CN115028366A

CN115028366A - Atomizing core, preparation method thereof and electronic atomizing device

Info

Publication number: CN115028366A
Application number: CN202110250683.6A
Authority: CN
Inventors: 江品颐; 杨伟强; 刘双任; 吴学通; 林信平
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2021-03-08
Filing date: 2021-03-08
Publication date: 2022-09-09
Anticipated expiration: 2041-03-08
Also published as: CN115028366B

Abstract

The application provides a preparation method of an atomization core, which comprises the following steps: preparing a mixed material containing inorganic hollow microspheres with the particle size distribution range of 40-120 mu m, a pore-forming agent and a binder; integrally forming the mixed material and the heating body into an atomization core green body, and sintering to obtain an atomization core; or forming the mixed material into a ceramic substrate green body, then silk-printing a heating element pattern on the ceramic substrate green body, and sintering to obtain the atomizing core. The inorganic hollow microspheres with regular shapes are introduced, so that the mechanical strength of the obtained atomization core is improved, and the atomization core has a good and stable atomization effect. The application also provides the atomization core and an electronic atomization device.

Description

Atomizing core, preparation method thereof and electronic atomizing device

Technical Field

The application relates to the technical field of ceramic atomizing cores, in particular to an atomizing core, a preparation method thereof and an electronic atomizing device.

Background

The atomizing core is an important component in an electronic cigarette product, mainly comprises a porous ceramic matrix and a heating body arranged on the porous ceramic matrix, and can heat and atomize the tobacco tar under the electric heating action of the heating body by utilizing the porous ceramic matrix to adsorb the tobacco tar to the heating body. At present, a porous ceramic substrate is generally obtained by sintering a slurry of solid inorganic powder as an aggregate, a binder, a pore-forming agent, and the like. However, most of the existing solid inorganic powder is irregular particles, and when a porous ceramic matrix bears load, cracks are easily generated due to stress concentration, so that the strength of the porous ceramic matrix is low, and the phenomena of powder falling and slag falling are easily generated; in addition, the particle size uniformity of the irregular solid inorganic powder is poor, and the gaps are irregular, so that the pore diameters of the porous ceramic matrix are inconsistent, and the atomization effect is not improved favorably.

Disclosure of Invention

In view of this, the present application provides a method for preparing an atomizing core, in which inorganic hollow microspheres with regular shapes and uniform particle sizes are introduced as aggregates to prepare the atomizing core, so that the mechanical strength of the obtained atomizing core is improved, and a good and stable atomizing effect is achieved.

In a first aspect, the present application provides a method of making an atomizing core, comprising the steps of:

preparing a mixed material containing inorganic hollow microspheres, a pore-forming agent and a binder; wherein the particle size of the inorganic hollow microsphere is 40-120 μm;

integrally forming the mixed material and the heating body into an atomization core green body, and sintering to obtain an atomization core; or forming the mixed material into a ceramic substrate green body, then silk-printing a heating element pattern on the ceramic substrate green body, and sintering to obtain the atomizing core.

The preparation method of atomizing core that this application first aspect provided, prepare ceramic atomizing core as the ceramic aggregate through inorganic hollow microballon, can be with the help of inorganic hollow microballon's regular shape, smooth surface, even particle diameter etc, reduce atomizing core and produce the risk of crackle because of stress concentration, promote its mechanical properties (such as crushing strength, bending strength), and can improve the homogeneity of atomizing core aperture with the help of inorganic hollow microballon's particle diameter homogeneity and the regular clearance of the suitable size that suitable particle diameter scope brought, and then promote the fineness of atomizing smog, and the atomizing core is difficult for taking place to stick with paste the core, the circumstances such as oil leak, in order to have good and stable atomization effect. In addition, the atomization core prepared by using the hollow microspheres as the aggregate has lower heat conductivity than the atomization core prepared by using solid particles/microspheres, and is more beneficial to concentrating heat generated by a heating body, so that the response speed of tobacco tar atomization can be improved.

In the application, the mixed material may be specifically a mixed powder containing inorganic hollow microspheres, a pore-forming agent and a binder, or a mixed slurry formed by heating the mixed powder. The forming mode of the mixed material can be slip casting or powder pressing. Wherein, the slip casting can be formed by injecting the mixed slurry into a mould or a mould with a heating element at a certain temperature and pressure. The powder pressing is to press the mixed powder under a certain pressure. The mixed powder can be feeding particles of inorganic hollow microspheres, pore-forming agent and binder.

In the present embodiment, the inorganic hollow microspheres are regular spheres, which are substantially hollow inside and have no micropores on the surface. The inorganic hollow microspheres are regular in shape, and gaps among the inorganic hollow microspheres in a porous ceramic matrix prepared from the inorganic hollow microspheres are regular, so that the pore diameter uniformity of the porous ceramic matrix is improved; and the porous ceramic matrix has low thermal conductivity, so that the atomization core can improve the atomization speed and the atomization fineness of the tobacco tar.

Specifically, the material of the inorganic hollow microsphere may be one or more of alumina, silica, titania, silicon carbide, aluminosilicate, glass, and the like. In the embodiment of the application, the particle size distribution range of the inorganic hollow microspheres is 40-120 μm. The inorganic hollow microsphere has the grain diameter within the range, is not easy to generate stress concentration, has strong shock resistance, and can better improve the mechanical property (such as crushing resistance) of the atomizing core. In addition, by adopting the inorganic hollow microspheres with the particle size within the range, the porous ceramic matrix of the atomization core obtained after sintering can have a proper number of hollow microsphere gaps with proper size, so that the tobacco tar can be ensured to have proper conduction speed in the porous ceramic matrix and can be atomized more finely.

If the particle size of the inorganic hollow microspheres is too large, the contact area between the microspheres in the porous ceramic matrix of the atomization core is small, the cohesion is weak, and the gap between the inorganic hollow microspheres is too large, which is not beneficial to the promotion of the fineness of the atomized smoke, and simultaneously, the capillary force of the pores can be reduced, so that the oil locking capacity is reduced, and the atomization core is easy to leak oil when in use. If the particle size of the inorganic hollow microspheres is too small, the number of gaps among the inorganic hollow microspheres is too large and too small, which is not beneficial to increasing the conduction speed of tobacco tar.

Illustratively, the particle size of the inorganic hollow microspheres may specifically be 45 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, or 110 μm. In some embodiments of the present application, the inorganic hollow microspheres have a particle size distribution ranging from 45 μm to 90 μm. At this moment, the atomizing core can give consideration to high mechanical strength and good atomizing effect better. In other embodiments, the inorganic hollow microspheres have a particle size distribution ranging from 45 μm to 65 μm, 50 μm to 60 μm, or 60 μm to 80 μm.

Optionally, the inorganic hollow microspheres have a D50 particle size ranging from 50 μm to 80 μm. Alternatively, the D90 particle size range of the inorganic hollow microspheres is 80-120 μm. The D10 particle size range of the inorganic hollow microspheres is 10-40 μm.

Further, the particle size of the inorganic hollow microsphere satisfies the following conditions: (D90 grain diameter-D10 grain diameter)/D50 grain diameter is less than or equal to 1.5. At the moment, the size concentration ratio of the inorganic hollow microspheres is higher, the atomization core prepared from the inorganic hollow microspheres is more difficult to generate the condition of stress concentration, and the aperture is more uniform, so that the mechanical property of the atomization core is better, and the atomization effect is more excellent.

The pore former may leave voids during sintering of the green body. Optionally, the pore-forming agent includes one or more of a high temperature decomposable salt, an inorganic carbon material, natural organic particles, organic microspheres, and the like, but is not limited thereto. The inorganic carbon material, natural organic matter particles, organic microspheres and the like can be removed during sintering to leave gaps/holes, the high-temperature decomposable salt can be decomposed during sintering to generate gas capable of overflowing, and the high-temperature decomposable salt and the gas can generate a hole structure in the material after sintering. Specifically, the inorganic carbon material may include one or more of graphite, carbon black, carbon fiber, and the like. The high temperature decomposable salts can include bicarbonates (e.g., ammonium bicarbonate, sodium bicarbonate, etc.), ammonium carbonate, ammonium chloride, and the like. The natural organic matter particles may include starch particles, plant material (e.g., sawdust, rice hulls), and the like. The organic microspheres may include polymethyl methacrylate (PMMA) microspheres, Polystyrene (PS) microspheres, polyvinyl alcohol (PVA) microspheres, etc., and may also be referred to as "high molecular polymer microspheres". In some embodiments of the present application, the pore former comprises one or more of sodium bicarbonate, graphite powder, carbon black powder, and starch. In some embodiments, the pore former is a spherical pore former. The spherical pore-forming agent has regular appearance and more controllable particle size. Alternatively, the pore former may have a particle size of 10 μm to 100 μm, which may provide the atomizing core with a suitably sized pore size. In some embodiments of the present application, the pore former may have a particle size of 10 μm to 90 μm or 20 μm to 80 μm. In some embodiments, the pore former has a particle size of 10 μm to 30 μm. In this case, the pore-forming agent having a particle diameter within this range may be mixed with the porous ceramic substrate having an appropriate pore diameter in the form of the inorganic hollow microspheres. Optionally, the particle size of the pore former satisfies: the (D90 particle size-D10 particle size)/D50 particle size is less than or equal to 1.5, so that the pore-forming agent can generate higher pore diameter uniformity.

In the embodiment of the application, the binder is organic binder, and it can be molten under the uniform temperature and be the liquid phase, does benefit to the promotion binding force between each granule (like between inorganic hollow microsphere, between the pore-forming agent, between inorganic hollow microsphere and the pore-forming agent) in the mixing material is convenient for become the unburned bricks that have certain shape, still can improve the slip casting mobility of mixing material can better fill the die cavity of complicated shape under the pressure effect, improves the shaping effect. Wherein the organic binder is selected from at least one of Paraffin wax (Paraffin wax), microcrystalline wax (CW), palm wax, sodium alginate, gelatin, polyvinyl alcohol (PVA), Ethylene Vinyl Acetate (EVA), polystyrene, polyethylene, polypropylene, and the like, but is not limited thereto. In particular, when the mixture is formed by dry pressing, the organic binder is preferably at least one organic high molecular compound such as PVA, EVA, polystyrene, polyethylene, polypropylene, and the like; when the mixed material is formed by slip casting, the organic binder is preferably paraffin wax, microcrystalline wax and other wax.

In the embodiment of the application, the mixed material comprises the following components in percentage by mass: 40-80% of inorganic hollow microspheres, 10-30% of pore-forming agent, 4-30% of binder, 0-20% of sintering aid and 0-5% of surfactant. In some embodiments, the inorganic hollow microspheres are present in the mixture in an amount of 40%, 45%, 50%, 60%, 70%, 75%, or 80% by weight. Wherein, the inorganic hollow microspheres are controlled in the range, so that the porous ceramic matrix sintered by the mixed material has proper mechanical strength and certain pores.

Optionally, the mass percentage of the sintering aid in the mixed material is 5% -20%. The proper amount of sintering aid can generate proper liquid phase in the ceramic sintering process to bond the skeleton phase, promote sintering densification and improve the strength of the obtained ceramic. Wherein the sintering aid is selected from one or more of glass powder, kaolin, feldspar, quartz, alumina, sodium silicate and the like, but is not limited thereto.

Optionally, the surfactant is 0.1-5% by mass of the mixed material. The appropriate amount of surfactant can improve the dispersibility of the components in the mixed material. The surfactant is selected from one or more of stearic acid, silane coupling agent, oleic acid, ethyl cellulose and the like.

In some embodiments of the present application, the mixture includes the following components by mass: 40 to 80 percent of inorganic hollow microspheres, 10 to 30 percent of pore-forming agent, 4 to 30 percent of binder, 5 to 20 percent of sintering aid and 0.1 to 5 percent of surfactant. The proportion can ensure that the porous ceramic matrix sintered by the mixed material has good mechanical strength and proper porosity. In some embodiments, the sintering aid is present in the mixture in an amount of 10% to 30% by weight. Specifically, the mass percentage of the sintering aid in the mixed material is 10%, 12%, 15%, 20%, 25%, 28% or 30%.

In some embodiments of the present application, the mass of the sintering aid is 10% to 30% of the mass of the inorganic hollow microspheres. The sintering aid can better improve the density and cohesion of the porous ceramic matrix obtained by sintering in the range, and further can improve the mechanical strength of the porous ceramic matrix. In some embodiments, the mass of the sintering aid is 17% to 28% of the mass of the inorganic hollow microspheres.

In this application, the heat-generating body has certain resistance, can generate heat under the circular telegram circumstances, and then makes the tobacco tar heating atomizing. The heating element may have a porous structure, and the material thereof may be metal, conductive ceramic, or the like. The metal heating sheet with the porous structure can be perforated by at least one of laser drilling, mechanical stamping, mechanical drilling, chemical etching and the like on the metal sheet so as to prepare holes with certain size and spacing on the metal heating sheet. In some embodiments of the present application, the heating element integrally formed with the mixture may be a metal heating sheet with a porous structure, or a conductive ceramic with a porous structure prepared by sintering ceramic powder or slurry. When the ceramic base green body is subjected to screen printing of a heating element pattern and then sintered, the obtained atomizing core is still integrally formed, and it is not necessary to provide a separate connecting member between the porous ceramic base and the heating element.

Illustratively, the sintering temperature during sintering is 800-. The duration of the heat preservation at the sintering temperature can be 20min-2 h.

The preparation method of the atomization core provided by the first aspect of the application has the advantages of simple and controllable process and easiness in operation, and can obtain the atomization core with good mechanical strength and atomization effect.

In a second aspect, the present application provides an atomizing core, which includes a porous ceramic substrate and a heating element disposed on the porous ceramic substrate, wherein the atomizing core is prepared by the preparation method of the first aspect of the present application.

In an embodiment of the present invention, the porous ceramic base and the heating element are integrally molded. The problem of stress concentration at the joint caused by split molding can be avoided.

In an embodiment of the present application, the porous ceramic matrix has a porosity of 30% to 60%. The pore diameter of the porous ceramic matrix is in the range of 10-100 μm. The pore diameter and the porosity of the porous ceramic matrix prepared by the preparation method are in the ranges, so that the porous ceramic matrix has proper tobacco tar conduction rate and atomization effect under the condition of proper mechanical strength.

In some embodiments, the porous ceramic matrix has a pore size in the range of 10-30 μm. The porosity of the porous ceramic matrix is 40-60%. At the moment, the porous ceramic matrix can better give consideration to good mechanical properties, proper tobacco tar conduction rate and atomization rate and good atomization effect.

Optionally, the porous ceramic matrix has a pore size distribution such that: (D90 pore size-D10 pore size)/D50 pore size < 1.

In an embodiment of the present application, the crush strength of the atomizing core is 75MPa or more. In some embodiments, the crush strength of the atomizing core is in the range of 75 to 130 MPa.

In the embodiment of the present application, the atomizing core has a bending strength of 13MPa or more.

The atomizing core that this application second aspect provided through introducing aforementioned inorganic hollow microsphere as the ceramic aggregate of porous ceramic base member, can promote the mechanical properties of atomizing core betterly, makes it have even and suitable aperture of particle diameter to have good and stable atomization effect.

In a third aspect, the present application provides an electronic atomization device, which includes the atomization core described in the present application. The electronic atomization device may be an electronic smoking set.

In particular, the atomizing core may be located within a cartridge of the electronic smoking article. The atomizing core can guide tobacco tar in the tobacco tar bin into the heating body on the atomizing core, and smoke can be evaporated when the heating body is heated.

Owing to adopt aforementioned atomizing core, the smog taste that this electron atomizing device produced is better, and the plumpness of smog is high, and is high to the degree of reduction of tobacco tar taste, can bring better user experience for the user, plays and replace the cigarette effect, and this electron atomizing device's mechanical properties is good, long service life.

Drawings

Fig. 1 is a schematic structural diagram of an atomizing core in the embodiment of the present application.

Detailed Description

The present application is further illustrated by the following specific examples.

Example 1

A method of making an atomizing core comprising:

(1) mixing hollow glass microspheres (D90 particle diameter-D10 particle diameter)/D50 particle diameter 1.4) with a pore-forming agent, a binder, a sintering aid and a surfactant at 90 ℃ (at the temperature, the binder is in a liquid state) to obtain mixed slurry, wherein the particle size range of the hollow glass microspheres is 40-70 microns, and the particle size of the hollow glass microspheres is D50 and is 50 microns; the mixed slurry comprises the following components in percentage by mass: 43 wt% of hollow glass microspheres, 12 wt% of pore-forming agent (specifically graphite powder, the particle size range is 10-30 μm, (D90-D10)/D50 is 0.5), 25 wt% of binder (specifically paraffin), 19 wt% of sintering aid (specifically solid glass powder) and 1 wt% of surfactant (specifically stearic acid);

(2) putting a heating element (specifically a metal sheet with a plurality of holes) with a certain resistance into a mould and fixing, then transferring the mixed slurry into a forming machine, and injecting the mixed slurry into the mould at a certain temperature and pressure to obtain an atomization core green body embedded with the heating element;

(3) and (3) putting the atomization core green body into a burning boat, carrying out heat preservation sintering at 900 ℃ for 2h, cooling to room temperature along with a furnace to obtain an atomization core crude product, and then polishing, cleaning and drying to obtain an atomization core finished product.

Fig. 1 shows a schematic structural view of an atomizing core obtained in example 1, wherein a ceramic atomizing core 100 provided in example 1 includes a porous ceramic base 10 and a heating element 20 integrally formed on the porous ceramic base 10.

Example 2

A method of making an atomizing core comprising:

(1) mixing hollow silicon carbide microspheres (D90 particle diameter-D10 particle diameter)/D50 particle diameter ═ 1) with the particle diameter range of 60-90 μm and the particle diameter of D50 particle diameter of 70 μm with a pore-forming agent, a bonding agent and a sintering aid, and granulating the obtained mixed powder to obtain feed particles; wherein the feed particles comprise the following components in percentage by mass: 61 wt% of hollow silicon carbide microspheres, 13 wt% of pore-forming agent (the particle size range is 10-40 μm, specifically the mixture of carbon black powder and starch particles), 12 wt% of binder (specifically the mixture of polyvinyl alcohol and polystyrene) and 14 wt% of sintering aid (specifically solid spherical alumina powder);

(2) putting the feeding particles into a mould for dry pressing under the pressure of 120MPa to obtain a ceramic matrix green body;

(3) and (3) screen printing a heating body pattern on the ceramic matrix green body, sintering at 1200 ℃ for 1.5 hours to obtain an atomization core crude product, and then polishing, cleaning and drying to obtain an atomization core finished product, wherein the atomization core finished product is shown in figure 1.

Example 3

A method of preparing an atomizing core, which differs from example 1 in that: the hollow glass microspheres of example 1 were replaced with hollow alumina microspheres having a particle size in the range of 47 μm to 62 μm and a D50 particle size of 50 μm.

Example 4

A method of preparing an atomizing core, which differs from example 1 in that: the hollow glass microspheres of example 1 were replaced with hollow aluminosilicate microspheres having a particle size ranging from 90 μm to 120 μm and a D50 particle size of 100. mu.m.

Example 5

A method of making an atomizing core, which differs from example 3 in that: the (D90 particle size-D10 particle size)/D50 particle size of the hollow alumina microspheres is 2.

To highlight the advantageous effects of the present application, the following comparative examples 1 to 3 are now provided

Comparative example 1

An irregular solid alumina powder (particle size distribution range of 47 μm to 62 μm, D50 particle size of 50 μm) was selected as a ceramic aggregate, and an atomized core was prepared according to the method described in example 1.

Comparative example 2

The atomized core was prepared according to the method described in example 1, using hollow alumina microspheres with a particle size range of 10 μm to 35 μm as the ceramic aggregate.

Comparative example 3

The atomized core was prepared according to the method described in example 1, using as the ceramic aggregate hollow alumina microspheres with a particle size in the range of 150 μm to 200 μm.

In order to further embody the beneficial effects of the present application, the porous ceramic matrixes in the atomizing cores provided in the above examples and comparative examples were tested for pore characteristics such as pore size distribution range, porosity and the like, and for mechanical properties such as crushing strength and bending strength of the atomizing core. In addition, the atomizing cores provided in the above examples and comparative examples were respectively loaded into cartridges of electronic cigarettes, the atomizing effect on tobacco tar was observed, and the corresponding oil guiding rate was recorded. The relevant results are summarized in table 1.

The method for testing the pore diameter range comprises the following steps: and (3) testing by adopting a mercury-pressing porosity tester through a mercury pressing method, wherein the minimum 10% of the pore diameter range is used as a lower limit, and the maximum 90% is used as an upper limit. The porosity test method comprises the following steps: calculating the volume V of the atomizing core, and weighing the weight m of the atomizing core ₁ Putting the atomizing core into pure water, vacuumizing, keeping the vacuum state for 2min, taking out a sample, wiping off excessive water on the surface, and weighing the sample by weight m ₂ The porosity ρ is calculated by the following formula: ρ ═ m ₂ -m ₁ ) and/V. The crushing strength was measured by a universal mechanical testing machine, and the load applied to the atomized core when cracks occurred was recorded (GB/T11837-2009). The bending strength is obtained by hot-press casting the ceramic into a strip sample, sintering the sample, and then using a universal mechanical testing machine to record the load applied when the ceramic sample strip is broken (GB/T6569-2006).

Table 1 test results of different atomizing cores

Furthermore, each cartridge has, in terms of the response speed to the smoke produced: example 3, example 5 > example 1 > example 2 > example 4 > comparative example 2 > comparative example 1 > comparative example 3; the smoke fineness is as follows: example 1, example 3 > example 5 > example 2 > example 4 > comparative example 2 > comparative example 1 > comparative example 3.

From table 1 and the atomization results, it can be known that the atomization core prepared by the preparation method provided by the embodiment of the application has a proper oil guiding rate, and the response speed of the atomization core for generating smoke is also proper, so that the atomization is fine; moreover, the atomizing core has high crushing strength and high bending strength.

From the comparison between the example 3 and the comparative examples 1 to 3, it can be known that the atomizing core of the example 3 can well take all aspects of performances into consideration, the response speed of generating smoke by heating is high, the fineness of the smoke is high, and the situations of frying oil and pasting the core hardly occur. In addition, the solid ceramic aggregate has higher thermal conductivity and irregular appearance than the inorganic hollow microspheres, so that the smoke response speed of the smoke generated by the smoke bomb in the comparative example 1 is slower, the fineness of the smoke is deviated, and the mechanical property of the atomizing core is deviated. When the particle size of the used inorganic hollow microspheres is too small, the porosity of the porous ceramic matrix in the comparative example 2 is too high, the mechanical property is the worst, the oil guiding speed of the comparative example 2 is lower than that of the example 3, and the atomization fineness is higher than that of other comparative examples. When the particle size of the used inorganic hollow microspheres is too large, the pore size of the porous ceramic matrix of comparative example 3 is also the largest, the oil guiding speed of the atomizing core is too high, the smoke oil cannot reach the required atomizing temperature, and the response speed and the smoke fineness of the generated smoke are the worst.

The results show that the atomization core prepared by using the inorganic hollow microspheres with the particle size within the range of 40-120 mu m provided by the application as the ceramic aggregate can well give consideration to various atomization performances under the condition of good mechanical properties.

The above-mentioned embodiments only express a few exemplary embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The preparation method of the atomizing core is characterized by comprising the following steps of:

preparing a mixed material containing inorganic hollow microspheres, a pore-forming agent and a binder; wherein the particle size distribution range of the inorganic hollow microspheres is 40-120 μm;

2. The method of claim 1, wherein the inorganic hollow microspheres have a D50 particle size of 50 μm to 80 μm.

3. The method of claim 2, wherein the inorganic hollow microspheres have a particle size of: (D90 grain diameter-D10 grain diameter)/D50 grain diameter is less than or equal to 1.5.

4. The method according to claim 1, wherein the inorganic hollow microspheres are made of one or more materials selected from the group consisting of alumina, silica, titania, silicon carbide, aluminosilicate, and glass.

5. The preparation method of claim 1, wherein the mixed material comprises the following components in percentage by mass: 40-80% of the inorganic hollow microspheres, 10-30% of the pore-forming agent, 4-30% of the binder, 0-20% of the sintering aid and 0-5% of the surfactant.

6. The preparation method according to claim 5, wherein the sintering aid is 5 to 40 mass percent of the mixed material; the mass percentage of the surfactant in the mixed material is 2-20%.

7. The preparation method according to claim 6, wherein the mass of the sintering aid is 10% to 30% of the mass of the inorganic hollow microspheres.

8. The preparation method according to claim 5, wherein the pore-forming agent is selected from one or more of a high-temperature decomposable salt, an inorganic carbon material, natural organic particles, and organic microspheres;

the adhesive is an organic adhesive, and the organic adhesive is selected from one or more of paraffin, microcrystalline wax, palm wax, sodium alginate, gelatin, polyvinyl alcohol, polystyrene, ethylene-vinyl acetate copolymer, polystyrene, polyethylene and polypropylene;

the sintering aid is selected from one or more of glass powder, kaolin, feldspar, quartz and sodium silicate;

the surfactant is selected from one or more of stearic acid, silane coupling agent, oleic acid and ethyl cellulose.

9. An atomizing core, comprising a porous ceramic substrate and a heating element disposed on the porous ceramic substrate, wherein the atomizing core is prepared by the preparation method according to any one of claims 1 to 8.

10. The atomizing core of claim 9, wherein the porous ceramic matrix has a porosity of 30% to 60% and a pore size in the range of 10 to 100 μ ι η.

11. The atomizing core of claim 9 or 10, wherein the atomizing core has a crush strength of 75MPa or greater.

12. An electronic atomisation device comprising an atomising core according to any of the claims 9 to 11.