Heating slurry, heating film and preparation method thereof

Abstract

The invention belongs to the technical 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 binder, the solid powder comprises a main alloy material and a doped alloy material, and the melting point of the doped alloy material is lower than that of the main alloy material. According to the technical scheme, the sintering temperature of the heating slurry can be reduced, energy is effectively saved, and 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] As an important functional material, stainless steel heating paste is widely used in various heating elements and thermal management systems. This type of heating paste is coated on the stainless steel substrate through a specific process and sintered at high temperature to form a heating film, thus giving the stainless steel material heating properties. However, in the actual production process, the sintering temperature of the stainless steel heating film is extremely high, usually higher than 1200℃.

[0003] Such a high sintering temperature not only increases the energy consumption in the production process, but also puts more stringent requirements on production equipment. High energy consumption not only increases production costs, but also creates an additional burden on the environment, which is not conducive to sustainable development. At the same time, the high-temperature sintering process may also cause subtle changes in material properties, such as increased thermal stress and changes in microstructure, all of which may affect the final performance and stability of the heating film.

[0004] Therefore, how to lower the sintering temperature while ensuring the performance of the heating film, thereby reducing energy consumption and improving production efficiency, has become a technical problem that needs to be urgently solved in the current field of heating slurry for stainless steel materials. Summary of the invention

[0005] The technical problem to be solved by the present application is that the existing heating paste has high sintering temperature and high energy consumption, and is likely to affect the performance of the heating film.

[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 heat-generating slurry comprises solid powder and an organic binder, wherein the solid powder comprises a high TCR main alloy material and a doped alloy material, and the melting point of the doped alloy material is lower than the melting point of the main alloy material.

[0008] In order to solve the above technical problems, an embodiment of the present application further provides a heating film, which includes the heating 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 obtain a slurry precursor, wherein the solid powder comprises a high TCR main alloy material and a doped alloy material, and the melting point of the doped alloy material is lower than the melting point of the main alloy material;

[0011] Grinding the slurry precursor 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 sintered according to a preset sintering process to form a heating film.

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

[0015] The present application provides a heating slurry, which includes a solid powder and an organic binder. The solid powder includes a high TCR main alloy material and a doped alloy material. The melting point of the doped alloy material is lower than the melting point of the main alloy material. By adding the low-melting-point doped alloy material to the main alloy material, the sintering temperature of the heating slurry can be reduced, effectively saving energy and reducing 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, wherein the solid powder includes a high TCR main alloy material and a doped alloy material, and the melting point of the doped alloy material is lower than the melting point of the main alloy material.

[0025] In this embodiment, the main alloy material is a material with a high TCR (temperature coefficient of resistance). By adding a doped alloy material with a lower melting point than the main alloy material, the material composition of the heating slurry is improved, thereby adjusting the sintering temperature of the heating slurry. The heating slurry maintains a high TCR while being sintered at a sintering temperature lower than that of the main alloy material, thereby achieving effective energy saving and reducing costs.

[0026] In this embodiment, the high TCR material generally refers to a material having a TCR value greater than or equal to 800 ppm / °C.

[0027] It should be understood that when the heating paste with a high TCR value works at a constant voltage, its heating power will drop rapidly as the temperature rises. This characteristic enables the heating element to automatically stabilize at a certain predetermined temperature value after reaching the temperature, thereby automatically controlling the temperature of the heating element and effectively preventing the heating element from overheating and damage.

[0028] In some embodiments, the main alloy material is selected from stainless steel alloy powder, and the doped alloy material is selected from nickel-boron alloy powder. Among them, stainless steel alloy powder and nickel-boron alloy powder are both easily available materials, which can reduce costs. Stainless steel alloy powder is mainly composed of elements such as iron (Fe), chromium (Cr), and nickel (Ni), with a melting point of about 1450°C and a large TCR value. The melting point of nickel-boron alloy powder is about 980°C. By adding an appropriate amount of nickel-boron alloy powder to the stainless steel alloy powder, the sintering temperature of the heat-generating slurry can be reduced.

[0029] In some embodiments, both the stainless steel alloy powder and the nickel-boron alloy powder are micron-sized powders with a large specific surface area, which can be mixed more fully, thereby improving the utilization rate of the materials and enhancing the bonding force between the powders to form a denser microstructure.

[0030] In some embodiments, the weight fraction of the stainless steel alloy powder in the solid powder is 65-80%, and the weight fraction of the nickel-boron alloy powder in the solid powder is 10-20%. Among them, the weight fraction of the stainless steel alloy powder in the solid powder can be 65-70%, 65-75%, 70-75%, 70-80% or 75-80%, specifically, the weight fraction of the stainless steel alloy powder in the solid powder can be 65%, 70%, 75% or 80%, etc.; the weight fraction of the nickel-boron alloy powder in the solid powder can be 10-15% or 15-20%, specifically 10%, 15% or 20%. The weight fractions of the stainless steel alloy powder and the nickel-boron alloy powder in the solid powder can be selected according to actual conditions and are not limited here.

[0031] Mixing appropriate amounts of nickel-boron alloy powder and stainless steel alloy powder can improve material utilization and mixing effect.

[0032] In some embodiments, the solid powder further comprises a reinforcing material, and the weight fraction of the reinforcing material in the solid powder is 10-15%. 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.

[0033] In some embodiments, the reinforcing material includes glass powder and boric acid. Glass powder is usually made of kaolin and is an inorganic oxide powder. After high-temperature solid-phase reaction, it forms a glass homogeneous body with disordered structure; boric acid can play a supporting and reinforcing role in the heat-generating slurry.

[0034] In some embodiments, the weight fraction of the glass powder in the solid powder is 9-13%, and the weight fraction of the boric acid in the solid powder is 1-2%.

[0035] Among them, the average particle size of glass powder and boric acid is in the micron level, which enhances the bonding force between different powders of the heating slurry and forms a denser microstructure.

[0036] In some embodiments, the organic binder is selected from one or more combinations of pineneol, butyl carbitol, tributyl citrate, lecithin and ethyl cellulose. The organic binder can provide strong bonding force to ensure that the components in the heating paste are tightly combined, thereby improving the strength and stability of the overall material; at the same time, the organic binder usually has good chemical resistance and can resist the erosion of external environments such as moisture, acid and alkali, thereby extending the service life of the heating paste.

[0037] In some embodiments, the weight fraction of the organic binder in the heat-generating slurry is 12-20%, and the weight fraction of the solid powder in the heat-generating slurry is 80-88%.

[0038] It should be understood that the total mass of the organic binder and the solid powder should be 100%.

[0039] In some embodiments, the average particle size of the heat-generating slurry is less than 50 μm, which can ensure the uniformity of the heat-generating slurry and enhance the strength and durability of the heat-generating slurry.

[0040] Specifically, the average particle size of the heat-generating slurry may be 10 μm, 20 μm, 30 μm, 40 μm or 45 μm, etc., which may be determined according to actual conditions and is not limited here.

[0041] In some embodiments, the organic binder is 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%.

[0042] The present application also provides a heating film, which comprises the heating paste as described above. The heating film is formed by sintering the heating paste as described above, so that the heating film has high compatibility and stability.

[0043] In some embodiments, the temperature coefficient of resistance (TCR) of the heating film is 850-1000 ppm / ° C. This further indicates that the sintering temperature of the heating paste can be lowered while ensuring that the heating film has a high TCR value.

[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 a solid powder and an organic binder to obtain a slurry precursor, wherein the solid powder includes a main alloy material and a doped alloy material, and the melting point of the doped alloy material is lower than the melting point of the main alloy material;

[0046] Step S20, grinding the slurry precursor 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, and sintering according to a preset sintering process to form a heating film.

[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 860-960°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) The above solid powders, including stainless steel alloy powder, nickel-boron low temperature alloy powder, glass powder, and boric acid, are weighed according to the corresponding weight fractions, put into a mixing barrel, and evenly mixed for 6-12 hours;

[0056] 2) weighing the above organic components, 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 80-88%, and premixing and stirring to form a slurry precursor;

[0058] 4) The slurry precursor prepared in step 3 is placed in a three-roll mill and fully milled 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 (860-960°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 weight proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 69% stainless steel alloy powder, 20% nickel-boron low-temperature alloy powder, 9% glass powder, and 2% boric acid;

[0066] 2) adding each component of the organic binder according to the weight ratio into a beaker, heating in a water bath at 80° C., and stirring and dissolving the components 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 certain proportion, premixing and stirring to form a slurry precursor, wherein the solid content of the solid powder is 84%;

[0068] 4) placing the slurry precursor 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;

[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 860°C, heating rate 10°C / min; ④ Keep at 860°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 powder is well integrated, the service life is qualified, and the heating film TCR≈850ppm / ℃.

[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 weight proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 72.5% stainless steel alloy powder, 15% nickel-boron low-temperature alloy powder, 11% glass powder, and 1.5% boric acid;

[0076] 2) adding each component of the organic binder according to the weight ratio into a beaker, heating in a water bath at 80° C., and stirring and dissolving 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 slurry precursor, wherein the solid content of the solid powder is 88%;

[0078] 4) placing the slurry precursor 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;

[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 910°C, heating rate 10°C / min; ④ Keep at 910°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, the alloy powder is well integrated, the service life is qualified, and the heating film TCR≈920ppm / ℃.

[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 weight proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 76% stainless steel alloy powder, 10% nickel-boron low-temperature alloy powder, 13% glass powder, and 1% boric acid;

[0086] 2) adding each component of the organic binder according to the weight ratio into a beaker, heating in a water bath at 80° C., and stirring and dissolving 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 slurry precursor, wherein the solid content of the solid powder is 80%;

[0088] 4) placing the slurry precursor 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;

[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 960°C, heating rate 10°C / min; ④ Keep at 960°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 powder is well integrated, the service life is qualified, and the heating film TCR≈1000ppm / ℃.

[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 weight proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 69% stainless steel alloy powder, 20% nickel-boron low-temperature alloy powder, 9% glass powder, and 2% boric acid;

[0096] 2) adding each component of the organic binder according to the weight ratio into a beaker, heating in a water bath at 80° C., and stirring and dissolving the components 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 certain proportion, premixing and stirring to form a slurry precursor, wherein the solid content of the solid powder is 84%;

[0098] 4) placing the slurry precursor 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;

[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 820°C, heating rate 10°C / min; ④ Keep at 820°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, the alloy powder is poorly fused, and the service life is short.

[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 weight proportions and put into a mixing barrel, and mixed evenly for 8 hours, wherein the solid powder includes 76% stainless steel alloy powder, 10% nickel-boron low-temperature alloy powder, 13% glass powder, and 1% boric acid;

[0106] 2) adding each component of the organic binder according to the weight ratio into a beaker, heating in a water bath at 80° C., and stirring and dissolving 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 slurry precursor, wherein the solid content of the solid powder is 80%;

[0108] 4) placing the slurry precursor 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;

[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 1000°C, heating rate 10°C / min; ④ Keep at 1000°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 powder is 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 suitable sintering temperature of the heating paste of the present application is 860-960°C, and the sintering temperature is too low (820°C) or too high (1000°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 860-960°C, and the sintering temperature is much lower than the melting point of the main alloy material, which 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 a higher TCR value, and the components are well compatible, the particle size is uniform, the heating film is firm, the stability is good, and the service life is qualified.

[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 a high TCR main alloy material and a doped alloy material, and the melting point of the doped alloy material is lower than the melting point of the main alloy material.

2. The heat-generating slurry according to claim 1, characterized in that: The main alloy material is selected from stainless steel alloy powder, and the doped alloy material is selected from nickel-boron alloy powder; and / or, The weight fraction of the stainless steel alloy powder in the solid powder material is 65-80%, and the weight fraction of the nickel-boron alloy powder in the solid powder material is 10-20%.

3. The heat-generating slurry according to claim 1, characterized in that: The solid powder further comprises a reinforcing material, and the weight fraction of the reinforcing material in the solid powder is 10-15%.

4. The heat-generating slurry according to claim 3, 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 9-13%, and the weight fraction of the boric acid in the solid powder is 1-2%.

5. The heat generating paste 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; and / or, The weight fraction of the organic binder in the heat-generating slurry is 12-20%, and the weight fraction of the solid powder in the heat-generating slurry is 80-88%; and / or, The average particle size of the heat-generating slurry is less than 50 μm.

6. The heat-generating slurry according to claim 5, characterized in that: The organic binder is 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%.

7. A heating film, characterized in that: The heat-generating film includes the heat-generating paste according to any one of claims 1 to 6.

8. The heating film according to claim 7, characterized in that: The temperature coefficient of resistance TCR of the heating film is 850-1000 ppm / °C.

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 obtain a slurry precursor, wherein the solid powder comprises a main alloy material and a doped alloy material, and the melting point of the doped alloy material is lower than the melting point of the main alloy material; Grinding the slurry precursor 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 sintered according to a preset sintering process to form a heating film.

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 860-960°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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