Coated metal sheet, coating compositions and uses of coated metal sheet

Abstract

A coated metal sheet, obtainable by a process for manufacturing a coated metal sheet comprising the following steps: (i) Providing a sheet of metal; (ii) Applying a coating composition to at least one side of the metal sheet; and (iii) Baking the coating composition; wherein - the coating composition includes a thermoplastic polymer; - the coating composition is a dispersion comprising the thermoplastic polymer in the form of dispersed particles; - the dispersed particles have a mean particle diameter of at least 10 µm; - the coating composition does not include any fluorinated compound; and - the application of the coating composition includes dip coating, doctor blade coating, casting, roller coating or a combination of two or more of these.

Description

Field of invention

[0001] The present invention further relates to a coated metal sheet. The present invention also relates to coating compositions for producing a coated metal sheet. Finally, the invention relates to a cooking or baking accessory, preferably a pan or pot, a component of a conveyor belt, or a sanitary or kitchen appliance, in particular a basin, such as a sink, comprising the coated metal sheet. Background of the invention

[0002] PTFE coatings are known from the prior art and are typically applied as a triple coating to higher-quality cookware. First, a base coat (inner layer), usually consisting of a solvent-soluble binder resin, for example, PAI dissolved in NMP, is wet-sprayed, dried, and pre-cured. Then, a transition layer and a topcoat are wet-sprayed on, the topcoat being primarily a fluoropolymer, usually PTFE. The entire coating is then baked for approximately 10 minutes at 420°C. These coatings can be modified with pigments and various fillers.

[0003] The use of fluoropolymers such as PTFE is disadvantageous in this context, primarily because the curing temperature at which a PTFE-containing coating is applied to a substrate is significantly higher than the decomposition temperature of PTFE. This can lead to the formation of hazardous substances, particularly per- and polyfluoroalkyl substances (PFAS). The use of bisphenols and polyethersulfones in such coatings can also be problematic for health and environmental reasons. Object of the invention

[0004] It is therefore the object of the present invention to provide a coated metal sheet, a method for producing the same, and coating compositions for producing the same, which overcome the disadvantages of the prior art, in particular to provide a high-quality coating on metal sheets without the use of critical substances, especially without fluoropolymers and without PFAS (per- or polyfluorinated alkyl substances), but preferably also without bisphenol or polyethersulfone. Disclosure of the invention

[0005] This problem is solved according to the subject matter of the independent claims. Preferred embodiments are described in the dependent claims and the following description.

[0006] The problem is solved in particular by a coated process for producing a coated metal sheet, which includes the following steps: (i) Providing a sheet of metal; (ii) Applying a coating composition to at least one side of the metal sheet; and (iii) Baking of the coating composition; where - the coating composition includes a thermoplastic polymer; - the coating composition is a dispersion comprising the thermoplastic polymer in the form of dispersed particles; - the dispersed particles have a mean particle diameter of at least 10 µm; - the coating composition does not include any fluorinated compound, in particular no fluoropolymer, no per- and polyfluoroalkyl substances, no polytetrafluoroethylene, no hexafluoropropylene oxide dimeric acid (GenX), no bisphenol, no polyethersulfone, no N-methyl-2-pyrrolidone and no N-ethyl-2-pyrrolidone; and - the application of the coating composition includes dip coating, doctor blade coating, casting, roller coating or a combination of two or more of these.

[0007] The problem is further solved by a coated metal sheet, which can be obtained according to the previously described method, comprising the coated metal sheet - a sheet of metal; and - a coating on at least one side of the metal sheet.

[0008] The problem is further solved by a coating composition for producing an inner partial layer of a coated metal sheet, comprising: - 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 50 parts by weight of a solid mixture, based on the total weight of the coating composition, wherein the solid mixture is dispersed in the solvent mixture; where - the solid mixture contains 80 to 120 parts by weight of a thermoplastic polymer, wherein the thermoplastic polymer is selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide and a mixture of two or more thereof, based on the total weight of the solid mixture; and wherein the coating composition does not include a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone.

[0009] The problem is further solved by a coating composition for producing an outer partial layer of a coated metal sheet, comprising: - 40 to 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 40 parts by weight of a silicone oil, a silicone resin or a mixture of two or more thereof; where - is an organic solvent with a boiling point of more than 100°C under normal pressure or consists of a mixture of two or more solvents, each with a boiling point of more than 100°C under normal pressure; wherein the coating composition does not include a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone.

[0010] The problem is further solved by a coating composition for producing an outer partial layer of a coated metal sheet, comprising: - 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 50 parts by weight of a solid mixture, based on the total weight of the coating composition, wherein the solid mixture is dispersed in the solvent mixture; where - the solvent is an organic solvent with a boiling point of more than 100°C under normal pressure or consists of a mixture of two or more solvents, each with a boiling point of more than 100°C under normal pressure; - the solid mixture contains 70 to 100 parts by weight of a thermoplastic polymer, wherein the thermoplastic polymer is selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide, a polyimide and a mixture of two or more thereof, based on the total weight of the solid mixture; and wherein the coating composition does not include a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone.

[0011] Finally, the task is solved by a cooking or baking accessory, preferably a pan or pot, a component of a conveyor belt or a sanitary or kitchen appliance, in particular a basin, such as a sink, comprising the coated metal sheet. Method for producing a coated metal sheet

[0012] A first aspect of the present invention relates to a coated metal sheet obtainable by a method for producing a coated metal sheet. Surprisingly, it was found that the method according to the invention, as described in detail below with reference to preferred embodiments, leads to the production of a coated metal strip that was particularly easy to process. In particular, no significant delamination of the coating from the metal sheet and high scratch resistance were observed. Especially in tests under 20 N using an Ericsson test bar, no delamination was observed, only plastic indentations. Even with tight forming operations of the coated sheets with a radius of only 0.5 mm, no delamination occurred. In particular, the metal sheet coated in this way can be formed dry, without the need to add oil or apply an additional film.Bearings produced in this way from metal sheet coated according to the invention have particularly good wear properties.

[0013] In particular, the coated metal sheet according to the invention can be understood as a pre-coated metal sheet. In this context, a pre-coated metal sheet refers to a coated metal sheet which, after the coating has been applied, is transformed by forming into a product intended for use, such as a product with a storage function, baking or cooking accessories, preferably a pan or pot, a baking tray, baking molds, a cake tray, a pie plate, or sanitary or kitchen equipment, in particular a basin, such as a sink, with a non-stick effect. Surprisingly, it was found that the coating in the coated metal sheet according to the invention withstands subsequent forming without (significant) damage. The advantages of the coating are thus reflected as properties of the formed material.The subsequent forming process can be embossing, drawing, rolling, bending, punching, or a combination of two or more of these. Within the scope of the invention described herein, corresponding products can be manufactured more cost-effectively and to a higher quality than is possible according to the prior art. For example, a Bundt cake mold or a bearing with a layer thickness of 40-50 µm can be manufactured simply and cost-effectively. Providing a sheet of metal

[0014] The process for manufacturing the coated metal sheet includes, as a first step, the provision of a metal sheet.

[0015] The metal sheet can be a metal strip, a metal sheet (such as a coiled metal sheet), a pre-coated metal sheet, a blank (round sheet metal blank), a rectangular blank (for example, for the production of baking trays), or a Gastronorm container (GN container). Blanks, blanks, and GN containers can be coated while lying on a conveyor belt. For blanks, especially pan blanks, the coating can be applied by pad printing.

[0016] The metal sheet can be single-layered or multi-layered, in the latter case comprising or consisting of several metal layers in direct contact with each other, whereby the metal or metals that form the respective metal layers can be the same or different independently of each other.

[0017] The metal sheet essentially comprises or (preferably) consists of a metal or a mixture of two or more metals. Preferably, the metal can be independently selected from the group consisting of aluminum, iron, in particular stainless steel, aluminized steel, galvanized steel, chromated steel, nickel-plated steel, titanium, and copper, and mixtures thereof, in particular multilayer materials such as steel / aluminum / steel.

[0018] The metal sheet can have a thickness in the range of 0.05 to 5 mm, preferably 0.1 to 3 mm. The metal sheet can be made of steel and have a thickness in the range of 0.1 to 1 mm, preferably 0.15 to 0.6 mm. The metal sheet can be made of aluminum, copper, titanium, or a mixture of two or more of these, preferably aluminum, and have a thickness in the range of 1 to 3 mm, preferably 1.5 to 2.5 mm. The metal sheet can be a multilayer material and have a total thickness of 0.9 to 2.6 mm, wherein the multilayer material preferably has a steel / aluminum / steel structure and the steel layers each have a thickness of no more than 0.6 mm.

[0019] The thicknesses specified herein, particularly of the metal sheet and the coating, were determined in accordance with DIN EN ISO 2808:2019-12 in the version valid on the priority date. The specified coating thicknesses are average values ​​resulting from at least three measurements at one location and at least three different locations on a surface. The coating thickness is measured using a coating thickness gauge, e.g., the "QNIX 4500" device from Automation Dr. Nix GmbH & Co KG. For non-magnetic substrates and coatings, the measurement is performed using eddy currents (DIN EN ISO 2360 in the version valid on the priority date, ASTM D7091 in the version valid on the priority date). The principles of measurement technology are observed (DIN 1319, Parts 1 and 3 in the version valid on the priority date). Applying a coating composition

[0020] In the next process step, a coating composition is applied to at least one side of the metal sheet. The coating composition can be applied to the entire relevant side (entire relevant surface) of the metal sheet or only to a part of it.

[0021] According to the invention, the application of the coating composition comprises dip coating, doctor blade coating, casting, roller coating, or a combination of two or more of these. Surprisingly, it has been found that the coating composition, with at least technically insoluble thermoplastics such as PEEK, PPS, etc., without soluble components such as PAI or PES in an aqueous or substantially water-based dispersion, can be applied by these techniques, optionally dried, optionally tempered, and even baked above the liquidus temperature of the thermoplastics, and that a uniform and smooth coated metal sheet is obtained, which can be used advantageously for non-stick, wear-resistant, sliding, and insulating applications. Other non-aqueous solvents are also possible, without changing the fact that the thermoplastic polymer powder particles remain insoluble.

[0022] The coating can be applied using the coil coating process.

[0023] The application process may include a step of dipping the metal sheet into the coating solution, followed by a step of rolling the resulting coated metal sheet. This allows for a particularly uniform coating.

[0024] One step of dipping to apply the coating composition is particularly advantageous because no overspray and therefore no waste is produced, and the metal sheet can be completely surrounded and wetted by the dispersion liquid.

[0025] For example, the coating composition can be applied using coating rollers. At least two rollers, rotating either in the same direction or in opposite directions, are used. The coating composition is applied to the first roller. From there, the coating composition is transferred directly or indirectly and uniformly to a second roller, the coating roller. From there, the coating composition is applied to the metal strip to be coated. This type of coating (roller application) is advantageous for coating the two sides of the metal strip with different layer thicknesses or with different layer compositions. It also allows for simple one-sided coating.

[0026] In a preferred process step, the application may comprise one or more of the following sub-steps: A metal strip, preferably with a thickness between 0.05 mm and 3 mm, is unwound and coated over its entire width or a portion thereof by coating rollers rotating in the same or opposite directions. Two or three rollers are used to distribute the coating composition (“coating”) evenly. The coating composition is defined herein. The coating composition is contained in a container from which a required quantity is pumped and poured onto the metering roller, forming a bead of coating between the metering roller and the coating roller, or between the metering roller and the transfer roller. The coating composition is then applied to the metal strip via the coating roller. The metal strip may have been previously cleaned, degreased, and optionally roughened and / or treated with an adhesion promoter.Examples of adhesion promoters include titanates, zirconates, silanes, as well as metals and their oxides, for example chromium, nickel, aluminium, etc.

[0027] The coated strip enters an oven chamber for solvent evaporation and is dried, resulting in a powdery coating consisting of the solid components of the dispersion. Upon further heating in a hotter oven zone, the thermoplastic material liquefies and forms a uniform liquid film on the metal strip, thereby establishing adhesion.

[0028] The strip is then cooled, and the applied material solidifies into a firm, uniform coating. Finally, the metal strip is wound up. For further processing, the coated metal strip is unwound by the customer and processed in standard deep-drawing, forming, or stamping presses.

[0029] Surprisingly, the formation of a homogeneous and continuous coating using the described roller application process is very thin, even thinner than the average particle size. Layer thicknesses in the range of 4-8 µm were achieved with powder particle sizes of D50 = 25 µm. This is significant because milling these high-performance thermoplastic polymers is very expensive, and the costs increase exponentially with decreasing particle size.

[0030] According to the invention, the coating composition is a dispersion comprising the thermoplastic polymer in the form of dispersed particles. The dispersed particles have a mean particle size (particle diameter) D50 of at least 10 µm. It is possible for the dispersed particles to have a mean particle diameter selected from the group consisting of at least 15 µm, at least 20 µm, at least 25 µm, and at least 30 µm. In this context, it is possible for the particles to have a mean particle size (particle diameter) D50 of 60 µm or less, 50 µm or less, 40 µm or less, 30 µm or less, or 25 µm or less according to ISO 13320-1 in the version valid on the priority date. The particle size D50 is a statistical characteristic value derived from a particle size distribution.It describes the particle size below which 50% of the total mass of the particles lies.

[0031] It may be provided that a mixture of particles of different average particle sizes D50 is included in the dispersion.

[0032] The dispersion may be designed to have a solids content of at least 5% by weight, at least 7.5% by weight, or at least 10% by weight, based on the total weight of the dispersion. It may also be designed to have a solids content of at most 50% by weight, at most 40% by weight, or at most 30% by weight, based on the total weight of the dispersion. The viscosity of the dispersion can be adjusted and a desirable coating thickness achieved by appropriately adjusting the quantities of solids.

[0033] The dispersion may be aqueous. The aqueous dispersion may be entirely aqueous, i.e., comprising water as the sole dispersing agent. Alternatively, the aqueous dispersion may contain, in addition to water, at least one solvent, preferably an alcohol, for example, ethylene glycol, propylene glycol, or isopropanol. Frost resistance for transport may be achieved, for example, by the addition of ethylene glycol, propylene glycol, or isopropanol.

[0034] The aqueous dispersion may further contain one or more coating additives. The coating additive may be selected from the group consisting of a thickener, a wetting agent, a defoamer, and an adhesion promoter (preferably zirconate, titanate, or silane). These may be decomposed during the tempering or baking process and are then no longer present in the final coating.

[0035] The thickener may be an acrylate. The acrylate may be an acrylate resin and / or an acrylic copolymer.

[0036] It may be specified that the acrylate resin has a viscosity of 400 to 1200 mPas·s, of 500 to 1100 mPas·s, or of 550 to 1070 mPas·s, according to DIN 51562-1 in the version valid on the priority date.

[0037] It may be specified that the acrylate resin has a weight-mean molecular weight (Mw) of 100,000 to 500,000 g / mol, 100,000 to 300,000 g / mol, 100,000 to 200,000 g / mol, or 120,000 to 160,000 g / mol, for example, approximately 140,000 g / mol, as measured by GPC. For the corresponding GPC measurement, 8 mg of the sample were dissolved in 8 ml of 1,2,4-trichlorobenzene at 160°C for 90 min. Then, 200 µl of the sample solution were injected into the high-temperature GPC with IR5, an infrared detector (Polymer Char, Spain), at a flow rate of 0.5 ml / min at 145°C in the column zone and 160°C in the detector zone. Data was processed using the software GPC One® (Polymer Char, Spain).

[0038] It may be provided that the acrylate resin has a glass transition temperature of 30 to 40 °C or of 32 to 36 °C, for example about 34 °C, according to ISO 11337-1 in the version valid on the priority date.

[0039] The coating composition may include an additive. The additive may be a dispersant, for example a multifunctional amino alcohol additive such as 2-amino-2-methyl-1-propanol, a lubricant such as titanium dioxide, or a cross-linking agent, in particular a cross-linking agent for cross-linking silicone oils and / or resins, or a mixture of two or more of these.

[0040] It may be possible to repeat the application process multiple times. In this context, it may be possible to cure the applied coating composition after one, several, or (preferably) each application step before applying the next coating composition. The curing temperature in each subsequent step may be equal to, or preferably lower than, any curing temperature in the preceding curing steps. This allows the required coating thickness and / or desired properties to be achieved. In particular, it allows for the achievement of high coating thicknesses, greater than the thickness of the metal sheet, and the sealing of the metal sheet, thus producing a dense coating.

[0041] It can be provided that the application is carried out multiple times and that a different coating composition is used in at least one application step than in the other application steps. According to the invention, it is only necessary that at least one of the applied coating compositions, preferably the coating composition that is applied directly to the metal sheet, comprises the thermoplastic polymer, which is preferably selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide, or a mixture of two or more thereof.In one or more further layers, preferably in layers that are not in direct contact with the metal sheet, a thermoplastic polymer may be included, which is preferably selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide, a polyimide, a polyamide-imide or a mixture of two or more thereof, preferably a polyaryletherketone (PAEK), a polyarylene sulfide, a polyimide or a mixture of two or more thereof.

[0042] The coating does not comprise any fluoropolymer, in particular no PTFE, i.e., it is free of fluoropolymer, especially PTFE. According to the invention, this is particularly the case if the coating comprises at most 1000 ppb, preferably at most 100 ppb, and particularly preferably at most 25 ppb total fluorides, as measured by time-of-flight ion chromatography (TOF-CIC).

[0043] Specifically, to carry out the combustion ion chromatography (TOF-CIC) measurement method according to the invention, samples of the coating are filled into ceramic boats and placed in an oven where pyrohydrolysis takes place at 900-1000 °C in a humid, O2-rich environment. Under these conditions, the samples are oxidized, the strong carbon-fluorine bond is broken, and the vapors are passed through an absorption solution containing Ar. The HF produced during the combustion of organic fluorine dissociates in the absorption solution to form H₂. + - and F - -ions. The samples of the absorption solution, which also contains an internal standard for calibrating the analytical results, are then transferred to an ion chromatograph for analysis, where fluoride is measured.

[0044] It may be provided that all applied coating compositions do not contain bisphenol. Bisphenols are a group of chemical compounds consisting of two phenol groups linked by a bridge structure – often via a carbon or other alkyl group. It may be provided that all applied coating compositions do not contain substances used to manufacture bisphenols. It may be provided that all applied coating compositions do not contain polyethersulfone. It may be provided that the coating composition does not contain fluoropolymers, per- and polyfluoroalkyl substances, polytetrafluoroethylene, hexafluoropropylene oxide dimeric acid (GenX), PFSA, PFOA, bisphenol, preferably also substances used to manufacture bisphenols, polyethersulfone, N-methyl-2-pyrrolidone, or N-ethyl-2-pyrrolidone.

[0045] The terms "free from", "does not contain", "comprises no", etc., used in this context, do not exclude impurities that cannot be removed by standard purification steps of the commercially available materials used. These impurities have no technical impact with regard to the objective of the present invention.

[0046] The coating composition includes a thermoplastic polymer. A thermoplastic polymer is a plastic that becomes soft or molten when heated, allowing it to be shaped or processed – and solidifies again upon cooling without undergoing any chemical change.

[0047] The thermoplastic polymer contained in the coating composition may be selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide, and a mixture of two or more thereof. It may be provided that the thermoplastic polymer contained in the coating is selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide, or a mixture of two or more thereof.

[0048] The preferred thermoplastics are selected for continuous use at temperatures above 220°C, preferably above 240°C, and then preferably from the PAEK group (PEEK, PEK, PEKK, PEKEKK etc. and their copolymers) and PPS.

[0049] Preferably, the coating composition may include at least two PAEK polymers, or at least one PAEK polymer and one PPS polymer. Preferably, the at least two PAEK polymers, or at least one PAEK polymer and at least one PPS polymer, have different melting temperatures. Preferably, the two PAEK polymers, or at least one PAEK polymer and at least one PPS polymer, have different melt viscosities, measured according to ISO 11443 at 400°C in the version valid on the priority date. Preferably, the average melt viscosity of at least one thermoplastic polymer is more than 150 Pa·s, more preferably 200–500 Pa·s, and more preferably 300–500 Pa·s, measured according to ISO 11443 at 400°C in the version valid on the priority date. This particularly improves the adhesion of the second layer to the first layer.Preferably, the mean melt viscosity of at least one further thermoplastic polymer is at most 150 Pa·s, more preferably at most 120 Pa·s, more preferably at most 100 Pa·s, or particularly preferably at most 90 Pa·s, measured according to ISO 11443 at 400°C in the version valid on the priority date. This allows the coating to be applied to a surface to be coated to be significantly smoother when heated. The non-stick effect of the coated surface is thereby improved. This applies even if the particles are large relative to the layer thickness (e.g., 25 µm particle size D50 for a 25 µm layer thickness).

[0050] Preferably, the coating composition comprises at least two thermoplastic polymers, and preferably, powder particles comprising a first thermoplastic polymer have a mass-specific particle size distribution D50, measured by static image analysis according to ISO 13322-1:2014, which is at most 70 µm, preferably at most 60 µm, more preferably at most 50 µm, even more preferably at most 40 µm, and particularly preferably at most 30 µm. Preferably, powder particles comprising a second thermoplastic polymer have a mass-specific particle size distribution D50, measured by static image analysis according to ISO 13322-1:2014, which is at most 30 µm, preferably 25 µm, more preferably at most 20 µm, even more preferably at most 15 µm, and particularly preferably 10 µm. This can increase the mechanical resistance.Even smaller mass-related concentrations of PEK and / or PEKK as a second thermoplastic polymer of at least 2 wt.%, preferably at least 5 wt.%, and particularly preferably at least 10 wt.%, result in a wear-reducing effect. Conversely, the use of PPS as the first thermoplastic polymer in an amount of up to 80 wt.%, 90 wt.%, or 95 wt.% can further reduce the curing temperature during coating production and further improve the non-stick effect of the coating.

[0051] It can be provided that the thermoplastic polymer is at least one thermoplastic polymer with a mean melt viscosity of more than 150 Pa·s, preferably 200–500 Pa·s, more preferably 300–500 Pa·s, and preferably also a thermoplastic polymer with a mean melt viscosity of at most 150 Pa·s, more preferably at most 120 Pa·s, more preferably at most 100 Pa·s, or particularly preferably at most 90 Pa·s, measured according to ISO 11443 at 400°C in the version valid on the priority date. Using a thermoplastic polymer with a mean melt viscosity greater than or equal to 150 Pa·s improves adhesion to the metal sheet as well as mechanical strength and ductility. Using a further thermoplastic polymer with a mean melt viscosity of at most 150 Pa·s improves the coating's flow during production.In addition, it facilitates the production of a sufficiently fine dispersion (relative to the solid).

[0052] The PAEK, preferably the PEEK, can have a density of 1.27 to 1.37 g / cm³ 3 , from 1.30 to 1.34 g / cm³ 3 , for example, about 1.32 g / cm³ 3 , according to ISO 1183 in the version valid on the priority date.

[0053] The PAEK, preferably the PEEK, can have a continuous service temperature of more than 250°C, from 250°C to 300°C, for example 260°C (or 260°C) or more. The continuous service temperature is the highest temperature at which a polymer or plastic can be used for a long period of time (typically ≥ 20,000 hours) without significant impairment of its mechanical, electrical, or thermal properties.

[0054] The PAEK, preferably the PEEK, can have a glass transition temperature of 130°C to 160°C or of 140°C to 150°C, for example of about 143°C, as measured by DSC.

[0055] The PAEK, preferably the PEEK, can have a melting temperature of 300°C to 400°C, of ​​320°C to 360°C or of 340°C to 350°C, for example of about 343°C, as measured by DSC.

[0056] The PAEK, preferably the PEEK, can have a König hardness of 150 to 250 sec, of 180 to 220 sec, or of 190 to 210 sec, for example about 200 sec, according to ISO 1522 in the version valid on the priority date.

[0057] The PAEK, preferably the PEEK, can have a drying temperature of 100 to 200°C, for example of about 150°C, with a drying time of 1 to 5 h, for example about 3 h.

[0058] Suitable PAEKs, in particular PEEKs, with one or preferably several of the properties described above have proven to be particularly suitable for producing a coating with similar or even better properties compared to a corresponding PTFE-containing coating.

[0059] It may be intended that the polyarylene sulfide is a polyphenylene sulfide (PPS).

[0060] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a particle size (diameter of the particles) D10 of 1 to 15 µm, of 3 to 12 µm, or of 5 to 9 µm according to ISO 13320-1 in the version valid on the priority date. The particle size D10 is a statistical characteristic value derived from a particle size distribution. It describes the particle size below which 10% of the total mass of the particles lies.

[0061] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a particle size (diameter of the particles) D50 of 5 to 30 µm, of 7 to 26 µm, or of 8.7 to 24 µm according to ISO 13320-1 in the version valid on the priority date. The particle size D50 is a statistical characteristic value derived from a particle size distribution. It describes the particle size below which 50% of the total mass of the particles lies.

[0062] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a particle size (diameter of the particles) D90 of 10 to 100 µm, 12 to 70 µm, or 15 to 50 µm according to ISO 13320-1 in the version valid on the priority date. The particle size D90 is a statistical characteristic value derived from a particle size distribution. It describes the particle size below which 90% of the total mass of the particles lies.

[0063] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a maximum particle size (diameter of the particles) of 20 to 200 µm, of 40 to 150 µm or of 43 to 145 µm according to ISO 13320-1 in the version valid on the priority date.

[0064] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a density of 0.25 to 0.40 g / ml or of 0.28 to 0.34 g / ml according to ASTM D 1895 as amended on the priority date.

[0065] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a melt flow rate at 315°C / 5kg of 4000 to 5000 g / 10 min, of 4200 to 4800 g / 10 min or of 4400 to 4600 g / 10 min, for example about 4500 g / 10 min according to ISO 1133-1 in the version valid on the priority date.

[0066] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a melting temperature of 250 to 300°C, of ​​270 to 290°C or of 280 to 287°C, according to ISO 11337-1 in the version valid on the priority date.

[0067] It may be provided that the polyarylene sulfide, preferably the polyphenylene sulfide, has a glass transition temperature of 70 to 100°C, of ​​80 to 100°C or of about 90°C, according to ISO 11337-1 in the version valid on the priority date.

[0068] Corresponding polyarylene sulfides with a high melt flow rate and / or narrow particle size distribution exhibit excellent properties for the production of the coating, including high temperature resistance, excellent corrosion protection and good flame retardancy.

[0069] The coating composition may include polyarylene sulfide, preferably PPS, preferably in an amount of at least 10% by weight, based on the total weight of the coating composition.

[0070] The coating composition may further comprise at least one filler, preferably a mineral filler, a ceramic filler, or a mixture of two or more thereof, wherein the filler may be a dry lubricant. The filler may be selected from the group consisting of graphite, MoS₂, boron nitride, Al₂O₃, BaSO₄, iron oxide, or a mixture of two or more thereof.

[0071] The coating composition may also include a dry lubricant. This dry lubricant may be graphite, MoS2, boron nitride, or a mixture of two or more of these. This can further improve the cohesion of sub-layers and wear resistance.

[0072] The coating composition may include the dry lubricant in an amount of 0.1 to 20 wt.%, based on the total weight of the solid contained in the coating composition.

[0073] It may be specified that the graphite has a carbon content of 96 to 98 wt.% and an ash content of 2 to 4 wt.%.

[0074] It may be specified that the graphite has a grain size distribution, min. 99.9%, of less than 60 µm, less than 50 µm or less than 40 µm.

[0075] The graphite may have a particle size (diameter of the particles) D50 of 1 to 10 µm, 2 to 7 µm, or 3 to 5 µm, measured by laser diffraction. It may also have a particle size (diameter of the particles) D50 of 2 to 15 µm, 5 to 10 µm, or 6 to 8.5 µm, measured by laser diffraction. Finally, it may be possible to specify a particle size (diameter of the particles) D90 of 10 to 50 µm, 15 to 25 µm, or 15 to 20 µm, measured by laser diffraction.

[0076] It may be provided that the boron nitride has a particle size (diameter of the particles) D50 of 0.5 to 50 µm, of 5 to 20 µm or of 10 to 15 µm, for example about 12 µm measured by laser diffraction according to ASTM B822.

[0077] It may be provided that the boron nitride has a specific surface area (BET) of 1 to 20 m². 2 / g or from 5 to 10 m 2 / g, for example about 7 m2 / g has.

[0078] It may be provided that the MoS2 has a particle size (diameter of the particles) D50 of 0.1 µm to 10 µm, of 0.5 µm to 5 µm or of 1 µm to 2 µm.

[0079] It may be provided that the coating composition also includes an oil or resin.

[0080] It may be specified that the oil is a silicone oil. It may be specified that the silicone oil is selected from the group consisting of polyether-functionalized polydimethylsiloxane, polyethersiloxane copolymer, and polydimethylsiloxane.

[0081] It may be assumed that the polyether-functionalized polydimethylsiloxane has a kinematic viscosity of 500 to 200 mm. 2 / s or from 600 to 1400 mm 2 / s according to DIN 51562-1 in the version valid on the priority date.

[0082] It may be provided that the polyether-functionalized polydimethylsiloxane has a refractive index of 1.4500 to 1.4550 according to DIN 51423 in the version valid on the priority date.

[0083] It may be intended that the polyether-functionalized polydimethylsiloxane has a cloud point of 37 to 40°C.

[0084] It may be assumed that the polyether-functionalized polydimethylsiloxane has a density of 1.00 to 1.10 g / cm³ 3 , for example, about 1.04 g / cm³ 3 according to DIN 51757 in the version valid on the priority date.

[0085] It may be provided that the polyether-functionalized polydimethylsiloxane has a volatility (5g / 2h / 150°C) of 0.0 to 3.0 wt.%.

[0086] It may be specified that the polydimethylsiloxane has a refractive index of 1.400 to 1.410, for example about 1.404.

[0087] It may be assumed that the polydimethylsiloxane has a density of 0.9 to 1.0 g / cm³. 3 or from 0.95 to 0.99 g / cm³ 3 , for example, approximately 0.97 g / cm³ 3 according to DIN 51757 in the version valid on the priority date.

[0088] It may be provided that the polydimethylsiloxane has a flash point of more than 300°C according to ISO 2592 in the version valid on the priority date.

[0089] Alternatively, it may be provided that the polydimethylsiloxane has a flash point of more than 250°C, of ​​270°C to 300°C or of 270°C to 280°C, for example about 274°C according to ISO 2719 in the version valid on the priority date.

[0090] It may be stipulated that the polydimethylsiloxane has an ignition temperature of 400 to 500°C or of 410 to 450°C according to DIN 51794 in the version valid on the priority date.

[0091] It may be assumed that the polydimethylsiloxane has a kinematic viscosity of 500 mm. 2 / s up to 15000 mm 2 or 1000 mm 2 / s up to 10000 mm 2 at 25°C according to DIN 53019 in the version valid on the priority date.

[0092] It may be assumed that the polydimethylsiloxane has a kinematic viscosity of 500 mm. 2 / s up to 1500 mm 2 or 800 mm 2 / s up to 1200 mm 2 / s, for example about 1000 mm 2 / s 25°C according to DIN 53019 in the version valid on the priority date.

[0093] Alternatively, it can be stipulated that the polydimethylsiloxane has a kinematic viscosity of 5000 mm. 2 / s up to 15000 mm 2 or 8000 mm 2 / s up to 12000 mm 2 , for example, about 10000 mm 2 / s 25°C according to DIN 53019 in the version valid on the priority date.

[0094] It may be intended that the resin is a silicone resin.

[0095] The silicone resin may be expected to have a weight-mean molecular weight (Mw) of 2000 to 5000 g / mol, or of 2000 to 3000 g / mol, for example, approximately 2600 g / mol, as measured by GPC. For corresponding GPC measurements, 8 mg of the sample was dissolved in 8 ml of 1,2,4-trichlorobenzene at 160°C for 90 min. Then, 200 µl of the sample solution was injected into the high-temperature GPC system with an IR5 infrared detector (Polymer Char, Spain) at a flow rate of 0.5 ml / min at 145°C in the column zone and 160°C in the detector zone. The data were processed using the GPC One® software (Polymer Char, Spain).

[0096] It may be specified that the silicone resin has an OH content of 3.5 to 7 wt.%, based on the total weight of the silicone resin.

[0097] The silicone resin may be used in the form of flakes and / or granulated flakes and / or a powder for the production of the coating. Alternatively, the silicone resin may be used in the form of an emulsion or a solution.

[0098] It may be specified that the silicone resin has a bulk density of 500 to 700 kg / m³. 3 , from 530 to 650 kg / m² 3 or from 550 to 610 kg / m² 3 according to DIN 53466 in the version valid on the priority date.

[0099] It may be provided that the silicone resin has a carbon content of 15 to 20 wt.%, for example about 18 wt.%, based on the total weight of the silicone resin.

[0100] It may be provided that the silicone resin has a melting point of 30 to 60°C, preferably of 35 to 55°C as measured by DSC.

[0101] It may be provided that the silicone resin is used in the form of a powder and has a particle size D10 of 5 to 10 µm or of 6 to 8 µm, for example about 7.2 µm, a particle size D50 of 10 to 30 µm, or of 15 to 25 µm, for example about 21.8 µm and a particle size D90 of 40 to 80 µm or of 60 to 70 µm, for example about 58.7 µm, each according to ISO 13322 in the version valid on the priority date.

[0102] Alternatively, it may be provided that the silicone resin is used in the form of flakes and has a particle size D10 of 200 to 1000 µm or of 600 to 700 µm, for example about 750 µm, a particle size D50 of 1500 to 2500 µm, or of 2000 to 2200 µm, for example about 2100 µm and a particle size D90 of 2500 to 3500 µm or of 3000 to 3200 µm, for example about 3100 µm, each according to ISO 13322 in the version valid on the priority date.

[0103] The coating composition may further comprise a pigment, preferably a black pigment. An example of a suitable black pigment is copper chromite black spinel.

[0104] It can be provided that at least the last applied layer is coated with a coating composition comprising or consisting of an oil or resin, preferably a silicone oil or a silicone resin, and particularly preferably a silicone oil. It can be provided that this coating composition, with which the last applied layer is applied, is anhydrous and comprises one or more organic solvents, preferably xylene and / or toluene and / or butyl acetate and / or n-butanol. It can be preferred that the solvent is a mixture of xylene, butyl acetate, and butanol, moreover preferably in a weight ratio of 3:(0.5 to 1.5):(0.5 to 1.5), for example, 60% xylene / 20% butyl acetate / 20% butanol. Alternatively, it is preferred that the solvent is a mixture of xylene and butyl acetate, preferably in a weight ratio of 1:(0.5 to 1.5), for example 50 xylene / 50 butyl acetate.Preferably, this coating composition, with which the final layer is applied, contains silicone oil dissolved in an organic solvent, for example xylene or toluene, in a concentration of 1-10 wt.%, preferably 1-4 wt.%, for example about 1-3 wt.%, based on the total weight of the coating composition with which the final layer is applied. Surprisingly, a coating produced in this way exhibits non-stick properties just as good as a PTFE or silicone coating, but shows much better mechanical and chemical resistance and durability. The improvement in the non-stick effect is permanent and differs significantly from simple oiling, where the oil can subsequently be washed off.

[0105] If the outer layer contains only oil and is baked on, the non-stick properties have a much better durability than if the surface is only oiled cold.

[0106] In another embodiment, the coating composition for applying the final layer contains a mixture of silicone oil and resin dissolved in a solvent with a total concentration of 10-40 wt.%, preferably 30-30 wt.%, for example, about 23 wt.%, based on the total weight of the layer. In another embodiment, the coating composition for applying the final layer contains a solvent dissolved in a solvent with a concentration of 1-5 wt.%, preferably 2-4 wt.%, for example, about 3 wt.%, based on the total weight of the layer. In yet another embodiment, the coating composition for applying the final layer contains silicone resin dissolved in a solvent with a total concentration of 10-30 wt.%, preferably 15-25 wt.%, for example, about 20 wt.%, based on the total weight of the layer.

[0107] Suitable silicone resins include methyl, phenyl, and methylphenyl resins, as well as mixtures of different resins. The silicone resin may contain methyl polysiloxane in an amount of 30 to 100% by weight, based on the total weight of the silicone resin. Preferably, this final applied layer (topcoat) is clear without pigmentation or contains a maximum of 5% inorganic pigments. In another embodiment, the topcoat consists of a mixture of water and an organic solvent, for example, isopropanol. The topcoat may also contain thickening agents, defoamers, and wetting agents. The same applies to the dispersions of the underlying thermoplastic layer(s).The firing temperature of this uppermost, thermoplastic-free layer(s) is below that of the underlying layers, preferably below the liquidus temperature of the thermoplastic polymer or the mixture of thermoplastic polymers, but above the glass transition temperature of the same, for example at 230°C.

[0108] The process may further include a drying step between application and curing. Drying serves to remove solvents, particularly water and any organic solvents that may be present. Drying can be carried out at a temperature in the range of 80 to 100 °C (normal pressure). The drying step is optional and may be omitted, especially when producing thin coatings.

[0109] The process can further include a tempering step between drying and baking. Tempering can last from 1 to 30 minutes, for example, 3 to 5 minutes. Baking of the coating composition

[0110] In a further process step, the applied coating composition is baked on.

[0111] It may be planned that the curing process takes place at a temperature higher than the liquidus temperature of the thermoplastic polymer. The liquidus temperature is the temperature at which a substance is completely molten, meaning it no longer contains any solid particles.

[0112] Baking can be done in an oven, by irradiating with infrared or near-infrared radiation, by irradiating with a laser, or a combination of two or more of these. Coated metal sheet

[0113] A second aspect of the present invention relates to a coated metal sheet. The coated metal sheet can be obtained by the inventive method for producing a coated metal sheet, as described in detail herein. The coating produced according to the inventive method is largely pore-free and is characterized by a high degree of uniformity. Remarkably, it is possible to form the coated metal sheets to obtain baking molds, sliding bearing shells, etc., without the coating flaking off or cracking.

[0114] In the preceding description of the method for producing a coated metal sheet, embodiments of the coated metal sheet mentioned are also embodiments for the coated metal sheet according to the invention.

[0115] The coated metal sheet according to the invention comprises a metal sheet and a coating on at least one side of the metal sheet. The coating can be obtained based on the coating composition as described in detail in connection with the method for producing the coated metal sheet.

[0116] The coating may be provided with a layer thickness selected from the group consisting of at least 5 µm, at least 10 µm, at least 15 µm, and at least 20 µm. Alternatively, the coating may be provided with a thickness in the range of 5 to 200 µm, 50 to 150 µm, or preferably 50 to 100 µm.

[0117] It can be provided that the coating thickness is on the order of the thickness of the metal sheet, thus completely and tightly covering the metal sheet. A coating thickness of approximately 50% to 100% of the thickness of the metal sheet is preferred.

[0118] The coating comprises a thermoplastic polymer. The thermoplastic polymer may preferably be one or more of the following, as described in detail in connection with the coating composition, and in particular selected from the group consisting of polyaryletherketone (PAEK), especially the aforementioned embodiments thereof, and a polyarylene sulfide, especially the aforementioned embodiments thereof, or a mixture of two or more thereof. Further components of the coating are also preferably those, for example, fillers, dry lubricants, etc., as described in detail in connection with the coating composition.

[0119] Preferably, the coated metal sheet has a contact angle of the coating against water of at least 90°, preferably at least 95°, and particularly preferably 100° to 120°. For measurement, water droplets are placed on the coating and the contact angle is optically evaluated using a camera. According to the invention, the measurements are carried out in accordance with DIN EN ISO 19403-2:2020-04 in the version valid on the priority date. With the coating according to the invention, correspondingly very good non-stick properties, which can even surpass those of PTFE, can be achieved.

[0120] The coating may contain the thermoplastic polymer in an amount of 60 to 99% by weight, based on the total weight of the coating.

[0121] It may be provided that the coating contains solvents in an amount of no more than 90% by weight, based on the total weight of the coating.

[0122] The coating according to the invention, based on thermoplastic polymers selected from polyaryletherketone (PAEK), a polyarylene sulfide, or a mixture of two or more thereof, enables the production of an environmentally friendly product that does not contain critical substances such as PFAS, fluoropolymers, bisphenols, etc., and yet exhibits comparable (or improved) properties to conventional products. In particular, the coatings obtained in this way are more durable, mechanically resistant, and resistant to water vapor.

[0123] It may be provided that the coating is obtainable by simply applying a suitable coating composition and subsequent appropriate treatment (baking, drying, hardening, etc.). Alternatively, it may be provided that the coating is obtainable by multiple applications of a suitable coating composition and subsequent appropriate treatment (baking, drying, hardening, etc.), whereby the same or different coating compositions can be used independently for each application in order to obtain different sublayers and achieve the required layer thickness or the desired properties of the coating. It may be provided that the coating is obtainable by multiple applications of a suitable coating composition and subsequent appropriate treatment (baking, drying, hardening, etc.).) is available, with the thickness of the outermost sublayer ranging from 1 nm to 10 µm. The metal sheet is then tightly sealed. It is not necessary for all sublayers obtained through multiple coating processes to contain the thermoplastic polymer, as long as at least one of the sublayers contains the thermoplastic polymer. The sublayers can also be indistinguishable, so that the coating appears as a single layer.

[0124] It may be provided that the coating comprises an inner sub-layer and an outer sub-layer, where - the inner sublayer is obtained by applying and baking on a coating composition; and - the outer partial layer is obtained by applying and baking on another coating composition.

[0125] It may be provided that the coating comprises an inner sub-layer and an outer sub-layer, wherein - the inner sublayer preferably comprises polyarylene sulfide in an amount of at least 10 wt.%, preferably at least 20 wt.%, more preferably at least 30 wt.%, further preferably at least 40 wt.%, most preferably at least 50 wt.%, based on the total weight of the inner sublayer; and / or - the outer layer contains a silicone oil and / or a silicone resin and preferably does not comprise a thermoplastic polymer.

[0126] The inner layer may comprise polyarylene sulfide, preferably polyphenylene sulfide, in an amount of at least 20%, 30%, 40%, or 50% by weight, based on the total weight of the inner layer. The inner layer may consist entirely of polyarylene sulfide, preferably polyphenylene sulfide. If the inner layer consists only of polyaryletherketone(s), the surface of such an inner layer will be disturbed when the outer layer, containing silicone oil and / or silicone resin, is baked on above the liquidus temperature of the thermoplastic. In such a case, "fisheye" patterns and an uneven surface may be observed. However, if the inner layer contains polyarylene sulfide, preferably polyphenylene sulfide, in the aforementioned large quantities, the surface remains surprisingly undisturbed.This applies to curing temperatures above the liquidus temperature of PPS as well as above the liquidus temperature of PEEK in mixtures, for example at 280°C, 300°C, 340°C, 360°C, 400°C and higher. The use of PPS in the inner sublayer, especially in the aforementioned large quantities, therefore makes the coated metal sheet more flexible and improves adhesion and impregnation with the silicone oil and / or silicone resin.

[0127] The inner sublayer may comprise silicone oil, silicone resin, elastomer, in particular acrylate, polyester, and epoxy resin in an amount of not more than 5% by weight, preferably not more than 1% by weight, based on the total weight of the inner sublayer. The inner sublayer may also be free of silicone oil, silicone resin, polyester, and epoxy resin, whereby the term "free of" does not exclude impurities that cannot be prevented by conventional technical measures.

[0128] The outer sublayer may comprise thermoplastic polymer in an amount of no more than 5% by weight, preferably no more than 1% by weight, based on the total weight of the outer sublayer. The outer sublayer may be free of thermoplastic material, the term "free of" not excluding impurities that cannot be prevented by conventional engineering measures.

[0129] It may be provided that the outer sublayer comprises at least one further component selected from the group consisting of a pigment, an acrylate, a polyester, an epoxy resin, an additive and a dry lubricant, preferably a dry lubricant as mentioned above.

[0130] It may be provided that the outer sublayer has a thickness of 0.01 µm to 20 µm, for example from 0.01 to 5 µm or from 10 to 20 µm. Coating composition

[0131] A third aspect of the present invention relates to a coating composition, or several different coating compositions, for producing the coated metal sheet using the method according to the invention, which is described in detail above. Coating composition for producing an inner sublayer

[0132] The present invention relates, inter alia, to a coating composition for producing an inner partial layer of a coated metal sheet, comprising: - 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 50 parts by weight of a solid mixture, based on the total weight of the coating composition, wherein the solid mixture is dispersed in the solvent mixture; where - the solid mixture comprises 80 to 100 parts by weight of a thermoplastic polymer, the thermoplastic polymer being selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide and a mixture of two or more thereof, based on the total weight of the solid mixture; and wherein the coating composition does not include a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone.

[0133] The coating composition can be an aqueous dispersion comprising the thermoplastic polymer in the form of dispersed particles.

[0134] The dispersed particles can have a mean particle size (particle diameter) D50 of at least 10 µm. It is possible for the dispersed particles to have a mean particle diameter selected from the group consisting of at least 15 µm and at least 20 µm. In this context, it is possible for the particles to have a mean particle size (particle diameter) D50 of 60 µm or less, 50 µm or less, 40 µm or less, 30 µm or less, or 25 µm or less, according to ISO 13320-1 in the version valid on the priority date. The particle size D50 is a statistical characteristic derived from a particle size distribution. It describes the particle size below which 50% of the total mass of the particles lies.

[0135] The dispersion can have a solids content of at least 20% by weight, based on the total weight of the dispersion.

[0136] The coating composition is used to produce an inner sublayer of a coated metal sheet. The coated metal sheet and the inner sublayer can, in particular, be the coated metal sheet and the inner sublayer described in detail above.

[0137] In the foregoing relating to the coated metal sheet, the method for producing the coated metal sheet (particularly in connection with coating compositions described in the method for producing the coated metal sheet) and embodiments mentioned in the general context of a coating composition, relating, for example, to certain materials, substances, additional components, their properties, quantities thereof, etc., embodiments for the coating composition for producing an inner sublayer of a coated metal sheet are also embodiments.

[0138] It may be provided that the solvent contains 30 to 100 parts by weight of water, based on the total weight of the solvent; and that the solvent preferably contains 5 to 70 parts by weight of organic solvent, based on the total weight of the solvent.

[0139] It may be provided that the coating composition for producing an inner sub-layer of a coated metal sheet includes organic solvents in an amount of 5 to 50 percent by weight, based on the total weight of the solvent, for example in an amount of 5 to 15 percent by weight, for example about 10 percent by weight.

[0140] It may be provided that the solvent is water and organic solvent in a weight ratio of 20:1 to 1:1, 15:1 to 5:1, 12:1 to 8:1, or 10:1 to 8:1, for example 9:1.

[0141] It may be provided that the organic solvent is selected from the group consisting of isopropanol, ethylene glycol, butyl glycol, propylene glycol, methoxypropanol, n-propoxypropanol, dipropylene glycol methyl ether (DPM) or methoxypropanol acetate and a mixture thereof, for example isopropanol or a mixture of ethylene glycol and isopropanol, for example in a weight ratio of 2:1 to 1:1.

[0142] Alternatively, the solvent may be an organic solvent or a mixture of two or more organic solvents.

[0143] The solvent may consist of a mixture of two or more solvents, each with a boiling point above 100°C under normal pressure.

[0144] It may be specified that the solvent is an organic solvent. It may be specified that the solvent has a boiling point in the range of more than 100°C to 20°C, or 110°C to 150°C.

[0145] It may be provided that the solvent is selected from the group consisting of xylene, n-butanol, and butyl acetate. It may be provided that the solvent is a mixture of two solvents selected from the group consisting of xylene, n-butanol, toluene, and butyl acetate. It may be provided that the solvent is a mixture of two solvents, one of which is xylene and the other being n-butanol or butyl acetate, preferably n-butanol, preferably in a weight ratio of xylene:n-butanol of 5:1 to 3:1, for example, about 4:1.

[0146] The solvent may be a mixture of xylene, n-butanol, and butyl acetate, preferably in a weight ratio of 6:(1 to 3):(1 to 3).

[0147] It is intended that the solvent and the solid mixture are included in the coating composition for producing an inner partial layer of a coated metal sheet in a weight ratio of 10:1 to 1:1 or of 10:1 to 3:1.

[0148] The solid mixture may contain the thermoplastic polymer in an amount of 80 to 99 parts by weight, or 85 to 97 parts by weight, or 90 to 95 parts by weight, based on the total weight of the solid mixture.

[0149] It may be provided that the thermoplastic polymer is selected from the group consisting of PEEK, PEK, PPS and a mixture of two or more thereof. It may be provided that the thermoplastic polymer is a mixture of PEEK and PPS, for example in a weight ratio of 2:1 to 1:1 or in a weight ratio of 1:6 to 1:10, preferably 1:8 to 1:10, PEK, or a mixture of two different PEEKs, for example in a weight ratio of 1:1 to 1:3.

[0150] It may be provided that the thermoplastic polymer is a mixture of PEEK and PPS, for example in a weight ratio of 2:1 to 1:1 or in a weight ratio of 1:8 to 1:10, wherein at least one of the PEEK and PPS components has a particle diameter D 50 of no more than 20 µm.

[0151] It may be intended that the thermoplastic polymer consists of a PEK.

[0152] It can be provided that the thermoplastic polymer is a mixture of a first PEEK and a second PEEK, for example in a weight ratio of 2:7 to 2:8, wherein at least one of the first PEEK and the second PEEK has a particle diameter D 50 of no more than 20 µm or of no more than 15 µm.

[0153] It may be provided that the solid mixture is present in the solvent in the form of a dispersed fine powder.

[0154] The solid mixture may further comprise a pigment, preferably a black pigment. The solid mixture may contain the pigment in an amount of 1 to 15 parts by weight or 5 to 10 parts by weight, based on the total weight of the solid mixture, for example, in an amount of 4 to 6 parts by weight or 8 to 10 parts by weight.

[0155] The solid mixture may further comprise a dry lubricant. The dry lubricant may be graphite, MoS₂, boron nitride, or a mixture of two or more of these. The dry lubricant may be present in the solid mixture in an amount of 0.2 to 5 parts by weight or 0.5 to 2 parts by weight, based on the total weight of the solid mixture. The dry lubricant may be graphite, a mixture of graphite and MoS₂, for example in a weight ratio of 2:1 to 1:2, or boron nitride.

[0156] The solvent may further comprise an antifoam, a lacquer additive, a wetting agent, a thickener, an adhesion promoter (e.g., zirconate, titanate, or silane), or a mixture of two or more of these. The solvent may further comprise an antifoam, a lacquer additive, a wetting agent, a thickener, and an adhesion promoter. The antifoam, lacquer additive, wetting agent, thickener, and adhesion promoter (if present) may each be contained in an amount of 0.5 to 2 parts by weight, for example, approximately 1 part by weight, in the solvent, based on the total weight of the solvent.

[0157] It may be provided that the coating composition for producing an inner sublayer of a coated metal sheet essentially comprises the solvent and the solid mixture. It may be provided that the coating composition for producing an inner sublayer of a coated metal sheet consists of the solvent and the solid mixture.

[0158] It may be intended that the solvent essentially comprises the listed components. It may be intended that the solvent consists of the listed components.

[0159] It may be provided that the solid mixture essentially comprises the listed components. It may be provided that the solid mixture consists of the listed components.

[0160] It may be provided that the coating composition for producing an inner partial layer of a coated metal sheet has a viscosity in a range of 10 to 100 s, 20 to 80 s, or 40 to 60 s, measured with the flow cup according to DIN 53211. Coating composition for producing an outer partial layer (first embodiment)

[0161] The following coating compositions are used to produce an outer partial layer of a coated metal sheet. The coated metal sheet and the outer partial layer can, in particular, be the coated metal sheet and the outer partial layer described in detail above.

[0162] In the foregoing relating to the coated metal sheet, the method for producing the coated metal sheet (particularly in connection with coating compositions described in the method for producing the coated metal sheet) and embodiments mentioned in the general context of a coating composition, relating, for example, to certain materials, substances, additional components, properties thereof, quantities thereof, etc., embodiments for the coating composition for producing an outer partial layer of a coated metal sheet are also embodiments.

[0163] In this embodiment, the invention further relates to a coating composition for producing an outer partial layer of a coated metal sheet, comprising: - 40 to 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 40 parts by weight of a silicone oil, a silicone resin or a mixture of two or more thereof; where - is an organic solvent with a boiling point of more than 100°C under normal pressure or consists of a mixture of two or more solvents, each with a boiling point of more than 100°C under normal pressure; wherein the coating composition does not include a fluoropolymer and preferably does not include isphenol and / or polyethersulfone.

[0164] It may be provided that the solvent consists of a mixture of two solvents, each with a boiling point of more than 100°C under normal pressure.

[0165] It may be specified that the solvent is an organic solvent. It may be specified that the solvent has a boiling point in the range of more than 100°C to 20°C, or 110°C to 150°C.

[0166] It may be provided that the solvent is selected from the group consisting of xylene, n-butanol, and butyl acetate. It may be provided that the solvent is a mixture of two solvents selected from the group consisting of xylene, n-butanol, toluene, and butyl acetate. It may be provided that the solvent is a mixture of two solvents, one of which is xylene and the other being n-butanol or butyl acetate, preferably n-butanol, preferably in a weight ratio of xylene:n-butanol of 5:1 to 3:1, for example, about 4:1.

[0167] The coating composition may include the solvent in an amount of 45 to 85 parts by weight or 50 to 80 parts by weight, based on the total weight of the coating composition, for example, 55 to 65 parts by weight, 75 to 85 parts by weight, or 45 to 55 parts by weight.

[0168] It may be provided that the coating composition for producing an outer partial layer of a coated metal sheet comprises the silicone oil, the silicone resin or the mixture of two or more thereof in an amount of 10 to 35 parts by weight or 15 to 33 parts by weight, based on the total weight of the coating composition, for example in an amount of 15 to 25 parts by weight, of 20 to 25 parts by weight, or of 22 to 24 parts by weight.

[0169] The coating composition may include a silicone oil and a silicone resin, for example in a weight ratio of silicone oil:silicone resin of 1:1 to 1:15, 1:2 to 1:12, 1:4 to 1:8, or 1:5 to 1:7.

[0170] The coating composition may include silicone oil in an amount of 1 to 12 parts by weight or 1 to 5 parts by weight, based on the total weight of the coating composition, for example in an amount of 2 to 4 parts by weight.

[0171] The coating composition may include the silicone resin in an amount of 8 to 32 parts by weight or 10 to 30 parts by weight, based on the total weight of the coating composition, for example in an amount of 15 to 25 parts by weight or 18 to 22 parts by weight.

[0172] The coating composition for producing an outer partial layer of a coated metal sheet may further contain a thickener, preferably in an amount of 1 to 15 parts by weight or 5 to 10 parts by weight, based on the total weight of the coating composition. The thickener may be an acrylate. It may also be an acrylate resin, preferably a thermoplastic acrylate resin.

[0173] The coating composition for producing an outer partial layer of a coated metal sheet may further comprise a wetting agent. The coating composition may contain the wetting agent in an amount of 1 to 5 parts by weight, 1 to 3 parts by weight, or 1.5 to 2.5 parts by weight, based on the total weight of the coating composition.

[0174] The coating composition may further comprise a dry lubricant. The dry lubricant may be graphite. The dry lubricant may be present in the coating composition in an amount of 0.2 to 5 parts by weight or 1 to 2 parts by weight, based on the total weight of the coating composition.

[0175] The coating composition may further comprise a pigment, preferably a black pigment. The coating composition may comprise the pigment in an amount of 1 to 15 parts by weight or 3 to 10 parts by weight, based on the total weight of the coating composition, for example, in an amount of 2 to 4 parts by weight, 4 to 6 parts by weight, or 8 to 10 parts by weight.

[0176] It may be provided that the coating composition for producing an outer partial layer of a coated metal sheet has a viscosity in the range of 10 to 30 s. Coating composition for producing an outer partial layer (alternative embodiment)

[0177] The following coating compositions are used to produce an outer partial layer of a coated metal sheet. The coated metal sheet and the outer partial layer can, in particular, be the coated metal sheet and the outer partial layer described in detail above.

[0178] In the foregoing relating to the coated metal sheet, the method for producing the coated metal sheet (particularly in connection with coating compositions described in the method for producing the coated metal sheet) and embodiments mentioned in the general context of a coating composition, relating, for example, to certain materials, substances, additional components, properties thereof, quantities thereof, etc., embodiments for the coating composition for producing an outer partial layer of a coated metal sheet are also embodiments.

[0179] In this alternative embodiment, the invention relates to a coating composition for producing an outer partial layer of a coated metal sheet, comprising: - 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 50 parts by weight of a solid mixture, based on the total weight of the coating composition, wherein the solid mixture is dispersed in the solvent mixture; where - the solvent is an organic solvent with a boiling point of more than 100°C under normal pressure or consists of a mixture of two or more solvents, each with a boiling point of more than 100°C under normal pressure; - the solid mixture contains 70 to 100 parts by weight of a thermoplastic polymer, wherein the thermoplastic polymer is selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide, a polyimide and a mixture of two or more thereof, based on the total weight of the solid mixture; and wherein the coating composition does not include a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone.

[0180] The coating composition may include the solvent in an amount of 45 to 85 parts by weight or 50 to 80 parts by weight, based on the total weight of the coating composition, for example, 55 to 65 parts by weight, 75 to 85 parts by weight, or 45 to 55 parts by weight.

[0181] The solvent may consist of a mixture of two or more solvents, each with a boiling point above 100°C under normal pressure.

[0182] It may be specified that the solvent is an organic solvent. It may be specified that the solvent has a boiling point in the range of more than 100°C to 20°C, or 110°C to 150°C.

[0183] It may be provided that the solvent is selected from the group consisting of xylene, n-butanol, and butyl acetate. It may be provided that the solvent is a mixture of two solvents selected from the group consisting of xylene, n-butanol, toluene, and butyl acetate. It may be provided that the solvent is a mixture of xylene, n-butanol, and butyl acetate, preferably in a weight ratio of 6:(1 to 3):(1 to 3).

[0184] The solid mixture may contain the thermoplastic polymer in an amount of 80 to 99 parts by weight or 90 to 95 parts by weight, based on the total weight of the solid mixture.

[0185] It may be intended that the thermoplastic polymer consists of a PEK.

[0186] It may be provided that the thermoplastic polymer is a mixture of a first PEEK and a second PEEK, for example in a weight ratio of 2:7 to 2:8, wherein at least one of the first PEEK and the second PEEK has a particle diameter D50 of no more than 20 µm or of no more than 15 µm.

[0187] It may be provided that the solid mixture is present in the solvent in the form of a dispersed fine powder.

[0188] The solid mixture may further comprise a pigment, preferably a black pigment. The solid mixture may contain the pigment in an amount of 1 to 15 parts by weight or 5 to 10 parts by weight, based on the total weight of the solid mixture, for example, in an amount of 4 to 6 parts by weight or 8 to 10 parts by weight.

[0189] The solid mixture may further comprise a dry lubricant. The dry lubricant may be graphite, MoS₂, boron nitride, or a mixture of two or more of these. The dry lubricant may be present in the solid mixture in an amount of 0.2 to 5 parts by weight or 0.5 to 2 parts by weight, based on the total weight of the solid mixture. The dry lubricant may be graphite, a mixture of graphite and MoS₂, for example in a weight ratio of 2:1 to 1:2, or boron nitride.

[0190] The solvent may further comprise an antifoam, a varnish additive, a wetting agent, a thickener, an adhesion promoter, or a mixture of two or more of these. The solvent may further comprise an antifoam, a varnish additive, a wetting agent, a thickener, and an adhesion promoter. The antifoam, varnish additive, wetting agent, thickener, and adhesion promoter (if present) may each be contained in an amount of 0.5 to 2 parts by weight, for example, approximately 1 part by weight, in the solvent, based on the total weight of the solvent.

[0191] It may be provided that the coating composition for producing an outer partial layer of a coated metal sheet has a viscosity in a range of 10 to 100 s, 20 to 80 s or 40 to 60 s. Use of the coated metal sheet

[0192] A third aspect of the present invention relates to the use of the coated metal sheet, as described in detail above, as a component of a cooking or baking accessory, preferably a pan or pot, or as a rack. The embodiments of the coated metal sheet, the inventive method, and the inventive coating composition mentioned above are also embodiments for use according to the invention.

[0193] According to the invention, the term "cooking and baking accessories" encompasses any object suitable by its shape for holding food and subsequently cooking and baking it. Therefore, in addition to pans, baking trays, baking tins, cake trays, pie plates, bread boxes, etc., as well as grill trays, grill containers, grill racks, etc., are included in the above term.

[0194] Also included is the use of the coated metal sheet in the form of a storage container, for example a food storage container, such as a bread box.

[0195] Also included is the use of the coated metal sheet in the form of sanitary or kitchen equipment, in particular a basin, such as a sink.

[0196] Also included is the use of the coated metal sheet for the manufacture of a bearing, in particular a plain bearing, by forming the coated metal sheet. General Definitions

[0197] Unless expressly stated otherwise, a feature specified in the singular (a, an...) also includes the plural. For example, if it is stated that the composition according to the invention contains a dye, this also includes the case in which the composition contains a mixture of several dyes.

[0198] Unless expressly stated otherwise, terms such as "comprising," "containing," etc., include the meanings "essentially comprising," "essentially containing," or "consisting of." "Essentially comprising" in this context means comprising at least 70%, 80%, 90%, 95%, 98%, or 99% by weight of the respective component, based on the total weight of the item, composition, etc.

[0199] The quantities given as percentages add up to a total quantity of 100% by weight, thus giving the total quantity. Examples of implementation

[0200] The invention is explained below, with reference to specific examples to illustrate its function and benefits. Application example 1:1. Layer

[0201] Coating composition (wet dispersion) for producing a coating (inner partial layer) on a metal sheet: Solvent: 90% H2O / 10% isopropanol with varnish additives: approx. 1% defoamer, approx. 1% wetting agent, approx. 1% thickener, approx. 1% adhesion promoter This contains approximately 20-30% solids (in the form of fine powder dispersed in the solvent with the following composition: 50% PEEK (Vicote 703) 40% PPS (Fortron, D50 10 µm) 10% black pigment (ferro black)

[0202] The viscosity of the liquid is in the range of approximately 20-80 seconds, ideally 40-60 seconds. A viscosity higher than 80 seconds leads to orange peel-like consistency.

[0203] The coating composition was applied by roller coating to chrome-nickel pretreated steel sheet (sheet thickness 0.4 mm) in a continuous oven, with drying and baking in the oven taking place for approximately 2 minutes at 360°C - 380°C.

[0204] The resulting inner layer of the coating, with a thickness of 50 to 80 µm, already has very good sliding properties. 2nd shift

[0205] To achieve a Teflon-equivalent non-stick effect, a second layer (outer partial layer) was applied.

[0206] Coating composition (wet dispersion) for producing a second coating (outer partial layer) on the inner partial layer: Solvent: 65% (80% xylene / 20% n-butanol) 10% thickener (Mitsubishi DIANAL) 2% wetting agent (Tego Wet 265) 20% silicone resin (Wacker SilRes MK) 3% silicone oil (Wacker AK 1,000) 2% black pigment (Heucodur black)

[0207] The metal strip, already coated with the first layer, was passed through a second coating chamber and given a second layer. This second layer acts as an impregnation of the first, resulting in a thin coating thickness of max. 5 µm. The viscosity of the second layer can be set lower, with a curing time between 10 and 30 seconds (DIN flow cup).

[0208] Drying and then firing in an oven for 2 minutes at 350°C. Surprisingly, it was found that the progression of the first layer was not disrupted, even though its liquidus temperature was exceeded.

[0209] The surface was subsequently completely dry, closed, and smooth.

[0210] The coating produced in this way proved to be very flexible, almost as easily formable as an uncoated material of the same quality, and drawing marks were avoided during the forming process. The non-stick effect was even better compared to PTFE, comparable to silicone. The mechanical properties and wear resistance, on the other hand, were even better than those of PTFE, comparable to pure PEEK.

[0211] Further tests revealed that the properties can be specifically tailored by selecting the thermoplastic polymers (of the first layer(s), the amount of dry lubricant, and the chosen thicknesses of the non-metallic metal sheet and the layer thicknesses of the first and, if applicable, second layer). The more PEEK or even PEK the base layer contains, the more wear-resistant and temperature-resistant the coating.

[0212] Metal strips manufactured in this way, with their non-stick and sliding properties, do not tear or break in the scratch test with the Errichsson test rod at 20 N, as would be the case with silicone resin. Adhesion according to the cross-cut test is GT0, which does not diminish even after acid exposure. Temperature resistance is 300°C, and the non-stick effect passes all standard tests. Application example 2: 1st layer

[0213] Coating composition (wet dispersion) for producing a coating (inner partial layer) on a non-metallic metal sheet: Solvent: 60% xylene / 20% butanol / 20% butyl acetate with lacquer additives: approx. 1% defoamer, approx. 1% wetting agent, approx. 3% thickener, approx. 1% adhesion promoter.

[0214] It contains approximately 10-30% solids in the form of fine powder dispersed with the following composition: 10% PEEK (Vicote 703) 90% PPS (Fortron; D50 10 mm) 10% black pigment (ferro black)

[0215] The viscosity of the liquid should be in the range of approximately 20-80 seconds, ideally 40-60 seconds. Higher viscosity leads to orange peel-like texture.

[0216] The coating composition was applied by roller coating to chrome-nickel pretreated steel sheet (sheet thickness 0.6 mm) in a continuous oven, with drying and baking in the oven taking place for approximately 2 minutes at 300°C to 370°C. 2nd shift

[0217] To improve the sliding and wear properties, a second layer was applied: Solvent: 60% xylene / 20% butanol / 20% butyl acetate with lacquer additives: approx. 1% defoamer, approx. 1% wetting agent, approx. 3% thickener, approx. 1% adhesion promoter

[0218] It contains approximately 10-30% solids in the form of fine powder dispersed with the following composition: 30% PEEK (Vicote 707) 61% PEEK (Vicote 703) 5% black pigment (ferro black) 2% graphite 0.5% MoS2 0.5% boron nitrite Optionally, add 1% oil, for example silicone oil.

[0219] The viscosity of the liquid is in the range of approximately 20-80 s, ideally 40-60 s. Higher viscosity leads to orange peel-like texture.

[0220] Drying and tempering in the oven for approximately 2 minutes at 360°C - 410°C.

[0221] The metal strip, already coated with the first layer, was passed through a second coating chamber and given a second layer.

[0222] The second layer contains more dry lubricant and has improved sliding properties, but on its own would have worsened adhesion properties during the short curing times.

[0223] The resulting strip proved to be very flexible, almost as malleable as an uncoated material of the same quality, and drawing marks were avoided during the forming process. Wear resistance was 2-10 times lower than comparable coatings containing PTFE or PES. Friction was less than or equal to PV at higher loads, and slightly higher at lower loads, which could be improved by adding oil.

[0224] Further tests revealed that the properties can be specifically tailored by selecting the thermoplastic polymers (of the first layer(s), the amount of dry lubricant, and the chosen thicknesses of the non-metallic metal sheet and the layer thicknesses of the first and, if applicable, second layer). The more PEEK or even PEK the base layer contains, the more wear-resistant and temperature-resistant the coating.

[0225] The sheets produced in this way were suitable for the manufacture of all kinds of bearing parts, such as bearing shells, bearing cages, etc., especially plain bearings. Non-stick coated sheets could be used for the production of baking molds, pots, pans, baking trays, cake or pie trays, sanitary or kitchen equipment such as basins, for example sinks, storage containers such as bread boxes, etc., but also as high-quality conveyor belts, for example in plastics and food production.

[0226] The features of the invention disclosed in the foregoing description and in the claims can be essential for the realization of the invention in its various embodiments, both individually and in any combination. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited non-patent literature

[0000] DIN EN ISO 2808:2019-12

[0019] DIN EN ISO 2360

[0019] DIN 1319

[0019] DIN 51562-1 [0036, 0081] ISO 11443 [0049, 0051] ISO 13322-1:2014

[0050] ISO 1183

[0052] ISO 1522

[0056] ISO 13320-1 [0060, 0061, 0062, 0063] ISO 1133-1

[0065] ISO 11337-1 [0066, 0067] DIN 53019

[0093] DIN 53466

[0098] ISO 13322

[0101] DIN EN ISO 19403-2:2020-04

[0119]

Claims

A coated metal sheet obtainable by a process for producing a coated metal sheet comprising the following steps: (i) providing a metal sheet; (ii) applying a coating composition to at least one side of the metal sheet; and (iii) curing the coating composition; wherein: - the coating composition comprises a thermoplastic polymer; - the coating composition is a dispersion comprising the thermoplastic polymer in the form of dispersed particles; - the dispersed particles have a mean particle diameter of at least 10 µm; - the coating composition does not comprise a fluorinated compound; and - the application of the coating composition comprises dip coating, doctor blade coating, casting, roller coating, or a combination of two or more of these. The coated metal sheet according to claim 1, wherein the application is carried out using the coil coating process. The coated metal sheet according to claim 1 or 2, wherein the thermoplastic polymer is selected from the group consisting of polyaryletherketone (PAEK), a polyarylene sulfide and a mixture of two or more thereof. The coated metal sheet according to one of the preceding claims, wherein the polyaryletherketone (PAEK) is a polyaryletheretherketone (PEEK), a polyaryletherketoneketone (PEKK), a polyaryletherketoneetherketoneketone (PEKEKK), a copolymer of two or more thereof, or a mixture of two or more thereof. The coated metal sheet according to one of the preceding claims, wherein the polyarylene sulfide is a polyphenylene sulfide. The coated metal sheet according to one of the preceding claims, wherein the dispersed particles have a mean particle diameter selected from the group consisting of at least 15 µm, at least 20 µm, at least 25 µm and at least 30 µm. The coated metal sheet according to one of the preceding claims, wherein the coating composition further comprises at least one filler, preferably a mineral filler, a ceramic filler or a mixture of two or more thereof. Coated metal sheet obtainable by a method as characterized in any of the preceding claims, comprising: a metal sheet; and a coating on at least one side of the metal sheet. Coated metal sheet according to claim 8, wherein the coating has a layer thickness selected from the group consisting of at least 5 µm, at least 10 µm, at least 15 µm and at least 20 µm. Coated metal sheet according to claim 8 or 9, wherein the coating comprises an inner sublayer and an outer sublayer, wherein the inner sublayer is obtainable by applying and baking on the coating composition; and the outer sublayer is obtainable by applying and baking on the further coating composition. A coating composition for producing an inner partial layer of a coated metal sheet, comprising: - 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 50 parts by weight of a solid mixture, based on the total weight of the coating composition, wherein the solid mixture is dispersed in the solvent mixture; wherein - the solid mixture comprises 80 to 100 parts by weight of a thermoplastic polymer, the thermoplastic polymer being selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide and a mixture of two or more thereof, based on the total weight of the solid mixture; and wherein the coating composition does not comprise a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone. A coating composition for producing an outer partial layer of a coated metal sheet, comprising: - 40 to 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 40 parts by weight of a silicone oil, a silicone resin, or a mixture of two or more thereof; wherein - is an organic solvent having a boiling point above 100°C under normal pressure or consists of a mixture of two or more solvents, each having a boiling point above 100°C under normal pressure; wherein the coating composition does not include a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone. A coating composition for producing an outer partial layer of a coated metal sheet, comprising: - 100 parts by weight of a solvent, based on the total weight of the coating composition; and - 5 to 50 parts by weight of a solid mixture, based on the total weight of the coating composition, wherein the solid mixture is dispersed in the solvent mixture; wherein - the solvent is an organic solvent having a boiling point above 100°C under normal pressure or consists of a mixture of two or more solvents, each having a boiling point above 100°C under normal pressure;- the solid mixture comprises 70 to 100 parts by weight of a thermoplastic polymer, wherein the thermoplastic polymer is selected from the group consisting of a polyaryletherketone (PAEK), a polyarylene sulfide, a polyimide and a mixture of two or more thereof, based on the total weight of the solid mixture; and wherein the coating composition does not include a fluoropolymer and preferably does not include bisphenol and / or polyethersulfone. A cooking or baking accessory, preferably a pan or pot, a baking tray, a baking tin, a cake tray, a pie plate, a component of a conveyor belt, a sanitary or kitchen fitting, in particular a basin, such as a sink, a storage container, in particular a bread box, or a bearing, in particular a sliding bearing, comprising the coated metal sheet according to one of claims 1 to 10.