Composite disc with an electrically conductive coating and at least one layer of comprehensively selectively absorbent nanoparticles

Description

[0001] The invention relates to a composite disc with an electrically conductive coating and at least one layer comprising selectively absorbing nanoparticles.

[0002] Laminated glass with electrically conductive coatings is well-known in the automotive sector, for example, as a windshield with a heated, transparent coating. The coating typically comprises several silver layers applied alternately with dielectric layers, ensuring both high electrical conductivity and sufficient transmission in the visible spectrum. More complex electrically conductive coatings for windshields are also known, used, for example, as IR-reflective coatings to reduce the heating of the vehicle interior and thus improve thermal comfort. These coatings can also be used as heated coatings by connecting them to a voltage source, causing an electric current to flow through the coating.Suitable coatings contain conductive, metallic layers, particularly those based on silver. Since these layers are susceptible to corrosion, it is common practice to apply them to the surface of the outer or inner pane facing the intermediate layer, thus preventing contact with the atmosphere. Silver-containing transparent coatings are known, for example, from WO03 / 024155, US2007 / 0082219A1, US2007 / 0020465A1, WO2013 / 104438, and WO2013 / 104439.

[0003] In addition, so-called LowE coatings are also known, which contain, for example, a functional layer of ITO, such as WO2013 / 131667. Unlike silver-based coatings, such coatings are not susceptible to corrosion and can therefore be used on an external surface of the laminated glass, in particular the interior surface of the inner pane.

[0004] US 2015 / 0202846 A1 discloses a PVB film with a low plasticizer content and an electrically conductive or reflective coating.

[0005] US 2010 / 0220388 A1 describes a laminate comprising a layer that absorbs radiation in the wavelength range of 200 nm to 500 nm.

[0006] Especially in the automotive sector, solar control coatings are sought that are not only heatable but also have low total solar transmission (TTS), low external reflection, and neutral or blue / green reflective colors. Yellow, red, and violet reflective colors, in particular, are perceived as bothersome and should be avoided. Good solar control properties of vehicle glazing also contribute to reducing the energy consumption of the air conditioning system and are therefore desirable from an environmental perspective. In electric cars, reduced energy consumption of secondary systems, such as air conditioning and heating, means an increase in driving range. Low total solar transmission (TTS) is generally associated with high external reflectivity of the coating; however, in practice, the lowest possible values ​​for both are desirable.Furthermore, windshields must comply with the legal requirements specified in ECE-R 43, Annex 3, Section 9.1, for testing the light transmittance of motor vehicle windows, according to which the total transmission (TL) must be at least 70%. This further complicates achieving low total solar transmission. These requirements for low total solar transmission, the coating's ability to be heated, and sufficient light transmittance often mean that the criterion of an optically appealing reflection color of the coating cannot be met. Besides the reddish reflection color of the coating, which is hardly acceptable to end customers, the reflection color of images reflected from the laminated glass is also affected. For example, when the laminated glass is used as a head-up display, a red-shifted ghost image appears.

[0007] There is therefore a need for laminated glass panes with electrically conductive coatings of a neutral color, in particular a neutral reflective color on the outer surface. The present invention aims to provide such an improved laminated glass pane.

[0008] The object of the present invention is achieved according to the invention by a composite disk according to claim 1. Preferred embodiments are described in the dependent claims.

[0009] The composite disc according to the invention comprises an outer disc with an outer surface (side I) and an inner surface (side II), an inner disc with an outer surface (side III) and an inner surface (side IV), and a thermoplastic intermediate layer connecting the inner surface of the outer disc with the outer surface of the inner disc. The composite disc has at least one electrically conductive coating and at least one layer of selectively absorbing nanoparticles between the outer and inner discs. The electrically conductive coating and the layer of selectively absorbing nanoparticles are arranged overlapping in a planar fashion, the layer sequence of the two elements being variable and their arrangement being directly or indirectly adjacent.In this context, "arranged superimposed over a surface" means that the projection of the layer of selectively absorbing nanoparticles onto the plane of the electrically conductive coating is at least partially coincident with the electrically conductive coating. The layer of selectively absorbing nanoparticles exhibits absorption within the wavelength range of 580 nm to 750 nm. The layer of selectively absorbing nanoparticles absorbs electromagnetic radiation of one or more wavelengths within this range, which corresponds to the yellow and red regions of the visible light spectrum. Light reflected from the electrically conductive coating, which passes through the layer of selectively reflective nanoparticles after reflection from the coating, is filtered in terms of its color.The layer of selectively absorbing nanoparticles exhibits selective absorption in the wavelength range of 580 nm to 750 nm, while absorption in the remaining wavelength range of visible light is only negligible. After passing through the layer of selectively absorbing nanoparticles, the light intensity in the yellow and red regions is significantly reduced. Due to the absorption in the red region of the visible light spectrum, the overall color of the laminated glass shifts towards blue-green. The reddish reflection caused by the electrically conductive coating can thus be compensated for. This results in a more neutral color impression. Bluish or greenish reflections are perceived as pleasant by end customers and vehicle manufacturers and, unlike reddish hues, are accepted.The invention thus makes it possible to select electrically conductive coatings primarily with regard to their electrical properties and total solar transmission, whereby the reflection color of the coating plays a subordinate or no role.

[0010] The laminated glass pane is designed to separate the interior from the external environment in a window opening, particularly the window opening of a vehicle. For the purposes of the invention, the term "inner pane" refers to the pane of the laminated glass facing the interior (especially the vehicle interior). The term "outer pane" refers to the pane facing the external environment. The laminated glass pane is preferably a vehicle windshield (especially the windshield of a motor vehicle, for example, a passenger car or truck), or more preferably, a vehicle roof window. The outer pane and the inner pane each have an outer and an interior surface and a circumferential edge running between them. For the purposes of the invention, the term "outer surface" refers to the main surface that is intended to face the external environment when installed.For the purposes of the invention, the term "interior surface" refers to the main surface which, in the installed position, is intended to face the interior. The interior surface of the outer pane and the exterior surface of the inner pane face each other and are connected by the thermoplastic intermediate layer.

[0011] The intermediate layer of the composite disc is formed by at least one layer of thermoplastic material. This intermediate layer can consist of this single layer of thermoplastic material and be, for example, a single polymer film or cast resin layer. However, the intermediate layer can also comprise several layers of thermoplastic material and, for example, be formed from several polymer films arranged one above the other. Particularly preferably, the intermediate layer comprises one or more thermoplastic composite films. Multiple thermoplastic composite films are used especially when the thermoplastic intermediate layer includes carrier films that are inserted between the thermoplastic composite films.

[0012] The laminated glass also features at least one layer of selectively absorbing nanoparticles. This layer can be arranged on the outer and / or inner side of the electrically conductive coating. The outer arrangement is preferred because it allows for advantageous control of the reflective color visible from the vehicle's surroundings. The outer arrangement means that the layer of selectively absorbing nanoparticles is located between the outer surface of the outer pane and the conductive coating. In the inner arrangement, the layer of selectively absorbing nanoparticles is located between the inner surface of the inner pane and the conductive coating. The layer of selectively absorbing nanoparticles preferably overlaps the entire conductive coating when viewed through the laminated glass.

[0013] The at least one layer of selectively absorbing nanoparticles is preferably formed by a thermoplastic film of the intermediate layer into which selectively absorbing nanoparticles are embedded. Alternatively, a layer of selectively absorbing nanoparticles can be applied to another layer of the layer stack. Particularly preferably, the thermoplastic intermediate layer is formed from at least one thermoplastic film, and selectively absorbing nanoparticles are embedded in the at least one thermoplastic film to form the layer of selectively absorbing nanoparticles, wherein, in particular, at least 0.1 wt.%, preferably at least 1 wt.%, selectively absorbing nanoparticles are embedded in the at least one thermoplastic film. For example, between 1 wt.% and 5 wt.% selectively absorbing nanoparticles can be embedded in at least one thermoplastic film.

[0014] Thus, various positionings of the at least one layer of selectively absorbing nanoparticles are possible: On a surface of one of the panes, in particular on the inner surface of the outer pane and / or the outer surface of the inner pane. Embedded on a carrier film within the intermediate layer. The carrier film can, for example, be made of polyethylene terephthalate (PET) with a thickness of approximately 50 µm and be positioned between two layers of thermoplastic material. Embedded within a thermoplastic composite film of the intermediate layer.

[0015] The electrically conductive coating is preferably arranged on the inner surface of the outer pane or the outer surface of the inner pane. Alternatively, the electrically conductive coating can be arranged on a carrier film that is inserted between two thermoplastic composite films of the intermediate layer. The carrier film can, for example, be made of polyethylene terephthalate (PET) with a thickness of approximately 50 µm.

[0016] In a preferred embodiment, the at least one layer of selectively absorbing nanoparticles is arranged on the outside of the electrically conductive coating. Accordingly, the distance between the at least one layer of selectively absorbing nanoparticles and the outer pane is less than the distance between the electrically conductive coating and the outer pane. Ambient light incident on the composite pane thus falls onto the outer pane, passes through the at least one layer of selectively absorbing nanoparticles, is partially reflected by the electrically conductive coating, and the reflected light component again passes through the at least one layer of selectively absorbing nanoparticles, exits the outer pane of the composite pane, and is perceived there as the reflected color.When light passes through the layer of selectively absorbing nanoparticles, a portion of the light in the yellow or red part of the spectrum is removed by absorption, so that the outer reflection color appears neutral to greenish or bluish.

[0017] In a further preferred embodiment, at least one layer of selectively absorbing nanoparticles is arranged on the inside of the electrically conductive coating. The distance between the at least one layer of selectively absorbing nanoparticles and the inner pane is less than the distance between the electrically conductive coating and the inner pane. Light incident on the composite pane from the vehicle interior thus falls onto the inner pane of the composite pane, passes through the at least one layer of selectively absorbing nanoparticles, is partially reflected by the electrically conductive coating, and the reflected light component again passes through the at least one layer of selectively absorbing nanoparticles, exits at the inner pane of the composite pane, and is perceived there as the reflected color.In this case, too, the absorption of the yellow or red light component by the layer of selectively absorbing nanoparticles shifts the inner reflection color towards neutral or slightly bluish or greenish color impressions.

[0018] In a further preferred embodiment, the composite disc has at least two layers of selectively absorbing nanoparticles, with the electrically conductive coating arranged between the layers of selectively absorbing nanoparticles. In this way, both the reflection color visible on the outside and the inside of the composite disc can be shifted towards an attractive color tone.

[0019] The electrically conductive coating and the at least one layer of selectively absorbing nanoparticles can each be applied to the inner surface (II) of the outer pane, to the outer surface (III) of the inner pane, and / or to a carrier film embedded in the thermoplastic interlayer. The layer of selectively absorbing nanoparticles can also be directly incorporated into the thermoplastic interlayer by having a material of a thermoplastic composite film of the thermoplastic interlayer selectively absorbing nanoparticles.

[0020] Particularly preferred is the arrangement of at least one layer of selectively absorbing nanoparticles on the outside of the electrically conductive coating, wherein the electrically conductive coating is arranged on the outer surface (III) of the inner disk and the at least one layer of selectively absorbing nanoparticles is arranged within the intermediate layer. The layer of selectively absorbing nanoparticles can be arranged on a carrier film embedded in the intermediate layer. In particular, however, the nanoparticles are directly incorporated into the material of a thermoplastic composite film of the intermediate layer. Electrically conductive coatings on glass substrates can be produced cost-effectively and with very high quality using industrially applicable methods such as magnetron sputtering.If the layer of selectively reflective nanoparticles is integrated directly into the material of the thermoplastic intermediate layer, the existing production process can be continued unchanged, with only a different intermediate layer being used. Furthermore, the attractive external reflective color achieved in this embodiment is a crucial criterion for vehicle manufacturers and end customers.

[0021] In a further particularly preferred embodiment, the at least one layer of selectively absorbing nanoparticles is arranged on the inner side of the electrically conductive coating, wherein the electrically conductive coating is arranged on the inner surface (II) of the outer pane and the at least one layer of selectively absorbing nanoparticles is arranged within the intermediate layer. The layer of selectively absorbing nanoparticles can be arranged on a carrier film embedded in the intermediate layer; however, in this case as well, the nanoparticles are preferably incorporated directly into the material of a thermoplastic composite film of the intermediate layer. This embodiment is preferred if, in particular, the color of the interior reflection visible in the vehicle interior is to be improved. This is especially advantageous for reflection-based display applications, such as head-up displays.

[0022] In another possible embodiment, the composite pane has an electrically conductive coating between at least two layers of selectively absorbing nanoparticles, wherein the electrically conductive coating is applied to a carrier film that is embedded in the thermoplastic intermediate layer. The at least two layers of selectively absorbing nanoparticles are arranged on the inner surface (II) of the outer pane and the outer surface of the inner pane (III), respectively. Particularly preferably, one or both layers of selectively absorbing nanoparticles are integrated directly above the thermoplastic composite films of the intermediate layer surrounding the carrier film by incorporating the nanoparticles into the material of the intermediate layer. Such an embodiment is advantageous if matching the reflection color on both sides is desired.Alternatively, one or both layers of selectively absorbing nanoparticles could also be incorporated into the layer stack via carrier films.

[0023] The thermoplastic interlayer is formed from at least one thermoplastic composite film. If a carrier film is to be integrated into the layer stack of the composite disc, the interlayer comprises at least two thermoplastic composite films, between which the carrier film is inserted. The thermoplastic composite films can also be composed of several individual composite films. The thermoplastic interlayer contains at least one thermoplastic polymer, preferably ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or mixtures, copolymers, or derivatives thereof, particularly preferably PVB. The thickness of the interlayer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm. If a wedge-shaped interlayer is used, the thickness is determined at its thinnest point, typically at the bottom edge of the composite disc.

[0024] Preferably, the layer of selectively absorbing nanoparticles is integrated directly into the thermoplastic interlayer itself. For this purpose, selectively absorbing nanoparticles are embedded in at least one thermoplastic composite film to form the layer of selectively absorbing nanoparticles from the thermoplastic film. This has the advantage that, on the one hand, no additional carrier films are required, and on the other hand, no additional steps are necessary for applying the nanoparticles to a disc surface. The thermoplastic composite film containing the layer of selectively absorbing nanoparticles can be inserted into the layer stack of the composite disc without altering the production process. The production of the composite film containing the layer of selectively absorbing nanoparticles takes place beforehand and does not affect the production process of the composite disc.

[0025] The layer of selectively absorbing nanoparticles preferably comprises nanoparticles based on semiconductor materials, particularly preferably based on silicon (Si), zinc selenide (ZnSe), and / or cadmium telluride (CeTe), and / or based on perovskites. The inventors have found that these materials provide sufficient selective absorption. Perovskites, in particular, have proven to be especially suitable in this respect. Nanoparticles based on halogen-containing cesium-lead perovskites, for example CsPbl3 or CsPb(I / Br)3, are particularly suitable. The term "perovskites" describes compounds of the general structure ABX3, where A and B are cations, the diameter of A is larger than that of B, and X is anionic oxide (O2-< ) or halogens (F-< , Br, I-< ).In addition, there are also perovskites with a mixed cation structure of the type (AA')(BB')O 6 , where the A and A' cations and the B and B' cations are each located on the lattice sites A and B.

[0026] Preferably, the layer of selectively absorbing nanoparticles exhibits absorption in the wavelength range of 580 nm to 700 nm, particularly preferably in the wavelength range of 590 nm to 690 nm. In this way, red tints of the reflected color can be avoided particularly effectively.

[0027] The layer of selectively absorbing nanoparticles preferably exhibits an absorption of at least 20%, preferably at least 30%, and particularly preferably at least 40% within the selectively absorbing wavelength range.

[0028] The electrically conductive coating is preferably applied to the inner or outer pane, i.e., to the outer surface of the inner pane facing the intermediate layer or the inner surface of the outer pane facing the intermediate layer. Alternatively, the coating can be arranged within the intermediate layer. For this purpose, the coating is typically applied to a carrier film, for example, made of polyethylene terephthalate (PET) with a thickness of approximately 50 µm, which is arranged between two layers of thermoplastic material, for example, between two polymer films. Preferably, at least 80% of the pane surface is provided with the coating according to the invention.In particular, the laminated glass pane is fully coated with the coating, with the exception of a surrounding edge area and optionally local areas that serve as communication, sensor, or camera windows to ensure the transmission of electromagnetic radiation through the laminated glass and are therefore not coated. The surrounding uncoated edge area, for example, has a width of up to 20 cm. It prevents direct contact between the coating and the surrounding atmosphere, thus protecting the coating inside the laminated glass from corrosion and damage.

[0029] The electrically conductive coating is, in particular, a transparent, electrically conductive coating. The conductive coating can, for example, be provided as an IR-reflective solar control coating or as a heatable coating that is electrically contacted and heats up when an electric current flows through it. In a particularly preferred embodiment, the laminated glass is a windshield of a motor vehicle, wherein the electrically conductive coating is transparent. A transparent coating is understood to be one that has an average transmission in the visible spectral range of at least 70%, preferably at least 75%, and thus does not significantly restrict the view through the glass. If the laminated glass is intended, for example, as roof glazing for a motor vehicle, the transmission of the coating can also be correspondingly lower.

[0030] The electrically conductive coating comprises at least one electrically conductive layer. The conductive layer may contain metal, particularly silver-based, as is common for IR-reflective solar control coatings and heatable coatings.

[0031] The electrically conductive coating is preferably a stack or sequence of layers comprising one or more electrically conductive, in particular metal-containing, layers, wherein each electrically conductive layer is arranged between two dielectric layers or sequences. The coating is thus a thin-film stack with n electrically conductive layers and (n+1) dielectric layers or sequences, where n is a natural number and where a conductive layer and a dielectric layer or sequence alternately follow each lower dielectric layer or sequence. Such coatings are known as solar control coatings and heatable coatings, wherein the electrically conductive layers are typically silver-based.The conductive coating preferably comprises at least two electrically conductive layers, more preferably at least three electrically conductive layers, and most preferably at least four electrically conductive layers. The higher the number of conductive layers, the better the coating can be optimized with regard to a desired transmittance, color, or surface resistance.

[0032] The electrical conductivity of the coating is achieved through functional, electrically conductive layers. By dividing the total conductive material into several separate layers, each layer can be made thinner, thereby increasing the coating's transparency. Each electrically conductive layer preferably contains at least one metal or metal alloy, for example, silver, aluminum, copper, or gold, and is particularly preferably metal- or alloy-based, meaning it consists essentially of the metal or metal alloy apart from any dopants or impurities. Silver or a silver-containing alloy is preferably used. In an advantageous embodiment, the electrically conductive layer contains at least 90 wt.% silver, preferably at least 99 wt.% silver, and particularly preferably at least 99.9 wt.% silver.

[0033] In a particularly preferred embodiment, the conductive coating contains at least three electrically conductive layers, especially those based on silver. Such coatings often result in a red reflective color, so the invention is particularly advantageous in this respect.

[0034] According to the invention, dielectric layers or sequences of layers are arranged between the electrically conductive layers, as well as below the lowest conductive layer and above the uppermost conductive layer. Each dielectric layer or sequence of layers has at least one anti-reflective layer. The anti-reflective layers reduce the reflection of visible light and thus increase the transparency of the coated disk. The anti-reflective layers contain, for example, silicon nitride (SiN), silicon-metal mixed nitrides such as silicon zirconium nitride (SiZrN), aluminum nitride (AlN), or tin oxide (SnO₂). The anti-reflective layers may also contain dopants.

[0035] The anti-reflective coatings can be further subdivided into at least two sublayers, in particular a dielectric layer with a refractive index of less than 2.1 and an optically high-refractive-index layer with a refractive index greater than or equal to 2.1. Preferably, at least one anti-reflective layer arranged between two electrically conductive layers is subdivided in this way; more preferably, each anti-reflective layer arranged between two electrically conductive layers is subdivided in this way. Subdividing the anti-reflective layer results in lower surface resistance of the electrically conductive coating while simultaneously providing high transmission and high color neutrality. The order of the two sublayers can, in principle, be chosen arbitrarily, with the optically high-refractive-index layer preferably being arranged above the dielectric layer, which is particularly advantageous with regard to surface resistance.The thickness of the optically high-refractive layer is preferably from 10% to 99%, and particularly preferably from 25% to 75%, of the total thickness of the anti-reflective layer.

[0036] The optically high-refractive-index layer with a refractive index greater than or equal to 2.1 contains, for example, a silicon-metal mixed nitride, such as silicon-zirconium mixed nitride (SiZrN). This is particularly advantageous with regard to the surface resistance of the electrically conductive coating. The silicon-zirconium mixed nitride preferably contains dopants. The layer of an optically high-refractive-index material can, for example, contain an aluminum-doped silicon-zirconium mixed nitride.

[0037] The dielectric layer with a refractive index of less than 2.1 preferably has a refractive index n between 1.6 and 2.1, particularly preferably between 1.9 and 2.1. The dielectric layer preferably contains at least one oxide and / or one nitride, particularly preferably silicon nitride.

[0038] In an advantageous embodiment, one or more dielectric layer sequences have a first matching layer, preferably each dielectric layer sequence, arranged below an electrically conductive layer. The first matching layer is preferably arranged above the anti-reflective layer.

[0039] In an advantageous embodiment, one or more dielectric layer sequences have a smoothing layer, preferably each dielectric layer sequence arranged between two electrically conductive layers. The smoothing layer is arranged below one of the first matching layers, preferably between the anti-reflective layer and the first matching layer. The smoothing layer is particularly preferably in direct contact with the first matching layer. The smoothing layer optimizes, in particular smooths, the surface for a subsequently applied electrically conductive layer above it. An electrically conductive layer deposited on a smoother surface exhibits a higher transmittance with a simultaneously lower surface resistance. The smoothing layer preferably has a refractive index of less than 2.2.

[0040] The smoothing layer preferably contains at least one non-crystalline oxide. The oxide can be amorphous or partially amorphous (and thus partially crystalline), but is not fully crystalline. The non-crystalline smoothing layer has low roughness and thus forms an advantageously smooth surface for the layers to be applied above it. Furthermore, the non-crystalline smoothing layer improves the surface structure of the layer deposited directly above it, which is preferably the first matching layer. The smoothing layer can, for example, contain at least one oxide of one or more of the elements tin, silicon, titanium, zirconium, hafnium, zinc, gallium, and indium. The smoothing layer particularly preferably contains a non-crystalline mixed oxide. The smoothing layer most preferably contains a tin-zinc mixed oxide (ZnSnO). The mixed oxide may contain dopants.The smoothing layer can, for example, contain an antimony-doped tin-zinc mixed oxide. The mixed oxide preferably has a substoichiometric oxygen content.

[0041] In an advantageous embodiment, one or more dielectric layer sequences have a second matching layer, preferably each dielectric layer sequence, arranged above an electrically conductive layer. The second matching layer is preferably arranged below the anti-reflective layer.

[0042] The first and second adaptation layers improve the coating's surface resistance. The first and / or second adaptation layer preferably contains zinc oxide (ZnO) with 0 ≤ δ ≤ 0.01. The first and / or second adaptation layer further preferably contains dopants. For example, the first and / or second adaptation layer can contain aluminum-doped zinc oxide (ZnO:Al). The zinc oxide is preferably deposited substoichiometrically with respect to oxygen to prevent a reaction of excess oxygen with the silver-containing layer.

[0043] In an advantageous embodiment, the electrically conductive coating comprises one or more blocker layers. Preferably, at least one, and more preferably each, electrically conductive layer is associated with at least one blocker layer. The blocker layer is in direct contact with the electrically conductive layer and is arranged directly above or directly below it. No further layer is arranged between the electrically conductive layer and the blocker layer. Alternatively, a blocker layer can be arranged directly above and directly below a conductive layer. The blocker layer preferably contains niobium, titanium, nickel, chromium, and / or alloys thereof, particularly nickel-chromium alloys.A blocker layer directly below the electrically conductive layer serves, in particular, to stabilize the electrically conductive layer during heat treatment and improves the optical quality of the electrically conductive coating. A blocker layer directly above the electrically conductive layer prevents contact between the sensitive electrically conductive layer and the oxidizing reactive atmosphere during the deposition of the subsequent layer by reactive cathode sputtering, for example, the second matching layer.

[0044] If a first layer is arranged above a second layer, this means, within the meaning of the invention, that the first layer is arranged further away from the substrate on which the coating is applied than the second layer. If a first layer is arranged below a second layer, this means, within the meaning of the invention, that the second layer is arranged further away from the substrate than the first layer. If a first layer is arranged above or below a second layer, this does not necessarily mean, within the meaning of the invention, that the first and second layers are in direct contact with each other. One or more further layers may be arranged between the first and second layers, unless this is explicitly excluded. The stated values ​​for refractive indices were measured at a wavelength of 550 nm.If a layer is formed based on a material, the layer consists predominantly of this material, along with any impurities or dopants.

[0045] If the electrically conductive coating is intended as a heating coating, it is electrically connected to an external voltage source in a manner known per se, whereby the coating is heated by applying a voltage. The electrical contact is realized by suitable connecting cables, for example, foil conductors, which are preferably connected to the electrically conductive coating via so-called busbars, for example, strips of an electrically conductive material or electrically conductive imprints.

[0046] Preferably, at least two busbars are applied to the electrically conductive coating and electrically connected to it. These at least two busbars are preferably arranged along opposite edges of the laminated glass and can be electrically connected to opposite poles of a voltage source for heating the glass. The coating area between the busbars can be electrically heated. In a possible embodiment of the invention, three busbars are applied, with one busbar running parallel to the horizontal edges of the laminated glass when installed as a windshield of a motor vehicle, and the third busbar extending from the roof edge towards the center of the glass.The first busbar is located adjacent to the roof edge, while the second busbar is located adjacent to the motor edge, and both busbars run parallel to these horizontal side edges. In a particularly preferred embodiment, one or more busbars are shaped to fit any stripped areas for sensor windows used to mount sensors. The busbars have a thickness of 5 µm to 20 µm, preferably 8 µm to 15 µm. The width of the busbars is 0.5 mm to 30 mm, preferably 1 mm to 20 mm.

[0047] An opaque cover layer, for example in the form of a screen print, is preferably applied to the edge of the laminated glass pane, such that this screen print outlines the viewing area of ​​the pane or forms its outer edge. Any busbars and electrical conductors arranged in the edge of the laminated glass pane, as well as any uncoated edge area, are preferably concealed by this cover print and thus visually masked. The opaque screen print is applied, for example, to the outer surface (side III) of the inner pane and / or to the inner surface (side II) of the outer pane. Preferably, the electrically conductive coating is omitted along a circumferential strip along the perimeter edge of the laminated glass pane. This uncoated area is masked by the opaque cover print. This gives the laminated glass pane an aesthetically pleasing appearance.

[0048] In one possible embodiment, the laminated glass pane serves as a windshield and incorporates a projection surface for a head-up display (HUD). A HUD projector is positioned inside the vehicle, projecting an image onto the laminated glass pane from the interior-facing surface of the inner pane. HUD projectors predominantly operate with s-polarized radiation and illuminate the windshield at an angle of incidence of approximately 65%, which is close to the Brewster angle for an air-glass interface. This presents the problem that the projector image is reflected from both external surfaces of the windshield. Further reflection occurs at the electrically conductive coating. As a result, in addition to the desired main image, a slightly offset secondary image, known as a ghost image, also appears.The problem is typically mitigated by aligning the glass surfaces at an angle to each other, particularly by using a wedge-shaped interlayer for laminating the windshields designed as laminated glass, so that the main image and ghost image are superimposed. Laminated glass with wedge films for HUDs is known, for example, from WO2009 / 071135A1, EP1800855B1, or EP1880243A2. In a preferred embodiment of the laminated glass, this interlayer comprises at least one wedge-shaped thermoplastic laminate film.

[0049] The outer and inner panes are preferably made of glass, in particular soda-lime glass, which is common for window panes. However, the panes can also be made of other types of glass (for example, borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (for example, polymethyl methacrylate or polycarbonate). The thickness of the outer and inner panes can vary widely. Preferably, panes with a thickness in the range of 0.7 mm to 5 mm, more preferably from 1.4 mm to 2.5 mm, are used, for example, those with the standard thicknesses of 1.6 mm or 2.1 mm.

[0050] The outer pane, the inner pane, and the thermoplastic interlayer can be clear and colorless, or tinted or colored. In a preferred embodiment, the total transmission through the laminated glass is greater than 70%. The term "total transmission" refers to the procedure for testing the light transmittance of motor vehicle windows as specified in ECE-R 43, Annex 3, Section 9.1. The outer pane and the inner panes can be independently untempered, partially tempered, or tempered. If at least one of the panes is to have a temper, this can be thermal or chemical.

[0051] The laminated glass is preferably curved in one or more spatial directions, as is common for automotive windshields, with typical radii of curvature ranging from about 10 cm to about 40 m. However, the laminated glass can also be flat, for example, if it is intended as a windshield for buses, trains, or tractors.

[0052] The laminated glass pane can be manufactured using methods known per se. The outer and inner panes are laminated together via the intermediate layer, for example by autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators, or combinations thereof. The bonding of the outer and inner panes typically occurs under the influence of heat, vacuum, and / or pressure.

[0053] The layer of selectively absorbing nanoparticles can, for example, be applied in the form of a solution comprising selectively absorbing nanoparticles to a disc surface, carrier film, or thermoplastic composite film to form the layer of selectively absorbing nanoparticles. Preferably, selectively absorbing nanoparticles are incorporated directly into the thermoplastic starting material during the extrusion of the thermoplastic composite film, so that the layer of selectively absorbing nanoparticles is formed directly within the thermoplastic composite film.

[0054] The electrically conductive coating is preferably applied to the substrate by physical vapor deposition (PVD), particularly preferably by sputtering, and most preferably by magnetically assisted sputtering. The coatings are preferably applied to the disks before lamination. Instead of applying the electrically conductive coating to a disk surface, it can also be provided on a carrier film that is placed in the intermediate layer.

[0055] If the laminated glass is to be curved, the outer and inner panes are preferably bent before lamination and preferably after any coating processes. Preferably, the outer and inner panes are bent congruently together (i.e., simultaneously and using the same tool) because this ensures that the shape of the panes is optimally matched for the subsequent lamination. Typical temperatures for glass bending processes are, for example, 500°C to 700°C.

[0056] The invention further comprises the use of the composite glass as a windshield, rear window, side window and / or roof window, particularly preferably as a windshield of a motor vehicle.

[0057] The invention is explained in more detail below with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way.

[0058] They show: Fig. 1 shows an embodiment of the composite disc according to the invention comprising an electrically conductive coating on the outer surface of the inner disc and a layer of selectively absorbing nanoparticles in the thermoplastic composite film. Fig. 2a shows a reflection spectrum of a composite disc according to the invention. Fig. 1 in comparison to a reflection spectrum of a composite disc not according to the invention, each measured at 8°, Fig. 2, reflection spectrum of a composite disc according to the invention. Fig. 1in comparison to a reflection spectrum of a non-inventive composite disc measured at 60°, Fig. 3 a further embodiment of an inventive composite disc comprising an electrically conductive coating on the interior surface of the outer disc and a layer of selectively absorbing nanoparticles in the thermoplastic composite film.

[0059] Figure 1Figure 1 shows a cross-section of an embodiment of a composite glass pane 10 according to the invention, which is intended as a windshield for a passenger car. The composite glass pane 10 consists of an outer pane 1 and an inner pane 2, which are bonded together via a thermoplastic intermediate layer 3. In its installed position, the outer pane 1 faces the external environment, and the inner pane 2 faces the vehicle interior. The outer pane 1 has an outer surface I, which in its installed position faces the external environment, and an inner surface II, which in its installed position faces the interior. Similarly, the inner pane 2 has an outer surface III, which in its installed position faces the external environment, and an inner surface IV, which in its installed position faces the interior.

[0060] The outer pane 1 and the inner pane 2 are made of, for example, soda-lime glass. The outer pane 1 has a thickness of, for example, 2.1 mm, and the inner pane 2 has a thickness of 1.6 mm. The thermoplastic interlayer 3 is made of a single thermoplastic composite film, for example, a PVB film with a thickness of 0.76 mm.

[0061] The composite disc 10 also includes an electrically conductive coating 20, which is applied to the outer surface III of the inner disc 2 and is designed as a heatable coating. The electrically conductive coating 20 has busbars and electrical leads for electrically connecting the coating 20 to a voltage source (not shown).

[0062] The thermoplastic intermediate layer 3 comprises a layer of selectively absorbing nanoparticles 30, in that the nanoparticles are directly incorporated into the material of the thermoplastic composite film. The selectively absorbing nanoparticles used are based on CsPBI 3, which exhibit selective absorption of light in the wavelength range of 610 nm to 700 nm. The layer of selectively absorbing nanoparticles 30 thus absorbs in the red region of the visible light spectrum. This compensates for the reddish tint caused by the conductive coating 20. The outer reflection color is shifted towards blue, resulting in a more pleasing color impression.

[0063] Table 1 shows an exemplary structure of an electrically conductive coating 20, specifying the materials and layer thicknesses. The coating 20 is applied to the inner disk 2, with the layer sequence corresponding to that shown in Table 1. The electrically conductive coating comprises three electrically conductive layers 21.1, 21.2, 21.3. Each electrically conductive layer 21 is positioned between two of a total of four anti-reflective layers 22.1, 22.2, 22.3, 22.4. The anti-reflective layers 22.3, 22.4 are each subdivided into a dielectric layer 22a.3, 22a.4 and an optically high-refractive-index layer 22b.3, 22b.4. The coating 20 also contains three smoothing layers 23.1, 23.2, 23.3, three first adaptation layers 24.1, 24.2, 24.3, three second adaptation layers 25.2, 25.3, 25.4 and three blocker layers 26.1, 26.2, 26.3. Table 1 Reference sign Layer thickness SiZrN 22b.4 22.4 9.6 nm Si 3 N 4 22a.4 9.9 nm ZnO 25.4 13.0 nm NiCr 26.3 0.2 nm AG 21.3 9.0 nm ZnO 24.3 14.0 nm ZnSnO 23.3 7.0 nm SiZrN 22b.3 22.3 21.3 nm Si 3 N4 22a.3 25.8 nm ZnO 25.3 10.0 nm NiCr 26.2 0.3 nm AG 21.2 9.5 nm ZnO 24.2 9.0 nm ZnSnO 23.2 8.0 nm SiZrN 22.2 42.5 nm ZnO 25.2 12.0 nm NiCr 26.1 0.2 nm AG 21.1 9.5 nm ZnO 24.1 13.0 nm ZnSnO 23.1 7.0 nm SiZrN 22.1 10.9 nm Glass 2 1.6 mm Example

[0064] A composite disk 10 according to the invention was produced. Figure 1 The inventive material is produced, wherein the electrically conductive coating 20 was configured according to Table 1. A composite disc not according to the inventive material was constructed in the same way as a comparison example, with the difference that a layer of selectively absorbing nanoparticles 30 was omitted in the comparison example. The observations of the reflection color (measured at an angle of 8° and 60°, respectively) are summarized in Table 2. The color values ​​a* and b* in the L*a*b* color space are given (light source D65), followed by the observation angle. Table 2 TL / % a* (80) b* (8°) a* (60°) b* (60°) Comparative example 72,2 +0,5 -5,1 -1,0 +5,5 Example 71,2 -0,7 -5,4 -3,9 +4,8

[0065] It can be seen that the a* values ​​are reduced by the use of the layer of selectively absorbing nanoparticles, while the b* values ​​are also slightly reduced. Particularly at an observation angle of 8°, a change in the sign of the a* value can be observed, with the reflected color shifting from an undesirable reddish-blue hue to a greenish-blue. The resulting color is thus more neutral and more pleasing to the viewer. The total transmission (light source A) is above 70% in both cases, making the glass suitable for use as windshields.

[0066] Figures 2a and 2b show reflection spectra of the composite disk 10 according to Figure 1 with a coating 20 according to Table 1 (example) compared to the composite disc of the comparison example (without a layer of selectively absorbing nanoparticles). In Figure 2aThe reflection spectra measured at an observation angle of 8° are shown, while the spectra of the Figure 2b exhibit an observation angle of 60°. The reflection spectra of the composite disks according to the example and the comparison example each show a significant deviation from each other in the wavelength range from 640 nm to 690 nm, with the composite disk according to the example exhibiting an advantageously reduced reflectance in this red region of the spectrum. The composite disk according to the example of the invention thus shows a significantly improved reflection color compared to the comparison example, both at an observation angle of 8° and at an observation angle of 60°, with a color change in the direction of green-blue.

[0067] Figure 3 shows a further embodiment of the composite disk 10 according to the invention, which is essentially the embodiment of the Figure 1This corresponds to the electrically conductive coating 20, in contrast to the previous configuration, which is applied to the interior surface (II) of the outer pane 1. This embodiment is particularly preferred for achieving an attractive reflection color of a HUD image projected onto the composite pane 10 from the interior surface (IV). If the composite pane 10 is Figure 3 When used as a HUD disc, the thermoplastic intermediate layer 3 comprising the layer of selectively absorbing nanoparticles 30 is preferably designed as a wedge foil. Reference symbol list:

[0068] (10) Laminated glass (1) Outer glass (2) Inner glass (3) Thermoplastic interlayer (4) Opaque cover print (20) Electrically conductive coating (21.1), (21.2), (21.3), (21.4) Electrically conductive layers (22.1), (22.2), (22.3), (22.4) Anti-reflective coatings (22a.3), (22a.4) Dielectric coatings (22b.3), (22b.4) High refractive index coatings (23.1), (23.2), (23.3) Smoothing coatings (24.1), (24.2), (24.3) First matching layers (25.2), (25.3), (25.4) Second matching layers (26.1), (26.2), (26.3) Blocker layers (30) Layer of selectively absorbing nanoparticles (I) Outer, separated from the interlayer 3. surface of the outer pane 1 facing away from the intermediate layer 3 (II) surface of the outer pane 1 facing inwards towards the intermediate layer 3 (III) surface of the inner pane 2 facing away from the intermediate layer 3 (IV) surface of the inner pane 2 facing inwards away from the intermediate layer 3

Claims

1. Laminated pane (10) which has an electrically conductive coating (20), at least comprising an outer pane (1), which has an outer-side surface (I) and an interior-side surface (II), and an inner pane (2), which has an outer-side surface (III) and an interior-side surface (IV), wherein the interior-side surface (II) of the outer pane (1) and the outer-side surface (III) of the inner pane (2) are connected to one another via a thermoplastic intermediate layer (3), and wherein between the interior-side surface (II) of the outer pane (1) and the outer-side surface (III) of the inner pane (2) at least: - the electrically conductive coating (20) and - at least one layer of selectively absorbing nanoparticles (30) which have an absorption within the wavelength range of 580 nm to 750 nm are arranged flat and one on top of the other.

2. Laminated pane (10) according to claim 1, wherein at least one layer of selectively absorbing nanoparticles (30) is arranged on the outer side of the electrically conductive coating (20).

3. Laminated pane (10) according to claim 1 or claim 2, wherein at least one layer of selectively absorbing nanoparticles (30) is arranged on the inner side of the electrically conductive coating (20).

4. Laminated pane (10) according to claim 2, wherein the electrically conductive coating (20) is arranged on the outer-side surface (III) of the inner pane (2), and the at least one layer of selectively absorbing nanoparticles (30) is arranged within the intermediate layer (3).

5. Laminated pane (10) according to claim 3, wherein the electrically conductive coating (20) is arranged on the interior-side surface (II) of the outer pane (1), and the at least one layer of selectively absorbing nanoparticles (30) is arranged within the intermediate layer (3).

6. Laminated pane (10) according to any of claims 1 to 5, wherein the thermoplastic intermediate layer (3) is formed from at least one thermoplastic film, and selectively absorbing nanoparticles are embedded in the at least one thermoplastic film in order to form the layer of selectively absorbing nanoparticles (30) from the thermoplastic film, and preferably at least 0.1 wt% of selectively absorbing nanoparticles are embedded in the at least one thermoplastic film.

7. Laminated pane (10) according to any of claims 1 to 6, wherein the layer of selectively absorbing nanoparticles (30) comprises nanoparticles based on semiconductor materials, preferably based on silicon (Si), zinc selenide (ZnSe) and / or cadmium telluride (CeTe), and / or based on perovskites, preferably based on halogen-containing cesium-lead perovskites, in particular CsPbl3 or CsPb(I / Br)3.

8. Laminated pane (10) according to any of claims 1 to 7, wherein the layer of selectively absorbing nanoparticles (30) has an absorption in the wavelength range from 580 nm to 700 nm, preferably in the wavelength range from 590 nm to 690 nm.

9. Laminated pane (10) according to any of claims 1 to 8, wherein the layer of selectively absorbing nanoparticles (30) has, in the absorbed wavelength range, an absorption of at least 20%, preferably at least 30%, particularly preferably at least 40%.

10. Laminated pane (10) according to any of claims 1 to 9, wherein the electrically conductive coating (20) comprises at least one electrically conductive layer, preferably at least two electrically conductive layers, particularly preferably at least three electrically conductive layers, each of which is arranged between two dielectric layers or layer sequences.

11. Laminated pane (10) according to claim 10, wherein the at least one electrically conductive layer comprises silver.

12. Laminated pane (10) according to any of claims 1 to 11, wherein the electrically conductive coating (20) has at least two busbars via which the electrically conductive coating (20) can be connected to an electrical voltage source.

13. Use of the laminated pane (10) according to any of claims 1 to 12 in motor vehicles, preferably as a windshield, rear window, side window and / or roof window, particularly preferably as a windshield of a motor vehicle.