Non-stick coating

Abstract

The present invention relates to a coating (3) for a household article on a metallic support (2) in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b), which coating is a single-layer or multi-layer coating, the single layer or each of the layers of the multi-layer coating comprising: - one or more polymers chosen from the group consisting of one or more polyarylether ketone(s) (PAEK), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, - optionally one or more organopolysiloxane polymer(s), - optionally one or more fluorocarbon resin(s), - optionally one or more filler(s), - optionally one or more additive(s), - optionally one or more coloring agent(s),and the monolayer or at least one of the layers of the multilayer coating comprising slow-release particles (4) comprising: - a slow-release material (41) having a porous structure and / or a layered structure; - a silicone oil (42), bonding to the slow-release material. Figure for abbreviation: Figure 3,

Description

Title of the invention: Non-stick coating FIELD OF INVENTION

[0001] The field of the invention is that of household articles which are heated or capable of being heated, in particular cooking articles, comprising an element coated by a coating according to the invention. STATE OF THE ART

[0002] In the field of household articles, in particular that of culinary articles, the coatings applied to substrates most often metallic (aluminum, aluminum casting, stainless steel, cast steel...) are of various kinds.

[0003] More specifically regarding the interior surfaces of these household items, PTFE-type fluorinated resin coatings have been known for over 50 years, prized for their excellent non-stick and cleanability properties, thermal stability, and resistance to chemicals and various foods. However, PTFE's inherent weakness is its ductility, which makes the coatings easily marked, scratched, and worn by metal utensils (spatulas, forks, spoons, immersion blenders, etc.).

[0004] Organic polymer undercoats are known in the prior art of cookware, however, only described for improving the scratch resistance of "soft" coatings based on fluorinated polymers such as PTFE. Furthermore, in most cases, the described process requires double curing, heating the heat-stable polymer above its melting point before cooling and applying the fluorinated layers, which remains very expensive.

[0005] Polymers such as polyaryletherketones (PAEK) and in particular oxy-1,4-phenylenephenylene-oxy-1,4-phenylene carbonyl 1,4-phenylene or PEEK, are used in advanced applications for their thermal, mechanical, chemical resistance properties, for example in aeronautics, in health.

[0006] This type of polymer is commercially available in the form of granules and powders obtained from grinding these granules. These powders can then be dispersed in liquid formulations of aqueous or solvent-based coatings, for application by spraying, roller coating, etc.

[0007] Electrostatic spraying of PEEK in powder form is also possible and has been described. This technique has the advantage of considerably limiting overspray since the negatively charged metallic substrate attracts the positively charged polymer powder. However, this approach requires a highly technical and specialized setup. The metallic substrate must either be connected to ground throughout the The manufacturing process of the article, designed to prevent the powder from detaching, involves heating it to a temperature above the polymer's melting point. This is therefore an expensive technique. Description of the invention

[0008] The present invention proposes an alternative to coatings based on a majority of PTFE in order to obtain good resistance to mechanical wear of the coatings, in particular by kitchen utensils for culinary articles and thus improve the durability of their mechanical resistance, in particular when hot and / or their cleanability, in order to extend the life of the article but also good non-stickness.

[0009] To overcome the weaknesses of PTFE-type coatings, the invention proposes a coating comprising one or more high-performance thermoplastic polymer(s) for good mechanical resistance and slow-release particles of silicone oil for good anti-adhesion.

[0010] It is possible to obtain a durable non-stick effect by forming an effective oil film that separates food from the coated surface.

[0011] During food cooking, for example, the release of silicone oil is slowed down, which helps to maintain a durable non-stick effect. Summary of the invention

[0012] A first object of the invention relates to a coating (3) for a household article on a metallic support (2) in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b), which coating is a single-layer or multi-layer coating, the single layer or each of the layers of the multi-layer coating comprising:

[0013] - one or more polymers chosen from the group consisting of one or more polyarylether ketone(s) (PAEK), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

[0014] - possibly one or more organopolysiloxane polymer(s),

[0015] - possibly one or more fluorocarbon resin(s),

[0016] - possibly one or more charge(s),

[0017] - possibly one or more additive(s),

[0018] - possibly one or more coloring agent(s),

[0019] and the monolayer or at least one of the layers of the multilayer coating comprising slow-release particles comprising:

[0020] - a slow-release material having a porous structure and / or a structure in layers;

[0021] - a silicone oil, bonding to the slow-release material.

[0022] Another object of the invention relates to a coated heating element (1) for a household article, comprising a metallic substrate (2) coated on at least one face (2a) with a coating according to the invention, in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b).

[0023] The invention also relates to a method for manufacturing a coated heating element (1) according to the invention comprising the following successive steps:

[0024] i. Supply of a metallic substrate (2) having a face (2a),

[0025] ii. Optionally, pretreatment of the face (2a) of said metallic substrate (2) intended to be coated,

[0026] iii. Application of the coating layer(s) (3) onto the face (2a),

[0027] iv. Cooking of the element obtained in step iii.

[0028] The invention also relates to a household article comprising a coated heating element (1) according to the invention characterized in that it is a cooking article and in that the face (3b) of the coating according to the invention is capable of receiving food, as well as an electric cooking appliance comprising a coated heating element (1) according to the invention and a heating source configured to heat said coated heating element (1). DEFINITIONS

[0029] For the purposes of this invention, the terms "layer" or "coating" refer to a continuous or discontinuous layer. A continuous layer (also called a monolithic layer) is a single unit forming a flat, completely covering the surface on which it is laid. A discontinuous layer (or non-monolithic layer) may comprise several parts and is therefore not a single unit.

[0030] The term "base layer" means all the layers from the first layer applied directly to the substrate (it is preferable that this layer adheres well to the substrate and provides all its mechanical properties to the coating: hardness, scratch resistance) to the last layer applied before the first decorative layer, when present.

[0031] The term "finish layer" refers to a continuous, transparent surface layer that allows perfect visibility of the decorative layer while protecting it from mechanical damage and giving the coating its non-stick properties. Preferably, the final finish layer is intended to come into contact with food.

[0032] The term "decoration" or "decoration layer" means one or more continuous or discontinuous layers comprising a pigment composition. The decoration may take the form of one or more motifs, or one or more colors. A decoration is clearly visible to the user with the naked eye and at the normal operating distance of the household item.

[0033] The term "overlapping layers" refers to layers that are partially or completely superimposed. These layers may take the form of partially overlapping patterns, for example concentric disks.

[0034] The term "adjacent layers" refers to non-superimposed layers. These layers may be in the form of identical or different non-superimposed patterns, preferably uniformly distributed.

[0035] A "temperature reference pigment composition" is defined as a composition comprising a pigment which, at a given temperature, indicates to the user that the optimal operating temperature has been reached. This indication is made by comparing the colors of the thermochromic pigment composition and the temperature reference pigment composition. The optimal operating temperature is reached either when the colors are identical or when the colors are visually very different.

[0036] The "temperature reference pigment composition" may include a pigment that exhibits:

[0037] - the same color as the thermochromic pigment composition at temperature for optimal use,

[0038] * either because this pigment has the same color at room temperature as the Thermochromic pigment composition at optimal use temperature and does not change color with temperature.

[0039] * either because this pigment has a different color at room temperature of that of the thermochromic pigment composition which evolves to the same color as the thermochromic pigment composition at the optimal operating temperature,

[0040] - a color very different from that of the thermochromic pigment composition the optimal operating temperature, whether this pigment changes color or not with temperature changes.

[0041] The optimal operating temperature can be achieved when the color of the temperature reference pigment composition corresponds to a color indicated in the user guide of the household article comprising the coating of the invention or to a color indicated on a color scale provided to the user with said article.

[0042] The temperature reference pigment composition is thermochromic or thermostable.

[0043] The reference temperature pigment composition can be, for example, a reference cooking temperature pigment composition or an indication of risk of overheating.

[0044] For the purposes of this invention, "thermochromic pigment or pigment composition" means a pigment or pigment composition that changes color with temperature within a given temperature range, this change being reversible. This color change is visible to the user with the naked eye at normal viewing distances.

[0045] The term "thermostat pigment" means a pigment which does not exhibit a change of color when subjected to a temperature rise within a given temperature range or which exhibits a change of hue when subjected to a temperature rise within a given temperature range so small that it is not visible to the user with the naked eye and at a conventional operating distance.

[0046] Preferably, the thermostable pigments have a color difference AE* between 25°C and 200°C of less than 10, AE* being defined by the CIE1976 formula in the CIELAB color space:

[0047] „ r ; oer~

[0048] Li*, ai* and bi* characterizing the L*a*b values ​​of said compound at room temperature

[0049] L2*, a2* and b2* characterizing the L*a*b values ​​of said compound at 200°C.

[0050] By "the colours are identical" we mean indistinguishable by the user to the naked eye and at a normal operating distance.

[0051] The term "culinary article" should be understood, for the purposes of the present invention, as an object intended for cooking. To this end, it is intended to receive heat treatment.

[0052] The expression "object intended to receive heat treatment" should be understood in the context of the present invention as an object which will be heated by an external heating system such as pans, pots, sauté pans, woks, barbecue grills and which is capable of transmitting the heat energy supplied by this external heating system to a material or food in contact with said object.

[0053] For the purposes of this invention, the term "electric cooking appliance" means a heating object having its own heating system, such as an electric crepe maker, electric raclette appliance, electric fondue appliance, electric grill, electric griddle, electric cooker, bread machine, or electric pressure cooking appliance.

[0054] The term “coating” means the layer covering the metallic substrate and adhering to that substrate.

[0055] In the present invention, the % by weight are expressed in dry weight, i.e. without solvent. DESCRIPTION OF THE FIGURES

[0056] [Fig. 1] represents a cross-sectional view of an example embodiment of an element of coated heater (1) for household article, comprising a metallic substrate (2) coated on at least one face (2a) with a coating (3) in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b).

[0057] [Fig.2] is a schematic view that shows slow-release particles in a Coating material according to the present invention. 41 = the slow-release material, 42 = the silicone oil

[0058] [Fig.3] represents a cross-sectional view of an example embodiment of an element heating element coated (1) for household article with a single-layer coating according to the invention. 2 = substrate, 3 = single-layer coating, 4 = slow-release particles, 3a = coating face in contact with the substrate, 3b = coating face visible to the user

[0059] [Fig.4] represents a cross-sectional view of an example embodiment of an element heating element coated (1) for household article by a multilayer coating according to the invention. 2 = substrate, 3 = bilayer coating, 31 = penultimate layer underlying the last layer forming face (3b), 32 = last layer forming face (3b), 4 = slow-release particles, 3a = coating face in contact with the substrate, 3b = coating face visible to the user.

[0060] [Fig. 5] represents a cross-sectional view of an example embodiment of an element heating element coated (1) for household article by a multilayer coating according to the invention. 2 = substrate, 3 = bilayer coating, 31 = penultimate layer underlying the last layer forming face (3b), 32 = last layer forming face (3b), 4 = slow-release particles, 3a = coating face in contact with the substrate, 3b = coating face visible to the user.

[0061] The slow-release particles are present only in the penultimate layer underlying the last layer forming the face (3b). DETAILED DESCRIPTION OF THE INVENTION Coating

[0062] A first object of the invention relates to a coating (3) for a household article on a metallic support (2) in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b), which coating is a single-layer or multi-layer coating, the single layer or each of the layers of the multi-layer coating comprising:

[0063] - one or more polymers chosen from the group consisting of one or more polyarylether ketone(s) (PAEK), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

[0064] - possibly one or more organopolysiloxane polymer(s),

[0065] - possibly one or more fluorocarbon resin(s),

[0066] - possibly one or more charge(s),

[0067] - possibly one or more additive(s),

[0068] - possibly one or more coloring agent(s),

[0069] and the monolayer or at least one of the layers of the multilayer coating comprising slow-release particles (4) comprising:

[0070] - a slow-release material having a porous structure and / or a structure in layers(41);

[0071] - a silicone oil, binding to the slow-release material (42).

[0072] Advantageously, the thickness of the coating (3) according to the invention is between 5 and 200 pm, preferably between 10 and 80 pm.

[0073] According to one embodiment, it is a single-layer coating with a thickness between 5 and 200 pm.

[0074] Advantageously, the proportion of slow-release particles in each layer in which they are present ranges from 5 to 35% by weight of said layer, preferably from 5.15 to 32.97% by weight of said layer.

[0075] According to one embodiment, it is a multilayer coating comprising one or more primary layer(s), one or more intermediate layer(s), and one or more finishing layer(s), the slow-release particles being present in one or more intermediate layer(s) and / or one or more finishing layer(s). Slow-release particles

[0076] Advantageously, the size of the slow-release particles is between 5 and 60 pm, preferably less than or equal to 20 pm.

[0077] Advantageously, the slow-release material / silicone oil ratio ranges from 1:2 to 2:1.

[0078] The slow-release material 41 has a layered and / or porous structure. Thus, the silicone oil 42 can be bound to a surface of the slow-release material and / or absorbed into the porous and / or layered structure. The slow-release material 41 has a porous and / or layered structure and is bound to the silicone oil. Thus, when using a cookware item with a non-stick coating formed by a coating material according to the present invention, the silicone oil 42 bound to the material slow release 41 can be released slowly, which greatly improves the durable non-stick character of the non-stick coating formed by the coating material.

[0079] Slow-release material

[0080] According to the invention, a porous structure is defined as a structure with open porosity. This is a structure having open pores, some of which are interconnected and form a network extending from one face to the other of said structure.

[0081] Thus, the porous structure has a volume of air voids, also called open pores, incorporated within the thickness of the structure to absorb the silicone oil deposited on the porous structure. These air voids or open pores originate from spaces left free in the material of the structure during its formation. The air voids or open pores tend to be interconnected and can therefore form a network of through-pore porosity that can be filled by the silicone oil through absorption. The silicone oil is thus accumulated within the porous structure. The absorption of silicone oil by the porous structure is a physical or chemical process during which atoms, molecules, or ions enter the solid phase of the porous structure. The absorbed silicone oil, in turn, penetrates into the interior of the phase (i.e., deep into the volume).

[0082] It should also be possible for the porous structure to be able to bind the silicone oil by means of adsorption, meaning that the porous structure (adsorbent) can attach the silicone oil (adsorbate) to its surface. The interactions between the adsorbent and the adsorbate are most often electrostatic in nature, and therefore weak and reversible.

[0083] By the term "bond" according to the invention, it is to be understood either a non-polar covalent bond, a polar covalent bond, an ionic bond, a hydrogen bond, an electrostatic bond or any weak bond.

[0084] Advantageously, the slow-release material comprises at least one of the following materials: vermiculite, zeolite, bentonite, diatomaceous earth, alpha alumina, silica aerogel, fumed silica, precipitated silica, amorphous silica, hollow glass micropowder, porous silicate, stratified silicate, porous phosphate, stratified phosphate, porous carbonate, stratified carbonate, porous sulfate and stratified sulfate.

[0085] Silicone oil

[0086] The silicone oil can be selected from at least one methyl silicone oil, one dimethyl silicone oil, one methyl phenyl silicone oil, one hydroxyl silicone oil, one alkoxylated silicone oil, one vinylated silicone oil, one hydrogen-containing silicone oil and one polyether-modified silicone oil.

[0087] By weight percentage, the silicone oil may comprise 20 to 30% low molecular weight silicone oil, 40 to 60% medium molecular weight silicone oil and 20 to 30% high molecular weight silicone oil. The molecular weight of low molecular weight silicone oil can be between 500 and 1,000, the molecular weight of medium molecular weight silicone oil can be between 3,000 and 6,000, and the molecular weight of high molecular weight silicone oil can be between 12,000 and 30,000.

[0088] High molecular weight silicone oil binds more strongly to the slow-release material and has a slower release rate; low molecular weight silicone oil has better free mobility and therefore better anti-adhesion; furthermore, medium molecular weight silicone oil has both free mobility and intermediate bond strength. Therefore, by combining low molecular weight silicone oil, medium molecular weight silicone oil, and high molecular weight silicone oil, it is possible to obtain both slow release and better anti-adhesion.

[0089] Coupling agent

[0090] Furthermore, in order to improve the bond strength between the silicone oil and the slow-release material, a coupling agent may also be present between the slow-release material and the silicone oil. In this case, the coupling agent may include a silane coupling agent. However, the embodiments are not limited to this, and the coupling agent may be omitted.

[0091] Advantageously, the slow-release particles comprise a silane coupling agent, preferably a methoxysilane.

[0092] Method for preparing slow-release particles

[0093] A method for preparing slow-release particles consists of providing a slow-release material and a silicone oil and mixing them, for example mixing 35 to 58 parts by weight of the slow-release material with 42 to 60 parts by weight of one or more silicone oil(s).

[0094] As is known in the prior art, the slow-release material comprising a porous or layered structure can absorb silicone oil in its open porosity.

[0095] Furthermore, the silicone oil can be bound to the slow-release material in at least two ways: adsorption and bonding. It should be understood that adsorption refers to the attachment of the silicone oil to the surface of the slow-release material, which can be physical or chemical adsorption, but the interactions between the adsorbent (slow-release material having a porous structure) and the adsorbate (silicone oil) are often weak.

[0096] On the other hand, the bond refers to a stronger chemical bond obtained through interactions between atoms.

[0097] In the present invention, for example, it may be the condensation of the hydroxyl groups of the silicone oil and the hydroxyl groups of the slow-release material.

[0098] During the mixing step, the silicone oil, the slow-release material, and a coupling agent can be uniformly mixed and ground to a particle size of 30 µm or less, allowing some of the silicone oil to be adsorbed onto the slow-release material. Next, a catalyst is added to the mixture, and grinding continues until the particle size is 20 µm or less. Then, ultrasonic treatment is performed for 0.5 h to 1 h to further bond the silicone oil to the slow-release material. Finally, the silicone oil can be dried to a semi-solid state by heating and solidification and bonded to the slow-release material in colloidal form to obtain the slow-release particle.

[0099] The particle size of the slow-release material is, for example, between 5 and 150 pm. Besides ultrasonic treatment, other methods known to the person skilled in the art can also be used to achieve the bond between the silicone oil and the slow-release material, such as heating and pressurization, and / or the use of acidic / basic salts, etc.

[0100] A suitable-sized slow-release material precursor (i.e., a pre-milling slow-release material; where the milling step is omitted, the slow-release material precursor can be considered the slow-release material ultimately used) can be selected to prepare the slow-release particles. The slow-release material precursor may have a layered and / or porous structure. By way of example, the slow-release material precursor may comprise at least one of the following: vermiculite, zeolite, bentonite, diatomaceous earth, alpha alumina, silica aerogel, fumed silica, precipitated silica, amorphous silica, hollow glass micropowder, porous silicate, layered silicate, porous phosphate, layered phosphate, porous carbonate, layered carbonate, porous sulfate, and layered sulfate.The slow-release material precursor has a porous and / or layered structure and is ground to form a slow-release material, which is bonded to a silicone oil.

[0101] According to one embodiment, the particle size of the slow-release precursor material can be between 5 and 150 pm, and the particle size of the slow-release precursor material within this range can follow a normal distribution. When the particle size is too large (for example, less than 150 pm), it can increase the grinding process or make the size of the ground particles of the slow-release material still too large, ultimately affecting the appearance of a non-stick coating made using the coating material. On the other hand, a particle size that is too small (for example, less than 5 pm; in Furthermore, the particle size will become smaller after grinding, making efficient absorption of silicone oil difficult and thus making it difficult to achieve a good slow release effect of silicone oil.

[0102] When the slow-release material precursor has the aforementioned particle size distribution, a two-pass milling process, as described below, can be used to ensure that the particle size of the final slow-release material is less than 20 µm. However, the embodiments are not limited to this. In other words, when the slow-release material precursor is selected to have a relatively small value between 5 and 150 µm, one pass of the milling process can be omitted. Furthermore, when the particle size of the slow-release material precursor is chosen to have an even smaller value within the aforementioned range, the entire milling process can be eliminated.When at least one step of the grinding process is omitted, the omitted grinding process may be replaced by an agitation process, or no treatment may be performed on the mixture.

[0103] According to one example, 35 to 58 parts by weight of the slow-release material precursor can be mixed with 42 to 60 parts by weight of silicone oil to obtain a mixture, and 1 to 3 parts by weight of a coupling agent (e.g., methoxysilane coupling agent), 0.3 parts by weight of a catalyst (e.g., titanate catalyst), and 1 to 1.5 parts by weight of a dispersant can be added to the mixture. However, embodiment examples are not limited to this. The coupling agent and the catalyst are used to improve the bond strength between the silicone oil and the slow-release material, and the dispersant is used to improve the dispersion of the slow-release material in the silicone oil.

[0104] According to a particular example, silicone oil, a slow-release material precursor of 5 to 150 pm, and a silane coupling agent can be uniformly mixed and ground until the particle size is less than or equal to 30 pm. At this stage, some of the silicone oil is adsorbed by the slow-release material. A catalyst is then added to the mixture, and grinding continues until the particle size is less than or equal to 20 pm. Next, ultrasonic treatment is carried out at room temperature for 0.5 h to 1 h to allow more silicone oil to be bonded to the slow-release material by adhesion. Finally, the silicone oil can be dried to a semi-solid state by heating and solidification and bonded to the slow-release material in a colloidal form. This yields slow-release particles.Here, by first mixing the silicone oil and the slow-release material and grinding until the particle size is less than or equal to 30 µm, the silicone oil and the slow-release material can be homogeneously mixed. Then, grinding under the action... Using a catalyst until the particle size is 20 µm or less allows the silicone oil to be firmly absorbed by the slow-release material. Besides ultrasonic treatment, other methods known to those skilled in the art can also be used to achieve bonding between the silicone oil and the slow-release material, such as heating and pressurization, and / or the use of acidic / basic salts, etc. Furthermore, when the particle size of the slow-release material is less than 30 µm, the first grinding can be omitted, and an agitation process may be included, or the second grinding can be performed directly. Additionally, when the particle size of the slow-release material is less than 20 µm, the second grinding process can be omitted, and an agitation process may be included. PAEK

[0105] Advantageously, the polyaryletherketone(s) (PAEK) is / are chosen from the group consisting of: polyetherketones (PEK), polyetheretherketone (PEEK), polyetherketoneketones (PEKK), polyetheretherketoneketones (PEEKK) and polyetherketoneetherketoneketones (PEKEKK), preferably from the group consisting of polyetheretherketones (PEEK), polyetherketoneketones (PEKK) and mixtures thereof, particularly preferably is / are PEEK.

[0106] The advantage of using these polymers with very high thermal stability under continuous use conditions at 260°C is also to benefit from their very high mechanical properties (Young's modulus, tribology, low coefficient of friction, low surface energy etc.) and their chemical resistance properties (in acidic and basic conditions, excellent resistance to many solvents), their biocompatibility, their biostability and their recyclability.

[0107] According to one embodiment, each of the layers of the coating (3) according to the invention comprises at least 1%, preferably at least 5% by weight of one or more polyaryletherketone(s) (PAEK).

[0108] Advantageously, the polyarylether ketone(s) (PAEK) present in each of the layers is a polyetheretherketone (PEEK) or a polyetherketoneketones (PEKK). PAES

[0109] By way of example, suitable according to the invention are poly(phenylene oxide) (PPO), poly(arylethersulfone) polymer (PAES), and in particular polyethersulfone (PES), polyphenylene ether sulfone (PPSU), polyphenylene sulfide (PPS), poly(arylene sulfide) (PAS), liquid crystal polymers and mixtures thereof, preferably from the group consisting of polyethersulfone (PES), polyphenylene sulfide (PPS) and their mixtures.

[0110] An amorphous, non-crystalline, aromatic thermoplastic polymer, such as PPSU / PES (Polyethersulfone), improves the coating's film formation because its glass transition temperature is much lower than that of PAEK, thus enhancing adhesion to the substrate. This also advantageously improves the material's ductility and enhances its stretchability and stampability. Heterocyclic thermoplastic polymers

[0111] By way of suitable heterocyclic thermoplastic polymers, polyetherimide (PEI), polyimides (PI), polyamideimides (PAI), and polybenzymidazole (PBI), or mixtures thereof, are cited as examples of such polymers. Organopolysiloxane polymers

[0112] By way of suitable example of organopolysiloxane polymers according to the invention, those obtained from organopolysiloxane polymeric or oligomeric precursors are cited, either in the form of silicone oils of varying degrees of branching, or in the form of silicone resins of varying degrees of pre-crosslinking, or copolymers of silicone resins such as silicone-polyester, silicone-alkyd, silicone-polyurethane, and silicone-epoxy resins, or in the form of a mixture of silicone oils, silicone resins, and silicone resin copolymers. The silicon atoms may be substituted by alkyl (in particular methyl) or aryl (in particular phenyl) groups, or mixtures thereof. The oils or resins preferably comprise one or more (2, 3 or more) hydroxy or alkoxy functional groups (in particular methoxy, ethoxy, butoxy) as substituents for silicon atoms.

[0113] Preferably, the organopolysiloxane polymer(s) of the coating according to the invention comprises / include a copolymer of silicone resins and / or a silicone oil. Organopolysiloxanes

[0114] This family of polymers allows the combination of different properties, depending on the polymer structure, such as thermal resistance, lubrication and anti-sticking, hydrophobicity, resistance to heat, thermo-oxidation and chemical and biological aggressions, etc.

[0115] Advantageously, when the coating comprises an organopolysiloxane polymer, it can be obtained by a crosslinking process leading to a polymeric network, continuous or discontinuous at the microscopic scale in the polymer phase, depending on the concentration, nature, and conformation of the other components in the coating. "Crosslinking" refers to the chemical reaction leading to one or more covalent bonds between the polymer precursors. organopolysiloxane and / or between these same precursors and other components of the coating.

[0116] 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 exhibit high hardness or high flexibility such as an elastomer.

[0117] The organopolysiloxane polymer network may consist of a combination of 4 simple organosiloxane units designated M, D, T and Q depending on the degree of substitution by the oxygen of the silicon atom, as described in the following table, where R is an organic substituent described later.

[0118] [Tables 1]

[0119] The organopolysiloxane polymer is obtained by crosslinking from precursors that may be monomeric or polymeric, or, as an intermediate step, oligomeric. The organopolysiloxane polymer may also be obtained from a mixture of these different types of precursors. When the network contains a higher number of T and Q units than D units, the crosslinking density is higher. The distribution among the M, D, T, and Q units depends on the chemical structure of the precursors, in particular on this M, D, T, and Q distribution within the precursors.

[0120] The polymeric precursors are organopolysiloxanes. These macromolecules are formed of M, D, T, and / or Q units as described in the table, where R is independently an alkyl group, in particular methyl, or aryl group, in particular phenyl, different natures of R being able to be present on the same macromolecule.

[0121] Organopolysiloxanes can be either linear or sparsely branched (majority of D groups), or branched or highly branched (majority of T and Q groups). Linear or sparsely branched organopolysiloxanes are generally liquids, more or less viscous at room temperature, and are called silicone oils. Branched or highly branched (pre-crosslinked) organopolysiloxanes form a network at the scale of the individual macromolecule and are called silicone resins. At room temperature, these resins are essentially in solid form, or in liquid form, provided they have a sufficiently low molecular weight, either as a solution in a solvent or as an aqueous emulsion. They can be copolymerized with organic polymers or oligomers that do not contain silicon, particularly those chosen from polyesters, acrylics, alkyds, polyurethanes, and epoxy resins.

[0122] When the crosslinking is a hydrolysis-polycondensation: it is carried out by means of the reactive hydroxy or alkoxy functions, in particular methoxy, ethoxy or butoxy, present on the organopolysiloxane.

[0123] When the crosslinking is a polyaddition (or hydrosilyl tion): it takes place by reaction between the reactive vinyl functions (-CH=CH2) present on one of the organopolysiloxanes and the reactive silyl hydride functions (Si-H) present on the other organopolysiloxane mixed with the first.

[0124] All these reactive functions are present on each organopolysiloxane, with at least one present and two, three, or more present... as much as the molecular structure allows. Silicone oils containing at least one reactive function are called "reactive oils." The reactive functions can be located either at the end of the macromolecular chain (termination) or distributed along the chain.

[0125] Silicone-polyester resins in particular have silicone / polyester mass ratios for example 90 / 10, 80 / 20, 70 / 30, 60 / 40, 50 / 50, 40 / 50, 30 / 70, 20 / 80, 10 / 90, advantageously between 80 / 20 and 50 / 50.

[0126] Linear PDMS silicone oils, pure or pre-emulsified in water, are characterized first by their molecular weight, which is directly proportional to the viscosity of the pure oil. They are then characterized by the presence or absence of reactive functional groups, for example hydroxyl groups on the silicon atoms (silanol), their number, and their location on the molecular chain. For example, reactive oils with viscosities between 50 and 20,000 mPa·s, and in particular between 300 and 5,000 mPa·s, can be used, possessing at least one reactive functional group, preferably at least two, which can be located at the ends of the chain (positions a, w).

[0127] Polymeric precursors reacting by polyaddition may include, for example, polymethylhydrosiloxane, vinylmethylsiloxane, vinyl-terminated polydimethylsiloxane (PDMS), particularly linear-terminated diphenylsiloxane-dimethylsiloxane copolymers, hydride-terminated polydimethylsiloxanes, hydride-terminated polyphenylmethylsiloxanes, cyclic vinylmethylsiloxane, vinyl-MQ resin, polymethylhydrosiloxane terminated trimethylsilyl, methylhydrosiloxane copolymer and dimethylsiloxane terminated trimethylsiloxane, MQ resin hydride, and the like, and their combinations.

[0128] Polymeric precursors reacting by hydrolysis-polycondensation, whether silicone resins or silicone oils, may include, for example, poly(methylsilsesquioxanes), poly(propylsilsesquioxanes), poly(phenylsilsesquioxanes), polydimethylsiloxane (PDMS), polydimethylsiloxane (PDMS), terminated trimethylsilyl, polydimethylsiloxane (PDMS) terminated hydroxyl, polydimethylsiloxane (PDMS) terminated silanol, polyphenylsiloxane (PDMS) terminated silanol, diphenylsiloxane-dimethylsiloxane copolymer terminated silanol, poly(2-acetoxyethylsilsesquioxanes), organo-modified alkoxysilanes and their oligomers, and all similar macromolecules and mixtures thereof.

[0129] The organopolysiloxane polymer can 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 having more than two reactive functions as described above, advantageously much more than two, can be added to the mixture as a "co-binder" to promote a high crosslinking density of the organopolysiloxane polymer ultimately obtained.

[0130] Monomeric, oligomeric and / or polymeric precursors, in particular silicone resins, copolymerized or not with an organic polymer, play the role of polymeric binder in order to obtain the solid organopolysiloxane polymer combined with the TP of each layer.

[0131] Silicone oil-type organopolysiloxane precursors can be considered as additives if they are added in small quantities (generally between 0.1 and 5% dry) to the overall formula of a layer, independently of the other components for the formation of the solid organopolysiloxane polymer.

[0132] Crosslinking may require a catalyst: - In the case of the crosslinking of organopolysiloxanes by hydrolysis-polycondensation, the formula may include a metallic catalyst, such as 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. - In the case of crosslinking 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.

[0133] A crosslinking agent, for example bearing Si-H bonds, may be present. Fluorocarbon resins

[0134] The fluorocarbon resin(s) is / are advantageously chosen from the group consisting of: polytetrafluoroethylene (PTFE), tetrafluoroethylene and perfluoropropyl vinyl ether (PFA) copolymer, tetrafluoroethylene and hexafluoropropylene (FEP) copolymer and mixtures thereof, particularly preferably comprising PTFE.

[0135] Advantageously, the coating according to the invention does not comprise fluorocarbon resin. Charges

[0136] The fillers within the meaning of the invention make it possible to provide mechanical reinforcement and can also provide lubricating properties, hydrophobic properties, while improving the mechanical resistance and thermal conductivity of the coating.

[0137] The fillers do not only have the function of adding color to the coating, but can contribute to it.

[0138] The presence of fillers with excellent thermal conductivity makes it possible to compensate for the low thermal conductivity of PAEK polymers.

[0139] Advantageously, the filler(s) is / are chosen from the group consisting of ceramic fillers (SiO2, etc.) and / or mineral and / or metallic fillers (Al2O3, TiO2, etc.) and / or hydrophobic silicas and / or diamond particles.

[0140] Preferably, the filler(s) is / are chosen from the group consisting of metal oxides, metal carbides, metal oxynitrides, metal nitrides, and their mixtures.

[0141] Advantageously, said metal is a transition metal, such as at least one of the elements selected from B, Ni, Ti, Zr or Hf.

[0142] Preferably, the charge(s) is / are chosen from the group consisting of: - fillers for reinforcement: hard organic or inorganic fillers; the hard inorganic fillers are preferably particles of silicon carbide or alumina or zirconia or graphite, or ceramics, or carbonate, or hydrated alumina, aluminum trihydroxide or one or more metal oxide(s), graphite, graphene; - other fillers for reinforcement chosen from among the metallic oxides: silica, micas, lamellar fillers, clays such as montmorillonite, sepiolite, gypsite, kaolinite and laponite, zinc dioxide, quartz, and zirconium phosphate, alumina, zirconia, zinc oxide, copper oxide, iron oxide; - fillers chosen from among the reinforcing fibers: glass fiber or carbon fiber or aramid fiber; - conductive charges comprising a transition metal carbide and / or a transition metal nitride: characterized in that the transition metal is at least one of the elements selected from B, Ni, Ti, Zr or Hf,

[0143] for example: Cubic boron nitride, diamond particles, metallic particles; - lamellar fillers that can confer lubricating properties, such as clays, graphene or graphite.

[0144] Preferred fillers in combination with organopolysiloxanes are: - reinforcing fillers: silica or carbonates with filler levels of at least 10-15% / wt and up to 60% / wt, - alumina, hydrated alumina, aluminum trihydroxide, - silica (precipitated or pyrogenated) with a d50 < 0.1 pm and a specific surface area BET > 30 m² / g and preferably between 30 and 500 m² / g, - or a mixture of quartz and silica, diatomaceous earth or crushed quartz, titanium, mica, talc, kaolin, barium sulfate, slaked lime, zinc oxide, expanded vermiculite, non-expanded vermiculite, calcium carbonate etc.

[0145] Advantageously, the average diameter d50 of the charges is between 0.1 and 50 pm, advantageously still between 5 and 15 pm.

[0146] Advantageously, the proportion of fillers in a layer is between 0.5 and 30% by dry weight relative to the total weight of said layer after baking, preferably between 5 and 20%.

[0147] Advantageously, the proportion of fillers in the coating (3) is less than 10% by weight relative to the total weight of the coating (3). Additives

[0148] Advantageously, said additives are chosen from the group consisting of antifoaming agents, dispersing agents, wetting agents, thickeners, and pH adjusters.

[0149] The said antifoaming agent(s) (is) preferably chosen from the group consisting of mineral oils, diols, hydrocarbons, glycerides, oxyrane, emulsified fatty acids.

[0150] The surfactant(s) is / are preferably chosen from the group consisting of glycol ether, ethoxylated alcohol excluding alkyl phenol ethoxylates (APEs), gemini surfactants.

[0151] The dispersing agent(s) is / are preferably chosen from the group consisting of anionic dispersants such as fatty acid derivatives.

[0152] Said thickeners are preferably chosen from the group consisting of acrylic-based or polyurethane-based copolymer, cellulose, fumed silica.

[0153] Said pH adjusters are preferably chosen from the group consisting of Brønsted bases: ammonia, amines (triethylamine, triethanolamine...), hydroxides (sodium hydroxide, potassium hydroxide...), carbonates.

[0154] A preferred adhesion promoter in combination with organopolysiloxanes is an organosilane or an organopolysiloxane having three silicon-linked hydrolyzable groups per molecule

[0155] Advantageously, the proportion of additives in the coating (3) is less than 20% by weight relative to the total weight of said coating (3).

[0156] Advantageously, the proportion of additives in each layer of the coating (3) is less than 20% by weight relative to the total weight of said layer. Coloring agents

[0157] Advantageously, the coating according to the invention comprises one or more coloring agent(s) selected from the group consisting of thermochromic pigments, thermostable pigments, glitter, holographic glitter and mixtures thereof. • Thermochromic pigments

[0158] Preferably, the thermochromic pigment(s) is / are chosen from the group consisting of Bi2Û3, BiOCi ZDZ, Fe2Û3, V2O5, WO3, CeCL, h^CL, Yi^CaojgTii^Vo.ieOi^ , Agi, (Bil xAx)(Vi yMy)O4 with : - x is equal to 0 or x is between 0.001 and 0.999, - y is equal to 0 or y is between 0.001 and 0.999, - A and M are chosen from the group consisting of nitrogen, phosphorus, an alkali metal, an alkaline earth metal, a transition metal, a post-oxidation metal, a metalloid, or a lanthanide, - A and M are different from each other - C and D are chosen from the group consisting of iodine, fluorine, chlorine and the bromine, - C and D are different from each other, and - z is between 0 and 1.

[0159] Given that A and M are different from each other, when:

[0160] - A is an alkali metal, it can be chosen from Li, Na, K, Rb, Cs,

[0161] - M is an alkali metal, it can be chosen from Li, Na, K, Rb, Cs,

[0162] - A is an alkaline earth metal, it can be chosen from Be, Mg, Ca, Sr, Ba,

[0163] - M is an alkaline earth metal, it can be chosen from Be, Mg, Ca, Sr, Ba,

[0164] - A is a transition metal, it can be chosen from Sc, Ti Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir,

[0165] - M is a transition metal; it can be chosen from Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Ta, W, Ir,

[0166] - A is a base metal; it can be chosen from Al, Zn, Ga, In, Sn,

[0167] - M is a low-grade metal; it can be chosen from Al, Zn, Ga, In, Sn,

[0168] - A is a metalloid, it can be chosen from B, Si, Ge, Sb,

[0169] - M is a metalloid, it can be chosen from B, Si, Ge, Sb,

[0170] - A is a lanthanide, it can be chosen from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,

[0171] - M is a lanthanide, it can be chosen from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.

[0172] Preferably, A and M different from each other are B and / or Mg.

[0173] Preferably, the pigment (Bii_xAx)(Vi_yMy)04 has a monoclinic scheelite crystallographic form at room temperature.

[0174] Preferably, x and y are 0, that is, the pigment (Bii_xAx)(Vi_yMy)O4 is Bismuth Vanadate (BiVO4). Advantageously, a BiVO4 with a monoclinic scheelite crystallographic structure at room temperature is used.

[0175] Bismuth vanadate is a yellow inorganic compound with the formula BiVO4, widely used for its coloristic properties and lack of toxicity. Registered in the Colour Index International database as QI Pigment Yellow 184, it is marketed by companies including Heubach (Vanadur®), BASF (Sicopal®), FERRO (Lysopac), and Bruchsaler Farbenfabrik (Brufasol®). • Heat-stable pigments

[0176] Preferably, the thermostable pigment(s) is / are chosen from the group consisting of:

[0177] - Titanium rutile-type yellow pigment,

[0178] - Yellow pigment derived from bismuth, for example selected from the vanadates of stabilized bismuth (Py i84)

[0179] - Red pigment, for example selected from perylene red (for example PR149, PR178 and PR224), iron oxide,

[0180] - Orange pigment of the bismuth oxyhalide type (PO85),

[0181] - Bismuth vanadate orange pigment (PO86)

[0182] - Zinc tin titanium orange pigment (PO82)

[0183] - Orange pigment of cerium sulfide (PO75; PO78)

[0184] - Yellow-orange rutile-type pigment of antimony titanium chromium (PBr24)

[0185] - Yellow-orange pigment of the tin and zinc rutile type (Py2i6)

[0186] - Yellow-orange pigment of niobium oxide tin zinc sulfide (Py227)

[0187] - Orange-yellow pigment of double oxides of tin and niobium

[0188] - Co3(PO4)2

[0189] - LiCoPO4

[0190] - CoA12O4

[0191] - Cr2O3

[0192] - TiO2

[0193] - Black pigment PBk28 (Copper chromite black spinel)

[0194] - and their mixtures. • Sequins

[0195] The glitter used in the context of the present invention can be independently selected from mica glitter, coated or uncoated, silica glitter, coated or uncoated, aluminum glitter, coated or uncoated, iron oxide glitter, coated or uncoated, or mica or silica glitter coated with titanium dioxide. The glitter used in the context of the present invention can be treated to give a particular color effect.

[0196] Preferably, the glitter(s) is / are particles selected from the group consisting of mica particles, aluminum particles, titanium dioxide-coated mica particles or mixtures thereof. • Hologram glitter

[0197] Advantageously, the glitter(s) is / are holographic glitter, that is to say a mixture of magnetizable and non-magnetizable particles.

[0198] Magnetizable particles may advantageously be particles comprising at least one ferromagnetic metal. These magnetizable particles may be homogeneous, i.e., made of the same material, or composite, i.e., having a core-shell structure in which the ferromagnetic metal is located in the core and / or 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 corrosion protection during the coating application stages, or plastic material flakes coated with iron oxide Fe2O3, or flakes whose The core is made of ferromagnetic metal and the outer shell is made of a plastic material or a sol-gel material.

[0199] According to one embodiment, a portion of said magnetizable particles is oriented so as to form a three-dimensional decoration.

[0200] Advantageously, the mixture of magnetizable and non-magnetizable particles represents between 1% and 5% by weight of the weight of the layer, preferably between 2% and 3% by weight.

[0201] Advantageously, the percentage of non-magnetizable particles in the mixture of magnetizable and non-magnetizable particles is between 15% and 40% by weight relative to the total weight of the mixture of magnetizable and non-magnetizable particles.

[0202] Advantageously, the magnetizable particles have a D50 dimension less than or equal to 23 pm.

[0203] The term “D50” means, in the context of the present invention, the maximum dimension that 50% of the particles have by number.

[0204] Advantageously, the non-magnetizable particles have a D90 dimension between 20% and 250% of the D90 dimension of the magnetizable particles.

[0205] The term “D90” means, in the context of the present invention, the maximum dimension that 90% of the particles have by number.

[0206] Advantageously, the magnetizable particles and / or the non-magnetizable particles are colored on the surface.

[0207] Advantageously, the non-magnetizable particles are made of mica, aluminum, or mica coated with titanium dioxide.

[0208] Advantageously, the magnetizable particles consist of iron, iron oxide, aluminum coated with iron, or mica coated with iron, the iron being in ferritic form. Architectures

[0209] According to one embodiment, the coating according to the invention comprises one or more layers applied to the substrate. It may be a single-layer or multi-layer coating, the different layers being applied successively.

[0210] Advantageously, the coating according to the invention comprises one to three layers, preferably two, applied to the support.

[0211] Advantageously, the coating according to the invention comprises intermediate layers, preferably two, which may be decorative layers.

[0212] Advantageously, the coating according to the invention is a non-stick coating, that is to say, preferably food does not stick to the coating.

[0213] Advantageously, the coating according to the invention is a single-layer non-stick coating.

[0214] When the coating is a multilayer coating, the slow-release particles are preferentially present in the upper layers, i.e. those closest to the (3b) face.

[0215] Preferably, the content of slow-release particles in the penultimate layer underlying the last layer forming face (3b) ranges from 0 to 32.97 parts by weight per 100 parts by weight of this layer.

[0216] Preferably, the content of slow-release particles in the layer forming the face (3b) ranges from 5.15 to 32.97 parts by weight per 100 parts by weight of this layer.

[0217] When the coating is a multilayer coating and the slow-release particles are present in only one layer, they are preferentially present in the last layer forming face (3b) or in the penultimate layer underlying the last layer forming face (3b). When the slow-release particles are present only in the penultimate layer underlying the last layer forming face (3b), their release is slowed down by the last layer forming face (3b).

[0218] When the coating is a multilayer coating and the slow-release particles are present in several layers, the content of slow-release particles may differ in each of the layers in which they are present. Preferably, the content of slow-release particles increases from face (3a) to face (3b).

[0219] When the coating is a multilayer coating and the slow-release particles are present in several layers, the size of the slow-release particles may be different in each of the layers in which they are present.

[0220] Scenery

[0221] According to one embodiment, the decoration layer(s) is / are continuous and covers the entirety of the lower layer.

[0222] According to another embodiment, the decoration layer(s) do not cover the entire lower layer and form at least one decoration.

[0223] Advantageously, the decoration layer(s) make up several decorations, one (i) comprising one or more thermochromic pigment(s) and the other (j) comprising at least one temperature reference pigment composition.

[0224] According to one embodiment, each of the two decorations (i) and (j) is presented in the form of adjacent, non-overlapping motifs. For example, each decoration is represented by different geometric motifs distributed uniformly over the entire surface and alternating with respect to each other.

[0225] According to another embodiment, the two decorations (i) and (j) are partially overlapping. For example, each decoration is represented by different geometric patterns distributed evenly over the entire surface and partially overlapping.

[0226] Preferably, the two designs (i) and (j) are overlapping, either because one of the two designs is a continuous layer and the other design covers it in the form of patterns, or because the two designs (i) and (j) are in the form of overlapping patterns.

[0227] According to another embodiment, the decorations are applied directly onto the substrate.

[0228] The decoration can be applied by any method well known to those skilled in the art, for example by screen printing or pad printing.

[0229] According to one embodiment, the coating according to the invention is a single-layer coating comprising:

[0230] - at least 70% by weight of a polymeric phase, comprising: • at least 50%, by weight, of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50%, by weight, of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); - slow-release particles including: • a slow-release material having a porous structure and / or a layered structure; • a silicone oil, which binds to the slow-release material.

[0231] - possibly one or more charge(s);

[0232] - possibly one or more additive(s);

[0233] - possibly one or more coloring agent(s).

[0234] According to one embodiment, the coating according to the invention is a single-layer coating comprising:

[0235] - at least 70% by weight of a polymeric phase, consisting of: • at least 50%, by weight, of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50%, by weight, of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); - slow-release particles including: • a slow-release material having a porous structure and / or a layered structure; • a silicone oil, which binds to the slow-release material.

[0236] - possibly one or more charge(s);

[0237] - possibly one or more additive(s);

[0238] - possibly one or more coloring agent(s).

[0239] According to one embodiment, the coating according to the invention is a single-layer coating consisting of:

[0240] - at least 70% by weight of a polymeric phase, consisting of: • at least 50%, by weight, of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50%, by weight, of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); - slow-release particles including: • a slow-release material having a porous structure and / or a layered structure; • a silicone oil, which binds to the slow-release material.

[0241] - possibly one or more charge(s);

[0242] - possibly one or more additive(s);

[0243] - possibly one or more coloring agent(s).

[0244] According to one embodiment, the coating according to the invention is a multilayer coating, each of the layers of the multilayer coating comprising:

[0245] - one or more polymers selected from the group consisting of one or more polyarylether ketone(s) (PAEK), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

[0246] - possibly one or more organopolysiloxane polymer(s),

[0247] - possibly one or more fluorocarbon resin(s),

[0248] - possibly one or more charge(s),

[0249] - possibly one or more additive(s),

[0250] - possibly one or more coloring agent(s),

[0251] at least one of the layers of the multilayer coating comprising slow-release particles comprising:

[0252] - a slow-release material having a porous structure and / or a structure in layers;

[0253] - a silicone oil, bonding to the slow-release material.

[0254] and at least one of the layers of the multilayer coating comprising at least 70% by weight of a polymeric phase comprising: • at least 50%, by weight, of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50%, by weight of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s).

[0255] According to one embodiment, the coating according to the invention is a multilayer coating, each of the layers of the multilayer coating comprising:

[0256] - one or more polymers selected from the group consisting of one or more polyarylether ketone(s) (PAEK), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

[0257] - possibly one or more organopolysiloxane polymer(s),

[0258] - possibly one or more fluorocarbon resin(s),

[0259] - possibly one or more charge(s),

[0260] - possibly one or more additive(s),

[0261] - possibly one or more coloring agent(s),

[0262] at least one of the layers of the multilayer coating comprising slow-release particles comprising:

[0263] - a slow-release material having a porous structure and / or a structure in layers;

[0264] - a silicone oil, bonding to the slow-release material.

[0265] and at least one of the layers of the multilayer coating comprising at least 70% by weight of a polymeric phase consisting of: • at least 50%, by weight, of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50%, by weight of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s).

[0266] According to one embodiment, the coating according to the invention is a multilayer coating, each of the layers of the multilayer coating comprising: - at least 70% by weight of a polymeric phase consisting of: • at least 50%, by weight, of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or - at least 50%, by weight of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s).

[0267] - possibly one or more charge(s),

[0268] - possibly one or more additive(s),

[0269] - possibly one or more coloring agent(s),

[0270] and at least one of the layers of the multilayer coating comprising slow-release particles comprising:

[0271] - a slow-release material having a porous structure and / or a structure in layers;

[0272] - a silicone oil, bonding to the slow-release material.

[0273] According to one embodiment, the coating (3) according to the invention is a multilayer coating, consisting of: • one or more layer(s) consisting of:

[0274] - at least 70% by weight of a polymeric phase consisting of: • at least 50% by weight of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50% by weight of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); - slow-release particles including: • a slow-release material having a porous structure and / or a layered structure; • a silicone oil, which binds to the slow-release material.

[0275] - possibly one or more charges,

[0276] - possibly one or more additive(s),

[0277] - possibly one or more coloring agent(s)

[0278] and • one or more layer(s) made up of:

[0279] - at least 70% by weight of a polymeric phase consisting of: • at least 50% by weight of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50% by weight of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s);

[0280] - possibly one or more charges,

[0281] - possibly one or more additive(s),

[0282] - possibly one or more coloring agent(s).

[0283] According to one embodiment, the coating (3) according to the invention is a multilayer coating, consisting of: • one or more layer(s) made up of:

[0284] - at least 70% by weight of a polymeric phase consisting of: • at least 50% by weight of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50% by weight of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); - slow-release particles including: • a slow-release material having a porous structure and / or a layered structure; • a silicone oil, which binds to the slow-release material.

[0285] - possibly one or more charges,

[0286] - possibly one or more additive(s),

[0287] - possibly one or more coloring agent(s)

[0288] and • one or more layer(s) made up of:

[0289] - at least 70% by weight of a polymeric phase consisting of: • at least 50% by weight of a polyether ether ketone (PEEK), the remainder being made up of polyethersulfone (PES), and possibly PTFE; or • at least 50% by weight of polyethersulfone (PES), the remainder being made up of a polyether ether ketone (PEEK) and possibly PTFE;

[0290] - one or more charges,

[0291] - possibly one or more additive(s),

[0292] - possibly one or more coloring agent(s).

[0293] According to one embodiment, the coating (3) according to the invention is a multilayer coating, consisting of: • one or more layer(s) consisting of:

[0294] - at least 70% by weight of a polymeric phase consisting of: • at least 50% by weight of one or more polyarylether ketone(s) (PAEK(s)), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); or • at least 50% by weight of one or more polymer(s) chosen from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); - slow-release particles including: • a slow-release material having a porous structure and / or a layered structure; • a silicone oil, which binds to the slow-release material.

[0295] - possibly one or more charges,

[0296] - possibly one or more additive(s),

[0297] - possibly one or more coloring agent(s)

[0298] and • one or more layer(s) made up of:

[0299] - at least 70% by weight of a polymeric phase consisting of: • at least 50% by weight of a polyether ether ketone (PEEK), the remainder being composed of a silicone oil, and possibly PTFE; or • at least 50% by weight of a silicone oil, the remainder being made up of a polyether ether ketone (PEEK) and possibly PTFE;

[0300] - one or more charges,

[0301] - possibly one or more additive(s),

[0302] - possibly one or more coloring agent(s). Coated heating element

[0303] The term “coated heating element” means an assembly of a metallic substrate and a coating according to the invention on said metallic substrate, the substrate being capable of being heated.

[0304] Advantageously, a coated heating element according to the invention is a coated cooking element.

[0305] Another object of the invention, illustrated in [Fig. 1], relates to a coated heating element (1) for a household appliance, comprising a metallic substrate (2) coated on at least one face (2a) with a coating (3) according to the invention, in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b). Metallic substrate

[0306] Advantageously, said metallic substrate (2) is a substrate of aluminum, stainless steel, cast iron or aluminum, iron, titanium or copper.

[0307] For the purposes of this invention, aluminium means a metal consisting of 100% aluminium or an aluminium alloy.

[0308] Advantageously, the metallic substrate (2) is an aluminum substrate, a stainless steel substrate, or a multilayer metallic substrate. The metallic substrate (2) can be a two-layer or three-layer substrate, these multilayers being obtained, for example, by co-lamination, by hot diffusion under load (solid state bonding), or by hot or cold impact bonding.

[0309] Preferably, the metallic substrate (2) comprises an alternation of layers of metal and / or metallic alloy.

[0310] According to one embodiment, the metallic substrate (2) is an aluminum alloy substrate, a stainless steel substrate or a multilayer metallic substrate whose face (2a) is made of aluminum alloy or stainless steel.

[0311] Preferably, the metallic substrate (2) is an aluminum substrate.

[0312] Advantageously, the thickness of the metallic substrate (2) is between 0.5 mm and 10 mm.

[0313] Advantageously, the face (2a) of the metallic substrate (2) has previously undergone a surface treatment to improve the adhesion of the coating to said substrate.

[0314] According to one embodiment, the surface of the face (2a) of the metallic substrate (2) has undergone a surface treatment, said surface treatment being a chemical attack, a brushing, a hydration, a sandblasting, a shot blasting, a physicochemical treatment of the plasma or corona or laser type, a chemical activation or a combination of these different techniques.

[0315] 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 For an aluminum substrate, this treatment can be performed by anodizing (creating a tubular alumina structure), chemical etching, sandblasting, brushing, shot blasting, or by adding material using a technology such as thermal spraying (flame, plasma, or arc spray). Other metallic substrates can also be polished, sandblasted, brushed, bead-blasted, or have material added using a technology such as thermal spraying (flame, plasma, or arc spray).

[0316] As examples of metallic substrates that can be used in the present invention, advantageous examples include substrates made of anodized or unanodized aluminum, optionally polished, brushed, sandblasted, shot-blasted or micro-beaded; substrates made of anodized or unanodized aluminum alloy, optionally polished, brushed, sandblasted or micro-beaded; substrates made of steel, optionally polished, brushed, sandblasted, shot-blasted or micro-beaded; substrates made of stainless steel, optionally polished, brushed, sandblasted or micro-beaded; substrates made of cast steel, aluminum or iron; and substrates made of copper, optionally hammered or polished.

[0317] Advantageously, the substrate can be selected from substrates comprising ferritic stainless steel / aluminum / austenitic stainless steel layers, substrates comprising stainless steel / aluminum / copper / aluminum / austenitic stainless steel layers, cast aluminum caps, aluminum or aluminum alloy caps lined with an outer stainless steel base, metallic co-laminated substrates, for example two-layer co-laminated substrates comprising a stainless steel layer (for example intended to form the inner face of the article) and an aluminum or aluminum alloy layer, anodized or not (for example intended to form the outer face of the article).

[0318] Advantageously, the mean arithmetic roughness Ra of the surface of the face (2a) of the metallic substrate (2) is greater than or equal to 1 pm.

[0319] The arithmetic mean roughness Ra is measured using a roughness tester according to ISO 4287. Ra represents the arithmetic mean of the deviations from the mean. Surface topography can be studied, in particular, with a profilometer with a probe equipped with a fine stylus fitted with a diamond tip, or with an optical metrology device such as the Altisurf®, in which a chromatic confocal sensor allows for non-contact measurement. The study of this surface topography makes it possible to define the arithmetic mean roughness Ra. Process

[0320] Another object of the invention relates to a method for manufacturing a coated heating element (1) according to the invention comprising the following successive steps:

[0321] i. Supply of a metallic substrate (2) having a face (2a),

[0322] ii. Optionally, pretreatment of the face (2a) of said metallic substrate (2) intended to be coated,

[0323] iii. Application of the coating layer(s) (3) onto the face (2a),

[0324] iv. baking of the element obtained in step iii.

[0325] Advantageously, step iii is carried out by spraying, screen printing, roller application, electrostatic projection of the coating composition(s) in liquid or powder form of the coating layer(s) (3).

[0326] In step iii, the coats can be applied wet on wet or a drying period can be applied between each coat.

[0327] By baking the coated substrate, we mean, in the context of the present invention, a heat treatment which makes it possible to densify the thermostable coating layer(s) applied to the substrate.

[0328] In step iv, a heating, also called sintering in some cases, is carried out. Generally, the heating temperature of step iv is from 230°C to 420°C. Advantageously, the heating temperature of step iv is from 380 to 420°C in the presence of fluorocarbon resins in the polymer phase. The advantageous heating temperature of step iv is from 230 to 300°C in the presence of organopolysiloxane polymers in the polymer phase, preferably from 230 to 280°C, and even more preferably from 230 to 250°C. The advantageous heating temperature of step iv. is between 230 and 300°C in the presence of thermoplastic polymers, excluding fluorocarbon resins, in the polymeric phase, preferably between 250 and 400°C, even more preferably between 280 and 380°C.

[0329] Drying can be carried out by convection or IR.

[0330] Advantageously, the manufacturing process for a coated heating element (1) according to the invention includes a drying step between 80 and 150°C after application of each of the layers.

[0331] Advantageously, the manufacturing process for a coated heating element (1) according to the invention comprises a single final baking step iv of all the applied layers. This single baking step is carried out simultaneously for all the applied layers. This embodiment makes it possible to film, fuse, and crosslink all the layers together so that they form a single layer. The coating (3) thus forms a single layer, even if this single layer may not be homogeneous, that is to say, it may exhibit compositional heterogeneity such as, for example, a concentration gradient of its constituents.

[0332] Advantageously, the manufacturing process for a coated heating element (1) according to the invention includes a shaping step of said support (2) before or after step iii. The shaping is also called stamping.

[0333] The application of the coating according to the invention by the process according to the invention can be carried out on the flat substrate or on the shaped substrate or on a A locally flat area of ​​the substrate is shaped. A thermostable coating layer is obtained. Generally, this coating layer is moist.

[0334] For the purposes of this invention, wet layer means that the layer includes all or part of its solvents.

[0335] Preferably, all or part of the solvents in the wet layer are removed, either naturally or by physical treatment, for example by thermal drying, airflow drying or vacuum treatment.

[0336] Advantageously, the coating composition according to the invention may further comprise at least one solvent. Advantageously, the solvent may be protic. Advantageously, the solvent may be non-toxic.

[0337] The solvent usable in the coating composition according to the invention may advantageously comprise at least one alcohol, and may preferably be chosen from isopropanol, methanol, ethanol and mixtures thereof.

[0338] According to a variant of the method according to the invention, the coating can be applied in several layers. In this case, the deposition of at least one layer of a coating composition according to the invention onto at least one of the two opposite faces of said substrate is repeated several times. In this case, the coating according to the invention is multilayer. Each layer is preferably produced in a single printing step, the whole forming a multilayer. Preferably, according to this variant, a drying step is carried out between the application of each layer, and then the coating of said substrate is baked after the application of the last layer.

[0339] When the shaping step precedes the application iii of the coating, the coating is preferably carried out by spraying.

[0340] When this shaping step is subsequent to the application iii of the coating, the coating is preferably carried out by screen printing or by roller.

[0341] The coating formula is generally aqueous, with the polymers of the polymeric phase being in suspension form. Other non-aqueous solvents may also be suitable.

[0342] According to one variant, the PAEK suspensions have a particle size with a d50 of about 10 pm to 15 pm. Household item

[0343] Another object of the invention relates to a household article comprising a coated heating element (1) according to the invention.

[0344] According to one embodiment, said household article is a cooking article and the face (3b) of the coating according to the invention is capable of receiving food.

[0345] According to one embodiment, the cooking article comprises a heating surface intended to be brought into contact with an external heating source, the surface of heating element being opposite the cooking surface intended to come into contact with the food during cooking.

[0346] Advantageously, the culinary article according to the invention is chosen from the group consisting of saucepan, frying pan, fondue or raclette pan, stockpot, wok, sauté pan, crepe pan, grill, plancha, pot, casserole dish, cooker or bread machine bowl, culinary mold.

[0347] The invention also relates to an electric cooking appliance comprising a coated heating element (1) according to the invention and a heating source configured to heat said coated heating element (1).

[0348] Advantageously, the electric cooking appliance is chosen from the group consisting of electric crepe maker, electric raclette appliance, electric fondue appliance, electric grill, electric plancha, electric cooker, bread machine, electric pressure cooking appliance.

[0349] According to another embodiment, the household item is an everyday item that the user heats.

[0350] This can be an iron or a garment steamer, the coating according to the invention covering the sole.

[0351] This may be a hair straightener, the coating according to the invention covering the plates of said hair straightener.

[0352] The heating household article according to the present invention may in particular be a cooking article or a small household appliance such as an iron, a hair care article, an insulated pot (for example for a coffee maker) or a mixing bowl.

[0353] The small household heating appliance article according to the present invention may in particular be a cooking article, and in particular a cooking article of which one of the two opposite faces of the substrate is an interior face, possibly concave, intended to be disposed on the side of food likely to be introduced into or onto said article, and of which the other face of the substrate is an exterior face, possibly convex, intended to be disposed towards a heat source.

[0354] By way of non-limiting examples of cooking articles conforming to the present invention, mention shall be made in particular of cooking articles such as saucepans and frying pans, woks and sauté pans, stockpots and casseroles, crepe makers, waffle irons, grills, molds and baking sheets, planchas, barbecue plates and grills, raclette or fondue appliances, rice cookers, jam makers, bread machine bowls, preparation bowls.

[0355] The small household heating appliance article according to the present invention may in particular be an iron, such as a steam iron or a steam generator, and the coated element according to the present invention is the sole of the iron.

[0356] The small household heating appliance according to the present invention may in particular be a hair care item, such as a curling iron or straightening iron, and the coated element according to the present invention is one of the heating plates of the hair care item. EXAMPLES

[0357] The aims, aspects and advantages of the present invention will be better understood from the following description of a particular embodiment of the invention presented by way of non-limiting example.

[0358] Of course, the invention is in no way limited to the embodiment described and illustrated, which has been given only by way of example. Modifications remain possible, particularly with regard to the composition of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Demands

1. Coating (3) for a household article on a metallic support (2) in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b), which coating is a single-layer or multi-layer coating, the single layer or each of the layers of the multi-layer coating comprising: - one or more polymers selected from the group consisting of one or more polyarylether ketone(s) (PAEK), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, - optionally one or more organopolysiloxane polymer(s), - optionally one or more fluorocarbon resin(s), - optionally one or more filler(s), - optionally one or more additive(s), - optionally one or more coloring agent(s),and the monolayer or at least one of the layers of the multilayer coating comprising slow-release particles (4) comprising: - a slow-release material (41) having a porous structure and / or a layered structure; - a silicone oil (42), bonding to the slow-release material.

2. Coating (3) for household article according to claim 1, wherein the slow-release material comprises at least one of the following: vermiculite, zeolite, bentonite, diatomaceous earth, alpha alumina, silica aerogel, fumed silica, precipitated silica, amorphous silica, hollow glass micropowder, porous silicate, stratified silicate, porous phosphate, stratified phosphate, porous carbonate, stratified carbonate, porous sulfate and stratified sulfate.

3. Coating (3) for household article according to claim 1 or 2, characterized in that the size of the slow-release particles is between 5 and 60 pm.

4. Coating (3) for household article according to any one of the preceding claims, characterized in that the slow-release particles (4) comprise a silane coupling agent, preferably a methoxysilane.

5. Coating (3) for household article according to any one of the preceding claims, characterized in that the proportion of slow-release particles in each layer in which they are present ranges from 5 to 35% by weight of said layer.

6. Coating (3) for household article according to any one of the preceding claims, characterized in that the proportion of slow-release material / silicone oil ranges from 1:2 to 2:

1.

7. Coating (3) for household article according to any one of the preceding claims, characterized in that it is a single-layer coating of thickness between 5 and 200 pm.

8. Coating (3) for household article according to any one of the preceding claims, characterized in that it is a single-layer coating comprising: - at least 70% by weight of a polymeric phase, comprising: • at least 50% by weight of one or more polyarylether ketone(s) (PAEK), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, optionally one or more organopolysiloxane polymer(s) and optionally one or more fluorocarbon resin(s);or • at least 50%, by weight, of one or more polymer(s) selected from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s); - slow-release particles comprising: • a slow-release material having a porous structure and / or a layered structure; • a silicone oil, bonding to the slow-release material. - possibly one or more charges; - possibly one or more additive(s); - possibly one or more coloring agent(s).

9. Coating (3) for household article according to any one of claims 1 to 6, characterized in that it is a multilayer coating comprising one or more primary layer(s), one or more intermediate layer(s) and one or more finishing layer(s), the slow-release particles being present in one or more intermediate layer(s) and / or one or more finishing layer(s).

10. Coating (3) for household article according to any one of claims 1 to 6 and 9, characterized in that it is a multilayer coating, each of the layers of the multilayer coating comprising: - one or more polymers selected from the group consisting of one or more polyarylether ketone(s) (PAEK), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, - optionally one or more organopolysiloxane polymer(s), - optionally one or more fluorocarbon resin(s), - optionally one or more filler(s), - optionally one or more additive(s), - optionally one or more coloring agent(s), at least one of the layers of the multilayer coating comprising slow-release particles comprising: - a slow-release material having a porous structure and / or a layered structure;- a silicone oil, bonding to the slow-release material, and at least one of the layers of the multilayer coating comprising at least 70% by weight of a polymeric phase comprising: • at least 50%, by weight of one or more polyarylether ketone(s) (PAEK), the remainder being selected from the group consisting of one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, possibly one or more polymer(s); organopolysiloxane(s) and possibly one or more fluorocarbon resin(s); or • at least 50%, by weight of one or more polymer(s) selected from the group consisting of aromatic thermoplastic polymers other than PAEK, heterocyclic thermoplastic polymers, and mixtures thereof, the remainder consisting of one or more polyarylether ketone(s) (PAEK), possibly one or more organopolysiloxane polymer(s) and possibly one or more fluorocarbon resin(s).

11. Coating (3) according to any one of the preceding claims, characterized in that the polyarylether ketone(s) (PAEK) is / are selected from the group consisting of polyetherketones (PEK), polyetheretherketone (PEEK), polyetherketoneketones (PEKK), polyetheretherketoneketones (PEEKK) and polyetherketoneetherketoneketones (PEKEKK) and mixtures thereof, preferably from the group consisting of polyetheretherketones (PEEK), polyetherketoneketones (PEKK) and mixtures thereof.

12. Coating (3) according to any one of the preceding claims, characterized in that the aromatic thermoplastic polymer(s) other than PAEK is / are selected from the group consisting of poly(phenylene oxide) (PPO), poly(arylethersulfones) polymer (PAES), and in particular polyethersulfone (PES), polyphenylene ether sulfone (PPSU), polyphenylene sulfide (PPS), poly(arylene sulfide) (PAS), liquid crystal polymers and mixtures thereof, preferably from the group consisting of polyethersulfone (PES), polyphenylene sulfide (PPS) and mixtures thereof.

13. Coating (3) according to any one of the preceding claims, characterized in that the heterocyclic thermoplastic polymer(s) is / are selected from the group consisting of polyetherimide (PEI), polyimides (PI), polyamide imides (PAI) and polybenzymidazole (PBI) and mixtures thereof.

14. Coating (3) according to any one of the preceding claims, characterized in that the polymer(s) organopolysiloxanes is / are chosen from the group consisting of polymers obtained from organopolysiloxane polymeric or oligomeric precursors, either in the form of silicone oils of varying degree of branching, or in the form of silicone resins of varying 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.

15. Coating (3) according to any one of the preceding claims characterized in that the filler(s) is / are selected from the group consisting of ceramic and / or mineral and / or metallic and / or hydrophobic silica fillers and / or diamond particles.

16. Coating (3) according to any one of the preceding claims characterized in that it is a non-stick coating.

17. Coated heating element (1) for household article, comprising a metallic substrate (2) coated on at least one face (2a) with a coating according to any one of the preceding claims, in contact by one of its faces (3a) with the metallic substrate (2) and visible to the user by its face (3b).

18. A method for manufacturing a coated heating element (1) according to claim 17 comprising the following successive steps: i. Supplying a metallic substrate (2) having a face (2a), ii. Optionally, pre-treating the face (2a) of said metallic substrate (2) intended to be coated, iii. applying the coating layer(s) (3) onto the face (2a), iv. baking the element obtained in step iii.

19. Method of manufacturing a coated heating element (1) according to claim 18, characterized in that step iii is carried out by spraying, screen printing, roller application, electrostatic projection of the coating composition(s) in liquid or powder form of the coating layer(s) (3).

20. Method of manufacturing a coated heating element (1) according to claim 18 or 19, comprising a drying step between 80 and 150°C after application of each layer(s).

21. Method of manufacturing a coated heating element (1) according to any one of claims 18 to 20 comprising a single final baking step iv of all the applied layers.

22. Household article comprising a coated heating element (1) according to claim 17 characterized in that it is a cooking article and in that the face (3b) of the coating according to any one of claims 1 to 16 is capable of receiving food.

23. Culinary article according to claim 22 selected from the group consisting of saucepan, frying pan, fondue or raclette pan, stockpot, wok, sauté pan, crepe pan, grill, plancha, pot, casserole dish, cooker or bread machine bowl, and culinary mold.

24. Electric cooking appliance comprising a coated heating element (1) and a heating source configured to heat said coated heating element (1), characterized in that said coated heating element (1) conforms to claim 17.

25. Electric cooking appliance according to claim 24, selected 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.

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