METHOD FOR PRODUCE A DISC WITH A STRUCTURED COATING

Description

[0001] The invention relates to a method for manufacturing a disc with a structured coating.

[0002] For the purposes of the invention, a structured coating is understood to be a coating that is not applied to the surface of a substrate over its entire area or in the form of a closed surface of a simple geometric shape. Instead, a substrate with a structured coating has coated and uncoated areas, which are arranged, in particular, in the form of a regular geometric pattern, for example, in the form of parallel coated lines between which uncoated areas are arranged, as a matrix-like arrangement of coated points on an otherwise uncoated surface, or conversely, as a coating with matrix-like arranged point-like uncoated areas.For the present invention, structured coatings are of particular interest in which the coated and uncoated areas have dimensions in the micrometer range (for example, the line width in line-like structures or the diameter and spacing in point-like structures). Such structured coatings are known per se. They can be used, for example, to provide the surface of the substrate with desired optical properties or hydrophilic or hydrophobic properties.

[0003] Several methods exist for creating structured coatings. For example, a large area of ​​the substrate surface can be coated, and the uncoated areas can then be created using mechanical stripping, etching, or laser processes. Alternatively, lithographic methods, particularly interference lithography, can be used to create the uncoated areas. Structured coatings can also be created directly without a stripping step using so-called "layer-by-layer" deposition or certain sol-gel processes. Stamp-like methods such as UV curing nanoimprint lithography are also possible.

[0004] However, all these methods have certain disadvantages with regard to industrial use. For example, some methods, such as laser stripping, are only suitable for creating more structured coatings where the uncoated areas are relatively small compared to the coated areas. Other methods are technically very complex or only applicable to small substrates or small areas of substrates.

[0005] FR3048244A1 discloses a method for producing a disc with a structured coating, wherein a structured organic marking coating is applied, a functional coating is applied thereon, and the masking coating with the areas of the functional coating arranged thereon is removed by heat treatment. Similar methods are known from US2008213482A1, EP1348673A1, and US2003232197A1. EP2105950A1 also discloses a similar method of this type.

[0006] The present invention is based on the objective of providing an improved method for the production of discs with structured coatings, which is technically relatively easy to implement and applicable to a wide variety of structures and substrate sizes.

[0007] The object of the present invention is achieved according to the invention by a method according to claim 1. Preferred embodiments are described in the dependent claims.

[0008] The inventive method for producing a disc with a structured coating comprises at least the following process steps: a) Forming an organic, polymeric masking coating on masking areas of a glass substrate surface, wherein coating areas of the glass substrate surface are not provided with the masking coating; b) Applying a functional coating to the surface of the glass substrate by vacuum-based vapor deposition; and c) Heat treatment of the glass substrate at a temperature of at least 200 °C, whereby the masking coating and the functional coating applied thereto are removed from the surface. The functional coating remains on the coating areas of the surface.

[0009] The method according to the invention allows the production of large-area structured coatings that are not limited to specific types of structures. The structures to be produced can be modified more easily than, for example, in printing or lithographic processes, making the method according to the invention very flexible. This flexibility also extends to the area of ​​the glass substrate to be coated with the structured layer. In particular, the method is relatively easy to implement technically because it uses elements that are already common in glass manufacturing. For example, coating by means of vacuum-based vapor deposition is well-established in glass manufacturing, and polymer coatings that can be removed by heat treatment are commonly used to protect coated glass surfaces during transport, storage, and handling.Such a polymer coating is, for example, marketed and used by the company Saint-Gobain under the name SGG EASYPRO®. These are significant advantages of the present invention.

[0010] For the purposes of the invention, a structured coating is understood to be a coating on a substrate, wherein the substrate has coated and uncoated areas, the coated areas being arranged on the substrate surface such that adjacent coated areas are spaced apart from one another. Uncoated areas are located between adjacent coated areas. The coated and uncoated areas are arranged alternately on the substrate. In other words, the coating is interrupted (in particular regularly) by uncoated areas.The coated areas are arranged in particular in the form of a regular geometric pattern, for example in the form of parallel coated lines between which uncoated areas are arranged, as a matrix-like arrangement of coated points or surfaces on an otherwise uncoated surface or conversely as a coating with matrix-like arranged uncoated areas in the form of points or surfaces.

[0011] The surface of the glass substrate to be coated has masking areas and coating areas. Masking areas are those areas of the surface that are not to be subsequently coated with the desired coating (referred to as a functional coating in the context of the invention). Coating areas are those areas of the surface that are to be permanently coated with the desired coating. The masking areas or the coating areas can also be interconnected, so that, strictly speaking, there is only a single area instead of a multitude of areas.

[0012] The coating areas are arranged on the substrate surface such that adjacent coating areas are spaced apart. Masking areas are located between adjacent coating areas. This results in the structure of the coating. The coating areas are preferably arranged in a regular pattern on the substrate surface, but irregular structures are also possible in principle.

[0013] First, a structured masking coating is applied to a surface of the glass substrate. This masking coating is organic-polymeric and forms on the masking areas, while the coating areas remain uncoated. The coating areas can be excluded from the masking coating application from the outset, or the masking coating can be removed from the coating areas after application. The masking coating thus forms a negative image of the desired structured coating, with the masking areas completely covered and the coating areas remaining completely free of the masking coating.

[0014] After the masking coating has been created on the substrate surface, the functional coating, i.e., the ultimately desired coating, is applied to the same substrate surface using vacuum-based vapor deposition. The functional coating is then in contact with the substrate surface in the coating areas and with the masking coating to which it is applied in the masking areas.

[0015] After the functional coating has been applied, the glass substrate undergoes a heat treatment at a temperature of at least 200 °C. This thermally decomposes the masking coating, removing it and the functional coating it contains from the substrate surface. The functional coating, however, remains on the coated areas of the substrate surface. This creates the desired structured functional coating.

[0016] For the masking coating, an organic polymeric material is selected that is suitable for thermal decomposition during the final heat treatment, and in particular, for decomposition without leaving any residue. In a particularly proven design, the masking coating is based on a UV-curing lacquer, especially an acrylic lacquer. Such lacquers are easy to apply and readily removed by the final heat treatment. To create the masking coating, a coating solution containing the polymer precursors (monomers or oligomers), usually in a solvent, is applied to the surface of the substrate. Optionally, further additives such as photosensitizers and / or catalysts may also be included.The coating solution is then irradiated with UV radiation, initiating a polymerization reaction (especially radical polymerization) in which the precursors to the polymeric masking coating are cross-linked. Alternatively, other masking coatings are also conceivable, for example, those based on thermally curing lacquers, in which the polymer is dissolved in a solvent and deposits as a masking coating on the substrate surface when the solvent evaporates. In a preferred embodiment, the coating solution, whether based on a UV-curing or thermally curing lacquer, also contains an adhesion promoter that ensures the coating adheres to the glass surface. Besides acrylic lacquers, suitable resins include, for example, alkyd, polyester, epoxy, polyurethane, polystyrene, polyvinyl, or silicone resins.

[0017] The masking coating preferably has a layer thickness of 100 nm to 20 µm, particularly preferably from 500 nm to 15 µm, for example, about 10 µm. Within this range, the masking coating is sufficiently thick to reliably mask the substrate surface, yet thin enough to allow the formation of fine structures and to be effectively thermally decomposed. The finer the structures to be formed, the thinner the masking coating should be.

[0018] According to the invention, the functional coating is applied to the surface of the substrate and the masking coating by means of vacuum-based vapor deposition. In a preferred embodiment, the functional coating is applied by means of physical vapor deposition (PVD) or chemical vapor deposition (CVD), in particular by means of physical vapor deposition. Cathode sputtering has proven particularly effective ( Sputtern ) , in particular magnetic field-assisted cathode sputtering ( Magnetronsputtern ) ,which is widely used for producing thin films on glass substrates. However, other types of physical vapor deposition can also be used, such as thermal evaporation (vapor deposition), electron beam evaporation, laser beam evaporation, arc evaporation, or molecular beam epitaxy. Preferred CVD processes are plasma-enhanced chemical vapor deposition (PECVD) and atomic layer deposition (ALD).

[0019] The functional coating is preferably formed as a so-called thin film with a layer thickness in the micrometer or nanometer range. In a preferred embodiment, the layer thickness of the functional coating is from 10 nm to 50 µm, and particularly preferably from 50 nm to 20 µm. This yields especially good results. The exact layer thickness depends on the desired function of the coating and can be selected appropriately by a person skilled in the art.

[0020] In a preferred embodiment, the functional coating is based on a metal, a metal oxide, or a metal nitride. For the purposes of this invention, the term "metal" also includes semimetals. Suitable materials that have proven effective as coatings on glass substrates include, for example, silver (Ag), silicon (Si), aluminum (Al), tin (Sn), zinc (Zn), zirconium (Zr), vanadium (V), or titanium (Ti), as well as their nitrides and oxides, and nickel-chromium alloy (NiCr). Mixtures, alloys, or mutual doping of the aforementioned materials are also possible, for example, silicon-zirconium nitride (SiZrN), tin-zinc oxide (SnZnO), or aluminum-doped silicon nitride (SiN:Al). Nitrides and oxides can be formed stoichiometrically, substoichiometrically, or superstoichiometrically.The choice of material for the functional coating depends in particular on the requirements of the individual case and can be selected by a specialist according to the intended application.

[0021] Beneath the actual functional coating, further coatings can also be applied, such as adhesion promoter layers to improve the adhesion of the functional coating to the substrate, adaptation or smoothing layers to influence the morphology of the functional coating, or blocker layers to prevent alkali diffusion from the glass substrate into the functional layer. Suitable adhesion promoter layers are based, for example, on silicon nitride (SiN) or oxide (SiO) or aluminum nitride (AlN) or oxide (AlO), suitable adaptation layers are based, for example, on SnZnO or zinc oxide (ZnO), and suitable blocker layers are based, for example, on NiCr or SiN.

[0022] If the final functional coating is to be based on a metal oxide, then in process step (b) the pure metal can first be applied, which is later completely or partially oxidized to the metal oxide, for example during the final temperature treatment.

[0023] According to the invention, the heat treatment in process step (c) is carried out at a temperature of at least 200 °C, preferably at least 300 °C, particularly preferably at least 400 °C, and most preferably at least 500 °C. At such temperatures, conventional polymeric masking coatings are effectively thermally decomposed. The temperature in each individual case can be selected appropriately depending on the material used for the masking layer in order to ensure complete and rapid decomposition. In a particularly advantageous embodiment, the heat treatment is carried out as part of a tempering process in which the glass substrate is thermally tempered. In such a tempering process, the glass substrate is heated, typically to just below its softening temperature, and then rapidly cooled (quenched).This process creates characteristic stresses in the glass substrate (compressive stresses on the surfaces, tensile stresses in the core), thereby improving the glass's fracture resistance. Furthermore, in the event of breakage or penetration of the central tensile stress zone by a sharp object, the glass substrate shatters into very small fragments, posing only a minimal risk of injury. Typical temperatures for heating the glass substrate range from 600 °C to 800 °C, for example, 640 °C, 690 °C, or 750 °C. The glass is typically quenched by applying a stream of air.

[0024] The coating areas and masking areas can be created in any shape that a person skilled in the art can choose depending on the specific application. This flexibility is a major advantage of the invention. In an advantageous embodiment, the coating areas are arranged in a regular pattern, particularly preferably as parallel lines or as dots or circles in a matrix or grid-like arrangement. If the coating areas are formed as parallel lines, adjacent coating areas are separated by a masking area, which is also formed as a line. If the coating areas are arranged as a matrix of dots, the masking areas form a continuous area around the coating areas.For typical applications of structured coatings, the width of the coating areas and the distances between adjacent coating areas are preferably from 10 µm to 1 mm, and particularly preferably from 25 µm to 500 µm. The width is defined as the extent along the shortest length dimension, i.e., the line width or the diameter of the coating areas in the case of linear or circular coating areas. The distances are measured from the center of the coating areas; that is, in the case of linear coating areas, from the center of the lines, measured perpendicular to the direction of the lines, and in the case of circular coating areas, from the center of the circle.

[0025] The structured coating can essentially cover the entire surface of the substrate, so that the coated areas are distributed across the entire surface. However, it is equally possible to apply the structured coating to only a portion of the substrate's surface, while other areas of the surface remain uncoated.

[0026] The formation of the structured masking coating in process step (a) can be achieved in various ways. In a first embodiment of the process according to the invention, an organic coating solution is first applied to the masking areas and the coating areas, and then the masking coating is formed over a large area from the coating solution. In particular, the coating solution is polymerized and / or dried, whereby the masking coating is produced on the masking areas and the coating areas. Preferably, the masking coating is produced over the entire surface of the substrate. Subsequently, the masking coating is removed from the coating areas by means of laser radiation, in particular completely removed, so that it remains only on the masking areas.

[0027] If the masking coating is based on a UV-curing lacquer, the layer is formed by irradiation with UV radiation, for example with a wavelength of 250 nm to 400 nm, which initiates a polymerization process that creates the masking coating. Irradiation is preferably carried out over a large area using a UV lamp.

[0028] The removal of the masking coating from the coating areas is achieved using a laser with a wavelength at which the masking coating absorbs. For typical organic masking coatings, wavelengths from 250 nm to 600 nm are particularly suitable, preferably from 300 nm to 500 nm, and most preferably from 300 nm to 400 nm. For example, a frequency-doubled or frequency-tripled Nd:YAG laser, which is widely used and proven, can be employed, but other types of lasers such as dye lasers, semiconductor lasers, or fiber lasers are also suitable.

[0029] In an advantageous embodiment, the laser is operated in pulsed mode, preferably with pulses in the nanosecond or femtosecond range. The pulse energy is preferably from 20 µJ / pulse to 250 µJ / pulse, and particularly preferably from 50 µJ / pulse to 200 µJ / pulse. Particularly efficient laser ablation is achieved in this range. The pulse energy can be adjusted by the laser's output power, pulse repetition rate, and pulse duration. The output power is preferably from 1 W to 40 W (for example, 1 W to 10 W or 3 W to 6 W for nanosecond pulses, and 20 W to 30 W for femtosecond pulses), and the pulse repetition rate is preferably from 10 kHz to 100 kHz, and more preferably from 20 kHz to 50 kHz.

[0030] The area of ​​the laser spot on the masking coating depends on the dimensions of the coating areas and should be adapted to them in order to cover the entire width of the coating area as comprehensively as possible. This enables time-saving coating removal. For typical applications, the diameter of the laser spot is preferably from 1 µm to 100 µm, particularly preferably from 5 µm to 50 µm, and most preferably from 8 µm to 30 µm. In an advantageous embodiment, the power density of the laser radiation on the masking coating should be from 1 kW / mm² to 10 kW / mm², and particularly from 1 kW / mm² to 7.5 kW / mm². This achieves particularly efficient laser coating removal without placing excessive stress on the glass substrate. The power density is calculated by dividing the power of the laser radiation by the extent of the laser radiation on the opaque coating, expressed as the area ("area of ​​the laser spot").

[0031] Particularly when the coating areas are linear, the laser radiation is moved across the masking coating or the glass substrate at a speed of 0.5 m / s to 5 m / s, preferably 0.6 m / s to 3 m / s, for example, 0.6 m / s to 0.8 m / s. This is especially advantageous for time-saving yet complete coating removal. This refers to the relative movement, which can be achieved by moving the radiation, moving the substrate, or a combination of both. Preferably, the substrate remains stationary during coating removal while the laser radiation is moved. If the coating areas are point-like, the laser radiation can also be moved significantly slower, for example, from 1 to 50 mm / s.Ideally, the point-like coating areas are created without moving the laser by stationary irradiation, provided the size of the laser spot is matched to the size of the coating areas.

[0032] The laser radiation is preferably focused onto the masking coating by means of at least one optical element, such as a lens or objective. f-theta lenses or objectives are particularly suitable. These ensure that the foci of the laser radiation are arranged in a single plane at different exit angles, thus enabling a constant speed of movement of the laser radiation across the coating. The laser radiation can be guided between the laser and the focusing optical element by at least one optical waveguide, such as a fiber optic cable. Additional optical elements can also be arranged in the laser beam path, such as collimators, apertures, filters, or frequency doubling elements.

[0033] The laser beam is preferably moved by at least one mirror connected to a movable component. The movable component allows the mirror to be tilted in two directions, preferably two mutually orthogonal directions, most preferably horizontally and vertically. The laser beam can also be moved by several mirrors, each connected to a movable component. For example, the laser beam can be moved by two mirrors, one of which can be tilted horizontally and the other vertically.

[0034] The first embodiment of the invention described above is particularly suitable when the dimensions of the coating areas are relatively small. This is because the fine coating areas can be efficiently introduced into the large-area masking coating using the laser. The dimensions of the coating areas can be small compared to those of the masking areas (i.e., the distances between adjacent coating areas can be large compared to their dimensions) or be of the same order of magnitude.In an advantageous embodiment, the width of the coating areas (for example, the line widths in the case of linear coating areas and the circle diameters in the case of point-like coating areas) is from 5 µm to 100 µm, preferably from 10 µm to 50 µm, and the distances between adjacent coating areas are from 5 µm to 1 mm (for example, from 100 µm to 1 mm), preferably from 10 µm to 500 µm (for example, from 10 µm to 150 µm or from 150 µm to 500 µm). Larger coating areas can also be produced, for which the laser radiation is preferably moved across the coating area in a raster pattern.

[0035] In a second embodiment of the inventive method, an organic coating solution is first applied to the masking areas and the coating areas. Subsequently, the masking coating is formed from the coating solution only in the masking areas by means of laser radiation; in particular, the coating solution is polymerized and / or dried in the masking areas by means of laser radiation, so that the masking areas are provided with the masking coating, in particular completely provided, while the unprocessed (in particular unpolymerized) coating solution remains in the coating areas. The coating solution is then removed from the coating areas.

[0036] If the masking coating is based on a UV-curing lacquer, the laser radiation used for layer formation should ideally have a wavelength in the UV range, preferably between 250 nm and 400 nm. For example, a frequency-tripled Nd:YAG laser (355 nm) can be used. However, lacquers that can be polymerized with wavelengths up to 1000 nm are also known.

[0037] The laser can be operated in continuous wave mode or in pulsed mode. When operated in pulsed mode, the pulse energy is preferably from 1 nJ / pulse to 100 nJ / pulse, and particularly preferably from 2 nJ / pulse to 10 nJ / pulse. In this range, efficient layer formation is achieved without damaging the substrate or masking coating. The output power is preferably from 0.1 W to 10 W, and the pulse repetition frequency is preferably from 1 kHz to 250 MHz, and more preferably from 100 kHz to 1 MHz.

[0038] The area of ​​the laser spot on the coating solution depends on the dimensions of the masking areas and should be adapted to them to cover as much of the masking area as possible. This enables time-saving layer formation. For typical applications, the diameter of the laser spot is preferably from 5 µm to 50 µm, and particularly preferably from 8 µm to 30 µm. In an advantageous embodiment, the power density of the laser radiation on the coating solution should be from 10 µW / mm² to 200 kW / mm², and preferably from 20 µW / mm² to 45 kW / mm². This results in particularly good outcomes.

[0039] The laser radiation is preferably moved across the glass substrate at a speed of 0.5 m / s to 5 m / s, particularly preferably from 0.6 m / s to 3 m / s, and most preferably from 0.6 m / s to 1 m / s, for example from 0.6 m / s to 0.8 m / s. This is particularly advantageous with regard to time-saving yet complete layer formation. This refers to the relative motion, which can be achieved by moving the radiation, moving the substrate, or a combination of both. Preferably, the substrate remains stationary while the laser radiation is moved.

[0040] The laser radiation is preferably focused onto the coating solution by means of at least one optical element, for example a lens or objective, in particular by means of an f-theta lens or an f-theta objective. The movement of the laser radiation is preferably effected by at least one movable mirror, in particular by two mirrors, wherein one mirror can be tilted in the horizontal direction and the other mirror in the vertical direction.

[0041] The second embodiment of the invention described above is particularly suitable when the dimensions of the masking areas are relatively small. The fine masking areas can be efficiently coated with the masking layer using a laser. The dimensions of the coating areas can be large compared to those of the masking areas (i.e., the distances between adjacent coating areas can be small compared to their dimensions) or be of the same order of magnitude. In an advantageous embodiment, the width of the coating areas (for example, the line widths in the case of line-like coating areas and the circle diameters in the case of point-like coating areas) is from 5 µm to 1 mm, preferably from 100 µm to 1 mm, and particularly preferably from 150 µm to 500 µm, and the distances between adjacent coating areas are from 5 µm to 100 µm, preferably from 10 µm to 80 µm, and particularly preferably from 25 µm to 50 µm.However, larger masking areas can also be created, for which the laser radiation is preferably moved across the masking area in a grid-like pattern.

[0042] The coating solution can be removed from the coated areas, for example, by simple mechanical wiping. Preferably, however, the coating solution is removed with a solvent, in particular by wiping or rinsing, and most preferably by an organic solvent. The solvent is selected to efficiently remove the unprocessed coating solution from the coated areas without attacking the masking coating in those areas. For typical masking coatings, suitable solvents include, for example, toluene, ethyl acetate, acetone, dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), or dimethylformamide (DMF), especially when the masking coating is based on an acrylic lacquer.

[0043] The glass substrate is made of glass or glass-ceramic. In an advantageous embodiment, the glass substrate is made of soda-lime glass, which is commonly used as window glass. However, other types of glass are also conceivable, for example, borosilicate glass, aluminosilicate glass, or quartz glass. The thickness of the glass substrate can be freely selected according to the specific requirements. Typical thicknesses range from 2 mm to 20 mm, particularly from 3 mm to 6 mm. The glass substrate can be flat or curved in one or more directions. The glass substrate can also be part of a laminated glass unit, in which case the glass substrate is bonded to another pane via a thermoplastic interlayer (in particular, a PVB-EVA or PU film).

[0044] In an advantageous embodiment, the structured functional coating is suitable and designed to provide the disc with hydrophobic or superhydrophobic properties. In the case of hydrophobic properties, the contact angle of a water droplet is greater than 90°, and in the case of superhydrophobic properties, it is greater than 150°. In a further advantageous embodiment, the structured functional coating can provide the disc with desired optical properties, for example, with a reflective color, a specific scattering behavior, or increased or decreased light absorption. Such applications for structured coatings are known per se, and those skilled in the art can select the design of the coating with regard to material and layer thickness to meet the requirements of the individual case. However, other applications that can be realized with structured coatings are also conceivable.

[0045] The disc according to the invention with the structured coating is preferably used in the automotive, architectural, or household sectors. It can, for example, be used as a window pane in a vehicle or building, as a glass roof, as a refrigerator door, or as a shower cubicle. Such applications particularly benefit from hydrophobic properties or adjustable optical properties. A hydrophobic refrigerator door, for example, can have a low tendency to fog up, less liquid collects on a hydrophobic shower cubicle, and a hydrophobic glass roof facilitates the sliding of snow.

[0046] The invention is explained in more detail with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way. It shows: Fig. 1 a top view of a disc with a structured coating, Fig. 2 a top view of another disc with a structured coating, Fig. 3 an embodiment for producing the structured masking coating according to the invention, Fig. 4 a further embodiment for producing the structured masking coating according to the invention, Fig. 5 the production of a structured coating according to the invention starting from the disc made of Fig. 2 , Fig. 6 a flowchart of an embodiment of the method according to the invention, Fig. 7 a flowchart of a further embodiment of the method according to the invention, Fig. 8 a top view of another disc with a structured coating.

[0047] Fig. 1 Figure 1 shows an exemplary section of a disc with a structured coating that can be produced using the method according to the invention. The disc comprises a flat glass substrate 1 made of soda-lime glass with a thickness of, for example, 4 mm. One surface of the glass substrate 1 has masking areas M and coating areas B, which are arranged in the form of alternating, parallel lines, such that adjacent coating areas B are each separated from one another by a masking area M. The parallel lines extend, for example, over the entire surface of the glass substrate 1, but can also cover only a partial area of ​​the surface. The coating areas B have, for example, a width (line width) of about 50 µm, and the masking areas M of about 150 µm.

[0048] The coating areas B are completely covered with a functional coating 3. The functional coating 3 is, for example, made of titanium oxide (TiO) with a layer thickness of approximately 10 µm and is bonded to the surface of the glass substrate 1 via a 50 nm thick silicon nitride-based adhesive layer. Structured coatings of the type shown can, for example, be used to give the glass surface superhydrophobic properties, causing liquid droplets to bead up and roll off the surface.

[0049] Fig. 2 Figure 1 shows an example of a section of another disc with a structured coating that can be produced using the inventive method. The coating areas B with the functional coating 3 are formed here as points (more precisely, as full circles) and arranged in a matrix, i.e., in rows and columns. The structured coating does not extend over the entire surface of the glass substrate 1, but only over a sub-area that is to be provided with specific properties. The masking areas M form a continuous area around the coating areas B or the functional coating 3. The coating areas B with the functional coating 3 have, for example, a diameter of 50 µm and a center-to-center spacing of, for example, 150 µm.

[0050] Fig. 3 Figure 1 shows a disk at various times during the production of a structured polymeric masking coating 2 (first preferred embodiment). The masking coating 2 is, in effect, the negative of the planned structured functional coating 3. First, the glass substrate 1 is prepared with the planned masking areas M and coating areas B (part a). A masking coating 2 is then applied over the entire surface of the glass substrate 1 (part b). For this purpose, the surface is coated with a coating solution and irradiated over a large area with a UV lamp (not shown), which cross-links the components of the coating solution to form an acrylic lacquer that constitutes the masking coating 2. The masking coating 2 has, for example, a layer thickness of 10 µm.The masking coating 2 is then removed from the coating areas B by means of the radiation S of a laser L (part c) and remains only on the masking areas M, thereby creating the desired structured masking coating 2 (part d). The laser L is, for example, a frequency-tripled Nd:YAG laser with a wavelength of 355 nm. Its radiation S is focused onto the surface of the glass substrate 1 by means of a focusing element F, for example, a lens or objective, and moved along the linear coating areas B by means of one or more movable mirrors B at a speed of, for example, 0.75 m / s to remove the masking coating 2. The laser is pulsed with a pulse energy of, for example, 100 µJ / pulse.The size of the laser spot on the surface is chosen such that the width of the coating areas B is covered and the entire masking coating 2 is removed when the radiation S is moved once along the linear coating area B.

[0051] The first preferred embodiment shown is particularly suitable in the case where the masking areas M are wider than the coating areas B.

[0052] Fig. 4 Figure 1 shows a disk at various times during the production of a structured polymeric masking coating 2 according to an alternative process (second preferred embodiment). First, the glass substrate 1 with the planned masking areas M and coating areas B is prepared (part a). A coating solution C is applied over the entire surface of the glass substrate 1 (part b). Subsequently, the coating solution C is crosslinked in the masking areas M by means of the ultraviolet radiation S of a laser L to form an acrylic lacquer, which constitutes the masking coating 2 (part c). The laser L is, for example, a frequency-tripled Nd:YAG laser with a wavelength of 355 nm.Its radiation S is focused onto the surface of the glass substrate 1 by means of a focusing element F, for example a lens or objective, and moved along the linear masking areas M by means of one or more movable mirrors B at a speed of, for example, 0.75 m / s to form the masking coating 2. The laser is pulsed with a pulse energy of, for example, 4 nJ / pulse. The size of the laser spot on the surface is chosen such that the width of the masking areas M is covered and the entire coating solution C is crosslinked to form the masking coating 2 when the radiation S is moved once along the linear masking area M.

[0053] After the masking areas M have been coated with the masking coating 2 using the laser L, the unreacted coating solution C (not shown) remains in the coating areas B. This is then removed, for example by wiping or rinsing with an organic solvent such as toluene. The structured masking coating 2 remains on the masking areas M (part d).

[0054] The second preferred embodiment shown is particularly suitable in the case where the coating areas B are wider than the masking areas M.

[0055] Fig. 5 shows a disc at different times during an embodiment of the inventive production of a structured coating using the example of the glass substrate 1 with the structured masking coating 2 made of Fig. 3 However, the process is equally applicable to the glass substrate 1 made of Fig. 4 applicable. First, the glass substrate 1 with the masking coating 2 is prepared on the masking areas M (part a). Subsequently, a functional coating 3 is applied to the entire surface of the glass substrate 1 with the masking coating 2 (part b), for example by means of magnetic field-assisted cathode sputtering ( Magnetronsputtern ) .Optionally, an adhesive layer or other auxiliary layer can be applied before the functional coating 3. The glass substrate 1 is then subjected to a heat treatment, which can be carried out, for example, as part of a thermal tempering process in which the glass substrate 1 is heated to a temperature of, for example, 750 °C and subsequently quenched by an air stream. During this heat treatment, the polymeric masking coating 2 decomposes, so that it, along with the functional coating 2 applied to it, is removed from the masking areas M. The structured functional coating 3 remains on the coating areas B (part c), as shown in the example in Fig. 1 is shown.

[0056] If the functional coating 3 is to be made of a metal oxide, for example titanium oxide, the metal can be applied as a precursor using cathode sputtering, which is then oxidized to the oxide during the heat treatment.

[0057] Fig. 6 shows an embodiment of the method according to the invention by means of a flowchart (first preferred embodiment).

[0058] Fig. 7 Another embodiment of the method according to the invention is shown using a flowchart (second preferred embodiment).

[0059] Fig. 8 Figure 1 shows an exemplary section of another disc with a structured coating that can be produced using the inventive method. The coating areas B with the functional coating 3 are similar to those shown in Figure 2. Fig. 1 The coatings are arranged in the form of parallel lines, but not across the entire surface of the glass substrate 1, only over a partial area. Furthermore, there are two additional coating areas B that run perpendicular to the majority of the coating areas B and connect their ends. Strictly speaking, the coating areas B therefore form a continuous area, which, however, is internally structured and surrounds several masking areas M. Examples

[0060] Glass substrates 1 (soda-lime glass, 4 mm) were coated with structured masking coatings 2 of different designs. In each case, one surface of the glass substrate 1 was completely coated with a masking coating 2, which was a UV-curing acrylic lacquer with a layer thickness of approximately 10 µm. Subsequently, the masking coating was removed from the coated areas B using an Nd:YAG laser operating at either tripled frequency (355 nm) or doubled frequency (532 nm). The coated areas B were formed as lines, as shown in Fig. 1 represented, or dot-like in the form of a matrix as in Fig. 2 The dimensions of the coating areas B (line width or diameter) were varied over a range from approximately 25 µm to approximately 80 µm, and the distances between adjacent coating areas B from approximately 80 µm to approximately 500 µm.

[0061] In all examples, a structured masking coating 2 was successfully produced as planned. The substrates 1 were then coated with a 50 nm thick silicon nitride adhesive layer and subsequently with a 10 µm thick titanium functional coating 3. The glass substrates 1 were then heated to 750 °C and thermally prestressed. During this heat treatment, the masking coating 2 was completely decomposed in all cases, leaving behind an oxidized, structured titanium oxide functional coating 3. Reference symbol list:

[0062] (1) Glass substrate (2) Masking coating (3) Functional coating (M) Masking area of ​​the glass substrate 1 (B) Coating area of ​​the glass substrate 1 (C) Coating solution (L) Laser (S) Radiation of the laser L (F) Focusing element (B) Movable mirror

Claims

1. Method for producing a pane with a structured coating, comprising the following process steps: (a) forming an organic, polymeric masking coating (2) on masking regions (M) of a surface of a glass substrate (1), with coating regions (B) of the surface of the glass substrate (1) not being provided with the masking coating (2); (b) applying a functional coating (3) to the surface of the glass substrate (1) by means of vacuum-based vapor deposition; and (c) temperature treatment of the glass substrate (1) at a temperature of at least 200 °C, as a result of which the masking coating (2) with the functional coating (3) applied thereto is removed from the surface, the functional coating (3) remaining on the coating regions (B) of the surface, characterised in that in method step (a) (I) (a.1) an organic coating solution (C) is applied to the masking regions (M) and the coating regions (B), (a.2) the masking coating (2) is formed from the coating solution (C), and (a.3) the masking coating (2) is removed from the coating regions (B) by means of laser radiation (S), or (II) (a.1) an organic coating solution (C) is applied to the masking regions (M) and the coating regions (B), (a.2) in the masking regions (M), the masking coating (2) is formed from the coating solution (C) by means of laser radiation (S), and (a.3) the coating solution (C) is removed from the coating regions (B).

2. Method according to claim 1, wherein the coating regions (B) are arranged in the form of a regular pattern as parallel lines or in a dot-like or circular manner in a matrix- or grid-like arrangement and a masking region (M) is arranged between adjacent coating regions (B), and wherein the width of the coating regions (B) and the distances between adjacent coating regions (B) are from 10 µm to 1 mm.

3. Method according to claim 1 or 2, wherein the masking coating (2) is formed on the basis of a UV-curing lacquer, in particular a UV-curing acrylic lacquer.

4. Method according to one of claims 1 to 3, wherein the masking coating (2) has a thickness of 100 nm to 20 µm.

5. Method according to one of claims 1 to 4, carried out in variant (I), wherein the laser (L) is operated in pulsed mode with a pulse energy of 20 µJ / pulse to 250 µJ / pulse, preferably from 50 µJ / pulse to 200 µJ / pulse.

6. Method according to one of claims 1 to 4, carried out in variant (I), or according to claim 5, wherein the coating regions (B) are arranged in the form of a regular pattern as parallel lines or in a dot-like or circular manner in a matrix- or grid-like arrangement and the width of the coating regions (B) is from 5 µm to 100 µm and the distances between adjacent coating regions (B) are from 5 µm to 1 mm.

7. Method according to one of claims 1 to 4, carried out in variant (II), wherein the laser (L) is operated in pulsed mode with a pulse energy of 1 nJ / pulse to 100 nJ / pulse.

8. Method according to one of claims 1 to 4, carried out in variant (II), or according to claim 7, wherein the coating solution (C) in method step (a.3) is removed using an organic solvent.

9. Method according to one of claims 1 to 4, carried out in variant (II), or according to claim 7 or 8, wherein the coating regions (B) are arranged in the form of a regular pattern as parallel lines or in a dot-like or circular manner in a matrix- or grid-like arrangement and the width of the coating regions (B) is from 5 µm to 1 mm and the distances between adjacent coating regions (B) are from 5 µm to 100 µm.

10. Method according to one of claims 1 to 9, wherein the functional coating (3) is applied in method step (b) by means of physical vapour deposition, preferably by means of magnetic field-assisted cathode sputtering.

11. Method according to one of claims 1 to 10, wherein the temperature treatment in method step (c) takes place within the framework of a prestressing process in which the glass substrate (1) is thermally prestressed.

12. Method according to one of claims 1 to 11, wherein the glass substrate (1) is made of soda-lime glass with a thickness of 2 mm to 20 mm.

13. Method according to one of claims 1 to 12, wherein the functional coating (3) is suitable for providing the glass substrate (1) with hydrophobic or superhydrophobic properties, such that the contact angle of a water droplet is greater than 90°, preferably greater than 150°, or for providing it with improved optical properties, such that the reflection colour, scattering behaviour or light absorption of the glass substrate (1) is changed.