Temperature-response adjustable cigarette core material for heating cigarettes and preparation method of temperature-response adjustable cigarette core material

Abstract

The invention discloses a temperature-response-adjustable cigarette core material for heating cigarettes and a preparation method thereof.The temperature-response-adjustable cigarette core material for heating cigarettes is composed of graft modified cellulose nanofibers, an aroma releasing substance and an atomizing agent, and the mass ratio of the graft modified cellulose nanofibers to the atomizing agent to the aroma releasing substance is (0.5-15): (7-25): (60-85). According to the invention, the cellulose nanofiber is used as a carrier, a substance with microwave sensing capability is grafted to a cellulose nanofiber skeleton through grafting modification, and the microwave sensing capability of the material can be controlled by controlling the grafting amount, so that the heating rate of the material under microwave heating is controlled, and the purposes of adjustable and controllable temperature and quick response are achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of heated cigarettes, and particularly relates to a temperature response controllable cigarette core material for heated cigarettes and a preparation method thereof. BACKGROUND

[0002] With the improvement of people's living quality and the strengthening of tobacco control, new requirements for harm reduction of cigarette products have been put forward, and new tobacco products have emerged as the times require. As one of the important categories of new tobacco, heated cigarettes are heated to 200-400 DEG C to make the cigarette core material distill and pyrolyze to release nicotine and flavor components to meet the needs of consumers. Because the harmful or potentially harmful components in the aerosol of the cigarette core material are significantly reduced under low-temperature heating conditions, in recent years, heated cigarettes have become a field widely concerned by domestic and foreign tobacco companies and tobacco industry researchers.

[0003] In the existing cigarette core material, the atomizing agent, flavoring substance and tobacco substance are generally tobacco particles, tobacco sheets and the like obtained by blending and forming treatment. However, in the existing cigarette core material, it takes tens of seconds or even thirty seconds to heat to 200-400 DEG C, the speed of generating aerosol is slow, and the atomizing agent and flavoring substance are easily released due to the low evaporation temperature, while the nicotine in the tobacco and the self-flavor components released by pyrolysis require a large temperature interval, and the speed of temperature rise affects the synchronous release of flavor substances, thereby affecting the smoking experience.

[0004] How to quickly reach the smoking temperature has become a major problem in the development of heated cigarettes. Microwave heating has many advantages such as rapid heating, good uniformity, short reaction time, low energy consumption and "volume heating". Under the mode of microwave heating, the use of cigarette core material with high dielectric loss or magnetic loss is the key to solving the problem, that is, it is a big difficulty to introduce functional components to make the cigarette core material of heated cigarettes quickly absorb electromagnetic waves and convert them into heat energy. In order to solve at least one of the above problems, the present application is proposed. SUMMARY

[0005] The present application aims to provide a temperature response controllable cigarette core material for heated cigarettes and a preparation method thereof. Cellulose nanofiber is used as a carrier, wave-absorbing particles are grafted onto the cellulose nanofiber skeleton through graft modification, the microwave perception ability of the material is controlled by controlling the grafting amount, the temperature rise rate of the material under microwave heating is controlled, the purpose of rapid heating is achieved, and in addition, the grafted nanofiber is uniformly distributed in the cigarette core material, so that the material is heated uniformly and is beneficial to stable release of smoke.

[0006] The purpose of the present application can be achieved by the following technical solutions: A temperature-responsive controllable heating cigarette core material is composed of grafted modified cellulose nanofiber, flavor-releasing substance and atomizing agent, and the mass ratio of the grafted modified cellulose nanofiber, the atomizing agent and the flavor-releasing substance is (0.5-15):(7-25):(60-85).

[0007] Further, the grafted modified cellulose nanofiber refers to grafting a substance with microwave sensing ability onto the cellulose nanofiber, and the grafting rate of the substance with microwave sensing ability is 5-200%.

[0008] Further, the cellulose nanofiber is one or a mixture of two or more of cellulose nanocrystal CNC, cellulose nanofibril CNF and microcrystalline cellulose MCC, and the cellulose nanofiber has a diameter in the range of 5-100 nm and a length in the range of 20 nm-100 μm.

[0009] Further, the grafted substance with strong microwave sensing ability is one or several of titanium carbide (TiC), titanium dioxide (TiO2), silicon carbide (SiC), ferrite (such as Fe3O4 and CoFe2O4), graphene, graphene oxide (GO), carbon nanotube (CNTs) and carbon black.

[0010] When the substance with microwave sensing ability is titanium dioxide and / or ferrite, the substance is activated by using a modified ligand to improve its dispersibility, and then grafted. The modified ligand can be one or a mixture of two or more of dopamine, oleic acid, citric acid, chitosan and dodecyl phosphonic acid groups. Generally, the modified ligand accounts for 5-30 wt% of the titanium dioxide and / or ferrite.

[0011] The flavor-releasing layer includes but is not limited to tobacco substance, tobacco coating liquid and / or herbal plant extract.

[0012] The tobacco substance is tobacco powder, and the particle size of the tobacco powder is in the range of 20-400 mesh.

[0013] The herbal plant extract includes but is not limited to one or more of tobacco, cocoa, chicory and other herbal plant extracts.

[0014] The atomizing agent is one or more of propylene glycol, butylene glycol, glycerol, glycerol ester and derivatives thereof.

[0015] There are three methods for preparing the above-mentioned temperature-responsive controllable heating cigarette core material. In one method, the grafted cellulose nanofiber is used as an internal core material, and the atomizing agent and the flavor-releasing substance are sequentially wrapped outside the skeleton material to prepare a layered and wrapped granular core material. Figure 3); secondly, the grafted modified cellulose nanofiber is blended with the fragrance-releasing substance and the atomizing agent to prepare uniform particles, so that the grafted modified cellulose nanofiber is distributed at various positions of the particles; in addition, the fragrance-releasing substance is blended with the atomizing agent inside, and the grafted modified cellulose nanofiber is wrapped outside the blend Figure 2 ].

[0016] The particle size range of the above tobacco core material is 0.5 mm-10 mm.

[0017] Compared with the prior art, the present application has the following beneficial effects: 1. The tobacco core material for heating cigarettes according to the present application can take advantage of rapid heating, good uniformity, short reaction time and other advantages of microwave heating, and weaken the problem of less outlet smoke caused by initial heating hysteresis.

[0018] 2. The cellulose nanofiber is used as a carrier, a substance with microwave sensing ability is grafted onto the cellulose nanofiber skeleton through grafting modification, the microwave sensing ability of the material can be controlled by controlling the grafting amount, and then the heating rate of the material under microwave heating can be controlled, so as to achieve the purpose of temperature adjustment, controllability and rapid response.

[0019] 3. The grafted nanofiber is uniformly distributed in the tobacco core material, and the substance with microwave sensing ability carried by the grafting modification can convert microwave into heat energy as an internal heat source during the microwave heating process, and is uniformly distributed in the tobacco core material, so that the material is heated uniformly, which is beneficial to stable release of smoke.

[0020] 4. By adjusting the proportion of the grafted modified cellulose nanofiber in the tobacco core material, firstly, the heating rate of the tobacco core material under fixed microwave power can be adjusted, and secondly, particles with different grafting amounts can be mixed and packed, under fixed microwave power, the particles with high grafting amount reach the set temperature first to release smoke aerosol, and the particles with low grafting amount reach the set temperature later to release smoke aerosol, by adjusting the proportion of different grafting amounts, the effect of stable release of smoke aerosol per puff is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Schematic diagram of grafting modification of cellulose nanofiber skeleton material; Figure 2 Schematic diagram of tobacco core material in which fragrance-releasing substance is blended with atomizing agent inside, and grafted modified cellulose nanofiber is wrapped outside the blend; Figure 3 Schematic diagram of tobacco core material in which grafted skeleton material of cellulose nanofiber is embedded inside; Figure 4 Glycerin residue of tobacco core particles prepared in Example 1 and ordinary tobacco core particles; Figure 5 Results of the per- cigarette smoke delivery for the two cigarette cores in Example 2. DETAILED DESCRIPTION

[0022] The application will be further described in connection with specific embodiments which should not be interpreted as in any way limiting the scope of the application. After reading the application, various modifications to the application in addition to those described will become apparent to those of ordinary skill in the art from the disclosure.

[0023] Example 1 A preparation method of a temperature-responsive controllable heating cigarette core material, using Fe3O4 nanoparticles as a microwave sensing substance, is as follows: Step one, dopamine (DA) ligand is used to coat Fe3O4 nanoparticles, and then the hydroxyl group at the end of the Fe3O4 ligand is connected to the hydroxyl group on the cellulose nanofiber through acetalization reaction to obtain Fe3O4 grafted modified cellulose nanofiber.

[0024] The specific experimental process is as follows: (1) 1 g Fe3O4 nanoparticles are introduced into 200 mL deionized water while stirring, and then the solution is ultrasonically treated for 30 min to obtain a uniform solution.

[0025] (2) 10 mM tris-hydroxymethyl aminomethane buffer solution (pH 8.5) is added to the solution in step (1), and the pH is monitored in real time to stabilize the solution pH at 8.0-8.5. According to the mass ratio of DA to Fe3O4 of 1:10, 2 mg / mL DA aqueous solution is slowly added, and stirred in the dark for 12 h to polymerize into a polydopamine coated Fe3O4-PDA layer. Then, the precipitate is separated by a magnet and washed with deionized water and ethanol alternately for 3-4 times to remove unabsorbed dopamine, and Fe3O4-PDA nanoparticles are obtained and dispersed in 50 mL water for use.

[0026] (3) The mass ratio of Fe3O4-PDA to cellulose nanofiber is controlled to be 1:5, and the volume of 1 wt% cellulose nanofiber (average diameter 50 nm, average length 300 nm) aqueous solution required is calculated. 0.1 g of p-toluenesulfonic acid is added to the weighed 1 wt% cellulose nanofiber aqueous solution, and the pH is adjusted to 4.5 with 0.5 mol / L hydrochloric acid, and the mixture is stirred at 50°C for 30 min to obtain activated cellulose nanofiber.

[0027] (4) The Fe3O4-PDA solution from step (2) was slowly added dropwise into the activated cellulose nanofibers from step (3). Nitrogen gas was introduced to remove oxygen during the experiment, the temperature was raised to 60 °C, and the mixture was magnetically stirred for 6 h to carry out the acetalization reaction.

[0028] After the reaction was complete, the mixture was cooled to room temperature, and the pH was adjusted to neutral with a 0.1 mol / L sodium hydroxide solution. The mixture was then centrifuged (8000 rpm, 10 min). The precipitate was washed 2-3 times with deionized water to remove the catalyst p-benzenesulfonic acid and unreacted particles, finally yielding the Fe3O4-PDA-cellulose composite material. A schematic diagram of the structure is shown below. Figure 1 As shown, from Figure 1 It can be seen that Fe3O4 is grafted into the fiber network structure.

[0029] Step two: Prepare materials according to the mass ratio of grafted modified cellulose nanofibers to atomizing agent and aroma-releasing substance of 10:20:70. Add 100 g of aroma-releasing substance (200 mesh tobacco powder, provided by Henan China Tobacco Xuchang Thin Sheet Factory) and 28.5 g of atomizing agent (glycerin) to 20 g of deionized water and stir to mix evenly. Use a twin-screw extruder to extrude the mixture into particles with a diameter of 4 mm.

[0030] Step 3: The particles from Step 2 are dried in a vertical fluidized bed. The Fe3O4-PDA-cellulose composite material prepared in Step 1 is dispersed in deionized water to prepare a homogeneous solution with a concentration of 30wt%. Then, the Fe3O4-PDA-cellulose composite material is sprayed onto the periphery of the particles from Step 2 using the liquid spraying device built into the fluidized bed. After drying with forced air, granular tobacco core material with a moisture content of 8% and a particle size of 4.2mm is obtained. The structural diagram is shown below. Figure 2 As shown, the grafted and modified fiber network structure is wrapped around the atomizer.

[0031] Preparation of ordinary tobacco core pellets: 28.5 g of atomizing agent (glycerin), 100 g of aroma-releasing substance (200 mesh tobacco powder, provided by Henan Zhongyan Xuchang Thin Sheet Factory), and 20 g of deionized water were mixed evenly. The mixture was then extruded using a twin-screw extruder to produce 4.2 mm tobacco core pellets.

[0032] The obtained Fe3O4 core particles and ordinary core particles are filled into a 7.2mm diameter cigarette tube made of the same cigarette paper, the same filter rod is installed, and the same tipping paper is attached to form a cigarette that is identical except for the core material.

[0033] Two types of cigarettes were microwave-heated (600W, set temperature 260℃). The initial temperature of both samples was 25℃, and the particle temperature changes are shown in Table 1. The smoke release was tested by loading Fe3O4 cigarette core particles and existing ordinary cigarette core particles into cigarettes. In the full-mouth smoke aerosol test, the proportion of glycerol in the smoke, filter rod retention, and cigarette core residue was as follows: Figure 4 As shown.

[0034] Table 1 As shown in Table 1, during microwave heating, the Fe3O4 core particles reached the set temperature of 260℃ within 2 seconds, while existing ordinary core particles required 30 seconds to reach 260℃. Figure 4 As shown, in the whole-mouth smoke aerosol test of ordinary cigarette core particles, the proportions of glycerol in the smoke, filter rod retention and cigarette core residue were 9%, 70% and 21%, respectively. In the cigarette filled with Fe3O4 cigarette core particles in Example 1, the proportions of glycerol in the smoke, filter rod retention and cigarette core residue were 20%, 75% and 5%, respectively.

[0035] Example 2 Samples A and B are 3 mm diameter particles prepared from GO-grafted modified cellulose nanofibers with an atomizing agent and aroma-releasing substance in a ratio of 5:20:75. The specific preparation process is the same as in Example 1, except for the grafting modification step. Specifically, GO and CNF are mixed uniformly using ultrasound (500 W, 1 h) to ensure complete cross-linking of the carboxyl groups of GO and the hydroxyl groups of CNF. The mixture is then transferred to a hydrothermal reactor and reacted at 160 °C for 10 h to reduce GO to reduced graphene oxide (rGO). Simultaneously, the residual carboxyl / hydroxyl groups on the rGO surface undergo dehydration condensation with the hydroxyl groups of CNF under high temperature and pressure to form stable COC bonds, thus achieving grafting. Other preparation steps are the same as in Example 1.

[0036] Sample A used grafted modified cellulose nanofibers with a grafting rate of 70%. Sample B used GO grafted modified cellulose nanofibers with grafting rates of 70%, 60%, and 50%, with the three grafting rates used in a 50:30:20 ratio when filling the cigarettes. Both were filled into cigarette tubes with the same diameter (7.2 mm) made from identical cigarette paper, fitted with the same filter rods and the same tipping paper, forming cigarettes identical except for the core material. The puff-by-puff smoke release of samples A and B was tested using a 500W microwave at 300℃. The results are as follows: Figure 5 As shown.

[0037] The analysis compared the individual smoke emissions from 12 puffs of samples A and B. The mean, standard deviation, and coefficient of variation were calculated for evaluation. The average smoke emission of sample A was 1.80 mg, with a standard deviation of approximately 0.17 mg and a coefficient of variation of approximately 9.44%. The average smoke emission of sample B was 1.89 mg, with a standard deviation of approximately 0.04 mg and a coefficient of variation of approximately 2.12%. The comparison shows that sample B's overall values ​​are slightly higher than A's, and its dispersion is much smaller, with a coefficient of variation only about one-quarter that of A. This indicates that sample B's data stability is significantly better than sample A's, with its 12 puff smoke emissions being more concentrated and less volatile.

[0038] Although preferred embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

Claims

1. A temperature-responsive heated cigarette core material, characterized in that, It is composed of grafted modified cellulose nanofibers, aroma-releasing substances and atomizing agents, wherein the mass ratio of grafted modified cellulose nanofibers to atomizing agents and aroma-releasing substances is (0.5~15):(7~25):(60~85).

2. The temperature-responsive adjustable heated cigarette core material according to claim 1, characterized in that, The grafted modified cellulose nanofibers refer to cellulose nanofibers onto which a substance with microwave sensing capability is grafted, with the grafting rate of the microwave sensing capability being 5-200%.

3. The temperature-responsive adjustable heated cigarette core material according to claim 2, characterized in that, The cellulose nanofibers are one or a mixture of two or more of cellulose nanocrystals (CNC), cellulose nanofibers (CNF), and microcrystalline cellulose (MCC) in any proportion. The diameter of the cellulose nanofibers ranges from 5 to 100 nm, and the length ranges from 20 nm to 100 μm.

4. The temperature-responsive adjustable heated cigarette core material according to claim 2, characterized in that, Materials with microwave sensing capabilities include one or more of titanium carbide, titanium dioxide, silicon carbide, ferrite, graphene, graphene oxide, carbon nanotubes (CNTs), and carbon black.

5. The temperature-responsive adjustable heated cigarette core material according to claim 4, characterized in that, When the material with microwave sensing capability is titanium dioxide and / or ferrite, it is necessary to activate it with modified ligands to improve its dispersibility before grafting.

6. The temperature-responsive adjustable heated cigarette core material according to claim 1, characterized in that, The aroma-releasing substance is one or more of the following: tobacco substances, tobacco coating liquid, and herbal plant extracts, in any proportion: a mixture of two or more of these.

7. The temperature-responsive adjustable heated cigarette core material according to claim 5, characterized in that, The tobacco substance is tobacco powder, and the particle size of the tobacco powder ranges from 20 mesh to 400 mesh.

8. The temperature-responsive adjustable heated cigarette core material according to claim 1, characterized in that, The atomizing agent is one or more of propylene glycol, butylene glycol, glycerol, glycerides and their derivatives.

9. A method for preparing the temperature-responsive adjustable heated cigarette core material according to any one of claims 1 to 7, characterized in that, By using grafted modified cellulose nanofibers as the inner core material, atomizing agents and aroma-releasing substances are sequentially wrapped around the grafted modified cellulose nanofibers to prepare a layered, granular cigarette core material. Alternatively, grafted modified cellulose nanofibers can be mixed with aroma-releasing substances and atomizing agents to prepare uniform particles, so that the grafted modified cellulose nanofibers are distributed in various positions of the particles. Alternatively, aroma-releasing substances can be blended with atomizing agents inside, and grafted modified cellulose nanofibers can be wrapped around the blend to form granular cigarette core materials.

10. The method for preparing the temperature-responsive adjustable heated cigarette core material according to claim 9, characterized in that, The particle size range of the core material is 0.5 mm to 10 mm.

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