Composite glass pane with an opaque masking area and a partially transparent reflective coating

Abstract

The invention relates to a composite glass pane comprising an outer glass pane (1) and an inner glass pane (2) which are joined to one another by means of a thermoplastic intermediate layer (3), wherein the composite glass pane has an opaque masking region (M) and a transparent see-through region (D), wherein the intermediate layer (3) has a functional element (4) which covers the entire see-through region (D), wherein at least one region of the side edge of the functional element (4) does not extend to the side edge of the composite glass pane, but is arranged in the masking region (M), and wherein the surface (I) of the outer glass pane (1) which faces away from the intermediate layer (3) has a pattern of coated regions (b) in the masking region (M), which are equipped with a partially transparent reflective coating (11).

Description

[0001] The present invention relates to a composite glass pane having a transparent see-through area and an opaque masking area and the use thereof.

[0002] Composite glass panes are conventionally used as glazing in the field of vehicles and in the field of architecture. They consist of an outer glass pane and an inner glass pane which are joined to one another by means of a thermoplastic intermediate layer. Herein, various types of functional elements are usually embedded in the intermediate layer, which equip the composite glass pane with the desired functionality. Examples of such functional elements are IR-reflecting and / or heatable coatings. Another example is a functional element having electrically controllable optical properties, such as an SPD functional element Suspension particle device ), a PDLC functional element Polymer dispersed liquid crystal ) or an electrochromic functional element. The optical properties of such functional elements and of the composite glass pane equipped therewith, in particular their light transmission or light scattering, can be controlled by means of an applied voltage.

[0003] The side edges of the functional elements usually do not extend to the side edges of the composite glass pane, so that the functional elements are reliably embedded in the composite glass pane and are protected from corrosion and damage. If the side edges of the functional elements are located in the see-through area of the composite glass pane, this appears disturbing to the observer and reduces the aesthetic value of the composite glass pane. This applies in particular to functional elements which have to be electrically contacted, such as heatable layers or functional elements having electrically controllable optical properties. The electrical contacting is usually achieved by means of busbars and cables which should also not be visible to the observer. Therefore, the composite glass pane is usually equipped with an opaque masking area which is usually located in a surrounding fashion in the outer peripheral edge area, by means of which the side edges of the functional elements and possibly the electrical contacts appear to be concealed. The masking area is usually formed by means of an opaque, usually black, cover print on the outer glass pane and the inner glass pane. Examples are known from WO2017157626A1.

[0004] WO2020094324A1 and WO2014174308A1 also disclose composite glass panes having embedded functional elements and an opaque masking area.

[0005] Such opaque masking areas for windshield panes, rear glass panes and roof glass panes have been common in the field of vehicles for a long time in order to protect the adhesives used for the installation from UV radiation. In contrast, for other glass panes, such as for vehicle side glass panes or architectural glazing, masking areas are not common and therefore appear unusual and visually less appealing to the observer. Therefore, there is a need for composite glass panes having an opaque masking area which are aesthetically appealing and considered less disturbing by the observer.

[0006] Printed partially transparent reflective coatings comprising metal oxides are known from the subsequently published international patent applications WO 2022117955 A1 and WO 2022073894 A1.

[0007] It is a basic object of the present invention to provide an improved composite glass pane having a functional element, a transparent see-through region and an opaque masking region, wherein the masking region is designed to be aesthetically appealing.

[0008] This object is achieved by a composite glass pane according to independent claim 1. Preferred embodiments emerge from the dependent claims.

[0009] The composite glass pane according to the invention comprises at least one outer glass pane and an inner glass pane, which are joined to one another by means of a thermoplastic intermediate layer. The composite glass pane is provided for separating an interior space from an exterior environment in a window opening, in particular a window opening of a vehicle, but alternatively also a window opening of a building or a room. In the sense of the invention, the inner glass pane means the glass pane facing the interior space. The outer glass pane means the glass pane facing the exterior environment. The outer glass pane and the inner glass pane each have an outer and an inner side surface and a circumferential side edge surface extending therebetween. In the sense of the invention, the outer side surface means the main surface which is provided to face the exterior environment in the installed position. In the sense of the invention, the inner side surface means the main surface which is provided to face the interior space in the installed position. The inner side surface of the outer glass pane and the outer side surface of the inner glass pane face one another and are joined to one another by means of the thermoplastic intermediate layer.

[0010] The outer glass pane and the inner glass pane are preferably glass panes, in particular made of soda-lime glass, as is common for window glass panes. However, one or both of the glass panes can also be made of other types of glass, for example quartz glass, borosilicate glass or aluminosilicate glass, or of a rigid clear plastic, for example polycarbonate or polymethyl methacrylate. The glass panes can be clear or tinted or colored. The thickness of the outer glass pane and the inner glass pane is preferably 0.5 mm to 5 mm, in particular preferably 1 mm to 3 mm, independently of one another.

[0011] The intermediate layer is preferably formed by at least one thermoplastic film (joining film). The at least one film (joining film) is preferably based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) or polyurethane (PU), in particular preferably on PVB. This means that the film mainly comprises the stated material (in a proportion of more than 50% by weight) and can also comprise optional further ingredients, for example plasticizers, stabilizers, UV or IR absorbers. The thickness of each thermoplastic film is preferably 0.2 mm to 2 mm, in particular preferably 0.3 mm to 1 mm. For example, films having a standard thickness of 0.38 mm or 0.76 mm, in particular PVB films, can be used.

[0012] The composite glass pane according to the application has an opaque masking region and a transparent see-through region. In the sense of the application, the masking region is a region of the composite glass pane through which no see-through is possible. The light transmission of the masking region is preferably essentially 0%. In the sense of the application, the see-through region is a region of the glass pane through which see-through is possible and which therefore has a certain transparency or at least translucency. The light transmission of the see-through region is preferably at least 10%, particularly preferably at least 20%. If the functional element according to the application has electrically controllable optical properties, the specification is based on the transparent state of the functional element (maximum light transmission and / or minimum light scattering).

[0013] In one typical embodiment, the masking region surrounds the see-through region in the form of a frame. The masking region is thus arranged in a surrounding manner around the see-through region. The masking region usually forms at least locally here an edge region of the composite glass pane. This means that the masking region is at least adjacent to a section of a side edge of the composite glass pane.

[0014] The masking region is formed by an opaque element which is arranged on the outside with respect to the functional element. This means that the opaque element is at a smaller distance from the outside than the functional element. Thereby, it is prevented that the side edges of the functional element are visible from the outside.

[0015] In one preferred embodiment, the masking region is formed by a cover print on the inner side surface of the outer glass pane which faces the interlayer. In other words, the inner side surface of the inner glass pane is equipped with a cover print, whereby see-through through the composite glass pane is prevented and a masking region is created. Such cover prints are widespread in particular in the field of vehicles, in particular for windshield panes, rear glass panes and roof glass panes. The cover print usually contains pigments and glass frit. The glass frit can be melted, whereby the cover print is permanently joined (fused) with the glass surface. The pigments provide the opacity of the masking region. The cover print is preferably printed onto the outer glass pane, in particular by means of a screen printing method. The pigments are usually black pigments, such as carbon black (carbon black), aniline black, bone black, iron oxide black, spinel black and / or graphite. The cover print preferably has a thickness of 5 pm to 50 pm, particularly preferably 8 pm to 25 pm. Optionally, the inner glass pane can also be equipped with a cover print, in particular its inner side surface.

[0016] However, alternatively, the masking region can also be formed by a colored or tinted film in the interlayer. For example, at least one thermoplastic bonding film between the functional element and the outer glass pane can be colored in the masking region, or the bonding layer can be composed of a plurality of sections of different films, wherein a colored film is used in the masking region and a clear film is used in the see-through region. Alternatively, an opaque film can also be embedded into the interlayer between the functional element and the outer glass pane.

[0017] Optionally, a further non-transparent element can also be arranged in the masking area on the inner side with respect to the functional element. Thereby, the side edge of the functional element is also prevented from being seen from the inside. For example, the inner glass pane can also be equipped with a cover print, in particular on its inner side surface, or there can be a non-transparent film between the functional element and the inner glass pane.

[0018] In addition to the joining film, the intermediate layer also has the functional element. In other words, the intermediate layer comprises the functional element, the intermediate layer is equipped with the functional element, or the functional element is embedded in the intermediate layer. The functional element is thus arranged between the outer glass pane and the inner glass pane and can optionally be in direct physical contact with the surface of the outer glass pane and / or the inner glass pane facing the intermediate layer. In particular, the functional element is arranged in face form between the outer glass pane and the inner glass pane, substantially parallel to said glass panes.

[0019] In the sense of the present application, a functional element is understood to mean a flat, in particular layer-like or film-like element or component which equips the see-through area of the composite glass pane with additional functions or properties. This can relate to color, for example, influence on electromagnetic radiation, heating function or the possibility of electrically controlling the optical properties, in particular the degree of light transmission or light scattering.

[0020] The functional element covers the entire see-through area of the composite glass pane. This means that the functional element is arranged between the outer glass pane and the inner glass pane such that the entire see-through area is equipped with the functional element. Light passing through the see-through area of the composite glass pane also necessarily always passes through the functional element.

[0021] According to the application, at least one region of the side edge of the functional element does not extend to the side edge of the composite glass pane. Thus, at least one region of the side edge of the functional element is not arranged flush with the side edge of the composite glass pane, which is formed by the (substantially flush) side edges of the inner glass pane, the outer glass pane and the intermediate layer. Instead, said region of the side edge of the functional element is recessed with respect to the side edge of the composite glass pane and arranged in a masking area. The area of the functional element is thus greater than the area of the see-through area, but smaller than the area of the entire composite glass pane.

[0022] Generally, the entire surrounding side edge of the functional element does not extend to the side edge of the composite glass pane, but is arranged in a masking area. Thus, there is no region of the side edge of the functional element which is arranged flush with the side edge of the composite glass pane. The surrounding side edge of the functional element thus appears to be recessed with respect to the side edge of the composite glass pane. In an advantageous embodiment, the distance between the side edge of the functional element and the side edge of the composite glass pane is at least 15 mm to ensure a stable joint between the outer glass pane and the inner glass pane in the edge region and to prevent moisture from penetrating into the functional element.

[0023] Since the side edges of the functional element do not extend to the side edges of the composite glass pane, direct contact between the functional element and the surrounding atmosphere can be prevented. Instead, the functional element is completely embedded in the composite glass pane. This is particularly advantageous when the functional element contains a metal component which would corrode when exposed to the atmosphere. In a particularly advantageous embodiment, the functional element thus contains a metal, in particular at least one thin layer based on a metal.

[0024] Since the side edges of the functional element are arranged in the masking area, they are not visible to an observer. Visible side edges would appear disruptive and reduce the aesthetic value of the composite glass pane.

[0025] According to the application, the outer side surface of the outer glass pane facing away from the intermediate layer has a pattern of coated areas in the masking area, which are equipped with a partially transparent, reflective coating. The pattern is present at least in sections of the masking area and can optionally extend beyond the masking area onto the viewing area. By means of the pattern of coated areas according to the application, the masking area is designed to be more aesthetically appealing to an outside observer. This is a great advantage of the application. The masking area appears less disruptive at this point. This is particularly advantageous for such glass panes which generally do not have a masking strip, which would appear particularly disruptive to an observer (for example composite glass panes in the field of architecture or side glass panes of vehicles, in particular of elevatable and lowerable side glass panes). The inner side surface of the inner glass pane facing away from the intermediate layer can likewise optionally be equipped with a pattern of coated areas with a partially transparent, reflective coating, whereby the masking area is also designed to be more aesthetically pleasing to an outside observer.

[0026] In the sense of the present application, a partially transparent, reflective coating is understood to mean a coating which transmits a significant proportion of electromagnetic radiation in the visible spectral range of 380 nm to 780 nm which is incident thereon and also reflects a significant proportion of said radiation. A significant proportion is understood here in particular to mean a proportion of more than 10%. In an advantageous embodiment, if the coating is applied to a clear soda-lime glass pane having a thickness of 3.85 mm, the total luminous transmission and the total luminous reflection each amount to at least 10%, preferably at least 15%, particularly preferably at least 20%, measured using the D65 light source. Here, the luminous reflection is measured at an angle of incidence and an angle of observation of 10°, wherein in addition to the directional reflection also the diffuse reflection is taken into account. The total luminous transmission under the stated conditions is particularly preferably 60% to 90%, in particular 70% to 80%, and the total luminous reflection is 10% to 40%, in particular 20% to 30%.

[0027] The pattern of the coated regions means that in the masked regions, in addition to the coated regions, there are also uncoated regions which are not equipped with the partially transparent reflective coating. The masked regions are therefore not completely equipped with the partially transparent reflective coating. The pattern is preferably designed in such a way that the coated regions are not continuous with one another. Instead, the coated regions are isolated from one another in such a way that each coated region is separated from the other coated regions by an overall continuous uncoated region. The coated regions appear to be designed as islands. The pattern of the coated regions is preferably designed in such a way that the area occupancy of the coated regions, i.e. the proportion of the coated regions in the total area of the pattern, is in the range from 5% to 90%, particularly preferably in the range from 10% to 50% and very particularly preferably in the range from 20% to 40%.

[0028] The coated regions can be designed, for example, in the form of geometric figures or in the form of symbols or logos, for example the company logo of the glass manufacturer or of the vehicle manufacturer in the case of vehicle glazing.

[0029] The size of each coated region is preferably at least 0.2 mm, particularly preferably at least 0.4 mm and very particularly preferably in the range from 0.4 mm to 15 mm. The distance between adjacent coated regions is preferably at least 0.5 mm and the distance between a coated region and a side edge of the composite glass pane is preferably at least 1.5 mm.

[0030] The functional element can be designed in different ways. In one embodiment, the functional element has a reflective effect on electromagnetic radiation which passes through the see-through region, in particular on the infrared (IR) or ultraviolet radiation portion. Thereby, the thermal comfort of the interior space can be improved by avoiding excessive heating due to solar radiation. The functional element can for example be a coating which is applied to the inner side surface of the outer glass pane or to the outer side surface of the inner glass pane. The coating is particularly preferably an IR-reflective coating which consists of a stack of thin layers which comprise at least one layer based on metal, in particular on silver. The functional element can also be a coated polymer film in which a carrier film is equipped with such an IR-reflective coating. The carrier film is usually formed on the basis of polyethylene terephthalate (PET) and has a thickness in the range from 20 μιη to 200 μιη. The coated polymer film is preferably arranged between the two joining films of the interlayer.

[0031] In another embodiment, the functional element has a heating function, whereby the composite glass pane can be electrically heated. Here, a thin-layer coating of the type as described above as an IR-reflective coating is preferably used which is deposited on the outer glass pane or on the inner glass pane or on a carrier film. The conductive coating is connected in an electrically contacting manner with an external voltage source, whereby it can be heated by an electric current. The two poles of the voltage source are usually connected to mutually opposite side edges of the coating.

[0032] The functional element can also be a colored coating or a colored coated or printed film to change the color of the see-through area.

[0033] In another embodiment, the functional element has an electrically controllable optical property. Such a functional element comprises an active layer or layer sequence arranged between the first and the second planar electrode. The active layer or layer sequence has a variable optical property, which can be controlled by a voltage applied to the planar electrodes. The variable optical property relates, inter alia, to the degree of light transmission and / or the degree of light scattering, wherein light in the sense of the present application is understood to mean, inter alia, visible light in the spectral range from 380 nm to 780 nm. The electrically controllable optical property is understood in the sense of the present application to mean, inter alia, such a property which can be continuously controlled. However, it is also conceivable in principle that the electrically controllable optical property can only be switched between two discrete states. It is also conceivable that the electrically controllable optical property can be switched between more than two discrete states.

[0034] The electrically controllable functional element can be a PDLC functional element (polymer dispersed liquid crystal). The PDLC functional element comprises an active layer between the planar electrodes. The active layer is a PDLC layer and comprises liquid crystals embedded in a polymer matrix. The PDLC functional element is usually operated using an alternating voltage. If no voltage is applied to the planar electrodes, the liquid crystals are arranged in a disordered manner, which leads to a strong scattering of light passing through the active layer. If a voltage is applied to the planar electrodes, the liquid crystals are aligned in a common direction and the transmission of light through the active layer increases. Such a functional element is known, for example, from DE 102008026339 A1. The expression PDLC is to be interpreted broadly in the sense of the present application and includes related functional elements based on liquid crystal alignment, for example a PNLC functional element (polymer network liquid crystal).

[0035] Alternatively, the electrically controllable functional element can be an SPD functional element (suspended particle device). The SPD functional element comprises an active layer between the planar electrodes. The active layer comprises suspended particles, which are preferably embedded in a viscous matrix. The SPD functional element is operated using an alternating voltage. The absorption of light by the active layer can be changed by applying a voltage to the planar electrodes, which leads to a change in the positioning of the suspended particles. Such a functional element is known, for example, from EP 0876608 B1 and WO 2011033313 A1.

[0036] Alternatively, the electrically controllable functional element can be an electroluminescent functional element. Here, the active layer comprises an electroluminescent material, which can be inorganic or organic (OLED). The luminescence of the active layer is excited by applying a voltage to the planar electrodes. Such a functional element is known, for example, from US 2004227462 A1 and WO 2010112789 A2.

[0037] In a particularly preferred embodiment, the electrically controllable functional element is an electrochromic functional element. The electrochromic functional element comprises an active layer sequence (electrochromic layer sequence) between the planar electrodes. The active layer sequence is stacked in face form on top of one another in the following order:

[0038] - an ion storage layer,

[0039] - an electrolyte layer and

[0040] - an electrochromic layer.

[0041] The electrochromic layer is the actual carrier of the electrically controllable optical properties. It is an electrochemically active layer, the light transmission of which depends on the degree of intercalation of ions. Ions (for example H + , Li + , Na + or K + ions) are stored in and provided by the ion storage layer. The electrolyte layer spatially separates the electrochromic layer from the electrochromic layer and serves for the migration of ions. If a direct voltage of suitable polarity is applied to the planar electrodes, the ions migrate from the ion storage layer through the electrolyte layer into the electrochromic layer, as a result of which the optical properties (color, light transmission) of the electrochromic layer change depending on the degree of migration of the ions. If a direct voltage of opposite polarity is applied to the planar electrodes, the ions migrate from the electrochromic layer back through the electrolyte layer into the ion storage layer, and the optical properties of the electrochromic layer change of the opposite type. If no voltage is applied to the planar electrodes, the transients remain stable. Suitable electrochromic layers comprise electrochromic materials, for example inorganic oxides (for example tungsten oxide or vanadium oxide), complex compounds (for example Prussian blue) or conductive polymers (for example 3,4-polyethylene dioxythiophene (PEDOT) or polyaniline). Electrochromic functional elements are known, for example, from WO 2012007334 A1, US 20120026573 A1, WO 2010147494 A1 and EP 1862849 A1. The electrolyte layer is usually designed as a film of an organic or inorganic electrically insulating material with high ionic conductivity, which is based on lithium phosphorus oxynitride, for example. The ion storage layer is permanently transparent (pure ion storage) or has an electrochromic behavior opposite to that of the electrochromic layer. An example of a pure ion storage is a layer containing mixed oxides of titanium and cerium, an example of an anodic electrochromic ion storage layer is a layer containing iridium oxide or nickel oxide.

[0042] Electrochromic functional elements are thus particularly preferred because they have a slow switching behavior compared to other controllable functional elements. As a result, in the case of a switching operation, the user does not perceive a simultaneous and uniform change in the optical properties, i.e. the see-through area does not simultaneously and uniformly darken, for example. Instead, the change in the optical properties begins at the location of the planar electrode connected to the voltage source and propagates apparently to other areas of the functional element. This inhomogeneous, locally delayed change in the optical properties appears unusual and disturbing to the user. In this case, the pattern of the printed areas with partially transparent reflective coatings according to the application can be used to appear to visually accompany the propagation of the change in the optical properties. By means of this pattern, a direction can be indicated which corresponds to the direction of propagation of the change in the optical properties, so that the inhomogeneous, delayed switching behavior is perceived as less disturbing, if not even desirable. Suitable and preferred pattern embodiments for this will be discussed later.

[0043] The planar electrodes of the functional element with electrically controllable optical properties are preferably transparent, which in the sense of the application means that they have a light transmittance of at least 50%, preferably at least 70%, particularly preferably at least 80% in the visible spectral range. The planar electrodes are in particular electrically conductive thin layers or thin layer stacks. The planar electrodes preferably comprise at least one metal, metal alloy or transparent conductive oxide (transparent conductive oxide, TCO). The planar electrodes particularly preferably comprise at least one transparent conductive oxide. The planar electrodes can be formed, for example, on the basis of silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (indium tin oxide, ITO), gallium-doped or aluminum-doped zinc oxide and / or fluorine-doped or antimony-doped tin oxide, preferably on the basis of silver or ITO, in particular ITO. The planar electrodes preferably have a thickness of 10 nm to 2 pm, particularly preferably 20 nm to 1 pm, very particularly preferably 30 nm to 500 nm, in particular 50 nm to 200 nm. If the thin layer is formed on the basis of one material, this means in the sense of the application that the layer consists mainly of this material (more than 50% by weight, preferably more than 90% by weight, in particular more than 99% by weight), wherein the layer can comprise small amounts of further materials, for example dopants.

[0044] The functional element with electrically controllable optical properties can be formed directly on the inner side surface of the outer glass pane or on the outer side surface of the inner glass pane. In one preferred embodiment, however, the functional element is designed as a multilayer film. A multilayer film is a layer stack, wherein the layers of the layer stack at least comprise a first carrier film, a first planar electrode, an active layer or a sequence of active layers, a second planar electrode and a second carrier film, which are stacked on top of one another in this order in a plane. The layers of the layer stack are durably stably joined to one another, for example by gluing or lamination. Multilayer films of this type are generally commercially available and can be purchased, for example, from glass manufacturers, cut to size and embedded into a composite glass pane.

[0045] The carrier films preferably comprise or are based on at least one thermoplastic polymer, particularly preferably polyethylene terephthalate (PET), polypropylene, polyvinyl chloride, fluorinated ethylene-propylene, polyvinyl fluoride or ethylene-tetrafluoroethylene, very particularly preferably PET. This is particularly advantageous for the stability of the multi-layer film. The thickness of each carrier film is preferably from 0.05 mm to 1 mm, particularly preferably from 0.1 mm to 0.5 mm, in particular from 0.1 mm to 0.2 mm. On the one hand, by virtue of the carrier films having such low thicknesses, a low thickness of the glazing in which the multi-layer film is to be used is advantageously achieved. On the other hand, effective protection of the active layer and the electrically conductive layer is ensured. In the method according to the application, the carrier films are preferably not damaged, i.e. the insulation wires do not extend to the carrier films.

[0046] The side edges of the multi-layer film can be sealed, for example by melting of the carrier films or by (preferably polymeric) tapes. In this way, the active layer can be protected, in particular against diffusion of components, in particular plasticizers, of the interlayer of the composite glass pane in which the multi-layer film is embedded, into the active layer, which can lead to a deterioration of the functional element.

[0047] The multi-layer film is preferably embedded in the interlayer of the composite glass pane. To this end, each carrier film is preferably joined to one of the glass panes by at least one thermoplastic joining film. The joining is carried out under the action of heat, vacuum and / or pressure according to methods known per se. Preferably, the two joining films protrude beyond the multi-layer film on both sides of the multi-layer film, preferably in a surrounding fashion. The side edges of the multi-layer film are particularly preferably surrounded in a surrounding fashion by a third thermoplastic joining film which is frame-like. This third thermoplastic joining film has a recess into which the multi-layer film is inserted.

[0048] The planar electrodes of the functional element having electrically controllable optical properties are preferably electrically contacted by so-called busbars (conductor bars, busbars). These are preferably designed as strips of electrically conductive film, for example strips of copper film. The width of the busbars is preferably from 1 mm to 10 mm, for example approximately 5 mm. The thickness of the busbars is preferably from 50 pm to 200 pm, for example approximately 90 pm. These busbars are preferably arranged in the edge region of the functional element and are in direct physical contact with the planar electrodes. In particular, the busbars are arranged completely in the masking region of the composite glass pane, so that they are not visible. The busbars themselves are connected to a voltage source by means of electrical cables.

[0049] The functional element generally has a substantially polygonal shape, depending on the shape of the composite glass pane, for example a substantially rectangular, triangular or trapezoidal shape. The shape can deviate slightly from a strict geometric polygon, for example the sides can be slightly curved rather than straight. However, the surrounding side edges of the functional element have a plurality of segments which are straight or slightly curved (i.e. have a constant or continuously changing direction of extension), wherein adjacent segments are separated from one another by a corner at which the direction of extension changes abruptly.

[0050] The planar electrodes are preferably electrically contacted by the respective busbars in at least one section of the circumferential edge region of the functional element. It is particularly preferred that the busbar of the first planar electrode and the busbar of the second planar electrode are arranged in the same section of the circumferential edge region and are arranged in particular substantially flush. It is very particularly preferred that the busbars are arranged along at least a portion of at least one side of the polygonal shape, for example along at least 80% or at least 90% of the side.

[0051] In this case, at least the section of the masking region in which the busbar is arranged is equipped with a pattern of coated regions having a partially transparent reflective coating. In the section, the pattern preferably extends over at least 80%, particularly preferably at least 90%, in particular substantially the entire width of the masking region. If the functional element (and the composite glass pane) is designed to be substantially polygonal and the busbar is arranged on one side of the polygon, in particular along a substantial portion of the side, there will be a frame-like masking region to hide the circumferential side edge of the functional element at least for the common case in which the functional element is completely embedded in the interlayer and does not extend to the side edge of the composite glass pane. Corresponding to the shape of the composite glass pane, the frame-like masking region will also have a substantially polygonal shape. At this point, the pattern of coated regions is present at least in the region in which the busbar is also arranged, in particular the entire face of the polygonal masking region in which the busbar is arranged is equipped with the pattern. This is particularly advantageous in the case of functional elements having a relatively slow switching behavior, i.e. in particular in the case of electrochromic functional elements, since the change in the optical properties propagates from the busbar via the see-through region of the composite glass pane. By means of the pattern of the printed region assigned to the busbar, the direction of propagation can be indicated so that the inhomogeneous switching behavior appears less disturbing or even desirable to the user.

[0052] In a particularly preferred embodiment, the busbars (completely or interrupted) are arranged in a circumferential manner on the planar electrode. Thus, the busbars are not only arranged on one side of the functional element, but also along the entire circumferential edge region. This is particularly advantageous in the case of functional elements having a relatively slow switching behavior, i.e. in particular in the case of electrochromic functional elements, since the circumferential electrical contact leads to a more rapid change in the optical properties after a switching operation. At this point, the change in the optical properties starts from the circumferential edge of the see-through region and propagates to the center of the see-through region, which is also referred to as "iris effect". The busbars can be formed by a single circumferential strip of the electrically conductive film (completely circumferential, wherein there can be a gap between the ends of the circumferential strip). However, alternatively, the busbars can also have gaps (interrupted circumferential). They can consist of a plurality of strips of the electrically conductive film, and there can be gaps between these strips, in particular at the corners of a polygonal functional element. However, at least 80% of the circumferential edge region of the planar electrode should be equipped with busbars, preferably at least 90%, in particular at least 95%. The masking region surrounds the see-through region in the form of a frame and covers the circumferential side edges of the functional element as well as the circumferential busbars. In this case, the masking region is completely circumferentially equipped with the pattern of the coating region. By the pattern of the printed region assigned to the circumferential busbars, it is possible to indicate the direction of propagation towards the center of the see-through region, so that the iris effect appears less disturbing or even desirable to the user.

[0053] If the circumferential busbars consist of a plurality of strips of the electrically conductive film, the individual strips can optionally be electrically contacted independently of one another. In this way, independent switching regions can be realized in the see-through region. The individual strips are connected to the control unit, for example a flexible printed circuit board laminated into the composite glass pane, for example by a filament. The filament preferably has a diameter of 90 to 110 pm. For practical and electrical reasons, the filament should have a distance of at least 5 mm from one another and at least 6 mm from the side edges of the composite glass pane. The filament should also extend completely in the masking region.

[0054] The partially transparent reflective coating preferably comprises a metal oxide. Here, the metal is particularly preferably selected from the group consisting of aluminum, tin, titanium, copper, chromium, cobalt, iron, manganese, zirconium, cerium, yttrium, silver, gold, platinum and palladium. The coating can also comprise mixtures of the mentioned oxides or mixed oxides of the mentioned metals. With such metal oxides, visually appealing partially transparent reflective properties can be achieved. The content of the metal oxide in the reflective coating is preferably at least 70%, particularly preferably at least 80%, very particularly preferably at least 90%.

[0055] The thickness of the partially transparent reflective coating is preferably 5 pm to 50 pm, particularly preferably 8 pm to 16 pm. In this way, particularly good results are achieved.

[0056] The partially transparent reflective coating is preferably applied, i.e. printed, onto the coated area using a printing method. Here, the coating is applied as a printing paste onto the coated area and dried or fired there.

[0057] Particularly preferred is the screen printing method. Here, the printing paste is printed through a fabric with fine mesh. For example, a rubber squeegee is used to press the printing ink through the fabric. Usually, a stencil made of metal or plastic, for example, is arranged on the fabric, which has areas that are permeable to the printing paste and areas that are not permeable to the printing paste, thus defining the geometry of the print, in this case the pattern of the printed areas. Instead of a stencil, the fabric itself can be designed to have permeable and non-permeable areas, thus itself acting as a stencil.

[0058] Alternatively, however, other printing methods can also be used, such as pad printing or stamping. Instead of printing, the coating can also be applied manually, for example with a brush.

[0059] In addition to the reflective material, in particular metal oxides, the printing paste usually also contains a solvent. Alcohols, glycols, such as polypropylene glycol, or derivatives thereof are preferred as solvents. The printing paste also preferably contains a thickener, such as a cellulose derivative or polyacrylic acid.

[0060] Such a paste for the production of a reflective layer is commercially available, for example from the company Ferro GmbH. Furthermore, such a coating is known from the patent literature, for example from WO 2005063645.

[0061] The partially transparent reflective coating can be printed onto the outer glass pane before or after the production of the composite glass pane. After the printing paste has been printed, the outer glass pane (or the composite glass pane) is subjected to a temperature treatment, in which the solvent is expelled by evaporation and the coating is fixed on the surface of the outer glass pane. The temperature treatment can also be carried out in several steps, for example a drying step at 50 to 180°C and a firing step (calcination) at 200 to 1000°C, in particular at 400 to 700°C.

[0062] The partially transparent reflective coating is particularly preferably a sol-gel coating, i.e. is produced on the coated area by means of the sol-gel process. Thereby a mechanically and chemically stable coating with good partial transparency properties can be obtained. First, a sol containing the coating precursors is provided here and is ripened. The ripening can comprise the hydrolysis of the precursors and / or a (partial) reaction between the precursors (in particular a partial aggregation by polycondensation). In the sense of the present application, this sol is referred to as a precursor sol and preferably comprises metal oxide precursors in a solvent. The metal oxide precursors can be present, for example, as organometallic compounds, as metal alkoxides or as metal carboxylates. In a preferred embodiment, the metal (for example metal alkoxide or metal carboxylate) is stabilized here by ligands in the form of chemical complexes, thus the reactivity can be reduced and the sol's resistance to air moisture can be improved. For example, 2,4-diketones are often used as ligands.

[0063] The solvent of the sol is preferably an alcohol, an ether or a diol. Particularly preferred are alcohols, such as ethanol, n-propanol, isopropanol or butanol. Also particularly preferred are diols, for example di-, tri-, tetra-, penta- or hexa-ethyleneglycol, polypropylene glycol (for example dipropylene glycol, tripropylene glycol or tetrapropylene glycol) and derivatives thereof. Furthermore, ethers, such as dimethyl ether or diethyl ether, are particularly preferred. Mixtures of the mentioned solvents can also be used.

[0064] In addition to the precursors and the solvent, the sol preferably contains a thickening agent, particularly preferably a cellulose derivative (for example methylcellulose or ethylcellulose) or a polyacrylic acid. By means of the thickening agent, the viscosity of the sol can be adjusted, in particular for the printing process in which the sol is applied (as a printing paste) to the surface of the glass pane.

[0065] When it is suitably selected, the solvent or the thickening agent can also act as a complexing agent for the metal oxide precursors. In this case, it is not necessary to add additional ligands specifically.

[0066] The sol can also comprise common additives as are customary in the field of sol-gel technology and are known to the person skilled in the art.

[0067] The sol is deposited on the outer side surface of the outer glass pane, preferably printed as a printing paste. Subsequently, drying can be carried out, in which the solvent evaporates. This drying can be carried out at ambient temperature or by separate heating (for example at temperatures of up to 120°C). Prior to the application of the solution, the surface is usually cleaned by methods known per se.

[0068] The sol subsequently condenses, whereby the coating of the application is formed. The condensation can comprise a temperature treatment, for example at temperatures of 500 to 700°C. Here, the cross-linking process usually takes place between the precursors, wherein the precursors initially combine to form aggregates (agglomeration, usually caused by hydrolysis of the precursors and polycondensation reactions between them), which subsequently cross-link to form a gel (gelation). The agglomeration can also have taken place partly in solution before it is applied to the surface of the glass pane.

[0069] In a particularly advantageous embodiment, the partially transparent reflective coating is matched in terms of color to the functional element, such that the coating and the functional element have a similar, ideally substantially the same, color tone in the darkened state. This leads to particularly aesthetic results. This is advantageous in particular in the case of electrochromic functional elements, which are characterized by a significant coloration (for example in comparison with SPD or PDLC functional elements).

[0070] In an advantageous embodiment, the area density of the pattern of coated regions decreases in the direction of the see-through region. This means that the proportion of uncoated regions of the pattern increases in the direction of the see-through region, while the proportion of coated regions decreases in the direction of the see-through region. This can be achieved by decreasing the number of coated regions per unit area in the direction of the see-through region and / or by decreasing the size of the coated regions in the direction of the see-through region. The area occupancy depends on the distance from the see-through region, wherein the area occupancy becomes higher as the distance from the see-through region increases. This is advantageous in particular in the case of functional elements with a relatively slow switching behavior, i.e. in particular in the case of electrochromic functional elements. In the case of such functional elements, the change in the optical properties of the see-through region is not perceived by the user as being simultaneous and uniform, but rather propagates significantly from the edge of the see-through region (with a small distance from the busbar) in the direction of the center of the glass pane. The direction of this temporally delayed change in the optical properties appears visually to be indicated by the non-uniform pattern of coated regions, the area occupancy of which decreases in the direction of the see-through region, thereby making the delay perceived by the user as being less disruptive, if not even intentionally designed. Alternatively, the area density of the pattern of coated regions can also be increased in the direction of the see-through region, depending on the application case.

[0071] In another advantageous embodiment, the pattern of coated regions is formed by lines or strips pointing towards the see-through region. In other words, the coated regions are designed as lines or strips, and their direction of extension points towards the see-through region. This embodiment is also advantageous in the case of functional elements with a relatively slow switching behavior, i.e. in particular in the case of electrochromic functional elements. The direction of the temporally delayed change in the optical properties appears visually to be indicated by the positioning of the lines or strips, thereby making the delay perceived by the user as being less disruptive, if not even intentionally designed.

[0072] Ideally, the functional element should be protected from the ultraviolet (UV) and infrared (IR) parts of the solar radiation, which cause its deterioration. Protection from UV radiation is preferably provided by the thermoplastic layer between the functional element and the outer glass pane comprising a UV blocker. Protection from IR radiation is preferably achieved by an IR-reflective coating. The IR-reflective coating can be arranged directly on the outer glass pane, in particular on its inner side surface. If both the cover print and the IR-reflective coating are arranged on the inner side surface of the inner glass pane, the cover print can optionally have a decomposition property against the IR-reflective coating, such that the IR-reflective coating is automatically removed in the area of the cover print. The IR-reflective coating can be arranged above or below (with respect to the outer glass pane) the cover print. A common IR-reflective coating is a thin layer stack with at least one silver-based layer.

[0073] However, the IR-reflective coating can also be provided on a carrier film and embedded into the interlayer between the functional element and the outer glass pane. For this purpose, the coated carrier film is preferably arranged between two joining films. The carrier film is usually formed on the basis of PET and has a thickness of 20 μιη to 200 μιη.

[0074] The composite glass pane according to the application can be manufactured by methods known per se. The outer glass pane and the inner glass pane with the layers of the interlayer located therebetween are arranged together with the functional element to form a layer stack and are laminated to one another, for example by autoclave method, vacuum bag method, vacuum ring method, calender method, vacuum laminator or a combination thereof. The joining of the outer glass pane and the inner glass pane by the interlayer is here usually carried out under the action of heat, vacuum and / or pressure. The partially transparent reflective coating can be applied to the outer side surface of the outer glass pane before or after the lamination of the composite glass pane. As already described, the partially transparent reflective coating is preferably applied by a printing method and is formed by a sol-gel method.

[0075] The composite glass pane can be flat or curved in one or two spatial directions, as is common, in particular for the vehicle glazing of manned motor vehicles. Usually, the outer glass pane and the inner glass pane are curved before they are laminated to form the composite glass pane. The partially transparent reflective coating is preferably applied before the glass pane is curved, since the coating is easier to carry out on a flat glass pane.

[0076] The invention also includes the use of the composite glass panel according to the invention as a vehicle glass panel, particularly preferably as a vehicle side glass panel, especially for side glass panels that are to be opened, raised, and lowered. Since concealed areas are uncommon in such glass panels, the partially transparent reflective coating according to the invention, which makes them less visually conspicuous, has a particularly advantageous effect. However, the composite glass panel can also be used as other types of vehicle glass panels, such as windshield panels, roof panels, or rear panels. The composite glass panel can also be used in the architectural field, for example as window panels for buildings or windows for rooms inside buildings, or as glass facades.

[0077] The invention will be explained in more detail with reference to the accompanying drawings and embodiments. The drawings are schematic and not to scale. The drawings do not limit the invention in any way. They illustrate:

[0078] Figure 1 A top view of one embodiment of the composite glass plate according to the present invention.

[0079] Figure 2 Crossing along X-X' according to Figure 1 The cross-section of the composite glass plate,

[0080] Figure 3 according to Figure 1 A top view of the functional components of the composite glass panel.

[0081] Figure 4 Crossing along Y-Y' according to Figure 3 The cross-section of the functional component,

[0082] Figure 5 A top view of another embodiment of the functional element.

[0083] Figure 6 A top view of another embodiment of the functional element.

[0084] Figure 7 Based on Figure 6 A top view of a composite glass plate containing functional components.

[0085] Figure 8 In one embodiment of the present invention Figure 1 A magnified view of the details of Z.

[0086] Figure 9 A magnified view of a portion of Z in another embodiment.

[0087] Figure 10 A magnified view of a portion of Z in another embodiment, and

[0088] Figure 11Enlarged view of the detail Z in another embodiment.

[0089] Figure 1 and Figure 2 Each shows a detail of a composite glass pane according to the application. The composite glass pane is for example provided as a side glass pane of a manned motor vehicle which is to be opened, i.e. can be raised and lowered. The composite glass pane comprises an outer glass pane 1 and an inner glass pane 2 which are joined to one another by means of an intermediate layer 3. The outer glass pane 1 and the inner glass pane 2 consist of clear soda-lime glass having a thickness of 2.1 mm. In the installed position, the outer glass pane 1 faces the outside environment, while the inner glass pane 2 faces the vehicle interior. The outer glass pane 1 has an outer side surface I and an inner side surface II. Likewise, the inner glass pane 2 has an outer side surface III and an inner side surface IV. In the installed position, the outer side surfaces I, III face the outside environment, while the inner side surfaces II, IV face the vehicle interior.

[0090] The composite glass pane has a central transparent, see-through region D and an opaque masking region M which surrounds it in the form of a frame. The opaque masking region M is realized by a cover print 10 on the inner side surfaces II, IV of the outer glass pane 1 and the inner glass pane 2. This cover print 10 is formed from black enamel which contains black pigments and glass frit and is fired into the surfaces II, IV. The masking region M surrounds the region of the side glass pane which is visible in the closed state in a surrounding edge region. Below the masking region M and the see-through region D, the composite glass pane has a mounting region B which is always arranged within the vehicle body and serves to seat the composite glass pane on the mechanism for raising and lowering it. To this end, the mounting region B can have holes and / or mounting elements which are not shown.

[0091] The intermediate layer 3 comprises a total of three thermoplastic layers 3a, 3b, 3c which are each formed from a thermoplastic PVB film. The first thermoplastic layer 3a is joined to the outer glass pane 1, has a thickness of for example 0.76 mm and contains a UV blocker. The second thermoplastic layer 3b is joined to the inner glass pane 2 and has a thickness of for example 0.38 mm. The third thermoplastic layer 3c which is located therebetween has a thickness of for example 0.38 mm and is designed with a cutout into which the functional element 4 having electrically controllable optical properties is inserted substantially precisely, i.e. approximately flush on all sides. The third thermoplastic layer 3c thus appears to form a kind of frame or housing for the approximately 0.4 mm thick functional element 4 which does not extend to the side edges of the composite glass pane but is completely encapsulated in the thermoplastic material and is thus protected. The functional element 4 is an electrochromic multilayer film which can be switched from a transparent, uncoloured state to a coloured state having reduced light transmission.

[0092] The functional element 4 completely covers the see-through area D and extends into the masking area M, with its side edges arranged in this masking area so that they are not visible. The user can electrically control the light transmission of the see-through area D by means of the functional element 4.

[0093] The functional element 4 is protected from UV radiation by the first thermoplastic layer 3a, which is UV- blocking. In order to protect the functional element 4 from the infrared portion of sunlight, a solar protection coating 13 is arranged on the inner side surface II of the outer glass pane 1. The solar protection coating 13 is, for example, a sputtered thin-layer stack with one or more silver layers. The surrounding edge region of the outer glass pane 1 is free of the solar protection coating 13, so that it is not in contact with the atmosphere and is protected from corrosion. The side edges of the solar protection coating 13 are also arranged in the masking area M.

[0094] Modifications of the illustrated embodiment are conceivable. For example, the masking area M can also be realized by an opaque colored region of at least one of the thermoplastic layers 3a, 3b, 3c, instead of by the cover print 10. The IR protection can also be realized by an IR-reflecting film, instead of by the solar protection coating 13 on the outer glass pane 1. Such a film consists, for example, of a PET carrier film with an IR-reflecting coating. In general, the IR-reflecting film is embedded between two layers of the interlayer 3, in particular between the first thermoplastic layer 3a and a further thermoplastic layer arranged between the first thermoplastic layer 3a and the outer glass pane 1. The further thermoplastic layer can be designed, for example, as a PVB film with a thickness of 0.38 mm.

[0095] In the masking area M, the outer side surface I of the outer glass pane 1 is equipped with a pattern of coated regions b with a partially transparent, reflective coating 11. The coating 11 is a sol-gel coating applied to the surface I by silk-screen printing. It contains a metal oxide, for example titanium oxide, and has a thickness of preferably 50 nm to 200 nm, for example 70 nm. The pattern of coated regions b serves to make the masking area aesthetically more attractive. Since masking areas for side glass panes are not common, the observer perceives the masking area M as less disruptive due to the coated regions b.

[0096] Figure 3 and Figure 4 each shows Figure 1The functional element 4 is an electrochromic multilayer film. The multilayer film is delimited by a first carrier film 8 and a second carrier film 9. The carrier films 8, 9 consist of PET and have a thickness of, for example, 0.125 mm. The carrier films 8, 9 are each equipped with an ITO coating having a thickness of approximately 100 nm, which forms the first planar electrode 6 and the second planar electrode 7. An active layer sequence 5 is arranged between the planar electrodes 6, 7. The layer sequence 5 is an electrochromic layer sequence and consists of an ion storage layer 5a, an electrolyte layer 5b and an electrochromic layer 5c. By means of a direct voltage applied to the planar electrodes 6, 7, ions can be excited to migrate from the ion storage layer 5a through the electrolyte layer 5b into the electrochromic layer 5c and vice versa. The proportion of ions in the electrochromic layer 5c determines their optical properties, in particular the light transmission and the color.

[0097] Both planar electrodes 6, 7 are in electrical contact with the respective busbar 12 in a surrounding manner. The busbars 12 serve to connect the planar electrodes 6, 7 to an external voltage source in order to provide the voltage required for controlling the optical properties. The busbars 12 are arranged in the masking region M. Each busbar 12 is formed by a single strip of copper film which completely surrounds the respective planar electrode 6, 7, wherein only a gap exists between the end portions of the strip.

[0098] The surrounding busbars 12 are advantageous for electrochromic functional elements 4, since they have a relatively slow switching behavior. By means of the surrounding electrical contact, a more rapid change in the optical properties of the see-through region D is achieved. However, the observer does not perceive the change in the optical properties as uniform, but rather it begins at the edge region of the see-through region D and continues apparently towards the center. This observation is also referred to as "iris effect". The pattern of the printed region b according to the application can be used to indicate the direction of the delayed change in the optical properties and to present this iris effect as intentionally produced, which increases the aesthetic value of the composite glass pane. Possible embodiments of the pattern are exemplary shown in Figures 8 to 11 .

[0099] Figure 5 Another embodiment of the functional element 4 with surrounding busbars 12 is shown. The busbars 12 are each composed of a plurality of strips of copper film, wherein a gap can be formed between adjacent strips. This embodiment can be advantageous over the embodiment of Figure 3 for reasons of manufacturing technology. In addition, it opens up the possibility of independently electrically controlling the individual strips of the busbar 12, thereby achieving independent switching regions, the optical properties of which can be controlled independently of one another.

[0100] Figure 6 and Figure 7 each show details of another embodiment of a composite glass pane according to the application, which is also a side glass pane of a manned motor vehicle to be opened. Figure 6a top view of the functional element 4 with the busbar 12 is shown, Figure 7 a top view of a composite glass pane equipped therewith is shown.

[0101] This embodiment is essentially constituted in the same way as the embodiment in Figures 1 to 4 The difference is that the busbar 12 is not in a surrounding form, but only along the lower edge of the functional element 4. The change of the optical properties of the electrochromic functional element 4 thus starts from the lower edge and continues in the direction of the upper edge. With reference to the "iris effect", here it can be said to be a "sunrise effect". In order to indicate the direction of the delayed change of the optical properties, in this case only the section of the masking area M with the busbar and adjacent to the lower edge of the see-through area D (starting point of the change of the optical properties) is equipped with the pattern of the printed area b. Alternatively, it is also possible to additionally equip the opposite section of the masking area M adjacent to the upper edge of the see-through area D with the pattern (end point of the change of the optical properties). Alternatively, it is also possible to equip the entire masking area M in a surrounding form with the pattern in this embodiment.

[0102] Figure 8 In a further embodiment of the pattern of the coated areas b according to the application, a section Z of Figure 1 is shown enlarged. The pattern is uniform, i.e. the coated areas b are designed to be uniformly distributed and identical. The individual coated areas b are exemplarily shown as triangles, but can also have any other shape. The triangles indicate a shape with a preferred direction pointing to the see-through area (the tip of the triangle points upwards). Despite the uniformity of the pattern, the direction of the change of the optical properties can thereby be indicated.

[0103] Figure 9 In a further embodiment of the pattern of the coated areas b according to the application, a section Z of Figure 1 is shown enlarged. The pattern is not uniform. Instead, the area occupancy of the coating 11 decreases in the direction of the see-through area D. The direction of the change of the optical properties can thereby be indicated. The individual printed areas b are designed to be identical with the same shape and size. The change of the area occupancy is achieved by a decreasing number of printed areas b per unit area in the direction of the see-through area D. The individual coated areas b are exemplarily shown as circles, but can also have any other shape, for example a company logo of the vehicle manufacturer.

[0104] Figure 10 In a further embodiment of the pattern of the coated areas b according to the application, a section Z of Figure 1of the partial area Z. The pattern is also inhomogeneous here. Instead, the area occupancy of the coating 11 decreases in the direction of the perspective area D. Thereby the direction of the change in the optical properties can be indicated. The change in the area occupancy is achieved by making the size of the individual printed areas smaller in the direction of the perspective area D. The individual coating areas b are exemplarily shown as circular, but can also have any other shape, for example a company logo of the vehicle manufacturer.

[0105] Figure 11 An enlargement in another embodiment of the pattern of coating areas b according to the application is shown in Figure 1 of the partial area Z. The individual coating areas b are designed as thin strips in the form of lines, which point in the direction of the perspective area D. Thereby the direction of the change in the optical properties can be indicated.

[0106] List of reference signs:

[0107] (1) outer glass pane

[0108] (2) inner glass pane

[0109] (3) thermoplastic intermediate layer

[0110] (3a) first layer of the intermediate layer 3

[0111] (3b) second layer of the intermediate layer 3

[0112] (3c) third layer of the intermediate layer 3

[0113] (4) functional element

[0114] (5) active layer sequence of the functional element 4

[0115] (5a) ion storage layer of the electrochromic layer sequence 5

[0116] (5b) electrolyte layer of the electrochromic layer sequence 5

[0117] (5c) electrochromic layer of the electrochromic layer sequence 5

[0118] (6) first planar electrode of the functional element 4

[0119] (7) second planar electrode of the functional element 4

[0120] (8) first carrier film of the functional element 4

[0121] (9) second carrier film of the functional element 4

[0122] (10) overprint

[0123] (11) partially transparent reflective coating

[0124] (12) busbar

[0125] (13) sun protection coating

[0126] (I) outer side surface of the outer glass pane 1

[0127] (II) inner side surface of the outer glass pane 1

[0128] (III) outer side surface of the inner glass pane 2

[0129] (IV) inner side surface of the inner glass pane 2

[0130] (M) opaque masking area of the composite glass pane

[0131] (D) transparent see-through area of the composite glass pane

[0132] (B) mounting area of the composite glass pane

[0133] (b) coated area of the outer side surface I of the outer glass pane 1

[0134] X-X' cutting line

[0135] Y-Y' cutting line

[0136] Z enlarged area.

Claims

1. Composite glass pane comprising an outer glass pane (1) and an inner glass pane (2) which are joined to one another by means of a thermoplastic intermediate layer (3), wherein the composite glass pane has an opaque masking region (M) and a transparent see-through region (D), wherein the intermediate layer (3) has a functional element (4) which covers the entire see-through region (D), wherein at least one region of the lateral edges of the functional element (4) does not extend to the lateral edges of the composite glass pane, but is arranged in the masking region (M), and wherein the surface (I) of the outer glass pane (1) which faces away from the intermediate layer (3) has a pattern of coated regions (b) in the masking region (M), which are equipped with a partially transparent reflective coating (11), wherein the partially transparent reflective coating (11) has a transmission and a reflection of at least 10% each in the visible spectral range.

2. Composite glass pane according to claim 1, wherein the masking region (M) surrounds the see-through region (D) in a frame-like manner.

3. Composite glass pane according to claim 1 or 2, wherein the masking region (M) is formed by a cover print (10) on the surface (II) of the outer glass pane (1) which faces the intermediate layer (3) or by a colored or pigmented film in the intermediate layer (3).

4. Composite glass pane according to claim 3, wherein the functional element (4) is an electrochromic functional element which comprises an electrochromic active layer sequence (5) between two planar electrodes (6, 7).

5. Composite glass pane according to claim 4, wherein the planar electrodes (6, 7) are electrically contacted in at least one section of the edge region of the functional element (4) by a respective busbar (12), wherein the busbar (12) is arranged in the masking region (M), and wherein at least the section of the masking region (M) in which the busbar (12) is arranged is equipped with a pattern of coated regions (b).

6. Composite glass pane according to claim 4 or 5, wherein - the busbar (12) is arranged in a surrounding manner on the planar electrodes (6, 7), - the masking region (M) surrounds the see-through region (D) in a frame-like manner, and - the masking region (M) is equipped with a pattern of coated regions (b) in a surrounding manner.

7. Composite glass pane according to any of claims 1 to 2, wherein the partially transparent reflective coating (11) is printed onto the coated regions (b).

8. Composite glass pane according to claim 7, wherein the partially transparent reflective coating (11) is printed onto the coated regions (b) by means of a screen printing method.

9. Composite glass pane according to any of claims 1 to 2, wherein the partially transparent reflective coating (11) is a sol-gel coating.

10. Composite glass pane according to any of claims 1 to 2, wherein the partially transparent reflective coating (11) comprises a metal oxide.

11. Composite glass pane according to claim 10, wherein the metal is selected from the group consisting of aluminum, tin, titanium, copper, chromium, cobalt, iron, manganese, zirconium, cerium, yttrium, silver, gold, platinum and palladium.

12. The composite glass pane according to any one of claims 1 to 2, wherein the partially transparent reflective coating (11) has a thickness of 5 pm to 50 pm.

13. The composite glass pane according to claim 12, wherein the partially transparent reflective coating (11) has a thickness of 8 pm to 16 pm.

14. The composite glass pane according to any one of claims 1 to 2, wherein the occupation density of the pattern of coated areas (b) decreases in direction of the see-through area (D).

15. The composite glass pane according to any one of claims 1 to 2, wherein the pattern of coated areas (b) is formed by lines or strips pointing to the see-through area (D).

16. Use of a composite glass pane according to any one of claims 1 to 15 as a vehicle glazing.

17. Use according to claim 16, wherein the composite glass pane is used as a vehicle side glazing.

Images