Non-fluorinated PAEK / elastomeric silicone coating

Abstract

The invention relates to a coated heating element (1) for a household appliance, comprising a metal substrate (2) coated on at least one surface (2a) with a coating (3) that does not comprise a fluorocarbon resin, and having at least the following layers in the stated order proceeding from the metal substrate (2): (3a) a primer layer comprising one or more polyaryletherketone(s) (PAEK); (3b) optionally one or more intermediate layer(s) comprising one or more polyaryletherketone(s) (PAEK); (3c) a finishing layer consisting of: - an elastomeric silicone obtained from at least one organopolysiloxane bearing reactive vinyl functions (-CH=CH2) and at least one other organopolysiloxane bearing reactive silyl hydride functions (Si-H) or reactive thiol functions (S-H); and optionally: - one or more thermoplastic polymers, and / or - one or more additives, and / or - one or more coloring agents.

Description

[0001]Non-fluorinated PAEK / elastomer silicone coating The invention applies to the field of non-stick coatings for household items, which are heated or can be heated, in particular for cookware and electrical cooking appliances. Cookware coated with PTFE (polytetrafluoroethylene) is popular on the market because it allows food to be cooked without, or with little, added fat and is easy to maintain. However, an inherent weakness of these coatings is their low mechanical strength, especially when hot. Another inherent weakness of PTFE is its ductility, which results in coatings that are easy to mark, scratch, or wear with metal utensils (spatulas, forks, spoons, blender sticks, etc.).To remedy this, many technical solutions have been proposed which consist of reinforcing the coating with hard fillers or by interposing hard sub-layers of an inorganic or organic type. In the case of primers reinforced with hard organic or inorganic fillers, significant improvements are indeed observed in abrasion resistance, but impacts to metal are also observed when cooking foods such as pork chops or when using metal spatulas. In the case of hard inorganic bases such as those made from enamel or metal oxides, abrasion resistance is further improved and the problem of impacts is limited without being eliminated. Organic polymer sub-layers are also known. These sub-layers can indeed considerably reduce the appearance of scratches or even eliminate them.This strategy is therefore very interesting. The polymers used are very often thermoplastic polymers with high thermal resistance and a high melting point, such as polyaryletherketone, particularly oxy-1,4-phenylenephenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene or PEEK, or phenylene sulfides. The PEEK polymer is interesting in cookware because it has a high melting point (343°C) and excellent thermal stability under operating conditions of 260°C. The following coating techniques can be used to obtain a sub-layer from this type of polymer: spray coating, roller coating, curtain coating, pad printing, screen printing, thermal projection, electrostatic spraying, inkjet. Pure silicone resins are described as relatively non-stick and resistant to temperatures above 220-230°C.On the other hand, they are considered to have poor adhesion to the substrate. Conversely, silicone-polyester resins are very widespread in molding because they are non-stick while being adherent to the substrate and compatible with stamping processes. However, they degrade at temperatures above 230°C. Indeed, the temperature range of use of cookware is between 50 and 250°C and it is not surprising to rise to temperatures of 300°C or even 350°C in the case of articles with induction bases. Their use is therefore not compatible with the temperatures of use in the field of cookware. The present invention deals with the technical problem of improving the non-stick properties of a coating with high thermo-mechanical properties. The present invention also deals with the technical problem of replacement solutions for coatings based on fluororesin of the PTFE type.The present invention provides an alternative to predominantly PTFE-based coatings in order to obtain good resistance to mechanical wear of the coatings, in particular by kitchen utensils for culinary articles and thus improve the durability of their mechanical resistance, in particular when hot and / or their cleanability, in order to extend the life of the article. DEFINITIONSBy the term "layer", it is meant, within the meaning of the present invention, a continuous or discontinuous layer. A continuous layer (or also called a monolithic layer) is a single whole forming a total flat area completely covering the surface on which it is placed. A discontinuous layer (or non-monolithic layer) may comprise several parts which are not thus a single whole.The term "base coat", "primer coat", "bonding coat" or "bonding primer" means all the layers from the first layer applied directly to the support (it is preferable that this layer adheres well to the support and provides all its mechanical properties to the coating: hardness, scratch resistance) to the last layer before the first intermediate or decorative layer or the finishing layer if the coating does not include an intermediate layer. The first layer of the coating is a primer coat. The term "intermediate layer" means the layers inserted between the primary layer(s) and the finishing layer(s). The intermediate layer(s) may be "decorations" or "decorative layers". The intermediate layer(s) is / are not intended to be in contact with food.The term "finish coat" or "finish" means one or more continuous surface layers applied after the intermediate layer(s) if the coating comprises one or more intermediate layer(s) or after the primary layer(s). The last layer of the coating is a finishing layer. Usually, at least the last finishing layer, or even all the finishing layers, is / are transparent to allow visibility of the underlying layers, in particular when the underlying layers are decorative layers. The finishing layer(s) protect the underlying layers from mechanical attack and give the coating its non-stick properties. Preferably, in the case of a cookware or electrical cooking appliance, the last finishing layer is intended to be in contact with food.The term "decor" or "decorative layer" means one or more continuous or discontinuous layers comprising a pigment composition. The decor may be in the form of one or more patterns, in one or more colors. A decor is clearly visible to the user with the naked eye and at a conventional distance for using the household item. The term "overlapping layers" means partially or completely superimposed layers. These layers may be in the form of partially overlapping patterns, for example concentric discs. The term "adjacent layers" means non-superimposed layers. These layers may be in the form of identical or different non-superimposed patterns, preferably uniformly distributed.The term "temperature reference pigment composition" means a composition comprising a pigment which, at a given temperature, indicates to the user that the optimum operating temperature has been reached. This indication is made by comparing the colours of the thermochromic pigment composition and the temperature reference pigment composition. Either the optimum operating temperature is reached when the colours are identical, or the optimum operating temperature is reached when the colours are visually very different.The "temperature reference pigment composition" may comprise a pigment which has:- the same colour as the thermochromic pigment composition, at the optimum temperature of use, * either because this pigment has at room temperature the same colour as the thermochromic pigment composition at the optimum temperature of use, and does not change colour with the temperature, * or because this pigment has at room temperature a colour different from that of the thermochromic pigment composition which evolves to the same colour as the thermochromic pigment composition at the optimum temperature of use,- a colour very different from that of the thermochromic pigment composition at the optimum temperature of use, whether or not this pigment changes colour with the change in temperature.The optimum use temperature can be achieved when the color of the temperature reference pigment composition corresponds to a color indicated in the user guide of the household article comprising the coating of the invention or to a color indicated on a color scale provided to the user with said article. The temperature reference pigment composition is thermochromic or thermostable. The temperature reference pigment composition may be, for example, a cooking temperature reference pigment composition or an indication of the risk of overheating. The expression "thermochromic semiconductor" is to be understood, within the meaning of the present invention, to be a mineral or organic compound, which exhibits a reversible change in color upon an increase in temperature.The progressive and reversible thermochromic character of these semiconductor compounds is linked to the decrease in the width of the band gap of the semiconductor due to the expansion of the material. Indeed, the periodicity of the network of anions and cations leads to the gathering of energy levels into energy bands. The filled energy band with the highest energy is called the valence band and the empty energy band with the lowest energy is called the conduction band. Between these two bands, there is a band gap called the gap. The color of a semiconductor material can come from the presence of a charge transfer which corresponds to the passage of an electron either from a valence band to a conduction band on the same atom, or commonly from the orbital of an anion to the orbital of a cation (interatomic photon absorption).In the fields of application envisaged for the present invention, the optimal conditions are reached when the coating reaches a temperature suitable for cooking food, preferably between 100 and 250°C. By "thermochromic pigment or pigmentary composition", it is meant, within the meaning of the present invention, a pigment or a pigmentary composition which changes color depending on the temperature in a given temperature range, this change being reversible. This change of color is visible to the user with the naked eye and at a conventional operating distance.The term "thermostable pigment" means a pigment which does not exhibit a change in color when subjected to an increase in temperature in a given temperature range or which exhibits a change in hue when subjected to an increase in temperature in a given temperature range so small that it is not visible to the user with the naked eye and at a conventional operating distance. Preferably, the thermostable pigments exhibit a color difference ΔE* between 25°C and 200°C of less than 10, ΔE* being defined by the CIE1976 formula in the colorimetric space. CIELAB : = ^ ∗ − ^ ∗ ^ − ^ ∗ −² L1*, a1* and b1* ambient L2*, a2* and b2* characterizing the L*a*b values ​​of said compound at 200°C. By "the colors are identical" is meant indistinguishable by the user with the naked eye and at a conventional operating distance. By the expression "cooking article", it is necessary to understand within the meaning of the present invention an object intended to cook and to be heated by an external heating system such as frying pans, saucepans, sauté pans, woks, barbecue grills. A cooking article is capable of transmitting the heat energy provided by this external heating system to a material or food in contact with said article. By the expression "electric cooking appliance", it is necessary to understand within the meaning of the present invention a heating object having its own heating system such as an electric crepe maker, an electric raclette appliance, an electric fondue appliance, an electric grill, an electric griddle, an electric cooker, a bread maker,electric pressure cooking appliance. The term "coating" means all the layers adhering to the metal substrate and covering this substrate. The coating according to the invention obtained is advantageously solid, "solid" means the characteristic of a cohesive material insoluble in water, in usual solvents, in food components such as aqueous or fatty mixtures, even if the material may have great hardness or great flexibility such as an elastomer. In the present invention, the % by weight are expressed in dry weight, i.e. without solvent. SUMMARY OF THE INVENTION A first subject of the invention relates to a coated heating element (1) for a household article,comprising a metal substrate (2) coated on at least one face (2a) with a coating (3) free of fluorocarbon resin and comprising at least the following layers and in this order starting from the metal substrate (2): (3a) a primer layer comprising one or more polyarylether ketone(s) (PAEK); (3b) optionally one or more intermediate layer(s) comprising one or more polyarylether ketone(s) (PAEK); (3c) a finishing layer consisting of: - an elastomer silicone obtained from at least one organopolysiloxane bearing reactive vinyl functions (-CH=CH2) and at least one other organopolysiloxane bearing reactive silyl hydride functions (Si-H) or reactive thiol functions (SH), and optionally: - one or more thermoplastic polymers, and / or - one or more additive(s),and / or- one or more coloring agents.Another subject of the invention relates to a method for manufacturing a household article comprising a heating element coated (1) with a coating (3) according to the invention, characterized by the following steps: a) a step of providing a metal substrate (2) in the form of a substantially flat metal substrate comprising two opposite faces or a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22); b) where appropriate, when a metal substrate in the form of a substantially flat metal substrate is provided during step (a), a step of shaping said substrate to give it the shape of a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22), said step (b) being carried out either before step (a) or before step (d) of producing the layers (3a) and (3b) of the coating (3),either after the baking step (f) and before the step (g) of producing the finishing layer or either after the step (g);c) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a primer layer (3a) on the support (2);d) a step of applying the layers (3a) and possibly (3b) of the coating (3);e) optionally a drying step between 50°C and 150°C after application of each of said layers (3a) (3b);f) optionally a step of baking the element obtained in step d) or e) at a temperature between 250°C and 420°C;g) a step of applying the finishing layer (3c) on the element obtained in step d), e), ou f) ;h) optionally a step of baking the element obtained in step g) at a temperature between 250°C and 420°C. Another subject of the invention relates to a household article comprising a coated heating element (1) according to the invention or capable of being obtained according to the method of the invention. FIGURES [Fig. 1]: diagram of a heating element according to the invention with the layer (3b) being continuous and covering the entire layer (3a) [Fig. 2]: diagram of a heating element according to the invention with the layer (3b) not covering the entire layer (3a) and forming a decoration [Fig. 3]: diagram of a heating element according to the invention with the layer (3b) consisting of two decorations (i) and (j) [Fig. 4]: diagram of the distribution of the patterns. 4A = adjacent non-overlapping patterns. 4B = partially overlapping patterns. 4C = overlapping patterns. [Fig.5]: diagram of a cooking article according to the invention [Fig.6]: diagram of an electric cooking appliance according to the invention DETAILED DESCRIPTION A first objectof the invention relates to a coated heating element (1) for a household article, comprising a metal substrate (2) coated on at least one face (2a) with a coating (3) free of fluorocarbon resin and comprising at least the following layers and in this order from the metal substrate (2): (3a) a primer layer comprising one or more polyarylether ketone(s) (PAEK); (3b) optionally one or more intermediate layer(s) comprising one or more polyarylether ketone(s) (PAEK); (3c) a finishing layer consisting of: - an elastomer silicone obtained from at least one organopolysiloxane bearing reactive vinyl functions (-CH=CH2) and at least one other organopolysiloxane bearing reactive silyl hydride functions (Si-H) or reactive thiol functions (SH), and optionally: - one or more thermoplastic polymers and / or - of one or more additive(s), and / or- of one or more coloring agents.Advantageously, the layers (3a),optionally (3b) and (3c) form a coating (3) which coats the metal substrate (2). This coating (3) has non-stick properties and forms a non-stick coating, which non-stick is particularly conferred by the layer (3c). Advantageously, the layer (3a) is in contact by one of its faces with the metal substrate (2) by its face (2a). When the household item is a culinary item or an electrical cooking appliance, the coated face (2a) of the metal substrate forms a cooking face. In other words, the coating (3) according to the invention is then intended to be in contact with food. Advantageously, the finishing layer (3c) is then in contact by one of its faces with food and thus forms a cooking surface (5). The coating (3) according to the invention does not comprise fluorocarbon resin, also called fluorinated polymer or fluoropolymer. In other words, said coating (3) is free of fluorocarbon resin. Thus, thecoating (3) does not comprise or emit perfluoroalkyl and polyfluoroalkyl compounds.Advantageously, the thickness of the layer(s) (3a) and (3b) is between 1 µm and 100 µm, preferably between 2 µm and 30 µm, particularly preferably between 3 µm and 10 µm.Advantageously, the thickness of the layer (3c) is between 0.1 µm and 10 µm, preferably between 0.5 µm and 5 µm, even more preferably between 1 and 2 µm.LAYERS (3a) and (3b)The primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise one or more polyarylether ketone(s) (PAEK). Advantageously, the polyaryletherketone(s) (PAEK) is(are) chosen from the group consisting of: polyetherketones (PEK), polyetheretherketone (PEEK), polyetherketoneketones (PEKK), polyetheretherketoneketones (PEEKK) and polyetherketoneetherketoneketones (PEKEKK). Advantageously, the primer layer(s) (3a) or the layer(s)optional intermediate(s) (3b) comprises / comprise from 20% to 100% by weight of one or more polyarylether ketone(s) (PAEK) relative to the weight of said layer.According to one embodiment, at least one intermediate layer (3b) is present in the coating (3) according to the invention. Advantageously, in this case, the at least one intermediate layer (3b) is different from at least one primer layer (3a). More preferably, in this case, all the intermediate layers (3b) are different from the primer layer(s) (3a). According to one embodiment, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise one or more polymer(s) chosen from the group consisting of polyetherimides (PEI), polyimides (PI), polyamide imides (PAI) and polybenzymidazole (PBI). Advantageously, in this case, the primer layer(s) (3a) or the optional intermediate layer(s)(3b) comprises between 20% and 100% by weight of the total weight of said layer of one or more polyaryletherketones (PAEK) and one or more polymer(s) selected from the group consisting of polyetherimides (PEI), polyimides (PI), polyamide imides (PAI) and polybenzymidazole (PBI), preferably PAI, preferably with a weight ratio PAEK:(PEI+PI+PAI+PBI) of between 1:1 and 15:1. According to this embodiment, advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprises polyetheretherketones (PEEK) and polyamide imides (PAI), preferably without any other polymer in said layer. According to this embodiment, advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise from 20 to 40% by weight of said layer of a PAEK and (PEI and / or PI and / or PAI and / or PBI) mixture in a weight ratio PAEK:(PEI+PI+PAI+PBI) includedbetween 6:1 and 12:1. According to this embodiment, advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise from 40 to 80% of said layer of a mixture of PAEK and (PEI and / or PI and / or PAI and / or PBI) in a weight ratio PAEK:(PEI+PI+PAI+PBI) of between 12:1 and 15:1. According to this embodiment, advantageously, the PAEK and (PEI and / or PI and / or PAI and / or PBI) mixture represents 25 to 40% by weight of the total weight of said layer, preferably 25 to 35%. According to one embodiment, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise one or more polymers chosen from the group consisting of polyphenylene sulfides (PPS) and polyethersulfones (PES), preferably PES, preferably in an amount of at least 20%, more preferably at least 25%, by weight of the total weight of said layer. According to this embodiment, the ratioby weight between:- the PAEK polymers and the PPS and / or PES polymers or- the PAEK and (PEI and / or PI and / or PAI and / or PBI) mixture and the PPS and / or PES polymers is advantageously between 2:5 and 2:3, preferably between 1:2 and 1:3. Advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise one or more fillers. According to this embodiment, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise less than 40%, preferably less than 30%, by weight of fillers relative to the total weight of said layer, preferably between 5 and 25% by weight. According to one embodiment, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises one or more acrylic resin(s). The acrylic resin(s) is / are advantageously chosen from the group consisting of polymers derived from aemulsion polymerization of different monomers with other acrylic-based monomers. According to one embodiment, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises one or more coloring agent(s). Advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise less than 30%, preferably less than 20%, by weight of one or more coloring agent(s) of the total weight of said layer.Advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) further comprises / comprise water and / or one or more solvents, preferably unlabeled, for example propionamide, N-formylmorpholine (NFM), N-Methyl Imidazole (NMI), N-ButylPyrrolidone (NBP), dimethyl sulfoxide (DMSO), or alcoholics, for example Propylene Glycol (PPG), Diethylene glycol, di propylene glycol butyl ether (DPNB).Advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) comprises / comprise one or more surfactants. Advantageously, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) further comprises / comprise one or more anti-foaming agents. According to one embodiment, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) is / are made up of one or more polyaryletherketone(s) (PAEK) and optionally:- one or more additive(s), and / or- one or more coloring agents, and / or- one or more fillers.According to one embodiment, the primer layer(s) (3a) or the optional intermediate layer(s) (3b) is / are made up of one or more polyaryletherketone(s) (PAEK), one or more polymer(s) chosen from the group consisting of polyetherimides (PEI), polyimides (PI), polyamidesimides (PAI) and polybenzymidazole (PBI) and optionally:- one or more additive(s), and / or- one or more coloring agents, and / or- one or more fillers.LAYER (3c)The finishing layer (3c) consists of:- a silicone elastomer obtained from at least one organopolysiloxane bearing reactive vinyl functions (-CH=CH2) and at least one other organopolysiloxane bearing reactive silyl hydride functions (Si-H) or reactive thiol functions (SH), and optionally: - one or more thermoplastic polymers, and / or- one or more additive(s), and / or- one or more coloring agents.The silicone elastomer of layer (3c) forms a network which can be made up of a combination of 4 simple organosiloxane units called M, D, T and Q in function of the degree of substitution by oxygen of the silicon atom, as described in the following table, where R is an organic substituent described below. Tableau 1The precursors of the elastomer are organopolysiloxanes. These macromolecules are formed of M, D, T, and / or Q units as described in the table, where R is independently an alkyl group, in particular methyl, or aryl, in particular phenyl, different natures of R can be present on the same macromolecule. Organopolysiloxanes can be either linear or weakly branched (majority of D groups). Linear or weakly branched organopolysiloxanes are generally liquid, more or less viscous at room temperature, and are called silicone oils. Organopolysiloxanes carrying reactive functions of layer (3c) are precursors which react by a crosslinking which is a polyaddition.This crosslinking is carried out by reaction between the reactive vinyl functions (-CH=CH2) present on one of the organopolysiloxanes and the reactive silyl hydride functions (Si-H) or the reactive thiol functions (SH) present on the other organopolysiloxane mixed with the first. This crosslinking can be carried out by thermal activation, activation by UV irradiation or chemical activation. Preferably, this crosslinking is carried out in the presence of a catalyst or a radical initiator. According to one embodiment, when the crosslinking is carried out by reaction between the reactive vinyl functions (-CH=CH2) present on one of the organopolysiloxanes and the reactive silyl hydride functions (Si-H) present on the other organopolysiloxane mixed with the first, the reaction is preferably carried out in the presence of a metal catalyst, for example platinum or a suitable platinum-based catalyst such as the Karstedt catalyst or the Ashbys catalyst.According to one embodiment, when the crosslinking is carried out by reaction between the vinyl reactive functions (-CH=CH2) present on one of the organopolysiloxanes and the thiol reactive functions (SH) present on the other organopolysiloxane mixed with the first, the reaction is preferably carried out in the presence of a radical initiator. According to one embodiment, it may be a thermally activated radical initiator such as, for example, 2,2′-Azobis(2-methylpropionamidine) dihydrochloride (or V50). According to one embodiment, it may be a radical initiator activated by UV irradiation such as, for example, Irgacure®651 (2,2-Dimethoxy-2-phenylacetophenone). Advantageously, the organopolysiloxanes carrying reactive functions of layer (3c) are silicone oils.The reactive functions are present on each organopolysiloxane in the number of at least one and can be present in the number of 2, 3, or more… as much as the molecular structure allows. Silicone oils comprising at least one reactive function are called “reactive oils”. The reactive functions can be found either at the end of the macromolecular chain (termination), or distributed over the chain. ADDITIONAL THERMOPLASTIC POLYMERS Advantageously, the thermoplastic polymer(s) is / are chosen from the group consisting of aromatic thermoplastic polymer(s) such as polyaryletherketone(s) (PAEK), poly(arylethersulfones) (PAES), poly(arylene sulfides) (PAS) or poly(phenylene oxide) (PPO), liquid crystal polymers, heterocyclic thermoplastic polymers and their mixtures.PAEK Advantageously, the polyaryletherketone(s) (PAEK) is (are) chosen from the group consisting of: polyetherketones (PEK), polyetheretherketone (PEEK), polyetherketoneketones (PEKK), polyetheretherketoneketones (PEEKK) and polyetherketoneetherketoneketones (PEKEKK), particularly preferably is (are) PEEK. Other aromatic thermoplastic polymers As aromatic thermoplastic polymer(s), examples suitable according to the invention are poly(phenylene oxide) (PPO), poly(arylethersulfone) polymer (PAES), and in particular polyethersulfone (PES), polyphenyleneether sulfone (PPSU), poly(arylene sulfides) (PAS) and in particular polyphenylene sulfide (PPS), liquid crystal polymers and mixtures thereof.Heterocyclic thermoplastic polymers As heterocyclic thermoplastic polymers, examples suitable according to the invention are polyetherimides (PEI), polyimides (PI), polyamideimides (PAI) and polybenzymidazole (PBI), or mixtures thereof. Advantageously, the nature of the thermoplastic polymer(s) in layers (3a), (3b) and (3c) may be identical or different. Advantageously, layer (3c) comprises one or more thermoplastic polymer(s), preferably in a proportion by weight of said layer of less than 15%, preferably. à 10 %.FILLERS The fillers within the meaning of the invention provide mechanical reinforcement and can also provide hydrophobicity properties, while improving the mechanical strength and thermal conductivity of the coating. The fillers do not only have the function of providing color to the coating, but can contribute to it. The presence of fillers with excellent thermal conductivity makes it possible to compensate for the low thermal conductivity of PAEK polymers. Advantageously, the filler(s) is / are chosen from the group consisting of ceramic (SiO2, etc.) and / or mineral and / or metallic (Al2O3, TiO2, etc.) and / or silica and / or diamond particles. Preferably, the filler(s) is / are chosen from the group consisting of metal oxides, metal carbides, metal oxynitrides, metal nitrides, and mixtures thereof. Advantageously, said metal is a transition metal,as at least one of the elements chosen from B, Ni, Ti, Zr or Hf. More preferably, the filler(s) is / are chosen from the group consisting of:- fillers for reinforcement: organic or inorganic hard fillers; the inorganic hard fillers are preferably particles of silicon carbide or alumina or zirconia or graphite, or ceramics, or carbonate, or hydrated alumina, aluminum trihydroxide or one or more metal oxide(s), graphite, graphene;- other fillers for reinforcement chosen from metal oxides: silica, micas, lamellar fillers, clays such as montmorillonite, sepiolite, gypsite, kaolinite and laponite, zinc dioxide, quartz, and zirconium phosphate, alumina, zirconia, zinc oxide, copper oxide,iron oxide;- fillers chosen from reinforcing fibers: glass or carbon or aramid fiber;- conductive fillers comprising a transition metal carbide and / or a transition metal nitride: characterized in that the transition metal is at least one of the elements chosen from B, Ni, Ti, Zr or Hf, for example: cubic boron nitride, diamond particles, metal particles;- lamellar fillers capable of conferring lubricating properties, such as for example clays, graphene or graphite. More preferably, the filler(s) is / are chosen from the group consisting of alumina, silicon carbide, tungsten carbide, boron nitride, quartz, and mixtures thereof. Advantageously, the fillers present in the primer layer(s) (3a) or the optional intermediate layer(s) (3b) are inorganic hard fillers, preferably metal oxides, carbides, nitrides,preferably alumina, silicon carbides or fumed silica. Certain inorganic hard fillers such as silicon carbide, in addition to their mechanical reinforcement performance, also have the advantage of being conductive fillers and therefore provide excellent thermal conductivity. The addition of this type of filler makes it possible to improve the culinary rendering with better diffusion of heat from the metal substrate to the food in contact with the coating. Advantageously, the average diameter d50 of the fillers is between 0.1 and 50 µm, advantageously still between 5 and 15 µm. Advantageously, the proportion of fillers in a layer, when it comprises them, is between 0.5 and 30% by dry weight relative to the total weight of said layer after cooking, preferably between 5 and 20%. Advantageously, the proportion of fillers in the layer (3a) is greater than 20% by weight, preferably greater than 30% by weight,relative to the total weight of said layer. Advantageously, the proportion of fillers in layers (3a) and (3b) may be identical or different. Advantageously, the nature of the fillers in layers (3a) and (3b) may be identical or different. ADDITIVES Advantageously, said additives are chosen from the group consisting of anti-foam agents, dispersing agents, wetting agents, thickeners, pH adjusters, reactive silicone oils. Said anti-foam agent(s) are preferably chosen from the group consisting of mineral oils, diols, hydrocarbons, glycerides, oxirane, emulsified fatty acids. The surfactant(s) is (are) preferably chosen from the group consisting of glycol ether, ethoxylated alcohol excluding alkyl phenol ethoxylates (APE),gemini surfactants. The dispersing agent(s) is (are) preferably chosen from the group consisting of anionic dispersants such as fatty acid derivatives. Said thickener(s) is (are) preferably chosen from the group consisting of acrylic-based or polyurethane-based copolymer, cellulose, fumed silica. Said pH adjuster(s) is (are) preferably chosen from the group consisting of Bronsted bases: ammonia, amines (triethylamine, triethanolamine, etc.), hydroxides (soda, potash, etc.), carbonates. Advantageously, the proportion of additives in layer (3a) is less than 1% by weight relative to the total weight of said layer. Advantageously, the proportion of additives in layer (3c) is less than 20% by weight relative to the total weight of said layer. COLOURING AGENTS Advantageously, the colouring agent(s) is / are chosen from the group consisting of thermochromic pigments, thermostable pigments,glitter, preferably hologram glitter, and mixtures thereof.Advantageously, the proportion of coloring agents in layers (3a), (3b) and (3c) is between 0.5 and 50% by dry weight relative to the total weight of said layer after baking.Advantageously, the proportion of coloring agents in layers (3a) and (3b) ranges from 10% to 40% by weight relative to the total weight of said layer. Advantageously, the proportion of coloring agents in layer (3c), when present, is less than 10% by weight relative to the total weight of said layer.Advantageously, the proportion of coloring agents in layers (3a), (3b) and (3c) may be identical or different. Advantageously, the nature of the coloring agents in layers (3a), (3b) and (3c) may be identical or different. Advantageously, layer (3c) is transparent. In this case, if it includes coloring agents, these coloring agents are glitters. Thermochromic pigments Preferably,the thermochromic pigment(s) is / are chosen from the group consisting of Bi2O3, Fe2O3, V2O5, WO3, CeO2, In2O3, Y1.84Ca0.16Ti1.84V0.16O1.84, AgI, (Bi1-xAx)(V1-yMy)O4 with:- x is equal to 0 or x is from 0.001 to 0.999,- y is equal to 0 or y is from 0.001 to 0.999,- A and M are chosen from the group consisting of nitrogen, phosphorus, an alkali metal, an alkaline earth metal, a transition metal, a poor metal, a metalloid or a lanthanide, -A and M are different from each other.Knowing that A and M are different from each other, when:- A is an alkali metal, it can be chosen from Li, Na, K, Rb, Cs,- M is an alkali metal, it can be chosen from Li, Na, K, Rb, Cs,- A is an alkaline earth metal, it can be chosen from Be, Mg, Ca, Sr, Ba,- M is an alkaline earth metal, it can be chosen from Be, Mg, Ca, Sr, Ba,- A is a transition metal, it can be chosen from Sc, Ti Cr, Mn, Fe, Co, Ni, Cu, Y, Zr,Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir,- M is a transition metal, it can be chosen from Sc, Ti Cr, Mn, Fe, Co, Ni, Cu, Y, Zr,Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir,- A is a poor metal, it can be chosen from Al, Zn, Ga, In, Sn,- M is a poor metal, it can be chosen from Al, Zn, Ga, In, Sn,- A is a metalloid, it can be chosen from B, Si, Ge, Sb,- M is a metalloid, it can be chosen from B, Si, Ge, Sb,- A is a lanthanide, it can be chosen from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho,Er, Tm, Yb, Lu,- M is a lanthanide, it can be chosen from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho,Er, Tm, Yb, Lu. Preferably, A and M different from each other are B and / or Mg. Preferably, the pigment (Bi, 1-x HAS x )(V 1-y M y)O4has a monoclinic scheelite crystallographic form at room temperature. Preferably, x and y are 0, i.e. the pigment (Bi1-xAx)(V1-yMy)O4 is Bismuth Vanadate (BiVO4). Advantageously, a BiVO4 with a monoclinic scheelite crystallographic structure at room temperature is used. Bismuth Vanadate is a yellow inorganic compound, with the formula BiVO4, widely used for its coloristic properties and its lack of toxicity. Registered in the Colour Index International database as QI Pigment Yellow 184, it is notably marketed by the companies Heubach (Vanadur®), BASF (Sicopal®), FERRO (Lysopac) and Bruchsaler Farbenfabrik (Brufasol®).Thermostable pigments Preferably, the thermostable pigment(s) is / are selected from the group consisting of:- Yellow pigment of titanium rutile type,- Yellow pigment derived from bismuth, for example selected from stabilized bismuth vanadates (Py184)- Red pigment, for example selected from perylene red (for example PR149, PR178 and PR224), iron oxide,- Orange pigment of bismuth oxyhalides type (PO85),- Orange pigment of bismuth vanadate (PO86)- Orange pigment of zinc tin titanium (PO82)- Orange pigment of cerium sulfide (PO75; PO78)- Orange yellow pigment of antimony titanium chromium rutile type (PBr24)- Orange yellow pigment of zinc tin rutile type (Py216)- Niobium tin zinc sulfide orange yellow pigment (Py227)- Orange yellow pigment of double oxides of tin and niobium- Co3(PO4)2. - LiCoPO4 - CoAl2O4 - Cr2O3 - TiO2- Black pigment PBk28 (Copper chromite black spinel)- and mixtures thereof.DecorationsAccording to one embodiment, the layer(s) (3b) is(are) continuous and covers(covers) the entire layer (3a) (see Figure 1).According to another embodiment, the layer(s) (3b) does(do) not cover the entire layer (3a) and forms(forms) at least one decoration (see Figure 2).Advantageously, the layer(s) (3b) compose(s) several decorations, one (i) comprising one or more thermochromic pigment(s) and the other (j) comprising at least one temperature reference pigment composition (see Figure 3).According to one embodiment, each of the two decorations (i) and (j) is in the form of adjacent non-overlapping patterns. For example, each decoration is represented by different geometric patterns distributed evenly over the entire surface and alternating with each other (see Figure 4A).According to another embodiment, the two decorations (i) and (j) are partially overlapping. For example, each decoration is represented by different geometric patterns distributed uniformly over the entire surface and partially overlapping (see Figure 4B). Preferably, the two decorations (i) and (j) are overlapping, either because one of the two decorations is a continuous layer and the other decoration covers it in the form of patterns, or because the two decorations (i) and (j) are in the form of overlapping patterns (see Figure 4C). Flakes The flakes that can be used in the context of the present invention can be independently chosen from mica flakes, coated or not, silica flakes, coated or not, aluminum flakes, coated or not, iron oxide flakes, coated or not. Mica or silica flakes coated with titanium dioxide.The flakes usable in the context of the present invention can be treated to give a particular color effect. Advantageously, the flake(s) is / are particles chosen from the group consisting of particles of mica, aluminum, mica coated with titanium dioxide or mixtures thereof. Hologram flakes Advantageously, the flake(s) is / are hologram flakes, i.e. a mixture of magnetizable particles and non-magnetizable particles. The magnetizable particles can advantageously be particles comprising at least one ferromagnetic metal. These magnetizable particles can be of a homogeneous nature, i.e. made of the same material, or of a composite nature, i.e. these magnetizable particles have a core-shell structure, in which the ferromagnetic metal is found in the core and / or in the shell of said particles.Examples of composite magnetizable particles include mica flakes coated with iron oxide Fe2O3 or stainless steel fibers coated with a sol-gel material, as protection against corrosion during the steps of implementing the coating, or plastic flakes coated with iron oxide Fe2O3, or flakes whose core is made of ferromagnetic metal and the shell is formed of a plastic material or a sol-gel material. According to one embodiment, a portion of said magnetizable particles is oriented so as to form a three-dimensional decoration. Advantageously, the mixture of magnetizable particles and non-magnetizable particles represents between 1% and 5% by weight of the weight of the layer, preferably between 2% and 3% by weight.Advantageously, the percentage of non-magnetizable particles in the mixture of magnetizable particles and non-magnetizable particles is between 15% and 40% by weight relative to the total weight of the mixture of magnetizable particles and non-magnetizable particles. Advantageously, the magnetizable particles have a dimension D50 of less than or equal to 23 µm. The term "D50" is understood to mean, for the purposes of the present invention, the maximum dimension that 50% of the particles have by number. Advantageously, the non-magnetizable particles have a dimension D90 of between 20% and 250% of the dimension D90 of the magnetizable particles. The term "D90" is understood to mean, for the purposes of the present invention, the maximum dimension that 90% of the particles have by number. Advantageously, the magnetizable particles and / or the non-magnetizable particles are surface-colored.Advantageously, the non-magnetizable particles consist of mica, aluminum, or titanium dioxide-coated mica. Advantageously, the magnetizable particles consist of iron, iron oxide, iron-coated aluminum, or iron-coated mica, the iron being in ferritic form. PREFERRED ARCHITECTURESAccording to one variant, the intermediate layer(s) (3b) is (are) composed of:^ one or more polyarylether ketone(s) (PAEK),^ one or more coloring agent(s), in particular pigments and / or glitter, advantageously holograms, ^ one or more thermoplastic polymer(s) advantageously chosen from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzymidazole (PBI), polyethersulfone (PES), polyphenylene ether sulfone (PPSU), and mixtures thereof, ^ from 0 to 10% of fillers,^ from 0 to 20% of additives,^ optionally one or more silicone resin(s).According to another variant, the intermediate layer(s) (3b) is (are) made up of:^ one or more polyarylether ketone(s) (PAEK),^ one or more coloring agent(s), in particular pigments and / or glitter, advantageously holograms, ^ from 0 to 10% fillers,^ from 0 to 20% additives,^ one or more silicone resin(s), and^ optionally one or more thermoplastic polymer(s) advantageously chosen from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzymidazole (PBI), polyethersulfone (PES), polyphenylene ether sulfone (PPSU), and mixtures thereof.According to another particular variant, the intermediate layer(s) (3b) is (are) made up of:^ one or more polyarylether ketone(s) (PAEK),^ one or more coloring agent(s), in particular pigments and / or glitter, advantageously holograms, ^ one or more thermoplastic polymer(s) advantageously chosen from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzymidazole (PBI), polyethersulfone (PES), polyphenylene ether sulfone (PPSU), and mixtures thereof, ^ from 0 to 10% of fillers,^ from 0 to 20% of additives,^ one or more silicone resin(s). According to a particular embodiment, the coating comprises two intermediate layers (3b), including at least one decorative layer. Advantageously, the layer(s) (3b) compose several decorations, one (i) comprising one or more thermochromic pigment(s) and the other (j) comprising at least one temperature reference pigment composition.Preferably, when present, the intermediate layer(s) (3b) only partially cover the base layer (3a). METAL SUBSTRATE Advantageously, said metal substrate (2), also called support, is a substrate made of aluminum, stainless steel, cast iron or aluminum, iron, titanium or copper. For the purposes of the present invention, aluminum means a metal consisting of 100% aluminum or an aluminum alloy. Advantageously, the metal substrate (2) is a substrate made of aluminum, stainless steel or a multi-layer metal substrate. The metal substrate (2) may be a two-layer or three-layer substrate, these multi-layers being able to be obtained for example by co-rolling, by hot diffusion under load (solid state bonding) or by hot or cold impact bonding. Preferably, the metal substrate (2) comprises alternating layers of metal and / or metal alloy.According to one embodiment, the metal substrate (2) is an aluminum alloy substrate, a stainless steel substrate or a multilayer metal substrate whose face (2a) is made of aluminum alloy or stainless steel. Preferably, the metal substrate (2) is an aluminum substrate. Advantageously, the thickness of the metal substrate (2) is between 0.5 mm and. 10 mm.Advantageously, the face (2a) of the metal substrate (2) has previously undergone a surface treatment making it possible to improve the adhesion of the coating to said substrate. According to one embodiment, the surface of the face (2a) of the metal substrate (2) has undergone a surface treatment, said surface treatment being a chemical attack, brushing, hydration, sandblasting, shot blasting, a physicochemical treatment of the plasma or corona or laser type, a chemical activation or a combination of these different techniques.Advantageously, the face of the substrate (2a) on which the coating (3) according to the invention will be applied can be treated so as to increase its specific surface area; for an aluminum substrate, this treatment can be done by anodization (creation of a tubular alumina structure), by chemical attack, by sandblasting, by brushing, by shot blasting or by adding material by means of a technology such as thermal projection (flame, plasma or arc spray). The other metal substrates can also be polished, sandblasted, brushed, micro-blasted or receive an addition of material by means of a technology such as thermal projection (flame, plasma or arc spray).As metallic substrates which can be used in the present invention, mention may advantageously be made of anodized or non-anodized aluminum substrates, optionally polished, brushed, sandblasted, shot-blasted or micro-blasted, anodized or non-anodized aluminum alloy substrates, optionally polished, brushed, sandblasted or micro-blasted, steel substrates, optionally polished, brushed, sandblasted, shot-blasted or micro-blasted, stainless steel substrates, optionally polished, brushed, sandblasted or micro-blasted, cast steel, aluminum or iron substrates, and copper substrates, optionally hammered or polished.Advantageously, the substrate may be chosen from substrates comprising ferritic stainless steel / aluminum / austenitic stainless steel layers, substrates comprising stainless steel / aluminum / copper / aluminum / austenitic stainless steel layers, cast aluminum, aluminum or aluminum alloy caps lined with an outer base of stainless steel, metal co-laminated substrates, for example two-layer co-laminated substrates comprising a stainless steel layer (for example intended to constitute the inner face of the article) and a layer of aluminum or aluminum alloy, anodized or not (for example intended to constitute the outer face of the article). Advantageously, the average arithmetic roughness Ra of the surface of the face (2a) of the metal substrate (2) is greater than or equal to 1 µm. The average arithmetic roughness Ra is measured using a roughness meter according to standard ISO 4287.Ra represents the arithmetic mean of the deviations from the mean. Surface topography can be studied in particular with a profilometer with a probe equipped with a fine stylus fitted with a diamond tip, or with an optical metrology device such as Altisurf®, in which a chromatic confocal sensor allows contactless measurement. The study of this surface topography makes it possible to define the arithmetic mean roughness Ra.PROCESSThe invention also relates to a method for manufacturing a heating element coated (1) with a coating (3) for a household article according to the invention, characterized by the following steps: a) a step of providing a metal substrate (2) comprising two opposite faces; c) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a primer layer (3a) to the support (2); d) a step of applying the layers (3a) and possibly (3b) of the coating (3); e) optionally a drying step between 50°C and 150°C after application of each of said layers (3a) (3b);f) optionally a baking step of the element obtained in step d) or e) at a temperature between 250°C and 420°C;g) a step of applying the finishing layer (3c) to the element obtained in step d), e). ou f) ;h) optionally a step of baking the element obtained in step g) at a temperature between 250°C and 420°C.The invention also relates to a method of manufacturing a household article comprising a heating element coated (1) with a coating (3) according to the invention characterized by the following steps: a) a step of providing a metal substrate (2) in the form of a substantially flat metal substrate comprising two opposite faces or a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22);b) where appropriate, when a metal substrate in the form of a substantially flat metal substrate is provided during step (a), a step of shaping said substrate to give it the shape of a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22), said step (b) being carried out either before step (a), or before step (d) of producing the layers (3a) and (3b) of the coating (3), or after step (f) of baking and before step (g) of producing the finishing layer or after step (g); c) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a primer layer (3a) on the support (2); d) a step of applying the layers (3a) and possibly (3b) of the coating (3);e) optionally a drying step between 50°C and 150°C after application of each of said layers (3a) (3b);f) optionally a baking step of the element obtained in step d) or e) at a temperature between 250°C and 400°C;g) a step of applying the finishing layer (3c) to the element obtained in step d), e); ou f) ;h) optionally a step of baking the element obtained in step g) at a temperature between 250°C and 400°C. Advantageously, during step d), the layer(s) (3a) and (3b) is / are applied by pad printing, electrostatic powdering, spraying, screen printing, roller application or digital printing, preferably by spraying. Advantageously, the spraying is carried out in a solvent-based or aqueous phase. Advantageously, during step g), the finishing layer (3c) is applied by electrostatic powdering, spraying, screen printing, spray gun, doctor blade, coating cylinder, brush, roller application or digital printing, preferably by spraying. According to an advantageous arrangement of the invention, the finishing layer (3c) is applied to the coated support at a deposition rate of less than or equal to 5 g / m 2, preferably between 0.1 and 2.5 g / m2, even more preferably between 0.2 and 2 g / m2.Advantageously, the method according to the invention comprises a step of crosslinking g') of the finishing layer (3c) subsequent to or simultaneously with step g). According to a variant, the crosslinking of the composition of the layer (3c) can generally be activated, for example, by heat treatment, at a temperature between 50 and 400°C, preferably between 50 and 300°C, obviously taking into account the maximum resistance of the support to heat.Advantageously, the crosslinking g') of the varnish of the finishing layer (3c) is carried out at a temperature of 300°C for a period of 10 min. Advantageously, the higher the crosslinking temperature, the shorter the crosslinking time. According to one embodiment, the crosslinking step g') does not require heat treatment, in particular because the support is hot at the time of step g).According to one embodiment, when at least one of the organopolysiloxanes of the layer (3c) carries reactive thiol (SH) functions, the crosslinking step g') can be carried out under UV irradiation using a radical initiator activated by UV irradiation such as, for example, Irgacure®651 (2,2-Dimethoxy-2-phenylacetophenone). The method can also comprise an additional step g'') of crosslinking the composition applied in step g), by UV irradiation. Advantageously, the steps of the method according to the invention make it possible to coat the metal support (2) with a coating (3) formed by the layers (3a), (3b) if applicable, and (3c). Generally, these layers are wet during their application. By wet layer, it is understood within the meaning of the present invention that the layer comprises all or part of its solvents. Advantageously, the top coat (3c) is a thin, protective, hard, smooth, shiny and transparent surface coat.For the purposes of the invention, the finishing layer (3c) has, for example, a substantially homogeneous thickness less than or equal to 10 µm, preferably less than 5 µm. The thickness of the finishing layer (3c) is advantageously between 0.1 µm and 10 µm, preferably between 0.5 µm and 5 µm, even more preferably between 1 and 2 µm. According to a variant, it is possible to provide several layers (3c) deposited one above the other. The layer (3c) is obtained from a composition which is liquid during its application. The viscosity of the composition for the layer (3c) is adjustable by dilution with solvents depending on the deposition methods used. The composition for the layer (3c) may comprise a solvent. Advantageously, when the composition for layer (3c) comprises at least one organopolysiloxane carrying reactive silyl hydride (Si-H) functions, the solvent is an aliphatic solvent.Advantageously, when the composition for the layer (3c) comprises at least one organopolysiloxane carrying reactive thiol (SH) functions, the solvent is an aliphatic or alcoholic solvent. Advantageously, the aliphatic solvent is chosen from the group consisting of aliphatic, linear or cyclic hydrocarbons, the carbon number of which is between 5 and 10, and mixtures thereof. The composition for the layer (3c) may thus comprise a solvent present at a content greater than or equal to 40%, preferably greater than or equal to 50%, particularly preferably greater than or equal to 60% by weight relative to the weight of the liquid composition for the layer (3c).Surprisingly, a composition for the layer (3c) comprising a very high solvent content makes it possible to obtain layers (3c) which, after crosslinking, have a very thin thickness while being homogeneous and which are capable of making non-stick or improving the non-stick of a coating (3) applied to the face (2a) of the support (2) of a heating element (1) for a household article. Particularly advantageously, the solvent content of the composition for the layer (3c) is greater than or equal to 70% or 80% by weight relative to the weight of the liquid composition for the layer (3c). Most particularly advantageously, the solvent content of the composition for the layer (3c) ranges from 70% to 90% or from 80% to 90% by weight relative to the weight of the liquid composition for the layer (3c). The shaping is also called stamping.When the shaping step precedes the application d) of the coating, the coating is preferably carried out by spraying. When this shaping step is subsequent to the application d) of the coating, the coating is preferably carried out by screen printing or by roller. ARTICLE The invention also relates to a household article comprising a heating element coated according to the invention or capable of being obtained according to the method of the invention. According to one embodiment, this household article is a culinary article or an electrical cooking appliance and the layer (3c) forms a cooking surface (5). In this case, the layer (3c) is advantageously transparent. In this case, the coloring agent of the layer (3c) is advantageously glitter.Advantageously, the culinary article (100) according to the invention is chosen from the group consisting of saucepan, frying pan, skillets or caquelons for fondue or raclette, stewpot, wok, sauté pan, crepe maker, grill, griddle, pot, casserole dish, cooker or bread machine bowl, cooking mold, molds and baking trays, barbecue plates and grills, preparation bowls. According to one embodiment, the culinary article (100) comprises a heating face (6) intended to be placed in contact with an external heating source, the heating face (6) being opposite the cooking face (5) intended to be placed in contact with the food during cooking. According to embodiments, the layer (3c) is intended to be placed in contact with a heating source.The cooking article according to the present invention may in particular be a cooking article of which one of the two opposite faces of the substrate is an inner face, possibly concave, intended to be arranged on the side of food likely to be introduced into or onto said article, and of which the other face of the substrate is an outer face, possibly convex, intended to be arranged towards a heat source. Advantageously, the electric cooking appliance (200) is chosen from the group consisting of electric crepe maker, electric raclette appliance, electric fondue appliance, electric grill, electric griddle, electric cooker, bread maker, electric pressure cooking appliance, waffle makers, rice cookers and jam makers. The electric cooking appliance (200) comprises a coated cooking element (1) according to the invention and a heating source (210) configured to heat said coated cooking element (1).According to one embodiment, the household article according to the invention is a small heating household appliance. It may be an iron and the coated heating element is the soleplate of the iron or a hair care article and the coated heating element is one of the heating plates of said article. EXAMPLES The aims, aspects and advantages of the present invention will be better understood from the description given below of a particular embodiment of the invention presented by way of non-limiting example. Of course, the invention is in no way limited to the embodiment described and illustrated which has been given only by way of example. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention. 1 - Raw materials Aromatic polymers PolyArylEtherKetone. ketone) supplied by the company VICTREX under the name VICOTE Coatings F804 “Vicote F804”: particle size d50 = 10 µm; dry extract between 35.5 and 39%; pH between 9.6 and 11.9; viscosity of approximately 11 sec DIN Cup n°6. Aromatic thermoplastic polymers micronized VERADEL 3100 UFP from SOLVAY, polymer powder with a d50 < 40 µm. Heterocyclic thermoplastic polymers Polyamide imide (PAI) powder resin: TORLON AI10LS from Solvay, powder containing 90% dry extract in N-methylpyrrolidone (NMP / Water). Silicone resins - RS1: Methyl ethoxy functionalized organopolysiloxane resin in aqueous emulsion, Viscosity at 25 °C Approx. Approx. 1500 mPas, Solids content = 52%- PDMS_1: Polydimethylsiloxane (PDMS) resin in aqueous emulsion Functionalized PDMS, Solids content 62% Co-Solvent- High boiling alcohol: MPG (monopropylene glycol)- Low boiling alcohol: IPA (isopropanol)Additives- Base to adjust the pH and solubilize certain additives: for example AMP90 or other such as ammonia solution, triethanolamine,etc.- Antifoam: Moussex 7114HL from SynthonOther additives Acrylic resin:- Rohagit SD 15: 30% acrylic polymer solution in aqueous phase or Synthomer- Modarez FA365 from Synthron (anionic acrylic resin), or other type and / or gradeReinforcing fillers- Aerosil R972 (Evonik): Post-treated silica fume dimethyl dichlorosilane, specific surface area (BET) = 90 to 130 m² / g- Alumina: CAHPF 240 d50 = 45-50 µm from Alteo at 100%- Graphene: Graphen from Carbon Waters, graphene in dispersed form- Silica: Levasil CC301,Surface-modified colloidal silica in the form of an aqueous dispersion of nanoparticles with a dry extract of 30% Pigments - parylene red - thermochromic pigments: bismuth oxide or commercial pigments based on mixed oxide of bismuth and vanadium - carbon black: - Sicopal® black K 0098 FK (Sun Chemical) - Derussol VDP 641: Black pigment concentrate in aqueous phase 2 - Examples and counter-examples of the production of cookware The aluminum discs are an alloy 4006 in the annealed state, 3.4 mm thick and 340 mm in diameter. They have been treated by brushing (roughness Ra approximately 2 µm). The coating is carried out flat on aluminum discs, by screen printing or by spraying. The coating is carried out as follows: - each layer (3a), if applicable (3b),is coated by screen printing;- layer (3c) is spray coated. Baking of layers (3a) and (3b) before applying the top coat (3c) is carried out in an oven between 250 and 380°C for 30 to 45 minutes, then the discs are left to cool. Examples 1 to 8 as well as counter-example 2 were carried out according to the different combinations of drying and baking protocols described above. Example 1The coating comprises a layer (3a) obtained by screen printing coating with a thickness of 30 µm to 40 µm and a layer (3c) obtained by spray coating with a thickness of 1 to, 2 µm. Layer (3a): The PEAK ratio is such that the PEEK resin is at 100%. Table 2 gives the composition of the wet formula for layer (3a). Tableau 2 Component % by massVicote F804 73.6 MPG 8,1 IPA 2 Modarez FA365 5.1Rohagit SD15 5.1 AMP90 1 Moussex 7114HL 1Derussol VDP 641 2Demineralized water 2 TOTAL 100Viscosity is 12000 to 13000 cP, measured on Brookfield at 10 rpm, spindle #4. The pH is between 9.0 and 10.5. Layer (3c1): Layer (3c1) is obtained after crosslinking the following composition expressed in relative parts in dry mass: - an organopolysiloxane carrying vinyl reactive functions (-CH=CH2): 100 parts, - another organopolysiloxane carrying silyl hydride reactive functions (Si-H): 8 parts, and - a metal catalyst: 6 parts. This dry composition above is mixed with a solvent to obtain a dry extract of the order of 10% to 20% by mass. After application of layer (3c1), the assembly is placed in an oven at 300°C for 30 to 45 minutes in order to dry and then crosslink layer (3c1), then the discs are left to cool.Example 2The coating comprises a layer (3a) identical to the layer (3a) according to example 1, a layer (3c1) identical to the layer (3c1) according to example 1, as well as an intermediate layer (3b) representing a decoration deposited by pad printing in interlayers with an architecture according to figure 3. The layer (3b) (j) is a thermochromic decoration and the layer (3b) (i) is a thermostable decoration. Example 3The coating comprises:- a layer (3a) identical to the layer (3a) according to example 1 except for its thickness between 10 µm and 20 µm, - a layer (3c1) identical to the layer (3c1) according to example 1, and- an intermediate layer (3b1) whose composition appears in the table below. Layer (3b1) is obtained by screen printing coating and has a thickness of 10 µm to 20 µm. Layer (3b1): The PEAK / heterocyclic polymer ratio is such that PEEK / PAI = 70 / 30 by weight.The sum of thermoplastic polymers (PEEK + PAI) in solid phase after curing in the coating is 76.4% by weight. The rate of fillers (pigment + reinforcing fillers) in the cured coating is 23.1% by weight. Tableau 3% in solid phase after curing in the PAI coating: TORLONAI10 LS 22.9% PEEK dispersion: F804 53.5% Sicopal® black K 0098 FK 5.3% Graphen 17.8% Moussex 7114HL 0.5% 100.0% Example 4The coating comprises:- a layer (3a) identical to the layer (3a) according to example 3,- a layer (3c1) identical to the layer (3c1) according to example 1, and- an intermediate layer (3b2) whose composition is shown in the table below. Layer (3b2) is obtained by screen printing coating and has a thickness of 10 µm to 20 µm. Layer (3b2): The PEAK / aromatic polymer ratio is such that PEEK / PES = 90 / 10 by weight. The sum of the thermoplastics (PEEK + PES) in solid phase after curing in the coating is 75.5% by weight. The rate of fillers (pigment + reinforcing fillers) in the cured coating is 24% by weight. Tableau 4 % in solid phase after baking in the PES coating: VERADEL 3100 USFP 7.4% PEEK dispersion: F804 68.1% Sicopal® black K 0098 FK 5.6% Graphen 18.4% Moussex 7114HL 0.5%100,0 %Example 5The coating comprises a layer (3a) identical to that of example 1 and a layer (3c2) obtained by spray coating with a thickness of 1 to 2 µm.Layer (3c2):Layer (3c2) is obtained after crosslinking the following composition expressed in relative parts in dry mass:- an organopolysiloxane carrying reactive vinyl functions (-CH=CH2): 100 parts,- another organopolysiloxane carrying reactive thiol functions (SH): 8 parts, and- a radical initiator: 15 parts. This dry composition above is mixed with a solvent to obtain a dry extract of the order of 10% to 20% by mass. After application of the layer (3c2), the assembly is passed into an oven at 100°C for 20 minutes in order to dry and then crosslink the layer (3c2) then into an oven at 300°C for 20 minutes in order to finalize the cooking. Finally, the discs are left to cool.Example 6The coating comprises a layer (3a) identical to layer (3a) according to example 1, a layer (3c2) identical to layer (3c2) according to example 5, as well as an intermediate layer (3b) (identical to that of example 2) representing a decoration deposited by interlayer tampoprinting with an architecture according to figure 3. Layer (3b) (j) is a thermochromic decoration and layer (3b) (i) is a thermostable decoration. Example 7The coating comprises:- a layer (3a) identical to the layer (3a) according to example 1 except for its thickness between 10 µm and 20 µm, - a layer (3c2) identical to the layer (3c2) according to example 5, and- an intermediate layer (3b1) identical to the layer (3b1) of example 3.Example 8The coating comprises:- a layer (3a) identical to the layer (3a) according to example 7,- a layer (3c2) identical to the layer (3c2) according to example 5,- as well as an intermediate layer (3b2) identical to the layer (3b2) of example 4.Counterexample 1The coating comprises:- a layer (3a') obtained by spraying with a thickness of 30 µm to 40 µm, the composition of which is indicated in the table below; and- a layer (3c1) identical to layer (3c1) according to example 1.Layer (3a'):The ratio of heterocyclic thermoplastic is such that the PAI resin is at 100%.There is no PolyArylEtherKetone resin, no PEEK in particular. The rate of fillers (pigment + reinforcing fillers) in the baked coating is 11.7% / weight. Tableau 5 % in solid phase after baking in the TORLON AI10LS coating 80.6% L evasil CC301 9,3%Sicopal® black K 0098 FK 2.4%Modarez SD 15 7.7%DRY BASE 100.0%Counter-example 2The coating comprises:- a layer (3a') identical to layer (3a') of counter-example 1; and- a layer (3c2) identical to layer (3c2) according to example 5.Counter-example 3The coating is made in 2 identical layers by screen printing coating.A liquid coating based on an aqueous dispersion of PEEK from the company VICTREX, PEEK dispersion: F804 is applied by spraying. A first sintering step at 380°C of this layer for 30 minutes is followed by cooling to room temperature.The thickness of this first layer is between 10 µm and 20 µm. Once the surface of this coating has cooled to room temperature, the same aqueous dispersion of PEEK is sprayed onto the first layer. A second sintering step at 380°C of this layer for 30 minutes is followed by cooling to room temperature.The coating has a very rough surface to the touch and a thickness of between 40 µm and 60 µm. 3 - Tests Method for assessing drawability: A drawing test, known as the Swift test, is carried out using a Zwick BPU 400 drawing machine. Experimental conditions: - cutting of discs to a diameter of 64 mm - 33 mm punch (Limiting Drawing Ratio = 1.9) - drawing die: 40 mm The drawability of a coating on a given substrate is expressed in a rating binaire :- OK: good drawability = the adhesion of the coating to the substrate after deformation by drawing is good - Not OK: poor drawability = the adhesion of the coating to the substrate after deformation by drawing is not good. The deformation by drawing was carried out in two ways; the evaluation of the adhesion is evaluated differently depending on the deformation method. These methods are estimated to give comparable results. Laboratory scale method: The coated aluminum substrate is deformed over a small area (a disc of approximately 10 cm diameter is required) by a press according to the "Erichsen" or "Godet" method: "Erichsen": the press deforms the surface with a conical and rounded punch to a depth of about 1 to 2 cm, with the coating on the outside. This deformation method also subjects the coating to stretching.If after deformation, the coating appears very cracked or flaking / detached from the substrate, its resistance to stamping deformation is poor. To amplify the differences, one can first make a grid (according to ISO 2409 standard) on the area where the punch is applied and then observe if many tiles have detached (with or without application of adhesive tape). "Godet": the press deforms the substrate with a cylindrical punch (rounded edge), with coating inside: this simulates more the deformation of the substrate during pan stamping, even if in the tests carried out, a 0% stretch on the skirt (the cylindrical edge) was carried out. The result is poor when one visually observes any detachment, wrinkling, etc., of the coating after deformation.Non-stick properties:Method for evaluating the properties of the non-stick coating: PERFORMANCE EGG TEST The method for evaluating the properties of the non-stick coating is carried out using the egg test described in the AFNOR NF D 21-511 standard, paragraph 3.3.2, and implemented as follows:The sample is cleaned, then the water remaining on the surface is wiped off.The inner surface of the container body is dried and then oiled.The cooking container, thus oiled, is heated on a gas stove to a temperature between 140 and 170°C.A 60 / 65 caliber egg is broken and poured into the center of the hot cooking container and waited for the egg to coagulate (6 to 9 minutes); the egg is removed from the cooking container using a spatula, the coating is cleaned using a damp vegetable sponge and the non-stick properties of the cooking container are assessed through this action, then recorded: Score of 100: the egg can be removed completely using a plastic spatula; Score of 75: the egg cannot be removed completely but the coating is easily cleaned with a damp sponge, Score of 25: the egg cannot be removed completely and the coating is not cleaned with a damp sponge, Score of 0: the egg cannot be removed and the coating cannot be cleaned with a damp sponge. Results The results of the drawability and non-stick performance tests are summarized below:. Tableau 6 SWIFT TEST Examples Egg Test Drawability 1 OK 100 2 OK 100 3 OK 754 OK 75 5 OK 100 6 OK 100 7 OK 75 8 OK 75 COUNTER EXAMPLE 1 NOK 0COUNTER EXAMPLE 2 NOK 0COUNTER EXAMPLE 3 NOK 0The coatings according to the invention comprising a layer (3a) and a layer (3c) make it possible to obtain satisfactory resistance (adhesion) of the coating when new and after three aging cycles in boiling water and oil, good corrosion resistance and good anti-adhesion performance.

Claims

CLAIMS 1 . Elément de chauffe revêtu (1) pour article ménager, comportant un substrat metallic (2) coated on at least one face (2a) with a coating (3) free of fluorocarbon resin and comprising at least the following layers and in this order from the metallic substrate (2): (3a) une couche de primaire comprenant une ou plusieurs polyarylether cétone(s) (PAEK) ; (3b) optionally one or more intermediate layer(s) comprising one or plusieurs polyarylether cétone(s) (PAEK) ; (3c) une couche de finition constituée : - d’un silicone élastomère obtenu à partir d’au moins un organopolysiloxane porteur de reactive vinyl functions (-CH=CH2) and at least one other organopolysiloxane carrying fonctions réactives hydrure de silyle (Si-H) ou de fonctions réactives thiol (S-H), et éventuellement : - d’un ou plusieurs polymères thermoplastiques, et / ou - d’un ou plusieurs additif(s), et / ou - d’un ou plusieurs agents colorants.

2. Elément de chauffe revêtu (1) selon la revendication 1, caractérisé en ce que the organopolysiloxanes carrying reactive functions of layer (3c) are silicone oils. 3 . Elément de chauffe revêtu (1) selon l’une quelconque des revendications previous, characterized in that the thickness of the finishing layer (3c) is included entre 0,1 µm et 10 µm, préférentiellement entre 0,5 µm et 5 µm, encore plus préférentiellement entre 1 µm et 2 µm.

4. Elément de chauffe revêtu (1) selon l’une quelconque des revendications précédentes, caractérisé en ce que le silicone élastomère de la couche (3c) est obtenu à from at least one organopolysiloxane carrying reactive vinyl functions (-CH=CH2) and at least one other organopolysiloxane carrying reactive silyl hydride functions (Si- H) en présence d’un catalyseur métallique.

5. Elément de chauffe revêtu (1) selon l’une quelconque des revendications 1 à 3, caractérisé en ce que le silicone élastomère de la couche (3c) est obtenu à partir d’au at least one organopolysiloxane carrying reactive vinyl functions (-CH=CH2) and at least un autre organopolysiloxane porteur de fonctions réactives thiol (S-H) en présence d’un radical initiator. 6 . Elément de chauffe revêtu (1) selon l’une quelconque des revendications précédentes, caractérisé en ce que la couche de primaire (3a) comprend 100 % en poids par relative to the total weight of said layer of one or more polyarylether ketone(s) (PAEK). 7 . Procédé de fabrication d’un article ménager comprenant un élément de chauffe revêtu (1) d’un revêtement (3) selon l’une quelconque des revendications characterized by the following steps: a) a step of providing a metal substrate (2) in the form of a substantially flat metal substrate comprising two opposite faces or a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22); b) where appropriate, when a metal substrate in the form of a substantially flat metal substrate is provided during step (a), a step of shaping said substrate to give it the shape of a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22), said step (b) being carried out soit avant l’étape (a), soit avant l’étape (d) de réalisation des couches (3a) et (3b) ducoating (3), either after the cooking step (f) and before the production step (g) of the couche de finition ou soit après l'étape (g) ; c) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a layer of primaire (3a) sur le support (2) ; d) une étape d’application des couches (3a) et éventuellement (3b) du revêtement (3) ; e) optionally a drying step between 50°C and 150°C after application of each desdites couches (3a) (3b) ; f) optionally a step of cooking the element obtained in step d) or e) at a température comprise entre 250°C et 420°C ; g) une étape d’application de la couche de finition (3c) sur l’élément obtenu à l'étape d), e) ou f) ; h) optionally a step of cooking the element obtained in step g) at a temperature between 250°C and 420°C. 8 . Procédé selon la revendication 7, caractérisé en ce que, lors de l’étape g), la top coat (3c) is applied by electrostatic powder coating, spraying, by screen printing, by gun, by doctor blade, by coating cylinder, by brush, by application au rouleau ou par impression digitale, préférentiellement par pulvérisation.

9. Procédé selon la revendication 7 ou 8, caractérisé en ce qu’il comprend une étape de réticulation g’) de la couche de finition (3c) ultérieure ou simultanée à l’étape g).

10. Procédé selon la revendication 9, caractérisé en ce que la réticulation g’) de la couche de finition (3c) est réalisée à une température de 300°C pendant une durée de 10 min.

11. Article ménager comprenant un élément de chauffe revêtu (1) selon l’une quelconque des revendications 1 à 6 ou susceptible d’être obtenu selon l’une quelconque des revendications 7 à 10.

12. Article ménager selon la revendication 11 caractérisé en ce qu’il s’agit d’un article culinaire ou d’un appareil électrique de cuisson et en ce que la couche (3c) formeune surface de cuisson (5).

13. Article ménager selon la revendication 12, caractérisé en ce que l’agent coloring of layer (3c) is glitter. 1 4. Article ménager selon la revendication 11 caractérisé en ce qu’il s’agit d’un article culinaire ou appareil électrique de cuisson et en ce que la couche (3c) est destinée à être mise en contact avec une source de chauffage.

15. Article ménager selon l’une quelconque des revendications 11 à 14, characterized in that it is a culinary article (100) chosen from the group consisting of saucepan, frying pan, skillets or caquelons for fondue or raclette, stewpot, wok, sauté pan, crepe maker, grill, griddle, pot, casserole dish, cooker or bread machine bowl, culinary mold. 1 6. Article ménager selon l’une quelconque des revendications 11 à 14, caractérisé en ce qu’il s’agit d’un appareil électrique de cuisson (200) choisi dans le groupe consisting of electric crepe maker, electric raclette machine, electric fondue machine, electric grill, electric griddle, electric cooker, bread machine, appliance électrique de cuisson sous pression, les gaufriers, les cuiseurs à riz et les confituriers.

17. Article ménager selon la revendication 11, caractérisé en ce qu’il s’agit d’un small household heating equipment. 1 8. Article ménager selon la revendication 17 caractérisé en ce qu’il s’agit d’un iron and the coated heating element (1) is the soleplate of the iron or a hair care article and the coated heating element is one of the heating plates of said article.

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