Non-stick coating

Abstract

The present invention relates to a coating (3) for a household article on a metal substrate (2), wherein the coating is in contact, by one of its faces (3a), with the metal substrate (2) and visible to the user via its face (3b), wherein the coating is a single-layer or multilayer coating, the single layer or each of the layers of the multilayer coating comprising one or more organopolysiloxane polymers, and the single layer 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; and - a silicone oil (42), binding to the slow-release material.

Description

[0001] DESCRIPTION

[0002] Non-stick coating

[0003] FIELD OF INVENTION

[0004] 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 with a coating according to the invention.

[0005] STATE OF THE ART

[0006] In the field of household goods, particularly culinary goods, the coatings applied to substrates, most often metallic (aluminum, aluminum casting, stainless steel, cast steel, etc.), are of diverse natures.

[0007] Regarding the interior surfaces of these household items more specifically, PTFE-based 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.).

[0008] The present invention addresses the technical problem of improving the anti-stick properties of a coating with high thermo-mechanical properties.

[0009] The present invention also addresses the technical problem of alternative solutions to PTFE-type fluorinated resin-based coatings.

[0010] DESCRIPTION OF THE INVENTION

[0011] The present invention proposes an alternative to PTFE-based coatings for achieving good resistance to mechanical wear, particularly on kitchen utensils and cookware, thereby improving their durability, especially at high temperatures, and / or their cleanability, thus extending the product's lifespan. It also provides good non-stick properties. To overcome the weaknesses of PTFE-type coatings, the invention proposes a coating comprising one or more high-performance thermoplastic polymers for good mechanical resistance and slow-release silicone oil particles for good non-stick properties.

[0012] It is possible to achieve a durable non-stick effect by forming an effective oil film that separates food from the coated surface.

[0013] During food cooking, for example, the release of silicone oil is slowed down, which helps to maintain a durable non-stick effect.

[0014] SUMMARY OF THE INVENTION

[0015] 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:

[0016] - one or more organopolysiloxane polymer(s),

[0017] - possibly one or more polymer(s) selected from the group consisting of one or more polyarylether ketone(s) (PAEK(s)), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

[0018] - possibly one or more fluorocarbon resin(s),

[0019] - possibly one or more load(s),

[0020] - possibly one or more additive(s),

[0021] - possibly 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:

[0022] - a slow-release material (41) having a porous structure and / or a layered structure;

[0023] - a silicone oil (42), which binds to the slow-release material.

[0024] Another object of the invention 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 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). The invention also relates to a method for manufacturing a coated heating element (1) according to the invention comprising the following successive steps: i. Supplying a metallic substrate (2) having one 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) to the face (2a), iv. Baking the element obtained in step iii.

[0025] 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 a household article comprising a coated heating element (1) according to the invention and a heating source configured to heat said coated heating element (1), characterized in that said household article is an electric cooking appliance and in that the face (3b) of the coating according to the invention is capable of receiving food.

[0026] DEFINITIONS

[0027] The terms "layer" or "coating" should be understood, for the purposes of this invention, as referring 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.

[0028] The term "base layer" refers to 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.

[0029] The term "finish coat" refers to a continuous, transparent surface layer that allows perfect visibility of the decorative layer while protecting it from mechanical damage and giving the coating its non-stick properties. Preferably, the final finish coat is intended to come into contact with food.

[0030] The term "decoration" or "decorative layer" refers to one or more continuous or discontinuous layers comprising a pigment composition. The decoration may take the form of one or more patterns, or one or more colors. A decoration is clearly visible to the user with the naked eye and from a typical viewing distance.

[0031] The term "overlapping layers" refers to layers that are partially or completely superimposed. These layers may appear in partially overlapping patterns, such as concentric disks.

[0032] The term "adjacent layers" refers to non-overlapping layers. These layers may be in the form of identical or different non-overlapping patterns, preferably distributed uniformly.

[0033] A "temperature reference pigment composition" is defined as a composition containing a pigment that, at a given temperature, indicates to the user that the optimal operating temperature has been reached. This indication is made by comparing the colors of the thermochromic pigment composition with those of the temperature reference pigment composition. The optimal operating temperature is reached either when the colors are identical or when the colors are visually very different.

[0034] The "temperature reference pigment composition" may include a pigment that exhibits:

[0035] - the same color as the thermochromic pigment composition, at the optimal operating temperature,

[0036] * either because this pigment has the same color at room temperature as the thermochromic pigment composition at the optimal operating temperature, and does not change color with temperature,

[0037] * either because this pigment has a different color at room temperature than the thermochromic pigment composition, which evolves to the same color as the thermochromic pigment composition at the optimal operating temperature,

[0038] - a color very different from that of the thermochromic pigment composition at the optimal operating temperature, whether or not this pigment changes color with temperature changes.

[0039] The optimal operating temperature can be achieved when the color of the temperature reference pigment composition corresponds to a color indicated in the user manual for the household item incorporating the coating of the invention, or to a color indicated on a color chart provided to the user with said item. The temperature reference pigment composition is thermochromic or thermostable.

[0040] The reference pigment composition for temperature can be, for example, a reference pigment composition for cooking temperature or an indication of risk of overheating.

[0041] For the purposes of this invention, "thermochromic pigment or pigment composition" means a pigment or pigment composition that changes color with temperature within a given temperature range, and this change is reversible. This color change is visible to the user with the naked eye at normal viewing distances.

[0042] A "thermostable pigment" is defined as a pigment that does not change color when subjected to a temperature rise within a given temperature range, or that changes color when subjected to a temperature rise within a given temperature range so small that it is not visible to the user with the naked eye and at a normal operating distance.

[0043] Preferably, 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:

[0044] Li*, a and bi* characterizing the L*a*b values ​​of said compound at room temperature

[0045] L2*, a2* and b2* characterizing the L*a*b values ​​of said compound at 200°C.

[0046] By "the colours are identical" we mean indistinguishable by the user to the naked eye and at a normal viewing distance.

[0047] The term "culinary article" should be understood, for the purposes of this invention, as an object intended for cooking. To this end, it is designed to receive heat treatment.

[0048] The term "object intended to receive heat treatment" should be understood, for the purposes of this invention, as an object heated by an external heating system, such as frying pans, saucepans, sauté pans, woks, or barbecue grills, and capable of transferring the heat energy supplied by this external heating system to a material or food in contact with said object. The term "electric cooking appliance" should be understood, for the purposes of this invention, as a heating appliance possessing its own heating system, such as an electric crepe maker, electric raclette grill, electric fondue set, electric grill, electric griddle, electric cooker, bread maker, or electric pressure cooker.

[0049] The term "coating" refers to the layer covering the metallic substrate and adhering to that substrate.

[0050] In the present invention, % by weight are expressed in dry weight, i.e. without solvent.

[0051] DESCRIPTION OF THE FIGURES

[0052] [Fig. 1] represents a cross-sectional view of an example of an embodiment of a coated heating element (1) for a 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).

[0053] [Fig. 2] is a schematic view showing slow-release particles in a coating material according to the present invention. 41 = the slow-release material, 42 = the silicone oil

[0054] [Fig. 3] shows a cross-sectional view of an example embodiment of a coated heating element (1) for a household appliance 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

[0055] [Fig. 4] shows a cross-sectional view of an example embodiment of a coated heating element (1) for a household article with 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 = face of the coating in contact with the substrate, 3b = face of the coating visible to the user.

[0056] [Fig. 5] shows a cross-sectional view of an example embodiment of a coated heating element (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 = face of the coating in contact with the substrate, 3b = face of the coating visible to the user.

[0057] Slow-release particles are present only in the penultimate layer underlying the last layer forming face (3b).

[0058] DETAILED DESCRIPTION OF THE INVENTION

[0059] Coating

[0060] 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:

[0061] - one or more organopolysiloxane polymer(s),

[0062] - possibly one or more polymer(s) selected from the group consisting of one or more polyarylether ketone(s) (PAEK(s)), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

[0063] - possibly one or more fluorocarbon resin(s),

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

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

[0066] - possibly 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:

[0067] - a slow-release material (41) having a porous structure and / or a layered structure;

[0068] - a silicone oil (42), which binds to the slow-release material.

[0069] Advantageously, the thickness of the coating (3) according to the invention is between 5 and 200 pm, preferably between 10 and 80 pm.

[0070] According to one embodiment, it is a single-layer coating with a thickness between 5 and 200 µm. 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.

[0071] 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).

[0072] Slow-release particles

[0073] Advantageously, the size of the slow-release particles is between 5 and 60 pm, preferably less than or equal to 20 pm.

[0074] Advantageously, the slow-release material / silicone oil ratio ranges from 1:2 to 2:1.

[0075] 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. Therefore, 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 slow-release material 41 can be released slowly, which significantly improves the durable non-stick properties of the coating formed by the coating material.

[0076] Slow-release material

[0077] 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.

[0078] Thus, the porous structure has a volume of air voids, also called open pores, incorporated within its thickness to absorb the silicone oil deposited on it. These air voids or open pores originate from spaces left free within the structure's material during its formation. These air voids or open pores tend to be interconnected and can therefore form a network of through-pore porosity that can be filled by 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 this phase (i.e., deep within the volume).

[0079] It should also be possible for the porous structure to bind the silicone oil through 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.

[0080] The term "bond" according to the invention means either a non-polar covalent bond, a polar covalent bond, an ionic bond, a hydrogen bond, an electrostatic bond, or any weak bond.

[0081] 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.

[0082] Silicone oil

[0083] The silicone oil can be chosen from at least one methyl silicone oil, a dimethyl silicone oil, a methyl phenyl silicone oil, a hydroxyl silicone oil, an alkoxylated silicone oil, a vinylated silicone oil, a hydrogen-containing silicone oil, and a polyether-modified silicone oil.

[0084] In percentage by weight, silicone oil can 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 range from 500 to 1,000, the molecular weight of medium molecular weight silicone oil from 3,000 to 6,000, and the molecular weight of high molecular weight silicone oil from 12,000 to 30,000.

[0085] High molecular weight silicone oil binds more strongly to slow-release materials and has a slower release rate; low molecular weight silicone oil has better free mobility and therefore better anti-adhesion properties; furthermore, medium molecular weight silicone oil has both free mobility and intermediate bond strength. Therefore, by combining low molecular weight, medium molecular weight, and high molecular weight silicone oils, it is possible to achieve both slow release and improved anti-adhesion properties.

[0086] Coupling agent

[0087] Furthermore, to enhance the bond strength between the silicone oil and the slow-release material, a coupling agent may also be used between the slow-release material and the silicone oil. In this case, the coupling agent may include a silane coupling agent. However, embodiments are not limited to this, and the coupling agent may be omitted.

[0088] Advantageously, the slow-release particles include a silane coupling agent, preferably a methoxysilane.

[0089] Process for preparing slow-release particles

[0090] One method for preparing slow-release particles involves 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 oils.

[0091] As is known in the prior art, slow-release material comprising a porous or layered structure can absorb silicone oil in its open porosity.

[0092] Furthermore, silicone oil can bind to the slow-release material in at least two ways: adsorption and bonding. It is important to understand that adsorption refers to the attachment of silicone oil to the surface of the slow-release material, which can be physical or chemical, but the interactions between the adsorbent (slow-release material with a porous structure) and the adsorbate (silicone oil) are often weak.

[0093] On the other hand, a bond refers to a stronger chemical bond obtained through interactions between atoms.

[0094] In the present invention, for example, it may involve the condensation of the hydroxyl groups of the silicone oil and the hydroxyl groups of the slow-release material.

[0095] During the mixing step, silicone oil, the slow-release material, and a coupling agent are 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. The mixture is then treated ultrasonically for 0.5 to 1 hour to further bond the silicone oil to the slow-release material. Finally, the silicone oil is dried to a semi-solid state by heating and solidification and then bonded to the slow-release material in a colloidal form to obtain the slow-release particle.

[0096] The particle size of the slow-release material is, for example, between 5 and 150 µm. Besides ultrasonic treatment, other methods known to those 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.

[0097] A suitable-sized slow-release material precursor (i.e., a pre-milling slow-release material; when the milling step is omitted, the slow-release material precursor can be considered the final slow-release material) 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 include 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.

[0098] According to one embodiment, the particle size of the slow-release precursor material can range from 5 to 150 µm, and the particle size distribution within this range can be normal. When the particle size is too large (e.g., less than 150 µm), it can increase the grinding process or result in the ground particles of the slow-release material being 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 (e.g., less than 5 µm; furthermore, the particle size will decrease after grinding) makes efficient absorption of the silicone oil difficult, thus hindering the achievement of a good slow-release effect.

[0099] 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, implementation examples are not limited to this. In other words, when the slow-release material precursor is selected to have a relatively small particle size between 5 and 150 µm, one milling pass 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.

[0100] As an 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 blend, 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 blend. However, embodiment examples are not limited to this. The coupling agent and catalyst are used to enhance 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.

[0101] In one specific example, silicone oil, a 5–150 µm slow-release material precursor, and a silane coupling agent can be uniformly mixed and ground to a particle size of 30 µm or less. 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 20 µm or less. Next, ultrasonic treatment is performed at room temperature for 0.5 to 1 h to allow more silicone oil to bond to the slow-release material. Finally, the silicone oil can be heated and solidified to a semi-solid state and bonded to the slow-release material in a colloidal form, resulting in slow-release particles.Here, by first mixing the silicone oil and the slow-release material and grinding them to a particle size of 30 µm or less, the silicone oil and the slow-release material can be homogeneously blended. Then, grinding under the action of a catalyst to a particle size of 20 µm or less allows the silicone oil to be firmly absorbed by the slow-release material on the outside. Besides ultrasonic processing, 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 step can be omitted and an agitation process may be used, or the second grinding step 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 used.

[0102] Organopolysiloxane polymers are given as suitable examples according to the invention, including those obtained from organopolysiloxane polymeric or oligomeric precursors, either in the form of silicone oils with varying degrees of branching, or in the form of silicone resins with varying degrees of pre-crosslinking, or copolymers of silicone resins such as silicone-polyester, silicone-alkyd, silicone-polyurethane, and silicone-epoxy resins, or in the form of mixtures of silicone oils, silicone resins, and silicone resin copolymers. 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) hydroxyl or alkoxy (in particular methoxy, ethoxy, or butoxy) functional groups as substituents for silicon atoms.

[0103] Preferably, the organopolysiloxane polymer(s) of the coating according to the invention comprises / include a copolymer of silicone resins and / or a silicone oil.

[0104] This family of polymers allows for the combination of various properties, depending on the polymer structure, such as thermal resistance, lubrication and anti-adhesion properties, hydrophobicity, resistance to heat, thermo-oxidation, and chemical and biological attack, etc. Advantageously, when the coating contains an organopolysiloxane polymer, it can be obtained through a crosslinking process leading to a continuous or discontinuous polymer network at the microscopic scale within the polymer phase, depending on the concentration, nature, and conformation of the other components in the coating. "Crosslinking" refers to the chemical reaction that leads to one or more covalent bonds between the precursors of the organopolysiloxane polymer and / or between these same precursors and other components of the coating.

[0105] 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.

[0106] The organopolysiloxane polymer network can be made up of a combination of 4 simple organosiloxane units named M, D, T and Q depending on the degree of substitution by the oxygen of the silicon atom, as described in the following table, where R is an organic substituent described later.

[0107] [Table 1] Organopolysiloxane polymers are obtained by crosslinking precursors that can be monomeric, polymeric, or, as an intermediate step, oligomeric. Organopolysiloxane polymers can also be obtained from a mixture of these different types of precursors. When the network contains a higher number of T and Q units than D units, the crosslinking density is higher. The distribution of M, D, T, and Q units depends on the chemical structure of the precursors, specifically on this M, D, T, and Q distribution within the precursors.

[0108] 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.

[0109] Organopolysiloxanes can be either linear or sparsely branched (predominantly D groups) or branched or highly branched (predominantly T and Q groups). Linear or sparsely branched organopolysiloxanes are generally liquids, with varying degrees of viscosity at room temperature, and are called silicone oils. Branched or highly branched (pre-crosslinked) organopolysiloxanes form a network at the scale of the individual macromolecule and are called silicone resins. At room temperature, the resins are essentially in solid form, or in liquid form, provided they have a sufficiently low molecular weight, either as a solution in a solvent or as an aqueous emulsion. They can be copolymerized with organic polymers or oligomers that do not contain silicon, particularly polyesters, acrylics, alkyds, polyurethanes, and epoxy resins.

[0110] When crosslinking is a hydrolysis-polycondensation: it is carried out by means of the reactive hydroxy or alkoxy functions, in particular methoxy, ethoxy or butoxy, present on the organopolysiloxane.

[0111] When crosslinking is a polyaddition (or hydrosilylation): it takes place by reaction between the reactive vinyl functions (-CH=CH2) present on one of the organopolysiloxanes and the reactive silyl hydride functions (Si-H) present on the other organopolysiloxane mixed with the first.

[0112] All these reactive functional groups are present on each organopolysiloxane, with at least one present and potentially two, three, or more, as much as the molecular structure allows. Silicone oils containing at least one reactive functional group are called "reactive oils." These reactive functional groups can be located either at the ends of the macromolecular chain (termination) or distributed along the chain.

[0113] 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.

[0114] Linear PDMS silicone oils, whether pure or pre-emulsified in water, are primarily characterized by their molecular weight, which is directly proportional to the viscosity of the pure oil. They are then characterized by the presence or absence of reactive functional groups, such as hydroxyl groups on the silicon atoms (silanol), their number, and their location on the molecular chain. For example, reactive oils with viscosities between 50 and 20,000 mPa·s, and particularly between 300 and 5,000 mPa·s, can be used, possessing at least one reactive functional group, preferably at least two, which can be located at the ends of the chain (positions a, w).

[0115] Polymeric precursors reacting by polyaddition may include, for example, polymethylhydrosiloxane, vinylmethylsiloxane, vinyl-terminated polydimethylsiloxane (PDMS), particularly linear-terminated diphenylsiloxane-dimethylsiloxane copolymers, hydride-terminated polydimethylsiloxanes, hydride-terminated polyphenylmethylsiloxanes, cyclic vinylmethylsiloxane, vinyl-MQ resin, trimethylsilyl-terminated polymethylhydrosiloxane, trimethylhydrosiloxane-terminated dimethylsiloxane copolymer, MQ resin hydride, and the like, and combinations thereof.

[0116] Polymeric precursors reacting by hydrolysis-polycondensation, whether silicone resins or silicone oils, may include, for example, poly(methylsilsesquioxanes), poly(propylsilsesquioxanes), poly(phenylsilsesquioxanes), polydimethylsiloxane (PDMS), polydimethylsiloxane (PDMS), trimethylsilyl-terminated polydimethylsiloxane (PDMS), hydroxyl-terminated polydimethylsiloxane (PDMS), silanol-terminated polyphenylsiloxane (PDMS), silanol-terminated diphenylsiloxane-dimethylsiloxane silanol-terminated copolymer, poly(2-acetoxyethylsilsesquioxanes), organo-modified alkoxysilanes and their oligomers, and all similar macromolecules and mixtures thereof.

[0117] 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, along with one or more oligomeric precursors, which may be linear, branched, or cyclic. These oligomeric precursors have a lower molecular weight than the polymeric precursors. Polymeric and / or oligomeric precursors with more than two reactive functional groups as described above, advantageously much more than two, can be added to the mixture as a co-binder to promote a high crosslinking density of the final organopolysiloxane polymer.

[0118] 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.

[0119] Silicone oil-type organopolysiloxane precursors can be considered additives if added in small quantities (generally between 0.1 and 5% dry weight) to the overall formula of a layer, independently of other components for the formation of the solid organopolysiloxane polymer.

[0120] Crosslinking may require a catalyst:

[0121] 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.

[0122] 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.

[0123] A crosslinking agent, for example carrying Si-H bonds, may be present.

[0124] PAEK

[0125] 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.

[0126] 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.

[0127] 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).

[0128] Advantageously, the polyarylether ketone(s) (PAEK) present in each of the layers is a polyetheretherketone (PEEK) or a polyetherketoneketone (PEKK).

[0129] PAES

[0130] As examples of aromatic thermoplastic polymers other than PAEK, suitable according to the invention are poly(phenylene oxide) (PPO), poly(arylethersulfones) polymer (PAES), and in particular polyethersulfone (PES), polyphenylene ether sulfone (PPS11), polyphenylene sulfide (PPS), poly(arylene sulfide) (PAS), liquid crystal polymers and mixtures thereof, preferably in the group consisting of polyethersulfone (PES), polyphenylene sulfide (PPS) and mixtures thereof.

[0131] An amorphous, non-crystalline, aromatic thermoplastic polymer, such as PPSU / PES (Polyethersulfone), improves coating film formation because its glass transition temperature is much lower than the melting temperature of PAEK, thus enhancing adhesion to the substrate. This also advantageously improves the material's ductility and enhances its stretchability and stampability.

[0132] As suitable examples of heterocyclic thermoplastic polymers according to the invention, polyetherimide (PEI), polyimides (PI), polyamideimides (PAI), and polybenzymidazole (PBI), or mixtures thereof, are cited. Fluorocarbon resins

[0133] 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.

[0134] Advantageously, the coating according to the invention does not comprise fluorocarbon resin.

[0135] The fillers within the meaning of the invention provide mechanical reinforcement and can also provide lubricating properties, hydrophobic properties, while improving the mechanical resistance and thermal conductivity of the coating.

[0136] The fillers do not only serve to add color to the coating, but can contribute to it.

[0137] The presence of fillers with excellent thermal conductivity makes it possible to compensate for the low thermal conductivity of PAEK polymers.

[0138] Advantageously, the filler(s) is / are chosen from the group consisting of ceramic fillers (SiC>2, etc.) and / or mineral and / or metallic fillers (Al2O3, TiC>2, etc.) and / or hydrophobic silicas and / or diamond particles.

[0139] Preferably, the filler(s) is / are chosen from the group consisting of metal oxides, metal carbides, metal oxynitrides, metal nitrides, and their mixtures.

[0140] Advantageously, said metal is a transition metal, like at least one of the elements chosen from B, Ni, Ti, Zr or Hf.

[0141] Preferably, the filler(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 metal oxides: silica, micas, lamellar fillers, clays such as montmorillonite, sepiolite, gypsite, kaolinite and laponite, zinc dioxide, quartz, and zirconium phosphate, alumina, zirconia, zinc oxide, copper oxide, iron oxide; fillers chosen from reinforcing fibers: glass or carbon or aramid fiber;conductive fillers comprising a transition metal carbide and / or a transition metal nitride: characterized in that the transition metal is at least one of the elements selected from B, Ni, Ti, Zr or Hf, for example: cubic boron nitride, diamond particles, metallic particles; lamellar fillers capable of conferring lubricating properties, such as clays, graphene or graphite.

[0142] Preferred fillers in combination with organopolysiloxanes are: reinforcing fillers: silica or carbonates with minimum filler levels of 10-

[0143] 15% wt and up to 60% wt, alumina, hydrated alumina, aluminum trihydroxide, silica (precipitated or pyrogenated) with a d50 < 0.1 pm and a BET specific surface area > 30 m² 2 / g and preferably between 30 and 500 m 2 / g, or mixture of quartz and silica, diatomaceous earth or crushed quartz, titanium, mica, talc, kaolin, barium sulfate, slaked lime, zinc oxide, expanded vermiculite, non-expanded vermiculite, calcium carbonate etc.

[0144] Advantageously, the average diameter d50 of the loads is between 0.1 and 50 pm, advantageously still between 5 and 15 pm.

[0145] 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%.

[0146] Advantageously, the proportion of fillers in the coating (3) is less than 10% by weight relative to the total weight of the coating (3).

[0147] Additives Advantageously, said additives are chosen from the group consisting of antifoaming agents, dispersing agents, wetting agents, thickeners, and pH adjusters.

[0148] The said antifoaming agent(s) (is) preferably chosen from the group consisting of mineral oils, diols, hydrocarbons, glycerides, oxyrane, emulsified fatty acids.

[0149] The surfactant(s) is / are preferably chosen from the group consisting of glycol ether, ethoxylated alcohol excluding alkyl phenol ethoxylates (APEs), gemini surfactants.

[0150] The dispersing agent(s) is / are preferentially chosen from the group consisting of anionic dispersants such as fatty acid derivatives.

[0151] The said thickeners are preferably chosen from the group consisting of acrylic-based or polyurethane-based copolymer, cellulose, fumed silica.

[0152] These pH adjusters are preferentially chosen from the group consisting of Brønsted bases: ammonia, amines (triethylamine, triethanolamine...), hydroxides (sodium hydroxide, potassium hydroxide...), carbonates.

[0153] A preferred adhesion promoter in combination with organopolysiloxanes is an organosilane or organopolysiloxane having three silicon-linked hydrolyzable groups per molecule.

[0154] Advantageously, the proportion of additives in the coating (3) is less than 20% by weight relative to the total weight of said coating (3).

[0155] 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.

[0156] 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, heat-stable 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- z Dz, Fe20s, V2O5, WO3, CeO2, ln20s, Yi,84Cao,i6T,84Vo,i60i,84, Agi, (Bii. x HAS x (Vi. yMy)C>4 with:

[0159] - 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,

[0160] - 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,

[0161] - A and M are different from each other

[0162] C and D are chosen from the group consisting of iodine, fluorine, chlorine and bromine, C and D are different from each other, and z is from 0 to 1.

[0163] Given that A and M are different from each other, when:

[0164] - A is an alkali metal; it can be chosen from Li, Na, K, Rb, Cs.

[0165] - M is an alkali metal; it can be chosen from Li, Na, K, Rb, Cs.

[0166] - A is an alkaline earth metal; it can be chosen from Be, Mg, Ca, Sr, Ba,

[0167] - M is an alkaline earth metal; it can be chosen from Be, Mg, Ca, Sr, Ba,

[0168] - 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,

[0169] - 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,

[0170] - A is a base metal; it can be chosen from Al, Zn, Ga, In, Sn.

[0171] - M is a low-grade metal; it can be chosen from Al, Zn, Ga, In, Sn.

[0172] - A is a metalloid; it can be chosen from B, Si, Ge, Sb,

[0173] - M is a metalloid; it can be chosen from B, Si, Ge, Sb,

[0174] - A is a lanthanide; it can be chosen from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,

[0175] - M is a lanthanide, it can be chosen from La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.

[0176] Preferably, A and M, different from each other, are B and / or Mg.

[0177] Preferably, the pigment (Bii- x Ax)(Vi-yMy)O4 exhibits a monoclinic scheelite crystallographic form at room temperature. Preferably, x and y are 0, i.e., the pigment (Bii- xAx)(Vi-yMy)O4 is Bismuth Vanadate (BiVC>4). Advantageously, a BiVC>4 with a monoclinic scheelite crystallographic structure at room temperature is used.

[0178] Bismuth vanadate is a yellow inorganic compound with the formula BiVCL, 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®).

[0179] V. Heat-stable pigments

[0180] Preferably, the heat-stable pigment(s) is / are chosen from the group consisting of:

[0181] - Yellow pigment of the titanium rutile type,

[0182] - Yellow pigment derived from bismuth, for example selected from stabilized bismuth vanadates (Pyi84)

[0183] - Red pigment, for example selected from perylene red (e.g. PR149, PR178 and PR224), iron oxide,

[0184] - Orange pigment of the bismuth oxyhalide (POss) type,

[0185] - Bismuth vanadate orange pigment (POse)

[0186] - Zinc tin titanium orange pigment (PO82)

[0187] - Orange pigment of cerium sulfide (PO75; PO3s)

[0188] - Yellow-orange pigment of the rutile type of antimony titanium chromium (PBr24)

[0189] - Yellow-orange pigment of the tin and zinc rutile type (Py2ie)

[0190] - Yellow-orange pigment of niobium oxide tin zinc sulfide (Py22?)

[0191] - Yellow-orange pigment of double oxides of tin and niobium

[0192] - CO3(PO4)2

[0193] - UCOPO4

[0194] - COAI2O4

[0195] - Cr2Û3

[0196] - TiO2

[0197] - Black pigment PBk28 (Copper chromite black spinel)

[0198] - and mixtures thereof. Glitter. The glitter usable within the scope of the present invention may 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. Mica or silica glitter coated with titanium dioxide. The glitter usable within the scope of the present invention may be treated to give a particular color effect.

[0199] Preferably, the glitter is / are particles selected from the group consisting of mica, aluminum, titanium dioxide-coated mica, or mixtures thereof. Holographic glitter

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

[0201] Magnetizable particles can advantageously be particles comprising at least one ferromagnetic metal. These magnetizable particles can be homogeneous, meaning they are made of the same material, or composite, meaning they have a core-shell structure in which the ferromagnetic metal is located in the core and / or the shell of the particles. Examples of composite magnetizable particles include mica flakes coated with iron oxide (Fe2O3) or stainless steel fibers coated with a sol-gel material, as corrosion protection during the coating application process; plastic flakes coated with iron oxide (Fe2Cl3); or flakes whose core is made of a ferromagnetic metal and whose shell is made of a plastic or sol-gel material.

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

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

[0204] Advantageously, the percentage of non-magnetizable particles in the mixture of magnetizable and non-magnetizable particles is between 15% and 40% by weight relative to the total weight of the mixture of magnetizable and non-magnetizable particles.

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

[0206] The term "D50" means, in the context of the present invention, the maximum dimension that 50% of the particles have by number.

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

[0208] The term "D90" means, in the context of the present invention, the maximum dimension that 90% of the particles have by number.

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

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

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

[0212] Architectures

[0213] 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.

[0214] Advantageously, the coating according to the invention comprises one to three layers, preferably two, applied to the substrate.

[0215] Advantageously, the coating according to the invention comprises intermediate layers, preferably two, which may be decorative layers.

[0216] Advantageously, the coating according to the invention is a non-stick coating, meaning that food preferentially does not stick to the coating. Advantageously, the coating according to the invention is a single-layer non-stick coating.

[0217] 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.

[0218] 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.

[0219] Preferably, the content of slow-release particles in the layer forming face (3b) ranges from 5.15 to 32.97 parts by weight per 100 parts by weight of this layer.

[0220] When the coating is a multilayer coating and the slow-release particles are present in only one layer, they are preferentially located 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 by the last layer forming face (3b).

[0221] When the coating is a multilayer coating and the slow-release particles are present in several layers, the concentration of slow-release particles may differ in each of the layers in which they are present. Preferably, the concentration of slow-release particles increases from face (3a) to face (3b).

[0222] When the coating is a multi-layer 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.

[0223] Decorations

[0224] In one embodiment, the decorative layer(s) is / are continuous and covers / covers the entire lower layer. In another embodiment, the decorative layer(s) does / do not cover the entire lower layer and forms / are at least one decorative element.

[0225] 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.

[0226] According to one embodiment, each of the two decorations (i) and (j) is presented in the form of adjacent, non-overlapping motifs. For example, each decoration is represented by different geometric motifs distributed evenly over the entire surface and alternating with respect to each other.

[0227] 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.

[0228] 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 presented in the form of overlapping patterns.

[0229] According to another embodiment, the decorations are applied directly onto the substrate.

[0230] The decoration can be applied by any method well known to a person skilled in the art, for example by screen printing or pad printing.

[0231] According to one embodiment, the coating according to the invention is a single-layer coating comprising:

[0232] - at least 70% by weight of a polymeric phase, comprising at least 50% by weight of one or more organopolysiloxane polymer(s), optionally one or more polymer(s) 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, and optionally one or more fluorocarbon resin(s)

[0233] - slow-release particles comprising: o a slow-release material having a porous and / or layered structure; o a silicone oil, binding to the slow-release material. - optionally one or more filler(s);

[0234] - possibly one or more additive(s);

[0235] - possibly one or more coloring agent(s).

[0236] According to one embodiment, the coating according to the invention is a single-layer coating comprising:

[0237] - at least 70% by weight of a polymeric phase, consisting of at least 50% by weight of one or more organopolysiloxane polymer(s), possibly one or more polymer(s) 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, and possibly one or more fluorocarbon resin(s)

[0238] - slow-release particles comprising: o a slow-release material having a porous structure and / or a layered structure; o a silicone oil, binding to the slow-release material.

[0239] - possibly one or more charges;

[0240] - possibly one or more additive(s);

[0241] - possibly one or more coloring agent(s).

[0242] According to one embodiment, the coating according to the invention is a single-layer coating consisting of:

[0243] - at least 70% by weight of a polymeric phase, consisting of at least 50% by weight of one or more organopolysiloxane polymer(s), possibly one or more polymer(s) 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, and possibly one or more fluorocarbon resin(s)

[0244] - slow-release particles comprising: o a slow-release material having a porous structure and / or a layered structure; o a silicone oil, binding to the slow-release material.

[0245] - possibly one or more charges;

[0246] - possibly one or more additive(s);

[0247] - optionally one or more coloring agent(s). According to one embodiment, the coating according to the invention is a multilayer coating, each layer of the multilayer coating comprising:

[0248] - one or more organopolysiloxane polymer(s),

[0249] - possibly one or more polymer(s) selected from the group consisting of one or more polyarylether ketone(s) (PAEK(s)), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

[0250] - possibly one or more fluorocarbon resin(s),

[0251] - possibly one or more load(s),

[0252] - possibly one or more additive(s),

[0253] - possibly one or more coloring agent(s), at least one of the layers of the multilayer coating comprising slow-release particles including:

[0254] - a slow-release material having a porous structure and / or a layered structure;

[0255] - 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 organopolysiloxane polymer(s), optionally one or more polymer(s) 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 and optionally one or more fluorocarbon resin(s).

[0256] According to one embodiment, the coating according to the invention is a multilayer coating, each of the layers of the multilayer coating comprising:

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

[0258] - possibly one or more polymer(s) selected from the group consisting of one or more polyarylether ketone(s) (PAEK(s)), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof,

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

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

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

[0262] - possibly one or more coloring agent(s), at least one of the layers of the multilayer coating comprising slow-release particles including: - a slow-release material having a porous structure and / or a layered structure;

[0263] - 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 consisting of at least 50% by weight of one or more organopolysiloxane polymer(s), optionally one or more polymer(s) 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 and optionally one or more fluorocarbon resin(s).

[0264] According to one embodiment, the coating according to the invention is a multilayer coating, each layer 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 organopolysiloxane polymer(s), optionally one or more polymer(s) selected from the group consisting of one or more polyarylether ketone(s) (PAEK(s)), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s) and mixtures thereof, and optionally one or more fluorocarbon resin(s); at least one of the layers of the multilayer coating comprising slow-release particles comprising:

[0265] - a slow-release material having a porous structure and / or a layered structure;

[0266] - a silicone oil, which binds to the material with slow release.

[0267] 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:

[0268] - at least 70% by weight of a polymeric phase consisting of at least 50% by weight of one or more organopolysiloxane polymer(s), possibly one or more polymer(s) 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 and possibly one or more fluorocarbon resin(s);

[0269] - slow-release particles comprising: o a slow-release material having a porous structure and / or a layered structure; o a silicone oil, binding to the slow-release material.

[0270] - possibly one or more charges,

[0271] - possibly one or more additives, - possibly one or more coloring agents and one or more layers made up of:

[0272] - at least 70% by weight of a polymeric phase consisting of at least 50% by weight of one or more organopolysiloxane polymer(s), possibly one or more polymer(s) 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 and possibly one or more fluorocarbon resin(s);

[0273] - possibly one or more charges,

[0274] - possibly one or more additive(s),

[0275] - possibly one or more coloring agent(s).

[0276] Coated heating element

[0277] 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.

[0278] Advantageously, a coated heating element according to the invention is a coated cooking element.

[0279] Another object of the invention, illustrated in Figure 1, relates to a coated heating element (1) for household article, 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).

[0280] Metallic substrate

[0281] Advantageously, said metallic substrate (2) is a substrate of aluminum, stainless steel, cast iron or aluminum, iron, titanium or copper.

[0282] Aluminium, as used in the present invention, means a metal consisting of 100% aluminium or an aluminium alloy.

[0283] 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.

[0284] Preferably, the metallic substrate (2) comprises an alternation of layers of metal and / or metallic alloy.

[0285] 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.

[0286] Preferably, the metallic substrate (2) is an aluminum substrate.

[0287] Advantageously, the thickness of the metallic substrate (2) is between 0.5 mm and 10 mm.

[0288] 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.

[0289] 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.

[0290] Advantageously, the surface of the substrate (2a) onto which the coating (3) according to the invention is to be applied can be treated to increase its specific surface area; for an aluminum substrate, this treatment can be carried out by anodizing (creation of a tubular alumina structure), chemical etching, sandblasting, brushing, shot peening, or by adding material using a technology such as thermal spraying (flame, plasma, or arc spray). Other metallic substrates can also be polished, sandblasted, brushed, bead-blasted, or have material added using a technology such as thermal spraying (flame, plasma, or arc spray).

[0291] As examples of usable metallic substrates in the present invention, advantageous examples include substrates made of anodized or unanodized aluminum, possibly polished, brushed, sandblasted, shot-blasted or micro-beaded; substrates made of anodized or unanodized aluminum alloy, possibly polished, brushed, sandblasted or micro-beaded; substrates made of steel, possibly polished, brushed, sandblasted, shot-blasted or micro-beaded; substrates made of stainless steel, possibly polished, brushed, sandblasted or micro-beaded; substrates made of cast steel, aluminum or iron; and substrates made of copper, possibly hammered or polished.Advantageously, the substrate may be selected from substrates comprising layers of ferritic stainless steel / aluminum / austenitic stainless steel, substrates comprising layers of stainless steel / aluminum / copper / aluminum / austenitic stainless steel, cast aluminum caps, aluminum caps, or aluminum alloy caps lined with an outer stainless steel base, and 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). Advantageously, the average arithmetic roughness Ra of the surface of face (2a) of the metallic substrate (2) is greater than or equal to 1 µm.

[0292] The arithmetic mean roughness Ra is measured using a surface 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 Altisurf®, in which a chromatic confocal sensor allows for non-contact measurement. The study of this surface topography allows the arithmetic mean roughness Ra to be defined.

[0293] Process

[0294] 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: 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) to the face (2a), iv. baking the element obtained in step iii.

[0295] 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).

[0296] In step iii, the layers can be applied wet-on-wet, or a drying period can be applied between each layer. For the purposes of this invention, "curing" the coated substrate means a heat treatment that densifies the layer(s) of heat-stable coating applied to the substrate.

[0297] In step iv, a heating process, also called sintering in some cases, is carried out. Generally, the heating temperature of step iv is between 230°C and 420°C. Advantageously, the heating temperature of step iv is between 380°C and 420°C in the presence of fluorocarbon resins in the polymer phase. The advantageous heating temperature of step iv is between 230°C and 300°C in the presence of organopolysiloxane polymers in the polymer phase, preferably between 230°C and 280°C, and even more preferably between 230°C and 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.

[0298] Drying can be achieved by convection or IR.

[0299] 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.

[0300] Advantageously, the manufacturing process for a coated heating element (1) according to the invention comprises a single final curing step iv of all the applied layers. This single curing step is carried out simultaneously for all the applied layers. This embodiment allows the layers to be filmed, fused, and cross-linked together so that they form a single layer. The coating (3) thus forms a single layer, even if this single layer is not homogeneous, that is, it may exhibit compositional heterogeneity such as, for example, a concentration gradient of its constituents.

[0301] 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 i or step iii. The shaping is also called stamping.

[0302] The coating according to the invention can be applied to a flat substrate, a shaped substrate, or a locally flat area of ​​a shaped substrate. A thermostable coating layer is obtained. Generally, this coating layer is wet.

[0303] For the purposes of this invention, a wet layer is understood to mean that the layer comprises all or part of its solvents.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] According to a variant of the process 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 coated substrate is baked after the application of the last layer.

[0308] When the shaping step precedes the application iii of the coating, the coating is preferably carried out by spraying.

[0309] 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.

[0310] The coating formulation is generally aqueous, with the polymers in the polymeric phase in suspension form. Other non-aqueous solvents may also be suitable. In one variant, the PAEK suspensions have a particle size with a d50 of approximately 10 µm to 15 µm.

[0311] Article me

[0312] Another object of the invention relates to a household article comprising a coated heating element (1) according to the invention.

[0313] 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.

[0314] According to one embodiment, the cooking article includes a heating face intended to be brought into contact with an external heating source, the heating face being opposite the cooking face (3b) intended to be brought into contact with the food during cooking.

[0315] 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.

[0316] The invention also relates to a household article comprising a coated heating element (1) according to the invention and a heating source configured to heat said coated heating element (1), characterized in that said household article is an electric cooking appliance and in that the face (3b) of the coating according to the invention is capable of receiving food.

[0317] Advantageously, the electric cooking appliance is chosen from the group consisting of electric crepe maker, electric raclette appliance, electric fondue appliance, electric grill, electric griddle, electric cooker, bread machine, electric pressure cooker.

[0318] According to another embodiment, the household item in question is an everyday item that the user heats up.

[0319] This could be an iron or a garment steamer, the coating according to the invention covering the soleplate. It could also be a hair straightener, the coating according to the invention covering the plates of said straightener.

[0320] 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.

[0321] The small household heating appliance according to the present invention may in particular be a cooking article, and in particular a cooking article in which one of the two opposite faces of the substrate is an interior face, possibly concave, intended to be positioned on the side of food that may be introduced into or onto said article, and in which the other face of the substrate is an exterior face, possibly convex, intended to be positioned towards a heat source.

[0322] By way of non-limiting examples of cooking articles conforming to the present invention, we will mention in particular 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 pans, preparation bowls.

[0323] The small household heating appliance 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.

[0324] The small household heating appliance according to the present invention may in particular be a hair care item, such as a curling iron or straightener, and the coated element according to the present invention is one of the heating plates of the hair care item.

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 organopolysiloxane polymer(s), - possibly one or more polymer(s) selected from the group consisting of one or more polyarylether ketone(s) (PAEK(s)), one or more aromatic thermoplastic polymer(s) other than PAEK, one or more heterocyclic thermoplastic polymer(s), and mixtures thereof, - possibly one or more fluorocarbon resin(s), - possibly one or more load(s), - possibly one or more additive(s), - possibly 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), which binds 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) according to any one of the preceding claims, characterized in that the organopolysiloxane polymer(s) is / are selected 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.

9. 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.

10. 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 (PPS11), 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.

11. 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.

12. 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).

13. Method for manufacturing a coated heating element (1) according to claim 12 comprising the following successive steps: i. Supplying a metallic substrate (2) having a face (2a), ii. Optionally, pre-treatment of the face (2a) of said metallic substrate (2) intended to be coated, iii. application of the coating layer(s) (3) on the face (2a), iv. baking of the element obtained in step iii.

14. Household article comprising a coated heating element (1) according to claim 12 characterized in that said household article is a cooking article and in that the face (3b) of the coating according to any one of claims 1 to 11 is capable of receiving food.

15. Household article comprising a coated heating element (1) according to claim 12 and a heating source configured to heat said coated heating element (1), characterized in that said household article is an electric cooking appliance and in that the face (3b) of the coating according to any one of claims 1 to 11 is capable of receiving food.

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