A low boiling point smoke agent based on azeotropic solvent system and preparation method thereof

Abstract

The present invention relates to a heating cigarette technology, and aims to provide a low-boiling point smoke agent based on an azeotropic solvent system and a preparation method thereof. The smoke agent is a mixture of glycerol and an azeotropic solvent, and its boiling point ranges from 250.3 to 272.5°C; in the smoke agent, the mass content of glycerol is 60% to 90%, and the mass content of the azeotropic solvent is 10% to 40%; the azeotropic solvent is at least one of propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate. The product of the present invention has an azeotropic solvent system, which can reduce the boiling point and smoke temperature of the smoke agent, reduce the formation time of the aerosol, and improve its anti-hygroscopicity. The added food-grade azeotropic solvent is often used as a flavor and fragrance, has a sweet smell, and can also enhance the consumer's smoking experience. The preparation method of the present invention is simple, the conditions are mild, only solvent blending is required, the production cost is low, the pollution is small, and large-scale industrial production can be achieved.

Description

Technical Field

[0001] The invention relates to a heating cigarette technology, and in particular to a low-boiling-point smoking agent based on an azeotropic solvent system and a preparation method thereof. Background Art

[0002] In recent years, with consumers' increasing concern about their own health issues and the increase in global tobacco control efforts, new tobacco represented by heated cigarettes has developed rapidly and is favored by consumers. Heated cigarettes are the focus of future research and development in the global tobacco industry. Heated cigarettes heat the tobacco core material through a heating source, heating its atomized matrix segment to 300-400°C, so that the tobacco produces smoke similar to traditional cigarettes without burning, in order to meet consumers' smoking requirements. Compared with traditional cigarettes, the harmful chemicals and biological toxicity in the smoke of heated cigarettes are greatly reduced, while restoring the taste of cigarettes, reducing harm to the human body and the environment.

[0003] However, there is still a certain gap between the smoking experience of heated cigarettes and traditional cigarettes. Under low temperature conditions, the tobacco smoke output is low and the tobacco aroma is not fully released. In order for heated cigarettes to produce enough smoke when smoking, a certain amount of smoke-generating agent is usually required. At present, the smoke-generating agent used in heated cigarettes is mainly glycerol (glycerin), which re-condenses and absorbs moisture after heating and vaporization to form small droplets of smoke, thereby achieving the effect of smoking. Although glycerol has a good smoking effect, it has strong hygroscopicity. The inhalation of water will reduce the amount of smoke, which is not conducive to the storage of cigarettes. In addition, glycerol is easy to seep out after absorbing water, contaminating the cigarette paper and causing the cigarette paper to show yellow spots, which seriously affects the quality stability of heated cigarettes and the smoking experience of consumers.

[0004] At present, there are also some research reports on methods to solve the problem of smoke agents in heated cigarettes being extremely easy to absorb moisture. Chinese patent (CN113729269A) discloses a smoke agent for anti-hygroscopic cigarettes and its preparation method and application, using an inorganic hydrophobic microcapsule shell to wrap the smoke agent; Chinese patent (CN113615861A) discloses a heat-not-burn plant particle with a moisture-proof layer and its preparation method, and the plant particles loaded with flavor substances and smoke agents are coated with a moisture-proof layer to improve the hygroscopicity of the plant particles; Chinese patent (CN113287781A) uses hydrophobic polymers such as polylactic acid and polymerized sugars to encapsulate porous materials containing smoke agents to solve the problem of water absorption of smoke agents during storage. The above methods all use hydrophobic materials to coat the smoke agent, reduce the direct contact of the smoke agent with the solvent and air, and thus improve the anti-hygroscopicity. However, the smoke temperature of the modified smoke agent is relatively high, the preparation process is cumbersome, and the coating efficiency of the smoke agent is required to be high. Therefore, it is very important to develop new smoking agents for heated cigarettes, reduce the smoking temperature, ensure high smoke volume, and improve anti-hygroscopicity. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a low-boiling-point smoke agent based on an azeotropic solvent system and a preparation method thereof, so as to reduce the boiling point of the smoke agent and improve its anti-hygroscopicity.

[0006] To solve the above technical problems, the solution of the present invention is:

[0007] Provided is a low-boiling-point smoke agent based on an azeotropic solvent system. The smoke agent is prepared by mixing glycerol and an azeotropic solvent, and has a boiling point range of 250.3-272.5°C. In the smoke agent, the mass content of glycerol is 60%-90%, and the mass content of the azeotropic solvent is 10%-40%. The azeotropic solvent is at least one of propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate.

[0008] As a preferred embodiment, the propyl benzoate, methyl salicylate, ethyl salicylate or isopentyl salicylate is a food grade product.

[0009] The present invention further provides a method for preparing the aforementioned low-boiling-point smoke agent, characterized in that it comprises:

[0010] (1) respectively measuring glycerol and azeotropic solvent in a mass ratio of 60-90:10-40;

[0011] (2) At a temperature of 35 to 70° C. and under stirring conditions, glycerol and an azeotropic solvent are uniformly mixed to obtain a smoke generating agent.

[0012] As a preferred solution, during mixing, the temperature is controlled at 35-70°C.

[0013] As a preferred solution, stirring is performed by magnetic force, and the rotation speed during stirring is 50 to 200 rpm.

[0014] The present invention also provides an application method of the aforementioned low-boiling point smoke agent, which comprises spraying the smoke agent on dried tobacco leaf raw materials, controlling the mass content of the smoke agent to be 20% of the tobacco leaf raw materials; then drying the tobacco leaf raw materials at a low temperature of 40 to 70°C, and then preparing heated cigarettes through a cigarette making machine.

[0015] Description of the invention principle:

[0016] Propyl benzoate, methyl salicylate, ethyl salicylate and isoamyl salicylate are widely used in daily necessities, food and other fields and are important fine chemicals. Because they have strong fragrance, they are usually used as fixatives for daily fragrances and food flavors and spices. In the tobacco processing industry, methyl salicylate can also be used as one of the flavor ingredients (patent CN111269753A). However, there has never been a document record about using such products as smoke-generating agent components.

[0017] Propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate can form an azeotropic solvent system with glycerol in a specific ratio. For example, after propyl benzoate, methyl salicylate, ethyl salicylate and isoamyl salicylate form an azeotropic solvent system with glycerol, their azeotropic points are 228.8, 221.4, 230.5 and 267°C respectively (Anal. Chem. 1947, 19, 508-600). Compared with the boiling point of pure glycerol (290.0°C), the azeotropic solvent system has a lower boiling point.

[0018] Its principle can be explained as, food grade propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate and other solvents form azeotropic solvent system with glycerol, which has lower boiling point than pure glycerol. Therefore, adding such azeotropic solvents in glycerol can reduce the boiling point and smoke temperature of smoke-generating agent, and reduce the formation time of aerosol. In addition, the hydroxyl in glycerol easily forms intermolecular hydrogen bonds with water molecules in the air, and has extremely strong hygroscopicity. Compared with pure glycerol rich in hydroxyl, the hygroscopicity of propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate is relatively poor, so adding such azeotropic solvents in glycerol can also reduce the hygroscopicity of smoke-generating agent, and improve its anti-hygroscopic effect. In summary, adding such azeotropic solvents in glycerol can reduce the boiling point of smoke-generating agent while improving its anti-hygroscopicity.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. Add food-grade azeotropic solvent to glycerol. This solvent can form an azeotropic solvent system with glycerol, reduce the boiling point and smoke temperature of the smoke-generating agent, reduce the formation time of the aerosol, and improve its anti-hygroscopicity.

[0021] 2. The added food-grade azeotropic solvent is often used as a flavor and fragrance. It has a sweet smell and can also enhance consumers' smoking experience.

[0022] 3. The preparation method of the smoke agent is simple, the conditions are mild, only solvent blending is required, the production cost is low, the pollution is small, and large-scale industrial production can be realized. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with specific embodiments:

[0024] The raw materials used in the present invention are described as follows: food grade glycerol (purity ≥99%) was purchased from Xi'an Musen Bioengineering Co., Ltd.; food grade propyl benzoate (purity ≥99%), methyl salicylate (purity ≥99%), ethyl salicylate (purity ≥99%) and isopentyl salicylate (purity ≥99%) were purchased from Hubei Chengfeng Chemical Co., Ltd.; potassium carbonate (purity ≥99%) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0025] The following examples can enable professionals in this field to more fully understand the present invention, but do not limit the present invention in any way.

[0026] 1. The low boiling point smoke agent based on the azeotropic solvent system of the present invention comprises the following steps:

[0027] (1) Glycerol and an azeotropic solvent are measured at a mass ratio of 60-90:10-40 respectively; the azeotropic solvent can be selected from at least one of propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate, and is a food grade product.

[0028] (2) Evenly mix the glycerol and the azeotropic solvent under stirring conditions at a temperature of 35 to 70° C.; magnetic stirring may be used during the mixing, and the stirring speed is 50 to 200 rpm.

[0029] After being uniformly mixed, a smoke agent is obtained, and the boiling point of the smoke agent ranges from 250.3 to 272.5°C.

[0030] 2. In Examples 1 to 8, smoke generating agents based on solvent azeotropy were prepared respectively according to the above method. The preparation parameters and boiling points of the smoke generating agents in each example are shown in Table 1.

[0031] Table 1

[0032]

[0033] 3. The application method of the smoke generating agent in the present invention is exemplified as follows:

[0034] The smoke generating agent is sprayed on the dried tobacco raw material, and the mass content of the smoke generating agent is controlled to be 20% of the tobacco raw material; the tobacco raw material is then dried at a low temperature of 40-70°C, and then prepared into heated cigarettes through a cigarette making machine.

[0035] 4. Comparative proportion:

[0036] (1) Comparative Example 1: Pure propylene glycol was used as a smoke generating agent, and its boiling point was 292.0°C.

[0037] (2) Comparative Example 2: A smoke-generating agent was prepared according to the records in the public literature (J. Phys. Conf. Ser. 2021, 1802, 022025; Journal of Chinese Tobacco Science, 2021, 27, 1-9), wherein the mass proportion of glycerol was 90%, the mass proportion of propylene glycol was 10%, and the boiling point thereof was 260°C.

[0038] 5. Comparative test and analysis conclusions:

[0039] (1) Test subjects

[0040] Referring to the contents of the aforementioned application method, the smoke-generating agent products in Examples 1 to 8 and Comparative Examples 1 to 2 are respectively used in the cigarette manufacturing process; in the final obtained cigarette products containing smoke-generating agent, the mass content of smoke-generating agent in tobacco raw materials is 20%. Each cigarette product is defined in sequence as Examples 9 to 16 and Comparative Examples 3 to 4, which correspond to Examples 1 to 8 and Comparative Examples 1 to 2, respectively, and are jointly used as test objects.

[0041] (2) Comparative test

[0042] Hygroscopicity tests were conducted on the smoking agents and cigarette products described in Examples 1 to 16 and Comparative Examples 1 to 4:

[0043] (2.1) Place saturated potassium carbonate solution in a sealed container and control the relative humidity to 60±2%.

[0044] (2.2) Place 0.5 g of the sample in an open constant weight weighing bottle, and then place it in the sealed container containing the saturated potassium carbonate solution.

[0045] (2.3) After being placed at a constant temperature of 25±1℃ for 5 days, record the mass of the sample.

[0046] (2.4) Based on the mass change of the sample before and after placement, calculate the moisture absorption rate of the sample. Each sample is tested in parallel 3 times and the average value is taken.

[0047] The moisture absorption data of the samples in various embodiments and comparative examples are shown in Table 2.

[0048] Table 2

[0049] Smoke Generator Moisture absorption rate (%) Smoking materials containing smoke-generating agents Moisture absorption rate (%) Example 1 28.2 Example 9 12.8 Example 2 29.3 Example 10 13.3 Example 3 29.1 Embodiment 11 13.0 Example 4 28.8 Example 12 13.2 Example 5 33.5 Example 13 14.9 Example 6 37.1 Embodiment 14 16.1 Example 7 36.5 Embodiment 15 15.9 Example 8 34.2 Example 16 15.3 Comparative Example 1 42.1 Comparative Example 3 19.2 Comparative Example 2 40.3 Comparative Example 4 18.2

[0050] (3) Analysis and conclusion

[0051] From the data of Table 1, Table 2 and the comparative example, it can be seen that adding propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate to glycerol can reduce the boiling point of the smoke-generating agent, improve its anti-hygroscopicity, and further reduce the moisture absorption rate of the cigarette product. The application data of each embodiment of the present invention show that the anti-hygroscopicity effect is better than that of each comparative example.

[0052] From Examples 1, 5 and 6, it can be seen that as the content of the azeotropic solvent increases, the hygroscopicity of the smoke-generating agent decreases and the anti-hygroscopicity improves. From Examples 1 to 4 and 9 to 12, it can be seen that when methyl salicylate is added to glycerol, it has a lower boiling point than other azeotropic solvents, but the anti-hygroscopicity of the smoke-generating agent and the cigarette product is not much different.

[0053] Finally, it should be noted that the above examples are only specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and many variations are possible. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

Claims

1. A low boiling point smoke agent based on an azeotropic solvent system, characterized in that: The smoke generating agent is a mixture of glycerol and an azeotropic solvent, and has a boiling point range of 250.3-272.5°C; in the smoke generating agent, the mass content of glycerol is 60%-90%, and the mass content of the azeotropic solvent is 10%-40%; the azeotropic solvent is at least one of propyl benzoate, methyl salicylate, ethyl salicylate or isoamyl salicylate; The application method of the smoke agent is as follows: spraying the smoke agent on the dried tobacco raw material, controlling the mass content of the smoke agent to be 20% of the tobacco raw material; then drying the tobacco raw material at a low temperature of 40-70°C, and then preparing heated cigarettes through a cigarette making machine.

2. The low boiling point smoke generating agent based on the azeotropic solvent system according to claim 1, characterized in that: The propyl benzoate, methyl salicylate, ethyl salicylate or isopentyl salicylate is a food grade product.

3. The method for preparing the low-boiling-point smoke-generating agent based on the azeotropic solvent system according to claim 1, characterized in that: include: (1) respectively measuring glycerol and azeotropic solvent in a mass ratio of 60-90:10-40; (2) At a temperature of 35 to 70° C. and under stirring conditions, glycerol and an azeotropic solvent are uniformly mixed to obtain a smoke generating agent.

4. The method according to claim 3, characterized in that: During mixing, the temperature is controlled at 35-70°C.

5. The method according to claim 3, characterized in that: The stirring was performed by magnetic force, and the rotation speed during stirring was 50 to 200 rpm.

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