Composite cold aluminum for medicine packaging and preparation method thereof

Abstract

The invention discloses composite cold aluminum for medicine packaging and a preparation method of the composite cold aluminum. The composite cold aluminum comprises a PA layer, an Al layer, a PVC barrier layer and a PE moisture absorption layer which are sequentially arranged from outside to inside. The PVC barrier layer is prepared from 100 to 120 parts of PVC resin and 30 to 40 parts of high-barrier microspheres; the PE moisture absorption layer comprises 80-100 parts of PE resin and 15-20 parts of moisture absorption particles; the moisture absorption particles are beeswax coated calcium oxide particles; the high-barrier microspheres are porous polymer microspheres loaded with 3, 4, 5-trihydroxybenzoic acid. According to the composite cold aluminum film, the moisture absorption particles and the high-barrier microspheres with special components are added into the two inner film layers of the composite cold aluminum film correspondingly, the moisture absorption capacity and the barrier performance of the composite cold aluminum film can be remarkably improved, and meanwhile the situation that the film layers absorb moisture and then release the moisture into a packaging cavity is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of pharmaceutical packaging materials, in particular to composite cold aluminum for pharmaceutical packaging and a preparation method thereof. Background Art

[0002] Humidity is a common environmental indicator in everyday life, and the relative humidity within buildings significantly impacts human health and living comfort. Surveys have found that when indoor relative humidity is below 40% or above 65%, bacteria and viruses multiply significantly, potentially causing or exacerbating respiratory illnesses. As living standards continue to improve, people are increasingly paying attention to humidity regulation.

[0003] To prevent food or medicine from spoiling due to exposure to air and moisture, a conventional practice is to place a desiccant inside the package. However, since the desiccant comes into contact with the food or medicine, there is a safety risk of a reaction with the desiccant. Furthermore, desiccants use microporous technology to absorb moisture. The desiccant itself contains fine particles, which may contaminate the contents to a certain extent. Furthermore, after absorbing moisture, conventional desiccants tend to re-emit the moisture. Therefore, the moisture absorption effect is reversible, which is not conducive to the long-term storage of packaged medicines and food.

[0004] Currently, food and pharmaceutical packaging commonly uses composite films containing aluminum foil to block moisture and oxygen from affecting the contents. However, the PE film used for heat sealing in the inner layer of the composite film typically has poor moisture absorption, making it difficult to ensure a dry interior. Furthermore, despite aluminum's strong barrier properties, moisture and oxygen can penetrate the inner film layer from the edges of the package, potentially entering the interior after being absorbed by the film. Consequently, this moisture can be absorbed and released back into the package, making it difficult to meet moisture barrier requirements.

[0005] In view of this, this application is hereby filed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the existing PE film has poor moisture absorption effect, and the external moisture may be released again into the interior of the package after being coated with the film layer. In addition, the oxygen permeability of PE is also high, so it is difficult to meet the moisture absorption barrier requirements. The purpose is to provide a composite cold aluminum for pharmaceutical packaging and a preparation method thereof. By adding hygroscopic particles and high-barrier microspheres of special components to the two inner film layers of the composite cold aluminum film, the moisture absorption capacity and barrier performance of the composite cold aluminum can be significantly improved, while preventing the film layer from absorbing moisture and then releasing it into the packaging cavity.

[0007] The present invention is achieved through the following technical solutions: The first aspect of the present application provides a composite cold aluminum for medicine packaging, comprising a PA layer, an Al layer, a PVC barrier layer and a PE moisture absorption layer arranged from outside to inside. The PVC barrier layer comprises 100-120 parts of PVC resin and 30-40 parts of high barrier microspheres. The PE moisture absorption layer comprises 80-100 parts of PE resin and 15-20 parts of moisture absorption microparticles. The moisture absorption microparticles are beeswax-coated calcium oxide particles. The high barrier microspheres are porous polymer microspheres loaded with 3,4,5-trihydroxybenzoic acid.

[0008] The present application can significantly improve the moisture absorption capacity and barrier performance of the composite cold aluminum by adding moisture absorption microparticles and high barrier microspheres to the two inner film layers of the composite cold aluminum film, while avoiding the release of water absorbed by the film layers into the packaging cavity.

[0009] The present application obtains a PE moisture absorption layer by adding moisture absorption microparticles to the PE film, and the moisture absorption microparticles are beeswax-coated calcium oxide particles. At room temperature, low temperature and low humidity environment, beeswax is in a solid state to coat calcium oxide particles, and beeswax itself has good moisture absorption. Therefore, at low humidity, beeswax can absorb water, and under the difference between the internal and external structures of the moisture absorption microparticles, the absorbed water can penetrate into the internal structure of the moisture absorption microparticles and react with calcium oxide to achieve water locking. The coating of fixed beeswax further ensures that the water is locked in the internal structure of the moisture absorption microparticles. If the humidity or temperature in the environment continues to increase, the beeswax on the outer layer will continue to soften and deform, exposing the calcium oxide particles in the internal structure of the moisture absorption microparticles, increasing the area of water in the film that directly contacts the calcium oxide, and thereby generating calcium hydroxide through the exposed calcium oxide particles, significantly improving the moisture absorption capacity of the PE film and avoiding the penetration of water from the outside of the film into the packaging.

[0010] In a specific embodiment, the wax layer covering the hygroscopic microparticles is porous, which can expose part of the surface of the calcium oxide, and the wax layer has a non-uniform thickness on the entire coating interface. When the wax layer is deformed in a high-humidity and high-temperature environment, the thinner part of the wax layer can quickly break and deform to the thicker part, thereby quickly forming a hole penetrating the calcium oxide and exposing more of the surface of the calcium oxide. When the humidity and temperature of the external environment decrease, the thicker part of the wax layer can again solidify to cover part of the surface of the calcium oxide, thereby ensuring the "locking" of the adsorbed water. In addition, the porous structure of the wax layer can allow the calcium oxide to react with water to form calcium hydroxide precipitate in the porous structure, thereby avoiding the deformation of the film layer caused by the volume expansion of the reaction molecules and affecting the mechanical properties. In addition, the wax solid has good sliding toughness, so the presence of the wax layer can also toughen the film to some extent and improve the mechanical properties.

[0011] In a specific embodiment, the preparation method of the hygroscopic microparticles is as follows: The beeswax is heated to a molten state at 60-70 DEG C, and the pore-forming agent polyoxyethylene ether and calcium oxide are added in sequence and stirred uniformly. After cooling to room temperature, the pore-forming agent is removed by anhydrous ethanol, and the hygroscopic microparticles are obtained.

[0012] In a specific embodiment, the mass ratio of the beeswax to the calcium oxide is 1:2-3.

[0013] The present application adds high-barrier microspheres to the PVC film to obtain a PVC barrier layer. The high-barrier microspheres are porous polymer microspheres loaded with 3,4,5-trihydroxybenzoic acid. The porous polymer microspheres are made of ethylene-vinyl alcohol copolymer, which has a compact polymer chain with alternating ethylene and vinyl alcohol monomer units that can provide excellent barrier effect to gas. The microspheres doped in the PVC film can prevent external oxygen from penetrating and passing through the film layer, thereby preventing the external oxygen from entering the packaging interior through the PVC film layer. In addition, the ethylene-vinyl alcohol copolymer also has good mechanical strength, stretchability, wear resistance, etc., so adding it as a reinforcing particle to the PVC film can also improve the mechanical properties of the PVC film and improve the fracture synchronization of the PVC film layer and the aluminum foil layer under stress, thereby avoiding film layer delamination.

[0014] 3,4,5-trihydroxybenzoic acid can react with oxygen to absorb it, and can improve the barrier effect of oxygen by loading it in porous polymer microspheres; since the ethylene-vinyl alcohol copolymer molecular structure contains hydroxyl groups, it has hydrophilicity and hygroscopicity, can adsorb moisture, and improve the moisture absorption performance of the PE film; but when adsorbing moisture, the barrier performance of ethylene-vinyl alcohol copolymer to oxygen will be affected, therefore, the 3,4,5-trihydroxybenzoic acid is loaded on the porous ethylene-vinyl alcohol copolymer microspheres, first, the carboxyl group of 3,4,5-trihydroxybenzoic acid can bond with part of the hydroxyl group of ethylene-vinyl alcohol copolymer, reducing the adsorption of ethylene-vinyl alcohol copolymer and moisture, second, 3,4,5-trihydroxybenzoic acid has more hydroxyl groups, on the one hand, further improving the moisture absorption effect, on the other hand, the hydroxyl group of 3,4,5-trihydroxybenzoic acid can compete with the hydroxyl group of ethylene-vinyl alcohol copolymer for water molecules, reducing the influence of the barrier performance of ethylene-vinyl alcohol copolymer after absorbing moisture, finally, high concentration of water vapor can further activate the oxygen absorption reaction of 3,4,5-trihydroxybenzoic acid, accelerating the absorption of oxygen by 3,4,5-trihydroxybenzoic acid, therefore, 3,4,5-trihydroxybenzoic acid in the PVC film layer can also compete for oxygen from the PE film end face into the film layer, thereby greatly improving the moisture absorption and barrier performance of the whole composite cold aluminum material. Therefore, the high barrier microspheres of porous polymer microspheres loaded with 3,4,5-trihydroxybenzoic acid, the two synergies not only improve the barrier ability of the PVC film layer to oxygen, but also make the PVC film have a moisture absorption effect.

[0015] In summary, the high barrier microspheres in the PVC barrier layer and the moisture absorption particles in the PE moisture absorption layer synergistically improve the moisture absorption and barrier performance of the composite cold aluminum, not only ensuring the dryness of the packaging cavity, but also avoiding the entry of air and moisture from the outside through the packaging end face of the composite cold aluminum into the packaging cavity.

[0016] In a specific embodiment, the mass ratio of the porous polymer microspheres to 3,4,5-trihydroxybenzoic acid is 4-5:1.

[0017] In a specific embodiment, the preparation method of the high barrier microspheres is as follows: The ethylene-vinyl alcohol copolymer is dissolved in chloroform to obtain a copolymer solution; The copolymer solution is slowly added to the polyvinyl alcohol aqueous solution to form a mixed solution system, and the mixed solution system is subjected to high-speed shock emulsification, and after removing the solvent, washing and drying, the porous polymer microspheres are obtained; 3,4,5-trihydroxybenzoic acid is added to anhydrous ethanol, stirred and dissolved, then porous polymer microspheres are added and continuously stirred to form a dispersion, and the solvent is separated and dried to obtain the high barrier microspheres.

[0018] In a second aspect, the present application provides a preparation method of composite cold aluminum for medicine packaging, comprising the following steps: 1) heating and melting beeswax to a molten state, adding pore-forming agent and calcium oxide in sequence, stirring uniformly, cooling to room temperature, removing the pore-forming agent after crushing, obtaining hygroscopic microparticles, mixing the hygroscopic microparticles and PE resin to granulate, and extruding to form a film to obtain a PE hygroscopic film; 2) adding 3,4,5-trihydroxybenzoic acid to anhydrous ethanol, stirring and dissolving, then adding porous polymer microspheres to continuously stir to form a dispersion, separating the solvent and drying to obtain the high-barrier microspheres, mixing the high-barrier microspheres and PVC resin to granulate, and extruding to form a film to obtain a PVC barrier film; 3) bonding the PA film, Al aluminum foil, PVC barrier film and PE hygroscopic film by using an adhesive to obtain a composite cold aluminum material.

[0019] Compared with the prior art, the present application has the following advantages and beneficial effects: 1) The composite cold aluminum for medicine packaging and the preparation method provided by the present application can significantly improve the hygroscopic capacity and barrier performance of the composite cold aluminum by adding hygroscopic microparticles and high-barrier microspheres of special components to the two inner film layers of the composite cold aluminum film, while avoiding the release of water absorbed by the film layers into the packaging cavity; 2) The hygroscopic microparticles are beeswax-coated calcium oxide particles, which can absorb water at room temperature, low temperature and low humidity environment, and the beeswax itself has good hygroscopicity, so it can absorb water at low humidity, and the absorbed water can penetrate into the interior of the hygroscopic microparticles and react with calcium oxide to lock the water, and the coating of the fixed beeswax further ensures that the water is locked in the interior of the hygroscopic microparticles; 3) The hygroscopic microparticles of the composite cold aluminum for medicine packaging and the preparation method provided by the present application can significantly improve the hygroscopic capacity of the PE film by exposing the calcium oxide particles in the hygroscopic microparticles and increasing the area of direct contact between the water in the film and the calcium oxide, thereby directly absorbing water through the exposed calcium oxide particles to generate calcium hydroxide, thereby avoiding the penetration of water outside the film into the packaging interior; 4、The preparation method of the composite cold aluminum for medicine packaging provided by the embodiment of the present application, the high-barrier microspheres are porous polymer microspheres loaded with 3,4,5-trihydroxybenzoic acid, the ethylene-vinyl alcohol copolymer has a polymer chain with a compact structure, and the alternating arrangement of ethylene and vinyl alcohol monomer units can achieve excellent barrier effect on gas; the preparation of the microspheres doped in the PVC film can prevent external oxygen from permeating and penetrating through the film layer, thereby avoiding the penetration of the external oxygen into the packaging through the PVC film layer; in addition, the ethylene-vinyl alcohol copolymer also has good mechanical strength, stretchability, wear resistance and the like, so that the addition of the ethylene-vinyl alcohol copolymer as a reinforcing particle into the PVC film can also improve the mechanical properties of the PVC film and the fracture synchronism of the PVC film layer and the aluminum foil layer under stress, thereby avoiding the delamination of the film layer. 5、The preparation method of the composite cold aluminum for medicine packaging provided by the embodiment of the present application, the 3,4,5-trihydroxybenzoic acid can react with oxygen to absorb the oxygen, and the loading of the 3,4,5-trihydroxybenzoic acid in the porous polymer microspheres can improve the barrier effect on oxygen. DETAILED DESCRIPTION

[0020] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application in combination with embodiments, and the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and not as a limitation to the present application.

[0021] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application can be practiced without these specific details. In other instances, well-known methods have not been described in detail in order to avoid obscuring the present application.

[0022] Throughout this specification, the recitation of "one embodiment," "an embodiment," "one example," or "an example” means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the application. Therefore, the appearance of the phrases "in one embodiment,” "in an embodiment,” "in one example,” or "in an example” in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0023] Embodiment 1 The preparation method of the composite cold aluminum for medicine packaging provided by the embodiment of the present application includes the following steps: 1) heating the beeswax to a molten state at 60~70℃, adding the pore-forming agent polyoxyethylene ether and calcium oxide in sequence, stirring until uniform, the mass ratio of beeswax, calcium oxide and polyoxyethylene ether being 1:2:0.01, cooling to room temperature, crushing, removing the pore-forming agent with anhydrous ethanol, obtaining moisture-absorbing microparticles, mixing the moisture-absorbing microparticles and PE resin, granulating, extruding to form a film, obtaining a PE moisture-absorbing film; wherein the PE resin is 80 parts and the moisture-absorbing microparticles are 15 parts; 2) dissolving the ethylene-vinyl alcohol copolymer in chloroform to obtain a copolymer solution; slowly adding the copolymer solution to a 2wt% polyvinyl alcohol aqueous solution to form a mixed solution system, high-speed shock emulsifying the mixed solution system, removing the solvent, washing and drying to obtain porous polymer microspheres (this step uses a conventional porous microsphere preparation method, so it is not described in detail); adding 3,4,5-trihydroxybenzoic acid to anhydrous ethanol, stirring and dissolving, then adding the porous polymer microspheres and continuously stirring to form a dispersion, the mass ratio of the porous polymer microspheres to 3,4,5-trihydroxybenzoic acid being 4:1, separating the solvent and drying to obtain the high-barrier microspheres; mixing the high-barrier microspheres and PVC resin, granulating, extruding to form a film, obtaining a PVC barrier film; the PVC resin is 100 parts and the high-barrier microspheres are 30 parts; 3) using an adhesive to bond the PA film, Al foil, PVC barrier film and PE moisture-absorbing film to obtain a composite cold aluminum material.

[0024] Example 2 The preparation method of the composite cold aluminum for medicine packaging provided by the embodiments of the present application comprises the following steps: 1) heating the beeswax to a molten state at 60~70℃, adding the pore-forming agent polyoxyethylene ether and calcium oxide in sequence, stirring until uniform, the mass ratio of beeswax, calcium oxide and polyoxyethylene ether being 1:2.5:0.01, cooling to room temperature, crushing, removing the pore-forming agent with anhydrous ethanol, obtaining moisture-absorbing microparticles, mixing the moisture-absorbing microparticles and PE resin, granulating, extruding to form a film, obtaining a PE moisture-absorbing film; wherein the PE resin is 90 parts and the moisture-absorbing microparticles are 18 parts; 2) dissolving the ethylene-vinyl alcohol copolymer in chloroform to obtain a copolymer solution; slowly adding the copolymer solution to a 2wt% polyvinyl alcohol aqueous solution to form a mixed solution system, high-speed shock emulsifying the mixed solution system, removing the solvent, washing and drying to obtain porous polymer microspheres; adding 3,4,5-trihydroxybenzoic acid to anhydrous ethanol, stirring and dissolving, then adding the porous polymer microspheres and continuously stirring to form a dispersion, the mass ratio of the porous polymer microspheres to 3,4,5-trihydroxybenzoic acid being 4.5:1, separating the solvent and drying to obtain the high-barrier microspheres; The high-barrier microspheres and PVC resin are mixed and granulated, and a film is prepared by an extruder to obtain a PVC barrier film; the PVC resin is 110 parts, and the high-barrier microspheres are 35 parts; 3) The PA film, Al aluminum foil, PVC barrier film and PE moisture absorption film are bonded by using an adhesive to obtain a composite cold aluminum material.

[0025] Example 3 The preparation method of the composite cold aluminum for medicine packaging provided by the embodiment of the present application comprises the following steps: 1) The beeswax is heated to a molten state at 60-70 DEG C, and then the pore-forming agent polyoxyethylene ether and calcium oxide are sequentially added and uniformly stirred, and the mass ratio of the beeswax, calcium oxide and polyoxyethylene ether is 1:3:0.01, and then the mixture is cooled to room temperature, crushed, and then the pore-forming agent is removed by using anhydrous ethanol to obtain moisture absorption microparticles, and then the moisture absorption microparticles and PE resin are mixed and granulated, and a film is prepared by an extruder to obtain a PE moisture absorption film; the PE resin is 100 parts, and the moisture absorption microparticles are 20 parts; 2) The ethylene-vinyl alcohol copolymer is dissolved in chloroform to obtain a copolymer solution; The copolymer solution is slowly added to a 2wt% polyvinyl alcohol aqueous solution to form a mixed solution system, and the mixed solution system is subjected to high-speed shock emulsification, and then the solvent is removed, washed and dried to obtain porous polymer microspheres; The 3,4,5-trihydroxybenzoic acid is added to anhydrous ethanol, stirred and dissolved, and then the porous polymer microspheres are added and continuously stirred to form a dispersion, and the mass ratio of the porous polymer microspheres to the 3,4,5-trihydroxybenzoic acid is 5:1, and then the solvent is separated and dried to obtain the high-barrier microspheres; The high-barrier microspheres and PVC resin are mixed and granulated, and a film is prepared by an extruder to obtain a PVC barrier film; the PVC resin is 120 parts, and the high-barrier microspheres are 40 parts; 3) The PA film, Al aluminum foil, PVC barrier film and PE moisture absorption film are bonded by using an adhesive to obtain a composite cold aluminum material.

[0026] Comparative Example 1 The preparation method of the composite cold aluminum for medicine packaging provided by the embodiment of the present application comprises the following steps: 1) The ethylene-vinyl alcohol copolymer is dissolved in chloroform to obtain a copolymer solution; The copolymer solution is slowly added to a 2wt% polyvinyl alcohol aqueous solution to form a mixed solution system, and the mixed solution system is subjected to high-speed shock emulsification, and then the solvent is removed, washed and dried to obtain porous polymer microspheres; The 3,4,5-trihydroxybenzoic acid is added to anhydrous ethanol, stirred and dissolved, and then the porous polymer microspheres are added and continuously stirred to form a dispersion, and the mass ratio of the porous polymer microspheres to the 3,4,5-trihydroxybenzoic acid is 5:1, and then the solvent is separated and dried to obtain the high-barrier microspheres; The high-barrier microspheres and PVC resin are mixed, granulated, and extruded into a film to obtain a PVC barrier film; the PVC resin is 120 parts, and the high-barrier microspheres are 40 parts; 2) The PA film, Al aluminum foil, PVC barrier film, and PE film are bonded using an adhesive to obtain a composite cold aluminum material.

[0027] The difference between this comparative example and Example 3 is that the PE film does not contain hygroscopic microparticles.

[0028] Comparative Example 2 This comparative example provides a preparation method of a composite cold aluminum for drug packaging, including the following steps: 1) Hygroscopic microparticles and PE resin are mixed, granulated, and extruded into a film to obtain a PE hygroscopic film; the PE resin is 100 parts, and the calcium oxide is 20 parts; 2) Ethylene-vinyl alcohol copolymer is dissolved in chloroform to obtain a copolymer solution; The copolymer solution is slowly added to a 2wt% polyvinyl alcohol aqueous solution to form a mixed solution system, and the mixed solution system is subjected to high-speed shock emulsification. After removing the solvent, washing, and drying, porous polymer microspheres are obtained; 3,4,5-trihydroxybenzoic acid is added to anhydrous ethanol, stirred and dissolved, and then porous polymer microspheres are added for continuous stirring to form a dispersion. The mass ratio of the porous polymer microspheres to the 3,4,5-trihydroxybenzoic acid is 5:1. The solvent is separated and dried to obtain the high-barrier microspheres; The high-barrier microspheres and PVC resin are mixed, granulated, and extruded into a film to obtain a PVC barrier film; the PVC resin is 120 parts, and the high-barrier microspheres are 40 parts; 3) The PA film, Al aluminum foil, PVC barrier film, and PE hygroscopic film are bonded using an adhesive to obtain a composite cold aluminum material.

[0029] The difference between this comparative example and Example 3 is that the calcium oxide in the PE hygroscopic film is not coated with a porous beeswax layer.

[0030] Comparative Example 3 This comparative example provides a preparation method of a composite cold aluminum for drug packaging, including the following steps: 1) Beeswax is heated to a molten state at 60-70°C, and a pore-forming agent polyoxyethylene ether and calcium oxide are sequentially added and stirred uniformly. The mass ratio of the beeswax, calcium oxide, and polyoxyethylene ether is 1:3:0.01. After cooling to room temperature, the mixture is crushed and the pore-forming agent is removed using anhydrous ethanol to obtain hygroscopic microparticles. The hygroscopic microparticles and PE resin are mixed, granulated, and extruded into a film to obtain a PE hygroscopic film; the PE resin is 100 parts, and the hygroscopic microparticles are 20 parts; 2) The PA film, Al aluminum foil, PVC film, and PE hygroscopic film are bonded using an adhesive to obtain a composite cold aluminum material.

[0031] The difference between this comparative example and Example 3 is that the high-barrier microspheres are not contained in the PVC film.

[0032] Comparative Example 4 The preparation method of the composite cold aluminum for medicine packaging provided by this comparative example comprises the following steps: 1) Heat the beeswax to a molten state at 60-70°C, add the pore-forming agent polyoxyethylene ether and calcium oxide in sequence, stir until uniform, and then cool to room temperature. After crushing, remove the pore-forming agent with anhydrous ethanol to obtain hygroscopic microparticles. Mix the hygroscopic microparticles and PE resin, granulate, and extrude a film to obtain a PE hygroscopic film; wherein the mass ratio of the PE resin to the hygroscopic microparticles is 100:20. 2) Dissolve the ethylene-vinyl alcohol copolymer in chloroform to obtain a copolymer solution; Slowly add the copolymer solution to a 2wt% polyvinyl alcohol aqueous solution to form a mixed solution system, and perform high-speed shock emulsification on the mixed solution system. After removing the solvent, washing, and drying, porous polymer microspheres are obtained. Mix the porous polymer microspheres and PVC resin, granulate, and extrude a film to obtain a PVC barrier film; wherein the mass ratio of the PVC resin to the porous polymer microspheres is 120:40. 3) Use an adhesive to bond the PA film, Al aluminum foil, PVC barrier film, and PE hygroscopic film to obtain a composite cold aluminum material.

[0033] The difference between this comparative example and Example 3 is that the high-barrier microspheres in the PVC barrier film are not loaded with 3,4,5-trihydroxy benzoic acid.

[0034] Comparative Example 5 The composite cold aluminum for medicine packaging provided by this comparative example is different from Example 3 in that the calcium oxide in the PE hygroscopic film is not coated with a porous beeswax layer, and the high-barrier microspheres in the PVC barrier film are not loaded with 3,4,5-trihydroxy benzoic acid.

[0035] Comparative Example 6 The composite cold aluminum for medicine packaging provided by this comparative example is different from Example 3 in that the PE film does not contain hygroscopic microparticles, and the PVC film does not contain high-barrier microspheres.

[0036] The mechanical properties, moisture absorption, and barrier properties of the composite cold aluminum or packaging material formed by packaging obtained in Examples 1-3 and Comparative Examples 1-6 were tested. The normal temperature test conditions were a temperature of 25°C and a humidity of 50%; the high-temperature and high-humidity test conditions were a temperature of 40°C and a humidity of 75%. The results are shown in Table 1.

[0037] Table 1

[0038] Table 2

[0039] Table 3

[0040] From the above Table 1-Table 3, it can be seen that the PE moisture-absorbing film prepared by the embodiments 1-3 of the present application has good moisture-absorbing and barrier properties, and the mechanical properties of the film layer are significantly improved.

[0041] From the comparative example 1, it can be seen that the moisture-absorbing microparticles are not added in the PE film, so the moisture-absorbing property of the composite cold aluminum is significantly reduced, and the barrier property and the mechanical property are also reduced; from the comparative example 2, it can be seen that the moisture-absorbing microparticles added in the PE film are not coated with beeswax, and the moisture-absorbing property and the barrier property of the composite cold aluminum are only slightly reduced, while the mechanical property is significantly reduced, which is because the calcium oxide particles alone absorb water, and the system expands, thereby affecting the mechanical property of the PE film layer, resulting in the decrease of the overall mechanical property of the composite cold aluminum; from the comparative example 3, it can be seen that the high-barrier microspheres are not added in the PVC film, and the moisture-absorbing property of the composite cold aluminum is only slightly reduced, but the barrier property and the mechanical property are significantly reduced; from the comparative example 4, it can be seen that the high-barrier microspheres are added in the PVC film, but the 3,4,5-trihydroxybenzoic acid is not loaded on the microspheres, and the moisture-absorbing property and the mechanical property of the composite cold aluminum are not obviously affected, but the oxygen permeability is significantly increased, indicating that the barrier property of the PVC film layer to oxygen is significantly reduced; from the comparative example 5, it can be seen that the calcium oxide in the PE moisture-absorbing film is not coated with a porous beeswax layer, and the 3,4,5-trihydroxybenzoic acid is not loaded on the high-barrier microspheres in the PVC barrier film, the moisture-absorbing property of the composite cold aluminum is reduced, and the barrier property and the mechanical property are significantly reduced. The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above-described specific embodiments are only specific embodiments of the present application, and are not used to limit the protection scope of the present application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. Composite cold aluminum for pharmaceutical packaging, characterized by: It includes a PA layer, an Al layer, a PVC barrier layer and a PE moisture absorbing layer arranged in sequence from the outside to the inside; The PVC barrier layer comprises 100-120 parts of PVC resin and 30-40 parts of high-barrier microspheres; The PE moisture-absorbing layer comprises 80-100 parts of PE resin and 15-20 parts of moisture-absorbing particles; The hygroscopic particles are beeswax-coated calcium oxide particles; The high-barrier microspheres are porous polymer microspheres loaded with 3,4,5-trihydroxybenzoic acid.

2. The composite cold aluminum for medicine packaging according to claim 1, characterized in that: The beeswax layer coated on the outside of the hygroscopic particles has a porous structure.

3. The composite cold aluminum for medicine packaging according to claim 2, characterized in that: The mass ratio of the beeswax to calcium oxide is 1:2-3.

4. The composite cold aluminum for medicine packaging according to claim 2, characterized in that: The preparation method of the hygroscopic particles is as follows: The beeswax is heated and melted to a molten state, a pore-forming agent and calcium oxide are added in sequence and stirred evenly, and then cooled to room temperature. The pore-forming agent is removed after being crushed to obtain hygroscopic particles.

5. The composite cold aluminum for medicine packaging according to claim 4, characterized in that: The pore-forming agent is polyoxyethylene ether, and the pore-forming agent is removed by using anhydrous ethanol.

6. The composite cold aluminum for medicine packaging according to claim 1, characterized in that: The porous polymer microspheres are made of ethylene-vinyl alcohol copolymer.

7. The composite cold aluminum for medicine packaging according to claim 6, characterized in that: The mass ratio of the porous polymer microspheres to 3,4,5-trihydroxybenzoic acid is 4-5:

1.

8. The composite cold aluminum for medicine packaging according to claim 6, characterized in that: The preparation method of the high barrier microspheres is as follows: dissolving ethylene-vinyl alcohol copolymer in an oil phase organic solvent to obtain a copolymer solution; The copolymer solution is slowly added dropwise to the polyvinyl alcohol aqueous solution to form a mixed solution system, and the mixed solution system is subjected to high-speed oscillation emulsification, and the solvent is removed, washed, and dried to obtain porous polymer microspheres; 3,4,5-trihydroxybenzoic acid is added to anhydrous ethanol and stirred to dissolve, and then porous polymer microspheres are added and stirred continuously to form a dispersion, and the solvent is separated and dried to obtain the high-barrier microspheres.

9. The composite cold aluminum for medicine packaging according to claim 8, characterized in that: The oil phase organic solvent is chloroform.

10. The method for preparing the composite cold aluminum for drug packaging according to any one of claims 1 to 9, characterized in that: The steps include: 1) Heat beeswax to melt, add pore-forming agent and calcium oxide in sequence and stir evenly, cool to room temperature, crush and remove pore-forming agent to obtain hygroscopic particles, mix the hygroscopic particles with PE resin to form granules, and extruder to produce PE hygroscopic film; 2) adding 3,4,5-trihydroxybenzoic acid to anhydrous ethanol and stirring to dissolve, then adding porous polymer microspheres and continuously stirring to form a dispersion, separating the solvent, and drying to obtain the high-barrier microspheres, mixing the high-barrier microspheres with PVC resin to form granules, and extruding to form a film to obtain a PVC barrier film; 3) Adhesive is used to bond the PA film, Al foil, PVC barrier film and PE moisture absorbing film to obtain a composite cold aluminum material.

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