Heating slurry, heating film and preparation method thereof

Abstract

The invention belongs to the field of electronic cigarettes, and relates to heating slurry, a heating film and a preparation method thereof.The heating slurry comprises solid powder and an organic binding agent, the solid powder comprises nickel-chromium alloy powder and improved alloy powder, the melting point of the improved alloy powder is lower than that of the nickel-chromium alloy powder, the weight fraction of the solid powder is 82-92%, and the weight fraction of the organic binding agent is 80-90%. A proper amount of the improved alloy powder with the melting point lower than that of the nickel-chromium alloy powder is added into the nickel-chromium alloy powder and used for improving material components of the heating slurry, so that the heating slurry can be sintered at the temperature lower than the sintering temperature of the main body nickel-chromium alloy powder, energy is effectively saved, and the sintering cost is reduced.

Description

Technical Field

[0001] The present application relates to the field of electronic cigarette technology, and more specifically, to a heating slurry, a heating film and a preparation method thereof. Background Art

[0002] In the field of electronic cigarette technology, the performance of heating elements is crucial to the user experience and efficiency of the product. In traditional electronic cigarette heating devices, nickel-chromium heating slurry, as a common heating material, is widely used due to its good conductivity and thermal stability. However, under existing technical conditions, the heating film prepared with nickel-chromium heating slurry needs to reach a higher temperature during the sintering process, and the sintering temperature is usually set at around 1100°C. This high-temperature sintering requirement not only increases the energy consumption in the production process, but also puts higher heat resistance and stability requirements on the production equipment, thereby increasing the overall production cost.

[0003] Specifically, the sintering temperature of 1100°C means that this high temperature environment must be maintained throughout the sintering cycle, which not only consumes a lot of energy, but may also cause the performance of the material to degrade under long-term high temperatures, such as micro cracks caused by thermal stress or changes in the material structure, which are not conducive to the stability and safety of the heating film in long-term use. In addition, high-temperature sintering also limits the degree of automation and flexibility of the production line, because equipment maintenance and operation in a high-temperature environment are more complicated.

[0004] Therefore, although nickel-chromium heating slurry has certain advantages in e-cigarette applications, its high-energy consumption sintering process has become one of the key factors restricting the cost control and production efficiency improvement of e-cigarette products. Summary of the invention

[0005] The technical problem to be solved by the present application is that the existing nickel-chromium heating slurry has a high sintering temperature, resulting in high energy consumption during the sintering process.

[0006] In order to solve the above technical problems, the present application provides a heat-generating slurry, which adopts the following technical solution:

[0007] The heating paste comprises solid powder and organic binder, wherein the solid powder comprises nickel-chromium alloy powder and improved alloy powder, wherein the melting point of the improved alloy powder is lower than that of the nickel-chromium alloy powder, and the weight fraction of the solid powder is 82-92%.

[0008] In order to solve the above technical problems, an embodiment of the present application provides a heat-generating film, which includes the heat-generating slurry as described above.

[0009] In order to solve the above technical problems, the present application also provides a method for preparing a heating film, which adopts the following technical solution:

[0010] Premixing a solid powder and an organic binder to prepare a premixed slurry, wherein the solid powder comprises a nickel-chromium alloy powder and an improved alloy powder, wherein the melting point of the improved alloy powder is lower than the melting point of the nickel-chromium alloy powder, and the weight fraction of the solid powder is 82-92%;

[0011] Grinding the premixed slurry to obtain a heat-generating slurry, wherein the average particle size of the heat-generating slurry is less than 50 μm;

[0012] The heating slurry is printed onto the porous ceramic surface by printing technology, and then dried to obtain a sintered precursor;

[0013] The sintering precursor is placed in a sintering furnace, and is heated to a sintering temperature according to a preset sintering process to form a heating film, wherein the sintering temperature is 830-930°C.

[0014] Compared with the prior art, this application has the following beneficial effects:

[0015] The present application provides a heating slurry, which comprises a solid powder and an organic binder, wherein the solid powder comprises a nickel-chromium alloy powder and an improved alloy powder, wherein the melting point of the improved alloy powder is lower than the melting point of the nickel-chromium alloy powder, and the weight fraction of the solid powder is 82-92%. By adding a proper amount of the improved alloy powder having a melting point lower than that of the nickel-chromium alloy powder to the nickel-chromium alloy powder, the material composition of the heating slurry is improved, so that the heating slurry can be sintered at a sintering temperature lower than that of the main nickel-chromium alloy powder, thereby achieving effective energy saving and reducing sintering costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the scheme in the present application, a brief introduction is given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 is a flow chart of an embodiment of a method for preparing a heating film according to the present application;

[0018] Figure 2 It is a schematic diagram of the microstructure of an embodiment of the heating film of the present application;

[0019] Figure 3 It is a schematic diagram of the microstructure of a comparative example of the heating film of the present application;

[0020] Figure 4 It is a schematic diagram of the microstructure of another comparative example of the heating film of the present application. DETAILED DESCRIPTION

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0022] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0024] An embodiment of the present application provides a heat-generating slurry, which includes a solid powder and an organic binder. The solid powder includes a nickel-chromium alloy powder and an improved alloy powder, wherein the melting point of the improved alloy powder is lower than the melting point of the nickel-chromium alloy powder, and the weight fraction of the solid powder is 82-92%.

[0025] In this embodiment, the component of the solid powder is micron-sized powder. The micron-sized powder has a large specific surface area and can be mixed more fully, thereby improving the uniformity of mixing and the utilization rate of the material. At the same time, it enhances the bonding force between the components, which helps the heat-generating slurry to form a denser microstructure.

[0026] In this embodiment, nickel-chromium alloy powder is the main material with a melting point of 1250°C. The melting point of the improved alloy powder is lower than 1250°C. The improved alloy powder with a low melting point can reduce the sintering temperature of the heating slurry, thereby reducing the sintering temperature of the heating film formed by sintering the heating slurry, thereby saving energy and reducing costs and improving production efficiency.

[0027] The organic binder can provide strong bonding force to ensure that the various components in the heating paste are tightly combined, thereby improving the overall strength and stability of the heating paste.

[0028] In this embodiment, the weight fraction of the solid powder in the heat generating slurry is 82-92%, wherein the total weight of the organic binder and the solid powder is 100%, and the weight fraction of the organic binder in the heat generating slurry may be 8-18%.

[0029] Among them, the weight fraction of the solid powder in the heating slurry can be any value among 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, or the range formed by any two values.

[0030] By selecting an appropriate ratio of solid powder and organic binder, it is possible to ensure that the organic binder is evenly distributed in the heating slurry, thereby increasing the overall strength of the heating slurry and, at the same time, improving the toughness and wear resistance of the heating slurry.

[0031] In some embodiments, the solid powder further includes a reinforcing material, and the reinforcing material is used to improve the filling performance of the heat-generating slurry, thereby enhancing the strength and stability of the heat-generating slurry.

[0032] In some embodiments, the improved alloy powder is selected from nickel-boron alloy powder, wherein the melting point of the nickel-boron alloy powder is 980°C, which is lower than the melting point of the nickel-chromium alloy powder of 1250°C.

[0033] In some embodiments, the weight fraction of nickel-boron alloy powder in the solid powder is 8-15%, the weight fraction of nickel-chromium alloy powder in the solid powder is 71-83%, and the weight fraction of reinforcing material in the solid powder is 9-14%.

[0034] Among them, the weight fraction of nickel-boron alloy powder in the solid powder can be any one of 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%, or a range formed by any two values; the weight fraction of nickel-chromium alloy powder in the solid powder can be any one of 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, and 83%, or a range formed by any two values; the weight fraction of reinforcing material in the solid powder can be any one of 9%, 10%, 11%, 12%, 13%, and 14%, or a range formed by any two values.

[0035] Selecting a suitable weight ratio of each component in the heat-generating slurry can improve the overall performance of the heat-generating slurry, while improving processing performance and production efficiency, reducing raw material consumption, and lowering costs.

[0036] In some embodiments, the reinforcing material includes glass powder and boric acid. The glass powder is usually composed of kaolin and is an inorganic oxide powder. After a high-temperature solid-phase reaction, it forms a disordered glass homogeneous body. Boric acid can play a supporting and reinforcing role in the heat-generating slurry.

[0037] In some embodiments, the weight fraction of the glass powder in the solid powder is 8-12%, and the weight fraction of the boric acid in the solid powder is 1-2%.

[0038] In some embodiments, the organic binder is selected from one or more combinations of terpineol, butyl carbitol, tributyl citrate, lecithin and ethyl cellulose. The above organic binders are common and easily available, which can reduce production costs.

[0039] In some embodiments, the organic binder is a combination of pineol, butyl carbitol, tributyl citrate, lecithin and ethyl cellulose, wherein the weight fraction of pineol in the organic binder is 54-76%, the weight fraction of butyl carbitol in the organic binder is 10-25%, the weight fraction of tributyl citrate in the organic binder is 5.5-7.5%, the weight fraction of lecithin in the organic binder is 0.5-1.5%, and the weight fraction of ethyl cellulose in the organic binder is 8-12%.

[0040] In some embodiments, the average particle size of the heat-generating slurry is less than 50 μm. The micron-level particle size can ensure the uniformity of the heat-generating slurry and enhance the mixing uniformity, strength and durability of the heat-generating slurry.

[0041] In some embodiments, the sintering temperature of the heating slurry is 830-930°C, wherein the sintering temperature can be any value of 830°C, 840°C, 850°C, 860°C, 870°C, 880°C, 890°C, 900°C, 910°C, 920°C, and 930°C, or a range formed by any two values. The specific sintering temperature can be selected according to actual conditions and is not limited here.

[0042] The sintering temperature of the heating paste of the present application is lower than the melting point of nickel-boron alloy powder, and is much lower than the sintering temperature of 1100°C for forming a heating film using nickel-chromium heating paste, indicating that the use of nickel-boron alloy powder can significantly reduce the sintering temperature of the heating paste, save energy consumption, and reduce production costs.

[0043] The present application also provides a heating film, which comprises the heating paste as described above. The heating paste as described above is sintered to form the heating film, so that the heating film has high stability and uniform internal structure.

[0044] The present application also provides a method for preparing a heating film, see Figure 1 As shown, the following steps are included:

[0045] Step S10, premixing solid powder and organic binder to prepare premixed slurry, wherein the solid powder includes nickel-chromium alloy powder and improved alloy powder, wherein the melting point of the improved alloy powder is lower than the melting point of the nickel-chromium alloy powder, and the weight fraction of the solid powder is 82-92%;

[0046] Step S20, grinding the premixed slurry to obtain a heat-generating slurry, wherein the average particle size of the heat-generating slurry is less than 50 μm;

[0047] Step S30, printing the heat-generating slurry onto the surface of the porous ceramic by printing technology, and drying to obtain a sintered precursor;

[0048] Step S40, placing the sintering precursor into a sintering furnace, heating it to a sintering temperature according to a preset sintering process, and sintering it to form a heating film, wherein the sintering temperature is 830-930°C.

[0049] In some embodiments, the predetermined sintering process includes the following stages:

[0050] The first stage: the temperature of the sintering furnace is heated from room temperature to 500°C at a heating rate of 3-8°C / min;

[0051] The second stage: keep warm at 500℃ for 30-60min;

[0052] The third stage: heating the temperature of the sintering furnace from 500°C to the sintering temperature at a heating rate of 5-10°C / min, wherein the sintering temperature is 830-930°C;

[0053] The fourth stage: keep the sintering temperature at 60 to 180 minutes, then stop heating and cool down with the furnace to complete sintering.

[0054] In a specific embodiment, the method for preparing the heating film comprises the following steps:

[0055] 1) weighing the above solid powders, including nickel-chromium alloy powder, nickel-boron alloy powder, glass powder, and boric acid according to corresponding weight fractions, putting them into a mixing barrel, and uniformly mixing them for 6-12 hours;

[0056] 2) weighing the above organic binders, including terpineol, butyl carbitol, tributyl citrate, lecithin, and ethyl cellulose according to the corresponding weight fractions, adding them into a beaker, heating them in a water bath at 75-85° C., and stirring them thoroughly to dissolve them uniformly to prepare an organic binder carrier;

[0057] 3) weighing the solid powder prepared above and the organic binder carrier according to a preset ratio, wherein the solid content of the solid powder is 82-92%, and premixing and stirring to form a premixed slurry;

[0058] 4) placing the premixed slurry prepared in step 3 into a three-roll mill and fully grinding it to complete the preparation of the heat-generating slurry, wherein the average particle size of the heat-generating slurry is less than 50 μm;

[0059] 5) Using screen printing technology, the obtained heating slurry is printed on the surface of the porous ceramic, and then placed in a drying oven for drying at 80° C. for 30-60 minutes;

[0060] 6) The heating film is sintered in a high-temperature sintering furnace (atmosphere reduction furnace or vacuum furnace) to form a continuous, stable and fused heating film; the sintering process conditions are as follows: ① room temperature to 500°C, heating rate 3-8°C / min; ② 500°C insulation, insulation for 30-60min; ③ 500°C to sintering temperature (830-930°C), heating rate 5-10°C / min; ④ sintering temperature insulation for 60-180min, then stop heating and cool down with the furnace;

[0061] 7) Sintering is completed, the heating film is prepared, and the performance is tested.

[0062] The following is a more specific description of the content of the present application in conjunction with specific embodiments, and further elaboration of the present application, but these embodiments are by no means limiting the present application.

[0063] Example 1

[0064] This embodiment provides a method for preparing a heating film, comprising the following steps:

[0065] 1) The components of the solid powder are weighed according to their mass proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 82% nickel-chromium alloy powder, 8% nickel-boron alloy powder, 8% glass powder, and 2% boric acid;

[0066] 2) The components of the organic binder are weighed according to their mass proportions and added into a beaker, heated in a water bath at 80° C., and stirred and dissolved to prepare an organic binder carrier, wherein the organic binder includes 63% terpineol, 20% butyl carbitol, 6% tributyl citrate, 0.7% lecithin, and 10.3% ethyl cellulose;

[0067] 3) weighing the solid powder part and the organic binder carrier part prepared above according to a proportion, premixing and stirring to form a premixed slurry, wherein the solid content of the solid powder is 87%;

[0068] 4) placing the premixed slurry into a three-roll mill and fully grinding it to complete the preparation of the exothermic slurry, wherein the average particle size of the exothermic slurry is less than 50 μm;

[0069] 5) Printing the obtained heat-generating slurry onto the surface of the porous ceramic by screen printing technology, and drying it in a drying oven at 80° C. for 45 minutes;

[0070] 6) The heating film is sintered in a high-temperature sintering furnace (atmosphere reduction furnace or vacuum furnace) to form a continuous, stable and fused heating film; sintering process conditions: ① Heating from room temperature to 500°C, heating rate 5°C / min; ② Keep at 500°C for 30min; ③ Heating from 500°C to 920°C, heating rate 10°C / min; ④ Keep at 920°C for 100min, then stop heating and cool down with the furnace;

[0071] 7) Sintering is completed, the heating film is prepared, and the performance is tested.

[0072] The performance test results are: the heating film is sintered firmly, the alloy powders in the heating film are well integrated, and the service life is qualified.

[0073] Example 2

[0074] This embodiment provides a method for preparing a heating film, comprising the following steps:

[0075] 1) The components of the solid powder are weighed according to their mass proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 77% nickel-chromium alloy powder, 11.5% nickel-boron alloy powder, 10% glass powder, and 1.5% boric acid;

[0076] 2) The components of the organic binder are weighed according to their mass proportions and added into a beaker, heated in a water bath at 80° C., and stirred and dissolved to prepare an organic binder carrier, wherein the organic binder includes 61% terpineol, 25% butyl carbitol, 5.5% tributyl citrate, 0.5% lecithin, and 8% ethyl cellulose;

[0077] 3) weighing the solid powder part and the organic binder carrier part prepared above according to a proportion, premixing and stirring to form a premixed slurry, wherein the solid content of the solid powder is 92%;

[0078] 4) placing the premixed slurry into a three-roll mill and fully grinding it to complete the preparation of the exothermic slurry, wherein the average particle size of the exothermic slurry is less than 50 μm;

[0079] 5) Printing the obtained heat-generating slurry onto the surface of the porous ceramic by screen printing technology, and drying it in a drying oven at 80° C. for 45 minutes;

[0080] 6) The heating film is sintered in a high-temperature sintering furnace (atmosphere reduction furnace or vacuum furnace) to form a continuous, stable and fused heating film; sintering process conditions: ① Heating from room temperature to 500°C, heating rate 5°C / min; ② Keep at 500°C for 30min; ③ Heating from 500°C to 870°C, heating rate 10°C / min; ④ Keep at 870°C for 100min, then stop heating and cool down with the furnace;

[0081] 7) Sintering is completed, the heating film is prepared, and the performance is tested.

[0082] The performance test results are: Figure 2 As shown, the heating film is sintered firmly, and the alloy powders in the heating film are well integrated; the service life is qualified.

[0083] Example 3

[0084] This embodiment provides a method for preparing a heating film, comprising the following steps:

[0085] 1) The components of the solid powder are weighed according to their mass proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 72% nickel-chromium alloy powder, 15% nickel-boron alloy powder, 12% glass powder, and 1% boric acid;

[0086] 2) The components of the organic binder are weighed according to their mass proportions and added into a beaker, heated in a water bath at 80° C., and stirred and dissolved to prepare an organic binder carrier, wherein the organic binder includes 69% terpineol, 10% butyl carbitol, 7.5% tributyl citrate, 1.5% lecithin, and 12% ethyl cellulose;

[0087] 3) weighing the solid powder part and the organic binder carrier part prepared above according to a proportion, premixing and stirring to form a premixed slurry, wherein the solid content of the solid powder is 82%;

[0088] 4) placing the premixed slurry into a three-roll mill and fully grinding it to complete the preparation of the exothermic slurry, wherein the average particle size of the exothermic slurry is less than 50 μm;

[0089] 5) Printing the obtained heat-generating slurry onto the surface of the porous ceramic by screen printing technology, and drying it in a drying oven at 80° C. for 45 minutes;

[0090] 6) The heating film is sintered in a high-temperature sintering furnace (atmosphere reduction furnace or vacuum furnace) to form a continuous, stable and fused heating film; sintering process conditions: ① Heating from room temperature to 500°C, heating rate 5°C / min; ② Keep at 500°C for 30min; ③ Heating from 500°C to 830°C, heating rate 10°C / min; ④ Keep at 830°C for 100min, then stop heating and cool down with the furnace;

[0091] 7) Sintering is completed, the heating film is prepared, and the performance is tested.

[0092] The performance test results are: the heating film is sintered firmly, the alloy powders in the heating film are well integrated, and the service life is qualified.

[0093] Comparative Example 1

[0094] This comparative example provides a method for preparing a heating film, comprising the following steps:

[0095] 1) The components of the solid powder are weighed according to their mass proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 85% nickel-chromium alloy powder, 5% nickel-boron alloy powder, 8% glass powder, and 2% boric acid;

[0096] 2) The components of the organic binder are weighed according to their mass proportions and added into a beaker, heated in a water bath at 80° C., and stirred and dissolved to prepare an organic binder carrier, wherein the organic binder includes 63% terpineol, 20% butyl carbitol, 6% tributyl citrate, 0.7% lecithin, and 10.3% ethyl cellulose;

[0097] 3) weighing the solid powder part and the organic binder carrier part prepared above according to a proportion, premixing and stirring to form a premixed slurry, wherein the solid content of the solid powder is 87%;

[0098] 4) placing the premixed slurry into a three-roll mill and fully grinding it to complete the preparation of the exothermic slurry, wherein the average particle size of the exothermic slurry is less than 50 μm;

[0099] 5) Printing the obtained heat-generating slurry onto the surface of the porous ceramic by screen printing technology, and drying it in a drying oven at 80° C. for 45 minutes;

[0100] 6) The heating film is sintered in a high-temperature sintering furnace (atmosphere reduction furnace or vacuum furnace) to form a continuous, stable and fused heating film; sintering process conditions: ① Heating from room temperature to 500°C, heating rate 5°C / min; ② Keep at 500°C for 30min; ③ Heating from 500°C to 800°C, heating rate 10°C / min; ④ Keep at 800°C for 100min, then stop heating and cool down with the furnace;

[0101] 7) Sintering is completed, the heating film is prepared, and the performance is tested.

[0102] The performance test results are: Figure 3 As shown, the heating film is not fully sintered, and the alloy powders in the heating film are poorly fused; the service life is poor.

[0103] Comparative Example 2

[0104] This comparative example provides a method for preparing a heating film, comprising the following steps:

[0105] 1) The components of the solid powder are weighed according to their mass proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 67% nickel-chromium alloy powder, 20% nickel-boron alloy powder, 12% glass powder, and 1% boric acid;

[0106] 2) The components of the organic binder are weighed according to their mass proportions and added into a beaker, heated in a water bath at 80° C., and stirred and dissolved to prepare an organic binder carrier, wherein the organic binder includes 69% terpineol, 10% butyl carbitol, 7.5% tributyl citrate, 1.5% lecithin, and 12% ethyl cellulose;

[0107] 3) weighing the solid powder part and the organic binder carrier part prepared above according to a proportion, premixing and stirring to form a premixed slurry, wherein the solid content of the solid powder is 82%;

[0108] 4) placing the premixed slurry into a three-roll mill and fully grinding it to complete the preparation of the exothermic slurry, wherein the average particle size of the exothermic slurry is less than 50 μm;

[0109] 5) Printing the obtained heat-generating slurry onto the surface of the porous ceramic by screen printing technology, and drying it in a drying oven at 80° C. for 45 minutes;

[0110] 6) The heating film is sintered in a high-temperature sintering furnace (atmosphere reduction furnace or vacuum furnace) to form a continuous, stable and fused heating film; sintering process conditions: ① Heating from room temperature to 500°C, heating rate 5°C / min; ② Keep at 500°C for 30min; ③ Heating from 500°C to 980°C, heating rate 10°C / min; ④ Keep at 980°C for 100min, then stop heating and cool down with the furnace;

[0111] 7) Sintering is completed, the heating film is prepared, and the performance is tested.

[0112] The performance test results are: Figure 4 As shown, the heating film is sintered at an over-temperature and all the alloy powders in the heating film are melted.

[0113] It can be seen from the performance test results of the heating films of the above-mentioned Examples 1-3 and Comparative Examples 1-2 that the sintering temperature of the heating paste of the present application is 830-930°C, and a sintering temperature that is too low (800°C) or too high (980°C) will affect the performance of the heating film. It can be seen that the sintering temperature of the heating paste of the present application is 830-930°C, and the sintering temperature is much lower than the melting point of the main material nickel-chromium alloy powder. During the sintering process, it can effectively save energy and reduce costs. At the same time, the heating film formed by sintering the heating paste of the present application has good compatibility of the components, uniform particle size, firm heating film, good stability, and qualified service life.

[0114] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A heat-generating slurry, characterized in that: It comprises solid powder and organic binder, wherein the solid powder comprises nickel-chromium alloy powder and improved alloy powder, wherein the melting point of the improved alloy powder is lower than that of the nickel-chromium alloy powder, and the weight fraction of the solid powder is 82-92%.

2. The heat-generating slurry according to claim 1, characterized in that: The solid powder further comprises a reinforcing material; and / or, The improved alloy powder is selected from nickel-boron alloy powder; and / or, The weight fraction of the nickel-boron alloy powder in the solid powder is 8-15%, the weight fraction of the nickel-chromium alloy powder in the solid powder is 71-83%, and the weight fraction of the reinforcing material in the solid powder is 9-14%.

3. The heat-generating slurry according to claim 2, characterized in that: The reinforcing material comprises glass powder and boric acid; and / or, The weight fraction of the glass powder in the solid powder is 8-12%, and the weight fraction of the boric acid in the solid powder is 1-2%.

4. The heat-generating slurry according to claim 1, characterized in that: The organic binder is selected from one or more combinations of terpineol, butyl carbitol, tributyl citrate, lecithin and ethyl cellulose.

5. The heat-generating slurry according to claim 4, characterized in that: The organic binder is a combination of pineol, butyl carbitol, tributyl citrate, lecithin and ethyl cellulose, wherein the weight fraction of the pineol in the organic binder is 54-76%, the weight fraction of the butyl carbitol in the organic binder is 10-25%, the weight fraction of the tributyl citrate in the organic binder is 5.5-7.5%, the weight fraction of the lecithin in the organic binder is 0.5-1.5%, and the weight fraction of the ethyl cellulose in the organic binder is 8-12%.

6. The heat-generating slurry according to any one of claims 1 to 5, characterized in that: The average particle size of the heat-generating slurry is less than 50 μm.

7. The heat-generating slurry according to claim 6, characterized in that: The sintering temperature of the heat-generating slurry is 830-930°C.

8. A heating film, characterized in that: The heat-generating film comprises the heat-generating paste according to any one of claims 1 to 7.

9. A method for preparing a heating film, characterized in that: The following steps are involved: Premixing a solid powder and an organic binder to prepare a premixed slurry, wherein the solid powder comprises a nickel-chromium alloy powder and an improved alloy powder, wherein the melting point of the improved alloy powder is lower than the melting point of the nickel-chromium alloy powder, and the weight fraction of the solid powder is 82-92%; Grinding the premixed slurry to obtain a heat-generating slurry, wherein the average particle size of the heat-generating slurry is less than 50 μm; The heating slurry is printed onto the porous ceramic surface by printing technology, and then dried to obtain a sintered precursor; The sintering precursor is placed in a sintering furnace, and is heated to a sintering temperature according to a preset sintering process to form a heating film, wherein the sintering temperature is 830-930°C.

10. The method for preparing a heating film according to claim 9, characterized in that: The preset sintering process includes the following stages: The first stage: heating the temperature of the sintering furnace from room temperature to 500°C at a heating rate of 3-8°C / min; The second stage: keep warm at 500℃ for 30-60min; The third stage: heating the temperature of the sintering furnace from 500°C to the sintering temperature at a heating rate of 5-10°C / min, wherein the sintering temperature is 830-930°C; The fourth stage: keep the sintering temperature at 60 to 180 minutes, then stop heating and cool down with the furnace.

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