A heat-conducting heat-not-burn cigarette paper, a preparation method and application thereof

Abstract

The application discloses a kind of heat-conducting heat-not-burn cigarette paper and its preparation method and application, belong to cigarette paper processing technical field. Including the following steps: nitric acid and sulfuric acid are mixed, carbon nanotube is placed in mixed acid and is soaked modification, then is washed to neutral, and modified carbon nanotube is obtained;Modified carbon nanotube is oscillated with tea polyphenol ethanol solution, is filtered and dried, and modified drug-loaded carbon nanotube is obtained;Paper pulp, modified drug-loaded carbon nanotube and calcium carbonate are mixed uniformly, and mixed pulp is obtained;Base sheet is obtained by papermaking to mixed pulp, drying, carboxymethyl cellulose aqueous solution is coated on base sheet, and drying is obtained. The cigarette paper is loaded by the three-dimensional network of modified CNT and the π-π bond of tea polyphenol, and the uniform heat transfer at low temperature is realized;Calcium carbonate interface filling and CMC surface packaging cooperate, and the flame retardance and air permeability are considered. Solve the problem such as uneven heat transfer, high brittleness, heavy odor and other problems of traditional cigarette paper, adapt to the demand of low-temperature heat-not-burn cigarette.

Description

Technical Field

[0001] This invention relates to the field of cigarette paper processing technology, and in particular to a thermally conductive, heat-conducting, non-combustible cigarette paper, its preparation method, and its application. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Low-harm tobacco products have become a core trend in the industry. Heated tobacco products (HNB) cigarettes, with their advantages of releasing tobacco flavor through low-temperature heating and significantly reducing the formation of harmful substances such as tar, are gradually becoming an important alternative to traditional cigarettes. As a core component of HNB cigarettes, cigarette paper not only fulfills the basic function of wrapping tobacco but also needs to possess efficient heat conduction capabilities to quickly and evenly transfer heat from the external heating element to the interior of the tobacco, ensuring the stable release of flavor substances and nicotine within a specific low-temperature range. Its thermal conductivity directly determines the taste and low-harm characteristics of the cigarette.

[0004] Currently, the industry's optimization of the thermal conductivity of HNB (Heated Tobacco Not Burner) cigarette paper mainly relies on adding thermally conductive fillers or improving the papermaking process. However, there are technical bottlenecks that are difficult to overcome in practical applications. In existing technologies, commonly used metal oxide thermally conductive fillers require relatively high addition amounts to meet basic thermal conductivity requirements. Excessive addition significantly reduces key physical properties of cigarette paper, such as flexibility and tensile strength, leading to increased brittleness and easy breakage, making it unsuitable for the actual needs of cigarette production and use. While carbon-based thermally conductive materials possess excellent thermal conductivity potential, their strong hydrophobic surface makes them prone to agglomeration in aqueous pulp systems, making it difficult to form continuous thermal conduction paths. This results in limited improvement in thermal conductivity efficiency and cannot simultaneously address the loading and stability of functional additives. Therefore, obtaining a heated tobacco not burner cigarette paper that combines high thermal conductivity, good mechanical properties, functional load-bearing capacity, and stable performance is an urgent technical problem to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a thermally conductive, heat-conducting, non-combustible cigarette paper, its preparation method, and its application.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides a method for preparing thermally conductive, heat-conducting, non-combustible cigarette paper, comprising the following steps: Nitric acid and sulfuric acid are mixed, and carbon nanotubes are immersed in the mixed acid for modification. Then, they are washed until neutral to obtain modified carbon nanotubes. Modified carbon nanotubes were shaken with a tea polyphenol ethanol solution, filtered and dried to obtain modified drug-loaded carbon nanotubes. The pulp, modified drug-loaded carbon nanotubes, and calcium carbonate are mixed evenly to obtain a mixed slurry; The mixed slurry is used to form a substrate, which is then dried. A carboxymethyl cellulose aqueous solution is then coated onto the substrate and dried to obtain the final product.

[0007] Preferably, the volume ratio of nitric acid to sulfuric acid is 1:2-1:4, the modification temperature is 60-100℃, and the modification time is 1-3h.

[0008] Preferably, the concentration of the tea polyphenol ethanol solution is 5-15 mg / mL, and the solid-liquid ratio of the modified carbon nanotubes to the tea polyphenol ethanol solution is 1:5-1:10 g / mL.

[0009] Preferably, the oscillation temperature is 23-27℃ and the oscillation time is 23-25h.

[0010] Preferably, the mass ratio of the pulp, modified drug-loaded carbon nanotubes, and calcium carbonate is 80-90:1-5:10-15; Preferably, the mass ratio is 85:1-5:12.

[0011] Preferably, the pulp includes one or more of softwood pulp and hardwood pulp.

[0012] Preferably, the pulp is first pulped to a freeness of 20-60°SR using a PFI refiner, and then mixed with modified drug-loaded carbon nanotubes and calcium carbonate.

[0013] Preferably, the concentration of the carboxymethyl cellulose aqueous solution is 1-3 wt%, and the coating amount is 0.5-1.5 g / m³. 2 .

[0014] Secondly, the present invention provides a thermally conductive, heat-conducting, non-combustible cigarette paper, obtained by the above-described preparation method.

[0015] Thirdly, the present invention provides the application of the above-mentioned thermally conductive heating non-combustible cigarette paper in low-temperature heated cigarettes, wherein the temperature of the heated cigarette in the low-temperature heated cigarette is 150-350°C.

[0016] The beneficial effects of this invention are as follows: (1) In this invention, carbon nanotubes are modified by soaking in a mixed acid to graft carboxyl / hydroxyl groups onto their surface, which greatly enhances their dispersibility in pulp. The modified carbon nanotubes form a continuous three-dimensional network between fibers, breaking through the limitations of point-to-point heat transfer in traditional fillers and constructing a highly efficient heat conduction channel. This allows heat to be transferred more quickly and evenly in cigarette paper, achieving rapid and uniform heat transfer within the efficient range of 150-350℃ required for heating non-combustible cigarettes at low temperatures. This effectively solves the problem of uneven heating of tobacco caused by the poor thermal conductivity of traditional cigarette paper, and improves the taste and aroma quality of cigarettes.

[0017] (2) In this invention, modified carbon nanotubes are subjected to oscillation and adsorption with a tea polyphenol ethanol solution, so that the surface of the carbon nanotubes is loaded with tea polyphenols through π-π bonds. While achieving thermal conductivity, this effectively inhibits the generation of irritating odors during the heating process of cigarette paper. At the same time, the functional groups on the surface of the modified carbon nanotubes form hydrogen bonds with tobacco polysaccharides, which can inhibit the release of cellulose odors at high temperatures during heating, reduce the generation of harmful substances, and further improve the quality and safety of cigarettes.

[0018] (3) In this invention, pulp, modified drug-loaded carbon nanotubes, and calcium carbonate are mixed evenly and then used to form a substrate. A carboxymethyl cellulose aqueous solution is then used for surface coating. This allows the modified carbon nanotubes to be evenly distributed in the gaps between the pulp fibers, forming a continuous thermally conductive network. Calcium carbonate fills the interfacial gaps between the fibers and the carbon nanotubes, which not only helps to improve the uniformity of thermal conductivity but also enhances the flame retardant properties of the cigarette paper, preventing the paper from overheating and breaking during heating. At the same time, the reasonable mixing of the three components can avoid the decline in the physical properties of the paper caused by adding too much of a single filler, thus balancing thermal conductivity and flexibility. The coating of the carboxymethyl cellulose aqueous solution not only encapsulates the carbon nanotubes to prevent them from falling off but also regulates the air permeability of the paper, ensuring the smooth release of smoke inside the cigarette and optimizing the smoking experience. Detailed Implementation

[0019] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] This invention provides a method for preparing thermally conductive, heat-conducting, non-combustible cigarette paper, comprising the following steps: Nitric acid and sulfuric acid are mixed, and carbon nanotubes are immersed in the mixed acid for modification. Then, they are washed until neutral to obtain modified carbon nanotubes. Modified carbon nanotubes were shaken with a tea polyphenol ethanol solution, filtered and dried to obtain modified drug-loaded carbon nanotubes. The pulp, modified drug-loaded carbon nanotubes, and calcium carbonate are mixed evenly to obtain a mixed slurry; The mixed slurry is used to form a substrate, which is then dried. A carboxymethyl cellulose aqueous solution is then coated onto the substrate and dried to obtain the final product.

[0022] In some embodiments, the volume ratio of nitric acid to sulfuric acid is 1:2-1:4, the modification temperature is 60-100℃, and the modification time is 1-3 hours. Under these conditions, the modified CNTs exhibit both optimal hydrophilic dispersibility and the highest loading capacity for tea polyphenols. If the acid concentration is too low or the time is too short, the grafted functional groups are insufficient, resulting in limited improvement in dispersibility; if the acid concentration is too high or the time is too long, the CNTs will be over-etched, destroying their aspect ratio and reducing the construction efficiency of the thermally conductive network. This range ensures a balance between the modification effect and structural integrity.

[0023] In some embodiments, the concentration of the tea polyphenol ethanol solution is 5-15 mg / mL, and the solid-liquid ratio of the modified carbon nanotubes to the tea polyphenol ethanol solution is 1:5-1:10 g / mL. Under these conditions, tea polyphenol molecules can be adsorbed onto the surface of the modified CNTs through π-π bonds. If the concentration is too low or the solid-liquid ratio is too high, the drug loading rate is insufficient, and the harm reduction effect is not obvious; if the concentration is too high or the solid-liquid ratio is too low, tea polyphenols are prone to multilayer accumulation on the CNT surface or even block the pores, which may affect the bonding between CNTs and slightly reduce the thermal conductivity. This range achieves a synergistic effect of high drug loading and high thermal conductivity.

[0024] In some embodiments, the oscillation temperature is 23-27°C, and the oscillation time is 23-25 ​​hours. These mild conditions provide optimal kinetic equilibrium for the physical adsorption process. Excessively high temperatures may lead to the oxidative degradation of tea polyphenols, while excessively low temperatures result in an excessively long adsorption equilibrium time. In some embodiments, the mass ratio of the pulp, modified drug-loaded carbon nanotubes, and calcium carbonate is 80-90:1-5:10-15; Preferably, the mass ratio is 85:1-5:12.

[0025] Pulp serves as the base material to ensure basic physical strength; calcium carbonate, as a conventional filler and flame retardant, maintains the paper's whiteness, opacity, and basic flame-retardant properties. The key lies in the fact that modified CNTs, added in a low range of 1-5 parts by weight, can construct a highly efficient three-dimensional thermally conductive network. Below this range, CNTs are insufficient to form continuous heat conduction pathways, resulting in minimal improvement in thermal conductivity; above this range, the tendency for CNTs to aggregate increases, dispersing becomes more difficult, and costs rise while the improvement in thermal conductivity plateaus.

[0026] In some embodiments, the pulp includes one or more of softwood pulp and hardwood pulp.

[0027] In some embodiments, the pulp is first beating to a freeness of 20-60°SR using a PFI refiner before being mixed with modified drug-loaded carbon nanotubes and calcium carbonate. The aim is to optimize the dispersibility and interweaving properties of the pulp fibers. By defining the pulp beating process, the pulp fibers are fully defilamentized, increasing the fiber specific surface area. This facilitates the adhesion and uniform dispersion of modified drug-loaded carbon nanotubes and calcium carbonate on the fiber surface, while simultaneously enhancing the bonding force between fibers. The effect is to ensure a compact substrate structure and sufficient strength after papermaking, avoiding problems such as broken heat conduction channels and easy paper breakage caused by uneven fiber dispersion, further improving the thermal uniformity and mechanical properties of cigarette paper.

[0028] In some embodiments, the concentration of the carboxymethyl cellulose aqueous solution is 1-3 wt%, and the coating amount is 0.5-1.5 g / m². 2 By limiting the concentration and coating amount of carboxymethyl cellulose aqueous solution, a uniformly thick encapsulation layer is formed, avoiding excessive coating amount leading to low air permeability and obstructed flue gas release, or insufficient coating amount leading to poor encapsulation effect and filler detachment.

[0029] This invention provides a thermally conductive, heat-conducting, non-combustible cigarette paper, obtained by the above-described preparation method.

[0030] This invention provides the application of the above-mentioned thermally conductive, heat-resistant, non-combustible cigarette paper in low-temperature heated cigarettes, wherein the temperature of the heated cigarette in the low-temperature heated cigarette is 150-350℃.

[0031] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments and comparative examples.

[0032] Example 1: This embodiment provides a method for preparing thermally conductive, heat-conducting, non-combustible cigarette paper, the specific steps of which are as follows: Take softwood pulp board and pulp it using a PFI refiner to a freeness of 45°SR, then set aside.

[0033] 25 ml of concentrated nitric acid (HNO3) and 75 ml of concentrated sulfuric acid (H2SO4) were mixed at a volume ratio of 1:3 to obtain a mixed acid, which was then diluted to 200 ml. 10 g of the original CNTs were added to 200 mL of the mixed acid, and the mixture was refluxed and stirred in an 80°C water bath for 2 hours for modification. After the reaction was complete, the mixture was repeatedly washed with deionized water and filtered until the pH of the filtrate was 7, yielding modified carbon nanotubes.

[0034] 10 g of tea polyphenols were dissolved in 1000 ml of anhydrous ethanol to prepare a 10 mg / mL tea polyphenol ethanol solution. 10 g of the modified CNTs and 50 ml of the tea polyphenol ethanol solution were mixed at a solid-liquid ratio of 1:5 (g / mL), and the mixture was incubated at 25 °C with shaking for 24 hours for adsorption. After adsorption was complete, the mixture was filtered, washed with anhydrous ethanol, and vacuum dried to obtain the modified drug-loaded carbon nanotubes. The drug loading rate of the tea polyphenols was determined to be 18.7% by ultraviolet spectrophotometry.

[0035] 170g of pretreated softwood pulp fiber, 6g of the modified drug-loaded carbon nanotubes prepared above, and 24g of calcium carbonate (CaCO3) were placed in a fiber descrambling machine at a mass ratio of 85:3:12. 1800ml of deionized water was added, and the mixture was dispersed at 4000 rpm for 10 minutes to obtain a uniform mixed slurry.

[0036] Take 18.84g of the above mixed slurry, and form it using a PTI sheeter. Dry it at 105℃ until the moisture content is 5±0.5%, obtaining a substrate with a density of 60±2 g / m². Prepare a 1.5 wt% carboxymethyl cellulose (CMC) aqueous solution, and evenly coat it onto the substrate surface using a doctor blade coater, with a coating amount of 1.2 g / m². After coating, dry it again at 105℃ to obtain the finished thermally conductive, heat-resistant, non-combustible cigarette paper.

[0037] Example 2: The difference between this embodiment and Embodiment 1 is that in step 3, the mass ratio of pulp fiber, modified drug-loaded carbon nanotubes, and calcium carbonate is adjusted to 85:1:12. The remaining steps and parameters are exactly the same.

[0038] Example 3: The difference between this example and Example 1 is that in step 3, the mass ratio of pulp fiber, modified drug-loaded carbon nanotubes, and calcium carbonate is adjusted to 85:5:12. The remaining steps and parameters are exactly the same.

[0039] Comparative Example 1: The difference between this comparative example and Example 1 is that in step 3, no modified drug-loaded carbon nanotubes are added; only pulp fiber and calcium carbonate are used in a mass ratio of 85:12. The remaining steps and parameters are exactly the same.

[0040] Comparative Example 2: Using unmodified CNTs The difference between this comparative example and Example 1 is that in step 2, the mixed acid modification step is omitted, and the original CNTs are directly subjected to oscillation adsorption with tea polyphenol ethanol solution at the same solid-liquid ratio. The remaining steps and parameters are exactly the same.

[0041] Comparative Example 3: No tea polyphenols loaded with drugs The difference between this comparative example and Example 1 is that in step 2, the tea polyphenol loading step is omitted, and only acid-modified CNTs are directly mixed with pulp and calcium carbonate. The remaining steps and parameters are exactly the same.

[0042] Comparative Example 4: No CMC Coating The difference between this comparative example and Example 1 is that in step 4, after the substrate is fabricated, CMC aqueous solution coating is not performed; the finished product is obtained directly by drying. The remaining steps and parameters are exactly the same.

[0043] Comparative Example 5: High Addition of CNT The difference between this comparative example and Example 1 is that in step 3, the mass ratio of pulp fiber, modified drug-loaded carbon nanotubes, and calcium carbonate is adjusted to 85:10:12. The remaining steps and parameters are exactly the same.

[0044] Performance testing 1. Test items and methods: (1) Thermal conductivity: The thermal conductivity coefficient of the sample at 250℃ (typical temperature in the high efficiency range of 150-350℃ in this application) was tested using a laser thermal conductivity analyzer (LFA1000) in accordance with ISO 22007-2 standard; at the same time, the temperature difference from the center to the edge of the tobacco section was tested under the heating condition of 250℃ to evaluate the heat transfer uniformity.

[0045] (2) Mechanical properties: The tensile index of the samples was tested using a universal tensile testing machine in accordance with GB / T 457 standard to evaluate the physical strength of the paper. The basis weight and thickness of the samples were tested in accordance with GB / T 451 standard to calculate the paper density and evaluate the physical properties of the paper.

[0046] (3) Odor and harmful substances: The total amount of aldehydes (formaldehyde, acetaldehyde, acrolein) generated in the sample under heating conditions of 250℃ was tested using a GC-MS instrument to evaluate the odor suppression effect and the ability to reduce harmful substances.

[0047] (4) Air permeability: According to GB / T 458 standard, test the air permeability (CU) of the sample to evaluate the smoothness of flue gas release.

[0048] (5) Filler shedding performance: Place the sample in a simulated cigarette smoking environment (heated at 250℃ for 10 min), observe whether the filler detaches from the sample surface, and test the amount of shedding by weight method (amount of shedding = mass before heating - mass after heating).

[0049] The test results are shown in the table below.

[0050] Table 1 Test Results

[0051] As can be seen from Example 1 and Comparative Example 1, the thermal conductivity of Example 1 is greatly improved: the modified drug-loaded CNT forms a continuous three-dimensional thermally conductive network in the pulp, which increases the thermal conductivity by more than 8 times and reduces the temperature difference by 4.9℃, proving that CNT is the core component for constructing an efficient heat conduction channel.

[0052] The mechanical properties of both remained basically the same, and the tensile index remained almost unchanged, indicating that the low addition amount (3 parts) of CNT did not have a negative impact on the paper strength. The slight increase in density in Example 1 indicates that the fiber filling was more compact.

[0053] The increase in total aldehyde content in Example 1 may be due to the release of trace amounts of small-molecule volatiles (such as residual carboxyl decomposition products) from CNTs themselves at high temperatures, or the pyrolysis of tea polyphenols on their surface during the initial heating phase. Nevertheless, the significant improvement in thermal conductivity is the main objective of this invention, and the aldehyde problem can be further improved by optimizing the drug loading process or post-treatment.

[0054] In Example 1, the air permeability decreased slightly and the filler shedding increased slightly. The effect of CMC coating on air permeability was not significant in the difference between the two. The shedding of Comparative Example 1 was lower because it did not contain CNTs and had a smaller total filler content.

[0055] As can be seen from Example 1 and Comparative Example 2, the addition of unmodified CNTs did not significantly improve the thermal conductivity, which was 0.375 W / (m·K), an increase of 2.84 times. This is because unmodified CNTs have fewer polar groups on their surface, failing to form a tight adsorption with the fiber surface, resulting in significant loss during papermaking and the inability to form a continuous thermally conductive network, thus leading to a poor thermal conductivity effect. There was a slight advantage in the total aldehyde content, possibly because the CNTs were not acidified, resulting in a lower content of carboxyl groups on their surface and a lower amount of small-molecule volatiles during combustion and pyrolysis.

[0056] As can be seen from Example 1 and Comparative Example 3, the thermal conductivity and basic strength of the heated non-combustible cigarette paper without added tea polyphenols are almost unchanged from those of the examples, but the total amount of aldehydes is significantly increased. It is preliminarily believed that tea polyphenols work synergistically with carbon nanotubes to adsorb some small molecules during the heating process, resulting in a decrease in the total amount of aldehydes.

[0057] As can be seen from Example 1 and Comparative Example 4, the thermal conductivity of the uncoated heated tobacco paper did not change much, the mechanical strength decreased by 24.8%, the filler shedding increased by 69.6%, and the air permeability increased by 13.1%. This indicates that CMC coating can improve the physical strength of heated tobacco paper, but it reduces the air permeability of the paper.

[0058] As can be seen from Example 1 and Comparative Example 5, when the proportion of loaded carbon nanotubes is increased to 10 parts, the improvement in thermal conductivity is no longer significant, and the physical strength indicators do not change much, but the total amount of aldehydes increases significantly. This indicates that excessive modified CNTs will partially decompose during heating, leading to the generation of some small molecule volatiles. On the other hand, from an economic point of view, it is unnecessary to add such a high proportion of modified carbon nanotubes.

[0059] It should be noted that the amount of modified drug-loaded carbon nanotubes added in Example 2 (1 part by mass) is one-third of that in Example 1 (3 parts). At this low addition amount, the thermally conductive network formed by the carbon nanotubes between the pulp fibers may not have reached the ideal percolation state, and some areas still have thermally resistive interfaces where fibers directly contact each other. Therefore, although the thermal conductivity (0.531 W / (m·K)) is about 4 times higher than that of Comparative Example 1 (without carbon nanotubes), it is lower than that of Example 1 (1.231 W / (m·K)) and Example 3 (1.317 W / (m·K)). This result precisely verifies that the amount of carbon nanotubes added is a key parameter for controlling the thermal conductivity of cigarette paper. In Example 1, the addition amount of 3 parts was sufficient to effectively overlap the carbon nanotubes to form a continuous thermally conductive pathway. When the amount was increased to 5 parts (Example 3), the improvement in thermal conductivity tended to plateau, indicating that a stepwise control of thermal conductivity can be achieved within the range of 1-5 parts, meeting the differentiated needs of different heated cigarette products. Although Example 2 has relatively low thermal conductivity, its aldehyde release (21.4 μg / g) is the lowest among the three examples, demonstrating the unique advantage of low addition in reducing harm, and further confirming the flexibility and adjustability of the technical solution of the present invention.

[0060] Examples 1-3 of this invention significantly improve thermal conductivity while maintaining good mechanical strength and stability in use. Although the total aldehyde content is higher than that of the comparative example, this is a side effect that is difficult to completely avoid after the introduction of CNTs and CMCs. Moreover, by controlling the addition of CNTs to a low amount of 1-5 parts, the increase in aldehyde content can be controlled within an acceptable range (far lower than that of comparative example 5). This invention achieves a multi-objective balance of high thermal conductivity, high strength, low shedding, and low addition amount for the first time, providing a practical solution for heated non-combustible cigarette paper.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing thermally conductive, heat-conducting, non-combustible cigarette paper, characterized in that, Includes the following steps: Nitric acid and sulfuric acid are mixed, and carbon nanotubes are immersed in the mixed acid for modification. Then, they are washed until neutral to obtain modified carbon nanotubes. Modified carbon nanotubes were shaken with a tea polyphenol ethanol solution, filtered and dried to obtain modified drug-loaded carbon nanotubes. The pulp, modified drug-loaded carbon nanotubes, and calcium carbonate are mixed evenly to obtain a mixed slurry; The mixed slurry is used to form a substrate, which is then dried. A carboxymethyl cellulose aqueous solution is then coated onto the substrate and dried to obtain the final product.

2. The preparation method according to claim 1, characterized in that, The volume ratio of nitric acid to sulfuric acid is 1:2-1:4, the modification temperature is 60-100℃, and the modification time is 1-3h.

3. The preparation method according to claim 1, characterized in that, The concentration of the tea polyphenol ethanol solution is 5-15 mg / mL, and the solid-liquid ratio of the modified carbon nanotubes to the tea polyphenol ethanol solution is 1:5-1:10 g / mL.

4. The preparation method according to claim 1, characterized in that, The oscillation temperature is 23-27℃, and the oscillation time is 23-25h.

5. The preparation method according to claim 1, characterized in that, The mass ratio of the pulp, modified drug-loaded carbon nanotubes, and calcium carbonate is 80-90:1-5:10-15; Preferably, the mass ratio is 85:1-5:

12.

6. The preparation method according to claim 1, characterized in that, The pulp includes one or more of softwood pulp and hardwood pulp.

7. The preparation method according to claim 1, characterized in that, The pulp needs to be pulped to a freeness of 20-60°SR using a PFI refiner before being mixed with modified drug-loaded carbon nanotubes and calcium carbonate.

8. The preparation method according to claim 1, characterized in that, The concentration of the carboxymethyl cellulose aqueous solution is 1-3 wt%, and the coating amount is 0.5-1.5 g / m³. 2 .

9. A thermally conductive, heat-conducting, non-combustible cigarette paper, characterized in that, Obtained by the preparation method according to any one of claims 1-8.

10. The application of the thermally conductive, heat-generating, non-combustible cigarette paper of claim 9 in a low-temperature heated cigarette, wherein the temperature of the heated cigarette in the low-temperature heated cigarette is 150-350°C.

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