Heating element of electric tobacco

Abstract

To provide a heating element of an electric tobacco with a simple configuration which can heat a tobacco component in a cartridge up to 400°C or higher in a short period of time.SOLUTION: A heating element 10 of an electric tobacco which generates an aerosol by heating an aerogel generation component stored therein, includes: a cylindrical case 100 in which the aerosol generation element is inserted; a cylindrical first ceramic layer 101 provided on an outer peripheral face of the case 100; a heating layer 102 provided on the outer peripheral face of the first ceramic layer 101 and on which a heating pattern is formed by a heating paint; and a cylindrical second ceramic layer 103 formed by coating the heating layer 102. At least the first ceramic layer 101, the heating layer 102, and the second ceramic layer 103 are integrally formed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electronic cigarette that generates an aerosol by heating an aerosol-generating component housed therein, and particularly to a heating element for an electronic cigarette that can uniformly heat the aerosol-generating component to a high temperature of 400°C or higher in a short time and can be manufactured at a low cost.

Background Art

[0002] As an example of an electronic cigarette, there is known one that generates an aerosol containing a tobacco component by heating a cartridge containing the tobacco component (aerosol-generating component) and guides it to a suction nozzle for suction. FIG. 5 is a schematic diagram for explaining the configuration of an electronic cigarette for aerosolizing a tobacco component for smoking. Although various forms of this type of electronic cigarette are commercially available, the illustrated electronic cigarette 1 has a cylindrical main body 11 imitating a cigarette as a main component. A suction port 15 is formed at the rear end of the main body 11, and a cartridge 14 containing a tobacco component 17 is housed in front of the suction port 15. A heating element 10 for heating the cartridge is provided on the outer periphery of the cartridge 14, and a battery 12 for supplying power to the heating element 10 is housed in the front part of the main body 11. A control unit 13 is disposed between the battery 12 and the cartridge 14 to electrically connect the battery 12 and the heating element 10 via a conducting wire 16 and control the ON / OFF switching of the power supply from the battery 12 to the heating element 10 and the amount of electric power, etc. When the cartridge 14 is heated by the heating element 10, the tobacco component contained in the cartridge 14 is aerosolized, and the aerosolized tobacco component can be sucked from the suction port 15.

[0003] Incidentally, the cartridge 14 contains a tobacco component 17 in which finely shredded tobacco leaves are mixed with an organic solvent such as glycerin inside a cylindrical stainless-steel cartridge case 14a. The heating element 10 is generally provided on the outer peripheral surface of the cartridge case 14a that constitutes the cartridge 14. As the heating element 10, a polyimide heater in which a conductive pattern is formed by etching on the surface of polyimide, which is an insulating material, is generally used (see, for example, paragraph 0051 of Patent Document 1).

[0004] Since the heat-resistant temperature of polyimide is about 300°C, the heating temperature of the cartridge 14 by the heating element 10 using the polyimide heater is limited to 250°C to 300°C. However, in order to generate sufficient aerosol preferred by smokers, it is necessary to heat the tobacco component 17 to 400°C or higher. However, there is a problem that the heating temperature of the polyimide heater is low and it is difficult to generate sufficient aerosol. In addition, the polyimide heater has a problem that uniform heating is difficult. Furthermore, the heating element 10 needs to quickly raise the temperature of the cartridge 14 from when the switch is turned ON to the temperature at which aerosol is generated. However, as described above, since the heat-resistant temperature of polyimide is about 300°C, the temperature can be raised in a short time up to about 250°C, but it takes time to raise the temperature from 250°C to 300°C, and it takes a long time from when the switch is turned ON until smoking starts.

[0005] Therefore, in the heater assembly described in Patent Document 1, the graphite layer 40 is provided inside the heating element 20 to uniformly disperse the heating element 20 so that the heating chamber 60 (corresponding to the cartridge 14 in FIG. 5) can be uniformly heated. However, the problems of low heating temperature and slow temperature rise due to the use of the polyimide heater cannot be solved.

[0006] In addition, the electronic cigarette heater described in Patent Document 2 includes a ceramic heating element 10 that can withstand high temperatures and uniformly heat the cartridge, and is provided with a preheating device 20. By preheating the cartridge to 200°C before starting smoking, the temperature rise time of the cartridge by the ceramic heating element 10 is shortened. Further, in the electronic cigarette heater described in Patent Document 2, the ceramic heating element 10 is housed in a sealed cover 4 to prevent the air heated by the ceramic heating element 10 from being dissipated. Regarding the material of this sealed cover 4 and the gap dimensions with the ceramic heating element 10, there is no description in the specification or the like and it is unclear. However, in the electronic cigarette heater described in this document, it is premised on heating up to 280°C to 320°C, which is about the same as that of a polyimide heater, and there is no concept of heating to a higher temperature (see, for example, the description in paragraph 0109). Therefore, it can be inferred that the sealed cover 4 is formed of a resin such as polyimide. Further, in the electronic cigarette heater described in this document, a preheating device 20 is provided separately from the ceramic heating element 10. By preheating this preheating device 20 to about 200°C in advance, the heating time is shortened. However, preheating does not fundamentally solve the problem of shortening the heating time. Instead, there are problems such as shortening the battery life, complicating the device configuration of the electronic cigarette, and increasing the cost.

[0007] Furthermore, the electronic cigarette heating element described in Patent Document 3 is formed by winding a substrate 2 on which a thick film resistor 3 is printed with a heating paint around the outer periphery of a ceramic pipe 1. Although the material of the substrate 2 is unclear from the description in Patent Document 3, since a member that seems to be an insulating layer (no symbol and explanation are found) is interposed between the thick film resistor 3 and the substrate 2, it can be inferred that the substrate 2 is a metal sheet such as stainless steel. According to the electronic cigarette heating element described in this Document 3, although the material of the insulating layer is unclear, if it is a general resin film insulating layer, its heat resistance temperature is about the same as that of polyimide, and the problem of uniform heating can be solved. However, the two problems of improving the heating temperature and shortening the heating time cannot be solved.

[0008] Further, the ceramic heater described in Patent Document 4 forms a resistive heating element on the surface of a sheet material 11 made of ceramic, wraps the sheet material 11 around a ceramic core material 12 three times, and is fired at a high temperature of 1500°C to 1600°C. However, in the ceramic heater described in this document, the resistive heating element formed on the surface of the sheet material 11 must contain a glass component composed of Al2O3, CaO, and SiO2 in a general conductive material such as tungsten, molybdenum, tantalum, niobium, and titanium. Therefore, it is difficult to form a precise conductive pattern, the mass productivity is low, and the cost is high. In addition, since the sheet material 11 is wound three times, gaps are likely to occur at the stepped portions between the first and second layers and between the second and third layers. Defects such as cracks are likely to occur in these gaps, and there is also a problem that the heat generation efficiency decreases. Furthermore, although the ceramic heater described in this document can be heated at a high temperature of 1000°C or higher, it requires a large-capacity power supply and is not suitable for small devices such as electronic cigarettes. As a heating element for electronic cigarettes that is sufficient for heating at 450°C to 550°C, it has excessive performance and is also a problem in terms of cost waste.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Disclosure of the Invention

Problems to be Solved by the Invention

[0010] The present invention has been made to solve the problems of these prior arts, and an object thereof is to provide a heating element suitable for an electronic cigarette that can uniformly heat the tobacco component in the cartridge to 400°C or higher in a short time and can be manufactured at a low cost.

Means for Solving the Problems

[0011] As a result of intensive research by the inventors of the present invention to achieve the above object, it was conceived that the problem can be solved by sandwiching a ceramic that can equalize the heat generation of the heat generating layer and is excellent in insulation and heat resistance from the inside and outside of the heat generating layer to integrate them. That is, the invention according to claim 1 is a heating element for an electronic cigarette that generates an aerosol by heating an aerosol generating component housed therein, a cylindrical case into which the aerosol generating component is inserted, and a cylindrical first ceramic layer provided on the outer peripheral surface of this case, and a heat generating layer provided on the outer peripheral surface of this first ceramic layer and having a heat generating pattern formed by a heat generating paint, and a cylindrical second ceramic layer formed by covering this heat generating layer, and at least the first ceramic layer, the heat generating layer, and the second ceramic layer are integrally formed. As described in claim 2, a cylindrical heat insulating layer may be provided outside the second ceramic layer. At least one of the first ceramic layer and the second ceramic layer may be formed by applying a ceramic resin paint to the case or the heat generating layer and sintering it, as described in claim 3. Also, as described in claim 4, if the case is formed of ceramic, the case can be configured as the first ceramic layer. Furthermore, as described in claim 5, the second ceramic layer may be formed by winding a plate-shaped ceramic green body around the surface of the first ceramic layer and sintering it integrally with the first ceramic layer and the heat generating layer. The method for manufacturing a heating element for an electronic cigarette according to the present invention is, as described in claim 6, a method for manufacturing a heating element for an electronic cigarette that generates an aerosol by heating an aerosol generating component housed therein. A cylindrical case into which the aerosol generating component is inserted is prepared. After applying a ceramic resin paint to the surface of this case, the surface is smoothed to form a first ceramic layer. On the surface of this first ceramic layer, a heating layer having a heating pattern formed by applying a heat-generating paint is formed. On the outside of the heating pattern layer, a ceramic resin paint is applied to form a second ceramic layer. The first ceramic layer, the heating layer, and the second ceramic layer are fired and integrated. As described in claim 7, the cylindrical case may be used as the first ceramic layer. As described in claim 8, the surface of the second ceramic layer may be smoothed, and a cylindrical heat insulating layer may be provided outside thereof. As described in claim 9, a titanium-based ceramic resin paint can be used as the ceramic resin paint, and it may be fired at 350°C to 450°C, which has sufficient heat resistance within the operating temperature range of the heating element and cures with a certain degree of hardness to maintain a certain form.

Advantages of the Invention

[0012] In the present invention, since the heating layer is sandwiched from the inside and outside by a ceramic excellent in heat resistance, heating uniformity, and insulation, it is possible to uniformly heat the aerosol generating component up to a high temperature of 400°C or higher. Also, since it is possible to heat up to a temperature around 500°C, the heating-up time up to 400°C can be extremely shortened. Furthermore, since the configuration is very simple, it is possible to manufacture the heating element at a low cost.

Best Mode for Carrying Out the Invention

[0013] Hereinafter, a preferred embodiment of the heating element of the electronic cigarette of the present invention will be described in detail with reference to the drawings. In the following embodiment, an electronic cigarette using a tobacco component as the aerosol generating component will be described as an example. FIG. 1 is a perspective view for explaining the overall configuration of a heating element according to a first embodiment of the present invention, FIG. 2 is an enlarged partial cross-sectional view of the heating element in FIG. 1, and FIG. 3 is a developed plan view of a heat-generating paint layer in which a heat-generating pattern is applied and formed on a first ceramic layer. The heating element 10 includes a cylindrical case 100 made of a metal such as stainless steel, a first ceramic layer 101 formed on the outer peripheral surface of the case 100, a heat-generating layer 102 formed on the outer peripheral surface of the first ceramic layer 101, and a second ceramic layer 103 formed on the outer peripheral surface of the heat-generating layer 102.

[0014] [Case 100] The case 100 corresponds to the cartridge case 14a in FIG. 5, can withstand heating at 400° C. or higher, and is formed in a cylindrical shape of a metal having excellent thermal conductivity such as stainless steel or copper so as to be able to quickly transfer heat to the tobacco components in the cartridge 14 (see FIG. 5). In order to efficiently transfer the heat of the heat-generating layer 102 to the cartridge 14, the inner diameter of the case 100 is made to coincide with the outer diameter of the cartridge 14 so that the inner peripheral surface of the case 100 is in close contact with the outer peripheral surface of the cartridge 14. Note that since the metal case 100 expands by heating, a slit for absorbing this expansion may be formed in the axial direction of the case 100.

[0015] [First Ceramic Layer 101] The first ceramic layer 101 electrically insulates the heat-generating layer 101 and the metal case 100, and quickly transfers the heat generated by the heat-generating layer 102 to the case 100 at a uniform temperature. As a ceramic material for forming the first ceramic layer 101, for example, fine ceramic-based ceramics having high electrical insulation and thermal conductivity such as alumina, zirconia, reinforced alumina (alumina added with zirconia), silicon nitride (SiN), silicon carbide (SiC), aluminum nitride (AlN), and aluminum titanate can be used. A cylindrical body having a length and an inner diameter that are in close contact with the outer peripheral surface of the case 100 is formed of such a ceramic, and the first ceramic layer 101 is constituted by this cylindrical body.

[0016] [Heating layer 102] As shown in FIG. 3, a linear heating pattern 102a is formed on the surface of the first ceramic layer 101 by a heating paint. Although the form of the heating pattern 102a shown in FIG. 3 is wavy, it may be strip-shaped or solid-coated covering more than half of the surface of the first ceramic layer 101. From both ends of the heating pattern 102a, lead-out portions 102b extend in parallel and reach the edge of the first ceramic layer 101. A conducting wire 16 for supplying power to the heating pattern 102a is connected to one end of these two lead-out portions 102b. The heating layer 102 is composed of the heating pattern 102a and the lead-out portions 102b. As described above, since the necessary temperature for generating an aerosol sufficient for smokers is 400° C. or higher, if heating can be performed in the range of 450° C. to 550° C., this heating condition is satisfied, and the upper limit temperature can be sufficiently higher than the necessary temperature. Therefore, the cartridge 14 (see FIG. 5) can be heated quickly to 400° C. Note that a heating paint that generates heat up to a temperature of 550° C. or higher may be used. By using such a high-temperature heat-generating heating paint, it is possible to further shorten the heating time of the cartridge 14. However, considering the capacity and cost of the battery 12 (see FIG. 5) mounted on the electronic cigarette, it is sufficient if heating can be performed in the range of 450° C. to 550° C.

[0017] The heating paint forming the heating pattern 102a and the lead-out portions 102b has a heat generation temperature that changes depending on the coating thickness, and the heat generation temperature increases as the coating thickness increases. Although it also depends on the type of the heating paint, the coating thickness of the heating pattern 102a is preferably about 50 μm to 100 μm in order to make the heat generation temperature 400° C. or higher. Further, since the conducting wire 16 may peel off when the lead-out portion 102b becomes hot, it is preferable to set the heat generation temperature to around 100° C., and within the range where power can be sufficiently supplied to the lead-out portion 102b, the line width and the coating thickness are made smaller than those of the heating pattern 102a. As the heat-generating paint, any known or commercially available paint can be used as long as it has good adhesion to the first ceramic layer 101 and can generate heat up to about 450°C to 550°C. For example, Japanese Patent Publication No. 06-089270 discloses a heat-generating paint that can be freely adjusted to a desired temperature over a temperature range up to about 450°C. Also, for example, Japanese Patent Application Laid-Open No. 4-7377 discloses a heat-generating paint that can be heated up to 1000°C.

[0018] [Second ceramic layer 103] The second ceramic layer 103 is for reflecting the heat generated in the heat-generating layer 102 toward the cartridge 14 with a uniform temperature distribution, and is provided integrally in close contact with the heat-generating layer 102 outside the heat-generating layer 102. As the ceramic material for forming such a second ceramic layer 103, a ceramic resin paint is preferable. For example, the titanium-based ceramic resin paint "Tyrano Coat" (registered trademark) manufactured by Ube Industries, Ltd. can be used. "Tyrano Coat" (registered trademark) has a heat-resistant temperature of about 800°C, and this is spray-coated or dip-coated and then fired. In the heating element of the present invention, the first ceramic layer 101 and the second ceramic layer 103 only need to have sufficient heat resistance at 450°C to 550°C, which is the operating temperature range of the heating element, and can be cured with a certain degree of hardness to maintain a certain form. Therefore, it may be fired within the range of 350°C to 450°C, for example, at about 380°C until it reaches the desired hardness. In this way, after forming the second ceramic layer 103 so as to cover the entire heat-generating layer 102, the outer surface of the second ceramic layer 103 may be finished to a flat surface by shaving or the like. In this first embodiment, the heating element 10 is composed of the above-described case 100, and the integrally formed first ceramic layer 101, heat-generating layer 102, and second ceramic layer 103.

[0019] [Second Embodiment] FIG. 4 is an exploded perspective view for explaining the overall configuration of a heating element according to a second embodiment of the present invention. The same parts and members as those in the previous embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted. In this second embodiment, the case 100′ is formed of a ceramic having the same material as the first ceramic layer 101 of the previous embodiment. Therefore, in this embodiment, the case 100′ functions as the first ceramic layer 101. Since the case 100′ functions as the first ceramic layer 101 in the heating element 10′ of the second embodiment, the heating element 10′ of the second embodiment has the advantages that the configuration can be simplified and the thickness can be reduced compared to the heating element 10 of the first embodiment. Further, an insulating layer for heat insulation is formed outside the second ceramic layer 103. In this embodiment, the integrated case 100′, the heating layer 102, and the second ceramic layer 103 are housed in a cylindrical heat insulating case 105. The inner diameter of the heat insulating case 105 is made to coincide with the outer diameter of the second ceramic layer 103 so that the inner peripheral surface of the heat insulating case 105 and the outer peripheral surface of the second ceramic layer 103 are in close contact with each other. Various heat insulating cases 105 can be used as long as they have heat resistance that can withstand a temperature higher than the upper limit of the heat generation temperature of the heating layer 102. For example, mica can be mentioned. As described above, in the second embodiment, the heating element 10′ is constituted by the integrated case (first ceramic layer) 100′, the heating layer 102, the second ceramic layer 103, and the heat insulating layer (heat insulating case 105).

[0020] Although the preferred embodiments of the present invention have been described, the present invention is not limited to the above embodiments. For example, in the first embodiment, the first ceramic layer 101 has been described as being previously formed in a cylindrical shape so as to accommodate the case 100. However, the same ceramic resin paint as the second ceramic layer in the first embodiment may be applied to the outside of the case 100, or a plate-shaped ceramic green body may be wound around the outside of the case 100 and then fired to form an integral structure with the case 100. In this case, before forming the conductive pattern with the conductive paint, the surface of the first ceramic layer may be smoothed by machining or the like. Also, the second ceramic layer 103 may be formed integrally with the first ceramic layer and the heating layer by winding a plate-shaped ceramic green body around the first ceramic layer and sintering it. Also, in the second embodiment, the heat insulating layer has been described as the heat insulating case 105 such as mica that is in close contact with the outer peripheral surface of the second ceramic layer 103. However, the heat insulating layer is not limited to this as long as it can suppress heat dissipation from the second ceramic layer 103. Other forms include a gap formed between the heat insulating case and the outer peripheral surface of the second ceramic layer 103 and filled with an inert gas such as air, argon gas, or nitrogen gas, or a gap with a vacuum inside. Further, the gap may be filled with a heat insulating material.

Industrial Applicability

[0021] In the above description, the tobacco component has been given as an example of the aerosol generating component. However, the present invention is also applicable to an electronic cigarette that uses herbs such as mint and peppermint as the aerosol generating component for inhalation.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Explanation of Reference Numerals

[0023] 1 Electronic cigarette 10, 10′ Heating element 100, 100′ Case 101 First ceramic layer 102 Heating paint layer 102a Heating pattern 102b Lead-out portion 11 Main body of the electronic cigarette 12 Battery 13 Control unit 14 Cartridge 14a Cartridge case 15 Mouthpiece 16 Conductive wire 17 Tobacco component (aerosol generating component)

Claims

1. In a heating element for an electronic cigarette that generates an aerosol by heating an aerosol - generating component housed therein, a cylindrical case into which the aerosol - generating component is inserted; a cylindrical first ceramic layer provided on the outer peripheral surface of this case; a heating layer provided on the outer peripheral surface of this first ceramic layer, with a heating pattern formed by a heating paint; a cylindrical second ceramic layer formed to cover this heating layer; having; at least the first ceramic layer, the heating layer, and the second ceramic layer being integrated; A heating element for an electronic cigarette, characterized by the above.

2. The heating element for an electronic cigarette according to claim 1, characterized in that a cylindrical heat - insulating layer is provided outside the second ceramic layer.

3. The heating element for an electronic cigarette according to claim 1 or 2, characterized in that at least one of the first ceramic layer and the second ceramic layer is formed by applying a ceramic resin paint to the case or the heating layer.

4. The heating element for an electronic cigarette according to claim 1 or 2, characterized in that the case is made of ceramic and constitutes the first ceramic layer.

5. The heating element for an electronic cigarette according to claim 1 or 2, characterized in that the second ceramic layer is formed by winding a plate - shaped ceramic green body around the surface of the first ceramic layer and sintering it integrally with the first ceramic layer and the heating layer.

6. In a method for manufacturing a heating element for an electronic cigarette that generates an aerosol by heating an aerosol - generating component housed therein, preparing a cylindrical case into which the aerosol - generating component is inserted; after applying a ceramic resin paint to the surface of this case, smoothing the surface to form a first ceramic layer; forming a heating layer having a heating pattern by applying a heating paint on the surface of this first ceramic layer; forming a second ceramic layer by applying a ceramic resin paint outside the heating pattern layer; firing the first ceramic layer, the heating layer, and the second ceramic layer to integrate them; A method for manufacturing a heating element for an electronic cigarette, characterized by the above.

7. In a method for manufacturing a heating element for an electronic cigarette that generates an aerosol by heating an aerosol - generating component housed therein, preparing a ceramic cylindrical case into which the aerosol - generating component is inserted, Taking this case as the first ceramic layer, a heating layer with a heating pattern formed by applying a heat-generating paint is formed on its surface. A second ceramic layer is formed by applying a ceramic resin paint outside the heating pattern layer. The first ceramic layer, the heating layer, and the second ceramic layer are fired and integrated. A method for manufacturing a heating element for an electronic cigarette, characterized by the above.

8. The method for manufacturing a heating element for an electronic cigarette according to claim 6 or 7, characterized in that the surface of the second ceramic layer is smoothed, and a cylindrical heat-insulating layer is provided outside it.

9. The method for manufacturing a heating element for an electronic cigarette according to claim 6 or 7, characterized in that the ceramic resin paint is a titanium-based ceramic resin paint and is fired at 350°C to 450°C.

Images