Heating film and preparation method therefor, heating element and electric heating appliance

Abstract

A heating film and a preparation method therefor, a heating element and an electric heating appliance. The heating film comprises graphene and an auxiliary, wherein the auxiliary comprises at least one of a reinforcing agent, a temperature increasing agent and a spectral modifier; the reinforcing agent comprises at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol and chitin; the temperature increasing agent comprises at least one of carbon nanotubes, fullerene, carbon black and graphene microsheets; and the spectral modifier comprises at least one of silicon carbide, boron nitride and silicon nitride.

Description

Heating diaphragm and preparation method thereof, heating element and heating appliance

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims the benefit of priority to Chinese patent application No. 2023117507525, filed on December 18, 2023, and incorporates the entirety of the patent application herein. Technical Field

[0003] The present disclosure relates to the field of electrical appliance technology, and more specifically, to a heating diaphragm and a preparation method thereof, a heating element, and a heating appliance. Background Art

[0004] Traditional electric ovens mainly heat the air in the cavity through heating elements, thereby heating the food, and directly heat the surface of the food through heat radiation. Currently, the heating elements used in electric ovens, microwave ovens, steam ovens and other heating appliances on the market mainly include metal heating tubes (maximum heating temperature range between 550 and 750 ° C), quartz heating tubes (heating wire temperature range between 660 and 800 ° C), halogen heating tubes (maximum heating temperature less than 1000 ° C) and carbon fiber heating tubes (maximum heating temperature less than 1000 ° C). However, the above heating elements have disadvantages such as a small proportion of radiation heating in the heating temperature range, a long temperature rise time in the heating area, low heating efficiency, and inability to effectively concentrate energy. As a result, the heating tubes have problems such as low heating efficiency, slow temperature rise rate, insufficient temperature, insufficient heating speed, and slow temperature rise rate. This prolongs the cooking time and makes it difficult to achieve crispy outside and tender inside food during the heating process, resulting in a poor user experience.

[0005] Summary of the Invention

[0006] The present disclosure aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one purpose of the present disclosure is to provide a heating film having a high heating temperature, which can effectively increase the heating temperature of a heating element using the heating film.

[0007] In one aspect of the present disclosure, the present disclosure provides a heating film. According to an embodiment of the present disclosure, the heating film includes graphene and an auxiliary agent, and the auxiliary agent includes at least one of an enhancer, a warming agent and a spectrum regulator, wherein the enhancer includes at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol and chitin; the warming agent includes at least one of carbon nanotubes, fullerenes, carbon black and graphene microsheets; the spectrum regulator includes at least one of silicon carbide, boron nitride and silicon nitride. Therefore, graphene as the heating material of the heating film can make the heating film have a better heating temperature, a faster heating rate and a higher emissivity; and the graphene and the heating film are both sheet structures. When the heating film generates heat, the heat is mainly radiated along the vertical direction of the heating surface, with strong directivity and more concentrated radiated heat, thereby better improving the heating efficiency.

[0008] According to an embodiment of the present disclosure, the heating film satisfies at least one of the following conditions: the heating film is the graphene; or, based on the total mass of the heating film, the heating film includes 95% to 99.95% of the graphene and 0.05% to 5% of the enhancer in terms of mass percentage; or, based on the total mass of the heating film, the heating film includes 70% to 80% of the graphene and 20% to 30% of the warming agent in terms of mass percentage; or, based on the total mass of the heating film, the heating film includes 90% to 99% of the graphene and 1% to 10% of the spectrum regulator in terms of mass percentage; or, based on the total mass of the heating film, the heating film includes 70% to 80% of the graphene, 0.05% to 5% of the enhancer and 20% to 30% of the warming agent; or, based on the total mass of the heating film, the heating film includes 80% to 99% of the graphene, 0.05% to 5% of the enhancer and 1% to 10% of the spectrum regulator; or, based on the total mass of the heating film, the heating film includes 70% to 80% of the graphene, 20% to 30% of the warming agent and 1% to 10% of the spectrum regulator; or, based on the total mass of the heating film, the heating film includes 70% to 80% of the graphene, 0.05% to 5% of the enhancer, 20% to 30% of the warming agent and 1% to 10% of the spectrum regulator.

[0009] According to an embodiment of the present disclosure, the maximum heating temperature of the heating film is 500°C to 1700°C.

[0010] According to an embodiment of the present disclosure, the emission wavelength of the heating film is 3 to 15 microns.

[0011] According to an embodiment of the present disclosure, the thickness of the heating film is 20 to 1000 microns.

[0012] According to an embodiment of the present disclosure, the heating film includes a plurality of heating units sequentially arranged along the length direction, and adjacent heating units are arranged at intervals and connected by connecting sections.

[0013] According to an embodiment of the present disclosure, the outer peripheral wall of the heating unit is formed in an oblong or polygonal shape.

[0014] According to an embodiment of the present disclosure, each of the heating units is provided with a hollow hole.

[0015] According to an embodiment of the present disclosure, the heating diaphragm includes a first heating segment and a second heating segment adjacent to each other in the length direction, the first heating segment includes a plurality of connected heating units, the second heating segment includes a plurality of adjacent heating units, the size of the heating unit corresponding to the first heating segment is smaller than the size of the heating unit corresponding to the second heating segment; and / or, the first heating segment and the second heating segment are staggered in the width direction of the heating diaphragm.

[0016] According to an embodiment of the present disclosure, the heating membrane includes a plurality of notches arranged at intervals along the length direction.

[0017] According to an embodiment of the present disclosure, each of the gaps is defined by separating a portion of the heating membrane from the remaining portion and then bending it.

[0018] In another aspect of the present disclosure, a method for preparing the aforementioned heating film is provided. According to an embodiment of the present disclosure, the method for preparing the heating film comprises: uniformly dispersing graphene oxide and an auxiliary agent in a solvent to obtain a dispersion, wherein the auxiliary agent comprises at least one of an enhancer, a warming agent, and a spectrum modifier; applying and drying the dispersion to obtain a graphene oxide film layer; sequentially performing a low-temperature treatment, a carbonization treatment, and a graphitization treatment on the graphene oxide film layer to obtain a graphene film layer; and rolling and cutting the graphene film layer to obtain the heating film. Therefore, the heating diaphragm is prepared by the above method, and graphene is used as the heating material of the heating diaphragm, which can make the heating diaphragm have a better heating temperature, a faster heating rate and a higher emissivity; and both graphene and the heating diaphragm are sheet structures. When the heating diaphragm generates heat, the heat is mainly radiated along the vertical direction of the heating surface, with strong directionality and more concentrated radiated heat, thereby better improving the heating efficiency; furthermore, the raw material for preparation is graphene oxide, the production process is simple and easy to implement, and it is easy to modify it, so as to improve the performance of the heating diaphragm.

[0019] According to an embodiment of the present disclosure, the solid content of the dispersion is 1% to 10%, preferably 3% to 7%.

[0020] According to an embodiment of the present disclosure, the maximum temperature of the low-temperature treatment is 250°C to 400°C, and the holding time at the maximum temperature is 5 min-3 h; the maximum temperature of the carbonization treatment is 900°C to 1300°C, and the holding time is 5 min-3 h; the maximum temperature of the graphitization treatment is 1800°C to 3150°C, and the holding time is 5 min-3 h.

[0021] According to an embodiment of the present disclosure, the carbon content of the graphene film layer is greater than or equal to 99%.

[0022] In another aspect of the present disclosure, a heating element is provided. According to an embodiment of the present disclosure, the heating element includes the aforementioned heating diaphragm. As a result, the heating element has a higher heating temperature, a faster heating rate, a larger radiant heating ratio, and a more concentrated heating area, greatly improving the heating efficiency of the heating element. Those skilled in the art will appreciate that the heating element has all the features and advantages of the aforementioned heating diaphragm, and no further details will be given here.

[0023] In yet another aspect of the present disclosure, a heating appliance is provided. According to an embodiment of the present disclosure, the heating appliance includes the aforementioned heating element. As a result, the heating appliance achieves a higher heating temperature, a faster heating rate, a larger radiant heating ratio, and a more concentrated heating area, significantly improving the heating efficiency of the heating element.

[0024] According to an embodiment of the present disclosure, the heating appliance is an electric oven, a microwave oven, a steam oven, an electric kettle, an electric blanket, an electric fan heater, an electric heater, a bathroom heater, an electric ceramic stove or a disinfection cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and / or additional aspects and advantages of the present disclosure will become apparent and readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0026] FIG1 is a schematic structural diagram of a heating membrane in an embodiment of the present disclosure;

[0027] FIG2 is a schematic structural diagram of a heating film in some other embodiments of the present disclosure;

[0028] FIG3 is a schematic structural diagram of a heating film in other embodiments of the present disclosure;

[0029] FIG4 is a schematic structural diagram of a heating film in other embodiments of the present disclosure;

[0030] FIG5 is a schematic structural diagram of a heating element in some other embodiments of the present disclosure;

[0031] FIG6 is a schematic structural diagram of a heating element in some other embodiments of the present disclosure;

[0032] FIG7 is a schematic structural diagram of a heating element in some other embodiments of the present disclosure. DETAILED DESCRIPTION

[0033] The scheme of the present disclosure will be explained below in conjunction with the examples. Those skilled in the art will understand that the following examples are only used to illustrate the present disclosure and should not be considered to limit the scope of the present disclosure. Where specific techniques or conditions are not specified in the examples, they are carried out according to the techniques or conditions described in the literature in this area or according to the product instructions. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0034] The present disclosure is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present disclosure in any way.

[0035] In one aspect of the present disclosure, the present disclosure provides a heating film. According to an embodiment of the present disclosure, the heating film includes graphene and an auxiliary agent, and the auxiliary agent includes at least one of an enhancer, a warming agent and a spectrum regulator, wherein the enhancer includes at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol and chitin; the warming agent includes at least one of carbon nanotubes, fullerenes, carbon black and graphene microsheets; the spectrum regulator includes at least one of silicon carbide, boron nitride and silicon nitride. Therefore, graphene as the heating material of the heating film can make the heating film have a better heating temperature, a faster heating rate and a higher thermal radiation power; and the graphene and the heating film are both sheet structures. When the heating film generates heat, the heat is mainly radiated along the vertical direction of the heating surface, with strong directivity and more concentrated radiated heat, thereby better improving the heating efficiency. Furthermore, the present disclosure uses graphene, which has a sheet-like structure, and the single-layer graphene is relatively close to each other, and the thickness of the single-sheet graphene is relatively thin, which can make the graphene film have good bending resistance, that is, it helps to improve the bending resistance of the heating film. When designing the cutting shape of the heating film, it can be unaffected by easy bending, and the operating controls are large, which is convenient for assembly, thereby improving the production yield. Furthermore, the inventors found that under the condition of a certain density, the resistance of the graphene film decreases with the increase of thickness; under the condition of a certain thickness and density, the resistance of the graphene film increases with the increase of temperature. Based on this, the resistance of the heating film can be flexibly designed according to the thickness of the heating film and the heating temperature and other conditions, and then its power can be adjusted. In this way, in the present disclosure, heating films of various powers can be obtained by adjusting the above-mentioned different parameters. As for the above advantages, the inventors have not found that any material currently used to make heating films can achieve the above-mentioned technical effects of the present disclosure.

[0036] Furthermore, the auxiliary agent included in the heating film can be used in the preparation process, and the auxiliary agent may include at least one of an enhancer, a warming agent and a spectrum regulator to improve the performance of the heating film. Specifically, the above-mentioned small molecule or high molecular organic matter forms a chemical bond (CC bond) between its carbon element and graphene, and the enhancer can effectively enhance the connectivity between graphene layers, thereby better improving the structural stability of the heating film. Specifically, it may include at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol and chitin; in some embodiments, the warming agent may be carbon nanoparticles, specifically, it may include at least one of carbon nanotubes, fullerenes, carbon black and graphene microsheets. In the process of preparing the heating film, it can effectively prevent the secondary graphitization of graphite materials at high temperatures, reduce melting, and also It helps to effectively improve the maximum operating temperature of the heating film, that is, to increase the maximum heating temperature of the heating film; in some embodiments, the spectrum regulator can be nanoparticles, and the spectrum regulator includes at least one of silicon carbide, boron nitride and silicon nitride. The above-mentioned spectrum regulator can effectively adjust the emission spectrum of the heating film to obtain a heating film with a larger emission spectrum. Moreover, the above-mentioned spectrum regulator is non-conductive and high-temperature resistant (temperature resistance is greater than or equal to 1300°C). The resistance of the heating film can be adjusted by adjusting the amount of the spectrum regulator. The higher the content used, the greater the resistance of the heating film, the relatively lower the maximum heating temperature of the heating film, and the relatively longer the emission wavelength of the heating film. In summary, in the present disclosure, a heating film with a suitable maximum heating temperature and a larger emission wavelength can be obtained by adjusting the amount of auxiliary agents such as the warming agent and the spectrum regulator (the shorter the emission wavelength, the higher the radiation energy of the heating film).

[0037] Among them, graphene has a relatively high emissivity coefficient of over 90%, which is much higher than the 60% of natural graphite and 80% of artificial graphite. Therefore, in the present disclosure, the use of graphene can effectively improve the emissivity coefficient of the heating diaphragm, thereby increasing its thermal radiation power, and increasing the heating rate and maximum heating temperature of the heating diaphragm.

[0038] According to some embodiments of the present disclosure, the heating film is graphene, that is, the heating film is made only of graphene. In this way, the heating film has a higher heating temperature, higher thermal radiation power, and better bending resistance, which is beneficial to a variety of different cutting designs of the heating film.

[0039] According to some embodiments of the present disclosure, based on the total mass of the heating film, the heating film includes 95% to 99.95% (such as 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, 99.95%, etc.) of graphene and 0.05% to 5% (such as 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4% of graphene). %, 4.5%, 5%, etc.) of the reinforcing agent, that is, when preparing the heating film, a certain amount of reinforcing agent is added to the graphene. The reinforcing agent in the above proportion can ensure a higher heating temperature, higher thermal radiation power, and better bending resistance of the heating film, while further improving the layer connection force between the multiple graphene layers in the heating film, thereby better improving the structural stability of the heating film to prevent the undesirable phenomenon of dislocation or falling off of the graphene layer of the heating film in subsequent processing technology.

[0040] According to some embodiments of the present disclosure, based on the total mass of the heating film, the heating film includes 70% to 80% (such as 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) of the graphene and 20% to 30% (such as 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) of the warming agent in terms of mass percentage. That is, when preparing the heating film, a certain amount of warming agent is added to the graphene. The above proportion of warming agent can further increase the maximum heating temperature of the heating film while ensuring higher thermal radiation power and better bending resistance of the heating film.

[0041] According to some embodiments of the present disclosure, based on the total mass of the heating film, the heating film includes 90% to 99% (for example, 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, etc.) of graphene and 1% to 10% (for example, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, etc.) of spectrum regulator, that is, when preparing the heating film, a certain amount of enhancer is added to the graphene. The enhancer in the above proportion can further improve the emission spectrum of the heating film while ensuring a higher heating temperature and better bending resistance of the heating film, thereby further improving the thermal radiation power of the heating film.

[0042] According to some embodiments of the present disclosure, based on the total mass of the heating film, the heating film includes 70% to 80% (such as 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) of graphene, 0.05% to 5% (such as 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.) of the reinforcing agent and 20% to 30% (such as 20%, 21%, 22%, 23%, 24%, 25%, 26%, etc.) of the heating film. %, 27%, 28%, 9%, 30%, etc.) of the warming agent, that is, when preparing the heating film, a certain amount of the reinforcing agent and the warming agent are added to the graphene. The reinforcing agent and the warming agent in the above proportion can ensure the higher heating temperature, higher thermal radiation power and better bending resistance of the heating film, while further improving the layer connection force between the multi-layer graphene layers in the heating film, thereby better improving the structural stability of the heating film, to prevent the undesirable phenomenon of dislocation or falling off of the graphene layer of the heating film in the subsequent processing technology, and further improve the maximum heating temperature of the heating film.

[0043] According to some embodiments of the present disclosure, based on the total mass of the heating film, the heating film includes 80% to 99% (such as 80%, 81%, 82%, 83%, 84%, 85%, 6%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, etc.) of graphene, 0.05% to 5% (such as 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.) of the reinforcing agent and 1% to 10% (such as 1%, 1.5%, 2%, 2.5%, 3%. 5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, etc.), that is, when preparing the heating film, a certain amount of enhancer and spectrum regulator is added to the graphene. The enhancer and spectrum regulator in the above proportion can ensure the higher heating temperature, higher thermal radiation power and better bending resistance of the heating film, while further improving the layer connection force between the multi-layer graphene layers in the heating film, thereby better improving the structural stability of the heating film, to prevent the undesirable phenomenon of dislocation or falling off of the graphene layer of the heating film in the subsequent processing technology, and further improve the emission spectrum of the heating film, thereby further improving the thermal radiation power of the heating film.

[0044] According to some embodiments of the present disclosure, based on the total mass of the heating film, the heating film includes 70% to 80% (such as 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) of graphene, 20% to 30% (such as 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) of warming agent and 1% to 10% (such as 1%, 1.5%, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) of graphene. 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, etc.) of the spectrum regulator, that is, when preparing the heating film, a certain amount of warming agent and spectrum regulator is added to the graphene. The warming agent and spectrum regulator in the above proportion can ensure a higher heating temperature, higher thermal radiation power, and better bending resistance of the heating film, while further increasing the maximum heating temperature of the heating film, and further increasing the emission spectrum of the heating film, thereby further increasing the thermal radiation power of the heating film.

[0045] According to some embodiments of the present disclosure, based on the total mass of the heating film, the heating film includes 70% to 80% (such as 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) of graphene, 0.05% to 5% (such as 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, etc.) of graphene, and 0.05% to 5% (such as 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, etc.) of graphene. %, 4%, 4.5%, 5%, etc.) of an enhancer, 20% to 30% (such as 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) of a warming agent and 1% to 10% (such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, etc.) of a spectrum regulator. The above-mentioned proportions of enhancers, warming agents and spectrum regulators can further improve the layer connection strength between the multiple graphene layers in the heating film while ensuring a higher heating temperature, higher thermal radiation power and better bending resistance of the heating film, thereby better improving the structural stability of the heating film to prevent the undesirable phenomenon of dislocation or falling off of the graphene layer of the heating film in subsequent processing technology. It can also further increase the maximum heating temperature of the heating film, and further improve the emission spectrum of the heating film, thereby further improving the thermal radiation power of the heating film.

[0046] According to some embodiments of the present disclosure, the heating temperature of the heating film is 500°C to 1700°C. For example, the heating temperature of the heating film can be 500°C, 550°C, 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C, 1200°C, 1300°C, 1400°C, 1500°C, 1600°C, 1700°C, etc. It can be seen that the heating temperature of the heating film of the present disclosure can reach up to 1700°C. Moreover, those skilled in the art can flexibly adjust the maximum heating temperature of the heating film by adjusting the amount of auxiliary agents such as warming agents and the amount of graphene according to the specific application requirements of the heating film, thereby meeting more application heating requirements of the heating film.

[0047] According to some embodiments of the present disclosure, the emission wavelength of the heating film is 3 to 15 microns, such as 3 microns, 4 microns, 5 microns, 6 microns, 7 microns, 8 microns, 9 microns, 10 microns, 12 microns, 13 microns, 14 microns, 15 microns, etc. It can be seen that the maximum emission wavelength of the heating film of the present disclosure can reach 15 microns, that is, the heating film has a larger proportion of radiation heating, which can better improve the heating rate, thereby improving the heating efficiency, and improving the centralized heating effect of heat addition, thereby improving energy utilization. Moreover, in the present disclosure, the specific emission wavelength of the heating film can be flexibly adjusted by adjusting the content of the spectrum regulator, so that the heating film can meet a variety of application requirements.

[0048] According to some embodiments of the present disclosure, the thickness of the heating film is 20 to 1000 microns, such as 20 microns, 50 microns, 70 microns, 100 microns, 130 microns, 150 microns, 180 microns, 200 microns, 250 microns, 300 microns, 350 microns, 400 microns, 450 microns, 500 microns, 550 microns, 600 microns, 650 microns, 700 microns, 750 microns, 800 microns, 850 microns, 900 microns, 950 microns, 1000 microns, etc. As mentioned above, under the condition of a certain density, the resistance of the graphene film decreases with increasing thickness; under the condition of a certain thickness and density, the resistance of the graphene film decreases with increasing temperature. Thus, in the present disclosure, the resistance of the heating film can be adjusted by simultaneously adjusting the thickness, density, etc. of the heating film, thereby adjusting the heating temperature and emission wavelength of the heating film. Under the above thickness conditions, while meeting the higher heating temperature and emission wavelength of the heating film, the heating film has an appropriate density, which facilitates the design of various cutting types of the heating film.

[0049] In the embodiments of the present disclosure, the specific cutting shape of the heating film can be diversified. Those skilled in the art can flexibly design the cutting shape of the heating film according to the actual requirements of the resistance, power, etc. of the heating film. The following introduces some cutting shapes of the heating film based on some specific embodiments of the present disclosure:

[0050] In some embodiments of the present disclosure, referring to FIG1 , the heating film includes a plurality of heating units 01 arranged sequentially along the length direction, with adjacent heating units 01 spaced apart and connected by connecting segments 02 . Thus, the heating film of the present disclosure can be cut into a variety of decoupled strands of different cuts to meet different usage requirements. Specifically, in some embodiments of the present disclosure, referring to FIG1 , the outer peripheral wall of the heating unit is formed into an oblong or polygonal shape.

[0051] In some embodiments of the present disclosure, referring to (b), (c), and (i) of FIG1 , each heating unit 01 is provided with a hollow hole 03. Thus, the provision of the hollow hole can accelerate the heat dissipation rate of the heating membrane and accelerate the heating rate of the object to be heated.

[0052] In some embodiments of the present disclosure, referring to FIG2 , the heating diaphragm includes a first heating segment S1 and a second heating segment S2 adjacent to each other in the length direction, the first heating segment S1 includes a plurality of connected heating units 01, the second heating segment S2 includes a plurality of adjacent heating units 10, the size of the heating unit 01 corresponding to the first heating segment S1 is smaller than the size of the heating unit 10 corresponding to the second heating segment S2, such as in FIG2 (a), the length of the heating unit 01 corresponding to the first heating segment S1 and the length of the heating unit 10 corresponding to the second heating segment S2 are the same, but the widths d1 and d2 of the two are different, such as in FIG2 (b) and (c), the width of the heating unit 01 corresponding to the first heating segment S1 and the width of the heating unit 10 corresponding to the second heating segment S2 are the same, but the lengths d1 and d2 of the two are different. This can achieve the diversification of the heating diaphragm structure.

[0053] In some embodiments of the present disclosure, referring to FIG3 , the first heating segment S1 and the second heating segment S2 are staggered in the width direction of the heating diaphragm, thereby achieving a diversified structure of the heating diaphragm.

[0054] In some embodiments of the present disclosure, referring to (d), (e), (f), (h), (i), and (j) in FIG1 , the heating diaphragm includes a plurality of notches spaced apart along its length. This allows for a variety of heating diaphragm structures. Furthermore, in some embodiments of the present disclosure, referring to (i) in FIG1 , each notch is defined by separating a portion of the heating diaphragm from the rest and then bending it.

[0055] In some embodiments, as shown in FIG. 4 , the same heating film may include a plurality of different cut types, or include the same cut type with uneven density distribution.

[0056] In another aspect of the present disclosure, the present disclosure provides a method for preparing the aforementioned heating film. According to an embodiment of the present disclosure, the method for preparing the heating film includes:

[0057] S100: uniformly dispersing graphene oxide and an additive in a solvent to obtain a dispersion.

[0058] According to some embodiments of the present disclosure, the auxiliary agent includes at least one of an enhancer, a warming agent, and a spectrum modifier, wherein the solvent may be water.

[0059] According to some embodiments of the present disclosure, the solids content of the dispersion is 1% to 10%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc. In dispersions with these solids contents, solutes such as graphene are more evenly dispersed and facilitate uniform coating. If the solids content is less than 1%, the dispersion is relatively thin and has relatively high fluidity, which is not conducive to coating and also affects the uniformity of the resulting graphene oxide film. If the solids content of the dispersion is greater than 10%, the dispersion is relatively difficult to disperse evenly. In some specific embodiments, the solids content of the dispersion is 3% to 7%.

[0060] S200: coating and drying the dispersion to obtain a graphene oxide film layer.

[0061] There are no special requirements for the specific coating method. Those skilled in the art can flexibly select an appropriate coating method according to actual conditions, such as spin coating, scraping coating, etc., as long as it is conducive to obtaining a graphene oxide film with uniform thickness.

[0062] S300: performing low-temperature treatment, carbonization treatment and graphitization treatment on the graphene oxide film layer in sequence to obtain a graphene film layer.

[0063] In the above steps, the graphene oxide is deoxidized by low-temperature treatment, carbonization treatment and graphitization treatment to obtain a graphene film layer.

[0064] In some embodiments, the maximum temperature of the low-temperature treatment is 250°C to 400°C, such as 250°C, 280°C, 300°C, 320°C, 350°C, 380°C, 400°C, etc., and the holding time at the maximum temperature is 5min-3h (such as 5min, 10min, 30min, 45min, 1h, 1.5h, 2h, 2.5h, 3h, etc.). Under the above conditions, the graphene oxide begins to deoxidize and its oxygen content can be controlled within 10%; the maximum temperature of the carbonization treatment is 900°C to 1300°C, such as 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, 1250°C, 1300°C, etc., and the holding time at the maximum temperature is 5min-3h (such as 5min, 10min, 30mi n, 45min, 1h, 1.5h, 2h, 2.5h, 3h, etc.), under the above carbonization conditions, the graphene oxide continues to be deoxidized, and its oxygen content can be controlled within 5%; the maximum temperature of the graphitization treatment is 1800°C to 3150°C, such as 1800°C, 1900°C, 2000°C, 2100°C, 2200°C, 2300°C, 2400°C, 2500°C, 2600°C, 2700°C, 2800°C, 2900°C, 3000°C, 3100°C, 3150°C, etc., and the holding time at the maximum temperature is 5min-3h (such as 5min, 10min, 30min, 45min, 1h, 1.5h, 2h, 2.5h, 3h, etc.). Under the above conditions, the deoxidation treatment of the graphene oxide can be effectively completed to obtain a graphene film layer.

[0065] According to some embodiments of the present disclosure, the heating film comprises only graphene, i.e., no additives such as enhancers, warming agents, or spectrum modifiers are added to the heating film. The carbon content of the graphene film layer prepared by the above method is greater than or equal to 99%. As a result, the graphene in the prepared graphene film layer is of high purity, which facilitates the production of a heating film with better performance.

[0066] S400: rolling and shearing the graphene film layer to obtain a heating film. The cut shape of the heating film obtained after shearing can be referred to Figures 1 to 4.

[0067] According to the embodiments of the present disclosure, graphene is used as the heating material of the heating diaphragm, which can make the heating diaphragm have a better heating temperature, a faster heating rate and a higher thermal radiation power; and both graphene and the heating diaphragm are sheet-like structures. When the heating diaphragm generates heat, the heat is mainly radiated along the vertical direction of the heating surface, with strong directivity and more concentrated radiated heat, thereby better improving the heating efficiency. Furthermore, the present disclosure uses graphene, which has a sheet-like structure, and the single-layer graphene is relatively close to each other, and the thickness of the single-sheet graphene is relatively thin, thereby making the graphene film have good bending resistance, that is, it helps to improve the bending resistance of the heating diaphragm. When designing the cutting shape of the heating diaphragm, it can be unaffected by easy bending, and the operating controls are large and easy to assemble, thereby improving the production yield. Furthermore, the inventors found that under the condition of a certain density, the resistance of the graphene film decreases as the thickness increases; under the condition of a certain thickness and density, the resistance of the graphene film decreases as the temperature increases. Based on this, the resistance of the heating film can be flexibly designed according to the thickness of the heating film and the heating temperature and other conditions, and then its power can be adjusted. In this way, in the present disclosure, heating films of various powers can be obtained by adjusting the above-mentioned different parameters. As for the above-mentioned advantages, the inventors have not found that any material currently used to make heating films can achieve the above-mentioned technical effects of the present disclosure. Furthermore, the raw material for preparation is graphene oxide, the production process is simple and easy to implement, and it is easy to modify it, so as to improve the performance of the heating film.

[0068] Moreover, in some embodiments, the enhancer includes at least one of ammonia, glucose, ethylene glycol, ethylenediamine, carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol and chitin. The above-mentioned small molecule or high molecular organic matter forms a chemical bond (CC bond) between its carbon element and graphene. The enhancer can effectively enhance the connectivity between graphene layers, thereby better improving the structural stability of the heating film; in some embodiments, the warming agent can be carbon nanoparticles, specifically including at least one of carbon nanotubes, fullerenes, carbon black and graphene microsheets. In the process of preparing the heating film, it can effectively prevent the secondary graphitization of the graphite material at high temperature and reduce melting. It also helps to effectively increase the maximum operating temperature of the heating film, that is, to increase the maximum heating temperature of the heating film; in some embodiments, the spectrum regulator can be nanoparticles, and the spectrum regulator includes at least one of silicon carbide, boron nitride and silicon nitride. The above-mentioned spectrum regulator can effectively adjust the emission spectrum of the heating film to obtain a heating film with a larger emission spectrum. Moreover, the above-mentioned spectrum regulator is non-conductive and high-temperature resistant (temperature resistance is greater than or equal to 1300°C), and the resistance of the heating film can be adjusted by adjusting the amount of spectrum regulator. The higher the content used, the greater the resistance of the heating film, the relatively lower the maximum heating temperature of the heating film, and the relatively longer the emission wavelength of the heating film. In summary, in the present disclosure, a heating film with a suitable maximum heating temperature and a larger emission wavelength can be obtained by adjusting the amount of auxiliary agents such as the warming agent and the spectrum regulator.

[0069] In another aspect of the present disclosure, a heating element is provided. According to an embodiment of the present disclosure, the heating element includes the aforementioned heating diaphragm. As a result, the heating element has a higher heating temperature, a faster heating rate, a larger radiation heating ratio, and a more concentrated heating area, greatly improving the heating efficiency of the heating element. Those skilled in the art will understand that the heating element has all the features and advantages of the aforementioned heating diaphragm, and will not be elaborated on here.

[0070] In some embodiments, referring to Figure 5 (the S area in the figure refers to a partial cross-sectional view of the sleeve), Figure 6 and Figure 7, the heating element also includes a sleeve 10, and the heating membrane 20 is placed in the sleeve 10. Terminals 21 are provided at both ends of the heating membrane 20, wherein the sleeve can be a quartz glass tube, etc.

[0071] In yet another aspect of the present disclosure, a heating appliance is provided. According to an embodiment of the present disclosure, the heating appliance includes the aforementioned heating element. As a result, the heating appliance achieves a higher heating temperature, a faster heating rate, a larger radiant heating ratio, and a more concentrated heating area, significantly improving the heating efficiency of the heating element.

[0072] According to an embodiment of the present disclosure, the heating appliance is an electric oven, a microwave oven, a steam oven, an electric kettle, an electric blanket, or an electric fan heater.

[0073] Those skilled in the art will understand that, in addition to the above-mentioned heating elements, the heating appliance also includes the necessary structures or components of the heating appliance. Taking the electric oven as an example, in addition to the above-mentioned heating elements, it also includes the necessary structures or components such as the shell, heating space, base, and plug.

[0074] Example

[0075] Example 1

[0076] The graphene oxide is homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 6%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 300°C, insulation time of 0.5h), carbonization treatment (temperature of 1100°C, insulation time of 1h), and graphitization treatment (temperature of 2000°C, insulation time of 2h) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, a low-power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 750°C (i.e., the maximum heating temperature) and the emission wavelength is 10μm.

[0077] Example 2

[0078] Graphene oxide and glucose are mixed in a mass ratio of 1:0.1 and homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 4.2%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 400°C, holding time of 1h), carbonization treatment (temperature of 1200°C, holding time of 0.5h), and graphitization treatment (temperature of 2600°C, holding time of 1h) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, a low-power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 950°C (i.e., the maximum heating temperature) and the emission wavelength is 8μm.

[0079] Example 3

[0080] Graphene oxide and carboxymethyl cellulose are mixed in a mass ratio of 1:0.15 and homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 4.5%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 350°C, holding time of 1h), carbonization treatment (temperature of 1150°C, holding time of 0.5h), and graphitization treatment (temperature of 2800°C, holding time of 15min) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, a low-power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 850°C (i.e., the maximum heating temperature) and the emission wavelength is 9μm.

[0081] Example 4

[0082] After mixing graphene oxide and carbon nanotubes in a mass ratio of 7:3, they are homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 5.5%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 400°C, holding time of 2h), carbonization treatment (temperature of 1300°C, holding time of 0.5h), and graphitization treatment (temperature of 3100°C, holding time of 0.5h) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, an ultra-high power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 1700°C (i.e., the maximum heating temperature) and the emission wavelength is 3μm.

[0083] Example 5

[0084] Graphene oxide and silicon carbide nanoparticles are mixed in a mass ratio of 9:1 and homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 3.5%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 250°C, holding time of 1h), carbonization treatment (temperature of 1300°C, holding time of 0.5h), and graphitization treatment (temperature of 2400°C, holding time of 3h) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, a low-power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 600°C (i.e., the maximum heating temperature) and the emission wavelength is 12μm.

[0085] Example 6

[0086] Graphene oxide, carboxymethyl cellulose and carbon nanotubes are mixed in a mass ratio of 9:0.1:1 and homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 4%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 400°C, holding time of 2h), carbonization treatment (temperature of 1200°C, holding time of 1.5h), and graphitization treatment (temperature of 2400°C, holding time of 2h) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, a low-power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 800°C (i.e., the maximum heating temperature) and the emission wavelength is 10 μm.

[0087] Example 7

[0088] Graphene oxide, carboxymethyl cellulose and carbon nanotubes are mixed in a mass ratio of 7:0.1:2.9 and homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 3.5%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 400°C, holding time of 1h), carbonization treatment (temperature of 1200°C, holding time of 1h), and graphitization treatment (temperature of 3100°C, holding time of 2h) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, an ultra-high power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 1700°C (i.e., the maximum heating temperature) and the emission wavelength is 3μm.

[0089] Example 8

[0090] Graphene oxide, carboxymethyl cellulose, carbon nanotubes, and silicon carbide nanoparticles are mixed in a mass ratio of 7:0.2:2.3:0.5 and homogeneously dispersed to obtain a uniform graphene oxide dispersion with a solid content of 5%. The dispersion is then coated and dried, and then subjected to low-temperature treatment (temperature of 300°C, holding time of 1h), carbonization treatment (temperature of 1100°C, holding time of 15min), and graphitization treatment (temperature of 2000°C, holding time of 1h) in sequence to obtain a graphene film layer. Finally, the graphene film layer is rolled to a specified thickness and cut (as shown in Figure 1) to obtain a heating film. Then, a low-power graphene heating tube is prepared. The filament temperature of the graphene heating tube is 650°C (i.e., the maximum heating temperature) and the emission wavelength is 11μm.

[0091] The parameters and test results of the above embodiments can be compared with those in Table 1. The peeling force test method comprises the following steps: affixing double-sided tape (4972 double-sided tape) to both surfaces of the heating film, then removing the release paper from the double-sided tape on one side and fixing it to a steel plate, and peeling the double-sided tape on the other side 180° at a glass speed of 300 mm / min. The peeling force during the peeling process is tested, and the average value of the stable period is taken. The greater the peeling force, the better the interlayer interaction force of the heating film.

[0092] Table 1

[0093] From the above Table 1, it can be seen by comparing Examples 1, 2 and 3 that the interlayer force of the heating film is effectively improved by adding the enhancer; by comparing Examples 1 and 4, it can be seen that the heating temperature of the heating film is greatly improved by adding the warming agent, that is, the filament temperature of the heating tube is greatly improved, but due to the addition of the warming agent, the emission wavelength of the heating film is relatively reduced; by comparing Examples 1 and 5 and Examples 5 to 8, it can be seen that the emission wavelength of the heating film is effectively improved by adding the spectrum regulator, but because the spectrum regulator is not conductive, the resistance of the heating film will be relatively increased after adding it, so that the heating temperature is relatively reduced; according to the test data of Examples 6 and 7, it can be seen that the heating temperature and emission wavelength of the heating film can be adjusted by adjusting the amount of the warming agent. In summary, the present disclosure can obtain a heating film with a higher heating temperature, a better emission spectrum and a more stable structure by adjusting the components and the amount in the heating film.

[0094] 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 the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0095] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0096] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A heating film, wherein: The heating film comprises graphene and an auxiliary agent, wherein the auxiliary agent comprises at least one of an enhancing agent, a warming agent and a spectrum adjusting agent, wherein: The enhancer comprises at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol and chitin; The temperature increasing agent includes at least one of carbon nanotubes, fullerenes, carbon black and graphene microsheets; The spectrum modifier includes at least one of silicon carbide, boron nitride and silicon nitride.

2. The heating film according to claim 1, wherein: The heating film satisfies at least one of the following conditions: The heating film is the graphene; Or, based on the total mass of the heating film, the heating film comprises 95% to 99.95% of the graphene and 0.05% to 5% of the reinforcing agent in terms of mass percentage; Or, based on the total mass of the heating film, the heating film comprises 70% to 80% of the graphene and 20% to 30% of the warming agent in terms of mass percentage; Or, based on the total mass of the heating film, the heating film comprises 90% to 99% of the graphene and 1% to 10% of the spectrum regulator in terms of mass percentage; Or, based on the total mass of the heating film, the heating film includes 70% to 80% of the graphene, 0.05% to 5% of the reinforcing agent and 20% to 30% of the warming agent in terms of mass percentage; Or, based on the total mass of the heating film, the heating film includes, by mass percentage, 80% to 99% of the graphene, 0.05% to 5% of the enhancer and 1% to 10% of the spectrum regulator; Or, based on the total mass of the heating film, the heating film includes, by mass percentage, 70% to 80% of the graphene, 20% to 30% of the warming agent and 1% to 10% of the spectrum regulator; Or, based on the total mass of the heating film, the heating film includes, by mass percentage, 70% to 80% of the graphene, 0.05% to 5% of the enhancer, 20% to 30% of the warming agent and 1% to 10% of the spectrum regulator.

3. The heating film according to any one of claims 1 to 2, wherein: The maximum heating temperature of the heating film is 500°C to 1700°C.

4. The heating film according to any one of claims 1 to 3, wherein: The emission wavelength of the heating film is 3 to 15 microns.

5. The heating film according to any one of claims 1 to 4, wherein: The thickness of the heating film is 20 to 1000 microns.

6. The heating film according to any one of claims 1 to 5, wherein: The heating film comprises a plurality of heating units sequentially arranged along the length direction, and adjacent heating units are arranged at intervals and connected via a connecting section.

7. The heating film according to claim 6, wherein: Each of the heating units is provided with a hollow hole.

8. The heating film according to claim 6 or 7, wherein: The heating film comprises a first heating section and a second heating section adjacent to each other in the length direction, the first heating section comprises a plurality of connected heating units, the second heating section comprises a plurality of adjacent heating units, and the size of the heating unit corresponding to the first heating section is smaller than the size of the heating unit corresponding to the second heating section; and / or The first heating section and the second heating section are staggered in the width direction of the heating film.

9. The heating film according to any one of claims 6 to 8, wherein: The heating film comprises a plurality of notches arranged at intervals along the length direction.

10. The heating film according to claim 9, wherein: Each of the notches is defined by bending a portion of the heating film after it is separated from the rest of the film.

11. A method for preparing the heating film according to any one of claims 1 to 10, wherein: include: Uniformly dispersing graphene oxide and an auxiliary agent in a solvent to obtain a dispersion, wherein the auxiliary agent includes at least one of an enhancer, a temperature increaser, and a spectrum adjuster; Applying and drying the dispersion to obtain a graphene oxide film layer; The graphene oxide film layer is subjected to low temperature treatment, carbonization treatment and graphitization treatment in sequence to obtain a graphene film layer; The graphene film layer is rolled and cut to obtain the heating film.

12. The method according to claim 11, wherein: The solid content of the dispersion is 1% to 10%.

13. The method according to any one of claims 11 or 12, wherein: The solid content of the dispersion is 3% to 7%.

14. The method according to any one of claims 11 to 13, wherein: The maximum temperature of the low temperature treatment is 250°C to 400°C, and the holding time at the maximum temperature is 5min-3h; The maximum temperature of the carbonization treatment is 900°C to 1300°C, and the holding time is 5min-3h; The temperature of the graphitization treatment is 1800° C. to 3150° C., and the insulation time is 5 min to 3 h.

15. The method according to any one of claims 11 to 14, wherein: The carbon content of the graphene film layer is greater than or equal to 99%.

16. A heating element, wherein: The invention comprises the heating film according to any one of claims 1 to 10.

17. A heating appliance, wherein: Comprising the heating element of claim 16.

18. The heating appliance according to claim 17, wherein: The heating appliance is an electric oven, a microwave oven, a steam oven, an electric kettle, an electric blanket, an electric fan, an electric heater, a bathroom heater, an electric ceramic stove or a disinfection cabinet.

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