Substrate for home appliances and induction heating type cooktop comprising same

Abstract

The present invention relates to a novel substrate for home appliances that secures high heat resistance and anti-discoloration performance. Specifically, the substrate for home appliances is characterized in that a color coating laminate is coated on one surface, and the color coating laminate comprises a color / adhesive layer in contact with the surface of the substrate and a protective layer on top of the color / adhesive layer.

Description

Technology Field

[0001] The present invention relates to a substrate for home appliances and an induction heating type cooktop including the same. Background Technology

[0003] Various types of cooking appliances are used to heat food in homes and restaurants. Traditionally, gas ranges using gas as fuel have been widely used; however, recently, devices that heat objects using electricity instead of gas—such as cooking vessels like pots—are becoming more popular.

[0004] Methods of heating an object using electricity are broadly divided into resistance heating and induction heating. The electric resistance method heats an object by transferring heat generated when an electric current is passed through a metal resistance wire or a non-metallic heating element, such as silicon carbide, to the object (e.g., a cooking vessel) through radiation or conduction. The induction heating method, on the other hand, is a method in which an eddy current is generated in an object made of metal components by utilizing the magnetic field generated around a coil when high-frequency power of a predetermined magnitude is applied to the coil, thereby heating the object itself.

[0005] Recently, induction heating methods are mostly applied to cooktops.

[0007] Generally, a ceramic glass material with excellent heat resistance is used for the upper part of the cooktop.

[0008] The ceramic glass applied to the cooktop must have sufficiently low transparency so that the heating elements at the bottom are not visible, and must be able to withstand localized high temperatures during the cooking process.

[0009] Conventionally, methods have been adopted to color ceramic glass or to impart color to colorless transparent ceramic glass using single-layer or multi-layer coatings.

[0010] The above coating can be applied in various ways. First, the coating can utilize a deposition method. However, the deposition method involves high process costs and offers limited freedom in color. Additionally, coatings produced by the deposition method are thin, resulting in low opacity. Second, the coating can utilize an enamel coating method. While enamel coatings allow for high-temperature use, defects such as cracks may occur due to the significant difference in the coefficient of thermal expansion between the enamel coating and the ceramic glass. Third, the coating can utilize a fluoropolymer coating. However, the use of fluoropolymer coatings is restricted due to regulations on perfluorinated compounds. Fourth, the coating can utilize a silicone coating. Although silicone materials offer excellent durability at high temperatures, applying the silicone coating to ceramic glass for cooktops may result in peeling or discoloration of the coating. The problem to be solved

[0012] To solve the aforementioned technical problem, the present invention aims to provide a novel substrate for home appliances that secures color freedom while reducing costs.

[0013] In addition, the present invention aims to provide a novel substrate for home appliances that secures high heat resistance and anti-discoloration performance.

[0014] In addition, the present invention aims to provide a novel substrate for home appliances that can ensure long-term reliability even in high-temperature environments.

[0015] The objects of the present invention are not limited to those mentioned above, and other unmentioned objects and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0017] A substrate for home appliances according to the present invention has a color coating laminate comprising a color / adhesive layer and a protective layer coated on one surface. Accordingly, the present invention can provide a substrate for home appliances that secures freedom of color while reducing costs. In addition, the substrate for home appliances according to the present invention has excellent heat resistance and anti-discoloration performance.

[0018] Specifically, the substrate for a home appliance according to the present invention is a substrate for a home appliance having a color coating laminate coated on one surface, wherein the color coating laminate comprises a color / adhesive layer located in contact with the surface of the substrate and a protective layer located on top of the color / adhesive layer.

[0019] Here, the color / adhesive layer may be formed from a color / adhesive layer paste coating solution comprising glass frit, inorganic pigment, and inorganic filler.

[0020] Preferably, the color / adhesive layer paste coating liquid may comprise 5 to 70 weight% of the glass frit, 5 to 70 weight% of the inorganic pigment, and 10 to 60 weight% of the inorganic filler.

[0021] Also preferably, the inorganic filler is Li (1-x) Al (1-x) Si (1+x) It may include O4 (where x satisfies 0 ≤ x ≤ 0.42).

[0023] In addition, an induction heating type cooktop according to another embodiment of the present invention includes a working coil for heating magnetic materials and a heating thin film coating for heating non-magnetic materials, thereby being able to heat both magnetic and non-magnetic materials.

[0024] The induction heating type cooktop according to the present invention includes a working coil and a heating thin film coating that are provided to overlap each other in the vertical direction, wherein the heating thin film coating has a laminated structure in which an adhesive layer and a heating layer are sequentially laminated, and has at least one characteristic among magnetic and non-magnetic properties, so that eddy currents are induced by the working coil to induce heating.

[0025] In addition, since the skin depth of the heating thin film coating is deeper than the thickness of the heating thin film coating, when heating an object made of a magnetic material, the magnetic field generated by the working coil passes through the thin film and is transmitted to the object being heated, and as a result, eddy currents can be induced in the object being heated.

[0026] In addition, when heating an object made of a non-magnetic material, eddy currents may be induced in the heating thin film coating due to the magnetic field generated by the working coil.

[0027] This allows the object to be heated directly or indirectly using the same heat source.

[0028] In addition, the induction heating type cooktop of the present invention has the aforementioned substrate for home appliances applied as a top plate. Accordingly, the cooktop of the present invention has long-lasting durability and reliability. Effects of the invention

[0030] The present invention can provide a novel substrate for home appliances that secures color freedom while reducing costs.

[0031] In addition, the present invention can provide a novel substrate for home appliances that secures high heat resistance and anti-discoloration performance.

[0032] In addition, the present invention can provide a novel substrate for home appliances that can ensure long-term reliability even in high-temperature environments.

[0033] In addition, the induction heating cooktop according to the present invention can heat both magnetic and non-magnetic materials. Furthermore, the induction heating cooktop according to the present invention can heat an object regardless of the placement location and type of the object to be heated. Accordingly, the user can place the object to be heated on any heating area on the top plate and heat it without needing to determine whether the object to be heated is magnetic or non-magnetic.

[0034] In addition, since the induction heating cooktop according to the present invention can heat an object to be heated directly or indirectly using the same heat source, there is no need to provide a separate heating plate or radiant heater. Accordingly, the present invention can not only increase heating efficiency but also reduce material costs.

[0035] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0037] FIG. 1 is a cross-sectional view of a substrate for a home appliance according to one embodiment of the present invention. FIG. 2 is a drawing illustrating an induction heating type cooktop according to one embodiment of the present invention. Figure 3 is a drawing illustrating the components provided inside the case of the induction heating type cooktop shown in Figure 2. FIGS. 4 and FIGS. 5 are drawings illustrating embodiments of a heated thin film coating according to the present invention. Figures 6 and 7 are drawings illustrating the relationship between the thickness of the heating module and the skin depth. Figures 8 and 9 are drawings illustrating the change in impedance between the heated thin film coating and the heated object depending on the type of heated object. FIG. 10 is a drawing illustrating an induction heating type cooktop according to another embodiment of the present invention. FIG. 11 is a drawing describing the components provided inside the case of the induction heating type cooktop shown in FIG. 10. FIG. 12 is a drawing illustrating the arrangement of a heated object on an induction heating cooktop shown in FIG. 10. Figure 13 is a graph evaluating the heat resistance of the example and the comparative example. Specific details for implementing the invention

[0038] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0039] In the following, the statement that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0040] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0042] Hereinafter, a substrate for an excitation device according to one embodiment of the present invention will be described.

[0044] FIG. 1 is a cross-sectional view of a substrate for a home appliance according to one embodiment of the present invention.

[0045] First, referring to FIG. 1, a substrate (15) for a home appliance according to one embodiment of the present invention refers to a substrate (10) having a color coating laminate (11, 12) coated on one surface. Here, the color coating laminate includes a color / adhesive layer (11) in contact with the surface of the substrate (10) and a protective layer (12) located on top of the color / adhesive layer (11).

[0047] The substrate (15) for home appliances of the present invention includes the color coating laminate and can express various colors, and also has excellent reliability even when exposed to high temperatures for a long period of time.

[0048] First, the above substrate can be any known substrate used for home appliances, but most preferably, a substrate made of ceramic glass material can be used.

[0050] The above color coating laminate includes a color / adhesive layer (11). The color / adhesive layer (11) refers to a layer that has adhesive properties to be able to come into contact with the surface of the substrate and can also impart color to the substrate.

[0051] The above color / adhesive layer (11) may be formed from a color / adhesive layer paste coating liquid comprising glass frit, inorganic pigment, and inorganic filler.

[0052] Here, the color / adhesive layer paste coating liquid may comprise 5 to 70 weight% of the glass frit, 5 to 70 weight% of the inorganic pigment, and 10 to 60 weight% of the inorganic filler.

[0053] At this time, the color / adhesive layer paste coating solution may additionally include a solvent and a binder for coating workability.

[0054] One or more of the above solvents may be used, including Xylene, Ethylbenzene, Toluene, benzene, IPA (Isopropyl alcohol), and BCA (butyl carbitol acetate).

[0055] In addition, the above binder may be cellulose, etc.

[0057] The above glass frit is used to improve the adhesion and heat resistance of the coating. While known glass frits used in the industry may be used, preferably, a glass frit with a coefficient of thermal expansion of 50 to 110 x 10⁻⁶ -7 It may include glass frit with a softening point of 300 to 600 ℃ and a temperature of / ℃.

[0058] The glass frit may include silicate-based glass compositions, phosphate-based glass compositions, etc., and as a specific example, the glass frit may include Bi2O3, B2O3, SiO2, BaO, ZrO2, P2O5.

[0059] The above color / adhesive layer paste coating liquid may contain 5 to 70 weight percent of the glass frit.

[0060] If the above glass frit is less than 5 weight%, sufficient adhesion to the color / adhesive layer is not secured to the substrate, and heat resistance may also be reduced. In addition, if the above glass frit exceeds 70 weight%, cracks may occur in the coating.

[0062] The above inorganic pigment is used to express color on a substrate. Among the above inorganic pigments, one or more oxides of Fe, Al, Mn, Ni, Ti, Mo, Si, Mg, Co, Sn, and Zr may be used.

[0063] Preferably, the inorganic pigment may be used in an amount of 5 to 70 weight percent. If the inorganic pigment is less than 5 weight percent, color expression may be insufficient and the heat resistance of the coating may be reduced. In addition, if the inorganic pigment exceeds 70 weight percent, the coating's formability and adhesion may be reduced and difficulty in color adjustment may occur.

[0065] The above inorganic filler is used to improve the physical properties of the color / adhesive layer. One or more of various known inorganic materials may be used as the above inorganic filler.

[0066] As a specific example, the above-mentioned inorganic filler is (Mg,Fe)2Al4Si5O 18 , LiAl(SiO3)2, Li (1-x) Al (1-x) Si (1+x) O4, Be3Al2Si6O 18 It may include one or more of , NaZr2(PO4)3, CaZr4(PO4)6, Nb2O5, Al2TiO5, Zr2P2O9, TiO2, Fe2O3 and Al2O3.

[0067] Preferably, the inorganic filler is Li capable of improving all physical properties of the color / adhesive layer, such as adhesion, heat resistance, and transmittance. (1-x) Al (1-x) Si (1+x) It may include O4 (where x satisfies 0 ≤ x ≤ 0.42). More preferably, x may satisfy 0.1 ≤ x ≤ 0.42.

[0068] The color / adhesive layer of the present invention uses Li as an inorganic filler. (1-x) Al (1-x) Si (1+x) By including O4, the color / adhesive layer exhibits excellent adhesion, heat resistance, and transmittance across a wide thickness range.

[0069] Here, if x exceeds 0.42, a crystalline phase may be formed in the color / adhesive layer and heat resistance may be reduced.

[0070] The above Li (1-x) Al (1-x) Si (1+x) Inorganic fillers containing O4 can be manufactured by preparing raw materials according to their composition, ball-milling them to mix them thoroughly, and then synthesizing them at 1000 to 1800 ℃ for 1 to 96 hours in an atmospheric pressure atmosphere.

[0071] One or more of the above-mentioned inorganic fillers may be used according to the intended use, and the content is preferably 10 to 60 weight %. If the above-mentioned inorganic filler is less than 10 weight %, cracks may occur in the coating. If the above-mentioned inorganic filler exceeds 60 weight %, the adhesion of the coating may be reduced and the color may be affected.

[0073] Next, the color coating laminate includes a protective layer (12). The protective layer (12) is configured to protect the color / adhesive layer (11). Specifically, the protective layer (12) prevents scratches on the laminate and minimizes oxygen exposure. The protective layer (12) is located on top of the color / adhesive layer (11).

[0074] The above protective layer (12) may be formed from a protective layer paste coating solution containing an inorganic material. The above inorganic material may include a glass frit-based inorganic coating. Specifically, the above inorganic material may be V2O5, P2O5, B2O3, Bi2O3, ZnO, SiO3, B2O3, Al2O3, Al(OH)3, TiO2, CaCO3, CaO, Ca(OH)2, Ba S One or more of O4, ZnO, glass fiber, and talc may be used.

[0075] At this time, the protective layer paste coating solution may additionally include a solvent and a binder for coating workability.

[0076] One or more of the above solvents may be used, including Xylene, Ethylbenzene, Toluene, benzene, IPA (Isopropyl alcohol), and BCA (butyl carbitol acetate).

[0077] In addition, the above binder may be cellulose, etc.

[0079] The thickness of the color / adhesive layer (11) may be 5 to 150 μm, and preferably 30 to 120 μm. If the thickness of the color / adhesive layer (11) is less than 5 μm, the color may not be expressed and there may be limitations in implementing the opacity. In addition, if the thickness of the color / adhesive layer (11) exceeds 150 μm, cracks may occur.

[0080] The thickness of the protective layer (12) may be 0.1 to 50 μm, and preferably 10 to 40 μm. If the thickness of the protective layer (12) is less than 0.1 μm, the ability to protect the color / adhesive layer (11) from contaminants may be reduced, and if the thickness of the protective layer (12) exceeds 50 μm, cracks may occur.

[0082] The above color coating laminate can preferably be formed by a screen printing method. A color / adhesive layer (11) can be formed by coating the above-described color / adhesive layer paste coating liquid on one surface of the substrate (10). At this time, the color / adhesive layer (11) can be formed through a drying process at approximately 100 to 250°C for 1 to 30 minutes followed by a firing process at 550 to 850°C for 3 to 30 minutes. After that, a protective layer (12) can be formed by coating the protective layer paste coating liquid on top of the color / adhesive layer (11). The protective layer (12) can be formed in the same manner as the color / adhesive layer (11).

[0084] Next, an induction heating type cooktop according to one embodiment of the present invention will be described below.

[0086] FIG. 2 is a drawing illustrating an induction heating type cooktop according to an embodiment of the present invention. FIG. 3 is a drawing illustrating a component provided inside the case of the induction heating type cooktop shown in FIG. 2. FIG. 4 and FIG. 5 are drawings illustrating embodiments of a heating thin film coating according to the present invention. FIG. 6 and FIG. 7 are drawings illustrating skin depth characteristics according to the relative permeability of the thin film. FIG. 8 and FIG. 9 are drawings illustrating the change in impedance between the thin film and the object to be heated according to the type of object to be heated.

[0088] First, referring to FIG. 2, an induction heating type cooktop (1) according to one embodiment of the present invention may include a case (25), a cover plate (20), working coils (WC1, WC2; i.e., first and second working coils), and heating thin film coatings (TL1, TL2; i.e., first and second heating thin film coatings).

[0089] Working coils (WC1, WC2) can be installed in the case (25).

[0090] For reference, in addition to the working coils (WC1, WC2), the case (25) may be equipped with various devices related to the operation of the working coils (e.g., a power supply unit that provides AC power, a rectifier unit that rectifies the AC power of the power supply unit into DC power, an inverter unit that converts the DC power rectified by the rectifier unit into a resonant current through a switching operation and provides it to the working coil, a control module that controls the operation of various devices within the induction heating type cooktop (1) (the control module includes a control module for the inverter that controls the switching operation of the inverter unit and a control module for the input interface that controls the input interface), a relay or a semiconductor switch that turns on or off the working coils, etc.), but a detailed description thereof will be omitted.

[0091] A cover plate (20) is coupled to the top of a case (25), and a top plate (15) on which a heated object (not shown) is placed on the top surface may be provided. Here, the top plate (15) is provided with the substrate for the home appliance described above. At this time, the surface coated with a color coating laminate may be located at the bottom.

[0092] Specifically, the cover plate (20) may include a top plate (15) for placing a heating object, such as a cooking vessel.

[0093] Here, the top plate (15) may be made of, for example, a glass material (for example, ceramic glass).

[0094] Additionally, the top plate (15) may be provided with an input interface (not shown) that receives input from a user and transmits the input to the aforementioned control module. Of course, the input interface may be provided at a location other than the top plate (15).

[0095] For reference, the input interface is a module for inputting the desired heating intensity or the operating time of the induction heating cooktop (1) and can be implemented in various ways, such as physical buttons or touch panels. In addition, the input interface may be equipped with, for example, a power button, a lock button, power level control buttons (+, -), timer control buttons (+, -), and a charging mode button. Furthermore, the input interface transmits the input received from the user to a control module for the input interface (not shown), and the control module for the input interface transmits the said input to a control module for the inverter (not shown). In addition, the control module for the inverter can control the operation of various devices (e.g., a working coil) based on the input received from the control module for the input interface (i.e., user input), and specific details regarding this are omitted.

[0096] Meanwhile, on the top plate (15), whether the working coil (e.g., the first and second working coils (WC1, WC2)) is driven and the heating intensity (i.e., heat power) can be visually displayed in the shape of a fireball. This fireball shape can be displayed by an indicator (not shown) composed of a plurality of light-emitting elements (e.g., LEDs) provided within the case (25).

[0097] The first and second working coils (WC1, WC2) can be installed inside the case (25) to heat the object to be heated.

[0098] Specifically, the first and second working coils (WC1, WC2) can be driven by a control module for an inverter, and when a heated object is placed on the upper plate (15), it can be driven by a control module for an inverter.

[0099] In addition, the first and second working coils (WC1, WC2) can directly heat a magnetic object to be heated (i.e., a magnetic material) and can indirectly heat a non-magnetic object to be heated (i.e., a non-magnetic material) through the first and second heating thin film coatings (TL1, TL2) described later.

[0100] And the first and second working coils (WC1, WC2) can heat the object to be heated by an induction heating method and can be provided to overlap the first and second heating thin film coatings (TL1, TL2) in the vertical direction (i.e., vertical direction or up and down direction), respectively.

[0101] For reference, FIG. 2 is illustrated as having two working coils (WC1, WC2) installed in the case (25), but it is not limited thereto. That is, one or three or more working coils may be installed in the case (25), but for convenience of explanation, in one embodiment of the present invention, two working coils (WC1, WC2) installed in the case (25) will be described as an example.

[0102] The heating thin film coating may include a first and second heating thin film coating (TL1, TL2). The heating thin film coating is provided on either side of the top plate or on either side of the insulating material. In other words, the heating thin film coating may be formed on the upper or lower surface of the top plate, or on the upper or lower surface of the insulating material.

[0103] As an example, the first and second heating thin film coatings (TL1, TL2) may each be provided on the lower surface of the top plate (15) spaced apart from each other.

[0104] And the first and second heating thin film coatings (TL1, TL2) may be provided to overlap the first and second working coils (WC1, WC2) in the longitudinal direction (i.e., vertical direction or up and down direction), respectively.

[0105] In addition, the first and second heated thin film coatings (TL1, TL2) may have at least one of magnetic and non-magnetic properties (i.e., magnetic, non-magnetic, or both magnetic and non-magnetic).

[0107] As shown in FIG. 4, the heating thin film coating (TL1) according to the present invention has a stacked structure in which an adhesive layer (TLA1) and a heating layer (TLH1) are sequentially stacked.

[0109] The adhesive layer (TLA1) is configured to bond the top plate or the insulation material with the heating layer (THL1). Additionally, the adhesive layer (TLA1) protects the heating layer (TLH1) from ion leaching of the top plate caused by long-term high-temperature application and prevents performance degradation of the heating layer (TLH1).

[0110] The adhesive layer (TLA1) may include one or more of inorganic materials and metal oxides to achieve the above-described function. As a specific example, the adhesive layer (TLA1) may include transition metals such as Ti, Cr, Fe, Ni, and Cu, or metal oxides such as Al2O3 and SiO2.

[0111] Preferably, the adhesive layer (TLA1) may be formed by coating an adhesive layer paste coating solution comprising one or more of an inorganic material and a metal oxide. More specifically, the adhesive layer paste coating solution may comprise 60 to 85 weight% of one or more of the inorganic material and the metal oxide, 5 to 25 weight% of a binder resin, 5 to 25 weight% of a solvent, and 0.5 to 5 weight% of an inorganic filler. Additionally, the adhesive layer paste coating solution may further comprise additives such as a leveling agent, an antifoaming agent, and a dispersing agent as needed.

[0112] Among the above inorganic materials and metal oxides, one or more may be used from among V2O5, P2O5, PbO, B2O3, Bi2O3, ZnO, SiO3, B2O3, Al2O3, BaO, MoO3, TeO2, Ta2O5, Nb2O5, and CaO. The above inorganic materials and metal oxides are used in the form of particles, and particles of any shape, such as spherical, plate-shaped, or amorphous, may be used. The softening point of the above materials may satisfy the range of 400 to 800°C, and the crystallization temperature (Tc) may satisfy the range of 450 to 850°C. The size of the above particles may be 1 µm to 5 µm. If one or more of the above inorganic materials and metal oxides are contained in an amount of less than 60 weight%, the protective ability against the heating layer may be reduced. On the other hand, if one or more of the above inorganic materials and metal oxides exceed 85 weight percent, work performance may be reduced and may cause cracks.

[0113] In addition, the binder resin forms a three-dimensional chain structure by fixing one or more of the inorganic materials and metal oxides. Furthermore, the binder resin affects the formation of a uniform coating film and influences durability, chemical resistance, and adhesion to the substrate. If the binder is not completely thermally decomposed during the firing process, it may form pores or remain in the electrode, which can increase the resistivity of the thin film. It is preferable to use polyurethane, polyester, polyacrylic, polycellulose, etc., as the binder resin, which has a thermal decomposition temperature within 100 to 300°C and a molecular weight within the range of 2,000 to 2,000,000. If the binder resin content is less than 5 weight%, the viscosity is low, making it difficult to form a uniform coating film and potentially increasing resistivity; if it exceeds 25 weight%, the coating workability may decrease.

[0114] The above solvent can improve the coating properties and workability of the coating solution. The thermal decomposition temperature of the solvent is preferably within 50 to 200°C, and may include one or more from the group consisting of butyl cellosolve, ethylene glycol monobutyl ether acetate, ethyl cavitol, ethyl cavitol acetate, butyl cavitol, ethoxyethyl acetate, butyl acetate, propylene glycol monotyl ether, ethyl alcohol, butyl alcohol, etc. As described above, the content of the solvent is preferably 5 to 25 weight%.

[0115] The above-mentioned inorganic filler is an additive used to improve the physical properties of the coating. The above-mentioned inorganic filler may be Al2O3, Al(OH)3, TiO2, CaCO3, CaO, Ca(OH)2, SiO2, BaSO4, ZnO, Glass Fiber, Talc, etc., which may be used in the present invention, and one or more types may be used depending on the purpose of use. The size of the above-mentioned inorganic filler may be 1㎛ to 5㎛, and the content is preferably 0.5 to 5 weight %.

[0116] In addition, the above additive may be used as a leveling agent, defoaming agent, dispersing agent, flow control agent, etc. to improve the dispersibility, storage stability, and coating performance of the coating, and preferably, silicone-based (polyether hydroxy polymethylsilane-based, polyether dimethylpolysiloxane-based, polymethylalkylsiloxane-based, polyether polymethylalkylsiloxane-based, polyester hydroxy polymethylsiloxane-based, polyether polymethylsiloxane-based), non-silicone-based (non-ionic polyacrylic-based, ionic polyacrylic-based, polyacrylate-based, alcohol alcohol silate-based, acrylate-based), alcohol-based (ethanol, butanol), etc. may be used. Preferably, 0.05 to 5 weight percent of the above additive may be added to the coating solution.

[0117] Although the thickness of the adhesive layer (TLA1) is not particularly limited, it is preferable to form it with 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 top plate, etc., may be reduced, and the protective performance against the heating layer may not be sufficient. On the other hand, if the thickness of the adhesive layer (TLA1) exceeds 10 μm, the induction heating function of the heating thin film coating (TLA1) may be reduced.

[0119] Next, the heating layer (TLH1) is configured to allow the cooktop according to the present invention to selectively heat a body to be heated.

[0120] The heating layer (TLH1) may include one or more materials among metals and metal alloys to achieve the above-described function. As a specific example, the heating layer (TLH1) may include one or more metals among Sn, Co, Cr, Fe, Ni, Al, Cu, Ag, and Au.

[0121] Preferably, the heating layer (TLH1) may be formed by coating a heating layer paste coating liquid comprising one or more of the metal and metal alloy. More specifically, the heating layer paste coating liquid may comprise 40 to 90 weight% of one or more of the metal and metal alloy, 2 to 25 weight% of a binder resin, 5 to 25 weight% of a solvent, 0.5 to 5 weight% of an inorganic material, and 0.5 to 5 weight% of an inorganic filler.

[0122] Among the above metals and metal alloys, one or more of Pd, Au, Pt, W, Ni, RuO2, Ag, and Cu may be used, and may be used in particle form. The particles may be spherical, plate-shaped, amorphous, etc., and it is preferable to select a shape that can increase the contact area between them. The size of the particles is preferably 0.5㎛ to 20㎛, and it is preferable to mix them in single or 2 to 4 sizes to increase the contact density between each particle. If one or more of the above metals and metal alloys is less than 40 weight%, the heating performance of the heating layer may be reduced, and if it exceeds 90 weight%, film flatness may be reduced, clumping may occur, and sinterability may be reduced during the coating process.

[0123] In addition, the binder resin fixes one or more of the metals and metal alloys to form a three-dimensional chain structure. Furthermore, the binder resin affects the formation of a uniform coating film and influences durability, chemical resistance, and adhesion to the substrate. If the binder is not completely thermally decomposed during the firing process, it may form pores or remain in the electrode, which can increase the resistivity of the thin film. It is preferable to use polyurethane, polyester, polyacrylic, polycellulose, etc., as the binder resin, which has a thermal decomposition temperature within 100 to 300°C and a molecular weight within the range of 2,000 to 2,000,000. If the binder resin content is less than 2 weight%, the viscosity is low, making it difficult to form a uniform coating film and potentially increasing resistivity; if it exceeds 25 weight%, the coating workability may decrease.

[0124] The above solvent can improve the coating properties and workability of the coating solution. The thermal decomposition temperature of the solvent is preferably within 50 to 200°C, and may include one or more from the group consisting of butyl cellosolve, ethylene glycol monobutyl ether acetate, ethyl cavitol, ethyl cavitol acetate, butyl cavitol, ethoxyethyl acetate, butyl acetate, propylene glycol monotyl ether, ethyl alcohol, butyl alcohol, etc. As described above, the content of the solvent is preferably 5 to 25 weight%.

[0125] The above inorganic material may be used to improve the adhesion of the heating layer. The above inorganic material may be one or more of V2O5, P2O5, PbO, B2O3, Bi2O3, ZnO, SiO2, B2O3, Al2O3, BaO, MoO3, TeO2, Ta2O5, Nb2O5, and CaO, and may be used in particle form. The particles may be spherical, plate-shaped, amorphous, etc., and may be used as a single material or in a mixture of 2 to 6 types. The softening point of the particles is preferably 400 to 700°C, and the crystallization temperature (Tc) is preferably 450 to 750°C. The size of the particles may be 1㎛ to 5㎛, and the content is preferably 0.1 to 5 weight %.

[0126] The above-mentioned inorganic filler is an additive used to improve the physical properties of the coating. The above-mentioned inorganic filler may be Al2O3, Al(OH)3, TiO2, CaCO3, CaO, Ca(OH)2, SiO2, BaSO4, ZnO, Glass Fiber, Talc, etc., which may be used in the present invention, and one or more types may be used depending on the purpose of use. The size of the above-mentioned inorganic filler may be 1㎛ to 5㎛, and the content is preferably 0.5 to 5 weight %.

[0127] In addition, the above additive may be used as a leveling agent, defoaming agent, dispersing agent, flow control agent, etc. to improve the dispersibility, storage stability, and coating performance of the coating, and preferably, silicone-based (polyether hydroxy polymethylsilane-based, polyether dimethylpolysiloxane-based, polymethylalkylsiloxane-based, polyether polymethylalkylsiloxane-based, polyester hydroxy polymethylsiloxane-based, polyether polymethylsiloxane-based), non-silicone-based (non-ionic polyacrylic-based, ionic polyacrylic-based, polyacrylate-based, alcohol alcohol silate-based, acrylate-based), alcohol-based (ethanol, butanol), etc. may be used. Preferably, 0.05 to 5 weight percent of the above additive may be added to the coating solution.

[0128] Although the thickness of the heating layer (TLH1) is not specifically limited, it is preferable to form it with a thickness of 1 μm to 60 μm. If the thickness of the heating layer (TLH1) is less than 1 μm, the selective heating function may be reduced. On the other hand, if the thickness of the heating layer (TLH1) exceeds 60 μm, a problem may arise in which the heating performance itself is reduced.

[0129] In addition, the heating layer (THL1) may, of course, be formed into one or more layers (not shown) as needed.

[0131] Next, referring to FIG. 5, the heating thin film coating (TL1) according to the present invention may further include a protective layer (TLP1). The heating thin film coating (TL1) according to the present invention may be formed on either one side of the top plate or the insulating material as described above. In particular, when the heating thin film coating (TL1) according to the present invention is formed on the upper surface of the top plate, it is preferable that the heating thin film coating (TLA1) further include the protective layer (TLP1) in order to protect the heating layer from the object to be heated. Accordingly, 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).

[0132] The protective layer (TLP1) may include one or more materials among inorganic materials and metal oxides to protect the heating layer (TLH1). As a specific example, the protective layer may include one or more oxides among SiO2, Al2O3, CeO, and MgO.

[0133] The above protective layer (TLP1) can be formed from the same paste coating liquid as the adhesive layer paste coating liquid.

[0134] Although the thickness of the protective layer (TLP1) is not particularly limited, it is preferable to form it with a thickness of 1 μm to 60 μm. If the thickness of the protective layer (TLP1) is less than 1 μm, the protective performance against the heating layer may not be sufficient. On the other hand, if the thickness of the protective layer (TLP1) exceeds 60 μm, the induction heating function of the heating thin film coating (TLA1) may be degraded.

[0136] The heated thin film coating (TL1) according to the present invention described above is preferably formed by paste coating. The coating method in the present invention is not particularly limited. The present invention may use one of gravure printing, spray printing, and screen printing.

[0138] When the above-mentioned heating thin film coating (TL1) is formed by a paste coating method, a thin film with uniform density can be obtained. Accordingly, the heating thin film coating (TL1) formed by the paste coating method has superior basic performance, such as heating performance, compared to a thin film formed by other methods.

[0139] The paste coating process according to the present invention may proceed in the order of washing, coating, drying, sintering, and cooling. An adhesive layer may be formed first on the surface of an object such as a top plate and an insulating material, and then a heating layer may be formed. In the present invention, it is preferable that sintering be performed in a temperature range of 400 to 900 ℃ to ensure conductivity of the heating coating thin film.

[0140] In addition, the paste coating liquid of each component constituting the heated thin film coating (TL1) is as described above.

[0142] The first and second heating thin film coatings (TL1, TL2) are formed with a thickness that can be inductively heated by a working coil, and specific details regarding this will be described later.

[0143] In addition, the diameter (i.e., size) of each of the first and second heated thin film coatings (TL1, TL2) may be smaller than the diameter of the top plate (15).

[0145] Next, referring to FIG. 3, an induction heating type cooktop (1) according to one embodiment of the present invention may further include an insulating material (35), a shielding plate (45), a support member (50), and a cooling fan (55).

[0146] For reference, the components placed around the first working coil (WC1) and the components placed around the second working coil (WC2 in FIG. 1) are identical. Therefore, for convenience of explanation, the components surrounding the first working coil (WC1) (first heating thin film coating (TL1), insulation material (35), shielding plate (45), support member (50), cooling fan (55)) will be described below with the first working coil (WC1) as the center.

[0147] The insulating material (35) can be provided between the first heating film coating (TL1) and the first working coil (WC1).

[0148] This insulating material (35) can block heat generated as the first heating film coating (TL1) or the object to be heated (HO) is heated by the driving of the first working coil (WC1) from being transferred to the first working coil (WC1).

[0149] That is, when the first heating thin film coating (TL1) or the object to be heated (HO) is heated by electromagnetic induction of the first working coil (WC1), the heat of the first heating thin film coating (TL1) or the object to be heated (HO) is transferred to the top plate (15), and the heat of the top plate (15) is transferred back to the first working coil (WC1), so that the first working coil (WC1) may be damaged.

[0150] In this way, the insulating material (35) can prevent the first working coil (WC1) from being damaged by heat by blocking the heat transferred to the first working coil (WC1), and furthermore, can prevent the heating performance of the first working coil (WC1) from deteriorating.

[0151] For reference, although not an essential component, a spacer (not shown) may be installed between the first working coil (WC1) and the insulation (35).

[0152] Specifically, a spacer can be inserted between the first working coil (WC1) and the insulating material (35) so that the first working coil (WC1) and the insulating material (35) do not come into direct contact. Accordingly, the spacer can block heat generated as the first heating film coating (TL1) or the object to be heated (HO) is heated by the operation of the first working coil (WC1) from being transferred to the first working coil (WC1) through the insulating material (35).

[0153] Since the above spacer can partially share the role of the insulation material (35), the thickness of the insulation material (35) can be minimized, and thereby the gap between the object to be heated (HO) and the first working coil (WC1) can be minimized.

[0154] Additionally, the above spacers may be provided in multiple numbers, and the multiple spacers may be arranged spaced apart from each other between the first working coil (WC1) and the insulation material (35). Accordingly, air sucked into the case (25) by the cooling fan (55) described later can be guided to the first working coil (WC1) by the spacers.

[0155] That is, the above spacer can improve the cooling efficiency of the first working coil (WC1) by guiding the air introduced into the case (25) by the cooling fan (55) to be properly delivered to the first working coil (WC1).

[0156] The shielding plate (45) is mounted on the lower surface of the first working coil (WC1) and can block the magnetic field generated downward when the first working coil (WC1) is driven.

[0157] Specifically, the shielding plate (45) can block the magnetic field generated downward when the first working coil (WC1) is driven, and can be supported upward by the support member (50).

[0158] The support member (50) is installed between the lower surface of the shielding plate (45) and the lower surface of the case (25) to support the shielding plate (45) upward.

[0159] Specifically, the support member (50) can indirectly support the first working coil (WC1), the insulating material (35), and the first heating thin film coating (TL1) upward by supporting the shielding plate (45) upward, thereby maintaining a constant distance between the first working coil (WC1) and the object to be heated (HO).

[0160] For reference, the support member (50) may include, for example, an elastic body (e.g., a spring) for supporting the shielding plate (45) upward, but is not limited thereto. Also, since the support member (50) is not an essential component, it may be omitted in the induction heating type cooktop (1).

[0161] A cooling fan (55) can be installed inside the case (25) to cool the first working coil (WC1).

[0162] Specifically, the cooling fan (55) can be driven by the aforementioned control module and can be installed on the side wall of the case (25). Of course, the cooling fan (55) may be installed at a location other than the side wall of the case (25), but in one embodiment of the present invention, for convenience of explanation, the cooling fan (55) is installed on the side wall of the case (25) as an example.

[0163] In addition, as shown in FIG. 2, the cooling fan (55) can draw in air from outside the case (25) and transfer it to the first working coil (WC1), or draw in air (especially heat) from inside the case (25) and discharge it to the outside of the case (25).

[0164] Through this, efficient cooling of the components inside the case (25) (especially the first working coil (WC1)) is possible.

[0165] In addition, as described above, the air outside the case (25) delivered to the first working coil (WC1) by the cooling fan (55) can be guided to the first working coil (WC1) by the spacer. Accordingly, direct and efficient cooling of the first working coil (WC1) becomes possible, thereby improving the durability of the first working coil (WC1) (i.e., improving durability by preventing thermal damage).

[0167] As such, an induction heating type cooktop (1) according to one embodiment of the present invention may have the aforementioned features and configuration. Hereinafter, the features and configuration of the aforementioned heating module will be explained in more detail with reference to FIGS. 6 to 9.

[0168] For reference, the thicknesses of each component shown in FIGS. 6 and FIGS. 7 are schematically represented for convenience of explanation and are unrelated to the actual scale, and the relative thickness differences between each component are also unrelated to the actual.

[0169] Figures 6 and 7 are diagrams illustrating the relationship between the thickness of the thin film and the skin depth. Figures 8 and 9 are diagrams illustrating the change in impedance between the thin film and the heated object depending on the type of heated object.

[0170] For reference, the first heated thin film coating (TL1) and the second heated thin film coating (TL2) have the same technical characteristics. For convenience of explanation, the first heated thin film coating (TL1) will be used as an example for the following description.

[0171] The characteristics of the first heated thin film coating (TL1) are as follows.

[0172] The first heated thin film coating (TL1) may be made of a material having low relative permeability, and the specific material is as described above.

[0173] Specifically, the relative permeability of the first heating thin film coating (TL1) may be low, and the skin depth of the first heating thin film coating (TL1) may be deep. Here, skin depth refers to the depth of current penetration from the surface of the material, and the relative permeability may be inversely proportional to the skin depth. Accordingly, 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).

[0174] In addition, the skin depth of the first heating thin film coating (TL1) may be deeper than the thickness of the first heating thin film coating (TL1). That is, since the first heating thin film coating (TL1) has a thin thickness and the skin depth of the first heating thin film coating (TL1) is deeper than the thickness of the first heating thin film coating (TL1), the magnetic field generated by the first working coil (WC1) passes through the first heating thin film coating (TL1) and is transmitted to the object to be heated (HO), thereby inducing an eddy current in the object to be heated (HO).

[0176] That is, as shown in FIG. 6, if the skin depth of the first heating thin film coating (TL1) is shallower than the thickness of the first heating thin film coating (TL1), it can be seen that the magnetic field generated by the first working coil (WC1) is difficult to reach the object to be heated (HO).

[0177] However, as in one embodiment of the present invention (i.e., as shown in FIG. 6), when the skin depth of the first heating thin film coating (TL1) is deeper than the thickness of the first heating thin film coating (TL1), it can be seen that the magnetic field generated by the first working coil (WC1) is mostly transmitted to the object to be heated (HO). That is, in one embodiment of the present invention, since the skin depth of the first heating thin film coating (TL1) is deeper than the thickness of the first heating thin film coating (TL1), the magnetic field generated by the first working coil (WC1) passes through the first heating thin film coating (TL1) and is mostly consumed at the object to be heated (HO), thereby allowing the object to be heated (HO) to be heated mainly.

[0178] Meanwhile, the first heating thin film coating (TL1) has a thin thickness as described above and can have a resistance value that can be heated by the first working coil (WC1).

[0179] Specifically, the thickness of the first heating thin film coating (TL1) may be inversely proportional to the resistance value (i.e., surface resistance value) of the first heating module (HM1). That is, the thinner the thickness of the first heating thin film coating (TL1), the greater the resistance value (i.e., surface resistance) of the first heating thin film coating (TL1).

[0181] The first heating thin film coating (TL1) having such characteristics exists to heat a non-magnetic material, and the impedance characteristics between the first heating thin film coating (TL1) and the object to be heated (HO) can change depending on whether the object to be heated (HO) placed on the upper surface of the top plate (15) is a magnetic material or a non-magnetic material.

[0182] First, the case where the object to be heated is a magnetic material is explained as follows.

[0183] Referring to FIGS. 3 and FIGS. 8, when a magnetic object to be heated (HO) is placed on the upper surface of the upper plate (15) and the first working coil (WC1) is driven, the resistance component (R1) and inductor component (L1) of the magnetic object to be heated (HO) can form an equivalent circuit with the resistance component (R2) and inductor component (L2) of the first heating module (HM1).

[0184] In this case, the impedance of the heated object that is magnetic in the equivalent circuit (i.e., the impedance composed of R1 and L1) may be smaller than the impedance of the first heated thin film coating (TL1) (i.e., the impedance composed of R2 and L2).

[0185] Accordingly, when the aforementioned equivalent circuit is formed, the magnitude of the eddy current (I1) applied to the magnetic object to be heated (HO) may be greater than the magnitude of the eddy current (I2) applied to the first thin film (TL1). More specifically, most of the eddy current may be applied to the object to be heated (HO), thereby heating the object to be heated (HO).

[0186] That is, when the object to be heated (HO) is a magnetic material, the aforementioned equivalent circuit is formed and most of the eddy current is applied to the object to be heated (HO), so the first working coil (WC1) can directly heat the object to be heated (HO).

[0187] Of course, some eddy current is applied to the first heating thin film coating (TL1) so that the first heating thin film coating (TL1) can be slightly heated, and the object to be heated (HO) can be indirectly slightly heated by the first heating thin film coating (TL1). However, compared to the degree to which the object to be heated (HO) is directly heated by the first working coil (WC1), the degree to which the object to be heated (HO) is indirectly heated by the first heating thin film coating (TL1) cannot be considered significant.

[0188] On the other hand, the case where the object to be heated is a non-magnetic material is explained as follows.

[0189] Referring to FIGS. 3 and FIGS. 9, when a non-magnetic object to be heated (HO) is placed on the upper surface of the upper plate (15) and the first working coil (WC1) is driven, there is no impedance in the non-magnetic object to be heated (HO), and there may be impedance in the first heating thin film coating (TL1). That is, a resistance component (R) and an inductor component (L) may exist only in the first heating thin film coating (TL1).

[0190] Accordingly, the eddy current (I) may be applied only to the first heating thin film coating (TL1), and the eddy current may not be applied to the non-magnetic object to be heated (HO). More specifically, the eddy current (I) may be applied only to the first heating thin film coating (TL1) so that the first heating thin film coating (TL1) can be heated.

[0191] That is, when the object to be heated (HO) is a non-magnetic material, as described above, an eddy current (I) is applied to the first heating thin film coating (TL1) to heat the first heating thin film coating (TL1), and the object to be heated (HO) that is not magnetic can be indirectly heated by the first heating thin film coating (TL1) heated by the first working coil (WC1).

[0192] For reference, the protection temperature of the top plate (15) can be pre-set by the top plate manufacturer or the cooktop manufacturer. That is, if the top plate manufacturer transmits information regarding the lifespan of the top plate by temperature to the cooktop manufacturer, the cooktop manufacturer can calculate the product lifespan taking into account the cooking time and set the protection temperature of the top plate (15).

[0193] In addition, a temperature sensor may be mounted in one area of ​​the upper plate (15) to detect a change in temperature of the upper plate (15) and provide the detected temperature information to the aforementioned control module.

[0194] In summary, regardless of whether the object to be heated (HO) is a magnetic or non-magnetic material, the object to be heated (HO) can be heated directly or indirectly by a single heat source called the first working coil (WC1). That is, if the object to be heated (HO) is a magnetic material, the first working coil (WC1) directly heats the object to be heated (HO), and if the object to be heated (HO) is a non-magnetic material, the first heating thin film coating (TL1) heated by the first working coil (WC1) can indirectly heat the object to be heated (HO).

[0195] As described above, the induction heating type cooktop (1) according to one embodiment of the present invention can heat both magnetic and non-magnetic materials, and thus can heat the object to be heated regardless of the placement location and type of the object to be heated. Accordingly, the user can place the object to be heated on any heating area on the top plate without needing to determine whether the object to be heated is magnetic or non-magnetic, thereby improving convenience of use.

[0196] In addition, the induction heating type cooktop (1) according to one embodiment of the present invention can heat an object to be heated directly or indirectly with the same heat source, so there is no need to provide a separate heating plate or radiant heater. Accordingly, not only can heating efficiency be increased, but material costs can also be reduced.

[0198] Hereinafter, an induction heating type cooktop according to another embodiment of the present invention will be described.

[0199] FIG. 10 is a drawing illustrating an induction heating type cooktop according to another embodiment of the present invention. FIG. 11 is a drawing illustrating components provided inside the case of the induction heating type cooktop illustrated in FIG. 10. FIG. 12 is a drawing illustrating an object to be heated placed on the induction heating type cooktop illustrated in FIG. 10.

[0200] For reference, the induction heating type cooktop (2) according to another embodiment of the present invention is identical to the induction heating type cooktop (1) of FIG. 1 except for some components and effects, so the differences will be explained in detail.

[0201] Referring to FIGS. 10 and 11, the induction heating type cooktop (2) according to another embodiment of the present invention may be a zone-free type cooktop, unlike the induction heating type cooktop (1) of FIG. 1.

[0202] Specifically, the induction heating type cooktop (2) may include a case (25), a cover plate (20), a plurality of heating thin film coatings (TLG), an insulating material (35), a plurality of working coils (WCG), a shielding plate (45), a support member (50), a cooling fan (not shown), a spacer (not shown), and a control module (not shown).

[0203] Here, a plurality of heating thin film coatings (TLG) and a plurality of working coils (WCG) can overlap each other in the vertical direction and can be arranged so that each corresponds one-to-one.

[0204] Of course, the plurality of heating thin film coatings (TLG) and the plurality of working coils (WCG) may not correspond in a one-to-one manner, but rather in a many-to-one or one-to-many manner. However, for the convenience of explanation, in another embodiment of the present invention, the plurality of heating thin film coatings (TLG) and the plurality of working coils (WCG) are arranged to correspond in a one-to-one manner, and this will be explained as an example.

[0205] The induction heating type cooktop (2) is a zone-free type cooktop comprising a plurality of heating thin film coatings (TLG) and a plurality of working coils (WCG). Accordingly, the cooktop (2) according to the present invention can simultaneously heat a single object to be heated (HO) with some or all of the plurality of working coils (WCG) or simultaneously heat it with some or all of the plurality of heating thin film coatings (TLG). Of course, the object to be heated (HO) can also be heated using both some or all of the plurality of working coils (WCG) and some or all of the plurality of heating thin film coatings (TLG).

[0206] Accordingly, as shown in FIG. 10, in an area where a plurality of working coils (WCG in FIG. 8) and a plurality of heating thin film coatings (TLG) exist (e.g., the upper plate portion (15) area), heating of the object to be heated (HO1, HO2) is possible regardless of the size, position, or type of the object to be heated (HO1, HO2).

[0208] Examples

[0209] Hereinafter, the structure and operation of the present invention will be explained in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be interpreted in any way as limiting the present invention.

[0210] Details not listed here can be sufficiently technically inferred by a person skilled in this field, so their explanation will be omitted.

[0212] 1. Manufacturing of circuit boards for home appliances

[0214] A substrate made of ceramic glass material was prepared, and a color / adhesive layer and a protective layer were sequentially laminated thereon to form a color coating laminate. The thickness, composition, and content of the color / adhesive layer are as shown in Table 1 below, and the thickness, composition, and content of the protective layer are as shown in Table 2 below.

[0216] Glass Frit (weight%) Inorganic pigment (weight%) Inorganic Filler (Weight%) Average thickness Comparative example A 65 B 35 - 　 3 Example 1 A 58 B 30 Nb2O5 12 10 Example 2 A 60 B 30 (Mg,Fe)2Al4Si5O 18 10 15 Example 3 A 52 B 30 (Mg,Fe)2Al4Si5O 18 18 50 Example 4 A 44 B 31 There 0.9 To 0.9 Yes 1.1 O4 25 15 Example 5 A 40 B 30 There 0.9 To 0.9 Yes 1.1 O4 30 50 Example 6 A 34 B 28 There 0.9 To 0.9 Yes 1.1 O4 38 100 Example 7 A 60 B 25 Be3Al2Si6O 18 15 5 Example 8 A 52 B 32 Al2TiO5 16 10 Example 9 A 50 B 30 LiAl(SiO3)2 20 15 Example 10 A 36 B 29 LiAl(SiO3)2 35 50 Example 11 A 59 B 26 Zr2P2O9 15 10 Example 12 A 58 B 31 NaZr2(PO4)3 11 15 Example 13 A 48 B 30 NaZr2(PO4)3 22 50 Example 14 A 55 B 33 CaZr4(PO4)6 12 10

[0218] Inorganic material (weight%) Average thickness Comparative example C 100 15 Example 1 C 100 15 Example 2 C 100 15 Example 3 C 100 15 Example 4 C 100 15 Example 5 C 100 15 Example 6 C 100 15 Example 7 C 100 15 Example 8 C 100 15 Example 9 C 100 15 Example 10 C 100 15 Example 11 C 100 15 Example 12 C 100 15 Example 13 C 100 15 Example 14 C 100 15

[0220] A: Glass frit having a composition of Bi2O3 73 wt%, B2O3 9 wt%, SiO2 6 wt%, BaO 5 wt%, ZrO2 5 wt%, and P2O5 2 wt%.

[0221] B: Oxides of Fe, Ni, and Mo

[0222] C: Inorganic material having a composition of V2O54 wt%, P2O511 wt%, B2O326 wt%, Bi2O318 wt%, ZnO12 wt%, SiO314 wt%, B2O312 wt%, and Al2O33 wt%.

[0224] The above color-coated laminate was formed by a screen printing method. A color / adhesive layer was formed by coating a color / adhesive layer paste coating solution onto one surface of the substrate. The color / adhesive layer was formed through a firing process at 700°C for 20 minutes after drying at 200°C for 10 minutes. Subsequently, a protective layer was formed by coating a protective layer paste coating solution onto the top of the color / adhesive layer. The protective layer was also formed through the same process as the color / adhesive layer.

[0226] 2. Evaluation of Physical Properties of Substrates for Home Appliances

[0228] (1) Adhesion evaluation

[0229] For the substrates according to the above examples and comparative examples, the adhesion of the coating was evaluated by using a tester (0.1~0.2 mm) to completely adhere a scratching tape (11 horizontal lines, 11 vertical lines, 1 mm spacing) to the scratched area, peeling it off at a 45-degree angle, and then visually inspecting the surface.

[0231] If there are no surface abnormalities: ○

[0232] In cases where there are minor surface abnormalities: △

[0233] In cases of severe surface abnormalities: X

[0235] (2) Heat resistance evaluation

[0236] For the substrates according to the above examples and comparative examples, heat resistance was evaluated by comprehensively checking the surface condition, whether peeling occurred, and whether the color difference ΔE = 3 or less after leaving them at 400°C for 1 hour and then cooling them at room temperature.

[0238] If there are no surface abnormalities: ○

[0239] In cases where there are minor surface abnormalities: △

[0240] In cases of severe surface abnormalities: X

[0242] (3) Transmittance evaluation

[0243] For the substrates according to the above examples and comparative examples, transmittance was evaluated by measuring the degree of light absorption by transmitting light through the coating film using a transmittance measuring device (LS116, Linshang).

[0245] x > 0.02 : Lower part see-through

[0246] 0.01 < x < 0.02 : Fine transparency at the bottom

[0247] x < 0.01 : No lower see-through

[0249] (4) Measurement results

[0250] The results of measuring the physical properties of the examples and comparative examples are as shown in Table 3.

[0252] adhesive heat resistance Transmittance Comparative example △ X - Example 1 ○ ○ 0.028 Example 2 ○ ○ 0.012 Example 3 △ △ 0.008 Example 4 ○ ○ 0.01 Example 5 ○ ○ 0.005 Example 6 ○ ○ 0 Example 7 △ △ 0.033 Example 8 ○ ○ 0.03 Example 9 ○ ○ 0.023 Example 10 △ △ 0.014 Example 11 △ △ 0.021 Example 12 ○ ○ 0.014 Example 13 △ △ 0.008 Example 14 △ △ 0.015

[0254] It can be seen that in the comparative example in which inorganic fillers were not used, the adhesion was good, but the heat resistance, etc., was reduced.

[0255] It can be confirmed that all the examples generally exhibit excellent physical properties, such as adhesion and heat resistance. In particular, among the examples, Li (1-x) Al (1-x) Si (1+x) It is confirmed that Examples 4, 5, and 6, which used O4 as an inorganic filler, are the most effective.

[0257] (5) Heat resistance evaluation compared to a coating layer of organic material

[0258] The heat resistance of Example 1 and Comparative Example 2, which used an organic material including polysiloxane as a color / adhesive layer, was compared.

[0260] Heat resistance evaluation was performed using a method of measuring the color difference for up to 168 hours while leaving specimens according to Example 1 and Comparative Example 2 in a 400°C high-temperature furnace without separate atmosphere conditions.

[0262] Referring to FIG. 13, it is confirmed that Comparative Example 2, coated with an organic material including polysiloxane, has a color difference exceeding 3, whereas the specimen according to Example 1 maintains a color difference of 1 or less.

[0264] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention were not explicitly described while explaining the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

Claims

Claim 1 A substrate for a home appliance having a color coating laminate coated on one surface, wherein the color coating laminate comprises: a color / adhesive layer located in contact with the surface of the substrate; and a protective layer located on top of the color layer. Claim 2 A substrate for a home appliance according to claim 1, wherein the color / adhesive layer is formed from a color / adhesive layer paste coating liquid comprising glass frit, an inorganic pigment, and an inorganic filler. Claim 3 In paragraph 2, the color / adhesive layer paste coating liquid comprises 5 to 70 weight% of the glass frit, 5 to 70 weight% of the inorganic pigment, and 10 to 60 weight% of the inorganic filler, for a substrate for a home appliance. Claim 4 In paragraph 2, the above-mentioned inorganic filler is Li (1-x) Al (1-x) Si (1+x) A substrate for a home appliance comprising O4 (where x satisfies 0 ≤ x ≤ 0.42). Claim 5 In paragraph 2, the above-mentioned inorganic pigment is a substrate for home appliances comprising an oxide of one of Fe, Al, Mn, Ni, Ti, Mo, Si, Mg, Co, Sn, and Zr. Claim 6 In claim 5, the glass frit has a coefficient of thermal expansion of 50 to 110 x 10 -7 A substrate for electrical equipment with a softening point of 300 to 600 ℃. Claim 7 In claim 1, the protective layer is a substrate for a home appliance formed from a protective layer paste coating solution comprising an inorganic material. Claim 8 A substrate for a home appliance according to claim 1, wherein the thickness of the color / adhesive layer is 5 to 150 μm and the thickness of the protective layer is 0.1 to 50 μm. Claim 9 In claim 1, the substrate is a substrate for a home appliance comprising a ceramic glass material. Claim 10 A cooktop of an induction heating method comprising: a case; a cover plate coupled to the top of the case and having a top plate portion on which an object to be heated is disposed on its upper surface; a working coil provided inside the case to heat the object to be heated; an insulating material provided on the upper part of the working coil; and a heating thin film coating provided on either side of the top plate portion or on either side of the insulating material, having a laminated structure in which an adhesive layer and a heating layer are sequentially laminated; wherein the top plate portion is an induction heating type cooktop to which a substrate for a home appliance according to claim 1 is applied. Claim 11 In claim 10, the heating thin film coating further comprises a protective layer laminated on one surface of the heating layer; an induction heating type cooktop. Claim 12 An induction heating type cooktop according to claim 10, further comprising: a shielding plate mounted on the lower surface of the working coil to block a magnetic field generated downward when the working coil is driven; a support member installed between the lower surface of the shielding plate and the lower surface of the case to support the shielding plate upward; and a cooling fan installed inside the case to cool the working coil. Claim 13 In claim 10, the above support member is an induction heating type cooktop comprising an elastic body for supporting the shielding plate upward. Claim 14 In claim 10, the cooling fan sucks in air from outside the case and transfers it to the working coil or sucks in air from inside the case and discharges it to outside the case, and the insulating material blocks heat generated as the object to be heated or the heating thin film coating is heated by the driving of the working coil from being transferred to the working coil.

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