Single layer coating

Abstract

The invention relates to a coating (3) for household items on a metal substrate (2), which is in contact with the metal substrate (2) via one of its surfaces (3a) and is visible to a user via its surface (3b), comprising one or more layers, each of which comprises one or more polyaryletherketones (PAEKs), and at least one of the layers consists of:-a PEAK-based polymer phase; -one or more fillers; -optionally one or more additives; -optionally, one or more colorants.

Description

Technical Field

[0001] The field of this invention is heated or heatable household items, particularly cooking items, including elements coated with a coating according to the invention. Background Technology

[0002] In the field of household goods, especially cooking products, coatings applied to the most common metal substrates (aluminum, cast aluminum, stainless steel, cast steel, etc.) have different properties.

[0003] More specifically, regarding the inner surfaces of these household items, coatings based on PTFE-type fluorinated resins have been known for over 50 years and are highly regarded for their excellent non-stick and cleanability, thermal stability and chemical resistance, as well as their tolerance to a wide variety of foods. However, the inherent weakness of PTFE is its ductility, which makes the coating susceptible to scratches, abrasions, and marks from metal utensils (spatulas, forks, spoons, stirrer feet, etc.).

[0004] Organic polymer underlayers are known in existing technologies for cooking items, but are only described as improving the scratch resistance of “soft” coatings based on fluoropolymers such as PTFE. Furthermore, in most cases, the described process requires double baking, allowing the thermosetting polymer to exceed its melting point before cooling and continuing to apply the fluorinated layer, which remains very expensive.

[0005] Application WO2000 / 54895 mentions the use of a lower layer consisting solely of oxy-1,4-phenylenephenylene-oxy-1,4-phenylenecarbonyl-1,4-phenylene, PEEK (particle size between 5 μm and 100 μm, with d50 preferably 20 μm) deposited on a metal substrate, the lower layer covering between 60% and 95% of the article surface, followed by a single or multiple layer of non-stick coating based on fluorinated resins and fluorinated copolymers. The PEEK lower layer can be deposited either by pad printing or screen printing, or by spraying in a dispersed form.

[0006] The thickness of the PEEK layer is between 5µm and 100µm.

[0007] The disadvantage of this process is that it requires a double baking of the PEEK-based fluorinated coating. The first baking requires a temperature above the melting point of the polymer constituting the underlying layer (for PEEK, this is between 380°C and 400°C) to allow it to bond to the metal substrate. Then, it is necessary to intensely cool the article, which is very expensive in terms of time and energy, but essential for applying continuous fluorinated layers, which will be sintered during the second high-temperature (>420°C) baking.

[0008] Polymers such as polyaryletherketone (PAEK), and especially oxy-1,4-phenylenephenylene-oxy-1,4-phenylenecarbonyl-1,4-phenylene or PEEK, are used in cutting-edge applications, such as in aerospace and healthcare, due to their heat resistance, mechanical resistance and chemical resistance.

[0009] This type of polymer is commercially available in the form of granules and powders produced by grinding these granules. These powders can then be dispersed in water-based or solvent-based liquid coating formulations for application by spraying (spraying), rolling, etc.

[0010] Electrostatic spraying of PEEK in powder form is also possible and has been described. This technique has the advantage of significantly limiting excessive spraying, as the negatively charged metal substrate attracts the positively charged polymer powder. However, this method requires highly technical and specialized installation. The metal substrate must either be grounded throughout the article's manufacturing process to prevent powder peeling, or it must be heated to temperatures above the polymer's melting point. Therefore, this is an expensive technique. Summary of the Invention

[0011] This invention proposes an alternative to coatings primarily based on PTFE to achieve good mechanical abrasion resistance, particularly for kitchen utensils used in cooking, and thus improves the durability of their mechanical abrasion resistance, especially under thermal conditions and / or their cleanability, to extend the life of the items.

[0012] To overcome the weaknesses of PTFE-type coatings, the present invention proposes a coating comprising one or more PAEKs as high-performance thermoplastic polymers in all its layers, and combined with one or more other polymers different from PAEKs in at least one of its layers.

[0013] These other polymers are used to provide properties complementary to PAEK polymers. This could be: - One or more fluorocarbon resins: These secondary polymers remain of interest for providing a good level of non-stick properties for certain applications such as long-handled pans; - Another aromatic thermoplastic polymer, such as PES (polyethersulfone): its glass transition temperature, which is much lower than that of PEAK, allows for improved film formation of the coating, which in turn improves adhesion to the substrate. - One or more organopolysiloxane polymers: These polymers remain of interest for providing ductility to coatings and enhancing their stretchability and stampability; - Another heterocyclic thermoplastic polymer.

[0014] Summary of the Invention The first subject of the present invention relates to a coating (3) on a metal substrate (2) for use in household articles, the coating (3) being in contact with the metal substrate (2) through one of its surfaces (3a) and visible to the user through its surface (3b), the coating comprising: Or multiple layers, each comprising one or more polyaryletherketones (PAEKs), and at least one of these layers being composed of: - At least 70% by weight of a polymer phase, said polymer phase comprising the following: o At least 50% by weight of one or more polyaryletherketones (PAEKs), the remainder being selected from the group consisting of: one or more organopolysiloxane polymers, one or more aromatic thermoplastic polymers other than PAEKs, one or more heterocyclic thermoplastic polymers and mixtures thereof, and optionally one or more fluorocarbon resins; or o At least 50% by weight of one or more polymers, said polymers being selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, organopolysiloxane polymers and mixtures thereof, the remainder consisting of one or more polyaryletherketones (PAEK) and optionally one or more fluorocarbon resins; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants; Or it may be a single layer, wherein the single layer consists of the following: - At least 70% by weight of a polymer phase, said polymer phase comprising the following: o At least 50% by weight of one or more polyaryletherketones (PAEKs), the remainder being selected from the group consisting of: one or more aromatic thermoplastic polymers other than PAEKs, one or more heterocyclic thermoplastic polymers and mixtures thereof, and optionally one or more fluorocarbon resins; or o At least 50% by weight of one or more polymers, said polymers being selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers and mixtures thereof, the remainder consisting of one or more polyaryletherketones (PAEK) and optionally one or more fluorocarbon resins; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0015] Another subject of the invention relates to a coated heating element (1) for household articles, comprising a metal substrate (2) having a coating according to the invention coated on at least one surface (2a), the coating being in contact with the metal substrate (2) through one of its surfaces (3a) and visible to the user through its surface (3b).

[0016] The present invention also relates to a method for manufacturing a coated heating element (1) according to the present invention, comprising the following sequential steps: i. Provide a metal substrate (2) having a surface (2a); ii. Optionally, the surface (2a) of the metal substrate (2) for coating is pretreated; iii. Apply one or more layers of the coating (3) to the surface (2a); iv. Bake the components obtained in step iii.

[0017] The present invention also relates to a household article comprising a coated heating element (1) according to the present invention, characterized in that the household article is a cooking article and the surface (3b) of the coating according to the present invention is capable of holding food. The present invention also relates to an electric cooking device comprising a coated heating element (1) according to the present invention and a heating source configured to heat the coated heating element (1).

[0018] definition The term "layer" or "coating" should be understood in the context of this invention as a continuous or discontinuous layer. A continuous layer (or also called a monolithic layer) is a single, integral unit that completely covers the entire plane on which it is laid. A discontinuous layer (or non-monolithic layer) may comprise multiple parts that are therefore not a single, integral unit.

[0019] The term "base layer" can be understood as all layers from the first layer applied directly to the substrate (preferably one that adheres well to the substrate and provides all of its mechanical properties to the coating: hardness, scratch resistance) to the last layer applied before the first decorative layer when the first decorative layer is present.

[0020] The term "finishing layer" or "final finish" can be understood as a continuous and transparent surface layer that leaves the decorative layer fully visible while protecting it from mechanical damage and giving the coating its anti-stick properties. Preferably, the final finishing layer is intended for contact with food.

[0021] The term "decoration" or "decorative layer" can be understood as one or more continuous or discontinuous layers comprising a pigment composition. Decoration can be presented in the form of one or more patterns and one or more colors. Decoration is clearly visible to the naked eye and at normal usage distances from household items.

[0022] The term "overlapping layer" can be understood as a layer that is partially or completely superimposed. These layers can be presented in the form of partially overlapping patterns, such as concentric discs.

[0023] The term "adjacent layers" can be understood as non-overlapping layers. These layers can be presented in the form of identical or different patterns that are non-overlapping and preferably uniformly distributed.

[0024] The term "temperature reference pigment composition" can be understood as a composition comprising a pigment that, at a given temperature, allows the user to indicate that the optimal operating temperature has been reached. This indication is made by comparing the colors of the thermochromic pigment composition and the temperature reference pigment composition. Either the optimal operating temperature is reached when the colors are the same, or when the colors are visually very different.

[0025] The term "temperature reference pigment composition" may include a pigment that exhibits: - Same color as thermochromic pigment compositions at optimal operating temperatures; * Or it may be because the pigment exhibits the same color at ambient temperature as the thermochromic pigment composition at its optimal use temperature, and does not change color with temperature; * Or it may be because the pigment exhibits a different color from the thermochromic pigment composition at ambient temperature, and this color evolves until it is the same color as the thermochromic pigment composition at its optimal use temperature; - A color that is very different from the color of a thermochromic pigment composition at its optimal operating temperature, regardless of whether the pigment changes color with temperature.

[0026] The optimal operating temperature can be achieved when the color of the temperature reference pigment composition corresponds to the color indicated in the user guide of the household article including the coating of the present invention or to the color indicated on the color chart provided to the user with the article.

[0027] Temperature-referenced pigment compositions are either thermochromic or thermally stable.

[0028] Temperature reference pigment compositions can be, for example, used for cooking or to indicate the risk of overheating.

[0029] The term "pigment or thermochromic pigment composition" should be understood in the context of this invention as a pigment or pigment composition that changes color with temperature within a given temperature range, and this change is reversible. This color change is visible to the naked eye and at normal usage distances.

[0030] The term "heat-stable pigment" can be understood as a pigment that does not change color when subjected to temperature increases within a given temperature range, or a pigment that exhibits a hue change when subjected to temperature increases within a given temperature range, such a hue change being so small that it is not visible to the naked eye and at normal usage distances.

[0031] Preferably, the heat-stabilized pigment has a color difference ΔE* of less than 10 between 25°C and 200°C, where ΔE* is defined by formula CIE 1976 in the CIELAB colorimetric space: ; L1*, a1*, and b1* characterize the L*a*b values ​​of the compound at ambient temperature. L2*, a2*, and b2* characterize the L*a*b values ​​of the compound at 200°C.

[0032] "The colors are the same" can be understood as being indistinguishable to the naked eye and at normal usage distances.

[0033] In the context of this invention, the term "cooking article" should be understood as an object used for cooking. Therefore, this object is intended to undergo heat treatment.

[0034] The term "object for receiving heat treatment" should be understood in the context of this invention as an object that is heated by an external heating system, such as a long-handled frying pan, a pan with a handle, a frying pan, a wok, or a grill, and that is capable of transferring the heat energy provided by the external heating system to materials or food in contact with the object.

[0035] In the context of this invention, the term "electric cooking equipment" should be understood as a heated object having its own heating system, such as an electric crepe maker, a lacrete appliance, a cheese fondue appliance, an electric grill, an electric barbecue grill, an electric steamer, a bread maker, and a pressure cooking appliance.

[0036] The term "coating" can be understood as a layer that covers and adheres to a metal substrate.

[0037] In this invention, weight percent is expressed as dry weight, meaning no solvent is used. Attached Figure Description

[0038] Figure 1 A cross-sectional view of an embodiment of a coated heating element (1) for household use is shown. The coated heating element (1) includes a metal substrate (2) coated with a coating (3) on at least one surface (2a). The coating (3) is in contact with the metal substrate (2) through one of its surfaces (3a) and is visible to the user through its surface (3b).

[0039] Figure 2 An implementation scheme for a hot blade test, which is used to evaluate the mechanical durability and heat scratch resistance of the coating (3), is shown. Detailed Implementation

[0040] coating The first subject of the present invention relates to a coating (3) on a metal substrate (2) for use in household articles, the coating (3) being in contact with the metal substrate (2) through one of its surfaces (3a) and visible to the user through its surface (3b), the coating comprising: Or multiple layers, each comprising one or more polyaryletherketones (PAEKs), and at least one of these layers being composed of: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of one or more polyaryletherketones (PAEKs), the remainder being selected from the group consisting of: one or more organopolysiloxane polymers, one or more aromatic thermoplastic polymers other than PAEKs, one or more heterocyclic thermoplastic polymers and mixtures thereof, and optionally one or more fluorocarbon resins; or o At least 50% by weight of one or more polymers selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, organopolysiloxane polymers and mixtures thereof, with the remainder consisting of one or more polyaryletherketones (PAEKs) and optionally one or more fluorocarbon resins. - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants; Or it can be a single layer, which consists of the following: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of one or more polyaryletherketones (PAEKs), the remainder being selected from the group consisting of: one or more aromatic thermoplastic polymers other than PAEKs, one or more heterocyclic thermoplastic polymers and mixtures thereof, and optionally one or more fluorocarbon resins; or o At least 50% by weight of one or more polymers selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers and mixtures thereof, with the remainder consisting of one or more polyaryletherketones (PAEKs) and optionally one or more fluorocarbon resins; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0041] It is understood that each of the layers in coating (3) includes one or more polyaryletherketones (PAEKs).

[0042] Advantageously, the thickness of the coating (3) according to the invention is between 5 μm and 200 μm, preferably between 10 μm and 80 μm.

[0043] polymer phase PAEK Preferably, one or more polyaryletherketones (PAEKs) are selected from the group consisting of polyetherketones (PEKs), polyetheretherketones (PEEKs), polyetherketoneketones (PEKKs), polyetheretherketoneketones (PEEKKs), and polyetherketoneetherketoneketones (PEKEKKs), particularly preferably PEEKs.

[0044] PAES As aromatic thermoplastic polymers different from PAEK, suitable examples according to the present invention include: polyphenylene ether (PPO), poly(aryl ether sulfone) (PAES) polymers, and in particular polyether sulfone (PES), polyphenylene ether sulfone (PPSU), polyphenylene sulfide (PPS), poly(aryl sulfide) (PAS), liquid crystal polymers and mixtures thereof.

[0045] Heterocyclic thermoplastic polymers As heterocyclic thermoplastic polymers according to the present invention, suitable examples include: polyetherimide (PEI), polyimide (PI), polyamideimide (PAI) and polybenzimidazole (PBI) and mixtures thereof.

[0046] Organopolysiloxane polymers As organopolysiloxane polymers, according to the present invention, suitable examples include polymers obtained from polymeric or oligomeric organopolysiloxane precursors, which are either in the form of silicone oils with variable branching, or in the form of silicone resins or silicone resin copolymers with variable pre-crosslinking, such as silicone polyester resins, silicone alkyd resins, silicone polyurethane resins, silicone epoxy resins, or in the form of mixtures of silicone oils, silicone resins, and silicone resin copolymers. Silicon atoms may be substituted with alkyl (especially methyl) or aryl (especially phenyl) groups or mixtures thereof. The oil or resin preferably includes one or more (2, 3, or more) hydroxyl or alkoxy (especially methoxy, ethoxy, butoxy) functional groups as substituents for the silicon atoms.

[0047] Preferably, one or more organopolysiloxane polymers of the coating according to the present invention are silicone oils or silicone resin copolymers.

[0048] The advantages of using these thermally stable polymers, especially PAEK, under continuous use conditions at 260°C also lie in their very high mechanical properties (Young's modulus, tribology, low coefficient of friction, low surface energy, etc.) and their chemical resistance (excellent resistance to many solvents under acidic and alkaline conditions), their biocompatibility, their biostability, and their recyclability.

[0049] According to one embodiment, each of the plurality of layers of the coating (3) according to the invention comprises at least 1% by weight, preferably at least 5% by weight, one or more polyaryletherketones (PAEK).

[0050] Advantageously, one or more polyarylether ketones (PAEKs) present in each of the multiple layers are polyether ether ketones (PEEKs) or polyether ketone ketones (PEKKs).

[0051] Advantageously, one or more aromatic thermoplastic polymers other than PAEK include polyethersulfone (PES) or polyphenylene sulfide (PPS).

[0052] An amorphous, non-crystalline aromatic thermoplastic polymer such as PPSU / PES (polyethersulfone) allows for improved film formation of the coating because its glass transition temperature is much lower than the melting temperature of PAEK, which improves adhesion to the substrate. This also advantageously allows for increased ductility of the material and promotes its stretchability and stamping capability.

[0053] organopolysiloxanes This family of polymers allows for the combination of different properties based on the polymer structure, such as heat resistance, lubricity and non-stick properties, hydrophobicity, resistance to heat, thermal oxidation, and chemical and biological erosion.

[0054] Advantageously, when the polymer phase comprises an organopolysiloxane polymer, this organopolysiloxane polymer can be obtained through a crosslinking process that generates a continuous or discontinuous polymer network at the microscale in the polymer phase, depending on the concentration, properties, and conformation of other components in the coating. The term "crosslinking" can be understood as a chemical reaction that generates one or more covalent bonds between precursors of the organopolysiloxane polymer and / or between these same precursors and other components of the coating.

[0055] The coating obtained according to the invention is advantageously solid. The term "solid" can be understood as the property of a cohesive material that is insoluble in water, in common solvents, or in food components such as aqueous or fat mixtures, even if the material may have high hardness or high flexibility, such as an elastomer.

[0056] The organopolysiloxane polymer network can be composed of a combination of four simple organosiloxane units, designated M, D, T, and Q according to the degree of oxygen substitution of the silicon atom, as shown in the table below, where R is an organic substituent as described below.

[0057] [Table 1]

[0058] Organopolysiloxane polymers are obtained from precursors via crosslinking. These precursors can be monomeric or polymeric, or oligomers as intermediates. Organopolysiloxane polymers can also be obtained from mixtures of these different types of precursors. The crosslinking density is higher when the network contains a higher number of T and Q units than D. The distribution among M, D, T, and Q units depends on the chemical structure of the precursors, and particularly on this distribution of M, D, T, and Q within the precursor.

[0059] The polymerization precursors are organopolysiloxanes. These macromolecules are formed from the M, D, T and / or Q units described in the table, wherein R is independently an alkyl group, particularly methyl, or an aryl group, particularly phenyl, and different properties of R can exist on the same macromolecule.

[0060] Organopolysiloxanes can be linear or slightly branched (mostly D-groups), or branched or highly branched (mostly T and Q-groups). Linear or slightly branched organopolysiloxanes are typically liquids, more or less viscous at room temperature, and are referred to as silicone oils. Branched or highly branched (pre-crosslinked) organopolysiloxanes form a network of individual macromolecules and are referred to as silicone resins. At ambient temperatures, the resins are essentially solid, or liquid (especially under conditions with relatively low molecular weights), in solutions in solvents or as aqueous emulsions. These resins can be copolymerized with non-silicone organic polymers or oligomers, particularly selected from polyesters, acrylics, alkyds, polyurethanes, and epoxy resins.

[0061] When crosslinking is hydrolysis-condensation: this is due to the presence of reactive hydroxyl or alkoxy functional groups, especially methoxy, ethoxy, or butoxy functional groups, on the organopolysiloxane.

[0062] When crosslinking is polyaddition (or hydrosilanization): this is carried out by a reaction between a reactive vinyl functional group (-CH═CH2) present on one of the organopolysiloxanes and a reactive hydromethionide functional group (Si-H) present on another organopolysiloxane mixed with the first.

[0063] All these reactive functional groups are present on each organopolysiloxane in at least one quantity, and may be present in quantities of two, three or more, within the limits allowed by the molecular structure. Silicone oils containing at least one reactive functional group are called "reactive oils". Reactive functional groups may be located at the ends (terminals) of the macromolecular chain or distributed throughout the entire chain.

[0064] Silicone polyester resins are particularly characterized by silicone / polyester mass ratios, such as 90 / 10, 80 / 20, 70 / 30, 60 / 40, 50 / 50, 40 / 50, 30 / 70, 20 / 80, and 10 / 90, with an advantage between 80 / 20 and 50 / 50.

[0065] Linear PDMS silicone oils, whether pure or pre-emulsified in water, are characterized firstly by their molecular weight, which changes directly with increasing viscosity of the pure oil. Then, these silicone oils are characterized by the presence of reactive functional groups, such as hydroxyl functional groups on silicon atoms (silanols), their number, and their positions on the molecular chain. For example, reactive oils with viscosities between 50 mPa·s and 20,000 mPa·s, and particularly between 300 mPa·s and 5,000 mPa·s, can be used. These reactive oils have at least one reactive functional group, preferably at least two, which can be located at the chain ends (positions α, ω).

[0066] Polymer precursors obtained by addition polymerization may include, for example, polymethylhydrosiloxanes, vinylmethylsiloxanes, particularly linear vinyl-terminated polydimethylsiloxanes (PDMS), vinyl-terminated diphenylsiloxane-dimethylsiloxane copolymers, hydride-terminated polydimethylsiloxanes, hydride-terminated polyphenylmethylsiloxanes, cyclic vinylmethylsiloxanes, vinyl MQ resins, trimethylsilyl-terminated polymethylsiloxanes, trimethylsiloxane-terminated methylhydrosiloxane and dimethylsiloxane copolymers, resin hydrides MQ, and combinations thereof.

[0067] Polymer precursors obtained through hydrolysis-condensation reactions, whether silicone resins or silicone oils, may include, for example: poly(methylsilsesquioxane), poly(propylsilsesquioxane), poly(phenylsilsesquioxane), polydimethylsiloxane (PDMS), trimethylsilyl-terminated polydimethylsiloxane (PDMS), hydroxyl-terminated polydimethylsiloxane (PDMS), silanol-terminated polydimethylsiloxane (PDMS), silanol-terminated polyphenylsiloxane (PDMS), silanol-terminated diphenylsiloxane-dimethylsiloxane copolymer, poly(2-acetoxyethylsiloxane), organically modified alkoxysilanes and their oligomers, and all similar macromolecules and mixtures thereof.

[0068] Organopolysiloxane polymers can also be obtained by crosslinking one or more monomer precursors and one or more polymers as described above, as well as a mixture of one or more oligomer precursors that may be linear, branched, or cyclic. These oligomer precursors have a lower molecular weight than the polymer precursors. Polymers and / or oligomer precursors comprising more than two, advantageously much more than two, reactive functional groups as described above can be added to the mixture as a “co-binder” to promote a high crosslinking density of the final organopolysiloxane polymer.

[0069] Monomer precursors, oligomer precursors, and / or polymer precursors, particularly silicone resins, whether or not copolymerized with organic polymers, act as polymer binders to obtain solid organopolysiloxane polymers bonded to each layer of TP.

[0070] Silicone oil-based organopolysiloxane precursors, if added in small amounts (typically between 0.1% and 5% by dry weight) throughout a single-layer formulation, can be considered additives, independent of other components used to form solid organopolysiloxane polymers.

[0071] Crosslinking may require a catalyst: - In the case of crosslinking organopolysiloxanes via hydrolysis condensation, the formulation may include metal catalysts, such as metal complexes based on platinum, tin, zinc, zirconium and cerium, particularly platinum-cyclovinylmethylsiloxane complexes, tin ethylhexanoate, zinc ethylhexanoate, zirconium ethylhexanoate, cerium ethylhexanoate and dibutyltin laurate.

[0072] - In the case of crosslinking organopolysiloxanes by hydrogenation acylation, it may be necessary to add a catalyst: this can be, for example, platinum or a suitable platinum-based catalyst, such as Karstedt catalyst or Ashbys catalyst.

[0073] Crosslinking agents, such as those carrying Si-H bonds, may be present.

[0074] Fluorocarbon resin One or more fluorocarbon resins are advantageously selected from the group consisting of: polytetrafluoroethylene (PTFE), copolymers of tetrafluoroethylene and perfluoropropyl vinyl ether (PFA), copolymers of tetrafluoroethylene and hexafluoropropylene (FEP), and mixtures thereof, particularly preferably including PTFE.

[0075] Advantageously, the coating according to the invention does not include fluorocarbon resin.

[0076] filler In the sense of this invention, the filler allows for mechanical reinforcement and can also provide lubrication and hydrophobic properties, while improving the mechanical strength and thermal conductivity of the coating.

[0077] Fillers do not have the sole function of giving a coating color, but they can help with it.

[0078] The presence of fillers with excellent thermal conductivity allows for compensation of the low thermal conductivity of PAEK polymers.

[0079] Advantageously, one or more fillers are selected from the group consisting of ceramic fillers (SiO2, etc.) and / or mineral fillers and / or metal fillers (Al2O3, TiO2, etc.) and / or hydrophobic silica and / or diamond particles.

[0080] Preferably, one or more fillers are selected from the group consisting of metal oxides, metal carbides, metal oxynitrides, metal nitrides, and mixtures thereof.

[0081] Advantageously, the metal is a transition metal, such as at least one element selected from B, Ni, Ti, Zr or Hf.

[0082] More preferably, one or more packing materials are selected from the group consisting of: - Reinforcing filler: organic or inorganic hard filler; inorganic hard filler is preferably silicon carbide or alumina or zirconium oxide or graphite, or ceramic, or carbonate, hydrated alumina, aluminum hydroxide or one or more metal oxides, graphite or graphene particles. - Other reinforcing fillers selected from metal oxides: mica, layered fillers, clays such as montmorillonite, sepiolite, gypsum, kaolinite and laponite, zinc dioxide, quartz, as well as zirconium phosphate, alumina, zirconium oxide, zinc oxide, copper oxide, and iron oxide; - Filler selected from reinforcing fibers: glass fiber, carbon fiber, or aramid fiber; - A conductive filler comprising transition metal carbides and / or transition metal nitrides: characterized in that the transition metal is at least one element selected from B, Ni, Ti, Zr or Hf; For example: cubic boron nitride, diamond particles, metal particles; - Layered fillers that can impart lubricating properties, such as clay, graphene, or graphite.

[0083] Preferred fillers for use with organopolysiloxanes are: - Reinforcing filler: The filler content is a minimum of 10-15% by weight and can reach 60% by weight of silica or carbonate; - Alumina, hydrated alumina, aluminum hydroxide; - d50 < 0.1 μm and specific surface area BET > 30 m² 2 / g and preferably between 30m 2 / g and 500m 2Silicon dioxide (precipitated or pyrolyzed) between / g; - Or a mixture of quartz and silica, diatomaceous earth or ground quartz, titanium, mica, talc, kaolin, barium sulfate, quicklime, zinc oxide, expanded vermiculite, non-expanded vermiculite, calcium carbonate, etc.

[0084] Advantageously, the average diameter d50 of the packing is between 0.1 μm and 50 μm, and more advantageously between 5 μm and 15 μm.

[0085] Advantageously, the proportion of filler in a layer is between 0.5% and 30% of the total dry weight of the layer after baking, preferably between 5% and 20%.

[0086] Advantageously, the proportion of filler in the coating (3) is less than 10% by weight relative to the total weight of the coating (3).

[0087] additive Advantageously, the additive is selected from the group consisting of defoamers, dispersants, wetting agents, thickeners and pH adjusters.

[0088] One or more defoamers are preferably selected from the group consisting of mineral oil, glycol, hydrocarbon, glycerol ester, ethylene oxide, and emulsified fatty acids.

[0089] One or more surfactants are preferably selected from the group consisting of glycol ethers, ethoxylated alcohols excluding alkylphenol ethoxylates (APE), and Gemini surfactants.

[0090] One or more dispersants are preferably selected from the group consisting of free anionic dispersants, such as fatty acid derivatives.

[0091] The thickener is preferably selected from the group consisting of acrylic or polyurethane copolymers, cellulose, and pyrolytic silica.

[0092] The pH adjuster is preferably selected from the group consisting of Bronsted bases: ammonia, amines (triethylamine, triethanolamine, etc.), hydroxides (sodium hydroxide, potassium hydroxide, etc.), and carbonates.

[0093] Preferred adhesion promoters for use with organopolysiloxanes are organosilanes or organopolysiloxanes having three hydrolyzable groups linked to silicon per molecule.

[0094] Advantageously, the proportion of additives in the coating (3) is less than 20% by weight relative to the total weight of the coating (3).

[0095] Advantageously, the proportion of the additive in each layer of the coating (3) is less than 20% by weight relative to the total weight of the layers.

[0096] Colorant Advantageously, the coating according to the invention comprises one or more colorants selected from the group consisting of thermochromic pigments, heat-stabilized pigments, glitter, holographic glitter, and mixtures thereof.

[0097] Thermochromic Pigments Preferably, one or more thermochromic pigments are selected from Bi2O3, Fe2O3, V2O5, WO3, CeO2, In2O3, and Y. 1.84 Ca 0.16 Ti 1.84 V 0.16 O 1.84 AgI, (Bi 1-x A x (V) 1-y M y The group consists of O4, where: - x equals 0 or x is between 0.001 and 0.999; - y equals 0 or y is between 0.001 and 0.999; - A and M are selected from groups composed of nitrogen, phosphorus, alkali metals, alkaline earth metals, transition metals, depleted metals, metalloids, or lanthanides; - A and M are different from each other.

[0098] Given that A and M are different from each other, when: - When A is an alkali metal, it can be selected from Li, Na, K, Rb, and Cs; - When M is an alkali metal, it can be selected from Li, Na, K, Rb, and Cs; - When A is an alkaline earth metal, it can be selected from Be, Mg, Ca, Sr, and Ba; - When M is an alkaline earth metal, it can be selected from Be, Mg, Ca, Sr, and Ba; - When A is a transition metal, it can be selected from Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, and Ir; - When M is a transition metal, it can be selected from Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir; - When A is a metal-poor element, it can be selected from Al, Zn, Ga, In, and Sn; - When M is a metal-poor element, it can be selected from Al, Zn, Ga, In, and Sn; - When A is a metalloid, it can be selected from B, Si, Ge, and Sb; - When M is a metalloid, it can be selected from B, Si, Ge, and Sb; - When A is a lanthanide element, it can be selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; - When M is a lanthanide element, it can be selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0099] Preferably, the different A and M are B and / or Mg.

[0100] Preferably, pigment (Bi) 1-x A x (V) 1-y M y O4 exists in the form of monoclinic alum crystals at ambient temperature.

[0101] Preferably, x and y equal 0, that is, the pigment (Bi) 1-x A x (V) 1-y M y Bis(VO4) is bismuth vanadate. Advantageously, BiVO4 with a monoclinic jussite crystal structure is used at ambient temperature.

[0102] Bismuth vanadate is a yellow inorganic compound with the molecular formula BiVO4, widely used for its coloring properties and non-toxicity. It is registered in the International Color Index Database as QI Pigment Yellow 184, and is particularly marketed by Heubach (Vanadur®), BASF (Sicopal®), FERRO (Lysopac), and Bruchsaler Farbenfabrik (Brufasol®).

[0103] Thermally stable pigments Preferably, one or more thermally stable pigments are selected from the group consisting of: - Titanium redstone type yellow pigment; - Yellow pigments derived from bismuth, such as those selected from stabilized bismuth vanadate (Py 184 ); - Red pigments, such as those selected from perilla red (e.g., PR149, PR178 and PR224), iron oxide; - Bismuth oxyhalide (PO) 85 Type 1 orange pigment; - Bismuth vanadate orange pigment (PO) 86 ); - Zinc-tin-titanium orange pigment (PO) 82); - Cerium sulfide orange pigment (PO) 75 ;PO 78 ); - Antimony-titanium-chromium rutile orange-yellow pigment (PBr) 24 ); - Tin and zinc rutile orange-yellow pigments (Py 216 ); - Niobium tin oxide zinc sulfide orange-yellow pigment (Py 227 ); - A tin and niobium bioxide orange-yellow pigment; - Co3(PO4)2; - LiCoPO4; - CoAl2O4; - Cr2O3; - TiO2; - Black pigment PBk28 (black spinel copper chromite); - and its mixtures.

[0104] sequins The glitter usable within the scope of this invention can be independently selected from coated or uncoated mica glitter, coated or uncoated silica glitter, coated or uncoated aluminum glitter, and coated or uncoated iron oxide glitter. Mica or silica glitter coated with titanium dioxide may also be used. The glitter usable within the scope of this invention can be processed to give specific color effects.

[0105] Preferably, one or more glitter particles are selected from the group consisting of mica particles, aluminum particles, mica particles coated with titanium dioxide, or mixtures thereof.

[0106] Holographic sequins Advantageously, one or more sequins are holographic sequins, that is, a mixture of magnetizable and non-magnetizable particles.

[0107] Magnetizable particles can advantageously be particles comprising at least one ferromagnetic metal. These magnetizable particles can be homogeneous, i.e., composed of the same material, or composite, i.e., having a core-shell structure in which the ferromagnetic metal is located in the core and / or shell of the particle. Examples of composite magnetizable particles include, in particular, mica flakes coated with iron oxide (Fe2O3) or stainless steel fibers coated with a sol-gel material as corrosion protection during the coating process; or plastic flakes coated with iron oxide (Fe2O3); or flakes with a core made of a ferromagnetic metal and a shell formed of plastic or sol-gel material.

[0108] According to one embodiment, a portion of the magnetizable particles is oriented to form a three-dimensional decoration.

[0109] Advantageously, the mixture of magnetizable and nonmagnetizable particles accounts for between 1% and 5% of the layer weight, preferably between 2% and 3% by weight.

[0110] Advantageously, the percentage of non-magnetizable particles in the mixture of magnetizable and non-magnetizable particles is between 15% and 40% by weight relative to the total weight of the mixture of magnetizable and non-magnetizable particles.

[0111] Advantageously, the magnetizable particles have a size D50 of less than or equal to 23 μm.

[0112] In the context of this invention, the term "D50" can be understood as the maximum size of 50% of the particles.

[0113] Advantageously, the non-magnetizable particles have a size D90 that is between 20% and 250% of the size D90 of the magnetizable particles.

[0114] In the context of this invention, the term "D90" can be understood as the maximum size of 90% of the particles.

[0115] Advantageously, magnetizable and / or non-magnetizable particles are colored on the surface.

[0116] Advantageously, the non-magnetizable particles are composed of mica, aluminum, or mica coated with titanium dioxide.

[0117] Advantageously, the magnetizable particles consist of iron, iron oxide, iron-coated aluminum, or iron-coated mica, with the iron present in ferrite form.

[0118] structure According to one embodiment, the coating according to the invention comprises one or more layers applied to a substrate. The coating may be a single-layer coating or a multi-layer coating, with different layers applied sequentially.

[0119] Advantageously, the coating according to the invention comprises one to three layers, preferably two layers, which are applied to a substrate.

[0120] Advantageously, the coating according to the invention includes an intermediate layer, preferably two intermediate layers, which may be decorative layers.

[0121] Advantageously, the coating according to the invention is an anti-stick coating, that is, preferably food does not adhere to the coating.

[0122] Advantageously, the coating according to the invention is a single-layer anti-stick coating.

[0123] decorate According to one embodiment, one or more decorative layers are continuous and cover the entirety of the underlying layer.

[0124] According to another embodiment, one or more decorative layers do not cover the entirety of the underlying layer and form at least one decoration.

[0125] Advantageously, one or more decorative layers include multiple decorations, one decoration (i) including one or more thermochromic pigments, and another decoration (j) including at least one temperature-referenced pigment composition.

[0126] According to one implementation, each of the two decorations (i) and (j) is presented as adjacent, non-overlapping patterns. For example, each decoration is represented by different geometric patterns that are uniformly distributed across the entire surface and alternate with each other.

[0127] According to another implementation, the two decorations (i) and (j) partially overlap. For example, each decoration is represented by different geometric patterns that are evenly distributed across the entire surface and partially overlap.

[0128] Preferably, the two decorations (i) and (j) overlap, either because one of the two decorations is a continuous layer and the other decoration covers the continuous layer in the form of a pattern, or because the two decorations (i) and (j) are presented in the form of an overlapping pattern.

[0129] According to another embodiment, the decoration is applied directly to the substrate.

[0130] Decoration can be applied by any method known to those skilled in the art, such as by screen printing or pad printing.

[0131] Preferably, the polymer phase comprising at least 70% by weight of one or more layers of the polymer phase includes at least 60% by weight, more preferably at least 70% by weight of one or more polyarylether ketones (PAEK).

[0132] The polymer phase may include one or more polyarylether ketones (PAEKs) of greater than 75% by weight, greater than 80% by weight, greater than 85% by weight, greater than 90% by weight, or greater than 95% by weight.

[0133] Preferably, the polymer phase of one or more layers consisting of at least 70% by weight of the polymer phase comprises at least 60% by weight, more preferably at least 70% by weight, one or more polymers selected from the group consisting of aromatic thermoplastic polymers, heterocyclic thermoplastic polymers, organopolysiloxane polymers (when they are present in the layers) and mixtures thereof, other than PAEK.

[0134] The polymer phase may include more than 75% by weight, more than 80% by weight, more than 85% by weight, more than 90% by weight, or more than 95% by weight of one or more polymers selected from the group consisting of aromatic thermoplastic polymers, heterocyclic thermoplastic polymers, organopolysiloxane polymers (when they are present in the layer) and mixtures thereof, other than PAEK.

[0135] According to one embodiment, all layers of the coating (3) according to the invention consist of the following: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of one or more polyaryletherketones (PAEKs), the remainder being selected from the group consisting of: one or more organopolysiloxane polymers, one or more aromatic thermoplastic polymers other than PAEKs, one or more heterocyclic thermoplastic polymers and mixtures thereof, and optionally one or more fluorocarbon resins; or o At least 50% by weight of one or more polymers selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, organopolysiloxane polymers and mixtures thereof, with the remainder consisting of one or more polyaryletherketones (PAEKs) and optionally one or more fluorocarbon resins. - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0136] According to another embodiment, the coating (3) comprises a plurality of layers, and all of the layers comprise polyetheretherketone (PEEK), and at least one of these layers is composed of: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of polyetheretherketone (PEEK), with the remainder consisting of polyethersulfone (PES) and optionally PTFE; or o At least 50% by weight of polyethersulfone (PES), with the remainder consisting of polyetheretherketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0137] According to another embodiment, the coating (3) comprises a plurality of layers, and all of the layers comprise polyetheretherketone (PEEK), and at least one of these layers is composed of: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of polyetheretherketone (PEEK), with the remainder consisting of silicone oil and optionally PTFE; or o At least 50% by weight of silicone oil, the remainder consisting of polyetheretherketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0138] According to another embodiment, the coating (3) comprises a single layer, which is composed of the following: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of polyetheretherketone (PEEK), the remainder consisting of polyethersulfone (PES) or polyamide-imide (PAI) or polyphenylene sulfide (PPS) or mixtures thereof and optionally PTFE; or o At least 50% by weight of polyethersulfone (PES) or polyamide-imide (PAI) or polyphenylene sulfide (PPS) or a mixture thereof, the remainder consisting of polyether ether ketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0139] According to another embodiment, the coating (3) comprises a single layer, which is composed of the following: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of polyetheretherketone (PEEK), with the remainder consisting of polyethersulfone (PES) and optionally PTFE; or o At least 50% by weight of polyethersulfone (PES), with the remainder consisting of polyetheretherketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0140] According to another embodiment, the coating (3) comprises a single layer, which is composed of the following: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of polyetheretherketone (PEEK), with the remainder consisting of polyamide-imide (PAI) and optionally PTFE; or o At least 50% by weight of polyamide-imide (PAI), with the remainder consisting of polyetheretherketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0141] According to another embodiment, the coating (3) comprises a single layer, which is composed of the following: - At least 70% by weight of a polymer phase, which consists of the following: o At least 50% by weight of polyetheretherketone (PEEK), with the remainder consisting of polyphenylene sulfide (PPS) and optionally PTFE; or o At least 50% by weight of polyphenylene sulfide (PPS), with the remainder consisting of polyether ether ketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

[0142] Coated heating element The term "coated heating element" can be understood as an assembly consisting of a metal substrate and a coating according to the invention on the metal substrate, the substrate being capable of being heated.

[0143] Advantageously, the coated heating element according to the invention is a coated cooking element.

[0144] Figure 1 Another subject of the invention shown relates to a coated heating element (1) for a household item, comprising a metal substrate (2) having a coating (3) according to the invention coated on at least one surface (2a), the coating (3) being in contact with the metal substrate (2) through one of its surfaces (3a) and visible to the user through its surface (3b).

[0145] metal substrate Advantageously, the metal substrate (2) is made of aluminum, stainless steel, cast iron or cast aluminum, iron, titanium or copper.

[0146] In the context of this invention, aluminum can be understood as a metal composed of 100% aluminum or aluminum alloys.

[0147] Preferably, the metal substrate (2) is an aluminum substrate, a stainless steel substrate, or a multilayer metal substrate. The metal substrate (2) can be a two-layer or three-layer substrate, which can be obtained, for example, by lamination, by thermal diffusion under load (solid-state bonding), or by thermal or cold shock (shock bonding).

[0148] Preferably, the metal substrate (2) comprises alternating layers of metal and / or metal alloy.

[0149] According to one embodiment, the metal substrate (2) is a substrate made of aluminum alloy or stainless steel, or a multilayer metal substrate with a surface (2a) made of aluminum alloy or stainless steel.

[0150] Preferably, the metal substrate (2) is an aluminum substrate.

[0151] Advantageously, the thickness of the metal substrate (2) is between 0.5 mm and 10 mm.

[0152] Advantageously, the surface (2a) of the metal substrate (2) has been pre-treated, which allows for improved adhesion of the coating to the substrate.

[0153] According to one embodiment, the surface (2a) of the metal substrate (2) has undergone a surface treatment, which is a combination of chemical etching, brushing, hydration, sandblasting, shot peening, plasma or corona or laser type physicochemical treatment, chemical activation or a combination of these different techniques.

[0154] Advantageously, the surface of the substrate (2a) to which the coating (3) according to the invention is to be applied can be treated to increase its specific surface area; for aluminum substrates, treatment can be performed by anodizing (forming a tubular alumina structure), by chemical etching, by sandblasting, by brushing, by shot peening, or by adding materials using techniques such as thermal spraying (flame, plasma, or arc spraying). Other metal substrates can also be polished, sandblasted, brushed, microbeaded, or have materials added using techniques such as thermal spraying (flame, plasma, or arc spraying).

[0155] Advantageous examples of metal substrates that can be used in this invention include: aluminum substrates that are anodized or non-anodized, optionally polished, brushed, sandblasted, shot-peened, or microbead-blasted; aluminum alloy substrates that are anodized or non-anodized, optionally polished, brushed, sandblasted, or microbead-blasted; steel substrates that are optionally polished, brushed, sandblasted, or microbead-blasted; stainless steel substrates that are optionally polished, brushed, sandblasted, or microbead-blasted; cast steel, cast aluminum, or cast iron substrates; and copper substrates that are optionally forged or polished.

[0156] Advantageously, the substrate can be selected from: a substrate including a ferritic stainless steel / aluminum / austenitic stainless steel layer, a substrate including a stainless steel / aluminum / copper / aluminum / austenitic stainless steel layer, a cast aluminum, aluminum or aluminum alloy cover with an inner stainless steel outer bottom, a metal laminate substrate including a stainless steel layer (e.g. for constituting the inner surface of the article) and an anodized or non-anodized aluminum or aluminum alloy layer (e.g. for constituting the outer surface of the article), such as a double laminate substrate.

[0157] Advantageously, the average arithmetic roughness Ra of the surface (2a) of the metal substrate (2) is greater than or equal to 1 μm.

[0158] According to standard ISO 4287, the average arithmetic roughness Ra is measured using a roughness meter. Ra represents the arithmetic mean of the average deviations. Surface topography can be studied, in particular, using a profilometer with a detector equipped with a fine stylus fitted with a diamond tip, or also using an Altisurf® type optical metrology device, where a color confocal sensor allows for non-contact measurement. The study of this surface topography allows for the determination of the average arithmetic roughness Ra.

[0159] method Another subject of the present invention relates to a method for manufacturing a coated heating element (1) according to the present invention, comprising the following sequential steps: i. Provide a metal substrate (2) having a surface (2a); ii. Optionally, the surface (2a) of the metal substrate (2) for coating is pretreated; iii. Apply one or more layers of coating (3) to surface (2a); iv. Bake the components obtained in step iii.

[0160] Advantageously, step iii is performed by spraying, screen printing, roller coating, or electrostatic spraying one or more layers of coating (3) of one or more coating compositions in liquid or powder form.

[0161] In step iii, layers may be applied in a wet-on-wet manner, or a drying process may be applied between each layer.

[0162] In the context of this invention, baking the coated substrate can be understood as heat treatment, which allows one or more heat-stable coatings applied to the substrate to be densified.

[0163] Baking, or in some cases sintering, is performed in step iv. Typically, the baking temperature in step iv is between 230°C and 420°C. Advantageously, in the case where a fluorocarbon resin is present in the polymer phase, the baking temperature in step iv is between 380°C and 420°C. In the case where an organopolysiloxane polymer is present in the polymer phase, the advantageous baking temperature in step iv is between 230°C and 300°C, preferably between 230°C and 280°C, more preferably between 230°C and 250°C. In the case where a thermoplastic polymer is present in the polymer phase without fluorocarbon resin, the advantageous baking temperature in step iv is between 230°C and 300°C, preferably between 250°C and 400°C, more preferably between 280°C and 380°C.

[0164] Drying can be carried out by convection or IR (infrared).

[0165] Advantageously, the method according to the invention for manufacturing a coated heating element (1) includes a drying step between 80°C and 150°C after applying each of a plurality of layers.

[0166] Advantageously, the method according to the invention for manufacturing a coated heating element (1) includes a single step iv of final baking of all applied layers. This single baking step is performed simultaneously on all applied layers. This embodiment allows all layers to be film-formed, merged, and crosslinked with each other, such that they form only one layer. Thus, the coating (3) forms a monolayer, even if the monolayer may not be homogeneous, that is, it may have compositional heterogeneity, such as a concentration gradient of its components.

[0167] Advantageously, the method according to the invention for manufacturing a coated heating element (1) includes the step of forming the substrate (2) before or after step i or step iii. Forming is also known as stamping.

[0168] The coating according to the invention can be applied on a flat substrate, a shaped substrate, or a locally flat area of ​​a shaped substrate using the method according to the invention. A thermally stable coating layer is obtained. Typically, this coating layer is wet.

[0169] The term "wet layer" in the sense of this invention can be understood as the layer comprising all or part of its solvent.

[0170] Preferably, all or part of the solvent in the wet layer is eliminated either naturally or through physical processes such as thermal drying, air drying, or vacuum treatment.

[0171] Advantageously, the coating composition according to the invention may further include at least one solvent. Advantageously, the solvent may be protic. Advantageously, the solvent may be non-toxic.

[0172] The solvents that can be used in the coating compositions according to the invention may advantageously include at least one alcohol, and may preferably be selected from isopropanol, methanol, ethanol and mixtures thereof.

[0173] According to a variation of the method according to the invention, the coating can be applied in multiple layers. In this case, the deposition of at least one layer of the coating composition according to the invention on at least one of two opposing surfaces of the substrate is repeated multiple times. In this case, the coating according to the invention is multilayered. Each layer is preferably applied in a single imprinting step, forming a multilayer structure. Preferably, according to this variation, a drying step is performed between the application of each layer, and then the coated substrate is baked after the application of the last layer.

[0174] When the forming step precedes the coating application step iii, coating is preferably performed by spraying.

[0175] When the forming step follows the coating application step iii, the coating is preferably applied by screen printing or roll coating.

[0176] The coating formulation to be applied is typically in aqueous form, with the polymer phase in suspension. Other non-aqueous solvents may also be suitable.

[0177] According to one variant, the PAEK suspension has a particle size of approximately 10 μm to 15 μm with a d50.

[0178] Household items Another subject of the present invention relates to household articles comprising a coated heating element (1) according to the present invention.

[0179] According to one embodiment, the household item is a cooking item and the surface (3b) of the coating according to the invention is capable of holding food.

[0180] According to one embodiment, the cooking article includes a heating surface for contact with an external heating source, which is opposite to a cooking surface for contact with food during cooking.

[0181] Advantageously, the cooking articles according to the invention are selected from the group consisting of a frying pan with a handle, a long-handled frying pan, a small frying pan or casserole dish with a handle for cheese fondue or lacquer, a double-handled lidded pan, a frying pan, a frying pan, a crepe maker, a grill, a grill plate, a pressure cooker, a stew pot, a steamer or bread machine container, and cooking molds.

[0182] The present invention also relates to an electric cooking device, comprising a coated heating element (1) according to the present invention and a heating source configured to heat the coated heating element (1).

[0183] Advantageously, the electric cooking equipment is selected from a group consisting of electric crepe makers, lacrete appliances, cheese fondue appliances, electric grills, electric barbecue grills, electric cookers, bread makers, and pressure cooking appliances.

[0184] According to another embodiment, the household item is an everyday item that the user heats.

[0185] It can be an iron or flat iron, with the coating covering the base plate according to the invention.

[0186] It can be a hair straightener, with the coating according to the invention covering the plates of the hair straightener.

[0187] The heating household items according to the invention can be, in particular, cooking items or small household appliances, such as irons, hair care items, thermos flasks (e.g. for coffee makers) or mixing bowls.

[0188] The article for small household heating devices according to the invention can be, in particular, a cooking article, and especially a cooking article in which one of the two opposing surfaces of the substrate is an inner surface, optionally concave, for being disposed on the food side that can be introduced into or onto the article, and wherein the other surface of the substrate is an outer surface, optionally convex, for being disposed toward a heat source.

[0189] As non-limiting examples of cooking articles according to the invention, cooking articles will be particularly listed, such as pans with handles and frying pans with long handles, frying pans and frying pans, double-handled lidded pans and pressure cookers, crepe makers, iron molds for baking honeycomb cakes, grills, molds and plates for pastries, grill plates, grilling plates and grills, equipment for lacrete or cheese fondue, rice cookers, jam jars, bread machine containers, and preparation bowls.

[0190] The small household heating device article according to the invention can be, in particular, an iron, such as a steam iron or a steam generator, and the coating element according to the invention is the soleplate of the iron.

[0191] The small household heating device article according to the invention can be, in particular, an article for hair care, such as a curling iron or a straightener, and the coating element according to the invention is one of the heating plates of the article for hair care.

[0192] Example The objects, aspects, and advantages of the invention will be better understood from the following description of specific embodiments of the invention, shown by way of non-limiting example.

[0193] Of course, the present invention is by no means limited to the embodiments described and illustrated as examples only. Modifications can be made to the present invention without departing from the scope of protection of the invention, especially in terms of the composition of various elements or by substitution with technical equivalents.

[0194] 1) Raw materials: Metal substrate: The aluminum discs are annealed alloy 4006, 3.4 mm thick and 340 mm in diameter. They have been brushed (roughness Ra approximately 2 µm).

[0195] Screen printing coating is performed according to the following parameters: - Between 1 and 4 layers, preferably 2 or 3 layers for multi-layer coatings and 1 layer for single-layer coatings; - It is conceivable to partially dry each layer before applying the next layer; - Final baking in an oven between 250°C and 420°C for 10 to 30 minutes, then allow the pan to cool; - The obtained thickness is between 20 μm and 50 μm, preferably between 30 μm and 40 μm.

[0196] The coating plate is stamped and stretched to form a flat pan with a handle and an inner diameter of 20 cm.

[0197] Silicone resin: - RS1: Ethoxy-functionalized methyl organopolysiloxane resin in an aqueous emulsion has a viscosity of approximately 1500 mPas at 25°C and a solids content of 52%. - RS2: Ethoxylated functionalized polyester organopolysiloxane resin (80% organopolysiloxane / 20% polyester), viscosity approximately 2000 mPas in solvent phase at 25°C, solids content = 75%. - PDMS_1: Polydimethylsiloxane (PDMS) resin in aqueous emulsions Functionalized PDMS, 62% solids content - PDMS_2: Polydimethylsiloxane (PDMS) resin: Functionalized linear PDMS-OH chain ends, viscosity at 25°C approximately 600 mPa·s, 100% solids content. Polyaryletherketone: - Polyetheretherketone (PEEK) powder resin, VICTREX's Vicote 704, polymer powder with a d50 of 10µm. - VICTREX PEEK (polyetherketone) aqueous dispersion, named VICOTE Coatings F804 "VicoteF804": particle size d50 = 10 μm; dry extract 35%; pH between 9.6 and 11.9; viscosity approximately 11 d900 DIN Cup 6.

[0198] - Arkema's powdered resin PEKK, KEPSAN 7002 PT, d50 is 20µm Aromatic thermoplastic polymers: - SOLVAY's micronized VERADEL 3100 UFP grade polyethersulfone (PES) powder resin, polymer powder with d50 < 40µm. - Polyphenylene sulfide (PPS) powder resin: SOLVAY's Ryton® M110000UFP Heterocyclic thermoplastic polymers: - Polyamide-imide (PAI) powder resin: Solvay's TORLON AI10LS, a powder containing 90% dry extract in N-methylpyrrolidone (NMP / water). - Polyimide powder resin (PI): Evonik's P84®NT - Polybenzylimidazolium resin (PBI): Celazole® PBI U-60 Fluorinated resin: - 60% fluoropolymer (PTFE) aqueous dispersion in aqueous phase Reinforcing filler: - Aerosil R972 (Evonik) Dimethyl dichlorosilane post-treatment of silica fume, specific surface area (BET) = 90 m² 2 / g to 130 m 2 / g - Talc LUZENAC EL10: Talc / chlorite / dolomite mineral powder - Alumina: CAHPF 240 alumina, d50=45-50μm, 100% Alteo - Silicon carbide: SIKA® F800 d50=6.6µm 100% FIVEN or SIKA® F320 d50=29.2µm 100% FIVEN - Graphene: Graphene dispersed in an aqueous phase, 5 g / kg, Carbon Waters Graph'Up W3 grade - Layered filler: clay, montmorillonite, sepiolite, laponite pigment: - Sicopal black K0098FK (Sun Chemical): Chromium oxide / iron oxide powder: Index = P.BR.29 Alcohol solvent: - Ethyl 2-methoxy-1-methylacetate (MPA) - Butylene glycol acetate (BGA) - Butyl acetate (BA) - Propylene glycol (MPG) Polar aprotic solvents: - N-Methylimidazole (NMI) - Dimethyl sulfoxide (DMSO) additive Defoamer - Synthon's Moussex 7114HL - Evonik's Tego foamex K7 - Clariant's Genapol X089 Other additives: - Acrylic acid: Rohagit SD 15: 30% acrylic polymer solution in aqueous phase or SYnthotik 2) Tests conducted Mechanical durability assessment test - heat scratch resistance The coating's excellent mechanical properties were evaluated based on hot blade testing.

[0199] This test method evaluates the scratch resistance of a coating applied to the inner surface of a cooking item placed on a heat source. The test uses... Figure 2 The test, shown, is performed using a moving system consisting of three hard metal tips (ballpoint pens). Also known as the "tiger claw" test, it induces rotation around its axis and describes epicycloid motion on the coated surface. Degradation of the coating (the appearance of spots and scratches on the metal, and delamination of the coating) is visually assessed after different time periods.

[0200] This test ultimately allows for the evaluation of two output data points: - Delamination of the coating on the metal surface after the test time (duration).

[0201] - Appearance of metal scratches: Metal scratches appear after the test time (duration).

[0202] Mechanical durability assessment test - abrasion resistance Then, the item is subjected to abrasion test using an abrasive pad, followed by a milk test and a scratch test.

[0203] - Scratch test and wear coefficient This test assesses the coating's resistance to the effects of an abrasive buffer applied to its surface through a milk carbonization test, and also assesses the decrease in the coating's anti-adhesion properties after undergoing abrasion cycles. The test is based on a standard test with specific adaptation characteristics: NF D 21-511.

[0204] The device used is a horizontally movable abrasion tester. A fixed arm supports a rectangular pad measuring 70±5mm x 30±5mm, on which an abrasion buffer of the same size is placed. The fixed arm includes a tare weight that allows a 21N load (including the lever arm mass) to be applied. The abrasive moves at a rate of 33 reciprocations per minute. The wear surface is 70mm x 130mm, meaning the travel distance after 1000 wear cycles (i.e., 1000 reciprocations of the abrasive) is 100mm.

[0205] Methods for assessing stampability: Stamping tests, also known as Swift tests, were performed using a Zwick BPU 400 stamping press.

[0206] Experimental conditions: - Cut a disc with a diameter of 64mm. - 33 mm punch (limit drawing ratio = 1.9) - Stamping die: 40mm According to the present invention, the aluminum disc, after being brushed, hydrated, pickled, and coated, is stamped into a long-handled flat-bottomed pan with a diameter of 26 cm.

[0207] The stampability of the coating on a given substrate is converted into binary symbols: - Normal: Good stampability = good adhesion of the coating to the substrate after stamping deformation. - Abnormal: Poor stampability = poor adhesion of the coating to the substrate after stamping deformation. Stamping deformation was assessed using two methods; adhesion was evaluated based on different deformation methods. These methods yielded comparable results.

[0208] Laboratory size method: The coated aluminum substrate is deformed on a small surface using a press according to the "Erichsen" or "Godet" method (requiring a disc with a diameter of approximately 10 cm): - "Erichsen": The press uses conical and round punches to deform the surface to a depth of approximately 1 to 2 cm, with the coating on the outside. This deformation pattern also subjectes the coating to tension. If the coating appears very cracked or peels / detaches from the substrate after deformation, its tensile deformation resistance is poor. To magnify the difference, a grid can be drawn first in the area where the punches were applied (according to ISO 2409 standard), and then observed whether many squares have come off (with or without tape).

[0209] - "Godet": The press uses a cylindrical punch (circular edge) to deform the substrate, which has an internal coating: This further simulates the deformation, pressing of a handled pan, even with 0% stretching on the skirt (cylindrical edge) during the tests conducted. The results were poor when any peeling, folding, etc. of the coating were visually observed after deformation.

[0210] 3) An embodiment of the cooking article according to the present invention: The coating is applied to a flat aluminum disc using a screen printing process.

[0211] The aluminum discs are annealed alloy 4006, 3.4 mm thick and 340 mm in diameter. These aluminum discs have undergone a brushing process (roughness Ra is approximately 2 µm).

[0212] Screen printing coating is performed according to the following parameters: - Deposit 1 to 4 layers on the disk, preferably 2 or 3 layers, for multi-layer coatings multiple layers, or for single-layer coatings 1 layer; - Each layer is coated using a screen printing process.

[0213] The final drying of all layers is first carried out at ambient temperature for 5 minutes, and then at 120°C (disc temperature) for 5 minutes by convection or infrared.

[0214] - Finally, bake in an oven between 250°C and 420°C for 10 minutes, then allow the pan to cool.

[0215] - The obtained thickness is between 20 μm and 50 μm, preferably between 30 μm and 40 μm.

[0216] The coated disc is stamped to form a flat-handled pan with an inner diameter of 20 cm, and the aluminum has a stretch rate of 0% on the "skirt" (circular vertical section).

[0217] The aqueous composition of the coating layer is prepared based on the principle of ball milling. Ball milling involves loading a jar with the sample to be ground and so-called grinding balls, and rotating the jar around its axis at a certain speed. The rotation of the jar is typically achieved using a drum mill. The sample can be ground in dry form or dispersed in a suitable solvent (e.g., in water, in alcohol, or in a solvent). The dispersion may also contain certain auxiliary agents (e.g., dispersants or defoamers).

[0218] [Table 2]

[0219] [Table 3]

[0220] [Table 4]

[0221]

[0222] Example 4: A multilayer having a base layer according to Example 2 and a top layer according to the composition described below: [Table 5]

[0223] [Table 6]

[0224] [Table 7]

[0225]

[0226] [Table 8]

[0227] [Table 9]

[0228]

[0229] [Table 10]

[0230] [Table 11]

[0231] [Table 12]

[0232] Swift, hot blade, and wear test results [Table 13]

Claims

1. A coating (3) on a metal substrate (2) for use in household articles, the coating (3) being in contact with the metal substrate (2) through one of its surfaces (3a) and visible to a user through its surface (3b), the coating comprising: Or multiple layers, each comprising one or more polyaryletherketones (PAEKs), and at least one of these layers being composed of: - At least 70% by weight of a polymer phase, said polymer phase comprising the following: o At least 50% by weight of one or more polyaryletherketones (PAEKs), the remainder being selected from the group consisting of: one or more organopolysiloxane polymers, one or more aromatic thermoplastic polymers other than PAEKs, one or more heterocyclic thermoplastic polymers and mixtures thereof, and optionally one or more fluorocarbon resins; or o At least 50% by weight of one or more polymers, said polymers being selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, organopolysiloxane polymers and mixtures thereof, the remainder consisting of one or more polyaryletherketones (PAEK) and optionally one or more fluorocarbon resins; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants; Or it may be a single layer, wherein the single layer consists of the following: - At least 70% by weight of a polymer phase, said polymer phase comprising the following: o At least 50% by weight of one or more polyaryletherketones (PAEKs), the remainder being selected from the group consisting of: one or more aromatic thermoplastic polymers other than PAEKs, one or more heterocyclic thermoplastic polymers and mixtures thereof, and optionally one or more fluorocarbon resins; or o At least 50% by weight of one or more polymers, said polymers being selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers and mixtures thereof, the remainder consisting of one or more polyaryletherketones (PAEK) and optionally one or more fluorocarbon resins; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

2. The coating (3) according to claim 1, characterized in that, One or more polyaryletherketones (PAEKs) are selected from the group consisting of: polyetherketones (PEKs), polyetheretherketones (PEEKs), polyetherketoneketones (PEKKs), polyetheretherketoneketones (PEEKKs), and polyetherketoneetherketoneketones (PEKEKKs) and mixtures thereof.

3. The coating (3) according to claim 1, characterized in that, One or more aromatic thermoplastic polymers other than PAEK are selected from the group consisting of: polyphenylene ether (PPO), poly(aryl ether sulfone) (PAES) polymers, and in particular polyether sulfone (PES), polyphenylene ether sulfone (PPSU), polyphenylene sulfide (PPS), poly(aryl sulfide) (PAS), liquid crystal polymers and mixtures thereof.

4. The coating (3) according to claim 1, characterized in that, One or more heterocyclic thermoplastic polymers are selected from the group consisting of: polyetherimide (PEI), polyimide (PI), polyamideimide (PAI) and polybenzimidazole (PBI) and mixtures thereof.

5. The coating (3) according to any one of the preceding claims, characterized in that, One or more organopolysiloxane polymers are selected from the group consisting of polymers obtained from polymers or oligomeric organopolysiloxane precursors, said polymers being either in the form of silicone oils with variable branching, or in the form of silicone resins or silicone resin copolymers with variable pre-crosslinking, such as silicone polyester resins, silicone alkyd resins, silicone polyurethane resins, silicone epoxy resins, or in the form of mixtures of silicone oils, silicone resins and silicone resin copolymers.

6. The coating (3) according to any one of the preceding claims, characterized in that, At least one of the polyarylether ketones (PAEK) present in each of the layers is polyether ether ketone (PEEK) or polyether ketone ketone (PEKK).

7. The coating (3) according to any one of the preceding claims, characterized in that, One or more aromatic thermoplastic polymers other than PAEK include polyethersulfone (PES) or polyphenylene sulfide (PPS).

8. The coating (3) according to any one of the preceding claims, characterized in that, One or more organopolysiloxane polymers are silicone oil or silicone resin copolymers.

9. The coating (3) according to any one of the preceding claims, characterized in that, The polymer phase comprises at least 60% by weight of one or more polyarylether ketones (PAEK).

10. The coating (3) according to any one of the preceding claims, characterized in that, The polymer phase comprises at least 70% by weight of one or more polyarylether ketones (PAEK).

11. The coating (3) according to any one of claims 1 to 8, characterized in that, The polymer phase comprises at least 60% by weight of one or more polymers selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, organopolysiloxane polymers and mixtures thereof.

12. The coating (3) according to claim 11, characterized in that, The polymer phase comprises at least 70% by weight of one or more polymers selected from the group consisting of: aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, organopolysiloxane polymers and mixtures thereof.

13. The coating (3) according to any one of claims 1 to 8, characterized in that, The coating comprises multiple layers, and all of the layers comprise polyetheretherketone (PEEK), and at least one of these layers consists of the following: - At least 70% by weight of a polymer phase, said polymer phase comprising the following: o At least 50% by weight of polyetheretherketone (PEEK), with the remainder consisting of polyethersulfone (PES) and optionally PTFE; or o At least 50% by weight of polyethersulfone (PES), with the remainder consisting of polyetheretherketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

14. The coating (3) according to any one of claims 1 to 8, characterized in that, The coating comprises multiple layers, and all of the layers comprise polyetheretherketone (PEEK), and at least one of these layers consists of the following: - At least 70% by weight of a polymer phase, said polymer phase comprising the following: o At least 50% by weight of polyetheretherketone (PEEK), with the remainder consisting of silicone oil and optionally PTFE; or o At least 50% by weight of silicone oil, the remainder consisting of polyetheretherketone (PEEK) and optionally PTFE; - One or more fillers; - Optionally one or more additives; - Optionally one or more colorants.

15. The coating (3) according to any one of the preceding claims, characterized in that, One or more fillers are selected from the group consisting of ceramic and / or mineral and / or metal and / or hydrophobic silica fillers and / or diamond particles.

16. The coating (3) according to any one of the preceding claims, characterized in that, The coating (3) is an anti-stick coating.

17. A coated heating element (1) for household articles, comprising a metal substrate (2) having a coating on at least one surface (2a) according to any one of the preceding claims, the coating being in contact with the metal substrate (2) through one of its surfaces (3a) and visible to a user through its surface (3b).

18. A method for manufacturing a coated heating element according to claim 17, comprising the following sequential steps: i. Provide a metal substrate (2) having a surface (2a); ii. Optionally, the surface (2a) of the metal substrate (2) for coating is pretreated; iii. Apply one or more layers of the coating (3) to the surface (2a); iv. Bake the components obtained in step iii.

19. The method for manufacturing a coated heating element (1) according to claim 18, characterized in that, Step iii is performed by spraying, screen printing, roller coating, or electrostatic spraying one or more layers of the coating (3) in liquid or powder form using one or more coating compositions.

20. The method for manufacturing a coated heating element (1) according to claim 18, comprising a step of drying between 80°C and 150°C after each layer is applied.

21. The method for manufacturing a coated heating element (1) according to claim 18, comprising step iv of final baking of the entire applied layer.

22. The method for manufacturing a coated heating element (1) according to any one of claims 16 to 21, comprising the step of forming the substrate (2) before or after step i or step iii.

23. A household article comprising a coated heating element (1) according to claim 17, characterized in that, The household item is a cooking item, and the surface (3b) of the coating according to any one of claims 1 to 16 is capable of holding food.

24. The cooking article of claim 23, wherein the cooking article is selected from the group consisting of a frying pan with handle, a long-handled frying pan, a small frying pan or casserole dish with handle for cheese fondue or lacrete, a double-handled lidded pot, a frying pan, a frying pan for frying, a crepe maker, a grill, a grill plate for grilling, a pressure cooker, a stew pot, a steamer or bread machine container, and cooking molds.

25. An electric cooking appliance comprising a coated heating element (1) and a heating source configured to heat said coated heating element (1), characterized in that, The coated heating element (1) is as described in claim 17.

26. The electric cooking apparatus according to claim 25, wherein the electric cooking apparatus is selected from the group consisting of an electric crepe maker, a lacrete appliance, a cheese fondue appliance, an electric grill, an electric grill plate, an electric steamer, a bread maker, and a pressure cooking appliance.

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