Method for coating article

Abstract

The invention relates to a method for coating an article, preferably a wear-prone sliding article, in particular a cooking and baking appliance, with at least two layers, the invention relates to a method for producing a first layer, comprising the following steps: 1) producing a first layer, comprising: a) applying a powder mixture, in the form of a dry powder or a dispersion in a liquid, to an article, in particular a cooking and baking appliance, said powder mixture comprising powder particles of at least one polyphenylene sulfide (PPS) polymer and optionally one polyaryletherketone (PAEK) polymer, the powder mixture can be prepared without the addition of fluorine or fluorine-containing compounds, preferably by electrostatic process, fluidized bed sintering process or in the form of a dispersion in a liquid, in particular in water; b) completely removing the liquid in the case of a dispersion; the invention relates to a method for producing a powder mixture, comprising the steps of: a) preparing a first layer, b) preparing a powder mixture, c) heating the powder mixture to form a polycondensate, and d) roasting the powder mixture, preferably at a temperature above the melting point of the polymer, 2) preparing a second or a third or more layer on the first layer, in which the sub-steps a) to c) are repeated, and step d) is carried out individually for each layer or together for at least two layers.

Description

Technical Field

[0001] The present invention relates to a method for coating articles, preferably wear-prone (slippery) articles, particularly cooking and baking utensils, comprising at least two layers, and an article, preferably wear-prone (slippery) article, particularly cooking and baking utensils or parts in contact with food, coated by said method. Background Technology

[0002] Existing PTFE coatings are typically applied as a three-layer process for higher-end cooking appliances, involving at least two firings. The process begins with a primer, usually composed of a binder resin dissolved in a solvent, such as PAI dissolved in NMP, applied wet-sprayed, dried, and pre-cured. A transition layer and a topcoat are then applied wet-on-wet, with the topcoat primarily containing a fluoropolymer (typically PTFE). The entire coating is then fired at approximately 420°C for about 10 minutes. These coatings can be modified with pigments and various fillers. The disadvantages include the use of fluoropolymers and the fact that the firing temperature is significantly higher than the decomposition temperature of PTFE, potentially leading to the formation of PFAS (phospholipids of concern). Furthermore, they also have the drawback of releasing toxic PFAS during high-temperature use.

[0003] Furthermore, so-called ceramic sol-gel coatings are known to contain silicone to achieve a non-stick effect, and are generally very brittle and not durable.

[0004] According to EU regulations, from 2024 onwards, the EU's PFAS limits will be significantly reduced, to the point that, from the current perspective, PTFE coatings ("Teflon") as non-stick coatings must be replaced. Summary of the Invention

[0005] The objective of this invention is to provide a universally applicable coating method for articles, preferably wear-prone sliding articles, and particularly for cooking and baking utensils or parts that come into contact with food, wherein the method does not use fluoropolymers and does not add fluorine.

[0006] The aforementioned task is achieved by providing the method according to claim 1, and the article according to claim 17, preferably a wear-prone (slippery) article, particularly a cooking and baking utensil or a part that comes into contact with food. Preferred embodiments are given in the dependent claims. The term "cooking and baking utensil or a part that comes into contact with food" according to the invention includes articles of any shape suitable for holding food and subsequently cooking and baking. Thus, in addition to frying pans, baking pans, molds, etc., as well as baking trays, grill racks, grill wires, etc., are also included within the above concept, as well as mechanical parts for processing food.

[0007] In a first aspect of the invention, a method is provided for coating articles, preferably abrasive (slippery) articles, particularly cooking and baking utensils or parts in contact with food, with at least two layers, the method comprising the steps of:

[0008] 1) Preparing the first layer, which includes:

[0009] a) Applying a powder mixture to articles, particularly cooking and baking appliances, the powder mixture being in the form of a dry powder or a dispersion in a liquid, the mixture comprising powder particles of at least one polyphenylene sulfide (PPS) polymer and, if necessary, a polyarylether ketone (PAEK) polymer, wherein the powder mixture can be prepared without the addition of fluorine or fluorine-containing compounds, the application preferably being carried out by electrostatic method, fluidized bed sintering method or as a dispersion in a liquid, particularly in water;

[0010] b) In the case of dispersions, the liquid is completely removed;

[0011] c) Heating the powder mixture to form a condensate; and

[0012] d) Preferably, the powder mixture is calcined at a temperature higher than the melting point of the polymer;

[0013] 2) Prepare a second, third or more layers on the first layer, wherein sub-steps a) to c) are repeated, and step d) is performed individually for each layer or together for at least two layers.

[0014] According to the present invention, the powder mixture can be prepared without the addition of fluorine or fluorine-containing compounds. It particularly meets the requirements of the present invention when the total fluoride content of the powder mixture does not exceed a specific limit after combustion in a humid, oxygen-rich atmosphere at 900°C–1000°C. Therefore, the powder mixture preferably contains a total fluoride content of up to 1000 ppb, up to 100 ppb, and particularly preferably up to 25 ppb as determined by combustion ion chromatography (TOF-CIC).

[0015] Specifically, to perform a combustion ion chromatography (TOF-CIC) measurement procedure, according to the present invention, a powder mixture sample is loaded into a ceramic boat and placed in a furnace for high-temperature hydrolysis in a humid, oxygen-rich environment at 900-1000°C. Under these conditions, the sample is oxidized, strong carbon-fluorine bonds break, and vapor is introduced into the absorption solution via an argon carrier. HF produced by the combustion of organic fluorine dissociates in the absorption solution, forming H+ and F- ions. The sample in the absorption solution, which also contains internal standards for calibrating the analytical results, is subsequently transferred to an ion chromatograph for analysis to measure fluorides.

[0016] Surprisingly, articles prepared by the method of this invention exhibit coatings with sliding properties equal to or even better than those of PEEK or PTFE coatings. In the Tiber abrasion test (ISO 9352, ASTM D 1044, DIN EN Standard 438-6), the abrasion amount is only about 10% of that of a fluoropolymer-containing PEEK coating, or only about 5% of that of a fluoropolymer-containing coating.

[0017] The abrasion resistance of a coating can be measured using the Tiber abrasion test. The abrasion load is generated by two friction rollers with abrasive particles, which press against a rotating specimen at a specified pressure. Evaluation is performed by differential weighing, thereby determining the worn portion of the specimen. Alternatively, wear depth / roughness can be measured or optical recording can be performed.

[0018] Furthermore, the method described in this invention for coating articles, preferably easily worn (slippery) articles, and particularly cooking and baking utensils or parts that come into contact with food, is particularly suitable. The coating prepared by the method of this invention achieves the expected non-stick effect for cooking utensils (as determined by the pancake test method according to DIN EN 60350-2 standard) without the addition of oil or any fluorinated components. In particular, when performing the method of this invention to prepare this coating, it is not necessary to use fluorinated surfactants to promote leveling. Finally, cooking and baking utensils or parts that come into contact with food are subject to wear and tear during use due to stirring and washing processes. To maintain performance, the lowest possible rate of wear is crucial for service life. Especially in professional applications, the load is approximately ten times that of household use.

[0019] Furthermore, compared to conventional coatings in existing technologies, the new coating can be applied entirely solvent-free in powder form, for example, by electrostatic application. Another advantage is that the calcination step can be performed not only in a furnace but also based on radiation, for example, by laser.

[0020] In the method of the present invention, preferably, the powder mixture used for the first layer contains a higher proportion of PPS polymer than the powder mixture used for the second layer, preferably greater than 60% by weight, more preferably greater than 70% by weight, further preferably greater than 90% by weight, even more preferably greater than 95% by weight, and particularly preferably greater than 99% by weight of PPS polymer based on the total mass of the dry powder mixture.

[0021] Preferably, in the method of the present invention, the powder mixture used for the second, third or more layers, preferably at least the surface layer, contains a higher proportion of PAEK polymer than the powder mixture used for the first layer, containing preferably more than 60% by weight, more preferably more than 70% by weight, further preferably more than 90% by weight, even more preferably more than 95% by weight, and particularly preferably more than 99% by weight of PAEK polymer based on the total mass of the dry powder mixture.

[0022] Preferably, in the method of the present invention, the calcination temperature (base temperature) during the preparation of each layer, especially the first layer, is 40-60°C higher than the liquidus temperature of the polymer when the polymer with a higher melting point is mixed, or 350-360°C when all layers are prepared at a uniform calcination temperature.

[0023] Preferably, the method is carried out, particularly in the step of heating the powder mixture to form a condensate, without the use of fluorosurfactants.

[0024] Preferably, in the method of the present invention, the powder mixture further contains tin (Sn), preferably 0.1 to 5% by weight, more preferably 0.1 to 2% by weight, even more preferably 0.5 to 1.5% by weight, particularly 1% by weight, based on the total mass of the dry powder mixture.

[0025] Preferably, in the method of the present invention, the powder mixture exists in the form of a dispersion, and preferably the liquid in the dispersion contains water.

[0026] Preferably, in the method of the present invention, the powder mixture comprises at least two PAEK polymers, or at least one PAEK polymer and a PPS polymer, wherein the PAEK polymer is preferably selected from the group consisting of polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), and polyetherketoneetherketone (PEKKEK). Preferably, these polymers have different melting point temperatures and / or preferably have different melt viscosities.

[0027] Preferably, in the method of the present invention, the average melt viscosity of at least one polymer is at most 150 Pa·s, preferably at most 120, more preferably at most 100 Pa·s, or particularly preferably at most 90 Pa·s, as measured according to ISO 11443 at 400°C. This results in a significantly smoother leveling effect when polycondensation is performed on the surface to be coated. The non-stick effect of the coated surface is also improved. This applies even when the particle size is relatively large compared to the coating thickness (e.g., for a coating thickness of 25 µm, the particle size D50 is 25 µm).

[0028] Preferably, in the method of the present invention, the powder mixture further comprises a dry lubricant, excluding fluoropolymers and PFAS, and preferably a component selected from polyamide-imide (PAI), polyimide (PI), graphite, molybdenum disulfide (MoS2), boron nitride (hexagonal crystal form; α-boron nitride), and mixtures thereof. This can further improve wear resistance.

[0029] Preferably, in the method of the present invention, the powder mixture further comprises a reinforcing component, a metal filler and its oxide, a ceramic filler and a mineral filler, flake or spherical glass particles, glass fiber or carbon fiber or carbon black. Preferably, the components are present in nanoscale dimensions, i.e., less than 100 nm, preferably 1 to 100 nm. Particularly preferred are nanomaterials as defined in ISO / TS 27687:2008, having three external dimensions, preferably 1 to 100 nm.

[0030] In a second aspect of the invention, an article, preferably a wear-prone (slippery) article, particularly a cooking and baking utensil, is provided having a coating prepared by the method according to the first aspect of the invention. Attached Figure Description

[0031] The present invention will now be described in detail with reference to embodiments and related drawings.

[0032] The accompanying drawings are for better understanding of the invention only and are schematic illustrations, not to scale. The invention should not be limited to the embodiments. Identical or functionally equivalent parts are referred to by the same reference numerals.

[0033] Figure 1 A schematic cross-sectional view of a cooking and baking appliance with a coated dispersion layer, according to a reference example, is shown.

[0034] Figure 2 Showing cooking and baking appliances according to a reference example,

[0035] Figure 3 illustrates the coating process sequence for manufacturing the cooking and baking appliances of the present invention through different process stages.

[0036] Figure 4 The diagram shows the coating process flow using the dispersion method. Detailed Implementation

[0037] The item to be coated, or the area of ​​the cooking and baking utensil to be coated, constitutes the substrate (SU) to be coated. First, the surface to be coated may undergo chemical and / or mechanical activation treatment. This can be done through mechanical roughening, such as sandblasting, etching with acids or alkalis, or plasma or laser treatment. Appropriately pretreated surfaces have additional chemical / physical bonding sites, are clean and grease-free, and have a larger surface area in the roughened state, which helps to improve the adhesion of the coating to be applied.

[0038] Subsequently, a dispersion layer DS is applied to the surface. This dispersion contains all the components of the coating and is dispersed in a solvent or solvent mixture, with a fine and as uniform a particle size distribution as possible. A suitable application method is selected to achieve the desired coating thickness. The average particle size (D50) of the solid particles contained in the dispersion corresponds at most to the desired coating thickness, but a smaller particle size is preferred. Figure 1 A substrate SU coated in this way and a dispersion layer DS applied on it are shown.

[0039] After performing a temperature program, the substrate or cooking and baking appliance with the dispersion layer DS is heated to a temperature higher than the melting point of one or more thermoplastics contained in the dispersion, thereby obtaining a uniform coating BS. This coating is non-porous, dense, and has good mechanical cohesion and good adhesion to the substrate SU. Figure 2 Showing cooking and baking appliances made according to a reference example.

[0040] In this process, only a portion of the surface can be coated. The remaining uncoated areas can be covered, or a dispersion application method that distinguishes different surface areas can be chosen, such as smearing or printing. Alternatively, a masking stencil can be used when spraying the dispersion. This masking stencil can also be in the form of a thin film, applied to the surface of the substrate SU, leaving the area to be coated exposed. After applying the dispersion layer DS, the film can be removed, for example, peeled off, along with the area of ​​the dispersion layer DS covering it.

[0041] Figure 3 illustrates the method of the present invention for coating articles, preferably easily worn (slippery) articles, particularly cooking and baking utensils or parts in contact with food, the method comprising at least two layers. For this purpose, after applying the first dispersion layer DS1 (as shown in Figure 3a), at least the solvent is removed, or the first dispersion layer is pre-cured by a corresponding heat treatment. In the second step, the dispersion coating process is repeated and a second dispersion layer DS2 is applied. If necessary, this layer can also be pre-cured, and the coating steps are repeated again. Finally, as shown in Figure 3c, in the final step, the dispersion layer structure consisting of multiple sublayers is heated to a temperature above the melting point of the thermoplastic, thereby obtaining a completely dense, non-porous closed coating BS on the substrate SU.

[0042] A composition suitable for application by dispersion method and capable of reducing friction according to the present invention comprises, for example, the following solid components in parts by weight:

[0043] For DS1: 100 weight percentage PPS For DS2: 100 weight percentage PAEK

[0044] Coloring additives may be added if necessary. One or more coats may be applied.

[0045] If necessary, the solid components are dispersed in a solvent using an auxiliary agent. This solvent may be water, or advantageously miscible or mixable with water, such as alcohols, particularly isopropanol. The dispersion mixture then contains about 30% by weight of the aforementioned solid components.

[0046] exist Figure 4 The process described above is illustrated more clearly in the flowchart. The method includes the preparation and handling of the powder mixture as step 1. For this purpose, selected components, chosen from thermoplastic polymers, fillers, and dry lubricants, are either processed to a suitable particle size, preferably by grinding and / or subsequently particle size classification according to the desired narrowest possible particle size distribution.

[0047] In parallel, a solvent is prepared in step 2, which is preferably harmless in terms of environmental protection and health, preferably water-based, and particularly composed of a mixture of alcohol and water, such as isopropanol and water. An advantageous solvent composition includes, for example, 25 to 75% by weight of isopropanol in water. Particularly preferred is an aqueous solution containing about 25-50% by weight of isopropanol.

[0048] In step 3, a dispersion is prepared by mixing the prepared powder mixture with a solvent, wherein the solid content is preferably maintained at 20 to 50% by weight. To improve dispersion stability, a small amount of a known dispersant may be added.

[0049] In step 4, the surface of the article is coated, for example by spraying, dipping, smearing, printing, or splattering. During this process, efforts are made to ensure the dispersion layer thickness is as uniform as possible, and areas on the surface that do not require coating are excluded from the coating process if necessary.

[0050] In step 5, the solvent is removed, preferably by evaporation, which may be assisted by negative pressure or by increasing the temperature, for example, to 80°C if necessary.

[0051] In the next step, 6, the cooking and baking appliance with the applied and dried dispersion layer is transformed into a uniform coating by heating and melting the thermoplastic, preferably at a temperature above the melting point of the polymer. The cooking and baking appliance is then cooled again.

[0052] According to the invention, a second layer (and possibly a third or more layers if necessary) is then prepared on the first layer, wherein sub-step 1 is repeated (as long as it is necessary to prepare a second or more layers with different compositions) and steps 2 to 6. Calcination at a temperature above the melting point of the polymer is performed individually or together on at least two layers.

[0053] Subsequently, a finished coating can be obtained at point 7.

[0054] According to the first variant V1 of the method, steps 4 to 7 can be executed again directly after step 5.

[0055] The second variant V2 follows step 6, wherein after melting the first dispersion layer, a new dispersion layer is applied (step 4) and a corresponding densification treatment is performed (steps 5 to 7).

[0056] According to the third variant V3 of the method, after preparing the first coating according to step 6, a second sub-layer different from the first coating is applied. For this purpose, another dispersion is prepared according to steps 1 to 3 of the method, and the cooking and baking utensils are coated accordingly according to steps 4 to 6. Here, the method can also be modified by repeating individual method steps or a sequence of individual method steps to achieve the desired coating thickness.

[0057] In particular, when using fine particles to prepare dispersions, a particularly uniform coating can be obtained, and multi-layer coating is advantageous or even necessary due to the small particle diameter.

[0058] Although the invention has been described by way of only a few embodiments, it is not limited thereto. Possible variations arise, in particular, from the appropriate selection of fillers and, if necessary, mixtures of different fillers. The proportions of the components in the coating are selected according to the load the coating is required to withstand. The coating thickness is also not limited to the examples described. The coating is preferably applied to a metallic surface, but can also be applied to other surfaces, such as ceramics, glass, or suitable plastics.

[0059] Example

[0060] PAEK polymers are known for their excellent sliding properties, and PTFE is often included as a dry lubricant in friction-optimized mixtures. Tests showed that by omitting PTFE, the wear rate was reduced by up to 10% compared to mixtures containing 3% PTFE. In the tests, stainless steel plates were coated to a thickness of 60 µm, and then subjected to Tiber tests under the following parameters:

[0061] Unless otherwise stated, all contents are expressed as a percentage by weight (wt%).

[0062] -model:

[0063] -Tiber rotary grinder / Model No.: 1700

[0064] - Pressure per roller: 1000g

[0065] Schleifmittel TABER Industries

[0066] S-33 Sandpaper Strips Batch number: 84944

[0067] All samples were coated with a thickness of approximately 60 µm, equivalent to the thickness of a typical high-quality 3-layer non-stick coating.

[0068] The measurement is the number of cycles until the first wear to the substrate occurs.

[0069] Experiment 1: Coating: 3 layers of PTFE, manufacturer PPG, Eclipse system: Result: 150 cycles

[0070] Experiment 2: Coating: 90% PEEK / 5% Black Pigment / 3% PTFE / 2% Graphite 300 cycles

[0071] Experiment 3: Coating: 92% PEEK / 5% Black Pigment / 2% Graphite 1500 cycles

[0072] Experiment 4: Layer 1, 40µm thick: 84% PPS / 5% black pigment / 5% PEEK / 1% tin / 5% glass flakes Layer 2, 20 µm thick: PEEK / 10% PPS / 5% black pigment / optional 1% graphite or boron nitride (hexagonal) (no difference) Roast together at 360°C: 2000 cycles Firing at 360°C twice: > 3000 cycles

[0073] Surprisingly, the coating of this invention is 10 times more durable than the well-developed PTFE coating and twice as durable as the simple PEEK coating.

[0074] Furthermore, surprisingly, the coating of this invention exhibits sufficiently good non-stick properties for use with cooking utensils. Pancakes made according to DIN standards can be easily removed with the new coating. Even after the aforementioned abrasion test, the non-stick effect did not diminish and remained as good as with the new coating. The coating does not have significant oleophobic properties, therefore it does not have a large contact angle with oils and greases, but this is not a disadvantage in use, as it makes grease lubrication particularly effective.

[0075] Dishwasher tests showed that the coating of this invention is completely resistant to dishwasher cleaning, and no damage was caused after 1,000 cycles.

[0076] In particular, the coating of this invention is alkali-resistant and hot water-resistant. The latter was determined by testing in a 130°C autoclave (under pressure) for 100 hours.

[0077] Other embodiments:

[0078] Experiment 5: Layer 1, 20µm thick: 84% PPS / 5% black pigment / 5% PEEK / 1% tin / 5% glass flakes Firing temperature 320°C Layer 2, 20 µm thick: PEEK / 10% PPS / 5% black pigment / optional 1% graphite or boron nitride (hexagonal) (no difference) Firing temperature 350°C

[0079] Experiment 6: Layer 1, 10µm thick: 84% PPS / 5% black pigment / 5% PEEK / 1% tin / 5% glass flakes Layer 2, 10 µm thick: PEEK / 10% PPS / 5% black pigment / optional 1% graphite or boron nitride (hexagonal) (no difference) Wet-on-wet spraying in the form of an aqueous dispersion, followed by calcination at 350°C after drying.

[0080] Experiments 7, 8, and 9: Layer 1, 20µm thick: 84% PPS / 5% black pigment / 5% PEEK / 1% tin / 5% glass flakes Layer 2, 40 µm thick: PEEK / 10% PPS / 5% black pigment / optional 1% graphite or boron nitride (hexagonal) (no difference) Roasted together at 400°C, 380°C, and 360°C respectively.

[0081] Experiment 10: Layer 1, 30µm thick: 84% PPS / 5% black pigment / 5% PEEK / 1% tin / 5% glass flakes Layer 2, 10 µm thick: PEEK / 10% PPS / 5% black pigment / optional 1% graphite or boron nitride (hexagonal) (no difference) Roasted together at 400°C, 380°C, and 360°C respectively.

[0082] As the firing temperature decreases, the coating's abrasion resistance and non-stick properties improve. As the firing temperature increases, the coating's temperature resistance (short-term) improves. When the temperature reaches 380°C, the coating no longer melts even at 380°C, although its respective liquidus temperatures are 285°C and 342°C, respectively.

[0083] All tests can be alternatively applied wet in dispersion form, such as by spraying or dipping, or dry in powder form, such as by fluidized bed sintering or electrostatic spraying.

[0084] In the case of the latter powder coating, the drying step can be omitted.

[0085] In all the described embodiments, the melting point of the finished coating is not negatively affected by PPS, but is at the melting point of PEEK, i.e., 342°C or higher.

Claims

1. A method for coating an article, preferably a wear-prone (slippery) article, particularly a cooking and baking appliance or a part that comes into contact with food, in at least two layers, the method comprising the steps of: 1) Preparing the first layer, which includes: a) Applying a powder mixture to the article, particularly the cooking and baking appliance, the powder mixture being in the form of a dry powder or a dispersion in a liquid, the mixture comprising powder particles of at least one polyphenylene sulfide (PPS) polymer and, if necessary, a polyarylether ketone (PAEK) polymer, wherein the powder mixture can be prepared without the addition of fluorine or fluorine-containing compounds, wherein the application is preferably carried out by electrostatic method, fluidized bed sintering method or as a dispersion in a liquid, particularly in water; b) In the case of the dispersion, the liquid is completely removed; c) Heating the powder mixture to form a condensate; and d) Preferably, the powder mixture is calcined at a temperature higher than the melting point of the polymer; 2) Prepare a second, third or more layers on the first layer, wherein sub-steps a) to c) are repeated, and step d) is performed individually for each layer or together for at least two layers.

2. The method according to claim 1, wherein, The powder mixture used for the first layer contains a higher proportion of PPS polymer than the powder mixture used for the second layer, preferably greater than 60% by weight, more preferably greater than 70% by weight, further preferably greater than 90% by weight, even more preferably greater than 95% by weight, and particularly preferably greater than 99% by weight of PPS polymer based on the total mass of the dry powder mixture.

3. The method according to any one of the preceding claims, wherein, The powder mixture used for the second, third, or more layers, preferably at least the surface layer, contains a higher proportion of PAEK polymer than the powder mixture used for the first layer, preferably greater than 60% by weight, more preferably greater than 70% by weight, further preferably greater than 90% by weight, even more preferably greater than 95% by weight, and particularly preferably greater than 99% by weight of PAEK polymer based on the total mass of the dry powder mixture.

4. The method according to any one of the preceding claims, wherein, The calcination temperature (base temperature) during the preparation of each layer is 40-60°C higher than the liquidus temperature of the polymer when mixing polymers with higher melting points, or 350-360°C when all layers are prepared at a uniform calcination temperature.

5. The method according to any one of the preceding claims, wherein, The method is carried out, particularly in the step of heating the powder mixture to form a condensate, without the use of fluorinated surfactants.

6. The method according to any one of the preceding claims, wherein, The powder mixture contains a maximum of 1000 ppb, a maximum of 100 ppb, and particularly preferably a maximum of 25 ppb of total fluoride as determined by combustion ion chromatography (TOF-CIC).

7. The method according to any one of the preceding claims, wherein, The powder mixture also contains tin (Sn), preferably 0.1 to 5% by weight, more preferably 0.1 to 2% by weight, further preferably 0.5 to 1.5% by weight, and particularly 1% by weight, based on the total mass of the dry powder mixture.

8. The method according to any one of the preceding claims, wherein, The powder mixture exists in the form of a dispersion, and the liquid contains water.

9. The method according to any one of the preceding claims, wherein, The powder mixture comprises at least one PAEK polymer and a PPS polymer, wherein the PAEK polymer is preferably selected from the group consisting of polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), and polyetherketoneetherketone (PEKKEK).

10. The method according to claim 9, wherein, The polymers have different melting point temperatures.

11. The method according to claim 9 or 10, wherein the PAEK polymer has different melt viscosities as determined according to ISO 11443 at 400°C.

12. The method according to any one of the preceding claims, wherein the average melt viscosity of at least one polymer is at most 150 Pa·s, preferably at most 120, more preferably at most 100 Pa·s or particularly preferably at most 90 Pa·s, as determined according to ISO 11443 at 400°C.

13. The method according to any one of the preceding claims, wherein, The powder mixture also contains a dry lubricant excluding fluoropolymers and PFAS, preferably selected from polyamide-imide (PAI), polyimide (PI), graphite, molybdenum disulfide, boron nitride (hexagonal; α-boron nitride) and mixtures thereof.

14. The method according to any one of the preceding claims, wherein, The powder mixture also includes reinforcing components, metal fillers and their oxides, ceramic fillers and mineral fillers, flake or spherical glass particles, glass fibers or carbon fibers or carbon black.

15. The method according to claim 14, wherein, The components exist at the nanoscale.

16. The method of claim 14, wherein, The size of the components is on the order of the coating thickness before the final layer is applied.

17. An article, preferably a wear-prone (slippery) article, particularly a cooking and baking utensil or a part that comes into contact with food, having a coating prepared by the method according to any one of claims 1 to 16.

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