Composite pane with electro-optical functional element and design element

Abstract

The invention relates to a composite pane (1) at least comprising an outer pane (2), a first thermoplastic intermediate layer (3), and electro-optical functional element (4), a second thermoplastic intermediate layer (5), a design element (6), and an inner pane (7), wherein the functional element (4) is arranged in a region of the composite pane (1) between the outer pane (2) and the inner pane (7); the first thermoplastic intermediate layer (3) is arranged between the outer pane (2) and the electro-optical functional element (4); the second thermoplastic intermediate layer (5) is arranged between the electro-optical functional element (4) and the inner pane (7); the design element (6) is arranged in a region of the composite pane (1) which, when viewed through the composite pane (1), lies completely in the region in which the electro-optical functional element (4) is arranged; the electro-optical functional element (4) can be electrically controlled from a first state, in which the functional element has a first color, into a second state, in which the functional element has a second color, and vice versa; and the design element (6) has a third color which corresponds to the first color of the electro-optical functional element (4).

Description

[0001] Composite pane with electro-optical functional element and design element

[0002] The invention relates to a composite pane with an electro-optical functional element and a design element.

[0003] Composite panes with electrically controllable optical properties are known as such. They include composite panes equipped with electro-optical functional elements, i.e., functional elements whose optical properties can be changed by an applied electrical voltage. Examples of electro-optical functional elements are SPD functional elements (SPD = Suspended Particle Device), known, for example, from EP 0876608 B1 and WO 2011033313 A1, and PDLC functional elements (PDLC = Polymer Dispersed Liquid Crystal), known, for example, from DE 102008026339 A1.

[0004] WO 2019 / 086653 A1 discloses a composite pane comprising a laminated stack of an outer pane, a first intermediate layer, a second intermediate layer, and an inner pane, and a functional element with electrically controllable optical properties, which is arranged at least partially between the first intermediate layer and the second intermediate layer. At least one transparent body is arranged in sections between the outer pane and the functional element and / or between the inner pane and the functional element. The contour of the transparent body remains visible to the human eye over the entire operating range of the functional element.

[0005] There is increasing interest in providing the laminated panes with electrically controllable properties with characters such as lettering, symbols, logos, trademarks or simple graphics which are visually prominent for an observer in one state of the electro-optical functional element and are not visually prominent for the observer in another state of the electro-optical functional element.

[0006] It is known to incorporate switchable patterns into a PDLC element by laser segmentation. CN 110471206 A discloses a method for producing a PDLC film with patterns and / or text by direct laser etching. However, not every structure can be incorporated into a PDLC functional element using laser segmentation, since, for example, minimum distances between the laser lines and minimum radii must be observed.

[0007] WO 2021 / 105070 A1 discloses a method for producing an optical device which is operable in at least two optical states and electrically switchable between them, wherein in one of the optical states an image with at least one closed feature can be displayed by combining open shapes.

[0008] The object of the invention is to provide an improved composite pane with an electro-optical functional element and a design element. Furthermore, the composite pane should be capable of being manufactured in a simple and cost-effective manner.

[0009] The problem is solved by a composite pane and by methods according to the independent patent claims.

[0010] The invention relates to a composite pane comprising at least an outer pane, a first thermoplastic intermediate layer, an electro-optical functional element, a second thermoplastic intermediate layer, a design element, and an inner pane. The electro-optical functional element is arranged in a region of the composite pane between the outer pane and the inner pane. The first thermoplastic intermediate layer is arranged between the electro-optical functional element and the outer pane, and the second thermoplastic intermediate layer is arranged between the electro-optical functional element and the inner pane. The design element is arranged in a region of the composite pane which, when viewed through the composite pane, lies entirely in the region in which the electro-optical functional element is arranged.

[0011] The electro-optical functional element can be electrically controlled from a first state, in which it has a first color, to a second state, in which it has a second color. In addition, the electro-optical functional element can also be electrically controlled conversely, from the second state to the first state. It is understood that the first color and the second color of the electro-optical functional element are different, i.e. the first color and the second color do not correspond to one another. According to the invention, the design element has a third color, which corresponds to the first color of the electro-optical functional element, i.e. the color of the electro-optical functional element in the first state. Thus, the electro-optical functional element in the first state and the design element have the same color.Since the first color and the second color of the electro-optical functional element do not correspond to one another and the third color of the design element corresponds to the first color of the electro-optical functional element, it is understood that the third color of the design element does not correspond to the second color of the electro-optical functional element. When the electro-optical functional element is present in the composite pane in the first state, the design element does not stand out visually. The design element and its contours are therefore not recognizable as such by the observer when the electro-optical functional element is present in the composite pane in the first state. The observer therefore perceives the electro-optical functional element together with the design element as a homogeneous element of a constant color. However, when the electro-optical functional element is present in the composite pane in the second state, the design element stands out visually due to its third color.The viewer can therefore clearly see the design element and its contours when the electro-optical functional element in the composite pane is in its second state.

[0012] The design element can be arranged in front of or behind the electro-optical functional element when viewed through the composite pane. Preferably, the design element is arranged behind the electro-optical functional element, as seen from the viewer's perspective.

[0013] It is understood that the design element does not necessarily have to be formed in one piece; the design element can also be formed from a plurality of elements which can be arranged directly adjacent to one another or at a distance from one another. For example, the design element can be designed as lettering, a symbol, a simple graphic, or a logo. The design element can also be designed as lettering and a simple graphic, for example, with the lettering and the simple graphic being arranged in different areas of the composite pane. As described above, the design element is arranged in an area of ​​the composite pane which, when viewed through the composite pane, lies entirely in the area in which the electro-optical functional element is arranged.It is understood that if the design element is formed from a plurality of elements, each of these elements, when viewed through the composite pane, lies entirely in the area in which the electro-optical functional element is arranged.

[0014] If the composite pane is intended to separate an interior space from the exterior environment in a window opening of a vehicle or building, the inner pane, within the meaning of the invention, refers to the pane facing the interior (vehicle interior). The outer pane refers to the pane facing the exterior environment. If the composite pane is intended to separate a room from a hallway, for example, in a window opening in a building, the inner pane, within the meaning of the invention, refers to the pane facing the interior, and the outer pane refers to the pane facing the hallway.

[0015] The outer pane and the inner pane each have an outer surface and an inner surface, and a circumferential side edge running between them. For the purposes of the invention, the "outer surface" refers to the main surface intended to face the outside environment in the installed position. For the purposes of the invention, the "interior surface" refers to the main surface intended to face the interior in the installed position. The interior surface of the outer pane and the outer surface of the inner pane face each other and are connected by the thermoplastic intermediate layer.

[0016] The outside surface of the outer pane is called Side I. The inside surface of the outer pane is called Side II. The outside surface of the inner pane is called Side III. The inside surface of the inner pane is called Side IV.

[0017] In a preferred embodiment of a composite pane according to the invention, the design element is formed as a print on one of the pane surfaces. In one embodiment, the design element is formed as a print on the outside surface of the outer pane. In an alternative embodiment, the design element is formed as a print on the inside surface of the outer pane. In an alternative embodiment, the design element is formed as a print on the outside surface of the inner pane. In an alternative embodiment, the design element is formed as a print on the inside surface of the inner pane.

[0018] Preferred embodiments are those in which the design element is formed as a print on the outside surface of the outer pane or as a print on the inside surface of the inner pane.

[0019] Particularly preferred are embodiments in which the design element is designed as a print on the interior surface of the outer pane or as a print on the exterior surface of the inner pane, since in these embodiments the design element is arranged in the interior of the composite pane and is thus protected from external influences.

[0020] A design element formed as an imprint on one of the pane surfaces is typically made of an enamel containing glass frits and a pigment. By selecting the pigment, the third color of the design element can be adjusted to match the first color of the functional element. Suitable pigments are known to those skilled in the art.

[0021] In an advantageous embodiment of the invention, a design element formed as a print on one of the pane surfaces has a thickness of 5 pm (micrometers) to 40 pm, preferably 10 pm to 25 pm. In an alternative advantageous embodiment, a design element formed as a print on one of the pane surfaces has a thickness of less than 5 pm.

[0022] In an alternative preferred embodiment of a composite pane according to the invention, the design element is formed as a print on the first thermoplastic intermediate layer or as a print on the second thermoplastic intermediate layer. The print can be arranged on the first thermoplastic intermediate layer either on the surface which, in the composite pane, faces towards the outer pane or on the surface which, in the composite pane, faces towards the electro-optical functional element. The print can be arranged on the second thermoplastic intermediate layer either on the surface which, in the composite pane, faces towards the inner pane or on the surface which, in the composite pane, faces towards the electro-optical functional element.In these embodiments, the print is preferably arranged on the first thermoplastic intermediate layer on the surface facing the outer pane in the composite pane, or on the second thermoplastic intermediate layer on the surface facing the inner pane in the composite pane. This arrangement of the print is particularly advantageous because the first or second thermoplastic intermediate layer is then arranged between the print and the electro-optical functional element, thus preventing the design element from exerting pressure on the active layer of the electro-optical functional element.

[0023] A design element formed as a print on the first thermoplastic intermediate layer or as a print on the second thermoplastic intermediate layer is typically formed from a composition containing water- or solvent-based color pigments or dyes.

[0024] In an advantageous embodiment of the invention, a design element formed as a print on the first thermoplastic intermediate layer or the second thermoplastic intermediate layer has a thickness of 5 pm (micrometers) to 40 pm, preferably from 5 pm to 20 pm. In an alternative advantageous embodiment, a design element formed as a print on the first thermoplastic intermediate layer or the second thermoplastic intermediate layer has a thickness of less than 5 pm.

[0025] In an alternative preferred embodiment of a composite pane according to the invention, the design element is designed as an insert element. The insert element is a prefabricated element that is arranged in the layer stack to be laminated during the manufacture of the composite pane prior to lamination. A design element designed as an insert element can be arranged in the composite pane according to the invention between the electro-optical functional element and the first thermoplastic intermediate layer, or between the electro-optical functional element and the second thermoplastic intermediate layer, or between the first thermoplastic intermediate layer and the outer pane, or between the second thermoplastic intermediate layer and the inner pane.

[0026] Preferably, the insert element is arranged between the outer pane and the first thermoplastic intermediate layer or between the inner pane and the second thermoplastic intermediate layer. This arrangement of the insert element is particularly advantageous because the first or second thermoplastic intermediate layer is then arranged between the insert element and the electro-optical functional element, thus preventing the insert element from exerting pressure on the active layer of the electro-optical functional element.

[0027] Preferably, the insert element comprises or consists of colored polyethylene terephthalate (PET), polyvinyl butyral (PVB), polyethylene (PE) or ethylene vinyl acetate (EVA).

[0028] The insert element is preferably between 10 pm (micrometers) and 80 pm, more preferably between 20 pm and 60 pm, and most preferably between 25 pm and 50 pm thick. In preferred embodiments, the insert element is 25 pm or 50 pm thick. In an alternative embodiment, the insert element can also be less than 5 pm thick.

[0029] In an alternative preferred embodiment of a composite pane according to the invention, the design element is designed as an adhesive tape, wherein the adhesive tape is glued to the outside surface of the outer pane, to the inside surface of the outer pane, to the outside surface of the inner pane or to the inside surface of the inner pane.

[0030] Particularly preferred embodiments are those in which the design element is designed as an adhesive tape bonded to the outside surface of the outer pane or as an adhesive tape bonded to the inside surface of the inner pane, since in these cases the adhesive tape can be bonded in particular only after lamination of a stacking sequence to form a composite pane and does not necessarily have to be bonded before lamination. In these embodiments, it is also possible to remove the design element from the pane to which it is bonded at a later time and to bond on a differently shaped design element in the form of an adhesive tape. The replacement of the design element is thus possible without difficulty in these embodiments, in particular without damaging the other components of the composite pane according to the invention.

[0031] In an alternative preferred embodiment of a composite pane according to the invention, the design element is formed as a satin-finished region of one of the pane surfaces. In one embodiment, the design element is formed as a satin-finished region of the outside surface of the outer pane. In an alternative embodiment, the design element is formed as a satin-finished region of the inside surface of the outer pane. In an alternative embodiment, the design element is formed as a satin-finished region of the outside surface of the inner pane. In an alternative embodiment, the design element is formed as a satin-finished region of the inside surface of the inner pane.

[0032] A satin-finished area is defined as a roughened area. The satin-finished area can be created on the window surface by roughening the area to be satin-finished, for example, using sandblasting or treatment with hydrofluoric acid (etching) or hydrofluoric acid vapor. The areas of the window surface that are not to be satin-finished are covered, for example, with stencils and / or adhesive films. Stencils and adhesive films can also be computer-aided.

[0033] With sandblasting, the desired area of ​​the disc surface can be blasted with sand. However, for health reasons, fine corundum grains are typically used for blasting ("blasting corundum"). Blasting corundum is a synthetic, mineral blasting media and is melted from high-quality bauxite or alumina in an arc furnace at over 2000°C. It is also used in the production of grinding wheels and sandpaper. Blasting corundum is not hygroscopic. Selecting different grain sizes results in different degrees of roughness and thus different design options.

[0034] The production of the satin-finished area of ​​a window surface by etching, for example, using hydrofluoric acid as the etching medium, is preferred because the satin-finished area can be formed more homogeneously than by sandblasting. Depending on the process, the concentration of the reactants, the temperature of the etching medium, and the chemical composition of the glass, the optical appearance of the satin-finished window surface can vary after treatment. To limit the etching to the desired area, adhesive film can be used, which is removed after the etching process. Another option for producing a satin-finished area of ​​a window surface is laser processing.

[0035] In preferred embodiments, the design element has a thickness of less than 50 pm, preferably less than 25 pm, particularly preferably less than 12.5 pm, most particularly preferably less than 5 pm.

[0036] In a preferred embodiment of the composite pane according to the invention, the design element is formed on the outer surface of the outer pane or on the interior surface of the inner pane. This embodiment is particularly advantageous because, with design elements formed on the outer surface of the outer pane or on the interior surface of the inner pane, it is impossible for the design element to exert pressure on the active layer of the electro-optical functional element.

[0037] Particularly preferred are therefore embodiments in which the design element is designed as a print on the outside surface of the outer pane, as a print on the inside surface of the inner pane, as an adhesive tape glued to the outside surface of the outer pane, as an adhesive tape glued to the inside surface of the inner pane, as a satin-finished area of ​​the outside surface of the outer pane or as a satin-finished area of ​​the inside surface of the inner pane.

[0038] The electro-optical functional element is preferably arranged over a large area in the composite pane. The electro-optical functional element is preferably smaller in area than the composite pane; for example, the edges of the electro-optical functional element are spaced between 2 mm and 20 mm from the respective nearest edge of the composite pane. The electro-optical functional element is thus encapsulated by the thermoplastic intermediate layers and protected from contact with the ambient atmosphere and corrosion.

[0039] In a preferred embodiment of a composite pane according to the invention, the composite pane additionally has a third thermoplastic intermediate layer, and the functional element is surrounded all around by the third thermoplastic intermediate layer. The third thermoplastic intermediate layer is frame-like with a recess into which the electro-optical functional element is inserted. The outer dimensions of the recess, i.e. the length and width, correspond to the dimensions of the electro-optical functional element, so that the latter is arranged flush in the recess. There is therefore no gap between the electro-optical functional element and the third thermoplastic intermediate layer. The third thermoplastic intermediate layer can be formed by a thermoplastic film into which the recess has been cut out.Alternatively, the third thermoplastic intermediate layer can also be composed of several film sections around the electro-optical functional element. The third thermoplastic intermediate layer preferably has the same thickness as the electro-optical functional element. This allows, if necessary, the local thickness difference of the composite pane introduced by the locally limited electro-optical functional element to be compensated, thus preventing glass breakage during lamination.

[0040] The electro-optical functional element is in particular a PDLC functional element, an SPD functional element, a PNLC functional element, an electrochromic functional element or a functional element with liquid crystal dye cells.

[0041] In a preferred embodiment of a composite pane according to the invention, the electro-optical functional element is a PDLC functional element (PDLC = polymer dispersed liquid crystal). The active layer of a PDLC functional element contains liquid crystals embedded in a polymer matrix. If no voltage is applied to the surface electrodes, the liquid crystals are randomly aligned, which leads to strong scattering of the light passing through the active layer. If a voltage is applied to the surface electrodes, the liquid crystals align in a common direction, and the transmission of light through the active layer is increased. PDLC functional elements are known, for example, from US 20150301367 A1.

[0042] In a further preferred embodiment of a composite pane according to the invention, the electro-optical functional element is an SPD functional element (SPD = suspended particle device). The principle is similar to that of PDLC functional elements, except that in SPD functional elements, suspension droplets in which light-polarizing particles are suspended are not liquid crystal droplets embedded in a polymer matrix. Such systems are described, for example, in EP 0551138 A1. In a further preferred embodiment of a composite pane according to the invention, the electro-optical functional element is a PNLC functional element (PNLC = polymer network liquid crystal). The active layer contains liquid crystals embedded in a polymer network, the functionality otherwise being analogous to that of a PDLC functional element.

[0043] In a further preferred embodiment of a composite pane according to the invention, the electro-optical functional element is an electrochromic functional element. In this case, the transmission of visible light through the electro-optical functional element depends on the degree of ion incorporation. The ions are released, for example, through an ion storage layer and incorporated into an electrochromic layer. The light transmission can be influenced by the voltage applied to the electro-optical functional element, which causes the ions to migrate. Suitable electrochromic layers preferably contain at least tungsten oxide or vanadium oxide.

[0044] In a further preferred embodiment of a composite pane according to the invention, the electro-optical functional element is a functional element with liquid crystal dye cells (so-called guest-host cells).

[0045] PDLC, SPD, and PNLC functional elements, electrochromic functional elements, and functional elements with liquid crystal dye cells are commercially available as functional elements. The electro-optical functional elements mentioned and their mode of operation are known per se to those skilled in the art, so a detailed description is unnecessary here.

[0046] Delta E (AE) can be used to determine whether a color difference is noticeable to an observer. AE is a measure of the distance between two colors and indicates whether the difference between two colors can be perceived. It is therefore a relative measure with reference to the peculiarities of human color perception. An AE always refers to two colors that are to be compared. AE is calculated by calculating the Euclidean distance between the a*, b*, and L* values. The symbols a* and b* are values ​​of the L*a*b* color space, a color model that describes all perceivable colors. L* indicates the brightness value and can have values ​​between 0 and 100, a* indicates the chromaticity and color intensity between green and red, while b* indicates the chromaticity and color intensity between blue and yellow. The more negative or positive the values ​​of b* and a* are, the more intense the hue.For values ​​close to 0 for a* and b*, the color tone is rather dull, i.e. neutral.

[0047] The fact that the third color of the design element corresponds to the first color of the electro-optical functional element, i.e. the color of the electro-optical functional element in the first state, means in the context of this application that the color difference AE between the third color of the design element and the first color of the electro-optical functional element is less than or equal to 10, preferably less than or equal to 5, particularly preferably less than or equal to 2. Thus, no color difference is perceptible to an observer between the design element and the electro-optical functional element in the first state.

[0048] The formula for calculating AE is as follows: with

[0049] Li* = luminance of the electro-optical functional element in the first state

[0050] L2* = Luminance of the design element ai* = Value for the green or red component of the first color of the electro-optical functional element a2* = Value for the green or red component of the third color of the design element bi* = Value for the blue or yellow component of the first color of the electro-optical functional element b2* = Value for the blue or yellow component of the third color of the design element

[0051] AE = Euclidean distance between the L*a*b* values ​​of the first color of the electro-optical functional element and the L*a*b* values ​​of the third color of the design element

[0052] Common measurement methods for determining a*, b*, and L* values ​​of the L*a*b* color space (CIELAB) are generally known to those skilled in the art. As described above, the first color and the second color of the electro-optical functional element do not correspond to each other, and the third color of the design element, which corresponds to the first color of the electro-optical functional element, therefore also does not correspond to the second color of the electro-optical functional element.

[0053] The fact that the third color of the design element does not correspond to the second color of the electro-optical functional element, i.e., the color of the electro-optical functional element in the second state, means in the context of this application that the color difference between the third color of the design element and the second color of the electro-optical functional element is greater than 10. Thus, a viewer can perceive a color difference between the design element and the electro-optical functional element in the second state.

[0054] The formula for calculating the color difference between the third color of the design element and the second color of the electro-optical functional element is analogous to the calculation of the color difference between the third color of the design element and the first color of the electro-optical functional element as follows: with

[0055] L3* = luminance of the electro-optical functional element in the second state

[0056] L2* = luminance of the design element

[0057] 33* = Value for the green or red component of the second color of the electro-optical functional element a2* = Value for the green or red component of the third color of the design element bs* = Value for the blue or yellow component of the second color of the electro-optical functional element b2* = Value for the blue or yellow component of the third color of the design element

[0058] AE' = Euclidean distance between the L*a*b* values ​​of the second color of the electro-optical functional element and the L*a*b* values ​​of the third color of the design element. In one embodiment of a composite pane according to the invention, the electro-optical functional element has a first opacity and a first light transmittance in the first state and a second opacity and a second light transmittance in the second state, and the design element has a third opacity and a third light transmittance.The third opacity and the third light transmittance are adapted to the first opacity, the first light transmittance, the second opacity and the second light transmittance such that the design element, when the electro-optical functional element is in the first state, does not visually stand out to a viewer and the design element, when the electro-optical functional element is in the second state, does visually stand out to a viewer.

[0059] For the purposes of the invention, “optically prominent” means that the design element, including its contours, is visible to the viewer as a separate element, and “optically non-prominent” means that the design element is not visible to the viewer as a separate element, but is perceived together with the electro-optical functional element as a homogeneous element, and no contours of the design element are recognizable to the viewer.

[0060] In a preferred embodiment of a composite pane according to the invention, the design element has a haze of less than 30%, preferably less than 15%, particularly preferably less than 5%.

[0061] In a preferred embodiment of a composite pane according to the invention, the electro-optical functional element is a PDLC functional element, an SPD functional element or a PNLC functional element and the design element has a haze of less than 30%, preferably less than 15%, particularly preferably less than 5%.

[0062] Common measurement methods for determining turbidity (haze) are generally known to those skilled in the art.

[0063] In one embodiment of a composite pane according to the invention, the electro-optical functional element is a PDLC functional element, an SPD functional element, or a PNLC functional element, and the design element has a light transmittance of at least 70%, preferably at least 80%, particularly preferably at least 90%. The light transmittance refers to the transmission in the visible spectral range and is expressed here as a percentage. In particular, the term "light transmittance" refers to the light transmittance according to the ECE R43 Revision 4 standard of April 3, 2017, illuminant A, which is also abbreviated as TL or TL(A).

[0064] According to the invention, a composite pane is also provided, comprising at least an outer pane with an outer surface and an interior surface, a first thermoplastic intermediate layer, an electro-optical functional element, a second thermoplastic intermediate layer, a design element and an inner pane with an outer surface and an interior surface, wherein the electro-optical functional element is arranged in a region of the composite pane between the outer pane and the inner pane, the first thermoplastic intermediate layer is arranged between the outer pane and the electro-optical functional element, the second thermoplastic intermediate layer is arranged between the electro-optical functional element and the inner pane, the design element is arranged in a region of the composite pane which, when viewed through the composite pane, lies entirely in the region,in which the electro-optical functional element is arranged, the electro-optical functional element is electrically controllable from a first state in which it has a first color, a first turbidity and a first transmittance, to a second state in which it has a second color, a second turbidity and a second transmittance and vice versa, and wherein the design element has a third color, a third turbidity and a third transmittance, the third color corresponds to the first color and the third turbidity and the third transmittance are adapted to the first turbidity and the first transmittance of the electro-optical functional element and to the second turbidity and the second transmittance of the electro-optical functional element in such a way that the design element, when the electro-optical functional element is in the first state,does not stand out visually for a viewer and when the electro-optical functional element is in the second state, it stands out visually for a viewer.

[0065] In one embodiment of the invention, the electro-optical functional element is divided into segments by insulation lines. The individual segments are connected to the voltage source independently of one another, allowing them to be controlled separately, i.e., the segments are electrically controllable independently of one another. Thus, different segments of the electro-optical functional element can be electrically controlled independently of one another from the first state, in which they exhibit a first color, to the second state, in which they exhibit a second color, and vice versa.

[0066] In one embodiment, the composite pane according to the invention additionally has a peripheral opaque cover print, in particular made of black enamel, which serves in particular to protect the adhesive used to install the composite pane from UV radiation and to visually conceal it. This peripheral opaque cover print is preferably also used to conceal one or more edges of the electro-optical functional element.

[0067] The first thermoplastic intermediate layer and the second thermoplastic intermediate layer and the optionally present third thermoplastic intermediate layer independently contain in one embodiment at least polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU) or mixtures or copolymers or derivatives thereof, preferably polyvinyl butyral (PVB), particularly preferably polyvinyl butyral (PVB) and additives known to the person skilled in the art, such as plasticizers.

[0068] The first thermoplastic intermediate layer and the second thermoplastic intermediate layer and the optionally present third thermoplastic intermediate layer can be formed independently of one another by a single film or by more than one film.

[0069] The thickness of the first thermoplastic intermediate layer and the second thermoplastic intermediate layer is independently of one another preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm, for example 0.38 mm or 0.78 mm.

[0070] The first thermoplastic intermediate layer and / or the second thermoplastic intermediate layer and / or the third thermoplastic intermediate layer can, independently of one another, also be a functional intermediate layer, in particular an intermediate layer with acoustically dampening properties, an infrared-reflecting intermediate layer, an infrared-absorbing intermediate layer, or a UV-absorbing intermediate layer. The outer pane and the inner pane are preferably made of transparent glass, in particular of soda-lime glass, which is common for window panes. However, the panes can in principle also be made of other types of glass (e.g., borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (e.g., polymethyl methacrylate or polycarbonate). The thickness of the outer pane and the inner pane can vary widely.Preferably, panes with a thickness in the range of 0.8 mm to 5 mm, preferably 1.4 mm to 2.5 mm, are used, for example, those with the standard thicknesses of 1.6 mm or 2.1 mm. The outer pane and the inner panes can be independently non-tempered, partially tempered, or tempered. If at least one of the panes is to be tempered, this can be thermally or chemically tempered.

[0071] The outer pane and / or the inner pane may have 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.

[0072] The composite pane according to the invention can comprise one or more additional intermediate layers, in particular functional intermediate layers. An additional intermediate layer can be, in particular, an intermediate layer with acoustic damping properties, an infrared-reflecting intermediate layer, an infrared-absorbing intermediate layer, or a UV-absorbing intermediate layer. If several additional intermediate layers are present, these can also have different functions.

[0073] The fact that the design element is arranged in a region of the composite pane which, when viewed through the composite pane, lies entirely in the region in which the electro-optical functional element is arranged means that the orthogonal projection from the design element to the plane of the electro-optical functional element is arranged entirely within the electro-optical functional element.

[0074] Since the design element is arranged in a region of the composite pane that, when viewed through the composite pane, lies entirely within the region in which the electro-optical functional element is arranged, the design element cannot be larger than the electro-optical functional element in terms of external dimensions. The region in which the design element is arranged and the region in which the electro-optical functional element is arranged are, in particular, also not congruent, i.e., the region in which the electro-optical functional element is arranged is, in particular, larger than the region in which the design element is arranged.

[0075] The area of ​​the design element is preferably less than or equal to 80%, particularly preferably less than or equal to 50%, very particularly preferably less than or equal to 25% of the area of ​​the electro-optical functional element.

[0076] The area of ​​the design element is preferably at least 0.01%, particularly preferably at least 0.1%, very particularly preferably at least 1.0% of the area of ​​the electro-optical functional element.

[0077] The invention also relates to a method for producing a composite pane according to the invention.

[0078] In one embodiment of the method, the method comprises at least the following steps: a) Providing a stacking sequence at least comprising an outer pane with an outer surface and an interior surface, a first thermoplastic intermediate layer, an electro-optical functional element, a second thermoplastic intermediate layer, a design element and an inner pane with an outer surface and an interior surface, wherein the electro-optical functional element is arranged in a region of the composite pane between the outer pane and the inner pane, the first thermoplastic intermediate layer is arranged between the outer pane and the electro-optical functional element, the second thermoplastic intermediate layer is arranged between the electro-optical functional element and the inner pane, the design element is arranged in a region of the composite pane,which, when viewed through the composite pane, lies entirely in the area in which the electro-optical functional element is arranged, the electro-optical functional element being electrically controllable from a first state in which it has a first color to a second state in which it has a second color, and vice versa, and wherein the design element has a third color corresponding to the first color of the electro-optical functional element; b) lamination of the stacking sequence.

[0079] In this embodiment of the method, the design element is thus introduced into the stacking sequence prior to lamination. By means of this embodiment of the method, in particular, a composite pane according to the invention can be produced in which the design element is designed as a print on one of the surfaces of the panes, as a print on the first or second thermoplastic intermediate layer, as an insert element arranged between the first thermoplastic intermediate layer and the electro-optical functional element or between the second thermoplastic intermediate layer and the electro-optical functional element, as an adhesive tape bonded to one of the pane surfaces, or as a satin-finished region of one of the pane surfaces.

[0080] In an alternative embodiment, the design element is applied to a laminated stacking sequence only after lamination. In this alternative embodiment, the method comprises at least the following steps: a) Providing a stacking sequence comprising at least an outer pane with an outer surface and an inner surface, a first thermoplastic intermediate layer, an electro-optical functional element, a second thermoplastic intermediate layer, and an inner pane with an outer surface and an inner surface, wherein the electro-optical functional element is arranged in a region of the composite pane between the outer pane and the inner pane, the first thermoplastic intermediate layer is arranged between the outer pane and the electro-optical functional element, and the second thermoplastic intermediate layer is arranged between the functional element and the inner pane,the electro-optical functional element is electrically controllable from a first state in which it has one color to a second state in which it has a second color, and vice versa; b) lamination of the stacking sequence to form a laminated stacking sequence; c) application of a design element in an area on the outside surface of the outer pane or on the inside surface of the inner pane of the laminated stacking sequence, wherein the area in which the design element is applied lies, when viewed through the composite pane, entirely in the area in which the electro-optical functional element is arranged, and wherein the design element has a third color corresponding to the first color of the electro-optical functional element.

[0081] In this alternative embodiment of the method, the design element is thus introduced into the laminated stacking sequence after lamination. By means of this embodiment of the method, a composite pane according to the invention can consequently be produced in which the design element is formed as a print on the outside surface of the outer pane, as a print on the inside surface of the inner pane, as an adhesive tape bonded to the outside surface of the outer pane, as an adhesive tape bonded to the inside surface of the inner pane, as a satin-finished area of ​​the outside surface of the outer pane, or as a satin-finished area of ​​the inside surface of the inner pane.

[0082] The lamination of the stacking sequence in a process according to the invention can be carried out using common lamination processes. For example, so-called autoclave processes can be carried out at an elevated pressure of approximately 10 bar to 15 bar and temperatures of 130°C to 145°C for approximately 2 hours. Alternatively, autoclave-free processes are also possible. Conventional vacuum bag or vacuum ring processes operate, for example, at approximately 200 mbar and 80°C to 110°C. The stacking sequence can also be pressed in a calender between at least one pair of rollers. Systems of this type are known for the production of discs and normally have at least one heating tunnel upstream of a pressing unit. The temperature during the pressing process is, for example, between 40°C and 150°C. Combinations of calender and autoclave processes have proven particularly successful in practice. Alternatively, vacuum laminators can be used.These consist of one or more heatable and evacuable chambers in which the stacking sequence is laminated within, for example, approximately 60 minutes at reduced pressures of 0.01 mbar to 800 mbar and temperatures of 80 °C to 170 °C. The preferred embodiments of the composite pane according to the invention described above also apply accordingly to processes for producing a composite pane according to the invention, and vice versa.

[0083] The invention also relates to the use of a composite pane according to the invention in buildings, in particular in the access or window area, as a built-in part in furniture and appliances, or in means of transport for traffic on land, in the air or on water, in particular in trains, ships and motor vehicles, in particular as a windscreen, rear window, side window and / or roof window.

[0084] The invention is explained in more detail below with reference to drawings and exemplary embodiments. Identical or equivalent elements are provided with the same reference numerals. They show a simplified representation, not to scale:

[0085] Fig. 1 and Fig. 2 a plan view of an embodiment of an inventive

[0086] composite pane,

[0087] Fig. 3 shows a cross section through an embodiment of an inventive

[0088] composite pane,

[0089] Fig. 4 shows a cross section through a further embodiment of an inventive

[0090] composite pane,

[0091] Fig. 5 shows a cross section through a further embodiment of an inventive

[0092] composite pane,

[0093] Fig. 6 shows a cross section through a further embodiment of an inventive

[0094] composite pane,

[0095] Fig. 7 shows a cross section through a further embodiment of an inventive

[0096] composite pane,

[0097] Fig. 8 shows a cross section through a further embodiment of an inventive

[0098] composite pane,

[0099] Fig. 9 shows a cross section through a further embodiment of an inventive

[0100] composite pane,

[0101] Fig. 10 and Fig. 11 a plan view of a further embodiment of a composite pane according to the invention,

[0102] Fig. 12 shows a cross section through a further embodiment of a composite pane according to the invention, Fig. 13 shows a plan view of a further embodiment of a composite pane according to the invention,

[0103] Fig. 14 is a plan view of another embodiment of a composite pane according to the invention,

[0104] Fig. 15 is a flow chart of a method for producing a composite pane according to the invention,

[0105] Fig. 16 is a flow chart of another method for producing a composite pane according to the invention.

[0106] 1 and 2 each show a plan view of an embodiment of a composite pane 1 according to the invention, wherein Fig. 1 and Fig. 2 only differ in that in Fig. 1 the electro-optical functional element 4 is in the second state, whereas in Fig. 2 the electro-optical functional element 4 is in the first state. The composite pane 1 shown in Fig. 1 and Fig. 2 comprises an outer pane 2, a first thermoplastic intermediate layer 3, an electro-optical functional element 4, a second thermoplastic intermediate layer 5, a design element 6 and an inner pane 7. The electro-optical functional element 4 is arranged in a region of the composite pane 1. The design element 6 is arranged in a region of the composite pane 1 which, when viewed through the composite pane 1, lies entirely in the region in which the electro-optical functional element 4 is arranged. The design element 6 is in the position shown in Figs.1 and 2, the design element 6 has a third color, which corresponds to the first color of the electro-optical functional element 4 in the first state. Thus, the design element 6 only stands out visually when the electro-optical functional element 4 is in the second state and is not recognizable to an observer as a separate element, but is perceived by the observer together with the electro-optical functional element 4 as a homogeneous element when the electro-optical functional element 4 is in the first state. When the electro-optical functional element 4 is in the first state, as can be seen from Fig. 2, no contours of the design element are recognizable to the observer. The composite pane 1 shown in Figs. 1 and 2 can be constructed as shown in cross section in Figs. 3 to 9. For better illustration, the cross-section shown in Figs.1 and 2, the side edge of the electro-optical functional element 4 is shown in dashed lines. Fig. 3 shows a cross section along the section line X'-X through an embodiment of the composite pane 1 according to the invention shown in Fig. 1 and Fig. 2. In the embodiment shown in Fig. 3, the composite pane 1 comprises an outer pane 2, a first thermoplastic intermediate layer 3, an electro-optical functional element 4, a second thermoplastic intermediate layer 5, a design element 6 and an inner pane 7. The electro-optical functional element 4 is arranged in a region of the composite pane 1. The design element 6 is arranged on the outer surface I of the outer pane 2 in a region of the composite pane 1 which, when viewed through the composite pane 1, lies entirely in the region in which the electro-optical functional element 4 is arranged. The design element 6 is in the embodiment shown in Fig.In the embodiment shown in Figure 3, the layer thickness is formed, for example, as a print, an adhesive tape, or a satin-finished area. The thickness of the outer pane 2 and the thickness of the inner pane 7 are, for example, 2.1 mm. The first thermoplastic intermediate layer 3 consists, for example, of PVB and is 0.76 mm thick. The second thermoplastic intermediate layer 5 consists, for example, of PVB and is 0.76 mm thick. The electro-optical functional element 4 is, for example, a PDLC element.

[0107] Fig. 4 shows a cross-section along the section line X'-X through a further embodiment of the composite pane 1 according to the invention shown in Fig. 1 and Fig. 2. The embodiment shown in Fig. 4 differs from that shown in Fig. 3 only in that the design element 6 is not arranged on the outside surface I of the outer pane 2, but is arranged between the outer pane 2 and the first thermoplastic intermediate layer 3. In the embodiment shown in Fig. 4, the design element 6 is designed, for example, as a print on the inside surface II of the outer pane 2, as a print on the surface of the first thermoplastic intermediate layer 3 adjacent to the outer pane 2, as an adhesive tape on the inside surface II of the outer pane 2, as an insert element or as a satin-finished area of ​​the inside surface II of the outer pane 2.

[0108] Fig. 5 shows a cross-section along the section line X'-X through a further embodiment of the composite pane 1 according to the invention shown in Fig. 1 and Fig. 2. The embodiment shown in Fig. 5 differs from that shown in Fig. 3 only in that the design element 6 is not arranged on the outer surface I of the outer pane 2, but is arranged between the first thermoplastic intermediate layer 3 and the electro-optical functional element 4. In the embodiment shown in Fig. 5, the design element 6 is designed, for example, as a print on the surface of the first thermoplastic intermediate layer 3 adjacent to the electro-optical functional element 4 or as an insert element.

[0109] Fig. 6 shows a cross-section along the section line X'-X through a further embodiment of the composite pane 1 according to the invention shown in Fig. 1 and Fig. 2. The embodiment shown in Fig. 6 differs from that shown in Fig. 3 only in that the design element 6 is not arranged on the outer surface I of the outer pane 2, but is arranged between the electro-optical functional element 4 and the second thermoplastic intermediate layer 5. In the embodiment shown in Fig. 6, the design element 6 is designed, for example, as a print on the surface of the second thermoplastic intermediate layer 5 adjacent to the electro-optical functional element 4 or as an insert element.

[0110] Fig. 7 shows a cross-section along the section line X'-X through a further embodiment of the composite pane 1 according to the invention shown in Fig. 1 and Fig. 2. The embodiment shown in Fig. 7 differs from that shown in Fig. 3 only in that the design element 6 is not arranged on the outer surface I of the outer pane 2, but is arranged between the second thermoplastic intermediate layer 5 and the inner pane 7. In the embodiment shown in Fig. 7, the design element 6 is designed, for example, as a print on the outer surface III of the inner pane 7, as a print on the surface of the second thermoplastic intermediate layer 5 adjacent to the inner pane 7, as an adhesive tape on the outer surface III of the inner pane 7, as an insert element or as a satin-finished region of the outer surface III of the inner pane 7.

[0111] Fig. 8 shows a cross-section along the section line X'-X through a further embodiment of the composite pane 1 according to the invention shown in Fig. 1 and Fig. 2. The embodiment shown in Fig. 8 differs from that shown in Fig. 3 only in that the design element 6 is not arranged on the outside surface I of the outer pane 2, but is arranged on the inside surface IV of the inner pane 7. In the embodiment shown in Fig. 8, the design element 6 is designed, for example, as a print or an adhesive tape or a satin-finished area.

[0112] Fig. 9 shows a cross-section through a further embodiment of a composite pane 1 according to the invention. The embodiment shown in Fig. 9 differs from that shown in Fig. 4 only in that the composite pane 1 has a third thermoplastic intermediate layer 8, which is arranged between the first thermoplastic intermediate layer 3 and the second thermoplastic intermediate layer 5 and which has a recess in which the electro-optical functional element 4 is received. The electro-optical functional element 4 is thus surrounded in a frame-like manner by the third thermoplastic intermediate layer 8. It is understood that the embodiments shown in Figs. 3 and 5 to 8 can also be modified in such a way that the composite pane 1 additionally has a third thermoplastic intermediate layer 8 with a recess in which the electro-optical functional element 4 is received.

[0113] 10 and 11 each show a plan view of a further embodiment of a composite pane 1 according to the invention, wherein Fig. 10 and Fig. 11 differ only in that in Fig. 10 the electro-optical functional element 4 is in the second state, whereas in Fig. 11 the electro-optical functional element 4 is in the first state. The embodiment shown in Figs. 10 and 11 differs from that shown in Figs. 1 and 2 only in that the composite pane 1 has a peripheral opaque cover print 9, for example made of black enamel. In the embodiment shown in Figs. 10 and 11, the edges of the electro-optical functional element 4 are covered by the peripheral opaque cover print 9 when viewed through the composite pane 1. For clarity, the side edge of the electro-optical functional element 4 is shown in dashed lines in Figs. 10 and 11.

[0114] Fig. 12 shows a cross section along the section line YY' through an embodiment of the composite pane 1 according to the invention shown in Fig. 10 and Fig. 11. In the embodiment shown in Fig. 12, the composite pane 1 comprises an outer pane 2, a first thermoplastic intermediate layer 3, an electro-optical functional element 4, a second thermoplastic intermediate layer 5, a design element 6 and an inner pane 7. The electro-optical functional element 4 is arranged in a region of the composite pane 1. The design element 6 is arranged between the electro-optical functional element 4 and the second thermoplastic intermediate layer 5 in a region of the composite pane 1 which, when viewed through the composite pane 1, lies entirely in the region in which the electro-optical functional element 4 is arranged. The design element 6 is in the embodiment shown in Fig.12, for example, as a print on the surface of the second thermoplastic intermediate layer 5 facing the electro-optical functional element 4 or as an insert element. The thickness of the outer pane 2 and the thickness of the inner pane 7 are, for example, 2.1 mm. The first thermoplastic intermediate layer 3 consists, for example, of PVB and is 0.76 mm thick. The second thermoplastic intermediate layer 5 consists, for example, of PVB and is 0.76 mm thick. The electro-optical functional element 4 is, for example, a PDLC element. A peripheral opaque cover print 9 made of a black enamel is applied to the interior-side surface II of the outer pane 2. The peripheral opaque cover print 9 can also be applied alternatively or additionally to the exterior surface I of the outer pane, the exterior surface III of the inner pane 7, or the interior-side surface IV of the inner pane 7.It is understood that the embodiments shown in Figs. 3, 4, 5, 7, 8 and 9 can also be modified such that the composite pane 1 additionally has a peripheral opaque cover print 9.

[0115] Fig. 13 shows a plan view of another embodiment of a composite pane 1 according to the invention, in which the functional element 4 is in the second state. The structure shown in Fig.

[0116] The embodiment shown in Fig. 13 differs from that shown in Fig. 1 only with regard to the design of the design element 6. In the embodiment shown in Fig. 13, the design element 6 is formed from a plurality of diamond-shaped elements which together form a uniform pattern.

[0117] Fig. 14 shows a plan view of another embodiment of a composite pane 1 according to the invention, in which the functional element 4 is in the second state. The structure shown in Fig.

[0118] The embodiment shown in Fig. 14 differs from that shown in Fig. 1 only with regard to the design of the design element 6. In the embodiment shown in Fig. 14, the design element 6 is formed from a plurality of elements, some of these elements each forming a lettering, a symbol or a simple graphic.

[0119] Fig. 15 shows a flow diagram of a method for producing a composite pane 1 according to the invention. The method comprises, in a first step S1, the provision of a stacking sequence comprising at least an outer pane 2 with an outer surface I and an interior surface II, a first thermoplastic intermediate layer 3, an electro-optical functional element 4, a second thermoplastic intermediate layer 5, a design element 6, and an inner pane 7 with an outer surface III and an interior surface IV, wherein the electro-optical functional element 4 is arranged in a region of the composite pane 1 between the outer pane 2 and the inner pane 7, the first thermoplastic intermediate layer 3 is arranged between the outer pane 2 and the electro-optical functional element 4, the second thermoplastic intermediate layer 5 is arranged between the electro-optical functional element 4 and the inner pane 7,The design element 6 is arranged in a region of the composite pane 1 which, when viewed through the composite pane 1, lies entirely within the region in which the electro-optical functional element 4 is arranged. The electro-optical functional element 4 is electrically controllable from a first state, in which it has a first color, to a second state, in which it has a second color, and vice versa. The design element 6 has a third color, which corresponds to the first color of the electro-optical functional element 4 in the first state. In a subsequent second step S2, the method comprises lamination of the stacking sequence provided in the first step S1.

[0120] Fig. 16 shows a flow diagram of an alternative method for producing a composite pane 1 according to the invention. The method comprises, in a first step P1, the provision of a stacking sequence comprising at least an outer pane 2 with an outer surface I and an inner surface II, a first thermoplastic intermediate layer 3, an electro-optical functional element 4, a second thermoplastic intermediate layer 5 and an inner pane 7 with an outer surface III and an inner surface IV, wherein the functional element 4 is arranged in a region of the composite pane 1 between the outer pane 2 and the inner pane 7, the first thermoplastic intermediate layer 3 is arranged between the outer pane 2 and the functional element 4, the second thermoplastic intermediate layer 5 is arranged between the electro-optical functional element 4 and the inner pane 7,and the electro-optical functional element 4 is electrically controllable from a first state, in which it has one color, to a second state, in which it has a second color, and vice versa. In a subsequent second step P2, the stacking sequence provided in step P1 is laminated. In a subsequent third step P3, the method comprises applying a design element 6 in a region on the outside surface I of the outer pane 2 or the inside surface IV of the inner pane 7 of the laminated stacking sequence, wherein the region in which the design element 6 is applied, when viewed through the laminated stacking sequence, lies entirely in the region in which the electro-optical functional element 4 is arranged, and wherein the design element 6 has a third color that corresponds to the first color of the electro-optical functional element 4 in the first state.

[0121] List of reference symbols:

[0122] 1 composite pane

[0123] 2 outer pane

[0124] 3 first thermoplastic intermediate layer

[0125] 4 electro-optical functional element

[0126] 5 second thermoplastic intermediate layer

[0127] 6 Design element

[0128] 7 Inner pane

[0129] 8 third thermoplastic intermediate layer

[0130] 9 Cover print

[0131] I outside surface of the outer pane

[0132] II Interior surface of the outer pane

[0133] III Outer surface of the inner pane

[0134] IV Interior surface of the inner pane

[0135] XX' cutting line

[0136] YY' cutting line

Claims

Patent claims Composite pane (1) comprising at least one outer pane (2) with an outer surface (I) and an inner surface (II), a first thermoplastic intermediate layer (3), an electro-optical functional element (4), a second thermoplastic intermediate layer (5), a design element (6) and an inner pane (7) with an outer surface (III) and an inner surface (IV), wherein the electro-optical functional element (4) is arranged in a region of the composite pane (1) between the outer pane (2) and the inner pane (7), the first thermoplastic intermediate layer (3) is arranged between the outer pane (2) and the electro-optical functional element (4), the second thermoplastic intermediate layer (5) is arranged between the electro-optical functional element (4) and the inner pane (7), the design element (6) is arranged in a region of the composite pane (1),which, when viewed through the composite pane (1), lies entirely within the area in which the electro-optical functional element (4) is arranged, the electro-optical functional element (4) being electrically controllable from a first state, in which it has a first color, to a second state, in which it has a second color, and vice versa, and wherein the design element (6) has a third color corresponding to the first color of the electro-optical functional element (4). Composite pane (1) according to claim 1, wherein the design element (6) is provided as an imprint on the outer surface (I) of the outer pane (2), as an imprint on the interior surface (II) of the outer pane (2), as an imprint on the outer surface (III) of the inner pane (7), as an imprint on the interior surface (IV) of the inner pane (7),as an imprint on the first thermoplastic intermediate layer (3) or as an imprint on the second thermoplastic intermediate layer (5). Composite pane (1) according to claim 1, wherein the design element (6) is formed as an insert element and is located between the electro-optical functional element (4) and the first thermoplastic intermediate layer (3) or between the electro-optical functional element (4) and the second thermoplastic intermediate layer (5) or between the first thermoplastic intermediate layer (3), and the outer pane (2) or between the second thermoplastic intermediate layer (5) and the inner pane (7).

4. Composite pane (1) according to claim 3, wherein the insert element comprises or consists of colored PET, PVB, PE or EVA.

5. Composite pane (1) according to claim 1, wherein the design element (6) is designed as an adhesive tape glued to the outside surface (I) of the outer pane (2), as an adhesive tape glued to the inside surface (II) of the outer pane (2), as an adhesive tape glued to the outside surface (III) of the inner pane (7) or as an adhesive tape glued to the inside surface (IV) of the inner pane (7).

6. Composite pane (1) according to claim 1, wherein the design element (6) is formed as a satin-finished region of the outside surface (I) of the outer pane (2), as a satin-finished region of the inside surface (II) of the outer pane (2), as a satin-finished region of the outside surface (III) of the inner pane (7) or as a satin-finished region of the inside surface (IV) of the inner pane (7).

7. Composite pane (1) according to one of claims 1, 2, 5 or 6, wherein the design element (6) is formed on the outside surface (I) of the outer pane (2) or on the inside surface (IV) of the inner pane (7).

8. Composite pane (1) according to one of claims 1 to 5, wherein the design element (6) has a thickness of less than 50 pm, preferably less than 25 pm, particularly preferably less than 12.5 pm, most particularly preferably less than 5 pm.

9. Composite pane (1) according to one of claims 1 to 8, additionally comprising a third thermoplastic intermediate layer (8) which is arranged between the outer pane (2) and the inner pane (7), has a recess and surrounds the electro-optical functional element (4) in a frame-like manner.

10. Composite pane (1) according to one of claims 1 to 9, wherein the electro-optical functional element (4) is a PDLC functional element, an SPD functional element, a PNLC functional element, an electrochromic functional element or a functional element with liquid crystal dye cells. Composite pane (1) according to one of claims 1 to 10, wherein the electro-optical functional element (4) has a first opacity and a first light transmittance in the first state and a second opacity and a second light transmittance in the second state, and the design element (6) has a third opacity and a third light transmittance, and the third opacity and the third light transmittance are adapted to the first opacity, the first light transmittance, the second opacity, and the second light transmittance in such a way that the design element (6) does not visually stand out to a viewer when the electro-optical functional element (4) is in the first state, and the design element (6) does visually stand out to a viewer when the electro-optical functional element (4) is in the second state.Composite pane (1) according to one of claims 1 to 11, wherein the electro-optical functional element (4) is divided by insulation lines into segments that are electrically controllable independently of one another and / or wherein the composite pane (1) additionally comprises a peripheral opaque cover print (9), preferably made of black enamel. A method for producing a composite pane (1) according to one of claims 1 to 12, comprising at least the following steps. - Providing a stacking sequence comprising at least an outer pane (2) with an outer surface (I) and an inner surface (II), a first thermoplastic intermediate layer (3), an electro-optical functional element (4), a second thermoplastic intermediate layer (5), a design element (6), and an inner pane (7) with an outer surface (III) and an inner surface (IV), wherein the electro-optical functional element (4) is arranged in a region of the composite pane (1) between the outer pane (2) and the inner pane (7), the first thermoplastic intermediate layer (3) is arranged between the outer pane (2) and the electro-optical functional element (4), the second thermoplastic intermediate layer (5) is arranged between the electro-optical functional element (4) and the inner pane (7), the design element (6) is arranged in a region of the composite pane (1),which, when viewed through the composite pane (1), lies entirely in the area in which the electro-optical functional element (4) is arranged, the electro-optical functional element (4) is electrically controllable from a first state in which it has a first color to a second state in which it has a second color, and vice versa, and wherein the design element (6) has a third color which corresponds to the first color of the electro-optical functional element (4); - Lamination of the stacking sequence. Experienced in producing a composite pane (1) according to one of claims 1, 2 or 5 to 12, at least comprising the following steps - Providing a stacking sequence comprising at least an outer pane (2) with an outer surface (I) and an inner surface (II), a first thermoplastic intermediate layer (3), an electro-optical functional element (4), a second thermoplastic intermediate layer (5), and an inner pane (7) with an outer surface (III) and an inner surface (IV), wherein the electro-optical functional element (4) is arranged in a region of the composite pane (1) between the outer pane (2) and the inner pane (7), the first thermoplastic intermediate layer (3) is arranged between the outer pane (2) and the electro-optical functional element (4), the second thermoplastic intermediate layer (5) is arranged between the electro-optical functional element (4) and the inner pane (7), and the electro-optical functional element (4) can be changed from a first state, in which it has a first color, to a second state,in which it has a second color and, conversely, is electrically adjustable; - Lamination of the stacking sequence to a laminated stacking sequence; - Applying a design element (6) in an area on the outside surface (I) of the outer pane (2) or the inside surface (IV) of the inner pane (7) of the laminated stacking sequence, wherein the area in which the design element (6) is applied, when viewed through the laminated stacking sequence, lies entirely in the area in which the electro-optical functional element (4) is arranged and wherein the design element (6) has a third color which corresponds to the first color of the electro-optical functional element (4). Use of the composite pane (1) according to one of claims 1 to 12 in buildings, in particular in the access or window area, as a built-in part in furniture and equipment, or in means of transport for land, air or Water, especially in trains, ships and motor vehicles, especially as windshields, rear windows, side windows and / or roof windows.

Images