Composite gel for cigarette filter rod and method for preparing the same

Abstract

The present application relates to the technical field of tobacco processing, and discloses a composite gel for a cigarette filter rod and a preparation method thereof. The composite gel is composed of a slow-release gel, an outer thin layer wrapped outside the slow-release gel, and a fixing layer deposited on the surface of the outer thin layer. The slow-release gel comprises mixed materials and essence materials. The mixed materials comprise the following raw materials in parts by weight: 10-50 parts of polyethylene glycol, 10-50 parts of octyl decanoate glyceride, 5-15 parts of propylene glycol fatty acid ester, 5-15 parts of monoglyceride, and 5-10 parts of citric acid. The present application solves the problems of easy volatilization of essence spices in the cigarette filter rod, short fragrance retention time, and uneven fragrance release, and improves the experience of users.

Description

Technical Field

[0001] This invention relates to the field of tobacco processing technology, and in particular to a composite gel for cigarette filter rods and its preparation method. Background Technology

[0002] As people's living standards improve, their health awareness also increases. While smokers gain physiological and psychological satisfaction from smoking, they also hope to minimize the harm caused by smoking. However, current technologies for reducing the harmful tar content in tobacco reduce some aroma components in cigarette smoke to varying degrees, affecting the smoker's experience. Therefore, developing a low-harm cigarette that can meet the harm reduction needs of smokers while maintaining a high aroma has become an important research topic in the tobacco industry in recent years. Adding important aroma-producing substances from plants to cigarettes to compensate for the loss of aroma substances due to dilution or runoff is an effective way to compensate for cigarette aroma. At the same time, adding functional particulate materials to cigarette filter rods can also effectively compensate for cigarette aroma in order to enrich the aroma.

[0003] In existing technologies, flavored filter rods are often made by embedding fragrance-impregnated cotton threads into a fiber bundle using a filter rod forming machine, or by dissolving fragrance in a plasticizer and applying it to the fiber bundle. However, cigarettes produced by these methods have a strong aroma in the first few puffs, but the aroma weakens in subsequent puffs, becoming very faint by the end of the cigarette. Furthermore, during cigarette storage, some flavorings, such as menthol, are volatile and have a short retention time, shortening the product's shelf life and significantly limiting the application of certain flavorings in cigarette filters.

[0004] Gel materials possess excellent adsorption and sustained-release properties, and are frequently used as sustained-release agents and stabilizers to control the release of fragrances and flavorings in specific situations, thereby effectively prolonging the fragrance duration and expanding the application range of fragrances and flavorings. However, gel-based fragrance addition suffers from problems such as complex production processes, low efficiency, and easy powdering after drying. Furthermore, existing gel technologies involve mixing gel materials with fragrances and flavorings and then preparing gel particles. Although stabilizers are used to reduce the volatilization of fragrances and flavorings, volatilization still occurs. In another method, tobacco flavoring is heated and mixed with a gel solution, then cooled to obtain a gel mixture. The tobacco flavoring is a volatile substance that easily volatilizes in air. Dissolving it in the gel can reduce its volatilization; however, even when the tobacco flavoring is uniformly dispersed in the gel, the flavoring on the gel surface evaporates rapidly, and volatilization also occurs slowly from the outside of the gel to the inside. Therefore, existing technologies using gel-flavored cigarettes can still enhance the flavor of cigarettes after they have been stored for a period of time. However, compared to freshly made cigarettes, the reduction in tobacco flavorings in the gel results in a lack of richness for the customer. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a composite gel for cigarette filter rods and its preparation method, which solves the problems of easy volatilization of flavorings and fragrances in cigarette filter rod flavoring particles, short fragrance retention time, and uneven fragrance release, thereby improving the user experience.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] A composite gel for cigarette filter rods, the composite gel being composed of a sustained-release gel, an outer thin layer encapsulating the sustained-release gel, and a fixing layer deposited on the surface of the outer thin layer. The sustained-release gel includes a mixture of materials and a flavoring material. The mixture includes the following raw materials in parts by weight: 10-50 parts polyethylene glycol, 10-50 parts caprylic / capric triglyceride, 5-15 parts propylene glycol fatty acid ester, 5-15 parts monoglyceride, and 5-10 parts citric acid.

[0008] Furthermore, the mixed material comprises the following raw materials in parts by weight: 35 parts polyethylene glycol, 20 parts caprylic / capric triglyceride, 10 parts propylene glycol fatty acid ester, 10 parts monoglyceride and 9 parts citric acid.

[0009] The composite gel in this invention employs a composite structure, with a thin outer layer encasing the sustained-release gel, and then a fixing layer encasing the outer thin layer. The outer thin layer effectively locks the tobacco flavoring in the flavoring particles within itself, reducing the volatilization of the aroma within the gel. The mixed materials in the sustained-release gel, through the dissolution and loading of tobacco flavoring by polyethylene glycol and caprylic / capric glycerides, provide sustained-release properties for the tobacco flavoring. Propylene glycol fatty acid esters serve as emulsifiers, defoamers, and stabilizers, and are used in conjunction with mono- and diglycerides. The combination of propylene glycol fatty acid esters and monoglycerides disperses the flavoring materials within the mixed materials. The added citric acid increases the acidity of the tobacco and reduces the irritation of tar. During inhalation, the volatilized flavoring combines with the tobacco aroma, enhancing the richness of the tobacco aroma.

[0010] Furthermore, the outer thin layer comprises the following raw materials in parts by weight: 20-40 parts palmitic acid, 10-30 parts beeswax, 10-20 parts sodium octenyl succinate starch, and 10-20 parts polycaprolactone.

[0011] Furthermore, the outer thin layer comprises the following raw materials in parts by weight: 30 parts palmitic acid, 30 parts beeswax, 10 parts sodium octenyl succinate starch, and 20 parts polycaprolactone.

[0012] In this invention, the outer thin layer protects the core sustained-release gel. This layer isolates the flavor particles from the air, reducing the evaporation rate of the flavor. The palmitic acid in the outer layer protects the tobacco flavor and improves the gel's water resistance. Beeswax possesses excellent plasticity, release properties, film-forming ability, and waterproof, moisture-proof, and oxidation-resistant characteristics. Combined with polycaprolactone, it enhances the plasticity and encapsulation properties of the outer thin layer. Sodium octenyl succinate starch has high and stable viscosity, improving the adhesiveness of the outer thin layer solution and facilitating encapsulation with the internal sustained-release gel. Furthermore, the outer thin layer material is non-toxic and odorless. When a cigarette is lit, the outer thin layer melts rapidly as the smoke passes through the filter rod, releasing the flavor within the sustained-release gel and enhancing the cigarette's flavor.

[0013] Furthermore, the fixing layer comprises the following raw materials in parts by weight: 50-60 parts polycaprolactone and 5-10 parts cellulose diacetate grafted polycaprolactone.

[0014] For existing cigarettes, the commonly used raw material for cigarette tow is cellulose acetate. When preparing cigarette filters, plasticizers are added to the tow to solidify and bond the surface of the cellulose acetate. However, this invention sets a fixing layer on the outermost layer of the composite gel. Under the action of the plasticizer, the surface of the fixing layer swells due to the grafting of polycaprolactone onto the cellulose acetate tow, resulting in a slight solidification and bonding with it. This achieves a composite between the composite gel and the cigarette filter tow, preventing displacement of the composite gel during cigarette production, storage, or use, which could lead to detachment or even filter rod bursting, thus improving the stability of the composite gel. The fixing layer, made from cellulose acetate grafted with polycaprolactone and polycaprolactone, is rapidly melted by the temperature of the smoke when the cigarette is lit. Therefore, the fixing layer does not affect the volatilization of the flavorings within the internal slow-release gel.

[0015] Furthermore, this invention also discloses a method for preparing the composite gel for cigarette filter rods, the specific preparation method of which is as follows:

[0016] S1: Add the fragrance material to the mixed material, stir continuously for 25-30 minutes at a temperature of 50-90℃ until well mixed, stop stirring, cool and solidify, and then granulate using a dry granulator to obtain a slow-release gel.

[0017] S2: Weigh palmitic acid, beeswax, sodium octenyl succinate starch and polycaprolactone according to the weight parts, mix them evenly and add them to the dissolving tank. Heat the temperature to 50-80℃ and stir for 20-30 minutes to obtain an outer thin layer solution.

[0018] S3: Place the sustained-release gel on a mesh oscillating conveyor belt, and convey each sustained-release gel forward without overlapping. Spray the outer thin layer solution onto the surface of the sustained-release gel so that each sustained-release gel can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low-temperature environment to cool and solidify, thus obtaining the intermediate product.

[0019] S4: Weigh out the polycaprolactone and cellulose diacetate grafted polycaprolactone according to the weight parts, mix them evenly, add them to the dissolving tank, heat the temperature to 70-80℃, stir for 10-20 minutes to obtain the fixed layer solution.

[0020] S5: Place the intermediate products on a mesh oscillating conveyor belt, and convey each intermediate product forward without overlapping. Spray the fixing layer solution onto the surface of the intermediate products so that each intermediate product can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low temperature environment to cool and solidify, thus obtaining a composite gel.

[0021] Furthermore, the specific operation of step S1 is as follows:

[0022] A1: Weigh out polyethylene glycol, caprylic / capric triglyceride, propylene glycol fatty acid ester, monoglyceride and citric acid, mix them evenly, add them to a heating tank, heat the mixture to 50-80℃ and stir thoroughly to completely dissolve the mixture to obtain the mixed material;

[0023] A2: Add tobacco flavoring to ethylene glycol, stir to dissolve, and prepare flavoring material with a concentration of 10% to 45%;

[0024] A3: Add the aroma material from step A2 to the mixture from step A1. The mass ratio of the aroma material to the mixture is 20-40:60-80. Stir and mix continuously for 25-30 minutes at a temperature of 50-90℃ to obtain a gel.

[0025] A4: After the prepared gel liquid is cooled and solidified, it is granulated using a dry granulator to obtain a sustained-release gel.

[0026] Furthermore, the method for preparing the cellulose diacetate grafted polycaprolactone is as follows:

[0027] B1: Add dried cellulose diacetate and ε-caprolactone to the polymerization tube, and add stannous octoate;

[0028] B2: After evacuation, heat the reactants to 150°C, then introduce nitrogen gas and stir for 12 hours;

[0029] B3: After stirring is stopped, the obtained reactants are dissolved in chloroform, precipitated by adding anhydrous methanol, filtered and dried to obtain cellulose diacetate grafted polycaprolactone.

[0030] Furthermore, the mass ratio of cellulose diacetate to ε-caprolactone is 15-20:2-5.

[0031] The beneficial effects of this invention are:

[0032] 1. In this invention, the composite gel has a three-layer composite structure. The flavoring of tobacco is loaded onto the slow-release gel, and the flavoring is uniformly dispersed in the slow-release gel, which improves the slow-release properties of the flavoring. The outer thin layer reduces the contact between the slow-release gel and the air, reducing the volatilization of the flavoring during storage, thereby ensuring that the flavoring is reduced during production and storage, and thus ensuring the aroma-enhancing effect on cigarettes when smoked. The outermost fixing layer improves the adhesion between the composite gel and the cigarette filter, and improves the stability of the composite gel during use.

[0033] 2. The outer thin layer in this invention can quickly encapsulate and shape the slow-setting gel, reducing the loss of flavoring materials. At the same time, the outer thin layer can melt quickly at the temperature of the flue gas, which can quickly enhance the flavor without affecting the user's smoking experience. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] Preparation of cellulose diacetate grafted with polycaprolactone

[0037] Cellulose diacetate and ε-caprolactone were weighed at a mass ratio of 20:3, dried, and added to a polymerization tube. Stannous octoate with a mass equal to that of cellulose diacetate was added, and the mixture was heated to 150°C under vacuum. Nitrogen gas was then introduced and the mixture was stirred for 12 hours. After stirring, the reaction mixture was dissolved in an equal volume of chloroform, and precipitated with 1 / 2 volume of anhydrous methanol. After filtration and drying, cellulose diacetate grafted polycaprolactone was obtained.

[0038] The composite gel was prepared as follows:

[0039] S1: Add the fragrance material to the mixture, stir continuously for 25 minutes at 85.6℃ until homogeneous, stop stirring, cool and solidify, then granulate using a dry granulator to obtain the sustained-release gel.

[0040] A1: Prepare the raw materials according to the following weight parts: 35 parts polyethylene glycol, 20 parts caprylic / capric triglyceride, 10 parts propylene glycol fatty acid ester, 10 parts monoglyceride and 9 parts citric acid. Mix the selected raw material components evenly, add them to a heating tank, heat the mixture to 50°C, and stir thoroughly to completely dissolve the mixture and obtain the mixed material.

[0041] A2: Add tobacco menthol flavoring to ethylene glycol to dissolve it, and prepare a flavoring material with a concentration of 25%;

[0042] A3: Add the fragrance material to the mixture, with a mixing ratio of 30:70. Stir continuously to obtain a gel, and maintain the temperature at 85.6℃. After stirring for 25 minutes, cool and solidify.

[0043] A4: The cooled gel solution is granulated using a dry granulator to obtain a sustained-release gel;

[0044] S2: Prepare the raw materials according to the following weight parts: 30 parts palmitic acid, 30 parts beeswax, 10 parts sodium octenyl succinate starch, and 20 parts polycaprolactone. Mix the weighed raw materials evenly and add them to the dissolving tank. Heat the temperature to 75°C and stir for 20 minutes to obtain an outer thin layer solution.

[0045] S3: Place the sustained-release gel on a mesh oscillating conveyor belt, and convey each sustained-release gel forward without overlapping. Spray the outer thin-layer solution onto the surface of the sustained-release gel. The mass mixing ratio of the sustained-release gel to the outer thin-layer solution is 8:1, so that each sustained-release gel can be completely coated by the outer thin-layer solution. After coating, it quickly thickens and falls directly into a low-temperature environment to cool and solidify, thus obtaining the intermediate product.

[0046] S4: Prepare raw materials according to the following weight parts: 50 parts polycaprolactone and 10 parts cellulose diacetate grafted polycaprolactone. Mix the weighed raw materials evenly and add them to the dissolving tank. Heat the temperature to 80℃ and stir for 20 minutes to obtain a fixed layer solution.

[0047] S5: Place the intermediate products on a mesh oscillating conveyor belt, and convey each intermediate product forward without overlapping. Spray the fixing layer solution onto the surface of the intermediate products. The mass ratio of intermediate products to fixing layer solution is 10:1, so that each intermediate product can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low temperature environment to cool and solidify, thus obtaining a composite gel.

[0048] The prepared composite gel is uniformly added to the cigarette tow, and the cigarette tow is prepared into a filter rod using conventional cigarette tow forming equipment.

[0049] To demonstrate the technical effectiveness of the gel in this embodiment, two different control groups were prepared. The cigarettes in control group 1 were of the same specifications as those in this embodiment, and an equal amount of menthol flavoring was directly added to the filter rod of the cigarettes.

[0050] The cigarettes in control group 2 were of the same specifications as those in this embodiment, and the same amount of sustained-release gel from step (2) was added to the cigarettes.

[0051] The samples from this embodiment were placed in the same environment as the samples from control groups 1 and 2. After 0, 10, 20, 30, and 60 days, the aroma loss rate in the cigarettes was measured, and menthol was detected using a GC / MS instrument. The results are shown in the table below:

[0052] Table 1. Aroma loss rate of cigarette samples after different storage times.

[0053] Example Control group 1 Control group 2 0d 0.3％ 5.2％ 3.1％ 10d 1.2％ 15.7％ 9.4％ 20d 5.3％ 34.8％ 15.7％ 30d 10.1％ 55.3％ 26.4％ 60d 30.4％ 70.8％ 42.3％

[0054] As can be seen from the data in Table 1, the composite gel of the present invention can significantly reduce the loss of tobacco flavoring during storage.

[0055] After the samples from this embodiment and the control group were ignited, the smoke was collected every minute. The menthol content during cigarette combustion was detected using a GC / MS instrument, and the menthol content per minute was recorded. The detection results are as follows:

[0056] Table 2. Aroma content of cigarette smoke per minute after combustion

[0057] Example (mg) Control group 1 (mg) Control group 2 (mg) 1min 15.3 20.3 16.9 2min 18.5 25.3 20.3 3min 20.3 18.6 25.9 4min 21.5 15.6 21.8 5min 23.6 12.9 18.6

[0058] As can be seen from the data in Table 2, the composite gel of the present invention has a better sustained-release effect on the fragrance than the control group. Therefore, the composite gel improves the sustained-release performance of cigarette aroma and enhances the uniformity of the aroma.

[0059] Example 2

[0060] Preparation of cellulose diacetate grafted with polycaprolactone

[0061] Cellulose diacetate and ε-caprolactone were weighed at a mass ratio of 15:2, dried, and added to a polymerization tube. Stannous octoate with a mass equal to that of cellulose diacetate was added, and the mixture was heated to 150°C under vacuum. Nitrogen gas was then introduced and the mixture was stirred for 12 hours. After stirring, the reaction mixture was dissolved in an equal volume of chloroform, and precipitated with anhydrous methanol at a volume equal to that of chloroform. After filtration and drying, cellulose diacetate grafted polycaprolactone was obtained.

[0062] The composite gel was prepared as follows:

[0063] S1: Add the fragrance material to the mixture, stir continuously for 20 minutes at 50℃ until homogeneous, stop stirring, and allow to cool and solidify. Then, granulate the mixture using a dry granulator to obtain a sustained-release gel.

[0064] A1: Prepare the raw materials according to the following weight parts: 10 parts polyethylene glycol, 10 parts caprylic / capric triglyceride, 5 parts propylene glycol fatty acid ester, 5 parts monoglyceride and 5 parts citric acid. Mix the selected raw material components evenly, add them to a heating tank, heat the mixture to 50°C, and stir thoroughly to completely dissolve the mixture and obtain the mixed material.

[0065] A2: Dissolve tobacco menthol flavoring in ethylene glycol to prepare a flavoring material with a concentration of 10%;

[0066] A3: Add the fragrance material to the mixture, with a mass ratio of fragrance material to mixture of 20:80. Stir continuously to obtain a gel solution, and maintain the temperature at 50℃. After stirring for 25 minutes, cool and solidify.

[0067] A4: The cooled gel solution is granulated using a dry granulator to obtain a sustained-release gel;

[0068] S2: Prepare raw materials according to the following weight parts: 20 parts palmitic acid, 10 parts beeswax, 10 parts sodium octenyl succinate starch, and 10 parts polycaprolactone. Mix the weighed raw materials evenly and add them to a dissolving tank. Heat the temperature to 50°C and stir for 20 minutes to obtain an outer thin layer solution.

[0069] S4: Prepare raw materials according to the following weight parts: 50 parts polycaprolactone and 10 parts cellulose diacetate grafted polycaprolactone. Mix the weighed raw materials evenly and add them to the dissolving tank. Heat the temperature to 80℃ and stir for 20 minutes to obtain a fixed layer solution.

[0070] S5: Place the intermediate products on a mesh oscillating conveyor belt, and convey each intermediate product forward without overlapping. Spray the fixing layer solution onto the surface of the intermediate products. The mass ratio of intermediate products to fixing layer solution is 10:1, so that each intermediate product can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low temperature environment to cool and solidify, thus obtaining a composite gel.

[0071] The prepared composite gel is uniformly added to the cigarette tow, and the cigarette tow is prepared into a filter rod using conventional cigarette tow forming equipment.

[0072] Example 3

[0073] Preparation of cellulose diacetate grafted with polycaprolactone

[0074] Cellulose diacetate and ε-caprolactone were weighed in a mass ratio of 18:5, dried, and added to a polymerization tube. Stannous octoate with a mass equal to that of cellulose diacetate was added, and the mixture was heated to 150°C under vacuum. Nitrogen gas was then introduced and the mixture was stirred for 12 hours. After stirring, the reaction mixture was dissolved in an equal volume of chloroform, and precipitated with 1 / 2 volume of anhydrous methanol. After filtration and drying, cellulose diacetate grafted polycaprolactone was obtained.

[0075] The composite gel was prepared as follows:

[0076] S1: Add the fragrance material to the mixture, stir continuously for 20 minutes at 90℃ until homogeneous, stop stirring, and allow to cool and solidify. Then, granulate the mixture using a dry granulator to obtain a sustained-release gel.

[0077] A1: Prepare the raw materials according to the following weight parts: 50 parts polyethylene glycol, 50 parts caprylic / capric triglyceride, 15 parts propylene glycol fatty acid ester, 15 parts monoglyceride and 10 parts citric acid. Mix the selected raw material components evenly, add them to a heating tank, heat the mixture to 90°C, and stir thoroughly to completely dissolve the mixture and obtain the mixed material.

[0078] A2: Add tobacco menthol flavoring to ethylene glycol to dissolve it, and prepare a flavoring material with a concentration of 45%;

[0079] A3: Add the fragrance material to the mixture. The ratio of the fragrance material to the mixture is 40:60. Stir continuously to obtain a gel and maintain the temperature at 90℃. After stirring for 30 minutes, cool and solidify.

[0080] A4: The cooled gel solution is granulated using a dry granulator to obtain a sustained-release gel;

[0081] S2: Prepare raw materials according to the following weight parts: 30 parts palmitic acid, 30 parts beeswax, 10 parts sodium octenyl succinate starch, and 20 parts polycaprolactone. Mix the weighed raw materials evenly and add them to a dissolving tank. Heat the temperature to 90°C and stir for 20 minutes to obtain an outer thin layer solution.

[0082] S3: Place the sustained-release gel on a mesh oscillating conveyor belt, and convey each sustained-release gel forward without overlapping. Spray the outer thin-layer solution onto the surface of the sustained-release gel. The mass mixing ratio of the sustained-release gel to the outer thin-layer solution is 8:1, so that each sustained-release gel can be completely coated by the outer thin-layer solution. After coating, it quickly thickens and falls directly into a low-temperature environment to cool and solidify, thus obtaining the intermediate product.

[0083] S4: Prepare raw materials according to the following weight parts: 60 parts polycaprolactone and 10 parts cellulose diacetate grafted polycaprolactone. Mix the weighed raw materials evenly and add them to the dissolving tank. Heat the temperature to 80℃ and stir for 20 minutes to obtain a fixed layer solution.

[0084] S5: Place the intermediate products on a mesh oscillating conveyor belt, and convey each intermediate product forward without overlapping. Spray the fixing layer solution onto the surface of the intermediate products. The mass ratio of intermediate products to fixing layer solution is 10:1, so that each intermediate product can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low temperature environment to cool and solidify, thus obtaining a composite gel.

[0085] The prepared composite gel is uniformly added to the cigarette tow, and the cigarette tow is prepared into a filter rod using conventional cigarette tow forming equipment.

[0086] Example 4

[0087] Preparation of cellulose diacetate grafted with polycaprolactone

[0088] Cellulose diacetate and ε-caprolactone were weighed at a mass ratio of 19:4, dried, and added to a polymerization tube. Stannous octoate with a mass equal to that of cellulose diacetate was added, and the mixture was heated to 150°C under vacuum. Nitrogen gas was then introduced and the mixture was stirred for 12 hours. After stirring, the reaction mixture was dissolved in an equal volume of chloroform, and precipitated with 1 / 2 volume of anhydrous methanol. After filtration and drying, cellulose diacetate grafted polycaprolactone was obtained.

[0089] The composite gel was prepared as follows:

[0090] S1: Add the fragrance material to the mixture, stir continuously for 15 minutes at 75℃ until homogeneous, stop stirring, and allow to cool and solidify. Then, granulate the mixture using a dry granulator to obtain a sustained-release gel.

[0091] A1: Prepare the raw materials according to the following weight parts: 25 parts polyethylene glycol, 40 parts caprylic / capric triglyceride, 8 parts propylene glycol fatty acid ester, 7 parts monoglyceride and 6 parts citric acid. Mix the selected raw material components evenly, add them to a heating tank, heat the mixture to 75°C, and stir thoroughly to completely dissolve the mixture and obtain the mixed material.

[0092] A2: Add tobacco menthol flavoring to ethylene glycol to dissolve it, and prepare a flavoring material with a concentration of 35%;

[0093] A3: Add the fragrance material to the mixture. The ratio of the fragrance material to the mixture is 25:75. Stir continuously to obtain a gel liquid and maintain the temperature at 75℃. After stirring for 30 minutes, cool and solidify.

[0094] A4: The cooled gel solution is granulated using a dry granulator to obtain a sustained-release gel;

[0095] S2: Prepare the raw materials according to the following weight parts: 25 parts palmitic acid, 15 parts beeswax, 15 parts sodium octenyl succinate starch, and 15 parts polycaprolactone. Mix the weighed raw materials evenly and add them to the dissolving tank. Heat the temperature to 75°C and stir for 15 minutes to obtain an outer thin layer solution.

[0096] S3: Place the sustained-release gel on a mesh oscillating conveyor belt, and convey each sustained-release gel forward without overlapping. Spray the outer thin-layer solution onto the surface of the sustained-release gel. The mass mixing ratio of the sustained-release gel to the outer thin-layer solution is 8:1, so that each sustained-release gel can be completely coated by the outer thin-layer solution. After coating, it quickly thickens and falls directly into a low-temperature environment to cool and solidify, thus obtaining the intermediate product.

[0097] The prepared sustained-release gel is added to a stirring device, and the outer thin-layer solution is added to a spraying device. The outer thin-layer solution is sprayed onto the sustained-release gel. The mass mixing ratio of the sustained-release gel to the outer thin-layer solution is 8:1. After the solution cools, an outer thin layer is formed on the fragrance particles, resulting in an intermediate particle size of 80-150 mesh.

[0098] S4: Prepare raw materials according to the following weight parts: 55 parts polycaprolactone and 8-diacetate cellulose grafted polycaprolactone. Mix the weighed raw materials evenly and add them to the dissolving tank. Heat the temperature to 80℃ and stir for 10 minutes to obtain a fixed layer solution.

[0099] S5: Place the intermediate products on a mesh oscillating conveyor belt, and convey each intermediate product forward without overlapping. Spray the fixing layer solution onto the surface of the intermediate products. The mass ratio of intermediate products to fixing layer solution is 10:1, so that each intermediate product can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low temperature environment to cool and solidify, thus obtaining a composite gel.

[0100] The prepared composite gel is uniformly added to the cigarette tow, and the cigarette tow is prepared into a filter rod using conventional cigarette tow forming equipment.

[0101] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications and substitutions should be covered within the scope of the claims of the present invention. Technical aspects, shapes, and structures not described in detail in this invention are all well-known technologies.

Claims

1. A composite gel for cigarette filter rods, characterized in that, The composite gel is composed of a sustained-release gel, an outer thin layer encapsulating the sustained-release gel, and a fixing layer deposited on the surface of the outer thin layer. The sustained-release gel includes a mixture of materials and a fragrance material. The mixture includes the following raw materials in parts by weight: 10-50 parts polyethylene glycol, 10-50 parts caprylic / capric triglycerides, 5-15 parts propylene glycol fatty acid esters, 5-15 parts monoglycerides, and 5-10 parts citric acid. The outer thin layer includes the following raw materials in parts by weight: 20-40 parts palmitic acid, 10-30 parts beeswax, 10-20 parts sodium octenyl succinate starch, and 10-20 parts polycaprolactone. The fixing layer includes the following raw materials in parts by weight: 50-60 parts polycaprolactone and 5-10 parts cellulose diacetate grafted with polycaprolactone.

2. The composite gel for cigarette filter rods according to claim 1, characterized in that, The mixed material comprises the following raw materials in parts by weight: 35 parts polyethylene glycol, 20 parts caprylic / capric triglyceride, 10 parts propylene glycol fatty acid ester, 10 parts monoglyceride and 9 parts citric acid.

3. The composite gel for cigarette filter rods according to claim 2, characterized in that, The outer thin layer comprises the following raw materials in parts by weight: 30 parts palmitic acid, 30 parts beeswax, 10 parts sodium octenyl succinate starch, and 20 parts polycaprolactone.

4. A method for preparing a composite gel for cigarette filter rods according to any one of claims 1-3, characterized in that, The preparation method of the composite gel is as follows: S1: Add the fragrance material to the mixed material, stir continuously for 25-30 minutes at a temperature of 50-90℃ until well mixed, stop stirring, cool and solidify, and then granulate using a dry granulator to obtain a sustained-release gel. S2: Weigh palmitic acid, beeswax, sodium octenyl succinate starch and polycaprolactone according to the weight parts, mix them evenly and add them to the dissolving tank. Heat the temperature to 50-80℃ and stir for 20-30 minutes to obtain an outer thin layer solution. S3: Place the sustained-release gel on a mesh oscillating conveyor belt, and convey each sustained-release gel forward without overlapping. Spray the outer thin layer solution onto the surface of the sustained-release gel so that each sustained-release gel can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low-temperature environment to cool and solidify, thus obtaining the intermediate product. S4: Weigh out the polycaprolactone and cellulose diacetate grafted polycaprolactone according to the weight parts, mix them evenly, add them to the dissolving tank, heat the temperature to 70-80℃, stir for 10-20 minutes to obtain the fixed layer solution. S5: Place the intermediate products on a mesh oscillating conveyor belt, and convey each intermediate product forward without overlapping. Spray the fixing layer solution onto the surface of the intermediate products so that each intermediate product can be completely wrapped by the outer thin layer solution. After the wrapping is completed, it quickly thickens and falls directly into a low temperature environment to cool and solidify, thus obtaining a composite gel.

5. A method for preparing a composite gel for cigarette filter rods according to claim 4, characterized in that, The specific operation of step S1 is as follows: A1: Weigh out polyethylene glycol, caprylic / capric triglyceride, propylene glycol fatty acid ester, monoglyceride and citric acid, mix them evenly, add them to a heating tank, heat the mixture to 50-80℃ and stir thoroughly to completely dissolve the mixture to obtain the mixed material; A2: Add tobacco flavoring to ethylene glycol, stir to dissolve, and prepare flavoring material with a concentration of 10% to 45%; A3: Add the fragrance material from step A2 to the mixture from step A1. The mass ratio of the fragrance material to the mixture is 20-40:60-80. Stir and mix continuously for 25-30 minutes at a temperature of 50-90℃ to obtain a gel solution. A4: After the prepared gel liquid is cooled and solidified, it is granulated using a dry granulator to obtain a sustained-release gel.

6. The method for preparing a composite gel for cigarette filter rods according to claim 4, characterized in that, The method for preparing the cellulose diacetate grafted polycaprolactone is as follows: B1: Add dried cellulose diacetate and ε-caprolactone to the polymerization tube, and add stannous octoate; B2: After evacuation, heat the reactants to 150°C, then introduce nitrogen gas and stir for 12 hours; B3: After stirring is stopped, the obtained reactants are dissolved in chloroform, precipitated by adding anhydrous methanol, filtered and dried to obtain cellulose diacetate grafted polycaprolactone.

7. A method for preparing a composite gel for cigarette filter rods according to claim 6, characterized in that, The mass ratio of cellulose diacetate to ε-caprolactone is 15-20:2-5.