Non-fluorinated silicon resin-based coating comprising temperature indicator

Abstract

The invention relates to a coated cooking element (1) for cookware or electric cooking utensils, comprising a metal base (2) coated on at least one face (2a) by at least the following layers, starting from the metal base (2) in the following order: (3a) a substrate layer consisting of one or more silicone resins and optionally from the following: one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one or more thermoplastic polymers, one and / or one or more colorants selected from the group consisting of thermochromic pigments, thermostable pigments, flakes and mixtures thereof, and / or one or more fillers, and / or one or more additives, (3b) one or more intermediate layers, the intermediate layer consists of one or more colorants selected from the group consisting of thermochromic pigments, thermostable pigments, flakes and mixtures thereof, and one or more silicone resins, and / or one or more thermoplastic polymers and / or one or more fillers, and / or one or more additives, optionally selected from the group consisting of one or more silicon resins, and / or one or more thermoplastic polymers and / or one or more fillers, and / or one or more additives. (3c) a facing layer of one or more thermoplastic polymers, and / or one or more fillers, and / or one or more additives, and / or flakes, of one or more silicone resins and optionally from the following; a method for manufacturing the cooking element; the invention also discloses a cooker and a cooking utensil comprising the cooking element.

Description

Technical Field

[0001] The present invention relates to cookware having a coating applied on one surface thereof, and more particularly to a silicone-based coating for such utensils. Background Art

[0002] In the cookware sector, coatings based on fluoropolymers, in particular polytetrafluoroethylene (PTFE), are known for their non-stick and heat-resistant properties.

[0003] However, these coatings have low mechanical strength.

[0004] Application WO2020 / 144051 relates to a fluoropolymer-based coating whose mechanical wear resistance is improved by introducing organic (SiC) and inorganic (Al 2 O 3 ) filler is improved.

[0005] The performance improvement achieved in terms of mechanical strength is satisfactory, but still not optimal.

[0006] Fluoropolymer-based coatings are mainly used for pots and pans, but due to their stamping properties other applications are possible in the field of molding (moulds, cake pans, waffle makers, etc.) or small household appliances (rice cookers, deep fryer containers, electric pancake makers).

[0007] Alternatives to PTFE coatings include the use of so-called "ceramic" coatings, which were developed by the sol-gel process and using tetraethyl orthosilicate (EP 2806776 B1). These coatings have the particular properties of being hard and resistant to mechanical wear, but also exhibit brittle behavior and lower non-stick properties compared to coatings based on fluoropolymers.

[0008] Furthermore, due to the lack of stamping properties, these coatings are not well suited for molding and small household devices.

[0009] In the field of molding (either by the general public or industrial molding), fluoropolymer based coatings are not widely used because the heat resistance limit is lower (up to 220°C) and allows the use of other types of coatings, such as silicone coatings.

[0010] Pure silicones are described as being anti-adhesive and resistant to temperatures greater than 220-230°C, whereas they are considered to have poor adhesion to substrates.

[0011] On the other hand, silicone-polyester resins are very widely used for molding, since they are non-sticky when adhered to the base and are compatible with stamping processes. However, they degrade at temperatures above 230°C, more particularly, cookware is used in the temperature range of 50-250°C, and in the case of utensils with induction bottoms, it is not surprising to reach temperatures of 300°C or even 350°C. Their use is therefore incompatible with the temperatures used in the cookware sector.

[0012] However, the control of cooking temperature is an important parameter as it determines the success of cooking and ensures the maintenance of the physicochemical properties of the non-stick coating. With this in mind, cooking start temperature indicators have been developed for consumers. The aim is to indicate, through a change of colour, the temperature at which consumers can start their cooking, thus avoiding any possible overheating.

[0013] The technology typically relies on the use of thermochromic pigments, whose color changes between room temperature and 250°C, depending on the nature of the material.

[0014] In addition to thermochromic pigments, other visually differentiating elements can be added to the coating (EP 2 675 328 A1 , EP 2 412 846 B1 ).

[0015] Patent EP2319631 describes the development of a two-layer silicone-based coating (base layer) combined with 0.5-20% of a high-temperature thermoplastic material, making it possible to obtain a coating that is mechanically strong, adheres to the base and is non-sticky. The properties of the thermoplastic vary between the base layer (PEEK) and the facing layer (PPS), and it is mainly located in the base layer to ensure adhesion to the base. The patent does not describe a temperature indicator.

[0016] Application US 2022 / 0073785 proposes a two-layer silicone / thermoplastic coating structure which is more concentrated in the thermoplastic material and also does not describe the introduction of a color indicator based on thermochromic pigments. Summary of the invention

[0017] A first object of the invention relates to a coated cooking element (1) for a cooker or electric cooking utensil, comprising a metal base (2) coated on at least one face (2a) with at least the following layers, in the following order, starting from the metal base (2):

[0018] (3a) A base layer composed of one or more silicone resins and selected from the following

[0019] - one or more thermoplastic polymers, and / or

[0020] - one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof, and / or

[0021] - one or more fillers, and / or

[0022] - One or more additives

[0023] (3b) one or more intermediate layers, the intermediate layers comprising one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof and one or more silicone resins, and / or

[0024] - one or more thermoplastic polymers and / or,

[0025] - one or more fillers, and / or

[0026] - One or more additives

[0027] (3c) A finishing layer composed of one or more silicone resins and selected from the following

[0028] - one or more thermoplastic polymers, and / or

[0029] - one or more fillers, and / or

[0030] - one or more additives, and / or

[0031] - Thin flakes.

[0032] Another object of the present invention relates to a method for manufacturing a coated cooking element (1) according to the present invention, comprising the following successive steps:

[0033] i. providing a metal base (2) having a surface (2a),

[0034] ii. Optionally, pre-treating the surface (2a) of the metal base (2) to be coated,

[0035] iii. applying the base layer (3a),

[0036] iv. drying the base layer (3a),

[0037] v. applying one or more intermediate layers (3b),

[0038] vi. optionally, drying the one or more intermediate layers (3b),

[0039] vii. Applying the finishing layer (3c).

[0040] Another object of the present invention relates to a kitchen appliance (100) comprising a coated cooking element (1) according to the present invention.

[0041] Another object of the present invention relates to an electric cooking appliance (200) comprising a coated cooking element (1) according to the present invention and a heating source (210) designed to heat the coated cooking element (1).

[0042] definition

[0043] In the context of the present invention, the term "layer" should be understood as a continuous or discontinuous layer. A continuous layer (also called an integral layer) is a single integral body that forms a whole planar surface that completely covers the surface to which it is applied. A discontinuous layer (or non-integral layer) may include multiple parts and is therefore not a single integral body.

[0044] The terms "substrate", "primer layer", "adhesive layer" or "adhesive primer" shall refer to all layers from the first layer applied directly to the carrier (preferably, this layer adheres well to the carrier and provides the coating with all its mechanical properties: hardness, scratch resistance) to the last layer before the first decorative layer.

[0045] The term "finish layer" or "finish" shall mean a continuous transparent surface layer which allows perfect visibility of the decorative layer while protecting it from mechanical attack and giving the coating non-stick properties. Preferably, the final finishing layer is intended for contact with food.

[0046] The term "decoration" or "decorative layer" refers to one or more continuous or discontinuous layers comprising a pigment composition. The decoration may be in the form of one or more patterns having one or more colors. The decoration is clearly visible to the naked eye of the user and is clearly visible at the usual distances at which the household article is used.

[0047] The term "overlapping layers" refers to layers that overlap partially or completely. The layers may be in the form of partially overlapping patterns, such as concentric disks.

[0048] The term "adjacent layers" shall mean non-overlapping layers. The layers may be in non-overlapping, identical or different patterns, preferably uniformly distributed.

[0049] The term "reference temperature pigment composition" refers to a composition comprising a pigment which, at a given temperature, indicates to the user that the optimum use temperature has been reached. This indication is made by comparing the color of the thermochromic pigment composition with the color of the reference temperature pigment composition. Either the optimum use temperature is reached when the colors are identical, or the optimum use temperature is reached when the colors are visually very different.

[0050] A "reference temperature pigment composition" may comprise a pigment having the following characteristics:

[0051] - the same color as the thermochromic pigment composition at the optimum use temperature,

[0052] * or because the pigment has the same color at room temperature as the thermochromic pigment composition at its optimal use temperature and does not change color with temperature,

[0053] * Or because the pigment has a different color from the thermochromic pigment composition at room temperature

[0054] The thermochromic pigment composition changes to the same color as the thermochromic pigment composition at the optimal use temperature,

[0055] - A color that is very different from that of a thermochromic pigment composition at the optimum use temperature, whether or not the pigment changes color with changes in temperature.

[0056] The optimum use temperature is reached when the color of the reference temperature pigment composition corresponds to the color indicated in the user guide of the household article comprising the coating according to the invention or to the color indicated on a color scale provided to the user together with the article.

[0057] The reference temperature pigment composition is thermochromic or thermally stable.

[0058] The reference temperature pigment composition may be, for example, a reference cooking temperature pigment composition or be used to indicate a risk of overheating.

[0059] The present invention has at least the following advantages:

[0060] - the coating according to the invention has a thermochromic function with a pronounced visibility, contrasting color change in a targeted temperature range and focused around food cooking temperatures, e.g. in kitchen appliances;

[0061] - when cooking food, the coating according to the invention can provide good temperature control, which is necessary for health and taste reasons, but also for safety and to limit accidental overheating that could weaken the coating;

[0062] - the thermochromic pigment composition has reversible thermochromic properties, i.e. after a color change under the action of heat, when the temperature is lowered, the compound returns to its initial state and its initial color; this color change cycle (reversibility) can be repeated indefinitely;

[0063] - The coating according to the invention has a remarkable thermal stability when the temperature is increased; it is stable up to about 450°C.

[0064] In the meaning of the present invention, the expression "thermochromic semiconductor" shall mean that it must include an inorganic or organic compound that has a reversible color change after an increase in temperature. The gradual and reversible thermochromic properties of these semiconductor compounds are related to the reduction of the width of the semiconductor band gap due to the expansion of the material. More specifically, the periodicity of the lattice of anions and cations leads to the aggregation of energy levels into energy bands. The filled energy band of higher energy is called the valence band, and the empty energy band of lower energy is called the conduction band. Between these two bands, there is a forbidden band called the band gap. The color of semiconductor materials can come from the presence of charge transfer, which corresponds to the passage of electrons from the valence band to the conduction band on a given atom, or generally from the anion orbit to the cation orbit (interatomic photon absorption).

[0065] In the field of application of the invention, optimal conditions are obtained when the coating reaches a temperature suitable for cooking food, preferably between 100 and 250°C.

[0066] In the context of the present invention, the term "thermochromic pigment or pigment composition" is understood to mean 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 and at a normal use distance.

[0067] The term "heat-stable pigment" refers to a pigment that does not show a color change when subjected to an increase in temperature within a given temperature range, or a pigment that shows a hue change when subjected to an increase in temperature within a given temperature range, the given temperature range being so small that it cannot be seen by the naked eye by the user at a normal usage distance.

[0068] The heat-stable pigment preferably has a color deviation ΔE* of less than 10 between 25°C and 200°C, ΔE* being defined in the CIELAB color space by the CIE 1976 formula:

[0069]

[0070] L 1 * 、a 1 * , b 1 * , the L*a*b* value characterizing the compound at room temperature,

[0071] L 2 * 、a 2 * , b 2 * , characterize the L*a*b* values ​​of the compound at 200°C.

[0072] The expression "same color" shall mean that they are indistinguishable by the user with the naked eye and at a distance of ordinary use.

[0073] In the context of the present invention, the expression "cooker" is to be understood as a utensil for cooking. To this end, it is intended to be subjected to heat treatment.

[0074] In the context of the present invention, the expression "article for heat treatment" is to be understood as an article to be heated by an external heating system, such as frying pans, pans, woks and grills, and which is capable of transferring the heat provided by the external heating system to the material or food in contact with the article.

[0075] In the context of the present invention, the expression "electric cooker" should be understood as a heating object having its own heating system, for example an electric pancake maker, an electric raclette maker, an electric fondue maker, an electric grill, an electric frying pan, a bread maker, an electric pressure cooker.

[0076] The term "coating" shall refer to all layers covering a metal substrate and adhering to that substrate.

[0077] The term "silicone-based coating" refers to a coating comprising one or more silicone resins in one or more of its layers. The coating obtained according to the invention is advantageously solid. The term "solid" refers to the property of a binding material that is insoluble in water, insoluble in conventional solvents, in food components such as aqueous or fatty mixtures, even though the material may have high hardness or high flexibility, such as an elastomer.

[0078] In the present invention, weight % is expressed on a dry weight basis, ie without taking into account the solvent. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] [ Figure 1 ]: Schematic diagram of a cooking element according to the invention, wherein layer (3b) is continuous and covers the entire layer (3a).

[0080] [ Figure 2 ]: Schematic diagram of a cooking utensil according to the invention, wherein layer (3b) does not cover the entire layer (3a) and forms a decoration.

[0081] [ Figure 3 ]: Schematic diagram of a cooking element according to the invention, wherein the layer (3b) comprises two decorations (i) and (j).

[0082] [ Figure 4 ]: Schematic diagram of pattern distribution. 4A = non-overlapping adjacent patterns. 4B = partially overlapping patterns. 4C = overlapping patterns.

[0083] [ Figure 5 ]: Schematic diagram of a cooking element according to the invention.

[0084] [ Figure 6 ]: Schematic diagram of an electric cooking appliance according to the present invention. DETAILED DESCRIPTION

[0085] The invention relates to a coated cooking element (1) for a cooker or electric cooking utensil, comprising a metal base (2) which is coated on at least one face (2a) with at least the following layers, starting from the metal base (2) in the following order:

[0086] (3a) A base layer composed of one or more silicone resins and selected from the following:

[0087] - one or more thermoplastic polymers, and / or

[0088] - one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof, and / or

[0089] - one or more fillers, and / or

[0090] - one or more additives;

[0091] (3b) one or more, preferably two, intermediate layers, said intermediate layers comprising one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof and any of the following:

[0092] Selected composition:

[0093] - one or more silicone resins, and / or

[0094] - one or more thermoplastic polymers and / or,

[0095] - one or more fillers, and / or

[0096] - one or more additives;

[0097] (3c) A finishing layer composed of one or more silicone resins and selected from the following:

[0098] - one or more thermoplastic polymers, and / or

[0099] - one or more fillers, and / or

[0100] - one or more additives, and / or

[0101] - Thin flakes.

[0102] Advantageously, the layers (3a), (3b) and (3c) form a coating (3) coating the metal substrate (2). The coating (3) has non-stick properties and forms a non-stick coating.

[0103] Advantageously, the layer ( 3 a ) is in contact via one of its faces with the metal base ( 2 ) via its face ( 2 a ).

[0104] Thus, at least one coated face (2a) of the metal base is a cooking face. In other words, the coating of the cooking element (1) according to the invention is in contact with the food.

[0105] Advantageously, said finishing layer (3c) is in contact with the food via one of its faces and thus forms a cooking surface (5).

[0106] The coating (3) of the cooking element (1) according to the invention does not comprise fluorinated polymers (also called fluoropolymers). In other words, the coating is free of fluorinated polymers.

[0107] Advantageously, the thickness of the layer ( 3 a ) is between 10 μm and 100 μm, preferably between 20 μm and 85 μm, particularly preferably between 30 μm and 70 μm.

[0108] Advantageously, the thickness of the layer ( 3 b ) is between 1 μm and 100 μm, preferably between 2 μm and 30 μm, particularly preferably between 3 μm and 10 μm.

[0109] 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. In a specific embodiment of the invention, the thickness of the layer (3c) is 100 nm + / - 5 nm.

[0110] According to one embodiment, the thickness of the layer ( 3 c ) is between 0.1 μm and 2 μm, preferably between 0.2 μm and 1.5 μm.

[0111] According to another embodiment, the thickness of the layer ( 3 c ) is between 10 μm and 100 μm, preferably between 20 μm and 85 μm, particularly preferably between 30 μm and 70 μm.

[0112] Metal base

[0113] Advantageously, the metal base (2) is a base made of aluminum, stainless steel, cast iron or cast aluminum, iron, titanium or copper.

[0114] Within the meaning of the present invention, aluminum is understood to be a metal consisting of 100% aluminum or an aluminum alloy.

[0115] Advantageously, the metal base (2) is a base made of aluminum, stainless steel or a multilayer metal base. The metal base (2) can be a two-layer or three-layer base, these multiple layers can be obtained, for example, by co-lamination, by thermal diffusion under load (solid state bonding) or by thermal or cold shock bonding.

[0116] Preferably, the metal base (2) comprises alternating layers of metals and / or metal alloys.

[0117] According to one embodiment, the metal base (2) is a base made of aluminum or a stainless steel alloy, or is a multi-layer metal base, wherein the face (2a) is aluminum or a stainless steel alloy.

[0118] Preferably, the metal base (2) is an aluminum base.

[0119] Advantageously, the thickness of the metal base (2) is between 0.5 mm and 10 mm.

[0120] Advantageously, the face (2a) of the metal base (2) has undergone a previous surface treatment in order to improve the adhesion of the coating to said base.

[0121] According to one embodiment, the surface of the face (2a) of the metal base (2) has undergone a surface treatment which is chemical etching, brushing, hydration, sandblasting, shot blasting, physicochemical plasma, corona or laser treatment, chemical activation or a combination of these different techniques.

[0122] Advantageously, the face (2a) of the substrate to which the coating (3) according to the invention is to be applied may be treated to increase its specific surface area; for aluminium substrates, this treatment may be by anodising (producing a tubular aluminium oxide structure), by chemical etching, sandblasting, brushing, shot peening or by adding material using techniques such as thermal spraying (flame, plasma or arc spraying). Other metal substrates may also be polished, sandblasted, brushed, micro-bead blasted or receive the addition of material using techniques such as thermal spraying (flame, plasma or arc spraying).

[0123] Metals that can be used as the base of the present invention advantageously include bases made of aluminum, which may or may not be anodized, optionally polished, brushed, sandblasted, shot peened or micro-bead blasted, bases made of aluminum alloys, which may or may not be anodized, optionally polished, brushed, sandblasted, shot peened or micro-bead blasted, bases made of steel, which are optionally polished, brushed, sandblasted, shot peened or micro-bead blasted, bases made of stainless steel, which are optionally polished, brushed, sandblasted or micro-bead blasted, bases made of cast steel, aluminum or iron, and bases made of copper, which are optionally hammered or polished.

[0124] Advantageously, the base can be chosen from a base comprising a ferritic stainless steel / aluminium / austenitic stainless steel layer, a base comprising a stainless steel / aluminium / copper / aluminium / austenitic stainless steel layer, a cast aluminium, an aluminium or aluminium alloy cap lined with a stainless steel outer bottom, a metal co-laminated base, such as a two-layer co-laminated base comprising a stainless steel layer (e.g. for constituting the inner surface of the element) and an anodised or unanodised aluminium or aluminium alloy layer (e.g. for constituting the outer surface of the element).

[0125] Advantageously, the surface of the face (2a) of the metal base (2) has an arithmetic mean roughness Ra greater than or equal to 1 μm.

[0126] The arithmetic mean roughness Ra is measured by a roughness meter according to standard ISO 4287. Ra represents the arithmetic mean of the deviations from the mean. The surface topography can be studied, in particular, using a profilometer with a probe equipped with a fine pen with a diamond tip, or using An optical metrology instrument of the type in which a confocal color sensor enables contactless measurement. By studying this surface topography data, the arithmetic mean roughness Ra can be determined.

[0127] Silicone

[0128] In the body of the specification, the expression "silicone" is used interchangeably to refer to silicone before or after it is crosslinked. In the body of the specification, the expression "silicone" refers to an organopolysiloxane material. Crosslinking is a step that makes it possible to convert the silicone into an insoluble material, for example by polyaddition, polycondensation or dehydrogenation. The crosslinking is carried out on a precursor, usually an oil or a silicone resin, which crosslinks to obtain a three-dimensional network, forming the material referred to as silicone in the specification.

[0129] This crosslinking can be performed by thermal activation or chemical activation using a catalyst such as platinum.

[0130] Silicone resins can be obtained from precursors which are advantageously soluble in solvents or in aqueous emulsion, such as crosslinkable oils or resins, in particular chosen from: silanes, polyisocyanates containing at least one vinyl group (—CH═CH 2 ), silicones or silicone-polyesters (copolymers) containing at least one alkoxy group, for example methoxy or ethoxy, and / or silicones or silicone-polyesters (copolymers) containing at least one alkoxy group, in particular ethoxy or hydroxyl group, and mixtures thereof. These precursors have the ability to crosslink in order to obtain silicone resins characterized by their insolubility and their substantially solid form.

[0131] Advantageously, these precursors are polymers or oligomers, or in the form of silicone oils with variable branching, or in the form of silicone resins with variable pre-crosslinking or silicone copolymers such as silicone-polyesters, silicone-alkyd resins, silicone-polyurethanes, silicone-epoxy resins, or in the form of mixtures of silicone oils, silicone resins and silicone copolymers. The silicon atom may be substituted by an alkyl (particularly methyl) or aryl (particularly phenyl) group or a mixture thereof. The oil or resin preferably contains one or more (2,3 or more) hydroxyl or alkoxy (particularly methoxy, ethoxy, butoxy) functional groups as substituents of the silicon atom.

[0132] Advantageously, the silicone resin or resins, obtained after crosslinking of their precursors (i.e. crosslinked), are chosen from methyl silicones and / or phenyl silicones and / or methyl-phenyl-silicone resins, methyl silicone-polyester resins (copolymers), phenyl silicone-polyester resins (copolymers), methyl-phenyl silicone-polyester resins (copolymers), silicone-alkyd resins (copolymers), modified silicone resins and mixtures thereof.

[0133] Advantageously, the one or more silicone resins are selected from methyl silicone and / or phenyl silicone and / or methyl-phenyl silicone resin, methyl silicone-polyester resin (copolymer), phenyl silicone-polyester resin (copolymer), methyl-phenyl silicone-polyester resin (copolymer), silicone-alkyd resin (copolymer), modified silicone resin and mixtures thereof.

[0134] The silicone resin of the monolayer (3) forms a network which may consist of a combination of four single organosiloxane units denoted M, D, T and Q depending on the degree of oxygen substitution of the silicon atom, as described in the table below, wherein R is an organic substituent as described below.

[0135]

[0136]

[0137] Organopolysiloxane materials or polymers are obtained by crosslinking precursors, which may be monomers or polymers, or in an intermediate manner, oligomers. Organopolysiloxane polymers may also be obtained from mixtures of these different types of precursors. The crosslinking density is higher when the network contains a greater number of T and Q units than D units. The distribution between M, D, T and Q units depends on the chemical structure of the precursors, in particular on the distribution of M, D, T, Q in the precursors.

[0138] The polymer precursor is an organopolysiloxane. These macromolecules are formed from the M, D, T and / or Q units described in the table, wherein R is independently an alkyl (especially methyl) or aryl (especially phenyl) group, and different types of R can exist on the same macromolecule.

[0139] Organopolysiloxanes can be linear or slightly branched (mainly D groups), or branched or very branched (mainly T and Q groups). Straight-chain or slightly branched organopolysiloxanes are generally liquid, more or less viscous at room temperature, and are referred to as silicone oils. Branched or very branched (pre-crosslinked) organopolysiloxanes form networks on the scale of individual macromolecules and are referred to as silicone resins. At room temperature, the resins are essentially in solid form, or in liquid form (provided in particular that they have a fairly low molecular weight), in the form of solutions in solvents, or in the form of aqueous emulsions. They can be copolymerized with organic polymers or oligomers that do not contain silicon, which are particularly selected from polyesters, acrylic acid, alkyd resins, polyurethanes and epoxy resins.

[0140] When the crosslinking is a hydrolysis-polycondensation: it is carried out using the hydroxyl or alkoxy reactive functional groups present on the organopolysiloxane, in particular the methoxy, ethoxy or butoxy groups.

[0141] When the crosslinking is by polyaddition (or hydrosilylation): it is through the reactive vinyl functional groups (-CH=CH 2 ) and reactive silyl-hydride functional groups (Si—H) present on other organopolysiloxanes mixed with the aforementioned organopolysiloxane.

[0142] All of these reactive functional groups are present on each organopolysiloxane, at least one in number, and may be present in 2, 3 or more numbers within the range permitted by the molecular structure. Silicone oils containing at least one reactive functional group are referred to as "reactive oils". The reactive functional groups may be at the end (terminus) of the macromolecular chain, or distributed throughout the chain.

[0143] The silicone-polyester has, in particular, a silicone / polyester mass ratio 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.

[0144] Linear PDMS silicone oils, pure or pre-emulsified in water, are characterized primarily by their molecular weight, which is a direct increasing function of the viscosity of the pure oil. They are then characterized by the presence or absence of reactive functional groups, such as hydroxyl groups on silicon atoms (silanols), their number and their position on the molecular chain. For example, reactive oils with a viscosity of 50-20,000 mPa.s, in particular 300-5000 mPa.s, can be used, which have at least one, preferably at least 2, reactive functional groups, which can be located at the end of the chain.

[0145] The polymer precursors that react by addition polymerization may include, for example, polymethylhydrogensiloxane, vinylmethylsiloxane, vinyl-terminated, especially linear polydimethylsiloxane (PDMS), vinyl-terminated diphenylsiloxane-dimethylsiloxane copolymers, hydride-terminated polydimethylsiloxane, hydride-terminated polyphenylmethylsiloxane, cyclic vinylmethylsiloxane, vinyl-MQ resin, trimethylsilyl-terminated polymethylhydrogensiloxane, copolymers of trimethylsiloxane-terminated methylhydrogensiloxane and dimethylsiloxane, MQ-resin hydrides, and the like, and combinations thereof.

[0146] The polymer precursors reacted by hydrolysis-condensation, whether they are silicone resins or silicone oils, can include, for example, poly(methylsilsesquioxane), poly(propylsilsesquioxane), poly(phenylsilsesquioxane), polydimethylsiloxane (PDMS), trimethylsilyl-terminated polydimethylsiloxane (PDMS), hydroxyl-terminated polydimethylsiloxane (PDMS), silanol-terminated polydimethylsiloxane (PDMS), silanol-terminated polyphenylsiloxane (PDMS), silanol-terminated diphenylsiloxane-dimethylsiloxane copolymers, poly(2-acetoxyethylsilsesquioxane), organically modified alkoxysilanes and their oligomers, and all similar macromolecules and mixtures thereof.

[0147] The organopolysiloxane material or polymer can also be obtained by crosslinking a mixture of one or more monomer precursors and one or more polymer precursors as described above and one or more oligomeric precursors, which can be linear, branched or cyclic. These oligomeric precursors have a lower molecular weight than the polymer precursors. In order to promote the high crosslinking density of the organopolysiloxane polymer finally obtained, a polymer and / or oligomeric precursor containing a number of reactive functional groups greater than 2, advantageously much greater than 2, as described above, can be added to the mixture as a "co-binder".

[0148] The monomers, oligomers and / or polymer precursors, in particular silicone resins, copolymerized or not copolymerized with organic polymers, act as polymeric binders to obtain solid organopolysiloxane polymers bonded to the thermoplastic of each layer.

[0149] If the silicone oil type organopolysiloxane precursor is added in a relatively small amount (typically 0.1-5% dry) in the overall formulation for forming a layer, independently of the other components forming the solid organopolysiloxane polymer, it can be considered an additive.

[0150] Crosslinking may require a catalyst:

[0151] In the case of crosslinking of organopolysiloxanes by hydrolysis-polycondensation, the formulations may include metal catalysts, for example metal complexes based on platinum, tin, zinc, zirconium and cerium, in particular complexes of platinum-cyclovinylmethyl-siloxane, tin ethylhexanoate, zinc ethylhexanoate, zirconium ethylhexanoate, cerium ethylhexanoate and dibutyltin laurate.

[0152] In the case of crosslinking of the organopolysiloxane by hydroalkylation, it may be necessary to add a catalyst; this may be, for example, platinum or a suitable platinum-based catalyst, such as a Karstedt catalyst or an Ashbys catalyst.

[0153] Crosslinkers may be present, bearing for example Si-H bonds.

[0154] According to one embodiment, the proportion of silicone resin in the layer ( 3 a ) is greater than or equal to 20% by weight, respectively, relative to the total weight of the layer ( 3 a ).

[0155] According to another embodiment, the proportion of silicone in the layer ( 3 a ) is greater than or equal to 40% by weight, respectively, relative to the total weight of the layer ( 3 a ).

[0156] According to yet another embodiment, the proportion of silicone resin in the layer (3a) is greater than or equal to 50% by weight, respectively, relative to the total weight of the layer (3a).

[0157] According to one embodiment, the proportion of silicone resin in the layer ( 3 b ) is greater than or equal to 20% by weight, respectively, relative to the total weight of the layer ( 3 b ).

[0158] According to another embodiment, the proportion of silicone in the layer ( 3 b ) is greater than or equal to 40% by weight, respectively, relative to the total weight of the layer ( 3 b ).

[0159] According to yet another embodiment, the proportion of silicone resin in the layer (3b) is greater than or equal to 50% by weight, respectively, relative to the total weight of the layer (3b).

[0160] According to one embodiment, the proportion of silicone resin in the layer ( 3 c ) is greater than or equal to 20% by weight, respectively, relative to the total weight of the layer ( 3 c ).

[0161] According to another embodiment, the proportion of silicone in the layer ( 3 c ) is greater than or equal to 40% by weight, respectively, relative to the total weight of the layer ( 3 c ).

[0162] According to yet another embodiment, the proportion of silicone resin in the layer (3c) is greater than or equal to 50% by weight, respectively, relative to the total weight of the layer (3c).

[0163] Thermoplastic polymers

[0164] Advantageously, the one or more thermoplastic polymers are selected from polyaryletherketones (PAEK), aromatic thermoplastic polymers such as polyarylethersulfones (PAES), polyarylethersulfones (PAS) or polyphenylene oxides (PPO), liquid crystal polymers, heterocyclic thermoplastic polymers and mixtures thereof.

[0165] PAEK

[0166] Advantageously, the one or more polyaryletherketones (PAEK) are selected from the group consisting of polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK) and polyetherketoneetherketoneketone (PEKEKK), particularly preferably PEEK.

[0167] Other aromatic thermoplastic polymers

[0168] According to the invention, aromatic thermoplastic polymers include, for example, polyphenylene oxide (PPO), poly(aryl ether sulfone) (PAES) polymers, in particular polyether sulfone (PES), polyphenylene ether sulfone (PPSU), polyarylene sulfide (PAS) and in particular polyphenylene sulfide (PPS), liquid crystal polymers and mixtures thereof.

[0169] Heterocyclic thermoplastic polymers

[0170] Heterocyclic thermoplastic polymers include, for example, polyetherimide (PEI), polyimide (PI), polyamideimide (PAI) and polybenzimidazole (PBI) according to the present invention, or mixtures thereof.

[0171] Advantageously, the one or more thermoplastic polymers are selected from polyethersulfone (PES), polyphenylene ethersulfone (PPSU), polyamideimide (PAI), polyimide (PI), polyphenylene ether (PPO), polyarylether sulfide (PAS), polyetherimide (PEI), polybenzimidazole (PBI), liquid crystal polymer (LCP), polyphenylene sulfide (PPS), polyaryletherketone (PAEK) and mixtures thereof, polyaryletherketone (PAEK) including polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK) and polyetherketoneetherketoneketone (PEKEKK).

[0172] According to one alternative, PAEK is used in the form of a suspension, and the PAEK particles in the PAEK suspension have a particle size distribution with a d50 of about 10 μm to 15 μm.

[0173] Advantageously, the nature of the thermoplastic polymer or polymers in layers (3a), (3b) and (3c) may be the same or different.

[0174] Advantageously, the layer (3a) comprises one or more thermoplastic polymers, preferably in a proportion by weight of less than 50%, preferably less than 40% of said layer.

[0175] Advantageously, the layer (3b) comprises one or more thermoplastic polymers, preferably in a proportion by weight of less than 30%, preferably less than 20% of said layer.

[0176] Advantageously, the layer (3c) comprises one or more thermoplastic polymers, preferably in a proportion by weight of less than 50%, preferably less than 40% of said layer.

[0177] According to one embodiment, layer (3a) and layer (3c) comprise one or more thermoplastic polymers, the proportion of thermoplastic polymer in layer (3c) being preferably greater than the proportion of thermoplastic polymer in layer (3a).

[0178] According to another embodiment, layer (3a) and layer (3c) comprise one or more thermoplastic polymers, the proportion of thermoplastic polymer in layer (3a) being greater than the proportion of thermoplastic polymer in layer (3c).

[0179] filler

[0180] The fillers of the present invention provide mechanical reinforcement and may also provide hydrophobicity while improving the mechanical strength and thermal conductivity of the coating.

[0181] Fillers not only provide color to the coating;

[0182] The presence of fillers with excellent thermal conductivity can compensate for the low thermal conductivity of PAEK polymer.

[0183] Advantageously, the one or more fillers are selected from ceramics (SiO 2 , etc.) and / or minerals and / or metals (Al 2 O 3 、TiO 2 , etc.) and / or silica and / or diamond particle fillers.

[0184] Preferably, the one or more fillers are selected from metal oxides, metal carbides, metal oxynitrides, metal nitrides and mixtures thereof.

[0185] Advantageously, the metal is a transition metal, for example at least one of the elements selected from B, Ni, Ti, Zr or Hf.

[0186] Still more preferably, the one or more fillers are selected from:

[0187] - Fillers for reinforcement: hard organic or inorganic fillers; hard inorganic fillers are preferably particles of silicon carbide, aluminum oxide, zirconium oxide, graphite, ceramics, carbonates, hydrated aluminum oxide, aluminum hydroxide, or one or more metal oxides, graphite, graphene;

[0188] - other fillers for reinforcement, chosen from metal oxides: silica, mica, lamellar fillers, clays (such as montmorillonite, sepiolite, gypsum, kaolinite and laponite), zinc dioxide, quartz and zirconium phosphate, alumina, zirconium oxide, zinc oxide, copper oxide and iron oxide;

[0189] - fillers chosen from reinforcing fibers: glass, carbon or aramid fibers;

[0190] - a conductive filler comprising a transition metal carbide and / or a transition metal nitride: characterized in that the transition metal is at least one element selected from B, Ni, Ti, Zr or Hf,

[0191] For example: cubic boron nitride, diamond particles, metal particles;

[0192] -Layered fillers, such as clay, graphene or graphite, can provide lubricity properties.

[0193] Preferred fillers for combination with organopolysiloxanes are:

[0194] - reinforcing fillers: silica or carbonates with a filler content of at least 10-15% by weight and at most 60% by weight,

[0195] -alumina, hydrated alumina, aluminum hydroxide,

[0196] - Silicon dioxide (precipitated or pyrogenic) with d50 < 0.1 μm and a specific surface area BET > 30 m 2 / g, preferably 30-500m 2 / g,

[0197] -Mixture of quartz and silicon dioxide, diatomaceous earth or quartz powder, titanium, mica, talc, kaolin, barium sulfate, slaked lime, zinc oxide, expanded vermiculite, unexpanded vermiculite, calcium carbonate, etc.

[0198] Still more preferably, the one or more fillers are selected from the group consisting of alumina, silicon carbide, tungsten carbide, boron nitride, quartz, and mixtures thereof.

[0199] Advantageously, the filler has a median diameter d50 of from 0.1 to 50 μm, more advantageously from 5 to 15 μm.

[0200] Advantageously, the proportion of filler in the layer is between 0.5 and 30% by dry weight, preferably between 5 and 20% by dry weight, relative to the total weight of said layer after curing.

[0201] Advantageously, the proportion of filler in layer (3a) is less than 10% by weight relative to the total weight of said layer.

[0202] Advantageously, the proportion of filler in layer ( 3 b ) is less than 10% by weight relative to the total weight of said layer.

[0203] Advantageously, the proportion of filler in layer ( 3 c ) is less than 10% by weight relative to the total weight of said layer.

[0204] Advantageously, the proportion of filler in layers (3a), (3b) and (3c) is less than 10% by weight, relative to the total weight of layer (3a) / layer (3b) / layer (3c), respectively.

[0205] Advantageously, the proportions of fillers in layers (3a), (3b) and (3c) may be the same or different.

[0206] Advantageously, the nature of the fillers in layers (3a), (3b) and (3c) may be the same or different.

[0207] additive

[0208] Advantageously, the additive is selected from defoamers, dispersants, wetting agents, thickeners, pH regulators, and reactive silicone oils.

[0209] The one or more defoaming agents are preferably selected from mineral oils, glycols, hydrocarbons, glycerides, ethylene oxide and emulsified fatty acids.

[0210] The one or more surfactants are preferably selected from glycol ethers, ethoxylated alcohols other than alkylphenol ethoxylates (APE), gemini surfactants.

[0211] The one or more dispersants are preferably selected from anionic dispersants, such as fatty acid derivatives.

[0212] The thickener is preferably selected from acrylic or polyurethane based copolymers, cellulose and fumed silica.

[0213] The pH adjuster is preferably selected from Bronsted bases: ammonia, amines (triethylamine, triethanolamine, etc.), (sodium, potassium, etc.), hydroxides, carbonates.

[0214] Advantageously, the proportion of additives in layer ( 3 a ) is less than 20% by weight relative to the total weight of said layer.

[0215] Advantageously, the proportion of additives in layer ( 3 b ) is less than 20% by weight relative to the total weight of said layer.

[0216] Advantageously, the proportion of additives in layer ( 3 c ) is less than 20% by weight relative to the total weight of said layer.

[0217] Advantageously, the proportion of additives in layer (3a), (3b) or (3c) is less than 20% by weight relative to the total weight of layer (3a) / layer (3b) / layer (3c).

[0218] Colorants

[0219] Advantageously, the one or more colorants are chosen from thermochromic pigments, thermally stable pigments, flakes and mixtures thereof.

[0220] Advantageously, the proportion of colorant in the layer is between 0.5 and 50% by dry weight relative to the total weight of said layer after curing.

[0221] Advantageously, when a colorant is present, the proportion of colorant in layer ( 3 a ) is between 10% and 40% by weight relative to the total weight of said layer.

[0222] Advantageously, the proportion of colorant in layer ( 3 b ) is between 10% and 40% by weight relative to the total weight of said layer.

[0223] Advantageously, when a colorant is present, the proportion of colorant in layer (3c) is less than 10% by weight relative to the total weight of said layer.

[0224] Advantageously, the proportions of colorants in layers (3a), (3b) and (3c) may be the same or different.

[0225] Advantageously, the nature of the colorants in layers (3a), (3b) and (3c) may be the same or different.

[0226] Thermochromic Pigments

[0227] Preferably, the one or more thermochromic pigments are selected from Bi 2 O 3 , Fe 2 O 3 、V 2 O 5 , WO 3 、CeO 2 、In 2 O 3 , Y 1.84 Ca 0.16 Ti 1.84 V 0.16 O 1.84 、AgI、(Bi 1-x A x )(V 1-y M y ) 4 ,in:

[0228] -x is equal to 0 or x is between 0.001 and 0.999,

[0229] -y is equal to 0 or y is between 0.001 and 0.999,

[0230] - A and M are selected from nitrogen, phosphorus, alkali metals, alkaline earth metals, transition metals, poor metals, metalloids or lanthanides,

[0231] -A and M are different from each other.

[0232] It is known that A and M are different from each other, at this time:

[0233] - A is an alkali metal, which can be selected from Li, Na, K, Rb, Cs,

[0234] - M is an alkali metal, which can be selected from Li, Na, K, Rb, Cs,

[0235] - A is an alkaline earth metal, which can be selected from Be, Mg, Ca, Sr, Ba,

[0236] - M is an alkaline earth metal, which can be selected from Be, Mg, Ca, Sr, Ba,

[0237] - A is a transition metal, which can be selected from Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir,

[0238] - M is a transition metal, which can be selected from Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir,

[0239] -A is a poor metal, which can be selected from Al, Zn, Ga, In, Sn,

[0240] -M is a poor metal, which can be selected from Al, Zn, Ga, In, Sn,

[0241] - A is a metalloid, which can be selected from B, Si, Ge, Sb,

[0242] -M is a metalloid, which can be selected from B, Si, Ge, Sb,

[0243] - A is a lanthanide element, which can be selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,

[0244] -M is a lanthanide element, which can be selected from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.

[0245] Preferably, A and M are different from each other and are B and / or Mg.

[0246] Preferably, the pigment (Bi 1-x A x )(V 1-y M y ) 4 At room temperature it has the crystalline form of monoclinic scheelite.

[0247] Preferably x and y are 0, that is, the pigment (Bi 1-x A x )(V 1-y M y ) 4 Bismuth vanadate (BiVO 4 ). Advantageously, BiVO 4 , which has a monoclinic scheelite structure at room temperature.

[0248] Bismuth vanadate is a yellow inorganic compound with the formula BiVO 4 , is widely used due to its coloring properties and non-toxicity. It is entered in the International Color Index as QI Yellow Pigment 184, specifically by Heubach BASF FERRO (Lysopac) and Bruchsaler Farbenfabrik Sale.

[0249] Heat stable pigments

[0250] Preferably, the one or more heat stable pigments are selected from:

[0251] -Titanium rutile yellow pigment,

[0252] - yellow pigments derived from bismuth, for example selected from stabilized bismuth vanadates (Py 184 ),

[0253] - red pigments, for example selected from perylene red (for example PR149, PR178 and PR224), iron oxide,

[0254] -Bismuth Oxyhalide Orange Pigment (PO 85 ),

[0255] -Bismuth vanadate orange pigment (PO 86 ),

[0256] -Tin-Titanium-Zinc Orange Pigment (PO 82 ),

[0257] -Cerium Sulfide Orange Pigment (PO 75 PO 78 ),

[0258] -Chromium antimony titanium rutile orange-yellow pigment (PBr 24 ),

[0259] -Zinc Tin Rutile Orange Yellow Pigment (Py 216 ),

[0260] -Zinc tin sulfide niobium oxide orange-yellow pigment (Py 227 ),

[0261] -Niobium tin double oxide orange-yellow pigment,

[0262] -Co 3 (PO 4 ) 2 ,

[0263] -LiCoPO 4 ,

[0264] -CoAl 2 O 4 ,

[0265] -Cr 2 O 3 ,

[0266] -TiO 2 ,

[0267] -Black pigment PBk28 (copper chrome black spinel),

[0268] - and mixtures thereof.

[0269] Thin slice

[0270] The flakes useful in the present invention may be independently selected from coated or uncoated mica flakes, coated or uncoated silica flakes, coated or uncoated aluminum flakes, and coated or uncoated iron oxide flakes. Mica or silica flakes coated with titanium dioxide. The flakes useful in the present invention may be treated to produce a specific color effect.

[0271] Advantageously, the flake or flakes are particles chosen from mica, aluminium, mica coated with titanium dioxide or mixtures thereof.

[0272] Holographic Sheets

[0273] Advantageously, one or more of the flakes are holographic flakes, ie a mixture of magnetizable particles and non-magnetizable particles.

[0274] The magnetizable particles may advantageously be particles comprising at least one ferromagnetic metal. These magnetizable particles may be homogeneous, i.e. formed from the same material, or composite, i.e. these magnetizable particles have a core-shell structure, wherein the ferromagnetic metal is located in the core and / or shell of the particles. Examples of composite magnetizable particles include in particular particles coated with iron oxide Fe 2 O 3 Mica flakes or stainless steel fibers coated with a sol-gel material as corrosion protection during the coating step, or made of a plastic material and coated with iron oxide Fe 2 O 3 A sheet having a core made of a ferromagnetic metal and a shell formed of a plastic material or a sol-gel material.

[0275] According to an embodiment, some of said magnetizable particles are oriented so as to form a three-dimensional decoration.

[0276] Advantageously, the mixture of magnetizable particles and non-magnetizable particles represents from 1% to 5% by weight, preferably from 2% to 3% by weight, based on the weight of the layer.

[0277] 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.

[0278] Advantageously, the magnetizable particles have a size D50 of less than or equal to 23 μm.

[0279] In the context of the present invention, the term "D50" refers to the largest dimension exhibited by 50% by number of the particles.

[0280] Advantageously, the non-magnetizable particles have a size D90 which is between 20% and 250% of the size D90 of the magnetizable particles.

[0281] In the context of the present invention, the term "D90" refers to the largest dimension exhibited by 90% by number of the particles.

[0282] Advantageously, the magnetizable particles and / or the non-magnetizable particles are colored on the surface.

[0283] Advantageously, the non-magnetizable particles are in the form of mica, aluminum or mica coated with titanium dioxide.

[0284] Advantageously, the magnetizable particles are formed from iron, iron oxide, aluminum coated with iron or mica coated with iron, the iron being in the form of ferrite.

[0285] decorate

[0286] According to one embodiment, the one or more layers (3b) are continuous and cover the entire layer (3a) (see Figure 1 ).

[0287] According to another embodiment, one or more layers (3b) do not cover the entire layer (3a) and form at least one decoration (see Figure 2 ).

[0288] Advantageously, one or more layers (3b) form a plurality of decorations, one layer (i) comprising one or more thermochromic pigments and another layer (j) comprising at least one reference temperature pigment composition (cf. Figure 3 ).

[0289] According to one embodiment, each of the two decorations (i) and (j) is in the form of non-overlapping adjacent patterns. For example, each decoration is represented by different geometric patterns that are evenly distributed over the entire surface and alternate with respect to each other (see Figure 4 A).

[0290] According to another embodiment, the two decorations (i) and (j) partially overlap. For example, each decoration is represented by a different geometric pattern evenly distributed over the entire surface and partially overlapping (see Figure 4 B).

[0291] Preferably, the two decorations (i) and (j) overlap, either because one of the two decorations is a continuous layer and the other decoration covers the continuous layer in the form of a pattern, or because the two decorations (i) and (j) are in the form of overlapping patterns (see Figure 4 C).

[0292] method

[0293] The invention also relates to a method for manufacturing a coated cooking element (1) according to any one of the preceding claims, comprising the following successive steps:

[0294] i. providing a metal base (2) having a surface (2a),

[0295] ii. Optionally, pre-treating the surface (2a) of the metal base (2) to be coated,

[0296] iii. applying the base layer (3a),

[0297] iv. drying the base layer (3a),

[0298] v. applying one or more intermediate layers (3b),

[0299] vi. optionally, drying one or more intermediate layers (3b),

[0300] vii. Applying a finishing layer (3c).

[0301] Advantageously, the steps of the method according to the invention make it possible to coat a metal substrate (2) with a coating (3) formed by three layers (3a), (3b) and (3c). Typically, these three layers are wet when they are applied. In the context of the present invention, a "wet layer" means that the layer contains all or part of its solvent.

[0302] Preferably, all or part of the solvent of the wet layer is removed naturally or by a physical treatment such as thermal drying, drying by a stream of air or by a vacuum treatment.

[0303] Advantageously, the coating composition according to the invention may further comprise at least one solvent. Advantageously, the solvent may be a protic solvent. Advantageously, the solvent may be non-toxic.

[0304] The solvent that can be used in the coating composition according to the invention may advantageously comprise at least one alcohol and may preferably be selected from isopropanol, methanol, ethanol and mixtures thereof.

[0305] The application of the coating is carried out in multiple layers. In this case, at least one layer of the coating (3) according to the invention is deposited on at least one of the two opposite faces of the substrate, which is repeated several times. Preferably, a drying step is carried out between the application of each layer, and then curing of the coated substrate is carried out after the application of the last layer. The application of the coating (3) on the substrate (2) by the method according to the invention makes it possible to obtain a layer of thermally stable coating.

[0306] The coating formulation to be applied is usually in aqueous form, with the polymer of the polymer phase in suspension form. Other non-aqueous solvents are also suitable.

[0307] Advantageously, the method for manufacturing a coated cooking element (1) according to the invention comprises one or more drying steps between 80° C. and 150° C. after the application of each layer. Drying can be carried out by convection or infrared.

[0308] The application of the coating of the invention by the method of the invention can be carried out on a flat substrate or on a shaped substrate, or even on a locally flat area of ​​a shaped substrate. A thermally stable coating is obtained. Typically, the coating is wet.

[0309] Advantageously, the method for manufacturing a coated cooking element (1) according to the invention comprises a step of shaping said support (2) before or after curing step iii. or after curing step vii. or viii. Shaping is also known as stamping.

[0310] When the shaping step precedes the coating iii, the coating is preferably carried out by spraying.

[0311] When this shaping step is performed after the application of the coating vii., it is preferably applied by screen printing or by roller coating.

[0312] The method according to the invention advantageously comprises a step viii. of curing the element obtained in step vii. of the method. In the context of the present invention, "curing the coated substrate" means a thermal treatment which densifies the coating or coatings applied on the substrate and crosslinks the organopolysiloxane (silicone) precursor.

[0313] The method also relates to a method for manufacturing a coated cooking element (1) according to any one of the preceding claims, comprising the following successive steps:

[0314] i. providing a metal base (2) having a surface (2a),

[0315] ii. Optionally, pre-treating the surface (2a) of the metal base (2) to be coated,

[0316] iii. applying the base layer (3a),

[0317] iv. drying the base layer (3a),

[0318] v. applying one or more intermediate layers (3b),

[0319] vi. optionally, drying one or more intermediate layers (3b),

[0320] vii. Applying finishing layer (3c)

[0321] viii. Curing the component obtained in step vii.

[0322] Curing is carried out in step viii. Typically, the curing temperature in step viii. is 230-420°C.

[0323] Advantageously, the method for producing a coated cookware (1) according to the invention comprises a single final curing step viii. of all applied layers. This single curing step is carried out simultaneously on all applied layers. This embodiment makes it possible to film-form, fuse and crosslink all layers together so that they form only one coating.

[0324] The coating steps (iii) and (vii) can be carried out by electrostatic powder coating, solvent phase or aqueous phase spraying, screen printing, roller printing or digital printing.

[0325] Applying step (v) may be performed by pad printing, screen printing, inkjet printing or flexographic printing.

[0326] In the context of the present invention, "curing the coated substrate" refers to a thermal treatment which densifies the coating layer or layers applied on the substrate and crosslinks the organopolysiloxane (silicone) precursor.

[0327] Advantageously, the method for manufacturing a coated cooking element (1) according to the invention comprises a step of shaping, also called stamping, of said support (2) before or after step iii.

[0328] Preferred hierarchy

[0329] According to one embodiment, the invention relates to a coated cooking element (1) for a cooker or electric cooking utensil, comprising a metal base (2) coated on at least one face (2a) with only the following three layers, superimposed starting from the metal base (2) in the following order:

[0330] (3a) A base layer composed of one or more silicone resins and selected from the following:

[0331] - one or more thermoplastic polymers, and / or

[0332] - one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof, and / or

[0333] - one or more fillers, and / or

[0334] - one or more additives;

[0335] (3b) one or more intermediate layers, the intermediate layers comprising one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes, and mixtures thereof, and selected from the following:

[0337] - one or more silicone resins, and / or

[0338] - one or more thermoplastic polymers, and / or

[0339] - one or more fillers, and / or

[0340] - one or more additives;

[0341] (3c) A finishing layer composed of one or more silicone resins and selected from the following:

[0342] - one or more thermoplastic polymers, and / or

[0343] - one or more fillers, and / or

[0344] - one or more additives.

[0345] According to one embodiment, the base layer (3a) consists of one or more silicone resins and optionally one or more thermoplastic polymers.

[0346] According to another embodiment, the base layer (3a) is composed of one or more silicone resins and optionally selected from the following:

[0347] - one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof, and / or

[0348] - one or more fillers, and / or

[0349] - one or more additives.

[0350] According to one embodiment, the base layer (3a) consists of one or more silicone resins and one or more thermoplastic polymers.

[0351] According to one embodiment, the base layer (3a) and the facing layer (3c) consist of one or more silicone resins and optionally one or more thermoplastic polymers.

[0352] According to one embodiment, the base layer (3a) and the facing layer (3c) consist of one or more silicone resins and one or more thermoplastic polymers.

[0353] In these embodiments, the one or more thermoplastic polymers are advantageously selected from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzimidazole (PBI), polyethersulfone (PES), polyphenylene ethersulfone (PPSU), polyaryletherketone (PAEK), and mixtures thereof.

[0354] Preferably, the colorant of the intermediate layer(s) (3b) comprises pigments and / or flakes, advantageously holographic flakes.

[0355] According to an alternative, the intermediate layer or layers (3b) consist of:

[0356] one or more colorants, in particular pigments and / or flakes, advantageously holographic flakes,

[0357] one or more thermoplastic polymers, advantageously chosen from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzimidazole (PBI), polyethersulfone (PES), polyphenylene ethersulfone (PPSU), polyaryletherketone (PAEK) and mixtures thereof,

[0358] 0-10% filler,

[0359] 0-20% additives,

[0360] • Optionally one or more silicone resins.

[0361] According to another alternative, the intermediate layer or layers (3b) consist of:

[0362] one or more colorants, in particular pigments and / or flakes, advantageously holographic flakes,

[0363] 0-10% filler,

[0364] 0-20% additives,

[0365] one or more silicone resins, and

[0366] Optionally, one or more thermoplastic polymers, advantageously chosen from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzimidazole (PBI), polyethersulfone (PES), polyphenylene ethersulfone (PPSU), polyaryletherketone (PAEK) and mixtures thereof,

[0367] According to one particular alternative, said intermediate layer or layers ( 3 b ) do not contain silicone.

[0368] According to another particular alternative, the intermediate layer or layers (3b) consist of:

[0369] one or more colorants, in particular pigments and / or flakes, advantageously holographic flakes,

[0370] one or more thermoplastic polymers, advantageously chosen from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzimidazole (PBI), polyethersulfone (PES), polyphenylene ethersulfone (PPSU), polyaryletherketone (PAEK) and mixtures thereof,

[0371] 0-10% filler,

[0372] 0-20% additives,

[0373] • One or more silicone resins.

[0374] According to one particular embodiment, the coating comprises two intermediate layers (3b), at least one of which is a decorative layer. Advantageously, said one or more layers (3b) form a plurality of decorations, one layer (i) comprising one or more thermochromic pigments and another layer (j) comprising at least one reference temperature pigment composition.

[0375] Typically, the thickness of one or more components of the intermediate layer ( 3 b ) is between 3 μm and 10 μm.

[0376] Preferably, the one or more intermediate layers (3b) only cover a portion of the base layer (3a).

[0377] According to one embodiment, the facing layer (3c) is composed of one or more silicone resins and optionally one or more thermoplastic polymers, and the thermoplastic polymer is advantageously selected from polyamideimide (PAI), polyimide (PI), polyetherimide (PEI), polybenzimidazole (PBI), polyethersulfone (PES), polyphenylene ether sulfone (PPSU), polyaryletherketone (PAEK) and mixtures thereof.

[0378] Typically, the thickness of the layer (3c) is between 0.1 μm and 10 μm.

[0379] In a specific embodiment, the thickness of layer (3a) is between 30 μm and 70 μm, the thickness of one or more layers (3b) is between 3 μm and 10 μm, and the thickness of layer (3c) is between 0.1 μm and 10 μm.

[0380] Utensils

[0381] The invention also relates to a cooker (100) comprising a coated cooking element (1).

[0382] According to one embodiment, the cooker (100) comprises a heating surface (6) for contact with an external heating source, the heating surface (6) being opposite to a cooking surface (5) for contact with food during cooking.

[0383] Advantageously, the cooker (100) according to the invention is chosen from a frying pan, a frying pan, a pot for fondue or raclette, a stew pot, a wok, a frying pan, a pancake maker, a grill, a frying pan, a cooking pot, a casserole, a container for a cooker or a bread maker, a cooking mould.

[0384] The present invention also relates to an electric cooking appliance (200) comprising a coated cooking element (1) according to the present invention and a heating source (210) configured to heat the coated cooking element (1).

[0385] Advantageously, the electric cooking appliance (200) is selected from the group consisting of an electric pancake maker, an electric raclette maker, an electric fondue maker, an electric grill, an electric frying pan, a bread maker, an electric pressure cooker, a waffle maker, an electric rice cooker and a jam maker.

[0386] The cookware according to the invention may in particular be a cookware in which one of the two opposite faces of the base is an (optionally concave) inner surface intended to be arranged on the side of food that may be introduced into or on the utensil, and the other face of the base is an (optionally convex) outer surface intended to be arranged facing the heat source.

[0387] By way of non-limiting example, cookware according to the invention comprises in particular cookware such as pots and pans, woks and frying pans, stew pots and casseroles, pancake makers, baking pans and dishes, roasting pans and grills and preparation bowls.

[0388] Example

[0389] The objectives, aspects and advantages of the present invention will be better understood on reading the following description of particular embodiments of the invention, given by way of non-limiting examples.

[0390] Of course, the present invention is in no way limited to the embodiments described and shown, which are given only by way of example. Modifications may still be made without exceeding the scope of protection of the present invention, particularly in the constitution of the various elements or by replacement of technical equivalents.

[0391] 1) Exemplary embodiments:

[0392] Metal base: This is an aluminum support that is sandblasted or shot blasted and then subjected to a surface treatment suitable for removing organic contaminants.

[0393] raw material:

[0394] -Silicone:

[0395] RS1: ethoxy functional polyester silicone resin in solvent phase (80% silicone / 20% polyester), viscosity at 25°C about 2000 mPas, solids content = 75%, RS2: ethoxy functional polyester silicone resin in solvent phase (50% silicone / 50% polyester), viscosity at 25°C about 2000 mPas, solids content = 75%, RS3: ethoxy functional polyester silicone resin in solvent phase (30% silicone / 70% polyester), viscosity at 25°C about 2000 mPas, solids content = 75%, RS4: methylphenyl functional polyester silicone resin in solvent phase, viscosity at 25°C about 2000 mPas, solids content = 75%,

[0396] RS5: methoxy-functional polyester silicone resin in solvent phase (50% silicone / 50% polyester), viscosity at 25°C about 2000 mPas, solids content = 75%, RS6: ethoxy-functional methyl organopolysilicone resin in aqueous emulsion, viscosity at 25°C about 1500 mPas, solids content = 52%;

[0397] -Heterocyclic polymer resins:

[0398] Polyamideimide resin (PAI), 29% dry extract in N-butylpyrrolidone (NBP), Torlon from SOLVAY;

[0399] -Other aromatic polymer resins:

[0400] Powdered polyetheretherketone (PEEK), Vicote 703 from VICTREX, powdered polymer with d50 of 25 μm,

[0401] Powdered polyetheretherketone (PEEK), Vicote 704 from VICTREX, powdered polymer with d50 of 10 μm,

[0402] Powdered PEKK resin, KEPSTAN 7002PT, from Arkema, d50 of 20 μm, Powdered PEKK resin, KEPSTAN 6002PT, from Arkema, d50 of 50 μm, Micronized grade of powdered polyethersulfone (PES) resin from SOLVAY, polymer powder with d50 of 40 μm.

[0403] -Alcohol solvents:

[0404] Dipropylene glycol butyl ether (DPNB),

[0405] 2-Methoxy-1-methylethyl acetate (MPA),

[0406] Butylene glycol acetate (BGA),

[0407] Butyl acetate,

[0408] -Surfactants and defoamers:

[0409] Mineral oil: Tego Foamex K7 from Evonik,

[0410] Fatty alcohol polyglycol ether: Genapol X080 from Clariant or

[0411] TergitolTMN-100X,

[0412] -Reinforcing fillers:

[0413] Fumed silica: Levasil CC301,

[0414] Fumed silica treated with dimethyldichlorosilane: Aerosil R972;

[0415] -pigment:

[0416] Mica: IRIODIN 100 or IRIODIN 300 and / or Magnapearl 5000,

[0417] Cr / Fe oxide: SiCopal Black K0098FK,

[0418] Carbon black: Derussol F25 or Cabot Monarch 4750,

[0419] Perylene Red: Piligen Red (PR178)

[0420] Iron oxide III: H856 brick;

[0421] -Acrylic resin:

[0422] Rohagit SD 15: 30% acrylic polymer solution in water;

[0423] -Silicone oil:

[0424] Polyether modified polysiloxane: TEGO GLIDE 100,

[0425] Dimethicone oil: CT 601M;

[0426] -Other additives:

[0427] AMP 90: Solution of 2-amino-2-methyl-1-propanol: 90% polymer in water, buffer,

[0428] Metlot368: fatty acid esters,

[0429] Dolfynox 1030: Propoxylated polyglycol ether, wetting agent,

[0430] Edaplan LA 451: solution of anionic ester in ethanol / water, wetting agent;

[0431] Tego Glide 407: Methylphenyl polysiloxane, flow agent.

[0432] Working Principle of Ball Mill (Mechanical Grinding Machine)

[0433] Ball milling involves placing the sample to be ground and the so-called grinding balls into a jar and rotating the jar around its axis at a certain speed. The rotation of the jar is usually achieved using a roller press. The sample can be ground in dry form or dispersed in a suitable solvent (for example in water or in ethanol). The dispersion may also contain certain additives (for example dispersants or defoamers).

[0434] The median diameter of the grinding balls must be adapted to the size of the particles to be ground. The finer the particles, the smaller the diameter of the balls used. The total volume of the balls including the spaces between the balls will account for approximately 50-60% of the internal volume of the tank. The balls of different sizes are advantageously distributed according to the following weight proportions relative to the total weight of the balls: small balls 25%, medium balls 50%, large balls 25%. The minimum size of the balls is between 2 and 10 mm. Stabilized aluminum oxide and zirconium oxide are generally used as materials for the balls.

[0435] Exemplary embodiments of the cooker according to the present invention:

[0436] On a shaped aluminium disk (30 cm diameter) previously degreased and sandblasted to obtain a roughness of 4-7 μm (Ra), successive layers 3a are deposited, selected from the following base layer compositions: base layer 3a1, base layer 3a2 and base layer 3a3:

[0437]

[0438]

[0439]

[0440]

[0441] The aqueous composition of the substrate layer 3a is prepared according to the ball milling principle. As mentioned above, the ball milling is carried out in a tank. The sample can be dry-milled or dispersed in a suitable solvent (for example, in water, ethanol or in a solvent). The dispersion can also contain certain auxiliary agents (such as dispersants or defoamers).

[0442] In this example, the thickness of the base layer 3a is between 10 μm and 20 μm, preferably between 12 μm and 15 μm.

[0443] The base, on which the continuous substrate layer 3a is applied, is coated, as described above, with a multilayer non-stick coating consisting of an intermediate layer 3b (6-8 μm) and a finishing layer 3c (14-18 μm) dried for 4 minutes at 100° C. After the deposition of the various layers, the assembly is finally heated to 250° C. for 1 hour, i.e. the process comprises only one curing step.

[0444] The composition of the intermediate layer 3b deposited by spraying is as follows (layer 3b1, layer 3b2 and layer 3b3):

[0445]

[0446]

[0447]

[0448]

[0449]

[0450] The composition of the finishing layer 3c deposited by spraying is as follows: layer 3c1 and layer 3c10:

[0451]

[0452]

[0453]

[0454]

[0455]

[0456]

[0457]

[0458]

[0459]

[0460]

[0461]

[0462]

[0463] Methods for Evaluating Nonstick Coating Performance: Egg Performance Test

[0464] The method for evaluating the performance of non-stick coatings is based on the egg test adapted from paragraph 3.3.2 of standard AFNOR NF D 21-511 and is carried out in the following way:

[0465] Clean the sample and wipe off any water remaining on the surface.

[0466] The inner surface of the container body is dried in advance.

[0467] Heat the cookware on a gas hob to 140 to 170°C.

[0468] An egg of size 60 / 65 is broken and then poured into the center of the hot cooking container. Then wait until the egg has set (6 to 9 minutes). The egg is removed from the cooking container with the aid of a spatula and the coating is cleaned with a damp vegetable sponge, by which the non-stick properties of the cooking container are evaluated. Then, the following is recorded:

[0469] Score 100: Use a plastic spatula to completely remove the egg;

[0470] Score 75: The egg cannot be completely removed, but the coating can be easily cleaned with a damp sponge.

[0471] Score 50: The egg cannot be completely removed, but the coating can be cleaned with a damp sponge.

[0472] Score 25: The egg cannot be completely removed and the coating cannot be cleaned with a wet sponge.

[0473] Score 0: The egg cannot be removed and the coating cannot be cleaned with a wet sponge.

[0474]

[0475] All silicone-polyester coatings according to the invention have good non-stick properties while being able to adhere to metal.

Claims

1. A coated cooking element (1) for a cooker or electric cooking utensil, comprising a metal base (2) which is coated on at least one face (2a) with at least the following layers, starting from the metal base (2) in the following order: (3a) A base layer composed of one or more silicone resins and selected from the following: - one or more thermoplastic polymers, and / or - one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof, and / or - one or more fillers, and / or - one or more additives; (3b) one or more intermediate layers, the intermediate layers comprising one or more colorants selected from thermochromic pigments, heat-stable pigments, flakes and mixtures thereof and selected from the following: - 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 composed of one or more silicone resins and selected from the following: - one or more thermoplastic polymers, and / or - one or more fillers, and / or - one or more additives, and / or - Thin flakes.

2. The coated cooking element (1) according to claim 1, characterized in that The one or more silicone resins are selected from methyl silicone and / or phenyl silicone and / or methyl-phenyl-silicone resin, methyl silicone-polyester resin (copolymer), phenyl silicone-polyester resin (copolymer), methyl-phenyl silicone-polyester resin (copolymer), silicone-alkyd resin (copolymer), and modified silicone resin.

3. The coated cooking element (1) according to claim 1 or 2, characterized in that The one or more fillers, when present, are selected from ceramic and / or mineral and / or metal and / or silica and / or diamond particle fillers.

4. The coated cooking element (1) according to any one of the preceding claims, characterized in that The one or more thermoplastic polymers, when present, are selected from polyethersulfone (PES), polyphenylene ethersulfone (PPSU), polyamideimide (PAI), polyimide (PI), polyphenylene oxide (PPO), polyarylether sulfide (PAS), polyetherimide (PEI), polybenzimidazole (PBI), liquid crystal polymer (LCP), polyphenylene sulfide (PPS), polyaryletherketone (PAEK) and mixtures thereof, polyaryletherketone (PAEK) including polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK) and polyetherketoneetherketoneketone (PEKEKK).

5. The coated cooking element (1) according to any one of the preceding claims, characterized in that One or more thermochromic pigments are selected from Bi2O3, Fe2O3, V2O5, WO3, CeO2, In2O3, Y 1.84 Ca 0.16 Ti 1.84 V 0.16 O 1.84 、AgI、(Bi 1-x A x )(V 1-y M y )O4, where: -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 selected from nitrogen, phosphorus, alkali metals, alkaline earth metals, transition metals, poor metals, metalloids or lanthanides, -A and M are different from each other.

6. The coated cooking element (1) according to any one of the preceding claims, characterized in that One or more heat stable pigments are selected from: -Titanium rutile yellow pigment, - yellow pigments derived from bismuth, for example selected from stabilized bismuth vanadates (Py 184 ), - red pigments, for example selected from perylene red, iron oxide, -Bismuth Oxyhalide Orange Pigment (PO 85 ), -Bismuth vanadate orange pigment (PO 86 ), -Tin-Titanium-Zinc Orange Pigment (PO 82 ), -Cerium Sulfide Orange Pigment (PO 75 PO 78 ), -Chromium antimony titanium rutile orange-yellow pigment (PBr 24 ), -Zinc Tin Rutile Orange Yellow Pigment (Py 216 ), -Zinc tin sulfide niobium oxide orange-yellow pigment (Py 227 ), -Niobium tin double oxide orange-yellow pigment, -Co3(PO4)2, -LiCoPO4, -CoAl2O4, -Cr2O3, -TiO2, -Black pigment PBk28 (copper chrome black spinel), - and mixtures thereof.

7. The coated cooking element (1) according to any one of the preceding claims, characterized in that The one or more holographic flakes, when present, are a mixture of magnetizable particles and non-magnetizable particles.

8. The coated cooking element (1) according to any one of the preceding claims, characterized in that The metal base (2) is a base made of aluminum, stainless steel, cast iron or cast aluminum, iron, titanium or copper.

9. The coated cooking element (1) according to any one of the preceding claims, characterized in that: The thickness of the layer (3a) is between 10 μm and 100 μm, preferably between 20 μm and 85 μm, particularly preferably between 30 μm and 70 μm, and the thickness of the layer or layers ( 3 b ) is between 1 μm and 100 μm, preferably between 2 μm and 30 μm, particularly preferably between 3 μm and 10 μm, and The thickness of the layer ( 3 c ) 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.

10. The coated cooking element (1) according to any one of the preceding claims, characterized in that The proportion of silicone resin in layer (3a) or layer (3c) is greater than or equal to 50% by weight relative to the total weight of layer (3a) or layer (3c), respectively.

11. The coated cooking element (1) according to any one of the preceding claims, characterized in that The filler, when present, has a proportion in the layer (3a), (3b) or (3c) of less than 10% by weight relative to the total weight of the layer (3a), layer (3b) or layer (3c), respectively.

12. The coated cooking element (1) according to any one of the preceding claims, characterized in that When present, the proportion of the additive in layer (3a), (3b) or (3c) is less than 20% by weight relative to the total weight of layer (3a) / layer (3b) / layer (3c).

13. The coated cooking element (1) according to any one of the preceding claims, characterized in that The layer (3a) and the layer (3c) comprise one or more thermoplastic polymers, the proportion of thermoplastic polymer in the layer (3c) being greater than the proportion of thermoplastic polymer in the layer (3a).

14. A method for manufacturing a coated cooking element (1) according to any one of the preceding claims, comprising the following steps: i. providing a metal base (2) having a surface (2a), ii. Optionally, pre-treating the surface (2a) of the metal base (2) to be coated, iii. applying the base layer (3a), iv. drying the base layer (3a), v. applying said one or more intermediate layers (3b), vi. optionally, drying the one or more intermediate layers (3b), vii. Applying the finishing layer (3c).

15. A cooker (100) comprising a coated cooking element (1) according to any one of claims 1 to 13.

16. The cooker (100) according to claim 15, characterized in that: The cooker comprises a heating surface (6) for contacting an external heat source, the heating surface (6) being opposite to a cooking surface (5) for contacting food during cooking.

17. The cooker (100) according to claim 15 or 16 is selected from a frying pan, a frying pan, a pot for cheese fondue or raclette, a stew pot, a wok, a frying pan, a pancake maker, a grill, a frying pan, a casserole, a container for a cooker or a bread maker, and a cooking mold.

18. An electric cooking appliance (200) comprising a coated cooking element (1) and a heat source (210) configured to heat the coated cooking element (1), characterized in that: The coated cooking element (1) is a cooking element according to any one of claims 1 to 13.

19. The electric cooking appliance (200) according to claim 18, which is selected from the group consisting of an electric pancake maker, an electric raclette maker, an electric fondue maker, an electric barbecue, an electric grill, an electric cooking pot, a bread maker, an electric pressure cooker, a waffle maker, an electric rice cooker and a jam maker.

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