Ceramic atomizing core, and preparation method therefor and use thereof

Abstract

A ceramic atomizing core, and a preparation method therefor and the use thereof. The ceramic atomizing core comprises a ceramic substrate. A surface of the ceramic substrate is provided with at least one metal thick-film electrode layer. A method for preparing the metal thick-film electrode layer comprises: step S1, forming a metal thick-film electrode slurry into a film on a substrate by means of a casting method or a coating method, and removing the substrate to obtain a metal thick-film electrode green body; and step S2, softening the metal thick-film electrode green body, then bonding same to the substrate, and performing sintering, so as to obtain the metal thick-film electrode. The ceramic atomizing core has a relatively high atomization efficiency, a relatively low maximum temperature for dry burning, a relatively long life under dry burning conditions, a relatively high TPM and performance ratio, and a relatively low content of Ni in smoke. During use, the ceramic atomizing core achieves more uniform heating and a greater atomization amount, can avoid both scorched flavor generated during smoking and potential safety hazards caused by the excessive inhalation of heavy metals during smoking, and can also improve the smoking experience of a user and the mouthfeel during smoking.

Description

Ceramic atomizing core and preparation method and application thereof

[0001] Cross-reference to related applications

[0002] The present application claims priority to Chinese Patent Application No. CN 202410834364.3, filed on June 26, 2024, and entitled "Ceramic atomizing core and preparation method and application thereof", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of electronic atomization, in particular to a ceramic atomizing core and a preparation method and application thereof. BACKGROUND

[0004] At present, the conductive film using metal as the conductive material is usually prepared by a screen printing method, which is to transfer the conductor paste, resistance paste or dielectric paste and other materials to the substrate through the printing knife head and printing screen, and then form a firmly adhered metal film on the substrate after high-temperature sintering. The method of screen printing to prepare the metal conductive film can print the conductive thick film on the planar substrate, and can also print the conductive film on the outer surface of the tubular substrate through a jig, but this method cannot be applied to the inner surface of the tubular substrate, the uneven material surface and the inner wall of the groove. In order to prepare the conductive film on the inner surface of the tubular substrate, the uneven material surface or the inner wall of the groove, a spraying method is usually directly used on the inner surface of the tubular substrate, the uneven material surface or the inner wall of the groove, but the conductive film prepared by this method cannot accurately control the quality and cannot prepare precise patterns. Although vacuum evaporation, sputtering and other methods can obtain metal conductive films with good quality, the preparation cost is too high, which greatly increases the production cost of enterprises and cannot be widely applied. SUMMARY

[0005] In order to overcome at least one technical problem existing in the prior art, one of the purposes of the present application is to provide a preparation method of a metal thick film electrode.

[0006] The second purpose of the present application is to provide a metal thick film electrode.

[0007] The third purpose of the present application is to provide a ceramic atomizing core.

[0008] The fourth purpose of the present application is to provide a preparation method of a ceramic atomizing core.

[0009] The fifth purpose of the present application is to provide an electronic atomizer.

[0010] The sixth object of the present application is to provide a preparation method of a metal thick film electrode and / or application of a ceramic atomized core in the field of electronic atomization.

[0011] To achieve the above object, the technical solution adopted by the present application is:

[0012] The first aspect of the present application provides a preparation method of a metal thick film electrode, comprising the following steps:

[0013] Step S1: forming a film of a metal thick film electrode paste on a substrate by using a flow casting method or a coating method, removing the substrate, and obtaining a metal thick film electrode green body;

[0014] Step S2: softening the metal thick film electrode green body and adhering it to a substrate, and sintering to obtain the metal thick film electrode.

[0015] In some embodiments, the preparation method further comprises a step of cutting the metal thick film electrode green body, which is located after step S1 and before step S2.

[0016] In some embodiments, the preparation method further comprises a step of laminating the obtained metal thick film electrode green body, which is located after step S1 and before step S2.

[0017] The metal thick film electrode green body in the present application has good flexibility and can be arbitrarily bent, cut and laminated. In order to prepare a metal thick film electrode green body that adheres well to the substrate, a metal thick film electrode green body with a certain film thickness, size and shape can be directly prepared on the substrate, and then adhered to the shape of the substrate without cutting; or the metal thick film electrode green body can be prepared first, then dried and separated from the substrate, and then cut and folded according to the needs to prepare a shape and size that conforms to the needs of the covered substrate. In addition, the metal thick film electrode green body has certain adhesion in an environment higher than room temperature, and can be adhered to the surface of a non-planar ceramic or glass substrate. After high-temperature sintering, a metal thick film electrode with controllable size, shape, film thickness, pore size and porosity can be obtained on the inner and outer surfaces of the non-planar material.

[0018] In some embodiments, the coating method is selected from the group consisting of doctor blade coating, roll coating, spray coating, dip coating and spin coating.

[0019] In some embodiments, the softening temperature is 40-80℃; further, the softening temperature is 40-60℃.

[0020] In some embodiments, the softening time is 0.5-10min; further, the softening time is 0.5-5min; and further, the softening time is 0.5-3min.

[0021] The softening step in the present application can soften the binder of the metal thick film electrode green body, and has good viscosity.

[0022] In some embodiments, the sintering temperature is 700-1200℃; further, the sintering temperature is 900-1200℃; in some embodiments, the sintering temperature is 1000-1200℃.

[0023] In some embodiments, the sintering time is 0.5-3h; further, the sintering time is 0.5-2h; in some embodiments, the sintering time is 0.8-1.2h.

[0024] In some embodiments, the sintering atmosphere is selected from air, vacuum, nitrogen.

[0025] In some embodiments, the metal thick film electrode paste comprises the following mass percentage of raw materials: metal powder 55-68%; binder 4-20%; plasticizing agent 1-5%; sintering aid 5-18%; solvent 15-35%.

[0026] In some embodiments, the metal powder is selected from at least one of nickel-chromium alloy, iron, chromium, aluminum, silver.

[0027] In some embodiments, the binder is selected from polyvinyl butyral, polyvinyl alcohol or a combination thereof.

[0028] In some embodiments, the plasticizing agent is selected from polyethylene glycol, glycerol or a combination thereof.

[0029] In some embodiments, the sintering aid is selected from at least one of glass powder, sodium silicate, calcium silicate.

[0030] In some embodiments, the solvent is selected from at least one of methanol, ethanol, acetone, ethyl acetate.

[0031] In some embodiments, the preparation method of the metal thick film electrode paste is: mixing the solvent, the binder and the plasticizing agent to obtain an organic carrier; then mixing the organic carrier with the metal powder and the sintering aid, and centrifuging and defoaming to obtain the metal thick film electrode paste; further, the preparation method of the metal thick film electrode paste is: stirring and mixing the solvent, the binder and the plasticizing agent at a stirring speed of 200-600rpm for 6-12h to obtain an organic carrier; then stirring and mixing the organic carrier with the metal powder and the sintering aid at a stirring speed of 200-600rpm for 30-120min, and centrifuging and defoaming at a centrifugation speed of 500-2000rpm for 1-5min to obtain the metal thick film electrode paste.

[0032] In some embodiments, the step of removing the substrate is removing the substrate after drying at 40-100℃ for 1-5h; further, the step of removing the substrate is removing the substrate after drying at 50-100℃ for 1-5h; in some embodiments, the step of removing the substrate is removing the substrate after drying at 50-80℃ for 1-5h.

[0033] In some embodiments, the substrate is selected from any one of a metal plate, a plastic plate, a ceramic plate, a glass plate, and a paper plate. The surface of the substrate can be engraved into any shape, thereby producing metal thick film electrodes of various shapes and achieving metal thick film electrode patterning.

[0034] In some embodiments, the substrate is a ceramic substrate or a metal substrate; further, the ceramic substrate is a porous ceramic substrate. The porous ceramic substrate in the present application is a ceramic substrate suitable for an electronic atomization core.

[0035] In some embodiments, the substrate has an irregularly shaped surface; the metal thick film electrode green body is located on the irregularly shaped surface of the substrate. The irregularly shaped surface in the present application refers to a surface with unevenness, or a recess inner wall, or an irregularly shaped surface other than a square, a rectangle, a rhombus, a triangle, and a regular polygon.

[0036] The second aspect of the present application provides a metal thick film electrode prepared by the preparation method provided in the first aspect of the present application; the thickness of the metal thick film electrode is 10-150μm, the pore size is 5-25μm, and the porosity is 35-60%.

[0037] In some embodiments, the pore size of the metal thick film electrode is 15-25μm.

[0038] In some embodiments, the thickness of the metal thick film electrode is 70-150μm. The thickness of the metal thick film electrode in the present application can be precisely controlled. The metal thick film electrode green body shrinks during sintering, and the thickness of the metal thick film electrode is precisely controlled by controlling the shrinkage amount of the film during sintering. Specifically, the shrinkage rate of the metal thick film electrode green body is determined according to the formula of the metal thick film electrode slurry. If a metal thick film electrode with a specific thickness is needed, the thickness of the metal thick film electrode green body is calculated according to the shrinkage rate, and the thickness of the metal thick film electrode is precisely controlled by controlling the thickness of the metal thick film electrode green body before sintering.

[0039] The third aspect of the present application provides a ceramic atomization core comprising a ceramic substrate; the surface of the ceramic substrate is provided with at least one layer of metal thick film electrode layer; the metal thick film electrode layer is a metal thick film electrode prepared by the preparation method provided in the first aspect of the present application.

[0040] In some embodiments, the ceramic substrate has an irregularly shaped surface, and the metal thick film electrode layer is disposed on the irregularly shaped surface of the ceramic substrate.

[0041] In some embodiments, the ceramic substrate is tubular, and the metal thick film electrode layer is disposed on the inner surface of the ceramic substrate.

[0042] In some embodiments, the ceramic atomizing core comprises a ceramic substrate and a first metal thick film electrode layer, a second metal thick film electrode layer and a third metal thick film electrode layer which are sequentially stacked on the ceramic substrate; the pore size of the second metal thick film electrode layer is smaller than that of the first metal thick film electrode layer or the third metal thick film electrode layer; the porosity of the second metal thick film electrode layer is smaller than that of the first metal thick film electrode layer or the third metal thick film electrode layer.

[0043] In some embodiments, the pore size of the second metal thick film electrode layer is 5-10 μm.

[0044] In some embodiments, the porosity of the second metal thick film electrode layer is 10-30%.

[0045] In some embodiments, the pore size of the first metal thick film electrode layer and the third metal thick film electrode layer is 15-25 μm.

[0046] In some embodiments, the porosity of the first metal thick film electrode layer and the third metal thick film electrode layer is 35-60%.

[0047] In some embodiments, the ceramic atomizing core further comprises a ceramic layer; the ceramic layer is disposed on the surface of the metal thick film electrode layer away from the ceramic substrate. When the number of layers of the metal thick film electrode layer is one, the ceramic layer is disposed on the surface of the metal thick film electrode layer away from the ceramic substrate. When the number of layers of the metal thick film electrode layer is not less than two, the ceramic layer is disposed on the surface of the metal thick film electrode layer farthest from the ceramic substrate (i.e. the metal thick film electrode layer farthest from the ceramic substrate).

[0048] In some embodiments, the ceramic atomizing core further comprises a ceramic layer; the ceramic layer is disposed on the surface of the third metal thick film electrode layer away from the ceramic substrate.

[0049] In some embodiments, the thermal conductivity of the ceramic layer is 0.4-10 W.m / k; further, the thermal conductivity of the ceramic layer is 5-10 W.m / k.

[0050] In some embodiments, the ceramic layer comprises the following mass percentage of raw materials: ceramic powder 50-80%, binder 5-10%, plasticizer 1-5%, solvent 10-40%.

[0051] In some embodiments, the ceramic powder is selected from at least one of alumina, aluminum nitride, silicon nitride, silicon carbide, diamond.

[0052] In some embodiments, the binder is selected from polyvinyl butyral, polyvinyl alcohol or a combination thereof.

[0053] In some embodiments, the plasticizer is selected from polyethylene glycol, glycerol or a combination thereof.

[0054] In some embodiments, the sintering aid is selected from at least one of glass powder, sodium silicate, calcium silicate.

[0055] In some embodiments, the solvent is selected from at least one of methanol, ethanol, acetone, ethyl acetate.

[0056] A fourth aspect of the present application provides a method for preparing the ceramic atomizing core according to the third aspect of the present application.

[0057] When the number of layers of the metal thick film electrode layer in the ceramic atomizing core is one, the method for preparing the ceramic atomizing core comprises the following steps:

[0058] Step a1: forming a metal thick film electrode slurry into a film on a substrate by a casting method or a coating method, removing the substrate to obtain a metal thick film electrode green body;

[0059] Step a2: softening the metal thick film electrode green body and adhering to a ceramic matrix, and sintering.

[0060] When the number of layers of the metal thick film electrode layer in the ceramic atomizing core is at least two, the method for preparing the ceramic atomizing core comprises the following steps:

[0061] Step a1: forming a metal thick film electrode slurry into a film on a substrate by a casting method or a coating method, removing the substrate to obtain a metal thick film electrode green body;

[0062] Step a2: laminating and compacting the at least two layers of metal thick film electrode green bodies, softening and adhering to a ceramic matrix, and sintering.

[0063] When a ceramic layer is arranged on the surface of the metal thick film electrode layer in the ceramic atomizing core, the method for preparing the ceramic atomizing core comprises the following steps:

[0064] Step b1: forming a metal thick film electrode slurry into a film on a substrate by a casting method or a coating method, removing the substrate to obtain a metal thick film electrode green body; and forming a ceramic slurry of a ceramic layer into a film on a substrate, removing the substrate to obtain a ceramic layer green body;

[0065] Step b2: The metal thick film electrode blank and the ceramic layer blank are bonded and pressed together, softened and then bonded to the ceramic substrate, and sintered to obtain the ceramic atomizing core.

[0066] In some implementations, the clamping pressure is 40-60 MPa.

[0067] In some implementations, the clamping time is 5-30 minutes; further, the clamping time is 5-15 minutes.

[0068] A fifth aspect of the present invention provides an electronic atomizer comprising the ceramic atomizing core provided in the third aspect of the present invention.

[0069] The sixth aspect of the present invention provides a method for preparing the metal thick film electrode provided in the first aspect of the present invention and / or the application of the ceramic atomizing core provided in the third aspect of the present invention in the field of electronic atomization.

[0070] The beneficial effects of this invention are: the method for preparing metal thick-film electrodes can be used on the inner and outer surfaces of planar materials, as well as on the inner and outer surfaces of irregularly shaped non-planar materials. The preparation method is simple, low-cost, operates under mild conditions, and is easy to operate, making it suitable for mass production. Furthermore, the method of this invention can also obtain metal thick-film electrodes with controllable size, shape, pore size, porosity, and film thickness by controlling the composition and ratio of the metal thick-film electrode slurry and adjusting the preparation process.

[0071] The metal thick film electrode of this invention has a lower maximum dry-burning temperature, a longer dry-burning life, higher TPM and efficiency ratio, and lower Ni content in flue gas.

[0072] The ceramic atomizing core of this invention features high atomization efficiency, a low maximum dry-burning temperature (890℃-1100℃), a long dry-burning lifespan, high TPM (8-11mg / puff) and efficiency ratio (1-1.3), and low Ni content in the smoke (100-500ng / 100 puffs). This avoids the burnt taste and safety hazards caused by excessive heavy metal inhalation during vaping. Furthermore, the ceramic atomizing core of this invention heats up more evenly and amplifies the smoke more effectively, improving the user's vaping experience and flavor. Attached Figure Description

[0073] Figure 1 is a schematic diagram of the porous ceramic atomizing core in Example 4.

[0074] Figure 2 is a SEM image of the metal thick film electrode in Example 1.

[0075] Figure 3 is a SEM image of the metal thick film electrode in Example 2.

[0076] Figure 4 is an SEM image of the metal thick film electrode in Comparative Example 1.

[0077] Figure 5 is an SEM image of the porous ceramic atomizing core in Example 4. DETAILED DESCRIPTION

[0078] The present application will be further described in conjunction with the accompanying drawings and examples, but the implementation and protection of the present application are not limited thereto. It should be noted that if the following processes are not specifically described in detail, they can be implemented or understood by those skilled in the art with reference to the prior art. If the reagents or instruments used are not marked with the manufacturer, they are conventional products that can be purchased on the market.

[0079] The porous ceramic cylinder used in the present application is a cylindrical porous ceramic substrate. The method for preparing the porous ceramic substrate in the present application uses conventional methods for preparing ceramics in the prior art.

[0080] Example 1:

[0081] This example provides a porous ceramic atomizing core, which comprises a porous ceramic cylinder and a metal thick film electrode, and the metal thick film electrode is arranged on the inner surface of the porous ceramic cylinder. The thickness of the metal thick film electrode is 130 μm, the pore size is 5-10 μm, and the porosity is 20%. The metal thick film electrode is made of the following preparation raw materials in mass percentage: Ni 80 Cr 20 alloy powder 65 wt%, glass powder 15 wt%, polyvinyl butyral 4 wt%, polyethylene glycol 1 wt%, ethanol 15 wt%, wherein the softening temperature of the glass powder is 950°C.

[0082] The porous ceramic atomizing core in this example is prepared by the following method, and the specific steps are as follows:

[0083] (1) Prepare the metal thick film electrode slurry:

[0084] Add polyvinyl butyral and polyethylene glycol in ethanol, mechanically stir at 400 rpm for 10 h to obtain an organic carrier; then add Ni 80 Cr 20 alloy powder and glass powder into the organic carrier, and mechanically stir at 300 rpm for 60 min to fully mix and uniformly mix the powders with the organic carrier, and then vacuum centrifugal defoam the mixture at 1000 rpm for 4 min to obtain the metal thick film electrode slurry.

[0085] (2) The metal thick film electrode slurry in step (1) is obtained by casting method on a glass substrate to obtain a metal thick film electrode green body with a thickness of 160 μm.

[0086] (3) After drying the metal thick film electrode green sheet prepared in step (2) in air at 50°C for 1 h, the metal thick film electrode green sheet was removed from the glass substrate, a rectangular metal film with a length of 4 mm and a width of 2 mm was cut out, and then the heated rectangular metal film was placed along the inner wall of the porous ceramic cylinder with a diameter of 2 mm and pressed to fit.

[0087] (4) The porous ceramic cylinder with the rectangular metal film on the inner wall was sintered at 1150°C for 1 h in a vacuum environment to prepare the porous ceramic atomizing core in this example. In the porous ceramic atomizing core, the inner surface of the porous ceramic cylinder formed a metal thick film electrode with a thickness of about 130 μm.

[0088] Example 2:

[0089] This example provides a porous ceramic atomizing core comprising a porous ceramic cylinder and a metal thick film electrode disposed on the inner surface of the porous ceramic cylinder. The metal thick film electrode is made of the following preparation raw materials by mass percentage: Ni 80 Cr 20 alloy powder 60 wt%, glass powder 5 wt%, polyvinyl alcohol 10 wt%, polyethylene glycol 5 wt%, ethanol 20 wt%, wherein the softening temperature of the glass powder is 950°C.

[0090] The porous ceramic atomizing core in this example is prepared by the following preparation method, and the specific steps are as follows:

[0091] (1) Preparation of metal thick film electrode slurry:

[0092] Polyvinyl alcohol and polyethylene glycol were added to ethanol, and mechanical stirring was carried out at a speed of 400 rpm for 6 h to obtain an organic carrier. Then, Ni 80 Cr 20 alloy powder and glass powder were added to the organic carrier, and mechanical stirring was carried out at a speed of 300 rpm for 60 min to fully mix and uniformly disperse the powders in the organic carrier. Then, vacuum centrifugal defoaming was carried out at a speed of 1000 rpm for 4 min to obtain the metal thick film electrode slurry.

[0093] (2) The metal thick film electrode slurry in step (1) was coated on the surface of the PET film by coating to obtain a metal thick film electrode green sheet with a thickness of 95 μm.

[0094] (3) After drying the metal thick film electrode green sheet prepared in step (2) in air at 50°C for 1 h, the metal thick film electrode green sheet was removed from the glass substrate, a rectangular metal film with a length of 4 mm and a width of 2 mm was cut out, and then the heated rectangular metal film was placed along the inner wall of the porous ceramic cylinder with a diameter of 2 mm and pressed to fit.

[0095] (4) Put the porous ceramic cylinder with the rectangular metal film covering the inner surface into a vacuum and sinter at 1150°C for 1 h to prepare a metal thick film electrode on the inner surface of the porous ceramic cylinder, i.e. to obtain the porous ceramic atomizing core in this example, wherein the thickness of the metal thick film electrode is about 76 μm.

[0096] Example 3

[0097] This example provides a porous ceramic atomizing core, which comprises a porous ceramic cylinder and a metal thick film electrode, the metal thick film electrode is arranged on the inner surface of the porous ceramic cylinder, and the thickness of the metal thick film electrode is 90 μm; the metal thick film electrode comprises conductive film B1, conductive film A and conductive film B2 arranged in sequence; the thickness and material of the conductive film B1 and the conductive film B2 are the same, the conductive film B1 and the conductive film B2 are both prepared by using the metal thick film electrode slurry in Example 2, and the conductive film A is prepared by using the metal thick film electrode slurry in Example 1.

[0098] The porous ceramic atomizing core in this example is prepared by the following preparation method, and the specific steps are as follows:

[0099] (1) Obtain the metal thick film electrode green body A with a thickness of 40 μm on a glass substrate by using the metal thick film electrode slurry in Example 1 by a casting method.

[0100] (2) Obtain the metal thick film electrode green body B with a thickness of 40 μm on a glass substrate by using the metal thick film electrode slurry in Example 2 by a casting method.

[0101] (3) After drying the metal thick film electrode green body A and the metal thick film electrode green body B at 50°C in air for 1 h, remove them from the glass substrate.

[0102] (4) Stack one layer of the metal thick film electrode green body B on each of the upper and lower surfaces of the metal thick film electrode green body A, and then place them in a constant temperature static pressure machine at 60°C to apply a pressure of 50 MPa for 10 min, so as to obtain a metal thick film with a three-layer structure.

[0103] (5) Cut the metal thick film with a three-layer structure into a rectangular metal film with a length of 4 mm and a width of 2 mm, then place it on a heating table at 60°C for 1 min, and then put the heated rectangular metal film along the inner wall of the porous ceramic cylinder with a diameter of 2 mm and press it to fit.

[0104] (6) Put the porous ceramic cylinder with the rectangular metal film covering the inner surface into a vacuum and sinter at 1150°C for 1 h to prepare the porous ceramic atomizing core in this example, wherein the thickness of the metal thick film electrode in the porous ceramic atomizing core is about 90 μm.

[0105] Example 4

[0106] Referring to the structural schematic diagram in Figure 1, the present example provides a porous ceramic atomizing core comprising a porous ceramic substrate, a metal thick film electrode and a high-thermal-conductivity ceramic thick film which are sequentially stacked; wherein the metal thick film electrode is prepared by using the metal thick film electrode slurry in Example 1; the high-thermal-conductivity ceramic thick film is prepared by using the following raw materials in mass percentage: aluminum nitride powder 60wt%, glass powder 15wt%, polyvinyl butyral 8wt%, polyethylene glycol 2wt%, ethanol 15wt%; the softening point of the glass powder is 950℃, and the thermal conductivity of the high-thermal-conductivity ceramic thick film is 5.2W.m / k.

[0107] The porous ceramic atomizing core in the present example is prepared by using the following preparation method, and the specific steps are as follows:

[0108] (1) The metal thick film electrode slurry in Example 1 is used to obtain a metal thick film electrode green body A with a thickness of 150μm on a glass substrate by using a casting method.

[0109] (2) Prepare a high-thermal-conductivity ceramic thick film slurry:

[0110] Add polyvinyl butyral and polyethylene glycol in ethanol, mechanically stir at a speed of 400rpm for 10h to obtain an organic carrier; then add aluminum nitride powder and glass powder in the organic carrier, and mechanically stir at a speed of 300rpm for 60min to fully mix and uniformly disperse the powder in the organic carrier; then centrifuge and defoam the mixture at a speed of 1000rpm for 4min under vacuum to obtain the high-thermal-conductivity ceramic thick film slurry.

[0111] (3) Apply the high-thermal-conductivity ceramic thick film slurry on the surface of a PET film to obtain a high-thermal-conductivity ceramic thick film green body B with a thickness of 150μm, and the thermal conductivity of the high-thermal-conductivity ceramic thick film green body B is 5.2W / (m·K).

[0112] (4) Cut the metal thick film electrode green body A into an electrode pattern with a length of 4mm, and the contact points at both ends of the pattern are 1mm long; cut the high-thermal-conductivity ceramic thick film green body B into a square piece with a length of 2mm and a width of 2mm.

[0113] (5) Align the cut electrode pattern and the cut high-thermal-conductivity ceramic thick film green body B at the center, then stack them, and then place them in a constant-temperature static press at 60℃ to apply a pressure of 50MPa for 10min to obtain a two-layer metal thick film.

[0114] (6) Place the two-layer metal thick film on a 60℃ heating table for 1min, and then place the two-layer metal thick film on the surface of a porous ceramic substrate with a length of 7mm and a width of 4mm, and press and adhere them.

[0115] (7) Put the porous ceramic substrate covered with the metal thick film into vacuum and sinter at 1150°C for 1 h to obtain the porous ceramic atomizing core of the present example, wherein the thickness of the metal thick film electrode is about 120 μm.

[0116] Comparative Example 1

[0117] The present example provides a porous ceramic atomizing core, which comprises a porous ceramic substrate and a metal thick film electrode, and the metal thick film electrode is arranged on the surface of the porous ceramic substrate, wherein the metal thick film electrode is a metal conductive film prepared by a magnetron sputtering method.

[0118] The porous ceramic atomizing core of the present example is prepared by the following method, and the specific steps are as follows:

[0119] (1) Put the porous ceramic substrate into a fixing jig;

[0120] (2) Fix the mask on the porous ceramic substrate with high-temperature double-sided adhesive;

[0121] (3) Sputter the mask pattern on the porous ceramic substrate by using the following magnetron sputtering process parameters:

[0122] Target material: high-purity platinum 99.99%, diameter 60 mm;

[0123] Power: 500 w; deposition thickness: 6 μm;

[0124] Deposition rate: 0.25 nm / s;

[0125] Sputtering time: 400 min;

[0126] Background vacuum: 5.0*10-4Pa;

[0127] Sputtering pressure: 0.3 Pa;

[0128] Ar flow rate: 80 ml / min;

[0129] Sample disc rotation speed: 15 rmp;

[0130] After magnetron sputtering is performed according to the above magnetron sputtering process parameters, the mask is removed, and the sample after film plating is placed in an alumina crucible. After annealing at 900°C in air for 30 min, the alumina crucible is taken out and naturally cooled to obtain the porous ceramic atomizing core of the present example.

[0131] Comparative Example 2

[0132] The example provides a porous ceramic atomizing core, which comprises a porous ceramic base body and a metal thick film electrode arranged on the surface of the porous ceramic base body, wherein the metal thick film electrode is a metal conductive film prepared by a screen printing method, and the metal thick film electrode is prepared from the following raw materials by mass percentage: Ni 80 Cr 20 alloy powder 79.2 wt%, glass powder 7.8 wt%, terpineol 5.2%, butyl carbitol 2.6%, butyl carbitol acetate 4.3%, ethyl cellulose 0.9%, and the softening point of the glass powder is 950 DEG C.

[0133] The porous ceramic atomizing core in the example is prepared by the following method, and the specific steps are as follows:

[0134] (1) preparing a metal thick film electrode slurry:

[0135] terpineol, butyl carbitol, butyl carbitol acetate and ethyl cellulose are mechanically stirred at a speed of 400 rpm for 8 hours to obtain an organic carrier; then Ni 80 Cr 20 alloy powder and glass powder are added to the organic carrier, and the powder and the organic carrier are fully mixed and uniformly stirred at a speed of 300 rpm for 10 minutes, and then the mixture is vacuum centrifuged and defoamed at a speed of 1500 rpm for 2 minutes to obtain the metal thick film electrode slurry.

[0136] (2) the metal thick film electrode slurry is printed on the porous ceramic base body by screen printing process, and then the printed porous ceramic base body is dried in a 150 DEG C oven for 20 minutes.

[0137] (3) after drying, it is placed in a vacuum at 1150 DEG C for 1 hour to sinter, and the porous ceramic atomizing core in the example is prepared.

[0138] Performance test:

[0139] (1) surface morphology test

[0140] The surface morphology of the metal thick film electrode prepared in example 1, example 2 and comparative example 1 is tested by scanning electron microscope, and the specific test results are shown in figures 2 to 4. As shown in figures 2 and 3, the Ni 80 Cr 20 alloy particles in the metal thick film electrode prepared in examples 1 and 2 are uniformly dispersed and have no falling phenomenon, and there are uniformly dispersed holes in the metal thick film electrode, and the hole size and porosity are determined by the metal thick film electrode itself. As shown in figure 4, the film layer prepared in comparative example 1 has falling phenomenon, and the film layer itself is a dense body, and the hole size and porosity are determined by the porous ceramic base body.

[0141] The surface morphology of the porous ceramic atomizing core in Example 4 was tested using a scanning electron microscope. The specific test results are shown in Figure 5. As can be seen from Figure 5, both the metal thick film electrode and the high thermal conductivity ceramic thick film in Example 4 have uniform surface morphology, and the interface between the two is in good contact with no interface separation phenomenon.

[0142] (2) Pore size, porosity and dry burning life test

[0143] The pore size, porosity, and dry-burning life of the metal thick-film electrodes in Examples 1-2 and Comparative Examples 1-2 were tested respectively. The specific test methods are as follows:

[0144] Porosity was tested using the test method described in GB / T1966-1996;

[0145] The pore size was tested using the bubble pressure method described in GB / T 1967-1996;

[0146] The dry-burning life test method is as follows: the metal thick-film electrode is energized at a certain power (8W) for 3 seconds and then de-energized for 15 seconds, and this is repeated as one cycle. The number of cycles in which no breakage occurs is recorded. The dry-burning life test can evaluate the metal thick-film electrode's ability to withstand cyclic thermal shock.

[0147] The pore size, porosity, and dry-burning life results obtained according to the above test method are shown in Table 1 below.

[0148] Table 1: Test results of pore size, porosity, and dry-burning life

[0149] As shown in Table 1 above, the pore size and porosity of the metal thick film electrodes in Examples 1-2 are controllable. The pore size and porosity can be adjusted by adjusting the formulation of the metal thick film electrode slurry. Furthermore, the metal thick film electrodes prepared in Examples 1-2 have a long dry-burning life, which further indicates that the metal thick film electrodes in this invention have excellent resistance to cyclic thermal shock.

[0150] (3) Testing of TPM, efficiency ratio and Ni content in flue gas

[0151] The porous ceramic atomizing cores prepared in Examples 1-4 were installed in the same model of electronic cigarette. At 8W power, the atomizing liquid with a volume ratio of 1,2-propanediol (PG):vegetable glycerol (VG) of 1:1 was used for inhalation. The TPM, efficiency ratio and Ni content in the smoke were tested during the inhalation process. TPM is the mass of aerosol atomized in a single puff; efficiency ratio = TPM / power. The specific test results are shown in Table 2 below.

[0152] Table 2: Test results of TPM, efficiency ratio and Ni content in flue gas

[0153] As can be seen from Table 2, compared with Comparative Example 1-2, the porous ceramic atomizing cores in Inventive Examples 1-4 all have higher TPM and efficiency ratio, and can significantly reduce the content of heavy metal Ni in flue gas. The porous ceramic atomizing core in Inventive Example 3 adopts a metal thick film electrode with a three-layer conductive film structure. The pore size and porosity of conductive film A are lower, and the heating speed and heating capacity are higher when powered on. The pore size and porosity of conductive film B1 and conductive film B2 are both larger, which can provide a larger atomization area. Through the synergistic effect of conductive film A, conductive film B1 and conductive film B2, the atomization efficiency of the entire porous ceramic atomizing core can be improved, thereby improving the TPM and efficiency ratio. Compared with Inventive Example 1-2, the porous ceramic atomizing cores in Inventive Examples 3-4 adopt three-layer and two-layer structures respectively, both of which have higher TPM and efficiency ratio, and can reduce the content of heavy metal Ni in flue gas.

[0154] (4) Maximum dry burning temperature

[0155] The maximum dry burning temperature of the porous ceramic atomizing cores prepared in Inventive Examples 1-4 at 8W power was tested respectively, and the dry burning life of Inventive Examples 3-4 was tested according to the above-mentioned dry burning life test method. The specific test results are shown in Table 3.

[0156] Table 3: Dry burning life and maximum dry burning temperature test results

[0157] As can be seen from Table 3, compared with Inventive Examples 1-2, the porous ceramic atomizing cores in Inventive Examples 3-4 adopt three-layer and two-layer structures respectively, both of which can reduce the maximum dry burning temperature and prolong the dry burning life. Among them, the metal thick film electrode in Inventive Example 4 is a metal heating layer, which mainly functions as electricity conduction and heating. The high-thermal-conductivity ceramic thick film is a uniform heating layer, which can uniformly distribute the heat of the metal thick film electrode to generate a larger atomization area, thereby improving the atomization efficiency. On the other hand, the uniform heat distribution avoids local extreme high temperature, which is beneficial to prolonging the service life of the electrode. The porous ceramic atomizing cores in Comparative Examples 1-2 all have uneven heating, which causes local high temperature, affecting the service life of the metal thick film electrode. During the smoking process, a smoky taste will be generated, and the content of heavy metal Ni in flue gas is also higher.

[0158] The above has made a detailed description of the inventive examples, but the present application is not limited to the above examples. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present application. In addition, the features in the inventive examples and the inventive examples can be combined with each other without conflict.

Claims

1. A method for preparing a metal thick-film electrode, comprising the following steps: Step S1: The metal thick film electrode paste is deposited on the substrate by casting or coating, and the substrate is removed to obtain the metal thick film electrode blank. Step S2: After softening the metal thick film electrode blank, it is bonded to the substrate and sintered to obtain the metal thick film electrode.

2. The method for preparing a metal thick-film electrode according to claim 1, wherein the softening temperature is 40℃-80℃; and / or, the softening time is 0.5-10 min; And / or, the sintering temperature is 700℃-1200℃; And / or, the sintering time is 0.5-3 hours; And / or, the metal thick film electrode paste comprises the following raw materials by mass percentage: 55-68% metal powder; 4-20% binder; 1-5% plasticizer; 5-18% sintering aid; and 15-35% solvent; And / or, the step of removing the substrate is: removing the substrate after drying at 40℃-100℃ for 1-5 hours.

3. A metal thick film electrode, wherein the electrode is prepared by the method described in claim 1 or 2; the metal thick film electrode has a thickness of 10-150 μm, a pore size of 5-25 μm, and a porosity of 35-60%.

4. A ceramic atomizing core, comprising a ceramic substrate; wherein at least one layer of thick metal electrode is disposed on the surface of the ceramic substrate; wherein the thick metal electrode is a thick metal electrode prepared by the preparation method according to claim 1 or 2.

5. The ceramic atomizing core according to claim 4, wherein the ceramic substrate has an irregularly shaped surface, and the metal thick film electrode layer is disposed on the irregularly shaped surface of the ceramic substrate; Alternatively, the ceramic substrate may be tubular, and the thick metal electrode layer may be disposed on the inner surface of the ceramic substrate.

6. The ceramic atomizing core according to claim 4, wherein the ceramic atomizing core comprises a ceramic substrate and a first metal thick film electrode layer, a second metal thick film electrode layer and a third metal thick film electrode layer sequentially stacked on the ceramic substrate; the pore size of the second metal thick film electrode layer is smaller than the pore size of the first metal thick film electrode layer or the third metal thick film electrode layer; the porosity of the second metal thick film electrode layer is smaller than the porosity of the first metal thick film electrode layer or the third metal thick film electrode layer.

7. The ceramic atomizing core according to any one of claims 4-6, wherein the ceramic atomizing core further comprises a ceramic layer; the ceramic layer is disposed on the surface of the metal thick film electrode layer away from the ceramic substrate.

8. The ceramic atomizing core according to claim 7, wherein the ceramic layer comprises the following raw materials by mass percentage: 50-80% ceramic powder, 5-10% binder, 1-5% plasticizer, and 10-40% solvent.

9. A method for preparing a ceramic atomizing core according to any one of claims 4-8, wherein the preparation method comprises the following steps: Step a1: The metal thick film electrode paste is deposited on the substrate by casting or coating, and the substrate is removed to obtain the metal thick film electrode blank. Step a2: Soften the metal thick film electrode blank and then bond it to the ceramic substrate, and sinter it; or, stack at least two layers of metal thick film electrode blanks and press them together, soften them and then bond them to the ceramic substrate, and sinter them. Alternatively, the preparation method includes the following steps: Step b1: The metal thick film electrode paste is deposited on the substrate by casting or coating, the substrate is removed, and the metal thick film electrode blank is obtained; the ceramic paste of the ceramic layer is deposited on the substrate, the substrate is removed, and the ceramic layer blank is obtained. Step b2: The metal thick film electrode blank and the ceramic layer blank are bonded and pressed together, softened and then bonded to the ceramic substrate, and sintered to obtain the ceramic atomizing core.

10. An electronic atomizer, comprising the ceramic atomizing core according to any one of claims 4-8.

11. The method for preparing the metal thick film electrode according to claim 1 or 2 and / or the application of the ceramic atomizing core according to any one of claims 4-8 in the field of electronic atomization.

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