CN116194416A - Vehicle glazing with anti-reflection coating of titanium nitride layer - Google Patents

Abstract

The invention relates to a vehicle glazing comprising-at least one transparent vitreous glazing (1) having an outer side surface (I, III) and an inner space side surface (II, IV), wherein the inner space side surface (II, IV) of the vitreous glazing (1) forms an exposed inner space side surface of the vehicle glazing, and-an anti-reflection coating (20) on the inner space side surface (II, IV) of the vitreous glazing (1), wherein the anti-reflection coating (20) comprises, in the following order starting from the vitreous glazing (1): -a high refractive dielectric lower layer (21) or layer sequence (21 a, 21 b) with a refractive index of more than 1.9, -a titanium nitride based IR reflecting layer (22), -a high refractive dielectric upper layer (23) or layer sequence with a refractive index of more than 1.9, and-a low refractive dielectric layer (24) or layer sequence with a refractive index of less than 1.6, wherein the IR reflecting layer (22) has a specific resistance of less than 100 μΩ cm.

Description

Vehicle glazing with anti-reflection coating of titanium nitride layer

The present invention relates to a vehicle glazing panel with an anti-reflective coating, its manufacture and use.

Vitreous glass plates with anti-reflection coatings are known. Whereby the reflection of light on the relevant surface of the vitreous glass plate can be significantly reduced. Various types of antireflective coatings are known. They are generally formed of a plurality of thin layers in which layers having a high refractive index and a low refractive index are alternately arranged, and an antireflection effect is caused by an interference effect. Such antireflective coatings are known, for example, from EP0490613A2, US6068914a and WO2019/179682 A1. Alternatively, antireflective coatings composed of nanoporous silica are known, wherein the antireflective effect is produced by avoiding interfaces with abrupt and abrupt refractive index changes. Such coatings produced in a sol-gel process are known, for example, from WO2008059170 A2. Anti-reflective coatings may also be used on vehicle glazing panels, for example to increase their light transmittance or to avoid interfering reflections into the vehicle interior.

Furthermore, infrared-reflective coatings are known which, as sun protection coatings, reflect the infrared component of solar radiation in the near infrared range or, as so-called low-E coatings, reduce the thermal radiation of the vitreous glass pane into the interior space. Such coatings are also widely used in vehicle glazing to improve thermal comfort in the interior space of a vehicle. low-E coatings and sun protection coatings with functional layers based on titanium nitride are known here, for example from WO2018129135A1 and WO2020128327 A1. It is particularly advantageous here if these coatings are corrosion-resistant, so that they can be used on the surface of the vehicle glass pane that is exposed with respect to the interior space. This is necessary for low E coatings. In the case of a composite glass sheet, the sun protection coating may be disposed between two monolithic glass sheets such that it is not in contact with the atmosphere and may be formed as a corrosion-susceptible silver coating. However, in the case of monolithic vehicle glazing, only the exposed surfaces are available, and thus corrosion resistant sun protection coatings are required in this case.

An antireflective coating is known from EP3124449A1, which comprises, starting from a substrate, a high refractive lower layer, a titanium nitride based layer, a high refractive upper layer and a low refractive layer. The titanium nitride based layer is not conductive and therefore does not have IR reflecting properties.

An IR reflecting coating is known from JPS63206333a, which comprises, starting from a substrate, a high refractive lower layer, a titanium nitride based layer, a high refractive upper layer and a thick silicon oxide layer having a thickness of at least 1 μm. The coating has no anti-reflective properties.

If the vehicle glazing is to have both infrared reflective and anti-reflective properties, two coatings are required. This increases the complexity of manufacturing the vehicle glazing and is a challenge especially in the case of monolithic vehicle glazing because the number of surfaces available for use is extremely limited.

It is an object of the present invention to provide a vehicle glazing panel having an improved coating with anti-reflective and IR reflective properties. The coating should also be less susceptible to corrosion so that it can be used on exposed surfaces that are in direct contact with the environment.

According to the invention, the object is achieved by a vehicle glazing according to claim 1. Preferred embodiments are evident from the dependent claims.

The vehicle glazing provides for separating the interior space from the external environment in the window opening of the vehicle. The vehicle glazing according to the invention comprises at least one transparent vitreous glazing and an anti-reflection coating. The vitreous glass plate has two surfaces (major faces), namely an outer side surface and an inner space side surface, and a surrounding land between the two major faces. The outer surface refers to that main surface which in the mounted position faces the external environment. The inner space side surface refers to that main surface which faces the vehicle inner space in the mounted position. The interior space side surface of the vitreous glass sheet also forms the exposed interior space side surface of the vehicle glass sheet. An anti-reflection coating is disposed on the interior space side surfaces of the vitreous glass plate and the vehicle glass plate. Exposed surface is referred to herein as an exposed or exposed surface that interfaces with the surrounding atmosphere and is accessible and accessible to humans. In the case of a single sheet of vitreous glass, both of its major faces are exposed surfaces. In the case of a composite glass sheet, the surfaces of the outer and inner glass sheets facing away from the interlayer and the respective other glass sheets are exposed surfaces.

According to the invention, the anti-reflection coating comprises, starting from a vitreous glass plate, at least in the following order:

an (optically) high-refractive dielectric underlayer or layer sequence with a refractive index of more than 1.9,

an infrared reflecting layer based on titanium nitride (TiN),

an (optical) high-refractive dielectric upper layer or layer sequence with a refractive index of more than 1.9, and

an (optical) low-refractive dielectric layer or layer sequence with a refractive index of less than 1.6.

A great advantage of the invention is that the coating according to the invention has Infrared (IR) reflecting properties in addition to its anti-reflecting properties in the visible spectrum. The antireflective effect is based in particular on a combination of a high refractive dielectric upper layer or layer sequence and a low refractive dielectric layer or layer sequence, wherein the high refractive dielectric lower layer or layer sequence also plays a role in this respect. The IR reflecting properties are provided in particular by means of an IR reflecting layer based on titanium nitride. Thus, the coating reduces light reflection (primary function) on the inner space side surface of the vitreous glass plate and heat input into the vehicle inner space (secondary function). The IR reflection properties are in the near infrared range, so that the coating is used as a sun protection coatingsolar control coating (solar energy control) Coating layer) And (partially) reflect the IR component of solar radiation. IR reflection properties also relate to heat radiation in the mid IR range, so it also serves as a coating to reduce emissivity (low E coating) and to reduce the amount of heat radiated by the vehicle glazing into the vehicle interior space. In addition, it is not easy to corrode due toThis can be used on the exposed surface, which is necessary for coatings that reduce emissivity (exposed surface on the interior side), and is inherently unavoidable in the case of monolithic vehicle glazing panels, since only the exposed surface is available. Furthermore, the coating is advantageously transparent, so that (depending on the vitreous glass plate used and its degree of tinting) a vehicle glass plate having a light transmittance of at least 70% can be achieved, as is required in particular for windshields and front side glazings. A relatively small layer thickness is required compared to conventional antireflective coatings (composed of alternating optical high-and low-refractive dielectric layers), whereby material can be saved and costs reduced.

The antireflective coating is preferably arranged over the entire surface on said surface, such that the entire surface is covered without exception by the coating. However, some areas of the surface may also be free of coatings, such as surrounding edge areas or locally uncoated areas, which serve as data transmission windows to improve the transmission of electromagnetic radiation (antenna signals). Such a data transfer window may be necessary or useful in order to ensure transmission of electromagnetic radiation (e.g., antenna signals), which may be attenuated or blocked by the TiN-based conductive layer. Preferably at least 80% of the surface is covered by the coating, particularly preferably at least 90%.

In one embodiment of the invention, the vehicle glazing is designed as a composite glazing. The composite glass sheet includes an outer glass sheet and an inner glass sheet that are interconnected by a thermoplastic interlayer. In the sense of the present invention, an inner glass pane refers to a glass pane of the composite glass pane facing the interior space of the vehicle. The outer glass sheet refers to a glass sheet facing the external environment. The glass pane according to the invention with the antireflection coating is here an inner pane of a composite pane of glass and its inner space-side surface faces away from the intermediate layer. Such composite glass sheets are used in the field of vehicles as so-called composite safety glass (VSG). The vehicle glazing may be, for example, a windscreen, side glazing, rear glazing or roof glazing.

In an alternative embodiment of the invention, the vehicle glass pane according to the invention is a monolithic vehicle glass pane, which is designed as a monolithic vitreous glass pane. Thus, there is no other glass sheet than the vitreous glass sheet with the anti-reflection coating. The vehicle glazing uses in particular a so-called single-layer safety glass (ESG), in which the vitreous glazing is thermally tempered. The integrated vehicle glazing panel may be, for example, a side glazing, a rear glazing or a roof glazing.

The IR reflecting layer based on titanium nitride is preferably a thin layer (thin layer) and in an advantageous embodiment has a layer thickness of 10nm to 20nm, preferably 12nm to 18nm, particularly preferably 13nm to 17 nm. Good IR reflection properties are thus achieved and the light transmittance of the vitreous glass plate is only slightly reduced. Preferably, the titanium nitride is deposited substantially stoichiometrically, i.e., with an atomic ratio of titanium to nitrogen of about 1:1. Titanium nitride is one of a few conductive nitrides and therefore has some conductivity and IR reflection is attributed to it. The specific resistance of the sheet is typically higher than the tabulated values for solids (volume [ ]bulkWerte). The specific resistance of the IR reflecting layer based on titanium nitride according to the invention is preferably less than 100 μΩ cm. The specific resistance is decisively dependent on the nitrogen proportion of the IR-reflecting layer, and in addition layer parameters such as density and crystallinity are also affected. The specific resistance is expressed in the refractive index of the IR reflecting layer. Strictly speaking, specific resistance refers to specific resistance, which is often also referred to as resistivity. Its reciprocal is the conductivity.

The refractive index (real part of complex refractive index) of the IR reflecting layer based on titanium nitride is preferably 0.5 to 1.4, particularly preferably 0.5 to 1.3. The extinction coefficient (imaginary part of the complex refractive index, also measured at a wavelength of 550 nm) of the IR reflecting layer based on titanium nitride is preferably 1.0 to 5.0.

Preferably, the titanium nitride based layer has a lower refractive index than the low refractive dielectric layer or layer sequence.

If the layer of the anti-reflection coating according to the invention is formed on the basis of a material, the majority of the layer consists of the material, in particular essentially of the material, except for possible impurities or dopants. The mentioned dielectric materials (oxides, nitrides) can be deposited stoichiometrically, stoichiometrically under-or stoichiometrically over-. Therefore, the stoichiometric coefficient is discarded when the molecular formula is given. The formulas are used for abbreviations only and they do not contain any information about stoichiometry.

By doping, for example, aluminum, zirconium, titanium or boron, the dielectric material may be provided with a certain conductivity. However, those skilled in the art recognize them as dielectric layers in terms of their function, as is common in the thin layer art. The material of the dielectric layer preferably has a dielectric constant of less than 10 ^-4 Conductivity (inverse of specific resistance) of S/m.

In the sense of the present invention, the thickness or layer thickness of a layer always refers to the geometric thickness unless otherwise specified. Conversely, if reference is made to an optical thickness which results from the product of the geometric thickness and the refractive index, this will be clearly indicated in each case. The thickness or layer thickness of a layer in the sense of the present invention always refers to the geometric thickness unless otherwise indicated. If reference is made to an optical thickness, which is given as the product of the geometric thickness and the refractive index, this will be specified in each case.

The values given for the refractive index are measured at 550 nm wavelength. The refractive index may be determined, for example, by means of ellipsometry. Ellipsometers are commercially available, for example from the company Sentech.

According to the invention, the high refractive dielectric underlayer or layer sequence has a refractive index of greater than 1.9, for example 1.9 to 2.5. It may be formed as a single layer (in which case there is a high refractive dielectric underlayer) or as a stack of layers (in which case there is a high refractive dielectric underlayer sequence). In the case of a layer sequence, all layers have a refractive index of greater than 1.9.

The high-refractive dielectric underlayer or layer sequence preferably has an optical thickness of 20nm to 120nm, particularly preferably 40nm to 100 nm. Particularly good anti-reflection properties are thereby achieved.

In an advantageous embodiment, the high refractive dielectric underlayer or layer sequence comprises or is formed of a nitride-based layer. This means that if a dielectric underlayer is present, it is formed on nitride basis and if a dielectric underlayer sequence is present, it comprises at least one nitride-based layer. The nitride is preferably silicon nitride (SiN) or a silicon-metal mixed nitride, such as silicon zirconium nitride (SiZrN), silicon hafnium nitride (SiHfN), silicon titanium nitride (sinn) or silicon aluminum nitride (SiAlN). They have a suitable refractive index (SiN: 2.0; siZrN: 2.2), can be produced relatively easily and cheaply, and are generally used for thin-layer coatings on vitreous glass sheets. In a further advantageous embodiment, the high-refractive dielectric underlayer or layer sequence comprises or is formed from an oxide-based layer, in particular titanium oxide (TiO, refractive index 2.3). The (average) refractive index of the high refractive underlayer (sequence) can thereby be further increased, which is advantageous for the anti-reflection effect.

In a particularly advantageous embodiment, the layer of the high refractive underlayer or layer sequence in direct contact with the TiN-based IR reflecting layer is formed on the basis of nitride, in particular on the basis of SiN or SiZrN. It is thereby possible to avoid that the IR reflecting layer is oxidized at the time of deposition or at the time of subsequent heat treatment, as may occur when in contact with the oxide layer. This may be achieved by the presence of a high refractive dielectric underlayer based on nitride formation, or by the presence of a high refractive dielectric underlayer sequence whose uppermost (i.e. furthest from the vitreous glass plate) layer is based on nitride formation.

In one embodiment, there is a single high refractive dielectric underlayer based on nitride, in particular on silicon nitride (SiN), with a layer thickness of 10nm to 60nm, in particular 20nm to 50nm, for example 35 nm to 45 nm, or on silicon zirconium nitride (SiZrN), with a layer thickness of 10nm to 50nm, in particular 15 nm to 45 nm. For other silicon-metal mixed nitrides, substantially the same layer thickness as SiZrN may be used.

In a particularly advantageous embodiment, there is a high refractive dielectric lower layer sequence, starting from a vitreous glass plate, comprising in the following order:

A first layer based on an oxide, in particular titanium oxide (TiO), and

a second layer based on a nitride, in particular silicon nitride (SiN), or a silicon-metal-mixed nitride, in particular silicon zirconium nitride (SiZrN).

The second layer is preferably in direct contact with the IR reflecting layer and prevents oxidation thereof. The first layer increases the average refractive index of the layer sequence. The TiO-based first layer preferably has a layer thickness of 5nm to 25nm, particularly preferably 10nm to 20nm or 10nm to 18nm. When the second layer is formed on the basis of SiN, it preferably has a layer thickness of 10nm to 40nm, particularly preferably 15nm to 35nm, in particular 25nm to 35nm or 30nm to 35 nm. When the second layer is formed on the basis of SiZrN, it preferably has a layer thickness of 10nm to 35nm, particularly preferably 15nm to 30 nm.

According to the invention, the high refractive dielectric upper layer or layer sequence has a refractive index of more than 1.9, for example 1.9 to 2.5. It can likewise be formed as a single layer (in which case there is one high refractive dielectric upper layer) or as a stack of layers (in which case there is one high refractive dielectric upper layer sequence). In the case of a layer sequence, all layers have a refractive index of greater than 1.9.

The high refractive dielectric upper layer or layer sequence preferably has an optical thickness of 40nm to 120nm, particularly preferably 60nm to 100 nm. Particularly good anti-reflection properties are thereby achieved.

The materials of the high refractive dielectric lower and upper layers or layer sequences can be selected independently of each other. In an advantageous embodiment, the high refractive dielectric upper layer or layer sequence comprises or is formed of a nitride-based layer. The nitride is preferably silicon nitride (SiN) or a silicon-metal-mixed nitride, such as silicon zirconium nitride (SiZrN), silicon hafnium nitride (SiHfN), silicon titanium nitride (sinn) or silicon aluminum nitride (SiAlN). In a further advantageous embodiment, the high refractive dielectric upper layer or layer sequence comprises or is formed from an oxide-based layer, in particular titanium oxide (TiO).

In a particularly advantageous embodiment, the layer of the high refractive upper layer or layer sequence that is in direct contact with the TiN-based IR reflecting layer is formed on the basis of nitride, in particular on the basis of SiN or SiZrN. It is thereby possible to avoid that the IR reflecting layer is oxidized when depositing a dielectric layer thereon or during a downstream heat treatment, as it may occur when in contact with an oxide layer. This may be achieved by the presence of a high refractive dielectric upper layer based on nitride formation or by the presence of a high refractive dielectric upper layer sequence whose lowermost (i.e. most near infrared reflecting layer) layer is based on nitride formation.

In a very particularly advantageous embodiment, there is a single high-refractive dielectric upper layer, based on nitride, in particular on silicon nitride (SiN), with a layer thickness of 20nm to 60nm, in particular 30nm to 50nm, particularly preferably 30nm to 50nm, or 40 nm to 50nm, or on zirconium silicon nitride (SiZrN), with a layer thickness of 15nm to 55 nm, particularly preferably 20nm to 45 nm. Monolayers are easier to prepare than layer sequences and dividing the layer sequence into different monolayers brings about fewer optical advantages in the case of a high refractive upper module than in the case of a high refractive index module.

However, a dielectric upper layer sequence may also be present. "bottom-up" (i.e., the direction from the vitreous glass sheet) preferably includes, in the following order:

a first layer based on a nitride, in particular silicon nitride (SiN), or a silicon-metal-mixed nitride, in particular zirconium silicon nitride (SiZrN), and

a second layer based on an oxide, in particular titanium oxide (TiO).

The first layer is preferably in direct contact with the IR reflecting layer and prevents oxidation thereof. The second layer increases the average refractive index of the layer sequence. The second TiO-based layer preferably has a layer thickness of 5nm to 25nm, particularly preferably 10nm to 20nm. When the first layer is formed based on SiN, it preferably has a layer thickness of 10nm to 30nm, particularly preferably 15nm to 25nm. When the first layer is formed on the basis of SiZrN, it preferably has a layer thickness of 10nm to 25nm, particularly preferably 15nm to 20nm.

According to the invention, the low refractive dielectric layer or layer sequence has a refractive index of less than 1.6, for example from 1.2 to 1.6, preferably less than 1.5. It may be formed as a single layer (in which case there is one low refractive dielectric layer) or as a stack of layers (in which case there is one low refractive dielectric layer sequence). In the case of a layer sequence, the refractive index of all layers is less than 1.6.

The low-refractive dielectric layer or layer sequence preferably has an optical thickness of 40nm to 130nm, particularly preferably 55nm to 115 nm. Particularly good anti-reflection properties are thereby achieved.

In an advantageous embodiment, the low refractive dielectric layer or layer sequence comprises or is formed of an oxide-based layer. The oxide is preferably silicon oxide (SiO). It has a suitable refractive index (1.45) and can be produced by thin-layer techniques, but can also be produced wet-chemically, as is usual for coatings on vitreous glass plates.

In a preferred embodiment, there is a single low-refractive dielectric layer, in particular based on SiO, with a layer thickness of from 30nm to 90nm, particularly preferably from 40nm to 80nm.

In one embodiment of the invention, the low refractive dielectric layer, in particular the SiO layer, is a thin layer made by vapor deposition.

In another embodiment of the invention, the low refractive dielectric layer, in particular the SiO layer, is a nanoporous sol-gel layer, in particular a sol-gel layer based on nanoporous silica. The refractive index of the SiO layer is further reduced by the porosity. An advantage of such a sol-gel layer over thin layers obtained from vapor deposition is on the one hand that it can be produced more cost-effectively. On the other hand, it has surprisingly been shown that better optical properties of the vehicle glazing are thereby achieved, since the anti-reflection coating has a smoother reflection spectrum in the visible spectral range, so that the color distortion is less pronounced.

The antireflective effect of such a sol-gel layer depends on the one hand on the refractive index and on the other hand on the thickness of the layer. The refractive index in turn depends on the pore size and the density of the pores. In a preferred embodiment, the size and distribution of the pores is such that the refractive index is from 1.2 to 1.4, particularly preferably from 1.25 to 1.35. The thickness of the sol-gel layer is preferably from 30nm to 200nm, particularly preferably from 50nm to 150nm, in particular from 50nm to 80nm. Thereby achieving good anti-reflection properties. The silicon oxide may be doped with, for example, aluminum, zirconium, titanium, boron, tin, or zinc. The optical, mechanical and chemical properties of the coating can be matched in particular by doping.

The pores of nanoporous SiO are in particular closed nanopores, but may also be open pores. Nanopores are understood to mean pores having dimensions in the nanometer range, i.e. from 1nm to less than 1000nm (1 μm). The holes preferably have a substantially circular cross-section (spherical holes), but may also have other cross-sections, such as elliptical, oval or elongated cross-sections (elliptical or oval holes). Preferably, at least 80% of all the holes have substantially the same cross-sectional shape. It may be advantageous if the pore size is at least 20nm or even at least 40 nm. The average pore size is preferably from 1nm to 500nm, particularly preferably from 1nm to 100nm, very particularly preferably from 20nm to 80nm. For circular holes, the size of the hole refers to the diameter, and for other shapes, the size of the hole refers to the greatest longitudinal extent. Preferably, at least 80% of all holes have a size within the indicated range, particularly preferably all holes have a size within the indicated range. The proportion of the pore volume in the total volume is preferably from 10% to 90%, particularly preferably less than 80%, very particularly preferably less than 60%.

Instead of a single low refractive layer, there may also be a sequence of low refractive dielectric layers consisting of a plurality of monolayers. The layer sequence may for example comprise a SiO-based layer produced by vapour deposition, and a sol-gel layer based on nanoporous SiO. In this case, the sol-gel layer is preferably the upper of the two layers, i.e. the layer farther from the vitreous glass plate. It is also possible that the low refractive dielectric layer sequence comprises a plurality of sol-gel layers, which layers differ, for example, in terms of porosity (size and/or density of pores).

The antireflective coating according to the invention is described above as comprising or including certain layers. This means that other layers than the mentioned layers may be present, for example between individual layers or layer sequences or as part of one or more layer sequences. However, it is preferred that the coating consists only of the high refractive lower layer (sequence), the IR reflecting layer, the high refractive upper layer (sequence) and the low refractive layer (sequence) and that no further layers are present between, above and below them. It is furthermore preferred that the individual layers (sequences) consist only of the layers explicitly mentioned above and do not contain further layers. The mentioned layers are sufficient to produce good anti-reflection and IR shielding effects. Additional layers may increase the cost and complexity of manufacture. Furthermore, the further layers may reduce the light transmittance, which is disadvantageous and may even exclude certain applications where the lowest light transmittance is specified.

The vitreous glass plate is preferably made of soda lime glass, which is common for window glass. In principle, however, it can also be made of other types of glass, such as borosilicate glass, quartz glass or aluminosilicate glass. The same applies to the outer glass pane if the vehicle glass pane is a composite glass pane. The thickness of the vitreous glass plate can be freely chosen according to the requirements of the application. Typically, the thickness is from 0.5mm to 10mm, especially from 1mm to 5mm.

The vitreous glass plate (and/or the outer glass plate in the case of a composite glass plate) may be made of transparent glass or of tinted or colored glass. Transparent glass is understood to mean that such a glass pane has a light transmittance normalized to ISO 9050 of at least 90%. The tinted or colored vitreous glass sheets have a lower normalized light transmittance.

The vehicle glazing is preferably curved in one or more spatial directions, as is commonly used for automotive glazing, with typical radii of curvature ranging from about 10cm to about 40 m. Here, the surface of the vehicle glass pane on the inner space side is generally concavely curved. However, the vehicle glazing may also be flat, for example if it is provided as a glazing for a bus, train or tractor.

The vehicle glazing according to the invention preferably has an internal space side emissivity of less than 40%, particularly preferably less than 35%, very particularly preferably less than 30%. Here, the internal space side emissivity refers to a measure of how much heat radiation the glass plate in the installed position emits into the internal space of, for example, a building or a vehicle, compared to an ideal heat radiator (blackbody). Emissivity in the sense of the present invention is understood to mean the normal emissivity at 283K according to standard EN 12898.

The vehicle glass pane according to the invention preferably has a TTS value of less than 65%, particularly preferably less than 60%. This applies in the case of vitreous glass sheets made of transparent glass (and also in the case of composite glass sheets for outer glass sheets, in which the thermoplastic interlayer is likewise transparent and uncolored). The TTS value can be further reduced by using a tinted vitreous glass plate. TTS values describe the total solar energy transmittance and are a measure of the amount of heat that enters the vehicle through the vehicle glazing. It is determined according to ISO 13837.

The vehicle glazing according to the invention preferably has a light transmittance of greater than 70%. This in turn applies to the case where the vitreous glass plate is made of transparent glass (and also to the outer glass plate in the case of a composite glass plate, where the thermoplastic interlayer is likewise transparent and uncolored). Light transmittance refers herein to normalized light transmittance measured with a light source of type a light according to ISO 9050.

The vehicle glazing according to the invention preferably has an interior side reflectivity of less than 5%, preferably less than 4.5%. Here, the internal space side reflectance is a normalized light reflectance when the internal space side surface having the coating according to the present invention is irradiated, measured with a light source of type a light at an incident angle of 8 ° and an observation angle of 2 ° to the surface normal of the internal space side.

The anti-reflective coating according to the present invention may also be used as a heating coating because it has conductivity due to the TiN-based layer. For this purpose, it has so-called bus bars (bus bars) which extend along two mutually opposite side edges of the vehicle glass pane and are connected to the electrodes of the voltage source so that an electric current can flow through the coating and thus heat the vehicle glass pane. Due to the planar resistance, a particularly advantageous heating effect is achieved when the voltage source has a voltage of 42 to 48 volts or even 300 to 400 volts. Such voltages are particularly suitable for use in electric vehicles.

The invention also includes a method for making a vehicle glazing panel, wherein

(a) Providing a transparent glass sheet having an exterior side surface and an interior side surface, wherein the interior side surface of the glass sheet provides an exposed interior side surface for forming a vehicle glass sheet,

(b) An antireflection coating was applied on the inner space side surface of the vitreous glass plate by depositing in the following order:

a high refractive dielectric underlayer or layer sequence having a refractive index of greater than 1.9,

an IR reflecting layer based on titanium nitride,

a high refractive dielectric upper layer or layer sequence with a refractive index of more than 1.9, and

Low refractive layer or layer sequence with refractive index less than 1.6.

The high refractive dielectric lower and upper layers or layer sequences are preferably deposited by vapor deposition, for example by Chemical Vapor Deposition (CVD), plasma-assisted chemical vapor deposition (PECVD), atomic layer depositionatomic layer depositionALD). Physical Vapor Deposition (PVD), such as vapor deposition, is particularly preferred, with cathodic sputtering ("sputtering"), in particular magnetic field assisted cathodic sputtering ("magnetron sputtering"), being very particularly preferred.

TiN-based IR reflecting layers can also be deposited by the methods described above, with magnetic field assisted cathode sputtering being particularly preferred here as well. In a particularly advantageous embodiment, the IR reflecting layer is sputtered by high power pulsed magnetron sputteringHigh Power Impulse Magnetron SputteringHiPIMS) deposition. It has been shown that IR reflecting layers with particularly advantageous crystallinity can be produced therefrom, which is manifested by particularly high light transmittance and particularly good IR reflecting properties.

High power pulsed magnetron sputtering is a special variant of magnetron sputtering, which is a variant of sputtering. During sputtering, the target (cathode) is bombarded with ions, and material is then released from the target, which is then deposited on the surface to be coated. In simple cathode sputtering only the electric field is applied, whereas in magnetron sputtering an additional magnetic field is arranged behind the cathode plate. Due to the superposition of the electric and magnetic fields, the charge carriers no longer move parallel to the electric field lines, but spiral on a spiral line above the target surface. Thereby extending its path and increasing the number of collisions per electron. The effectively higher ionization capacity of the electrons results in an increase in the sputtering rate. Thus, significantly higher coating rates can be achieved at the same process pressure. In addition, a denser layer can be created. High-performance pulsed magnetron sputtering is a further developed method based on this, which exploits the effect of pulsed discharges with a power of more than 1 MW (pulse duration much less than 1 mus, for example several tens of mus) to achieve a significantly improved ionization degree. The high ionization can significantly alter the properties of the grown layer by changing the growth mechanism and, for example, lead to higher adhesion strength deposition and to higher microstructure density. A relatively small pulse duty cycle (switching ratio) of less than 10% is particularly used. Since the pulse is applied to the target for only a very short time, followed by a relatively long "off time", a low average cathode power (e.g., 1 to 10 kW) is produced. Thus, the target material cools during the off-time, which ensures process stability. HiPIMS produces a high plasma density with a high proportion of target metal ions.

In this case, a titanium nitride target may be used. Alternatively, a titanium target may be used in which nitrogen gas is added as a reactive gas to the working gas, and nitrogen is embedded in the layer in addition to titanium, thereby forming a TiN-based layer (reactive sputtering). The target and sputtered layer may be doped with other materials, such as boron or aluminum, which may affect the mechanical properties of the layer and/or may increase the deposition rate.

In one embodiment of the invention, the low-refractive dielectric layer is likewise deposited by the mentioned vapor deposition method, wherein magnetic field-assisted cathode sputtering is also particularly preferred here. In another embodiment, the low refractive dielectric layer is manufactured by a sol-gel process, in particular as a nanoporous layer, preferably based on SiO. If a low-refractive dielectric layer sequence is present, it preferably consists of a lower layer, which is produced by vapor deposition (in particular magnetic field-assisted cathode sputtering), and an upper layer, which is produced as a nanoporous layer by the sol-gel method.

The sol-gel layer is deposited on the inner space side surface of the vitreous glass plate in a sol-gel process. First, a sol containing a coating precursor is provided and cured. Curing may include hydrolysis of the precursors and/or (partial) reactions between the precursors. In the sense of the present invention, the sol is referred to as precursor sol and comprises oxygen in a solvent And (3) a silicon precursor. The precursor is preferably a silane, in particular tetraethoxysilane or Methyltriethoxysilane (MTEOS). Alternatively, however, it is also possible to use silicates as precursors, in particular sodium, lithium or potassium silicate, for example tetramethyl orthosilicate, tetraethyl orthosilicate (TEOS), tetraisopropyl orthosilicate or of the formula R ² _n Si(OR ¹ ) _4-n Is an organosilane of (2). Here, R is ¹ Preferably alkyl, R ² Is alkyl, epoxy, acrylate, methacrylate, amine, phenyl or vinyl, n is an integer from 0 to 2. Silicon halides or silicon alkoxides may also be used. The solvent is preferably water, an alcohol (in particular ethanol) or a water-alcohol mixture.

The precursor sol is then mixed with a pore former dispersed in an aqueous phase. The pore former has the task of creating pores in the silica matrix as a placeholder (Platzhalter) when the antireflective coating is produced. The shape, size and density of the pores are determined by the shape, size and concentration of the pore former. By means of pore formers, the pore size, pore distribution and pore density can be controlled in a targeted manner and reproducible results are ensured. As pore formers, for example, polymer nanoparticles, preferably PMMA nanoparticles (polymethyl methacrylate), but alternatively nanoparticles made of polycarbonate, polyester or polystyrene, or copolymers of (meth) acrylic acid and (meth) acrylic acid, can also be used. Instead of polymer nanoparticles, nanodroplets of oil in the form of nanoemulsions may also be used. Of course, the use of different pore formers is also conceivable.

The solution thus obtained was applied to the inner space side surface of the vitreous glass plate. This is reasonably done by wet chemical methods, e.g. by dip coatingdip coating) Spinning coatingspin coating) Flow coatingflow coating) By application by means of rollers or brushes or by sprayingspray coating). Drying may then be performed, whereby the solvent is evaporated. The drying may be carried out at ambient temperature or by heating alone (e.g. with temperatures up to 120 ℃). The surface is generally cleaned by methods known per se before the coating is applied to the substrate.

The sol was then concentrated. The silica matrix is thus formed around the porogen. Condensation may include temperature treatment, for example at a temperature of, for example, up to 350 ℃. If the precursor has a UV-crosslinkable functional group (e.g., a methacrylate group, a vinyl group, or an acrylate group), the condensation may include UV treatment. Alternatively, in the case of suitable precursors (e.g., silicates), the condensation may include IR treatment. Optionally, the solvent may be evaporated at a temperature up to 120 ℃.

The porogen is then optionally removed again. For this purpose, the coated substrate is preferably subjected to a heat treatment at a temperature of at least 400 ℃, preferably at least 500 ℃, whereby the porogen decomposes. In this case, the organic pore former is carbonized (carbonized), in particular. The heat treatment may be performed in the range of a bending process or a thermal tempering process. The heat treatment is preferably carried out for a period of up to 15 minutes, particularly preferably up to 5 minutes. In addition to removing the pore former, a heat treatment can also be used to complete the condensation and thus densify the coating, which improves its mechanical properties, in particular stability.

Instead of by means of a heat treatment, the pore-forming agent can also be released from the coating by means of a solvent. In the case of polymer nanoparticles, the corresponding polymers must be soluble in solvents, for example Tetrahydrofuran (THF) can be used in the case of PMMA nanoparticles.

The porogen is preferably removed, thereby creating voids. However, it is in principle also possible to leave the pore-forming agent in the pores. If it has a refractive index different from that of silicon oxide, the anti-reflection effect is also achieved. The pores are then filled with a pore-forming agent, for example with PMMA nanoparticles. Hollow particles may also be used as porogens, for example hollow polymer nanoparticles such as PMMA nanoparticles or hollow silica nanoparticles. If such porogens remain in the pores without being removed, the pores have a hollow core and edge regions filled with porogens.

The sol-gel process described is capable of producing low refractive dielectric layers with regular, uniformly distributed pores. The shape, size and density of the holes can be specifically adjusted and the coating has a low tortuosity.

After application of the anti-reflective coating, the vitreous glass plate is preferably subjected to a temperature treatment, thereby improving the crystallinity of the layer and generally improving the light transmittance and optical properties of the vehicle glass plate. For example, the temperature treatment may be performed at a temperature of at least 500 ℃. The temperature treatment may also be carried out within the scope of the bending and/or tempering method.

After the anti-reflective coating is applied, the vitreous glass plate may be subjected to a bending process to bring it into a cylindrical or spherically curved shape, as is common for vehicle glass plates, in particular for vehicle glass plates of passenger cars or trucks. For bending, the vitreous glass sheet is softened by heating so that it becomes plastically formable and then shaped by methods known per se, such as gravity bending, press bending and/or suction bending. Typical temperatures for glass bending processes are, for example, 500 ℃ to 700 ℃.

If the vehicle glazing is to be designed as a composite glazing, the coated (and preferably bent) vitreous glazing is connected to the outer glazing by a thermoplastic interlayer. Lamination methods known per se, such as autoclave methods, vacuum bag methods, vacuum ring methods, calendaring methods, vacuum laminators or combinations thereof, are used herein. The glass panes are generally connected by an intermediate layer under the influence of heat, vacuum and/or pressure. The thermoplastic interlayer is preferably formed from at least one thermoplastic film, preferably a PVB film, EVA film or PU film. Typical thicknesses of such films are from 0.2mm to 2mm, in particular from 0.3mm to 1mm.

Furthermore, the invention includes the use of the vehicle glazing according to the invention as a glazing for land, water or air vehicles, preferably as a side glazing, rear glazing, windscreen or sunroof glazing. The vehicle is preferably a motor vehicle, in particular a passenger car, bus or truck, or a rail vehicle.

Various specific applications of the vehicle glazing according to the invention are conceivable:

the anti-reflection coating may thus be used to reduce reflection of display elements, lighting or other objects in the vehicle interior on the interior space side surface. Vehicle occupants, particularly the driver, may be disturbed by such reflections.

The vehicle glazing may serve as a projection surface for a head-up display (HUD) and may be illuminated by a projector to produce a display image. This is particularly important for windshields. When s-polarized projector radiation is used, it is essentially reflected on both outer surfaces of the vehicle glazing, which results in a dual display (primary and ghost images). The coating according to the invention reduces the reflection on the side surfaces of the interior space so that the ghost image appears less intense.

The vehicle glazing may be equipped with a camera or other optical sensor that detects light passing through the vehicle glazing from the outside. This is also particularly important for windshields that typically have optical sensors. Particularly in the case of cameras, it is often necessary to make the windshield as a composite glass sheet with two transparent glass sheets to achieve the desired specifications. However, such transparent windshields have poor thermal properties. The anti-reflective coating improves the thermal properties of such glass sheets. Optionally, the coating in the camera or sensor area may be removed to improve display quality and/or detection efficiency.

In a particularly advantageous application, the vehicle glazing is a side glazing or a rear glazing as a monolithic vitreous glazing. Heretofore, such glass sheets have only been difficult to have improved thermal properties because they have only exposed surfaces and typical IR reflective coatings, particularly silver coatings, are susceptible to corrosion. While the anti-reflective coating according to the invention is corrosion resistant and also provides IR reflective properties to the vehicle glazing.

The invention is explained in more detail below with the aid of the figures and examples. The figures are schematic representations and are not to scale. The drawings are not intended to limit the invention in any way.

Wherein:

figure 1 shows a cross section through one embodiment of a vehicle glazing according to the invention,

figure 2 shows a cross section through another embodiment of a vehicle glazing according to the invention,

figure 3 shows a cross section through one embodiment of an anti-reflection coating according to the invention on a vitreous glass plate,

FIG. 4 shows a cross section through another embodiment of an anti-reflective coating according to the invention on a vitreous glass plate, and

figure 5 shows a flow chart of an embodiment of the method according to the invention.

Fig. 1 shows one embodiment of a vehicle glazing according to the invention. The vehicle glazing is designed, for example, as a side window of a passenger vehicle. It is a monolithic vehicle glazing (monolithic vitreous glass sheet) comprising a monolithic vitreous glass sheet 1 made of thermally tempered soda lime glass having a thickness of 3.85 a mm a. The vitreous glass plate 1 has an outer side surface I facing the outside environment in the installation position and an inner space side surface II facing the vehicle inner space in the installation position. The inner space side surface II is completely provided with an anti-reflection coating 20 according to the invention.

The anti-reflection coating 20 according to the invention reduces reflection on the inner space side surface II. It thus increases the light transmittance of the vehicle glazing and reduces reflections from the vehicle, for example, interfering with the vehicle occupants of the display device. The advantage of the anti-reflective coating 20 according to the invention is in particular that it has IR-reflecting properties in addition to anti-reflective properties. It therefore also acts as a sun protection coating and as a coating to reduce emissivity (low-E coating). Thus, not only is the transparency of the vehicle glazing improved, but also the thermal comfort in the vehicle is improved, with less intense heating of the interior space.

Both surfaces I, II of the monolithic vitreous glass plate are exposed, i.e., in contact with the atmosphere. They cannot be coated with conventional corrosion-prone (e.g., silver-based) IR reflective coatings. Since the anti-reflective coating 20 according to the invention with an additional IR reflecting effect is not prone to corrosion, such a coating is possible without problems.

Fig. 2 shows another embodiment of a vehicle glazing according to the invention. The vehicle glazing is designed as a composite glazing, wherein a vitreous glazing 1 acts as an inner glazing and is connected to an outer glazing 2 by a thermoplastic interlayer 3. In the installed position, the outer glass pane 2 faces the outside environment. In the installed position, the vitreous glass plate 1 faces the vehicle interior space. The outer glass plate 2 has an outer side surface I and an inner space side surface II. The vitreous glass plate 1 likewise has an outer side surface III and an inner space side surface IV. The vitreous glass plate 1 and the other glass plate 2 are constituted by, for example, soda lime glass having a thickness of 2.1 mm. The thermoplastic interlayer 3 is formed, for example, from a polyvinyl butyral (PVB) -based film having a thickness of 0.76 mm. The vehicle glazing is designed, for example, as a windshield of a passenger vehicle.

The inner space side surface IV of the vitreous glass plate 1 forms the exposed inner space side surface of the composite glass plate and has an anti-reflection coating 20 according to the invention.

Fig. 3 shows an embodiment of an anti-reflection coating 20 according to the invention on a vitreous glass plate 1. The coating 20 is disposed on the inner space side surface (on II in the case of a single sheet of vitreous glass, on IV in the case of a composite glass sheet). The coating 20 consists of a high refractive dielectric lower layer 21, a titanium nitride based IR reflecting layer 22, a high refractive dielectric upper layer 23 and a low refractive dielectric layer 24 arranged on the glass plate 1 in this order, which are arranged on the glass plate 1 starting from its surfaces II, IV.

Exemplary materials and layer thicknesses for such embodiments of the coating 20 according to the present invention can be found in table 1 (examples 1, 2, 4 and 5).

The anti-reflection effect of the coating 20 is mainly provided by a high refractive dielectric upper layer 23 and a low refractive dielectric layer 24. The high refractive dielectric underlayer 21 also has an effect. And the IR reflecting effect is provided by the IR reflecting layer 22 based on titanium nitride. In the case of the coating 20 according to the invention, only a small layer thickness is required compared to conventional antireflective coatings, so that its production is simplified, accelerated and more cost-effective.

Fig. 4 shows another embodiment of an anti-reflective coating 20 according to the invention on a vitreous glass plate 1. It differs from the embodiment of fig. 3 in that instead of a single high refractive dielectric underlayer 21, there is a high refractive dielectric underlayer sequence. The layer sequence consists of a first high refractive dielectric layer 21a and a second high refractive dielectric layer 21b, which are arranged in this order on the vitreous glass plate 1, starting from its surfaces II, IV.

The first layer 21a is an oxide layer having a particularly high refractive index, which is advantageous in terms of antireflective properties. The second layer 21b is a nitride layer and is in direct contact with the IR reflecting layer 22. The second layer 21b prevents the IR reflecting layer 22 from contacting the first layer 21a of oxide, which could lead to undesired oxidation of the metal-containing IR reflecting layer 22 when these layers are deposited or in a temperature treatment downstream in time.

Exemplary materials and layer thicknesses for such an embodiment of a coating 20 according to the present invention can be found in table 1 (embodiment 3).

Fig. 5 shows an exemplary embodiment of a method according to the invention for producing a vehicle glass pane having an antireflection coating 20 by means of a flow diagram.

Examples

Different vehicle glass panels according to the invention were prepared. They are designed as a single-piece vitreous glass plate and comprise a vitreous glass plate 1 made of soda lime glass, on the surface of which an anti-reflection coating 20 according to the invention is applied. The layer sequence, materials and layer thicknesses can be found in table 1.

TABLE 1

The vitreous glass plate 1 is formed partly of transparent soda lime glass (light transmittance TL 90% in the case of a thickness of 4 mm) and partly of heavily coloured soda lime glass (light transmittance TL 10% in the case of a thickness of 4 mm). The high refractive dielectric lower layer 21 or the high refractive dielectric lower layer sequence 21a, 21b and the high refractive dielectric upper layer 23 are each deposited by magnetic field assisted cathode sputtering. The IR reflecting layer 22 is deposited by high power pulsed magnetron sputtering. In embodiments 1-4, low refractive dielectric layer 24 is also deposited by magnetic field assisted cathode sputtering; in example 5, it was formed as a nanoporous sol-gel layer. The coated vitreous glass plates 1 were each subjected to a temperature treatment at a temperature of 640 ℃ for a period of 8 minutes. The refractive indices of the dielectric materials used are summarized in table 2.

TABLE 2

Material	SiN	TiO	SiO	Nanoporous SiO
					Refractive index	2.0	2.3	1.5	1.35

Some observations of the example glass sheets are summarized in table 3. Wherein the method comprises the steps of

TL (a) is the integrated light transmittance (light source type a) according to ISO 9050;

RL (a) is the integrated light reflectance measured at an incidence angle of 8 ° and an observation angle of 2 ° (light source type a) on the inner space side;

-a and b are values of internal space side reflection color in the color space of L x a x b x measured under the same conditions as RL;

epsilon is the internal space side standard emissivity at 283K according to standard EN 12898,

TTS is the total incident solar energy measured according to ISO 13837.

TABLE 3 Table 3

	TL(A)	RL(A)	a*	b*	ε	TTS
							Example 1	72.9%	3.9%	+0.2	-15.2	42%	67.0%
Example 2	70.6%	4.7%	-1.6	-19.4	34%	63.7%
							Example 3	71.7%	4.0%	+2.5	-25.5	30%	61.4%
Example 4	8.1%	3.3%	+4.7	-20.1	42%	25.1%
							Example 5	71.3%	1.8%	+0.7	+0.0	34%	64.0%

An uncoated comparative glass plate made of a 3.85mm thick transparent soda lime glass had a light transmittance TL (a) of 90% and an internal space side integrated reflectance RL of 8%. An uncoated comparative glass plate made of 3.85mm thick tinted soda lime glass had a transmission TL (a) of 10% and an internal space side integrated reflectance of 4%.

It can be clearly seen that the anti-reflection coating 20 according to the present invention significantly increases the light transmittance TL (a) and significantly reduces the total reflectance RL on the inner space side. In this case, example 3 with a dielectric lower layer sequence 21a, 21b having a particularly high refractive index due to the TiO layer 21a has proved to be particularly effective, so that a relatively thick IR reflecting layer 22 can be used here, which in turn reduces the light transmittance. Better thermal performance can be achieved by thicker IR reflecting layer 22.

Thermal performance is characterized by internal space side emissivity epsilon and TTS values. An uncoated comparative glass plate made of 3.85 mm thick transparent soda lime glass had an emissivity epsilon of 83.7% and a TTS value of 88%. An uncoated comparative glass plate made of 3.85 mm thick colored soda lime glass had an emissivity epsilon of 83.7% and a TTS value of 32.7%. The anti-reflective coating 20 according to the present invention can significantly reduce both values. Thus, the thermal comfort is improved by the vehicle glazing according to the invention-in summer the vehicle interior space is less warm, while in winter it is less strongly cooled.

It can also be seen that the low refractive dielectric layer 24 of example 5 formed as a sol-gel layer of nanoporous SiO yields more neutral color values a and b than the sputtered low refractive dielectric layer 24. The reason is that the reflection spectrum is smoother. The reflected color has less color distortion, as can be seen from the values of a and b, which are close to 0.

List of reference numerals:

(1) Vitreous glass plate

(2) Outer glass plate

(3) Thermoplastic interlayers

(20) Anti-reflective coating

(21) High refractive dielectric underlayer

(21a) First layer of dielectric lower layer sequence

(21b) Second layer of dielectric lower layer sequence

(22) Titanium nitride based IR reflecting layer

(23) High refractive medium upper layer

(24) Low refractive dielectric layer

(I) The outer side surface of the vitreous glass plate 1 in the case of a monolithic vitreous glass plate/the outer side surface of the outer glass plate 2 in the case of a composite glass plate

(II) inner space side surface of the vitreous glass plate 1 in the case of a single-sheet vitreous glass plate/inner space side surface of the outer glass plate 2 in the case of a composite glass plate

(III) the outside surface of the vitreous glass pane 1 in the case of a composite glass pane

(IV) inner space side surface of the vitreous glass plate 1 in the case of the composite glass plate.

Claims (16)

1. A vehicle glazing comprising

-at least one transparent vitreous glass sheet (1) having an outer side surface (I, III) and an inner space side surface (II, IV), wherein the inner space side surface (II, IV) of the vitreous glass sheet (1) forms an exposed inner space side surface of the vehicle glass sheet, and

an anti-reflection coating (20) on the inner space-side surfaces (II, IV) of the vitreous glass plate (1),

wherein the anti-reflection coating (20) comprises, starting from the vitreous glass plate (1), in the following order:

a high refractive dielectric underlayer (21) or layer sequence (21 a, 21 b) with a refractive index of more than 1.9,

an IR reflecting layer (22) based on titanium nitride,

-a high refractive dielectric upper layer (23) or layer sequence with a refractive index of more than 1.9, and

a low refractive dielectric layer (24) or layer sequence having a refractive index of less than 1.6,

wherein the IR reflecting layer (22) has a specific resistance of less than 100 μΩ cm.

2. The vehicle glazing panel according to claim 1, wherein the refractive index of the IR reflecting layer (22) is smaller than the refractive index of the low refractive dielectric layer (24) or layer sequence, and wherein the IR reflecting layer (22) preferably has a refractive index of 0.5 to 1.4 and an extinction coefficient of 1.0 to 5.0.

3. The vehicle glazing panel according to claim 1 or 2, wherein the IR reflecting layer (22) has a layer thickness of 10nm to 20 nm.

4. A vehicle glazing according to any of claims 1 to 3, wherein the high refractive dielectric lower layer (21) or layer sequence (21 a, 21 b) and the high refractive dielectric upper layer (23) or layer sequence independently of each other comprise or are formed of a layer based on silicon nitride (SiN), silicon-metal-mixed nitride or titanium oxide (TiO).

5. The vehicle glazing panel according to any of claims 1 to 4, wherein the high refractive dielectric lower layer sequence (21 a, 21 b) comprises, starting from the vitreous glazing panel (1), in the following order:

(a) A first layer (21 a) based on titanium oxide (TiO) and

(b) A second layer (21 b) based on silicon nitride (SiN) or silicon-metal-mixed nitride.

6. The vehicle glazing panel according to any of claims 1 to 5, wherein the low refractive dielectric layer (24) or layer sequence comprises or is formed of a silicon oxide (SiO) based layer.

7. The vehicle glazing panel of claim 6, wherein the low refractive layer (24) or layer sequence comprises or is formed from a sol-gel layer based on nanoporous silica.

8. The vehicle glazing panel according to any of the claims 1 to 7, wherein the high refractive dielectric underlayer (21) or layer sequence (21 a, 21 b) has an optical thickness of 20nm to 120 nm.

9. The vehicle glazing panel according to any of claims 1 to 8, wherein the high refractive dielectric upper layer (23) or layer sequence has an optical thickness of 40nm to 120 nm.

10. The vehicle glazing panel according to any of claims 1 to 9, wherein the low refractive dielectric layer (24) or layer sequence has an optical thickness of 40nm to 130 nm.

11. Vehicle glazing according to any of claims 1 to 10, designed as a composite glazing, wherein the vitreous glazing (1) is connected to the outer glazing (2) by a thermoplastic interlayer (3).

12. The vehicle glazing panel according to any of claims 1 to 10, designed as a monolithic vitreous glazing panel.

13. Method for producing a vehicle glazing, wherein

(a) Providing a transparent vitreous glass plate (1) having an outer side surface (I, III) and an inner space side surface (II, IV), wherein the inner space side surface (II, IV) of the vitreous glass plate (1) provides an exposed inner space side surface for forming the vehicle glass plate,

(b) An anti-reflection coating (20) is applied to the inner space side surfaces (II, IV) of the vitreous glass plate (1), wherein the following sequence is deposited:

a high refractive dielectric underlayer (21) or layer sequence (21 a, 21 b) with a refractive index of more than 1.9,

an IR reflecting layer (22) based on titanium nitride,

-a high refractive dielectric upper layer (23) or layer sequence with a refractive index of more than 1.9, and

-a low refractive layer (24) or layer sequence having a refractive index of less than 1.6.

14. The method of claim 13, wherein the IR reflecting layer (22) is deposited by high power pulsed magnetron sputtering (HiPIMS).

15. The method according to claim 13 or 14, wherein the low refractive layer (24) or layer sequence is a nanoporous layer produced by a sol-gel process.

16. Use of a vehicle glazing panel according to any of the claims 1 to 12 as a glazing for a land, water or air vehicle, in particular a motor vehicle or rail vehicle, preferably as a side glazing, rear glazing, windscreen or sunroof glazing.

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