Heating film and its manufacturing method, heating element and heating electrical device

Abstract

The present disclosure provides a heating film, a manufacturing method thereof, a heating element, and a heating electrical device, the heating film comprising graphene and an auxiliary agent, the auxiliary agent comprising at least one of a reinforcing agent, a warming agent, and a spectral adjuster, the reinforcing agent comprising at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethylcellulose, polyvinyl alcohol, polyethylene glycol, and chitin, the warming agent comprising at least one of carbon nanotubes, fullerenes, carbon black, and graphene nanoplatelets, and the spectral adjuster comprising at least one of silicon carbide, boron nitride, and silicon nitride.

Description

[Technical Field]

[0001] The present disclosure relates to the technical field of electrical appliances, and in particular to a heating film and its manufacturing method, a heating element and an electrical heating appliance. [Background technology]

[0002] Conventional electric ovens primarily heat food by heating the air inside the oven using a heating element, or by directly heating the surface of the food using thermal radiation. Currently, heating components used in electric heating appliances such as electric ovens, microwave ovens, and steam ovens on the market mainly include metal heating tubes (maximum heating temperature range: 550-750°C), quartz heating tubes (heating wire temperature range: 660-800°C), halogen heating tubes (maximum heating temperature less than 1000°C), and carbon fiber heating tubes (maximum heating temperature less than 1000°C). However, these heating elements have disadvantages, such as a small proportion of radiant heating in the heating temperature range, a long temperature rise time in the heating area, low heating efficiency, and ineffective energy concentration. These disadvantages result in low heating efficiency, slow temperature rise, insufficient heat generation, and a slow temperature rise rate, which increases cooking times and makes it difficult to achieve a crispy exterior and soft interior during heating, resulting in user discomfort. Summary of the Invention [Problem to be solved by the invention]

[0003] The present disclosure aims to solve at least part of one of the technical problems in the related art, and therefore, an object of the present disclosure is to provide a heating film that has a high heat generation temperature and can effectively improve the heating temperature of a heating element using the heating film. [Means for solving the problem]

[0004] 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, the auxiliary agent including at least one of a reinforcing agent, a warming agent, and a spectral adjuster, the reinforcing agent including at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethylcellulose, polyvinyl alcohol, polyethylene glycol, and chitin, the warming agent including at least one of carbon nanotubes, fullerenes, carbon black, and graphene nanoplatelets, and the spectral adjuster including at least one of silicon carbide, boron nitride, and silicon nitride. By using graphene as the heat-generating material of the heating film, the heating film has a better heat-generating temperature, a fast heating rate, and a high emission coefficient. Furthermore, because both the graphene and the heating film have a sheet-like structure, when the heating film generates heat, heat is mainly radiated along the vertical direction of the heating surface, with strong directionality, more concentrated radiant heat, and improved heating efficiency.

[0005] According to an embodiment of the present disclosure, the heating film may be the graphene, or may contain, in parts by mass based on the total mass of the heating film, 95% to 99.95% of the graphene and 0.05% to 5% of the reinforcing agent, or may contain, in parts by mass based on the total mass of the heating film, 70% to 80% of the graphene and 20% to 30% of the warming agent, or may contain, in parts by mass based on the total mass of the heating film, 90% to 99% of the graphene and 1% to 10% of the spectral adjuster, or may contain, in parts by mass based on the total mass of the heating film, 70% to 80% of the graphene and 0.05% or the heating film contains, in parts by mass based on the total mass of the heating film, 80% to 99% of the graphene, 0.05% to 5% of the reinforcing agent, and 1% to 10% of the spectral adjuster; or the heating film contains, in parts by mass based on the total mass of the heating film, 70% to 80% of the graphene, 20% to 30% of the warming agent, and 1% to 10% of the spectral adjuster; or the heating film contains, in parts by mass based on the total mass of the heating film, 70% to 80% of the graphene, 0.05% to 5% of the reinforcing agent, 20% to 30% of the warming agent, and 1% to 10% of the spectral adjuster.

[0006] According to an embodiment of the present disclosure, the maximum heat generation temperature of the heating film is 500°C to 1700°C.

[0007] According to an embodiment of the present disclosure, the heating film has an emission wavelength of 3 to 15 microns.

[0008] According to an embodiment of the present disclosure, the heating film has a thickness of 20 to 1000 microns.

[0009] According to an embodiment of the present disclosure, the heating film comprises a plurality of heating units sequentially distributed along the longitudinal direction, with adjacent heating units spaced apart and connected by a connecting section.

[0010] According to an embodiment of the present disclosure, the outer wall of the heating unit is formed in an oval or polygonal shape.

[0011] According to an embodiment of the present disclosure, each of the heating units is provided with a recessed hole.

[0012] According to an embodiment of the present disclosure, the heating film comprises a first heating section and a second heating section adjacent in the longitudinal direction, the first heating section includes a plurality of connected heating units, the second heating section includes a plurality of adjacent heating units, 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 arranged offset in the width direction of the heating film.

[0013] According to an embodiment of the present disclosure, the heating film includes a plurality of notches spaced apart along the longitudinal direction.

[0014] According to an embodiment of the present disclosure, each of the notches is defined by folding a portion of the heating film after separating it from the remaining portion.

[0015] In another aspect of the present disclosure, the present disclosure provides a method for manufacturing the heating film described above. According to an embodiment of the present disclosure, the method for manufacturing the heating film includes the steps of uniformly dispersing graphene oxide and an auxiliary agent, including at least one of a reinforcing agent, a warming agent, and a spectral adjuster, in a solvent to obtain a dispersion, 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, by using the above-mentioned method to prepare a heating film and using graphene as the heat-generating material of the heating film, the heating film has a better heat-generating temperature, a fast heating rate and a high emission coefficient. In addition, both graphene and the heating film have a sheet-like structure, and when the heating film generates heat, the heat is mainly radiated along the vertical direction of the heating surface, with strong directionality, the radiated heat is more concentrated, and the heat generation efficiency can be further improved. Furthermore, the manufacturing raw material is graphene oxide, which has a simple and easy-to-implement preparation process and is easy to modify, which helps to improve the performance of the heating film.

[0016] According to an embodiment of the present disclosure, the solid content of the dispersion is 1% to 10%, preferably 3% to 7%.

[0017] 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 minutes to 3 hours; the maximum temperature of the carbonization treatment is 900°C to 1300°C, and the holding time is 5 minutes to 3 hours; and the maximum temperature of the graphitization treatment is 1800°C to 3150°C, and the holding time is 5 minutes to 3 hours.

[0018] According to an embodiment of the present disclosure, the carbon content of the graphene film layer is 99% or more.

[0019] In a further aspect of the present disclosure, the present disclosure provides a heating element. According to an embodiment of the present disclosure, the heating element comprises the heating film as described above. This allows the heating element to have a high heating temperature, a fast heating rate, and a large radiation heating rate, and the heating area is more concentrated, thereby 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 heating film as described above, and no further description will be given here.

[0020] In a further aspect of the present disclosure, the present disclosure provides an electric heating device, according to an embodiment of the present disclosure, the electric heating device comprises the heating element as described above, whereby the electric heating device has a high heating temperature, a fast heating rate, and a large radiation heating rate, and the heating area is more concentrated, thereby greatly improving the heating efficiency of the heating element.

[0021] According to an embodiment of the present disclosure, the heating electric appliance is an electric oven, a microwave oven, a steam oven, an electric kettle, an electric blanket, an electric space heater, an electric heater, a bath bomb, an electric ceramic stove, or a disinfection cabinet. [Brief explanation of the drawings]

[0022] The above and / or additional aspects and advantages of the present disclosure will become apparent and easier to understand from the following description of the embodiments taken in conjunction with the drawings. [Figure 1] FIG. 1 is a structural schematic diagram showing a heating film in an embodiment of the present disclosure. [Figure 2] 10A to 10C are structural schematic diagrams showing heating films in other embodiments of the present disclosure. [Figure 3] 10A to 10C are structural schematic diagrams showing heating films in other embodiments of the present disclosure. [Figure 4] 10A to 10C are structural schematic diagrams showing heating films in other embodiments of the present disclosure. [Figure 5] 10A to 10C are structural schematic diagrams illustrating heating elements in some other embodiments of the present disclosure. [Figure 6]10A to 10C are structural schematic diagrams illustrating heating elements in some other embodiments of the present disclosure. [Figure 7] 10A to 10C are structural schematic diagrams illustrating heating elements in some other embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following examples are used in combination to illustrate the present disclosure. Those skilled in the art can 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. If no specific techniques or conditions are shown in the examples, they should be carried out according to the techniques or conditions described in the literature of the field or according to the product specifications. If no manufacturer is shown for the reagents or equipment used, they are conventional products that can be purchased commercially.

[0024] The present disclosure will now be described with reference to specific examples, which should be understood as illustrative and not limiting of the present disclosure in any way.

[0025] 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, the auxiliary agent including at least one of a reinforcing agent, a warming agent, and a spectral adjuster, the reinforcing agent including at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethylcellulose, polyvinyl alcohol, polyethylene glycol, and chitin, the warming agent including at least one of carbon nanotubes, fullerenes, carbon black, and graphene nanoplatelets, and the spectral adjuster including at least one of silicon carbide, boron nitride, and silicon nitride. By using graphene as the heat-generating material of the heating film, the heating film has a better heat-generating temperature, a fast heating rate, and a high emission coefficient. Furthermore, because both the graphene and the heating film have a sheet-like structure, when the heating film generates heat, heat is mainly radiated along the vertical direction of the heating surface, with strong directionality, more concentrated radiant heat, and improved heating efficiency. Furthermore, the present disclosure employs graphene, which has a sheet-like structure, with the graphene monolayers closely spaced and each graphene layer relatively thin, thereby providing the graphene film with good bending resistance, which is advantageous for improving the bending resistance of the heating film. The cutting type of the heating film is not affected by its bendability, allowing for a wide operating range, easy assembly, and improved production yield. Furthermore, the inventors have discovered that, under conditions of constant density, the electrical resistance of a graphene film decreases as its thickness increases, and under conditions of constant thickness and density, the electrical resistance of a graphene film increases as its temperature increases. Based on this, the resistance of the heating film can be flexibly designed and its power can be further adjusted according to conditions such as the thickness and heating temperature of the heating film. Thus, the present disclosure allows for heating films with a variety of different power levels to be obtained by adjusting the above-mentioned different parameters. Regarding these advantages, the inventors have not found that any of the materials currently used to fabricate heating films can achieve the above-mentioned technical effects of the present disclosure.

[0026] Furthermore, auxiliary agents contained in the heating film can be used during the manufacturing process, and the auxiliary agents may include at least one of a reinforcing agent, a warming agent, and a spectral adjuster to improve the performance of the heating film. Specifically, the low-molecular-weight or high-molecular-weight organic material forms a chemical bond (C-C bond) between its carbon element and graphene. The reinforcing agent effectively enhances the connectivity between the graphene layers and further improves the structural stability of the heating film. Specifically, the auxiliary agents may include at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethylcellulose, polyvinyl alcohol, polyethylene glycol, and chitin. In some embodiments, the warming agent may be carbon nanoparticles, specifically at least one of carbon nanotubes, fullerenes, carbon black, and graphene nanoplatelets, which effectively prevents secondary graphitization of the graphite material at high temperatures and reduces meltdown during the manufacturing process of the heating film. and helps to increase the maximum use temperature of the heating film, i.e., the maximum heat generation temperature of the heating film. In some embodiments, the spectral adjuster may be nanometer particles, and the spectral adjuster may include at least one of silicon carbide, boron nitride, and silicon nitride. The spectral adjuster effectively adjusts the emission spectrum of the heating film, resulting in a heating film with a large emission spectrum. The spectral adjuster is also non-conductive and resistant to high temperatures (temperature resistance of 1300°C or higher). The resistance of the heating film can be adjusted by adjusting the amount of spectral adjuster used; the higher the amount used, the greater the resistance of the heating film, and the relatively lower the maximum heat generation temperature of the heating film and the relatively larger the emission wavelength of the heating film. Thus, in the present disclosure, by adjusting the amounts of auxiliary agents such as heating agents and spectral adjusters used, it is possible to obtain a heating film with an appropriate maximum heat generation temperature and a large emission wavelength (the shorter the emission wavelength, the higher the radiant energy of the heating film).

[0027] Graphene has a high emission coefficient of more than 90%, which is much higher than the 60% of natural graphite and the 80% of artificial graphite. Therefore, the present disclosure employs graphene to effectively increase the emission coefficient of the heating film, further increasing its thermal radiation power, and increasing the heat generation rate and maximum heat generation temperature of the heating film.

[0028] According to some embodiments of the present disclosure, the heating film is graphene, i.e., is fabricated from graphene in the heating film, thus the heating film has high heat generation temperature, high thermal radiation power, excellent bending resistance, and also lends itself to designing other kinds of different cutting types of the heating film.

[0029] According to some embodiments of the present disclosure, the heating film may comprise, in parts by weight, based on the total weight of the heating film, 95% to 99.95% (e.g., 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, 99.95%, etc.) graphene and 0.05% to 5% (e.g., 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.) reinforcing agent. That is, when producing the heating film, a certain amount of reinforcing agent is added to the graphene, and the reinforcing agent in the above proportion can ensure high heating temperature, high thermal radiation power, and excellent bending resistance of the heating film, while further increasing the interlayer connection strength between the multiple graphene layers in the heating film, and further improving the structural stability of the heating film, thereby preventing the graphene layers of the heating film from shifting or falling off in the subsequent processing steps.

[0030] According to some embodiments of the present disclosure, the heating film comprises, in parts by mass, 70% to 80% (e.g., 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) of the graphene and 20% to 30% (e.g., 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) of the heating agent, based on the total mass of the heating film. That is, when the heating film is produced, a certain amount of heating agent is added to the graphene. The heating agent in the above proportion can ensure high thermal radiation power and excellent bending resistance of the heating film, and can also increase the maximum heat generation temperature of the heating film.

[0031] According to some embodiments of the present disclosure, the heating film comprises, in parts by mass, based on the total mass of the heating film, 90% to 99% (e.g., 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, etc.) graphene and 1% to 10% (e.g., 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, etc.) spectral adjuster. That is, when producing the heating film, a certain amount of reinforcing agent is added to the graphene. The reinforcing agent in this proportion can ensure the high heating temperature and excellent bending resistance of the heating film, while also further improving the emission spectrum of the heating film and further increasing the thermal radiation power of the heating film.

[0032] According to some embodiments of the present disclosure, the heating film may comprise, in parts by weight, based on the total weight of the heating film, 70% to 80% (e.g., 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) graphene, 0.05% to 5% (e.g., 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.) reinforcing agent, and 20% to 30% (e.g., 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) reinforcing agent. The heating agent includes a heating agent such as a reinforcing agent or a heating agent, i.e., when producing the heating film, a certain amount of reinforcing agent and heating agent is added to the graphene, and the reinforcing agent and heating agent in the above proportions can ensure the heating film has a high heating temperature, high thermal radiation power, and excellent bending resistance, while further increasing the interlayer bonding strength between the multiple graphene layers in the heating film, better improving the structural stability of the heating film, preventing the graphene layers of the heating film from shifting or falling off in the subsequent processing, and further improving the maximum heating temperature of the heating film.

[0033] According to some embodiments of the present disclosure, the heating film comprises 80% to 99% (e.g., 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%, 99%, 100%, 101%, 102%, 103%, 104%, 105%, 106%, 107%, 108%, 109%, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, graphene at 0.05% to 5% (e.g., 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.), and reinforcing agents at 1% to 10% (e.g., 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.). , 6%, 7%, 8%, 9%, 10%, etc.), that is, when producing the heating film, a certain amount of reinforcing agent and spectral modifier is added to the graphene, and the reinforcing agent and spectral modifier in the above proportions can ensure the high heating temperature, high thermal radiation power, and excellent bending resistance of the heating film, while further increasing the interlayer bonding strength between the multiple graphene layers in the heating film, better improving the structural stability of the heating film, preventing the graphene layers of the heating film from shifting or falling off in the subsequent processing, and further improving the emission spectrum of the heating film and further increasing the thermal radiation power of the heating film.

[0034] According to some embodiments of the present disclosure, the heating film may comprise, in parts by weight, based on the total weight of the heating film, 70% to 80% (e.g., 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) graphene, 20% to 30% (e.g., 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) heating agent, and 1% to 10% (e.g., 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, The heating agent and the spectral modifier are added in an amount of 5%, 6%, 7%, 8%, 9%, 10%, etc., that is, when producing the heating film, a certain amount of the heating agent and the spectral modifier are added to the graphene. The heating agent and the spectral modifier in the above proportions can ensure the high heating temperature, high thermal radiation power, and excellent bending resistance of the heating film, and at the same time, can further improve the maximum heating temperature of the heating film, further improve the emission spectrum of the heating film, and further improve the thermal radiation power of the heating film.

[0035] According to some embodiments of the present disclosure, the heating film may comprise, in parts by weight based on the total weight of the heating film, 70% to 80% (e.g., 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) graphene, 0.05% to 5% (e.g., 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, etc.) graphene, 0.05% to 5% (e.g., 0.05%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 0.5%, 4%, 4.5%, 5%, etc.) strengthening agents, 20%-30% (e.g., 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 9%, 30%, etc.) warming agents and 1%-10% (e.g., 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, 10%, etc.) spectral adjusting agents. The above proportions of the reinforcing agent, warming agent and spectrum adjuster ensure the high heating temperature, high thermal radiation power and excellent bending resistance of the heating film, while further increasing the interlayer connection strength between the multiple graphene layers in the heating film, better improving the structural stability of the heating film, preventing the graphene layers of the heating film from shifting or falling off during subsequent processing, and further improving the maximum heating temperature, emission spectrum and thermal radiation power of the heating film.

[0036] According to some embodiments of the present disclosure, the heating film may have a heat generation temperature of 500°C to 1700°C, such as 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. As can be seen, the heating film according to the present disclosure can have a maximum heat generation temperature of 1700°C. Furthermore, those skilled in the art can flexibly adjust the maximum heat generation temperature of the heating film by adjusting the amount of additives such as heating agents and the amount of graphene used according to the specific use requirements of the heating film, thereby further satisfying more use heating requirements of the heating film.

[0037] According to some embodiments of the present disclosure, the emission wavelength of the heating film is 3-15 microns, for example, 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 from this that the maximum emission wavelength of the heating film according to the present disclosure can reach 15 microns, that is, the heating film has a large radiant heating ratio, can better improve the heating speed, further improve the heating efficiency, enhance the concentrated heating effect, and improve energy utilization rate. In addition, in the present disclosure, the specific emission wavelength of the heating film can be flexibly adjusted by adjusting the content of the spectral adjuster, so that the heating film can meet various usage requirements.

[0038] According to some embodiments of the present disclosure, the thickness of the heating film is 20 to 1000 microns, for example, 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 described above, under conditions of a constant density, the electrical resistance of the graphene film decreases as the thickness increases. Under conditions of both constant thickness and density, the electrical resistance of the graphene film decreases as the temperature increases. 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, and further the heat generation temperature and emission wavelength of the heating film can be adjusted. Under the above condition of thickness, the heating film can meet the high heating temperature and emission wavelength, and at the same time, the heating film has a suitable density, which is convenient for designing various cutting types of the heating film.

[0039] In the embodiments of the present disclosure, the specific cutting type of the heating film can be diversified, and those skilled in the art can flexibly design the cutting type of the heating film according to the actual requirements of the heating film, such as resistance, power, etc. Hereinafter, several cutting types of the heating film will be described in several specific embodiments of the present disclosure.

[0040] In some embodiments of the present disclosure, referring to Fig. 1, the heating film comprises a plurality of heating units 01 arranged sequentially along the longitudinal direction, with adjacent heating units 01 spaced apart and connected by connecting sections 02. As can be seen, the heating film according to the present disclosure can be cut into a variety of different cutting types of decoupling strands to meet different application requirements. In some embodiments of the present disclosure, referring to Fig. 1, the outer wall of the heating unit is formed in an oval or polygonal shape.

[0041] In some embodiments of the present disclosure, referring to (b), (c), and (i) in Figure 1, a cutout hole 03 is provided in each heating unit 01. This can increase the heat dissipation rate of the heating film and the heating rate of the object to be heated.

[0042] 2, in some embodiments of the present disclosure, the heating film includes a first heating section S1 and a second heating section S2 adjacent to each other in the longitudinal direction, the first heating section S1 including a plurality of connected heating units O1, and the second heating section S2 including a plurality of adjacent heating units 10, the size of the heating unit O1 corresponding to the first heating section S1 being smaller than the size of the heating unit 10 corresponding to the second heating section S2. For example, in (a) of FIG. 2, the length of the heating unit O1 corresponding to the first heating section S1 is similar to the length of the heating unit 10 corresponding to the second heating section S2, but the widths d1 and d2 are not equal. For example, in (b) and (c) of FIG. 2, the width of the heating unit O1 corresponding to the first heating section S1 is similar to the width of the heating unit 10 corresponding to the second heating section S2, but the lengths d1 and d2 are not equal. This allows for a variety of heating film structures.

[0043] In some embodiments of the present disclosure, the first heating section S1 and the second heating section S2 are offset in the width direction of the heating film, as shown in Figure 3, which allows for a variety of heating film structures.

[0044] In some embodiments of the present disclosure, as shown in (d), (e), (f), (h), (i), and (j) in Fig. 1, the heating film has a plurality of notches spaced apart along the longitudinal direction. This allows for a variety of heating film structures. Furthermore, in some embodiments of the present disclosure, as shown in (i) in Fig. 1, each notch is defined by folding a portion of the heating film after it has been separated from the remaining portion.

[0045] In some embodiments, the same heating film may include a variety of different cut types, or the same cut type may have a non-uniform density distribution, as shown in FIG.

[0046] In another aspect of the present disclosure, there is provided a method for manufacturing the heating film as described above. According to an embodiment of the present disclosure, the method for manufacturing the heating film includes the following steps:

[0047] In S100, graphene oxide and an auxiliary agent are uniformly dispersed in a solvent to obtain a dispersion.

[0048] According to some embodiments of the present disclosure, the auxiliary agent comprises at least one of a strengthening agent, a warming agent, and a spectral adjuster. The solvent may be water.

[0049] 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 a dispersion with such solids content, the dispersion of solutes such as graphene is relatively uniform and is advantageous for uniform coating. If the solids content is less than 1%, the dispersion becomes relatively thin and relatively unfluid, which is not only disadvantageous for coating the dispersion but also affects the uniformity of the graphene oxide film. If the solids content of the dispersion is greater than 10%, the dispersion is relatively difficult to disperse uniformly. In some specific embodiments, the solids content of the dispersion is 3% to 7%.

[0050] In S200, the dispersion is applied and dried to obtain a graphene oxide film layer.

[0051] There are no special requirements for the specific coating method, and those skilled in the art can flexibly select an appropriate coating method, such as spin coating or scraping coating, according to the actual situation, as long as it can help obtain a graphene oxide film with a uniform thickness.

[0052] In S300, the graphene oxide film layer is sequentially subjected to a low-temperature treatment, a carbonization treatment, and a graphitization treatment to obtain a graphene film layer.

[0053] In the above steps, the graphene oxide is deoxidized after the low-temperature treatment, carbonization treatment, and graphitization treatment to obtain a graphene film layer.

[0054] In some embodiments, the maximum temperature of the low-temperature treatment is 250°C to 400°C, e.g., 250°C, 280°C, 300°C, 320°C, 350°C, 380°C, 400°C, etc., and the heating time at the maximum temperature is 5 minutes to 3 hours (e.g., 5 minutes, 10 minutes, 30 minutes, 45 minutes, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.). Under these conditions, the graphene oxide begins to deoxidize and its oxygen content is controlled within 10%. The maximum temperature of the carbonization treatment is 900°C to 1300°C, e.g., 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, 1250°C, 1300°C, etc., and the heating time at the maximum temperature is 5 minutes to 3 hours (e.g., 5 minutes, 10 minutes, 30 minutes, 45 minutes, 1 hour, 1 hour, etc.). Under these carbonization conditions, the graphene oxide continues to be deoxidized, and its oxygen content can be controlled within 5%. The maximum temperature for the graphitization treatment is 1800°C to 3150°C, for example, 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 heating time at the maximum temperature is 5 minutes to 3 hours (for example, 5 minutes, 10 minutes, 30 minutes, 45 minutes, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, etc.). Under these conditions, the deoxidation treatment of the graphene oxide can be effectively completed, and a graphene film layer can be obtained.

[0055] According to some embodiments of the present disclosure, the heating film contains only graphene, i.e., no additives such as reinforcing agents, warming agents, or spectral adjusters are added to the heating film, and the carbon content of the graphene film layer produced by the above method is 99% or more, which is advantageous for obtaining a heating film with high graphene purity and better performance.

[0056] In S400, the graphene film layer is rolled and sheared to obtain a heating film. For the cut types of the heating film obtained after shearing, refer to Figures 1 to 4.

[0057] According to the embodiments of the present disclosure, by using graphene as the heat-generating material of the heating film, the heating film has a better heat-generating temperature, a fast heating rate, and a high thermal radiation coefficient. Furthermore, because both the graphene and the heating film have a sheet-like structure, when the heating film generates heat, the heat is mainly radiated in the direction perpendicular to the heating surface, with strong directionality, the radiated heat is more concentrated, and the heating efficiency is improved. Furthermore, because the graphene used in the present disclosure has a sheet-like structure, the graphene monolayers are closely spaced, and the thickness of each graphene monolayer is relatively thin, the graphene film has good bending resistance, which is advantageous for improving the bending resistance of the heating film. When designing the cutting type of the heating film, it is not affected by bendability, has a wide operating range, is easy to assemble, and improves production yield. Furthermore, the inventors discovered that, under conditions of constant density, the electrical resistance of a graphene film decreases as the thickness increases, and under conditions of both constant thickness and density, the electrical resistance of a graphene film decreases as the temperature increases. Based on this, the resistance of the heating film can be flexibly designed according to conditions such as the thickness of the heating film and the heating temperature, and the magnitude of its power can be further adjusted. In this way, in the present disclosure, heating films with various different powers can be obtained by adjusting the above different parameters. Regarding the above advantages, the inventors have not found that the above technical effects of the present disclosure can be achieved with any of the materials currently used to make heating films. Furthermore, the manufacturing raw material is graphene oxide, which has a simple and easy-to-implement manufacturing process and is easy to modify, helping to improve the performance of the heating film.

[0058] In some embodiments, the reinforcing agent comprises at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethylcellulose, polyvinyl alcohol, polyethylene glycol, and chitin, and the low molecular or high molecular organic matter forms a chemical bond (C-C bond) between its carbon element and graphene, and the reinforcing agent effectively enhances the connectivity between the graphene layers and further improves the structural stability of the heating film. In some embodiments, the heating agent may be carbon nanoparticles, specifically, may comprise at least one of carbon nanotubes, fullerenes, carbon black, and graphene nanoplatelets, which effectively prevents secondary graphitization of the graphite material at high temperatures and prevents melting during the manufacturing process of the heating film. and helps to increase the maximum use temperature of the heating film, i.e., the maximum heat generation temperature of the heating film. In some embodiments, the spectral adjuster can be nanometer particles, and the spectral adjuster includes at least one of silicon carbide, boron nitride, and silicon nitride. The spectral adjuster can effectively adjust the emission spectrum of the heating film, resulting in a heating film with a large emission spectrum. The spectral adjuster is also non-conductive and resistant to high temperatures (temperature resistance of 1300°C or higher). The resistance of the heating film can be adjusted by adjusting the amount of spectral adjuster used; the higher the amount used, the greater the resistance of the heating film, and the relatively lower the maximum heat generation temperature of the heating film and the relatively larger the emission wavelength of the heating film. Thus, in the present disclosure, by adjusting the amounts of auxiliary agents such as heating agents and spectral adjusters used, a heating film with an appropriate maximum heat generation temperature and a large emission wavelength can be obtained.

[0059] In a further aspect of the present disclosure, the present disclosure provides a heating element. According to an embodiment of the present disclosure, the heating element comprises the heating film as described above. This allows the heating element to have a high heating temperature, a fast heating rate, and a large radiation heating rate, and the heating area is more concentrated, thereby 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 heating film as described above, and no further description will be given here.

[0060] In some embodiments, referring to Figure 5 (the area S in the figure refers to a local cross-sectional view of the casing), Figure 6 and Figure 7, the heating element further comprises a casing 10, a heating film 20 is placed in the casing 10, and terminals 21 are provided on both ends of the heating film 20, and the casing may be a quartz glass tube or the like.

[0061] In a further aspect of the present disclosure, the present disclosure provides an electric heating device, which according to an embodiment of the present disclosure, comprises the heating element as described above, whereby the electric heating device has a high heating temperature, a fast heating rate, and a large radiation heating rate, and the heating area is more concentrated, thereby greatly improving the heating efficiency of the heating element.

[0062] According to an embodiment of the present disclosure, the heating electric appliance is an electric oven, a microwave oven, a steam oven, an electric kettle, an electric blanket, or an electric heater.

[0063] Those skilled in the art will understand that the heating electric equipment includes structures or components that need to be provided in the heating electric equipment in addition to the heating element described above, and taking an electric oven as an example, includes necessary structures or components such as a housing, a heating space, a base, a plug, etc. in addition to the heating element described above.

[0064] Example

[0065] Example 1

[0066] The graphene oxide was uniformly dispersed to obtain a uniform graphene oxide dispersion with a solid content of 6%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (temperature 300°C, heat retention time 0.5 hours), carbonization treatment (temperature 1100°C, heat retention time 1 hour), and graphitization treatment (temperature 2000°C, heat retention time 2 hours) to obtain a graphene film. Finally, the graphene film was rolled to a predetermined thickness and cut into a type (as shown in Figure 1) to obtain a heating film. A low-power graphene heating tube was then manufactured. The filament temperature of the graphene heating tube was 750°C (i.e., the maximum heating temperature) and the emission wavelength was 10 μm.

[0067] Example 2

[0068] Graphene oxide and glucose were mixed in a mass ratio of 1:0.1 and then uniformly dispersed to obtain a uniform graphene oxide dispersion with a solid content of 4.2%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (400°C, 1 hour), carbonization (1200°C, 0.5 hour), and graphitization (2600°C, 1 hour) to obtain a graphene film. Finally, the graphene film was rolled to a specified thickness and cut into a mold (see Figure 1) to obtain a heating film. A low-power graphene heating tube was then manufactured. The filament temperature of the graphene heating tube was 950°C (i.e., the maximum heating temperature) and the emission wavelength was 8 μm.

[0069] Example 3

[0070] Graphene oxide and carboxymethyl cellulose were mixed in a mass ratio of 1:0.15 and then uniformly dispersed to obtain a uniform graphene oxide dispersion with a solid content of 4.5%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (temperature 350°C, incubation time 1 hour), carbonization treatment (temperature 1150°C, incubation time 0.5 hour), and graphitization treatment (temperature 2800°C, incubation time 15 minutes) to obtain a graphene film. Finally, the graphene film was rolled to a predetermined thickness and cut into a mold (see Figure 1) to obtain a heating film. A low-power graphene heating tube was then manufactured. The filament temperature of the graphene heating tube was 850°C (i.e., the maximum heating temperature) and the emission wavelength was 9 μm.

[0071] Example 4

[0072] Graphene oxide and carbon nanotubes were mixed in a mass ratio of 7:3 and then uniformly dispersed to obtain a uniform graphene oxide dispersion with a solid content of 5.5%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (400°C, 2 hours), carbonization (1300°C, 0.5 hours), and graphitization (3100°C, 0.5 hours), to obtain a graphene film. Finally, the graphene film was rolled to a specified thickness and cut into a shape (as shown in Figure 1), resulting in a heating film. This produced an ultra-high-power graphene heating tube, with a filament temperature of 1700°C (i.e., the maximum heating temperature) and an emission wavelength of 3 μm.

[0073] Example 5

[0074] Graphene oxide and silicon carbide nanoparticles were mixed in a mass ratio of 9:1 and then uniformly dispersed to obtain a uniform graphene oxide dispersion with a solids content of 3.5%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (250°C, 1 hour), carbonization (1300°C, 0.5 hour), and graphitization (2400°C, 3 hours). This resulted in a graphene film layer. Finally, the graphene film layer was rolled to a predetermined thickness and cut into a mold (see Figure 1) to obtain a heating film. A low-power graphene heating tube was then manufactured. The filament temperature of the graphene heating tube was 600°C (i.e., the maximum heating temperature) and the emission wavelength was 12 μm.

[0075] Example 6

[0076] Graphene oxide, carboxymethyl cellulose, and carbon nanotubes were mixed in a mass ratio of 9:0.1:1 and then uniformly dispersed to obtain a uniform graphene oxide dispersion with a solids content of 4%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (400°C, 2 hours), carbonization (1200°C, 1.5 hours), and graphitization (2400°C, 2 hours) to obtain a graphene film. Finally, the graphene film was rolled to a predetermined thickness and cut into a mold (see Figure 1) to obtain a heating film. A low-power graphene heating tube was then manufactured. The filament temperature of the graphene heating tube was 800°C (i.e., the maximum heating temperature) and the emission wavelength was 10 μm.

[0077] Example 7

[0078] Graphene oxide, carboxymethyl cellulose, and carbon nanotubes were mixed in a mass ratio of 7:0.1:2.9 and then uniformly dispersed to obtain a uniform graphene oxide dispersion with a solid content of 3.5%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (400°C, 1 hour), carbonization (1200°C, 1 hour), and graphitization (3100°C, 2 hours) to obtain a graphene film. Finally, the graphene film was rolled to a specified thickness and cut into a shape (as shown in Figure 1) to obtain a heating film. This produced an ultra-high-power graphene heating tube. The filament temperature of the graphene heating tube was 1700°C (i.e., the maximum heating temperature) and the emission wavelength was 3 μm.

[0079] Example 8

[0080] Graphene oxide, carboxymethyl cellulose, carbon nanotubes, and silicon carbide nanoparticles were mixed in a mass ratio of 7:0.2:2.3:0.5 and then uniformly dispersed to obtain a uniform graphene oxide dispersion with a solids content of 5%. The dispersion was then coated and dried, and subsequently subjected to low-temperature treatment (temperature 300°C, incubation time 1 hour), carbonization treatment (temperature 1100°C, incubation time 15 minutes), and graphitization treatment (temperature 2000°C, incubation time 1 hour) to obtain a graphene film. Finally, the graphene film was rolled to a predetermined thickness and cut into a mold (see Figure 1) to obtain a heating film. A low-power graphene heating tube was then manufactured. The filament temperature of the graphene heating tube was 650°C (i.e., the maximum heating temperature) and the emission wavelength was 11 μm.

[0081] For a comparison of the parameters and test results of the above examples, please refer to Table 1. The procedure for testing the peel strength is as follows: attach double-sided tape (4972 double-sided tape) to both surfaces of the heating film, then peel off the release paper from one side of the double-sided tape and fix it to a steel plate, and peel off the other side of the double-sided tape at a 180° angle, at a peeling speed of 300 mm / min. The peel strength during peeling is tested and the average value of the stable part is taken. The higher the peel strength, the better the interlayer strength of the heating film.

[0082] [Table 1]

[0083] As can be seen from Table 1 above, by comparing Examples 1, 2, and 3, the addition of the reinforcing agent effectively improves the interlayer force of the heating film. A comparison of Examples 1 and 4 shows that the addition of the heating agent significantly increases the heating temperature of the heating film, i.e., significantly increases the filament temperature of the heating tube, but the addition of the heating agent relatively decreases the emission wavelength of the heating film. A comparison of Examples 1 and 5 and Examples 5-8 shows that the addition of the spectral control agent effectively improves the emission wavelength of the heating film, but because the spectral control agent is non-conductive, the addition of the spectral control agent relatively increases the resistance of the heating film and relatively decreases the heating temperature. The test data of Examples 6 and 7 shows that the amount of heating agent used can be adjusted to adjust the heating temperature and emission wavelength of the heating film. Thus, the present disclosure allows for the production of heating films with high heating temperatures, excellent emission spectra, and stable structures by adjusting the components and amounts used in the heating film.

[0084] Additionally, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as expressing or implying relative importance or the number of technical features being presented. Thus, a feature qualified by "first" or "second" can explicitly or implicitly include one or more of such features. In the description of this application, "plurality" means two or more, unless otherwise specified.

[0085] In the description herein, a statement referring to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples" means that a particular feature, structure, material, or characteristic described with reference to that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, general references to such terms do not necessarily refer to the same embodiment or example. In addition, a particular feature, structure, material, or characteristic described may be incorporated in any suitable manner in any one or more embodiments or examples. Furthermore, those skilled in the art can combine and combine the various embodiments or examples described herein and the features of the various embodiments or examples without mutual contradiction.

[0086] Although the embodiments of the present disclosure have been presented and described, the above embodiments are illustrative and should not be construed as limiting the present disclosure, and it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the above embodiments within the scope of the present disclosure. (CROSS-REFERENCE TO RELATED APPLICATIONS)

[0087] This application claims priority from a Chinese patent application with application number 2023117507525, proposed on December 18, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A heating film that generates heat and radiates heat, wherein the heating film comprises graphene and an auxiliary agent, The aforementioned auxiliary agent includes a warming agent, or includes a warming agent and a spectral modifier. The heating agent comprises at least one of carbon nanotubes, fullerenes, carbon black, and graphene nanoplatelets. The spectral modifier comprises at least one of silicon carbide, boron nitride, and silicon nitride, and is a heating film.

2. The aforementioned heating film is Based on the total mass of the heating film, the heating film contains, by mass, 70% to 80% of the graphene and 20% to 30% of the heating agent, or The heating film according to claim 1, wherein, based on the total mass of the heating film, the heating film satisfies at least one of the following conditions: by mass, the heating film contains 70% to 80% of the graphene, 20% to 30% of the heating agent, and 1% to 10% of the spectral modifier.

3. The heating film according to claim 1, wherein the maximum heating temperature of the heating film is 500°C to 1700°C.

4. The heating film according to claim 1, wherein the radiation wavelength of the heating film is 3 to 15 microns.

5. The heating film according to claim 1, wherein the thickness of the heating film is 20 to 1000 microns.

6. The heating film according to claim 1, comprising a plurality of heating units arranged sequentially along the longitudinal direction, wherein adjacent heating units are provided with gaps between them and connected by connecting sections.

7. The heating film according to claim 6, wherein each of the heating units is provided with a cutout hole.

8. The heating film comprises a first heating section and a second heating section adjacent to each other in the longitudinal direction, the first heating section includes a plurality of connected heating units, the second heating section includes a plurality of adjacent heating units, 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 heating film according to claim 6, wherein the first heating section and the second heating section are provided offset in the width direction of the heating film.

9. The heating film according to claim 6, wherein the heating film has a plurality of notches provided with gaps along its longitudinal direction.

10. The heating film according to claim 9, wherein each of the aforementioned notches is defined by a portion of the heating film being separated from the rest and folded.

11. A method for producing a heating film according to any one of claims 1 to 10, The steps include: uniformly dispersing graphene oxide and an auxiliary agent containing a reinforcing agent and a warming agent, or an auxiliary agent containing a reinforcing agent, a warming agent and a spectral modifier, in a solvent to obtain a dispersion; The steps include applying the dispersion and drying it to obtain a graphene oxide film layer, The steps include sequentially performing low-temperature treatment, carbonization treatment, and graphitization treatment on the aforementioned graphene oxide film layer to obtain a graphene film layer, The process includes the step of rolling and cutting the graphene film layer to obtain the heating film, The reinforcing agent comprises at least one of ammonia water, glucose, ethylene glycol, ethylenediamine, carboxymethylcellulose, polyvinyl alcohol, polyethylene glycol, and chitin. The heating agent comprises at least one of carbon nanotubes, fullerenes, carbon black, and graphene nanoplatelets. The spectral modifier comprises at least one of silicon carbide, boron nitride, and silicon nitride. method.

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

13. The method according to claim 11, wherein the solid content of the dispersion is 3% to 7%.

14. The maximum temperature for the aforementioned low-temperature treatment is 250°C to 400°C, and the duration of maintaining the maximum temperature is 5 minutes to 3 hours. The maximum temperature for the carbonization treatment is 900°C to 1300°C, and the holding time is 5 minutes to 3 hours. The method according to claim 11, wherein the temperature of the graphitization treatment is 1800°C to 3150°C, and the holding time is 5 minutes to 3 hours.

15. The method according to claim 11, wherein the carbon content of the graphene film layer is 99% or more.

16. A heating element comprising a heating film according to any one of claims 1 to 10.

17. An electrical heating device comprising the heating element described in claim 16.

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

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