Heated cigarette end face sealing film with antibacterial and antiseptic functions, preparation method thereof and heated cigarette

Abstract

The application provides a heating cigarette end face sealing film with antibacterial and antiseptic functions, a preparation method thereof and a heating cigarette, and belongs to the technical field of tobacco products. The heating cigarette end face sealing film comprises: a thermally adhesive layer, which is an inner layer for being in contact with the end face of the heating cigarette and being softened under heating conditions to realize adhesive fixation of the thermally adhesive layer and the end face of the heating cigarette; and a release layer, which is an outer layer for preventing the heating cigarette end face sealing film from being adhered to the inner wall of a heating device under the working state of the heating device. The antibacterial agent is uniformly dispersed in the thermally adhesive layer and / or the release layer. The central region of the heating cigarette end face sealing film is provided with a pre-cut structure penetrating through the film thickness, so as to facilitate the insertion and removal of the heating component in the heating device.

Description

Technical Field

[0001] This application belongs to the field of tobacco product technology, and in particular relates to a sealing film for the end face of heated cigarettes with antibacterial and anti-corrosion functions, its preparation method, and heated cigarettes. Background Technology

[0002] Heated cigarettes are tobacco products that produce an aerosol by heating rather than burning tobacco materials. To generate sufficient smoke, a large amount of smoke-generating agents, mainly glycerin and propylene glycol, are usually added to the tobacco. Because glycerin and propylene glycol are highly hydrophilic, heated cigarette tobacco is prone to absorbing moisture during storage and use. Studies have shown that in high-temperature and high-humidity environments, moisture absorption by the tobacco easily leads to mold growth and spoilage. In the early stages of mold growth, mold mycelium appears at both ends of the heated cigarette, the aroma is lost, and a sour, musty odor develops. In the later stages, mold growth intensifies, and the colonies change from white downy hairs to green, blue, or black powdery substances, severely affecting the smoking experience, deteriorating product quality, and shortening shelf life. Therefore, preventing mold growth on the ends of heated cigarettes due to moisture absorption during storage is a pressing issue. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a heated cigarette end-face sealing film with antibacterial and anti-corrosion functions, its preparation method, and a heated cigarette, aiming to at least partially solve the above-mentioned technical problems. The specific technical solution provided by this application is as follows.

[0004] As a first aspect of this application, a heated cigarette end-face sealing film with antibacterial and anti-corrosion functions is provided, comprising: a thermosetting adhesive layer, an inner layer for contacting the heated cigarette end-face and softening under heating conditions to achieve adhesion and fixation between the thermosetting adhesive layer and the heated cigarette end-face; and an anti-adhesion layer, an outer layer for preventing the heated cigarette end-face sealing film from adhering to the inner wall of the heated cigarette device during operation. An antibacterial agent is uniformly dispersed in the thermosetting adhesive layer and / or the anti-adhesion layer; the central region of the heated cigarette end-face sealing film has a pre-cut structure penetrating the film thickness to facilitate the insertion and removal of the heating component in the heated cigarette device.

[0005] As a second aspect of this application, a method for preparing a heated cigarette end-face sealing film is provided, comprising: providing a thermosensitive adhesive layer film-forming base liquid and an anti-adhesive layer film-forming base liquid, wherein an antibacterial agent is uniformly dispersed in the thermosensitive adhesive layer film-forming base liquid and / or the anti-adhesive layer film-forming base liquid; co-casting the thermosensitive adhesive layer film-forming base liquid and the anti-adhesive layer film-forming base liquid using a multilayer casting equipment to obtain a composite film layer in which the thermosensitive adhesive layer and the anti-adhesive layer are bonded together; and drying and cutting the composite film layer to obtain a heated cigarette end-face sealing film with antibacterial and anti-corrosion functions.

[0006] As a third aspect of this application, a heated cigarette is provided, comprising: a cigarette body, which includes a filter section, a hollow section and a tobacco section in sequence along the length of the cigarette body; and a heated cigarette end-face sealing film, which is attached to the end face of the tobacco section away from the hollow section.

[0007] In this embodiment, the antibacterial and antiseptic sealing film for heated cigarette ends (hereinafter referred to as the sealing film) provided in this application, by uniformly dispersing antibacterial agents in the thermosetting adhesive layer and / or anti-sticking layer, can continuously inhibit the growth of microorganisms during storage and prevent mold and spoilage of the heated cigarette end. Simultaneously, the sealing film has a pre-cut structure penetrating the film thickness in its central area, facilitating the smooth insertion and removal of heating components in the heated cigarette device. During assembly of the sealing film and the heated cigarette end, heating softens the thermosetting adhesive layer and achieves a firm bond with the end face of the tobacco segment. In the subsequent working state of the heated cigarette device, the anti-sticking layer effectively prevents the sealing film from adhering to the inner wall of the heated cigarette device, ensuring smooth operation. Prepared using a multi-layer casting and co-casting method, the process is simple and suitable for mass production. Applying the sealing film to the end face of the tobacco segment away from the hollow section provides reliable antibacterial protection, extends product shelf life, and improves the user experience. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of the sealing film for the heated cigarette end face in an embodiment of this application.

[0009] Explanation of reference numerals in the attached figures:

[0010] 10 - Heating the sealing film at the end of the cigarette;

[0011] 101-Cross Heated Joint;

[0012] 102 - Central tear-resistant seam;

[0013] 103 - Central anti-tear seam;

[0014] 104 - End tear-resistant seam. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0016] In realizing the concept of this application, it was discovered that existing anti-mold technologies mainly involve directly adding anti-mold agents to tobacco or applying them to the filter of traditional cigarettes. However, the tobacco segments of heated cigarettes are directly exposed to the environment, and during use, a central heating rod must be inserted into the tobacco segments, making the heated cigarette end face a major channel for mold invasion. Furthermore, the special nature of tobacco products requires that the added antibacterial substances strictly comply with the list of permitted tobacco additives. Based on this, this application provides a heated cigarette end face sealing film with antibacterial and anti-corrosion functions. By setting a thermosensitive adhesive layer in contact with the heated cigarette end face and an anti-sticking layer to prevent adhesion, and uniformly dispersing an antibacterial agent that meets the permitted requirements within these layers, a continuous antibacterial barrier is formed on the end face when the heated cigarette is not in use, thereby effectively inhibiting mold growth and preventing tobacco from becoming moldy and rotten, while also providing adhesion and anti-sticking functions during heating.

[0017] As a first aspect of this application, a heated cigarette end-face sealing film with antibacterial and anti-corrosion functions is provided, comprising: a thermosetting adhesive layer, an inner layer for contacting the heated cigarette end-face and softening under heating conditions to achieve adhesion and fixation between the thermosetting adhesive layer and the heated cigarette end-face; and an anti-adhesion layer, an outer layer for preventing the heated cigarette end-face sealing film from adhering to the inner wall of the heated cigarette device during operation. An antibacterial agent is uniformly dispersed in the thermosetting adhesive layer and / or the anti-adhesion layer; the central region of the heated cigarette end-face sealing film has a pre-cut structure penetrating the film thickness to facilitate the insertion and removal of the heating component in the heated cigarette device.

[0018] In this embodiment, the heated cigarette end-face sealing film with antibacterial and anti-corrosion functions provided in this application has a thermosensitive adhesive layer as the inner layer, which softens under heating conditions and firmly adheres to the heated cigarette end-face; and an anti-stick layer as the outer layer, which effectively prevents the sealing film from sticking to the inner wall of the heated cigarette device during operation, ensuring smooth use; at the same time, an antibacterial agent is uniformly dispersed in the thermosensitive adhesive layer and / or the anti-stick layer, which can continuously inhibit the growth of microorganisms during storage and prevent mold and spoilage of the heated cigarette end-face; in addition, the pre-cut structure in the central area that runs through the film thickness facilitates the smooth insertion and removal of the heating component in the heated cigarette device, avoiding film damage or inconvenience in operation. Thus, this sealing film integrates multiple functions such as reliable end-face sealing, anti-sticking, antibacterial and anti-corrosion, and adaptation to the insertion of heating components, significantly improving the storage stability and ease of use of heated cigarettes.

[0019] In some embodiments, the antibacterial agent is selected from at least one of benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, methylparaben, ethylparaben, propylparaben, and butylparaben.

[0020] In the embodiments of this application, the antibacterial agents selected are all anti-mold additives permitted by relevant standards in the tobacco industry, possessing good antibacterial activity and safety in use; they can effectively inhibit the growth and reproduction of microorganisms such as mold during the storage of heated cigarette ends, preventing mold, decay, and off-odors from occurring on the tobacco ends; at the same time, the antibacterial agents have good compatibility with the thermosetting adhesive layer and anti-sticking layer materials, and after uniform dispersion, they do not affect the adhesive and anti-sticking properties of the sealing film, thereby achieving reliable antibacterial and anti-corrosion effects while ensuring safety and compliance.

[0021] In some embodiments, the amount of antibacterial agent added is 0.1%-1% of the total weight of the thermosensitive adhesive layer or the release layer, for example, it can be 0.1%, 0.3%, 0.5%, 0.8%, or 1%.

[0022] In this embodiment, by controlling the amount of antibacterial agent added within an appropriate range, it is possible to ensure that the agent is evenly dispersed in the sealing film to achieve an effective antibacterial concentration, thereby persistently inhibiting the growth and reproduction of microorganisms such as mold on the heated cigarette end face and preventing mold and spoilage. At the same time, the amount added will not adversely affect the thermal adhesion performance of the thermosetting adhesive layer or the anti-adhesion performance of the anti-adhesion layer, nor will it cause excessive precipitation or migration of the antibacterial agent. Thus, while ensuring the antibacterial and anti-corrosion effects, the sealing film maintains good mechanical strength and reliability.

[0023] In some embodiments, the thermosensitive adhesive layer includes a first polymer material that softens and becomes tacky at 60-110°C.

[0024] Furthermore, the first polymeric material is selected from at least one of polypropylene copolymer and ethylene-vinyl acetate copolymer.

[0025] Furthermore, polypropylene copolymers include propylene / ethylene / butene copolymers, ethylene / propylene copolymers, etc., with an initial heat-sealing temperature of 100-115℃ and a melting point of 125-145℃; the mass content of vinyl acetate in ethylene-vinyl acetate copolymers is 18%-28%.

[0026] In this embodiment, a first polymeric material that softens and becomes viscous under heating conditions is selected as the thermosensitive adhesive layer. This material is selected from at least one of polypropylene copolymer or ethylene-vinyl acetate copolymer, wherein the polypropylene copolymer has a suitable heat-sealing temperature and melting point range, and the ethylene-vinyl acetate copolymer has an appropriate vinyl acetate content. This allows the thermosensitive adhesive layer to achieve reliable and uniform thermal bonding and fixation when assembled with the heated cigarette end face, and the bonding strength is moderate, without affecting the integrity of the film layer due to excessive flow. At the same time, the above material has good compatibility with the anti-stick layer and antibacterial agent, and maintains a stable physical form during storage and use, ensuring the overall structural strength and reliability of the sealing film.

[0027] In some embodiments, the anti-stick layer includes a second polymer material that remains solid at 150-170°C and has a non-sticky surface.

[0028] Furthermore, the second polymer material is selected from at least one of homopolymer polypropylene, polyethylene terephthalate, and polyamide.

[0029] In this embodiment, a second polymer material that remains solid and non-adhesive during the operation of the heated cigarette device is selected as the anti-adhesive layer. This material is selected from at least one of homopolymer polypropylene, polyethylene terephthalate, or polyamide. This ensures that the anti-adhesive layer can effectively maintain its morphological stability and non-adhesive properties within the operating temperature range of the heated cigarette device, thereby reliably preventing the sealing film at the end of the heated cigarette from adhering to the inner wall of the heated cigarette device, ensuring smooth insertion and removal of the heated cigarette. At the same time, the above-mentioned material has good mechanical strength and thermal stability, which can provide effective support for the temperature-induced adhesive layer, avoiding damage or deformation during storage or use, further improving the overall reliability and user experience of the sealing film.

[0030] In some embodiments, the thickness of the sealing film on the heated cigarette end face is 50μm-100μm, for example, it can be 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm; the basis weight is 20g / m². 2 -60g / m 2 For example, it can be 20g / m 2 30g / m 2 40g / m 2 50g / m 2 60g / m 2 The elongation at break is 100-200%, for example, it can be 100%, 120%, 150%, 180%, 200%; the heat seal strength is ≥2.5N / 15mm, for example, it can be 2.5N / 15mm, 5N / 15mm, etc.; the coefficient of friction is ≤0.3, for example, it can be 0.1, 0.2, 0.3.

[0031] In this embodiment, by controlling the thickness, weight, elongation at break, heat seal strength, and coefficient of friction of the sealing film on the heated cigarette end face within a suitable range, the sealing film possesses both good flexibility and mechanical strength, making it less prone to damage during storage and transportation. Simultaneously, it achieves a firm heat seal bond with the heated cigarette end face, ensuring the sealing film remains intact before use. Furthermore, the low coefficient of friction ensures a smooth surface for the anti-stick layer, effectively reducing contact resistance with the inner wall during the operation of the heated cigarette device, facilitating smooth insertion and removal of the heated cigarette. This comprehensively improves the sealing film's reliability, processing adaptability, and user convenience.

[0032] In some embodiments, the thickness of the heat-induced adhesive layer is 30 μm - 60 μm, and for example, it can be 30 μm, 40 μm, 50 μm, 60 μm; the thickness of the anti-sticking layer is 20 μm - 40 μm, and for example, it can be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm.

[0033] In the embodiments of the present application, by controlling the thicknesses of the heat-induced adhesive layer and the anti-sticking layer within appropriate ranges respectively, the overall structure of the sealing film ensures that the heat-induced adhesive layer has sufficient heat-bonding ability and structural integrity to firmly adhere to the end face of the heated cigarette, and at the same time ensures that the anti-sticking layer maintains a stable isolation effect and surface smoothness under the working state of the heating烟具, preventing adhesion. Meanwhile, the reasonable double-layer thickness ratio helps the sealing film to maintain uniformity during the casting process, improves the flexibility and tensile resistance of the sealing film, and avoids processing defects or usage failures caused by too thick or too thin single layers, thus achieving a good balance among bonding reliability, anti-adhesion effect, and preparation process stability.

[0034] Figure 1 It is a schematic structural diagram of the sealing film for the end face of the heated cigarette in the embodiments of the present application.

[0035] In some embodiments, as Figure 1 shown, a pre-cut structure penetrating the film thickness is provided in the central region of the sealing film 10 for the end face of the heated cigarette. The pre-cut structure includes a cross heating seam 101 and a central anti-tearing seam 102. Further, the pre-cut structure further includes a middle anti-tearing seam 103 and / or an end anti-tearing seam 104.

[0036] In some embodiments, the length of the cross heating seam 101 is 1 / 3 to 1 / 2 of the diameter of the sealing film, and the central anti-tearing seam 102 is arranged at an angle of 45° with the cross heating seam 101, so that the cross heating seam 101 and the central anti-tearing seam 102 jointly form a "rice" - shaped structure, and the length of the central anti-tearing seam 102 is 1 / 10 to 1 / 5 of the length of the cross heating seam 101. Through this "rice" - shaped pre-cut, it not only ensures that the heating component can be smoothly inserted, but also effectively controls the cracking direction and range of the sealing film layer, avoiding large - scale unexpected tearing of the sealing film.

[0037] Further, two middle anti-tearing seams 103 and two end anti-tearing seams 104 are arranged along the length direction of each heating seam in the cross heating seam 101. Among them, the spacing of the middle anti-tearing seams 103 is 0.5 mm - 1.0 mm; the lengths of the middle anti-tearing seams 103 and the end anti-tearing seams 104 are 0.2 mm - 0.5 mm. Both the middle anti-tearing seams 103 and the end anti-tearing seams 104 are perpendicular to the extending direction of the cross heating seam 101 where they are located.

[0038] Through the reasonable design of the above dimensions and layout, the central anti-tearing crack 102 and the cross heating crack 101 together form a "rice" - shaped guiding structure, which is convenient for the heating component to be aligned and inserted; the middle anti-tearing crack 103 and the end anti-tearing crack 104 further guide the sealing film to undergo a controllable small tear along a predetermined path when stressed, avoiding large - area damage or local warping of the sealing film caused by multiple insertions or extractions of the heating component. Thus, while ensuring the smooth passage of the heating component through the film layer, the use reliability and overall structural integrity of the sealing film are significantly improved.

[0039] As the second aspect of the present application, a method for preparing a heating cigarette end - face sealing film is provided, including: providing a thermo - induced adhesive layer film - forming base liquid and an anti - sticking layer film - forming base liquid, wherein an antibacterial agent is uniformly dispersed in the thermo - induced adhesive layer film - forming base liquid and / or the anti - sticking layer film - forming base liquid; using a multi - layer casting device to co - cast the thermo - induced adhesive layer film - forming base liquid and the anti - sticking layer film - forming base liquid to obtain a composite film layer in which the thermo - induced adhesive layer and the anti - sticking layer are adhered to each other; drying and cutting the composite film layer to obtain a heating cigarette end - face sealing film with antibacterial and anticorrosive functions.

[0040] In the embodiments of the present application, by separately preparing the thermo - induced adhesive layer film - forming base liquid and the anti - sticking layer film - forming base liquid, and uniformly dispersing an antibacterial agent in at least one layer, then using a multi - layer casting device for co - casting to obtain a double - layer composite film layer in one step, and then drying and cutting, a heating cigarette end - face sealing film with antibacterial and anticorrosive functions can be obtained. This method has a short process flow, is easy to operate, and is suitable for industrial continuous production; the co - casting technology ensures a tight interface bonding and no delamination between the thermo - induced adhesive layer and the anti - sticking layer, and at the same time, the antibacterial agent is evenly distributed in the layer, ensuring the antibacterial and anticorrosive effect of the sealing film; the drying and cutting processes can flexibly control the size according to requirements, and the product has good consistency and stable quality.

[0041] Exemplarily, the present application provides a method for preparing a heating cigarette end - face sealing film, and the specific process is as follows.

[0042] S1. Preparation of the thermo - induced adhesive layer film - forming base liquid: Dissolve the first polymer material in the first solvent, add an antibacterial agent that complies with the list of permitted tobacco additives, and stir evenly to obtain the thermo - induced adhesive layer film - forming base liquid.

[0043] S2. Preparation of the anti - sticking layer film - forming base liquid: Dissolve the second polymer material in the second solvent, add or not add an antibacterial agent, and stir evenly to obtain the anti - sticking layer film - forming base liquid.

[0044] S3. Multi - layer casting and compounding: Using a multi - layer casting device, simultaneously cast the thermo - induced adhesive layer film - forming base liquid and the anti - sticking layer film - forming base liquid onto a flat substrate to obtain a composite film layer in which the thermo - induced adhesive layer and the anti - sticking layer are adhered to each other, and control the total thickness of the composite film layer to be 60 - 120 μm.

[0045] S4. Laser Die Cutting: A laser cutting device is used to process a pre-cut structure in the center of the composite film layer. The pre-cut structure includes a cross-shaped heating seam and a central anti-tear seam, and further includes a middle anti-tear seam and / or an end anti-tear seam.

[0046] S5. Drying and shaping: Dry the die-cut composite film at 30-50℃ for 2-6 hours to remove the solvent. The drying temperature is lower than the softening point temperature of the first polymer material.

[0047] S6. Die-cutting: The dried composite film is die-cut into the required shape and size to obtain a heated cigarette end-face sealing film with antibacterial and anti-corrosion functions.

[0048] In some embodiments, in step S1, the first solvent is at least one of toluene and ethyl acetate, and the mass concentration of the first polymeric material is 15%-25%.

[0049] In some embodiments, in step S2, the second solvent is at least one of toluene and xylene, and the mass concentration of the second polymer material is 10%-20%.

[0050] In some embodiments, in step S4, the power of the laser cutting device is 10W-30W, the cutting speed is 50mm / s-200mm / s, and the kerf width is 20μm-50μm.

[0051] As a third aspect of this application, a heated cigarette is provided, comprising: a cigarette body, which includes a filter segment, a hollow segment and a tobacco segment in sequence along the length of the cigarette body; and a heated cigarette end-face sealing film, which is attached to the end face of the tobacco segment away from the hollow segment.

[0052] For example, the total length of the cigarette is 45mm, and along its length are a filter section, a hollow section and a tobacco section, wherein the length of the filter section is 7mm, the length of the hollow section is 26mm, and the length of the tobacco section is 12mm; the circumference of the cigarette is 22.6mm, and the corresponding diameter is 7.2mm.

[0053] In the embodiments of the present application, the heated cigarette provided by the present application attaches the end sealing film with antibacterial and anti-corrosion functions to the end surface of the tobacco rod section away from the hollow section, so that the sealing film continuously inhibits the growth of microorganisms during storage, prevents mildew or corruption of the end surface of the tobacco rod, and extends the product shelf life; at the same time, the pre-cut structure in the center of the sealing film facilitates the smooth insertion of the heating component of the heating烟具 into the tobacco rod section, and its anti-sticking layer can avoid adhesion to the inner wall of the heating烟具 during the heating working state, ensuring the smoothness of inserting and removing the heated cigarette. In addition, the sealing film, the filter rod section, and the hollow section together form a complete heated cigarette structure, which not only maintains the stable transmission path of the aerosol during suction but also ensures the integrity of the end surface seal, thus effectively improving the storage reliability and hygienic safety of the heated cigarette while ensuring the convenience of use and the suction experience.

[0054] The following further illustrates the present application through examples and related test experiments. In the following detailed description, for the sake of explanation, many specific details are elaborated to provide a comprehensive understanding of the embodiments of the present application. However, obviously, one or more embodiments can also be implemented without these specific details. Moreover, without conflict, the details in the following embodiments can be arbitrarily combined into other feasible embodiments. All instruments, consumables, reagents, etc. in the following embodiments can be obtained from commercial channels without special instructions.

[0055] Example 1

[0056] This example provides an end sealing film for a heated cigarette with antibacterial and anti-corrosion functions, and its structure is as follows:

[0057] The inner layer is a temperature-induced adhesive layer, using terpolypropylene (propylene / ethylene / butene copolymer) as the first polymer material. The initial heat sealing temperature of this material is 105 °C, and the melting point is 125 °C. Sodium benzoate, an antibacterial agent that complies with the list of permitted tobacco additives, is added to the inner layer, and the addition amount is 0.3% of the mass of the propylene / ethylene / butene copolymer.

[0058] The outer layer is an anti-sticking layer, using homopolypropylene as the second polymer material, with a melting point of 165 °C, and no antibacterial agent is added to the outer layer.

[0059] In the structure of the sealing film, the total thickness is 70 μm, of which the inner layer thickness is 45 μm and the outer layer thickness is 25 μm. The sealing film is circular, with a diameter of 7.2 mm and a grammage of 45 g / m 2 . A pre-cut structure is provided in the central area of the sealing film. Specifically: the length of the cross-shaped heating seam is 2.5 mm; the central anti-tearing seam is set at the cross point, at a 45° angle to the cross-shaped heating seam, with a length of 0.4 mm, forming an overall "rice" shape structure.

[0060] This embodiment also provides a method for preparing the above-mentioned heated cigarette end-face sealing film, which specifically includes the following steps:

[0061] S1. Preparation of the inner layer film-forming base solution: Add ternary copolymer polypropylene to a mixed solvent of toluene and ethyl acetate in a volume ratio of 7:3 to prepare a 20% (w / w) solution. Stir in a 60°C water bath until completely dissolved. Then add sodium benzoate and continue stirring for 30 minutes until homogeneous to obtain the inner layer film-forming base solution.

[0062] S2. Preparation of outer film-forming base solution: Add homopolymer polypropylene to xylene to prepare a solution with a mass concentration of 15%, and stir in an 80℃ water bath until completely dissolved to obtain the outer film-forming base solution.

[0063] S3. Multilayer Casting Composite: Using a double-layer casting equipment, the inner layer film-forming base liquid and the outer layer film-forming base liquid are simultaneously cast onto a polytetrafluoroethylene-coated glass plate, controlling the total casting thickness to be 85μm (the final thickness after drying shrinkage is 70μm), and the thickness ratio of the inner layer to the outer layer is approximately 6:4, to obtain a composite film layer.

[0064] S4. Laser Die Cutting: A laser cutting device with a power of 20W and a cutting speed of 100mm / s is used to process a pre-cut structure in the center of the composite film layer, with a kerf width of 30μm.

[0065] S5. Drying and Shaping: Place the die-cut composite film in a 40°C constant temperature drying oven for 4 hours until the residual solvent content is less than 2%. This drying temperature (40°C) is lower than the initial heat sealing temperature (105°C) of the inner ternary copolymer polypropylene. Therefore, the composite film remains solid and non-sticky during the drying process.

[0066] S6. Die-cutting: The dried composite film is cut into small circular pieces with a diameter of 7.2mm using a circular die-cutting mold, thus obtaining a heated cigarette end-face sealing film with antibacterial and anti-corrosion functions.

[0067] Example 2

[0068] In this embodiment, the inner thermotropic adhesive layer uses ethylene-vinyl acetate copolymer (EVA) as the first polymer material, with a vinyl acetate (VA) content of 22%, a softening point of approximately 65°C, and a melting point of approximately 85°C. The inner layer contains propylparaben, an antibacterial agent conforming to the licensed list, added at 0.2% of the mass of the ethylene-vinyl acetate copolymer. The outer anti-stick layer uses polyethylene terephthalate (PET) as the second polymer material and does not contain any antibacterial agent.

[0069] The sealing film structure has a total thickness of 70μm, with an inner layer thickness of 40μm and an outer layer thickness of 30μm. The pre-cut structure specifically consists of a cross-shaped heating seam with a length of 3.0mm and a central tear-resistant seam with a length of 0.5mm.

[0070] The preparation method in this embodiment is as follows:

[0071] Inner layer film-forming base solution preparation: Ethylene-vinyl acetate copolymer was added to ethyl acetate to prepare a solution with a mass concentration of 22%. Outer layer film-forming base solution was prepared according to the corresponding method in Example 1 (using PET and the corresponding solvent). The multilayer casting lamination, laser die-cutting, and die-cutting steps were basically the same as in Example 1, except that the drying temperature was 35°C and the drying time was 5 hours.

[0072] Example 3

[0073] In this embodiment, the inner thermosetting adhesive layer uses binary copolymer polypropylene (ethylene / propylene copolymer) as the first polymer material, with an initial heat-sealing temperature of 115°C and a melting point of 135°C. Potassium sorbate, an antibacterial agent conforming to the permitted list of tobacco additives, is added to the inner layer at 0.25% of the mass of the ethylene / propylene copolymer. The outer anti-stick layer uses homopolymer polypropylene as the second polymer material and does not contain any antibacterial agent.

[0074] The sealing film structure has a total thickness of 60 μm, with an inner layer thickness of 35 μm and an outer layer thickness of 25 μm. The pre-cut structure is the same as in Example 1.

[0075] The preparation method in this embodiment is as follows:

[0076] Inner layer film-forming base solution preparation: Ethylene / propylene copolymer was added to a toluene-ethyl acetate mixed solvent (7:3) to prepare a 20% (w / w) solution. Potassium sorbate was added and stirred until homogeneous. Outer layer film-forming base solution was prepared according to the method in Example 1. The multilayer casting lamination, laser die-cutting, and die-cutting steps were basically the same as in Example 1, except that the drying temperature was 45°C and the drying time was 3 hours.

[0077] Example 4

[0078] In this embodiment, the inner thermosetting adhesive layer uses ternary copolymer polypropylene (propylene / ethylene / butene copolymer) as the first polymer material, with an initial heat-sealing temperature of 105°C and a melting point of 125°C. Benzoic acid, an antibacterial agent conforming to the list of permitted tobacco additives, is added to the inner layer at 0.2% of the mass of the propylene / ethylene / butene copolymer. The outer anti-stick layer uses homopolymer polypropylene as the second polymer material and does not contain any antibacterial agent.

[0079] The sealing film structure has a total thickness of 90 μm, with an inner layer thickness of 50 μm and an outer layer thickness of 40 μm. The pre-cut structure is the same as in Example 1.

[0080] The preparation method in this embodiment is as follows:

[0081] Inner layer film-forming base solution preparation: Benzoic acid and ternary copolymer polypropylene were added together to a toluene-ethyl acetate mixed solvent (7:3) to prepare a 20% (w / w) solution, which was stirred until completely dissolved and uniformly dispersed. Outer layer film-forming base solution was prepared according to the method in Example 1. The multilayer casting lamination, laser die-cutting, and die-cutting steps were basically the same as in Example 1, except that the drying temperature was 40℃ and the drying time was 5 hours.

[0082] Comparative Example 1

[0083] The difference between Comparative Example 1 and Example 1 is that no antibacterial agent was added during the preparation of the sealing film.

[0084] Comparative Example 2

[0085] Comparative Example 2: The heated cigarettes were not sealed with a sealing film.

[0086] The following tests were conducted on heated cigarettes with sealing films from Examples 1-4 and Comparative Example 1, and on heated cigarettes from Comparative Example 2, and the results are as follows:

[0087] (1) Antibacterial performance test: Referring to GB 4789.2-2022 standard, Aspergillus niger was used as the test strain to test the antibacterial effect of the sealing film. Heated cigarettes with sealing films (Examples 1-4, Comparative Example 1) and heated cigarettes of Comparative Example 2 were placed in an environment with a temperature of 38℃ and a relative humidity of 100% for 14 days. The growth of mold was observed every 2 days. The test results are shown in Table 1. The results showed that: visible mold colonies appeared on the 6th day of Comparative Example 2, and obvious mold spots covered the surface of the tobacco shreds on the 10th day; no obvious mold growth was observed in Comparative Example 1 for the first 10 days, slight mold growth appeared on the 14th day, and more obvious mold growth appeared on the 21st day; no obvious mold growth was observed in Examples 1-4 until the 14th day, indicating that the sealing film has excellent antibacterial and anti-mold effects.

[0088] Table 1. Antibacterial and antifungal effects of heated cigarettes in Examples 1-4 and Comparative Examples 1 and 2.

[0089]

[0090] (2) Insertion test: The sealing films prepared in Examples 1-4 and Comparative Example 1 were pasted onto the end face of heated cigarettes. After pasting 100 cigarettes in each group, the cigarette straight-pull rate was evaluated using an internal evaluation table. The results are shown in Table 2. The results show that Examples 1-4 and Comparative Example 1 all passed the cigarette straight-pull rate test, indicating that the heated cigarettes prepared using the method of this application can meet the requirements for straight-pull heating of cigarettes.

[0091] Table 2 Evaluation results of the straight draw rate of heated cigarettes prepared in Examples 1-4 and Comparative Examples 1-2

[0092]

[0093] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A sealing film for the end face of heated cigarettes with antibacterial and antiseptic functions, characterized in that, The heated cigarette end-face sealing film includes: A thermosetting adhesive layer is an inner layer that contacts the end face of a heated cigarette and softens under heating conditions to achieve adhesion and fixation between the thermosetting adhesive layer and the end face of the heated cigarette; and The anti-stick layer is an outer layer used to prevent the sealing film on the end face of the heated cigarette from sticking to the inner wall of the heated cigarette when the heated cigarette is in operation. An antibacterial agent is uniformly dispersed in the thermosensitive adhesive layer and / or the anti-adhesive layer; The central area of ​​the sealing film on the end face of the heated cigarette has a pre-cut structure that extends through the film thickness to facilitate the insertion and removal of the heating component in the heated cigarette device.

2. The heated cigarette end-face sealing film according to claim 1, characterized in that, The antibacterial agent is selected from at least one of benzoic acid, sodium benzoate, sorbic acid, potassium sorbate, methylparaben, ethylparaben, propylparaben, and butylparaben.

3. The heated cigarette end-face sealing film according to claim 2, characterized in that, The amount of antibacterial agent added is 0.1%-1% of the total weight of the thermosensitive adhesive layer or the anti-adhesive layer.

4. The heated cigarette end-face sealing film according to claim 1, characterized in that, The thermosensitive adhesive layer includes a first polymer material, which softens and becomes sticky at 60-110°C. The non-stick layer includes a second polymer material, which remains solid at 150-170°C and has a non-sticky surface.

5. The heated cigarette end-face sealing film according to claim 4, characterized in that, The first polymer material is selected from at least one of polypropylene copolymer and ethylene-vinyl acetate copolymer; The second polymer material is selected from at least one of homopolymer polypropylene, polyethylene terephthalate, and polyamide.

6. The heated cigarette end-face sealing film according to claim 1, characterized in that, The thickness of the sealing film on the heated cigarette end face is 50μm-100μm, and the basis weight is 20g / m². 2 -60g / m 2 The elongation at break is 100-200%, the heat seal strength is ≥2.5N / 15mm, and the coefficient of friction is ≤0.

3.

7. The heated cigarette end-face sealing film according to any one of claims 1-6, characterized in that, The pre-cut structure includes a cross-shaped heating seam and a central tear-resistant seam.

8. The heated cigarette end-face sealing film according to claim 7, characterized in that, The pre-cut structure also includes a central tear-resistant seam and / or an end tear-resistant seam.

9. A method for preparing a heated cigarette end-face sealing film as described in any one of claims 1-8, characterized in that, include: A thermosensitive adhesive layer film-forming base liquid and an anti-adhesive layer film-forming base liquid are provided, wherein an antibacterial agent is uniformly dispersed in the thermosensitive adhesive layer film-forming base liquid and / or the anti-adhesive layer film-forming base liquid; The thermo-adhesive layer film-forming base liquid and the anti-adhesive layer film-forming base liquid are co-cast using a multilayer casting equipment to obtain a composite film layer in which the thermo-adhesive layer and the anti-adhesive layer are bonded together. After drying and cutting the composite film layer, a heated cigarette end-face sealing film with antibacterial and anti-corrosion functions is obtained.

10. A heated cigarette, characterized in that, The heated cigarette includes: The cigarette body, along its length, sequentially includes a filter section, a hollow section, and a tobacco section; and The heated cigarette end-face sealing film as described in any one of claims 1-8 is adhered to the end face of the tobacco section away from the hollow section.

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