Water storage and release material for humidifying cigarette smoke and preparation method and application thereof

Abstract

The application provides a preparation method of a water storage and release material for humidifying cigarette smoke, and comprises the following steps: mixing and reacting a water retention material and a cross-linking agent to obtain a hydrogel; the water retention material comprises one or more of hyaluronic acid, collagen, sodium alginate, polyacrylamide, polyethylene glycol or sodium polyacrylate; a low-temperature phase change material is melted into a liquid state or dissolved by a solvent to obtain a coating liquid; the hydrogel is immersed in the coating liquid, coated or dropped by a coaxial double-core dripping head to form a coating on the surface of the hydrogel, and the coating is rapidly cooled to obtain the water storage and release material. After the low-temperature phase change material is added to a cigarette filter rod, when the cigarette burns to generate high temperature, the phase change material absorbs part of the heat and changes phase, thereby releasing the stored water, so that the water content in the smoke remains stable. The material has good water retention when stored, and only needs the heat provided by the smoke to automatically, continuously and stably release the water.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tobacco, in particular to a water storage and release material for humidifying cigarette smoke, and a preparation method and application thereof. BACKGROUND

[0002] Dry smoke during cigarette smoking can cause throat discomfort and poor smoke taste, especially in low-tar cigarette products. Cigarette humidification technology can increase the humidity of smoke, making it closer to the natural humidity of the human respiratory tract, thereby reducing irritation and dryness of the respiratory tract. The ability to store water and slowly release it during cigarette smoking is crucial. Similar principles have been applied in the field of filter flavoring, where natural loss of volatile flavor components occurs during storage and needs to be controlled.

[0003] An effective water storage and release material is one that can store water at room temperature and release water for smoke humidification during cigarette smoking. The material disclosed in CN113367372A is added to tobacco raw materials (tobacco shreds or tobacco sheets) of a heated cigarette, and its use scenario is a high-temperature environment above 200℃. It is not suitable for scenarios with relatively low temperatures because the water storage capacity is too strong and the temperature is not high enough, making it difficult to release water, for example, when added to a cigarette filter, the temperature during cigarette smoking is only a few dozen degrees Celsius, and the released water is limited, which cannot achieve the effect of humidifying smoke.

[0004] CN105595417A only achieves an increase in the maximum water absorption ratio (i.e., the saturated water absorption rate) by replacing the material, which is not necessarily effective for the application scenario of humidifying smoke during cigarette smoking. The water absorption ratio must be appropriate to achieve the effect. Because the water absorption ratio reflects the material's ability to absorb water, after the material is placed in excess water and fully swells, the excess water is filtered out with a 100-mesh standard sieve, and the percentage of the added mass compared to the original mass is expressed.

[0005] Using a material with a large water absorption ratio for water release in a cigarette filter can have the opposite effect on water release if the initial water absorption is small during the preparation process and the water absorption of the hydrogel does not exceed the critical water absorption rate. If the initial water absorption is large and close to or reaches the saturated water absorption, the latent heat of water will consume a lot of heat energy in the smoke, which is not conducive to the phase change of the coating to open the water release channel.

[0006] Therefore, it is necessary to provide a water storage and release material that can adjust the water absorption capacity while achieving water absorption, thereby controlling the humidity of cigarette smoke. SUMMARY

[0007] Therefore, the present application aims to provide a water storage and release material for humidifying cigarette smoke, which can adjust water absorption capacity, has good water retention performance and is temperature sensitive.

[0008] The present application provides a preparation method of a water storage and release material for humidifying cigarette smoke, comprising the following steps:

[0009] A) mixing and reacting a water retention material and a cross-linking agent to obtain a hydrogel; the water retention material comprises one or more of hyaluronic acid, collagen, sodium alginate, polyacrylamide, polyethylene glycol or sodium polyacrylate;

[0010] B) dissolving a low-temperature phase change material in a solvent or melting it into a liquid state to obtain a coating liquid;

[0011] C) forming a coating on the surface of the hydrogel by immersing the hydrogel in the coating liquid, coating or coaxial double-core dripping, to obtain the water storage and release material.

[0012] Preferably, the cross-linking agent is selected from one or more of ethylene glycol dimethacrylate, aluminum dihydroxy aminoacetate or tetramethyl ethylenediamine.

[0013] The mass ratio of the mixed water retention material and cross-linking agent should satisfy that the proportion of the cross-linking agent ligand to the water retention material is preferably in the range of 0.3wt% to 1wt%.

[0014] Preferably, the coating thickness is 30 to 400 microns.

[0015] Preferably, the reaction temperature in step A) is 60 to 80℃, and the reaction time is 120 to 130 minutes.

[0016] Preferably, the low-temperature phase change material in step B) is selected from low-melting-point paraffin or tetracosane.

[0017] The phase change temperature is 40 to 70℃.

[0018] Preferably, the solvent in step B) is petroleum ether, toluene, acetone or n-hexane.

[0019] The selected dissolving temperature is room temperature, and the dissolving time is 30 to 60 minutes.

[0020] The room temperature in the present application refers to 20 to 30℃.

[0021] Preferably, the soaking in step C) is specifically for 5 to 300 seconds.

[0022] The coating includes rapid cooling after the coating, and the cooling medium is specifically constant-temperature cold water with a temperature of 2 to 6℃.

[0023] Preferably, the coaxial double-core droplet of step C) is specifically dropped by:

[0024] The hydrogel is used as the core material, the coating liquid is used as the wall material, both are respectively introduced into the dropping device with the coaxial double-core droplet, the wall material and the core material are dropped from the outer core and the inner core of the coaxial double-core droplet respectively, the wall material and the core material are simultaneously dropped into the cooling liquid through the coaxial double-core droplet, and are wrapped and formed in the cooling liquid, thereby obtaining the coaxial double-core droplet.

[0025] The dropping requirements are specifically that the dropping environment temperature is 15-30 DEG C, and the dropping environment relative humidity is 40-70%.

[0026] The application provides a water storage and release material for humidifying cigarette smoke.

[0027] The application provides a cigarette, which is characterized by comprising the water storage and release material.

[0028] Compared with the prior art, the application provides a preparation method of a water storage and release material for humidifying cigarette smoke, which comprises the following steps: A) mixing and reacting a water retention material and a crosslinking agent to obtain a hydrogel; the water retention material comprises one or more of hyaluronic acid, collagen, sodium alginate, polyacrylamide, polyethylene glycol or sodium polyacrylate; B) melting a low-temperature phase change material into a liquid state or dissolving the low-temperature phase change material in a solvent to obtain a coating liquid; and C) forming a coating on the surface of the hydrogel by immersing the hydrogel in the coating liquid, coating the coating liquid or coaxial double-core droplet dropping, and rapidly cooling to obtain the water storage and release material. After the low-temperature phase change material is added to the cigarette filter rod, when the cigarette burns to generate high temperature, the low-temperature phase change material absorbs part of the heat and changes phase, thereby releasing the stored water, so that the water content in the smoke remains stable. The material has good water retention during storage, does not need to be pinched during water release, does not need to be added with water before smoking, and only needs to use the heat provided by the smoke to make the coating change phase, so that the water storage material automatically, continuously and stably releases water. DETAILED DESCRIPTION

[0029] The application provides a water storage and release material for humidifying cigarette smoke, a preparation method and application thereof, and those skilled in the art can refer to the content herein, and appropriately improve the process parameters to realize. It should be particularly pointed out that all similar replacements and changes are obvious to those skilled in the art, and they all belong to the protection scope of the application. The method and application of the application have been described through the preferred embodiments, and relevant personnel can obviously change or appropriately change and combine the method and application herein without departing from the content, spirit and scope of the application, to realize and apply the technology of the application.

[0030] In the present application, the term "and / or", which describes the association relationship of the associated objects, indicates that there can be three kinds of relationships, for example, A and / or B can represent: the case of A alone, the case of A and B existing at the same time, and the case of B alone. Wherein A, B can be singular or plural.

[0031] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or the like means any combination of these items, including any combination of single item or multiple items.

[0032] It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and part or all of the steps can be executed in parallel or in sequence, and the execution order of the processes should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0033] The present application provides a preparation method of water storage and release material for humidifying the effect of cigarette smoke, comprising the following steps:

[0034] A) mixing and reacting water retention material and crosslinking agent to obtain hydrogel; the water retention material includes one or more of hyaluronic acid, collagen, sodium alginate, polyacrylamide, polyethylene glycol or sodium polyacrylate;

[0035] B) dissolving the low-temperature phase change material by melting into a liquid or a solvent to obtain a coating liquid;

[0036] C) forming a coating on the surface of the hydrogel by immersing the hydrogel in the coating liquid, coating or coaxial double-core droplet dripping, and rapidly cooling after cooling to obtain.

[0037] The preparation method of water storage and release material for humidifying the effect of cigarette smoke provided by the present application first mixes and reacts water retention material and crosslinking agent to obtain hydrogel.

[0038] The water retention material described in the present application can be a natural water retention material or a synthetic water retention material.

[0039] Among them, the natural water retention material includes hyaluronic acid, collagen or sodium alginate;

[0040] The synthetic water retention material includes polyacrylamide, polyethylene glycol or sodium polyacrylate.

[0041] The above-mentioned water retention material forms a saturated hydrogel after fully absorbing pure water or a functional aqueous solution (such as an organic acid aqueous solution).

[0042] The crosslinking agent ligand described in the present application is selected from one or more of ethylene glycol dimethyl acrylate, aluminum dihydroxy aminoacetate or tetramethyl ethylenediamine.

[0043] According to the application, the mass ratio of the water-retaining material and the cross-linking agent should satisfy that the ratio of the cross-linking agent ligand to the water-retaining material is preferably in the range of 0.3wt% to 1wt%.

[0044] In some embodiments, the cross-linking agent is added to the base material, and the cross-linking reaction is carried out after sufficient mixing.

[0045] The cross-linking agent plays the role of nucleation point and skeleton, and enhances the network structure.

[0046] In some embodiments, the preparation process of the cross-linking agent is as follows: the cross-linking agent is composed of a basic complex solvent and a ligand.

[0047] Specifically, 90% complex solvent (glycerol: water = 1:9) and 0.05% to 0.1% NaOH are used, and magnetic stirring is carried out in a water bath at 55℃ for 15 minutes. The pH value is tested by using a precision pH test paper (the test range is 8.2-10.0), and the pH value is between 9.0 and 9.5. Then the ligand is added, and the temperature is raised to 60℃ for 40 minutes to obtain the cross-linking agent.

[0048] The operation method of the cross-linking reaction is as follows: the cross-linking agent is added to a stirring mixer, and the liquid surface is formed into a vortex with a depth of 2-3 cm by adjusting the stirring speed. The cross-linking agent and the base material are added together, and the cross-linking reaction is carried out after sufficient mixing. The reaction temperature is 60-80℃, and the reaction time is 120-130 minutes.

[0049] The ratio of the ligand in the cross-linking agent to the water-retaining material is adjusted to control the cross-linking degree, so as to obtain a hydrogel with desired water absorption performance. The ratio of the cross-linking agent ligand to the water-retaining material is preferably in the range of 0.3% to 1%.

[0050] The coating liquid is prepared. The low-temperature phase change material is melted into a liquid state or dissolved by using a solvent to obtain the coating liquid.

[0051] The low-temperature phase change material is selected from low-melting-point paraffin or tetracosane, and the phase change temperature is 40-70℃.

[0052] Specifically, the solvent is petroleum ether, toluene, acetone or n-hexane.

[0053] The low-temperature phase change material is heated and melted into a liquid state as the coating liquid. The heating mode is water bath heating, the water bath pot is set to a temperature of 45℃ to 95℃, and the heating time is not shorter than the time required for the low-temperature phase change material to be completely melted into a liquid state, which is 20 minutes to 100 minutes. The melted liquid is used as the coating liquid.

[0054] The hydrogel is coated on the surface by immersing in the coating liquid, coating or coaxial double core dripping, and then cooled rapidly to obtain the product.

[0055] The coating is a key structure to keep the water and prevent the hydrogel from losing water during transportation, storage and other non-use processes. The thickness of the coating is extremely important for the realization of the present application. The water storage and release material of the present application is added to the cigarette filter, which can be added to the filament rod for molding or added to the composite cavity. According to different needs, the size, amount and adding position of the material in the filter rod will change accordingly, and the efficiency of receiving heat smoke energy during smoking will be different. In order to release water smoothly, the thickness of the coating is very important. The smoke energy is certain, and a part of the coating will not change phase if the coating is too thick, and the water cannot be released. A little thinner coating is beneficial to water release, but the water storage performance may not meet the requirements, such as the increase of the ambient temperature during storage and transportation, which will damage the too thin coating. The thickness of the coating in the product should be controlled in a certain range, which needs to be determined by a large number of experiments according to the use scene. The control method of the coating thickness will be described in detail below. For different forms of hydrogel, different properties of coating liquid and different coating tools, specific control methods are given respectively.

[0056] The coating thickness of the present application is 30-400 μm.

[0057] The method of coating the near-solid hydrogel of the present application can use immersion method or coating method.

[0058] In some embodiments, the hydrogel is coated on the surface by immersing in the coating liquid:

[0059] The water-absorbing and swelling water storage material is immersed in the melted low-temperature phase change material to ensure complete immersion and maintain a certain soaking time of 10-300 s. The soaking temperature is 45-95℃.

[0060] Before the material is taken out, the required coating thickness can be achieved by controlling the temperature of the soaking liquid. For a relatively thin coating thickness, such as 100 microns, the temperature of the paraffin liquid is increased to a higher range (such as 95℃), and the soaking time is appropriately shortened. For a relatively thick coating thickness, such as 500 microns, the temperature of the paraffin liquid is maintained at a lower range (such as 45℃), and the soaking time is appropriately prolonged. For other thicknesses, the temperature of the paraffin liquid and the soaking time can be adjusted as needed.

[0061] In some embodiments, the coating thickness can be controlled by adjusting the saturation degree of the low-temperature phase change material in the soaking liquid.

[0062] For example, in some embodiments, to obtain a thinner coating, the soaking solution can be prepared as a 30% saturated solution, an excess of solute (low-temperature phase change material) is mixed with the solvent to form a saturated solution (which can be regarded as a 100% saturated solution), and then 3 parts of the saturated solution is mixed with 7 parts of the solvent to obtain a 30% saturated solution. The saturation degree of the coating solution ranges from 30% to 100%.

[0063] In some embodiments, the hydrogel is coated by coating the coating solution to form a coating on the surface of the hydrogel.

[0064] The present application includes rapid cooling after coating, and the cooling medium is specifically constant-temperature cold water with a temperature of 2-6°C.

[0065] Rapid cooling after coating avoids the formation of a thick solidification point, which affects the uniformity of the coating. The hydrogel coated with the low-temperature phase change material cannot be dried by heating, and should be allowed to dry naturally, which can be placed in a place with high air flow to shorten the drying time. During the drying process, the solvent gradually volatilizes, and the low-temperature phase change material forms a dense coating.

[0066] The dip coating method and the spray coating method are not suitable for near-liquid hydrogel, and the coaxial dripping method can be used.

[0067] The coaxial double-core dripping head dripping according to the present application specifically refers to:

[0068] The hydrogel is used as the core material, and the coating solution is used as the wall material. The two are respectively introduced into the dripping device with the coaxial double-core dripping head. The wall material and the core material are dripped from the outer core and the inner core of the coaxial double-core dripping head, respectively. The wall material and the core material are simultaneously dripped into the cooling liquid through the coaxial double-core dripping head, and are wrapped and formed in the cooling liquid. The wet pellets after pure water washing are dried in the air strong convection rotary drum for 2-4 hours. It is not difficult to change the coating thickness, and only the feeding speed of the wall material pipeline needs to be adjusted, that is, the speed of the material pump is set in combination with the viscosity of the material liquid.

[0069] The requirements for the dripping according to the present application specifically refer to that the dripping environment temperature is 15-30°C, and the dripping environment relative humidity is 40-70%.

[0070] The present application provides a water storage and release material for humidifying cigarette smoke, which is prepared by the preparation method described in the above technical solution.

[0071] The preparation method has been clearly described above, and will not be repeated here.

[0072] The present application uses water-retaining materials with different crosslinking degrees to realize the water absorption function while adjusting the water absorption capacity, so as to control the humidity of cigarette smoke.

[0073] Due to the existence of crosslinking network, the water-retaining material can swell and retain a large amount of water, and the water absorption amount is closely related to the crosslinking degree. The higher the crosslinking degree, the lower the water absorption amount.

[0074] The crosslinking degree of the water-retaining material of the application refers to the number and strength of crosslinking points in the gel. The influence of the crosslinking degree of the water-retaining material on its water absorption performance is not linear. At a certain crosslinking degree, the water absorption capacity of the water-retaining material reaches a maximum; when the crosslinking degree continues to increase, the water absorption capacity begins to decrease. The more the number of crosslinking points and the greater the strength, the more compact and dense the structure of the gel, and the internal gap of the gel is too small for water molecules to smoothly pass through the gel structure and become difficult to enter. Therefore, the water-retaining material with high crosslinking degree has relatively low water absorption capacity, i.e. low water absorption rate. The inventors have found through experiments that the water-retaining material with low water absorption rate has low critical moisture content. The critical moisture content here refers to the division of water absorption or water release of the material during the smoking process. When the water content of the water-retaining material is lower than the critical moisture content, it will absorb the water in the smoke, and vice versa. If the water-retaining material is to play a humidifying role on the smoke, the water content thereof should be higher than the critical moisture content.

[0075] The application provides a cigarette, characterized in that it comprises the water storage and release material according to the above technical solution.

[0076] The application uses a proper amount of water-retaining materials with different crosslinking degrees to make hydrogels and coat them to become water storage and release materials, and then adds the materials to the cigarette filter rod to make a cigarette with a filter tip having water storage and release function.

[0077] The water storage and release material of the application is added to the cigarette filter tip, and the adding method can be added to the tows rod for molding, or added to the composite cavity. According to different requirements, the size, adding amount and adding position of the material in the filter rod will change accordingly, and the efficiency of receiving heat smoke energy during smoking will be different.

[0078] The present inventors have proved by experiments that water-retaining materials with different crosslinking degrees have different effects on the humidity of cigarette smoke, and can be adjusted for different cigarette products, such as cigarettes with different circumferences and cigarettes with different mouth ventilation degrees.a. For cigarette products with small circumferences, the heat energy carried by the smoke is small, and in order to release water smoothly, a water-retaining material with high crosslinking degree can be used, which has a low critical water content. Although the water absorption rate of the water-retaining material with high crosslinking degree is small, the smoke volume of the cigarette with small circumference is smaller, and the moisture needed for humidification is also small, so effective humidification can still be achieved.b. For cigarette products with high filter ventilation degree, more air is sucked in from the hole punched in the filter during smoking, which reduces the heat energy of the smoke. In order to release water smoothly, a water-retaining material with high crosslinking degree can also be used. The dry feeling of high-ventilation cigarette products is due to the decrease in the total amount of acidic components in the smoke, the increase in pH, and the increase in irritation. A certain amount of organic acid can be added during the preparation of the hydrogel to adjust the acid-base balance of the smoke, such as lactic acid, malic acid, tartaric acid, citric acid, etc.

[0079] The present application does not need to drip water before smoking; no need for skin and core; the moisture can be locked up more than 80% at room temperature for one year. The material of the present application has good water retention during storage, and does not need to be pinched during water release. Only the heat provided by the smoke is used to cause the phase change of the coating, so that the water storage material automatically, continuously and stably releases moisture. When the cigarette is smoked, the low-temperature phase change material encounters high-temperature smoke, which causes a phase change, thereby releasing the energy stored therein. The use of low-temperature phase change materials in cigarette filters can achieve the effect of slow-release of water. Specifically, after adding low-temperature phase change materials to the cigarette filter, when the cigarette burns and generates high temperature, the low-temperature phase change materials will absorb part of the heat and undergo a phase change, thereby releasing the stored water, so that the water content in the smoke remains stable.

[0080] In order to further illustrate the present application, the water storage and water release material for the effect of cigarette smoke humidification provided by the present application, its preparation method and application are described in detail below in combination with examples.

[0081] Comparative Example 1

[0082] The control cigarette is a cigarette without adding water storage and water release material in the filter, and is the same as all comparative examples and all examples of the present application in other aspects.

[0083] Example 1

[0084] The water storage and water release material is prepared according to the following four steps a-d:

[0085] a. Preparation of crosslinking agent

[0086] A 500 g alkaline complex solvent is prepared, which is glycerol: water = 1 : 9 with 0.8% NaOH added, and is magnetically stirred in a water bath at 55°C for 15 minutes. 0.3 g of crosslinking agent ligand ethylene glycol dimethacrylate is added, and the temperature is raised to 60°C for 40 minutes before being transferred to a stirring mixer, and the liquid surface is made to form a vortex 2-3 cm deep by adjusting the stirring speed.

[0087] b. Crosslinking reaction

[0088] 30 g of water-retaining material hyaluronic acid is added to the crosslinking agent vortex in the stirring mixer for crosslinking reaction, and the amount added satisfies the weight ratio of crosslinking agent ligand ethylene glycol dimethacrylate to water-retaining material hyaluronic acid of 1%. The reaction temperature is kept at 70°C, and the reaction time is 120 min.

[0089] c. Preparation of coating liquid

[0090] 180 g of low-temperature phase change material low-melting paraffin is added to 300 g of solvent petroleum ether to dissolve and obtain a supersaturated solution. After filtering out the solid residue, 300 g of solvent petroleum ether is added to the saturated solution and mixed to obtain a 50% saturated solution.

[0091] d. Coating and forming

[0092] The hydrogel is immersed in the coating liquid for 180 s and then quickly transferred to a constant-temperature cold water bath at 2-6°C for cooling and cooling for 200-600 s to form a uniform coating layer. Then, air drying is performed at room temperature for 48 h until the solvent is completely volatilized.

[0093] Finally, the obtained water storage and release material is added to the tobacco filter tow, and the prepared cigarette is detected for the water content in the smoke.

[0094] Example 2

[0095] The water storage and release material is prepared according to the following four steps a-d:

[0096] a. Preparation of crosslinking agent

[0097] A 500 g alkaline complex solvent is prepared, which is glycerol: water = 1 : 9 with 0.8% NaOH added, and is magnetically stirred in a water bath at 55°C for 15 minutes. 0.3 g of crosslinking agent ligand ethylene glycol dimethacrylate is added, and the temperature is raised to 60°C for 40 minutes before being transferred to a stirring mixer, and the liquid surface is made to form a vortex 2-3 cm deep by adjusting the stirring speed.

[0098] b. Crosslinking reaction

[0099] 30g of the water-retaining material hyaluronic acid was added to the vortex of the crosslinking agent in the stirring mixer for crosslinking reaction, and the amount of addition met the weight ratio of 1% of the crosslinking agent ligand ethylene glycol dimethacrylate to the water-retaining material hyaluronic acid. The reaction temperature was kept at 80°C, and the reaction time was 120 min.

[0100] c. Preparation of coating liquid

[0101] 500g of the low-temperature phase change material tetracosane was heated to complete melting in a water bath at 75°C for 60 min.

[0102] d. Coating and forming

[0103] After the hydrogel was immersed in the coating liquid for 10 s, it was quickly transferred to a constant-temperature cold water at 2-6°C for cooling and cooling for 200-600 s to form a uniform coating layer. Then, it was naturally dried at room temperature for 72 h.

[0104] Finally, the obtained water storage and release material was added to the tobacco filter tow, and the prepared cigarette was detected for the water content in the smoke.

[0105] Example 3

[0106] The water storage and release material was prepared according to the following four steps a-d:

[0107] a. Preparation of crosslinking agent

[0108] 500g of the alkaline composite solvent was prepared, which was glycerol: water = 1:9 and 0.8‰ NaOH was added, and was magnetically stirred in a water bath at 55°C for 15 min, 0.3g of the crosslinking agent ligand ethylene glycol dimethacrylate was added, and the temperature was raised to 60°C for 40 min, and then was transferred to the stirring mixer, and the liquid surface was formed into a vortex of 2-3 cm in depth by adjusting the stirring speed.

[0109] b. Crosslinking reaction

[0110] 30g of the water-retaining material hyaluronic acid was added to the vortex of the crosslinking agent in the stirring mixer for crosslinking reaction, and the amount of addition met the weight ratio of 1% of the crosslinking agent ligand ethylene glycol dimethacrylate to the water-retaining material hyaluronic acid. The reaction temperature was kept at 60°C, and the reaction time was 120 min.

[0111] c. Preparation of coating liquid

[0112] 500g of the low-temperature phase change material low-melting-point paraffin was heated to complete melting in a water bath at 70°C for 60 min.

[0113] d. Coating and forming

[0114] The hydrogel is immersed in the coating liquid for 300 seconds, then quickly transferred to a constant-temperature cold water at 2-6°C for cooling and cooling for 200-600 seconds to form a uniform coating layer. Then, the hydrogel is naturally dried at room temperature for 72 hours.

[0115] Finally, the obtained water storage and release material is added to the tobacco filter tow, and the prepared cigarette is detected for the water content in the smoke.

[0116] Example 4

[0117] The water storage and release material is prepared according to the following four steps a-d:

[0118] a. Preparation of crosslinking agent

[0119] 500g of alkaline composite solvent is prepared, which is glycerol: water = 1:9 and 0.8‰ NaOH is added, and magnetic stirring is carried out in a water bath at 55°C for 15 minutes, 0.3g of crosslinking agent ligand ethylene glycol dimethacrylate is added, and the temperature is raised to 60°C for 40 minutes, then transferred to a stirring mixer, and the liquid surface is formed into a vortex of 2-3 cm deep by adjusting the stirring speed.

[0120] b. Crosslinking reaction

[0121] 30g of water-retaining material sodium polyacrylate is added to the crosslinking agent vortex in the stirring mixer for crosslinking reaction, and the amount of addition meets the weight ratio of crosslinking agent ligand ethylene glycol dimethacrylate to water-retaining material hyaluronic acid of 1%. The reaction temperature is kept at 70°C, and the reaction time is 120 min.

[0122] c. Preparation of coating liquid

[0123] 180g of low-temperature phase change material low-melting-point paraffin is added to 300g of solvent petroleum ether to dissolve and obtain a supersaturated solution, and after filtering out the solid residues, 300g of solvent petroleum ether is added to the saturated solution to obtain a 50% saturated solution.

[0124] d. Drop forming

[0125] In the environment of temperature 15-30℃ and relative humidity 40-70%, the nearly liquid hydrogel is used as the core material, and the phase change material is heated and melted in a melting cylinder. The core material and the phase change material melt are pumped into the dropping equipment with coaxial double core droppers. The dropping tube is in the heat preservation medium (heat conductive silicone oil) to keep the temperature at 70℃. The phase change material melt and the core material are dropped from the outer core and the inner core of the coaxial double core dropper respectively, and are dropped into the cooling liquid at the same time. The dropping speed is 40 drops per minute, and the temperature of the cooling agent is maintained at 2-6℃. The core material is wrapped and formed in the cooling liquid. Different wall thicknesses of the coating can be obtained by adjusting the pump speed and the dropping speed. Specifically, the relative speed difference of the core material and the phase change material is changed by adjusting the pump speed of each pipeline. The coating will become thinner with the increase of the speed difference, and the coating will become thicker with the decrease of the speed difference. The water storage and release material is dried at room temperature.

[0126] Finally, the obtained water storage and release material is added into the tobacco filter tow, and the prepared cigarette is used for detecting the water content in the smoke.

[0127] Comparative Example 2

[0128] The water storage and release material is prepared according to the following a and b steps:

[0129] a. Preparation of coating solution

[0130] 180g low-temperature phase change material low-melting-point paraffin is added to 300g solvent naphtha to obtain a supersaturated solution. After filtering out the solid residues, 300g solvent naphtha is added to the saturated solution to obtain a 50% saturated solution.

[0131] b. Wrapping and coating forming

[0132] The water storage material hyaluronic acid is not crosslinked, and is directly dissolved in water to obtain a hydrogel. The hydrogel is immersed in the coating solution for 10s, and is quickly transferred to the constant-temperature cold water at 2-6℃ for cooling and cooling for 200-600s to form a uniform coating layer. Then, the hydrogel is dried at room temperature for 48h until the solvent is completely volatilized.

[0133] Finally, the obtained water storage and release material is added into the tobacco filter tow, and the prepared cigarette is used for detecting the water content in the smoke.

[0134] The scheme of the comparative example 2 of the application has not been subjected to the crosslinking step, and the water absorption multiple is large. The water absorption of the hydrogel does not exceed the critical water absorption rate, and the water in the smoke is absorbed during smoking.

[0135] Comparative Example 3

[0136] The water storage and release material is prepared according to the following a-d four steps:

[0137] a. Preparation of crosslinking agent

[0138] A 500 g alkaline complex solvent is prepared, which is glycerol: water = 1:9 with 0.8 ‰ NaOH, and is magnetically stirred in a water bath at 55 °C for 15 minutes, 1.5 g of crosslinking agent ligand ethylene glycol dimethacrylate is added, and the temperature is raised to 60 °C for 40 minutes before being transferred to a stirring mixer, and the liquid surface is formed into a vortex of 2-3 cm deep by adjusting the stirring speed.

[0139] b. Crosslinking reaction

[0140] 30 g of water-retaining material hyaluronic acid is added to the crosslinking agent vortex in the stirring mixer for crosslinking reaction, and the amount of addition meets the weight ratio of 5% of the crosslinking agent ligand ethylene glycol dimethacrylate to the water-retaining material hyaluronic acid. The reaction temperature is kept at 70 °C, and the reaction time is 120 min.

[0141] c. Preparation of coating liquid

[0142] 180 g of low-temperature phase change material low-melting paraffin is added to 300 g of solvent petroleum ether to dissolve and obtain a supersaturated solution, and after filtering out the solid residues, 300 g of solvent petroleum ether is added to the saturated solution to mix and obtain a 50% saturated solution.

[0143] d. Coating and forming

[0144] After the hydrogel is immersed in the coating liquid for 180 s, it is quickly transferred to a constant-temperature cold water at 2-6 °C for cooling and cooling for 200-600 s to form a uniform coating layer. Then, it is air-dried at room temperature for 48 h until the solvent is completely volatilized.

[0145] Finally, the obtained water storage and release material is added to the tow of the cigarette filter, and the cigarette made is detected for the water content in the smoke.

[0146] The scheme of Comparative Example 3 is crosslinked too much, the water absorption rate is reduced too much, and there is no obvious water release effect and no water absorption effect on the smoke.

[0147] Comparative Example 4

[0148] The water storage and release material is prepared according to the following four steps a-d:

[0149] a. Preparation of crosslinking agent

[0150] A 500 g alkaline complex solvent is prepared, which is glycerol: water = 1:9 with 0.8 ‰ NaOH, and is magnetically stirred in a water bath at 55 °C for 15 minutes, 1.5 g of crosslinking agent ligand ethylene glycol dimethacrylate is added, and the temperature is raised to 60 °C for 40 minutes before being transferred to a stirring mixer, and the liquid surface is formed into a vortex of 2-3 cm deep by adjusting the stirring speed.

[0151] b. Crosslinking reaction

[0152] 30g of water-retaining material hyaluronic acid was added to the crosslinking agent vortex in the stirring mixer for crosslinking reaction, and the amount of addition met the weight ratio of 1% of the crosslinking agent ligand ethylene glycol dimethacrylate to the water-retaining material hyaluronic acid. The reaction temperature was kept at 70°C, and the reaction time was 120 min.

[0153] c. Preparation of coating liquid

[0154] 180g of low-temperature phase change material low-melting paraffin was added to 300g of solvent petroleum ether to dissolve to obtain a supersaturated solution. After filtering out the solid residues, 300g of solvent petroleum ether was added to the saturated solution and mixed to obtain a 50% saturated solution.

[0155] d. Coating and forming

[0156] The hydrogel was immersed in the coating liquid for 1s and then quickly transferred to a constant-temperature cold water at 2-6°C for cooling and cooling for 200-600s to form a uniform coating layer. Then, air drying was carried out at room temperature for 48h until the solvent was completely volatilized.

[0157] Finally, the obtained water storage and release material was added to the tobacco filter tow, and the prepared cigarette was detected for the water content in the smoke.

[0158] The smoke water of Comparative Example 4 was 2.77mg, which was higher than that of Comparative Example 1.89mg, indicating that the water release property was good, but the water storage property was poor, and the coating was too thin, resulting in a large decrease in water retention rate after 6 months. It can be seen that the water loss is serious after a long storage time, and even the water in the smoke may be absorbed.

[0159] Comparative Example 5

[0160] The water storage and release material was prepared according to the following four steps a-d:

[0161] a. Preparation of crosslinking agent

[0162] 500g of alkaline composite solvent was prepared, which was glycerol: water = 1:9 and 0.8‰ NaOH was added, and magnetic stirring was carried out in a water bath at 55°C for 15 minutes. 0.3g of crosslinking agent ligand ethylene glycol dimethacrylate was added, and the temperature was raised to 60°C for 40 minutes, and then transferred to a stirring mixer. The stirring speed was adjusted to form a vortex of 2-3cm deep on the liquid surface.

[0163] b. Crosslinking reaction

[0164] 30g of water-retaining material hyaluronic acid was added to the crosslinking agent vortex in the stirring mixer for crosslinking reaction, and the amount of addition met the weight ratio of 1% of the crosslinking agent ligand ethylene glycol dimethacrylate to the water-retaining material hyaluronic acid. The reaction temperature was kept at 70°C, and the reaction time was 120 min.

[0165] c. Preparation of coating solution

[0166] Dissolve 180g low temperature phase change material low melting point paraffin in 300g solvent petroleum ether to obtain a supersaturated solution. After filtering out the solid residue, add 300g solvent petroleum ether to the saturated solution and mix to obtain a 50% saturated solution.

[0167] d. Coating and forming

[0168] After immersing the hydrogel in the coating solution for 600s, quickly transfer it to a constant temperature cold water bath at 2-6°C for cooling and cooling for 200-600s to form a uniform coating layer. Then dry it at room temperature for 48h until the solvent is completely volatilized.

[0169] Finally, add the obtained water storage and release material to the tobacco filter tow and make a cigarette to detect the moisture content in the smoke.

[0170] The coating in Comparative Example 5 is too thick due to long immersion time, and the water release capacity is almost lost. The thin coating has a more obvious effect on the moisture content in the smoke because the smoke flows from the burning end of the cigarette to the filter end, and the temperature is relatively high, which has a certain energy. Under similar smoking conditions (smoking capacity, smoking time), the total amount of smoke energy is also constant. Therefore, the thicker the coating made of phase change material, the more energy consumed in the process of opening the water release channel, and more phase change material will occupy the surface sites, so that the thick coating is prone to incomplete opening of the release channel.

[0171] Comparative Example 6

[0172] Prepare the water storage and release material according to the following four steps a-d:

[0173] a. Preparation of crosslinking agent

[0174] Prepare 500g of alkaline composite solvent, which is glycerol: water = 1:9 and 0.8‰ NaOH, and magnetically stir in a water bath at 55°C for 15 minutes. Add 0.3g of crosslinking agent ligand ethylene glycol dimethacrylate, and increase the temperature to 60°C for 40 minutes, then transfer to a stirring mixer, and adjust the stirring speed to form a vortex of 2-3cm deep on the liquid surface.

[0175] b. Crosslinking reaction

[0176] Add 30g of water-retaining material hyaluronic acid to the crosslinking agent vortex in the stirring mixer for crosslinking reaction. The amount added satisfies the weight ratio of crosslinking agent ligand ethylene glycol dimethacrylate to water-retaining material hyaluronic acid of 1%. The reaction temperature is kept at 40°C, and the reaction time is 120min.

[0177] c. Preparation of coating solution

[0178] The 180 g low-temperature phase change material low-melting paraffin was added to 300 g solvent naphtha to dissolve to obtain a supersaturated solution. After filtering out the solid residues, 300 g solvent naphtha was added to the saturated solution to mix to obtain a 50% saturated solution.

[0179] d. Coating forming

[0180] After the hydrogel was immersed in the coating liquid for 180 s, it was quickly transferred to a constant-temperature cold water at 2-6°C for cooling and cooling for 200-600 s to form a uniform coating layer. Then, air drying was performed at room temperature for 48 h until the solvent was completely volatilized.

[0181] Finally, the obtained water storage and release material was added to the tobacco filter tow to make a cigarette for detecting the water content in the smoke.

[0182] The crosslinking temperature of Comparative Example 6 was too low, the crosslinking failed, the water absorption rate was too large, the initial water absorption of the water-retaining material was large, and since the latent heat of water was large, a large amount of heat energy in the smoke was consumed, which was not conducive to the opening of the release water channel.

[0183] Comparative Example 7

[0184] The water storage and release material was prepared according to the following four steps a-d:

[0185] a. Preparation of crosslinking agent

[0186] A 500 g alkaline composite solvent was prepared, the solvent was glycerol: water = 1:9 and 0.8‰ NaOH was added, and magnetic stirring was performed in a water bath at 55°C for 15 minutes. 0.3 g of crosslinking agent ligand ethylene glycol dimethacrylate was added, and the temperature was raised to 60°C for 40 minutes, and then transferred to a stirring mixer, and the liquid surface was formed into a vortex of 2-3 cm deep by adjusting the stirring speed.

[0187] b. Crosslinking reaction

[0188] 30 g of water-retaining material hyaluronic acid was added to the crosslinking agent vortex in the stirring mixer for crosslinking reaction, and the amount of addition met the weight ratio of 1% of the crosslinking agent ligand ethylene glycol dimethacrylate to the water-retaining material hyaluronic acid. The reaction temperature was kept at 60°C, and the reaction time was 60 min.

[0189] c. Preparation of coating liquid

[0190] The 180 g low-temperature phase change material low-melting paraffin was added to 300 g solvent naphtha to dissolve to obtain a supersaturated solution. After filtering out the solid residues, 300 g solvent naphtha was added to the saturated solution to mix to obtain a 50% saturated solution.

[0191] d. Coating forming

[0192] After the hydrogel is immersed in the coating liquid for 180 s, it is quickly transferred to cold water at 2-6°C for cooling for 200-600 s to form a uniform coating layer. Then, the hydrogel is dried at room temperature for 48 h until the solvent is completely volatilized.

[0193] Finally, the obtained water storage and release material is added to the tobacco filter tow, and the prepared cigarette is detected for the water content in the smoke.

[0194] The crosslinking time of Comparative Example 7 is too short, and the water retention material still has a high water absorption rate. In the preparation process, the initial water absorption of the water retention material is small, and the water in the smoke is absorbed.

[0195] Comparative Example 8

[0196] The phase change material is polyethylene oxide PEO, which fails to form a stable coating, possibly because polyethylene oxide is water-soluble.

[0197] The results show that the experiment fails. Polyethylene oxide is water-soluble and cannot form a stable coating.

[0198] Comparative Example 9

[0199] The water storage and release material is prepared according to the following four steps a-d:

[0200] a. Preparation of crosslinking agent

[0201] 500 g of alkaline composite solvent is prepared, which is glycerol: water = 1:9 and 0.8‰ NaOH is added, and magnetic stirring is performed in a water bath at 55°C for 15 minutes. 0.3 g of crosslinking agent ligand ethylene glycol dimethacrylate is added, and the temperature is raised to 60°C for 40 minutes, and then transferred to a stirring mixer, and the liquid surface is formed into a vortex with a depth of 2-3 cm by adjusting the stirring speed.

[0202] b. Crosslinking reaction

[0203] 30 g of water retention material hyaluronic acid is added to the crosslinking agent vortex in the stirring mixer for crosslinking reaction, and the amount added satisfies the weight ratio of crosslinking agent ligand ethylene glycol dimethacrylate to water retention material hyaluronic acid of 1%. The reaction temperature is kept at 70°C, and the reaction time is 120 min.

[0204] c. Preparation of coating liquid

[0205] 500 g of phase change material polyethylene PE is heated in an oil bath at 140°C for 90 min until completely melted.

[0206] d. Coating and forming

[0207] The hydrogel is immersed in the coating liquid for 180s, then is quickly transferred to constant-temperature cold water at 2-6 DEG C for cooling for 200-600s to form a uniform coating layer.

[0208] Finally, the obtained water storage and release material is added into the tobacco filter tow, and the prepared cigarette is detected for the water content in smoke.

[0209] The results show that the phase transition temperature of polyethylene is too high, 85-136 DEG C, the heat carried by the smoke cannot trigger the phase transition of most coatings, the water storage material is always covered, the water cannot enter or exit, and thus the water content in smoke does not change.

[0210] The results of the inventive examples and the comparative examples are shown in Table 1.

[0211] Table 1

[0212]

[0213]

[0214] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for preparing a water-storing and water-releasing material for humidifying cigarette smoke, characterized in that, Includes the following steps: A) A water-retaining material and a crosslinking agent are mixed and reacted to obtain a hydrogel; the water-retaining material includes one or more of hyaluronic acid, collagen, sodium alginate, polyacrylamide, polyethylene glycol, or sodium polyacrylate; the crosslinking agent is composed of an alkaline composite solvent and a crosslinking agent ligand; the crosslinking agent ligand is selected from one or more of ethylene glycol dimethacrylate, aluminum dihydroxyaminoacetate, or tetramethylethylenediamine; The ratio of the crosslinking agent ligand to the water-retaining material ranges from 0.3 wt% to 1 wt%. The reaction temperature is 60~80℃; the reaction time is 120~130min; B) The low-temperature phase change material is melted into a liquid state or dissolved in a solvent to obtain a coating solution; the low-temperature phase change material is selected from low-melting-point paraffin or tetracosane; the temperature of the low-temperature phase change is 40~70℃; C) A coating is formed on the surface of the hydrogel by immersing it in a coating solution, coating it, or dripping it with a coaxial bicentric dropper; the coating thickness is 30~400μm; when the hydrogel is immersed in the coating solution, it is ensured that it is completely submerged and a certain soaking time is maintained; the soaking is specifically: soaking time is 5~300s; soaking temperature is room temperature~95℃.

2. The preparation method according to claim 1, characterized in that, Step B) The melting method is water bath heating, with a water bath temperature of 55℃~95℃; the melting time is 20~100min.

3. The preparation method according to claim 1, characterized in that, The solvent in step B) is petroleum ether, toluene, acetone, or n-hexane; The selected dissolution temperature is room temperature; the dissolution time is 30~60 min.

4. The preparation method according to claim 1, characterized in that, Step C) The coating process includes rapid cooling, and the cooling medium is specifically constant-temperature cold water with a temperature of 2~6℃.

5. The preparation method according to claim 1, characterized in that, Step C) The coaxial bicentric dropper dispensing process specifically involves: Hydrogel is used as the core material and coating liquid is used as the wall material. Both are fed into a dripping device equipped with a coaxial double-core dropper. The wall material and core material are dripped from the outer and inner core of the coaxial double-core dropper, respectively. Through the coaxial double-core dropper, the wall material and core material are dripped into the coolant at the same time and are encapsulated and shaped in the coolant to obtain the final product. The specific requirements for the dripping process are: an ambient temperature of 15℃~30℃ and a relative humidity of 40%~70%.

6. A water-storing and water-releasing material for humidifying cigarette smoke, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 5.

7. A cigarette, characterized in that, Includes the water storage and release material as described in claim 6.

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