NON-FLUORINE-COATED HYBRID PAEK / HETEROCYCLICAL THERMOPLASTIC / SILICONE RESIN

Description

[0001] The invention applies to the field of non-stick coatings for cooking surfaces of cookware and electric cooking appliances.

[0002] Cookware coated with PTFE (polytetrafluoroethylene) is popular because it allows for cooking with little or no added fat and is easy to clean. However, an inherent weakness of these coatings is their low mechanical resistance, especially at high temperatures.

[0003] To remedy this, numerous technical solutions have been proposed, which consist of reinforcing the coating with hard fillers or by interposing hard underlayers of inorganic or organic type.

[0004] In the case of primers reinforced with hard organic or inorganic fillers, significant improvements in abrasion resistance are indeed observed, but impacts to the metal are also observed when cooking foods such as pork ribs or when using metal spatulas.

[0005] 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 but not eliminated.

[0006] We are also familiar with organic polymer underlayers. These underlayers effectively reduce the appearance of scratches considerably, or even eliminate them altogether. This strategy is therefore very promising. The polymers used are very often thermoplastics with high heat resistance and a high melting point, such as polyaryl ether ketones, particularly oxy-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene (PEEK), or phenylene sulfides.

[0007] PEEK polymer is of interest in culinary articles because it has a high melting point (343°C) and excellent thermal stability under usage conditions at 260°C.

[0008] The following coating techniques can be used to obtain an undercoat from this type of polymer: spray coating, roller coating, curtain coating, pad printing, screen printing, thermal spraying, electrostatic spraying, inkjet printing.

[0009] Application WO 2000 / 54895 specifies the use of an undercoat composed solely of PEEK (with particle sizes ranging from 5 µm to 100 µm, and preferably with a d50 of 20 µm) deposited on a metallic substrate, covering between 60% and 95% of the article's surface, and then coated with a single- or multi-layer non-stick coating based on fluorinated resins and fluorinated copolymers. The PEEK undercoat is applied either by pad printing or screen printing, or by spraying as a dispersion.

[0010] The thickness of this PEEK layer is between 5 µm and 100 µm.

[0011] The drawback of the process as described is that it requires a double firing of the PEEK-based fluorinated coating. The first firing requires a temperature above the melting point of the polymer composing the underlayer (between 380 and 400°C for PEEK) to allow its adhesion to the metal substrate. The article must then be cooled significantly, which is very costly in terms of time and energy, but essential for applying the successive fluorinated layers that will be sintered during a second firing at a high temperature (> 420°C).

[0012] Application WO 2010 / 130954 describes a hard undercoat forming a continuous network, deposited discontinuously on the inner surface of the cookware. The material composing this undercoat is a ceramic (alumina-titanium mixture) or a metal or polymer (PAI, PEI, PI, PES, PPS, PEK, or PEEK). The surface area of ​​the cookware covered by this material is between 30% and 80%, and the spacing between the deposited droplets is between 2 µm and 50 µm. The surface of this hard undercoat has a roughness (Ra) of 2 µm to 12 µm, preferably 4 µm to 8 µm.

[0013] This material is projected by a flame spray process in powder form with a particle size preferably between 20 µm and 45 µm.

[0014] It is necessary to preheat the metallic substrate strongly before proceeding with the deposition of powders by flame spray above 180°C.

[0015] The fluorinated layers are then deposited by spray coating once the coating has cooled to room temperature. A single sintering at 430°C is then performed.

[0016] In patent FR 2 871 038, it is mentioned the use of a PEEK underlayer, with a PAI resin and fluorinated resins deposited on a metallic substrate then covered with a non-stick coating in one or more layers and without the presence of PEEK in these upper layers.

[0017] The underlayer is composed of a mixture of PAI, PEEK and PTFE such that the PTFE is between 9 and 15% w and the PAI resin is between 4 and 5% w.

[0018] In all cases the PEEK dry matter content in the final fluorinated film is in the range of 0.12% to 1.1% w, preferably 0.12% to 0.9% w.

[0019] PEEK powder has a D50 particle size of 5 to 35 µm.

[0020] In all cases, the first coating layer contains fluorinated resins.

[0021] This liquid coating is applied by spraying. Top layers of fluorinated coatings, also containing one or more adhesion primers, are then applied by spraying. All these layers are sintered in a single firing at 400 to 420°C.

[0022] The disadvantage of this application method is that the PEEK resin content in the first layer is very low and does not allow for sufficient mechanical performance to achieve a scratch-resistant coating.

[0023] In application WO 00 / 054896, it is mentioned that a PEEK undercoat without fluorinated resin is used, consisting of at least 50% by weight of PEEK powder, so that the PEEK-covered surface is between 60% and 95% of the surface of the article.

[0024] This primer, which contains at least 50% PEEK, may also contain a mixture with other pure or mixed thermostable resins such as polyphenylene sulfide (PPS), polyetherimide (PEI), polyimide (PI), polyetherketone (PEK), polyethersulfone (PES), polyamideimide (PAI).

[0025] It may also contain fillers selected from among metallic oxides: silica, mica, or lamellar fillers. It does not contain any fluorinated resin.

[0026] The first firing is carried out at a high temperature of at least 260°C, preferably greater than or equal to 340°C to melt the PEEK.

[0027] PEEK is in powder form with a particle size between 4 µm and 80 µm, with a d50 preferably of 20 µm. The thickness of this underlayer is between 5 µm and 100 µm.

[0028] This liquid coating is applied by spraying. Top layers of fluorinated coatings, or even primers with fluorinated topcoats, are then applied by spraying. All these layers are sintered in a second firing to sinter the fluorinated coating, at a temperature between 400°C and 420°C.

[0029] US patent 6,596,380 B1 describes a scratch-resistant fluorinated coating whose first layer contains at least 50% by weight of PEEK (preferably between 60% and 95%), mixed with a thermostable polymer resin such as PPS, PEI, PI, PAI and mixtures thereof, and fillers such as metal oxides, silica, micas, and in the absence of any fluorinated resin. This first layer has a thickness of between 5 and 100 µm.

[0030] PEEK is a powder with a particle size of 4 µm to 80 µm with a d50 of the order of 20 µm.

[0031] However, the process of obtaining such a coating necessarily involves a double-cooking / sintering between 400 and 420°C.

[0032] Pure silicone resins are described as non-stick and resistant to temperatures above 220-230°C. However, they are considered to have poor adhesion to the substrate.

[0033] Conversely, silicone-polyester resins are widely used in mold making because they are non-stick while still adhering to the substrate and are compatible with stamping processes. However, they degrade at temperatures above 230°C. Indeed, the operating temperature range for cookware is between 50 and 250°C, and it is not surprising to reach temperatures of 300°C or even 350°C in the case of items with induction bases. Their use is therefore incompatible with the operating temperatures required for cookware.

[0034] The present invention addresses the technical problem of improving the scratch and chip resistance of silicone coatings by creating an underlayer in contact with the metallic substrate based on blends of thermoplastic polymers with high thermo-mechanical properties. US 2022 / 073785 A1 describes, for example, a coated cooking element for a cookware item or electric cooking appliance, comprising a metallic substrate coated on at least one face with at least the following layers, in that order, starting from the metallic substrate: bonding undercoat comprising between 20% and 100% by weight of the total weight of the undercoat of one or more polymer(s) (α) selected from the group consisting of polyaryletherketones (PAEK) and one or more polymer(s) selected from the group consisting of polyetherimides (PEI), polyimides (PI), polyamide imides (PAI) and polybenzymidazole (PBI), a topcoat consisting of one or more silicone resin(s). DEFINITIONS

[0035] The term "layer," as used in the present invention, refers to a continuous or discontinuous layer. A continuous layer (also called a monolithic layer) is a single unit forming a flat surface that completely covers the area on which it is laid. A discontinuous layer (or non-monolithic layer) may comprise several parts and is therefore not a single unit.

[0036] The term "base coat", "primer coat", "bonding coat" or "bonding primer" refers to all the layers from the first coat applied directly to the substrate (it is preferable that this coat adheres well to the substrate and provides all its mechanical properties to the coating: hardness, scratch resistance) to the last coat before the first decorative coat.

[0037] The term "finish coat" refers to a continuous, transparent surface layer that allows perfect visibility of the decorative layer while protecting it from mechanical damage and giving the coating its non-stick properties. Preferably, the final finish coat is intended to come into contact with food.

[0038] The term "decoration" or "decorative layer" refers to one or more continuous or discontinuous layers comprising a pigment composition. The decoration may take the form of one or more patterns, or one or more colors. A decoration is clearly visible to the user with the naked eye and from a typical viewing distance.

[0039] The term "overlapping layers" refers to layers that are partially or completely superimposed. These layers may appear in partially overlapping patterns, such as concentric disks.

[0040] The term "adjacent layers" refers to non-overlapping layers. These layers may be in the form of identical or different non-overlapping patterns, preferably distributed uniformly.

[0041] A "temperature reference pigment composition" is defined as a composition containing a pigment that, at a given temperature, indicates to the user that the optimal operating temperature has been reached. This indication is made by comparing the colors of the thermochromic pigment composition with those of the temperature reference pigment composition. The optimal operating temperature is reached either when the colors are identical or when the colors are visually very different.

[0042] The "temperature reference pigment composition" may include a pigment that exhibits: the same color as the thermochromic pigment composition, at the optimal operating temperature, * either because this pigment has the same color at room temperature as the thermochromic pigment composition at the optimal operating temperature, and does not change color with temperature, * or because this pigment has a different color at room temperature than the thermochromic pigment composition which evolves to the same color as the thermochromic pigment composition at the optimal operating temperature, a color very different from that of the thermochromic pigment composition at the optimal operating temperature, whether this pigment changes color or not with temperature evolution.

[0043] The optimal operating 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 including the coating of the invention or to a color indicated on a color scale provided to the user with said article.

[0044] The reference temperature pigment composition is thermochromic or thermostable.

[0045] The reference pigment composition for temperature can be, for example, a reference pigment composition for cooking temperature or an indication of risk of overheating.

[0046] The present invention offers at least one of the following advantages: The coating according to the invention exhibits thermochromic functionality with marked visibility, a contrasting color change over a targeted and centered temperature range, for example around the cooking temperatures of food in a cooking appliance; the coating according to the invention can provide good temperature control during food cooking, which is necessary for health and taste reasons, but also for safety and to limit localized overheating that weakens the coating; the thermochromic pigment composition exhibits reversibility of its thermochromic properties, that is to say, after a color change under the action of heat, the compound returns to its initial state and its initial color when the temperature decreases; this color change cycle (reversibility) can be repeated indefinitely;The coating according to the invention exhibits significant thermal stability during temperature increases; it is stable up to approximately 450°C.

[0047] The term "thermochromic semiconductor," as used in the present invention, refers to a mineral or organic compound that undergoes a reversible color change upon temperature increase. The gradual and reversible thermochromic nature of these semiconductor compounds is due to the narrowing of the semiconductor's band gap caused by material expansion. The periodicity of the anion and cation network leads to the clustering of energy levels into energy bands. The band containing the highest energy is called the valence band, and the band containing the lowest energy is called the conduction band. Between these two bands lies a band 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).

[0048] In the fields of application envisaged for the present invention, the optimal conditions are achieved when the coating reaches a temperature suitable for cooking food, preferably between 100 and 250°C.

[0049] For the purposes of this invention, "thermochromic pigment or pigment composition" means 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 user with the naked eye at normal viewing distances.

[0050] A "thermostable pigment" is defined as a pigment that does not change color when subjected to a temperature rise within a given temperature range, or that changes color when subjected to a temperature rise within a given temperature range so small that it is not visible to the user with the naked eye and at a normal operating distance.

[0051] Preferably, thermostable pigments have a color difference ΔE* between 25°C and 200°C of less than 10, ΔE* being defined by the CIE1976 formula in the CIELAB color space: Δ E * = L 2 * − L 1 * 2 + a 2 * − a 1 * 2 + b 2 * − b 1 * 2 L 1 *, a 1 * and b 1 * characterizing the L*a*b values ​​of said compound at room temperature L 2 *, a 2 * and b 2 * characterizing the L*a*b values ​​of said compound at 200°C.

[0052] By "the colours are identical" we mean indistinguishable by the user to the naked eye and at a normal viewing distance.

[0053] The term "culinary article" should be understood, for the purposes of this invention, as an object intended for cooking. To this end, it is designed to receive heat treatment.

[0054] The expression "object intended to receive heat treatment" should be understood in the context of the present invention as an object which will be heated by an external heating system such as pans, pots, sauté pans, woks, barbecue grills and which is capable of transmitting the heat energy supplied by this external heating system to a material or food in contact with said object.

[0055] The term "electric cooking appliance" should be understood in the context of the present invention as a heating object having its own heating system such as an electric crepe maker, electric raclette appliance, electric fondue appliance, electric grill, electric griddle, electric cooker, bread machine, electric pressure cooking appliance.

[0056] The term “silicone resin-based coating” means a coating which includes one or more silicone resins in one or more of its layers.

[0057] The term "coating" refers to all the layers adhering to and covering the metallic substrate. The coating obtained according to the invention is advantageously solid; "solid" is understood to mean the characteristic of a cohesive material insoluble in water, in common solvents, and in food components such as aqueous or fatty mixtures, even if the material may exhibit high hardness or high flexibility, such as an elastomer.

[0058] In the present invention, % by weight are expressed in dry weight, i.e. without solvent. SUMMARY OF THE INVENTION

[0059] A first object of the invention relates to a coated cooking element according to claim 1.

[0060] Another object of the invention relates to a method for manufacturing a coated cooking element according to claim 11.

[0061] Another object of the invention relates to a culinary article according to claim 13.

[0062] Another object of the invention relates to an electric cooking appliance according to claim 15. FIGURES

[0063] [ Fig.1 ] : diagram of a cooking element according to the invention with layer (3b) is continuous and covers the entirety of layer (3a) [ Fig. 2 ] : diagram of a cooking element according to the invention with layer (3b) not covering the entirety of layer (3a) and forming a decoration [ Fig.3 ] : diagram of a cooking element according to the invention with layer (3b) consisting of two decorations (i) and (j) [ Fig. 4 ] : Pattern distribution diagram. 4A = adjacent non-overlapping patterns. 4B = partially overlapping patterns. 4C = overlapping patterns. Fig. 5 ] : diagram of a culinary item according to the invention [ Fig. 6 [ ] : diagram of an electric cooking appliance according to the invention DETAILED DESCRIPTION

[0064] A first object of the invention relates to a coated cooking element (1) for a cooking article or electric cooking appliance, comprising a metallic substrate (2) coated on at least one face (2a) by at least the following layers and in this order from the metallic substrate (2): (3a) a bonding underlayer comprising between 20% and 100% by weight of the total weight of the underlayer of one or more polymers (α) selected from the group consisting of polyaryletherketones (PAEK) and one or more polymers selected from the group consisting of polyetherimides (PEI), polyimides (PI), polyamide imides (PAI) and polybenzymidazole (PBI), with a PAEK:(PEI+PI+PAI+PBI) weight ratio of between 1:1 and 15:1, (3b) optionally, one or more intermediate layer(s), preferably two, consisting of one or more colorant(s) and optionally one or more silicone resin(s), and / or one or more thermoplastic polymer(s) and / or one or more filler(s),and / or one or more additive(s) (3c) a topcoat consisting of one or more silicone resin(s) in a proportion greater than or equal to 20% by weight relative to the total weight of the layer (3c) and possibly one or more thermoplastic polymer(s), and / or one or more filler(s), and / or one or more additive(s), and / or glitter.

[0065] Advantageously, layers (3a), optionally (3b) and (3c) form a coating (3) which covers the metallic substrate (2). This coating (3) has non-stick properties and forms a non-stick coating.

[0066] Advantageously, the layer (3a) is in contact with the metallic substrate (2) by one of its faces by its face (2a).

[0067] Therefore, at least one coated face (2a) of the metallic substrate is a cooking face.

[0068] In other words, the coating of the cooking element (1) is intended to come into contact with food.

[0069] The coating of the cooking element (1) does not contain a fluorinated polymer, also called a fluoropolymer. In other words, the coating is either not fluorinated or free of fluorinated polymer.

[0070] The coating of the cooking element (1) is intended to come into contact with food.

[0071] Advantageously, the finishing layer (3c) is in contact with food on one of its faces and thus forms a cooking surface (5).

[0072] Advantageously, the thickness of the layer (3b) is between 1 µm and 100 µm, preferably between 2 µm and 30 µm, particularly preferably between 3 µm and 10 µm.

[0073] Advantageously, the thickness of the layer (3c) is between 0.05 µm and 100 µm, preferably between 0.08 µm and 20 µm, particularly preferably between 0.1 µm and 10 µm.

[0074] According to one embodiment, the thickness of the (3c) layer is between 0.1 µm and 2 microns, preferably between 0.2 µm and 1.5 µm. In a particular embodiment, the thickness of the (3c) layer is 100 nm + / - 5 nm.

[0075] According to another embodiment, the thickness of the layer (3c) is between 10 µm and 100 µm, preferably between 20 µm and 85 µm, particularly preferably between 30 µm and 70 µm.

[0076] The coating of the cooking element (1) may comprise one or more optional layers (3ab) inserted between layer(s) (3a) and layer(s) (3b) or between layer(s) (3a) and layer(s) (3c) consisting of one or more silicone resins and possibly of one or more thermoplastic polymer(s), and / or one or more filler(s), and / or one or more additive(s),

[0077] Advantageously, the thickness of the layer(s) (3ab) is between 0.05 µm and 100 µm, preferably between 0.08 µm and 20 µm, particularly preferably between 0.1 µm and 10 µm.

[0078] Advantageously, the tack coat (3a) comprises one or more polymers (B) selected from the group consisting of polyphenylene sulfides (PPS) and polyethersulfones (PES), preferably in an amount of at least 20%, preferably at least 25%, by weight of the total weight of the tack coat, of one or more polymers selected from the group consisting of polyphenylene sulfides (PPS) and polyethersulfones (PES). Advantageously, the tack coat (3a) comprises less than 40%, preferably less than 30%, by weight of the total weight of the tack coat, of fillers, preferably between 5% and 25% by weight.

[0079] Advantageously, the bonding undercoat (3a) comprises one or more acrylic resin(s). The acrylic resin(s) is / are advantageously chosen from the group consisting of: polymers resulting from an emulsion polymerization of different monomers with other acrylic-based monomers.

[0080] Advantageously, the bonding undercoat (3a) includes one or more coloring agent(s).

[0081] Advantageously, the colorant(s) of the primer (3a) represent less than 30%, preferably less than 20%, by weight of the total weight of the primer.

[0082] Advantageously, the polyaryletherketone(s) (PAEK) is / are chosen from the group consisting of: polyetherketones (PEK), polyetheretherketone (PEEK), polyetherketoneketones (PEKK), polyetheretherketoneketones (PEEKK) and polyetherketoneetherketoneketones (PEKEKK).

[0083] Advantageously, the polymer(s) (α) is / are chosen from the group consisting of polyetheretherketones (PEEK) and polyamide imides (PAI).

[0084] Advantageously, when the (α) polymers represent 20 to 40% of the underlayer, the PAEK:(PEI+PI+PAI+PBI) weight ratio is between 6:1 and 12:1.

[0085] Advantageously, when the (α) polymers represent 40 to 80% of the underlayer, the PAEK:(PEI+PI+PAI+PBI) weight ratio is between 12:1 and 15:1.

[0086] Advantageously, the (α) polymers represent 25 to 40% by weight of the total weight of the underlayer, preferably 25 to 35%.

[0087] The weight ratio between polymers (α) and polymers (B) is advantageously between 2:5 and 2:3, preferably between 1:2 and 1:3.

[0088] 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.

[0089] Advantageously, the polymer(s) (α) is / are selected from the group consisting of polyaryletherketones (PAEK) and polyamide imides (PAI) and mixtures thereof. Particularly preferred, portion (α) is / are a mixture of PAEK and PAI polymers. Advantageously, the polymer(s) (α) is / are selected from the group consisting of polyetheretherketones (PEEK) and polyamide imides (PAI) and mixtures thereof. Particularly preferred, portion (α) is / are a mixture of PEEK and PAI polymers.

[0090] Advantageously, the polymer(s) (B) is / are a / the polyethersulfone(s) (PES).

[0091] In a preferred embodiment, parts (α) and (β) are a mixture consisting of PEEK, PAI and PES polymers.

[0092] Advantageously, the tack coat (3a) may further comprise one or more solvents, preferably polar aprotic, preferably unlabeled, for example N-formylmorpholine (NFM), N-Methyl Imidazole (NMI), N-ButylPyrrolidone (NBP), dimethyl sulfoxide (DMSO), or alcoholic, for example Propylene Glycol (PPG), Diethylene glycol.

[0093] Advantageously, the bonding undercoat (3a) may comprise one or more surfactants.

[0094] Advantageously, the bonding undercoat (3a) may further include one or more anti-foaming agents.

[0095] In a preferred embodiment, the bonding undercoat (3a) is a mixture consisting of PEEK, PAI, PES and optionally fillers, acrylic resins and coloring agents.

[0096] The thickness of the bonding undercoat (3a) is advantageously between 10 and 100 µm, preferably between 20 and 80 µm, preferably between 30 and 60 µm. METALLIC SUBSTRATE

[0097] Advantageously, said metallic substrate (2), also called support, is a substrate of aluminum, stainless steel, cast iron or aluminum, iron, titanium or copper.

[0098] Aluminium is defined as a metal made up of 100% aluminium or an aluminium alloy.

[0099] Advantageously, the metallic substrate (2) is an aluminum substrate, a stainless steel substrate, or a multilayer metallic substrate. The metallic substrate (2) can be a two-layer or three-layer substrate, these multilayers being obtained, for example, by co-lamination, by hot diffusion under load (solid state bonding), or by hot or cold impact bonding.

[0100] Preferably, the metallic substrate (2) comprises an alternation of layers of metal and / or metallic alloy.

[0101] According to one embodiment, the metallic substrate (2) is an aluminum alloy substrate, a stainless steel substrate or a multilayer metallic substrate whose face (2a) is made of aluminum alloy or stainless steel.

[0102] Preferably, the metallic substrate (2) is an aluminum substrate. Advantageously, the thickness of the metallic substrate (2) is between 0.5 mm and 10 mm.

[0103] Advantageously, the face (2a) of the metallic substrate (2) has previously undergone a surface treatment to improve the adhesion of the coating to said substrate.

[0104] According to one embodiment, the surface of the face (2a) of the metallic substrate (2) has undergone a surface treatment, said surface treatment being a chemical attack, a brushing, a hydration, a sandblasting, a shot blasting, a physicochemical treatment of the plasma or corona or laser type, a chemical activation or a combination of these different techniques.

[0105] Advantageously, the surface of the substrate (2a) to which the coating (3) will be applied can be treated to increase its specific surface area; for an aluminum substrate, this treatment can be carried out by anodizing (creation of a tubular alumina structure), chemical etching, sandblasting, brushing, shot peening, or by adding material using a technology such as thermal spraying (flame, plasma, or arc spray). Other metallic substrates can also be polished, sandblasted, brushed, bead-blasted, or have material added using a technology such as thermal spraying (flame, plasma, or arc spray).

[0106] Suitable metallic substrates include, advantageously, anodized or unanodized aluminum substrates, possibly polished, brushed, sandblasted, shot-blasted or micro-bead blasted; anodized or unanodized aluminum alloy substrates, possibly polished, brushed, sandblasted or micro-bead blasted; steel substrates, possibly polished, brushed, sandblasted, shot-blasted or micro-bead blasted; stainless steel substrates, possibly polished, brushed, sandblasted or micro-bead blasted; cast steel, aluminum or iron substrates; and copper substrates, possibly hammered or polished.

[0107] Advantageously, the substrate can be chosen from substrates comprising layers of ferritic stainless steel / aluminum / austenitic stainless steel, substrates comprising layers of stainless steel / aluminum / copper / aluminum / austenitic stainless steel, cast aluminum caps, aluminum or aluminum alloy caps lined with an outer stainless steel base, metallic co-laminated substrates, for example two-layer co-laminated substrates comprising a stainless steel layer (for example intended to form the inner face of the article) and an aluminum or aluminum alloy layer, anodized or not (for example intended to form the outer face of the article).

[0108] Advantageously, the average arithmetic roughness Ra of the surface of the face (2a) of the metallic substrate (2) is greater than or equal to 1 µm.

[0109] The arithmetic mean roughness Ra is measured using a roughness tester according to 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 the Altisurf®, in which a chromatic confocal sensor allows for non-contact measurement. The study of this surface topography allows the arithmetic mean roughness Ra to be defined. SILICONE RESINS

[0110] In the description, the term "silicone resin" is used interchangeably to refer to silicone before or after crosslinking. In the description, "silicone" refers to an organopolysiloxane material. Crosslinking is the process that transforms silicone into an insoluble material, for example, through polyaddition, polycondensation, or dehydrogenation. Crosslinking is carried out using precursors, which are generally silicone oils or resins, that crosslink to form a three-dimensional network, creating a material referred to as silicone resin in the description.

[0111] This crosslinking can be achieved by thermal activation, or chemical activation using a catalyst, such as platinum.

[0112] Silicone resins can be obtained from precursors, advantageously soluble in a solvent or emulsified in water, such as oils or crosslinkable resins, in particular selected from: a silicone hydride, a silicone oil resin comprising at least one vinyl group (-CH=CH₂), a silicone or silicone-polyester resin (copolymer) comprising at least one alkoxy group, for example methoxy or ethoxy, and / or a silicone or silicone-polyester resin (copolymer) comprising at least one alkoxy group, in particular ethoxy, or a hydroxyl group and mixtures thereof. These precursors have the ability to crosslink to obtain a silicone resin characterized by its insolubility and its substantially solid form.

[0113] Advantageously, these precursors are polymeric or oligomeric, either in the form of silicone oils of varying degrees of branching, or in the form of silicone resins of varying degrees of pre-crosslinking, or copolymers of silicone resins such as silicone-polyester, silicone-alkyd, silicone-polyurethane, and silicone-epoxy resins, or in the form of mixtures of silicone oils, silicone resins, and silicone resin copolymers. The silicon atoms may be substituted by alkyl (in particular methyl) or aryl (in particular phenyl) groups, or mixtures thereof. The oils or resins preferably comprise one or more (two, three, or more) hydroxyl or alkoxy (in particular methoxy, ethoxy, or butoxy) functional groups as substituents for the silicon atoms.

[0114] Advantageously, the silicone resin(s), obtained after crosslinking of their precursors, i.e. crosslinked, is / are chosen from the group consisting of methyl silicones and / or phenyl silicones and / or methyl-phenyl-silicones, methyl silicone-polyester resin (copolymers), phenyl silicone-polyester resin (copolymers), methyl-phenyl silicones-polyester resin (copolymers), silicone-alkyd resin (copolymers), modified silicone resin and their mixtures.

[0115] Advantageously, the silicone resin(s) is / are chosen from the group consisting of methyl silicones and / or phenyl silicones and / or methyl-phenyl-silicones, methyl silicone-polyester resin (copolymers), phenyl silicone-polyester resin (copolymers), methyl-phenyl silicones-polyester resin (copolymers), silicone-alkyd resin (copolymers), modified silicone resin and their mixtures.

[0116] Silicone resins can be obtained from precursors, notably chosen from: a silicone hydride, a silicone resin comprising at least one vinyl group (-CH=CH2), a silicone-polyester resin (copolymer) comprising at least one methoxy group, and / or a silicone-polyester resin (copolymer) comprising at least one ethoxy group, and mixtures thereof.

[0117] The silicone resin of the single layer (3) forms a network which may consist of a combination of 4 simple organosiloxane units named M, D, T and Q depending on the degree of substitution by the oxygen of the silicon atom, as described in the following table, where R is an organic substituent described later. Structure Degree of oxygen substitution Symbol R 3 Si-O- 1 M 2 D 3 T 4 Q

[0118] The organopolysiloxane material or polymer is obtained by crosslinking precursors that can be monomeric or polymeric, or, as an intermediate step, oligomeric. The organopolysiloxane polymer can also be obtained from a mixture of these different types of precursors. When the network contains a higher number of T and Q units than D units, the crosslinking density is higher. The distribution of M, D, T, and Q units depends on the chemical structure of the precursors, specifically on this M, D, T, and Q distribution within the precursors.

[0119] The polymeric precursors 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 group, in particular phenyl, different natures of R being able to be present on the same macromolecule.

[0120] Organopolysiloxanes can be either linear or sparsely branched (predominantly D groups) or branched or highly branched (predominantly T and Q groups). Linear or sparsely branched organopolysiloxanes are generally liquids, with varying degrees of viscosity at room temperature, and are called silicone oils. Branched or highly branched (pre-crosslinked) organopolysiloxanes form a network at the scale of the individual macromolecule and are called silicone resins. At room temperature, the resins are essentially in solid form, or in liquid form, provided they have a sufficiently low molecular weight, either as a solution in a solvent or as an aqueous emulsion. They can be copolymerized with organic polymers or oligomers that do not contain silicon, particularly polyesters, acrylics, alkyds, polyurethanes, and epoxy resins.

[0121] When crosslinking is a hydrolysis-polycondensation: it is carried out by means of the reactive hydroxy or alkoxy functions, in particular methoxy, ethoxy or butoxy, present on the organopolysiloxane.

[0122] When crosslinking is a polyaddition (or hydrosilylation): it takes place 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.

[0123] All these reactive functional groups are present on each organopolysiloxane, with at least one present and potentially two, three, or more, as much as the molecular structure allows. Silicone oils containing at least one reactive functional group are called "reactive oils." These reactive functional groups can be located either at the ends of the macromolecular chain (termination) or distributed along the chain.

[0124] Silicone-polyester resins in particular have silicone / polyester mass ratios for example 90 / 10, 80 / 20, 70 / 30, 60 / 40, 50 / 50, 40 / 50, 30 / 70, 20 / 80, 10 / 90, advantageously between 80 / 20 and 50 / 50.

[0125] Linear PDMS silicone oils, pure or pre-emulsified in water, are primarily characterized by their molecular weight, which is directly proportional to the viscosity of the pure oil. They are then characterized by the presence or absence of reactive functional groups, such as hydroxyl groups on the silicon atoms (silanol), their number, and their location on the molecular chain. For example, reactive oils with viscosities between 50 and 20,000 mPa·s, and particularly between 300 and 5,000 mPa·s, can be used, possessing at least one reactive functional group, preferably at least two, which can be located at the ends of the chain (positions □, □).

[0126] Polymeric precursors reacting by polyaddition may include, for example, polymethylhydrosiloxane, vinylmethylsiloxane, vinyl-terminated polydimethylsiloxane (PDMS), particularly linear-terminated diphenylsiloxane-dimethylsiloxane copolymers, hydride-terminated polydimethylsiloxanes, hydride-terminated polyphenylmethylsiloxanes, cyclic vinylmethylsiloxane, vinyl-MQ resin, trimethylsilyl-terminated polymethylhydrosiloxane, trimethylhydrosiloxane-terminated dimethylsiloxane copolymer, MQ resin hydride, and the like, and combinations thereof.

[0127] Polymeric precursors reacting by hydrolysis-polycondensation, whether silicone resins or silicone oils, may include, for example, poly(methylsilsesquioxanes), poly(propylsilsesquioxanes), poly(phenylsilsesquioxanes), polydimethylsiloxane (PDMS), polydimethylsiloxane (PDMS), trimethylsilyl-terminated polydimethylsiloxane (PDMS), hydroxyl-terminated polydimethylsiloxane (PDMS), silanol-terminated polyphenylsiloxane (PDMS), silanol-terminated diphenylsiloxane-dimethylsiloxane silanol-terminated copolymer, poly(2-acetoxyethylsilsesquioxanes), organo-modified alkoxysilanes and their oligomers, and all similar macromolecules and mixtures thereof.

[0128] The organopolysiloxane material or polymer can also be obtained by crosslinking a mixture of one or more monomeric precursors and one or more polymeric precursors as described above, along with one or more oligomeric precursors, which may be linear, branched, or cyclic. These oligomeric precursors have a lower molecular weight than the polymeric precursors. Polymeric and / or oligomeric precursors with more than two reactive functional groups as described above, advantageously much more than two, can be added to the mixture as a co-binder to promote a high crosslinking density of the final organopolysiloxane polymer.

[0129] Monomeric, oligomeric and / or polymeric precursors, in particular silicone resins, copolymerized or not with an organic polymer, play the role of polymeric binder in order to obtain the solid organopolysiloxane polymer combined with the thermoplastics of each layer.

[0130] Silicone oil-type organopolysiloxane precursors can be considered additives if added in small quantities (generally between 0.1 and 5% dry weight) to the overall formula of a layer, independently of other components for the formation of the solid organopolysiloxane polymer.

[0131] Crosslinking may require a catalyst: In the case of the crosslinking of organopolysiloxanes by hydrolysis-polycondensation, the formula may include a metallic catalyst, such as platinum-based, tin-based, zinc-based, zirconium-based, and cerium-based metal complexes, in particular platinum-cyclovinylmethylsilxane complexes, tin ethylhexanoate, zinc ethylhexanoate, zirconium ethylhexanoate, cerium ethylhexanoate, and tin dibutyl laurate. In the case of the crosslinking of organopolysiloxanes by hydrosylilation, the addition of a catalyst may be necessary: ​​this could be, for example, platinum or a suitable platinum-based catalyst such as the Karstedt catalyst or the Ashbys catalyst.

[0132] A crosslinking agent, for example carrying Si-H bonds, may be present.

[0133] According to one embodiment, the proportion of silicone resin in layer (3b) is greater than or equal to 20% by weight relative to the total weight of layer (3b).

[0134] According to another embodiment, the proportion of silicone resin in layer (3b) is greater than or equal to 40% by weight relative to the total weight of layer (3b).

[0135] According to yet another embodiment, the proportion of silicone resin in layer (3b) is greater than or equal to 50% by weight relative to the total weight of layer (3b).

[0136] The proportion of silicone resin in layer (3c) is greater than or equal to 20% by weight relative to the total weight of layer (3c).

[0137] According to another embodiment, the proportion of silicone resin in layer (3c) is greater than or equal to 40% by weight relative to the total weight of layer (3c).

[0138] According to yet another embodiment, the proportion of silicone resin in layer (3c) is greater than or equal to 50% by weight relative to the total weight of layer (3c).

[0139] According to one embodiment, the proportion of silicone resin in the layer(s) (3ab) is greater than or equal to 20% by weight relative to the total weight of the layer (3ab) respectively.

[0140] According to another embodiment, the proportion of silicone resin in the layer(s) (3ab) is greater than or equal to 40% by weight relative to the total weight of the layer (3ab) respectively.

[0141] According to yet another embodiment, the proportion of silicone resin in the layer(s) (3ab) is greater than or equal to 50% by weight relative to the total weight of the layer (3ab) respectively. THERMOPLASTIC POLYMERS

[0142] Advantageously, the thermoplastic polymer(s) is / are selected from the group consisting of polyethersulfone (PES), polyphenylene ether sulfone (PPSU), polyamideimide (PAI), polyimide (PI), poly(phenylene oxide) (PPO), poly(arylene sulfide) (PAS), polyetherimide (PEI), and polybenzymidazole (PBI), liquid crystal polymers (LCP), polyphenylene sulfide (PPS), polyarylether ketone (PAEK) including polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyether ether ketone ketone (PEEKK), polyether ketone ether ketone ketone (PEKEKK) and mixtures thereof. Heterocyclic thermoplastic polymers

[0143] As suitable examples of heterocyclic thermoplastic polymers, polyetherimides (PEI), polyimides (PI), polyamideimides (PAI) and polybenzymidazole (PBI), or mixtures thereof, are cited. PAEK

[0144] 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.

[0145] Advantageously, the nature of the thermoplastic polymer(s) in layers (3b) and (3c) can be identical or different.

[0146] Advantageously, layer (3b) comprises one or more thermoplastic polymer(s), preferably in a weight proportion of said layer less than 30%, preferably 20%.

[0147] Advantageously, layer (3c) comprises one or more thermoplastic polymer(s), preferably in a weight proportion of said layer less than 50%, preferably 40%.

[0148] Advantageously, the layer(s) (3ab) comprises one or more thermoplastic polymer(s), preferably in a proportion by weight of said layer less than 50%, preferably 40%.

[0149] According to one embodiment, layer (3b) and layer (3c) comprise one or more thermoplastic polymer(s), the proportion of thermoplastic polymer(s) in layer (3c) being preferably greater than the proportion of thermoplastic polymer(s) in layer (3b).

[0150] According to another embodiment, layer (3b) and layer (3c) comprise one or more thermoplastic polymer(s), the proportion of thermoplastic polymer(s) in layer (3b) being greater than the proportion of thermoplastic polymer(s) in layer (3c). CHARGES

[0151] The fillers provide mechanical reinforcement and can also impart hydrophobic properties, while improving the mechanical strength and thermal conductivity of the coating.

[0152] The fillers do not only serve to add color to the coating, but can contribute to it.

[0153] The presence of fillers with excellent thermal conductivity makes it possible to compensate for the low thermal conductivity of PAEK polymers.

[0154] Advantageously, the filler(s) is / are chosen from the group consisting of ceramic fillers (SiO2, etc.) and / or mineral and / or metallic fillers (Al2O3, TiO2, etc.) and / or silica and / or diamond particles.

[0155] Preferably, the filler(s) is / are chosen from the group consisting of metal oxides, metal carbides, metal oxynitrides, metal nitrides, and their mixtures.

[0156] Advantageously, said metal is a transition metal, like at least one of the elements chosen from B, Ni, Ti, Zr or Hf.

[0157] Preferably, the charge(s) is / are chosen from the group consisting of: fillers for reinforcement: hard organic or inorganic fillers; the hard inorganic 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 selected 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 selected 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 selected from B, Ni, Ti, Zr or Hf, for example: cubic boron nitride, diamond particles, metallic particles; lamellar fillers capable of conferring lubricating properties, such as clays, graphene or graphite.

[0158] The preferred fillers in combination with organopolysiloxanes are: reinforcing fillers: silica or carbonates with filler levels of min 10-15% / wt and up to 60% / wt, alumina, hydrated alumina, aluminum trihydroxide, silica (precipitated or pyrogenated) with a d50 < 0.1µm and a specific surface area BET > 30 m2 / g and preferably between 30 and 500 m2 / g, or mixture of quartz and silica, diatomaceous earth or crushed quartz, titanium, mica, talc, kaolin, barium sulfate, slaked lime, zinc oxide, expanded vermiculite, non-expanded vermiculite, calcium carbonate etc.

[0159] Preferably, the filler(s) is / are chosen from the group consisting of alumina, silicon carbide, tungsten carbide, boron nitride, quartz, and mixtures thereof.

[0160] Advantageously, the fillers present in the sublayer (3a) are hard inorganic fillers, preferably oxides, carbides, metallic nitrides, preferably alumina, silicon carbides or fumed silica.

[0161] Some hard inorganic 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.

[0162] Adding this type of charge improves culinary performance with better heat distribution from the metallic substrate to the food in contact with the coating.

[0163] Advantageously, the average diameter d50 of the charges is between 0.1 and 50 µm, advantageously still between 5 and 15 µm.

[0164] Advantageously, the proportion of fillers in a layer is between 0.5 and 30% by dry weight relative to the total weight of said layer after baking, preferably between 5 and 20%.

[0165] Advantageously, the proportion of loads in layer (3a) is greater than 20% by weight, preferably greater than 30% by weight, relative to the total weight of said layer.

[0166] Advantageously, the proportion of fillers in layer (3c) is less than 10% by weight relative to the total weight of said layer.

[0167] Advantageously, the proportion of charges in the layer(s) (3ab) is less than 10% by weight relative to the total weight of said layer.

[0168] Advantageously, the proportion of charges in layers (3a), (3ab), (3b) and (3c) can be identical or different.

[0169] Advantageously, the nature of the charges in layers (3a), (3ab), (3b) and (3c) can be identical or different. ADDITIVES

[0170] Advantageously, said additives are chosen from the group consisting of antifoaming agents, dispersing agents, wetting agents, thickeners, pH adjusters, reactive silicone oils.

[0171] The said antifoaming agent(s) (is) preferably chosen from the group consisting of mineral oils, diols, hydrocarbons, glycerides, oxyrane, emulsified fatty acids.

[0172] The surfactant(s) is / are preferably chosen from the group consisting of glycol ether, ethoxylated alcohol excluding alkyl phenol ethoxylates (APEs), gemini surfactants.

[0173] The dispersing agent(s) is / are preferentially chosen from the group consisting of anionic dispersants such as fatty acid derivatives.

[0174] The said thickeners are preferably chosen from the group consisting of acrylic-based or polyurethane-based copolymer, cellulose, fumed silica.

[0175] These pH adjusters are preferentially chosen from the group consisting of Brønsted bases: ammonia, amines (triethylamine, triethanolamine...), hydroxides (sodium hydroxide, potassium hydroxide...), carbonates.

[0176] Advantageously, the proportion of additives in layer (3a) is less than 1% by weight relative to the total weight of said layer.

[0177] Advantageously, the proportion of additives in layer (3c) is less than 20% by weight relative to the total weight of said layer.

[0178] Advantageously, the proportion of additives in the layer(s) (3ab) is less than 20% by weight relative to the total weight of said layer. COLORING AGENTS

[0179] Advantageously, the coloring agent(s) is / are chosen from the group consisting of thermochromic pigments, thermostable pigments, glitter, preferably holographic glitter, and mixtures thereof.

[0180] Advantageously, the proportion of coloring agents in layer (3b) and layer (3c) is between 0.5 and 50% by dry weight relative to the total weight of said layer after baking.

[0181] Advantageously, the proportion of coloring agents in layer (3b) ranges from 10% to 40% by weight relative to the total weight of said layer.

[0182] 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.

[0183] Advantageously, the proportion of coloring agents in layers (3b) and (3c) can be the same or different.

[0184] Advantageously, the nature of the coloring agents in layers (3b) and (3c) can be identical or different. Thermochromic pigments

[0185] Preferably, the thermochromic pigment(s) is / are chosen from the group consisting of Bi₂O₃, Fe₂O₃, V₂O₅, WO₃, CeO₂, In₂O₃, Y₁₈₄, Ca₀₁₆, Ti₁₈₄, V₁₈₆, O₁₈₆, Agl, (Bi₁₋ₓAₓ)(V₁₋ₓMy)O₄ with x is equal to 0 or x is between 0.001 and 0.999, y is equal to 0 or y is between 0.001 and 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 depletion metal, a metalloid or a lanthanide, A and M are different from each other.

[0186] Given 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 low-grade metal; it can be chosen from Al, Zn, Ga, In, Sn. M is a low-grade 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. ,

[0187] Preferably, A and M, different from each other, are B and / or Mg.

[0188] Preferably, the pigment (Bi 1-x A x )(V 1-y M y )O 4 exhibits a monoclinic scheelite crystallographic form at room temperature.

[0189] Preferably, x and y are equal to 0, that is, the pigment (Bi 1-x A x )(V 1-y M y )O 4 is Bismuth Vanadate (BiVO 4 ). Advantageously, a BiVO 4 with a monoclinic scheelite crystallographic structure at room temperature is used.

[0190] Bismuth vanadate is a yellow inorganic compound with the formula BiVO₄, widely used for its coloristic properties and lack of toxicity. Registered in the Colour Index International database as QI Pigment Yellow 184, it is marketed by companies including Heubach (Vanadur®), BASF (Sicopal®), FERRO (Lysopac), and Bruchsaler Farbenfabrik (Brufasol®). Heat-stable pigments

[0191] Preferably, the heat-stable pigment(s) is / are chosen from the group consisting of: Titanium rutile-type yellow pigment, Bismuth-derived yellow pigment, e.g., selected from stabilized bismuth vanadates (Py 184) Red pigment, e.g., selected from perylene red (e.g., PR149, PR178, and PR224), iron oxide, Bismuth oxyhalide-type orange pigment (PO 85), Bismuth vanadate-type orange pigment (PO 86) Zinc tin titanium orange pigment (PO 82) Cerium sulfide orange pigment (PO 75; PO 78) Antimony titanium chromium rutile-type yellow-orange pigment (PBr 24) Tin and zinc rutile-type yellow-orange pigment (Py 216) Niobium oxide tin zinc sulfide yellow-orange pigment (Py 227) Yellow-orange pigment double oxides of tin and niobium Co 3 (PO4) 2 LiCoPO 4 CoAl 2 O 4 Cr 2 O 3 TiO 2 Black pigment PBk28 (Copper chromite black spinel) and their mixtures. Decorations

[0192] According to one embodiment, the layer(s) (3b) is / are continuous and covers the entire layer (3a) (see Figure 1 ).

[0193] According to another embodiment, layer(s) (3b) do not cover the entire layer (3a) and form at least one decoration (see Figure 2 ).

[0194] 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 (see Figure 3 ).

[0195] According to one embodiment, each of the two decorations (i) and (j) is presented in the form of adjacent, non-overlapping motifs. For example, each decoration is represented by different geometric motifs distributed evenly over the entire surface and alternating with respect to each other (see Figure 4A ).

[0196] According to another embodiment, the two decorations (i) and (j) are partially overlapping. For example, each decoration is represented by different geometric patterns distributed evenly over the entire surface and partially overlapping (see Figure 4B ).

[0197] Preferably, the two designs (i) and (j) overlap, either because one of the designs is a continuous layer and the other design covers it in the form of motifs, or because the two designs (i) and (j) are presented as overlapping motifs (see Figure 4C ). Glitter

[0198] The available glitter can be independently selected from mica glitter (coated or uncoated), silica glitter (coated or uncoated), aluminum glitter (coated or uncoated), and iron oxide glitter (coated or uncoated). Mica or silica glitter coated with titanium dioxide is also available. The glitter can be treated to create a specific color effect.

[0199] Advantageously, the glitter(s) is / are particles selected from the group consisting of mica particles, aluminum particles, mica coated with titanium dioxide, or mixtures thereof. Hologram glitter

[0200] Advantageously, the glitter(s) is / are holographic glitter, that is to say a mixture of magnetizable and non-magnetic particles.

[0201] Magnetizable particles can advantageously be particles comprising at least one ferromagnetic metal. These magnetizable particles can be homogeneous, meaning they are made of the same material, or composite, meaning they have a core-shell structure in which the ferromagnetic metal is located in the core and / or the shell of the 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 corrosion protection during the coating application process; plastic flakes coated with iron oxide (Fe2O3); or flakes with a ferromagnetic metal core and a plastic or sol-gel material shell.

[0202] According to one embodiment, a portion of said magnetizable particles is oriented so as to form a three-dimensional decoration.

[0203] Advantageously, the mixture of magnetizable and non-magnetizable particles represents between 1% and 5% by weight of the layer weight, preferably between 2% and 3% by weight.

[0204] 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.

[0205] Advantageously, magnetizable particles have a D50 dimension less than or equal to 23 µm.

[0206] The term "D50" refers to the maximum size that 50% of the particles have by number.

[0207] Advantageously, non-magnetizable particles have a D90 dimension between 20% and 250% of the D90 dimension of magnetizable particles.

[0208] The term "D90" refers to the maximum dimension that 90% of the particles have by number.

[0209] Advantageously, magnetizable and / or non-magnetizable particles are colored on the surface.

[0210] Advantageously, non-magnetizable particles are made of mica, aluminum, or mica coated with titanium dioxide.

[0211] Advantageously, magnetizable particles consist of iron, iron oxide, aluminum coated with iron, or mica coated with iron, the iron being in ferritic form. FAVORITE ARCHITECTURES

[0212] The invention relates to a coated cooking element (1) for a cooking article or electric cooking appliance, comprising a metallic substrate (2) coated on at least one face (2a) only by the following layers superimposed in this order from the metallic substrate (2): (3a) a tack coat comprising between 20% and 100% by weight of the total weight of the coat of one or more polymers (α) selected from the group consisting of polyaryletherketones (PAEK) and one or more polymers selected from the group consisting of polyetherimides (PEI), polyimides (PI), polyamide imides (PAI) and polybenzymidazole (PBI), with a PAEK:(PEI+PI+PAI+PBI) weight ratio of between 1:1 and 15:1, (3b) optionally, one or more intermediate layers consisting of one or more colorants and optionally one or more silicone resins, and / or one or more thermoplastic polymers, and / or one or more fillers, and / or one or more additives, (3c) a finishing layer consisting of one or more silicone resin(s) in a portion greater than or equal to 20% by weight relative to the total weight of the layer (3c), and possibly one or more thermoplastic polymer(s),and / or one or more fillers, and / or one or more additives, and / or glitter.

[0213] The thickness of the bonding undercoat (3a) is advantageously between 30 and 60 µm.

[0214] Preferably, the colouring agent of the intermediate layer(s) (3b) comprises pigments and / or glitter, advantageously holographic.

[0215] According to one variant, the intermediate layer(s) (3b) is / are made up of: of one or more colouring agent(s), in particular pigments and / or glitter, advantageously holographic, of one or more thermoplastic polymer(s) advantageously chosen by polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzymidazole (PBI), polyethersulfone (PES), polyphenylene ether sulfone (PPSU), polyarylether ketone (PAEK), and mixtures thereof, of 0 to 10% fillers, of 0 to 20% additives, Optionally of one or more silicone resin(s).

[0216] According to another variant, the intermediate layer(s) (3b) is / are made up of: of one or more colouring agent(s), in particular pigments and / or glitter, advantageously holographic, of 0 to 10% fillers, of 0 to 20% additives, of one or more silicone resin(s), and optionally of one or more thermoplastic polymer(s) advantageously chosen by polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzymidazole (PBI), polyethersulfone (PES), polyphenylene ether sulfone (PPSU), polyarylether ketone (PAEK), and mixtures thereof.

[0217] According to a particular variant, the intermediate layer(s) (3b) does not include silicone resin.

[0218] According to another particular variant, the intermediate layer(s) (3b) is / are made up of: of one or more colouring agent(s), in particular pigments and / or glitter, advantageously holographic, of one or more thermoplastic polymer(s) advantageously chosen by polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzymidazole (PBI), polyethersulfone (PES), polyphenylene ether sulfone (PPSU), polyarylether ketone (PAEK), and mixtures thereof, of 0 to 10% fillers, of 0 to 20% additives, of one or more silicone resin(s).

[0219] According to a particular embodiment, the coating comprises two intermediate layers (3b), at least one of which is a decorative layer. Advantageously, the layer(s) (3b) comprise several decorative layers, one (i) comprising one or more thermochromic pigment(s) and the other (j) comprising at least one temperature reference pigment composition.

[0220] Typically, the thickness of the intermediate layer(s) (3b) is between 3 µm and 10 µm.

[0221] Preferably, when present, the intermediate layer(s) (3b) only partially covers the base layer (3a).

[0222] Alternatively, according to another embodiment, the coating is without an intermediate layer (3b). In this case, layer (3c) is applied on layer (3a) or on the last layer (3ab).

[0223] According to one embodiment, the finishing layer (3c) consists of one or more silicone resin(s) and optionally one or more thermoplastic polymer(s).

[0224] According to another embodiment, the top layer (3c) consists of one or more silicone resin(s) and one or more thermoplastic polymer(s).

[0225] Typically, the thickness of the (3c) layer is between 0.1 µm and 10 µm.

[0226] In a particular embodiment, the average thickness of the bonding undercoat (3a) is between 30 and 60 µm, the thickness of the layer (3b) is between 3 µm and 10 µm, and the thickness of the layer (3c) is between 0.1 µm and 10 µm.

[0227] The average thickness of the bonding underlayer (3a) is, for example, the average of at least 10 measurements, preferably 15 measurements, of thickness in 10, respectively 15, random locations. PROCESS

[0228] The invention also relates to a method for manufacturing a coated cooking element (1) according to the invention comprising the following successive steps: i. a step of supplying a metallic support (2), comprising two opposite faces, ii. optionally, a step of treating the face (2a) of the support (2), to obtain a treated face (2a) promoting the adhesion of a bonding undercoat (3a) to the support (2) iii. deposition on the face (2a) of the support (2) of one or more continuous layers of the bonding undercoat (3a), iv. optionally drying and / or sintering at a temperature > 400°C v. optionally application of the layer(s) (3ab) and / or the intermediate layer(s) (3b); vi. application of the topcoat (3c); vii. curing at a temperature of 230°C to 420°C.

[0229] Advantageously, the steps of the process according to the invention allow the metallic substrate (2) to be coated with a coating (3) formed by layers (3a), optionally (3ab) and (3b), and (3c). Generally, these layers are wet during their application. For the purposes of this invention, a wet layer means a layer containing all or part of its solvents.

[0230] Preferably, all or part of the solvents in the wet layer are removed, either naturally or by physical treatment, for example by thermal drying, airflow drying or vacuum treatment.

[0231] Advantageously, the coating composition may further comprise at least one solvent. Advantageously, the solvent may be protic. Advantageously, the solvent may be non-toxic.

[0232] The solvent usable in the coating composition may advantageously comprise at least one alcohol, and may preferably be chosen from isopropanol, methanol, ethanol and mixtures thereof.

[0233] The coating is applied in several layers. In this case, the application of at least one layer of the coating (3) to at least one of the two opposite faces of the substrate is repeated several times. Preferably, a drying step is carried out between the application of each layer, and then the coated substrate is baked after the application of the last layer. Applying the coating (3) by the method according to the invention to the substrate (2) results in a heat-stable coating layer.

[0234] The coating formula is generally aqueous, with the polymers in the polymeric phase being in suspension form. Other non-aqueous solvents may also be suitable.

[0235] Advantageously, the manufacturing process for a coated cooking element (1) includes one or more drying stages between 80 and 150°C after the application of each layer. Drying can be carried out by convection or infrared.

[0236] The application of the coating according to the invention by the method according to the invention can advantageously be carried out on a flat substrate, on a shaped substrate, or on a locally flat area of ​​the shaped substrate. A thermostable coating layer is obtained. Generally, this coating layer is wet.

[0237] Advantageously, the manufacturing process for a coated cooking element (1) includes a shaping step of said metallic support (2) before step iii, or after step vi, or after step vii of cooking. The shaping is also called stamping.

[0238] When the shaping step precedes the application iii of the coating, the coating is preferably carried out by spraying.

[0239] When this shaping step is subsequent to the application vii. of the coating, the coating is preferably carried out by screen printing or by roller.

[0240] The process according to the invention includes a step vii. of baking the element obtained in step vi. of the process. By baking the coated substrate, we mean, for the purposes of the present invention, a heat treatment which makes it possible to densify the coating layer(s) applied to the substrate, but also to crosslink the organopolysloxane precursors (silicone resin).

[0241] In step vii, the cooking is carried out. Generally, the cooking temperature in step viii is between 230°C and 420°C.

[0242] Advantageously, the manufacturing process for a coated baking element (1) comprises a single final baking step vii of all the applied layers. This single baking step is carried out simultaneously for all the applied layers.

[0243] Advantageously, the manufacturing process for a coated cooking element (1) includes a shaping step of said support (2) before or after step iii. The shaping is also called stamping.

[0244] Preferably, the metallic support (2) in step i) is in the form of a disc, preferably a flat disc whose shaping is carried out after application of the coating.

[0245] Advantageously, the process does not include any other drying and / or cooking step than that of step (vii).

[0246] Steps (iii) and (vi) of application and (v) of application of the layer(s) (3ab) can be carried out by electrostatic powder coating, by solvent-based or aqueous spray spraying, by screen printing, by roller or by digital printing.

[0247] Step (v) of applying the intermediate layer(s) (3b) can be carried out by pad printing, screen printing, inkjet printing, flexography. ARTICLE

[0248] The invention also relates to a cooking article (100) comprising a coated cooking element (1).

[0249] According to one embodiment, the cooking article (100) has a heating face (6) intended to be brought into contact with an external heating source, the heating face (6) being opposite the cooking face (5) intended to be brought into contact with the food during cooking.

[0250] Advantageously, the culinary article (100) is chosen from the group consisting of saucepan, frying pan, fondue or raclette pan, stockpot, wok, sauté pan, crepe pan, grill, plancha, pot, casserole dish, cooker or bread machine bowl, culinary mold.

[0251] The invention also relates to an electric cooking appliance (200) comprising a coated cooking element (1) according to the invention and a heating source (210) configured to heat said coated cooking element (1).

[0252] 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 machine, electric pressure cooker, waffle makers, rice cookers and jam makers.

[0253] The culinary article may in particular be a culinary article of which one of the two opposite faces of the substrate is an interior face, possibly concave, intended to be placed 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 exterior face, possibly convex, intended to be placed towards a heat source.

[0254] Examples of non-limiting cookware include cookware such as saucepans and frying pans, woks and sauté pans, stockpots and casseroles, crepe makers, baking molds and trays, barbecue plates and grills, and preparation bowls. EXAMPLES

[0255] The aims, aspects and advantages of the present invention will be better understood from the description given below of a particular embodiment presented by way of non-limiting example.

[0256] Of course, the invention is by no means limited to the embodiment described and illustrated, which has been given only by way of example. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention, as defined in the claims. 1) Examples of implementation: Raw materials for layer (3a):

[0257] Heterocyclic polymer resins: ∘ PolyAmide-Imide (PAI) resin with 29% dry extract in N-butylpyrrolidone (NBP), ∘ Resin in powder form: PolyAmic Acid with 90% dry extract in N-methylpyrrolidone (NMP / Water), SOLVAY reference, TORLON grade AI10LS, ∘ Resin in solvent: Polybenzimidazole (PBI) with 9% in dimethylacetamide (DMAc). Other aromatic polymer resins: ∘ PolyEtherEtherKetone (PEEK) powder resin, Vicote 704 from VICTREX, polymer powder with a d50 of 10 µm, ∘ PEKK powder resin, KEPSTAN 7002 PT from Arkema with a d50 of 20 µm, ∘ PEKK powder resin, KEPSTAN 6002 PT from Arkema with a d50 of 50 µm, ∘ PolyEtherSulfone (PES) powder resin, micronized grade from SOLVAY, polymer powder with a d50 of 40 µm. Fluorinated polymer resins (to be pre-dispersed at 20% in PPG with UltraTurrax, 20,000 rpm): ∘ 3M / DYNEON PTFE powder: TF 9207 Z, ∘ 3M / DYNEON FEP powder: 6233PZ.Unlabeled polar aprotic solvents (i.e., non-toxic): N-Formylmorpholine (NFM), N-Methyl Imidazole (NMI), N-Butylpyrrolidone (NBP). Alcohol solvent: Propylene Glycol (PPG), Diethylene Glycol (butyl diglycol). Surfactant and antifoaming agent: Tego Foamex K7 from Evonik, Genapol X089 from Clariant. Reinforcing fillers: Alumina, grade CAHP-F240 (particle size in d50: 50 µm), Silicon Carbide, grades SIKA 400, SIKA 320, Fumed Silica, MICA MILL200 / 325. Pigment: ∘ Black 100, ∘ Blue CM13, ∘ Perylene Brick Red (wear indicator), ∘ Titanium, ∘ Talc, ∘ Graphite. Acrylic resin: ∘ Modarez PW336: 30% aqueous acrylic polymer solution, ∘ Rohagit SD 15: 30% aqueous acrylic polymer solution. Raw materials for the intermediate layers (3b and 3b') and the topcoat (3c):

[0258] Silicone resins: ∘ RS1: Ethoxy functionalized silicone polyester resin (80% silicone / 20% polyester) in solvent phase, Viscosity at 25°C Approx. 2000 mPas, Solids content = 75% ∘ RS2: Ethoxy functionalized silicone polyester resin (50% silicone / 50% polyester) in solvent phase, Viscosity at 25°C Approx. 2000 mPas, Solids content = 75% ∘ RS3: Ethoxy functionalized silicone polyester resin (30% silicone / 70% polyester) in solvent phase, Viscosity at 25°C Approx. 2000 mPas, Solids content = 75% ∘ RS4: Methyl phenyl functionalized silicone polyester resin in solvent phase, Viscosity at 25°C Approx. 2000 mPas, Solids content = 75% ∘ RS5: Methoxy functionalized silicone polyester resin (50% silicone / 50% polyester) in solvent phase, Viscosity at 25 °C Approx. 2000 mPas, Solids content = 75% ∘ RS6: Ethoxy functionalized methyl organopolysiloxane resin in aqueous emulsion, Viscosity at 25 °C Approx. 1500 mPas,Solids content = 52% Heterocyclic polymer resins: o Polyamide-Imide (PAI) resin with 29% dry extract in N-butylpyrrolidone (NBP), Torlon from SOLVAY Other aromatic polymer resins: ∘ PolyEtherEtherKetone (PEEK) powder resin, Vicote 703 from VICTREX, polymer powder with a d50 of 25 µm, ∘ PolyEtherEtherKetone (PEEK) powder resin, Vicote 704 from VICTREX, polymer powder with a d50 of 10 µm, ∘ PEKK powder resin, KEPSTAN 7002 PT from Arkema with a d50 of 20 µm, ∘ PEKK powder resin, KEPSTAN 6002 PT from Arkema with a d50 of 50 µm, ∘ Polyethersulfone (PES) powder resin, micronized grade from SOLVAY, polymer powder with a d50 of 40 µm. Solvent: Alcohol, dipropylene glycol butyl ether (DPNB), 2-methoxy-1-methylethyl acetate (MPA), butyl glycol acetate (BGA), butyl acetate.Surfactant and antifoaming agent: Mineral oil: Tego foamex K7 from Evonik; Fatty alcohol polyglycol ether: Genapol X080 from Clariant or Tergitole TMN-100X; Reinforcing fillers: Fumed silica: Levasil CC301; Post-treated dimethyl dichlorosilane silica fume: Aerosil R972; Pigments: Mica: IRIODIN 100 or IRIODIN 300 and / or Magnapearl 5000; Cr / Fe oxide: Sicopal black K0098FK; Carbon black: Derussol F25 or Cabot Monarch 4750; Perlene red: Paliogen red (PR178); Iron trioxide: H856 brick; Acrylic resin: • Rohagit SD 15: 30% aqueous acrylic polymer solution; Silicone oil: • Polyether-modified polysiloxane: TEGO GLIDE 100; • Polydimethylsiloxane oil: CT 601M; Other additives: • AMP 90: 2-amino-2-methyl-1-propanol solution: 90% aqueous polymer, buffering agent; • Metolat 368: fatty acid ester; • Dolfynox 1030: propoxylated polyglycol ether, wetting agent∘ Edaplan LA 451: anionic ester in ethanol / water, wetting agent, ∘ Tego Glide 407: methylphenyl polysiloxane, flow agent. Operating principle of the jar grinder (mechanical grinding)

[0259] Ball milling involves loading a jar with the sample to be ground and grinding balls, then rotating the jar around its axis at a specific speed. This rotation is typically achieved using a roller mill. The sample can be ground in dry form or dispersed in a suitable solvent (e.g., water or alcohol). The dispersion may also contain additives (such as a dispersant or an antifoaming agent).

[0260] The average diameter of the grinding media should be adapted to the size of the particles to be ground. The finer the particles, the smaller the diameter of the media should be. The total volume of media, including the voids between the media, should represent approximately 50-60% of the internal volume of the jar. The media of different sizes is advantageously distributed according to the following weight proportions relative to the total weight of the media: 25% small media, 50% medium media, and 25% large media. The smallest media range in size from 2 to 10 mm. Alumina and stabilized zirconia are commonly used as media materials. Examples of how to create a culinary article:

[0261] On a shaped aluminium disc (30 cm in diameter), previously degreased and sandblasted to obtain a roughness of 4 to 7 µm (Ra), a continuous layer 3a chosen from the base layer compositions (3a1 to 3a4) as described below is sprayed: Layers 3a: Layer 3a1:

[0262] Preparation of an aqueous SF1 semi-finished composition based on a heterocyclic polymer with an amine and unlabeled polar aprotic solvent.

[0263] An aqueous composition of semi-finished product SF1 is prepared, comprising the following compounds, their respective quantities being indicated below: PAI resin with 29% dry extract in NBP 327,9 g NBP 117,7 g Triethylamine 32,8 g Demineralized water 521,6 g TOTAL 1000,0 g

[0264] The implementation of the PAI involves a step of transitioning to the aqueous phase via the production of a polyamide-amic acid salt. This step is carried out in a Discontimill® brand ball mill, at room temperature in the presence of amine.

[0265] The properties of the aqueous composition SF1 thus obtained are as follows: Theoretical dry extract: 9.5% Measured dry extract in the composition: 9.3%

[0266] Preparation of a semi-finished composition SF2 carried out in a ball mill for 20 minutes to obtain the ground paste below, referenced SF2. Propylene glycol 23,6 g NFM 23,6 g Genapol X089 4,7 g Tego foamex K7 1,9 g Black Pigment 100 14,9 g PEEK Vicote 704 14,2 g PES 17,1 g TOTAL 100 g Composition of underlayer 3a1

[0267] The final step is carried out in a Rayneri-type disperser to obtain the bonding undercoat shown below: SF1 10,8 g SF2 55,4 g water 19,3 g SIKA400 fillers 12,4 g Rohagit SD 15 Acrylic Resin 2,1 g TOTAL 100 g

[0268] The properties of the resulting 3a1 sublayer are as follows: The final mass ratio of the polymer resin mixture is as follows: PEEK / PAI / PES / Filler / Acrylic resin / Pigment: 19 / 3 / 23 / 30 / 5 / 20 Theoretical solids extract: 41.1% Viscosity measured in AFNOR CA6 cup: 45 sec

[0269] The thickness of layer 3a1 is between 50 µm and 100 µm, preferably 40 µm to 60 µm. Layer 3a2 :

[0270] Preparation of a semi-finished composition SF3 carried out in a ball mill for 20 minutes to obtain the ground paste below, referenced SF3. Propylene glycol 21,4 g NFM 21,4 g Genapol X089 8,0 g Tego foamex K7 1,5 g Black Pigment 100 15,9 g PEEK Vicote 704 12,9 g PES 18,9 g TOTAL 100 g Composition of underlayer 3a2

[0271] The final step is carried out in a Rayneri-type disperser to obtain the bonding undercoat shown below: SF1 11,7 g SF3 56,3 g water 17,1 g SIKA400 fillers 12,8 g Rohagit SD 15 Acrylic Resin 2,1 g TOTAL 100 g

[0272] The properties of the resulting 3a2 sublayer are as follows: The final mass ratio of the polymer resin blend is as follows: PEEK / PAI / PES / Filler / Acrylic Resin / Pigment: 17 / 3 / 25 / 30 / 5 / 20. Theoretical solids content: 42.4%. Viscosity measured in AFNOR CA6 cup: 55 sec.

[0273] The thickness of this SCD4 layer in example 4 is between 50 µm and 100 µm, preferably 40 µm to 60 µm. Layer 3a3 :

[0274] Preparation of a semi-finished composition SF4 carried out in a ball mill for 20 minutes to obtain the ground paste below, referenced SF4. Propylene glycol 20,1 g NFM 20,1 g Genapol X089 6,7 g Tego foamex K7 2,0 g PEEK Vicote 704 40,3 g PES 10,8 g TOTAL 100 g Composition of the 3a3 underlayer

[0275] The final step is carried out in a Rayneri-type disperser to obtain the hard undercoat shown below: SF1 18,5 g SF4 72,1 g Water 9,4 g TOTAL 100 g

[0276] The properties of the resulting 3a3 sublayer are as follows: The final mass ratio of the polymer resin blend is as follows: PEEK / PAI / PES: 75 / 5 / 20. Theoretical dry extract: 38.5%. Viscosity measured in AFNOR CA6 cup: 1 min 40 sec

[0277] The thickness of this SCD6 layer in example 6 is between 50 µm and 100 µm, preferably 40 µm to 60 µm. Layer 3a4:

[0278] Preparation of a semi-finished SF5 composition carried out in a ball mill for 20 minutes to obtain the ground paste below, referenced SF5. Propylene glycol 24,2 g NFM 24,2 g Genapol X089 8,1 g Tego foamex K7 1,7 g PEEK Vicote 704 28,3 g Black Pigment 100 13,5 g TOTAL 100 g

[0279] The composition of the 3a4 undercoat is carried out in a Rayneri-type disperser to obtain the hard undercoat shown below: SF1 11,2 g SF5 61,1 g WATER 13,3 g SIKA400 fillers 12,3 g Rohagit SD 15 Acrylic Resin 2,1 g TOTAL 100 g

[0280] The properties of the resulting 3a4 sublayer are as follows: The final mass ratio of the polymer resin mixture is as follows: PEEK / PAI / Filler / Acrylic Resin / Pigment: 42 / 3 / 30 / 5 / 20. Theoretical solids content: 41.0%. Viscosity measured in AFNOR CA6 cup: 55 sec.

[0281] The thickness of this SCD9 layer of counterexample 3 is between 50 µm and 100 µm, preferably 40 µm to 60 µm. Intermediate layer (3b)

[0282] Then, a continuous layer (3b) chosen from the layer compositions described below is sprayed onto one of the layers (3a): layer 3b1, layer 3b2 and layer 3b3: Component of layer 3b1 rôle % in cash % in solid phase, after cooking Silicone resin: RS1 or RS2 or RS3 or RS4 or RS5 or RS6 binder 30 59,6 dipropylene glycol butyl ether solvent 3 0 Fatty acid ester 3 0,5 Cr / Fe oxide pigment 10 33,1 Deionized water solvent 41,40 0 fatty alcohol polyglycol ether 4,60 0,6 Mineral oil Anti-foaming agent 2 0,7 silica 5 5 2-amino-2-methyl-1-propanol 0,5 0 Acrylic polymer thickening 0,5 0,5 TOTAL 100 100 Component of layer 3b2 rôle % in cash % in solid phase, after cooking Silicone resin: RS1 or RS2 or RS3 or RS4 or RS5 or RS6 binder 30 44,8 Thermoplastic polymers: PES or PAI or PEEK binder 10 24,9 dipropylene glycol butyl ether solvent 3 0 Fatty acid ester 3 0,4 Cr / Fe oxide pigment 10 24,9 Deionized water solvent 31,40 0 fatty alcohol polyglycol ether 4,60 0,5 Mineral oil Anti-foaming agent 2 0,5 silica 5 3,7 2-amino-2-methyl-1-propanol 0,5 1,14 Acrylic polymer thickening 0,5 0,4 TOTAL 100 100 Component of layer 3b3 rôle % in cash % in solid phase, after cooking RS2 silicone resin binder 62 78,81 2-Methoxy-1-Methylethyl acetate solvent 8 0 Cr / Fe oxide Pigment 10 21,19 Butyl Glycol acetate solvent 1 0 Butylacetate solvent 19 0 TOTAL 100 100

[0283] The aqueous composition of layer 3b is prepared according to the principle of ball milling. Ball milling is carried out in a jar as described above. The sample can be ground in dry form or dispersed in a suitable solvent (e.g., water, alcohol, or a solvent). The dispersion may also contain certain additives (such as a dispersant or an antifoaming agent).

[0284] The thickness of this layer 3b is between 10 µm and 20 µm, preferably 12 µm to 15 µm. Intermediate layer (3b') and finishing layer (3c)

[0285] The substrate, onto which layers 3a and 3b are applied continuously as described above, is coated with a multi-layer anti-stick coating consisting of an intermediate layer 3b' (6-8 µm) which is dried for 4 minutes at 100°C and a top layer 3c (14-18 µm). The entire assembly is then heated to 250°C for 1 hour, meaning the process involves only one curing step after the deposition of the different layers.

[0286] The compositions of the intermediate layers 3b' are deposited by spraying and are as described below: layer 3b'1 and layer 3b'2: Component of the intermediate layer 3b'1 rôle % in cash % in solid phase, after cooking Silicone resin: RS1 or RS2 or RS3 or RS4 or RS5 or RS6 binder 30 73,5 dipropylene glycol butyl ether solvent 3 0 Fatty acid ester Wetting agent 3 0,6 mica glitter 3 12,3 Cr / Fe oxide pigment 1 4,1 Deionized water solvent 46,40 0 fatty alcohol polyglycol ether Emulsifying agent 4,60 0,8 Mineral oil Anti-foaming agent 2 0,8 silica 5 6,1 2-amino-2-methyl-1-propanol 0,5 0 Acrylic polymer thickening 1,5 1,8 TOTAL 100 100 Component of the intermediate layer 3b'2 rôle % in cash % in solid phase, after cooking Silicone resin: RS1 or RS2 or RS3 or RS4 or RS5 or RS6 binder 30 80 dipropylene glycol butyl ether solvent 5 0 Propoxylated poly glycol ether Wetting agent 1 0,1 Perlene red pigment 3 13,3 Carbon black pigment 2 2,9 Deionized water solvent 52 0 fatty alcohol poly glycol ether Emulsifying agent 2 0,4 Mineral oil Anti-foaming agent 3 1,3 2-amino-2-methyl-1-propanol Buffer agent 0,5 0 Acrylic polymer thickening 1,5 2 TOTAL 100 100 Component of the intermediate layer 3b'3 rôle % in cash % in solid phase, after cooking Silicone resin: RS1 or RS2 or RS3 or RS4 or RS5 or RS6 binder 30 75,4 dipropylene glycol butyl ether solvent 5 0 Propoxylated polyglycol ether Wetting agent 1 0,1 iron trioxide pigment 5 21,0 Deionized water solvent 52 0 fatty alcohol polyglycol ether Emulsifying agent 2 0,3 Mineral oil Anti-foaming agent 3 1,3 2-amino-2-methyl-1-propanol Buffer agent 0,5 0 Acrylic polymer thickening 1,5 1,9 TOTAL 100 100

[0287] The compositions of the 3c finishing coats are applied by spraying and are as described below: coat 3c1 to 3c10: Component of the 3c1 topcoat rôle % in cash % in solid phase, after cooking RS1 silicone resin binder 35 95,5 dipropylene glycol butyl ether solvent 6 0 Propoxylated polyglycol ether 2 0,3 Mineral oil Anti-foaming agent 1 0,5 Mica pigment 0,5 2,3 Deionized water solvent 50,5 0 fatty alcohol polyglycol ether Emulsifying agent 4 0,7 2-amino-2-methyl-1-propanol Buffer agent 0,5 0 Acrylic polymer thickening 0,5 0,7 TOTAL 100 100 Component of the 3c2 topcoat rôle % in cash % in solid phase, after cooking RS1 silicone resin binder 35 91,5 dipropylene glycol butyl ether solvent 6 0 anionic ester in ethanol / water Wetting agent 1 0,1 Mineral oil Anti-foaming agent 1 0,4 Polyether modified polysiloxane oil 0,5 2,2 polydimethylsiloxane oil oil 1 4,4 Deionized water solvent 50,50 0 fatty alcohol poly glycol ether Emulsifying agent 4 0,7 2-amino-2-methyl-1-propanol Buffer agent 0,5 0 Acrylic polymer thickening 0,5 0,7 TOTAL 100 100 Component of the 3c3 topcoat rôle % in cash % in solid phase, after cooking RS1 silicone resin binder 67 100 2-Methoxy-1-Methylethyl acetate solvent 33 0 Component of the 3c4 topcoat rôle % in cash % in solid phase, after cooking RS4 silicone resin binder 69 100 2-Methoxy-1-Methylethyl acetate solvent 31 0 Component of the 3c5 topcoat rôle % in cash % in solid phase, after cooking RS4 silicone resin binder 80 100 2-Methoxy-1-Methylethyl acetate solvent 20 0 Component of the 3c6 topcoat rôle % in cash % in solid phase, after cooking RS1 silicone resin binder 75 87,38 2-Methoxy-1-Methylethyl acetate solvent 8 0 methyl phenyl polysiloxane Flow agent 0,5 0,97 Carbon black Pigment 5 9,71 Post-treated silica fume dimethyl dichlorosilane charge 1 1,94 Butyl Glycol acetate solvent 1 0 Butylacetate solvent 9,5 0 TOTAL 100 100 Component of the 3c7 topcoat rôle % in cash % in solid phase, after cooking RS1 silicone resin binder 75 94,74 2-Methoxy-1-Methylethyl acetate solvent 8 0 Post-treated silica fume dimethyl dichlorosilane charge 2 4,21 mica Pigment 0,5 1,05 Butyl Glycol acetate solvent 1 0 Butylacetate solvent 13,5 0 TOTAL 100 100 Component of the 3c8 topcoat rôle % in cash % in solid phase, after cooking RS6 silicone resin binder 30 74,26 Post-treated silica fume dimethyl dichlorosilane charge 2 8,25 dipropylene glycol butyl ether solvent 4,5 0 Fatty acid ester 3 5,94 Mica pigment 0,5 2,06 Deionized water solvent 51,6 0 fatty alcohol polyglycol ether Emulsifying agent 5,5 4,99 Mineral oil Anti-foaming agent 1,9 4 2-amino-2-methyl-1-propanol Buffer agent 0,5 0 Acrylic polymer thickening 0,5 0,5 TOTAL 100 100 Component of the 3c9 topcoat rôle % in cash % in solid phase, after cooking RS2 silicone resin binder 70 94,74 2-Methoxy-1-Methylethyl acetate solvent 8 0 Post-treated silica fume dimethyl dichlorosilane charge 2 4,21 mica Pigment 0,5 1,05 Butyl Glycol acetate solvent 1 0 Butylacetate solvent 13,5 0 TOTAL 100 100 Component of the 3c10 topcoat rôle % in cash % in solid phase, after cooking RS1 silicone resin binder 60 92,78 2-Methoxy-1-Methylethyl acetate solvent 8 0 Post-treated silica fume dimethyl dichlorosilane charge 2 4,21 mica Pigment 0,5 1,05 Butyl Glycol acetate solvent 1 0 Polydimethylsiloxane oil oil 1 2,06 Butylacetate solvent 19,7 0 TOTAL 100 100 Method for evaluating the properties of the non-stick coating: EGG PERFORMANCE TEST

[0288] The method for evaluating the properties of the non-stick coating is based on the egg test adapted from the AFNOR NF D 21-511 standard, paragraph 3.3.2, and implemented as follows: The sample is cleaned, and any remaining water is wiped off the surface. The inside of the container is dried beforehand. The cooking vessel is heated on a gas stove to a temperature between 140 and 170°C.A 60 / 65 size egg is cracked and poured into the center of the hot cooking container. Wait until the egg has coagulated (6 to 9 minutes). Remove the egg from the cooking container with a spatula, clean the coating with a damp vegetable sponge, and evaluate the non-stick properties of the cooking container. Record the scores: Score of 100: the egg is completely removed with a plastic spatula; Score of 75: the egg is not completely removed but the coating is easily cleaned with a damp sponge; Score of 50: the egg is not completely removed but the coating is cleanable with a damp sponge; Score of 25: the egg is not completely removed and the coating is not cleaned with a damp sponge. Rating of 0: the egg cannot be removed and the coating cannot be cleaned with a damp sponge. Constructions / architectures of cooking elements according to invention Base layer (3a) 3a1 or 3a2 or 3a3 or 3a4 Intermediate layer (3b) 3b1 or 3b2 or 3b3 Intermediate layer (3b') 3b'1 or 3b'2 or 3b'3 Top coat (3c) 3c1 3c2 3c3 3c4 3c5 3c6 3c7 3c8 3c9 3c10 Scores obtained on the egg test 50 50 50 50 50 50 50 50 50 50

[0289] All silicone-polyester resin-based coatings exhibit good non-stick properties while also adhering to metal.

Claims

1. Coated cooking element (1) for culinary articles or electric cooking appliances, comprising a metal substrate (2) coated on at least one face (2a) with at least the following layers in this order from the metal substrate (2): (3a) an adhesion sublayer comprising between 20% and 100% by weight of the total weight of the sublayer of one or more polymer(s) (α) selected from the group consisting of polyaryletherketones (PAEKs) and of one or more polymer(s) selected from the group consisting of polyetherimides (PEI), polyimides (PI), polyamide-imides (PAI), and polybenzimidazoles (PBI), with a weight ratio PAEK:(PEI+PI+PAI+PBI) between 1:1 and 15:1, (3b) optionally, one or more intermediate layer(s) composed of one or more coloring agent(s) and optionally ∘ one or more silicone resin(s), and / or ∘ one or more thermoplastic polymer(s) and / or, ∘ one or more filler(s), and / or ∘ one or more additive(s) (3c) a finishing layer composed of one or more silicone resin(s) in a proportion of at least 20% by weight relative to the total weight of the layer (3c) and optionally: ∘ one or more thermoplastic polymer(s), and / or ∘ one or more filler(s), and / or ∘ one or more additive(s), and / or o flakes.

2. Coated cooking element (1) according to claim 1, characterized in that the adhesion sublayer (3a) comprises one or more polymers (β) selected from the group consisting of polyphenylene sulfides (PPS) and polyethersulfones (PES).

3. Coated cooking element (1) according to claim 2, characterized in that the adhesion sublayer (3a) includes at least 20%, preferably at least 25%, by weight of the total weight of the sublayer of one or more polymers (β) selected from the group consisting of polyphenylene sulfides (PPS) and polyethersulfones (PES).

4. Coated cooking element (1) according to any preceding claim, characterized in that the adhesion sublayer (3a) includes, when present, less than 40%, preferably less than 30%, by weight of the total weight of the sublayer of fillers, preferably between 5% and 25% by weight.

5. Coated cooking element (1) according to any preceding claim, characterized in that the adhesion sublayer (3a) includes one or more acrylic resin(s).

6. Coated cooking element (1) according to any preceding claim, characterized in that the polyaryletherketones (PAEK) are selected from the group consisting of polyetherketones (PEK), polyetheretherketone (PEEK), polyetherketoneketones (PEKK), polyetheretherketoneketones (PEEKK), and polyetherketoneetherketoneketones (PEKEKK).

7. Coated cooking element (1) according to any preceding claim, characterized in that the polymer(s) (α) is selected from the group consisting of polyetheretherketones (PEEK) and polyamide-imides (PAI).

8. Coated cooking element (1) according to any preceding claim, characterized in that the coloring agent(s) is selected from the group consisting of thermochromic pigments, thermostable pigments, flakes, preferably holographic flakes, and their mixtures.

9. Coated cooking element (1) according to any preceding claim, characterized in that layer (3c) includes one or more thermoplastic polymer(s), the proportion of thermoplastic polymer(s) in layer (3c) being less than 50%, preferably less than 40%.

10. Coated cooking element (1) according to any preceding claim, characterized in that the thickness of the adhesion sublayer (3a) is comprised between 10 and 100 µm, preferably between 20 µm and 80 µm, most preferably between 30 and 60 µm.

11. Manufacturing process of a coated cooking element (1) according to any preceding claim, characterized by the following steps: i. providing a metal substrate (2), comprising two opposite faces, ii. optionally treating the face (2a) of the substrate (2), to obtain a treated face (2a) promoting the adhesion of an adhesion sublayer (3a) on the substrate (2), iii. depositing on the face (2a) of the substrate (2) one or more continuous layers of the adhesion sublayer (3a) as defined in the preceding claims, iv. optionally drying and / or sintering at a temperature > 400°C, v. optionally applying one or more layer(s) (3ab) and / or one or more intermediate layer(s) (3b), vi. applying the finishing layer (3c), vii. baking at a temperature of 230°C to 420°C.

12. Process according to claim 11, characterized in that the sintering temperature is comprised between 400°C and 440°C.

13. Culinary article (100) comprising a coated cooking element (1) according to any of claims 1 to 10.

14. Culinary article (100) according to claim 13, characterized in that it includes a heating face (6) intended to be in contact with an external heat source, the heating face (6) being opposite to the cooking face (5) intended to be in contact with food during cooking, preferably chosen from the group consisting of saucepan, frying pan, fondue or raclette pots, stewpot, wok, sauté pan, crepe pan, grill, plancha, pot, cocotte, cooker or bread machine tank, culinary mold.

15. Electric cooking appliance (200) comprising a coated cooking element (1) and a heat source (210) configured to heat said coated cooking element (1), characterized in that said coated cooking element (1) is according to any of claims 1 to 10, preferably chosen from the group consisting of electric crepe maker, electric raclette appliance, electric fondue device, electric grill, electric plancha, electric cooker, bread machine, electric pressure cooking device, waffle irons, rice cookers, and jam makers.