Heating assembly, preparation method thereof, and cooking utensil

Abstract

The present invention provides a heating assembly, a method for preparing the same, and a cooking appliance. The heating assembly comprises: a substrate; an organic insulating layer disposed on the surface of the substrate, the organic insulating layer comprising an organic matrix and heat-conductive particles dispersed within the organic matrix; and a heating layer disposed on the surface of the organic insulating layer distal from the substrate. The heating assembly exhibits high insulation reliability, good heating uniformity, high heating efficiency, excellent thermal conductivity, low noise, and a superior user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of cooking utensils, and more particularly to a heating component, a preparation method thereof, and a cooking utensil. Background Art

[0002] Metals have excellent thermal conductivity and are widely used in cooking appliance manufacturing. Electromagnetic heating is a common heating method, but it can cause EMC (electromagnetic compatibility) violations, generate high noise levels, and make temperature uniformity difficult to achieve. Membrane heating technology has been applied to some ceramic or glass insulating substrates, offering low noise levels and high heating uniformity. However, achieving insulation between the heating film and the metal substrate remains elusive.

[0003] Therefore, the relevant technology of current cooking utensils still needs to be improved. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one object of the present invention is to provide a heating assembly with high heating efficiency, high insulation reliability, good thermal conductivity, and good heating uniformity, as well as a preparation method and a cooking appliance.

[0005] In one aspect of the present invention, the present invention provides a heating component. According to an embodiment of the present invention, the heating component includes: a substrate; an organic insulating layer, the organic insulating layer is provided on the surface of the substrate, and the organic insulating layer includes an organic matrix and heat-conducting particles dispersed in the organic matrix; a heating layer, the heating layer is provided on the surface of the organic insulating layer away from the substrate, wherein the thermal conductivity of the substrate is greater than the thermal conductivity of the organic matrix. In this heating component, the organic insulating layer has excellent high-temperature insulation, which can effectively solve the insulation problem between the substrate and the heating layer during the use of the heating component, and can also reduce the thermal resistance of the heat generated by the heating layer to the substrate. During operation, it can effectively reduce the heat accumulation phenomenon and improve the insulation reliability of the insulating layer, so that the heating component has high insulation reliability, good heating uniformity, high heating efficiency, good thermal conductivity, low noise, and better user experience.

[0006] According to an embodiment of the present invention, the thermal conductivity of the thermally conductive particles is greater than the thermal conductivity of the organic matrix, and less than the thermal conductivity of the substrate.

[0007] According to an embodiment of the present invention, the thermal conductivity of the thermally conductive particles is in the range of 20-200 W / (m·K), and the thermal conductivity of the organic matrix is ​​in the range of 0.05-0.5 W / (m·K).

[0008] According to an embodiment of the present invention, the thermally conductive particles are insulating thermally conductive particles, and the breakdown voltage of the organic insulating layer at 300 degrees Celsius is greater than 0.8 KV, preferably greater than 1.2 KV.

[0009] According to an embodiment of the present invention, the thermally conductive particles are insulating thermally conductive particles, and the breakdown voltage of the organic insulating layer at 300 degrees Celsius is greater than 0.8Kv, preferably greater than 1.2Kv.

[0010] According to an embodiment of the present invention, the content of the thermally conductive particles on a side of the organic insulating layer close to the substrate is smaller than the content of the thermally conductive particles on a side of the organic insulating layer close to the heating layer.

[0011] According to an embodiment of the present invention, the content of the thermally conductive particles gradually decreases in a direction from the substrate to the heating layer.

[0012] According to an embodiment of the present invention, the organic insulating layer satisfies at least one of the following conditions: the material of the organic matrix includes polyimide; the thermal conductivity of the organic insulating layer is 0.2W / (m·K)-2W / (m·K); the thermally conductive particles include one or more of aluminum oxide, zirconium oxide, beryllium oxide, silicon nitride, boron nitride, and aluminum nitride; the particle size of the thermally conductive particles is 50 nanometers to 50 micrometers, preferably 200 nanometers to 10 micrometers; the thickness of the organic insulating layer is 10 micrometers to 200 micrometers, preferably 20 micrometers to 150 micrometers; based on the total mass of the organic insulating layer, the mass percentage of the thermally conductive particles is 0.1%-10%, preferably 0.2%-6%.

[0013] According to an embodiment of the present invention, the heating component satisfies at least one of the following conditions: the substrate is a metal substrate, and the material of the metal substrate includes at least one of aluminum, iron, copper and alloys thereof; the heating layer is composed of a whole surface heating film or is formed by a long strip of heating film wound in a ring shape; the material of the heating layer includes at least one of nickel-based alloys, semiconductor materials, carbon materials, conductive polymers, conductive ceramics and conductive glass.

[0014] According to an embodiment of the present invention, the heating assembly further comprises at least one of the following: an electrode electrically connected to the heating layer; and a terminal electrically connected to the heating layer or to the electrode.

[0015] In another aspect, the present invention provides a method for preparing the aforementioned heating assembly. According to an embodiment of the present invention, the method comprises the following steps: forming an organic insulating layer on the surface of a substrate; and forming a heating layer on the surface of the organic insulating layer remote from the substrate. This method according to an embodiment of the present invention is simple in steps, easy to operate, highly compatible with existing processes, requires relatively low technical expertise, and is easily scalable. The resulting heating assembly exhibits high insulation reliability, good heating uniformity, high heating efficiency, good thermal conductivity, low noise, and a better user experience.

[0016] According to an embodiment of the present invention, the organic insulating layer is formed by any one of the following steps: applying a solution coating on the surface of the substrate by spraying, screen printing, roller coating, brushing or dipping, and drying at a temperature of 80°C-380°C; spraying a powder coating on the surface of the substrate by an electrostatic spraying method and heating it to 150°C-400°C.

[0017] According to an embodiment of the present invention, the solution coating includes a resin or a resin precursor, thermally conductive particles, and a solvent; and the powder coating includes resin powder and thermally conductive particles.

[0018] According to an embodiment of the present invention, the solution coating satisfies at least one of the following conditions: the resin is polyimide; the precursor of the resin is polyacrylic acid; the solvent is at least one of N-methylpyrrolidone and dimethylacetamide; the mass ratio of the solvent to the resin is 1-15:1 or 1.5-9:1.

[0019] According to an embodiment of the present invention, the heating layer is formed by spraying, screen printing, roller coating or lamination.

[0020] In yet another aspect, the present invention provides a cooking appliance. According to an embodiment of the present invention, the cooking appliance includes the aforementioned heating assembly. This cooking appliance has excellent insulation between the substrate and the heating layer, and good heat transfer from the heating layer to the substrate. This ensures high heating efficiency, reduces heat loss and heat accumulation, and offers excellent heating uniformity and low noise.

[0021] According to an embodiment of the present invention, in the heating assembly, a first surface of the substrate away from the organic insulating layer is a surface for heating, and the first surface is in direct contact with food or attached to a cooking container. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a partial cross-sectional structural schematic diagram of a heating component according to an embodiment of the present invention.

[0023] Figure 2It is a partial planar structural schematic diagram of a heating assembly according to an embodiment of the present invention.

[0024] Figure 3 It is a partial planar structural schematic diagram of a heating assembly according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following embodiments of the present invention are described in detail. The embodiments described below are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in the art or in the product specifications shall be followed.

[0026] In one aspect of the present invention, the present invention provides a heating component. Figure 1 The heating component includes: a substrate 10; an organic insulating layer 20 provided on the surface of the substrate 10, and the organic insulating layer 20 includes an organic matrix and heat-conductive particles dispersed in the organic matrix; and a heating layer 30 provided on the surface of the organic insulating layer 20 away from the substrate 10, wherein the thermal conductivity of the substrate is greater than the thermal conductivity of the organic matrix. In this heating component, the organic insulating layer has excellent high-temperature insulation, which can effectively solve the insulation problem between the substrate and the heating layer during the use of the heating component, and can also reduce the thermal resistance of the heat generated by the heating layer to the substrate. During operation, it can effectively reduce heat accumulation and improve the insulation reliability of the insulating layer. This makes the heating component have high insulation reliability, good heating uniformity, high heating efficiency, good thermal conductivity, low noise, and better user experience.

[0027] According to an embodiment of the present invention, the specific material type of the substrate is not particularly limited, and it can be any material suitable for preparing a heating component. In some specific embodiments, the above-mentioned substrate can be a metal substrate, and the specific material of the metal substrate can include at least one of aluminum, iron, copper and their alloys. As a result, the heating component has high thermal conductivity, high heat transfer efficiency, high thermal utilization rate, and can better save energy consumption. In some specific examples, the specific material of the substrate can be cast aluminum or cast iron. Therefore, in addition to high thermal conductivity, the heating components made of cast aluminum and cast iron also have high dimensional stability, and the use effect is further improved.

[0028] According to the embodiments of the present invention, there are no special restrictions on the shape and structure of the substrate, and it can be flexibly selected according to the specific use requirements of the actual heating component, including but not limited to a round bottom with an open top, a flat bottom with an open top, a square disc, a circular disc, etc. There are no special restrictions on the thickness of the substrate. For example, the thickness at different positions can be basically the same, or the thickness at different positions can be different, such as the bottom thickness is greater than the side wall thickness, etc. It can be flexibly adjusted according to the actual use requirements, and the present invention does not impose any restrictions. It should be noted that the structure of the heating component is illustrated by an example of a planar structure in the drawings of the present invention, but it cannot be understood as a limitation to the present invention. The shape and structure of the heating component of the present invention can be flexibly adjusted with reference to the shape and structure of the above-mentioned substrate.

[0029] According to embodiments of the present invention, the organic insulating layer can be located on the entire surface of the substrate or on a portion of the substrate. The shape of the organic insulating layer is not particularly limited and can be a full-surface film layer or a patterned film layer, depending on actual use requirements. In some specific embodiments, the organic insulating layer is a full-surface film layer and covers the entire surface of the substrate. This facilitates preparation and provides better insulation performance.

[0030] According to an embodiment of the present invention, the material of the organic matrix can be PI (polyimide). As such, it has excellent insulation properties. According to experimental verification by the inventors, PI can well meet the insulation requirements of the heating component during use, thereby obtaining a heating component with high insulation reliability, good heating uniformity, and low noise.

[0031] According to an embodiment of the present invention, the thermal conductivity of the heat-conductive particles is greater than that of the organic matrix, but less than that of the substrate. This creates a thermal transition within the heating assembly, improving the thermal conductivity of the organic insulating layer while reducing heat loss within the layer. This ensures that heat generated by the heating layer is effectively transferred to the substrate, improving the heating efficiency of the heating assembly.

[0032] According to an embodiment of the present invention, the thermal conductivity of the thermally conductive particles is in the range of 20-200W / (m·K), for example, it can be 20W / (m·K), 50W / (m·K), 100W / (m·K), 130W / (m·K), 150W / (m·K), 200W / (m·K), etc., and the thermal conductivity of the organic matrix is ​​in the range of 0.05-0.5W / (m·K), for example, it can be 0.05W / (m·K), 0.1W / (m·K), 0.15W / (m·K), 0.2W / (m·K), 0.3W / (m·K), 0.4W / (m·K), 0.5W / (m·K), etc., thereby better improving the thermal conductivity of the organic insulating layer while better reducing the heat loss in the organic insulating layer, thereby further improving the heating efficiency of the heating component.

[0033] According to an embodiment of the present invention, the thermally conductive particles may be insulating thermally conductive particles, and the breakdown voltage of the organic insulating layer at 300 degrees Celsius may be greater than 0.8 kV, specifically greater than 1.2 kV, such as 0.9 kV, 1.0 kV, 1.1 kV, 1.2 kV, 1.3 kV, 1.4 kV, 1.5 kV, etc. This effectively ensures the high-temperature insulation reliability of the organic insulating layer and further improves the heating efficiency of the heating assembly.

[0034] According to an embodiment of the present invention, the thermally conductive particles used in the organic insulating layer may specifically include one or more of aluminum oxide, zirconium oxide, beryllium oxide, silicon nitride, boron nitride, and aluminum nitride. Thus, the use of these thermally conductive particles not only ensures that the organic insulating layer has satisfactory insulation and reliability, but also improves the thermal conductivity of the organic insulating layer, resulting in a higher thermal conductivity and insulation reliability during use of the heating assembly, better heat transfer performance and heating uniformity, and higher heating efficiency.

[0035] According to an embodiment of the present invention, the particle size of the thermally conductive particles may be 50 nanometers to 50 microns. In some specific embodiments, the particle size of the thermally conductive particles may be 200 nanometers to 10 microns. In some specific examples, the particle size of the thermally conductive particles may be 50 nanometers, 100 nanometers, 200 nanometers, 300 nanometers, 400 nanometers, 500 nanometers, 600 nanometers, 700 nanometers, 800 nanometers, 900 nanometers, 1 micron, 5 microns, 10 microns, 15 microns, 20 microns, 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns, etc. Therefore, within the above-mentioned particle size range, the thermally conductive particles can perform better than in other particle size ranges. Specifically, if the particle size of the thermally conductive particles is too small, the thermally conductive particles are prone to agglomeration, resulting in uneven dispersion of the thermally conductive particles in the organic matrix, limited improvement in the thermal conductivity of the organic insulating layer, and reduced insulation reliability of the organic insulating layer; and if the particle size of the thermally conductive particles is too large, on the one hand, the amount of thermally conductive particles added is reduced, resulting in increased thermal resistance of the organic insulating layer, thereby reducing the insulation reliability of the organic insulating layer; on the other hand, the density of the thermally conductive particles wrapped by the organic matrix in the organic insulating layer is reduced, which can easily cause a decrease in the local insulation performance of the organic insulating layer, affecting the use effect of the cooking utensils.

[0036] According to an embodiment of the present invention, the mass percentage of the thermally conductive particles may be 0.1%-10% based on the total mass of the organic insulating layer. In some specific embodiments, the mass percentage of the thermally conductive particles may be 0.2%-6% based on the total mass of the organic insulating layer. In some specific examples, the mass percentage of the thermally conductive particles may be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. based on the total mass of the organic insulating layer. Within the above-mentioned content range, the good high-temperature insulation reliability of the organic insulating layer can be guaranteed, and the organic insulating layer can have suitable thermal conductivity, and the preparation of the organic insulating layer is also easier to implement. If the content of the thermally conductive particles is low, the high-temperature insulation reliability of the organic insulating layer is poor; and if the content of the promoting ceramic particles is too much, on the one hand, during the preparation of the organic insulating layer, the molding difficulty of the coating increases, and it is difficult to form a regular film layer, and the insulation performance of the prepared organic insulating layer is reduced. On the other hand, the unevenness of the surface of the organic insulating layer is increased, thereby increasing the risk of uneven heat transfer from the heating layer to the organic insulating layer, and reducing the reliability of the high-temperature insulation of the organic insulating layer.

[0037] According to an embodiment of the present invention, the content of the thermally conductive particles on the side of the organic insulating layer close to the substrate is less than the content of the thermally conductive particles on the side of the organic insulating layer close to the heating layer. In other words, the organic insulating layer has a first side and a second side relative to each other, the first side close to the substrate, and the second side close to the heating layer, and the content of thermally conductive particles on the first side is less than the content of thermally conductive particles on the second side. In this way, the insulation performance of the organic insulating layer close to the heating layer can be improved, and the heat transfer performance of the organic insulating layer close to the substrate can be improved, thereby improving the insulation performance and insulation reliability of the heating component, ensuring its heating efficiency, and reducing heat loss.

[0038] According to some specific embodiments of the present invention, the content of the thermally conductive particles gradually decreases in the direction from the substrate to the heating layer. Specifically, the thermally conductive particle content can be gradually reduced in a gradient or linear manner, and the specific method is not particularly limited. This can effectively slow down heat loss, improve heat utilization, and reduce energy consumption.

[0039] According to an embodiment of the present invention, the thermal conductivity of the organic insulating layer can be 0.2W / (m·K)-2W / (m·K), specifically 0.2W / (m·K), 0.5W / (m·K), 1W / (m·K), 1.2W / (m·K), 1.5W / (m·K), 1.8W / (m·K), 2W / (m·K), etc. As a result, the cooking appliance has better insulation, higher insulation reliability, and higher thermal efficiency.

[0040] According to an embodiment of the present invention, the thickness of the organic insulating layer may be 10 microns to 200 microns. In some specific embodiments, the thickness of the organic insulating layer may be 20 microns to 150 microns. In some specific examples, the thickness of the organic insulating layer may be 10 microns, 20 microns, 30 microns, 40 microns, 50 microns, 60 microns, 70 microns, 80 microns, 90 microns, 100 microns, 110 microns, 120 microns, 130 microns, 140 microns, 150 microns, 160 microns, 170 microns, 180 microns, 190 microns, 200 microns, etc. Within this thickness range, the organic insulating layer can have a uniform film thickness and good thermal conductivity while ensuring insulation performance that meets the requirements of use. If the thickness of the organic insulating layer is too thick, the thermal conductivity of the organic insulating layer will be relatively poor; and if the thickness of the organic insulating layer is too thin, the thickness uniformity of the organic insulating layer will be relatively poor.

[0041] According to an embodiment of the present invention, the heating layer is provided on the surface of the organic insulating layer away from the substrate. It is understood that the heating layer may cover the entire surface of the organic insulating layer away from the substrate, or may only cover a portion of the surface of the organic insulating layer away from the substrate. As long as a uniform surface heating effect can be achieved, the specific arrangement of the heating layer may be flexibly adjusted according to specific usage requirements. In some specific embodiments, referring to Figure 2 , the heating layer 20 is composed of a whole surface heating film. In other specific embodiments, referring to Figure 3 The heating layer 20 is formed by winding a long strip of heating film in a ring shape. Specifically, the specific winding method of the heating layer 20 is not particularly limited, for example, it can be Figure 3 The serpentine winding shown can be an Archimedean spiral winding, a zigzag winding, etc., which will not be described in detail here. In addition, there are no special restrictions on the specific width of the long strip heating film and the distance between two adjacent long strip heating films. The principle is to achieve the best surface heating effect. The specific adjustment can be flexibly adjusted according to the actual application.

[0042] According to an embodiment of the present invention, the heating film in the heating component performs heating by passing electricity, and can also be called an electric heating film. Therefore, in order to achieve a better heating effect, the material of the heating film should have good heating performance while being conductive. In some specific embodiments, the specific material of the above-mentioned heating layer may include at least one of nickel-based alloys, semiconductor materials, carbon materials, conductive polymers, conductive ceramics and conductive glass. In some specific embodiments, the specific material of the above-mentioned heating layer may be any one of nickel-based alloys, semiconductor materials, carbon materials, conductive polymers, conductive ceramics and conductive glass. As a result, the heating component has increased heating power and better heating uniformity, and the heating layer has good high temperature resistance and can be used for a long time under a temperature of 500°C. At the same time, the material source of the heating layer is relatively wide and the cost is relatively low.

[0043] As mentioned above, the heating layer realizes the heating function by energizing the heating layer, and therefore, a necessary connection structure may be provided on the heating layer to connect to the power source. Figure 2 , the heating component may further include an electrode 40, and the electrode 40 is electrically connected to the heating layer 30. Thus, the heating layer can be connected to an external power source through the electrode to generate electricity and generate heat. Specifically, the specific material type of the electrode can be copper, silver, gold and other metals. Thus, it has good electrical conductivity and better connection effect. In other specific embodiments, according to the needs of use, the heating component may further include a terminal 50, and the terminal 50 is electrically connected to the heating layer 30 (refer to Figure 3 ) or electrically connected to the electrode 40 (refer to Figure 2). As a result, the positive and negative poles can be more easily contacted, the power connection function is realized, and the use is more convenient and easy.

[0044] In another aspect of the present invention, the present invention provides a method for preparing the aforementioned heating component. According to an embodiment of the present invention, the method comprises the following steps:

[0045] S10: forming an organic insulating layer on the surface of the substrate.

[0046] According to an embodiment of the present invention, the specific preparation method of the substrate used in this step is not particularly limited and can be flexibly selected according to actual needs, for example, including but not limited to die casting, stretching, etc., which can be specifically carried out with reference to conventional techniques and will not be described in detail here.

[0047] According to the embodiments of the present invention, there are no particular restrictions on the method for forming the organic insulating layer. In some specific embodiments, the organic insulating layer can be formed by forming a film layer using a coating.

[0048] In some specific embodiments, the organic insulating layer is formed by applying a solution coating and then curing it. Specifically, the following steps can be followed: the solution coating is applied to the surface of the substrate by spraying, screen printing, roller coating, brushing, or dipping, and then dried at a temperature of 80°C-380°C. This makes the operation simple and convenient, and the solution coating has good film-forming properties, a low operating temperature, and high safety. The solution coating may include a resin, thermally conductive particles, and a solvent; or the solution coating may include a resin precursor, thermally conductive particles, and a solvent.

[0049] Specifically, when a solution coating is used to form an organic insulating layer, in some specific embodiments, the solution coating may directly contain a polymer used to form an organic matrix. For example, when the organic matrix is ​​polyimide, the solution coating directly contains polyimide. After the coating is applied to form a coating film layer, the solvent in the coating film layer evaporates to form an organic insulating layer. During the film formation process, the solvent component in the solution coating does not undergo a curing reaction. In other specific embodiments, the solution coating may contain a precursor of a polymer used to form an organic matrix. For example, when the organic matrix is ​​polyimide, the solution coating may contain polyacrylic acid (PAA), a precursor of polyimide. After the solution coating is applied, the solvent evaporates, and at the same time, the polyimide precursor in the solution coating undergoes a curing reaction to form polyimide.

[0050] Specifically, the thermally conductive particles can be at least one of aluminum oxide (Al2O3), zirconium oxide (ZrO2), silicon nitride (Si3N4), and boron nitride (BN). The particle size of the thermally conductive particles can be 50 nanometers to 50 microns. The specific details are consistent with those described above and will not be detailed here. The specific type of solvent can be at least one of N-methylpyrrolidone (NMP) and dimethylacetamide (DMAC). This improves solubility, uniformly disperses the solvent components in the coating, and produces a solution coating with good film-forming properties and excellent fluidity, facilitating the preparation of the organic insulating layer and resulting in an organic insulating layer with better performance.

[0051] Specifically, in the solution coating, the mass ratio of the solvent to the resin may be 1-15:1. In some specific embodiments, the mass ratio of the solvent to the resin may be 1.5-9:1. In some specific examples, the mass ratio of the solvent to the resin may be 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, 10.5:1, 11:1, 11.5:1, 12:1, 12.5:1, 13:1, 13.5:1, 14:1, 14.5:1, 15:1, etc. As a result, the solution coating has good fluidity, is easy to process, and has good moldability, and the resulting organic insulating layer has good performance.

[0052] Specifically, the specific operating steps for spraying, screen printing, roller coating, brushing, or dipping can be performed in accordance with conventional techniques and will not be described in detail here. Drying can be performed in a vacuum or with forced air, and the specific operating steps can be performed in accordance with conventional techniques. The specific drying temperature can be 80°C-380°C, such as 80°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 380°C, etc. This temperature range allows the coating layer to dry quickly, saving processing time, and the resulting organic insulating layer has good thickness uniformity, flatness, and insulating properties.

[0053] In some specific embodiments, the organic insulating layer can be formed using a powder coating, specifically by the following steps: spraying the powder coating onto the surface of the substrate via electrostatic spraying and heating to 150°C-400°C. The specific electrostatic spraying steps can be performed according to conventional techniques and are not particularly limited herein. The specific heating temperature can be 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, etc. Thus, the resulting organic insulating layer has better practical performance.

[0054] S20: forming a heating layer on a surface of the organic insulating layer away from the substrate.

[0055] According to an embodiment of the present invention, in this step, the heating layer can be disposed on the surface of the organic insulating layer away from the substrate by spraying, screen printing, roller coating, or laminating. Specific spraying, screen printing, roller coating, or laminating methods can be performed with reference to conventional techniques and will not be described in detail here.

[0056] It should be noted that when the heating layer is a patterned shape (such as the heating layer is formed by a long strip of heating film wound in a ring), the patterning can be achieved by using a shielding plate, masking ink, etc. when preparing the heating layer, or the heating layer can be directly formed on a predetermined area to directly prepare a patterned heating layer in one step.

[0057] Specifically, the specific material of the heating layer can be at least one of a nickel-based alloy, a semiconductor material, a carbon material, a conductive polymer, a conductive ceramic, and a conductive glass. In some specific embodiments, the specific material of the heating layer can be any one of a nickel-based alloy, a semiconductor material, a carbon material, a conductive polymer, a conductive ceramic, and a conductive glass.

[0058] The method according to the embodiment of the present invention has simple steps, is easy to operate, is highly compatible with existing processes, has low requirements on the operational capabilities of technical personnel, is easy to achieve large-scale production, and the resulting cooking utensil has high insulation reliability, while also having improved heating uniformity, high heating efficiency, good thermal conductivity, low noise, and a better user experience.

[0059] In another aspect, the present invention provides a cooking appliance. According to an embodiment of the present invention, the cooking appliance includes the aforementioned heating assembly. In this cooking appliance, the organic insulating layer has excellent high-temperature insulation properties, which can effectively solve the insulation problem between the substrate and the heating layer during use of the cooking appliance. It can also reduce the thermal resistance of heat generated by the heating layer to the substrate, effectively reducing heat accumulation during operation and improving the reliability of the insulation layer. While having high insulation reliability, the heating assembly also has good heating uniformity, high heating efficiency, good thermal conductivity, low noise, and a better user experience.

[0060] According to embodiments of the present invention, the specific type of the cooking utensil is not particularly limited and can be any known cooking utensil. In some specific embodiments, the cooking utensil can include at least one of a wok, a frying pan, a casserole, a soup pot, an electric hot pot, and a frying pan. It will be appreciated that the specific shape and structure of the cooking utensil can be adjusted accordingly depending on the specific type of cooking utensil.

[0061] In some embodiments, in the heating assembly, the first surface of the substrate, distal from the organic insulating layer, is a surface for heating, and this first surface directly contacts the food. In other words, the substrate may constitute the body of the cooking appliance, i.e., the cooking appliance may include a body, an organic insulating layer disposed on the body, and a heating layer disposed on a surface of the organic insulating layer distal from the substrate. Electrodes and / or terminals electrically connected to the heating layer may also be provided as needed. Specifically, taking a grilling machine as an example, the substrate in the heating assembly may constitute the body of the grilling machine, or in other words, the grilling machine includes a substrate, an organic insulating layer disposed on the substrate, and a heating layer disposed on a surface of the organic insulating layer distal from the substrate, as well as electrodes and / or terminals electrically connected to the heating layer, as needed. Furthermore, it is understood that, in addition to the aforementioned heating assembly, the cooking appliance may also include the necessary structures and components of conventional cooking appliances. For example, a grilling machine may also include a handle, a lid, etc., which will not be detailed here.

[0062] In other embodiments, the heating assembly comprises a first surface of the substrate, distal from the organic insulating layer, that is a surface for heating, and the first surface is attached to a cooking container. Specifically, the cooking appliance comprises a housing defining a storage space and a cooking container disposed within the storage space, and the heating assembly is disposed on the housing for heating and cooking food in the cooking container. Examples of such appliances include rice cookers and electric stew pots.

[0063] The embodiments of the present invention are described in detail below.

[0064] Example 1

[0065] A solution coating (containing polyimide, aluminum oxide (particle size of 0.1 micron) and N-methylpyrrolidone, with a mass ratio of N-methylpyrrolidone to polyimide of 6:1) is sprayed onto the surface of a metal substrate (cast iron) and dried at 200°C to form an organic insulating layer with a thickness of 10 mm on the surface of the metal substrate (wherein the mass percentage of aluminum oxide is 0.1% based on the total mass of the organic insulating layer). Then, a nickel-based alloy is sprayed on the surface of the organic insulating layer away from the metal substrate to form a whole layer of heating layer, and then copper electrodes and connecting terminals are formed on the heating layer.

[0066] Example 2

[0067] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 1%, the particle size of aluminum oxide is 1 micron, and the thickness of the organic insulating layer is 20 mm.

[0068] Example 3

[0069] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 3%, the particle size of aluminum oxide is 5 microns, and the thickness of the organic insulating layer is 50 mm.

[0070] Example 4

[0071] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 5%, the particle size of aluminum oxide is 5 microns, and the thickness of the organic insulating layer is 100 mm.

[0072] Example 5

[0073] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 5%, the particle size of aluminum oxide is 10 microns, and the thickness of the organic insulating layer is 100 mm.

[0074] Example 6

[0075] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 7%, the particle size of aluminum oxide is 40 microns, and the thickness of the organic insulating layer is 150 mm.

[0076] Example 7

[0077] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 10%, the particle size of aluminum oxide is 50 microns, and the thickness of the organic insulating layer is 200 mm.

[0078] Example 8

[0079] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 0.01%, the particle size of aluminum oxide is 50 microns, and the thickness of the organic insulating layer is 200 mm.

[0080] Example 9

[0081] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 15%, the particle size of aluminum oxide is 100 microns, and the thickness of the organic insulating layer is 40 mm.

[0082] Example 10

[0083] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 5%, the particle size of aluminum oxide is 5 microns, and the thickness of the organic insulating layer is 50 mm.

[0084] Example 11

[0085] The same as Example 1, except that based on the total mass of the organic insulating layer, the mass percentage of aluminum oxide is 3%, the particle size of aluminum oxide is 1 micron, and the thickness of the organic insulating layer is 20 mm.

[0086] Example 12

[0087] Same as Example 4, except that the metal substrate is cast aluminum.

[0088] Example 13

[0089] Same as Example 4, except that the metal substrate is copper.

[0090] Example 14

[0091] Same as Example 4, except that the thermally conductive particles are silicon nitride.

[0092] Example 15

[0093] Same as Example 4, except that the thermally conductive particles are aluminum oxide and zirconium oxide.

[0094] Performance testing:

[0095] Breakdown voltage: In accordance with the withstand voltage test requirements for Class II electrical appliances specified in GB 4706.1-2005, Safety of Household and Similar Electrical Appliances Part 1: General Requirements, and GB / T 17627-2019, Technical Definitions, Test and Procedure Requirements, and Test Equipment for High Voltage Tests of Low-voltage Electrical Equipment, the organic insulating layer samples (100 mm × 100 mm × 3 mm) prepared in Examples 1-15 were tested using an insulation withstand voltage tester. Specifically, a certain AC voltage at a frequency of 50 Hz was applied to one side of the organic insulating layer sample heated to an operating temperature of 300°C, and the leakage current was detected on the other side of the organic insulating layer sample. If the leakage current was less than 100 mA, it was considered to meet the breakdown requirements at this voltage. The minimum voltage at which the leakage current was not less than 100 mA was the breakdown voltage of the organic insulating layer. The test results are shown in the table below.

[0096] Thermal efficiency of cooking appliances:

[0097] The heat power received by the metal substrate and the electrical power consumed by the heating layer of the cooking utensils prepared in Examples 1-15 were measured. The thermal efficiency of the cooking utensils = (heat power received by the metal substrate / electrical power consumed by the heating layer) × 100%. The test results are shown in the table below.

[0098] Thermal conductivity:

[0099] Test results

[0100]

[0101] In describing the present invention, it should be understood that, in the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0102] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0103] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A heating component, characterized in that: include: substrate; an organic insulating layer, the organic insulating layer being provided on the surface of the substrate and comprising an organic matrix and thermally conductive particles dispersed in the organic matrix; a heating layer, the heating layer being arranged on a surface of the organic insulating layer away from the substrate; The thermal conductivity of the substrate is greater than that of the organic matrix, and the thermal conductivity of the thermally conductive particles is greater than that of the organic matrix and less than that of the substrate. The thermally conductive particles are insulating thermally conductive particles, the content of the thermally conductive particles on the side of the organic insulating layer close to the substrate is less than the content of the thermally conductive particles on the side of the organic insulating layer close to the heating layer, and the breakdown voltage of the organic insulating layer at 300 degrees Celsius is greater than 0.8KV.

2. The heating assembly according to claim 1, wherein The thermal conductivity of the thermally conductive particles is within the range of 20-200 W / (m·K), and the thermal conductivity of the organic matrix is ​​within the range of 0.05-0.5 W / (m·K).

3. The heating assembly according to claim 1, wherein The breakdown voltage of the organic insulating layer at 300 degrees Celsius is greater than 1.2 KV.

4. The heating assembly according to claim 1, wherein: The content of the thermally conductive particles gradually decreases in a direction from the substrate to the heating layer.

5. The heating assembly according to claim 1, wherein: The organic insulating layer satisfies at least one of the following conditions: The material of the organic matrix includes polyimide; The thermal conductivity of the organic insulating layer is 0.2 W / (m·K)-2 W / (m·K); The thermally conductive particles include one or more of aluminum oxide, zirconium oxide, beryllium oxide, silicon nitride, boron nitride, and aluminum nitride; The particle size of the thermally conductive particles is 50 nanometers to 50 micrometers; The thickness of the organic insulating layer is 10 microns to 200 microns; Based on the total mass of the organic insulating layer, the mass percentage of the thermally conductive particles is 0.1%-10%.

6. The heating assembly according to claim 5, characterized in that The particle size of the thermally conductive particles is 200 nanometers to 10 micrometers; The thickness of the organic insulating layer is 20 microns to 150 microns; Based on the total mass of the organic insulating layer, the thermally conductive particles account for 0.2%-6%.

7. The heating assembly according to claim 1, wherein Meet at least one of the following conditions: The substrate is a metal substrate, and the material of the metal substrate includes at least one of aluminum, iron, copper and alloys thereof; The heating layer is composed of a whole surface heating film or a long strip of heating film wound in a ring shape; The material of the heating layer includes at least one of nickel-based alloy, semiconductor material, carbon material, conductive polymer, conductive ceramic and conductive glass.

8. The heating assembly according to claim 1, wherein: Also includes at least one of the following: an electrode, the electrode being electrically connected to the heating layer; A connection terminal is electrically connected to the heating layer or the electrode.

9. A method for preparing the heating component according to any one of claims 1 to 8, characterized in that: include: forming an organic insulating layer on a surface of a substrate; forming a heating layer on a surface of the organic insulating layer away from the substrate, Wherein, the thermal conductivity of the substrate is greater than the thermal conductivity of the organic matrix.

10. The method according to claim 9, characterized in that The organic insulating layer is formed by any one of the following steps: Applying the solution coating on the surface of the substrate by spraying, screen printing, roller coating, brushing or dipping, and drying at a temperature of 80° C. to 380° C.; The powder coating is sprayed on the surface of the substrate by an electrostatic spraying method and heated to 150° C.-400° C.

11. The method according to claim 10, characterized in that The solution coating comprises a resin or a prepolymer of the resin, thermally conductive particles, and a solvent; The powder coating comprises resin powder and the thermally conductive particles.

12. The method according to claim 11, characterized in that The solution coating satisfies at least one of the following conditions: The resin is polyimide; The precursor of the resin is polyacrylic acid; The solvent is at least one of N-methylpyrrolidone and dimethylacetamide; The mass ratio of the solvent to the resin is 1-15:1 or 1.5-9:

1.

13. The method according to claim 9, characterized in that The heating layer is formed by spraying, silk-screening, roller coating or laminating.

14. A cooking utensil, characterized in that: The heating component comprises the heating component according to any one of claims 1 to 8.

15. The cooking appliance according to claim 14, wherein In the heating assembly, a first surface of the substrate away from the organic insulating layer is a surface for heating, and the first surface is in direct contact with food or attached to a cooking container.

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