorine-doped or antimony-doped tin oxide. The flat electrodes preferably have a thickness of 10 nm to 2 μm, particularly preferably 10 nm to 1 μm, very particularly preferably 10 nm to 30 nm. In principle, the flat electrodes can be formed by any electrically conductive layer that can be electrically contacted .

The first carrier film and / or the second carrier film preferably contain at least one polymer that does not completely melt in the autoclave process, preferably Polyethylene terephthalate (PET). The first and the second carrier film particularly preferably consist of a PET film. This is particularly advantageous with regard to the stability of the multilayer film. The carrier films can also contain, for example, ethylene vinyl acetate (EVA) and / or polyvinyl butyral (PVB), polypropylene, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinyl chloride, polyacetate resin, casting resins, acrylates, fluorinated ethylene propylenes, polyvinyl fluoride and / or ethylene tetrafluoroethylene. The thickness of each carrier film is preferably from 0.1 mm to 1 mm, for example 0.20 mm. The carrier films according to the invention are preferably transparent. The flat electrodes are preferably arranged on a surface of the carrier film, that is to say on exactly one of the two sides of the carrier film (that is to say on its front side or its rear side). The carrier films are aligned in the layer stack of the multilayer film in such a way that the surface electrodes are arranged adjacent to the active layer.

In addition to the active layer, the surface electrodes and the carrier films, the functional element can of course have further layers known per se, for example barrier layers, blocker layers, anti-reflective layers, protective layers and / or smoothing layers. It goes without saying that if one or more of these layers are present, these additional layers must also be cut back for contacting the first surface electrode or the second surface electrode.

Electrically controllable optical properties are understood in the context of the invention to be those properties that are continuously controllable, but equally also those that can be switched between two or more discrete states.

In an advantageous embodiment, the functional element according to the invention is a PDLC functional element (polymer dispersed liquid crystal). The active layer of a PDLC functional element contains liquid crystals which are embedded in a polymer matrix. If no voltage is applied to the surface electrodes, the liquid crystals are aligned in a disordered manner, which leads to a strong scattering of the light passing through the active layer. If a voltage is applied to the surface electrodes, the liquid crystals align themselves in a common direction and the transmission of light through the active layer is increased. Such a functional element is known, for example, from DE 102008026339 A1. However, the advantages mentioned do not only occur in connection with PDLC elements, but analogously also with other functional elements. In further possible configurations, the active layer is an SPD, an electrochromic or an electroluminescent layer.

An SPD functional element (suspended particle device) contains an active layer comprising suspended particles, with the absorption of light by the active layer being able to be changed by applying a voltage to the surface electrodes. The change in absorption is based on the alignment of the rod-like particles in the electric field when an electric voltage is applied. SPD functional elements are known, for example, from EP 0876608 B1 and WO 2011033313 A1.

In the case of an electrochromic functional element, the active layer of the functional element is an electrochemically active layer. The transmission of visible light depends on the degree of incorporation of ions in the active layer, the ions being provided, for example, by an ion storage layer between the active layer and a surface electrode. The transmission can be influenced by the voltage applied to the surface electrodes, which causes the ions to migrate. Suitable functional layers contain, for example, at least tungsten oxide or vanadium oxide. Electrochromic functional elements are known, for example, from WO 2012007334 A1, US 20120026573 A1, WO 2010147494 A1 and EP 1862849 A1. The production of electrochromic elements is described in WO 2011/028254 A2 and WO 9829781.

In the case of electroluminescent functional elements, the active layer contains electroluminescent materials, in particular organic electroluminescent materials, the luminescence of which is excited by applying a voltage. Electroluminescent functional elements are known, for example, from US 2004227462 A1 and WO 2010112789 A2. The electroluminescent functional element can be used as a simple light source or as a display with which any representations can be shown.

The invention also relates to a composite pane with a functional element according to the invention with electrically controllable optical properties. The composite pane according to the invention comprises a first pane and a second pane, which are connected to one another via an intermediate layer, and a functional element according to the invention that is embedded in the intermediate layer. The functional element is integrated between the first pane and the second pane of the composite pane via an intermediate layer. The intermediate layer preferably comprises a first thermoplastic composite film, which connects the functional element to the first pane, and a second thermoplastic composite film, which connects the functional element to the second pane. The intermediate layer is typically formed by at least the first and second thermoplastic composite films, which are arranged flat on top of one another and are laminated to one another, the functional element being inserted between the thermoplastic composite films. The areas of the composite films that overlap with the functional element then form the areas that connect the functional element to the panes. In other areas of the pane where the thermoplastic composite films are in direct contact with one another, they can fuse during lamination in such a way that the two original layers may no longer be recognizable and instead a homogeneous intermediate layer is present.

A thermoplastic composite film can be formed, for example, by a single thermoplastic film. A thermoplastic composite film can also be formed from sections of different thermoplastic films, the side edges of which are placed against one another. In addition to a first thermoplastic composite film or a second thermoplastic composite film, further thermoplastic composite films can also be present. If necessary, these can also be used to embed further films comprising functional layers, for example infrared-reflecting layers or acoustically damping layers.

The thermoplastic composite films can also contain tinted or colored areas. Such films can be obtained, for example, by coextrusion. Alternatively, a non-tinted film section and a tinted or colored film section can be combined to form a thermoplastic composite film. The tinted or colored area can be colored or tinted homogeneously, that is to say have a location-independent transmission. The tint or coloration can, however, also be inhomogeneous, in particular a transmission profile can be implemented. In one embodiment of a windshield, the transmittance in the tinted or colored area decreases, at least in sections, as the distance from the front roof edge of the windshield increases. So can sharp edges of the tinted or colored area can be avoided, so that the transition from a sun visor to the transparent area of the windshield is gradual, which is more aesthetically pleasing.

In an advantageous embodiment, the area of the thermoplastic composite pane which is oriented in the direction of a pane used as the outer pane of a vehicle, that is to say the area between the functional element and the outer pane, is tinted. This creates a particularly aesthetic impression of the vehicle when viewed from the outside. The area of the other thermoplastic composite pane between the functional element and the inner pane can optionally also be colored or tinted.

In a preferred embodiment, the functional element, more precisely the side edges of the functional element, is surrounded circumferentially by a thermoplastic frame film. The frame film is designed like a frame with a recess into which the functional element is inserted. The thermoplastic frame film can be formed by a thermoplastic film into which the recess has been made by cutting out. Alternatively, the thermoplastic frame film can also be composed of several film sections around the functional element. In a preferred embodiment, the intermediate layer is thus formed from a total of at least three thermoplastic composite films arranged flat on top of one another, the frame film, as the middle layer, having a recess in which the functional element is arranged. During production, the thermoplastic frame film is arranged between the first and the second thermoplastic composite film, the side edges of all thermoplastic films preferably being in congruence. The thermoplastic frame film preferably has approximately the same thickness as the functional element. This compensates for the local difference in thickness of the composite pane, which is introduced by the locally limited functional element, so that glass breakage during lamination can be avoided.

The side edges of the functional element visible through the composite pane are preferably arranged flush with the thermoplastic frame film, so that there is no gap between the side edge of the functional element and the associated side edge of the thermoplastic frame film. This applies in particular to the lower edge of a functional element as a sun visor of a windshield, in which this edge is typically visible. The border between the thermoplastic frame film and the functional element is less noticeable. Automobile glazing, in particular windshields, rear windows and roof windows, usually have a circumferential, peripheral masking print made of an opaque enamel, which serves in particular to protect the adhesive used for installing the window from UV radiation and to cover it optically. This peripheral cover pressure is preferably used to also cover the edges of the functional element that are located in the edge area of the glazing. The busbars and the necessary electrical connections are also attached in the laminated pane according to the invention in the area of the cover print. In this way, the functional element is advantageously integrated into the appearance of the composite pane. At least the pane used as the outer pane preferably has such a cover print, particularly preferably both the first pane and the second pane (inner pane and outer pane) are printed so that viewing from both sides is prevented.

The functional element can also have recesses or holes, for example in the area of so-called sensor windows or camera windows. These areas are intended to be equipped with sensors or cameras, the function of which would be impaired by a controllable functional element in the beam path, for example rain sensors.

The functional element is preferably arranged over the entire width of the composite pane, minus an edge region on both sides with a width of, for example, 2 mm to 20 mm. The functional element is also preferably at a distance of, for example, 2 mm to 20 mm from the upper edge. The functional element is encapsulated within the intermediate layer and protected from contact with the surrounding atmosphere and corrosion.

The first thermoplastic composite film and the second thermoplastic composite film and the optional thermoplastic frame film preferably contain at least polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and / or polyurethane (PU), particularly preferably PVB.

The thickness of each thermoplastic composite film and, if present, the frame film, is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm, in particular from 0.3 mm to 0.5 mm, for example 0, 38 mm. The thickness of each thermoplastic composite film can also be 0.78 mm, for example. The first pane and the second pane are preferably made of glass, particularly preferably of soda-lime glass, as is customary for window panes. The panes can, however, also be made of other types of glass, for example quartz glass, borosilicate glass or alumino-silicate glass, or of rigid, clear plastics, for example polycarbonate or polymethyl methacrylate. The panes can be clear or tinted or colored. If the composite pane is used as a windshield, it should have sufficient light transmission in the central viewing area, preferably at least 70% in the main transparent area A in accordance with ECE-R43.

The outer pane, the inner pane and / or the intermediate layer can have further suitable coatings known per se, for example anti-reflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings or sun protection coatings or low-E coatings.

The thickness of the first disk and the second disk can vary widely and thus be adapted to the requirements in the individual case. The first disk and the second disk preferably have thicknesses of 0.5 mm to 5 mm, particularly preferably from 1 mm to 3 mm, very particularly preferably from 1.6 mm to 2.1 mm. For example, the first disk has a thickness of 2.1 mm and the second disk has a thickness of 1.6 mm.

In one embodiment of the composite pane according to the invention, the first pane is the inner pane and the second pane is the outer pane. In an alternative embodiment, the first disk is the outer disk and the second disk is the inner disk.

In a preferred embodiment of the composite pane according to the invention, this is designed as a roof pane of a motor vehicle. The roof window comprises a front roof edge which is adjacent to the windshield of the vehicle, a rear roof edge which points in the direction of the rear window and two side edges which run along the vehicle doors between the front roof edge and the rear roof edge. The functional element is designed as a large-area shading of the roof pane, with the functional element covering an area of at least 80% of the entire transparent area the roof pane, preferably at least 90%, for example 100%, of the entire see-through area is arranged.

In the roof pane according to the invention, the functional element is arranged in the composite pane in such a way that the first side edge of the functional element is aligned parallel to the front roof edge and / or parallel to the rear roof edge and that the first side edge of the functional element is aligned adjacent to the front roof edge or to the rear roof edge .

The functional element as roof shading has several slats, which correspond in their dimensions and arrangement to the segments of the first surface electrode and can be switched selectively. The segments of such a vehicle roof are preferably chosen to have a much larger area than in the case of sun visors. The functional element is preferably divided into 2 to 6, particularly preferably into 3 to 4 slats, the majority of the area of the slats running essentially orthogonally to the direction of travel of the vehicle. The segments thus mainly extend between the two side edges of the roof pane. Each segment of the first surface electrode is contacted by a first busbar which is attached to the first surface electrode in the vicinity of the first side edge of the functional element. The second surface electrode of the functional element is contacted via at least one second busbar, which is also arranged on the first side edge of the functional element. The first busbars located on the first side edge of the functional element and the at least one second busbar are concealed by the opaque cover print usually used in the edge region of the pane. The roof pane with a switchable functional element accordingly has an attractive appearance.

In a preferred embodiment of the roof pane, the area of the thermoplastic intermediate layer via which the functional element is connected to the outer pane or the inner pane is tinted or colored. The transmission of this range in the visible spectral range is therefore reduced compared to a non-tinted or colored layer. The tinted / colored area of the thermoplastic intermediate layer thus lowers the transmission of the windshield in the area of the sun visor. The tinted or colored area of the thermoplastic intermediate layer preferably has a transmission in the visible spectral range of 10% to 50%, particularly preferably of 20% to 40%. This achieves particularly good results in terms of glare protection and visual appearance.

In a preferred embodiment, the composite pane according to the invention is a windshield of a motor vehicle. The windshield comprises an upper edge and a lower edge as well as two side edges running between the upper edge and the lower edge. The upper edge, the lower edge and the two side edges together form the circumferential edge of the laminated pane. The upper edge denotes that edge which is intended to point upwards in the installed position in the direction of the vehicle roof. The top edge is usually referred to as the roof edge or the front edge of the roof. The lower edge denotes that edge which, in the installed position, is intended to point downwards in the direction of the hood of the vehicle. The bottom edge is commonly referred to as the engine edge. The side edges of the windshield are the window edges adjacent to the so-called A-pillars of the vehicle body when installed.

Windshields have a central field of vision, the optical quality of which is subject to high requirements. The central field of view must have a high light transmission (typically greater than 70%). Said central field of vision is in particular that field of vision which is referred to by the person skilled in the art as field of vision B, field of vision B or zone B. Field of vision B and its technical requirements are specified in Regulation No. 43 of the United Nations Economic Commission for Europe (UN / ECE) (ECE-R43, “Uniform Conditions for the Approval of Safety Glazing Materials and Their Installation in Vehicles”). Field of vision B is defined there in Appendix 18.

In this embodiment of the windshield, the functional element represents a sun visor and is arranged above the central field of vision (field of vision B). This means that the functional element is arranged in the area between the central field of vision and the front roof edge of the windshield. The functional element does not have to cover the entire area, but is positioned completely within this area and does not protrude into the central field of view. In other words, the functional element has a smaller distance from the upper edge of the windshield than the central viewing area. In this way, the transmission of the central field of vision is not impaired by the functional element, which is positioned at a location similar to that of a classic mechanical sun visor when it is folded down. The intermediate layer in the central field of vision of the windshield is clear and transparent. This ensures that the view through the central field of vision is not restricted, so that the pane can be used as a windshield. A transparent thermoplastic intermediate layer denotes a layer with a light transmission in the visible spectral range of at least 70%, preferably at least 80%. The transparent intermediate layer is present at least in field of view A, preferably also in field of view B according to ECE-R43.

The windshield is preferably provided for a motor vehicle, particularly preferably for a passenger vehicle.

The functional element as a sun visor has several lamellas, the dimensions and arrangement of which correspond to the segments of the first surface electrode and which can be switched selectively. At least one insulation line is introduced into the first surface electrode, the horizontal sections of which run essentially parallel to the front edge of the roof and the surface electrode is divided into at least two segments. The segments thus extend mainly between the two side edges of the windshield. Each segment of the first surface electrode is contacted by a first busbar, which is attached to the first side edge of the functional element on the first surface electrode of the functional element in the vicinity of the roof edge of the windshield. The second surface electrode of the functional element is contacted via at least one second busbar, which is attached adjacent to the roof edge of the windshield on the first side edge of the functional element on the second surface electrode of the functional element. The first busbars arranged on the first side edge of the functional element in the vicinity of the roof edge of the windshield and the at least one second busbar are concealed in the edge area of the windshield by the opaque cover pressure usually used in windshields. The windshield thus has an electrically switchable sun visor with an attractive appearance.

In a composite pane designed as a windshield, the functional element according to the invention is arranged in the composite pane in such a way that the first side edge of the functional element is aligned parallel to and adjacent to the roof edge. In one possible embodiment, a region of the thermoplastic intermediate layer, via which the functional element is connected to the outer pane or the inner pane, is tinted or colored. The transmission of this range in the visible spectral range is therefore reduced compared to a non-tinted or colored layer. The tinted / colored area of the thermoplastic intermediate layer thus lowers the transmission of the windshield in the area of the sun visor. In particular, the aesthetic impression of the functional element is improved because the tint leads to a more neutral appearance that is more pleasant to the viewer.

The tinted or colored area of the thermoplastic intermediate layer preferably has a transmission in the visible spectral range of 10% to 50%, particularly preferably from 20% to 40%. This achieves particularly good results in terms of glare protection and visual appearance.

The invention also relates to a method for producing a functional element according to the invention with electrically controllable optical properties with several side edges, wherein at least a) a stacking sequence of a first carrier film, a first surface electrode, an active layer, a second surface electrode, and a second carrier film is provided, b) at least one insulation line is introduced into the first surface electrode of the functional element, which divides the first surface electrode into at least two segments, c) on a first side edge in a first area the second carrier film, the second surface electrode and the active layer are first cut back and in a second area the first carrier film, the first surface electrode and the active layer are provided with a second cut back, d) a first busbar per segment is applied to the first surface electrode in such a way that the first Busbars in transparency in the area of the first cutback are arranged in a row adjacent to one another on the first surface electrode, and at least one second busbar is applied to the second surface electrode, in such a way that the at least one second busbar in transparency in the area of the second cutback on the second Surface electrode is arranged. The at least one isolation line can preferably be introduced by means of a laser method. The isolation lines are preferably produced by means of laser-induced degeneration within the surface electrodes. Such a laser-induced degeneration is, for example, the removal of the surface electrode or a chemical change in the surface electrode. The laser-induced degeneration results in an interruption in the electrical conductivity of the layer. A pulsed solid-state laser is preferably used as the laser.

The isolation lines are preferably generated through the carrier film closest to the surface electrode to be processed. The laser is focused through this carrier film onto the surface electrode.

It goes without saying that steps b) and c) can also be carried out in reverse order.

The isolation lines can also only be introduced after the arrangement of the first busbars on the surface electrode. In this embodiment of the method, in step d) the first busbars are to be attached to the first flat electrode in such a way that a first busbar per segment of the first flat electrode is then attached after the insulation lines have been introduced.

The busbars can be attached in particular by laying on, printing, soldering or gluing.

The bus bars are preferably implemented in the form of a printed and burned-in conductive structure. The printed busbars contain at least one metal, preferably silver. Suitable silver printing pastes are commercially available and known to the person skilled in the art.

When using the method according to the invention for contacting, the contacting of the first and second busbars on the first and second flat electrodes is carried out starting from different surfaces of the multilayer film. In order to make contact with a first surface electrode on a first carrier film, the second carrier film is cut back, the active layer is removed and the busbars are applied from the removed second carrier film. Analogously, the Contacting the second surface electrode on the second carrier film cut back the first carrier film. When this method is used, the first busbars and the second busbars are accordingly not congruent, but rather adjacent to one another.

Functional elements as multilayer films are commercially available. The functional element to be integrated and provided with cut-backs, isolation lines and bus bars is typically cut out of a multilayer film with larger dimensions in the desired shape and size. This can be done mechanically, for example with a knife. In an advantageous embodiment, the cutting out takes place by means of a laser. It has been shown that the side edge is more stable in this case than with mechanical cutting. In the case of mechanically cut side edges, there can be the risk that the material will, as it were, retreat, which is visually striking and has a detrimental effect on the aesthetics of the pane.

The method can additionally include the steps of attaching a first flat conductor to the group of first busbars, by means of which the group of first busbars can be contacted with a first pole of a voltage source, and attaching a second flat conductor to the at least one second busbar, by means of which the second surface electrode can be contacted with a second pole of the voltage source opposite the first pole.

Any prints that may be present, for example opaque cover prints and printed busbars for making electrical contact with the functional element, are preferably applied using the screen printing process.

The invention also comprises a method for producing a composite pane according to the invention, at least a) a functional element according to the invention, a first pane, an intermediate layer and a second pane being provided, b) the functional element and the intermediate layer being arranged between the first pane and the second pane , c) the first pane and the second pane are connected by lamination via the intermediate layer.

The functional element can be produced as described above. Optionally, in addition to said intermediate layer and the functional element, further thermoplastic composite films and / or carrier films with functional layers can also be arranged between the first pane and the second pane in step b).

The lamination in step c) is preferably carried out under the action of heat, vacuum and / or pressure. Processes known per se can be used for lamination, for example autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators or combinations thereof.

The side edges of the functional element, in the vicinity of which there are bus bars on the functional element, are preferably arranged at a distance of 0 mm to 100 mm, preferably 1 mm to 50 mm, particularly preferably 1 mm to 20 mm, from the circumferential edge of the laminated pane. As a result, the pane area equipped with the functional element is advantageously enlarged. In addition, the busbars can be concealed in this way by the circumferential covering pressure customary in the automotive sector in the edge area of windshields and roof windows. Side edges of a functional element on which there are no bus bars can, for example, also lie in the area of the composite pane that is visible after installation.

The invention also includes the use of a composite pane according to the invention with a functional element according to the invention with electrically controllable optical properties as interior glazing or exterior glazing in a vehicle or a building and the functional element according to the invention with electrically controllable optical properties as sun protection or as privacy protection.

The invention is explained in more detail with reference to drawings and exemplary embodiments. The drawings are schematic representations and are not true to scale. The drawings do not limit the invention in any way. Show it:

1 shows a plan view of an embodiment of a composite pane according to the invention

100,

FIG. 2 shows a cross section through the composite pane according to the invention from FIG. 1 along the section line CC ', 3 shows a plan view of an embodiment of a functional element 5 according to the invention,

Fig. 4 is a plan view of a further embodiment of an inventive

Functional element 5,

5 shows a cross section through the functional element 5 from FIG. 3 or 4 along the section line EE ‘,

Fig. 6 is a plan view of a further embodiment of an inventive

Composite pane 100,

Fig. 7 is a plan view of a further embodiment of an inventive

Functional element 5,

FIG. 8 shows a cross section through the functional element 5 from FIG. 7 along the section line EE ‘,

9 shows a plan view of a further embodiment of an inventive

Functional element 5,

FIG. 10 shows a cross section through the functional element 5 from FIG. 9 along the section line EE ‘,

11 shows a perspective view of an embodiment of a functional element 5 according to the invention,

12 shows a perspective view of a further embodiment of a functional element 5 according to the invention,

13 shows a perspective view of a further embodiment of a functional element 5 according to the invention,

14 shows a perspective view of a further embodiment of a functional element 5 according to the invention,

15 shows a plan view of a further embodiment of an inventive

Composite pane 100,

16 shows a cross section through the composite pane according to the invention from FIG. 15 along the section line CC ‘,

17 shows a circuit of an embodiment of a functional element 5 according to the invention, and

18 shows an exemplary embodiment of the method according to the invention on the basis of a flow chart.

Fig. 1 shows a plan view of an embodiment of a composite pane according to the invention

100, which is designed as a roof pane and FIG. 2 is a cross-sectional view of the Laminated pane 100 according to FIG. 1 along the section line CC '. The roof pane comprises a first pane 1, which serves as an outer pane, and a second pane 2, which serves as an inner pane. The inner pane is the pane facing the vehicle interior, while the outer pane faces the vehicle surroundings. The first pane 1 and the second pane 2 are connected to one another via an intermediate layer 3. The first pane 1 consists of clear soda-lime glass with a thickness of 2.1 mm. The second pane 2 consists of soda-lime glass with a thickness of 1.6 mm and is tinted gray. The tinted inner glass contributes to the attractive appearance of the window, also for the vehicle occupant when looking through the roof window. The composite pane as a roof pane has a front roof edge D facing the windshield in the installed position and a rear roof edge D ′ facing the rear window in the installed position.

The roof pane is equipped with a functional element 5 as a large-area shade, the functional element 5 being embedded in the intermediate layer 3. The intermediate layer 3 comprises a total of three thermoplastic composite films 6, 7, 8, which are each formed by a thermoplastic film with a thickness of 0.38 mm made of PVB. The first thermoplastic composite film 6 is connected to the first pane 1, the second thermoplastic composite film 7 to the second pane 2. The thermoplastic frame film 8 in between has a cutout into which the functional element 5 is inserted flush on all sides. The third thermoplastic layer 8 thus forms, as it were, a type of passepartout for the functional element 5, which is thus encapsulated all around in thermoplastic material and thus protected. Depending on the thickness of the multilayer film and the resulting difference in thickness from the area without functional element 5, the frame film 8 can be dispensed with. This is also dependent on the complexity of the bending of the laminated pane. In general, it can be stated that if there are small differences in thickness between areas with a functional element and areas without a functional element, and if the bending is less complex, a frame film can be dispensed with. The first thermoplastic composite film 6 and the second thermoplastic composite film 7 are tinted gray in order to make the appearance of the roof pane attractive.

Optionally, a further thermoplastic composite film (not shown) can be introduced adjacent to the outer pane (first pane 1). Carrier films with functional layers, for example a carrier film with an infrared-reflecting coating, can be incorporated over the further thermoplastic composite film. the The infrared-reflecting coating is oriented in the direction of the first pane 1 (outer pane) and serves to reduce the heating of the passenger compartment due to solar radiation.

The roof pane according to the invention has a circumferential cover print 9 which covers both the gluing of the windshield to the vehicle body and the electrical contacting of the surface electrodes of the functional element 5. The distance between the functional element 5 and the front roof edge D, the rear roof edge D ‘and the side edges of the roof pane is smaller than the width of the cover print 9, so that the side edges 4.1, 4.2, 4.3, 4.4 of the functional element 5 are covered by the cover print 9. The electrical connections are also sensibly attached in the area of the cover print 9 and are thus advantageously concealed.

3 and 4 each show a top view of embodiments of a functional element 5 of the composite pane 100 according to FIG. 1 before the functional element 5 is integrated into the composite pane 100, the electrical contacting of the functional element 5 also being evident. FIG. 5 shows a cross section through the functional element according to FIG. 3 or FIG. 4 along the section line EE ‘. For simplification, elements behind the cutting plane have been omitted in FIG. 5. For the sake of simplicity, Fig.

3 and 4, in which first area on the first side edge 4.1 the second carrier film 15, the second surface electrode 13 and the active layer 11 have a first cut-back 20 and in which second area on the first side edge 4.1 the first carrier film 14 , the first surface electrode 12 and the active layer 11 have a second cutback 21. The multilayer film of the functional element 5 is shown in FIG. 3 and FIG.

4 shown transparently, so that the bus bars 18, 19 can be seen. The controllable functional element 5 is a multilayer film, consisting of an active layer 11 between two surface electrodes 12, 13 and two carrier films 14, 15. The active layer 11 contains a polymer matrix with liquid crystals dispersed therein, which vary depending on the electrical voltage applied to the surface electrodes align, whereby the optical properties can be regulated. The carrier films 14, 15 are made of PET and have a thickness of, for example, 0.2 mm. The carrier foils 14, 15 are provided with a coating of ITO facing the active layer 11 with a thickness of approximately 30 nm, which form the first surface electrode 12 and the second surface electrode 13. The surface electrodes 12, 13 can be connected to the on-board electrical system via bus bars 18, 19 and connecting cables (not shown). The bus bars 18, 19 are through a silver-containing screen printing. The first surface electrode 12 has an isolation line 16 with a width of 200 μm each, which are introduced by means of a laser process and which divides the first surface electrode 12 into two segments 17. In the embodiment shown in FIG. 3, the insulation line 16, starting from the first side edge 4.1 of the functional element, has a vertical section 16.1 and a horizontal section 16.2. In the embodiment shown in FIG. 4, the insulation line 16, starting from the first side edge 4.1 of the functional element, has two vertical sections 16.1 and two horizontal sections 16.2, the vertical sections 16.1 and the horizontal sections 16.2 alternating. The vertical sections 16.1 of the insulation line 16 are in the installed state of the functional element 5 in the area of the cover print 9 (see FIG. 1). The vertical sections 16.1 of the isolation lines 16 run essentially perpendicular to the first side edge 4.1 and the horizontal sections 16.2 of the isolation lines 16 run essentially parallel to the first side edge 4.1. The isolation lines 16 electrically isolate the segments 17 from one another. The number of segments 17 can be freely selected depending on the application or customer requirements. The first surface electrode 12 has a first bus bar 18 per segment 17, accordingly a total of two first bus bars 18 in FIGS. 3 and 4. The first is the first bus bar 18 in the embodiments shown in FIGS. 3 and 4 each arranged on the first side edge 4.1 adjacent to the fourth side edge 4.4, the second of the first busbars 18 is arranged on the first side edge 4.1 adjacent to the first of the first busbars 18 and the second busbar 19 is arranged on the first side edge 4.1 adjacent to the second side edge 4.2.

The first side edge 4.1 of the functional element 5, which houses the first busbar 18 and the second busbar 19, is arranged in the installed position of the functional element 5 in a composite pane 100 designed as a roof pane on the front roof edge D or the rear roof edge D 'and in the installed position of the Functional element 5 arranged in a composite pane 100 designed as a windshield on the roof edge.

5 shows a cross section along the section line EE 'in FIGS. 3 and 4, which shows the arrangement of the first busbars 18 on the first flat electrode 12 and the arrangement of the second busbar 19 on the second flat electrode 13. For simplification, elements behind the cutting plane have been omitted in FIG. 5. The second carrier film 15, the second surface electrode 13 and the active layer 11 are removed in the region of the functional element 5 which is provided for the first busbar 18. Thus points on the first side edge 4.1 in this first area the second carrier film 15, the second surface electrode 13 and the active layer 11 have a first cut back 20. The first busbars 18 ensure the electrical contacting of the individual segments 17 of the first flat electrode 12. The second busbar 19 ensures the electrical contacting of the second flat electrode 13. A single second busbar 19 is sufficient in this case to make electrical contact with the functional element 5. In the area of the second busbar 19, according to FIG. 5, the first carrier film 14 together with the first surface electrode 12 is removed by cutting back the film. The active layer 11 is also removed in this area. Thus, on the first side edge 4.1 in this second region, the first carrier film 14, the first surface electrode 12 and the active layer 11 have a second cut back 21. The second busbar 19 is printed onto the exposed second surface electrode 13 and thereby makes electrical contact with the second surface electrode 13 in this area.

6 shows a top view of a further embodiment of a composite pane 100 according to the invention, which is designed as a roof pane. The embodiment shown in FIG. 6 differs from the one shown in FIG. 1 only in that the functional element has three insulation lines 16 and the first surface electrode 12 is thus divided into four segments 17, which are each contacted by means of a first busbar 18 .

FIG. 7 shows a top view of an embodiment of a functional element 5 of the composite pane 100 according to FIG. 6 before the functional element 5 is integrated into the composite pane 100, the electrical contacting of the functional element 5 also being evident. FIG. 8 shows a cross section through the functional element according to FIG. 7 along the section line EE '. For the sake of simplicity, elements behind the cutting plane have been omitted in FIG. 8. For the sake of simplicity, it is not shown in FIG. 7 in which first area on the first side edge 4.1 the second carrier film 15, the second surface electrode 13 and the active layer 11 have a first cutback 20 and in which second area on the first side edge 4.1 the first Carrier film 14, first surface electrode 12 and active layer 11 have a second cutback 21. The multilayer film of the functional element 5 is shown transparently in FIG. 7, so that the busbars 18, 19 can be seen. The embodiment of the functional element 5 shown in FIGS. 7 and 8 differs from that shown in FIGS. 4 and 5 only in that the functional element has three isolation lines 16 and the first surface electrode 12 is thus in four segments 17 is divided, which are each contacted by means of a first busbar 18. The first of the first busbars 18 in the embodiments shown in FIGS. 7 and 8 is arranged on the first side edge 4.1 adjacent to the fourth side edge 4.4, the second of the first busbars 18 on the first side edge 4.1 adjacent to the first of the first busbars 18 arranged, the third first busbar 18 is arranged adjacent to the second first busbar 18, the fourth first busbar 18 is arranged adjacent to the third first busbar 18 and the second busbar 19 is arranged on the first side edge 4.1 adjacent to the second side edge 4.2. The first busbars 18 are thus arranged in a row on the first side edge 4.1 starting from the fourth side edge 4.4 and the second busbar 19 is arranged at the corner where the first side edge 4.1 meets the second side edge 4.2.

FIG. 9 shows a top view of an embodiment of a functional element 5 of the composite pane 100 according to FIG. 6 before the functional element 5 is integrated into the composite pane 100, the electrical contacting of the functional element 5 also being evident. FIG. 10 shows a cross section through the functional element according to FIG. 9 along the section line EE ‘. For the sake of simplicity, elements behind the cutting plane have been omitted in FIG. 10. For the sake of simplicity, FIG. 9 does not show in which first area on the first side edge 4.1 the second carrier film 15, the second surface electrode 13 and the active layer 11 have a first cutback 20 and in which second area on the first side edge 4.1 the first Carrier film 14, first surface electrode 12 and active layer 11 have a second cutback 21. The multilayer film of the functional element 5 is shown transparently in FIG. 9, so that the busbars 18, 19 can be seen. The embodiment of the functional element 5 shown in FIGS. 9 and 10 differs from that shown in FIGS. 7 and 8 only in that the second busbar 19 in the embodiment shown in FIGS. 9 and 10 is adjacent to the first side edge 4.1 to the fourth first busbar 18 is arranged. Thus, the recesses 20 and 21 for making electrical contact with the functional element 5 are arranged directly adjacent to one another.

11 shows a perspective view of an embodiment of a functional element 5 according to the invention. In the embodiment shown in FIG. 11, the functional element 5 is designed as shown in FIG. 3 or 4. In FIG. 11, due to the perspective view, the first cutback 20 for area-wise exposure of the first surface electrode 12 of the functional element 5 and the second cutback 21 for Area-wise exposure of the second surface electrode 13 of the functional element 5 can be clearly seen.

12 shows a perspective view of a further embodiment of a functional element 5 according to the invention. This differs from the embodiment shown in FIG. 11 only in that, in the embodiment shown in FIG. 12, the functional element 5 has a first flat conductor 22 for connection the first busbar 18 to an external voltage source and a second flat conductor 23 for connecting the second busbar 19 to an external voltage source. The first flat conductor 22 is designed as a flexible printed circuit, a so-called flexible printed circuit. The arrangement of the first busbars 18 in a row on the first side edge 4.1 of the functional element 5 results in a compact arrangement and all first busbars 18 can be connected to an external voltage source by means of a single first flat conductor 22 designed as a flexible printed circuit.

FIG. 13 shows a perspective view of a further embodiment of a functional element 5 according to the invention. This differs from that shown in FIG. 11 only in that the functional element 5 is designed as shown in FIG. 9. In FIG. 13, due to the perspective view, the first cutback 20 for area-wise exposure of the first surface electrode 12 of the functional element 5 and the second cutback 21 for area-wise exposure of the second surface electrode 13 of the functional element 5 can be clearly seen.

14 shows a perspective view of a further embodiment of a functional element 5 according to the invention. This differs from that shown in FIG. 12 only in that the functional element 5 is designed as shown in FIG. 9. In FIG. 14, due to the perspective view, the first cutback 20 for the area-wise exposure of the first surface electrode 12 of the functional element 5 and the second cutback 21 for the area-wise exposure of the second surface electrode 13 of the functional element 5 can be clearly seen.

15 shows a top view of a composite pane 100 according to the invention, which is designed as a windshield of a motor vehicle. FIG. 16 shows a cross-sectional view of the windshield according to FIG. 15 along the section line C'C. The windshield comprises a first pane 1, which serves as an outer pane, and a second pane 2, which serves as Inner pane is used. The inner pane is the pane facing the vehicle interior, while the outer pane faces the vehicle surroundings. The first pane 1 and the second pane 2 are connected to one another via an intermediate layer 3. The first pane 1 has a thickness of 2.1 mm and consists of a green-colored soda-lime glass. The second pane 2 has a thickness of 1.6 mm and consists of a clear soda-lime glass. The composite pane as a windshield has a front roof edge D facing the roof in the installed position and an engine edge M facing the engine compartment in the installed position.

The windshield is equipped with a functional element 5 as an electrically controllable sun visor, which is attached in an area above the central viewing area B (as defined in ECE-R43). The sun visor is formed by a functional element 5 according to the invention, which is embedded in the intermediate layer 3 and in which the first surface electrode 12 is divided into four segments 17 by means of three isolation lines 16. The height of the sun visor is, for example, 21 cm. The intermediate layer 3 comprises a total of three thermoplastic composite films 6, 7, 8, which are each formed by a thermoplastic film with a thickness of 0.38 mm made of PVB. The first thermoplastic composite film 6 is connected to the first pane 1, the second thermoplastic composite film 7 to the second pane 2. The thermoplastic frame film 8 in between has a cutout in which the cut PDLC multilayer film fits precisely, i.e. flush on all sides, is inserted. The third thermoplastic layer thus forms, as it were, a kind of passe-partout for the functional element 5, which is thus encapsulated all around in thermoplastic material and thus protected. The first thermoplastic composite film 6 optionally has a tinted area 10 which is arranged between the functional element 5 and the first pane 1. The light transmission of the windshield is thereby additionally reduced in the area of the sun visor and the milky appearance of the PDLC functional element 5 is softened in the diffusive state. The aesthetics of the windshield is made much more appealing. In the case shown, the lower edges of the tinted area 10 and the PDLC functional element 5 are arranged flush. But this is not necessarily the case.

The composite pane according to the invention, in its embodiment as a windshield according to FIG Contacting the surface electrodes of the functional element 5 is covered. The circumferential peripheral cover print 9 is formed by an opaque enamel on the interior-side surfaces (facing the interior of the vehicle in the installed position) of the first pane 1 and the second pane 2. The distance between the functional element 5 and the front roof edge D and the side edges of the windshield is smaller than the width of the cover print 9, so that the side edges 4.1, 4.2, 4.4 of the functional element 5 - with the exception of the side edge 4.3 facing the central field of vision B - are affected by the cover print 9 are covered. The electrical connections and busbars are also sensibly attached in the area of the cover print 9 and thus advantageously concealed.

In a particularly convenient embodiment, the functional element 5 is controlled by a capacitive button arranged in the area of the sun visor, the driver defining the degree of darkening through the location at which he touches the window. Alternatively, the sun visor can also be controlled by non-contact methods, for example by recognizing gestures, or as a function of the pupil or eyelid state determined by a camera and suitable evaluation electronics.

For the thermoplastic composite films 6, 7 and the thermoplastic frame film 8, a so-called “high flow PVB” can preferably be used, which has a stronger flow behavior compared to standard PVB films. The layers flow more strongly around the functional element 5, which creates a more homogeneous visual impression and the transition from functional element 5 to frame film 8 is less noticeable. The “High Flow PVB” can be used for all or only for one or more of the thermoplastic films 6, 7, 8 with direct contact with the functional element 5.

FIG. 17 shows a circuit of an embodiment of a functional element 5 according to the invention. The functional element 5, the circuit of which is shown in FIG. 17, is designed as shown in FIG. The four segments of the first surface electrode 12, which are designated in the circuit with R1, R2, R3 and R4, are connected in parallel and via four first busbars 18 by means of a first flat conductor 22 in the form of a flexible printed circuit (in FIG. 17 with E1 denotes) connected to a first pole of a voltage source. The second flat electrode 13 is connected by means of a second flat conductor 23 (designated E2 in FIG. 17) via a second busbar 19 to the second pole of the voltage source opposite the first pole. FIG. 18 shows an exemplary embodiment of the method according to the invention for producing a functional element 5 according to the invention with electrically controllable optical properties with several side edges 4.1, 4.2, 4.3, 4.4 using a flowchart comprising the steps:

I providing a stacking sequence of a first carrier film 14, a first surface electrode 12 of an active layer 11, a second surface electrode 13, and a second carrier film 15,

II introducing an isolation line 16 into the first surface electrode 12 of the functional element 5, the isolation line 16 dividing the first surface electrode into at least two segments 17,

III Providing the second carrier film 15, the second surface electrode 13 and the active layer 11 with a first cut back 20 on a first side edge 4.1 in a first area and providing the first carrier film 14, the first surface electrode 12 and the active layer 11 with a second cut back 21 in a second area,

IV Attachment of a first bus conductor 18 per segment 17 on the first surface electrode 12 such that the first bus conductors 18 are arranged in a row adjacent to one another in the region of the first cut-back 20 on the first surface electrode 12, and at least one second bus conductor is attached 19 on the second surface electrode 13, in such a way that the at least one second busbar 19 is arranged in view in the region of the second cut-back 21 on the second surface electrode 13.

List of reference symbols:

1 first slice

2 second disc

3 intermediate layer

4.1 first side edge of the functional element 5

4.2 second side edge of the functional element 5

4.3 third side edge of the functional element 5

4.4 fourth side edge of the functional element 5

5 functional element with electrically controllable optical properties

6 first thermoplastic composite film

7 second thermoplastic composite film

8 thermoplastic frame film, third thermoplastic composite film

9 masking print

10 tinted area of the first thermoplastic composite film

11 active layer of the functional element 5

12 first surface electrode of the functional element 5

13 second surface electrode of the functional element 5

14 first carrier film

15 second carrier film

16 isolation lines

16.1 vertical sections of the isolation lines 16

16.2 horizontal sections of the isolation lines 16

17 segments

18 first busbar

19 second busbar

20 first cut back to expose the first surface electrode 12 of the

Functional element 5

21 second cut back to expose the second surface electrode 13 of the

Functional element 5

22 first flat conductor for connecting the first busbar 18 to an external voltage source

23 second flat conductor for connecting the second busbar 19 to an external voltage source

100 composite pane B field of view

D front edge of the roof

D ‘rear roof edge M engine edge

S side edges

C-C ‘, E-E‘ cutting line

Claims

1. Functional element (5) with electrically controllable optical properties with several side edges (4.1, 4.2, 4.3, 4.4), at least comprising a stacking sequence of a first carrier film (14), a first surface electrode (12), which by means of at least one isolation line (16 ) is divided into at least two segments (17), an active layer (11), a second surface electrode (13), and a second carrier film (15), the second carrier film (15) on a first side edge (4.1) in a first area ), the second surface electrode (13) and the active layer (11) have a first cut back (20) and in a second area the first carrier film (14), the first surface electrode (12) and the active layer (11) have a second cut back (21), a group of first busbars (18) makes electrically conductive contact with the first surface electrode (12) and each segment (17) of the first surface electrode (12) is connected by a busbar from the group of the first collector electrical conductor (18) is electrically contacted, at least one second busbar (19) makes electrically conductive contact with the second surface electrode (13), the first busbar (18) in the area of the first cutback (20) adjacent to the first surface electrode (12) are arranged in a row to one another, the first busbars (18) being electrically separated from one another by the at least one insulation line (16), and the at least one second busbar (19) in view in the region of the second cut-back (21) on the second surface electrode (13) is arranged.

2. Functional element (5) according to claim 1, wherein the at least one isolation line (16) extends from the first side edge (4.1) into at least one vertical section (16.1) which runs essentially perpendicular to the first side edge (4.1), and divided into at least one horizontal section (16.2) which runs essentially parallel to the first side edge (4.1).

3. Functional element (5) according to claim 2, wherein the at least one isolation line (16) is divided into two vertical sections (16.1), which run essentially perpendicular to the first side edge (4.1), and into two horizontal sections (16.2), which run essentially parallel to the first side edge (4.1), divided and the vertical sections (16.1) and the horizontal sections (16.2) alternate.

4. Functional element (5) according to one of claims 1 to 3, wherein the first cutback (20) and the second cutback (21) are arranged directly adjacent to one another.

5. Functional element (5) according to one of claims 1 to 4, wherein the first busbars (18) and the second busbars (19) comprise an electrically conductive structure, preferably containing silver, and have a thickness of 5 pm to 40 pm.

6. Functional element (5) according to one of claims 1 to 5, wherein the first surface electrode (12) and the second surface electrode (13) contain at least one metal, a metal alloy or a transparent conductive oxide, preferably a transparent conductive oxide, and a thickness from 10 nm to 2 pm, preferably from 10 nm to 30 nm.

7. Functional element (5) according to one of claims 1 to 6, wherein the active layer (11) contains or consists of liquid crystals, preferably polymer dispersed liquid crystals (PDLC).

8. Functional element (5) according to one of claims 1 to 7, additionally comprising a first flat conductor (22) and a second flat conductor (23), wherein by means of the first flat conductor (22) the first surface electrode (12) over the group of first busbars (18) can be contacted with a first pole of a voltage source and by means of the second flat conductor (23) the second flat electrode (13) can be contacted via the at least one second busbar (19) with a second pole of the voltage source opposite the first pole, and wherein the first flat conductor (22) is designed as a flexible printed circuit.

9. Composite pane (100) with functional element (5) with electrically controllable optical properties, at least comprising a first pane (1) and a second pane (2) which are connected to one another via an intermediate layer (3) and a Functional element (5) according to one of Claims 1 to 8, which is incorporated in the intermediate layer (3).

10. A composite pane according to claim 9, wherein the intermediate layer (3) has a first thermoplastic composite film (6) which is arranged between the functional element (5) and the first pane (1), and a second thermoplastic composite film (7) which has between the functional element (5) and second disc (2) is arranged.

11. composite pane (100) according to claim 9 or 10, wherein the composite pane (100) is a roof pane of a motor vehicle comprising a front roof edge (D), a rear roof edge (D ') and two side edges (S), the functional element (5) is designed as a large-area shading of the roof pane and the functional element (5) is arranged in the composite pane (100) in such a way that the first side edge (4.1) of the functional element (5) is parallel to the front roof edge (D) and / or parallel to the rear Roof edge (D ') is aligned and that the first side edge (4.1) of the functional element (5) is aligned adjacent to the front roof edge (D) or to the rear roof edge (D').

12. Composite pane (100) according to claim 9 or 10, wherein the composite pane (100) is a windshield of a motor vehicle, comprising an engine edge (M), a front roof edge (D) and two side edges (S), the functional element (5) is designed as a sun visor in the vicinity of the front roof edge (D) and wherein the functional element (5) is arranged in the composite pane (100) in such a way that the first side edge (4.1) of the functional element (5) is aligned parallel and adjacent to the roof edge (D) is.

13. A method for producing a functional element (5) according to one of claims 1 to 8 with electrically controllable optical properties with several side edges (4.1, 4.2, 4.3, 4.4), wherein at least a) a stacking sequence of a first carrier film (14), one first surface electrode (12), an active layer (11), a second surface electrode (13), and a second carrier film (15) is provided, b) in the first surface electrode (12) of the functional element (5) at least one isolation line (16) is introduced, which divides the first surface electrode (12) into at least two segments (17), c) on a first side edge (4.1) in a first area the second carrier film (15), the second surface electrode (13) and the active layer (11) are provided with a first cut back (20) and in a second area the first carrier film (14), the first surface electrode (12) and the active layer (11) are provided with a second cutback (21), d) a first busbar (18) per segment (17) is applied to the first surface electrode (12) , in such a way that the first busbars (18) are arranged in a row adjacent to one another in the area of the first cutback (20) on the first flat electrode (12), and at least one second busbar (19) on the second flat electrode (13) is attached in such a way that the at least one second busbar (19) is arranged on the second surface electrode (13) in the area of the second cut-back (21).

14. The method according to claim 13, additionally comprising the steps of attaching a first flat conductor (22) on the group of first busbars (18), by means of which the group of first busbars (18) can be contacted with a first pole of a voltage source and the Attaching a second flat conductor (23) to the at least one second busbar (19), by means of which the second flat electrode (13) can be contacted with a second pole of the voltage source opposite the first pole.

15. Use of a composite pane (100) with functional element (5) with electrically controllable optical properties according to one of claims 1 to 8 as internal glazing or external glazing in a vehicle or a building and the functional element (5) with electrically controllable optical properties as sun protection or as Privacy screen.