Composite pane having electro-optic functional elements and design elements

Abstract

The composite pane (1) comprises at least 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), wherein the functional element (4) is arranged between the outer pane (2) and the inner pane (7) in a region of the composite pane (1); the first thermoplastic intermediate layer (3) is arranged between the outer pane (2) and the electro-optical functional element (4); a 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 lies entirely in the region in which the electro-optical functional element (4) is arranged when viewed through the composite pane (1); the electro-optical functional element (4) is electrically controllable from a first state in which the electro-optical functional element has a first color to a second state in which the electro-optical functional element 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).

Description

Technical Field

[0001] The invention relates to a composite glass pane having an electro-optical functional element and a design element. Background Art

[0002] Composite glass panes (Verbundscheiben, sometimes also called composite sheets) with electrically controllable optical properties are well known. They include composite glass panes equipped with electro-optical functional elements, i.e. equipped with functional elements whose optical properties can be changed by an applied voltage. Examples of electro-optical functional elements are SPD (suspended particle device) functional elements (e.g. known from EP 0 876 608 B1 and WO 2011 033 313 A1) and PDLC (polymer dispersed liquid crystal) functional elements (e.g. known from DE 10 2008 026 339 A1).

[0003] WO2019 / 086653A1 discloses a composite glass pane, comprising a laminated stacking sequence of an outer glass pane, a first intermediate layer, a second intermediate layer and an inner glass pane, and a functional element with electrically controllable optical properties, the functional element being arranged at least in sections between the first intermediate layer and the second intermediate layer, wherein at least one transparent body is arranged in sections between the outer glass pane and the functional element and / or between the inner glass pane and the functional element. The contour of the transparent body remains visible to the human eye throughout the operating range of the functional element.

[0004] There is a growing interest in providing composite glass panes with electrically controllable properties with characters, such as text, symbols, logos, trademarks or simple graphics, which characters are visually prominent to an observer in one state of the electro-optical functional element and are visually inconspicuous to the observer in another state of the electro-optical functional element.

[0005] It is known that switchable patterns can be introduced into PDLC elements by laser segmentation. CN110471206A discloses a method for producing PDLC films with patterns and / or texts by direct laser etching.

[0006] However, not every structure can be incorporated into a PDLC functional element using laser segmentation, since, for example, a minimum distance between the laser lines and a minimum radius must be taken into account.

[0007] WO 2021 / 105070 A1 discloses a method for producing an optical device which is operable in at least two optical states and can be electrically switched between them, wherein in one of the optical states an image having at least one closed feature can be represented by a combination of open forms. Summary of the invention

[0008] The object of the invention is to provide an improved composite glass pane with electro-optical functional elements and design elements.In addition, the composite glass pane should be producible in a simple and cost-effective manner.

[0009] This object is achieved by a composite glass pane and a method according to the independent claims.

[0010] The invention relates to a composite glass pane, comprising at least an outer glass pane, a first thermoplastic interlayer, an electro-optical functional element, a second thermoplastic interlayer, a design element and an inner glass pane. The electro-optical functional element is arranged in a region of the composite glass pane between the outer glass pane and the inner glass pane. The first thermoplastic interlayer is arranged between the electro-optical functional element and the outer glass pane, and the second thermoplastic interlayer is arranged between the electro-optical functional element and the inner glass pane. The design element is arranged in a region of the composite glass pane which, when viewed through the composite glass pane, is completely located 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 the functional element has a first color to a second state in which the functional element has a second color. In addition, the electro-optical functional element can also be electrically controlled from the second state back to the first state. It should be understood that the first color and the second color of the electro-optical functional element are different, that is, the first color and the second color do not correspond to each other.

[0012] 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 and the design element in the first state have the same color. Since 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 corresponds to the first color of the electro-optical functional element, it should be 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 in the composite glass pane is in the first state, the design element does not stand out visually. Thus, when the electro-optical functional element is in the first state in the composite glass pane, the observer cannot recognize the design element with its contour as such. Thus, the observer perceives the electro-optical functional element together with the design element as a homogeneous element with a constant color. However, when the electro-optical functional element in the composite glass pane is in the second state, the design element stands out visually due to its third color. Thus, when the electro-optical functional element in the composite glass pane is in the second state, the observer can clearly see the design element and its contour.

[0013] When viewing through the composite glass pane, the design element can be arranged in front of or behind the electro-optical functional element. Preferably, the design element is arranged behind the electro-optical functional element as seen by an observer.

[0014] It will be appreciated that the design element does not necessarily have to be formed in one piece; the design element may also be formed by several elements, which may be arranged directly adjacent to one another or at a distance from one another. For example, the design element may be formed as text, or as a symbol or a simple graphic or as a logo. The design element may also be formed, for example, as text and a simple graphic, wherein the text and the simple graphic are arranged in different zones of the composite glass pane. As explained above, the design element is arranged in a zone of the composite glass pane which, when viewed through the composite glass pane, is completely located in the zone in which the electro-optical functional element is arranged. It will be appreciated that if the design element is formed by several elements, each of these elements, when viewed through the composite glass pane, is completely located in the zone in which the electro-optical functional element is arranged.

[0015] In the context of the present invention, when a composite glass panel is intended to separate an interior space from the exterior environment in a window opening of a vehicle or a building, the glass panel facing the interior space (the interior of the vehicle) is referred to as the "inner glass panel". The "outer glass panel" means the glass panel facing the exterior environment. For example, if a composite glass panel in a window opening in a building is used to separate a room from a corridor, in the context of the present invention, the inner glass panel refers to the glass panel facing the interior space and the outer glass panel refers to the glass panel facing the corridor.

[0016] The outer glass pane and the inner glass pane respectively have an outer side surface and an inner side surface and a circumferential side edge extending therebetween. In the sense of the present invention, the outer side surface means the main surface intended to face the external environment when installed. In the sense of the present invention, the inner side surface means the main surface intended to face the interior when installed. The inner side surface of the outer glass pane and the outer side surface of the inner glass pane face each other and are connected to each other by a thermoplastic interlayer.

[0017] The outer side surface of the outer glass sheet is designated as side I. The inner side surface of the outer glass sheet is designated as side II. The outer side surface of the inner glass sheet is designated as side III. The inner side surface of the inner glass sheet is designated as side IV.

[0018] In a preferred embodiment of the composite glass pane according to the invention, the design element is formed as an imprint on one of the glass pane surfaces. In one embodiment, the design element is formed as an imprint on the outer side surface of the outer glass pane. In an alternative embodiment, the design element is formed as an imprint on the inner side surface of the outer glass pane. In an alternative embodiment, the design element is formed as an imprint on the outer side surface of the inner glass pane. In an alternative embodiment, the design element is formed as an imprint on the inner side surface of the inner glass pane.

[0019] Preferred embodiments are those in which the design element is formed as an imprint on the outside surface of the outer glass pane, or as an imprint on the inside surface of the inner glass pane.

[0020] Particularly preferred are embodiments in which the design element is formed as an imprint on the inner surface of the outer glass pane or as an imprint on the outer surface of the inner glass pane, since in these embodiments the design element is arranged inside the composite glass pane and is therefore protected from external influences.

[0021] The design element formed as an imprint on one of the glass sheet surfaces is typically made of an enamel comprising glass frit and a pigment. By selecting the pigment, the third color of the design element can be arranged so that it corresponds to the first color of the electro-optical functional element. Suitable pigments are known to those skilled in the art.

[0022] In an advantageous embodiment of the invention, the design element formed as an imprint on one of the glass sheet surfaces has a thickness of 5 μm (micrometers) to 40 μm, preferably from 10 μm to 25 μm. In an alternative advantageous embodiment, the design element formed as an imprint on one of the glass sheet surfaces has a thickness of less than 5 μm.

[0023] In an alternative preferred embodiment of the composite glass pane according to the invention, the design element is formed as an imprint on the first thermoplastic interlayer or as an imprint on the second thermoplastic interlayer. The imprint can be arranged on the first thermoplastic interlayer either on the surface facing the outer glass pane in the composite glass pane or on the surface facing the electro-optical functional element in the composite glass pane. The imprint can be arranged on the second thermoplastic interlayer either on the surface facing the inner glass pane in the composite glass pane or on the surface facing the electro-optical functional element in the composite glass pane.

[0024] Preferably, in these embodiments, the imprint is arranged on the first thermoplastic interlayer on the surface facing the outer glass pane in the composite glass pane, or on the second thermoplastic interlayer on the surface facing the inner glass pane in the composite glass pane. This arrangement of the imprint is particularly advantageous because in this case the first thermoplastic interlayer or the second thermoplastic interlayer is arranged between the imprint and the electro-optical functional element, thus preventing the design element from exerting pressure on the active layer of the electro-optical functional element.

[0025] The design element formed as a print on the first thermoplastic interlayer or as a print on the second thermoplastic interlayer is typically formed from a composition containing a water-based or solvent-based color pigment or dye.

[0026] In an advantageous embodiment of the invention, the design element formed as an imprint on the first thermoplastic intermediate layer or the second thermoplastic intermediate layer has a thickness of 5 μm (micrometers) to 40 μm, preferably from 5 μm to 20 μm. In an alternative advantageous embodiment, the design element formed as an imprint on the first thermoplastic intermediate layer or the second thermoplastic intermediate layer has a thickness of less than 5 μm.

[0027] In an alternative preferred embodiment of the composite glass pane according to the invention, the design element is formed as an insert element. An insert element is a prefabricated element which is arranged in the layer stack to be laminated before lamination during the production of the composite glass pane. The design element formed as an insert element can be arranged in the composite glass pane according to the invention between the electro-optical functional element and the first thermoplastic interlayer, or between the electro-optical functional element and the second thermoplastic interlayer, or between the first thermoplastic interlayer and the outer glass pane, or between the second thermoplastic interlayer and the inner glass pane.

[0028] Preferably, the insertion element is arranged between the outer glass pane and the first thermoplastic interlayer or between the inner glass pane and the second thermoplastic interlayer. This arrangement of the insertion element is particularly advantageous because in this case the first thermoplastic interlayer or the second thermoplastic interlayer is arranged between the insertion element and the electro-optical functional element, thus preventing the insertion element from exerting pressure on the active layer of the electro-optical functional element.

[0029] Preferably, the insert element contains or consists of colored polyethylene terephthalate (PET), polyvinyl butyral (PVB), polyethylene (PE) or ethylene vinyl acetate (EVA).

[0030] The thickness of the insert element is preferably between 10 μm (micrometers) and 80 μm, particularly preferably between 20 μm and 60 μm, most particularly preferably between 25 μm and 50 μm. In a preferred embodiment, the thickness of the insert element is 25 μm or 50 μm. In an alternative embodiment, the thickness of the insert element can also be less than 5 μm.

[0031] In an alternative preferred embodiment of the composite glass pane according to the invention, the design element is formed as an adhesive tape, wherein the adhesive tape is adhered to the outer side surface of the outer glass pane, to the inner side surface of the outer glass pane, to the outer side surface of the inner glass pane or to the inner side surface of the inner glass pane.

[0032] Particularly preferred are embodiments in which the design element is formed as an adhesive tape which is adhered to the outer side surface of the outer glass pane or as an adhesive tape which is adhered to the inner side surface of the inner glass pane, since in these cases the adhesive tape can in particular only be adhered after lamination of the stacking sequence to form the composite glass pane and does not necessarily have to be adhered before lamination. In these embodiments, it is also possible to remove the design element from the glass pane to which it is adhered at a later point in time and to adhere it in the form of an adhesive tape to a design element of a different shape. In these embodiments, it is therefore possible to easily replace the design element, in particular without damaging other components of the composite glass pane according to the invention.

[0033] In an alternative preferred embodiment of the composite glass pane according to the invention, the design element is formed as a mercerized polished area of ​​one of the glass pane surfaces. In an embodiment, the design element is formed as a mercerized polished area of ​​the outer side surface of the outer glass pane. In an alternative embodiment, the design element is formed as a mercerized polished area of ​​the inner side surface of the outer glass pane. In an alternative embodiment, the design element is formed as a mercerized polished area of ​​the outer side surface of the inner glass pane. In an alternative embodiment, the design element is formed as a mercerized polished area of ​​the inner side surface of the inner glass pane.

[0034] Mercerized areas are roughened areas. Mercerized areas can be formed on the surface of the glass sheet by roughening the relevant surface in the area to be mercerized, for example by sandblasting or treatment with hydrofluoric acid (etching) or hydrofluoric acid vapor. For example, areas of the surface of the glass sheet that will not be mercerized can be covered by a template and / or an adhesive film. The template and the adhesive film can also be created with computer support.

[0035] With the sandblasting technique, the surface of the glass sheet can be blasted in the desired areas. However, for health reasons, sandblasting is typically performed with fine corundum particles ("sandblasting corundum"). Sandblasting corundum is a man-made mineral sandblasting medium and is made from high-quality bauxite or aluminum oxide melted in an arc furnace above 2000°C. It is also used to produce abrasives and sandpaper. Sandblasting corundum is not hygroscopic. The selection of different particle sizes results in different roughness and, therefore, different design options.

[0036] Producing a mercerized area of ​​the glass sheet surface by etching (e.g. using hydrofluoric acid as etching medium) is preferred because the mercerized area can be formed more uniformly than by sandblasting. Depending on the method, the concentration of the reactants, the temperature of the etching medium and the chemical composition of the glass sheet, the optical appearance of the mercerized glass sheet surface after treatment can vary. In order to limit etching to the desired area, an adhesive film can be used, which is then removed after the etching process.

[0037] Another option for producing a satin-finished area on the surface of a glass sheet is laser processing.

[0038] In a preferred embodiment, the design element has a thickness of less than 50 μm, preferably less than 25 μm, particularly preferably less than 12.5 μm, most particularly preferably less than 5 μm.

[0039] In a preferred embodiment of the composite glass pane according to the invention, the design element is formed on the outer side surface of the outer glass pane or on the inner side surface of the inner glass pane. This embodiment is particularly advantageous because, in the case where the design element is formed on the outer side surface of the outer glass pane or on the inner side surface of the inner glass pane, the design element cannot exert pressure on the active layer of the electro-optical functional element.

[0040] Therefore, particularly preferred are embodiments in which the design element is formed as a print on the outer side surface of the outer glass pane, as a print on the inner side surface of the inner glass pane, as an adhesive tape adhered to the outer side surface of the outer glass pane, as an adhesive tape adhered to the inner side surface of the inner glass pane, as a silk-finished area on the outer side surface of the outer glass pane, or as a silk-finished area on the inner side surface of the inner glass pane.

[0041] The electro-optical functional element is preferably arranged over a large area in the composite glass pane. The electro-optical functional element is preferably smaller in area than the composite glass pane, for example the edge of the electro-optical functional element is spaced between 2 mm and 20 mm from the respective nearest edge of the composite glass pane. The electro-optical functional element is thus encapsulated by the thermoplastic intermediate layer and is protected from contact with the surrounding atmosphere and from corrosion.

[0042] In a preferred embodiment of the composite glass sheet according to the present invention, the composite glass sheet also has a third thermoplastic interlayer, and the electro-optical functional element is surrounded by the third thermoplastic interlayer in the circumferential direction. The third thermoplastic interlayer is frame-shaped and has a recess, and the electro-optical functional element is inserted into the recess. 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. Therefore, there is no gap between the electro-optical functional element and the third thermoplastic interlayer. The third thermoplastic interlayer can be formed by a thermoplastic film, and the recess is introduced into the thermoplastic film by cutting. Alternatively, the third thermoplastic interlayer can also be composed of a plurality of film segments surrounding the electro-optical functional element. The third thermoplastic interlayer preferably has the same thickness as the electro-optical functional element. If necessary, this can compensate for the local thickness differences of the composite glass sheet introduced by the locally defined electro-optical functional element, so that glass breakage during lamination can be avoided.

[0043] The electro-optical functional element is specifically a PDLC functional element, an SPD functional element, a PNLC functional element, an electrochromic functional element or a functional element having a liquid crystal dye unit.

[0044] In a preferred embodiment of the composite glass sheet according to the present invention, the electro-optical functional element is a PDLC (polymer dispersed liquid crystal) functional element. The active layer of the PDLC functional element contains liquid crystals embedded in a polymer matrix. If no voltage is applied to the planar electrodes, the liquid crystals will be arranged in a disordered manner, which leads to strong scattering of light passing through the active layer. If a voltage is applied to the planar electrodes, the liquid crystals will be arranged in a common direction and increase the transmittance of light through the active layer. For example, PDLC functional elements can be learned from US20150301367A1.

[0045] In another preferred embodiment of the composite glass 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 a PDLC functional element, with the difference that in an SPD functional element there are not liquid crystal droplets, but suspended droplets in which light-polarizing particles embedded in a polymer matrix are suspended. Such a system is described, for example, in EP 0 551 138 A1.

[0046] In another preferred embodiment of the composite glass pane according to the invention, the electro-optical functional element is a PNLC (polymer network liquid crystal) functional element. The active layer contains liquid crystals embedded in a polymer network, and the mode of operation is otherwise similar to that of a PDLC functional element.

[0047] In another preferred embodiment of the composite glass pane according to the invention, the electro-optical functional element is an electrochromic functional element. In this case, the transmittance of visible light passing through the electro-optical functional element depends on the degree of embedding of the ions. For example, the ions are released through the ion storage layer and embedded in the electrochromic layer. The voltage applied to the electro-optical functional element and causing the migration of the ions can affect the light transmittance. Suitable electrochromic layers contain, for example, at least tungsten oxide or vanadium oxide.

[0048] In a further preferred embodiment of the composite glass pane according to the invention, the electro-optical functional element is a functional element having a liquid-crystalline dye unit (a so-called guest-host unit).

[0049] Commercially available functional elements are PDLC, SPD and PNLC functional elements, electrochromic functional elements and functional elements with liquid crystal dye units. The electro-optical functional elements mentioned and their modes of operation are known per se to those skilled in the art and therefore do not need to be described in detail here.

[0050] Delta E (ΔE) can be used to determine whether an observer perceives a color difference. ΔE is a measure of the distance between two colors and shows whether a difference between two colors is perceptible. It is therefore a relative measure regarding the characteristics of human color perception. ΔE always refers to the two colors being compared. ΔE is calculated by calculating the Euclidean distance between the a*, b* and L* values.

[0051] The symbols a* and b* are values ​​of the L*a*b* color space, i.e., values ​​of a color model that describes all perceptible colors. L* represents the lightness value and can have values ​​between 0 and 100. a* represents the chromaticity and color intensity between green and red, while b* represents the chromaticity and color intensity between blue and yellow. The more negative or positive the values ​​of b* and a*, the more intense the chromaticity. For values ​​of a* and b* close to 0, the hue is fairly colorless, i.e., neutral.

[0052] 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 the present application that the color difference ΔE 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, an observer cannot perceive any color difference between the design element and the electro-optical functional element in the first state.

[0053] The formula used to calculate ΔE is as follows: in L1* = Brightness of the electro-optical functional element in the first state L2* = Brightness of the design element a1*=value of the green or red component of the first color of the electro-optical functional element a2* = value of the green or red component of the third color of the design element b1*=value of the blue or yellow component of the first color of the electro-optical functional element b2* = value of the blue or yellow component of the third color of the design element ΔE=Euclidean distance between the L*a*b* value of the first color of the electro-optical functional element and the L*a*b* value of the third color of the design element

[0054] 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.

[0055] 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 corresponding 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.

[0056] 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 the present 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, an observer can perceive a color difference between the design element and the electro-optical functional element in the second state.

[0057] 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 shown below similarly 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: in L3* = Brightness of the electro-optical functional element in the second state L2* = Brightness of the design element a3*=value of the green or red component of the second color of the electro-optical functional element a2* = value of the green or red component of the third color of the design element b3*=value of the blue or yellow component of the second color of the electro-optical functional element b2* = value of the blue or yellow component of the third color of the design element ΔE' = the Euclidean distance between the L*a*b* value of the second color of the electro-optical functional element and the L*a*b* value of the third color of the design element

[0058] In one embodiment of the composite glass pane according to the invention, the electro-optical functional element has a first haze and a first light transmittance in the first state and a second haze and a second light transmittance in the second state, and the design element has a third haze and a third light transmittance. The third haze and the third light transmittance are adapted to the first haze, the first light transmittance, the second haze and the second light transmittance in such a way that the design element is not visually prominent to an observer when the electro-optical functional element is in the first state and is visually prominent to an observer when the electro-optical functional element is in the second state.

[0059] For the purposes of the present invention, "visually prominent" means that the design element (including its outline) is visible to an observer as a separate element, and "visually non-prominent" means that the design element is not visible to an observer as a separate element, but is perceived as a homogeneous element together with the electro-optical functional element, and the observer cannot see any outline of the design element.

[0060] In a preferred embodiment of the composite glass 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 the composite glass 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 element is designed to have a haze of less than 30%, preferably less than 15%, particularly preferably less than 5%.

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

[0063] In one embodiment of the composite glass 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 transmission of at least 70%, preferably at least 80%, particularly preferably at least 90%.

[0064] Light transmittance refers to the transmittance in the visible spectrum and is expressed here as a percentage. Specifically, the term "light transmittance" refers to the light transmittance according to standard ECER43 revision 4 of April 3, 2017, illuminant A, which is also abbreviated as TL or TL(A).

[0065] According to the invention, there is also provided a composite glass pane comprising at least an outer glass pane having an outer surface and an inner surface, a first thermoplastic interlayer, an electro-optical functional element, a second thermoplastic interlayer, a design element and an inner glass pane having an outer surface and an inner surface, wherein the electro-optical functional element is arranged between the outer pane and the inner pane in the region of the composite glass pane, A first thermoplastic intermediate layer is arranged between the outer glass pane and the electro-optical functional element, A second thermoplastic intermediate layer is arranged between the electro-optical functional element and the inner glass pane, the design element is arranged in a region of the composite glass pane which, when viewed through the composite glass pane, is completely located 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 the functional element has a first color, a first haze and a first transmittance to a second state in which the functional element has a second color, a second haze and a second transmittance, and vice versa, And wherein the design element has a third color, a third haze and a third transmittance, the third color corresponds to the first color, and the third haze and the third transmittance are adapted to the first haze and the first transmittance of the electro-optical functional element and the second haze and the second transmittance of the electro-optical functional element in a manner such that when the electro-optical functional element is in the first state, the design element is not visually prominent to the observer, and when the electro-optical functional element is in the second state, the design element is visually prominent to the observer.

[0066] In one embodiment of the invention, the electro-optical functional element is divided into segments by insulating wires. The individual segments are connected to a voltage source independently of each other so that they can be controlled individually, i.e., the segments can be electrically controlled independently of each other. Therefore, different segments of the electro-optical functional element can be electrically controlled independently of each other from a first state in which they have a first color to a second state in which they have a second color, and vice versa.

[0067] In one embodiment, the composite glass pane according to the invention also has a peripheral opaque cover print, in particular made of black enamel, which is particularly used to protect the adhesive used for mounting the composite glass pane from UV radiation and to visually hide the adhesive. This peripheral opaque cover print is preferably also used to cover one or more edges of the electro-optical functional element.

[0068] In one embodiment, the first thermoplastic intermediate layer, the second thermoplastic intermediate layer and the optional third thermoplastic intermediate layer independently contain 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 those skilled in the art, such as plasticizers.

[0069] 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 from a single film or from more than one film.

[0070] The thickness of the first thermoplastic intermediate layer and the thickness of the second thermoplastic intermediate layer are preferably independently of one another 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.

[0071] The first thermoplastic intermediate layer and / or the second thermoplastic intermediate layer and / or the third thermoplastic intermediate layer can also independently of one another be a functional intermediate layer, in particular an intermediate layer with acoustic damping properties, an intermediate layer reflecting infrared radiation, an intermediate layer absorbing infrared radiation or an intermediate layer absorbing UV radiation.

[0072] The outer pane and the inner pane are preferably made of transparent glass, in particular soda-lime glass, which is commonly used for window panes. In principle, however, the panes can also be made of other types of glass, such as borosilicate glass, quartz glass, aluminosilicate glass, or transparent plastic, such as polymethyl methacrylate or polycarbonate. The thickness of the outer pane and the inner pane can vary greatly. Preferably, panes with a thickness ranging from 0.8 mm to 5 mm, preferably from 1.4 mm to 2.5 mm, are used, for example panes with a standard thickness of 1.6 mm or 2.1 mm. The outer pane and the inner pane can be unprestressed, partially prestressed, or prestressed independently of one another. If at least one of the panes is prestressed, thermal prestressing or chemical prestressing can be used.

[0073] The outer pane and / or the inner pane may further have other suitable coatings known per se, such as, for example, an antireflective coating, a non-stick coating, an anti-scratch coating, a photocatalytic coating, or a sun protection coating, or a low-e coating.

[0074] The composite glass pane according to the invention may comprise one or more additional interlayers, in particular functional interlayers. The additional interlayer may in particular be an interlayer with acoustic damping properties, an interlayer reflecting infrared radiation, an interlayer absorbing infrared radiation or an interlayer absorbing UV radiation. If a plurality of additional interlayers are present, they may also have different functions.

[0075] The fact that the design element is arranged in a region of the composite glass pane which, when viewed through the composite glass pane, is completely in the region in which the electro-optical functional element is arranged means that an orthogonal projection from the design element to the plane of the electro-optical functional element is arranged completely within the electro-optical functional element.

[0076] Since the design element is arranged in a region of the composite glass pane which, when viewed through the composite glass pane, is completely located in the region in which the electro-optical functional element is arranged, the outer dimensions of the design element cannot be larger than the outer dimensions of the electro-optical functional element. The region in which the design element is arranged and the region in which the electro-optical functional element is arranged also do not specifically coincide, i.e. the region in which the electro-optical functional element is arranged is specifically larger than the region in which the design element is arranged.

[0077] The area of ​​the design element is preferably less than or equal to 80%, particularly preferably less than or equal to 50%, most particularly preferably less than or equal to 25% of the area of ​​the electro-optical functional element.

[0078] The area of ​​the design element is preferably at least 0.01%, particularly preferably at least 0.1%, most particularly preferably at least 1.0% of the area of ​​the electro-optical functional element.

[0079] According to the invention, a method according to the invention for producing a composite glass pane is also provided.

[0080] In one embodiment of the method, the method comprises at least the following steps: a) providing a stacking sequence comprising at least an outer glass pane having an outer side surface and an inner side surface, a first thermoplastic interlayer, an electro-optical functional element, a second thermoplastic interlayer, a design element and an inner glass pane having an outer side surface and an inner side surface, wherein the electro-optical functional element is arranged between the outer pane and the inner pane in the region of the composite glass pane, A first thermoplastic intermediate layer is arranged between the outer glass pane and the electro-optical functional element, A second thermoplastic intermediate layer is arranged between the electro-optical functional element and the inner glass pane, the design element is arranged in a region of the composite glass pane which, when viewed through the composite glass pane, is completely located 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 the functional element has a first color to a second state in which the functional element 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 stacking sequences.

[0081] In an embodiment of the method, the design element is introduced into the stacking sequence before lamination. By means of an embodiment of the method, in particular a composite glass pane according to the invention can be produced, wherein the design element is formed as an imprint on one of the surfaces of the glass pane, as an imprint on the first thermoplastic interlayer or the second thermoplastic interlayer, as an inserted element arranged between the first thermoplastic interlayer and the electro-optical functional element or between the second thermoplastic interlayer and the electro-optical functional element, as an adhesive strip adhered to one of the surfaces of the glass pane or as a silk-finished area on one of the surfaces of the glass pane.

[0082] In an alternative embodiment, the design element is applied to the laminate 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 glass pane having an outer side surface and an inner side surface, a first thermoplastic intermediate layer, an electro-optical functional element, a second thermoplastic intermediate layer and an inner glass pane having an outer side surface and an inner side surface, wherein the electro-optical functional element is arranged between the outer pane and the inner pane in the region of the composite glass pane, A first thermoplastic intermediate layer is arranged between the outer glass pane and the electro-optical functional element, A second thermoplastic intermediate layer is arranged between the functional element and the inner glass pane, the electro-optical functional element is electrically controllable from a first state in which the functional element has one color to a second state in which the functional element has a second color, and vice versa, b) laminating the stacking sequence to form a laminated stacking sequence; c) applying a design element in a region of the outer side surface of an outer glass pane or of the inner side surface of an inner glass pane of the laminated stacking sequence, wherein the region in which the design element is applied is located completely in the region in which the electro-optical functional element is arranged when viewed through the composite glass pane, and wherein the design element has a third color corresponding to the first color of the electro-optical functional element.

[0083] In an alternative embodiment of the method, the design element is introduced into the lamination stacking sequence after lamination. By means of this embodiment of the method, a composite glass pane according to the invention can therefore be produced, wherein the design element is formed as an imprint on the outer side surface of the outer glass pane, as an imprint on the inner side surface of the inner glass pane, as an adhesive tape adhered to the outer side surface of the outer glass pane, as an adhesive tape adhered to the inner side surface of the inner glass pane, as a satin-finished area on the outer side surface of the outer glass pane or as a satin-finished area on the inner side surface of the inner glass pane.

[0084] In the method according to the invention, the stacking sequence can be laminated using conventional lamination methods. For example, the so-called autoclave method can be carried out at an elevated pressure of about 10 bar to 15 bar and a temperature of 130° C. to 145° C. for about 2 hours. Alternatively, a method without autoclave is also feasible. The vacuum bag or vacuum ring method known per se operates, for example, at about 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 producing glass sheets and generally have at least one heating tunnel upstream of the pressing unit. The temperature during pressing is, for example, from 40° C. to 150° C. Practice has shown that the combination of the calender and autoclave method is particularly successful. A vacuum laminator can be used as an alternative. These consist of one or more heatable and evacuable chambers, in which the stacking sequence is laminated, for example, within about 60 minutes at a reduced pressure of 0.01 mbar to 800 mbar and a temperature of 80° C. to 170° C.

[0085] The preferred embodiments of the composite glass pane according to the invention described above also apply correspondingly to the method for producing the composite glass pane according to the invention, and vice versa.

[0086] The invention also relates to the use of the composite glass pane according to the invention in buildings, in particular in entrance or window areas, as built-in parts of furniture and appliances, or in means of transport for land, air or water transport, in particular in trains, ships and motor vehicles, for example as windshields, rear panes, side panes and / or roof panes. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] In the following, the invention is described in more detail with the aid of the drawings and examples of embodiments. Elements which are the same or have the same effect are provided with the same reference symbols. In simplified, not to scale illustrations: Figure 1 and Figure 2 shows a plan view of an embodiment of a composite glass pane according to the invention, Figure 3 shows a cross section through an embodiment of a composite glass pane according to the invention, Figure 4 shows a cross section through a further embodiment of a composite glass pane according to the invention, Figure 5 shows a cross section through a further embodiment of a composite glass pane according to the invention, Figure 6 shows a cross section through a further embodiment of a composite glass pane according to the invention, Figure 7 shows a cross section through a further embodiment of a composite glass pane according to the invention, Figure 8 shows a cross section through a further embodiment of a composite glass pane according to the invention, Fig. 9 shows a cross section through a further embodiment of a composite glass pane according to the invention, Fig.10 and Fig.11 A plan view showing another embodiment of a composite glass pane according to the present invention is shown, Fig.12 shows a cross section through a further embodiment of a composite glass pane according to the invention, Fig.13 is a plan view of another embodiment of a composite glass panel according to the present invention, Fig.14 is a plan view of another embodiment of a composite glass panel according to the present invention, Fig.15 is a flow chart of a method for producing a composite glass pane according to the present invention, Fig.16 FIG. 1 is a flow chart of another method for producing a composite glass pane according to the present invention. DETAILED DESCRIPTION

[0088] Figure 1 and Figure 2 The plan views of embodiments of the composite glass pane 1 according to the present invention are shown respectively, wherein Figure 1 and Figure 2 The only difference is that Figure 1 In the embodiment, the electro-optical functional element 4 is in the second state, and in Figure 2 In the embodiment, the electro-optical functional element 4 is in the first state. Figure 1 and Figure 2 The composite glass pane 1 shown in FIG. 1 comprises an outer glass pane 2, a first thermoplastic interlayer 3, an electro-optical functional element 4, a second thermoplastic interlayer 5, a design element 6 and an inner glass pane 7. The electro-optical functional element 4 is arranged in a region of the composite glass pane 1. The design element 6 is arranged in a region of the composite glass pane 1 which, when viewed through the composite glass pane 1, is completely located in the region in which the electro-optical functional element 4 is arranged. Figure 1 and Figure 2 In the embodiment shown in FIG, the design element 6 is formed as a text with a logo. Figure 1 and Figure 2It can be seen that 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, and therefore the design element 6 only stands out visually when the electro-optical functional element 4 is in the second state, and the observer cannot recognize it as a separate element, but rather perceives it as a homogeneous element together with the electro-optical functional element 4 when the electro-optical functional element 4 is in the first state. Figure 2 It can be seen that the outline of the design element is not visible to the observer. Figure 1 and Figure 2 The composite glass panel 1 shown in FIG. Figures 3 to 9 For better illustration, Figure 1 and Figure 2 The side edges of the electro-optical functional element 4 are shown by dashed lines.

[0089] Figure 3 Shown along the section line X'-X through Figure 1 and Figure 2 The cross section of an embodiment of a composite glass pane 1 according to the invention is shown in FIG. Figure 3 In the embodiment shown in , the composite glass pane 1 comprises an outer glass pane 2, a first thermoplastic interlayer 3, an electro-optical functional element 4, a second thermoplastic interlayer 5, a design element 6 and an inner glass pane 7. The electro-optical functional element 4 is arranged in a region of the composite glass pane 1. The design element 6 is arranged on the outer side surface I of the outer glass pane 2 in a region of the composite glass pane 1 which, when viewed through the composite glass pane 1, is completely located in the region in which the electro-optical functional element 4 is arranged. Figure 3 In the embodiment shown in , the design element 6 is formed, for example, as an imprint or an adhesive strip or a mercerized polished area. The thickness of the outer glass plate 2 and the thickness of the inner glass plate 7 are, for example, 2.1 mm. The first thermoplastic intermediate layer 3 is, for example, composed of PVB and has a thickness of 0.76 mm. The second thermoplastic intermediate layer 5 is, for example, composed of PVB and has a thickness of 0.76 mm. The electro-optical functional element 4 is, for example, a PDLC element.

[0090] Figure 4 Shown along the section line X'-X through Figure 1 and Figure 2 A further exemplary embodiment of a composite glass pane 1 according to the invention is shown in cross section. Figure 4 The embodiments shown in Figure 3 The embodiment shown in FIG. 1 differs only in that the design element 6 is not arranged on the outer side surface I of the outer glass pane 2 , but rather between the outer glass pane 2 and the first thermoplastic interlayer 3 . Figure 4In the embodiment shown in , the design element 6 is formed, for example, as an imprint on the inner surface II of the outer glass pane 2, as an imprint on the surface of the first thermoplastic interlayer 3 adjacent to the outer glass pane 2, as an adhesive strip on the inner surface II of the outer glass pane 2, as an inserted element or as a silk-finished area of ​​the inner surface II of the outer glass pane 2.

[0091] Figure 5 Shown along the section line X'-X through Figure 1 and Figure 2 A further exemplary embodiment of a composite glass pane 1 according to the invention is shown in cross section. Figure 5 The embodiments shown in Figure 3 The embodiment shown in FIG. 1 differs only in that the design element 6 is not arranged on the outer side surface I of the outer glass pane 2 , but rather between the first thermoplastic intermediate layer 3 and the electro-optical functional element 4 . Figure 5 In the embodiment shown in FIG. 4 , the design element 6 is formed, for example, as an imprint on the surface of the first thermoplastic intermediate layer 3 adjacent to the electro-optical functional element 4 or as an inserted element.

[0092] Figure 6 Shown along the section line X'-X through Figure 1 and Figure 2 A further exemplary embodiment of a composite glass pane 1 according to the invention is shown in cross section. Figure 6 The embodiments shown in Figure 3 The embodiment shown in FIG. 1 differs only in that the design element 6 is not arranged on the outer side surface I of the outer glass pane 2 , but rather between the electro-optical functional element 4 and the second thermoplastic intermediate layer 5 . Figure 6 In the embodiment shown in , the design element 6 is formed, for example, as an imprint on the surface of the second thermoplastic intermediate layer 5 adjacent to the electro-optical functional element 4 or as an inserted element.

[0093] Figure 7 Shown along the section line X'-X through Figure 1 and Figure 2 A further exemplary embodiment of a composite glass pane 1 according to the invention is shown in cross section. Figure 7 The embodiments shown in Figure 3 The embodiment shown in FIG. 1 differs only in that the design element 6 is not arranged on the outer side surface I of the outer glass pane 2 , but rather between the second thermoplastic intermediate layer 5 and the inner glass pane 7 . Figure 7 In the embodiment shown in , the design element 6 is formed, for example, as an imprint on the outer side surface III of the inner glass pane 7, as an imprint on the surface of the second thermoplastic interlayer 5 adjacent to the inner glass pane 7, as an adhesive strip on the outer side surface III of the inner glass pane 7, as an inserted element or as a silk-finished area of ​​the outer side surface III of the inner glass pane 7.

[0094] Figure 8 Shown along the section line X'-X through Figure 1 and Figure 2 A further exemplary embodiment of a composite glass pane 1 according to the invention is shown in cross section. Figure 8 The embodiments shown in Figure 3 The embodiment shown in FIG. 1 differs only in that the design element 6 is not arranged on the outer side surface I of the outer glass pane 2 , but on the inner side surface IV of the inner glass pane 7 . Figure 8 In the embodiment shown in FIG. 5 , the design element 6 is formed, for example, as an imprint or an adhesive strip or a mercerized area.

[0095] Fig. 9 A cross section through a further embodiment of a composite glass pane 1 according to the invention is shown. Fig. 9 The embodiments shown in Figure 4 The difference from the embodiment shown in FIG. 1 is that the composite glass pane 1 has a third thermoplastic interlayer 8, which is arranged between the first thermoplastic interlayer 3 and the second thermoplastic interlayer 5 and has a recess in which the electro-optical functional element 4 is accommodated. The electro-optical functional element 4 is therefore surrounded by the third thermoplastic interlayer 8 in a frame-like manner. It should be understood that Figure 3 and Figures 5 to 8 The exemplary embodiment shown in can also be modified in such a way that the composite glass pane 1 further comprises a third thermoplastic interlayer 8 which has a recess in which the electro-optical functional element 4 is accommodated.

[0096] Fig.10 and Fig.11 The plan views of another embodiment of the composite glass pane 1 according to the present invention are shown respectively, wherein Fig.10 and Fig.11 The only difference is that Fig.10 In the embodiment, the electro-optical functional element 4 is in the second state, and in Fig.11 In the embodiment, the electro-optical functional element 4 is in the first state. Fig.10 and 11 The embodiments shown in Figure 1 and 2 The embodiment shown in FIG. 1 differs only in that the composite glass pane 1 has a peripheral opaque cover print 9, for example made of black enamel. Fig.10 and 11 In the embodiment shown in , the edge of the electro-optical functional element 4 is covered by a peripheral opaque cover print 9 when viewed through the composite glass pane 1. For better illustration, Fig.10 and Fig.11 The side edges of the electro-optical functional element 4 are shown by dashed lines.

[0097] Fig.12Shown along the section line Y-Y' through Fig.10 and Fig.11 The cross section of an embodiment of a composite glass pane 1 according to the invention is shown in FIG. Fig.12 In the embodiment shown in , the composite glass pane 1 comprises an outer glass pane 2, a first thermoplastic interlayer 3, an electro-optical functional element 4, a second thermoplastic interlayer 5, a design element 6 and an inner glass pane 7. The electro-optical functional element 4 is arranged in a region of the composite glass pane 1. The design element 6 is arranged between the electro-optical functional element 4 and the second thermoplastic interlayer 5 in a region of the composite glass pane 1 which, when viewed through the composite glass pane 1, is completely located in the region in which the electro-optical functional element 4 is arranged. Fig.12 In the embodiment shown in , the design element 6 is formed, for example, as an imprint on the surface of the second thermoplastic interlayer 5 facing the electro-optical functional element 4 or as an inserted element. The thickness of the outer glass pane 2 and the thickness of the inner glass pane 7 are, for example, 2.1 mm. The first thermoplastic interlayer 3 is composed of PVB, for example, and has a thickness of 0.76 mm. The second thermoplastic interlayer 5 is composed of PVB, for example, and has a thickness of 0.76 mm. The electro-optical functional element 4 is, for example, a PDLC element. A peripheral opaque cover print 9 made of black enamel is applied to the inner surface II of the outer glass pane 2. The peripheral opaque cover print 9 may alternatively or additionally be applied to the outer side surface I of the outer glass pane, the outer side surface III of the inner glass pane 7, or the inner side surface IV of the inner glass pane 7. It should be understood that Figure 3 , 4 The embodiments shown in FIGS. 5 , 7 , 8 and 9 can also be modified so that the composite glass pane 1 also has a peripheral opaque cover print 9 .

[0098] Fig.13 A further embodiment of a composite glass pane 1 according to the invention is shown in a top view, wherein the functional element 4 is in the second state. Fig.13 The embodiments shown in Figure 1 The embodiments shown in differ only in the configuration of the design element 6. Fig.13 In the embodiment shown in , the design element 6 is formed by a plurality of rhombus-shaped elements which together form a consistent pattern.

[0099] Fig.14 A further embodiment of a composite glass pane 1 according to the invention is shown in a top view, wherein the electro-optical functional element 4 is in the second state. Fig.14 The embodiments shown in Figure 1 The embodiments shown in differ only in the configuration of the design element 6. Fig.14 In the embodiment shown in , the design element 6 is formed by a plurality of elements, some of which each form a word, a symbol or a simple graphic.

[0100] Fig.15 A flow chart of a method according to the invention for producing a composite glass pane 1 is shown. The method comprises: in a first step S1, providing a stacking sequence, which comprises at least an outer glass pane 2 having an outer side surface I and an inner side surface II, a first thermoplastic interlayer 3, an electro-optical functional element 4, a second thermoplastic interlayer 5, a design element 6 and an inner glass pane 7 having an outer side surface III and an inner side surface IV, wherein the electro-optical functional element 4 is arranged in a region of the composite glass pane 1 between the outer glass pane 2 and the inner glass pane 7, A first thermoplastic interlayer 3 is arranged between the outer glass pane 2 and the electro-optical functional element 4, a second thermoplastic interlayer 5 is arranged between the electro-optical functional element 4 and the inner glass pane 7, a design element 6 is arranged in a region of the composite glass pane 1 which, when viewed through the composite glass pane 1, is completely located in the region 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 the functional element has a first color to a second state in which the functional element 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 in the first state. In a subsequent second step S2, the method comprises laminating the stacking sequence provided in the first step S1.

[0101] Fig.16 A flow chart of an alternative method for producing a composite glass pane 1 according to the invention is shown. The method comprises providing in a first step P1 a stacking sequence comprising at least an outer glass pane 2 having an outer side surface I and an inner side surface II, a first thermoplastic interlayer 3, an electro-optical functional element 4, a second thermoplastic interlayer 5 and an inner glass pane 7 having an outer side surface III and an inner side surface IV, wherein the functional element 4 is arranged in a region of the composite glass pane 1 between the outer glass pane 2 and the inner glass pane 7, the first thermoplastic interlayer 3 is arranged between the outer glass pane 2 and the functional element 4, the second thermoplastic interlayer 5 is arranged between the electro-optical functional element 4 and the inner glass pane 7, and the electro-optical functional element 4 is electrically controllable from a first state in which the functional element has one color to a second state in which the functional element 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 an area of ​​the outer side surface I of the outer glass sheet 2 or the inner side surface IV of the inner glass sheet 7 of the laminated stacking sequence, wherein the area in which the design element 6 is applied is completely located in the area in which the electro-optical functional element 4 is arranged when viewed through the laminated stacking sequence, and wherein 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. Reference numerals list 1 Composite glass panel 2 Outer glass panels 3 First thermoplastic interlayer 4 Electro-optical functional elements 5 Second thermoplastic intermediate layer 6 Design elements 7 Inner glass panel 8 Third thermoplastic intermediate layer 9 Covering printed matter I External surface of the outer glass pane II Inner surface of outer glass pane III Outer surface of inner glass pane IV Inner surface of inner glass panel XX' section line YY' section line

Claims

1. A composite glass pane (1) comprising at least an outer glass pane (2) having an outer surface (I) and an inner surface (II), a first thermoplastic interlayer (3), an electro-optical functional element (4), a second thermoplastic interlayer (5), a design element (6) and an inner glass pane (7) having an outer surface (III) and an inner surface (IV), wherein the electro-optical functional element (4) is arranged in the region of the composite glass pane (1) between the outer glass pane (2) and the inner glass pane (7), The first thermoplastic intermediate layer (3) is arranged between the outer glass 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 glass pane (7), The design element (6) is arranged in a region of the composite glass pane (1) which, when viewed through the composite glass pane (1), is completely located in 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 the electro-optical functional element has a first color to a second state in which the electro-optical functional element has a second color, and vice versa, And the design element (6) has a third color corresponding to the first color of the electro-optical functional element (4).

2. The composite glass pane (1) according to claim 1, wherein: The design element (6) is formed as an imprint on the outer surface (I) of the outer glass sheet (2), as an imprint on the inner surface (II) of the outer glass sheet (2), as an imprint on the outer surface (III) of the inner glass sheet (7), as an imprint on the inner surface (IV) of the inner glass sheet (7), as an imprint on the first thermoplastic interlayer (3), or as an imprint on the second thermoplastic interlayer (5).

3. The composite glass panel (1) according to claim 1, wherein: The design element (6) is formed as an insert element and is arranged between the electro-optical functional element (4) and the first thermoplastic interlayer (3), or between the electro-optical functional element (4) and the second thermoplastic interlayer (5), or between the first thermoplastic interlayer (3) and the outer glass pane (2), or between the second thermoplastic interlayer (5) and the inner glass pane (7).

4. The composite glass panel (1) according to claim 3, wherein: The insert element comprises or consists of colored PET, PVB, PE or EVA.

5. The composite glass panel (1) according to claim 1, wherein: The design element (6) is formed as an adhesive tape adhered to the outer surface (I) of the outer glass plate (2), is formed as an adhesive tape adhered to the inner surface (II) of the outer glass plate (2), is formed as an adhesive tape adhered to the outer surface (III) of the inner glass plate (7), or is formed as an adhesive tape adhered to the inner surface (IV) of the inner glass plate (7).

6. The composite glass panel (1) according to claim 1, wherein: The design element (6) is formed as a mercerized polished area on the outer surface (I) of the outer glass plate (2), as a mercerized polished area on the inner surface (II) of the outer glass plate (2), as a mercerized polished area on the outer surface (III) of the inner glass plate (7), or as a mercerized polished area on the inner surface (IV) of the inner glass plate (7).

7. The composite glass pane (1) according to any one of claims 1, 2, 5 or 6, wherein: The design element (6) is formed on the outer side surface (II) of the outer glass plate (1) or on the inner side surface (IV) of the inner glass plate (7).

8. The composite glass pane (1) according to any one of claims 1 to 5, wherein: The design element (6) has a thickness of less than 50 μm, preferably less than 25 μm, particularly preferably less than 12.5 μm, most particularly preferably less than 5 μm.

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

10. The composite glass pane (1) according to any 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 having a liquid crystal dye unit.

11. The composite glass pane (1) according to any one of claims 1 to 10, wherein: The electro-optical functional element (4) has a first haze and a first light transmittance in a first state, and has a second haze and a second light transmittance in a second state, and the design element (6) has a third haze and a third light transmittance, and the third haze and the third light transmittance are adapted to the first haze, the first light transmittance, the second haze and the second light transmittance in a manner such that when the electro-optical functional element (4) is in the first state, the design element (6) is not visually prominent to an observer, and when the electro-optical functional element (4) is in the second state, the design element (6) is visually prominent to an observer.

12. The composite glass pane (1) according to any one of claims 1 to 11, wherein: The electro-optical functional element (4) is divided by insulating lines into segments which can be electrically controlled independently of one another, and / or wherein the composite glass pane (1) further comprises a peripheral opaque cover print (9) preferably made of black enamel.

13. A method for producing a composite glass panel (1) according to any one of claims 1 to 12, comprising at least the following steps: - providing a stacking sequence comprising at least an outer glass pane (2) having an outer side surface (I) and an inner side 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 glass pane (7) having an outer side surface (III) and an inner side surface (IV), wherein the electro-optical functional element (4) is arranged in the region of the composite glass pane (1) between the outer glass pane (2) and the inner glass pane (7), The first thermoplastic intermediate layer (3) is arranged between the outer glass 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 glass pane (7), The design element (6) is arranged in a region of the composite glass pane (1) which, when viewed through the composite glass pane (1), is completely located in 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 the functional element has a first color to a second state in which the functional element 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); - Lamination of said stacking sequence.

14. A method for producing a composite glass panel (1) according to any one of claims 1, 2 or 5 to 12, comprising at least the following steps: - providing a stacking sequence comprising at least an outer glass pane (2) having an outer side surface (I) and an inner side surface (II), a first thermoplastic intermediate layer (3), an electro-optical functional element (4), a second thermoplastic intermediate layer (5) and an inner glass pane (7) having an outer side surface (III) and an inner side surface (IV), wherein the electro-optical functional element (4) is arranged in the region of the composite glass pane (1) between the outer glass pane (2) and the inner glass pane (7), The first thermoplastic intermediate layer (3) is arranged between the outer glass 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 glass pane (7), and the electro-optical functional element (4) is electrically controllable from the first state in which the electro-optical functional element has a first color to a second state in which the electro-optical functional element has a second color, and vice versa; - laminating the stacking sequence to form a laminated stacking sequence; - applying a design element (6) in an area on the outer side surface (I) of an outer glass sheet (2) or the inner side surface (IV) of an inner glass sheet (7) of the laminated stacking sequence, wherein the area to which the design element (6) is applied is completely located in the area in which the electro-optical functional element (4) is arranged when viewed through the laminated stacking sequence, and wherein the design element (6) has a third color corresponding to the first color of the electro-optical functional element (4).

15. Use of a composite glass pane (1) according to any one of claims 1 to 12, wherein the composite glass pane is used in buildings, in particular in entrance or window areas, as built-in parts of furniture and appliances, or in means of transport for land, air or water transportation, in particular in trains, ships and motor vehicles, in particular as windshields, rear glass panes, side glass panes and / or roof glass panes.

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