Non-fluorinated pes-based exterior coating

Abstract

The invention relates to a coated cooking element (1) for a culinary utensil or electrical cooking appliance, comprising a metal substrate (2) coated on at least one surface (2a) with a coating (3) intended to form a cooking surface devoid of fluorocarbon resin, and coated at least on the other surface (2b) with a coating (4) comprising at least the following layers in the stated order proceeding from the metal substrate (2): - (4a) a primer layer comprising polyethersulfone (PES), - (4b) optionally, one or more intermediate layer(s) comprising polyethersulfone (PES) or a mixture of polyethersulfone (PES) and one or more silicone resins, - (4c) a finishing layer comprising polyethersulfone (PES) or one or more silicone resins or a mixture of polyethersulfone (PES) and one or more silicone resins.

Description

[0001] Non-fluorinated exterior coating based on PES

[0002] The invention applies in the field of exterior coatings for culinary articles or electrical cooking appliances.

[0003] The present invention addresses the technical problem of improving the thermomechanical properties of an outer coating of a cookware or an electrical cooking appliance. It aims in particular to improve its resistance to abrasion and, where appropriate, its ability to be drawn.

[0004] DEFINITIONS

[0005] The term "layer" is understood to mean, within the meaning of the present invention, a continuous or discontinuous layer. A continuous layer (or also called a monolithic layer) is a single whole forming a total flat area completely covering the surface on which it is placed. A discontinuous layer (or non-monolithic layer) may comprise several parts, thus not being a single whole.

[0006] The term "base coat", "primer coat", "bonding coat" or "bonding primer" means all the layers from the first layer applied directly to the support (it is preferable that this layer adheres well to the support and provides all its mechanical properties to the coating: hardness, scratch resistance) to the last layer before the first intermediate or decorative layer or the finishing layer if the coating does not include an intermediate layer. The first layer of the coating is a primer layer.

[0007] The term "intermediate layer" means the layers inserted between the primary layer(s) and the finishing layer(s). The intermediate layer(s) may be "decorations" or "decorative layers". The intermediate layer(s) is / are not intended to come into contact with food.

[0008] The term "finish coat" or "finish" means one or more continuous surface coats applied after the intermediate coat(s) if the coating includes one or more intermediate coat(s) or after the primary coat(s). The last coat of the coating is a finishing coat. Usually, at least the last finishing coat, or even all finishing coats, is / are transparent to allow visibility of the underlying coats, in particular when the underlying coats are decorative coats. The finishing coat(s) protect the underlying coats from mechanical attack and give the coating its non-stick properties. Preferably, in the case of a cookware or electrical cooking appliance, the last finishing coat is intended to be in contact with food.

[0009] The term "decor" or "decorative layer" means one or more continuous or discontinuous layers comprising a pigment composition. The decor may be in the form of one or more patterns, or one or more colors. A decor is clearly visible to the user with the naked eye and at a normal operating distance from the cookware or electrical cooking appliance.

[0010] The expression "cooking article" is understood to mean, within the meaning of the present invention, an object intended for cooking and being heated by an external heating system such as frying pans, saucepans, sauté pans, woks, barbecue grills. A cooking article is capable of transmitting the heat energy provided by this external heating system to a material or food in contact with said article.

[0011] The expression "electric cooking appliance" is understood to mean, within the meaning of the present invention, a heating object having its own heating system, such as an electric crepe maker, an electric raclette appliance, an electric fondue appliance, an electric grill, an electric griddle, an electric cooker, a bread maker, or an electric pressure cooking appliance.

[0012] The term "coating" means all the layers adhering to the metal substrate and covering this substrate. The coating according to the invention obtained is advantageously solid, "solid" means the characteristic of a cohesive material insoluble in water, in common solvents, in food components such as aqueous or fatty mixtures, even if the material may have great hardness or great flexibility such as an elastomer.

[0013] In the present invention, the % by weight are expressed in dry weight, i.e. without solvent. SUMMARY OF THE INVENTION

[0014] A first subject of the invention relates to a coated cooking element (1) for a cooking article or electrical cooking appliance, comprising a metal substrate (2) coated on at least one face (2a) with a coating (3) intended to form a cooking face free of fluorocarbon resin and coated on at least the other face (2b) with a coating (4) comprising at least the following layers and in this order starting from the metal substrate (2):

[0015] (4a) primer layer comprising polyethersulfone (PES),

[0016] (4b) optionally, one or more intermediate layer(s) comprising polyethersulfone (PES) or a mixture of polyethersulfone (PES) and one or more silicone resins,

[0017] (4c) topcoat comprising polyethersulfone (PES) or one or more silicone resins or a mixture of polyethersulfone (PES) and one or more silicone resins.

[0018] Another subject of the invention relates to a method for manufacturing a culinary article or electrical cooking appliance comprising a cooking element coated (1) with a coating (4) according to the invention, characterized by the following steps: a) a step of providing a metal substrate (2) in the form of a substantially flat metal substrate comprising two opposite faces; b) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a primer layer (4a) to the support (2); c) a step of applying the layers (4a), optionally (4b), and (4c) of the coating (4); d) optionally a drying step between 50°C and 150°C after application of said layers; e) a step of baking the element obtained in step c) or d) at a temperature between 250°C and 420°C.f) a step of shaping the element obtained to give it the shape of a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22).

[0019] Another subject of the invention relates to a culinary article or electrical cooking appliance comprising a coated cooking element (1) according to the invention or capable of being obtained according to the method of the invention, characterized in that the layer (4c) is intended to be placed in contact with a heating source.

[0020] FIGURES

[0021] [Fis.1]: diagram of a cooking element according to the invention in which the coating (4) comprises a layer (4a), a layer (4b) and a layer (4c)

[0022] [Fis.2] ' diagram of a culinary article according to the invention

[0023] [Fig.3]: diagram of an electrical cooking appliance according to the invention

[0024] DETAILED DESCRIPTION

[0025] A first subject of the invention relates to a coated cooking element (1) for a cooking article or electrical cooking appliance, comprising a metal substrate (2) coated on at least one face (2a) with a coating (3) intended to form a cooking face free of fluorocarbon resin and coated on at least the other face (2b) with a coating (4) comprising at least the following layers and in this order starting from the metal substrate (2):

[0026] (4a) primer layer comprising polyethersulfone (PES),

[0027] (4b) optionally, one or more intermediate layer(s) comprising polyethersulfone (PES) or a mixture of polyethersulfone (PES) and one or more silicone resins,

[0028] (4c) topcoat comprising polyethersulfone (PES) or one or more silicone resins or a mixture of polyethersulfone (PES) and one or more silicone resins.

[0029] Advantageously, the layer (4a) is in contact by one of its faces with the metal substrate (2) by its face (2b).

[0030] The coated face (2a) of the metal substrate forms a cooking face. In other words, the coating (3) according to the invention is then intended to be in contact with food. The coating (3) can be a non-stick coating of any kind.

[0031] The person skilled in the art will be able to choose the appropriate coating depending on the household item and its use(s). Advantageously, the coating (3) comprises one or more layers. Conventionally, the coating (3) comprises in this order from the substrate (2) one or more primer layer(s), possibly one or more intermediate layer(s) and one or more finishing layer(s).

[0032] The coating (3) does not comprise fluorocarbon resin, also called fluoropolymer or fluoropolymer. In other words, said coating (3) is free of fluorocarbon resin. Thus, the coating (3) does not comprise or emit perfluoroalkyl and polyfluoroalkyl compounds.

[0033] When the coating (3) comprises several layers, they may be identical or different in nature of the components, in percentage by weight of the components, in thickness, etc.

[0034] The coating (3) may comprise: one or more additive(s), and / or one or more coloring agent(s), and / or one or more filler(s).

[0035] The coating (3) may be organic, inorganic or hybrid in nature.

[0036] The other face (2b) of the metal substrate (2) is coated with the coating (4).

[0037] Advantageously, the thickness of each of the layers of the coating (4a), optionally (4b) and (4c) is from 5 pm to 15 pm.

[0038] According to one embodiment, at least one intermediate layer (4b) is present in the coating (4) according to the invention. The at least one intermediate layer (4b) is different from at least one primer layer (4a) and from at least one finishing layer (4c). More preferably, in this case, all the intermediate layers (4b) are different from the primer layer(s) (4a) and from the finishing layer(s) (4c).

[0039] PES

[0040] According to embodiments, the PES content increases from the primer layer (4a) to the topcoat layer (4c). Thus, in this case, the PES content in the primer layer (4a) is lower than the PES content in the layer(s) (4b) when present, which is itself lower than the PES content of the topcoat layer (4c).

[0041] Thus, advantageously, the PES content of the primer layer (4a) represents from 50% to less than 75% by weight of the primer layer (4a), preferably from 55% to 70%.

[0042] Advantageously, the PES content of the intermediate layer (4b), when present, represents from 75 to less than 85% by weight of the intermediate layer (4b), preferably from 75% to 80%.

[0043] Advantageously, the PES content of the finishing layer (4c) represents from 85% to 98% by weight of the finishing layer (4c), preferably from 85% to 95%.

[0044] In these embodiments, advantageously, the layers (4a), (4b) when present, and (4c) comprise polyethersulfone (PES) and optionally: one or more thermoplastics different from PES and / or one or more filler(s) and / or one or more additive(s), and / or one or more coloring agent(s).

[0045] In these embodiments, advantageously, layers (4a), (4b) when present, and (4c) comprise polyethersulfone (PES) and one or more fillers.

[0046] In these embodiments, advantageously, the filler content decreases from the primer layer (4a) to the finishing layer (4c).

[0047] According to other embodiments, the PES content decreases from the primer layer (4a) to the topcoat (4c).

[0048] Thus, in this case, the PES content in the primer layer (4a) is higher than the PES content in the layer(s) (4b), when present, which is itself higher than the PES content of the finishing layer (4c).

[0049] Thus, advantageously, the PES content of the primer layer (4a) represents from 25% to 30% by weight of the primer layer (4a). Advantageously, the PES of the intermediate layer (4b), when present, represents from 20% to less than 25% by weight of the intermediate layer (4b).

[0050] Advantageously, the PES of the finishing layer (4c) represents from 10% to less than 20% by weight of the finishing layer (4c), preferably from 15% to less than 20%.

[0051] In these embodiments, advantageously, the layers (4a), (4b) when present, and (4c) comprise a mixture of polyethersulfone (PES) and one or more silicone resins, and optionally: one or more thermoplastics different from PES, and / or one or more filler(s) and / or one or more additive(s), and / or one or more coloring agent(s).

[0052] In these embodiments, advantageously, the silicone resin content increases from the primer layer (4a) to the finishing layer (4c).

[0053] In these embodiments, advantageously, the PES content decreases from the primer layer (4a) to the finishing layer (4c) and the silicone content increases from the primer layer (4a) to the finishing layer (4c).

[0054] In these embodiments, advantageously, the content of (PES+silicone resin) of the layers (4a), (4b) and (4c) ranges from 40% to 90% or from 50% to 90%, preferably from 60% to 90%, even more preferably from 70% to 90% by weight of each layer.

[0055] In these embodiments, the presence of silicone resins and PES makes it possible to confer both the non-stick character of the coating as well as its ability to be drawn in the case where the coated heating element is shaped after deposition of the coating (4).

[0056] These embodiments are thus particularly suitable in the case of shaping the heating element to give it a convex shape, such as for a frying pan, for example.

[0057] According to other embodiments, in particular when the coated heating element is shaped by stamping after deposition of the coating (4) and the coating (4) is subjected to high stresses during this stamping step, the layer (4c) comprises polyethersulfone (PES) and one or more silicone resins and, optionally: one or more thermoplastics other than PES and / or one or more fillers and / or; one or more additives and / or; and one or more coloring agents. the PES content being between 60% and 80% by weight of the layer (4c), the silicone resin content being between 5% and 30% by weight of the layer (4c) and the (PES+silicone resin) content being between 70% and 98%, preferably between 80% and 98%, even more preferably between 90% and 98% by weight of the layer (4c).

[0058] Advantageously, the PES of the primer layer (4a) represents from 50% to less than 75% by weight of the primer layer, preferably from 55% to 70%. Advantageously, the PES of the intermediate layer (4b), when present, represents from 75 to less than 85% by weight of the intermediate layer, preferably from 75% to 80%.

[0059] The high PES content of layer (4c) as well as layers (4a) and (4b) ensures good drawability under high stress. The presence of silicone resin in layer (4c) also ensures good non-stick properties.

[0060] These embodiments are thus particularly suitable in the case of shaping the heating element to give it a hollow shape for a saucepan, for example.

[0061] CHARGES

[0062] Advantageously, the primer layer(s) (4a) and / or the optional intermediate layer(s) (4b) and / or the layer(s) (4c) comprises / comprise one or more fillers. According to this embodiment, the primer layer(s) (4a) and / or the optional intermediate layer(s) (4b) and / or the layer(s) (4c) comprises / comprise less than 40%, preferably less than 30%, by weight of fillers relative to the total weight of said layer, preferably between 5 and 25% by weight.

[0063] The fillers within the meaning of the invention provide mechanical reinforcement and can also provide hydrophobic properties, while improving the mechanical strength and thermal conductivity of the coating. The fillers do not only have the function of providing color to the coating, but can contribute to it.

[0064] Advantageously, the filler(s) is / are chosen from the group consisting of ceramic fillers (SiO?, etc.) and / or mineral and / or metallic fillers (AI2O3, TiO?, etc.) and / or silicas and / or diamond particles.

[0065] Preferably, the filler(s) is / are chosen from the group consisting of metal oxides, metal carbides, metal oxynitrides, metal nitrides, and mixtures thereof.

[0066] Advantageously, said metal is a transition metal, such as at least one of the elements chosen from B, Ni, Ti, Zr or Hf.

[0067] More preferably, the charge(s) is / are chosen from the group consisting of:

[0068] - fillers for reinforcement: organic or inorganic hard fillers; the inorganic hard fillers are preferably particles of silicon carbide or alumina or zirconia or graphite, or ceramics, or carbonate, or hydrated alumina, aluminum trihydroxide or one or more metal oxide(s), graphite, graphene;

[0069] - other fillers for reinforcement chosen from metal oxides: silica, micas, lamellar fillers, clays such as montmorillonite, sepiolite, gypsite, kaolinite and laponite, zinc dioxide, quartz, and zirconium phosphate, alumina, zirconia, zinc oxide, copper oxide, iron oxide;

[0070] - fillers chosen from reinforcing fibers: glass fiber, carbon fiber, or aramid fiber;

[0071] - conductive fillers comprising a transition metal carbide and / or a transition metal nitride: characterized in that the transition metal is at least one of the elements chosen from B, Ni, Ti, Zr or Hf, for example: cubic boron nitride, diamond particles, metallic particles;

[0072] - lamellar fillers that can provide lubricating properties, such as clays, graphene or graphite.

[0073] Among the fillers in combination with silicone resins, the preferred fillers are:

[0074] - reinforcing fillers: silica or carbonates with filler rates of at least 10-15% / wt and up to 60% / wt, - alumina, hydrated alumina, aluminium trihydroxide,

[0075] - silica (precipitated or pyrogenic) with a d50 < 0.1 pm and a BET specific surface area > 30 m2 / g and preferably between 30 and 500 m2 / g,

[0076] - or mixture of quartz and silica, diatomaceous earth or ground quartz, titanium, mica, talc, kaolin, barium sulfate, slaked lime, zinc oxide, expanded vermiculite, unexpanded vermiculite, calcium carbonate etc.

[0077] More preferably, the filler(s) is / are chosen from the group consisting of alumina, silicon carbide, tungsten carbide, boron nitride, quartz, and mixtures thereof.

[0078] Advantageously, the fillers present in the primer layer(s) (4a) or the optional intermediate layer(s) (4b) are inorganic hard fillers, preferably metal oxides, carbides, nitrides, preferably alumina, silicon carbides or fumed silica.

[0079] 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.

[0080] The addition of this type of filler improves the culinary rendering with better diffusion of heat from the metal substrate to the food in contact with the coating.

[0081] Advantageously, the average diameter d50 of the charges is between 0.1 and 50 pm, advantageously still between 5 and 15 pm.

[0082] 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 cooking, preferably between 5 and 20%.

[0083] Advantageously, the proportion of fillers in the layer (4a) is greater than 20% by weight, preferably greater than 30% by weight, relative to the total weight of said layer.

[0084] Advantageously, the proportion of fillers in the layer (4c) is less than 10% by weight relative to the total weight of said layer. Advantageously, the proportion of fillers in the layers (4a), (4b) and (4c) may be identical or different.

[0085] Advantageously, the nature of the charges in layers (4a), (4b) and (4c) may be identical or different.

[0086] ADDITIVES

[0087] Advantageously, the primer layer(s) (*a) and / or the intermediate layer(s) (4b) and / or the layer(s) (4c) comprises / comprise one or more additives.

[0088] Advantageously, the additive(s) is / are chosen from the group consisting of anti-foaming agents, dispersing agents, wetting agents, thickeners, pH adjusters, reactive silicone oils.

[0089] Said anti-foaming agent(s) are preferably chosen from the group consisting of mineral oils, diols, hydrocarbons, glycerides, oxirane, emulsified fatty acids.

[0090] The surfactant(s) is (are) preferably chosen from the group consisting of glycol ether, ethoxylated alcohol excluding alkyl phenol ethoxylates (APE), gemini surfactants.

[0091] The dispersing agent(s) is (are) preferably chosen from the group consisting of anionic dispersants such as fatty acid derivatives.

[0092] Said thickeners are preferably chosen from the group consisting of acrylic-based or polyurethane-based copolymer, cellulose, pyrogenic silica.

[0093] The said pH adjusters are preferably chosen from the group consisting of Bronsted bases: ammonia, amines (triethylamine, triethanolamine, etc.), hydroxides (soda, potash, etc.), carbonates.

[0094] Advantageously, the primer layer(s) (4a) and the intermediate layer(s) (4b) comprise 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.

[0095] Advantageously, the primer layer(s) (4a) or the intermediate layer(s) (4b) comprises one or more surfactants.

[0096] Advantageously, the primer layer(s) (4a) or the intermediate layer(s) (4b) further comprises one or more anti-foaming agents.

[0097] Advantageously, the primer layer(s) (4a) or the optional intermediate layer(s) (4b) further comprises / comprise water and / or one or more solvents, preferably unlabeled, for example propionamide, N-formylmorpholine (NFM), N-Methyl Imidazole (NMI), N-ButylPyrrolidone (NBP), dimethyl sulfoxide (DMSO), or alcoholics, for example Propylene Glycol (PPG), Diethylene glycol, di propylene glycol butyl ether (DPNB).

[0098] Advantageously, the finishing layer (4c) comprises a silicone oil. The presence of a silicone oil in the finishing layer can improve the stretchability of the coating (4) when it is subjected to mechanical stresses, such as during shaping by stamping for example.

[0099] Advantageously, the silicone oil represents from 1 to 5% by weight of the finishing layer (4c), preferably from 2% to 4%.

[0100] COLOURING AGENTS

[0101] Advantageously, the primer layer(s) (4a) or the optional intermediate layer(s) (4b) comprises / comprise one or more coloring agent(s). Advantageously, the primer layer(s) (4a) or the optional intermediate layer(s) (4b) comprises / comprise less than 30%, preferably less than 20%, by weight of one or more coloring agent(s) of the total weight of said layer.

[0102] Advantageously, the coloring agent(s) is / are chosen from the group consisting of thermostable pigments, glitter, preferably hologram glitter, and mixtures thereof. The proportion of coloring agents in layers (4a), (4b) and (4c) may be between 0.5 and 50% by dry weight relative to the total weight of said layer after baking.

[0103] Advantageously, the proportion of coloring agents in layers (4) and (4b) ranges from 10% to 40% by weight relative to the total weight of said layer.

[0104] Advantageously, the proportion of coloring agents in the layer (4c), when present, is less than 10% by weight relative to the total weight of said layer.

[0105] Advantageously, the proportion of coloring agents in layers (4a), (4b) and (4c) may be identical or different.

[0106] Advantageously, the nature of the coloring agents in layers (4a), (4b) and (4c) may be identical or different.

[0107] Advantageously, layer (4c) is transparent. In this case, if it includes coloring agents, these coloring agents are glitter.

[0108] Thermostable pigments

[0109] Preferably, the thermostable pigment(s) is / are chosen from the group consisting of:

[0110] - Yellow titanium rutile type pigment,

[0111] - Yellow pigment derived from bismuth, for example selected from stabilized bismuth vanadates (Pym)

[0112] - Red pigment, for example selected from perylene red (for example PR149, PR178 and PR224), iron oxide,

[0113] - Orange pigment of bismuth oxyhalides type (POss),

[0114] - Bismuth vanadate orange pigment (POSÔ)

[0115] - Zinc tin titanium orange pigment (POs?)

[0116] - Cerium sulfide orange pigment (PO75; PO?s)

[0117] - Orange-yellow pigment of the antimony titanium chrome rutile type (PBr?4)

[0118] - Orange-yellow pigment of the rutile type of tin and zinc (Pyz-iô)

[0119] - Orange-yellow pigment of niobium oxide tin zinc sulfide (Py???)

[0120] - Orange-yellow pigment of double oxides of tin and niobium

[0121] - CO3(P04)? - L1C0PO4

[0122] - C0AI2O4

[0123] - Cr?O3

[0124] - TiO2

[0125] - Black pigment PBk28 (Copper chromite black spinel)

[0126] - and their mixtures.

[0127] Sequins

[0128] The flakes usable in the context of the present invention may be independently chosen from mica flakes, coated or not, silica flakes, coated or not, aluminum flakes, coated or not, iron oxide flakes, coated or not. Mica or silica flakes coated with titanium dioxide. The flakes usable in the context of the present invention may be treated to give a particular color effect.

[0129] Advantageously, the flake(s) is / are particles chosen from the group consisting of particles of mica, aluminum, mica coated with titanium dioxide or mixtures thereof.

[0130] Hologram sequins

[0131] Advantageously, the glitter(s) is / are hologram glitter, i.e. a mixture of magnetizable particles and non-magnetizable particles.

[0132] The magnetizable particles may advantageously be particles comprising at least one ferromagnetic metal. These magnetizable particles may be of a homogeneous nature, i.e. made of the same material, or of a composite nature, i.e. these magnetizable particles have a core-shell structure, in which the ferromagnetic metal is found in the core and / or in the shell of said particles. Examples of composite magnetizable particles include mica flakes coated with iron oxide Fe2O3 or stainless steel fibers coated with a sol-gel material, as protection against corrosion during the steps of implementing the coating, or else plastic flakes coated with iron oxide Fe2O3, or flakes whose core is made of ferromagnetic metal and the shell is formed of a plastic material or a sol-gel material.According to one embodiment, a portion of said magnetizable particles is oriented so as to form a three-dimensional decoration.

[0133] Advantageously, the mixture of magnetizable particles and non-magnetizable particles represents between 1% and 5% by weight of the weight of the layer, preferably between 2% and 3% by weight.

[0134] Advantageously, the percentage of non-magnetizable particles in the mixture of magnetizable particles and non-magnetizable particles is between 15% and 40% by weight relative to the total weight of the mixture of magnetizable particles and non-magnetizable particles.

[0135] Advantageously, the magnetizable particles have a dimension D50 less than or equal to 23 pm.

[0136] The term “D50” means, within the meaning of the present invention, the maximum dimension presented by 50% of the particles by number.

[0137] Advantageously, the non-magnetizable particles have a dimension D90 of between 20% and 250% of the dimension D90 of the magnetizable particles.

[0138] The term “D90” means, within the meaning of the present invention, the maximum dimension presented by 90% of the particles by number.

[0139] Advantageously, the magnetizable particles and / or the non-magnetizable particles are colored on the surface.

[0140] Advantageously, the non-magnetizable particles are made of mica, aluminum, or mica coated with titanium dioxide.

[0141] Advantageously, the magnetizable particles consist of iron, iron oxide, iron-coated aluminum, or iron-coated mica, the iron being in ferritic form. THERMOPLASTICS

[0142] Thermoplastics are thermoplastic polymers.

[0143] Advantageously, the thermoplastic polymer(s) other than PES is / are chosen from the group consisting of polyaryletherketone(s) (PAEK), aromatic thermoplastic polymer(s) such as poly(arylethersulfones) (PAES), poly(arylene sulfides) (PAS) or poly(phenylene oxide) (PPO), liquid crystal polymers, heterocyclic thermoplastic polymers and mixtures thereof.

[0144] PAEK

[0145] 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.

[0146] Other aromatic thermoplastic polymers

[0147] As aromatic thermoplastic polymer(s), examples which are suitable according to the invention are poly(phenylene oxide) (PPO), poly(arylethersulfone) polymer (PAES), with the exception of polyethersulfone (PES), polyphenylene ether sulfone (PPSU), poly(arylene sulfides) (PAS) and in particular polyphenylene sulfide (PPS), liquid crystal polymers and their mixtures.

[0148] Heterocyclic thermoplastic polymers

[0149] Examples of heterocyclic thermoplastic polymers suitable according to the invention are polyetherimides (PEI), polyimides (PI), polyamideimides (PAI) and polybenzymidazole (PBI), or mixtures thereof.

[0150] Advantageously, the thermoplastic polymer(s) is / are chosen 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), 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.

[0151] Advantageously, the nature of the thermoplastic polymer(s) in layers (4a), (4b) and (4c) may be identical or different.

[0152] SILICONE RESINS

[0153] In the text of the description, the expression "silicone resin" is used interchangeably to refer to the silicone before its crosslinking or after its crosslinking. In the text of the description, the expression "silicone" designates an organopolysiloxane material. Crosslinking is the step which makes it possible to transform the silicone into an insoluble material, for example by polyaddition, polycondensation or dehydrogenation. Crosslinking is carried out from precursors which are generally silicone oils or resins, which crosslink to obtain a three-dimensional network forming a material called silicone resin, in the description.

[0154] This crosslinking can be done by thermal activation, or chemical activation using a catalyst, such as platinum.

[0155] The silicone resins can be obtained from precursors, advantageously soluble in a solvent or in emulsion in water, such as oils or crosslinkable resins, in particular chosen 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 hydroxy group and mixtures thereof. These precursors have the capacity to crosslink in order to obtain a silicone resin which is characterized by its insolubility and its substantially solid form.

[0156] Advantageously, these precursors are polymeric or oligomeric, either in the form of silicone oils with a variable degree of branching, or in the form of silicone resins with a variable degree of pre-crosslinking or copolymers of silicone resins such as silicone-polyester, silicone-alkyd, silicone-polyurethane, silicone-epoxy resins, or in the form of a mixture of silicone oils, silicone resins and copolymers of silicone resins. 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 (2, 3 or more) hydroxy or alkoxy (in particular methoxy, ethoxy, butoxy) functional groups as substituents of silicon atoms.

[0157] Advantageously, the silicone resin(s), obtained after crosslinking their precursors, i.e. crosslinked, is / are chosen from the group consisting of methyl silicone and / or phenyl silicone and / or methyl-phenyl-silicone resins, methyl silicone-polyester resin (copolymers), phenyl silicone-polyester resin (copolymers), methyl-phenyl silicone-polyester resin (copolymers), silicone-alkyd resin (copolymers), modified silicone resin and mixtures thereof.

[0158] Advantageously, the silicone resin(s) is / are chosen from the group consisting of methyl silicone and / or phenyl silicone and / or methyl-phenyl-silicone resins, methyl silicone-polyester resin (copolymers), phenyl silicone-polyester resin (copolymers), methyl-phenyl silicone-polyester resin (copolymers), silicone-alkyd resin (copolymers), modified silicone resin and mixtures thereof.

[0159] 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.

[0160] The silicone resin forms a network which may consist of a combination of 4 simple organosiloxane units called M, D, T and Q depending on the degree of substitution by oxygen of the silicon atom, as described in the following table, where R is an organic substituent described below.

[0161] The organopolysiloxane material or polymer is obtained by crosslinking from precursors which can be monomeric or polymeric, or intermediately which can be oligomeric. The organopolysiloxane polymer can also be obtained from a mixture of these different kinds of precursors. When the network contains a higher number of T and Q units, than D, the crosslinking density is higher. The distribution between the M, D, T and Q units depends on the chemical structure of the precursors, in particular on this M, D, T, Q distribution within the precursors.

[0162] The polymeric precursors are organopolysiloxanes. These macromolecules are formed from 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.

[0163] Organopolysiloxanes can be either linear or slightly branched (majority of D groups), or branched or highly branched (majority of T and Q groups). Linear or lightly branched organopolysiloxanes are generally liquid, more or less viscous at room temperature, and are called silicone oils. Branched or highly branched (pre-crosslinked) organopolysiloxanes form a network at the level of the individual macromolecule and are called silicone resins. At room temperature, the resins are substantially in solid form, or in liquid form, provided in particular that they have a fairly low molecular weight, in the form of a solution in a solvent or in the form of an aqueous emulsion. They can be copolymerized with organic polymers or oligomers not containing silicon, chosen in particular from polyesters, acrylics, alkyds, polyurethanes, epoxy resins.When the crosslinking is a hydrolysis-polycondensation: it is carried out thanks to the reactive hydroxy or alkoxy functions, in particular methoxy, ethoxy or butoxy, present on the organopolysiloxane.

[0164] When the crosslinking is a polyaddition (or hydrosilylation): it is carried out by reaction between the reactive vinyl functions (-CH=CH2) present on one of the organopolysiloxanes and the reactive silyl hydride functions (Si-H) present on the other organopolysiloxane mixed with the first.

[0165] All these reactive functions are present on each organopolysiloxane in number of at least one and can be present in number of 2, 3, or more ... as much as the molecular structure allows. Silicone oils containing at least one reactive function are called "reactive oils". The reactive functions can be found either at the end of the macromolecular chain (termination), or distributed over the chain.

[0166] Silicone-polyester resins in particular have silicone / polyester mass ratios of, 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.

[0167] Linear PDMS silicone oils, pure or pre-emulsified in water, are characterized firstly by their molecular mass, which is a direct increasing function of the viscosity of the pure oil. They are then characterized by the presence or absence of reactive functions, for example hydroxyls 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 in particular between 300 and 5,000 mPa.s, can be used, having at least one reactive function, preferably at least 2, which can be placed at the end of the chain.

[0168] Polymer precursors reacting by polyaddition may include, for example, polymethylhydrosiloxane, vinylmethylsiloxane, vinyl-terminated polydimethylsiloxane (PDMS), in particular linear, vinyl-terminated diphenylsiloxane-dimethylsiloxane copolymers, hydride-terminated polydimethylsiloxanes, hydride-terminated polyphenylmethylsiloxanes, cyclic vinylmethylsiloxane, vinyl-MQ resin, trimethylsilyl-terminated polymethylhydrosiloxane, trimethylsiloxane-terminated dimethylsiloxane copolymer, MQ resin hydride, and the like, as well as combinations thereof.Polymeric precursors reacting by hydrolysis-polycondensation, whether silicone resins or silicone oils, may include, for example, poly(methylsilsesquioxanes), poly(propylsilsesquioxanes), poly(phenylsilsesquioxanes), polydimethylsiloxane (PDMS), trimethylsilyl-terminated polydimethylsiloxane (PDMS), hydroxyl-terminated polydimethylsiloxane (PDMS), silanol-terminated polydimethylsiloxane (PDMS), silanol-terminated polyphenylsiloxane (PDMS), silanol-terminated diphenylsiloxane-dimethylsiloxane copolymer, poly(2-acetoxyethylsilsesquioxanes), organo-modified alkoxysilanes and their oligomers, and all similar macromolecules and their mixtures.

[0169] The organopolysiloxane material or polymer may also be obtained by crosslinking a mixture of one or more monomeric precursors and one or more polymeric precursors as described above, as well as 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 comprising a number of reactive functions as described above greater than 2, advantageously much greater than 2, may be added to the mixture as a “co-binder” in order to promote a high crosslinking density of the organopolysiloxane polymer finally obtained.

[0170] Monomeric, oligomeric and / or polymeric precursors, in particular silicone resins, copolymerized or not with an organic polymer, act as a polymeric binder in order to obtain the solid organopolysiloxane polymer combined with the thermoplastics of each layer.

[0171] Silicone oil-type organopolysiloxane precursors can be considered additives if they are added in small amounts (typically between 0.1 and 5% dry) to the overall formulation of a layer, independently of other components for the formation of the solid organopolysiloxane polymer.

[0172] Crosslinking may require a catalyst:

[0173] - In the case of crosslinking of organopolysiloxanes by hydrolysis-polycondensation, the formula may include a metal catalyst, such as, for example, metal complexes based on platinum, tin, zinc, zirconium and cerium, in particular platinum-cyclovinylmethyl-silxane complexes, tin ethylhexanoate, zinc ethylhexanoate, zirconium ethylhexanoate, cerium ethylhexanoate, and tin dibutyl laurate.

[0174] - In the case of crosslinking of organopolysiloxanes by hydrosylilation, the addition of a catalyst may be necessary: ​​this may be, for example, platinum or a suitable platinum-based catalyst such as the Karstedt catalyst or the Ashbys catalyst.

[0175] A crosslinking agent, for example carrying Si-H bonds, may be present.

[0176] OTHER ARCHITECTURES

[0177] Preferably, the intermediate layer(s) (4b) only partially cover the base layer (4a).

[0178] According to one embodiment, the finishing layer (4c) consists of one or more silicone resins, and optionally: one or more fillers and / or one or more additives, and / or one or more coloring agents.

[0179] According to one embodiment, the layer (4c) is made up of:

[0180] - an elastomer silicone obtained from at least one organopolysiloxane carrying reactive vinyl functions (-CH=CH2), at least one other organopolysiloxane carrying reactive silyl hydride functions (Si-H), preferably in the presence of a metal catalyst; and optionally:

[0181] - one or more thermoplastics

[0182] - one or more charges, and / or

[0183] - one or more additive(s), and / or

[0184] - one or more coloring agents. when at least one layer (4b) is present.

[0185] In this case, advantageously, the PES content increases from layer (4a) to layer (4b). Layer (4a) and layer (4b) may be as described above.

[0186] The organopolysiloxanes carrying reactive functions of layer (4c) are precursors which react by a crosslinking which is a polyaddition (or hydrosilylation). This crosslinking is carried out by reaction between the reactive vinyl functions (-CH=CH2) present on one of the organopolysiloxanes and the reactive silyl hydride functions (Si-H) present on the other organopolysiloxane mixed with the first.

[0187] This crosslinking can be done by thermal activation, or chemical activation using a catalyst.

[0188] Advantageously, the organopolysiloxanes carrying reactive functions of layer (4c) are silicone oils.

[0189] Reactive functions are present on each organopolysiloxane in the number of at least one and can be present in the number of 2, 3, or more ... as much as the molecular structure allows. Silicone oils containing at least one reactive function are called "reactive oils". The reactive functions can be found either at the end of the macromolecular chain (termination), or distributed over the chain.

[0190] The addition of a catalyst may be necessary for crosslinking: this could be, for example, platinum or a suitable platinum-based catalyst such as the Karstedt catalyst or the Ashbys catalyst.

[0191] The thermoplastics, additives and coloring agents are as described above. The thermoplastic in layer (4c) may also be PES.

[0192] Advantageously, the thickness of the finishing layer (4c) is from 0.1 pm to 10 pm, preferably from 0.5 pm to 5 pm, particularly preferably from 1 pm to 2 pm.

[0193] METAL SUBSTRATE

[0194] Advantageously, said metal substrate (2), also called support, is a substrate made of aluminum, stainless steel, cast iron or aluminum, iron, titanium or copper.

[0195] For the purposes of the present invention, aluminum means a metal consisting of 100% aluminum or an aluminum alloy.

[0196] Advantageously, the metal substrate (2) is an aluminum substrate, a stainless steel substrate or a multi-layer metal substrate. The metal substrate (2) may be a two-layer or three-layer substrate, these multi-layers being able to be obtained for example by co-rolling, by hot diffusion under load (solid state bonding) or by hot or cold impact bonding.

[0197] Preferably, the metal substrate (2) comprises alternating layers of metal and / or metal alloy.

[0198] According to one embodiment, the metal substrate (2) is an aluminum alloy substrate, a stainless steel substrate or a multi-layer metal substrate whose face (2a) is made of aluminum alloy or stainless steel.

[0199] Preferably, the metal substrate (2) is an aluminum substrate.

[0200] Advantageously, the thickness of the metal substrate (2) is between 0.5 mm and 10 mm.

[0201] Advantageously, the face (2a) of the metal substrate (2) has previously undergone a surface treatment making it possible to improve the adhesion of the coating to said substrate.

[0202] According to one embodiment, the surface of the face (2a) of the metal substrate (2) has undergone a surface treatment, said surface treatment being a chemical attack, brushing, hydration, sandblasting, shot blasting, a physicochemical treatment of the plasma or corona or laser type, a chemical activation or a combination of these different techniques.

[0203] Advantageously, the face of the substrate (2a) on which the coating (3) according to the invention will be applied can be treated so as to increase its specific surface area; for an aluminum substrate, this treatment can be done by anodization (creation of a tubular alumina structure), by chemical attack, by sandblasting, by brushing, by shot blasting or by adding material by means of a technology such as thermal projection (flame, plasma or arc spray). Other metal substrates can also be polished, sandblasted, brushed, micro-blasted or receive an addition of material by means of a technology such as thermal projection (flame, plasma or arc spray).

[0204] As metallic substrates which can be used in the present invention, mention may advantageously be made of anodized or non-anodized aluminum substrates, optionally polished, brushed, sandblasted, shot-blasted or micro-blasted, anodized or non-anodized aluminum alloy substrates, optionally polished, brushed, sandblasted or micro-blasted, steel substrates, optionally polished, brushed, sandblasted, shot-blasted or micro-blasted, stainless steel substrates, optionally polished, brushed, sandblasted or micro-blasted, cast steel, aluminum or iron substrates, and copper substrates, optionally hammered or polished.

[0205] Advantageously, the substrate may be chosen from substrates comprising ferritic stainless steel / aluminum / austenitic stainless steel layers, substrates comprising stainless steel / aluminum / copper / aluminum / austenitic stainless steel layers, cast aluminum, aluminum or aluminum alloy caps lined with an outer base of stainless steel, metallic co-laminated substrates, for example two-layer co-laminated substrates comprising a stainless steel layer (for example intended to constitute the inner face of the article) and a layer of aluminum or aluminum alloy, anodized or not (for example intended to constitute the outer face of the article).

[0206] Advantageously, the average arithmetic roughness Ra of the surface of the face (2a) of the metal substrate (2) is greater than or equal to 1 pm.

[0207] The arithmetic mean roughness Ra is measured using a roughness meter according to ISO 4287. Ra represents the arithmetic mean of the deviations from the mean. The surface topography can be studied in particular with a profilometer with a probe equipped with a fine stylus equipped with a diamond tip, or with an optical metrology device such as Altisurf®, in which a chromatic confocal sensor allows a contactless measurement. The study of this surface topography makes it possible to define the arithmetic mean roughness Ra.

[0208] PROCESS

[0209] The invention also relates to a method for manufacturing a coated cooking element (1) with a coating (4) for a household article according to the invention, characterized by the following steps: a) a step of providing a metal substrate (2) comprising two opposite faces; b) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a primer layer (4a) to the support (2); c) a step of applying the layers (4a), optionally (4b) and (4c) of the coating (4); d) optionally a drying step between 50°C and 100°C after application of said layers; e) a step of baking the element obtained in step c) or d) at a temperature between 250°C and 400°C

[0210] The invention also relates to a method for manufacturing a culinary article or electrical cooking appliance comprising a heating element coated (1) with a coating (4) according to the invention, characterized by the following steps: a) a step of providing a metal substrate (2) in the form of a substantially flat metal substrate comprising two opposite faces; b) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a primer layer (4a) to the support (2); c) a step of applying the layers (4a), optionally (4b), and (4c) of the coating (4); d) optionally a drying step between 50°C and 150°C after application of said layers; e) a step of baking the element obtained in step c) or d) at a temperature between 250°C and 420°C;f) a step of shaping the element obtained to give it the shape of a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22);

[0211] Advantageously, during step c), the layer(s) (4a), (4b) and (4c) is / are applied by pad printing, electrostatic powdering, spray spraying, screen printing, roller application or digital printing, preferably by spraying. Advantageously, the spraying is carried out in a solvent-based or aqueous phase.

[0212] Advantageously, when layer (4c) is made up of:

[0213] - an elastomer silicone obtained from at least one organopolysiloxane carrying reactive vinyl functions (-CH=CH2), at least one other organopolysiloxane carrying reactive silyl hydride functions (Si-H), preferably in the presence of a metal catalyst; and optionally: TJ

[0214] - one or more thermoplastics

[0215] - one or more charges, and / or

[0216] - one or more additive(s), and / or

[0217] - one or more coloring agents when at least one layer (4b) is present, the method according to the invention may comprise a step of crosslinking g) of the finishing layer (4c) subsequent to or simultaneously with step d).

[0218] According to a variant, the crosslinking of the composition of the layer (4c) can generally be activated, for example, by heat treatment, at a temperature between 50 and 400°C, preferably between 50 and 300°C, obviously taking into account the maximum resistance of the support to heat.

[0219] Advantageously, the crosslinking g) of the layer (4c) is carried out at a temperature of 300°C for a period of 10 min.

[0220] Advantageously, the higher the crosslinking temperature, the shorter the crosslinking time.

[0221] According to a variant, the crosslinking step g) does not require heat treatment, in particular because the support is hot at the time of step g).

[0222] Advantageously, during step c), this finishing layer (4c) is applied by electrostatic powdering, spray spraying, screen printing, spray gun, doctor blade, coating cylinder, brush, roller application or digital printing, preferably by spraying.

[0223] According to an advantageous arrangement of the invention, this finishing layer (4c) is applied to the coated support at a deposition rate of less than or equal to 5 g / m 2 , preferably between 0.1 and 2.5 g / m 2 , even more preferably between 0.2 and 2 g / m 2 .

[0224] Advantageously, the steps of the method according to the invention make it possible to coat the metal support (2) with a coating (4) formed by the layers (4a), optionally (4b) and (4c). Generally, these layers are wet when they are applied. By wet layer, it is understood within the meaning of the present invention that the layer comprises all or part of its solvents.

[0225] Shaping is also called stamping.

[0226] When the shaping step precedes the application d) of the coating, the coating is preferably carried out by spraying.

[0227] When this shaping step is subsequent to application d) of the coating, the coating is preferably carried out by screen printing or by roller.

[0228] ARTICLE

[0229] The invention also relates to a culinary article or an electrical cooking appliance comprising a cooking element coated according to the invention or capable of being obtained according to the method of the invention.

[0230] Advantageously, the culinary article (100) according to the invention is chosen from the group consisting of saucepan, frying pan, skillets or caquelons for fondue or raclette, stewpot, wok, sauté pan, crepe pan, grill, griddle, pot, casserole dish, cooker or bread machine bowl, culinary mold, molds and plates for pastry, barbecue plates and grills, preparation bowls.

[0231] According to one embodiment, the culinary article (100) comprises a heating face (6) intended to be placed in contact with an external heating source, the heating face (6) being opposite the cooking face (5) intended to be placed in contact with the food during cooking.

[0232] The culinary article according to the present invention may in particular be a culinary article of which one of the two opposite faces of the substrate is an inner face, possibly concave, intended to be arranged on the side of food likely to be introduced into or onto said article, and of which the other face of the substrate is an outer face, possibly convex, intended to be arranged towards a heat source.

[0233] Advantageously, the electric cooking appliance (200) is chosen from the group consisting of electric crepe maker, electric raclette appliance, electric fondue appliance, electric grill, electric griddle, electric cooker, bread maker, electric pressure cooking appliance, waffle makers, rice cookers and jam makers.

[0234] The electrical cooking appliance (200) comprises a coated cooking element (1) according to the invention and a heating source (210) configured to heat said coated cooking element (1).

[0235] EXAMPLES

[0236] The aims, aspects and advantages of the present invention will be better understood from the description given below of a particular embodiment of the invention presented by way of non-limiting example.

[0237] Of course, the invention is in no way limited to the embodiment described and illustrated, which has been given only as an example. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

[0238] 1) Examples of achievement:

[0239] Materials

[0240] PES Resin or PolyEtherSulfone (PES) powder resin, micronized grade from SUMITOMO, polymer powder with a d50 between 11 and 15 pm.

[0241] Solvents: o propionamide

[0242] Reinforcing fillers: o Alumina, o Silicon Carbide o Pyrogenic silica, o Colloidal silica o Colloidal alumina o Mica

[0243] Thickener: o 50% acrylic polymer solution in water o hydrogenated castor oil

[0244] Silicone resins: o Methyl-phenyl silicone resin, in flakes o Methyl silicone resin, in flakes

[0245] Solvent Alcohol o di propylene glycol butyl ether (DPNB), o MPG propylene glycol

[0246] Surfactant: o Fatty alcohol polyglycol ether

[0247] Anti-foam agent o Mineral oil

[0248] Pigments: o Mica or glitter o Carbon black:

[0249] Silicone oil: o A: non-reactive o B: reactive

[0250] Other additives: o buffering agent o anionic ester in ethanol / water, wetting agent, o aqueous dispersion of polydimethylsiloxane gum, surface tension agent

[0251] Examples of production of a culinary article according to the invention:

[0252] On a flat aluminum disc (30 cm in diameter), previously degreased and sandblasted to obtain a roughness of 4 to 7 pm (Ra), a continuous layer 3a is deposited by screen printing, chosen from the base layer compositions (4a1 and 4a2) as described below:

[0253] Layers 4a:

[0254] Layer 4a 1:

[0255] The thickness of this base layer 4a of the example is between 5 pm and 15 pm.

[0256] The substrate, on which the continuous base layer 4a as described above is applied, is coated with a multi-layer release coating consisting of an intermediate layer 4b (5-15 pm) which is dried at 80°C and a top layer 4c (5-15 pm). The whole is finally heated to 300°C for about 10 min, i.e. the process comprises only one baking step, after the deposition of the different layers. Layers 4b:

[0257] The compositions of the intermediate layers 4b deposited by screen printing are as described below (layer 4b1 and layer 4b2).

[0258] Layer 4b1:

[0259] The compositions of the 4c ​​finishing layers deposited by screen printing are as described below (layers 4c1 to 4c4): Finishing layer (4c)

[0260] Layer 4c 1: Layer 4c3:

[0261] Layer 4v4: Examples of construction / architecture of heating elements according to the invention:

Claims

CLAIMS 1. Coated cooking element (1) for a cooking article or electrical cooking appliance, comprising a metal substrate (2) coated on at least one face (2a) with a coating (3) intended to form a cooking face free of fluorocarbon resin and coated on at least the other face (2b) with a coating (4) comprising at least the following layers and in this order starting from the metal substrate (2): - (4a) primer layer comprising polyethersulfone (PES), - (4b) optionally, one or more intermediate layer(s) comprising polyethersulfone (PES) or a mixture of polyethersulfone (PES) and one or more silicone resins, - (4c) topcoat comprising polyethersulfone (PES) or one or more silicone resins or a mixture of polyethersulfone (PES) and one or more silicone resins.

2. Coated cooking element (1) according to claim 1, characterized in that the PES content increases from the primer layer (4a) to the finishing layer (4c).

3. Coated cooking element (1) according to claim 2, characterized in that the PES content of the primer layer (4a) represents from 50% to less than 75% by weight of the primer layer (4a).

4. Coated cooking element (1) according to any one of the preceding claims, characterized in that the PES content of the intermediate layer(s) (4b) represents from 75% to less than 85% by weight of said layer(s) when it is / are present.

5. Coated cooking element (1) according to any one of the preceding claims, characterized in that the PES content of the finishing layer (4c) represents from 85% to 98% by weight of the finishing layer (4c).

6. Coated cooking element (1) according to any one of the preceding claims, characterized in that the thickness of each of the layers of the coating (4a), (4b) and (4c) is from 5 μm to 15 μm.

7. Coated cooking element (1) according to claim 1, characterized in that the layer (4c) consists of: - an elastomer silicone obtained from at least one organopolysiloxane carrying reactive vinyl functions (-CH=CH2), at least one other organopolysiloxane carrying reactive silyl hydride functions (Si-H), preferably in the presence of a metal catalyst; and optionally: - one or more thermoplastics, and / or - one or more additive(s), and / or - one or more coloring agents when at least one layer (4b) is present.

8. A method of manufacturing a culinary article or electrical cooking appliance comprising a coated cooking element (1) with a coating (4) according to any one of the preceding claims, characterized by the following steps: a) a step of providing a metal substrate (2) in the form of a substantially flat metal substrate comprising two opposite faces; b) optionally, a step of treating at least one face (2a) of the metal substrate (2), to obtain a treated face (2a) promoting the adhesion of a primer layer (4a) to the support (2); c) a step of applying the layers (4a), optionally (4b), and (4c) of the coating (4); d) optionally a drying step between 50°C and 150°C after application of said layers; e) a step of baking the element obtained in step c) or d) at a temperature between 250°C and 420°C.f) a step of shaping the element obtained to give it the shape of a support (2) of convex or hollow shape defining a concave inner face (21) and a convex outer face (22).

9. Culinary article or electrical cooking appliance comprising a coated cooking element (1) according to any one of claims 1 to 7 or capable of being obtained according to claim 8, characterized in that the layer (4c) is intended to be placed in contact with a heating source.

10. Culinary article (100) according to claim 9, chosen from the group consisting of saucepan, frying pan, skillets or pots for fondue or raclette, stewpot, wok, sauté pan, crepe pan, grill, griddle, pot, casserole dish, cooker or bread machine bowl, culinary mold, molds and plates for baking, barbecue plates and grills, preparation bowls.

11. Electric cooking appliance (200) according to claim 9, 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 cooking appliance, waffle makers, rice cookers and jam makers.

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