Waterproof antibacterial metal foil for a cigarette case and method of manufacturing the same

Abstract

The embodiment of the present application provides a waterproof and antibacterial metal foil for a cigarette case and a manufacturing method thereof, and the manufacturing method comprises the following steps: a through hole is formed on an aluminum foil to obtain a holed aluminum foil; the aluminum foil and the holed aluminum foil are soaked in an aluminum foil treatment solution for 5-15 minutes, and the temperature of the aluminum foil treatment solution is maintained at 45-67 DEG C; the aluminum foil after the soaking treatment and the holed aluminum foil after the soaking treatment are respectively attached to the upper layer and the lower layer of a composite antibacterial film to obtain a composite film layer; and the composite film layer is heated to a preset hot pressing temperature and is pressed between the pressing rollers to obtain the corresponding waterproof and antibacterial metal foil. The manufacturing method described above clamps the composite antibacterial film between the aluminum foil and the holed aluminum foil to improve the tensile property of the metal foil, the composite antibacterial film is obtained by compounding a polymer layer and an antibacterial layer, the antibacterial compound is released through the through hole of the holed aluminum foil by the antibacterial layer, and the inside of the cigarette case is subjected to persistent antibacterial treatment.

Description

Technical Field

[0001] This invention relates to the field of processing and manufacturing technology, and in particular to a waterproof and antibacterial metal foil for cigarette boxes and its manufacturing method. Background Technology

[0002] To achieve reusable cigarette boxes, a type of reusable, infinitely openable metal or plastic box is currently used in the market, possessing cultural symbolic value and strong appeal. For reusable metal or plastic cigarette boxes, sealing is required during transportation and storage to prevent cigarettes from getting damp. Current technology typically uses an aluminum foil sealing process. However, while this method solves the sealing problem, external impurities entering the box can carry bacteria that may multiply inside during transportation, contaminating the clean environment inside the box. Therefore, the aluminum foil sealing technology used in current methods suffers from poor antibacterial performance. Summary of the Invention

[0003] This invention provides a waterproof and antibacterial metal foil for cigarette boxes and its manufacturing method, aiming to solve the problem of poor antibacterial effect in the existing technology of sealing cigarette boxes using aluminum foil bonding and sealing process.

[0004] This invention provides a method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes, comprising the following steps: Perforated aluminum foil is obtained by creating through holes in aluminum foil. The aluminum foil and the perforated aluminum foil are immersed in an aluminum foil treatment solution for 5 to 15 minutes, while maintaining the temperature of the aluminum foil treatment solution at 45 to 67°C. A composite film layer is obtained by attaching an impregnated aluminum foil and an impregnated perforated aluminum foil to the upper and lower layers of the composite antibacterial film, respectively. The composite film layer is heated to a preset hot-pressing temperature and placed between pressure rollers for pressing, thereby obtaining the corresponding waterproof and antibacterial metal foil; The composite antibacterial film is formed by combining a polymer layer and an antibacterial layer, with the antibacterial layer closely attached to the perforated aluminum foil. The polymer layer is composed of 35-45% polyurethane resin, 16-35% isocyanate, and 28-42% ethyl acetate by weight percentage. The antibacterial layer includes a polytetrafluoroethylene film with an attached antibacterial agent.

[0005] This invention also provides a waterproof and antibacterial metal foil for cigarette boxes, wherein the waterproof and antibacterial metal foil is manufactured using the manufacturing method for waterproof and antibacterial metal foil for cigarette boxes as described in the first aspect above; The waterproof and antibacterial metal foil includes stacked aluminum foil, a composite antibacterial film, and perforated aluminum foil. The composite antibacterial film is obtained by combining a polymer layer and an antibacterial layer, with the antibacterial layer being closely attached to the perforated aluminum foil.

[0006] This invention also provides a cigarette case, wherein the cigarette case includes a case body, a case lid, an inner tray, and a waterproof and antibacterial metal foil for the cigarette case as described in the second aspect above; The waterproof and antibacterial metal foil covers the cavity of the inner tray; the waterproof and antibacterial metal foil is sealed to the top surface of the side wall of the cavity; one edge of the lid is hinged to the box body, the box body and the lid together form a cavity, the inner tray is disposed in the cavity, and the inner tray is used to hold cigarettes.

[0007] This invention provides a waterproof and antibacterial metal foil for cigarette boxes and its manufacturing method. The manufacturing method includes: creating through holes in aluminum foil to obtain perforated aluminum foil; immersing the aluminum foil and the perforated aluminum foil in an aluminum foil treatment solution for 5-15 minutes, maintaining the temperature of the aluminum foil treatment solution at 45-67°C; attaching the immersed aluminum foil and the immersed perforated aluminum foil to the upper and lower layers of a composite antibacterial film, respectively, to obtain a composite film layer; heating the composite film layer to a preset hot-pressing temperature and pressing it between pressure rollers to obtain the corresponding waterproof and antibacterial metal foil. In this manufacturing method, a composite antibacterial film is sandwiched between the aluminum foil and the perforated aluminum foil to improve the tensile strength of the metal foil. The composite antibacterial film is composed of a polymer layer and an antibacterial layer. Antibacterial compounds are released through the through holes in the perforated aluminum foil by the antibacterial layer to achieve long-lasting antibacterial protection for the inside of the cigarette box. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a flowchart illustrating a method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes, as provided in an embodiment of the present invention. Figure 2 A schematic diagram of the cross-sectional structure of the waterproof and antibacterial metal foil provided in an embodiment of the present invention; Figure 3 A side view of the waterproof and antibacterial metal foil provided in an embodiment of the present invention; Figure 4 This is an overall structural diagram of a cigarette box provided in an embodiment of the present invention; Figure 5This is an exploded structural diagram of a cigarette box provided in an embodiment of the present invention. Detailed Implementation

[0010] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0011] Description of raw materials and equipment in the examples: The polyurethane resin, model 7118, was purchased from Anhui Chunxiao Chemical Co., Ltd. Isocyanate, purchased from Jinan Haiyuan Chemical Co., Ltd., model PM-200; Ethyl acetate, purchased from Shandong Jinding New Material Technology Co., Ltd., model number 0101; Aluminum foil, purchased from Dongguan Dingsheng Copper and Aluminum Materials Co., Ltd. Polyvinyl alcohol, purchased from Tianjin Yongda Chemical Reagent Co., Ltd., model number 9002-89-5; Chitosan, purchased from Sinopharm Chemical Reagent Co., Ltd., with a purity of 99%; Eugenol, purchased from Jiangxi Yisenyuan Plant Fragrance Co., Ltd., model number 97-53-0 Polytetrafluoroethylene membrane, purchased from Jiangsu Baize Polymer Co., Ltd. Ethanol, purchased from Tianjin Yongda Chemical Reagent Co., Ltd., model number 64-17-5; Sulfuric acid, purchased from Tianjin Bodi Chemical Co., Ltd., model number 7664-93-9; Citric acid, purchased from Hebei Zhentian Food Additives Co., Ltd., model number 77-92-9; Acetic acid, purchased from Changzhou Qidi Chemical Co., Ltd., model number 64-19-7; Gallic acid, purchased from Wuhan Hengbiao Technology Co., Ltd., model number 149-91-7; Cobalt sulfate, purchased from Shandong Mengqi Chemical Co., Ltd., model number 10124-43-3; Potassium fluorozirconate, purchased from Xiongxian Fuhang Refractory Materials Manufacturing Co., Ltd., model number 16923-95-8; Disodium hydrogen phosphate, purchased from Shandong Mengqi Chemical Co., Ltd., model number 7558-79-4; Castor oil, purchased from Tianjin Chemical Reagent Factory No. 3, model number 8001-79-4; Polypropylene glycol, purchased from Shanghai Feizhuo Polyurethane Co., Ltd., model number 25322-69-4; Isophorone diisocyanate, purchased from Qingdao Xinyutian Chemical Co., Ltd., model number 4098-71-9; Dibutyltin dilaurate, purchased from Aladdin Reagent Company, model number 77-58-7; Dimethylolpropionic acid, purchased from Jiangyin Moore Chemical New Materials Co., Ltd., model number 4767-03-7; Chain extender, purchased from Shandong Wenhui Chemical Co., Ltd.; Epoxy resin E-44 was purchased from Shanghai Feizhuo Polyurethane Co., Ltd. Ethylene-methyl acrylate copolymer, purchased from Dongguan Nabaichuan Plastics Co., Ltd.; Trimethylolpropane, purchased from Nantong Subei Chemical Raw Materials Co., Ltd., model number 77-99-6; Triethylamine, purchased from Nantong Subei Chemical Raw Materials Co., Ltd., model number 121-44-8; Ethylenediamine, purchased from Nantong Subei Chemical Raw Materials Co., Ltd., model number 107-15-3; Hydrogen peroxide, purchased from Nantong Subei Chemical Raw Materials Co., Ltd., model number 7722-84-1; Instruments and equipment: constant temperature shaker, drying oven, flask with reflux condensation function, roller press; The strength test uses a tensile test method to determine the tensile strength between the aluminum foil and the polymer layer; Characterization and testing methods: The antibacterial performance was tested by measuring the diameter of the antibacterial zone using the agar plate diffusion method.

[0012] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0013] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0014] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0015] Please see Figure 1 , Figure 1This is a flowchart illustrating a method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes, as provided in an embodiment of the present invention. The method for manufacturing this waterproof and antibacterial metal foil for cigarette boxes is used to produce the waterproof and antibacterial metal foil described in the above embodiment. As shown in the figure, the method for manufacturing the waterproof and antibacterial metal foil for cigarette boxes includes steps S110 to S140.

[0016] S110. Through holes are made in aluminum foil to obtain perforated aluminum foil.

[0017] The through holes in the perforated aluminum foil are either circular or rectangular; the diameter of the circular through holes is 0.2–2.5 mm; the length of the long side of the rectangular through holes is 0.2–2.5 mm, and the length of the short side is 0.15–2.5 mm. The coverage area of ​​the through holes in the perforated aluminum foil is 10–18%. By limiting the thickness of the aluminum foil and the perforated aluminum foil to the range of 10–35 micrometers, both sufficient mechanical strength of the metal foil and the release of antibacterial compounds into the cigarette box are ensured.

[0018] S120. Immerse the aluminum foil and the perforated aluminum foil in the aluminum foil treatment solution for 5 to 15 minutes, and maintain the temperature of the aluminum foil treatment solution at 45 to 67°C.

[0019] The aluminum foil treatment solution comprises a cross-linked modified waterborne polyurethane emulsion, cobalt sulfate, potassium fluorozirconate, disodium hydrogen phosphate, and water. To further improve the treatment effect of the aluminum foil treatment solution on the aluminum foil surface, hydrogen peroxide can be added to the aluminum foil treatment solution at a concentration of 1.3-2.50 g / L. Its strong oxidizing properties remove trace amounts of oil and impurities from the aluminum foil surface and perform micro-etching treatment on the aluminum foil surface.

[0020] In a more specific embodiment, the aluminum foil treatment solution is prepared as follows: cobalt sulfate and potassium fluorozirconate are dissolved in deionized water to obtain an initial solution; the concentrations of cobalt sulfate and potassium fluorozirconate in the initial solution are 0.12~0.38wt% and 0.04~0.16wt%, respectively; the crosslinked modified waterborne polyurethane emulsion is mixed with the initial solution at a volume ratio of 1:(3~6.5); disodium hydrogen phosphate is added to the initial solution to adjust the pH of the solution to 5.5-8 to obtain the aluminum foil treatment solution.

[0021] The preparation method of the crosslinked modified waterborne polyurethane emulsion is as follows: castor oil and polypropylene glycol are added to a flask equipped with reflux condensation function; isophorone diisocyanate and dibutyltin dilaurate are added at proportions of 0.75~2 g / L and 0.35~0.8 g / L respectively, based on the volume of the reaction solution, and the mixture is heated to 65~75℃ and reacted for 2 h; dimethylolpropionic acid and chain extender are added to the solution after the reaction for chain extension reaction for 1.5~2 h; then epoxy resin E-44 and trimethylolpropane are added and the mixture is kept at a constant temperature for 2.5~3.5 h; after the reaction is completed and cooled to room temperature, triethylamine is added to neutralize the cooled prepolymer solution, deionized water is added at 2~3.5 times the volume of the neutralized solution, and then ethylenediamine is added for chain extension to obtain the crosslinked modified waterborne polyurethane emulsion. By introducing cross-linked modified waterborne polyurethane emulsion into the aluminum foil treatment solution, the active groups in its molecular chain can chemically bond or physically adsorb onto the aluminum foil surface. At the same time, cobalt sulfate and potassium fluorozirconate form a dense conversion film on the aluminum foil surface, together constructing a high-strength interfacial bonding layer.

[0022] S130. An aluminum foil that has undergone soaking treatment and an open-cell aluminum foil that has undergone soaking treatment are respectively attached to the upper and lower layers of the composite antibacterial film to obtain a composite film layer.

[0023] The composite antibacterial film is formed by combining a polymer layer and an antibacterial layer, with the antibacterial layer closely adhering to the perforated aluminum foil. The polymer layer consists of 35-45% polyurethane resin, 16-35% isocyanate, and 28-42% ethyl acetate by weight percentage. The antibacterial layer comprises a polytetrafluoroethylene (PTFE) film with an attached antibacterial agent, or a PTFE film coated with a silver ion layer or sputtered with a silver ion layer. This application focuses on describing the method of attaching an antibacterial agent in specific embodiments. In other embodiments, a PTFE film coated with a silver ion layer can also be used as the antibacterial layer, or an antibacterial layer can be formed by sputtering a silver ion layer onto the surface of the PTFE film.

[0024] In a more specific embodiment, the antibacterial agent comprises polyvinyl alcohol, chitosan, and eugenol; the concentration of polyvinyl alcohol in the antibacterial agent is 0.45~1.2wt%, the concentration of chitosan is 0.07~0.15wt%, and the concentration of eugenol is 0.8~1.6wt%. By selecting polyvinyl alcohol, chitosan, and eugenol as composite antibacterial components, the film-forming properties of polyvinyl alcohol, the broad-spectrum antibacterial properties of chitosan, and the penetrating bactericidal effect of eugenol synergistically produce a significant antibacterial effect.

[0025] The preparation method of the antibacterial agent includes: slowly adding polyvinyl alcohol to deionized water, maintaining the solution temperature at 20-25°C and stirring; placing the mixed solution in a water bath, stirring and slowly increasing the water bath temperature to 85-95°C, then keeping it at this temperature for 2.2-3 hours, with the stirring speed set to 65-92 rpm; adding glutaraldehyde and additives sequentially to the solution, mixing completely, and then adding chitosan solution dissolved in 1.5% acetic acid solution and eugenol, reacting to obtain the antibacterial agent. The additive is composed of ethanol, acid, and sulfuric acid in a volume ratio of 1:(1.5-2.5):(0.3-0.75); the acid is obtained by mixing citric acid, acetic acid, and gallic acid. By using a composite additive composed of ethanol, acid, and sulfuric acid in a specific ratio, ethanol improves the compatibility of each component, the mixed acid solution composed of citric acid, acetic acid, and gallic acid adjusts the pH of the system and provides auxiliary antibacterial function, and sulfuric acid enhances the cross-linking reaction activity.

[0026] The method for preparing the antibacterial layer includes: immersing a polytetrafluoroethylene (PTFE) film in an antibacterial agent, quickly transferring it to a constant-temperature oscillator, setting the oscillation speed to 120-140 rpm for surface coating, coating time to 35-55 min, and coating temperature to 62-65°C; transferring the coated PTFE film to a drying oven for heat treatment at 45-48°C for 50-75 min. Surface coating using a constant-temperature oscillator, combined with specific temperature and time parameters, ensures that the antibacterial agent forms a uniform and strongly adherent coating on the PTFE film surface, while the subsequent low-temperature heat treatment further solidifies the coating.

[0027] Furthermore, to improve the mechanical strength of the antibacterial layer, the heat-treated antibacterial layer can be immersed in liquid nitrogen at -40~-35℃ for 12~25 minutes. Immersion in liquid nitrogen will result in an antibacterial layer with higher mechanical strength.

[0028] S140. The composite film layer is heated to the preset hot pressing temperature and placed between the pressure rollers for pressing, thereby obtaining the corresponding waterproof and antibacterial metal foil.

[0029] The preset hot pressing temperature is 85~100℃; the pressing force of the pressure roller is 25~60kg / dm. 2 By controlling the hot-pressing temperature within the range of 85~100℃, the polymer layer reaches a suitable flow state to fully wet the aluminum foil surface, while simultaneously applying 25~60kg / dm³ of heat. 2 The pressure is sufficient to ensure that the materials of each layer are tightly bonded without damaging the structure of the antibacterial layer.

[0030] This invention also provides a waterproof and antibacterial metal foil for cigarette boxes, wherein the waterproof and antibacterial metal foil is manufactured using the manufacturing method for waterproof and antibacterial metal foil for cigarette boxes as described in the above embodiments; Figure 2 and Figure 3 As shown, the waterproof and antibacterial metal foil 10 includes a laminated aluminum foil 11, a composite antibacterial film 12, and a perforated aluminum foil 13. The composite antibacterial film 12 is formed by combining a polymer layer 121 and an antibacterial layer 122, with the antibacterial layer 122 closely attached to the perforated aluminum foil 13. The thickness of both the aluminum foil 11 and the perforated aluminum foil 13 is 10-35 micrometers. The through-holes 131 on the perforated aluminum foil 13 are either circular or rectangular. The specific structure of the circular through-holes is shown below. Figure 3 As shown; the diameter of the circular through hole is 0.2~2.5 mm; the length of the long side of the rectangular through hole is 0.2~2.5 mm and the length of the short side is 0.15~2.5 mm. The thickness ratio of the aluminum foil 11, polymer layer 121, antibacterial layer 122, and perforated aluminum foil 13 is 1:(1.2~2.5):(0.3~0.65):1.

[0031] This invention also provides a cigarette case, wherein the cigarette case includes a body 2, a lid 1, an inner tray 3, and the waterproof and antibacterial metal foil 10 for the cigarette case described in the above embodiments; as follows: Figure 4 and Figure 5 As shown, the waterproof and antibacterial metal foil 10 covers the cavity of the inner tray 3; the waterproof and antibacterial metal foil 10 is sealed to the top surface of the side wall of the cavity; one edge of the lid 1 is hinged to the body 2, the body 2 and the lid 1 together form a cavity, the inner tray 3 is disposed in the cavity, and the inner tray 3 is used to hold cigarettes.

[0032] The cigarette box includes a box body 2, a lid 1, and an inner tray 3. One edge of the lid 1 is hinged to one side of the box body 2. The box body 2 and the lid 1 together form a cavity. The inner tray 3 is placed inside the cavity and is used to hold the cigarettes. The inner tray 3 has a recessed cavity to accommodate the cigarettes. During production, the cigarettes are first placed into the recessed cavity of the inner tray 3, then the top opening is sealed with a waterproof and antibacterial metal foil 10, and finally, the cigarettes are placed inside the box body 2 and secured. Specifically, the sealing method involves extruding ethylene-methyl acrylate copolymer granules at 285~320°C and coating them onto the surface of an open-pore aluminum foil to form a copolymer layer 14. The thickness of the copolymer layer 14 is 25~40 micrometers. The copolymer layer 14 is heated to 110~140°C, and pressure is applied to the waterproof and antibacterial metal foil 10, thereby achieving heat sealing of the top opening through the waterproof and antibacterial metal foil 10. The coverage area of ​​the copolymer layer 14 corresponds to the upper edge area of ​​the inner tray, as shown below. Figure 3 As shown.

[0033] The following comparison of multiple embodiments illustrates the specific implementation process and beneficial effects of the solution.

[0034] Example 1 This embodiment provides a method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes, aiming to verify the comprehensive performance of the metal foil prepared under specific process parameters.

[0035] The specific steps for manufacturing waterproof and antibacterial metal foil are as follows: (1) Preparation of crosslinked modified waterborne polyurethane emulsion: Castor oil and polypropylene glycol were added to a flask with reflux condensation function; based on the volume of the reaction solution, isophorone diisocyanate and dibutyltin dilaurate were added at a ratio of 1.5 g / L and 0.6 g / L respectively, and the temperature was raised to 70°C and reacted for 2 h; dimethylolpropionic acid and chain extender were added to the solution after the reaction and chain extension reaction was carried out for 1.8 h; then epoxy resin E-44 and trimethylolpropane were added and the reaction was kept at a constant temperature for 3 h; after the reaction was completed and cooled to room temperature, triethylamine was added to neutralize the prepolymer solution after cooling, deionized water was added at a volume of 3 times that of the neutralized solution, and then ethylenediamine was added to extend the chain to obtain crosslinked modified waterborne polyurethane emulsion.

[0036] (2) Preparation of aluminum foil treatment solution: Cobalt sulfate and potassium fluorozirconate were dissolved in deionized water to obtain an initial solution, wherein the concentration of cobalt sulfate was 0.25 wt% and the concentration of potassium fluorozirconate was 0.1 wt%; the above cross-linked modified waterborne polyurethane emulsion was mixed with the initial solution at a volume ratio of 1:5; disodium hydrogen phosphate was added to adjust the pH of the solution to 6.8; finally, hydrogen peroxide was added to make its concentration 2.0 g / L to obtain the aluminum foil treatment solution.

[0037] (3) Preparation of antibacterial agent: Polyvinyl alcohol is slowly added to deionized water, the solution temperature is maintained at 22°C and stirred; the mixed solution is placed in a water bath, stirred and the water bath temperature is slowly increased to 90°C, and then kept at the temperature for 2.5 hours, with the stirring speed set to 80 rpm; glutaraldehyde and additives (the additives are composed of ethanol, acid and sulfuric acid in a volume ratio of 1:2:0.5, and the acid is obtained by mixing citric acid, acetic acid and gallic acid) are added to the solution in sequence, and after complete mixing, chitosan solution dissolved in 1.5% acetic acid solution and eugenol are added, and the reaction is carried out to obtain antibacterial agent, wherein the concentration of polyvinyl alcohol in the antibacterial agent is 0.8 wt%, the concentration of chitosan is 0.1 wt%, and the concentration of eugenol is 1.2 wt%.

[0038] (4) Preparation of antibacterial layer: Immerse the polytetrafluoroethylene film in the above antibacterial agent, quickly transfer it to a constant temperature shaker, set the shaking speed to 130 rpm for surface coating, the coating time to 45 min, and the coating temperature to 63 °C; transfer the polytetrafluoroethylene film after coating to a drying oven for heat treatment, the heat treatment temperature to 46 °C, and the heat treatment time to 60 min to obtain the antibacterial layer.

[0039] (5) Preparation of composite antibacterial film: 40% polyurethane resin, 25% isocyanate and 35% ethyl acetate by mass percentage are mixed evenly, pre-baked at 60℃ for 40 min, then heated to 78℃ for 40 min to complete cross-linking, and then cured at 50℃ for 24 h after cooling to obtain composite film layer; the antibacterial layer and composite film layer are bonded together, heated to 65℃ and placed between pressure rollers for tight pressing to obtain composite antibacterial film.

[0040] (6) Preparation of metal foil: A circular through-hole with a diameter of 1.5 mm is opened on an aluminum foil with a thickness of 25 micrometers to obtain an open-hole aluminum foil, and the coverage area of ​​the through-hole on the open-hole aluminum foil is 15%; the aluminum foil and the open-hole aluminum foil are immersed in an aluminum foil treatment solution for 10 minutes, and the temperature of the aluminum foil treatment solution is maintained at 56°C; the immersed aluminum foil and the immersed open-hole aluminum foil are respectively attached to the upper and lower layers of the composite antibacterial film to obtain a composite film layer; the composite film layer is heated to 92°C and placed between pressure rollers for pressing, and the pressing force of the pressure rollers is 40 kg / dm. 2 This results in a waterproof and antibacterial metal foil.

[0041] Example 2 The purpose of this embodiment is to verify the feasibility of soaking the aluminum foil in the treatment solution at the lower limit of the scope of the claims.

[0042] With all other preparation conditions the same as in Example 1, the only difference was that the immersion time of the aluminum foil and the perforated aluminum foil in the aluminum foil treatment solution as defined in the claims was adjusted from 10 minutes to 5 minutes to obtain a waterproof and antibacterial metal foil.

[0043] Example 3 The purpose of this embodiment is to verify the feasibility of immersion time in the aluminum foil treatment solution at the upper limit of the claims.

[0044] With all other preparation conditions the same as in Example 1, the only difference was that the immersion time of the aluminum foil and the perforated aluminum foil in the aluminum foil treatment solution as defined in the claims was adjusted from 10 minutes to 15 minutes to obtain a waterproof and antibacterial metal foil.

[0045] Example 4 The purpose of this embodiment is to verify the feasibility of hot pressing at the lower limit of the claims.

[0046] With all other preparation conditions the same as in Example 1, only the preset hot-pressing temperature defined in the claims was adjusted from 92°C to 85°C to obtain a waterproof and antibacterial metal foil.

[0047] Example 5 The purpose of this embodiment is to verify the feasibility of hot pressing at the upper limit of the claims.

[0048] With all other preparation conditions the same as in Example 1, only the preset hot-pressing temperature defined in the claims was adjusted from 92°C to 100°C to obtain a waterproof and antibacterial metal foil.

[0049] Example 6 The purpose of this embodiment is to verify the feasibility of the polyurethane resin content in the polymer layer being at the lower limit of the scope of the claims.

[0050] With all other preparation conditions the same as in Example 1, the mass percentage of polyurethane resin in the polymer layer as defined in the claims was adjusted from 40% to 35% to obtain a waterproof and antibacterial metal foil.

[0051] Example 7 The purpose of this embodiment is to verify the feasibility of having a polyurethane resin content in the polymer layer at the upper limit of the claims.

[0052] With all other preparation conditions the same as in Example 1, only the mass percentage of polyurethane resin in the polymer layer as defined in the claims was adjusted from 40% to 45% to obtain a waterproof and antibacterial metal foil.

[0053] Example 8 The purpose of this embodiment is to verify the feasibility of implementing the polymer layer when the isocyanate content is at the lower limit of the scope of the claims.

[0054] With all other preparation conditions the same as in Example 1, only the mass percentage of isocyanate in the polymer layer as defined in the claims was adjusted from 25% to 16% to obtain a waterproof and antibacterial metal foil.

[0055] Example 9 The purpose of this embodiment is to verify the feasibility of the polymer layer containing isocyanate at the upper limit of the claims.

[0056] With all other preparation conditions the same as in Example 1, only the mass percentage of isocyanate in the polymer layer as defined in the claims was adjusted from 25% to 35% to obtain a waterproof and antibacterial metal foil.

[0057] Example 10 The purpose of this embodiment is to verify the feasibility of the polymer layer containing ethyl acetate at the lower limit of the scope of the claims.

[0058] With all other preparation conditions the same as in Example 1, the only difference was that the mass percentage of ethyl acetate in the polymer layer as defined in the claims was adjusted from 35% to 28%, resulting in a waterproof and antibacterial metal foil.

[0059] Example 11 The purpose of this embodiment is to verify the feasibility of having an ethyl acetate content in the polymer layer at the upper limit of the claims.

[0060] With all other preparation conditions the same as in Example 1, the only difference was that the mass percentage of ethyl acetate in the polymer layer as defined in the claims was adjusted from 35% to 42%, resulting in a waterproof and antibacterial metal foil.

[0061] Example 12 The purpose of this embodiment is to verify the feasibility of implementing a circular through-hole with a diameter at the lower limit of the scope of the claims.

[0062] With all other preparation conditions the same as in Example 1, only the diameter of the circular through hole as defined in the claims was adjusted from 1.5 mm to 0.2 mm, and the coverage area of ​​the through hole on the perforated aluminum foil was 10%, thus obtaining a waterproof and antibacterial metal foil.

[0063] Example 13 The purpose of this embodiment is to verify the feasibility of implementing a circular through-hole with a diameter at the upper limit of the claims.

[0064] With all other preparation conditions the same as in Example 1, only the diameter of the circular through hole as defined in the claims was adjusted from 1.5 mm to 2.5 mm, and the coverage area of ​​the through hole on the perforated aluminum foil was 18%, thus obtaining a waterproof and antibacterial metal foil.

[0065] Example 14 The purpose of this embodiment is to verify the feasibility of using an antibacterial agent with a polyvinyl alcohol concentration at the lower limit of the scope of the claims.

[0066] With all other preparation conditions the same as in Example 1, only the concentration of polyvinyl alcohol in the antibacterial agent as defined in the claims was adjusted from 0.8 wt% to 0.45 wt% to obtain a waterproof and antibacterial metal foil.

[0067] Example 15 The purpose of this embodiment is to verify the feasibility of using an antibacterial agent with a polyvinyl alcohol concentration at the upper limit of the claims.

[0068] With all other preparation conditions the same as in Example 1, only the concentration of polyvinyl alcohol in the antibacterial agent as defined in the claims was adjusted from 0.8 wt% to 1.2 wt% to obtain a waterproof and antibacterial metal foil.

[0069] Example 16 The purpose of this embodiment is to verify the feasibility of chitosan concentration at the lower limit of the scope of the claims.

[0070] With all other preparation conditions the same as in Example 1, only the concentration of chitosan as defined in the claims was adjusted from 0.1 wt% to 0.07 wt% to obtain a waterproof and antibacterial metal foil.

[0071] Example 17 The purpose of this embodiment is to verify the feasibility of chitosan concentration at the upper limit of the claims.

[0072] With all other preparation conditions the same as in Example 1, only the concentration of chitosan as defined in the claims was adjusted from 0.1 wt% to 0.15 wt% to obtain a waterproof and antibacterial metal foil.

[0073] Example 18 The purpose of this embodiment is to verify the feasibility of implementation when the eugenol concentration is at the lower limit of the scope of the claims.

[0074] With all other preparation conditions the same as in Example 1, only the concentration of eugenol as defined in the claims was adjusted from 1.2 wt% to 0.8 wt% to obtain a waterproof and antibacterial metal foil.

[0075] Example 19 The purpose of this embodiment is to verify the feasibility of implementing the claim when the eugenol concentration is at the upper limit of the scope of the claim.

[0076] With all other preparation conditions the same as in Example 1, only the concentration of eugenol as defined in the claims was adjusted from 1.2 wt% to 1.6 wt% to obtain a waterproof and antibacterial metal foil.

[0077] Example 20 The purpose of this embodiment is to verify the feasibility of coating time at the lower limit of the claims.

[0078] With all other preparation conditions the same as in Example 1, only the coating time specified in the claims was adjusted from 45 min to 35 min to obtain a waterproof and antibacterial metal foil.

[0079] Example 21 The purpose of this embodiment is to verify the feasibility of coating time at the upper limit of the claims.

[0080] With all other preparation conditions the same as in Example 1, only the coating time specified in the claims was adjusted from 45 min to 55 min to obtain a waterproof and antibacterial metal foil.

[0081] Example 22 The purpose of this embodiment is to verify the feasibility of heat treatment at the lower limit of the claims.

[0082] With all other preparation conditions the same as in Example 1, only the heat treatment temperature specified in the claims was adjusted from 46°C to 45°C to obtain a waterproof and antibacterial metal foil.

[0083] Example 23 The purpose of this embodiment is to verify the feasibility of heat treatment at the upper limit of the claims range.

[0084] With all other preparation conditions the same as in Example 1, only the heat treatment temperature specified in the claims was adjusted from 46°C to 48°C to obtain a waterproof and antibacterial metal foil.

[0085] Example 24 The purpose of this embodiment is to verify the feasibility of heat treatment time when it is within the lower limit of the claims.

[0086] With all other preparation conditions the same as in Example 1, only the heat treatment time specified in the claims was adjusted from 60 min to 50 min to obtain a waterproof and antibacterial metal foil.

[0087] Example 25 The purpose of this embodiment is to verify the feasibility of heat treatment time at the upper limit of the claims.

[0088] With all other preparation conditions the same as in Example 1, only the heat treatment time specified in the claims was adjusted from 60 min to 75 min to obtain a waterproof and antibacterial metal foil.

[0089] Comparative Example 1 This embodiment provides a metal foil for cigarette boxes. The specific steps for manufacturing and obtaining the metal foil are as follows: (1) Preparation of antibacterial agent: Polyvinyl alcohol is slowly added to deionized water, the solution temperature is maintained at 22°C and stirred; the mixed solution is placed in a water bath, stirred and the water bath temperature is slowly increased to 90°C, and then kept at the temperature for 2.5 hours, with the stirring speed set to 80 rpm; glutaraldehyde and additives (the additives are composed of ethanol, acid and sulfuric acid in a volume ratio of 1:2:0.5, and the acid is obtained by mixing citric acid, acetic acid and gallic acid) are added to the solution in sequence, and after complete mixing, chitosan solution dissolved in 1.5% acetic acid solution and eugenol are added, and the reaction is carried out to obtain antibacterial agent, wherein the concentration of polyvinyl alcohol in the antibacterial agent is 0.8 wt%, the concentration of chitosan is 0.1 wt%, and the concentration of eugenol is 1.2 wt%.

[0090] (2) Preparation of antibacterial layer: Immerse the polytetrafluoroethylene film in the above antibacterial agent, quickly transfer it to a constant temperature shaker, set the shaking speed to 130 rpm for surface coating, the coating time to 45 min, and the coating temperature to 63 ℃; transfer the polytetrafluoroethylene film after coating to a drying oven for heat treatment, the heat treatment temperature to 46 ℃, and the heat treatment time to 60 min to obtain the antibacterial layer.

[0091] (3) Preparation of composite antibacterial film: 40% polyurethane resin, 25% isocyanate and 35% ethyl acetate by mass percentage are mixed evenly, pre-baked at 60℃ for 40min, then heated to 78℃ for 40min to complete cross-linking, and then cured at 50℃ for 24h after cooling to obtain composite film layer; the antibacterial layer and composite film layer are bonded together, heated to 65℃ and placed between pressure rollers for tight pressing to obtain composite antibacterial film.

[0092] (4) Preparation of metal foil: A circular through hole with a diameter of 1.5 mm is made in an aluminum foil with a thickness of 25 micrometers to obtain an open-hole aluminum foil; the open-hole aluminum foil and the upper and lower layers of the composite antibacterial film are respectively coated to obtain a composite film layer; the composite film layer is heated to 92°C and placed between pressure rollers for pressing, and the pressing force of the pressure rollers is 40 kg / dm. 2 This process yields a metal foil.

[0093] Comparative Example 2 This embodiment provides a metal foil for cigarette boxes. The specific steps for manufacturing and obtaining the metal foil are as follows: (1) Preparation of crosslinked modified waterborne polyurethane emulsion: Castor oil and polypropylene glycol were added to a flask with reflux condensation function; based on the volume of the reaction solution, isophorone diisocyanate and dibutyltin dilaurate were added at a ratio of 1.5 g / L and 0.6 g / L respectively, and the temperature was raised to 70°C and reacted for 2 h; dimethylolpropionic acid and chain extender were added to the solution after the reaction and chain extension reaction was carried out for 1.8 h; then epoxy resin E-44 and trimethylolpropane were added and the reaction was kept at a constant temperature for 3 h; after the reaction was completed and cooled to room temperature, triethylamine was added to neutralize the prepolymer solution after cooling, deionized water was added at a volume of 3 times that of the neutralized solution, and then ethylenediamine was added to extend the chain to obtain crosslinked modified waterborne polyurethane emulsion.

[0094] (2) Preparation of aluminum foil treatment solution: Cobalt sulfate and potassium fluorozirconate were dissolved in deionized water to obtain an initial solution, wherein the concentration of cobalt sulfate was 0.25 wt% and the concentration of potassium fluorozirconate was 0.1 wt%; the above cross-linked modified waterborne polyurethane emulsion was mixed with the initial solution at a volume ratio of 1:5; disodium hydrogen phosphate was added to adjust the pH of the solution to 6.8; finally, hydrogen peroxide was added to make its concentration 2.0 g / L to obtain the aluminum foil treatment solution.

[0095] (3) Preparation of composite film: 40% polyurethane resin, 25% isocyanate and 35% ethyl acetate by mass percentage are mixed evenly, pre-baked at 60℃ for 40min, then heated to 78℃ for 40min to complete cross-linking, and then cured at 50℃ for 24h after cooling to obtain composite film layer; the composite film layer is laminated with polytetrafluoroethylene film, heated to 65℃ and placed between pressure rollers for tight pressing to obtain composite film.

[0096] (4) Preparation of metal foil: A circular through hole with a diameter of 1.5 mm is made in an aluminum foil with a thickness of 25 micrometers to obtain an open-hole aluminum foil; the aluminum foil and the open-hole aluminum foil are immersed in an aluminum foil treatment solution for 10 minutes, and the temperature of the aluminum foil treatment solution is maintained at 56°C; the immersed aluminum foil and the immersed open-hole aluminum foil are respectively attached to the upper and lower layers of the composite film to obtain a composite film layer; the composite film layer is heated to 92°C and placed between pressure rollers for pressing, and the pressing force of the pressure rollers is 40 kg / dm. 2 This process yields a metal foil.

[0097] Test Example 1 Metal foil tensile test: Tensile tests were performed on the metal foils obtained in Examples 1-11 and Comparative Example 1 of this invention. The cross-sectional area obtained from each example and comparative example was 2.4 mm². 2 Metal foils with a length of 20cm were subjected to tensile tests along their length, and the maximum tensile force that they could withstand when broken, significantly delaminated, or damaged was also tested. The test results are shown in Table 1.

[0098] Table 1 The metal foil processed using the technical methods described in this application exhibits strong stretchability, with the metal foil corresponding to Example 5 showing the best test results. Therefore, the metal foil processed using the technical methods described in this application demonstrates excellent tensile strength in practical applications.

[0099] Test Example 2 Antibacterial performance test: The metal foils obtained in Examples 1, 12-25 and Comparative Example 2 of the present invention were subjected to antibacterial tests. A liquid agar medium was prepared by heating and sterilizing 10g tryptone, 5g yeast extract, 10g NaCl, and 15g agar powder, adding deionized water to a final volume of 1000ml and adjusting the pH to 7.2-7.4. 10ml of this liquid agar medium was poured into a rectangular inner tray. After cooling to room temperature, Staphylococcus aureus culture was picked up using an inoculation loop and evenly inoculated into the rectangular inner tray. The inoculated inner tray was then sealed with the aforementioned metal foil. An ethylene-methyl acrylate copolymer (ethylene-methyl acrylate copolymer particles were heated to 290℃ to form a liquid polymer, extruded, and then coated onto the surface of the perforated aluminum foil, with a coating thickness of 30 micrometers) was applied to the surface of the perforated aluminum foil. The sealed inner tray was then incubated at 25℃ for 5 days. The number of grids in each inner tray where Staphylococcus aureus was inhibited (each grid was 0.25cm) was recorded using a cross-cutting method. 2 The square was divided into a total of 187 grids, and the results are shown in Table 2.

[0100] Table 2 The metal foils processed using the technical methods in the embodiments of this application all have strong antibacterial properties, with the optimal embodiment being Example 13.

[0101] The present invention provides a waterproof and antibacterial metal foil for cigarette boxes and a method for manufacturing the same. The manufacturing method includes: creating through-holes in aluminum foil to obtain perforated aluminum foil; immersing the aluminum foil and the perforated aluminum foil in an aluminum foil treatment solution for 5-15 minutes, maintaining the temperature of the treatment solution at 45-67°C; attaching the immersed aluminum foil and the immersed perforated aluminum foil to the upper and lower layers of a composite antibacterial film, respectively, to obtain a composite film layer; heating the composite film layer to a preset hot-pressing temperature and pressing it between pressure rollers to obtain the corresponding waterproof and antibacterial metal foil. In this manufacturing method, a composite antibacterial film is sandwiched between the aluminum foil and the perforated aluminum foil to improve the tensile strength of the metal foil. The composite antibacterial film is composed of a polymer layer and an antibacterial layer. Antibacterial compounds are released through the through-holes in the perforated aluminum foil via the antibacterial layer, thereby achieving long-lasting antibacterial protection for the interior of the cigarette box.

[0102] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes, characterized in that, The manufacturing method includes the following steps: Perforated aluminum foil is obtained by creating through holes in aluminum foil. The aluminum foil and the perforated aluminum foil are immersed in an aluminum foil treatment solution for 5 to 15 minutes, while maintaining the temperature of the aluminum foil treatment solution at 45 to 67°C. A composite film layer is obtained by attaching an impregnated aluminum foil and an impregnated perforated aluminum foil to the upper and lower layers of the composite antibacterial film, respectively. The composite film layer is heated to a preset hot-pressing temperature and placed between pressure rollers for pressing, thereby obtaining the corresponding waterproof and antibacterial metal foil; The composite antibacterial film is formed by combining a polymer layer and an antibacterial layer, with the antibacterial layer closely attached to the perforated aluminum foil. The polymer layer is composed of 35-45% polyurethane resin, 16-35% isocyanate, and 28-42% ethyl acetate by weight percentage. The antibacterial layer includes a polytetrafluoroethylene film with an attached antibacterial agent.

2. The method for manufacturing the waterproof and antibacterial metal foil for cigarette boxes according to claim 1, characterized in that, The antibacterial agent includes polyvinyl alcohol, chitosan, and eugenol; The antibacterial agent contains 0.45-1.2 wt% polyvinyl alcohol, 0.07-0.15 wt% chitosan, and 0.8-1.6 wt% eugenol. The method for preparing the antibacterial layer includes: immersing a polytetrafluoroethylene (PTFE) film in an antibacterial agent, followed by constant-temperature oscillation at a speed of 120-140 rpm for surface coating, a coating time of 35-55 min, and a coating temperature of 62-65°C; transferring the coated PTFE film to a drying oven for heat treatment at a temperature of 45-48°C for 50-75 min.

3. The method for manufacturing the waterproof and antibacterial metal foil for cigarette boxes according to claim 2, characterized in that, The method for preparing the antibacterial agent: Slowly add polyvinyl alcohol to deionized water, maintaining the solution temperature at 20~25℃ and stirring. Place the mixed solution in a water bath, stir and slowly increase the water bath temperature to 85~95℃, then keep it at this temperature for 2.2~3 hours, with the stirring speed set to 65~92 rpm; Glutaraldehyde and additives were added to the solution in sequence, and after complete mixing, chitosan solution dissolved in 1.5% acetic acid solution and eugenol were added to react and an antibacterial agent was obtained.

4. The method for manufacturing the waterproof and antibacterial metal foil for cigarette boxes according to claim 3, characterized in that, The additive is composed of ethanol, acid, and sulfuric acid in a volume ratio of 1:(1.5~2.5):(0.3~0.75); the acid is obtained by mixing citric acid, acetic acid, and gallic acid.

5. The method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes according to any one of claims 1-4, characterized in that, The aluminum foil treatment solution comprises a cross-linked modified aqueous polyurethane emulsion, cobalt sulfate, potassium fluorozirconate, disodium hydrogen phosphate, and water. The method for preparing the aluminum foil treatment solution includes dissolving cobalt sulfate and potassium fluorozirconate in deionized water to obtain an initial solution; the concentrations of cobalt sulfate and potassium fluorozirconate in the initial solution are 0.12~0.38wt% and 0.04~0.16wt%, respectively. The crosslinked modified waterborne polyurethane emulsion was mixed with the initial solution at a volume ratio of 1:(3~6.5); Add the disodium hydrogen phosphate to the initial solution to adjust the pH of the solution to 5.5-8 to obtain the aluminum foil treatment solution; The preparation method of the crosslinked modified waterborne polyurethane emulsion is as follows: castor oil and polypropylene glycol are added to a flask with reflux condensation function; isophorone diisocyanate and dibutyltin dilaurate are added at proportions of 0.75~2 g / L and 0.35~0.8 g / L respectively based on the volume of the reaction solution, and the mixture is heated to 65~75℃ and reacted for 2 hours; Dimethylolpropionic acid and a chain extender were added to the solution after the reaction to carry out a chain extension reaction for 1.5-2 hours; then epoxy resin E-44 and trimethylolpropane were added and the reaction was carried out at a warm temperature for 2.5-3.5 hours. After the reaction is completed and cooled to room temperature, triethylamine is added to neutralize the cooled prepolymer solution. Deionized water is added at 2 to 3.5 times the volume of the neutralized solution, followed by the addition of ethylenediamine for chain extension, to obtain a crosslinked modified waterborne polyurethane emulsion.

6. The method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes according to claim 5, characterized in that, The aluminum foil treatment solution also includes hydrogen peroxide, and the concentration of hydrogen peroxide in the aluminum foil treatment solution is 1.3-2.50 g / L.

7. The method for manufacturing a waterproof and antibacterial metal foil for cigarette boxes according to claim 6, characterized in that, The preset hot pressing temperature is 85~100℃; the pressing force of the pressure roller is 25~60kg / dm. 2 .

8. A waterproof and antibacterial metal foil for cigarette boxes, characterized in that, The waterproof and antibacterial metal foil is manufactured using the manufacturing method for waterproof and antibacterial metal foil for cigarette boxes as described in any one of claims 1-7; The waterproof and antibacterial metal foil includes stacked aluminum foil, a composite antibacterial film, and perforated aluminum foil. The composite antibacterial film is obtained by combining a polymer layer and an antibacterial layer, with the antibacterial layer being closely attached to the perforated aluminum foil.

9. The waterproof and antibacterial metal foil for cigarette boxes according to claim 8, characterized in that, The thickness of both the aluminum foil and the perforated aluminum foil is 10-35 micrometers. The through holes on the perforated aluminum foil are circular or rectangular. The diameter of the circular through holes is 0.2-2.5 mm. The length of the long side of the rectangular through holes is 0.2-2.5 mm and the length of the short side is 0.15-2.5 mm. The coverage area of ​​the through holes on the perforated aluminum foil is 10-18%.

10. A cigarette case, characterized in that, The cigarette case includes a case body, a lid, an inner tray, and a waterproof and antibacterial metal foil for the cigarette case as described in any one of claims 8-9; The waterproof and antibacterial metal foil covers the cavity of the inner tray; the waterproof and antibacterial metal foil is sealed to the top surface of the side wall of the cavity; one edge of the lid is hinged to the box body, the box body and the lid together form a cavity, the inner tray is disposed in the cavity, and the inner tray is used to hold cigarettes.

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