Antibacterial material for infusion container, film inner cap, and method for manufacturing film inner cap

Abstract

The application relates to the technical field of medical packaging materials, and particularly discloses an antibacterial material for an infusion container, a coated inner cover, and a preparation method of the coated inner cover. The antibacterial material comprises, by weight, 70-85 parts of polyethylene, 5-12 parts of modified nano silicon dioxide, and 8-18 parts of antibacterial microcapsules. The antibacterial microcapsules comprise core material, a first wall material layer wrapping the core material, and a second wall material layer wrapping the first wall material layer. The core material comprises Ag@ZnO, the raw material of the first wall material layer comprises polyurethane containing a diselenide bond, and the raw material of the second wall material layer comprises polycaprolactone, modified nano zero-valent iron-palladium, and citric acid. The application realizes on-demand release of the antibacterial agent by triggering microcapsule degradation through oxygen, ensures the antibacterial effect of the antibacterial agent, effectively prolongs the antibacterial period, and adopts the antibacterial material for the coating layer of the coated inner cover, so that the risk of liquid medicine pollution after sealing failure can be prevented, the storage stability of the product is improved, and the safety of medicine storage is ensured.

Description

Technical Field

[0001] This invention relates to the field of medical packaging materials technology, specifically disclosing an antibacterial material, a film-coated inner cap for infusion containers, and a method for preparing the film-coated inner cap. Background Technology

[0002] Intravenous infusion is one of the most fundamental and important methods of drug administration in clinical medicine, and its safety highly depends on the sealing integrity and antibacterial protection capabilities of the infusion container. Polypropylene composite caps are widely used for infusion container encapsulation due to their excellent physicochemical properties and sealing effect. Among these, the inner cap, as a key component that directly or indirectly contacts the drug solution, requires its coating material to meet extremely stringent medical standards.

[0003] Currently, to improve the antimicrobial protection level of infusion containers, antimicrobial agents are often added to the inner cap membrane material. However, such antimicrobial membrane materials have the following drawbacks: First, the antimicrobial agent is released indiscriminately and continuously during storage, causing its effectiveness to gradually decrease during non-essential periods when the container is well-sealed. When the container breaks or the seal fails, allowing external oxygen to enter and the medication to face the risk of microbial contamination, the antimicrobial agent in the membrane material is often already depleted, unable to provide effective protection. Second, long-term exposure of the antimicrobial agent and its continuous contact with the medication increases the risk of harmful substances migrating into the medication, potentially causing drug safety and biocompatibility issues.

[0004] To address the aforementioned shortcomings, existing technologies employ microencapsulation to encapsulate antibacterial agents as a core material within a wall material. The antibacterial agent is released through the degradation of the wall material, thus achieving long-lasting antibacterial effects. However, conventional microcapsules experience rapid and significant leakage of antibacterial agents in the initial stages of use, leading to excessive concentrations that can induce bacterial resistance, cause irritation, and result in uneven release, drastically shortening the effective antibacterial period. Furthermore, the release mechanism remains simple diffusion, lacking responsive triggering characteristics and failing to achieve on-demand release. Therefore, it is necessary to develop a coating material that releases antibacterial agents on demand. Summary of the Invention

[0005] To address the problem of untimely release of antimicrobial agents in existing technologies, this invention provides an antimicrobial material for infusion containers. This material achieves on-demand release of the antimicrobial agent through oxygen-triggered microcapsule degradation, ensuring the antimicrobial effect and effectively extending the antimicrobial cycle. Furthermore, the use of this antimicrobial material in the inner cap of the membrane enhances product storage stability.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides an antibacterial material for infusion containers, comprising, by weight, 70-85 parts of polyethylene, 5-12 parts of modified nano-silica, and 8-18 parts of antibacterial microcapsules; the antibacterial microcapsules comprise a core material, a first wall material layer encapsulating the core material, and a second wall material layer encapsulating the first wall material layer; the core material comprises Ag@ZnO, the raw material of the first wall material layer comprises polyurethane containing diselenyl bonds, and the raw material of the second wall material layer comprises polycaprolactone, modified nano-zero-valent iron-palladium, and citric acid.

[0007] Preferably, the modified nano-silica is prepared by dispersing nano-silica in γ-aminopropyltriethoxysilane and ultrasonically treating it. The mass ratio of nano-silica to γ-aminopropyltriethoxysilane is 100:3-8, and the particle size of nano-silica is 20-50 nm.

[0008] Preferably, the preparation method of Ag@ZnO is as follows: ZnO nanoparticles are dispersed in a mixed solution of water and ethanol, AgNO3 solution is added under light-protected conditions, the mixture is stirred for 30-60 min, reduced under ultraviolet light, centrifuged, washed alternately with deionized water and ethanol, and dried under vacuum at 50 °C to obtain Ag@ZnO. Specifically, the Ag loading is 5 wt%, the ZnO nanoparticle size is 50 nm, the Ag@ZnO particle size is 50-100 nm, and the antibacterial microcapsules have a particle size of 1-5 μm. In the mixed solution, the volume ratio of water to ethanol is 1:1.

[0009] Preferably, the modified nano-zero-valent iron-palladium is prepared as follows: under nitrogen protection, FeSO4·7H2O is reduced with NaBH4 to obtain nano-zero-valent iron, which is then reacted with K2PdCl6 solution to obtain nano-zero-valent iron-palladium metal particles. After magnetic separation and washing, these particles are added to a mixed solution of oleic acid and ethanol, stirred, and vacuum dried to obtain modified nano-zero-valent iron-palladium. The Pd content in the K2PdCl6 solution is 0.5wt%, and the mass ratio of nano-zero-valent iron to K2PdCl6 solution is 20:1. The volume ratio of oleic acid to anhydrous ethanol is 1:30, and the mass ratio of nano-zero-valent iron-palladium metal particles to the mixed solution of oleic acid and ethanol is 1:15-25.

[0010] Preferably, the method for preparing antibacterial microcapsules is as follows: Polyurethane containing diselenide bonds was dissolved in anhydrous dichloromethane to obtain a 5% w / v solution. Ag@ZnO was added to the solution and ultrasonically dispersed to obtain an oil phase. The oil phase was slowly added to a 5% (v / v) polyvinyl alcohol solution and subjected to high-speed shearing to form an O / W emulsion. After centrifugation, washing, and freeze-drying, core-shell microparticles were obtained. The mass ratio of Ag@ZnO to polyurethane containing diselenide bonds was 1:4-6. Polycaprolactone was dissolved in dichloromethane to form a 3% w / v solution. Modified nano-zero-valent iron-palladium and citric acid were added to the solution, and the mixture was ultrasonically dispersed to form a suspension. Core-shell microparticles were slowly added to the suspension and spray-dried to obtain antibacterial microcapsules. The mass ratio of polycaprolactone, modified nano-zero-valent iron-palladium, and citric acid was 10:2:1-2, and the solid-liquid ratio of the core-shell microparticles to the suspension was 3-7:100. Specifically, the citric acid was anhydrous citric acid micropowder.

[0011] Preparation method of polyurethane containing diselenide bonds: Di(2-hydroxyethyl)diselenide and isophorone diisocyanate are mixed, and dibutyltin dilaurate is added. The mixture is reacted at 60℃ for 20-40 min, and then trimethylolpropane is added to continue the reaction for 10-20 min. The mass ratio of di(2-hydroxyethyl)diselenide, isophorone diisocyanate, and trimethylolpropane is 10:10:0.2-0.5, and the mass of dibutyltin dilaurate is 2% of the total mass of di(2-hydroxyethyl)diselenide and isophorone diisocyanate.

[0012] Secondly, the present invention provides a membrane inner cover for an infusion container, comprising an inner cover substrate and a membrane layer laminated to the inner surface of the inner cover substrate, wherein the membrane layer comprises, in sequence, an adhesive layer, a barrier layer, a buffer layer and a functional surface layer; the functional surface layer is made of an antibacterial material for infusion containers.

[0013] Preferably, the adhesive layer comprises 85-95 parts by weight of modified polypropylene grafted maleic anhydride, 3-10 parts by weight of polyethylene wax, and 0.5-2 parts by weight of antioxidant; the grafting rate of the modified polypropylene grafted maleic anhydride is 0.8-1.5%, and the antioxidant comprises antioxidant 1010 and antioxidant 168 in a mass ratio of 1-2:1. The melt index (230℃, 2.16kg) of the modified polypropylene grafted maleic anhydride is 5-15g / 10min.

[0014] Preferably, the barrier layer comprises 60-75 parts by weight of ethylene-vinyl alcohol copolymer, 20-35 parts by weight of polyamide, and 3-8 parts by weight of compatibilizer; the polyamide is polyamide 6, and the compatibilizer is maleic anhydride-grafted polyolefin elastomer with a grafting rate of 0.5-1.2%. The ethylene content of the ethylene-vinyl alcohol copolymer is 25-35%, and the melt index (210℃, 2.16kg) is 3-8g / 10min.

[0015] Preferably, the buffer layer comprises, by weight, 70-85 parts of metallocene-catalyzed polyethylene, 10-20 parts of elastomer, and 2-5 parts of lubricant; the elastomer is an ethylene-octene copolymer, and the lubricant is erucamide or oleamide. The melt index (190°C, 2.16 kg) of the metallocene-catalyzed polyethylene is 2-6 g / 10 min; the melt index (190°C, 2.16 kg) of the ethylene-octene copolymer (POE) is 0.5-3 g / 10 min, and the Shore A hardness is 65-85.

[0016] Preferably, the total thickness of the coating layer is 30-80 μm, the thickness of the adhesive layer is 5-15 μm, the thickness of the barrier layer is 8-20 μm, the thickness of the buffer layer is 10-25 μm, and the thickness of the functional surface layer is 7-10 μm.

[0017] Thirdly, the present invention provides a method for preparing a film-coated inner cover, comprising the following steps: S1. Prepare adhesive layer mixture, barrier layer mixture and buffer layer mixture according to each layer component, and then put them into the corresponding extruder hopper of the three-layer co-extrusion blown film machine for three-layer co-extrusion composite to obtain the substrate; The functional surface layer mixture is laminated onto the surface of the substrate by low-temperature hot pressing to obtain a coating layer; S2. The inner cover substrate is obtained by injection molding homopolymer polypropylene in an injection molding machine; S3. Preparation of the film-coated inner cover: The antibacterial film layer is hot-pressed together with the inner cover substrate to obtain the film-coated inner cover.

[0018] Preferably, in step S1, during the four-layer co-extrusion compounding, the extrusion temperatures of each layer are: 180-200℃ for the adhesive layer, 200-220℃ for the barrier layer, and 170-190℃ for the buffer layer; low-temperature twin-roll hot-pressing compounding is used: upper roll 130℃, lower roll cooled to 25℃, and pressure 8-12MPa. In step S2, during injection molding, the injection molding machine barrel temperature is 185-215℃, the mold temperature is 40℃, the injection pressure is 80MPa, the holding pressure is 60MPa, and the cooling time is 12-16s. In step S3, during hot-pressing compounding, the hot-pressing temperature is 160-180℃, the pressure is 0.3-0.6MPa, and the holding time is 3-8s.

[0019] The technical solution of the present invention has at least the following advantages and beneficial effects: When the infusion container is properly sealed, the barrier layer effectively prevents external oxygen from entering. The wall structure of the antibacterial microcapsules is stable, and Ag@ZnO is firmly encapsulated, preventing release and contact with the medication, thus avoiding premature depletion and affecting the antibacterial effect. When the infusion container seal fails, external oxygen enters, causing the oxygen concentration inside the container to rise. Under the influence of moisture in the microenvironment, the oxygen dissolves citric acid in the second wall layer, forming acidic microdomains. This activates the nano-zero-valent iron-palladium metal particles, which efficiently convert oxygen in situ into hydrogen peroxide and a small amount of hydroxyl radicals through a two-electron oxygen reduction reaction. Simultaneously, the citric acid dissolves in situ, leaving behind a large network of channels. These channels penetrate the second wall layer, allowing these strong oxidizing substances to diffuse along the channel network to the first wall layer. This causes the diselenyl bonds in the first wall layer to oxidize and break, resulting in the degradation of the first wall layer and the release of Ag@ZnO. Ag@ZnO diffuses through the channel network to the coating surface, forming a long-lasting antibacterial barrier on the outside of the container. This exerts its antibacterial effect, inhibiting the growth of pathogenic bacteria such as Escherichia coli and Staphylococcus aureus, and preventing medication contamination.

[0020] This invention achieves targeted release of antibacterial agents through antibacterial microcapsules, using oxygen as a trigger condition. This solves the problems of premature depletion and accidental release associated with traditional long-release antibacterial agents, ensuring that the antibacterial effect is synchronized with the container's seal life. When the seal is intact, the antibacterial agent is not released, reducing contact time with the liquid and lowering the risk of harmful substance migration. Furthermore, the microcapsule wall and core materials are medical-grade, meeting biocompatibility requirements. Through the combined use of an adhesive layer, barrier layer, buffer layer, and functional surface layer, a strong bond is ensured between the coating layer and the inner cap substrate, providing excellent barrier properties. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise stated, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0022] Example 1 This embodiment provides an antibacterial material for infusion containers, comprising, by weight, 80 parts of medical-grade polyethylene micropowder (particle size 15μm), 10 parts of modified nano-silica, and 15 parts of antibacterial microcapsules, which are obtained by blending the components together.

[0023] Preparation of modified nano-silica: Nano-silica was dispersed in γ-aminopropyltriethoxysilane and ultrasonically treated to obtain the nano-silica. The mass ratio of nano-silica to γ-aminopropyltriethoxysilane was 100:5, and the particle size of nano-silica was 40 nm.

[0024] Preparation of Ag@ZnO: ZnO nanoparticles were dispersed in a mixed solution of water and ethanol with a volume ratio of ethanol to water of 1:1. AgNO3 solution was added under light protection and stirred for 50 min. After reduction under ultraviolet light, the nanoparticles were centrifuged, washed alternately with deionized water and ethanol, and dried under vacuum at 50 °C to obtain Ag@ZnO with an Ag loading of 5 wt% and a particle size of 60 nm.

[0025] Preparation of modified nano-zero-valent iron-palladium: Nano-zero-valent iron was prepared by reducing FeSO4·7H2O with NaBH4 under nitrogen protection. The FeSO4·7H2O was then reacted with K2PdCl6 solution to obtain nano-zero-valent iron-palladium metal particles. After magnetic separation and washing, the particles were added to a mixed solution of oleic acid and ethanol, stirred, and vacuum dried at 50℃ to obtain modified nano-zero-valent iron-palladium. The Pd content in the K2PdCl6 solution was 0.5wt%, and the mass ratio of nano-zero-valent iron to K2PdCl6 solution was 20:1. The volume ratio of oleic acid to anhydrous ethanol was 1:30, and the mass ratio of nano-zero-valent iron-palladium metal particles to the mixed solution of oleic acid and ethanol was 1:20.

[0026] Preparation of polyurethane containing diselenyl bonds: Di(2-hydroxyethyl)diselenyl ether and isophorone diisocyanate were mixed, and dibutyltin dilaurate was added. The mixture was reacted at 60°C for 20-40 min, and then trimethylolpropane was added to continue the reaction for 10-20 min. The mass ratio of di(2-hydroxyethyl)diselenyl ether, isophorone diisocyanate, and trimethylolpropane was 10:10:0.4, and the mass of dibutyltin dilaurate was 2% of the total mass of di(2-hydroxyethyl)diselenyl ether and isophorone diisocyanate.

[0027] Preparation of antibacterial microcapsules: Polyurethane containing diselenide bonds was dissolved in anhydrous dichloromethane to obtain a 5% w / v solution. Ag@ZnO was added to the solution, and the mixture was ultrasonically dispersed for 30 min to obtain an oil phase. The oil phase was slowly added to a 5% (v / v) polyvinyl alcohol solution, and the mixture was sheared at 10000 r / min for 3 min to form an O / W emulsion. After centrifugation, washing, and freeze-drying, core-shell microparticles were obtained. The mass ratio of Ag@ZnO to polyurethane containing diselenide bonds was 1:5. Polycaprolactone was dissolved in dichloromethane to form a 3% w / v solution. Modified nano-zero-valent iron-palladium and citric acid were added to the solution and ultrasonically dispersed in an ice bath for 20 min to form a suspension. Core-shell microparticles were slowly added to the suspension with stirring and spray-dried at 45℃ to obtain antibacterial microcapsules with a particle size of 5 μm. The mass ratio of polycaprolactone, modified nano-zero-valent iron-palladium and citric acid was 10:2:1.5, and the solid-liquid ratio of the core-shell microparticles to the suspension was 5:100.

[0028] Example 2 This embodiment provides an antibacterial material for infusion containers, comprising, by weight, 70 parts of medical-grade polyethylene micropowder (particle size 15μm), 5 parts of modified nano-silica, and 8 parts of antibacterial microcapsules, which are obtained by blending the components together.

[0029] Example 3 This embodiment provides an antibacterial material for infusion containers, comprising, by weight, 85 parts of medical-grade polyethylene micropowder (particle size 15μm), 12 parts of modified nano-silica, and 18 parts of antibacterial microcapsules, which are obtained by blending the components together.

[0030] Example 4 This embodiment provides a membrane inner cover for an infusion container, including an inner cover substrate and a membrane layer laminated to the inner surface of the inner cover substrate. The membrane layer consists of an adhesive layer, a barrier layer, a buffer layer, and a functional surface layer in sequence. The functional surface layer is made of the antibacterial material for infusion containers described in Embodiment 1.

[0031] The adhesive layer comprises 90 parts modified polypropylene grafted with maleic anhydride, 7 parts polyethylene wax, and 2 parts antioxidants (antioxidant 1010 and antioxidant 168 in a mass ratio of 1.5:1). The barrier layer comprises 70 parts ethylene-vinyl alcohol copolymer, 25 parts polyamide 6 (PA6), and 5 parts maleic anhydride grafted polyolefin elastomer. The buffer layer comprises 80 parts metallocene-catalyzed polyethylene, 15 parts ethylene-octene copolymer, and 5 parts erucamide.

[0032] The method for preparing the film-coated inner cover includes the following steps: S1. Prepare the adhesive layer mixture, barrier layer mixture and buffer layer mixture according to the components of each layer, and then put them into the corresponding extruder hopper of the three-layer co-extrusion blown film machine for three-layer co-extrusion composite to obtain the substrate; the extrusion temperature of each layer is: adhesive layer 190℃, barrier layer 210℃, buffer layer 180℃. The functional surface layer mixture is laminated onto the substrate surface by low-temperature hot pressing. The low-temperature double-roller hot pressing is used: the upper roller is 130°C and the lower roller is cooled to 25°C, with a pressure of 10MPa, to obtain the coating layer. The total thickness of the coating layer is 50 μm, the thickness of the adhesive layer is 10 μm, the thickness of the barrier layer is 15 μm, the thickness of the buffer layer is 20 μm, and the thickness of the functional surface layer is 5 μm. S2. Homopolymer polypropylene is used to injection mold an inner cover substrate with a thickness of 1.2mm in an injection molding machine. The injection molding machine barrel temperature is 200℃, the mold temperature is 40℃, the injection pressure is 80MPa, the holding pressure is 60MPa, and the cooling time is 15s. S3. Preparation of the coated inner cover: The coated layer and the inner cover substrate are hot-pressed together to obtain the coated inner cover. The hot-pressing temperature is 170℃, the pressure is 0.4MPa, and the holding time is 5s. A flatbed hot press is used, and a silicone pad is used to ensure uniform pressure. After lamination, there are no bubbles or delamination between the coated layer and the substrate, and the edge alignment is ≤0.1mm.

[0033] Example 5 The coating layer in this embodiment comprises an adhesive layer, a barrier layer, a buffer layer, and a functional surface layer. The components and amounts of each layer are as follows: The adhesive layer comprises 85 parts of modified polypropylene grafted with maleic anhydride, 10 parts of polyethylene wax, and 2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio). The barrier layer comprises 60 parts of ethylene-vinyl alcohol copolymer, 35 parts of polyamide 6 (PA6), and 5 parts of maleic anhydride grafted polyolefin elastomer. The buffer layer comprises 70 parts of metallocene-catalyzed polyethylene, 20 parts of ethylene-octene copolymer, and 5 parts of erucamide. The functional surface layer is prepared using the antibacterial material from Example 1.

[0034] The total thickness of the coating layer is 30 μm, the thickness of the adhesive layer is 5 μm, the thickness of the barrier layer is 8 μm, the thickness of the buffer layer is 10 μm, the thickness of the functional surface layer is 7 μm, and the preparation method of the coating inner cover is the same as that in Example 4.

[0035] Example 6 The coating layer in this embodiment comprises an adhesive layer, a barrier layer, a buffer layer, and a functional surface layer. The components and amounts of each layer are as follows: The adhesive layer comprises 95 parts of modified polypropylene grafted with maleic anhydride, 3 parts of polyethylene wax, and 2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a 2:1 mass ratio). The barrier layer comprises 75 parts of ethylene-vinyl alcohol copolymer, 20 parts of polyamide 6 (PA6), and 5 parts of maleic anhydride grafted polyolefin elastomer. The buffer layer comprises 85 parts of metallocene-catalyzed polyethylene and ethylene-octene copolymer. The functional surface layer is prepared using the antibacterial material from Example 1.

[0036] The total thickness of the coating layer is 70 μm, the thickness of the adhesive layer is 15 μm, the thickness of the barrier layer is 20 μm, the thickness of the buffer layer is 25 μm, and the thickness of the functional surface layer is 10 μm. The preparation method of the coating inner cover is the same as that in Example 4.

[0037] Example 7 The coating layer in this embodiment comprises an adhesive layer, a barrier layer, a buffer layer, and a functional surface layer. The components and amounts of each layer are as follows: The adhesive layer comprises 92 parts of modified polypropylene grafted with maleic anhydride, 5 parts of polyethylene wax, and 2 parts of antioxidant (antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio). The barrier layer comprises 68 parts of ethylene-vinyl alcohol copolymer, 27 parts of polyamide 6 (PA6), and 5 parts of maleic anhydride grafted polyolefin elastomer. The buffer layer comprises 82 parts of metallocene-catalyzed polyethylene, 13 parts of ethylene-octene copolymer, and 5 parts of oleamide. The functional surface layer is prepared using the antibacterial material from Example 1.

[0038] The total thickness of the coating layer is 60 μm, the thickness of the adhesive layer is 12 μm, the thickness of the barrier layer is 16 μm, the thickness of the buffer layer is 22 μm, the thickness of the functional surface layer is 10 μm, and the preparation method of the coating inner cover is the same as in Example 4.

[0039] Comparative Example 1 In this comparative example, the antibacterial microcapsules were replaced with Ag@ZnO without encapsulated wall material. The composition, thickness, and preparation process of the remaining layers were the same as in Example 4.

[0040] Comparative Example 2 In this comparative example, the wall material of the antibacterial microcapsules is polycaprolactone. The components, thickness, and preparation process of the remaining layers are the same as in Example 4.

[0041] Comparative Example 3 In this comparative example, the antibacterial microcapsules only include the first wall material layer. The components, thicknesses, and preparation processes of the remaining layers are the same as in Example 4.

[0042] Comparative Example 4 In this comparative example, the antibacterial microcapsules only include the second wall material layer. The components, thicknesses, and preparation processes of the remaining layers are the same as in Example 4.

[0043] Comparative Example 5 In this comparative example, the raw materials for the second wall layer of the antibacterial microcapsules consist only of polycaprolactone and citric acid. The components, thicknesses, and preparation processes of the remaining layers are the same as in Example 4.

[0044] Comparative Example 6 In this comparative example, the raw materials for the second wall layer of the antibacterial microcapsules consist only of polycaprolactone and modified nano-zero-valent iron-palladium. The components, thicknesses, and preparation processes of the remaining layers are the same as in Example 4.

[0045] Performance tests were conducted on the coated inner covers of Examples 4-7 and Comparative Examples 1-6. The test indicators and results are as follows: Peel strength between coating and substrate, YY / T0812-2010; Oxygen permeability, GB / T1038-2000; Number of puncture residues, YY0614.1-2018; Antimicrobial release rate, high performance liquid chromatography; Antimicrobial rate, GB / T31402-2015 (Escherichia coli, Staphylococcus aureus).

[0046] Table 1 Performance Test Results

[0047] As shown in Table 1, when the inner caps of Examples 4-7 were properly sealed, the barrier layer maintained a low-oxygen environment (≤1%) inside the container, the microcapsule wall material remained stable, and the antibacterial agent was sealed and not released. After the seal failed, the oxygen concentration rose to ≥10%, triggering the degradation of the wall material (24h degradation rate ≥80%), releasing Ag@ZnO for antibacterial action. Compared with Examples 4-7, the inner caps of Comparative Examples 1 and 2 showed higher antibacterial agent release rates in low-oxygen environments and lower antibacterial agent release rates in high-oxygen environments. Furthermore, the antibacterial rate was lower in high-oxygen environments after 24 hours, indicating that the antibacterial duration of the inner caps of Comparative Examples 1 and 2 did not correspond to their sealing performance, and their antibacterial efficacy was low. Compared with Examples 4-7, the antibacterial agent release rate and antibacterial rate of Comparative Examples 3-6 both decreased. The inner cap of this invention can achieve antibacterial efficacy that changes with sealing performance, reducing the risk of antibacterial agent migration. At the same time, it can ensure a firm bond between the cap and the substrate, excellent puncture resistance, and strong process compatibility. It is suitable for infusion containers such as infusion bottles and bags that need to be stored for a long time, significantly improving medication safety and reliability.

[0048] The performance test differences between Comparative Examples 1-2 and Example 4 are analyzed and compared as follows: Table 2 Performance Test Difference Analysis Table

[0049] As shown in Table 2, in Comparative Example 1, directly adding Ag@ZnO to the functional surface layer resulted in premature release of the antibacterial agent from the inner cap, leading to decreased antibacterial efficacy after 3 months of storage and a high risk of drug migration. Comparative Example 2 did not use an oxygen-sensitive wall material; the microcapsule wall material continuously and slowly degraded, resulting in minimal difference in antibacterial agent release rates between high and low oxygen environments, and no targeted triggering. Furthermore, the inner cap of Comparative Example 2 was sensitive to temperature fluctuations (40-60℃), and non-oxygen triggering could lead to accidental release of the antibacterial agent, resulting in poor stability. This indicates that the antibacterial microcapsules provided by this invention have good stability.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An antibacterial material for infusion containers, characterized in that, By weight, it includes 70-85 parts polyethylene, 5-12 parts modified nano silica and 8-18 parts antibacterial microcapsules; The antibacterial microcapsule includes a core material, a first wall material layer encapsulating the core material, and a second wall material layer encapsulating the first wall material layer; the core material includes Ag@ZnO, the raw material of the first wall material layer includes polyurethane containing diselenyl bonds, and the raw material of the second wall material layer includes polycaprolactone, modified nano-zero-valent iron-palladium, and citric acid.

2. The antibacterial material for infusion containers according to claim 1, characterized in that, The modified nano-silica is prepared by dispersing nano-silica in γ-aminopropyltriethoxysilane and ultrasonically treating it. The mass ratio of nano-silica to γ-aminopropyltriethoxysilane is 100:3-8, and the particle size of nano-silica is 20-50 nm.

3. The antibacterial material for infusion containers according to claim 1, characterized in that, The preparation method of Ag@ZnO is as follows: ZnO nanoparticles are dispersed in a mixed solution of water and ethanol, AgNO3 solution is added under light protection, stirred, reduced by ultraviolet light, washed and dried to obtain Ag@ZnO.

4. The antibacterial material for infusion containers according to claim 1, characterized in that, The modified nano-zero-valent iron-palladium is prepared as follows: under nitrogen protection, FeSO4·7H2O is reduced with NaBH4 to obtain nano-zero-valent iron, which is then reacted with K2PdCl6 solution to obtain nano-zero-valent iron-palladium metal particles. After magnetic separation and washing, the particles are added to a mixed solution of oleic acid and ethanol, stirred, and vacuum dried to obtain modified nano-zero-valent iron-palladium. The Pd content in the K2PdCl6 solution is 0.5wt%, and the mass ratio of nano-zero-valent iron to K2PdCl6 solution is 20:

1.

5. The antibacterial material for infusion containers according to any one of claims 1-4, characterized in that, The preparation method of antibacterial microcapsules is as follows: Polyurethane containing diselenide bonds was dissolved in anhydrous dichloromethane to obtain a 5% w / v solution. Ag@ZnO was added to the solution and ultrasonically dispersed to obtain an oil phase. The oil phase was slowly added to a 5% (v / v) polyvinyl alcohol solution and subjected to high-speed shearing to form an O / W emulsion. After centrifugation, washing, and freeze-drying, core-shell microparticles were obtained. The mass ratio of Ag@ZnO to polyurethane containing diselenyl groups is 1:4-6; Polycaprolactone was dissolved in dichloromethane to form a 3% w / v solution. Modified nano-zero-valent iron-palladium and citric acid were added to the solution and ultrasonically dispersed to form a suspension. Core-shell microparticles were slowly added to the suspension and spray-dried to obtain antibacterial microcapsules; The mass ratio of polycaprolactone, modified nano-zero-valent iron-palladium and citric acid is 10:2:1-2, and the solid-liquid ratio of the core-shell microparticles and the suspension is 3-7:

100.

6. A film-covered inner cap for an infusion container, characterized in that, The container includes an inner cover substrate and a coating layer laminated to the inner surface of the inner cover substrate. The coating layer consists of an adhesive layer, a barrier layer, a buffer layer, and a functional surface layer in sequence. The functional surface layer is made of the antibacterial material for infusion containers as described in any one of claims 1-5.

7. The membrane inner cap for an infusion container according to claim 6, characterized in that, The adhesive layer comprises, by weight, 85-95 parts of modified polypropylene grafted with maleic anhydride, 3-10 parts of polyethylene wax, and 0.5-2 parts of antioxidant; the grafting rate of the modified polypropylene grafted with maleic anhydride is 0.8-1.5%, and the antioxidant comprises antioxidant 1010 and antioxidant 168 in a mass ratio of 1-2:

1.

8. The membrane inner cap for an infusion container according to claim 6, characterized in that, The barrier layer comprises 60-75 parts by weight of ethylene-vinyl alcohol copolymer, 20-35 parts of polyamide, and 3-8 parts of compatibilizer; the polyamide is polyamide 6, and the compatibilizer is maleic anhydride-grafted polyolefin elastomer with a grafting rate of 0.5-1.2%.

9. The membrane inner cap for an infusion container according to claim 6, characterized in that, The buffer layer comprises, by weight, 70-85 parts of metallocene-catalyzed polyethylene, 10-20 parts of elastomer, and 2-5 parts of lubricant; the elastomer is an ethylene-octene copolymer, and the lubricant is erucamide or oleamide.

10. The method for preparing a membrane inner cap for an infusion container according to any one of claims 6-9, characterized in that, Includes the following steps: S1. Prepare adhesive layer mixture, barrier layer mixture and buffer layer mixture according to each layer component, and then put them into the corresponding extruder hopper of the three-layer co-extrusion blown film machine for three-layer co-extrusion composite to obtain the substrate; The functional surface layer mixture is laminated onto the surface of the substrate by low-temperature hot pressing to obtain a coating layer; S2. The inner cover substrate is obtained by injection molding homopolymer polypropylene in an injection molding machine; S3. Preparation of the film-coated inner cover: The film layer and the inner cover substrate are hot-pressed together to obtain the film-coated inner cover.

Images