CERAMIC HEATER AND PREPARATION METHOD AND USE OF CERAMIC HEATER

Abstract

The present disclosure provides a ceramic heat generation body and a preparation method thereof. The ceramic heat generation body includes a ceramic rod matrix, and electronic paste is printed on a surface of the ceramic rod matrix in a decalcomania manner. The preparation method includes printing the electronic paste on the ceramic rod matrix in the decalcomania manner In addition, the present disclosure further provides a use of the ceramic heat generation body in a heater for novel tobacco products.

Claims

1. A ceramic heat generation body, comprising: a ceramic rod matrix, wherein a resistance heat generation element is provided on a surface of the ceramic rod matrix, and the resistance heat generation element is an alloy containing tungsten, manganese and at least one selected from ruthenium, tellurium, germanium, and vanadium.

2. The ceramic heat generation body according to claim 1, wherein a material of the ceramic rod matrix is at least one of aluminum oxide, silicon nitride, glass, aluminum nitride and silicon carbide.

3. The ceramic heat generation body according to claim 1, wherein the resistance heat generation element is prepared by printing an electronic paste in a decalcomania manner, and the electronic paste contains tungsten, manganese, an additive and an organic vehicle, the additive being selected from at least one of ruthenium, tellurium, germanium and vanadium.

4. The ceramic heat generation body according to claim 1, wherein an end of the ceramic rod matrix is a tapered end, and the resistance heat generation element near the tapered end in a length direction of the ceramic rod matrix has a size larger than that of another end.

5. The ceramic heat generation body according to claim 3, wherein a weight ratio of the tungsten and manganese is 7:3 to 9.5:0.5.

6. The ceramic heat generation body according to claim 3, wherein a content of the additive is 0.5-5 wt % based on a total weight of the tungsten and manganese.

7. The ceramic heat generation body according to claim 3, wherein the organic vehicle is a mixture of terpineol, ethyl cellulose and absolute ethanol, and preferably, a content of the organic vehicle is 5-20 wt % based on the total weight of the tungsten and manganese.

8. A method for preparing the ceramic heat generation body according to claim 1, wherein the method comprises printing electronic paste on the ceramic rod matrix in a decalcomania manner

9. The method according to claim 8, wherein the printing in the decalcomania manner comprises printing the electronic paste on a paper-based film to form a decal paper.

10. The method according to claim 9, wherein the printing allows an end of the paper-based film to have a lager application amount of electronic paste than another end.

11. The method according to claim 9, wherein the paper-based film is made of at least one of a tissue paper, a wood pulp paper, a carbon fiber paper, a synthetic fiber paper, a natural fiber paper, and the like.

12. The method according to claim 9, wherein the printing in the decalcomania manner further comprises pasting the decal paper on the ceramic rod matrix treated with acid and alkali, and the printing in the decalcomania manner further comprises firing the ceramic rod matrix pasted with the decal paper at a temperature of 1200-1800° C. for 1-4 hours.

13. The method according to claim 8, further comprising: performing dip-glazing after printing in the decalcomania manner, and then firing at a temperature of 1000-1200° C.

14. A use of the ceramic heat generation body according to claim 1 and the ceramic heat generation body prepared by the method according to claim 8 in a heater for novel tobacco products.

15. The use according to claim 14, wherein the novel tobacco products are low-temperature cigarettes.

16. The ceramic heat generation body according to claim 4, wherein a weight ratio of the tungsten and manganese is 7:3 to 9.5:0.5.

17. The ceramic heat generation body according to claim 4, wherein a content of the additive is 0.5-5 wt % based on a total weight of the tungsten and manganese.

18. The ceramic heat generation body according to claim 5, wherein a content of the additive is 0.5-5 wt % based on a total weight of the tungsten and manganese.

19. The ceramic heat generation body according to claim 16, wherein a content of the additive is 0.5-5 wt % based on a total weight of the tungsten and manganese.

20. The ceramic heat generation body according to claim 4, wherein the organic vehicle is a mixture of terpineol, ethyl cellulose and absolute ethanol, and preferably, a content of the organic vehicle is 5-20 wt % based on the total weight of the tungsten and manganese.

Description

DETAILED DESCRIPTION

[0018] The specific embodiments of the present disclosure will be further illustrated in detail hereinafter. It should be understood that the specific embodiments described herein merely illustrate and explain the present disclosure, and does not limit the present disclosure.

[0019] The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and these ranges or values should be understood to comprise the values close to these ranges or values. In terms of the numerical ranges, one or more new numerical ranges may be obtained by combining endpoint values of each range, or by combining the endpoint value of each range and an individual point value, or by combining the individual point values, and these numerical ranges should be considered as specifically disclosed herein.

[0020] As described herein, the term “electronic paste” is a basic material for preparing the ceramic heat generation body and belongs to paste formed by mixing solid powder and liquid solvent uniformly through three-roll rolling processes. Depending on the difference in use, the electronic paste may be divided into dielectric paste, resistance paste and conductor paste; depending on the difference in substrate type, the electronic paste may be divided into ceramic substrate electronic paste, polymer substrate electronic paste, glass substrate electronic paste, metal insulation substrate electronic paste, and the like; depending on the difference in sintering temperature, the electronic paste may be divided into high-temperature drying electronic paste, medium-temperature drying electronic paste and low-temperature drying electronic paste; depending on the difference in use, the electronic paste may be further divided into general electronic paste and special electronic paste; and depending on the difference in price of the conductive phase, the electronic paste may be divided into precious metal electronic paste and base metal electronic paste.

[0021] As adopted herein, the term “temperature coefficient of resistance (TCR)” refers to relative changes in the resistance value when the temperature of the resistance changes by 1 degree (that is, the change rate of the resistance value relative to the resistance). The calculation formula thereof is TCR=(R.sub.T2−R.sub.T1)/[(T.sub.2−T.sub.1)×R.sub.T1], and the unit is ppm/° C., where T.sub.1 refers to a first temperature, T.sub.2 refers to a second temperature, R.sub.T1 refers to a resistance value at the first temperature, and R.sub.T2 refers to a resistance value at the second temperature. The TCR is a parameter closely related to the microstructure of the metal, and has a theoretical maximum value under the absence of any defects. That is, the magnitude of the TCR per se characterizes the performance of the metal process to some extent. During the research and development process or online monitoring of the new technology, the TCR may be adopted to conduct the early monitoring and make rapid evaluation of the reliability of metals.

[0022] As adopted herein, the term “printing in a decalcomania manner” refers to a process of printing a designed pattern on a surface of a specific paper or plastic film using a ceramic pigment by a printing process. Afterwards, the patterned paper is moved and pasted to the surface of the matrix, and then sintered at a high temperature, so that the decal is permanently adhered to the surface of the matrix.

[0023] In an aspect, the present disclosure provides a ceramic heat generation body. The ceramic heat generation body includes a ceramic rod matrix, wherein an electronic paste is printed on the surface of the ceramic rod matrix in a decalcomania manner.

[0024] According to the defects in the prior art to be solved by the present disclosure, the ceramic heat generation body provided by the present disclosure is a rod-shaped ceramic heat generation body commonly used in novel tobacco products, especially in low-temperature cigarettes. Thus, the ceramic heat generation body may generally include a ceramic rod matrix to provide a basic shape. For the material of the ceramic rod matrix, it is not particularly limited and may be a common ceramic matrix material in the art. According to a preferred embodiment, a material of the ceramic rod matrix is at least one of aluminum oxide, silicon nitride, glass, aluminum nitride and silicon carbide.

[0025] For tungsten-based paste, tungsten is the main heat generation element. Whereas, the TCR of tungsten is very high, which may cause the entire electronic paste to have a high TCR and make it difficult to acquire a heat generation element having a consistent and reliable TCR. However, the inventor found after research that the batches of products made by selected tungsten pastes having an appropriate composition may have an incredibly consistent TCR, and can further greatly reduce the TCR of the electronic paste, thereby achieving the beneficial effect that the ceramic heat generation body has a low TCR. Thus, in a preferred embodiment, the electronic paste may contain tungsten, manganese, an additive and an organic vehicle, and the additive is selected from at least one of the ruthenium, tellurium, germanium and vanadium. More preferably, a content of the additive may be 0.5-5 wt % (for example, 1.5 wt %, 2 wt %, or 2.5 wt %).

[0026] In addition, the type and content of the organic vehicle in the electronic paste of the present disclosure are not particularly limited, and may be the common type and content in the art. In a preferred embodiment, the organic vehicle may be a mixture of terpineol, ethyl cellulose and absolute ethanol, such as 90-95 wt % (e.g., 94 wt %) of terpineol, 3-5 wt % (e.g., 5 wt %) of ethyl cellulose, and 1-3 wt % (e.g., 1 wt %) of absolute ethanol, and preferably, the content of the organic vehicle may be 5-20 wt % based on the total weight of the tungsten and manganese.

[0027] According to the present disclosure, in order to facilitate insertion and extraction of the ceramic heat generation body from the low-temperature cigarettes, an end of the ceramic rod matrix may be formed into a sharp shape. Furthermore, according to the common way of inserting and extracting the ceramic heat generation body from the low-temperature cigarettes, the end having the sharp shape may serve as the insertion end to get closer to the cigarette structure, and the other end may get closer to the power source. In addition, the other end may be provided with less electronic paste and thereby have a lower temperature, so as to enable the ceramic heat generation body to protect the power source as much as possible while burning the cigarettes effectively. Thus, in a preferred embodiment, an end of the ceramic rod matrix may be a tapered end, and preferably, the concentration of the electronic paste close to the tapered end in the length direction of the ceramic rod matrix may be higher than the concentration of the electronic paste at the other end.

[0028] In another aspect, the present disclosure provides a method for preparing a ceramic heat generation body, wherein the method comprises printing electronic paste on a ceramic rod matrix in a decalcomania manner.

[0029] For the ceramic rod matrix and electronic paste in the method for preparing the ceramic heat generation body of the present disclosure, the preferred embodiments of the material and shape of the ceramic rod matrix and the composition of the electronic paste may be the same as those described above, which will not be repeated herein.

[0030] According to the present disclosure, in order to enable the ceramic heat generation body to have the advantages of quick heat generation and easy insertion and extraction from low-temperature cigarettes, the electronic paste is adhered to the ceramic rod matrix in a decalcomania manner according to the preparation method of the present disclosure, which not only can effectively reduce the thickness of the ceramic heat generation body but also allows the printed circuit (i.e., the electronic paste) to be directly exposed on the surface of the ceramic heat generation body, thereby greatly improving the heat generation efficiency. On the same account of protecting the power source, an end may also be provided with less electronic paste, so that the end has a lower operating temperature. In addition, during the process of printing in the decalcomania manner, it is easy to design different printed circuit patterns according to needs since the pattern is designed on a plane. Thus, the ceramic heat generation body as prepared can also have a desired appearance. In a preferred embodiment, the printing in the decalcomania manner may comprise printing (such as, skip printing, coating, etc.) the electronic paste on a paper-based film to form a decal paper, and preferably, the printing allows a concentration of the electronic paste at one end of the paper-based film to be greater than the concentration at the other end.

[0031] According to the present disclosure, the composition of the paper-based film is not particularly limited, and may be common raw materials in the art. In a preferred embodiment, the paper-based film is made of at least one of a tissue paper, a wood pulp paper, a carbon fiber paper, a synthetic fiber paper, a natural fiber paper, and the like.

[0032] According to the present disclosure, after the decal paper of the electronic paste of the present disclosure is formed, the decal paper may be transferred to the ceramic rod matrix, and then undergo subsequent processing to completely adhere the electronic paste to the surface of the ceramic rod matrix. In a preferred embodiment, the printing in the decalcomania manner further comprises pasting the decal paper on the ceramic rod matrix treated with acid and alkali, and preferably, the printing in the decalcomania manner further comprises firing the ceramic rod matrix pasted with the decal paper (preferably under a mixed gas of H.sub.2 and N.sub.2) at a temperature of 1200-1800° C. for 1-4 hours. In a more preferred embodiment, prior to the firing step, the printing in the decalcomania manner further comprises drying the ceramic rod matrix pasted with the decal paper at a temperature of 100-150° C., and then removing glue at a temperature of 300-600° C.

[0033] According to the present disclosure, a glaze layer may be provided on the surface of the ceramic heat generation body to insulate, strengthen and protect the heater. Thus, in a preferred embodiment, the method further comprises performing dip-glazing after printing in the decalcomania manner, and then firing at a temperature of 1000-1200° C. After completion of the firing, the ceramic heat generation body may be further provided with a lead wire. Thus, the method of the present disclosure may further comprise surface-treating the ceramic heat generation body at solder joints, and then fastening the lead wire, solder joints and solder by a wire-bonding tool to get into a furnace for lead soldering at about 700° C., so as to form the finished product.

[0034] The aforementioned respective preferred embodiments of the present disclosure may be used alone or in combination with other preferred embodiments. In a particularly preferred embodiment, the method for preparing the ceramic heat generation body of the present disclosure comprises: (1) designing, based on product requirements, a diameter and a length of a ceramic rod matrix, electronic paste meeting the requirements, a printing weight, and molds and tools required for production; (2) in a clean room, skip-printing, by a precision screen printer, a part of the electronic paste as prepared on a surface of a paper base through a circuit of a screen printing plate to form a decal paper, wherein the surface of the paper base is coated with water-soluble glue, and the paper base is made of at least one of a tissue paper, a wood pulp paper, a carbon fiber paper, a synthetic fiber paper, a natural fiber paper, and the like; (3) pasting the decal paper printed with a heat generation circuit on the ceramic rod matrix treated with acid and alkali; (4) drying the ceramic rod matrix pasted with the decal paper at a temperature of 100-150° C., and then removing glue at a temperature of 300-600° C.; (5) after removing the glue, firing as a whole under a mixture of H2 and N2 at a temperature of 1200-1800° C. for 1-4 hours; (6) putting a layer of transparent thin glaze on the ceramic heat generation rod after fired in a dip-glazing manner, and then pushing into a reducing atmosphere furnace to be fired at a temperature of 1000-1200° C.; and (7) after the ceramic heat generation body as fired is surface-treated at the solder joints, fastening the lead wire, solder joints, and solder by a wire-bonding tool to get into the furnace for lead soldering at about 700° C., thereby forming a finished product.

[0035] In still another aspect, the present disclosure further provides a use of the aforesaid ceramic heat generation body and the ceramic heat generation body prepared by the aforesaid method in a heater for novel tobacco products, and in particular a use in a heater for low-temperature cigarettes.

EXAMPLES

[0036] An organic vehicle is prepared by a mixture of 94 wt % of terpineol, 5 wt % of ethyl cellulose and 1 wt % of absolute ethanol, and the preparation is implemented by weighing the terpineol, ethyl cellulose and absolute ethanol in proportions and then mixing uniformly with a magnetic stirrer at a water bath temperature of 90° C. Firstly, 90 parts by weight of tungsten powder and 10 parts by weight of manganese powder are taken and mixed uniformly. Afterwards, the mixed powder is mixed with 10 parts by weight of organic vehicle and then put together into a planetary ball mill for a ball milling, wherein the absolute ethanol serves as a ball milling medium, and the weight ratio of the mixture to the ball milling medium is 1.5:1. In addition, the ball mill is run at a speed of 500 r/min for 1.5 h to prepare the electronic paste composition C1. Then, 5 batches of the electronic paste composition C1 are obtained in the same way.

[0037] Based on the content shown in Table 1, the electronic paste compositions C2-C8 are prepared in the same way as described above, with each electronic paste being prepared 5 batches. Then, all batches of the electronic paste composition are printed on the ceramic matrix by screen printing or other conventional techniques in the art to form heat generation elements. The resistance values of the heat generation elements as acquired from the electronic paste compositions C1-C8 at temperatures of 25° C., 83° C., 150° C., and 230° C. are measured, the results are shown in Table 2. Then, the TCR is acquired based on the resistance values of respective batch through the least square method and the linear fitting. For each of the electronic paste compositions C1-C8, the average TCR of 5 batches and the deviation rate of TCR for each batch ((TCRn-Average TCR)/Average TCR, where n is 1, 2, 3, 4 or 5) are calculated based on TCRs of the 5 batches, which are TCR1, TCR2, TCR3, TCR4 and TCRS respectively. Furthermore, the average deviation rate of TCRs of the 5 batches (an average value of the deviation rates of TCRs of the 5 batches) is calculated, as shown in Table 2

TABLE-US-00001 TABLE 1 Tungsten Manganese Iron Molybdenum Ruthenium Germanium Vanadium Tellurium C1 Tungsten 90 10 — — — — — — Manganese C2 Tungsten 90 10 2 — — — — — Manganese Iron C3 Tungsten 90 10 — 2 — — — — Manganese Molybdenum C4 Tungsten 98 — — — 2 — — — Ruthenium C5 Tungsten 90 10 — — 1 — — — Manganese Ruthenium C6 Tungsten 90 10 — — — 0.5 — — Manganese Germanium C7 Tungsten 90 10 — — — — 5 — Manganese Vanadium C8 Tungsten 90 10 — — — — — 2 Manganese Tellurium

TABLE-US-00002 TABLE 2 Average Average TCR1 TCR2 TCR3 TCR4 TCR5 TCR deviation rate C1 Tungsten 3742 3528 3854 3928 3468 3704 4.45% Manganese C2 Tungsten 3516 3324 3418 3589 3615 3492 2.78% Manganese Iron C3 Tungsten 2995 3258 3196 3298 3028 3155 3.64% Manganese Molybdenum C4 Tungsten 3395 3216 3329 3428 3365 3347 1.77% Ruthenium C5 Tungsten 3275 3329 3314 3228 3295 3288 0.89% Manganese Ruthenium C6 Tungsten 3108 3182 3189 3203 3199 3176 0.70% Manganese Germanium C7 Tungsten 2988 3077 2923 3081 3029 3020 1.70% Manganese Vanadium C8 Tungsten 3419 3499 3386 3420 3398 3424 0.87% Manganese Tellurium

[0038] As illustrated in the aforesaid example, the electronic paste compositions (C5-C8) of the present disclosure can prepare heat generation elements having an excellent performance. The average deviation of the TCR between the plurality of batches is significantly lower than the average deviation of the TCR of the heat generation elements prepared from other electronic paste compositions (C1-C4), which thereby shows the excellent performance in having a consistent and low TCR.

[0039] The preferred embodiments of the present disclosure are described in detail above, but the present disclosure is not limited to the specific details in the above embodiments. Various simple modifications can be made to the technical solution of the present disclosure within the scope of the technical concept of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0040] In addition, it should be understood that the various specific technical features described in the aforesaid specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the various possible combinations are not described separately in the present disclosure.

[0041] Furthermore, different embodiments of the present disclosure can also be combined arbitrarily, as long as they do not violate the concept of the present disclosure, and they should also be regarded as the content disclosed by the present disclosure.