Substrate for household appliance and induction heating stove comprising substrate

Abstract

The present invention relates to a novel substrate for household appliances, one surface of which is coated with a color coating laminate, the color coating laminate comprising: an adhesive layer in contact with the surface of the substrate; the color layer is positioned at the upper part of the bonding layer; and a protective layer on the upper portion of the color layer, thereby having high heat resistance and discoloration resistance.

Description

Technical Field

[0001] This invention relates to a substrate for household appliances and a cooktop using an induction heating method that includes the substrate. Background Technology

[0002] Cooking appliances used in homes and restaurants in various ways to heat food. Gas stoves, which use gas as fuel, were widely used in the past, but in recent years, devices that use electricity to heat objects such as pots and pans have become increasingly popular.

[0003] The main methods of heating objects using electricity are resistance heating and induction heating. Resistance heating involves transferring heat generated when current flows through a non-metallic heating element such as a metal resistance wire or silicon carbide to the object being heated (e.g., a cooking container) via radiation or conduction. Induction heating, on the other hand, utilizes the magnetic field generated around a coil when a specified amount of high-frequency power is applied to it. This magnetic field induces eddy currents in the object being heated, which is made of metal, thus heating the object itself.

[0004] In recent years, most cooktops have adopted induction heating.

[0005] Typically, a ceramic-glass material with excellent heat resistance is used for the upper part of the cooktop.

[0006] Ceramic glass used in cooktops needs to have sufficiently low light transmittance so that the heating element at the bottom is not visible, and it also needs to be able to withstand the localized high temperatures during cooking.

[0007] In the prior art, color is imparted to ceramic glass by coloring it or by applying single or multiple layers of coating on colorless transparent ceramic glass.

[0008] The coating can be applied in a variety of ways. First, the coating can be applied using a deposition method. However, deposition methods are costly and offer limited color freedom. Additionally, deposition results in a thinner coating, leading to lower hiding power. Second, the coating can be applied using an enamel coating method. Enamel coatings can withstand high temperatures, but due to the significant difference in thermal expansion coefficients between ceramic glass and enamel, defects such as scratches can occur. Third, the coating can be applied using fluoropolymer coatings. However, the use of fluoropolymer coatings is limited due to regulations on perfluorinated compounds. Fourth, the coating can be applied using a silicone coating. Silicone resins exhibit excellent durability at high temperatures, but when applied to ceramic glass for cooktops, coating peeling or discoloration can occur. Summary of the Invention

[0009] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide a new type of substrate for household appliances that can reduce costs while ensuring color freedom.

[0010] In addition, the present invention aims to provide a novel substrate for household appliances that can ensure high heat resistance and anti-discoloration performance.

[0011] In addition, the purpose of this invention is to provide a novel substrate for household appliances that can ensure long-term reliability even in high-temperature environments.

[0012] The objectives of this invention are not limited to those described above, and other objectives and advantages of the invention not mentioned therein can be understood from the following description, and will be more clearly understood from the embodiments of the invention. Furthermore, it will be apparent that the objectives and advantages of the invention can be achieved through the embodiments and combinations thereof as set forth in the claims.

[0013] In the household appliance substrate of the present invention, a color-coated laminate comprising an adhesive layer, a color layer, and a protective layer is coated on one surface. Therefore, the present invention provides a household appliance substrate that can reduce costs while ensuring color freedom. Furthermore, the household appliance substrate of the present invention exhibits excellent heat resistance and anti-discoloration properties.

[0014] Specifically, the household appliance substrate of the present invention is a household appliance substrate with a colored coating laminate coated on one surface, the colored coating laminate comprising: an adhesive layer in contact with the surface of the substrate; a colored layer located on top of the adhesive layer; and a protective layer located on top of the colored layer.

[0015] Here, the colored layer can be formed from a colored layer slurry coating liquid comprising phenyl-based polysiloxanes and phosphite-based antioxidants.

[0016] Preferably, the colored layer slurry coating liquid may include: the phenyl-based polysiloxane, 30-60% by weight; the antioxidant, 0.01-1% by weight; the effect pigment, 8-20% by weight; the colored inorganic pigment, 1-10% by weight; and the solvent, 10-60% by weight.

[0017] In another embodiment of the present invention, the induction heating stove may include a working coil for heating a magnetic body and a heating film coating for heating a non-magnetic body, thereby enabling the heating of both magnetic and non-magnetic bodies.

[0018] In another embodiment of the present invention, the induction heating stove may include: a housing; a cover plate, attached to the upper end of the housing, and having an upper plate portion on which a heated object is disposed; a working coil, disposed inside the housing to heat the heated object; a heat insulation member, disposed above the working coil; and a heating film coating, disposed on one side of the upper plate portion or one side of the heat insulation member, and having a stacked structure in which an adhesive layer and a heating layer are stacked in sequence; the upper plate portion uses the substrate for household appliances as described in claim 1.

[0019] In another embodiment of the present invention, a stove using induction heating may further include a protective layer stacked on one side of the heating layer.

[0020] In addition, another embodiment of the induction heating stove of the present invention may further include: a shielding plate installed on the bottom surface of the working coil and blocking the magnetic field generated downward when the working coil is driven; a support member disposed between the bottom surface of the shielding plate and the bottom surface of the housing and supporting the shielding plate upward; and a cooling fan disposed inside the housing to cool the working coil.

[0021] In another embodiment of the present invention, a stove using an induction heating method includes a support member that may include an elastic body for supporting the shielding plate upwards.

[0022] In another embodiment of the present invention, a stove using induction heating is provided, wherein the cooling fan can draw in air from outside the housing and transmit it to the working coil, or draw in air from inside the housing and discharge it to the outside of the housing, and the heat insulation member blocks the transmission of heat generated by the driving of the working coil to the heated object or heat generated by the heating film coating to the working coil.

[0023] The induction heating stove of the present invention may include a working coil and a heating film coating arranged to overlap each other in the longitudinal direction. The heating film coating has a stacked structure in which an adhesive layer and a heating layer are stacked in sequence, and has at least one of the properties of magnetic and non-magnetic, so that eddy currents can be induced by the working coil, thereby realizing induction heating.

[0024] In addition, since the skin depth of the heating film coating is deeper than the thickness of the heating film coating, when heating an object formed of a magnetic body, the magnetic field generated by the working coil can be transmitted to the heated object through the film, thus inducing eddy currents in the heated object.

[0025] Furthermore, when heating an object that has a non-magnetic body, eddy currents can be induced in the heating film coating due to the magnetic field generated by the working coil.

[0026] Therefore, the same heat source can be used to directly or indirectly heat the object being heated.

[0027] Furthermore, the induction heating cooker of the present invention uses the aforementioned household appliance substrate as the upper plate. Therefore, the cooker of the present invention possesses excellent durability and reliability.

[0028] This invention provides a novel substrate for household appliances that reduces costs while ensuring color freedom. Furthermore, this invention provides a novel substrate for household appliances that ensures high heat resistance and anti-discoloration properties. Moreover, this invention provides a novel substrate for household appliances that can maintain long-term reliability even in high-temperature environments.

[0029] Furthermore, the induction heating cooker of the present invention can heat both magnetic and non-magnetic materials. Additionally, the induction heating cooker of the present invention can heat any object regardless of its placement or type. Therefore, users do not need to determine whether the object is magnetic or non-magnetic, and can place and heat the object in any heating area on the upper plate.

[0030] Furthermore, the induction heating method of this invention allows the stove to directly or indirectly heat the object being heated using the same heat source, thus eliminating the need for an additional heating plate or radiant heater. Therefore, this invention not only improves heating efficiency but also reduces material costs.

[0031] In addition to the effects described above, the specific effects of the present invention will be explained in conjunction with the following description of the specific implementation of the invention. Attached Figure Description

[0032] Figure 1 This is a cross-sectional view of a substrate for household appliances according to an embodiment of the present invention.

[0033] Figure 2 This is a diagram illustrating a stove using an induction heating method according to an embodiment of the present invention.

[0034] Figure 3 This indicates that it is set in Figure 2 The diagram shows the internal components of the casing of a stove using induction heating.

[0035] Figure 4 and Figure 5 This is a diagram illustrating an embodiment of the heated thin film coating of the present invention.

[0036] Figure 6 and Figure 7 This is a graph illustrating the relationship between the thickness of the heating module and the skin depth.

[0037] Figure 8 and Figure 9 It is a graph illustrating the impedance changes between the heating film coating and the heated object, depending on the type of object being heated.

[0038] Figure 10 This is a diagram illustrating a stove using an induction heating method according to another embodiment of the present invention.

[0039] Figure 11 This indicates that it is set in Figure 10 The diagram shows the internal components of the casing of a stove using induction heating.

[0040] Figure 12 This means that in Figure 10 The diagram shows the state of an induction heating stove with the object being heated.

[0041] Figure 13 This is a graph evaluating the heat resistance of the examples and comparative examples.

[0042] Figure 14 These are photographs evaluating the durability of the embodiments and comparative examples.

[0043] Explanation of reference numerals in the attached figures

[0044] 15: Circuit boards for household appliances

[0045] 10: Substrate; 11: Adhesive layer

[0046] 12: Color layer 13: Protective layer

[0047] 20: Cover plate 25: Housing

[0048] TL1, TL2: First heating thin film coating and second heating thin film coating

[0049] WC1, WC2: First working coil and second working coil

[0050] 35: Thermal insulation component; 45: Shielding plate

[0051] 50: Supporting component; 55: Cooling fan Detailed Implementation

[0052] The foregoing objectives, features, and advantages will be described in detail below with reference to the accompanying drawings, thereby enabling those skilled in the art to readily implement the technical concept of this invention. During the description of this invention, detailed descriptions of well-known technologies related to this invention are omitted when it is determined that such detailed descriptions would obscure the main points of the invention. Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to refer to the same or similar constituent elements.

[0053] The following refers to the arrangement of any configuration on the "upper (or lower)" or "upper (or lower)" of a constituent element, meaning that the arbitrary configuration can not only be arranged in contact with the top (or bottom) surface of the constituent element, but also that other configurations can be inserted between the constituent element and the arbitrary configuration arranged on (or below) the constituent element.

[0054] In addition, when a constituent element is described as being "connected", "combined", or "in contact" with other constituent elements, the constituent elements may be directly connected or in contact with each other, but it should be understood that other constituent elements may also "intervene" between each constituent element, or each constituent element may be "connected", "combined", or "in contact" with other constituent elements.

[0055] Hereinafter, a substrate for household appliances according to an embodiment of the present invention will be described.

[0056] Figure 1 This is a cross-sectional view of a substrate for household appliances according to an embodiment of the present invention.

[0057] First, refer to Figure 1 In one embodiment of the present invention, the substrate 15 for household appliances refers to a substrate 10 having a color coating laminate 11, 12, 13 coated on one surface. Here, the color coating laminate includes an adhesive layer 11 in contact with the surface of the substrate 10, a color layer 12 located on top of the adhesive layer 11, and a protective layer 13 located on top of the color layer 12.

[0058] Since the substrate 15 for household appliances of the present invention includes the color-coated laminate, it can display a wide variety of colors, and it also has excellent reliability even when exposed to high temperatures for a long time.

[0059] First, the substrate can utilize any known substrate used in household appliances, but a substrate made of ceramic glass material is most preferably used.

[0060] The color-coated laminate includes an adhesive layer 11. The adhesive layer 11 is a layer that contacts the surface of the substrate.

[0061] The adhesive layer 11 can be formed from an adhesive layer slurry coating liquid including methyl-based polysiloxanes. The methyl-based polysiloxanes are components that enhance the adhesion of the colored coated laminate.

[0062] Here, the adhesive layer slurry coating liquid may include 30-70% by weight of the methyl-based polysiloxane and 30-70% by weight of solvent.

[0063] The methyl-based polysiloxane can be any methyl-based polysiloxane resin known in the art.

[0064] The solvent may be at least one of xylene, ethylbenzene, toluene, benzene, isopropyl alcohol (IPA), and butyl carbitolacetate (BCA).

[0065] The color-coated laminate includes a color layer 12. The color layer 12 is configured to impart a variety of colors to the substrate. Furthermore, the color layer 12 is configured to provide durability to the substrate. The color layer 12 is located on top of the adhesive layer.

[0066] The colored layer 12 can be formed from a colored layer slurry coating liquid comprising phenyl-based polysiloxanes and phosphite-based antioxidants. The phenyl-based polysiloxanes and phosphite-based antioxidants reduce the rate at which the colored layer 12 decomposes due to oxidation. Therefore, the substrate for household appliances of the present invention can ensure long-term reliability. Specifically, the phosphite-based antioxidants can decompose hydroperoxides generated within the colored coating laminate under high temperature / oxygen conditions. Thus, discoloration of the colored coating laminate can be prevented by the phosphite-based antioxidants, and the long-term reliability of the substrate can be maximized.

[0067] Additionally, the colored layer slurry coating liquid may also include effect pigments composed of a substrate coated with a metal oxide. The present invention can use these effect pigments to improve the heat resistance of the substrate.

[0068] Here, the colored layer slurry coating liquid may include 30-60% by weight of the phenyl-based polysiloxane, 0.01-1% by weight of the antioxidant, 8-20% by weight of the effect pigment, 1-10% by weight of the colored inorganic pigment, and 10-60% by weight of the solvent.

[0069] The phenyl-based polysiloxane can be any phenyl-based polysiloxane resin known in the art. The phenyl-based polysiloxane used is 30-60% by weight.

[0070] As described above, the antioxidant may include phosphite-based antioxidants. These phosphite-based antioxidants may include phenyl groups such as tris(nonylphenyl) phosphite, triphenyl phosphite, diphenyl isodecyl phosphite, 2-ethylhexyl diphenyl phosphate, and tris(2,4-di-tert-butylphenyl) phosphite. These phosphite-based antioxidants convert the peroxides (ROOH) that cause polymer decomposition at high temperatures into alcohols (ROH), thereby improving the heat resistance of the polymer itself. If more than 1% by weight of the phosphite-based antioxidant is added, the coatability deteriorates, leading to a decrease in the appearance quality of the substrate. Therefore, it is preferable to use 0.01 to 1% by weight of the phosphite-based antioxidant.

[0071] The effect pigment may include a plate-shaped pearlescent pigment coated with a metal oxide. The metal oxide may be SiO2, SnO2, TiO2, etc. Additionally, the substrate for the effect pigment may be mica, alumina, etc. 8-20% by weight of the effect pigment may be added. If the effect pigment content is less than 8% by weight, the heat resistance of the coating will decrease. Furthermore, if the effect pigment content exceeds 20% by weight, the coating's forming ability will decrease, leading to laminate peeling.

[0072] The colored inorganic pigment can be at least one of oxides of cobalt (Co), tin (Sn), aluminum (Al), zinc (Zn), zirconium (Zr), etc. 1 to 10% by weight of the colored inorganic pigment can be used. If the colored inorganic pigment is less than 1% by weight, the heat resistance of the coating will decrease. Furthermore, if the colored inorganic pigment exceeds 10% by weight, the coating's forming ability will decrease, leading to laminate peeling.

[0073] The solvent may be at least one selected from xylene, ethylbenzene, toluene, benzene, isopropyl alcohol (IPA), and butyl carbitolacetate (BCA). 10–60% by weight of the solvent may be used.

[0074] The color-coated laminate includes a protective layer 13. The protective layer 13 is configured to protect the color layer 12. Specifically, the protective layer 13 prevents scratches on the laminate and minimizes its exposure to oxygen. The protective layer 13 is located on top of the color layer 12.

[0075] The protective layer 13 may be formed from a protective layer slurry coating liquid comprising inorganic materials or silica sol-gel. The inorganic material may include an inorganic coating based on glass frit.

[0076] Preferably, the thickness of the adhesive layer 11 can be 1 to 10 μm, the thickness of the color layer 12 can be 30 to 100 μm, and the thickness of the protective layer 13 can be 1 to 10 μm.

[0077] The color-coated laminate can preferably be formed by screen printing. The adhesive layer 11 can be formed by coating one surface of the substrate 10 with the aforementioned adhesive paste coating liquid. Without requiring an additional curing process for the adhesive layer 11, the color layer 12 can be formed by directly coating the adhesive layer 11 with the color paste coating liquid. At this time, the color layer 12 can be formed by drying at approximately 200°C for 5–30 minutes, followed by curing at 400°C for 10–60 minutes. Subsequently, a protective layer 13 can be formed by coating the color layer 12 with the protective paste coating liquid.

[0078] Next, an induction heating stove according to an embodiment of the present invention will be described.

[0079] Figure 2 This is a diagram illustrating a stove using an induction heating method according to an embodiment of the present invention. Figure 3 This indicates that it is set in Figure 2 The diagram shows the internal components of the casing of a stove using induction heating. Figure 4 and Figure 5 This is a diagram illustrating an embodiment of the heated thin film coating of the present invention. Figure 6 and Figure 7 This is a graph illustrating the skin depth characteristics based on the relative permeability of the thin film. Figure 8 and Figure 9 It is a graph illustrating the impedance changes between the thin film and the heated object, depending on the type of object being heated.

[0080] First, refer to Figure 2 According to an embodiment of the present invention, the induction heating stove 1 may include a housing 25, a cover plate 20, working coils WC1 and WC2 (i.e., the first working coil and the second working coil), and heating film coatings TL1 and TL2 (i.e., the first heating film coating and the second heating film coating).

[0081] Working coils WC1 and WC2 can be provided in the housing 25.

[0082] For reference, in addition to the working coils WC1 and WC2, the housing 25 may be equipped with various devices related to the driving of the working coils (e.g., a power supply unit that provides AC power, a rectifier unit that rectifies the AC power from the power supply unit into DC power, an inverter unit that converts the DC power rectified by the rectifier unit into resonant current and provides it to the working coils through a switching operation, a control module that controls the operation of various devices in the induction heating stove 1 (the control module includes an inverter control module that controls the switching operation of the inverter unit and an input interface control module that controls the input interface), a relay or semiconductor switch that turns the working coils on or off, etc.), but specific descriptions of these are omitted.

[0083] The cover plate 20 can be attached to the upper end of the housing 25, and an upper plate portion 15 can be provided on its top surface for placing a heated object (not shown). Here, the upper plate portion 15 uses the aforementioned household appliance substrate. In this case, the surface coated with the color-coated laminate can be located at the bottom.

[0084] Specifically, the cover 20 may include an upper plate portion 15 for placing heated objects such as cooking containers.

[0085] Here, the upper plate 15 can be made of, for example, glass material (e.g., ceramic glass).

[0086] Additionally, the upper plate 15 may be provided with an input interface (not shown) for receiving input from the user and transmitting the corresponding input to the aforementioned control module. Of course, the input interface may also be provided in other locations besides the upper plate 15.

[0087] For reference, the input interface is a module for inputting the user's desired heating intensity or the driving time of the induction heating method of the stove 1, and can be implemented in various ways such as physical buttons or a touch panel. Additionally, the input interface may include, for example, a power button, a lock button, power level adjustment buttons (+, -), timer adjustment buttons (+, -), and a charging mode button. Furthermore, the input interface can transmit the input received from the user to an input interface control module (not shown), and the input interface control module can transmit the input to an inverter control module (not shown). Furthermore, the inverter control module can control the operation of various devices (e.g., the operating coil) based on the input received from the input interface control module (i.e., the user's input); details of this will be omitted.

[0088] On the other hand, the upper plate 15 can visually display, in a stove-like pattern, whether the working coils (e.g., the first working coil WC1 and the second working coil WC2) are driven and the heating intensity (i.e., the firepower). This stove-like pattern can be displayed by an indicator light (not shown) consisting of a plurality of light-emitting elements (e.g., LEDs) disposed within the housing 25.

[0089] The first working coil WC1 and the second working coil WC2 can be disposed inside the housing 25 to heat the object being heated.

[0090] Specifically, the first working coil WC1 and the second working coil WC2 can be driven by the inverter control module. When the object to be heated is placed on the upper plate 15, it can be driven by the inverter control module.

[0091] In addition, the first working coil WC1 and the second working coil WC2 can directly heat magnetic objects (i.e., magnetic bodies), and can indirectly heat non-magnetic objects (i.e., non-magnetic bodies) using the first heating film coating TL1 and the second heating film coating TL2, which will be described later.

[0092] Furthermore, the first working coil WC1 and the second working coil WC2 can heat the object being heated by induction heating, and can be configured to overlap with the first heating film coating TL1 and the second heating film coating TL2 in the longitudinal direction (i.e., the vertical direction or the up-down direction), respectively.

[0093] For reference only. Figure 2 The illustration shows a configuration where two working coils WC1 and WC2 are disposed in the housing 25, but it is not limited to this. That is, one or more working coils may be disposed in the housing 25, but for ease of explanation, in one embodiment of the present invention, two working coils WC1 and WC2 disposed in the housing 25 will be used as an example.

[0094] The heating film coating may include a first heating film coating TL1 and a second heating film coating TL2. The heating film coating is disposed on one side of the upper plate or one side of the heat insulation member. In other words, the heating film coating may be formed on the top or bottom surface of the upper plate, or on the top or bottom surface of the heat insulation member.

[0095] As an example, the first heating film coating TL1 and the second heating film coating TL2 can be respectively disposed on the bottom surface of the upper plate portion 15 and spaced apart from each other.

[0096] Furthermore, the first heating film coating TL1 and the second heating film coating TL2 can be configured to overlap with the first working coil WC1 and the second working coil WC2 in the longitudinal direction (i.e., the vertical direction or the up-down direction), respectively.

[0097] In addition, the first heating film coating TL1 and the second heating film coating TL2 may have at least one of the properties of magnetic and non-magnetic (i.e., magnetic, non-magnetic, or a combination of both).

[0098] like Figure 4 As shown, the heating thin film coating TL1 of the present invention has a stacked structure in which the adhesive layer TLA1 and the heating layer TLH1 are stacked sequentially.

[0099] The adhesive layer TLA1 is used to bond the upper plate or the heat insulation component and the heating layer TLH1 together. Furthermore, the adhesive layer TLA1 protects the heating layer TLH1 from the effects of leaching from the upper plate caused by prolonged high-temperature use, and prevents performance degradation of the heating layer TLH1.

[0100] To achieve the above-mentioned functions, the adhesive layer TLA1 may include at least one of inorganic materials and metal oxides. As a specific example, the adhesive layer TLA1 may include transition metals such as titanium (Ti), chromium (Cr), iron (Fe), nickel (Ni), and copper (Cu), or metal oxides such as Al2O3 and SiO2.

[0101] Preferably, the adhesive layer TLA1 can be formed by coating an adhesive layer slurry containing at least one of inorganic materials and metal oxides. More specifically, the adhesive layer slurry may include 60-85% by weight of at least one of the inorganic materials and metal oxides, 5-25% by weight of an adhesive resin, 5-25% by weight of a solvent, and 0.5-5% by weight of an inorganic filler. Additionally, depending on requirements, the adhesive layer slurry may also include additives such as leveling agents, defoamers, and dispersants.

[0102] At least one of the inorganic material and metal oxide can be selected from V₂O₅, P₂O₅, PbO, B₂O₃, Bi₂O₃, ZnO, SiO₂, B₂O₃, Al₂O₃, BaO, MoO₃, TeO₂, Ta₂O₅, Nb₂O₅, and CaO. The inorganic material and metal oxide can be used in particulate form, including spherical, plate-like, and amorphous particles. The softening point of the substance can be in the range of 400–800°C, and the crystallization temperature (Tc) can be in the range of 450–850°C. The particle size can be 1 μm–5 μm. If the content of at least one of the inorganic material and metal oxide is less than 60% by weight, the protective function of the corresponding heating layer will be reduced. Conversely, if the content of at least one of the inorganic material and metal oxide exceeds 85% by weight, workability will decrease and it will become a cause of cracking.

[0103] Furthermore, the binder resin fixes at least one of the inorganic materials and metal oxides, forming a three-dimensional chain structure. In addition, the binder resin affects the formation of a uniform coating and influences durability, chemical resistance, and adhesion to the substrate. If the binder is not completely thermally decomposed during the sintering process, pores will form and remain in the electrodes, thereby increasing the resistivity of the film. The thermal decomposition temperature of the binder resin is within 100–300°C, preferably polyurethane, polyester, polyacrylic acid, polycellulose, etc., with a molecular weight in the range of 2,000–2,000,000. Since the viscosity is low when the binder resin content is less than 5% by weight, a uniform coating cannot be formed, resulting in increased resistivity; if the content exceeds 25% by weight, the coating workability decreases.

[0104] The solvent can improve the coatability and workability of the coating liquid. The thermal decomposition temperature of the solvent is preferably within the range of 50–200°C, and it may include at least one of the following: butyl cellosolve, ethylene glycol monobutyl ether acetate, ethyl carbitol, ethyl carbitol acetate, butyl carbitol, ethoxyethyl acetate, butyl acetate, propylene glycol monobutyl ether, ethanol, butanol, etc. As described above, the content of the solvent is preferably 5–25% by weight.

[0105] The inorganic filler is an additive used to improve the physical properties of the coating. In this invention, the inorganic filler may be Al2O3, Al(OH)3, TiO2, CaCO3, CaO, Ca(OH)2, SiO2, BaSO4, ZnO, glass fiber, talc, etc., and at least one may be used depending on the intended use. The size of the inorganic filler may be 1 μm to 5 μm, and the content is preferably 0.5% to 5% by weight.

[0106] Furthermore, to improve the dispersibility, storage stability, and coating performance of the coating, the additive can be a leveling agent, defoamer, dispersant, flow modifier, etc., preferably an organosilicon-based (polyether hydroxy polymethylsilane, polyether dimethyl polysiloxane, polymethyl alkyl siloxane, polyether polymethyl alkyl siloxane, polyester hydroxy polymethyl siloxane, polyether polymethyl siloxane), non-organosilicon-based (nonionic polyacrylic acid, ionic polyacrylic acid, polyacrylate, alcohol silicate, acrylate), or alcohol-based (ethanol, butanol) substance. Preferably, 0.05–5% by weight of the additive is added to the coating solution.

[0107] The thickness of the adhesive layer TLA1 is not particularly limited, but it is preferably formed to a thickness of 0.01 μm to 10 μm. If the thickness of the adhesive layer TLA1 is less than 0.01 μm, the adhesion between the heating layer and the upper plate, etc., will decrease, and the protective performance of the heating layer will be insufficient. Conversely, if the thickness of the adhesive layer TLA1 exceeds 10 μm, the induction heating function of the heating film coating TL1 will decrease.

[0108] Then, the heating layer TLH1 is a configuration that enables the stove of the present invention to selectively heat the heated body.

[0109] To achieve the above functions, the heating layer TLH1 may include at least one substance selected from metals and metal alloys. As a specific example, the heating layer TLH1 may include at least one or two metals selected from Sn, Co, Cr, Fe, Ni, Al, Cu, Ag, and Au.

[0110] Preferably, the heating layer TLH1 can be formed by coating a heating layer slurry containing at least one of the metals and metal alloys. More specifically, the heating layer slurry may include 40-90% by weight of at least one of the metals and metal alloys, 2-25% by weight of an adhesive resin, 5-25% by weight of a solvent, 0.5-5% by weight of an inorganic material, and 0.5-5% by weight of an inorganic filler.

[0111] At least one of the metals and metal alloys may be selected from at least one of Pd, Au, Pt, W, Ni, RuO2, Ag, and Cu, and used in particulate form. The particles may be spherical, plate-like, amorphous, or any other shape, preferably a shape that increases the contact area between them. The particle size is preferably 0.5 μm to 20 μm, and it is preferable to use one or two to four particles of the same size to increase the contact density between them. When at least one of the metals and metal alloys is less than 40% by weight, the heating performance of the heating layer will decrease; if it exceeds 90% by weight, reduced film flatness, condensation, and reduced sintering properties will occur during the coating process.

[0112] Furthermore, the binder resin fixes at least one of the metals and metal alloys, forming a three-dimensional chain structure. In addition, the binder resin affects the formation of a uniform coating and influences durability, chemical resistance, and adhesion to the substrate. If the binder is not completely thermally decomposed during the sintering process, pores will form and remain in the electrodes, thereby increasing the resistivity of the film. The thermal decomposition temperature of the binder resin is within 100–300°C, and polyurethane, polyester, polyacrylic acid, polycellulose, etc., with a molecular weight in the range of 2,000–2,000,000 are preferred. When the binder resin content is less than 2% by weight, the viscosity decreases, resulting in an inability to form a uniform coating and an increase in resistivity; if it exceeds 25% by weight, the coating workability decreases.

[0113] The solvent can improve the coatability and workability of the coating liquid. The thermal decomposition temperature of the solvent is preferably within the range of 50–200°C, and it may include at least one of the following: butyl cellosolve, ethylene glycol monobutyl ether acetate, ethyl carbitol, ethyl carbitol acetate, butyl carbitol, ethoxyethyl acetate, butyl acetate, propylene glycol monobutyl ether, ethanol, butanol, etc. As described above, the content of the solvent is preferably 5–25% by weight.

[0114] To improve the adhesion of the heating layer, the inorganic material can be used. The inorganic material can be at least one selected from V₂O₅, P₂O₅, PbO, B₂O₃, Bi₂O₃, ZnO, SiO₂, B₂O₃, Al₂O₃, BaO, MoO₃, TeO₂, Ta₂O₅, Nb₂O₅, and CaO, and can be used in granular form. The granules can be spherical, plate-shaped, amorphous, etc., and can be used in combination of one or two to six different types. The softening point of the granules is preferably 400–700°C, and the crystallization temperature (Tc) is preferably 450–750°C. The particle size can be 1 μm–5 μm, and the content is preferably 0.1–5% by weight.

[0115] The inorganic filler is an additive used to improve the physical properties of the coating. In this invention, the inorganic filler may be Al₂O₃, Al(OH)₃, TiO₂, CaCO₃, CaO, Ca(OH)₂, SiO₂, BaSO₄, ZnO, glass fiber, talc, etc., and at least one may be used depending on the intended use. The size of the inorganic filler may be 1 μm to 5 μm, and the content is preferably 0.5% to 5% by weight.

[0116] Furthermore, to improve the dispersibility, storage stability, and coating performance of the coating, the additives can be leveling agents, defoamers, dispersants, flow modifiers, etc., preferably organosilicon-based (polyether hydroxy polymethylsilane, polyether dimethyl polysiloxane, polymethyl alkyl siloxane, polyether polymethyl alkyl siloxane, polyester hydroxy polymethyl siloxane, polyether polymethyl siloxane), non-organosililicon-based (nonionic polyacrylic acid, ionic polyacrylic acid, polyacrylate, alcohol silicate, acrylate), alcohol-based (ethanol, butanol), etc. Preferably, 0.05–5% by weight of the additives are added to the coating solution.

[0117] The thickness of the heating layer TLH1 is not particularly limited, but it is preferably formed to a thickness of 1 μm to 60 μm. When the thickness of the heating layer TLH1 is less than 1 μm, the selective heating function will be reduced. Conversely, when the thickness of the heating layer TLH1 exceeds 60 μm, the heating performance itself will be reduced.

[0118] In addition, depending on the requirements, the heating layer TLH1 can also be formed into one or more layers (not shown).

[0119] Then, refer to Figure 5 The heating film coating TL1 of the present invention may further include a protective layer TLP1. As described above, the heating film coating TL1 of the present invention may be formed on one side of the upper plate portion or the heat insulation member. In particular, when the heating film coating TL1 of the present invention is formed on the upper surface of the upper plate portion, in order to protect the heating layer from the influence of the heated body, the heating film coating TL1 preferably further includes the protective layer TLP1. Therefore, the protective layer TLP1 is formed on one side of the heating layer TLH1 (the side opposite to the side where the adhesive layer TLA1 is formed).

[0120] To protect the heating layer TLH1, the protective layer TLP1 may comprise at least one of inorganic materials and metal oxides. As a specific example, the protective layer may comprise at least one or two oxides selected from SiO2, Al2O3, CeO2, and MgO.

[0121] The protective layer TLP1 can be formed from the same slurry coating liquid as the adhesive layer slurry coating liquid.

[0122] The thickness of the protective layer TLP1 is not particularly limited, but it is preferably formed to a thickness of 1 μm to 60 μm. If the thickness of the protective layer TLP1 is less than 1 μm, the protective performance of the heating layer will be insufficient. Conversely, if the thickness of the protective layer TLP1 exceeds 60 μm, the induction heating function of the heating thin film coating TL1 will be reduced.

[0123] The heating film coating TL1 of the present invention is preferably formed by coating with a paste. In this invention, the coating method is not particularly limited. The present invention can use one of gravure printing, inkjet printing, or screen printing.

[0124] If the heating film coating TL1 is formed by slurry coating, a film with uniform overall density is obtained. Therefore, the heating film coating TL1 formed by slurry coating has superior basic properties, such as heating performance, compared to films formed by other methods.

[0125] The slurry coating process of the present invention can be performed in the order of cleaning, coating, drying, sintering, and cooling. First, an adhesive layer can be formed on the surface of the object, such as the upper plate and the heat insulation member, and then a heating layer can be formed. In the present invention, in order to ensure the conductivity of the heated coating film, sintering is preferably performed in a temperature range of 400 to 900°C.

[0126] Furthermore, the slurry coating liquids constituting the heating thin film coating TL1 are as described above.

[0127] The first heating film coating TL1 and the second heating film coating TL2 are formed to a thickness that can be inductively heated by the working coil, the details of which will be explained later.

[0128] In addition, the diameter (i.e., size) of the first heating film coating TL1 and the second heating film coating TL2 can be smaller than the diameter of the upper plate portion 15.

[0129] Next, refer to Figure 3 The stove 1 of the induction heating method according to an embodiment of the present invention may further include a heat insulation component 35, a shielding plate 45, a support component 50, and a cooling fan 55.

[0130] For reference, the constituent elements arranged around the first working coil WC1 and those arranged around the second working coil ( Figure 1 The components around the first working coil WC1 are the same as those around the first working coil WC2. For ease of explanation, the components around the first working coil WC1 (first heating film coating TL1, heat insulation 35, shielding plate 45, support member 50, cooling fan 55) will be explained below.

[0131] The heat insulation element 35 can be disposed between the first heating film coating TL1 and the first working coil WC1.

[0132] This heat insulation element 35 can block the transfer of heat generated by the first working coil WC1 driving the first heating film coating TL1 or the heated object HO to the first working coil WC1.

[0133] That is, if the first heating film coating TL1 or the heated object HO is heated under the electromagnetic induction of the first working coil WC1, the heat of the first heating film coating TL1 or the heated object HO can be transferred to the upper plate 15, and the heat of the upper plate 15 can be transferred to the first working coil WC1 again, causing the working coil WC to be damaged.

[0134] As described above, the heat insulation component 35 can prevent the first working coil WC1 from being damaged by heat by blocking the heat transferred to the first working coil WC1, thereby preventing the heating performance of the first working coil WC1 from being reduced.

[0135] For reference, although not a necessary component, a separator (not shown) may also be provided between the first working coil WC1 and the heat insulation member 35.

[0136] Specifically, a separator can be inserted between the first working coil WC1 and the heat insulation member 35, so that the first working coil WC1 and the heat insulation member 35 do not directly contact each other. Thus, the separator can prevent the heat generated by the driving of the first working coil WC1 to heat the first heating film coating TL1 or the heated object HO from being transferred to the first working coil WC1 through the heat insulation member 35.

[0137] The separator can share some of the function of the heat insulation member 35, and can minimize the thickness of the heat insulation member 35, thereby minimizing the gap between the heated object HO and the first working coil WC1.

[0138] Additionally, a plurality of the separators may be provided, and the plurality of separators may be configured to be spaced apart from each other between the first working coil WC1 and the heat insulation member 35. Thus, air drawn into the interior of the housing 25 by the cooling fan 55 (described later) may be guided to the first working coil WC1 by the separators.

[0139] That is, the separator can guide the air flowing into the interior of the housing 25 through the cooling fan 55 to be properly delivered to the first working coil WC1, thereby improving the cooling efficiency of the first working coil WC1.

[0140] The shielding plate 45 can be installed on the bottom surface of the first working coil WC1 to block the downward magnetic field generated when the first working coil WC1 is driven.

[0141] Specifically, the shielding plate 45 can block the downward magnetic field generated when the first working coil WC1 is driven, and can be supported upward by the support member 50.

[0142] The support member 50 can be disposed between the bottom surface of the shielding plate 45 and the bottom surface of the housing 25 to support the shielding plate 45 upward.

[0143] Specifically, the support member 50 can support the shielding plate 45 upwards, thereby indirectly supporting the first working coil WC1, the heat insulation member 35, and the first heating film coating TL1 upwards. As a result, the distance between the first working coil WC1 and the heated object HO can be maintained constant.

[0144] For reference, the support member 50 may include, for example, an elastic body (e.g., a spring) for supporting the shielding plate 45 upwards, but is not limited thereto. Furthermore, the support member 50 is not an essential component and can therefore be omitted from the induction heating type cooktop 1.

[0145] To cool the first working coil WC1, a cooling fan 55 can be installed inside the housing 25.

[0146] Specifically, the cooling fan 55 can be driven by the aforementioned control module and can be disposed on the side wall of the housing 25. Of course, the cooling fan 55 can also be disposed in other locations besides the side wall of the housing 25, but in one embodiment of the present invention, for ease of explanation, the example of the cooling fan 55 being disposed on the side wall of the housing 25 will be described.

[0147] In addition, such as Figure 2 As shown, the cooling fan 55 can draw in air from outside the housing 25 and pass it to the first working coil WC1, or it can draw in air (especially hot air) from inside the housing 25 and exhaust it to the outside of the housing 25.

[0148] This enables effective cooling of the components inside the housing 25 (especially the first working coil WC1).

[0149] Furthermore, as described above, the air delivered to the outside of the housing 25 of the first working coil WC1 by the cooling fan 55 can be guided to the first working coil WC1 through the separator. This enables direct and efficient cooling of the first working coil WC1, thereby improving its durability (i.e., durability improvement based on preventing thermal damage).

[0150] As described above, the induction heating stove 1 according to an embodiment of the present invention may have the aforementioned features and configuration. Hereinafter, reference will be made to... Figures 6 to 9 The features and structure of the aforementioned heating module will be described in more detail.

[0151] For reference and for ease of explanation, the following is shown schematically. Figure 6 and Figure 7 The thicknesses of the constituent elements shown are not related to the actual proportions, and the relative thickness differences between the constituent elements are also unrelated to reality.

[0152] Figure 6 and Figure 7This is a graph illustrating the relationship between film thickness and skin depth. Figure 8 and Figure 9 This describes the change in impedance between the thin film and the heated object, depending on the type of object being heated.

[0153] For reference, the first heating thin film coating TL1 and the second heating thin film coating TL2 have the same technical features. Hereinafter, for ease of explanation, the first heating thin film coating TL1 will be used as an example.

[0154] The first heating thin film coating TL1 has the following characteristics.

[0155] The first heating thin film coating TL1 is formed of a material with low relative permeability, as described above.

[0156] Specifically, the relative permeability of the first heating thin film coating TL1 can be relatively low, and the skin depth of the first heating thin film coating TL1 can be relatively deep. Here, skin depth refers to the depth to which current penetrates from the surface of the material, and the relative permeability is inversely proportional to the skin depth. Therefore, the lower the relative permeability of the first heating thin film coating TL1, the deeper the skin depth of the first heating thin film coating TL1.

[0157] Furthermore, the skin depth of the first heating thin film coating TL1 can be greater than the thickness of the first heating thin film coating TL1. That is, since the first heating thin film coating TL1 has a thinner thickness and the skin depth of the first heating thin film coating TL1 is greater than the thickness of the first heating thin film coating TL1, the magnetic field generated by the first working coil WC1 is transmitted to the heated object HO through the first heating thin film coating TL1, thereby inducing eddy currents in the heated object HO.

[0158] That is, such as Figure 6 As shown, when the skin depth of the first heating film coating TL1 is shallower than the thickness of the first heating film coating TL1, it can be seen that the magnetic field generated by the first working coil WC1 is difficult to reach the heated object HO.

[0159] However, as shown in one embodiment of the present invention (i.e., as...) Figure 6As shown, when the skin depth of the first heating film coating TL1 is deeper than the thickness of the first heating film coating TL1, it can be seen that most of the magnetic field generated by the first working coil WC1 is transmitted to the heated object HO. That is, in one embodiment of the present invention, the skin depth of the first heating film coating TL1 is deeper than the thickness of the first heating film coating TL1, the magnetic field generated by the first working coil WC1 passes through the first heating film coating TL1, and most of it is consumed in the heated object HO, thereby enabling the heated object HO to be heated primarily.

[0160] On the other hand, as described above, the first heating thin film coating TL1 can have a thinner thickness and a resistance value that can be heated by the first working coil WC1.

[0161] Specifically, the thickness of the first heating thin film coating TL1 can be inversely proportional to the resistance value (i.e., surface resistance value) of the first heating module HM1. That is, the thinner the first heating thin film coating TL1, the greater its resistance value (i.e., surface resistance).

[0162] The first heating film coating TL1, which has the features described above, is used to heat a non-magnetic body. The impedance characteristics between the first heating film coating TL1 and the heated object HO can be changed depending on whether the heated object HO, which is disposed on the top surface of the upper plate portion 15, is a magnetic body or a non-magnetic body.

[0163] First, the following explanation applies to the case where the object being heated is a magnetic material.

[0164] Reference Figure 3 and Figure 8 When a magnetic heated object HO is disposed on the top surface of the upper plate 15 and the first working coil WC1 is driven, the resistance component R1 and inductance component L1 of the magnetic heated object HO can form an equivalent circuit with the resistance component R2 and inductance component L2 of the first heating module HM1.

[0165] In this case, in the equivalent circuit, the impedance of the heated object with magnetism (i.e., the impedance formed by R1 and L1) can be less than the impedance of the first heating thin film coating TL1 (i.e., the impedance formed by R2 and L2).

[0166] Therefore, when the aforementioned equivalent circuit is formed, the magnitude of the eddy current I1 applied to the magnetic heated object HO can be greater than the magnitude of the eddy current I2 applied to the first heating thin film coating TL1. More specifically, most of the eddy current can be applied to the heated object HO and heat the heated object HO.

[0167] That is, when the object being heated HO is a magnetic body, the aforementioned equivalent circuit can be formed, and most of the eddy current can be applied to the object being heated HO, so that the first working coil WC1 can directly heat the object being heated HO.

[0168] Of course, a portion of the eddy current can also be applied to the first heating film coating TL1, so that the first heating film coating TL1 can be slightly heated, and thus the heated object HO can be indirectly and slightly heated by the first heating film coating TL1. However, the degree to which the heated object HO is indirectly heated by the first heating film coating TL1 is meaningless compared to the degree to which the heated object HO is directly heated by the first working coil WC1.

[0169] Conversely, the following explanation applies to the case where the object being heated is a non-magnetic body.

[0170] Reference Figure 3 and Figure 9 When a non-magnetic heated object HO is disposed on the top surface of the upper plate 15 and the first working coil WC1 is driven, there is no impedance in the non-magnetic heated object HO, but impedance may exist in the first heating thin film coating TL1. That is, only the first heating thin film coating TL1 contains the resistive component R and the inductive component L.

[0171] Therefore, eddy current I can be applied only to the first heating film coating TL1, without applying eddy current to the non-magnetic heated object HO. More specifically, eddy current I is applied only to the first heating film coating TL1, thereby heating the first heating film coating TL1.

[0172] That is, as described above, when the heated object HO is a non-magnetic body, the eddy current I can be applied to the first heating film coating TL1 and heat the first heating film coating TL1, and the non-magnetic heated object HO can be indirectly heated through the first heating film coating TL1 heated by the first working coil WC1.

[0173] For reference, the protection temperature of the upper plate 15 can be preset by the upper plate manufacturer or the cooktop manufacturer. That is, if the upper plate manufacturer transmits information about the lifespan of the upper plate as the temperature changes to the cooktop manufacturer, the cooktop manufacturer will calculate the product lifespan based on the cooktop's usage time and set the protection temperature of the upper plate 15.

[0174] In addition, a temperature sensor can be installed in a region of the upper plate 15 to sense temperature changes in the upper plate 15, and the sensed temperature information can be provided to the aforementioned control module.

[0175] In summary, regardless of whether the object HO to be heated is magnetic or non-magnetic, it can be heated directly or indirectly through a heat source called the first working coil WC1. That is, when the object HO is magnetic, the first working coil WC1 can directly heat the object HO; when the object HO is non-magnetic, the first heating film coating TL1, heated by the first working coil WC1, can indirectly heat the object HO.

[0176] As described above, the induction heating stove 1 of one embodiment of the present invention can heat both magnetic and non-magnetic objects, and can heat any object regardless of its placement or type. Therefore, users do not need to determine whether the object to be heated is magnetic or non-magnetic, and can place the object in any heating area on the upper plate, thereby improving ease of use.

[0177] Furthermore, the induction heating stove 1 of one embodiment of the present invention can directly or indirectly heat the object being heated using the same heat source, without the need for an additional heating plate or radiant heater. This not only improves heating efficiency but also reduces material costs.

[0178] The following describes a stove using an induction heating method according to another embodiment of the present invention.

[0179] Figure 10 This is a diagram illustrating a stove using an induction heating method according to another embodiment of the present invention. Figure 11 This indicates that it is set in Figure 10 The diagram shows the internal components of the casing of a stove using induction heating. Figure 12 This means that in Figure 10 The diagram shows the state of the object being heated in a stove using induction heating.

[0180] For reference, apart from some constituent elements and effects, another embodiment of the induction heating stove 2 of the present invention and Figure 1 Since the induction heating method of the stove is the same as that of appliance 1, the explanation will focus on the differences.

[0181] Reference Figure 10 and Figure 11 Another embodiment of the present invention includes a stove 2 using induction heating. Figure 1 Unlike induction heating stoves, this type of stove can be a zone-free stove.

[0182] Specifically, the induction heating stove 2 may include a housing 25, a cover plate 20, a plurality of heating film coatings TLG, a heat insulation element 35, a plurality of working coils WCG, a shielding plate 45, a support member 50, a cooling fan (not shown), a partition (not shown), and a control module (not shown).

[0183] Here, a plurality of heating thin film coatings (TLGs) and a plurality of working coils (WCGs) can overlap each other in the longitudinal direction and can be configured in a one-to-one correspondence.

[0184] Of course, in addition to a one-to-one correspondence, a plurality of heating thin film coatings (TLGs) and a plurality of working coils (WCGs) can also be configured as many-to-one or one-to-many. However, for ease of explanation, in another embodiment of the present invention, the case in which a plurality of heating thin film coatings (TLGs) and a plurality of working coils (WCGs) are configured as one-to-one correspondence will be used as an example for explanation.

[0185] The induction heating cooker 2 is a zoneless cooker comprising a plurality of heating film coatings (TLGs) and a plurality of working coils (WCGs). Therefore, in the cooker 2 of the present invention, a single object HO can be heated simultaneously using some or all of the plurality of working coils (WCGs), or a single object HO can be heated simultaneously using some or all of the plurality of heating film coatings (TLGs). Alternatively, the object HO can be heated using both some or all of the plurality of working coils (WCGs) and some or all of the plurality of heating film coatings (TLGs).

[0186] Therefore, as Figure 10 As shown, in a complex number of working coils ( Figure 8 Within the WCG and multiple heating film coating TLG regions (e.g., region 15 of the upper plate), the heated objects HO1 and HO2 can be heated regardless of their size, position, or type.

[0187] Example

[0188] The following description, through preferred embodiments of the present invention, will illustrate the structure and function of the invention in more detail. However, this is merely shown as a preferred example of the invention and should not be construed as limiting the invention in any way.

[0189] For any content not described in this specification, those skilled in the art can fully deduce it from the technical details, therefore, its description is omitted.

[0190] 1. Manufacturing of circuit boards for household appliances

[0191] (1) Example

[0192] A ceramic-glass substrate is prepared, and an adhesive layer, a color layer, and a protective layer are sequentially laminated on it to form a color-coated laminate. The adhesive layer, color layer, and protective layer are formed with the thickness, composition, and content shown in Table 1 below.

[0193] [Table 1]

[0194]

[0195] The colored coating laminate is formed by screen printing. An adhesive paste is applied to one surface of the substrate to form an adhesive layer. Without additional curing of the adhesive layer, a colored paste is applied directly onto the adhesive layer to form a colored layer. The colored layer is then formed by drying at approximately 200°C for 10 minutes followed by curing at 400°C for 20 minutes. Finally, a protective paste is applied onto the colored layer to form a protective layer.

[0196] (2) Comparative Examples

[0197] In the embodiment described, the antioxidant (tris(2,4-di-tert-butylphenyl)phosphate) used in the color layer was removed to manufacture a comparative example of a substrate for household appliances.

[0198] 2. Evaluation of the physical properties of substrates used in household appliances

[0199] (1) Color change evaluation

[0200] The substrates of the embodiments and comparative examples were placed in a high-temperature furnace at 400°C and left for 168 hours to evaluate whether they changed color.

[0201] Color change is evaluated using the color difference measurement method (CIE Lab).

[0202] Measurement equipment: Spectrophotometer (Manufacturer: Konica Minolta, Model: CM-700d)

[0203] Measurement method: After measuring the CIE Lab values ​​before and after the heat resistance evaluation, calculate ΔE(√ΔL). 2 +△a 2 +△b 2 ).

[0204] The L value ranges from 0 (black) to 100 (white), the a value ranges from + (red) to 0 (gray) to - (green), and the b value ranges from + (yellow) to 0 (gray) to - (blue), displayed in three dimensions. Color difference (△E) is measured by the distance between two points.

[0205] Reference Figure 13 Based on 168 hours, the color difference of the comparative example exceeded 3, but the color difference of the example was comparable to 2, thus reducing the degree of color change.

[0206] (2) Durability evaluation

[0207] Reference Figure 14 Based on 400°C and 168 hours, it can be confirmed by visual observation in the comparative example that the coating was peeled off, but no peeling occurred in the example.

[0208] As described above, although the invention has been illustrated with reference to the accompanying drawings, the invention is not limited to the embodiments and drawings disclosed in this specification, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the technical concept of the invention. Furthermore, even if the effects of the configuration of the invention are not explicitly stated or explained in the preceding description of the embodiments of the invention, the predictable effects of such configuration should be readily accepted.

Claims

1. A substrate for household appliances, wherein, A colored coating laminate is coated on one surface. The color-coated laminate includes: An adhesive layer that contacts the surface of the substrate; A colored layer is located on top of the adhesive layer; and A protective layer is located on top of the colored layer.

2. The substrate for household appliances according to claim 1, wherein, The colored layer is formed from a colored layer slurry coating liquid comprising phenyl-based polysiloxanes and phosphite-based antioxidants.

3. The substrate for household appliances according to claim 2, wherein, The colored layer slurry coating liquid also includes effect pigments composed of a substrate coated with metal oxides.

4. The substrate for household appliances according to claim 3, wherein, The colored layer slurry coating liquid includes: The phenyl-based polysiloxane, 30-60% by weight; The antioxidant is present in an amount of 0.01–1% by weight. The effect pigment, 8-20% by weight; Colored inorganic pigments, 1–10% by weight; and Solvent, 10-60% by weight.

5. The substrate for household appliances according to claim 1, wherein, The adhesive layer is formed from an adhesive slurry coating liquid comprising methyl-based polysiloxanes.

6. The substrate for household appliances according to claim 5, wherein, The adhesive layer slurry coating liquid comprises: The methyl-based polysiloxane, 30-70% by weight; and Solvent, 30-70% by weight.

7. The substrate for household appliances according to claim 1, wherein, The protective layer is formed from a protective layer slurry coating liquid comprising inorganic materials or silica sol-gel.

8. The substrate for household appliances according to claim 1, wherein, The thickness of the adhesive layer is 1–10 μm. The thickness of the colored layer is 30–100 μm. The thickness of the protective layer is 1–10 μm.

9. The substrate for household appliances according to claim 1, wherein, The substrate comprises a ceramic glass material.

10. A stove using induction heating, wherein, include: case; A cover plate is attached to the upper end of the housing and has an upper plate portion on which the object to be heated is disposed on the top surface; A working coil is disposed inside the housing to heat the object being heated; A heat insulation component is disposed on the upper part of the working coil; as well as A heating film coating is disposed on one side of the upper plate or one side of the heat insulation member, and has a stacked structure in which an adhesive layer and a heating layer are stacked in sequence; The upper plate uses the substrate for household appliances as described in claim 1.

Images