Segmented multilayer films with electrically controllable optical properties - Patent Application 20070122997

Abstract

The present invention relates to a multilayer film 1 with electrically controllable optical properties, comprising at least the following, arranged in a specified order and in a planar manner one above the other: (a) a first carrier film (5); (b) first planar electrode (3), (c) an active layer (2) or an active layer sequence (2') having electrically controllable optical properties, (d) a second planar electrode (4), and (e) the second carrier film (6); wherein the first planar electrode (3) and the active layer (2) or active layer sequence (2') are divided into at least two segments electrically isolated from one another by at least one insulating line (7), Here, at least one interruption line (7) is introduced by a laser (8) through at least one of the carrier films (5, 6) into the first planar electrode (3) and into the active layer (2) or active layer sequence (2').

Description

[Technical Field]

[0001] The present invention relates to a multilayer film having electrically controllable optical properties, to a method for producing the same and to its use, and to a laminate pane comprising such a multilayer film. [Background technology]

[0002] Glazing with electrically switchable optical properties is known. Such glazing typically has a functional element containing an active layer between two planar electrodes. The optical properties of the active layer can be changed by applying a voltage to the planar electrodes. Examples of this include electrochromic functional elements, as known, for example, from US Patent Application Publication No. 2012 / 0026573, WO 2010 / 147494, EP 1 862 849, and WO 2012 / 007334. Another example is PDLC (polymer dispersed liquid crystal) functional elements, as known, for example, from DE 10 2008 026 339. Another example is SPD (suspended particle device) functional elements, as known, for example, from EP 0 876 608 and WO 2011 / 033313. The electrically controlled optical properties are in particular light transmission (as in the case of electrochromic or SPD functional elements) or light scattering (as in the case of PDLC functional elements). Glazings with such functional elements can be electrically darkened in a convenient manner or provided with high light scattering.

[0003] Electrically switchable functional elements are often provided as multilayer films. The actual functional element is disposed between two polymer carrier films. Such multilayer films allow for simplified manufacturing of electrically switchable glazing. Typically, the multilayer film is laminated between two glass panes using conventional methods to produce a laminated pane with electrically switchable optical properties. In particular, multilayer films are commercially available, eliminating the need for glazing manufacturers to manufacture the switchable functional element themselves.

[0004] Glazings with electrically switchable optical properties can be used, for example, as window panes in vehicles, and their light transmission behavior can be electrically controlled. They can also be used, for example, as roof panels to reduce exposure to direct sunlight or diffuse reflection. Such roof panels are known, for example, from DE 10043141 A1 and EP 3456913 A1. Windshields in which electrically controllable sunscreens are realized by switchable functional elements have also been proposed to replace conventional mechanically foldable sunscreens in automobiles. Windshields with electrically controllable sunscreens are known, for example, from DE 102013001334 A1, DE 102005049081 A1, DE 102005007427 A1 and DE 102007027296 A1.

[0005] JP 2020-003644 A discloses a method for creating cross sections in a multilayer film by laser irradiation, thereby creating contact areas for planar electrodes. For this purpose, the carrier film, the planar electrode assigned to it, and the active layer adjacent to the cross section are removed in the edge areas, so that the other planar electrode is exposed and can be connected to an electrical cable.

[0006] It is also known to provide such glazing or controllable functional elements with multiple switching regions, the optical properties of which can be switched independently of each other. For example, one region of the functional element can be selectively darkened or provided with a high level of light scattering, while other regions remain transmissive (transparent). By way of example only, see WO2017157626 and WO2021057943.

[0007] WO 2011 / 101427 discloses a method for producing an electrochromic functional element having electrochromic cells connected in series. The electrochromic functional element is applied to a glass substrate, and the planar electrodes and active layer sequence are segmented, for example, by laser irradiation. U.S. Pat. No. 5,910,854 discloses a method for producing a segmented electrochromic multilayer film, in which at least one planar electrode is segmented on a carrier film, for example, by laser irradiation, before laminating the carrier film and the active layer sequence to form the multilayer film.

[0008] WO 2014 / 072137 discloses a method for producing a multilayer film with electrically controllable optical properties, which is segmented into a plurality of independently controllable segments. The multilayer film is provided as is. An insulating line is then introduced through the carrier film into one or both planar electrodes using laser irradiation, thereby dividing them into segments that are isolated from each other. The active layer between the planar electrodes is not segmented. Segments of at least one of the planar electrodes can be supplied with an electric potential independently of each other, thereby independently controlling the optical properties of the region of the active layer located between them and the other planar electrode (or a segment of the other planar electrode). The laser processing advantageously produces thin, barely noticeable insulating lines. Furthermore, the carrier film is not damaged, thereby preserving its protection against corrosion and contamination. Summary of the Invention [Problem to be solved by the invention]

[0009] In such segmented multilayer films, practical problems can sometimes be observed when a switching region is activated (i.e., a voltage is applied) while an adjacent switching region is not activated (i.e., no voltage is applied). The switching state of the activated switching region can spuriously spread into the non-activated switching regions, causing undesirable changes in the optical properties, especially in their edge regions facing the activated switching region. This effect is also known as leakage or crosstalk. This effect is particularly pronounced in electrochromic multilayer films, possibly due to the semiconducting properties of the electrochromic layer sequence. Crosstalk effects can also often be observed in PDLC devices. [Means for solving the problem]

[0010] Therefore, there is a need for a segmented multilayer film having electrically controllable optical properties, in which the segments are completely decoupled from one another. In particular, it is desirable that segments without voltage do not experience a change in optical properties when directly adjacent segments are activated. There is also a need for a method of making such a multilayer film. It is an object of the present invention to provide such an improved multilayer film and a method of making it. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows a plan view of one embodiment of a laminated pane according to the invention, having a multilayer film according to the invention.

[0012] [Figure 2] FIG. 2 shows a cross section along X-X' through the laminated pane according to FIG.

[0013] [Figure 3] FIG. 3 shows a plan view of the multilayer film prior to manufacturing the laminate pane according to FIG.

[0014] [Figure 4] FIG. 4 shows a cross section along YY′ through the multilayer film of FIG.

[0015] [Figure 5] FIG. 5 shows a cross section along YY′ of a further embodiment of a multilayer film according to the invention.

[0016] [Figure 6] FIG. 6 shows a cross section along YY′ of a further embodiment of a multilayer film according to the invention.

[0017] [Figure 7] FIG. 7 shows a cross section through a multilayer film according to FIG. 3 during a method according to the invention.

[0018] [Figure 8] FIG. 8 shows a plan view of a further embodiment of a multilayer film according to the present invention.

[0019] [Figure 9] FIG. 9 shows a plan view of a further embodiment of a multilayer film according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The objects of the present invention are achieved by a multilayer film with electrically controllable optical properties, comprising at least the following, arranged in a specified order and in a planar manner one above the other: (a) a first carrier film; (b) first planar electrode; (c) an active layer or layer sequence having electrically controllable optical properties; (d) a second planar electrode; and (e) Second carrier film. According to the invention, at least the first planar electrode and the active layer or active layer sequence are divided into at least two segments electrically isolated from one another by at least one interruption line. According to the invention, at least one interruption line is introduced by a laser through one of the carrier films into at least the first planar electrode and the active layer or active layer sequence. Optionally, the second planar electrode is also divided into at least two segments electrically isolated from one another by at least one interruption line, and at least one interruption line is introduced by a laser through one of the carrier films into the first planar electrode, the active layer or active layer sequence, and the second planar electrode.

[0021] The object of the present invention is also achieved by a method for producing a multilayer film with electrically switchable optical properties by first providing a multilayer film with electrically controllable optical properties (method step A), which comprises at least the following, arranged in a specified order and one above the other in a planar manner: (a) a first carrier film; (b) first planar electrode; (c) an active layer or layer sequence having electrically controllable optical properties; (d) a second planar electrode; and (e) Second carrier film. Laser radiation is then directed onto the multilayer film, in particular through the carrier film, onto the first planar electrode, the active layer or layer sequence, and the second planar electrode (method step B). The laser radiation is then moved along at least one line, and at least one interruption line is introduced (through the carrier film) into at least the first planar electrode and the active layer or layer sequence (method step C), thereby dividing at least the first planar electrode and the active layer or layer sequence into at least two segments that are electrically isolated from each other. Optionally, at least one interruption line can be introduced into the second planar electrode in method step C, thereby dividing the second planar electrode into at least two segments that are electrically isolated from each other.

[0022] The first planar electrode and the active layer / layer sequence (and in some embodiments also the second planar electrode) are divided into at least two segments electrically isolated from one another by at least one cut-off line. Each of these segments forms an independently controllable switching region of the multilayer film. By independently controllable switching region is meant a region of the multilayer film whose optical properties can be controlled independently of other switching regions. The switching regions separated from one another by a cut-off line therefore comprise all the structural features of the multilayer film, i.e., two carrier films, two planar electrodes, and active layer / layer sequences. No components of the film are removed adjacent to the cut-off line, as, for example, when one of the carrier films, its assigned planar electrode, and the active layer / layer sequence adjacent to the cut-off line is removed to locally expose the other planar electrode, thereby providing a contact area that can be connected to an external electrical cable.

[0023] A first planar electrode in the sense of the present invention is a planar electrode facing the laser in the method according to the present invention, while a second planar electrode faces away from the laser. In this way, laser radiation enters the multilayer film through the first carrier film and also exits the multilayer film through the second carrier film.

[0024] In the following, the multilayer film and the method will be described together, but the description and preferred embodiments relate equally to the multilayer film and the method. When preferred features are described in relation to the method, this means that the multilayer film is preferably designed accordingly. On the other hand, when preferred features are described in relation to the multilayer film, this means that the method is also preferably carried out accordingly.

[0025] An advantage of the present invention resides in the isolation line extending over at least the first planar electrode and the active layer or layer sequence. This achieves complete separation of the segments, in contrast to conventional segmented multilayer films in which only one or both planar electrodes are segmented by the isolation line, leaving the active layer or layer sequence unaffected by the segmentation. Undesirable changes in the optical properties of the de-energized segments are not caused by adjacent active segments (i.e., segments with voltage applied). The isolation line introduced using laser irradiation is thin and therefore visually unnoticeable. During processing, the carrier film remains intact, thereby protecting the planar electrode and one or more active layers from corrosion, moisture, and contamination. Therefore, at least one isolation line does not extend through the carrier film. Optionally, the isolation line may also extend over the second planar electrode, thereby achieving further improved separation of the segments.

[0026] The multilayer film is a layer stack, and the layers of the layer stack include at least one first carrier film, a first planar electrode, an active layer or layer sequence, a second planar electrode, and a second carrier film, which are arranged in this order, overlapping and planar. The layers of the layer stack are permanently connected to each other in a stable manner, for example, by gluing or lamination. In this way, the multilayer film is provided as a pre-laminated multilayer film. That is, the carrier film, the planar electrode, and the active layer or layer sequence are already bonded to form the multilayer film before the cut-off line is created. At least one cut-off line is introduced into this pre-laminated multilayer film by laser irradiation, i.e., after the carrier film, the planar electrode, and the active layer are bonded to form the multilayer film. This type of multilayer film is typically commercially available and can be purchased, for example, by a glass manufacturer, cut to the required size, and processed according to the present invention. However, the multilayer film can also be manufactured before processing itself.

[0027] According to the present invention, the first planar electrode and the active layer or layer sequence (and optionally the second planar electrode) are divided by at least one interruption line into at least two segments that are electrically isolated from each other. The at least one interruption line according to the present invention extends at least across the first planar electrode and one or more active layers, thereby dividing the first planar electrode and one or more active layers into at least two segments (partial regions) that are electrically isolated from each other. In other words, the first planar electrode and one or more active layers (and optionally the second planar electrode) each have an interruption line, which are aligned with each other. As a result of the electrical interruption, charges are not transferred from one segment to an adjacent segment, or at least not to a significant extent. The interruption line is a linear, non-conductive region formed in the first planar electrode and the active layer or layer sequence (and optionally the second planar electrode).

[0028] In one embodiment of the present invention, only the first planar electrode and the active layer or layer sequence are divided by at least one dividing line into at least two segments that are electrically isolated from one another, while the second planar electrode is not divided into segments by a dividing line. The at least one dividing line may leave the second planar electrode completely intact (i.e., not extend into the second planar electrode at all) or may extend partially across the second planar electrode, so that the second planar electrode is not divided into electrically isolated segments. The dividing line may, for example, extend across less than 50%, preferably less than 30%, particularly preferably less than 20% of the layer thickness of the second planar electrode.

[0029] In a further embodiment of the invention, both planar electrodes and the active layer or layer sequence are divided into at least two segments which are electrically isolated from one another by at least one isolation line.

[0030] According to the invention, the interruption lines are introduced into the first planar electrode and the active layer or layer sequence (and optionally the second planar electrode) by means of a laser. The interruption lines are produced by laser-induced modification. Such laser-induced modification is, for example, removal or chemical modification of the layer. The laser-induced modification results in a discontinuity in the electrical conductivity of the layer.

[0031] In a preferred embodiment, the segmented regions or partial regions of the first planar electrode and one or more active layers (and optionally the second planar electrode) are completely materially separated from one another by a blocking line. Thus, the blocking line extends completely through the first planar electrode and one or more active layers (and optionally the second planar electrode) in each case, across their entire thickness. Electrical isolation is particularly effective. Material separation means that the material of the planar electrode is not present in the region of the blocking line, i.e., it is either removed or chemically modified (e.g., oxidized) into a non-conductive material as a result of the laser irradiation. However, it is also possible in principle for the layer thickness of one or more of the elements to be only locally reduced by the blocking line, thereby reducing the conductivity and preventing significant charge transfer. In this case, the blocking line does not extend across the entire layer thickness of the element, but, for example, only across at least 80% or at least 90% of the layer thickness.

[0032] In a preferred embodiment, the laser radiation moves exactly once along at least one line. If multiple blocking lines are to be created, the laser radiation moves exactly once along the line. In this case, at least one blocking line is simultaneously introduced into the first planar electrode and the active layer or layer sequence (and optionally the second planar electrode). The method according to the invention is particularly suitable for such time-saving generation of one or more blocking lines, especially by appropriate selection of the laser radiation parameters (especially wavelength, power density, and movement speed). However, in an alternative embodiment, the laser radiation can be moved twice or several times along at least one line, so that a complete blocking line, i.e., a complete electrical blocking of a segment of one or more planar electrodes and the active layer or layer sequence, is gradually generated in several cycles.

[0033] The line width of the blocking line according to the invention may be, for example, 500 μm or less. In a preferred embodiment of the invention, the line width is 10 μm to 150 μm, particularly preferably 20 μm to 100 μm. Particularly good results are obtained in this line width range. On the one hand, the blocking line has a width sufficient to provide effective blocking of the layer. On the other hand, the line width is advantageously small enough to be barely visible to the observer. Blocking lines with such small line widths can be difficult to achieve by mechanical processing methods, or cannot be achieved at all. In the method according to the invention, the line width can be adjusted, in particular, by expanding the focus of the laser radiation and the power of the laser radiation.

[0034] The active layer or layer sequence has variable optical properties, which can be controlled by applying a voltage to the active layer via the planar electrodes. The optical properties of the active layer or layer sequence can be controlled by applying a voltage to the planar electrodes or by varying the voltage applied to the planar electrodes. Variable optical properties relate in particular to the degree of light transmission and / or the degree of light scattering, where light in the sense of the present invention is understood to mean visible light, in particular in the spectral range from 380 nm to 780 nm. In the context of the present invention, electrically controllable optical properties are understood in particular to mean such properties that are continuously controllable. In the context of the present invention, the switching state of the multilayer film refers to the degree to which the optical properties change compared to the no-voltage state. A 0% switching state corresponds to a no-voltage state, while a 100% switching state corresponds to the maximum change in the optical properties. Between these two states, all switching states can be continuously achieved by appropriately selecting the voltage. A 20% switching state, for example, corresponds to a 20% change of the maximum change in the optical properties. The optical properties relate in particular to light transmittance and / or scattering behavior. However, in principle, it is also conceivable that the electrically controllable optical properties can only be switched between two discrete states. In that case, there are only two switching states: 0% and 100%. It is also conceivable that the electrically controllable optical properties can be switched between more than two discrete states.

[0035] The two planar electrodes and the active layer or layer sequence located between them form the actual electrically controllable functional element of the multilayer film according to the invention. The functional element can in principle be any functional element with electrically controllable optical properties known per se to those skilled in the art. The composition of the active layer or layer sequence depends on the type of functional element.

[0036] In a particularly preferred embodiment, the multilayer film according to the invention is an electrochromic multilayer film and the functional element is an electrochromic functional element. The electrochromic functional element comprises an active layer sequence (electrochromic layer sequence) between planar electrodes. The active layer or layer sequence according to the invention is therefore an electrochromic active layer sequence. The active layer sequence comprises the following, arranged in the specified order and one above the other in a planar manner: - ion storage layer, - an electrolyte layer, and - Electrochromic layer. At least one interruption line extends through all layers of the layer sequence and in each case divides them into electrically isolated segments, with the ion storage layer preferably facing the first planar electrode and particularly preferably in direct tactile contact with it, and the electrochromic layer facing the second planar electrode and particularly preferably in direct tactile contact with it.

[0037] The electrochromic layer is the actual carrier of electrically controllable optical properties. It is an electrochemically active layer, the light transmittance of which depends on the degree of storage of ions (e.g. H + -, Li + , Na + - or K +The ions are stored in and supplied by the ion storage layer. The electrolyte layer spatially separates the electrochromic layer from the ion storage layer and facilitates ion migration. When a DC voltage of appropriate polarity is applied to the planar electrodes, ions migrate from the ion storage layer through the electrolyte layer into the electrochromic layer, and the optical properties (color, light transmittance) of the electrochromic layer change according to the extent of the ions migrated. When a DC voltage of opposite polarity is applied to the planar electrodes, ions migrate back from the electrochromic layer through the electrolyte layer into the ion storage layer, and the optical properties of the electrochromic layer change in the opposite manner. When no voltage is applied to the planar electrodes, the current state remains stable. Suitable electrochromic layers contain electrochromic materials, such as inorganic oxides (such as tungsten oxide or vanadium oxide), complex compounds (such as Berlin blue), or conductive polymers (such as 3,4-polyethylenedioxythiophene (PEDOT) or polyaniline). Electrochromic functional elements are known, for example, from WO 2012007334, US 2012 / 0026573, WO 2010147494, and EP 1862849. The electrolyte layer is typically designed as a film of an organic or inorganic, electrically insulating material with high ionic conductivity, based, for example, on lithium phosphate oxynitride. The ion storage layer is either permanently transparent (pure ion storage) or has electrochromic behavior opposite to that of the electrochromic layer. An example of a pure ion storage layer is a layer containing a mixed oxide of titanium and cerium; an example of an anodic electrochromic ion storage layer is a layer containing iridium oxide or nickel oxide.

[0038] Experience has shown that in conventional segmented electrochromic multilayer films, it is particularly often observed that the switching state of an individual segment has an undesirable effect on adjacent segments, causing undesirable changes in their optical properties. The inventors believe that this is due to the fact that the active layer sequence of the electrochromic multilayer film has semiconducting properties, which are particularly favorable for charge transport. This destructive effect can be effectively prevented by the blocking line according to the present invention, which makes the present invention particularly advantageous for electrochromic multilayer films.

[0039] It has been shown that complete separation of the segments is already achieved when only the first planar electrode and the active layer sequence in an electrochromic multilayer film are divided into segments that are separated from each other by at least one separation line. Segmentation of the second planar electrode is not necessary for this purpose and is therefore omitted in preferred embodiments. Therefore, preferably, the separation line does not extend through the second planar electrode or extends only partially through it (preferably over less than 50%, particularly preferably less than 30%, and in particular less than 20% of its layer thickness). Optionally, however, the separation line may extend through the second planar electrode, thereby dividing the latter into separate segments to further improve separation.

[0040] In electrochromic multilayer films, very particularly good results are obtained if the width of the interruption line is between 30 μm and 50 μm.

[0041] In a further preferred embodiment, the multilayer film according to the invention is a PDLC multilayer film, and the functional element is a PDLC (polymer dispersed liquid crystal) functional element. A PDLC functional element comprises an active layer between planar electrodes. The active layer or layer sequence according to the invention is thus designated as an active layer. The active layer is a PDLC layer containing liquid crystals embedded in a polymer matrix. PDLC functional elements are typically operated by an alternating voltage. When no voltage is applied to the planar electrodes, the liquid crystals will align in a disordered manner, resulting in strong scattering of light passing through the active layer. When a voltage is applied to the planar electrodes, the liquid crystals will align in a common direction, resulting in increased transmittance of light passing through the active layer. Such functional elements are known, for example, from DE 10 2008 026 339 A1. The term PDLC should be interpreted broadly within the meaning of the present invention and also includes related functional elements based on the alignment of liquid crystals, such as PNLC (polymer network liquid crystal) functional elements.

[0042] In the case of PDLC multilayer films, it has been found that particularly good results are obtained when the first planar electrode, active layer, and second planar electrode are divided into segments electrically isolated from one another by at least one isolation line. Simply segmenting the first planar electrode and active layer through isolation lines can also create independent switching regions, but in this case, the segments of the first planar electrode are electrically controlled independently of one another, while the second planar electrode, which has no isolation lines and collectively forms a counter electrode (reference potential) to all segments of the first planar electrode. When a voltage is applied to one or more of the switching regions, a current flows through the active layer in each switching region, which in turn leads to a shift in the potential in the unsegmented planar electrode due to the latter's electrical resistance. This effect is particularly pronounced because typical planar electrodes have relatively high electrical resistance (planar electrodes cannot be selected for optimal conductivity because they must be transparent to ensure visibility. ITO layers are typically used as planar electrodes, with relatively low conductivity or relatively high electrical resistance). This effect is also called ground shift (shift of reference potential). As a result, a constant voltage occurs in those switching areas that should not actually be switched, and this in turn changes their optical properties to some extent, even if undesired. The second planar electrode is also segmented so that a separate reference electrode is formed for each switching area, thereby advantageously avoiding ground shift and the associated crosstalk.

[0043] In PDLC multilayer films, very particularly good results are obtained if the width of the blocking line is less than 80 μm, for example between 30 μm and 80 μm, preferably between 50 μm and 80 μm.

[0044] In a further embodiment, the multilayer film according to the present invention is an SPD multilayer film and the functional element is an SPD (suspended particle device) functional element. The SPD functional element comprises an active layer between planar electrodes. The active layer comprises suspended particles, preferably embedded in a viscous matrix. The absorption of light through the active layer is changed by applying a voltage to the planar electrodes, which leads to a change in the orientation of the suspended particles. Such functional elements are known, for example, from EP 0 876 608 and WO 2011 / 033313.

[0045] In a further embodiment, the multilayer film is an electroluminescent multilayer film and the functional element is an electroluminescent functional element. The active layer contains an electroluminescent material, which can be inorganic or organic (OLED). The light emission of the active layer is excited by applying a voltage to the planar electrodes. Such functional elements are known, for example, from US Patent Application Publication No. 2004 / 227462 and WO 2010 / 112789.

[0046] The planar electrodes are provided for electrical connection to at least one external voltage source in a manner known per se. The electrical connection is provided by a suitable connecting cable, e.g., a foil conductor, which is optionally connected to the planar electrodes via a so-called busbar, e.g., a strip of conductive material or a conductive imprint. The connecting cable can be attached to the conductive layer before or after the introduction of the non-conductive wire according to the invention, for example, by soldering, gluing or insertion into a multilayer film.

[0047] The planar electrodes are preferably transparent, which in the context of the present invention means that they have a light transmittance in the visible spectral range of at least 50%, preferably at least 70%, particularly preferably at least 80%. Planar electrodes are in particular conductive thin films or thin film stacks. Planar electrodes preferably contain at least one metal, metal alloy, or transparent conductive oxide (TCO). Planar electrodes particularly preferably contain at least one transparent conductive oxide. Planar electrodes may be based, for example, on silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium- or aluminum-doped zinc oxide, and / or fluorine- or antimony-doped tin oxide, preferably silver or ITO, in particular ITO. Planar electrodes preferably have a thickness of 10 nm to 2 μm, particularly preferably 20 nm to 1 μm, very particularly preferably 30 nm to 500 nm, in particular 50 nm to 200 nm. When a thin film is formed based on a material, this means, according to the present invention, that the majority of the layer (more than 50% by weight, preferably more than 90% by weight, in particular more than 99% by weight) consists of that material, the layer may contain other materials, such as doping, to a small extent.

[0048] The carrier film preferably contains or is based on at least one thermoplastic polymer, particularly preferably polyethylene terephthalate (PET), polypropylene, polyvinyl chloride, fluorinated ethylene propylene, polyvinyl fluoride, or ethylene tetrafluoroethylene, and very particularly preferably PET. This is particularly advantageous in terms of the stability of the multilayer film. The thickness of each carrier film is preferably 0.1 mm to 1 mm, particularly preferably 0.1 mm to 0.5 mm, and especially 0.1 mm to 0.2 mm. On the one hand, the small thickness of the glazing in which the multilayer film is used is achieved by a carrier film having such a small thickness. On the other hand, effective protection of the active layer and the conductive layer is ensured. In the method according to the invention, the carrier film is preferably not damaged, i.e., no blocking lines extend onto the carrier film. When the polymer layer is based on a material, this means that, according to the invention, the majority (more than 50% by weight) of the layer consists of that material; the layer may contain other materials, such as plasticizers, stabilizers, or UV-blocking agents.

[0049] The side edges of the multilayer film can be sealed, for example by bonding a carrier film or by a (preferably polymeric) tape, in order to protect the active layer from components (especially plasticizers) of the intermediate layer of the laminated pane in which the multilayer film is embedded, which may diffuse into the active layer and thereby degrade the functional element.

[0050] In addition to the active layer or layer sequence, the planar electrode and the carrier film, the multilayer film may have further layers which are known per se, such as barrier layers, blocker layers, antireflection or reflective layers, protective layers and / or smoothing layers.

[0051] The laser radiation is directed onto the multilayer film and enters it through the carrier film. It irradiates the first planar electrode and the active layer or layer sequence (and optionally the second planar electrode), thereby introducing one or more insulating lines according to the invention into these elements and dividing them into segments that are (at least for the most part) electrically isolated from one another. For this purpose, the laser radiation moves along at least one line, creating at least one insulating line.

[0052] The laser radiation is preferably focused onto the multilayer film by at least one optical element, such as a lens or objective lens. The laser radiation can be focused, for example, onto the carrier film facing the laser, onto the first planar electrode facing the laser, or onto the surface of the active layer or layer sequence facing the laser. This allows the focal points of the laser radiation to be arranged in one plane with different exit angles, allowing a constant speed of movement of the laser radiation across the multilayer film.

[0053] The focal length of the focusing element determines the focusing range of the laser radiation. The focal length of the focusing optical element is preferably 5 cm to 100 cm, particularly preferably 10 cm to 40 cm. In this way, particularly good results are obtained. A relatively small focal length of the optical element requires an excessively small working distance between the multilayer film and the optical element. A relatively large focal length of the optical element leads to an excessively large extension of the laser focus, thereby limiting the resolution of the structuring method and the power density at the focus.

[0054] Between the laser and the focusing optics, the laser radiation may be guided through at least one optical fiber, such as a glass fiber. For example, the following optical elements may be placed in the beam path of the laser: a collimator, an aperture, a filter, or a frequency doubling element.

[0055] The cutoff line is created by moving the laser irradiation relative to the multilayer film. In an advantageous embodiment, the multilayer film is stationary during the introduction of the cutoff line, and the laser irradiation is moved across one or more planar electrodes and one or more active layers. The movement of the laser irradiation is preferably carried out by at least one mirror connected to a movable part. The mirror can be tilted in two directions, preferably in two mutually perpendicular directions, particularly preferably horizontally and vertically, using the movable part. The movement of the laser irradiation can also be carried out by multiple mirrors, each connected to a movable part. For example, the laser irradiation can be moved by two mirrors, one of which can be tilted horizontally and the other can be tilted vertically. Alternatively, the movement of the laser irradiation can be carried out by moving a focusing element and a laser, or by moving a focusing element and an optical fiber, across a stationary multilayer film. Alternatively, the laser irradiation can be stationary, and the multilayer film can be moved to introduce the cutoff line.

[0056] The laser beam preferably moves across the multilayer film at a speed of 100 mm / s to 10,000 mm / s, particularly preferably 200 mm / s to 5,000 mm / s, very particularly preferably 300 mm / s to 2,000 mm / s, for example 500 mm / s to 1,000 mm / s. In this way, particularly good results are obtained.

[0057] The wavelength of the laser radiation used to introduce conductive lines into the conductive layer is appropriately selected so that the planar electrodes and the active layer(s) exhibit a sufficiently high absorption of the laser radiation and the carrier film exhibits a sufficiently low absorption of the laser radiation, so that lines can be selectively introduced into the functional element, advantageously without damaging the carrier film.

[0058] The wavelength is preferably in the range of 200 nm to 1200 nm. It is particularly preferable to use laser radiation in the UV range or in the visible range, preferably 200 nm to 600 nm, particularly preferably 300 nm to 550 nm.

[0059] It has been found that the best results are obtained using laser radiation in the ultraviolet spectral range (UV range). The wavelength of the laser radiation is preferably 200 nm to 400 nm, more preferably 300 nm to 400 nm, for example 343 nm. For example, frequency-tripled or frequency-doubled solid-state lasers (e.g., Nd:YAG or Yb:YAG lasers), diode lasers, excimer lasers, or dye lasers may be used for this purpose. The use of laser radiation in the UV range is particularly advantageous, especially when the multilayer film is an electrochromic multilayer film.

[0060] However, satisfactory results can also be obtained using laser radiation in the visible spectral range, in particular substantially in the green spectral range. The wavelength of the laser radiation is preferably 500 nm to 600 nm, particularly preferably 510 nm to 550 nm, very particularly preferably 510 nm to 530 nm, for example 515 nm. For example, frequency-doubled solid-state lasers (e.g. Nd:YAG lasers or Yb:YAG lasers), diode lasers or dye lasers may be used for this purpose.

[0061] Alternatively, satisfactory results can be obtained using laser radiation in the infrared spectral range (IR range), in particular in the near-IR range. The wavelength of the laser radiation is preferably 800 nm to 1200 nm, particularly preferably 950 nm to 1100 nm, and very particularly preferably 1000 nm to 1050 nm, for example 1030 nm. For example, a solid-state laser (e.g., an Nd:YAG laser (1064 nm) or an Yb:YAG laser (1030 nm)), a diode laser (e.g., an InGaAs laser), or a gas laser may be used for this purpose. The use of laser radiation in the IR range is particularly advantageous, especially when the multilayer film is a PDLC multilayer film.

[0062] The absorption level of the planar electrode into which the cutoff line is introduced, compared to the laser irradiation, is preferably 0.1% or more, particularly preferably 0.3% or more, for example 0.3% to 20%. The absorption level is very particularly preferably 5% or more, especially preferably 10% or more. The absorption level of the carrier film, compared to the laser irradiation, is preferably 15% or less, particularly preferably 10% or less, very particularly preferably 7% or less.

[0063] In a particularly advantageous embodiment, the ratio of the absorption of the planar electrode and the active layer(s) to the absorption of the carrier film at the wavelength of the laser radiation is 0.5 or more, particularly preferably 1 or more, very particularly preferably 1.5 or more, in particular 2 or more, whereby a blocking line is advantageously introduced selectively.

[0064] The laser is preferably operated in pulsed mode. This is particularly advantageous with regard to high power density and effective introduction of the cutoff line. The pulse frequency is preferably 100 kHz or higher, particularly preferably 100 kHz to 1000 kHz. The pulse length is preferably 50 ns or less, particularly preferably 100 fs to 30 ns. This is particularly advantageous with regard to the power density of the laser during laser structuring. If the multilayer film is an electrochromic multilayer film, particularly good results are obtained using pulse lengths of 1 ns to 25 ns. If the multilayer film is a PDLC multilayer film, particularly good results are obtained using pulse lengths of 100 fs to 1 ps.

[0065] The power of the laser radiation is preferably 0.1 W to 50 W, for example 0.3 W to 10 W. The required power depends, inter alia, on the wavelength of the laser radiation used and the degree of absorption in the layers to be separated and can be determined by a person skilled in the art by simple experiments. It has been found that the power of the laser radiation affects the line width of the cutoff line, with higher powers leading to larger line widths.

[0066] The present invention also includes the use of the multilayer films according to the invention in glazing, in particular in laminated panes, in buildings, for example in access or window areas, or in land, air or water transport, in particular in trains, ships, aircraft and automobiles, for example as rear panes, side panes and / or roof panels.

[0067] The present invention also provides a laminated pane in which at least one multilayer film according to the present invention is arranged in a planar manner between two panes. The multilayer film is preferably embedded in the middle layer of the laminated pane. For this purpose, each carrier film is preferably connected to one pane via at least one thermoplastic adhesive film. The bonding is carried out by methods known per se under the action of heat, vacuum, and / or pressure. The thermoplastic adhesive film comprises at least one thermoplastic polymer, such as ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), particularly preferably PVB. The thickness of the thermoplastic adhesive film is preferably 0.25 mm to 2 mm, for example, with a typical thickness of 0.38 mm or 0.76 mm. The two adhesive films on both sides of the multilayer film preferably protrude circumferentially beyond the multilayer film. The side edges of the multilayer film are particularly preferably surrounded circumferentially by a frame-shaped third thermoplastic adhesive film, which has a recess into which the multilayer film is inserted.

[0068] The panes are preferably made of glass, particularly preferably soda-lime glass, or hard transparent plastic, such as polycarbonate (PC) or polymethyl methacrylate (PMMA). The panes may be clear and transparent, or tinted or colored. The thickness of the panes may vary widely and thus be adapted to the requirements of the individual case. The thickness of each pane is preferably 0.5 mm to 15 mm, particularly preferably 1 mm to 5 mm. The laminated panes may have any three-dimensional shape. They are preferably flat or slightly or strongly curved in one or more directions in space.

[0069] The at least one insulating line according to the present invention may be provided for various purposes. In a first preferred embodiment, the insulating line serves to divide the planar electrode and the active layer or layer sequence into at least two electrically insulating segments (partial regions), each of which forms an independent switching area of ​​the multilayer film. In a laminated pane, each switching area of ​​the multilayer film also forms an independent switching area of ​​the laminated pane. The planar electrodes of each segment are provided to be connected to a voltage source independently of each other, so that a voltage can be applied to each segment independently of the others, thereby controlling its optical properties independently of the other segments. For this purpose, each planar electrode of each segment is connected to an electric cable, preferably via a so-called busbar, which extends beyond the side edges of the multilayer film and, if the multilayer film is laminated in a laminated pane, beyond the side edges of the laminated pane and, if the multilayer film is laminated in a laminated pane, also beyond the side edges of the laminated pane and, depending on the application purpose, can have different shapes: At least one cut-off line may extend from one side edge of the multilayer film to the other side edge, in particular to the opposite side edge. If several cut-off lines are present, they preferably extend substantially parallel to one another. In this way, transition areas of the laminated pane can be produced which extend from one side edge to the opposite side edge and are arranged substantially parallel to one another. The multilayer film can form, for example, an electrically controllable sunscreen for a windshield, which has multiple switching areas arranged substantially horizontally (parallel to the roof edge), allowing the user to darken or provide high light scattering in continuous areas of the sunscreen adjacent to the side edges of the multilayer film, typically facing the upper edge (roof edge) of the windshield, to a degree dependent on the position of the sun. For example, an alternative application could involve a roof panel having switching areas extending between the side edges of the roof panel and each having a different distance from the leading edge or trailing edge. Depending on the position of the sun, the vehicle could then darken or provide high light scattering in different switching areas of the roof panel. Another exemplary application is the production of large glazing for open-plan offices, where the optical properties of various workstation areas can be switched independently of each other. In one development, at least one first cut-off line may extend between a pair of opposing side edges of the multilayer film, and at least one second cut-off line may extend between another pair of opposing side edges. At least two cut-off lines extend crosswise, dividing the functional element into at least four independent switching areas. For example, a roof panel can be realized in which each vehicle occupant (driver, front passenger, two rear passengers) is assigned a separate switching area located above them, the optical properties of which can be controlled independently by each occupant. At least one interruption line has a closed shape, which is designed for example as a geometric figure, a pictogram, a letter, a number or a symbol, which can be made visible in an aesthetically appealing manner by suitable selection of the switching states. - at least one interruption line may originate from a side edge of the multilayer film, may represent a defined shape and may extend back to the same side edge. The defined shape may again be, for example, a geometric figure, a pictogram, a letter, a number or a symbol, which may be made visible by an appropriate selection of the switching state. Compared to the above-mentioned embodiment with the interruption line as a closed form, this embodiment has the advantage that the switching area with a defined shape extends completely to the above-mentioned side edge of the multilayer film, in which case it can be electrically contacted in a visually unobtrusive manner.

[0070] In a second preferred embodiment, the insulating line serves to divide the planar electrode and the active layer or layer sequence into at least two electrically insulating segments (partial regions), at least one of which serves as an independent switching region and at least one of which serves as a region with constant, non-varying optical properties. The planar electrodes of these segments, intended to form the switching region, are connected to a voltage source independently of each other, allowing a voltage to be applied to each switching region (in the case of multiple switching regions: independently of the other segments), thereby controlling its optical properties independently of the other segments. The at least one insulating line may also have a different shape, for example, extending between two side edges. Preferably, the at least one insulating line has a closed shape, which is designed, for example, as a geometric figure, a pictogram, a letter, a number, or a symbol. The geometric figure, pictogram, letter, number, or symbol can be made visible in an aesthetically appealing manner by appropriate selection of the switching state. Thus, the multilayer film is not affected by the switching of the optical properties in the non-controlled segments. In this way, the shapes formed by the non-control segments are made visible in an aesthetically pleasing manner.

[0071] The invention will be explained in more detail with reference to the drawings and exemplary embodiments. The drawings are schematic representations and are not drawn to scale. The drawings do not limit the invention in any way. The following are shown:

[0072] FIG. 1 shows a plan view of one embodiment of a laminated pane according to the invention, having a multilayer film according to the invention.

[0073] FIG. 2 shows a cross section along X-X' through the laminated pane according to FIG.

[0074] FIG. 3 shows a plan view of the multilayer film prior to manufacturing the laminate pane according to FIG.

[0075] FIG. 4 shows a cross section along YY′ through the multilayer film of FIG.

[0076] FIG. 5 shows a cross section along YY′ of a further embodiment of a multilayer film according to the invention.

[0077] FIG. 6 shows a cross section along YY′ of a further embodiment of a multilayer film according to the invention.

[0078] FIG. 7 shows a cross section through a multilayer film according to FIG. 3 during a method according to the invention.

[0079] FIG. 8 shows a plan view of a further embodiment of a multilayer film according to the present invention.

[0080] FIG. 9 shows a plan view of a further embodiment of a multilayer film according to the present invention.

[0081] 1 and 2 each show details of a laminated pane according to the present invention having electrically controllable optical properties. The laminated pane may be used, for example, as a roof panel for a passenger vehicle, and its light transmittance may be electrically controlled in regions. The laminated pane has a first pane 12 (outer pane) and a second pane 13 (inner pane), which are connected to each other by a thermoplastic interlayer. The first pane 12 and the second pane 13 are made of soda-lime glass, which may optionally be tinted. For example, the first pane 12 has a thickness of 2.1 mm, and the second pane 13 has a thickness of 1.6 mm.

[0082] The intermediate layer has a thickness of 0.38 mm and is made of a thermoplastic film made of PVB. The first thermoplastic layer 14a is connected to the first pane 12, and the second thermoplastic layer 14b is connected to the second pane 13. The third thermoplastic layer 14c, located between them, has a notch into which the multilayer film 1 with electrically controllable optical properties is inserted, essentially flush across the entire surface. In this way, the third thermoplastic layer 14c forms a sort of mount or frame for the multilayer film 1, which is approximately 0.3 mm thick and thickens to approximately 0.4 mm in the edge regions due to bus bars used for electrical contact. In this way, the multilayer film 1 is completely sealed and protected within the thermoplastic material. The multilayer film 1 may be, for example, an electrochromic multilayer film, which can be switched from a transparent, uncolored state to a colored state with reduced light transmittance.

[0083] The laminated pane, for example, has four independent switching areas S1, S2, S3, S4 that can set the switching state of the multilayer film 1 independently of one another. The switching areas S1, S2, S3, S4 are arranged one behind the other in a direction from the leading edge to the trailing edge of the roof panel, the terms "leading edge" and "trailing edge" relating to the direction of travel of the vehicle. The switching areas S1, S2, S3, S4 allow the vehicle driver to choose to darken only one area of ​​the laminated pane, instead of the entire laminated pane (e.g., depending on the position of the sun), while the other areas remain transparent.

[0084] The laminated panes have peripheral areas provided with an opaque cover print 15. The cover print 15 is typically made of black enamel. It is imprinted as a printing ink using black pigment and glass frit in a screen printing process and baked into the pane surface. The cover print 15 is applied, for example, to the inner surface of the first pane 12 and also to the inner surface of the second pane 13. The side edges of the multilayer film 1 are covered by this cover print 15.

[0085] 3 and 4 show details of the multilayer film 1 before being laminated into the laminate pane according to FIG. 1. The multilayer film 1 is defined by a first carrier film 5 and a second carrier film 6. The carrier films 5 and 6 are made of PET and have a thickness of, for example, 0.125 mm. The carrier films 5 and 6 are provided with a coating of ITO having a thickness of approximately 100 nm, forming the first planar electrode 3 and the second planar electrode 4. The active layer sequence 2' is disposed between the planar electrodes 3 and 4. The layer sequence 2' is an electrochromic layer sequence and consists of an ion storage layer 2a, an electrolyte layer 2b, and an electrochromic layer 2c. A DC voltage applied to the planar electrodes 3 and 4 can excite ions to migrate from the ion storage layer 2a through the electrolyte layer 2b into the electrochromic layer 2c, and vice versa. The amount of ions in the electrochromic layer 2c determines its optical properties, particularly its light transmittance and color.

[0086] The multilayer film 1 has three interruption lines 7 extending parallel to one another from one side edge to the opposite side edge. The interruption lines 7 separate the first planar electrode 3 and the active layer sequence 2′ into electrically isolated segments. These segments form four independent switching regions S1, S2, S3, and S4 in the multilayer film 1 and beyond of the laminated pane. The second planar electrode 4 is not completely separated into segments by the interruption lines 7; instead, the interruption lines 7 extend only through a portion of the layer thickness of the second planar electrode 4, e.g., approximately 10%. The segments of the first planar electrode 3 are electrically connected to one another and connected to a voltage source independently, allowing the optical properties of the switching regions S1, S2, S3, and S4 to be controlled independently. The unsegmented second planar electrode 4 provides a reference potential for all segments of the first planar electrode 3.

[0087] 5 shows a cross section through a further embodiment of a multilayer film 1 according to the invention. The multilayer film 1 is an electrochromic multilayer film designed essentially as in FIG. 4. In contrast, the insulating lines 7 extend not only through the first planar electrode 3 and the active layer sequence 2′, but also through the second planar electrode 4. In this way, the second planar electrode 4 is also divided by the insulating lines 7 into segments that are electrically isolated from one another and that are in electrical contact with one another independently.

[0088] FIG. 6 shows a cross section through a further embodiment of a multilayer film 1 according to the present invention. It is a PDLC multilayer film. It also has two carrier layers 5, 6 and two planar electrodes 3, 4, which are designed similarly to the electrochromic multilayer film of FIG. 4. An active layer 2 is disposed between the planar electrodes 3, 4. The active layer 2 is a PDLC layer containing liquid crystals in a polymer matrix that can be aligned by an AC voltage applied to the planar electrodes 3, 4. The active layer 2 is transparent. When no voltage is applied, the liquid crystals exist in an unaligned state, leading to a strong light-scattering state. Both the planar electrodes 3, 4 and the active layer 2 are divided into four segments by three interruption lines 7, which form independent switching regions S1, S2, S3, and S4.

[0089] FIG. 7 shows a cross section through the electrochromic multilayer film 1 of FIG. 3 during a method according to the invention. For simplicity, the electrochromic layer sequence 2′ is shown as a single layer. The multilayer film 1 is cut, for example, from a purchased film. Using an fθ lens as a focusing element 10, radiation 9 of a laser 8 passes through the first carrier film 5 at position x0 and is directed toward the planar electrodes 3, 4 and the layer sequence 2′ located therebetween, for example, being focused onto the first planar electrode 3 (FIG. 7a). The radiation 9 can be moved along the direction x across the multilayer film 1 by a movable mirror 11. The movement of the laser radiation 9 leads to laser-induced modification of the first planar electrode 3 and all layers 2a, 2b, 2c of the layer sequence 2′. At a later point in time (FIG. 7b), the radiation 9 has moved from position x0 to position x1, resulting in a blocking line 7 in the first planar electrode 3 and all layers 2a, 2b, 2c of the layer sequence 2′ between positions x0 and x1. The interruption lines 7 are non-conductive linear regions that extend over the entire thickness of the first planar electrode 3 and the electrochromic layer sequence 2', and whose path depends on the direction of movement x. The second planar electrode 4 is only slightly affected by the laser and, in particular, is not completely cut off. The carrier film 5 is not damaged when the interruption lines 7 are introduced.

[0090] The figure should be understood merely as an example for explaining the principles according to the invention. To create the blocking line 7 according to Figure 3, it is advantageous to move the illumination 9 from one side edge (position x0) to the opposite side edge (position x1) of the multilayer film 1.

[0091] Appropriate process control makes it possible to cut through the first planar electrode 3 and the active layer sequence 2′ as well as the second planar electrode 4. This can be achieved by appropriately adapting the parameters of the laser irradiation and / or by repeatedly moving across the line to be cut.

[0092] FIG. 8 shows a further embodiment of the multilayer film 1 according to the present invention, again by way of example, an electrochromic multilayer film. The insulating line 7 represents a closed shape, shown as a square for simplicity. The planar electrodes 3, 4 and the active layer sequence 2′ are separated by the insulating line 7, thereby electrically isolating the enclosed area from the surrounding area. The surrounding area can be provided as a switching area S1, whose optical properties can be electrically controlled. In principle, the enclosed area could also be provided as a switching area, but this would require electrical contact in the viewing area of ​​the laminate pane to which the multilayer film 1 is laminated. This would be visually noticeable and therefore disadvantageous. Therefore, this embodiment is particularly suitable for electrically isolating the enclosed area and thereby exempting it from control of its optical properties. The enclosed area therefore retains its optical properties regardless of the switching state of the surrounding area. The insulating line 7 can, for example, have the shape of a symbol or a company logo, making it visible in an aesthetically appealing manner.

[0093] FIG. 9 shows a further embodiment of the multilayer film 1 according to the present invention, again showing an electrochromic multilayer film as an example. The two ends of the interruption line 7 are arranged on the side edges of the multilayer film 1 at a relatively small distance from each other. Thus, the interruption line 7 extends from the side edge toward the center of the multilayer film 1, where it represents a geometric figure, and then extends back to the same side edge. The two mutually separated partial regions of the planar electrodes 3, 4 and the active layer sequence 2′ can be designed as independent switching regions S1, S2. The switching region S2, surrounded by the interruption line 7, also extends to the side edge of the multilayer film 1, where it can be electrically connected in a visually unobtrusive manner. The geometric figure can be, for example, a symbol used to display information to the user when the switching states of the switching regions S1, S2 are different. [Example]

[0094] An electrochromic multilayer film 1 was provided as shown in FIG. 4. Using the method according to the invention, an interruption line 7 was introduced into the first planar electrode 3 and the active layer sequence 2′ to create a plurality of independent switching regions. The multilayer film 1 was then evaluated by visual inspection. Furthermore, the switching behavior was evaluated, in particular in terms of whether the switching state of a switching region causes an undesired change in the optical properties (leakage) in adjacent switching regions that are actually voltage-free.

[0095] The tests were carried out using laser radiation of various wavelengths and various pulse lengths. A Yb:YAG laser operating in pulsed mode was used in each case as laser 8, which operated with its fundamental radiation (1064 nm), frequency doubled (515 nm, second harmonic), and frequency tripled (343 nm, third harmonic).

[0096] The laser radiation 9 was focused onto and translated across the multilayer film 1 by an fθ lens with a focal length of 250 mm. The power of the laser radiation 9 was 10 W in each case and the translation speed was 1 m / s.

[0097] The observations at different wavelengths and pulse lengths are summarized in Table 1: [1] means optimal results: The segments are electrically isolated (no leaks) and no scorching or blisters occur in the multilayer film 1. [2] means less favorable results: The segments are electrically isolated (no leaks) and no scorching occurs, but blisters occur in the multilayer film 1. [3] means unacceptable results: - The segment is not electrically isolated (there is a leak). - Burning and blisters occur in the multilayer film 1.

[0098] [Table 1]

[0099] The best results were obtained with UV irradiation (343 nm) and pulse lengths in the nanosecond range. Acceptable results with pulse lengths in the femtosecond and picosecond range were obtained with green laser irradiation (515 nm). It is believed that slight defects (blisters) in the multilayer film 1 can be avoided by optimizing the laser parameters. With IR irradiation (1030 nm), acceptable results were obtained only in a single example (pulse length 800 fs).

[0100] This result suggests that when using UV radiation (e.g., 200 nm to 400 nm), pulse lengths in the nanosecond range are preferred (e.g., 1 ns to 25 ns), while when using radiation in the visible and IR ranges (e.g., 500 nm to 600 nm and 950 nm to 1050 nm), pulse lengths in the femtosecond and picosecond ranges are preferred (e.g., 100 fs to 50 ps). The present disclosure includes the following aspects. <Aspect 1> A multilayer film (1) having electrically controllable optical properties, comprising the following, arranged in a specified order and in a planar manner, one on top of the other: (a) a first carrier film (5); (b) first planar electrode (3), (c) an active layer (2) or an active layer sequence (2') having electrically controllable optical properties; (d) a second planar electrode (4), and (e) a second carrier film (6); wherein the first planar electrode (3) and the active layer (2) or active layer sequence (2') are divided into at least two segments electrically isolated from each other by at least one isolation line (7), wherein the at least one interruption line (7) is introduced by a laser (8) through one of the carrier films (5, 6) into the first planar electrode (3) and the active layer (2) or active layer sequence (2'). Multilayer film (1). <Aspect 2> 1. The multilayer film (1) according to claim 1, comprising an electrochromic active layer sequence (2′), wherein the electrochromic active layer sequence (2′) comprises the following, in the specified order and arranged one above the other in a planar manner: - ion storage layer (2a), - an electrolyte layer (2b), and - electrochromic layer (2c). <Aspect 3> A multilayer film (1) according to embodiment 1, which is a PDLC multilayer film having an active layer (2), the active layer (2) being a PDLC layer containing liquid crystals embedded in a polymer matrix, and the second planar electrode (4) also being divided into at least two segments electrically isolated from each other by the at least one insulating line (7). <Aspect 4> 4. The multilayer film (1) according to any one of claims 1 to 3, wherein the interruption line (7) extends through the first planar electrode (3), and the active layer (2) or active layer sequence (2'), and optionally the second planar electrode (4), over the entire layer thickness, and the material of the first planar electrode (3), and the active layer (2) or active layer sequence (2'), and optionally the second planar electrode (4), has been completely removed or chemically modified in the region of the interruption line (7) in order to electrically isolate the segments from each other. <Aspect 5> The multilayer film (1) according to any one of aspects 1 to 4, wherein the line width of the blocking line (7) is 500 μm or less, preferably 10 μm to 150 μm, and particularly preferably 20 μm to 100 μm. <Aspect 6> The multilayer film (1) according to any one of aspects 1 to 5, wherein the carrier films (5, 6) are formed based on polyethylene terephthalate (PET) and have a thickness of 0.1 mm to 0.5 mm. <Aspect 7> 7. The multilayer film (1) according to any one of the preceding embodiments, wherein the planar electrodes (3, 4) are formed based on silver or indium tin oxide (ITO) and have a thickness of 20 nm to 1 μm. <Aspect 8> A laminated pane (V) comprising a multilayer film (1) according to any one of aspects 1 to 7, wherein the multilayer film (1) is arranged between two panes (12, 13), in particular between glass panes, and is connected to each pane (12, 13) via at least one thermoplastic adhesive film (14a, 14b). <Aspect 9> A method for producing a multilayer film (1) having electrically switchable optical properties, comprising the steps of: (A) A multilayer film (1) having electrically controllable optical properties is provided, said multilayer film (1) having at least the following arranged one on top of the other in a specified order and in a planar manner: (a) a first carrier film (5); (b) first planar electrode (3), (c) an active layer (2) or an active layer sequence (2') having electrically controllable optical properties; (d) a second planar electrode (4), and (e) a second carrier film (6); (B) directing laser (8) radiation (9) through the carrier films (5, 6) onto the first planar electrode (3), the active layer (2) or the active layer sequence (2') and the second planar electrode (4); and (C) moving said irradiation (9) along at least one line and introducing at least one interruption line (7) into said first planar electrode (3), and said active layer (2) or active layer sequence (2'), and optionally said second planar electrode (4), thereby dividing said first planar electrode (3), and said active layer (2) or active layer sequence (2'), and optionally said second planar electrode (4), into at least two segments electrically isolated from each other; method. <Aspect 10> 10. The method of claim 9, wherein the irradiation (9) is moved exactly once along the at least one line, and the blocking line (7) is simultaneously introduced into the first planar electrode (3), the active layer (2) or active layer sequence (2'), and optionally the second planar electrode (4). <Aspect 11> The method according to aspect 9 or aspect 10, wherein the wavelength of the irradiation (9) is from 200 nm to 1200 nm, preferably from 300 nm to 550 nm. <Aspect 12> A method according to any one of aspects 9 to 11, wherein the wavelength of the irradiation (9) is 200 nm to 400 nm, preferably 300 nm to 400 nm. <Aspect 13> The method according to any one of aspects 9 to 12, wherein the irradiation (9) is moved at a speed of 100 mm / s to 10,000 mm / s, preferably 200 mm / s to 5,000 mm / s. <Aspect 14> 14. The method according to any one of aspects 9 to 13, wherein the laser (8) is operated in a pulsed mode, with a pulse length preferably equal to or less than 50 ns, preferably between 100 fs and 30 ns. <Aspect 15> Use of the multilayer film (1) according to any one of aspects 1 to 8 in glazing, in particular in laminated panes, in buildings, in particular in access or window areas, or in land, air or water transport, in particular in trains, ships, aircraft and automobiles, for example as a rear pane, side pane and / or roof panel. [Explanation of symbols]

[0101] (1) Multilayer film with electrically controllable optical properties (2) Active layer 1 of the multilayer film (2') Active layer sequence of multilayer film 1 (2a) Ion storage layer of the electrochromic layer sequence 2' (2b) Electrolyte layer of electrochromic layer sequence 2' (2c) Electrochromic layer of electrochromic layer sequence 2' (3) First planar electrode of multilayer film 1 (4) Second planar electrode of multilayer film 1 (5) First carrier film of multilayer film 1 (6) Second carrier film of multilayer film 1 (7) Breaking wire (8) Laser (9) Laser 8 irradiation (10) Focusing element (11) Tiltable mirror (12) First pane (13) Second pane (14a) First thermoplastic resin adhesive film (14b) Second thermoplastic resin adhesive film (14c) Third thermoplastic resin adhesive film (15) Cover printing (V) Stacked panes (S1, S2, S3, S4) Independent switching areas of multilayer film 1 or laminated pane V x Direction of movement of irradiation 9 x0, x1 Position of illumination 9 during the method according to the invention X-X' cutting line Y-Y' cutting line

Claims

1. A multilayer film (1) with electrically controllable optical properties, comprising the following, arranged in a specified order and in a planar manner, one on top of the other: (a) a first carrier film (5), (b) first planar electrode (3), (c) an active layer (2) or an active layer sequence (2') having electrically controllable optical properties; (d) a second planar electrode (4), and (e) a second carrier film (6), wherein the first planar electrode (3) and the active layer (2) or active layer sequence (2') are divided into at least two segments electrically isolated from each other by at least one isolation line (7), wherein the at least one interruption line (7) is introduced into the first planar electrode (3) and the active layer (2) or active layer sequence (2') by a laser (8) passing through one of the carrier films (5, 6), and the at least one interruption line (7) does not extend through the carrier film (5, 6). Multilayer film (1).

2. 10. A multilayer film (1) according to claim 1, comprising an electrochromic active layer sequence (2′), the electrochromic active layer sequence (2′) comprising the following in a specified order and arranged one above the other in a planar manner: an ion storage layer (2a), an electrolyte layer (2b), and - an electrochromic layer (2c).

3. 2. The multilayer film (1) of claim 1, which is a PDLC multilayer film having an active layer (2), the active layer (2) being a PDLC layer containing liquid crystals embedded in a polymer matrix, and wherein the second planar electrode (4) is also divided into at least two segments electrically isolated from each other by the at least one isolation line (7).

4. 4. The multilayer film according to claim 1, wherein the insulating line (7) extends through the first planar electrode (3), the active layer (2) or active layer sequence (2'), and optionally the second planar electrode (4) over the entire layer thickness, and the material of the first planar electrode (3), the active layer (2) or active layer sequence (2'), and optionally the second planar electrode (4) is completely removed or chemically modified in the region of the insulating line (7) in order to electrically isolate the segments from each other.

5. The multilayer film (1) according to any one of claims 1 to 3, wherein the line width of the interrupting line (7) is 500 µm or less.

6. The multilayer film (1) according to any one of claims 1 to 3, wherein the carrier films (5, 6) are made on the basis of polyethylene terephthalate (PET) and have a thickness of 0.1 mm to 0.5 mm.

7. The multilayer film (1) according to any one of claims 1 to 3, wherein the planar electrodes (3, 4) are made on the basis of silver or indium tin oxide (ITO) and have a thickness of 20 nm to 1 μm.

8. A laminated pane (V) comprising a multilayer film (1) according to any one of claims 1 to 3, wherein the multilayer film (1) is arranged between two panes (12, 13) and connected to each pane (12, 13) via at least one thermoplastic adhesive film (14a, 14b).

9. A method for producing a multilayer film (1) with electrically switchable optical properties, comprising: (A) A multilayer film (1) having electrically controllable optical properties is provided, said multilayer film (1) having at least the following arranged in a specified order and in a planar manner, one on top of the other: (a) a first carrier film (5), (b) first planar electrode (3), (c) an active layer (2) or an active layer sequence (2') having electrically controllable optical properties; (d) a second planar electrode (4), and (e) a second carrier film (6), (B) directing a laser (8) radiation (9) through the first carrier film (5) or the second carrier film (6) onto the first planar electrode (3), the active layer (2) or the active layer sequence (2') and the second planar electrode (4); and (C) moving said irradiation (9) along at least one line and introducing at least one interruption line (7) into said first planar electrode (3), and said active layer (2) or active layer sequence (2'), and optionally said second planar electrode (4), thereby dividing said first planar electrode (3), and said active layer (2) or active layer sequence (2'), and optionally said second planar electrode (4), into at least two segments electrically isolated from each other; method.

10. 10. The method according to claim 9, wherein the irradiation (9) is moved exactly once along the at least one line and the interruption line (7) is simultaneously introduced into the first planar electrode (3), the active layer (2) or active layer sequence (2'), and optionally into the second planar electrode (4).

11. The method according to claim 9 or claim 10, wherein the wavelength of the radiation (9) is between 200 nm and 1200 nm.

12. The method according to any one of claims 9 or 10, wherein the wavelength of the radiation (9) is between 200 nm and 400 nm.

13. The method according to claim 9 or claim 10, wherein the illumination (9) is moved at a speed of between 100 mm / s and 10,000 mm / s.

14. 11. A method according to claim 9 or claim 10, wherein the laser (8) is operated in pulsed mode, with a pulse length of 50 ns or less.

15. Use of a multilayer film (1) according to any one of claims 1 to 3 in glazing, in buildings or in land, air or water transport.

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