A spherical molten salt self-circulating cigarette smoke cooling material and its preparation method and application

Abstract

The present invention provides a spherical molten salt self-circulating cigarette smoke cooling material and its preparation method and application. The cooling material includes a molten salt core, a attapulgite ball shell and an outer film from the inside to the outside. In the present invention, the cooling material uses a hollow attapulgite ball as a carrier, a molten salt as a core, and an outer film is coated on the outside of the carrier. Through specific structural design and material selection, the cooling material has good heat transfer effect and high mechanical strength, can greatly reduce the cigarette smoke temperature, and can achieve self-circulation. The product is stable, has good air permeability, and is low in cost. It can be widely used in the field of cigarette smoke filtration and cooling.

Description

Technical Field

[0001] The invention belongs to the technical field of cigarette smoke filtering and cooling materials, and in particular relates to a spherical molten salt self-circulating cigarette smoke cooling material and a preparation method and application thereof. Background Art

[0002] Heated cigarettes are an important form of new tobacco products. They mainly heat tobacco materials to release aerosols by heating and distillation (below 500°C). Compared with traditional cigarettes, heated cigarettes only heat tobacco materials instead of burning them, which reduces the harmful components produced during the high-temperature combustion of tobacco, and the release of sidestream smoke and ambient smoke is also significantly reduced. Since heated cigarettes are shorter, the inlet smoke temperature is too hot. In this regard, various tobacco companies have adopted different solutions in the design of the cooling section of cigarettes. For example, embossed and gathered PLA films, fiber woven bundles with cooling effects, embossed and gathered aluminum foil composite paper, and cooling cavity firmware are used. In general, smoke cooling measures are mainly concentrated in two aspects: cooling by adding cooling materials and cooling by designing cooling structures. In terms of material cooling, heat-absorbing materials, heat storage materials, heat-conducting materials, etc. can all be used to cool the smoke of heated cigarettes to achieve the transfer of smoke heat. This method is also the most important research method at present. Such as polylactic acid phase change cooling materials. When high-temperature flue gas passes through the polylactic acid polymer, the polylactic acid undergoes a glass transition and absorbs heat, consuming the heat energy of the flue gas. On the other hand, the water vapor in the flue gas condenses on the surface of the polylactic acid polymer when passing through it, drying the flue gas. However, after the polylactic acid sheet contacts the high-temperature flue gas and undergoes a glass transition, it will melt and bond, blocking the longitudinally extending flue gas channel, and the flue gas will no longer flow through the inside of the polylactic acid sheet. At the same time, polylactic acid materials will also have a partial adsorption effect on glycerin in the flue gas, reducing the glycerin content in the flue gas and causing a decrease in the smoking quality.

[0003] In addition to adding heat-absorbing, heat-storing and heat-conducting additives to heated cigarettes to reduce smoke temperature, the smoke cooling effect can also be enhanced by adjusting the cigarette structure, such as using cavities to buffer heat storage, lengthening smoke channels, and enhancing heat exchange between smoke and the external environment. The above cooling measures can partially reduce smoke temperature, but there are still certain shortcomings.

[0004] Although existing cooling materials can achieve a good cooling effect, they will also have an adsorption effect on glycerin, thereby reducing the quality of flue gas, and there are problems such as adhesion during the use of the materials. Although cooling through structural design has little effect on the flue gas concentration, the cooling effect is limited.

[0005] In summary, it is a technical problem to be urgently solved in this field to study a self-circulating cooling material that can effectively reduce the smoke temperature without affecting the smoke concentration, has high material stability, can be self-circulated and has great practical significance for improving the quality of heated cigarette products. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a spherical molten salt self-circulating cigarette smoke cooling material and its preparation method and application. The cooling material uses a hollow attapulgite ball as a carrier, a molten salt as a core, and an outer film is coated on the outside of the carrier. Through specific structural design and material selection, the cooling material has good heat transfer effect, high mechanical strength, can greatly reduce the temperature of cigarette smoke, and can be used in a self-circulating manner. The product is stable, has good air permeability, and is low in cost. It can be widely used in the field of cigarette smoke filtration and cooling.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a spherical molten salt self-circulating cigarette smoke cooling material, wherein the cooling material comprises, from the inside to the outside, a molten salt inner core, a attapulgite ball outer shell, and an outer coating.

[0009] In the present invention, attapulgite balls are used as the outer shell. On the one hand, attapulgite has high mechanical strength and thermal stability, which can ensure that the material will not be damaged during the preparation and use process and has good stability; on the other hand, the hollow attapulgite balls have a small diameter, abundant internal pores, and a large specific surface area, which can realize efficient heat conduction between the cigarette smoke outside the shell and the molten salt inner core; the molten salt inner core is used as a heat absorbing material, which can efficiently and quickly absorb the heat of the smoke and then melt, thereby improving the smoke cooling capacity of the cooling material; at the same time, during the interval between smoking, the temperature drops and the molten salt solidifies again, realizing the self-circulation of the cooling material during the smoking process; and the outer coating can ensure that the molten salt melted by heat is always preserved in the core-shell structure, effectively avoiding the loss of the molten salt, and through the mutual cooperation of the attapulgite ball outer shell, the molten salt inner core and the outer coating, the cooling material can greatly reduce the cigarette smoke temperature, realize self-circulation and stable product performance.

[0010] Preferably, the melting point of the molten salt is 30-50°C, for example, 32°C, 34°C, 36°C, 38°C, 40°C, 42°C, 44°C, 46°C, 48°C, etc.

[0011] Preferably, the molten salt comprises sodium thiosulfate.

[0012] In the present invention, the molten salt is selected to meet the requirements of phase transition at 30-50° C. and being non-toxic and harmless. The best choice is sodium thiosulfate.

[0013] Preferably, the inner diameter of the attapulgite ball shell is 0.5-5μm, for example, it can be 0.6μm, 0.8μm, 1μm, 1.2μm, 1.4μm, 1.6μm, 1.8μm, 2μm, 2.2μm, 2.4μm, 2.6μm, 2.8μm, 3μm, 3.2μm, 3.4μm, 3.6μm, 3.8μm, 4μm, 4.2μm, 4.4μm, 4.6μm, 4.8μm, etc., and more preferably 1.5-2μm.

[0014] Preferably, the outer film comprises a polytetrafluoroethylene film.

[0015] In the present invention, polytetrafluoroethylene membrane is selected, which has strong stability and good air permeability at low temperatures. Cigarette smoke can effectively contact the spherical cooling material in the membrane, while ensuring that the molten salt melted by heat is always preserved in the core-shell structure, further effectively avoiding the loss of molten salt.

[0016] Preferably, the cooling material further includes a binder.

[0017] Preferably, the binder comprises polyvinyl alcohol.

[0018] In a second aspect, the present invention provides a method for preparing the spherical molten salt self-circulating cigarette smoke cooling material according to the first aspect, the preparation method comprising:

[0019] (1) mixing carbon balls, attapulgite and a solvent, and calcining to obtain an attapulgite ball shell;

[0020] (2) mixing the attapulgite ball shell obtained in step (2) with a molten salt solution, and drying to obtain a solid core-shell structure material;

[0021] (3) coating the outer coating material onto the surface of the solid core-shell structure material obtained in step (2) to obtain the spherical molten salt self-circulating cigarette smoke cooling material.

[0022] In the present invention, when preparing the cooling material, the carbon balls prepared by glucose hydrothermal method are not used as sacrificial templates, and the hollow attapulgite balls cannot be formed. The cooling material is a solid attapulgite ball, and the cooling effect is poor.

[0023] Preferably, the method for preparing the carbon spheres in step (1) comprises: subjecting an aqueous solution of a carbon sphere precursor to a hydrothermal reaction and calcining to obtain the carbon spheres.

[0024] Preferably, the aqueous solution of the carbon sphere precursor comprises an aqueous solution of glucose.

[0025] Preferably, the mass fraction of the aqueous glucose solution is 20-40%, for example, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, etc.

[0026] Preferably, the temperature of the hydrothermal reaction is 150-180°C, for example, 155°C, 160°C, 165°C, 170°C, 175°C, etc.

[0027] Preferably, the hydrothermal reaction time is 4 to 8 h, for example, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, etc.

[0028] In the present invention, the hydrothermal reaction further includes the steps of centrifugation and washing, wherein the washing step is performed until the supernatant is transparent.

[0029] Preferably, to obtain the carbon balls, the calcination temperature is 500-700°C, for example, 520°C, 540°C, 560°C, 580°C, 600°C, 620°C, 640°C, 660°C, 680°C, etc.

[0030] Preferably, to obtain the carbon spheres, the calcination time is 2 to 6 hours, for example, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, etc.

[0031] In the present invention, the calcination is carried out in a muffle furnace.

[0032] Preferably, the calcination is carried out in the presence of a protective atmosphere.

[0033] Preferably, the protective atmosphere includes but is not limited to nitrogen.

[0034] Preferably, the mixed material in step (1) also includes a binder.

[0035] Preferably, the mixing step in step (1) comprises: after mixing the binder and the solvent, adding carbon balls and attapulgite in sequence and mixing them.

[0036] Preferably, the mass ratio of the binder, solvent, carbon balls and attapulgite is 2:(20-40):(1-3):(20-50), wherein the specific value in (20-40) can be, for example, 22, 24, 26, 28, 30, 32, 34, 36, 38, etc.; the specific value in (1-3) can be, for example, 1.2, 1.4, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, etc.; the specific value in (20-50) can be, for example, 22, 24, 25, 26, 28, 30, 32, 34, 35, 36, 38, 40, 42, 44, 46, 48, etc.

[0037] Preferably, the temperature at which the binder and the solvent are mixed is 50-60° C., for example, 52, 54, 56, 58, etc.

[0038] Preferably, the calcination temperature in step (1) is 600-800°C, for example, 620°C, 640°C, 660°C, 680°C, 700°C, 720°C, 740°C, 760°C, 780°C, etc.

[0039] Preferably, the calcination time in step (1) is 2 to 4 h, for example, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h, etc.

[0040] In the present invention, the calcination in step (1) is carried out in an air atmosphere.

[0041] Preferably, the mass fraction of the molten salt solution in step (2) is 30-50%, for example, it can be 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, etc.

[0042] Preferably, the mixing method in step (2) comprises impregnation.

[0043] Preferably, the drying temperature in step (2) is 100-120°C, for example, 105°C, 110°C, 115°C, 118°C, etc.

[0044] Preferably, the drying time in step (2) is 1 to 2 hours, for example, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, etc.

[0045] Preferably, step (2) further includes a cooling step after the drying.

[0046] In the present invention, step (2) is repeated until a solid core-shell structure material is formed.

[0047] In the present invention, step (2) is not performed, that is, molten salt is not added, and the heat absorption capacity is low, resulting in poor cooling performance.

[0048] Preferably, the outer coating material in step (3) comprises a concentrated solution of the outer coating material.

[0049] Preferably, the mass concentration of the concentrated solution of the outer coating material is 60%.

[0050] Preferably, the coating comprises diluting the concentrated solution of the outer coating material with a solvent before coating.

[0051] Preferably, the mass ratio of the concentrate, the solvent and the solid core-shell structure material is 1:(9-29):(100-200), wherein the specific value in (9-29) can be, for example, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, etc.; the specific value in (100-200) can be, for example, 110, 120, 130, 140, 150, 160, 170, 180, 190.

[0052] Preferably, step (3) further includes a drying step after coating.

[0053] Preferably, the drying temperature is 100-120°C, for example, 105°C, 110°C, 115°C, 118°C, etc.

[0054] Preferably, the drying time is 0.5 to 1 h, for example, 0.6 h, 0.7 h, 0.8 h, 0.9 h, etc.

[0055] In the present invention, no outer coating treatment is performed, and the molten salt of the cooling material is lost, resulting in an insignificant decrease in the cooling performance.

[0056] As a preferred technical solution of the present invention, the preparation method comprises:

[0057] (1) After mixing an optional binder and a solvent at 50-60° C., carbon balls and attapulgite are added in sequence and mixed, and then calcined at 600-800° C. for 2-4 hours to obtain an attapulgite ball shell; the mass ratio of the binder, the solvent, the carbon balls and the attapulgite is 2:(20-40):(1-3):(20-50);

[0058] (2) immersing the outer shell of the attapulgite ball obtained in step (2) in a molten salt solution, and drying at 100 to 120° C. for 1 to 2 hours to obtain a solid core-shell structure material;

[0059] (3) The concentrated solution of the outer coating material is diluted with a solvent, applied to the surface of the solid core-shell structure material obtained in step (2), and dried at 100 to 120° C. for 0.5 to 1 h to obtain the spherical molten salt self-circulating cigarette smoke cooling material; the mass ratio of the concentrated solution, the solvent and the solid core-shell structure material is 1:(9 to 29):(100 to 200).

[0060] In a third aspect, the present invention provides a cigarette, wherein the cigarette comprises the cooling material as described in the first aspect.

[0061] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] The spherical molten salt self-circulating cigarette smoke cooling material provided by the present invention uses a hollow attapulgite ball as a carrier, a molten salt as a core, and an outer coating film on the outside of the carrier. Through specific structural design and material selection, the cooling material has good heat transfer effect and high mechanical strength, can greatly reduce the cigarette smoke temperature, and can be used in a self-circulating manner. The product is stable, has good air permeability, and is low in cost. It can be widely used in the field of cigarette smoke filtration and cooling; the maximum temperature of a cigarette including the cooling material when smoked is ≤49.2°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 This is the temperature test result diagram of the original cigarette during the smoking process;

[0065] Figure 2 A graph showing the temperature test results of a cigarette including the cooling material provided in Example 1 during smoking;

[0066] Figure 3 A graph showing the temperature test results of a cigarette including the cooling material provided in Example 2 during smoking;

[0067] Figure 4 A graph showing the temperature test results of a cigarette including the cooling material provided in Example 3 during smoking;

[0068] Figure 5 A temperature test result diagram of a cigarette including the cooling material provided in Comparative Example 1 during smoking;

[0069] Figure 6 A temperature test result diagram of a cigarette including the cooling material provided in Comparative Example 2 during smoking;

[0070] Figure 7 This is a graph showing the temperature test results of a cigarette including the cooling material provided in Comparative Example 3 during the smoking process. DETAILED DESCRIPTION

[0071] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0072] The materials used in the present invention are as follows:

[0073] Polytetrafluoroethylene: Beijing Inokai Technology Co., Ltd., Item No.: P816262-500g, CAS No.: 9002-84-0

[0074] Example 1

[0075] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which includes a sodium thiosulfate core, a attapulgite ball shell and a polytetrafluoroethylene membrane from the inside to the outside; the inner diameter of the attapulgite ball shell is 1.8 to 2.0 μm.

[0076] This embodiment provides a method for preparing a spherical molten salt self-circulating cigarette smoke cooling material, which specifically includes the following steps:

[0077] (1) Weigh 100.00 g of a 40% glucose aqueous solution, add it to a 100 mL hydrothermal reactor, and perform a hydrothermal reaction at 180° C. for 4 h. After the reaction is completed, centrifuge and wash with deionized water until the supernatant is transparent, place it in a muffle furnace and roast it at 600° C. for 4 h in a nitrogen atmosphere to obtain a sacrificial template-carbon sphere; weigh 2.00 g of polyvinyl alcohol and dissolve it in 40.00 g of deionized water, heat and stir at 50° C. for 10 min to obtain a polyvinyl alcohol solution, weigh 3.00 g of the carbon sphere and 50.00 g of attapulgite and stir until the mixture is uniformly mixed, then place it in a muffle furnace and roast it at 800° C. for 4 h in an air atmosphere, and after natural cooling, obtain a hollow attapulgite ball shell with micropores on the surface;

[0078] (2) Weigh 2.00 g of sodium thiosulfate and dissolve it in 2.00 g of deionized water, stir at room temperature until the mixture is uniformly mixed to obtain a molten salt solution; weigh 2.00 g of the attapulgite ball shell obtained in step (1) and immerse it in the molten salt solution to absorb the molten salt into the core, then place the attapulgite ball shell containing the molten salt solution in an oven at 120° C. and dry it for 1 h, then remove it from the oven and cool it to room temperature, and repeat this operation multiple times until a solid core-shell structure material is obtained;

[0079] (3) Weigh 1.00 g of PTFE concentrate (60% mass concentration) and dissolve it in 29.00 g of deionized water to obtain 30.00 g of PTFE diluted solution, and evenly apply the PTFE diluted solution on the surface of 200.00 g of the solid core-shell structure material obtained in step (2), then place it in a forced air drying oven and dry it at 120° C. for 0.5 h. After taking it out and cooling it, the spherical molten salt self-circulating cigarette smoke cooling material is obtained.

[0080] Example 2

[0081] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which includes a sodium thiosulfate core, a attapulgite ball shell and a polytetrafluoroethylene membrane from the inside to the outside; the inner diameter of the attapulgite ball shell is 1.6 to 1.8 μm.

[0082] This embodiment provides a method for preparing a spherical molten salt self-circulating cigarette smoke cooling material, which specifically includes the following steps:

[0083] (1) Weigh 100.00 g of a 30% glucose aqueous solution, add it to a 100 mL hydrothermal reactor, and perform a hydrothermal reaction at 150° C. for 8 h. After the reaction is completed, centrifuge and wash with deionized water until the supernatant is transparent, place it in a muffle furnace and roast it at 500° C. for 6 h in a nitrogen atmosphere to obtain a sacrificial template-carbon sphere; weigh 2.00 g of polyvinyl alcohol and dissolve it in 20.00 g of deionized water, heat and stir it at 55° C. for 10 min to obtain a polyvinyl alcohol solution, weigh 2.00 g of the carbon sphere and 40.00 g of attapulgite, stir until the mixture is uniformly mixed, then place it in a muffle furnace and roast it at 600° C. for 2 h in an air atmosphere, and after natural cooling, obtain a hollow attapulgite ball shell with micropores on the surface;

[0084] (2) Weigh 2.00 g of sodium thiosulfate and dissolve it in 4.00 g of deionized water, stir at room temperature until the mixture is uniformly mixed to obtain a molten salt solution; weigh 4.00 g of the attapulgite ball shell obtained in step (1) and immerse it in the molten salt solution to absorb the molten salt into the core, then place the attapulgite ball shell containing the molten salt solution in an oven at 100° C. and dry it for 2 h, then remove it from the oven and cool it to room temperature, and repeat this operation multiple times until a solid core-shell structure material is obtained;

[0085] (3) Weigh 1.00 g of PTFE concentrate (60% mass concentration) and dissolve it in 9.00 g of deionized water to obtain 10.00 g of PTFE diluted solution, and evenly apply the PTFE diluted solution on the surface of 100.00 g of the solid core-shell structure material obtained in step (2), then place it in a forced air drying oven at 100° C. for 1 h, take it out and cool it, so as to obtain the spherical molten salt self-circulating cigarette smoke cooling material.

[0086] Example 3

[0087] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which includes a sodium thiosulfate core, a attapulgite ball shell and a polytetrafluoroethylene membrane from the inside to the outside; the inner diameter of the attapulgite ball shell is 1.5 to 1.6 μm.

[0088] This embodiment provides a method for preparing a spherical molten salt self-circulating cigarette smoke cooling material, which specifically includes the following steps:

[0089] (1) Weigh 80.00 g of a 40% glucose aqueous solution, add it to a 100 mL hydrothermal reactor, and perform a hydrothermal reaction at 160° C. for 6 h. After the reaction is completed, centrifuge and wash with deionized water until the supernatant is transparent, place it in a muffle furnace and roast it at 700° C. for 2 h in a nitrogen atmosphere to obtain a sacrificial template-carbon sphere; weigh 2.00 g of polyvinyl alcohol and dissolve it in 30.00 g of deionized water, heat and stir at 60° C. for 10 min to obtain a polyvinyl alcohol solution, weigh 1.00 g of the carbon sphere and 20.00 g of attapulgite and stir until the mixture is uniformly mixed, then place it in a muffle furnace and roast it at 700° C. for 3 h in an air atmosphere, and after natural cooling, obtain a hollow attapulgite ball shell with micropores on the surface;

[0090] (2) Weigh 2.00 g of sodium thiosulfate and dissolve it in 3.00 g of deionized water, stir at room temperature until the mixture is uniformly mixed to obtain a molten salt solution; weigh 3.00 g of the attapulgite ball shell obtained in step (1) and immerse it in the molten salt solution to absorb the molten salt into the core, then place the attapulgite ball shell containing the molten salt solution in an oven at 110° C. and dry it for 1 h, then remove it from the oven and cool it to room temperature, and repeat this operation multiple times until a solid core-shell structure material is obtained;

[0091] (3) Weigh 1.00 g of PTFE concentrate (60% mass concentration) and dissolve it in 19.00 g of deionized water to obtain 20.00 g of PTFE diluted solution, and evenly apply the PTFE diluted solution on the surface of 150.00 g of the solid core-shell structure material obtained in step (2), then place it in a forced air drying oven at 100° C. for 1 h, take it out and cool it, so as to obtain the spherical molten salt self-circulating cigarette smoke cooling material.

[0092] Example 4

[0093] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which is different from Example 1 only in that, in the preparation method, the total amount of carbon balls and attapulgite in step (1) remains unchanged, and the mass ratio is 0.5:55, and the other components, amounts and preparation methods are the same as those in Example 1.

[0094] Example 5

[0095] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which differs from Example 1 only in that, in the preparation method, the total amount of carbon balls and attapulgite in step (1) remains unchanged, with a mass ratio of 4:18, and the other components, amounts and preparation methods are the same as those in Example 1.

[0096] Example 6

[0097] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which differs from Example 1 only in that, in the preparation method, the total amount of PTFE concentrate and solid core-shell structure material in step (3) remains unchanged, and the mass ratio is 1:80, and the other components, amounts and preparation methods are the same as those in Example 1.

[0098] Example 7

[0099] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which differs from Example 1 only in that, in the preparation method, the total amount of PTFE concentrate and solid core-shell structure material in step (3) remains unchanged, and the mass ratio is 1:220, and the other components, amounts and preparation methods are the same as those in Example 1.

[0100] Example 8

[0101] This embodiment provides a spherical molten salt self-circulating cigarette smoke cooling material, which is different from Example 1 only in that the polytetrafluoroethylene film is replaced by a polylactic acid film, and in the preparation method, the polytetrafluoroethylene concentrate is replaced by an equal amount of polylactic acid concentrate (60%), and the other components, amounts and preparation methods are the same as those in Example 1.

[0102] Comparative Example 1

[0103] This comparative example provides a cigarette smoke cooling material, which is different from Example 1 only in that the preparation method does not use glucose hydrothermal method to prepare carbon spheres as sacrificial templates, and other components, amounts and preparation methods are the same as those in Example 1.

[0104] Comparative Example 2

[0105] This comparative example provides a cigarette smoke cooling material, which differs from Example 1 only in that step (2) is not performed in the preparation method, that is, sodium thiosulfate is not added as a heat absorbing material, and other components, amounts and preparation methods are the same as those in Example 1.

[0106] Comparative Example 3

[0107] This comparative example provides a cigarette smoke cooling material, which differs from Example 1 only in that step (3) is not performed in the preparation method, that is, PTFE coating treatment is not performed, and other components, amounts and preparation methods are the same as those in Example 1.

[0108] Comparative Example 4

[0109] This comparative example provides a cigarette smoke cooling material, which is different from Example 1 only in that the attapulgite is replaced by an equal amount of bentonite, and the other components, amounts and preparation methods are the same as those in Example 1.

[0110] Application Examples

[0111] A heated cigarette, the cigarette is composited by a acetate fiber section, a cavity firmware cooling section, and a tobacco material smoking section (the tobacco material is tobacco sheet shreds with a certain amount of glycerol applied thereto), the cavity firmware of the cooling section containing the spherical molten salt self-circulating cigarette smoke cooling material provided in Examples 1 to 8 and Comparative Examples 1 to 4.

[0112] Performance Testing

[0113] According to the smoking mode of cigarettes specified in the national standard YC / T29-1996, simulated smoking was performed, and a K-type thermocouple temperature detector was used to detect the temperature at the center of the cigarette acetate fiber section 2mm away from the mouth end when the cigarette was smoked. The number of simulated smoking times was 9 times, and the interval between each smoking was 30s, and the highest temperature was recorded. The original cigarette (i.e. the original cigarette without adding cooling material) was used as a control example;

[0114] Among them, the temperature test results of the original smoke during the smoking process are shown in the figure below: Figure 1 As shown;

[0115] The temperature test results of the cigarette including the cooling material provided in Example 1 during the smoking process are shown in the figure below: Figure 2 As shown;

[0116] The temperature test results of the cigarette including the cooling material provided in Example 2 during the smoking process are shown in the figure below: Figure 3 As shown;

[0117] The temperature test results of the cigarette including the cooling material provided in Example 3 during the smoking process are shown in the figure below: Figure 4 As shown;

[0118] The temperature test results of the cigarette including the cooling material provided in Comparative Example 1 during the smoking process are shown in the figure below: Figure 5 As shown;

[0119] The temperature test results of the cigarette including the cooling material provided in Comparative Example 2 during the smoking process are shown in the figure below: Figure 6 As shown;

[0120] The temperature test results of the cigarette including the cooling material provided in Comparative Example 3 during the smoking process are shown in the figure below: Figure 7 shown.

[0121] The specific test results are shown in Table 1:

[0122] Table 1

[0123] Maximum flue gas temperature (℃) Example 1 42.7 Example 2 49.2 Example 3 45.1 Example 4 52.3 Example 5 57.2 Example 6 53.5 Example 7 58.7 Example 8 55.3 Comparative Example 1 60.6 Comparative Example 2 63.9 Comparative Example 3 63.2 Comparative Example 4 60.4 Comparison example 66.4

[0124] As can be seen from the above table, the spherical molten salt self-circulating cigarette smoke cooling material provided by the present invention uses a hollow attapulgite ball as a carrier, a molten salt as a core, and an outer film coated on the outside of the carrier. Through specific structural design and material selection, the cooling material has good heat transfer effect and high mechanical strength, can greatly reduce the cigarette smoke temperature, and can achieve self-circulation. As can be seen from Examples 1 to 3, the temperature of the cigarette including the cooling material during smoking is 42.7 to 49.2°C.

[0125] By comparing Example 1 with Examples 4 and 5, it can be seen that the mass ratio of the carbon balls to attapulgite is not within a specific range, and the cooling performance of the cooling material deteriorates.

[0126] It can be seen from the comparison between Example 1 and Examples 6 and 7 that the mass ratio of the PTFE concentrate to the solid core-shell structure material is not within a specific range, and the cooling performance of the cooling material deteriorates.

[0127] From the comparison between Example 1 and Example 8, it can be seen that when polylactic acid is used for the outer coating, the film-forming property is poor and the heat resistance is poor, resulting in the poor cooling performance of the cooling material.

[0128] It can be seen from the comparison between Example 1 and the comparative example that when the cooling material is not the specific structure or material of the present invention, the cooling performance is poor, and bentonite is used instead of attapulgite, the mechanical strength after molding is insufficient and it is easily damaged during use.

[0129] In summary, the cooling material provided by the present invention has good heat transfer effect and high mechanical strength through specific structural design and raw material selection, and can realize self-circulation of heat absorbing materials, thereby greatly reducing the temperature of cigarette smoke, and has low cost and high application value.

[0130] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A spherical molten salt self-circulating cigarette smoke cooling material, characterized in that: The cooling material comprises, from the inside to the outside, a molten salt core, a attapulgite ball shell and an outer coating; The melting point of the molten salt is 30-50°C; The molten salt includes sodium thiosulfate; The inner diameter of the attapulgite ball shell is 0.5-5 μm; The outer coating includes a polytetrafluoroethylene film; The spherical molten salt self-circulating cigarette smoke cooling material is prepared by the following method, which comprises the following steps: (1) mixing carbon balls, attapulgite and a solvent, and calcining to obtain an attapulgite ball shell; (2) mixing the attapulgite ball shell obtained in step (1) with a molten salt solution, and drying to obtain a solid core-shell structure material; (3) Coating the outer coating material onto the surface of the solid core-shell structure material obtained in step (2) to obtain the spherical molten salt self-circulating cigarette smoke cooling material.

2. The spherical molten salt self-circulating cigarette smoke cooling material according to claim 1, characterized in that: The inner diameter of the attapulgite ball shell is 1.5-2 μm.

3. The spherical molten salt self-circulating cigarette smoke cooling material according to claim 1, characterized in that: The cooling material further comprises a binder.

4. The spherical molten salt self-circulating cigarette smoke cooling material according to claim 3, characterized in that: The binder includes polyvinyl alcohol.

5. A method for preparing the spherical molten salt self-circulating cigarette smoke cooling material according to any one of claims 1 to 4, characterized in that: The preparation method comprises: (1) mixing carbon balls, attapulgite and a solvent, and calcining to obtain an attapulgite ball shell; (2) mixing the attapulgite ball shell obtained in step (1) with a molten salt solution, and drying to obtain a solid core-shell structure material; (3) Coating the outer coating material onto the surface of the solid core-shell structure material obtained in step (2) to obtain the spherical molten salt self-circulating cigarette smoke cooling material.

6. The preparation method according to claim 5, characterized in that: The method for preparing carbon spheres in step (1) comprises: The aqueous solution of the carbon sphere precursor is subjected to a hydrothermal reaction and calcined to obtain the carbon sphere.

7. The preparation method according to claim 6, characterized in that: The aqueous solution of the carbon sphere precursor includes a glucose aqueous solution.

8. The preparation method according to claim 7, characterized in that: The mass fraction of the glucose aqueous solution is 20-40%.

9. The preparation method according to claim 6, characterized in that: The temperature of the hydrothermal reaction is 150-180°C.

10. The preparation method according to claim 6, characterized in that: The hydrothermal reaction time is 4 to 8 h.

11. The preparation method according to claim 6, characterized in that: The carbon balls are obtained at a calcination temperature of 500-700°C.

12. The preparation method according to claim 6, characterized in that: The carbon spheres are obtained by calcining for 2 to 6 h.

13. The preparation method according to claim 5, characterized in that: The mixed material in step (1) also includes a binder.

14. The preparation method according to claim 13, characterized in that: The mixing step in step (1) comprises: mixing the binder and the solvent, and then sequentially adding carbon balls and attapulgite for mixing.

15. The preparation method according to claim 14, characterized in that: The mass ratio of the binder, the solvent, the carbon balls and the attapulgite is 2:(20-40):(1-3):(20-50).

16. The preparation method according to claim 14, characterized in that: The temperature at which the binder and the solvent are mixed is 50-60°C.

17. The preparation method according to claim 5, characterized in that: The calcination temperature in step (1) is 600-800°C.

18. The preparation method according to claim 5, characterized in that: The calcination time in step (1) is 2 to 4 hours.

19. The preparation method according to claim 5, characterized in that: The mass fraction of the molten salt solution in step (2) is 30-50%.

20. The preparation method according to claim 5, characterized in that: The mixing method in step (2) includes impregnation.

21. The preparation method according to claim 5, characterized in that: The drying temperature in step (2) is 100-120°C.

22. The preparation method according to claim 5, characterized in that: The drying time in step (2) is 1 to 2 hours.

23. The preparation method according to claim 5, characterized in that: The outer coating material in step (3) includes a concentrated solution of the outer coating material.

24. The preparation method according to claim 23, characterized in that: The mass concentration of the concentrated solution of the outer coating material is 60%.

25. The preparation method according to claim 5, characterized in that: The coating step includes diluting the concentrated solution of the outer coating material with a solvent before coating.

26. The preparation method according to claim 25, characterized in that: The mass ratio of the concentrated solution, the solvent and the solid core-shell structure material is 1:(9-29):(100-200).

27. The preparation method according to claim 5, characterized in that: Step (3) also includes a drying step after the coating.

28. The preparation method according to claim 27, characterized in that: The drying temperature is 100-120°C.

29. The preparation method according to claim 27, characterized in that: The drying time is 0.5 to 1 h.

30. The preparation method according to claim 13, characterized in that: The preparation method comprises: (1) After mixing the binder and the solvent at 50-60°C, carbon balls and attapulgite are added in sequence and mixed, followed by calcination at 600-800°C for 2-4 h to obtain an attapulgite ball shell; the mass ratio of the binder, the solvent, the carbon balls and the attapulgite is 2:(20-40):(1-3):(20-50); (2) immersing the outer shell of the attapulgite ball obtained in step (1) in a molten salt solution, and drying at 100-120° C. for 1-2 h to obtain a solid core-shell structure material; (3) The concentrated solution of the outer coating material is diluted with a solvent, coated on the surface of the solid core-shell structure material obtained in step (2), and dried at 100-120° C. for 0.5-1 h to obtain the spherical molten salt self-circulating cigarette smoke cooling material; the mass ratio of the concentrated solution, the solvent and the solid core-shell structure material is 1:(9-29):(100-200).

31. A cigarette, characterized in that: The cigarette comprises the cooling material according to any one of claims 1 to 4.

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