Stained paper for electromagnetic induction heating, insulating vessel module and preparation method thereof

Abstract

The invention provides stained paper for electromagnetic induction heating, an insulating vessel module and a preparation method thereof.The stained paper is used for being fixed to the bottom of an insulating vessel and comprises a separable substrate, a soluble release layer, an electric conduction heating layer, a pattern layer, a transparent protection layer and a separable protection layer which are sequentially arranged in a stacked mode; and the conductive heating layer is used for corresponding to a coil of the electromagnetic heating base, so that the conductive heating layer emits heat. Wherein the diameter of the conductive heating layer is Dmag, the diameters of the pattern layer and the transparent protection layer are both Dtop, and Dmag is smaller than Dtop. The diameter of the conductive heating layer is smaller than the diameters of the pattern layer and the transparent protection layer, in other words, the conductive heating layer is not matched with other layers in size, the diameter of the conductive heating layer is reduced, the conductive heating layer is not laid on the whole layer, and therefore the material consumption of the conductive heating layer can be saved on the basis that heating area matching is achieved.

Description

Technical Field

[0001] This application belongs to the field of decorative and functionalized insulating utensil technology, specifically relating to decorative paper for electromagnetic induction heating, insulating utensil modules, and their preparation methods. Background Technology

[0002] Existing electromagnetic heating tableware typically relies on a single metal base or thick metal inserts, which presents problems such as complex processes, food contact safety, and high costs. Furthermore, existing metal bases or metal inserts do not have a decorative function. Summary of the Invention

[0003] In view of this, the first aspect of this application provides a decorative paper for electromagnetic induction heating, the decorative paper being used to fix to the bottom of an insulating vessel, the decorative paper comprising a separable substrate, a soluble release layer, an electrically conductive heating layer, a pattern layer, a transparent protective layer, and a separable protective layer stacked sequentially, the electrically conductive heating layer being used to correspond to the coil of an electromagnetic heating base so as to cause the electrically conductive heating layer to heat up; The diameter of the conductive heating layer is D. mag The diameter of both the pattern layer and the transparent protective layer is D. top D mag <D top .

[0004] Optionally, the effective coupling outer diameter of the coil of the electromagnetic heating base is D. coil D mag / D coil =1.01~1.1; and / or, the decorative diameter of the bottom of the insulating vessel is D. decor D mag <D top ≤D decor .

[0005] Optionally, the decal is prepared by screen printing, and the pattern layer is also provided around the periphery of the electrically conductive heating layer to improve the stability of the decal.

[0006] Optionally, the material of the electrically conductive heating layer includes 65%~85% conductive powder, 5%~15% glass powder, and 10%~30% adhesive solution, wherein the melting point of the glass powder is 700℃~850℃.

[0007] Optionally, the particle size of the conductive powder is 1μm to 100μm; and / or, the particle size D50 of the conductive powder is 35μm to 50μm; and / or, the softening point of the glass powder is 450℃ to 600℃.

[0008] Optionally, the conductive heating layer may adopt a multi-ring, spiral, or radial pattern to optimize coupling and temperature field uniformity.

[0009] Optionally, the decal also includes an insulating ring disposed around the periphery of the conductive heating layer to suppress edge overheating and creepage.

[0010] A second aspect of this application provides a method for preparing an insulating vessel module, the method comprising: A separable substrate is provided, and a soluble release layer, an electrically conductive heating layer, a pattern layer, a transparent protective layer, and a separable protective layer are sequentially screen-printed onto the separable substrate to obtain an initial decal. The initial decal is dried at low temperature to obtain the decal for electromagnetic induction heating as provided in the first aspect of this application; The decal is soaked in water to separate the separable substrate; The soluble release layer is pre-bonded to the bottom of the insulating vessel; The decal is sintered to decompose the soluble release layer and the separable protective layer, and to fix the conductive heating layer to the bottom of the insulating vessel.

[0011] Optionally, sintering the decal includes: First, heat the decal to 120℃~180℃ and keep it warm while draining the water. After draining the decals, heat them to 350℃~450℃ and keep them warm to remove the glue. After the glue has been removed, the decal is heated to 700℃~850℃ and kept at that temperature to melt and solidify the glass powder. The solidified decals are cooled at a rate not exceeding 3℃ / s.

[0012] The third aspect of this application provides an insulating vessel module prepared using the method for preparing an insulating vessel module as provided in the second aspect of this application. The insulating vessel module includes an insulating vessel and sintered decals fixed to the bottom of the insulating vessel. The decals include a conductive heating layer, a pattern layer, and a transparent protective layer stacked together. The conductive heating layer is fixed to the bottom of the insulating vessel.

[0013] This application provides a decal, insulating utensil module, and its preparation method for electromagnetic induction heating. By aligning the conductive heating layer with the coil of the electromagnetic heating base, the two interact to heat the insulating utensil. Furthermore, by making the diameter of the conductive heating layer smaller than the diameters of the pattern layer and the transparent protective layer—in other words, by making the conductive heating layer size mismatched with other layers—the diameter of the conductive heating layer is reduced, and the conductive heating layer does not cover the entire layer. This saves material usage while achieving matching heating areas. A pattern layer and a transparent protective layer are also provided above the conductive heating layer. The pattern layer enhances the appearance of the decal, while the transparent protective layer encapsulates and protects the conductive heating layer and the pattern layer, thus meeting requirements such as food contact safety, dishwasher resistance, and resistance to thermal shock. In addition, the decal structure of this application is simple and compatible with conventional screen printing and ceramic insulating utensil decal firing production lines, enabling the formation of a stable conductive heating layer on insulating utensil in a low-cost, mass-production manner. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0015] Figure 1 This is a schematic diagram of an insulating vessel module disposed on an electromagnetic heating base according to one embodiment of this application.

[0016] Figure 2 This is a schematic diagram of an insulating vessel according to one embodiment of this application.

[0017] Figure 3 This is a schematic diagram of the decorative paper in one embodiment of this application.

[0018] Figure 4 This is a schematic diagram of an electromagnetic heating base according to one embodiment of this application.

[0019] Figure 5 This is a schematic diagram of the decorative paper in another embodiment of this application.

[0020] Figure 6 This is a schematic diagram of the decorative paper in another embodiment of this application.

[0021] Figure 7 This is a process flow diagram of the preparation method of the insulating vessel module in one embodiment of this application.

[0022] Figure 8 for Figure 7 The process flow diagram included in S500.

[0023] Figure 9 This is a schematic diagram of an insulating vessel module according to one embodiment of this application.

[0024] Label Explanation: Decorative paper - 1, Insulating container - 2, Insulating container module - 3, Electromagnetic heating base - 4, Coil - 5, Separable substrate - 10, Soluble release layer - 20, Conductive heating layer - 30, Pattern layer - 40, Transparent protective layer - 50, Separable protective layer - 60, Insulating ring - 70. Detailed Implementation

[0025] The following are preferred embodiments of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

[0026] In view of this, and in order to solve the above-mentioned technical problems, this application provides decals for electromagnetic induction heating, insulating vessel modules, and methods for their preparation. Please refer to these provisions. Figures 1-4 , Figure 1 This is a schematic diagram of an insulating vessel module disposed on an electromagnetic heating base according to one embodiment of this application. Figure 2 This is a schematic diagram of an insulating vessel according to one embodiment of this application. Figure 3 This is a schematic diagram of the decorative paper in one embodiment of this application. Figure 4 This is a schematic diagram of an electromagnetic heating base according to one embodiment of this application. This embodiment provides a decorative paper 1 for electromagnetic induction heating. The decorative paper 1 is used to fix to the bottom of an insulating container 2. The decorative paper 1 includes a separable substrate 10, a soluble release layer 20, an electrically conductive heating layer 30, a pattern layer 40, a transparent protective layer 50, and a separable protective layer 60, which are stacked sequentially. The electrically conductive heating layer 30 corresponds to the coil 5 of the electromagnetic heating base 4, so that the electrically conductive heating layer 30 heats up. The diameter of the electrically conductive heating layer 30 is D. mag The diameter of both the pattern layer 40 and the transparent protective layer 50 is D. top D mag <D top .

[0027] Decal 1 refers to a sticker with a specific color and pattern printed on the surface of an insulating vessel 2, such as ceramic, which can be fixed to the ceramic surface after sintering. Optionally, the material of the insulating vessel 2 includes, but is not limited to, ceramic, glass, enamel, etc., and the type can also be bowls, plates, cups, pots, etc. Further optionally, the ceramic surface can be treated with a base glaze or base coating before the decal application, that is, the ceramic surface can be decorated with decals with or without a glaze layer.

[0028] The decal 1 comprises a separable substrate 10, a soluble release layer 20, an electrically conductive heating layer 30, a pattern layer 40, a transparent protective layer 50, and a separable protective layer 60, which are stacked sequentially. The separable substrate 10 is a substrate made of materials such as paper, cotton, or soluble adhesive; in this embodiment and below, only a paper substrate is used for illustrative purposes. The separable substrate 10 decomposes or separates from other layers when exposed to water, thereby exposing the other layers.

[0029] The soluble release layer 20 is an adhesive layer structure. When the separable substrate 10 separates from water, the surface of the soluble release layer 20 is exposed, allowing it to be initially fixed to the surface of the insulating vessel 2. When not in use, it is protected by the separable substrate 10 below. Furthermore, the soluble release layer 20 decomposes at high temperatures.

[0030] The conductive heating layer 30 is a functional layer with electrical conductivity. Since the insulating vessel 2 in this embodiment needs to be placed on the electromagnetic heating base 4 to heat the liquid inside the insulating vessel 2, the conductive heating layer 30 needs to interact with the coil 5 inside the electromagnetic heating base 4 to heat the conductive heating layer 30, thereby transferring heat to the liquid inside the insulating vessel 2. Specifically, the conductive heating layer 30 and the coil 5 inside the electromagnetic heating base 4 undergo electromagnetic induction, and the conductive heating layer 30 heats up through a combination of eddy currents and hysteresis. The detailed principle will not be elaborated here. Furthermore, since the conductive heating layer 30 in the decal 1 needs to cooperate with the coil 5 inside the electromagnetic heating base 4, the insulating vessel 2 is usually placed on top of the electromagnetic heating base 4; therefore, the decal 1 needs to be fixed to the bottom of the insulating vessel 2.

[0031] The patterned layer 40 is a decorative layer with a specific pattern and color, which enhances the appearance. The transparent protective layer 50 primarily protects the underlying patterned layer 40 and the electrically conductive heating layer 30, and its transparency allows the pattern and color of the patterned layer 40 to be seen. The separable protective layer 60 primarily protects the underlying layers, and like the soluble release layer 20, it also decomposes at high temperatures.

[0032] Traditional decals 1 lack an electrically conductive heating layer 30 and only serve a decorative function, lacking effective electromagnetic coupling and heating capabilities. Even when an electrically conductive heating layer 30 is included, it is typically laid out across the entire width of the surface, forming a single layer. This significantly increases the amount of metal powder used and introduces potential risks such as stress cracking and insufficient glaze adhesion. Therefore, this embodiment reduces the diameter D of the electrically conductive heating layer 30... mag The diameter D of the pattern layer 40 and the transparent protective layer 50 is smaller than that of the pattern layer 40. top D mag <D topIn other words, the conductive heating layer 30 is not sized to match other layers, thus reducing its diameter. The conductive heating layer 30 does not cover the entire surface, saving material usage while achieving matching heating areas. Furthermore, a pattern layer 40 and a transparent protective layer 50 are provided above the conductive heating layer 30. The pattern layer 40 enhances the appearance of the decal 1, while the transparent protective layer 50 encapsulates and protects the conductive heating layer 30 and the pattern layer 40, preventing direct metal contact with food and cleaning media, thereby meeting requirements for food safety, dishwasher resistance, and resistance to thermal shock. Additionally, the decal 1 of this application has a simple structure and is compatible with conventional screen printing and ceramic insulating vessel decal firing production lines, enabling the formation of a stable conductive heating layer 30 on the insulating vessel 2 in a low-cost, mass-production manner.

[0033] In summary, this embodiment proposes a structure for the conductive heating layer 30 (decorative paper 1) with mismatched dimensions between the functional layer and the appearance layer by sintering a magnetically and electrically conductive composite thin layer at the bottom of the insulating vessel 2. The conductive heating layer 30 only covers the area effectively coupled with the electromagnetic coil 5. Through the mismatched layer size design, the material usage of the conductive heating layer 30 is optimized and matched with the heating area. Specifically, the amount of conductive powder can be reduced by 20-60% while the appearance layer fully covers the entire surface, ensuring decorative consistency. In this embodiment, the effective coupling outer diameter of the coil 5 of the electromagnetic heating base 4 is D. coil D mag / D coil =1.01~1.1; and / or, the decorative diameter of the bottom of the insulating vessel 2 is D. decor D mag <D top ≤D decor .

[0034] This embodiment allows the diameter D of the conductive heating layer 30 to be... mag The effective coupling outer diameter of the coil 5, which is slightly larger than that of the electromagnetic heating base 4, is D. coil Specifically, D mag / D coil =1.01~1.1. Specifically, the effective coupling outer diameter of the coil 5 of the electromagnetic heating base 4 is 4cm~12cm. In this embodiment, the diameter of the conductive heating layer 30 can be 5mm~10mm larger than the effective coupling outer diameter of the coil 5 of the electromagnetic heating base 4 to improve the coupling effect and further enhance the heating capacity.

[0035] Optionally, D mag It can be 1.01D. coil , or 1.02D coil 1.03D coil 1.04D coil 1.05D coil1.06D coil 1.07D coil 1.08D coil 1.09D coil 1.1D coil .

[0036] The decorative diameter of the bottom of the insulating vessel 2 can be D. decor In this embodiment, the diameter D of the pattern layer 40 and the transparent protective layer 50 can be made... top The diameter D is greater than 30 of the conductive heating layer. mag And not greater than the decorative diameter D at the bottom. decor Specifically, D mag <D top ≤D decor Optionally, this embodiment may enable D top =D decor Specifically, the diameters of the pattern layer 40 and the transparent protective layer 50 are 10mm to 30mm larger than the diameter of the electrically conductive heating layer 30. This allows the pattern layer 40 and the appearance layer to cover the bottom of the insulating vessel 2 to the greatest extent possible, facilitating splicing with the decorative paper 1 structure on the side, thus ensuring a continuous appearance and compatibility of the appearance decoration. This approach balances heating efficiency with decorative continuity and cost reduction.

[0037] In addition, the decal 1 also includes a separable substrate 10, a soluble release layer 20, and a separable protective layer 60. However, these three layers will separate and decompose during the process of fixing the decal 1 to the bottom of the insulating container 2. Therefore, the diameter of these three layers is not limited in this embodiment. Optionally, the diameters of the separable substrate 10, the soluble release layer 20, and the separable protective layer 60 are the same as the diameters D of the pattern layer 40 and the transparent protective layer 50. top The widths are equal, thus enabling the other layers, except for the electrically conductive heating layer 30, to have equal widths at the top and bottom.

[0038] Please refer to Figure 5 , Figure 5 This is a schematic diagram of the decal paper according to another embodiment of this application. In this embodiment, the decal paper 1 is prepared by screen printing, and the pattern layer 40 is also provided around the periphery of the electrically conductive heating layer 30 to improve the stability of the decal paper 1.

[0039] The decal 1 can be prepared using a screen printing process. Specifically, a separable substrate 10 is first provided, and then a soluble release layer 20, an electrically conductive heating layer 30, a pattern layer 40, a transparent protective layer 50, and a separable protective layer 60 are sequentially printed on the surface of the separable substrate 10 to obtain the decal 1 structure. Therefore, this embodiment can utilize mature screen printing and decal production lines, resulting in high yield, controllable cost, and mass production friendliness.

[0040] Furthermore, since each layer is printed individually, and the diameter of the conductive heating layer 30 is smaller than that of the soluble release layer 20, the conductive heating layer 30 is not fully covered during its formation, leaving excess space around its perimeter. Therefore, when the pattern layer 40 is printed, the paste of the pattern layer 40 automatically fills the excess space under the influence of gravity, resulting in a pattern layer 40 also being formed around the perimeter of the conductive heating layer 30, thus improving the density, integrity, and stability of the decal 1.

[0041] In this embodiment, the conductive heating layer 30 is made of 65%~85% conductive powder, 5%~15% glass powder, and 10%~30% adhesive solution, wherein the melting point of the glass powder is 700℃~850℃.

[0042] The conductive heating layer 30 is mainly composed of conductive powder, glass powder, and a binder solution. The conductive powder primarily enables the conductive heating layer 30 to conduct electricity, while the glass powder significantly improves its hardness and wear resistance. The binder solution not only ensures uniform mixing of the conductive powder and glass powder but also binds the components together. Traditional glass powder has a melting point as high as 1300℃, but such a high temperature can affect the insulating vessel 2 itself, for example, causing the glaze on the insulating vessel 2 to crack. Therefore, this embodiment controls the melting point of the glass powder to 700℃~850℃, achieving conductive continuity by allowing the conductive particles to sinter and connect together, resulting in good wetting effects. Furthermore, it is compatible with most household tableware glazes, does not affect the insulating vessel 2 itself, and requires no metal inserts.

[0043] Furthermore, if the temperature is too low, for example, below 700°C, the conductive powder cannot melt, or melts only a small amount, and cannot be effectively bonded together. If the temperature is too high, for example, above 850°C, the conductive powder, such as silver, will not only over-melt, but will also oxidize, thereby reducing the conductivity.

[0044] Furthermore, this embodiment controls the mass fraction of conductive powder to be 65%~85%, the mass fraction of glass powder to be 5%~15%, and the mass fraction of adhesive solution to be 10%~30%. If the content of conductive powder is too low, for example less than 65%, the conductive heating layer 30 will not conduct electricity; however, if the content of conductive powder is too high, for example greater than 85%, the cost will be too high. If the content of glass powder is too low, for example less than 5%, the bonding performance will decrease; however, if the content of glass powder is too high, for example greater than 15%, the conductivity will be affected. If the content of adhesive solution is too low, the bonding performance will decrease; however, if the content of adhesive solution is too high, the content of other components will be affected.

[0045] In summary, the conductive heating layer 30 in this embodiment uses conductive powder and low melting point glass phase composite, supplemented by an organic binder system to form a screen printing paste. After firing, the glass phase melts and penetrates, and the conductive particles are sintered and connected.

[0046] Optionally, the mass fraction of the conductive powder can be 65%, 70%, 75%, 80%, or 85%. The mass fraction of the glass powder can be 5%, 8%, 10%, 12%, or 15%. The mass fraction of the binder solution can be 10%, 15%, 20%, 25%, or 30%. The melting point of the glass powder can be 700℃, 750℃, 800℃, or 850℃.

[0047] Optionally, the conductive powder may be made of at least one of the following: silver powder, graphite powder, graphene powder, ferritic stainless steel powder 410 or 430, pure iron powder, Fe-Si powder, and ferrite powder. Optionally, the conductive powder may also include a small amount of Ni powder or soft magnetic powder crosslinking to improve relative permeability while maintaining conductivity, improve hysteresis effect, and further improve the heating effect of the conductive heating layer 30.

[0048] Optionally, the conductive powder can be in a regular or irregular shape, such as irregular spheres, flakes, or other irregularly shaped particles. Further, an irregular or flake-like morphology of the conductive powder facilitates overlapping, thereby achieving interconnection after sintering and connecting multiple powders together.

[0049] Optionally, the low-melting-point glass powder can be lead-free low-melting-point glass powder. The glass powder includes a network forging body and a network modifier. The network forging body constitutes the main component of the glass powder and has a high melting point. The network modifier can lower the melting point of the glass powder, controlling it to within 700℃~850℃. The network forging body is made of at least one of B2O3 and SiO2, and the network modifier is made of alkali metal, alkaline earth metal oxide, oxide containing sodium or potassium, or low-melting-point lead or borosilicate glass. Further optionally, the network modifier is made of at least one of Bi2O3, V2O3, and ZnO. Specifically, the glass powder is mainly based on systems such as ZnO-B2O3-SiO2 and Bi2O3-B2O3-SiO2.

[0050] In addition, auxiliary oxides such as Al2O3 and Sb2O3 can be added to the glass powder, mainly to adjust the thermal expansion rate and fluidity, with little effect on the melting point.

[0051] Optionally, the adhesive solution comprises an ethyl cellulose and terpineol system, or an acrylic system, to meet the requirements of print rheology and drying strength. This embodiment is only illustrated using a 5 wt% ethyl cellulose solution with terpineol as the solvent.

[0052] In this embodiment, the pattern layer 40 may be composed of pigments, low-melting-point glass powder, and an adhesive, and the transparent protective layer 50 may be composed of low-melting-point glass powder. The glass powder in the pattern layer 40 and the transparent protective layer 50 may have the same material and content as the glass powder in the electrically conductive heating layer 30; this will not be elaborated further in this embodiment.

[0053] In this embodiment, the particle size of the conductive powder is 1μm to 100μm; and / or, the particle size D50 of the conductive powder is 35μm to 50μm; and / or, the softening point of the glass powder is 450℃ to 600℃.

[0054] The diameter of the conductive powder can be controlled between 1 μm and 100 μm. If the particle size is too large, for example, greater than 100 μm, the required mass fraction is too high, resulting in excessive viscosity and a tendency for the finished product to crack. However, if the particle size is too small, for example, less than 1 μm, it will lead to poor particle contact during sintering, reducing conductivity. Preferably, the particle size D50 of the conductive powder can be 35 μm to 50 μm. The particle size and mass fraction of the conductive powder determine the through-conductivity and sheet resistance R. S .

[0055] Specifically, the particle size of the conductive powder can be 1μm, 10μm, 20μm, 30μm, 35μm, 40μm, 45μm, 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm.

[0056] Alternatively, the softening point, or melting temperature, of the glass powder is 450°C to 600°C. If the softening point is too high, for example, above 600°C, the melting temperature will be too high, causing the conductive powder to over-melt and easily oxidize. However, if the softening point is too low, for example, below 450°C, the cost will be too high. Specifically, the softening temperature of the glass powder can be 450°C, 500°C, 550°C, or 600°C.

[0057] In this embodiment, the conductive heating layer 30 can adopt a patterned scheme such as multi-ring, spiral, or radial to optimize coupling and temperature field uniformity. During screen printing, the conductive heating layer 30 can be patterned to optimize coupling and temperature field uniformity. For example, the conductive heating layer 30 can be made into a multi-ring, spiral, or radial pattern.

[0058] In this embodiment, the concentricity tolerance of each layer in the decal 1 is no greater than 0.5 mm. The decal 1 is composed of multiple layers stacked together. This embodiment can ensure that the concentricity tolerance of each layer in the decal 1 is ≤ ±0.5 mm, thereby aligning the centers of each layer and further improving the accuracy of the conductive heating layer 30 and the battery heating base coil 5, thus improving the heating effect.

[0059] In this embodiment, the decorative paper 1 is provided with positioning marks, and the number of positioning marks is not less than 2.

[0060] This embodiment can also provide at least two positioning marks on the decal 1, thereby further improving the accuracy of fixing the decal 1 to the bottom of the insulating container 2. In summary, the positioning and concentricity of the decal directly affect the coupling efficiency with the coil 5.

[0061] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the decal in another embodiment of this application. In this embodiment, the decal 1 further includes an insulating ring 70, which is disposed at the periphery of the conductive heating layer 30 to suppress edge overheating and creepage.

[0062] In this embodiment, a glass insulating ring 70 can be added to the outer periphery of the conductive heating layer 30 to suppress edge overheating and creepage by setting a dielectric isolation strip.

[0063] Please refer to Figure 7 , Figure 7 This is a process flow diagram of the fabrication method of an insulating vessel module according to one embodiment of this application. This embodiment provides a method for fabricating an insulating vessel module, the method comprising steps S100, S200, S300, S400, and S500. Detailed descriptions of steps S100, S200, S300, S400, and S500 are as follows.

[0064] S100, providing a separable substrate, and sequentially screen printing a soluble release layer, an electrically conductive heating layer, a pattern layer, a transparent protective layer, and a separable protective layer on the separable substrate to obtain an initial decal.

[0065] S200, the initial decal is dried at low temperature to obtain the decal for electromagnetic induction heating as provided in the above embodiments of this application.

[0066] S300, the decal is soaked in water to separate the separable substrate.

[0067] S400, the soluble release layer is pre-bonded to the bottom of the insulating vessel.

[0068] S500, sinter the decal to decompose the soluble release layer and the separable protective layer, and fix the conductive heating layer to the bottom of the insulating vessel.

[0069] Based on fixing the decal to the bottom of the insulating container, the decal can be prepared first. Specifically, a separable substrate can be provided first, and then a soluble release layer, an electrically conductive heating layer, a pattern layer, a transparent protective layer, and a separable protective layer can be sequentially screen-printed onto the separable substrate using a 180-400 mesh screen to obtain the initial decal. Before screen-printing the electrically conductive heating layer, the conductive powder, glass powder, and binder weighed according to the formula can be ground to a fineness of less than 100μm using a three-roll mill. Subsequently, it is dried at a low temperature of 60℃-120℃ using hot air or infrared for 5min-15min to obtain the aforementioned decal structure. In addition to the final low-temperature drying, low-temperature drying can be performed after each layer of screen printing.

[0070] After obtaining the decal, it is first soaked in water to separate the separable substrate, exposing the adhesive, soluble release layer. The decal is then transferred to the bottom glaze of the insulating vessel, and the soluble release layer is pre-bonded to the bottom of the vessel using an air-exploding scraper. Finally, the decal is sintered; during this process, the soluble release layer and the separable protective layer decompose and disappear. The conductive powder in the conductive heating layer melts and connects together, and the glass powder melts, thus fixing the conductive heating layer to the bottom of the insulating vessel.

[0071] The preparation method provided in this embodiment is simple. By aligning the conductive heating layer with the coil of the electromagnetic heating base, the two interact to heat the insulating vessel. Furthermore, by making the diameter of the conductive heating layer smaller than the diameters of the pattern layer and the transparent protective layer—in other words, by making the conductive heating layer size mismatched with other layers—the diameter of the conductive heating layer is reduced, and the conductive heating layer does not cover the entire layer. This saves material usage for the conductive heating layer while achieving matching heating areas. A pattern layer and a transparent protective layer are also provided above the conductive heating layer. The pattern layer enhances the appearance of the decal, while the transparent protective layer encapsulates and protects the conductive heating layer and the pattern layer, thus meeting requirements such as food contact safety, dishwasher resistance, and resistance to thermal shock. In addition, the decal structure prepared in this embodiment is simple and compatible with conventional screen printing and ceramic insulating vessel decal firing production lines, enabling the formation of a stable conductive heating layer on insulating vessels in a low-cost, mass-production manner.

[0072] In summary, after the decal transfer and sintering, the conductive heating layer forms a continuous composite film that is firmly bonded to the glaze at the bottom of the insulating vessel; the transparent protective layer covers and seals the underlying pattern layer and the conductive heating layer, ensuring food contact safety and resistance to media.

[0073] Please refer to Figure 8 , Figure 8 for Figure 7The process flow diagram includes S500. In this embodiment, the sintering of the decal in S500 includes S510, S520, S530, and S540. Detailed descriptions of S510, S520, S530, and S540 are as follows.

[0074] S510, first heat the decal to 120℃~180℃ and keep it warm while draining.

[0075] S520 involves heating the drained decals to 350℃~450℃ and maintaining the temperature for glue removal.

[0076] S530 involves heating the degummed decal to 700℃~850℃ and holding it at that temperature to melt and solidify the glass powder.

[0077] S540 cools the solidified decal at a rate not exceeding 3℃ / s.

[0078] During the sintering process, the decal can first be heated to 120℃~180℃ and held for 10min~20min to drain the glass. After draining, the decal is then heated to 350℃~450℃ and held for 10min~20min to remove the adhesive. After removing the adhesive, the decal is then heated to 700℃~850℃ and held for 5min~15min to melt and solidify the glass powder. The solidified decal is then cooled in a controlled manner at a rate not exceeding 3℃ / s.

[0079] This not only improves the adhesion between the conductive heating layer and the insulating vessel, but also makes the interior of the conductive heating layer more compact. Furthermore, it prevents metal oxidation within the conductive heating layer and reduces its internal stress.

[0080] Optionally, a small amount of insulating or slightly reducing atmosphere can be added to the decal on the basis of air atmosphere sintering to further prevent metal oxidation.

[0081] In this embodiment, the thickness of the electrically conductive heating layer in the decal after low-temperature drying is 50μm~200μm.

[0082] This embodiment allows the thickness of the screen-printed conductive heating layer to be 50μm~200μm after low-temperature drying. If the thickness is too large, for example, greater than 200μm, it will not only increase the overall thickness but also fail to improve thermal conductivity. However, if the thickness is too small, for example, less than 50μm, the maximum power will be reduced. The specific thickness of the conductive heating layer can be determined based on the required sheet resistance R. s The target was adjusted. Furthermore, the thickness of the conductive heating layer, patterned layer, and transparent protective layer will shrink by 10% to 30% after sintering.

[0083] In this embodiment, the sheet resistance R of the sintered decal is... SNot greater than 0.02Ω·m to 0.5Ω·m.

[0084] This embodiment controls the sheet resistance R of the sintered decal. S The sheet resistance should be ≤0.02Ω·m to 0.5Ω·m to meet the required heating efficiency. If the sheet resistance is too high, for example greater than 0.5Ω·m, the heating efficiency will be poor; if the sheet resistance is too low, for example less than 0.02Ω·m, it will increase costs. The specific value of the sheet resistance can be set according to the thickness of the conductive heating layer and the metal content.

[0085] In this embodiment, a final inspection can be performed after obtaining the final product, such as on appearance, adhesion (cross-cut, tape), sheet resistance, heating performance, and dishwasher / thermal shock resistance tests. Specifically, the appearance can be observed, and it should be free of pinholes, blistering, cracking, and other problems. Subsequently, the adhesion and washability of the ceramic decals are verified according to GB / T or ASTM relevant ceramic decal adhesion and washability tests. Adhesion is satisfied; after 100 dishwasher cycles and thermal shock (hot water 90℃, cold water 20℃, 10 cycles), there should be no blistering, peeling, or significant resistance drift. Sheet resistance Rs is measured using a four-probe method, with a drift ≤20% and a sheet resistance Rs ≤0.02Ω·m~0.5Ω·m. Furthermore, infrared thermography / embedded thermocouples are used to record the temperature rise curve. For example, under the condition of a matched electromagnetic heating base (e.g., 50W, 20kHz~120kHz), rapid heating and constant temperature maintenance can be achieved under standard water-filled conditions, with a set temperature rise and constant temperature deviation of ±2℃ under standard water-filled conditions. In addition, the final product after coating can pass relevant safety certifications; Table 1. Sheet resistance of conductive heating layers with different compositions after sintering

[0086] Additionally, please refer to Table 1, which provides three specific embodiments. Embodiment 1 uses silver powder, resulting in the lowest sheet resistance after sintering; however, silver powder is expensive, making it suitable for small-area applications. Embodiment 2 uses graphene powder, resulting in moderate sheet resistance after sintering, suitable for large-area applications. Embodiment 3 uses Ni powder or stainless steel powder, resulting in higher sheet resistance after sintering, but with superior dielectric resistance.

[0087] Please refer to Figure 9 , Figure 9 This is a schematic diagram of an insulating container module according to one embodiment of this application. This embodiment provides an insulating container module 3 prepared using the preparation method of the insulating container module 3 provided in the above embodiment of this application. The insulating container module 3 includes an insulating container 2 and a sintered decorative paper 1 fixed to the bottom of the insulating container 2. The decorative paper 1 includes a conductive heating layer 30, a pattern layer 40, and a transparent protective layer 50 stacked together. The conductive heating layer 30 is fixed to the bottom of the insulating container 2.

[0088] In this embodiment, by fixing the decorative paper 1 with an electrically conductive heating layer 30 to the bottom of the insulating container 2, and aligning the electrically conductive heating layer 30 with the coil 5 of the electromagnetic heating base 4, the two interact to heat the insulating container 2. Furthermore, by making the diameter of the electrically conductive heating layer 30 smaller than the diameters of the pattern layer 40 and the transparent protective layer 50—in other words, by making the size of the electrically conductive heating layer 30 mismatched with the other layers—and reducing the diameter of the electrically conductive heating layer 30, the electrically conductive heating layer 30 does not cover the entire layer. This saves material usage for the electrically conductive heating layer 30 while achieving matching heating areas. Additionally, a pattern layer 40 and a transparent protective layer 50 are provided on one side of the electrically conductive heating layer 30. The pattern layer 40 enhances the appearance of the decorative paper 1, while the transparent protective layer 50 encapsulates and protects the electrically conductive heating layer 30 and the pattern layer 40, thereby meeting requirements such as food contact safety, dishwasher resistance, and resistance to thermal shock. In addition, the decal 1 of this embodiment has a simple structure and is compatible with conventional screen printing and ceramic insulating vessel 2 decal firing production lines, so as to form a stable electrically conductive heating layer 30 on the insulating vessel 2 in a low-cost and mass production manner.

[0089] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0090] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise expressly specified. Moreover, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0091] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0092] The foregoing has provided a detailed description of the embodiments of this application, elucidating and explaining the principles and implementation methods of this application. These descriptions are merely for the purpose of aiding understanding the method and core ideas of this application. However, the content of this specification should not be construed as a limitation of this application. Those skilled in the art can make various modifications and variations to this application without departing from its spirit and scope. These modifications and variations fall within the scope of the claims of this application and their equivalents.

Claims

1. A type of decal for electromagnetic induction heating, characterized in that, The decorative paper is used to fix it to the bottom of the insulating container. The decorative paper includes a separable base, a soluble release layer, an electrically conductive heating layer, a pattern layer, a transparent protective layer, and a separable protective layer stacked in sequence. The electrically conductive heating layer is used to correspond to the coil of the electromagnetic heating base so that the electrically conductive heating layer heats up. Wherein, the diameter of the conductive heating layer is D mag The diameter of both the pattern layer and the transparent protective layer is D. top D mag <D top .

2. The decal for electromagnetic induction heating as described in claim 1, characterized in that, The effective coupling outer diameter of the coil of the electromagnetic heating base is D. coil D mag / D coil =1.01~1.1; and / or, the decorative diameter of the bottom of the insulating vessel is D. decor D mag <D top ≤D decor .

3. The decal for electromagnetic induction heating as described in claim 1, characterized in that, The decal is prepared by screen printing, and the pattern layer is also provided around the periphery of the electrically conductive heating layer to improve the stability of the decal.

4. The decal for electromagnetic induction heating as described in claim 1, characterized in that, The conductive heating layer is made of 65% to 85% conductive powder, 5% to 15% glass powder, and 10% to 30% adhesive solution, wherein the melting point of the glass powder is 700°C to 850°C.

5. The decal for electromagnetic induction heating as described in claim 4, characterized in that, The conductive powder has a particle size of 1μm to 100μm; and / or, the particle size D50 of the conductive powder is 35μm to 50μm; and / or, the softening point of the glass powder is 450℃ to 600℃.

6. The decal for electromagnetic induction heating as described in claim 1, characterized in that, The conductive heating layer can adopt a multi-ring, spiral, or radial pattern to optimize coupling and temperature field uniformity.

7. The decal for electromagnetic induction heating as described in claim 1, characterized in that, The decal also includes an insulating ring disposed around the periphery of the conductive heating layer to suppress edge overheating and creepage.

8. A method for preparing an insulating container module, characterized in that, The preparation method includes: A separable substrate is provided, and a soluble release layer, an electrically conductive heating layer, a pattern layer, a transparent protective layer, and a separable protective layer are sequentially screen-printed onto the separable substrate to obtain an initial decal. The initial decal is dried at low temperature to obtain the decal for electromagnetic induction heating as described in any one of claims 1 to 7; The decal is soaked in water to separate the separable substrate; The soluble release layer is pre-bonded to the bottom of the insulating vessel; The decal is sintered to decompose the soluble release layer and the separable protective layer, and to fix the conductive heating layer to the bottom of the insulating vessel.

9. The method for preparing the insulating vessel module as described in claim 8, characterized in that, The sintered decals include: First, heat the decal to 120℃~180℃ and keep it warm while draining the water. After draining the decals, heat them to 350℃~450℃ and keep them warm to remove the glue. After the glue has been removed, the decal is heated to 700℃~850℃ and kept at that temperature to melt and solidify the glass powder. The solidified decals are cooled at a rate not exceeding 3℃ / s.

10. An insulating container module prepared using the method for preparing an insulating container module as described in any one of claims 8 to 9, characterized in that, The insulating container module includes an insulating container and sintered decorative paper fixed to the bottom of the insulating container. The decorative paper includes a layered conductive heating layer, a pattern layer, and a transparent protective layer. The conductive heating layer is fixed to the bottom of the insulating container.

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