Plate-like glass or glass-ceramic element, and production method and use thereof

Abstract

To provide a plate-like glass or glass-ceramic element, in particular a glass or glass-ceramic element which can be used in home electric appliances and / or heating devices, and a method of producing the same.SOLUTION: A plate-like glass or glass-ceramic element 1 comprises: a plate-like glass or glass-ceramic substrate 10; and a coating 2 arranged at least partially on at least one main surface 11, 12 of the glass or glass-ceramic substrate. The coating contains a metal component and a semi-metal component, the glass or glass-ceramic substrate is formed transparent, the coating has a surface resistance of more than 1 MΩ, and the glass or glass-ceramic element has a light transmittance τvis of 0.5% to 10%, preferably 0.5% to 5%, at least in a region 101 in which the coating is arranged.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to plate-shaped glass or glass-ceramic elements, particularly glass or glass-ceramic elements that can be used in household appliances and / or heating appliances. In particular, the present invention relates to a plate-shaped glass or glass-ceramic element comprising a plate-shaped glass or glass-ceramic substrate and a coating that is at least partially disposed on at least one side of the substrate. A further aspect of the present invention relates to a method for manufacturing such glass or ceramic elements and their use.

[0002] Background of the Invention The plate-shaped glass or glass-ceramic element is used, for example, as a cover plate or partition plate for high-temperature applications, as a so-called cooktop plate, or as a viewing window for the flat or curved surface of an oven. In this case, it is necessary to adjust the transmissivity of electromagnetic radiation passing through the plate-shaped glass or glass-ceramic element as precisely as possible. For example, it may be necessary to enable high transmissivity in a specific wavelength range, for example in the infrared region, so that thermal radiation can pass through the glass or glass-ceramic element as unhindered as possible. However, it may also be necessary that the transmissivity is not too high. This is particularly relevant for the visible light region. In the visible light region, it is often necessary to produce the desired shading for the area behind the glass or glass-ceramic element as seen by the operator or user of the device. In that case, particularly for safety reasons, the glass or glass-ceramic element should provide a homogeneous, particularly so-called "dead front effect" when the device equipped with such a glass or glass-ceramic element is in the switched-off state, and in the switched-on state, electro-optical display elements such as displays or warning lights should be clearly visible in their original color tone through the element. This can significantly improve the safety of the users of such devices in particular.

[0003] For example, there are known glass-ceramic plates that contain glass-ceramic with a deep, almost black color that gives a sense of weight and richness when viewed from above.

[0004] Furthermore, the glass or glass-ceramic element may include a transparent glass or glass-ceramic substrate having a shading coating on the main surface of a plate-shaped glass or glass-ceramic substrate. For example, German Patent Application Publication No. 102007030503 relates to a coated glass-ceramic product in which the coating is designed to be reflective and have a light-shielding effect. For this purpose, a silicon coating is applied to the glass-ceramic plate. The layer thickness differs between high-temperature and low-temperature regions, with the high-temperature layer being thicker than the low-temperature layer. Such measures are necessary because, with a thin layer, the transmittance in the visible light region is sufficiently high, for example, the display element would be easily visible through this thin layer, and the temperature stability would be insufficient. On the other hand, a thicker layer, such as the one used in the high-temperature region in German Patent Application Publication No. 102007030503, certainly has high temperature stability, but at the same time, the transmittance in the visible light region is insufficient. So-called display functions can only be provided to a limited extent with these layers. Therefore, the glass-ceramic plate described in German Patent Application Publication No. 102007030503 is not suitable for the novel design of cooking appliances (so-called "cook anywhere" appliances) that allow for the complete and flexible separation of, for example, a display element on the one hand and a high-temperature area on the other.

[0005] German Patent Application Publication No. 102013104702 also relates to a coated glass-ceramic plate. The coating of the glass-ceramic cook plate described in German Patent Application Publication No. 102013104702 is a multilayer coating comprising a metallic layer of an alloy containing chromium, iron, nickel, and silicon, and a barrier layer in the form of an oxide of the alloy containing chromium, iron, nickel, and silicon. These layers have the advantage of combining metallic, mirror-like elegance with high heat resistance. While this coating can certainly be adjusted to be semi-transparent by selecting the appropriate layer thickness, it is not touch-sensitive and has insufficient IR transmittance.

[0006] The layer described in German Patent Application Publication No. 102013104702 is conductive due to its metallic properties. Therefore, so-called capacitive touch sensors cannot be used with this coating. Consequently, these layers are either not compatible with touch operation or are only compatible with touch operation within a very limited range.

[0007] Therefore, there is a need for glass or glass-ceramic elements that possess metallic elegance, high heat resistance, and at the same time, flexible touch and display functions.

[0008] Problems of the invention The object of the present invention is to provide a glass or glass-ceramic element that at least partially mitigates the weaknesses of the prior art. Further aspects of the present invention relate to a method for manufacturing such glass and glass-ceramic elements and the use of such elements.

[0009] Summary of the Invention The problems of the present invention are solved by the subject matter of the independent claims. Preferred and special embodiments, as well as further embodiments, can be found in the dependent claims, specification and drawings of this disclosure.

[0010] Accordingly, this disclosure relates to a plate-shaped glass or glass-ceramic element comprising a plate-shaped glass or glass-ceramic substrate and a coating at least partially disposed on at least one main surface of the glass or glass-ceramic substrate. The coating comprises a metallic component and a semimetallic component and has a surface resistance greater than 1 MΩ. The glass or glass-ceramic substrate is formed to be transparent. The glass or glass-ceramic element has a light transmittance τ of 0.5% to 10%, preferably 0.5% to 5%, at least in the region where the coating is disposed. vis It has.

[0011] In this disclosure, light transmittance refers to the transmittance in the wavelength range of 380 nm to 780 nm, as calculated and defined in accordance with, for example, DIN EN 410. vis It is sometimes written as such. This usually refers to the standard light source D65.

[0012] Spectral transmittance refers to the transmittance value for a given wavelength.

[0013] Such designs of glass or glass-ceramic elements are particularly advantageous for use in household electrical appliances and / or heating appliances.

[0014] The glass or glass-ceramic substrate itself is formed to be transparent. Forming the glass or glass-ceramic substrate to be transparent means, in particular, that the glass or glass-ceramic substrate has a visible light transmittance of at least 20%, preferably at least 40% τ. visThis means having (or light transmittance). It is also possible to have a higher value, for example, at least 80%. Such transmittance can be achieved, for example, by the glass or glass-ceramic substrate being uncolored, or by limiting the proportion of absorbing components, such as coloring ions, in the glass or glass-ceramic substrate. However, the transparency of the glass or glass-ceramic substrate can also be reduced by scattering, in addition to or instead of coloration by absorption. The stronger the scattering, the lower the transparency. Therefore, in this disclosure, a transparent glass or glass-ceramic substrate also means a glass or glass-ceramic substrate that is low turbidity.

[0015] In particular, it is possible for the glass or glass-ceramic substrate to be uncolored by absorption and, at the same time, to have low turbidity.

[0016] Thus, the glass or glass-ceramic substrate itself is very well suited to allowing the observer or operator to fully perceive display elements, such as displays and lighting, that are located behind the glass or glass-ceramic substrate. However, a drawback is that this also makes other components that may interfere with the perception of displays that are, for example, safety-critical, visible. Therefore, it is generally advantageous to apply a coating to the glass or glass-ceramic substrate, at least partially, so that the problematic components are correspondingly shaded, at least in the area where the coating is applied. Thus, the coating in the embodiment also means, or can be called, a light-shielding coating.

[0017] Therefore, glass or glass-ceramic elements can include, for example, uncoated portions or regions without coating.

[0018] However, this is not essential in the glass or glass-ceramic elements according to the embodiments. Known plate-shaped glass or glass-ceramic elements with shading or light-blocking coatings often require the omission of part of the coating. This is because such light-blocking coatings produce almost complete shading, making it impossible to see the display element and / or illumination through the coating. As a result, it becomes necessary to apply a further coating, formed semi-transparently, to this uncoated area as appropriate. Therefore, the manufacture of such glass or glass-ceramic elements involves different coating steps using different coating agents and coating materials, such as applying a special semi-transparent screen-printing paste to areas without a light-blocking coating, and this incurs corresponding costs.

[0019] In the case of coating according to the embodiment, this is unnecessary. This is because, at least in the area where the coating is applied, the glass or glass ceramic element has a light transmittance of 0.5% to 10%, preferably 0.5% to 5%, relative to a thickness of 4 mm of the glass or glass ceramic substrate. vis This is because the coating is formed to have such a light transmittance. This transmittance allows for sufficient shading while ensuring that observers or users of devices equipped with such glass or glass-ceramic elements, such as household appliances and / or heating appliances, can clearly perceive the display elements. At the same time, this also enables a very homogeneous elegance of the glass or glass-ceramic elements, especially when household appliances and / or heating appliances are switched off. This is because the application of further coatings, which may impair the homogeneous and uniform impression of the uncoated areas and / or glass or glass-ceramic elements, is no longer necessary.

[0020] Accordingly, according to one embodiment, the coating is applied to substantially the entire surface of at least one main surface of the glass or glass-ceramic substrate. This specifically means that the coating covers at least 90%, preferably at least 95%, of the at least one main surface. In particular, the coating may also cover 100% of the at least one main surface. Thus, according to one embodiment, the glass or glass-ceramic element is formed in a very simple manner and very advantageously to combine an aesthetically pleasing, highly homogeneous appearance with improved operator safety. This highly homogeneous and visually uniform appearance is also called a "dead front," and the resulting aesthetically pleasing, highly homogeneous and visually uniform appearance is also called the "dead front effect."

[0021] Another reason this is possible is that the coating is designed to have a surface resistance of over 1 MΩ, without being limited to the coverage of at least one main surface. This is because lowering the conductivity of the coating in this way allows for the use of capacitive touch sensors. In other words, this coating design is a crucial prerequisite for making the coating touch-operable.

[0022] Two criteria are important for the functionality of capacitive touch sensors, and specifically for the design of the coating as a touch-operable coating. First, two adjacent individual buttons must not be capacitively short-circuited, allowing them to be read separately. This is important not only for individual buttons that are adjacent to each other and store different switching functions, but also for sliding switches (sliders) composed of individual buttons. Capacitive short circuits can be caused by capacitive or electrically coupled conductive layers covering both switching surfaces (sensor surfaces) of individual buttons.

[0023] Secondly, it is necessary to prevent the interfering ground signal caused by capacitive coupling to the ground environment, known as stray capacitance, from becoming too large in individual switches. This undesirable effect can be amplified when the conductive layer is capacitively coupled to the switching surface of each button. This increases the effective switching area of ​​each button and strengthens the coupling to the ground environment (e.g., room air). This could cause the individual button to operate continuously and become unusable for switching. All of these undesirable effects can be avoided in combination with a conductive layer, at least in a typical capacitive control interface, when the surface resistance of the layer is greater than 1 MΩ, preferably greater than 5 MΩ, and especially preferably greater than 10 MΩ or more.

[0024] The higher the surface resistance, the closer the individual buttons can be placed next to each other. At the same time, increased surface resistance improves operational safety. Higher surface resistance reduces coupling with stray capacitance, resulting in higher detection sensitivity and a lower probability of false detection of sensor input.

[0025] There is no need to adjust the coating properties of a given area. In particular, there is no need to adjust the thickness of the coating layer in a given area of ​​the glass or glass-ceramic element to obtain a special "display area" or "sensor area." By designing the glass or glass-ceramic area as described in claim 1, a homogeneous coating that functions even in applications where high-temperature areas, display elements, and sensors are flexibly positioned, such as in so-called "cook anywhere" cooking appliances, can be applied with surprising ease.

[0026] Suitable sensors include, for example, the touch sensors (capacitive touch sensors or touch sensors) already mentioned. Sensors are also often installed on the underside or underside of the cover plates of household electrical appliances and / or heating devices, such as cooking appliances. Therefore, the coating must be transparent to these sensors, and these sensors typically emit light in the near-infrared region. The main types of sensors used are those for control and communication, such as communication with ventilation hoods in the case of cooking appliances, and temperature sensors.

[0027] In this disclosure, the following definitions apply: A plate-like article or product generally means that the article or product has a shape in which its transverse dimension in a first spatial direction of a Cartesian coordinate system is at most one-fifth of its transverse dimension in two further spatial directions of a Cartesian coordinate system perpendicular to the first spatial direction. In other words, the thickness of a plate-like article (or plate glass, plate, or strip) is at most one-fifth of its length and width. A plate-like article, such as a plate-like element, may be planar, i.e., flat, or it may be curved, such as a curved or curved plate glass. Furthermore, a plate or plate glass may generally have an uncoated portion, for example, for a feedthrough for mechanical rotation control, or especially for a conduit for a gas burner in a ventilation hood, if the plate-like article, plate-like element, or plate is used as a stove. In this disclosure, the terms plate glass and plate are used synonymously. In particular, plate-like design may also refer to plate glass-like design.

[0028] Furthermore, while it is generally possible for plate-shaped articles or elements to be designed such that the surface on which the coating is applied is smooth, it is also generally possible for this surface to have a raised shape. This may be the case, for example, particularly when the plate-shaped element is suitable for or intended to be used as a cook plate and contains or is formed from, for example, glass ceramic. However, designs with raised surfaces on the surface on which the coating is applied are not limited to plate-shaped elements that are suitable for and / or intended to be used as cook plates, but may also exist in other plate-shaped elements for other purposes or applications.

[0029] A base material refers to an uncoated article. An element includes both a base material and a coating. An element may also refer to a coated base material, in which case, the base material may correspondingly refer to an uncoated element.

[0030] In this invention, when referring to the thickness of a glass or glass-ceramic element, this generally means the thickness of the glass or glass-ceramic substrate. This is because the coating deposited on the glass or glass-ceramic substrate to obtain the glass or glass-ceramic element is very thin, at most a few micrometers or less, and therefore, from the viewpoint of measurement accuracy, the thickness of the element coincides with the thickness of the substrate.

[0031] In this invention, the main surface of a plate-like article, such as an element or substrate, refers to the surface that together accounts for more than 50% of the total surface area of ​​the article. The main surface is sometimes simply called a surface, and depending on the precise spatial arrangement, it may be called the front or back surface, or the top or bottom surface of a plate of glass or a plate. Therefore, the main surface is not, for example, the edge surface of a plate of glass or a plate-like article or product. The main surfaces may be arranged parallel to each other. Here, parallel arrangement means an arrangement in which the normals of the main surfaces form an angle of up to 5° with respect to each other.

[0032] In this invention, the formation of a metallic coating means that the coating contains nonmetals in a limited range, particularly that the nonmetal content in the coating is less than 4% by weight. Thus, metallic formation is in contrast to nonmetal formation, where the coating contains at least 4% by weight, preferably more than 4% by weight, and particularly more than 10% by weight of nonmetals. In particular, nonmetal formation means, and may also be called, formation in ceramic or partial ceramic, and for example, the coating material may be an oxide and / or nitride.

[0033] In this specification, elements that have properties intermediate between metals and nonmetals are called metalloids. In this specification, the group of metalloids includes: boron, silicon, germanium, arsenic, antimony, bismuth, selenium, tellurium, and polonium. Metalloid components mean components that contain metalloids. In particular, metalloid components include silicon and / or germanium.

[0034] A touch-sensitive coating specifically means that the coating has a sufficiently high surface resistance of over 1 MΩ.

[0035] According to one embodiment, the coating is formed to be reflective. In other words, the coating is designed to reflect electromagnetic radiation in the visible light region, i.e., in the range of 380 nm to 780 nm. According to one embodiment, the coating can have a specular effect, i.e., it can produce a metallic elegance. In particular, such a reflective structure can advantageously contribute to making the overall impression of the glass or glass-ceramic element very homogeneous, which can be especially important from a safety standpoint. This is because, in this way, deviations from the normal state of household appliances and / or heating appliances equipped with such glass or glass-ceramic elements can be very easily perceived, for example, by a visual indicator that flashes in the event of a malfunction, because such a visual indicator is visually very conspicuous in the overall impression of the element being generally homogeneous.

[0036] For example, the reflective properties of coatings, such as coatings according to the embodiments, generally depend on the precise design of the surface to which the coating is applied. For example, generally, the smoother the substrate surface, the higher the reflectivity. Here, for example, a coating that has the following reflective properties when applied to a substrate having a smooth surface is also understood to be reflective in the spirit of this disclosure: an average reflectivity in the visible spectral region, i.e., 380 nm to 780 nm, is achieved at 10% to 30% for coatings according to embodiments formed as a single layer, or at 20% to 70% for coatings according to embodiments formed as a multilayer system, particularly including three layers. These values ​​are particularly achieved in embodiments where the substrate is formed smoothly, i.e., unstructured, for example, without any raised areas or roughening. In particular, a substrate surface obtained by rolling with an unstructured roll is also understood to be smooth. In particular, roughness, especially roughness R a A substrate surface with a thickness of less than 1 μm can also be understood as an unstructured or smooth substrate surface.

[0037] On structured substrate surfaces, the reflectance value or reflectance level is lower, and in directional measurements, it is 2% to 20% in the visible spectral region, and the roughness R a The size is between 1 μm and 5 μm.

[0038] In other words, the glass or glass-ceramic element according to this embodiment may be designed such that the coating is formed to be reflective. Here, a coating is understood to be reflective, or referred to as reflective, if the glass or glass-ceramic element has the following reflective properties in at least one region: - The average reflectance in the visible spectral region, i.e., 380 nm to 780 nm, is 10% to 30%, which is achieved in particular for coatings formed as a single layer, or - The average reflectance in the visible spectral region, i.e., 380 nm to 780 nm, is 20% to 70%, which is achieved in particular for coatings formed as layered systems, especially those comprising at least three sublayers. In particular, these aforementioned values ​​are achieved when the glass or glass-ceramic element is formed to be smooth on the main surface or surface on which the coating is applied, and here in particular the main surface or surface of the plate obtained by rolling with unstructured rolls, e.g., the top or bottom surface, and / or roughness, especially roughness R a A main surface (or surface, such as the top or bottom surface) with a thickness of less than 1 μm is also understood to be smooth. Alternatively, the main surface or surface on which the coating is placed has a roughness of 1 μm to 5 μm and is preferably structured, and in this region the glass or glass ceramic element has an average reflectance of at least 2% to a maximum of 20% in the visible spectral region, i.e., 380 nm to 780 nm, or Glossiness, preferably glossiness measured using a Rhopoint Qs gloss meter, is at least 87 GU, preferably at least 100 GU, at a measuring angle of 20°, at least 93 GU, preferably at least 100 GU, at a measuring angle of 60°, and at least 97 GU, at a measuring angle of 85°, and the main surface or surface on which the coating is placed has a roughness of 1 μm to 5 μm, particularly roughness R a It has, and preferably is structured, or Glossiness, preferably the glossiness measured using a glossmeter Rhopoint Qs, particularly at a measurement angle of 20° is at least 500 GU, preferably at least 700 GU, particularly preferably at a measurement angle of 60° is at least 200 GU, preferably at least 250 GU, particularly preferably at least 270 GU, very particularly preferably at least 300 GU, and particularly preferably at a measurement angle of 85° is at least 99 GU. In particular, these values described above are achieved when the glass or glass-ceramic element is formed to be smooth on the main surface or surface where the coating is disposed. Herein particularly, the main surface or surface of the plate obtained by rolling using an unstructured roll, for example, the upper surface or the lower surface, and / or the roughness, particularly the roughness R a is understood to be smooth for a main surface (or surface, for example, the upper surface or the lower surface) having a value of less than 1 μm.

[0039] The average reflectance means the arithmetic mean of the reflectance values in a certain wavelength range.

[0040] Unless explicitly stated otherwise, in this disclosure, the reflectance measurement is performed on the visible surface or the operator surface of a plate-shaped glass or glass-ceramic element. That is, the measured value of the reflectance measurement relates to the visible surface or the operator surface. Therefore, the reflectance measurement is always performed through the substrate, that is, through the glass-ceramic material or the glass material. This is because the coating is always disposed on the "operating back surface / back surface / lower surface".

[0041] Here, the glossiness is defined in so-called gloss units GU (GU, gloss units). Using the above-described measuring instrument, particularly the measurement of the glossiness can be performed in accordance with the relevant international standards.

[0042] The obtained glossiness value depends, for example, on whether the region is structured or not. An example of the measured value is shown in the following table:

Table 1

[0043] During the measurements, each sample was placed on a black underlay. The measurements were performed through a glass or glass-ceramic element.

[0044] Here, sample number 1 is a glass element, and the coating is a four-layer coating including a silicon nitride layer. The main surface of the coating area, i.e., the measurement area, is structured. The visual impression of the coating when viewed through the glass substrate is grayish-silver.

[0045] Sample No. 2 is also a glass element, and the coating is a two-layer coating including a silicon nitride layer. The main surface of the coating area, i.e., the measurement area, is structured. In this case as well, the visual impression of the coating when viewed through the glass substrate is grayish-silver.

[0046] In Comparative Example 1 or Reference Example 1, a glass substrate or element that does not contain a coating but is structured within the measurement area is measured.

[0047] Samples 3 through 5 are glass-ceramic elements in which the main surface or surface within the coating region, i.e., the measurement region, is unstructured, i.e., smooth.

[0048] Sample number 3 is a four-layer coating containing SiO2, and when viewed from above, i.e., through the glass ceramic, the visual impression of this coating is silver.

[0049] Sample number 4 is a four-layer coating including a silicon nitride layer, and similarly appears silvery when viewed through glass ceramic.

[0050] Finally, sample number 5 is a two-layer coating including a silicon nitride layer, and in this case as well, the visual impression when viewed through the glass ceramic is silver.

[0051] Comparative Example 2, or Reference Example 2, is an uncoated glass-ceramic substrate.

[0052] However, the visual impression when looking at the coating itself can be completely different from these impressions, and in samples 1, 2, 4, and 5, the coating is formed to appear gold when viewed directly.

[0053] Measurements show that the coating increases gloss in at least one area of ​​the substrate or element compared to the uncoated substrate, particularly at viewing angles of 20° and 60°. This is especially noticeable when the surface is smooth in at least one area, as exemplified in samples 3–5.

[0054] The classification of glass grades by angle is as follows: 20 degrees: 0~2000GU (where 0 is completely matte and 2000 is perfectly mirror-like) 60 degrees: 0~1000GU (where 0 is completely matte and 1000 is perfectly mirror-like) 85 degrees: 0~199GU (where 0 is completely matte and 199 is perfectly mirror-like)

[0055] In other words, the above measurements show that, especially when the main surface of the substrate is smooth, a surface with very high specularity can be obtained in at least one area. Therefore, the coating is formed in this area to be almost metallic specular, or to have a so-called "metallic elegance" with sufficient opacity, a preferably neutral color impression in reflection (often called "silver"), and overall high reflectivity.

[0056] However, even if the main surface in at least one area where the coating is applied has a structured structure, a metallic elegance can be obtained, i.e., an impression similar to that obtained from stainless steel surfaces such as control panels or other surfaces, for example, stainless steel cover elements. Such structuring can produce the impression of a brushed metal surface, particularly brushed stainless steel.

[0057] Therefore, such elements are particularly desirable in order to achieve a uniform and elegant working environment. This is because, for example, a cover plate can be obtained that is visually almost inconspicuous or virtually indistinguishable from a normal metal surface.

[0058] This is illustrated in the photographic diagram of Figure 10 in the drawings. This shows a photograph of a glass element, observed through a glass substrate. The coating has uncoated areas, which are the dark areas in the lower right region of the photographic image. Here, a striped pattern extending from right to left is obtained, which appears in the photographic image as a local difference in the brightness of the coating. However, the overall metallic properties of the optical elegance are clearly recognizable.

[0059] Therefore, surprisingly, according to this disclosure, a cover plate can be obtained that is both reflective and touch-operable. Thus, this cover plate exhibits a metallic effect without the metallic properties of the coating, particularly high conductivity, which would be disadvantageous in the applications dealt with in this invention.

[0060] According to one embodiment, the glass or glass ceramic element is CIEL in at least the region where the coating is placed. * a * b * A chromaticity point in the system, L * is greater than 55, a * , b *The chromaticity point is in the range of -12 to +12, preferably -10 to +10, and particularly preferably -5 to +5. The chromaticity point is preferably measurable or measurable in a chromaticity measurement using a colorimeter, in which case the coating is located on the main surface of the glass or glass-ceramic substrate opposite to the colorimeter. If an additional coating is located on the surface of the element opposite to the coated surface, it is possible to remove this before measurement, for example by polishing or laser ablation, so that the coating is located on the main surface of the glass or glass-ceramic substrate opposite to the colorimeter for measurement. In particular, such a polishing process usually has no effect or at best negligible effect on the measurement result of the chromaticity point of the coating. Preferably, L * The value is greater than 60, preferably greater than 62. In this application, the chromaticity value or chromaticity point is generally measured against a black trap, and particularly preferably using a Konica-Minolta CM-700d spectrophotometer.

[0061] Therefore, according to this embodiment, the coating is formed as a reflective coating having a neutral chromaticity point in transmission. A neutral chromaticity point in transmission is particularly advantageous because it makes it possible to perceive the display elements and / or light-emitting elements through the coating in their original colors as much as possible. For example, chromaticity value a * , b * If each of them is in the range of -30 to +30, a neutral chromaticity point in transmission can already be given. For example, for a coating formed as a single layer, a * is 108 and b * A value of 22.4 can be achieved, and for a coating formed as a layer system (especially a layer system including at least three sublayers), a * is 46 and b * A value of 8.1 can be achieved with these chromaticity values ​​a * , b * This allows for a neutral chromaticity point in transmission.

[0062] Therefore, depending on the precise design of the coating and / or elements, it is possible to set a light color impression. For example, L significantly greater than 55 or 60, or 62. * You can obtain the value.

[0063] According to one embodiment, the coating has a thickness of less than 1000 nm, for example, less than 500 nm, or even less than 200 nm. A large coating thickness is undesirable because it can lead to cracking and delamination of the coating. Also, for manufacturing reasons, it may be desirable to select the smallest possible thickness. This is because, for example, in a PVD process, a thinner coating can be deposited in a shorter time than a thicker coating. Furthermore, if the coating thickness (or layer thickness) is very large, exceeding 1000 nm, it may be undesirable because the transmittance is too low.

[0064] However, to guarantee the shading effect of the coating, it may be advantageous to set the minimum thickness of the coating to preferably at least 20 nm. While this minimum layer thickness is preferably 20 nm, this value may vary depending on the exact composition of the coating. For example, a coating formed purely of metal can already produce sufficient shading with a smaller layer thickness than a coating formed in a certain non-metallic (or ceramic) form.

[0065] One of the special advantages of glass or glass-ceramic elements is that the coating is suitable for both so-called high-temperature regions and so-called low-temperature regions or display regions. It is not necessary to specifically adjust the thickness of the coating depending on whether the corresponding region of the glass or glass-ceramic element is used as a high-temperature region or a low-temperature region or display region. Therefore, in particular, according to one embodiment, the coating is provided to have a constant thickness.

[0066] A constant thickness here means that the thickness of the coating in at least one region of the glass or glass-ceramic element on which the coating is applied varies by up to 40%, preferably up to 20%, particularly preferably up to 10%, and very particularly preferably up to 5%, relative to the average thickness of the coating in that region. The average thickness is defined as the average value of the maximum thickness and the minimum thickness of the coating.

[0067] Furthermore, a special advantage of the coating is provided by the fact that the coating can be designed to be touch-operable on the one hand and reflective at the other hand. Therefore, according to one embodiment, the coating is designed to be both touch-operable and reflective. In particular, according to this embodiment, the coating is CIEL * a * b * A chromaticity point in the system, L * The chromaticity point may be formed to have a value greater than 55, preferably greater than 60, particularly preferably greater than 62, and even greater than that. In particular, the coating according to this embodiment enables the design of light-colored specular reflectivity, and at the same time, the glass or glass-ceramic element is touch-operable even in the area where the coating is applied.

[0068] Reflectance values ​​and / or chromaticity values ​​of coatings or plate-shaped glass or glass-ceramic elements according to embodiments, particularly L * Such designs for coatings or plate-shaped glass or glass-ceramic elements that possess both reflectivity and touch functionality were previously impossible. Such high reflectivity values, as obtained for unstructured substrates or surfaces, were previously only possible with pure metal coatings, but these coatings are conductive and therefore not designed to allow touch operation.

[0069] According to one embodiment of the coating, the coating, or at least a portion of the coating, particularly if the coating is formed as a layer system rather than a single layer, for example, including three layers, the lower layer or partial layer, is designed to have an absorption coefficient k greater than 0.1 at a wavelength of 550 nm. A large value of k is advantageous, and k may be, for example, greater than 1, for example, about 2, or even greater than 2. The refractive index n at 550 nm may be, for example, greater than 2. For example, in a coating formed of metal, it is advantageous when n at 550 nm is less than 2 and k is greater than 2. According to embodiments of non-metallic or (partially) ceramic coatings, it may be advantageous when n at 550 nm is greater than 2 and k is greater than 0.1 and less than 3. In such cases, it is advantageous to obtain a coating that is both absorbent and has high surface resistance, so that a glass or glass-ceramic element with an adjustable light transmittance of 0.5% to 5% is obtained, at least in the region where the coating is applied.

[0070] In further embodiments, the coating contains less than 10% by weight of hydrogen, preferably less than 5% by weight, and particularly preferably less than 2% by weight. This is advantageous because hydrogen generally reduces the heat resistance of the coating. Therefore, the hydrogen content of the coating should be limited, and as mentioned above, it is preferably less than 10% by weight. Therefore, preferably, no intentional addition of hydrogen is performed.

[0071] Further aspects of this disclosure also relate to glass or glass-ceramic elements, preferably to a method for manufacturing glass or glass-ceramic elements according to one embodiment of this disclosure. - A step of providing a transparent, plate-shaped glass or glass-ceramic substrate, - A step of introducing a glass or glass-ceramic substrate into a coating chamber, - A step of providing a target containing at least one semimetallic component and / or at least one metallic component in a coating chamber, - Adjust the pressure inside the coating chamber, ensuring the pressure is at least 5 × 10⁻⁶. -4 mbar ~ Maximum 5 x 10 -2 The step of assuming that it is mbar, - The coating is performed by sputtering, and the sputtering can be performed as DC sputtering or AC sputtering, for example, medium frequency sputtering or high frequency sputtering. This includes a plate-shaped glass or glass-ceramic substrate and a coating at least partially disposed on at least one main surface of the glass or glass-ceramic substrate, thereby providing a plate-shaped glass or glass-ceramic element. Here, the coating comprises a metallic component and a semimetallic component and has a surface resistance of more than 1 MΩ, and the glass or glass ceramic element has a light transmittance of 0.5% to 10%, preferably 0.5% to 5%, of a thickness of 4 mm of the glass or glass ceramic substrate, at least in the region where the coating is applied. vis It has.

[0072] In general, glass or glass-ceramic substrates may already have at least one coating before carrying out this method, i.e., they may have a coating on the top or bottom surface in the form of so-called cooking zone markings. However, it is also possible to apply another coating, or possibly even more, coatings only after sputtering.

[0073] According to this method, at least one target is provided within the coating chamber. For example, it is possible to provide only one target containing at least one semimetallic component and at least one metallic component. However, it is also possible to provide a target containing a semimetallic component and another target containing a metallic component. This is the case, for example, in so-called simultaneous sputtering.

[0074] A coating according to one embodiment may be formed as a metallic coating containing only aluminum and silicon, excluding unavoidable impurities, and can be manufactured, for example, by a so-called simultaneous sputtering process. In this process, a pure aluminum target is provided in the first magnetron and a silicon target in the second magnetron, and for technical reasons to facilitate sputtering, these targets may contain a certain amount of aluminum, for example, up to 20 wt% aluminum stabilizer. The two targets are positioned relative to each other such that the main directions of the sputtering globules are directed toward one plane of the substrate. In this plane, a tuned composition of the coating obtained according to selected process parameters is expected, however, on the substrate surface, it is shifted toward either aluminum or silicon. The sputtering process is operated such that the sputtering power to the aluminum target is approximately twice the power to the silicon target.

[0075] By adding reactive gases, compositions with a higher aluminum content than, for example, a coating formed from metal can be obtained. For instance, in this case, a composition with an aluminum-to-silicon ratio of 1:1 (by weight) can be obtained. If the proportion of aluminum in the coating is too high, the stabilizing properties of silicon may negatively impact the heat resistance and / or chemical resistance of the coating. The challenge in the manufacture of so-called (partially) ceramic coatings lies particularly in establishing and further controlling the correct operating point. This specifically concerns establishing the correct partial pressure of the reactive gases. Here, it is necessary to adjust the operating point located in the metallic portion of the so-called S-curve of reactive sputtering. This point can be stably established and maintained by controlling the reactive gases and using a partially ceramicized target, in which case a predetermined amount of residual gas in the apparatus is absolutely necessary. The aim of this particular operating point is to establish an absorbent, non-stoichiometric coating that has the highest possible surface resistance while retaining as much of its metallic properties as possible with respect to optical impression. Such a coating can also be described, for example, as having an absorption coefficient k of at least 0.1 at a wavelength of 550 nm and / or a refractive index of 2 or more at a wavelength of 550 nm.

[0076] Furthermore, the disclosure also relates to glass or glass-ceramic elements, and more particularly to glass or glass-ceramic elements according to embodiments of the disclosure, which are manufactured or at least can be manufactured by the methods of the disclosure.

[0077] Further aspects of the present disclosure also relate to the use of glass or glass-ceramic elements, in particular glass or glass-ceramic elements manufactured or at least manufacturable by the embodiments and / or by the methods of the embodiments of the present disclosure, for example, as cover plates for household appliances and / or heating appliances, in particular as cover plates for cooking appliances, in particular gas or induction cooking appliances, or as oven windows, or fireplace viewing windows, or refrigerator viewing windows, or microwave viewing windows, or operating elements, in particular operating elements for coffee machines, or oven front windows, or as tops for kitchen or laboratory equipment such as shelves or tables, or as operating surfaces for home appliances such as smartphones. [Brief explanation of the drawing]

[0078] [Figure 1] Schematic side view of glass or glass-ceramic element 1. [Figure 2] Top view of glass or glass-ceramic element 1. [Figure 3] A schematic perspective view of glass or glass-ceramic element 1. [Figure 4] A schematic side view of a glass or glass-ceramic element 1 including an additional coating 3. [Figure 5] Schematic cross-sectional view of glass or glass-ceramic element 1. [Figure 6] A figure showing a further embodiment of the glass or glass-ceramic element 1. [Figure 7] A diagram showing an exemplary household electrical appliance and / or heating appliance 60. [Figure 8] A diagram showing a glass or glass-ceramic element 1 including a sensor 80. [Figure 9] A diagram showing a further preferred embodiment of the glass or glass-ceramic element 1. [Figure 10] A diagram showing a photograph of a glass element. [Figure 11] A diagram showing the refractive index value n of glass or glass-ceramic elements. [Figure 12] A diagram showing the absorption coefficient k of glass or glass-ceramic elements.

[0079] The present invention will be described in more detail below with reference to the drawings.

[0080] Figure 1 is a schematic side view, not to exact scale, of a glass or glass-ceramic element 1 according to one embodiment. The glass or glass-ceramic element 1 includes a glass or glass-ceramic substrate 10, which is formed in a plate-like and planar manner. In general, the example of the planar, plate-like glass or glass-ceramic element 1 or glass or glass-ceramic substrate 10 shown in Figure 1 is not limited to the example, and the element 1 or substrate 10 may be formed to be curved or warped.

[0081] The plate-shaped glass or glass-ceramic substrate 10 includes two main surfaces 11 and 12. These main surfaces 11 and 12 are sometimes collectively referred to as surfaces 11 and 12, and depending on the precise spatial arrangement of the substrate 10, they may be called, for example, the top surface and bottom surface, or the front surface and back surface. Since the surfaces 11 and 12 of the substrate 10 correspond to the surfaces 11 and 12 of the coated substrate or element 1, the description of the main surfaces or surfaces 11 and 12 of the substrate 10 generally also applies to the surfaces or main surfaces of element 1.

[0082] As a general rule, the surface that is the uppermost or frontmost surface during the operation of a device equipped with such a base material 10 or element 1, such as a household electrical appliance and / or heating appliance, is referred to as the top surface or front surface.

[0083] The glass or glass-ceramic substrate 10 may be designed as, for example, a glass substrate. In this case, the glass substrate may include soda-lime glass, aluminosilicate glass, or borosilicate glass, and in particular may be designed as soda-lime plate glass or borosilicate plate glass. In this case, soda-lime glass is advantageous because it can be manufactured and processed at low cost. In particular, the substrate 10 may exist as a strengthened, preferably heat-strengthened, soda-lime plate glass. This is advantageous because it improves the mechanical durability of the substrate 10. However, in certain designs of the glass substrate 10, it may be preferable that the substrate 10 includes borosilicate glass and is formed as, for example, borosilicate plate glass. This is because borosilicate glass has improved chemical resistance compared to soda-lime glass, and also has improved heat resistance from the start, so it is not necessarily necessary to further strengthen such borosilicate plate glass. However, strengthening, such as heat strengthening, of borosilicate plate glass is not ruled out. Therefore, when using the glass substrate 10 in heating appliances with high operating temperatures, such as household electrical appliances and / or viewing windows of pyrolysis furnaces, it may be advantageous to design the glass substrate 10 as borosilicate glass or as chemically strengthened glass, such as aluminum silicate glass or lithium aluminum silicate glass.

[0084] According to one embodiment, the glass or glass-ceramic substrate 10 exists as a glass-ceramic substrate. In this case, the glass-ceramic is preferably formed to be transparent, i.e., not darkened by absorption, and at the same time preferably clear, i.e., exhibiting only slight scattering. Such a glass-ceramic substrate 10, and correspondingly the glass-ceramic element 1, can be used particularly advantageously in applications subjected to specific operating loads, especially high thermomechanical stress, for example, in cooking equipment such as so-called cook plates, especially in combination with a gas burner or heating induction coil.

[0085] As can be seen from the schematic side view of Figure 1, which is not precisely scaled, the coating 2 is at least partially applied to at least one main surface 11,12 of the glass or glass-ceramic substrate 10, in this case, to the main surface 12 which is formed as the bottom surface. That is, the glass or glass-ceramic element 1 has a region 101 on which the glass or glass-ceramic substrate 10 and the coating 2 are applied. The coating 2 may also be understood and / or referred to as a light-shielding coating, or a coating 2 having a light-shielding or shading effect.

[0086] The partial arrangement of the coating 2 on at least one surface 11,12 of the glass or glass-ceramic substrate 10 is further described here in Figure 2, a top view of the glass or glass-ceramic element 1. Here, as in Figure 1, the coating 2 is arranged on the underside of the glass or glass-ceramic substrate 10. As described, the glass or glass-ceramic substrate 10 is formed such that it has a light transmittance of at least 20%, preferably at least 40%, and preferably at least 80%, for a thickness of 3mm to 4.5mm, particularly preferably 4mm, so that an observer can perceive the coating 2 even through the glass or glass-ceramic substrate 10. Thus, the glass or glass-ceramic element 1 here includes a region 101 on which the coating 2 is arranged and a region 100 that does not include the coating 2. In the exemplary illustration of Figure 2, the region 100 is formed around the edge region of the glass or glass-ceramic substrate 10 or, correspondingly, the glass or glass-ceramic element 1, i.e., around the coating 2. In general, the coating may be applied to substantially the entire surface of the glass or glass-ceramic substrate 10, without being limited to the illustrative illustrations in Figures 1 and 2. A coating that is substantially the entire surface means a coating that covers at least 90%, preferably at least 95%, of at least one main surface. In particular, coating 2 may also cover 100% of at least one main surface 11 or 12.

[0087] In general, the glass or glass-ceramic element 1 or the glass or glass-ceramic substrate 10 can have a thickness of 0.03 mm to 10 mm or more, preferably 0.03 mm to 6 mm, particularly 0.7 mm to 5 mm, and especially preferably 3 mm to 5 mm. For example, the substrate 10 may be formed as a thin glass or glass-ceramic plate having a thickness in the range of 0.03 mm to 1 mm, or as a thick glass or glass-ceramic substrate having a thickness in the range of 1 mm to 10 mm or even more.

[0088] The light transmittance of element 1 in at least one region 101 is preferably measured for a substrate thickness of 3.0 mm to 4.5 mm, particularly preferably 4 mm, and is not limited to the exemplary illustration of element 1 in Figure 1. By comparing the light transmittances of element 1 with different substrate thicknesses or element thicknesses, it is possible to determine whether or not it is within the protected range.

[0089] For example, a thicker element 1 or base material 10 can be thinned down to a thickness of 4 mm.

[0090] Thinner elements 1 or substrates 10 can also be reduced to a thickness of 4 mm through lamination and, if necessary, thinning, allowing for physical measurements of transmittance and corresponding measurements of light transmittance to determine whether these thinner substrates 10 or elements 1 are within the protective perimeter. It should be noted that this thinning or lamination is solely for the purpose of adjusting the thickness of the substrate, i.e., the thickness of the glass or glass-ceramic material, and should not alter the thickness of coating 2 by the thinning or lamination performed, if necessary.

[0091] Designing a coating 2 with a high degree of coverage of at least 90%, at least 95%, or even 100% is particularly advantageous because it eliminates the need for complex structuring processes, such as incorporating a viewing window on which a display or operating element can be placed. Therefore, such a coating 2 can be manufactured very easily, for example, by a PVD process, or a sputtering process. Furthermore, the coating 2 does not need to be formed with different thicknesses in different regions of the glass or glass-ceramic element 1. According to an embodiment schematically and not precisely scaled in Figure 1, the coating 2 can have a constant thickness. This means that the thickness of the coating 2 can vary by up to 40% relative to the maximum thickness of the coating 2 in region 101.

[0092] These highly advantageous designs of the glass or glass-ceramic element 1 are made possible by the fact that the glass or glass-ceramic element 1 is designed such that, although not limited to the embodiments of the glass or glass-ceramic element 1 illustrated and described in general in Figures 1 and 2, the coating 2 comprises metallic and semimetallic components and has a surface resistance greater than 1 MΩ, and the glass or glass-ceramic element is designed to have a light transmittance of 0.5% to 5% with respect to a thickness of 4 mm of the glass or glass-ceramic substrate 10, at least in the region 101 on which the coating 2 is placed. According to the embodiments, the surface resistance may be greater than 5 MΩ, or even greater than 10 MΩ, in which case very high surface resistances in the GΩ range are also possible. However, preferably, the surface resistance is limited to 25 GΩ or less, preferably 10 GΩ or less, particularly preferably 1 GΩ or less, and very particularly preferably 100 MΩ or less.

[0093] As metallic components, the coating can generally contain aluminum, titanium, molybdenum, magnesium, silver, or zinc. Preferably, the coating contains aluminum, titanium, magnesium, molybdenum, silver, or zinc, particularly preferably aluminum, silver, magnesium, or zinc, and most preferably aluminum. These metals are preferred because they are highly reflective and produce high reflectivity when combined or alloyed. The metalloid component of coating 2 may be silicon or germanium, preferably silicon.

[0094] As for the structure of the glass or glass-ceramic element 1, it is preferable that a coating is placed on the lower surface (here, surface 12) of the glass or glass-ceramic substrate 10, as illustrated in Figure 1. This is because, according to one embodiment, a very thin coating 2 having a thickness of less than 1000 nm is protected from mechanical attack. This is advantageous, for example, when the glass or glass-ceramic element 1 is used as a so-called cooktop, because in this case, the upper surface of the glass or glass-ceramic element 1 is increasingly exposed to mechanical attack, for example, by contact with cookware. A very thin coating 2 can thus wear down quickly, at least partially, and as a result lose its shading effect. Preferably, the coating 2 is even thinner than 1000 nm, for example, having a thickness of less than 500 nm. Even smaller layer thicknesses, for example 200 nm or even smaller, are possible and may be preferred. This is because such a very thin layer means a reduction in manufacturing process time, and, depending on the precise design of the coating, allows for low light transmittance of, for example, only 0.5% or high light transmittance of, for example, 5% in region 101. In other words, very high-resolution display elements, such as high-resolution displays, can be advantageously used, especially with high light transmittance, beneath a well-designed, very thin coating 2. However, advantageously, the coating is preferably at least 20 nm thick.

[0095] According to one embodiment, the coating 2 is designed to have an absorption coefficient k greater than 0.1 at a wavelength of 550 nm. A large value of k is advantageous, and k may be, for example, greater than 1, for example about 2, or even greater than 2. The refractive index n at 550 nm may be, for example, greater than 2. For example, in a coating 2 formed of metal, it is advantageous when n at 550 nm is less than 2 and k is greater than 2. According to embodiments of non-metallic or (partially) ceramic coating 2, it may be advantageous when n at 550 nm is greater than 2 and k is greater than 0.1 and less than 3. In such cases, it is advantageous to obtain a coating 2 that is both absorbent and has high surface resistance, so that a glass or glass-ceramic element 1 having an adjustable light transmittance of 0.5% to 5% in at least one region 101 on which the coating 2 is placed can be obtained.

[0096] In a further embodiment, the coating 2 is formed to be reflective, particularly specular. That is, according to this embodiment, the coating 2 may be designed and formed as a reflective, particularly highly reflective, metallic-looking coating.

[0097] According to a further embodiment, the glass or glass ceramic element 1 is CIEL in at least the region 101 on which the coating 2 is placed. * a * b * A chromaticity point in the system, L * If a has a value greater than 55, * , b * Each has a chromaticity point in the range of -12 to +12, preferably -10 to +10, and particularly preferably -5 to +5. * The value is, for example, 60 or more, especially 62 *The above is also acceptable. The chromaticity point is preferably measured in a chromaticity measurement using a colorimeter with the coating 2 positioned on the main surface of the glass or glass-ceramic substrate 10 opposite to the colorimeter. In other words, the chromaticity measurement is preferably performed through the glass or glass-ceramic element 1, and therefore, in the embodiment of element 1 illustrated in Figure 1, the colorimeter is positioned on the main surface 11. The measurement is performed by reflection to a black trap.

[0098] In an advantageous embodiment, coating 2 is formed to be both touch-operable and reflective. In particular, according to this embodiment, coating 2 may be designed to be both specularly reflective and touch-operable. This allows for a combination of metallic elegance and touch operability, which was previously impossible. For example, reflective coatings were conventionally only possible using metallic materials, as described in German Patent Application Publication No. 102013104702. However, the metallic material described in German Patent Application Publication No. 102013104702 is conductive and has too low a surface resistance to be used with so-called capacitive touch operation, making it not touch-operable.

[0099] In further embodiments, coating 2 contains less than 10% by weight of hydrogen, preferably less than 5% by weight, and particularly preferably less than 2% by weight. This is advantageous because hydrogen generally reduces the heat resistance of coating 2. Therefore, the hydrogen content of coating 2 should be limited, and as described above, it is preferably less than 10% by weight.

[0100] According to one embodiment, coating 2 may be formed of metal. Formation of metal generally means that the nonmetal content of the coating is limited, preferably less than 4% by weight in total. Preferably, the elemental content of oxygen O and / or nitrogen N in coating 2 is less than 4% by weight in total, preferably less than 2% by weight each.

[0101] In general, without being limited to the embodiments described above, the coating may be, for example, composed of A x B y It can have, where A is at least one metal with high reflectivity such as aluminum, titanium, molybdenum, magnesium, silver, or zinc, preferably aluminum, titanium, magnesium, molybdenum, silver, or zinc, particularly preferably aluminum, silver, magnesium, or zinc, most preferably aluminum, and B is at least one metalloid such as silicon or germanium.

[0102] According to this embodiment, coating 2 preferably contains silicon (Si) as a metalloid component. The metallic component or metal is preferably aluminum (Al) or contains aluminum. Very preferably, the coating according to this embodiment has a silicon content of more than 70% by weight and an Al content of less than 30% by weight, relative to the total content of the metallic and metalloid components in the coating.

[0103] For example, coating 2 may be formed as an AlSi-based coating. Such a coating has a surface resistance of over 1 MΩ from a silicon content of at least about 70% by weight, preferably up to 99% by weight (relative to the total weight of the metallic and semimetallic components, respectively), which is sufficient to operate most commercially used touch sensors. Here, coating 2 is formed to be as electrically insulating as possible, as the semiconductor or semimetallic properties of silicon are advantageous for setting a high surface resistance. However, a coating of pure silicon is not useful for several reasons. On the one hand, this does not allow for sufficiently high brightness in reflection, and on the other hand, due to the semiconductor or semimetallic properties of silicon, such a system can be manufactured by processes such as sputtering, which have process drawbacks such as intense arcing. Therefore, it is advantageous here to adjust the aluminum content to be as high as possible. This can be achieved, for example, by providing a sputtering target containing aluminum and silicon. Surprisingly, it has been found that even with a high aluminum content in such targets and the corresponding coatings obtained therefrom, for example, up to nearly 30% by weight, it is still possible to achieve sufficiently high surface resistance. Conventionally, for example, in German Patent Application Publication No. 102007030503, it was assumed that the aluminum content should be kept as low as possible, or even avoided if necessary, by doping silicon targets with boron, for example.

[0104] In further embodiments, coating 2 may be formed of a nonmetal. Formation of a nonmetal may also mean that the coating is (partially) ceramic or ceramic. Formation of a coating or material of a nonmetal or (partially) ceramic is assumed in this case for a coating containing at least 4 wt% nonmetal. When coating 2 is formed of a nonmetal, preferably the metalloid component is silicon or contains silicon, and the metallic component is aluminum or contains aluminum. Particularly preferably, the coating contains the elements oxygen and / or nitrogen, for example in the case of a nitrogen admixture, the nitrogen content of coating 2 is preferably more than 4 wt%, and / or, for example in the case of an oxygen admixture, the oxygen content of the coating is preferably more than 10 wt%. According to a very particularly preferred modification of coating 2 formed of a nonmetal, the silicon content of coating 2 is more than 40 wt%, and the aluminum content of coating 2 is less than 60 wt%.

[0105] In both cases, residues of the other gases may be present within the layer. This is because these gases are accompanied through the substrate and / or transport medium. However, typically, the proportion of each other gas is in the range of less than 4% by weight, preferably less than 2% by weight, relative to coating 2.

[0106] The formation of such a nonmetallic coating 2 can be achieved, for example, by using an additional reaction gas, such as oxygen (O2) or nitrogen (N2), during the manufacturing process in a magnetron sputtering process. This allows for the formation of general formula A w B x O y N zA nitride or oxide, or oxynitride compound in general, is formed. In this case, A is at least one metal with high reflectivity such as aluminum, titanium, molybdenum, magnesium, silver, or zinc, preferably aluminum, titanium, magnesium, molybdenum, silver, or zinc, particularly preferably aluminum, silver, magnesium, or zinc, most preferably aluminum, and B is at least one metalloid such as silicon or germanium. However, the nitrogen N or oxygen O content by weight, or the sum of the oxygen O and nitrogen N content, is always lower in these coating materials than the sum of the content of components A and / or B. The coating is, for example, aluminum silicon nitride (AlSiN). x Alternatively, aluminum silicon oxide (AlSiO) y As, or generally, aluminum silicon oxynitride (AlSi z O y N x The coating may be formed as such, and the exact content of aluminum and silicon in the coating can be variable. In particular, it is not assumed that coating 2 contains aluminum and silicon in equal proportions, regardless of weight or amount. Depending on the strict design, coating 2 may generally contain more aluminum than silicon, or vice versa, whether formed as a nitride, oxide, or oxynitride. Therefore, it may be advantageous to increase the aluminum content of coating 2 in order to achieve the highest possible reflectivity. On the other hand, the touchability of coating 2 can be advantageously improved by increasing the silicon content of coating 2.

[0107] In one embodiment, the process is operated so that a substoichiometric oxide, nitride, or oxynitride is formed. Here, the substoichiometric nitride system is particularly advantageous because the addition of a small amount of nitrogen makes the aluminum and silicon more firmly incorporated into the coating structure, making the coating less susceptible to degradation under thermal load. In particular, this ensures that the surface resistance (or conductivity) remains within specified limits even during or after thermal load.

[0108] Substoichiometric compounds, such as oxides, nitrides, or oxynitrides, as used herein, mean that the nonmetal is added in excess of the metal and / or metalloid component so that the metal and / or metalloid component is not completely oxidized and / or not all atoms of one or more components exist, or do not need to exist, at the same oxidation state.

[0109] In this specification, substoichiometric oxides, nitrides, or oxynitrides mean, in particular, that the nitrogen content (N) in the nitride, the oxygen content (O) in the oxide, or the combined oxygen (O) and nitrogen (N) content in the oxynitride is always less than the proportion of the metalloid and / or metallic components of Coating 2, respectively, by weight.

[0110] When the weight ratio of silicon to aluminum in coating 2, which is formed as a nitride coating 2, or at least largely as a nitride coating 2, is 1:1, a sufficiently high surface resistance of at least 1 MΩ, preferably at least 5 MΩ, and particularly preferably at least 10 MΩ is achieved when the nitrogen content in coating 2 is 5% by weight or more. Here, the composition of coating 2 can preferably be determined by EDX at an accelerating voltage of 5 keV, where preferably several measurements, for example 5 measurements, are taken and the average value of the obtained measurement points is shown. The residual oxygen content of coating 2 is about 1% by weight, and this value is difficult to set and define precisely as it depends on the respective apparatus conditions. Therefore, in this disclosure, coating 2 which is nitride or formed to become nitride, or at least largely nitride (or formed to become largely nitride) means coating 2 in which only an unavoidable trace amount of oxygen is present during its manufacture. When coating 2 is obtained by a PVD process such as sputtering, this is a process that does not add oxygen as a reaction gas, for example, or does not use an oxidizing (partially) ceramic target. Here, the unavoidable trace amounts of oxygen vary depending on the manufacturing process, as explained above, and usually do not exceed 4% by weight.

[0111] In the case of coating 2 formed to be an oxide, a sufficiently high surface resistance can be obtained by setting the minimum oxygen content to 10% by weight or more, depending on the exact ratio of aluminum to silicon in coating 2. In the case of nitride coatings, or coatings that are mostly nitride, different limiting nitrogen or oxygen content may be sufficient or necessary to obtain sufficient surface resistance, depending on the aluminum to silicon ratio in coating 2.

[0112] Here, advantageous properties of the glass or glass-ceramic element 1 can be achieved by both forming a metal coating 2 and forming a non-metallic or (partially) ceramic coating 2. In particular, it is possible to provide a glass or glass-ceramic element 1 having at least a partial coating 2 on at least one of the main surfaces (or surfaces) 11, 12, and in the region 101 having at least a coating 2, preferably having a light transmittance of 0.5% to 5% with respect to a thickness of 4 mm of the glass or glass-ceramic element 1, and the coating having a surface resistance of more than 1 MΩ, preferably more than 5 MΩ, and particularly preferably more than 10 MΩ.

[0113] Figure 3 is a schematic, not-to-accurate, perspective view of a glass or glass-ceramic element 1 according to one embodiment, where the glass or glass-ceramic element 1 is positioned with the coating 2 facing upward. However, generally speaking, and without being limited to exemplary embodiments, it may be advantageous for the coating to be positioned on the main surface (or face) of the glass or glass-ceramic element 1 or the glass or glass-ceramic substrate 10, where this main surface (or face) is operationally formed as the underside or back surface of the glass or glass-ceramic element 1. This is because the coating 2 is protected by the substrate 10 from mechanical abrasion caused by the movement of cookware on the upper surface of the glass or glass-ceramic element 1, for example, when used as a cooktop. Here, the coating 2 is applied to the entire main surface or face of the glass or glass-ceramic substrate 10.

[0114] According to one embodiment, the glass or glass-ceramic element 1 may be provided to include a further coating 3, as schematically and not precisely shown in Figure 4. This further coating 3 is at least partially disposed between the glass or glass-ceramic substrate 10 and the coating 2, on at least one main surface 11,12, in this case on the main surface 12. In the schematic diagram of Figure 4, the main surface 12 of the glass or glass-ceramic element 1 or the glass or glass-ceramic substrate 10 is facing downward, i.e., formed as the bottom surface. The further coating 3 is disposed on the main surface 12, in this case directly on the substrate 10, and also within the region 101 of the glass or glass-ceramic element 1 where the coating 2 is disposed. However, in this case, the further coating 3 and the coating 2 do not completely overlap. However, in general, without being limited to the embodiment shown in Figure 4, it is also possible that the further coating 3 and the coating 2 are disposed to completely overlap, that is, the further coating 3 is also disposed between at least one main surface (in this case, the main surface or surface 12) of the substrate 10 and the coating 2, covering the entire region 101. One of the coatings, for example, the uncoated portion of coating 2 or the further coating 3, can be implemented or obtained, for example, by masking, particularly by so-called masking sheets. This is especially true for coatings obtained by physical or chemical vapor deposition. However, the uncoated portion can also be obtained by a printing process, for example, when the coating, such as the further coating 3, is implemented in the form of a pigment-filled enamel layer. This is because, by using a printing process, the lateral structuring of the coating in the form of uncoated and coated areas can be obtained directly in the application process. If this further coating 3 is placed on at least one main surface 11, it can be, for example, as a top decoration, particularly based on pigment-filled enamel, or particularly sputtered Al x Si y N zIt can function as a scratch-resistant layer based on the layer itself, or as a combination of both.

[0115] Depending on the precise type and design of the additional coating 3, it can exhibit different functions. Furthermore, it is possible to place multiple additional coatings 3 between the substrate 10 and the coating 2.

[0116] For example, the further coating 3 may be designed as a single layer containing or composed of SiO2, or collectively composed of silicon oxide. By making it a single layer in this way, the specular effect can be enhanced, thereby L * The value can be further increased. Advantageously, in this case, the additional coating 3 is designed to completely cover each other with coating 2, i.e., the additional coating 3 is also placed over the entire area of ​​the glass or glass-ceramic element 1 on which the additional coating 2 is provided. In this way, it is also possible to change the chromaticity point of the glass or glass-ceramic element 1 as needed. In particular, in this way, it is even possible to correct or compensate for any possible color cast of the glass or glass-ceramic substrate 10. This can be especially important with glass-ceramic substrates, because glass-ceramic substrates often exhibit a slight yellow cast due to trace amounts of iron resulting from impurities in the batch. This can be compensated for by the additional coating 3 designed as a color adjustment layer. In particular, it is generally possible that the additional coating 3 is designed as a layer system, for example, as an optical layer system containing multiple material layers. However, for economic reasons, it may be advantageous for coating 3 to be designed as a single layer.

[0117] Alternatively or additionally, the further coating 3 may be designed to prevent the diffusion of elements from the glass or glass ceramic. That is, as an alternative to the color adjustment and / or increase in reflectivity as described above, the further coating 3 may be designed to function as a diffusion barrier. In particular, according to one embodiment, the further coating 3 may be designed to function as a diffusion barrier against the elution of alkali metals or alkali metal ions from the substrate. This can advantageously extend the service life of the glass or glass ceramic substrate 10 and, correspondingly, the glass or glass ceramic element 1.

[0118] Alternatively or in addition to the further coating 3 described above, the glass or glass-ceramic element 1 may include a cover layer 4. This is illustrated in the schematic cross-sectional view of the glass or glass-ceramic element 1 in Figure 5, which is not to the exact scale. Here, the glass or glass-ceramic element 1 in Figure 3 further includes a cover layer 4 which is at least partially placed on the coating 2.

[0119] As schematically shown in Figure 5, the cover layer 4 may be designed not to completely cover the coating 2. Furthermore, as also schematically shown in Figure 5, the cover layer 4 and the further coating 3 may similarly be applied only to areas that partially overlap the main surface (or surface) of the glass or glass-ceramic substrate 10. However, in general, it is also possible for the cover layer 4 to completely cover the coating 2, without being limited to the specific embodiment shown in Figure 5. Furthermore, in general, it is also possible for the further coating 3 and the cover layer 4 to be applied to areas that completely overlap, without being limited to the specific embodiment shown in Figure 5. In particular, a design in which the further coating (or, where appropriate, multiple further coatings) 3, the coating 2 and the cover layer 4 are applied to the entire surface of one surface (e.g., the main surface 12) of the substrate 10 is also conceivable.

[0120] Here, it can be particularly advantageous if the cover layer 4 completely covers the coating 2. For example, such a layer 4 can function as protection against oxidation or corrosion of the coating 2. In particular, if the coating 2 is made of ceramic, but sub-ikiometry and / or nitride, if the coating 2 is made of metal, and / or if the glass or glass-ceramic element 1 is used in cooking applications, especially in applications where particularly high temperatures may occur, the formation of a coating layer as an oxygen barrier can be particularly advantageous. Furthermore, since the coating 2 is formed as a translucent coating, the cover layer 4 can also play a role in slightly altering or adjusting the chromaticity point of the glass or glass-ceramic element 1 in region 101.

[0121] In general, the additional coating 3 and / or cover layer 4 are SiO2, SiO x , SiON, SiN x AlO x , TiO x SnO x MgO x ZnO, ZrO x YO x MoO x , HfO x and / or mixtures of these substances may be included or consist of. Furthermore, porous coatings may also be considered as alternatives or additionally, and / or further coatings 3 and / or cover layers 4 may contain fluorides, such as MgF2.

[0122] Preferably, coating 2 is formed to be amorphous overall. Such formation of coating 2 as amorphous, particularly as an X-ray amorphous coating, can be particularly advantageous when high durability of coating 2 is desired. Therefore, such amorphous formation of coating 2 can be advantageous, particularly in applications where the glass or glass ceramic element 1 is exposed to high operating temperatures, but it is also advantageous in applications where the coating may be exposed to corrosive environments. Thus, such amorphous design can be particularly advantageous when the glass or glass ceramic element 1 is used in household appliances and / or heating appliances. This is because a coating formed to be amorphous in such a way does not have interfaces in the form of crystalline planes where the migration of corrosive substances to coating 2 can occur. In this way, coating 2 can also reduce corrosion of the substrate 10 to some extent. According to one embodiment, coating 2 is formed to be amorphous, and in particular has a structureless and / or X-ray amorphous morphology. Structureless morphology means that coating 2 is homogeneously formed without grain boundaries and / or other structures such as growth structures. In this disclosure, amorphous also specifically refers to X-ray amorphous. In other words, coating 2 according to one embodiment is not formed to be crystalline.

[0123] According to a further preferred embodiment, the glass or glass-ceramic element 1 has high heat resistance. The high heat resistance of the glass or glass-ceramic element 1 is demonstrated particularly in the stability of its optical properties, especially in the stability of its light transmittance and / or chromaticity point, which is defined as follows: - After applying a heat load to the glass or glass ceramic element 1 at 390°C for 80 hours, the difference in light transmittance of the glass or glass ceramic element 1 in the region 101 before and after the heat load is a maximum of 5% in absolute value, preferably a maximum of 3% in absolute value, and / or - After applying a heat load of 390°C to the glass or glass ceramic element 1 for 80 hours, the difference ΔE of the chromaticity points of the glass or glass ceramic element 1 in region 101 is at most 20, preferably at most 10, particularly preferably at most 5, and very particularly preferably at most 2, where ΔE is less than or equal to:

number

[0124] The fact that the difference in light transmittance of the glass or glass-ceramic element 1 in region 101 is a maximum of 5% in absolute value means that the light transmittance can vary by up to 5%. In other words, if the light transmittance in region 101 before heat loading is 5%, it can be between 0% and 10% after heat loading. However, preferably, this difference is less than 5%, and at most 3%.

[0125] According to a further embodiment, coating 2 has a refractive index value n of at least 2 or more and / or an absorption coefficient of at least 0.1 or more at a wavelength of 550 nm.

[0126] According to one embodiment, the glass or glass ceramic element 1 is formed as a glass element and has a light transmittance of 0.5% to 10%, preferably 0.5% to 5%, preferably 0.5% to 3.5%, and particularly preferably 0.5% to 1.5% in the region 101 where the coating 2 is placed.

[0127] According to a further embodiment, the glass or glass ceramic element 1 is formed as a glass ceramic element and has a light transmittance of 0.5% to 10%, preferably 0.5% to 5%, and particularly preferably 2% to 5% in the region 101 on which the coating 2 is placed.

[0128] Figure 6 shows a further embodiment schematically and without regard to precise scale. The glass or glass-ceramic element 1 is designed to include a structured layer 5 on at least one main surface, in this case the main surface (or surface) 12 which is designed as the underside of the glass or glass-ceramic substrate 10, in addition to the coating 2. This structured layer 5 can be a ceramic coating that can be structurally applied laterally by screen printing or inkjet printing, for example, so that the structured layer 5 is applied at least partially to the main surface, in this case the main surface 12.

[0129] For example, the structured layer 5 may be applied in the form of a grid in region 501, as shown as an example in Figure 6. This structured layer 5 may be a clear or very slightly diffusive colorless coating, such as a glass melt-based coating, which can be applied by printing processes such as screen printing or inkjet printing. The colorless coating may also be a sol-gel coating that does not contain pigments or dyes, and likewise can be applied by conventional coating processes such as printing, spraying, or dipping, for example by screen printing or inkjet printing. However, the structured layer 5 may also contain pigments, in particular effect pigments and / or dyes, in order to obtain the desired optical impression. By adding pigments and / or dyes, the transmittance of the coating can be influenced as intended, in addition to the reflection and light scattering behavior.

[0130] Here, unlike what is schematically shown in Figure 6, the surface of coating 2 in region 501 may not be smooth and may have relief corresponding to the convex portion of the structured layer 5, i.e., it may at least partially follow the convex portion of the structured layer 5. In general, such a structured layer 5 can be combined with one or more coatings 3 and / or cover layers 4, without being limited to the example of glass or glass ceramic element 1 shown in Figure 6. In particular, the structured layer 5 is positioned between the substrate 10 or at least one main surface or surface of the substrate 10 and the coating 2, preferably positioned directly adjacent to the substrate. In particular, even if one or more additional coatings 3 are present, the structured layer 5 may be formed as the bottom coating directly adjacent to the substrate 10. In that case, one or more additional coatings 3 and coatings 2, as well as any cover layers 4, are positioned above the structured layer 5.

[0131] However, deviating from the schematic and not precisely scaled diagram of Figure 6, it is also possible, and even preferable, for the structured layer 5 to be positioned on the surface 11 of the glass or glass-ceramic substrate 10 opposite to the coating 2. In this way, a 3D effect is obtained in the observer's visual perception, resulting from the mirror-like surface of the structured layer 5 on the coating 2. This effect can be advantageous because it conceals surface defects of the glass or glass-ceramic substrate 10. Therefore, arranging the coating on the glass or glass-ceramic substrate 10 in this manner allows for the selection of a particularly preferred sequence of process steps. For example, the structured layer 5 can be printed first, followed by the ceramicization of the substrate 10, thus converting it to glass-ceramic, or the substrate 10 can be subjected to thermal strengthening, during which the firing of the structured layer 5 can be carried out during the aforementioned thermal step. Finally, the coating 2 can be applied in a further step by sputtering.

[0132] Furthermore, the structured layer 5 is present on both sides of the base material 10, and in this case, it is generally possible and preferable for the structured layer to be applied to one side in a different pattern than the other side. If the structured layer 5 is present on the bottom surface of the base material 10, further layers, such as decorations, cooking zone marks, dot patterns, logos, etc., may be applied to the top surface as well.

[0133] Such a structured layer 5 may be particularly advantageous when it is desired to prevent excessive mirror-like effects of the coating 2, for example, to prevent excessive glare to operators or users of equipment equipped with glass or glass-ceramic elements 1 for safety reasons.

[0134] Such a structured layer 5 can also have additional aesthetic effects, for example, so that the glass or glass-ceramic element 1 designed in this way gives the impression of a brushed stainless steel surface.

[0135] Figure 7 shows an exemplary household appliance and / or heating appliance 60 schematically and not to an exact scale, which is here exemplary as a range including an oven and cooking appliance (also called a stove or cooktop). The cooking appliance may be a gas or induction cooking appliance in particular. Such a household appliance and / or heating appliance 60 generally includes a glass or glass-ceramic element 1 according to the embodiment. Generally, a household appliance and / or heating appliance 60 according to one embodiment may be designed to further include at least one indicator and / or operating element 70 and / or sensor 80. In the case of a cooking appliance, this may further include, for example, a gas burner or induction coil. Here, the exemplary appliance 60 includes two glass or glass-ceramic elements 1 according to the embodiment, namely, one as, for example, a cover plate in a cooking appliance and the other as a viewing window in an oven. Each coating 2 (not shown herein) is positioned in the installed state on the side of the glass or glass-ceramic element 1 opposite to the user or operator of the equipment 60, namely on the underside in the case of the upper element 1 designed as a cover plate for cooking equipment, and on the underside in the case of element 1 designed as a viewing window.

[0136] For illustrative purposes, Figure 7a) shows a first display element 70 in the switched-on state. This allows the display to be seen through the glass or glass-ceramic element. An operating element 70 is shown in the lower left region of this element 1, which may be designed as a touch area for operating, for example, the device 60. However, it is noteworthy that these operating elements 70 are visible here and can also be identified, for example, by the decoration on the top surface. However, the clear visibility of these operating elements 70 in Figure 2a) is particularly for illustrative purposes. After all, one of the advantages of the design of the glass or glass-ceramic element 1 is that these operating and / or display elements 70 do not need to be perceptible in a particularly intrusive way, thereby particularly creating the so-called "dead front effect".

[0137] This is illustrated schematically and not to an accurate scale in Figure 7b). Here, the display element 70 is switched off, i.e., covered by element 1 and not visible, and the further display element 70 in the lower left area of ​​the upper element 1 is also not perceptible. In particular, it is possible to design elements 1 in this way so that they create visual unity with the other components of the device 60, that is, they harmonize with each other in terms of their elegance. This is not only visually appealing, but also enhances the visibility of the display element 70 in the event of a malfunction of the device 60, for example, and also enhances the safety of the operator.

[0138] Finally, Figure 8 shows a schematic, and not precise, design of a glass or glass-ceramic element 1 including a sensor 80 on its lower surface 12. For example, this could be a glass or glass-ceramic element 1 designed as a cover plate for the device 60 shown in Figure 7, which further includes a sensor 80, such as a temperature sensor, in addition to display or operating elements 70 which are not shown here for clarity.

[0139] According to one embodiment, coating 2 has an unstructured and / or X-ray amorphous morphology. Unstructured morphology means that coating 2 is homogeneous and does not contain grain boundaries and / or other structures such as growth structures.

[0140] According to one embodiment, element 1 can communicate with a sensor because the coating 2 and the entire glass or glass-ceramic element 1 are designed to have near-infrared light transmittance, particularly in region 101. In other words, according to this embodiment, the spectral transmittance of the glass or glass-ceramic element 1, particularly in region 101, is at least 3% (i.e., 0.03) in the wavelength range of 850 nm to 2500 nm. That is, the transmittance values ​​measured in this wavelength range are always greater than 3% for each wavelength, particularly in region 101.

[0141] In general, without being limited to any of the embodiments shown in the figures, coating 2 may exist as a single layer or as a layered system. Coating 2 is understood to be a layered system if it includes multiple layers. An exemplary, schematic, and not-to-accurate-scale embodiment of coating 2 as a layered system is shown in Figure 9.

[0142] Figure 9 shows a further preferred embodiment of the glass or glass-ceramic element 1. According to this particular embodiment, the coating 2 is in the form of a layer system 20. In particular, the layer system 20 or coating 2 may be formed as a three-layer system, that is, it may include or consist of three layers.

[0143] Therefore, according to this particular embodiment, the coating 2 can be interrupted by a dielectric layer, thereby obtaining a three-layer system including layers 2a, 2b, and 2c. Here, layers 2a and 2c of the coating 2 are formed to include, in general, at least one metallic component and at least one semimetallic component. Therefore, when layers 2a and 2c are formed of metal, the general composition is A x B y Furthermore, if it is formed (partially) of ceramic, the composition AB x O y N zThe layers can have a composition in which A generally exists as a metallic component and B generally exists as a semimetallic component. In particular, layers 2a and 2c can be formed of metal, nonmetal or (partially) ceramic according to the embodiments described above in this disclosure. Here, the compositions of layers 2a and 2c may be the same or different within the range of normal manufacturing tolerances. In particular, one of layers 2a and 2c may be formed of (partially) ceramic and the other of metal, or both layers 2a and 2c may be formed of metal or (partially) ceramic but have different compositions. However, it is usually preferable for manufacturing reasons that the compositions of layers 2a and 2c be the same within the manufacturing tolerances. Layer 2b (also called the intermediate layer) may generally contain a dielectric material and may be called a dielectric layer or intermediate layer. Preferably, layer 2b is configured such that the refractive index n of layer 2b at 550 nm is smaller than the refractive index n of layers 2a and 2c at 550 nm, and the absorption coefficient k of layer 2b at 550 nm is smaller than the absorption coefficient k of layers 2a and 2c at 550 nm. Preferably, the intermediate layer 2b may contain or be composed of SiO2. The layer structure of coating 2 as the described layer system 20, that is, the layer structure composed of or including layers 2a, 2b and 2c, results in a surprisingly increased L * The value can be achieved very favorably, while other properties of coating 2, namely its high surface resistance and the precisely tuned transmittance in visible and near-infrared light, are maintained. In particular, in this way, L * It is possible to set the value to a very high value, up to 70 or more. Furthermore, further subdivision is possible; that is, the layer system 20 may include additional layers, for example, it may be designed as a 4-layer or 5-layer system.

[0144] Thus, generally, according to an embodiment, the glass or glass-ceramic element 1 has a coating 2 formed as a layer system 20 including sub-layers, preferably three sub-layers 2a, 2b, 2c, wherein at least two sub-layers 2a, 2c may be designed to include at least one metal component and at least one metalloid component. These surround at least one intermediate layer 2b. At least one intermediate layer 2b includes a dielectric material. Preferably, the refractive index value n at 550 nm of at least one intermediate layer 2b is smaller than the refractive index value n at 550 nm of at least two other sub-layers (2a, 2c). More preferably, the absorption coefficient k at 550 nm of the intermediate layer 2b is smaller than the absorption coefficient k at 550 nm of at least two other sub-layers (2a, 2c).

[0145] In such a design, it is particularly advantageous because a very high L value can be achieved while maintaining a surface resistance above 1 MΩ and a light transmittance between 0.5% and 5%. * This is because it is possible to achieve such a value, which is particularly advantageous.

[0146] Furthermore, by doing so, it is surprisingly easy to achieve a chromaticity point that is almost neutral when seen through. For example, in the case of a coating 2 formed as a single layer and having a high proportion of silicon, especially in the case of a coating 2 formed of a metal, the chromaticity point of the coating or the glass or glass-ceramic element 1 in the region 101 often has a yellowish tint. This is disadvantageous when incorporating displays or other display elements such as LEDs. Surprisingly, it has been found that this deviation of the chromaticity point can be avoided by realizing the coating 2 as the layer system 20 as described above, that is, by forming it to include a dielectric layer 2b between the layers 2a, 2c.

[0147] According to this embodiment having a coating 2 realized as the layer system 20, in particular, it is possible to achieve an a value and a b value in the range of +15 to -15 respectively, preferably in the range of +10 to 10 respectively. * value and b * value.

[0148] According to a specific example of coating 2 realized as layer system 20, a * Values ​​4.6 and b * We were able to achieve a value of 8.6.

[0149] The thicknesses of layers 2a, 2b, and 2c may be the same or different. Preferably, the total thickness of layers 2a, 2b, and 2c is in the range of at least 50 nm. In this case, the thickness of each individual layer 2a, 2b, and 2c can be less than 20 nm. Layer 2a is preferably 10 nm to 200 nm, layer 2b is preferably 20 nm to 300 nm, and layer 2c is preferably 10 nm to 200 nm.

[0150] Finally, Figures 11 and 12 show the refractive index n (Figure 11) and absorption coefficient k (Figure 12) against wavelength for four selected (partially) ceramic samples 6-9 of glass or glass-ceramic elements according to the embodiment.

[0151] The layer composition of these four samples was determined by the weight ratio of aluminum to silicon. The surface resistance and light transmittance τ obtained for these samples were also determined. vis The measured values ​​of the chromaticity and color are summarized in the following two tables. Table 2 shows the corresponding values ​​obtained after coating, and Table 3 shows the values ​​obtained after thermal loading at 390°C for 80 hours in this case.

[0152] [Table 2]

[0153] [Table 3]

[0154] Furthermore, the layer thicknesses of these samples are shown below: Sample 6: 176nm Sample 7: 117nm Sample 8: 100nm Sample 9: 110nm

[0155] Samples 6-9 exhibit good invariance of the chromaticity point even after temperature loading, as indicated by the corresponding ΔE values. Low transmittance in the visible light region, a light and reflective metallic color impression, and low conductivity complete the overall impression or profile of these coatings or glass or glass-ceramic elements containing these coatings.

[0156] Finally, the following two tables show exemplary values ​​for glass or glass-ceramic elements in embodiments including a coating formed with metal. Here again, values ​​are shown after coating ("after deposition") and, similarly, after a heat load of 80 hours at 390°C.

[0157] Sample 10 is a coating containing 23 parts by weight of Al and 77 parts by weight of silicon. The coatings of Samples 11 and 12 are coating systems, and as Coating 2, a coating containing metallic and semimetallic components, AlSi, and a further coating that can act as a barrier against oxidation, for example.

[0158] [Table 4]

[0159] [Table 5] [Explanation of symbols]

[0160] 1. Glass or glass-ceramic element 10 Glass or glass ceramic substrate 11,12 Element or surface or main surface of the substrate 100 Uncoated areas of the element or substrate with coating 2 101 Region of an element or substrate having coating 2 2. Coating, light-blocking coating Each layer of the 2a, 2b, and 2c layer system 20 layer system 3. Further coating 4. Cover layer 5 Structured layer 501 Regions in which a structured layer is applied at least partially. 60 Household electrical appliances and / or heating appliances 70 Display and / or Operation Elements 80 sensors

Claims

1. A plate-shaped glass or glass ceramic element (1) comprising a plate-shaped glass or glass ceramic substrate (10) and a coating (2) at least partially disposed on at least one main surface (11, 12) of the glass or glass ceramic substrate (10), The coating (2) comprises a metallic component and a semi-metallic component, The glass or glass-ceramic substrate (10) is formed to be transparent; said coating (2) having a surface resistance of more than 1 MΩ; The glass or glass-ceramic element (1) has, at least in the area (101) where the coating (2) is arranged, a light transmittance τ of 0.5% to 10%, preferably 0.5% to 5%. ｖｉｓ A glass or glass-ceramic element (1).

2. The coating (2) is configured to have reflectivity, whereby a coating (2) is understood to be reflective in particular if the glass or glass-ceramic element (1) has the following properties in the at least one region (101): an average reflectance in the visible spectral range, i.e. from 380 nm to 780 nm, of between 10% and 30%, which is achieved in particular for a coating (2) formed as a single layer, or an average reflectance in the visible spectral range, i.e. from 380 nm to 780 nm, of 20% to 70%, which is achieved in particular for a coating (2) formed as a layer system (20), in particular comprising at least three partial layers (2a, 2b, 2c); In particular, said values ​​are achieved when the glass or glass-ceramic element (1) is formed so as to be smooth on the main faces (11, 12) on which the coating (2) is arranged, in particular where the main faces (11, 12) are obtained by rolling with unstructured rolls and / or where the roughness, in particular the roughness R ａThe main surfaces (11, 12) having a surface roughness of less than 1 μm are also understood to be smooth, Alternatively, the main faces (11, 12) on which the coating (2) is arranged have a roughness of 1 μm to 5 μm and are preferably structured, and in the regions (101) the glass or glass-ceramic element (1) has an average reflectance in the visible spectral range, i.e. 380 nm to 780 nm, of at least 2% and at most 20%, or a glossiness, preferably measured with a glossmeter Rhopoint Qs, in particular at a measurement angle of 20°, preferably at least 87 GU, preferably at least 100 GU, particularly preferably at a measurement angle of 60°, preferably at least 93 GU, preferably at least 100 GU, particularly preferably at a measurement angle of 85°, and the main surface or surfaces on which the coating is arranged have a roughness of 1 μm to 5 μm, in particular a roughness R ａ and preferably structured or or The gloss, preferably measured with a glossmeter Rhopoint Qs, is in particular at least 500 GU, preferably at least 700 GU at a measuring angle of 20°, particularly preferably at least 200 GU at a measuring angle of 60°, preferably at least 250 GU, particularly preferably at least 270 GU, very particularly preferably at least 300 GU and very particularly preferably at least 99 GU at a measuring angle of 85°, in particular said values ​​being achieved when the glass or glass ceramic element is formed so as to be smooth on the main surface or surface on which the coating is arranged, in particular the main surface or surface of the plate obtained by rolling with unstructured rolls, for example the upper or lower surface, and / or the roughness, in particular the roughness R ａ A major surface (or surface, e.g., top or bottom surface) having a roughness of less than 1 μm is also understood to be smooth.

3. 3. The glass or glass-ceramic element (1) according to claim 1 or 2, wherein the coating (2) is configured to be touch-operable and at the same time reflective.

4. The glass or glass-ceramic element (1) has a CIE 10 ... ＊ a ＊ b ＊ The chromaticity point in the L ＊ is greater than 55, and a ＊ , b ＊ 2. The glass or glass-ceramic element (1) according to claim 1, wherein the glass or glass-ceramic substrate (10) has a color point in the range of −12 to +12, preferably −10 to +10, particularly preferably −5 to +5, the color point being preferably measured or measurable in a colorimetric color measurement, preferably against a black trap, particularly preferably using a Konica-Minolta CM-700d spectrophotometer, and the coating (2) is arranged on a main surface (11, 12) of the glass or glass-ceramic substrate (10) facing away from the colorimeter.

5. 2. The glass or glass-ceramic element (1) according to claim 1, wherein the coating (2) has a thickness of less than 1000 nm and preferably at least 20 nm.

6. The glass or glass-ceramic element (1) according to claim 1, wherein the coating (2) has a constant thickness.

7. said coating (2) is made of metal, Preferably, the content of the elements O and / or N of said coating (2) is less than 4% by weight each, preferably less than 2% by weight each; Preferably, the metalloid component comprises Si and the metal component comprises Al; Particularly preferred is a glass or glass-ceramic element (1) according to claim 1, in which the coating (2) has a Si content of more than 70% by weight and an Al content of less than 30% by weight.

8. said coating (2) is made of a non-metallic material; Preferably, the metalloid component comprises Si and the metal component comprises Al; 2. The glass or glass-ceramic element (1) according to claim 1 , wherein the coating (2) particularly preferably comprises the elements O and / or N, the N content of the coating (2) being preferably at least 4% by weight, preferably more than 4% by weight, and / or the O content of the coating (2) being preferably more than 10% by weight.

9. 9. The glass or glass-ceramic element (1) according to claim 8, wherein the Si-content of the coating (2) is greater than 40 wt.-% and the Al-content of the coating (2) is less than 60 wt.-%.

10. 2. The glass or glass-ceramic element (1) according to claim 1, having at least one of the following characteristics: the glass or glass-ceramic element (1) comprises a further coating (3) which is arranged on at least one of the main faces (11, 12) at least partially between the glass or glass-ceramic substrate (10) and the coating (2); the glass or glass-ceramic element (1) comprises a cover layer (4), the cover layer (4) being at least partially arranged on the coating (2); said coating (2) has, at a wavelength of 550 nm, a refractive index value n of at least 2 and / or an absorption coefficient of at least 0.1; - the coating (2) is formed so as to be amorphous; the glass or glass-ceramic element (1) comprises a structured layer (5) on at least one of its main faces (11, 12), the structured layer (5) being preferably arranged between the coating (2) and the glass or glass-ceramic substrate (10), particularly preferably adjacent to the glass-ceramic substrate (10); the glass or glass-ceramic element (1) is configured as a glass element and, in the area (101) in which the coating (2) is arranged, has a light transmittance τ of 0.5% to 5%, preferably 0.5 to 3.5%, particularly preferably 0.5 to 1.5%. ｖｉｓ having said glass or glass-ceramic element (1) is configured as a glass element and has, in the area (101) where said coating (2) is arranged, a light transmittance τ of 0.5% to 10%, preferably 0.5% to 5%, preferably 2% to 5% ｖｉｓ has.

11. 2. The glass or glass-ceramic element (1) according to claim 1, which has a thermal resistance, in particular a stability of its optical properties, such as: after subjecting said glass or glass-ceramic element (1) to a thermal load of 390° C. for 80 hours, the difference in the light transmission of said glass or glass-ceramic element (1) in said region (101) after and before the thermal load is at most 5% in absolute value, preferably at most 3% in absolute value, and / or after subjecting the glass or glass-ceramic element (1) to a thermal load of 390° C. for 80 hours, the difference ΔE in the color points of the glass or glass-ceramic element (1) in the region (101) is at most 20, preferably at most 10, particularly preferably at most 5 and very particularly preferably at most 2, where ΔE is [0010] Here, the chromaticity point E ｖＴ refers to the chromaticity point of the glass or glass-ceramic element (1) in the region (101) before thermal loading, and the chromaticity coordinate a ＊ ｖＴ , b ＊ ｖＴ , L ＊ ｖＴ and the chromaticity point E ｎＴ is the chromaticity point of the glass or glass-ceramic element (1) in the region (101) after thermal loading, and the chromaticity coordinate a ＊ ｎＴ , b ＊ ｎＴ , L ＊ ｎＴ and preferably measured against a black trap, in particular using a Konica-Minolta CM-700d spectrophotometer.

12. 2. The glass or glass-ceramic element according to claim 1, wherein the coating (2) is configured as a layer system (20) comprising sub-layers (2a, 2b, 2c), preferably as a layer system (20) comprising three sub-layers, at least two sub-layers (2a, 2c) comprising at least one metallic component and at least one semi-metallic component and surrounding at least one intermediate layer (2b), the at least one intermediate layer (2b) comprising a dielectric material, and preferably a refractive index value n at 550 nm of the at least one intermediate layer (2b) being smaller than the refractive index values ​​n at 550 nm of the at least two other sub-layers (2a, 2c), further preferably an absorption coefficient k at 550 nm of the intermediate layer (2b) being smaller than the absorption coefficient k at 550 nm of the at least two other sub-layers (2a, 2c).

13. 10. A household appliance and / or heating appliance (60) comprising a glass or glass-ceramic element (1) according to claim 1.

14. Domestic appliance and / or heating appliance (60) according to claim 13, comprising at least one display and / or operating element (70) and / or sensor (80).

15. A method for producing a glass or glass-ceramic element (1), preferably according to claim 1, said method comprising the steps of: - providing a transparent, formed, plate-shaped glass or glass-ceramic substrate (1); - introducing said glass or glass-ceramic substrate (1) into a coating chamber; providing a target comprising at least one semi-metallic component and / or at least one metallic component in said coating chamber; - adjusting the pressure in the coating chamber, wherein the pressure is at least 5×10 －４ mbar to maximum 5 x 10 －２ mbar; - carrying out the coating by sputtering, said sputtering being capable of being carried out as DC sputtering or AC sputtering, for example as medium frequency sputtering or high frequency sputtering; whereby a plate-shaped glass or glass ceramic element (1) is obtained, comprising a plate-shaped glass or glass ceramic substrate (10) and a coating (2) at least partially disposed on at least one main surface (11, 12) of said glass or glass ceramic substrate (10), wherein the coating (2) comprises metallic and semi-metallic components and has a surface resistance of more than 1 MΩ, and the glass or glass-ceramic element (1) has, at least in the area (101) where the coating (2) is arranged, a light transmittance τ of 0.5% to 10%, preferably 0.5% to 5%, for a thickness of 4 mm of the glass or glass-ceramic substrate (10). ｖｉｓ The method comprising:

16. 16. A glass-ceramic element (1), preferably a glass or glass-ceramic element (1) according to claim 1, which is produced or producible by a method according to claim 15.

17. Use of a glass or glass-ceramic element according to claim 1 or produced or producible by the method according to claim 15 as a cover plate for a household electrical appliance and / or heating appliance (60), in particular as a cover plate for a cooking appliance, or as a window for an oven, or as a sight glass for a fireplace, or as a sight glass for a refrigerator, or as a sight glass for a microwave oven, or as a front window for an operating element, in particular for an operating element of a coffee machine, or for an oven, or as a top for a kitchen or laboratory utensil, such as, for example, a shelf or a table, or as an operating surface for a household electrical appliance, such as, for example, a smartphone.

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