Environmentally friendly and recyclable drug packaging composite film and preparation method thereof

Abstract

The present invention relates to an environmentally friendly and recyclable composite film for drug packaging and a preparation method thereof, and belongs to the technical field of polymer materials. The present invention uses a vacuum aluminum-plated biaxially oriented polypropylene film as a middle layer, a cast polypropylene film as an inner layer, and a biaxially oriented polypropylene film as an outer layer, and obtains an environmentally friendly and recyclable composite film for drug packaging by layer-by-layer compounding. The composite film is suitable for hot filling, retort bags, aseptic bags and other fields. The environmentally friendly and recyclable composite film for drug packaging of the present invention has good oxygen barrier properties, can extend the shelf life of drugs, and because the three layers are all made of a single polypropylene material, it can realize the environmentally friendly concept of single material recyclability and replace glass bottled Chinese medicine oral liquid packaging to become an emerging packaging material in the oral liquid market, and can be mass-produced.

Description

Technical Field

[0001] The invention relates to an environmentally friendly and recyclable composite film for drug packaging and a preparation method thereof, belonging to the technical field of polymer materials. Background Art

[0002] Glass bottles have long been the mainstream packaging format for oral Chinese medicine liquids, dominating the market thanks to their high transparency, aesthetic appeal, and stable product properties. However, they also present numerous inconveniences during transportation and use. They suffer from fragility, difficulty administering medication, weak impact resistance, difficulty recycling, and increased shipping costs due to their weight. Against this backdrop, developing packaging materials and innovative packaging formats for oral Chinese medicine liquids have become key approaches to addressing the shortcomings of glass bottles. After extensive market research and comparison, composite packaging films have emerged as an emerging packaging material for the oral Chinese medicine liquid market.

[0003] Chinese patent document CN118358230A discloses a high-draw aluminum-plastic film and its processing method. The film comprises, from the surface to the inner layer, a nylon protective layer, a composite aluminum foil layer, and a three-layer co-extruded biaxially oriented polypropylene layer. The nylon protective layer and the composite aluminum foil layer, as well as the composite aluminum foil layer and the three-layer co-extruded biaxially oriented polypropylene layer, are dry-laminated using a dry laminating machine. The three-layer co-extruded biaxially oriented polypropylene layer is a three-layer co-extruded film produced by co-extrusion casting and comprises, from the outside to the inside, an aluminum foil adhesive layer, a heat-resistant layer, and a heat-sealing layer. The composite aluminum foil layer comprises an aluminum layer and a polymer layer, and the outer surface of the polymer layer is formed with an aluminum layer by physical vapor deposition. The composite film prepared in this patent document contains heavy metal chromium salts, making it unsuitable for drug packaging. Furthermore, the film uses multiple types of polymer materials, making it difficult to simply recycle. Therefore, there is an urgent need to develop a recyclable composite film suitable for drug packaging. Summary of the Invention

[0004] The purpose of the present invention is to provide an environmentally friendly and recyclable composite film for drug packaging and a preparation method thereof, so as to solve the problem that the current composite film cannot be recycled due to different materials.

[0005] The technical solution of the environmentally friendly and recyclable drug packaging composite film of the present invention is as follows:

[0006] An environmentally friendly and recyclable pharmaceutical packaging composite film comprises a biaxially oriented polypropylene film, a vacuum-aluminized biaxially oriented polypropylene film, and a cast polypropylene film, which are sequentially laminated. The vacuum-aluminized biaxially oriented polypropylene film comprises a biaxially oriented polypropylene layer and a vacuum-aluminized layer, and the vacuum-aluminized biaxially oriented polypropylene film is laminated with the biaxially oriented polypropylene film via the vacuum-aluminized layer. The cast polypropylene film comprises a transition layer, an adhesive layer, and a heat-sealing layer, which are sequentially laminated, and the cast polypropylene film is laminated with the biaxially oriented polypropylene layer of the vacuum-aluminized biaxially oriented polypropylene film via the transition layer. The transition layer is made of a transition layer material, which is homopolypropylene. The heat-sealing layer is made of a ternary copolymerized polypropylene, a heat-sealing agent, an anti-blocking agent, and a lubricant. The adhesive layer is made of an adhesive layer material, which is made by melt-extrusion granulation of maleic anhydride-grafted polypropylene, epoxy-group-modified nanoporous silica, and epoxy-group-modified nanofibrous wollastonite in a mass ratio of 100:2-3:4-5.

[0007] Preferably, the preparation method of the epoxy group-modified nanoporous silica is as follows: γ-glycidyloxypropyltrimethoxysilane, ethanol and water are mixed, the pH is adjusted to 3-4.5 with acid, nanoporous silica is added, and then heated to 70-80° C. and mixed for reaction for 7-10 hours.

[0008] Preferably, the mass ratio of γ-glycidyloxypropyltrimethoxysilane to nanoporous silica is 20-23:8-10.

[0009] Preferably, the preparation method of the epoxy group-modified nanofibrous wollastonite is as follows: nanofibrous wollastonite and γ-glycidyloxypropyltrimethoxysilane are mixed in ethanol at 60-70° C. for 2-4 hours.

[0010] Preferably, the mass ratio of the nanofibrous wollastonite to γ-glycidyloxypropyltrimethoxysilane is 80-100:10.

[0011] Preferably, the mass ratio of the terpolymer polypropylene, the heat sealant, the anti-blocking agent and the slip agent is 72:8:12:8.

[0012] Preferably, the heat sealant is propylene-butene copolymer.

[0013] Preferably, the lubricant is erucamide.

[0014] Preferably, the adhesive is silicon dioxide.

[0015] A method for preparing the above-mentioned environmentally friendly and recyclable composite film for drug packaging comprises the following steps: co-extruding a transition layer material, an adhesive layer material, and a heat-sealing layer material to obtain a cast polypropylene film; then coating glue between the biaxially oriented polypropylene film and the vacuum aluminum-plated biaxially oriented polypropylene film, followed by laminating to obtain a composite layer; and finally coating glue between the composite layer and the cast polypropylene film, followed by laminating to obtain the environmentally friendly and recyclable composite film for drug packaging.

[0016] The beneficial technical effects of the present invention are as follows:

[0017] (1) The present invention uses epoxy group-modified nanoporous silica and epoxy group-modified nanofibrous wollastonite to modify maleic anhydride grafted polypropylene to obtain a bonding layer material, and chemically grafts the nanoporous silica and nanofibrous wollastonite onto the maleic anhydride grafted polypropylene molecular chain to ensure that the nanoporous silica and nanofibrous wollastonite are evenly and firmly attached to the maleic anhydride grafted polypropylene molecular chain; when the bonding layer material, the transition layer material and the heat-sealing layer material are melt-extruded into a co-extrusion die, part of the fibrous wollastonite in the bonding layer material can enter the transition layer interface, and part can enter the heat-sealing layer interface. At the same time, part of the resin molecular chains at the transition layer interface can enter the pores of the porous silica under the action of extrusion, and part of the resin molecular chains at the heat-sealing layer interface can enter the pores of the porous silica under the action of extrusion. Therefore, the bonding layer, transition layer and heat seal layer are tightly bonded through the entanglement of polymer chains in the bonding layer, the transition connection of fibrous wollastonite and the porous adsorption of porous silica, thereby improving the adhesion between the transition layer and the heat seal layer.

[0018] (2) The cast polypropylene film prepared by the above-mentioned adhesive layer, transition layer and heat-sealing layer of the present invention contains a certain amount of nanoparticles, which can effectively improve the heat resistance of the cast polypropylene film and ensure that the packaged medicine is not damaged when heated. In addition, the transition connection effect of the fibrous wollastonite and the porous adsorption effect of the porous silica can effectively improve the density of the resin matrix, thereby improving the barrier properties of the composite film.

[0019] (3) The present invention uses vacuum aluminum-plated biaxially oriented polypropylene film as the middle layer, cast polypropylene film as the inner layer, and biaxially oriented polypropylene film as the outer layer, and obtains an environmentally friendly and recyclable drug packaging composite film by layer-by-layer compounding. The composite film of the present invention is portable, water-resistant, oxygen-resistant, and has good aroma retention, high mechanical strength, pressure resistance, and transportability, which are superior to glass bottles. The material structure fully meets customer needs. According to market feedback, the test samples have achieved the expected results in terms of breakage rate, shelf life, easy processing and transportation, and single material recyclability. The composite film of the present invention is suitable for hot filling, cooking bags, aseptic bags and other fields. The environmentally friendly and recyclable drug packaging composite film of the present invention has good oxygen barrier properties and can extend the shelf life of drugs. The composite film of the present invention was measured by a water vapor permeability meter and a gas permeability meter, and the water vapor and oxygen barrier rates of the composite film of the present invention were both less than 0.5 The barrier properties of this composite material rival those of aluminum foil, and all three layers are constructed from a single PP material, both environmentally friendly and recyclable. This single-material, recyclable packaging composite film boasts high mechanical strength, excellent pressure resistance, and is easy to transport and carry. It also offers excellent water and oxygen barrier properties, as well as aroma preservation, ensuring optimal drug stability. After pilot and pilot tests, this preparation method has proven to achieve the environmentally friendly concept of single-material recyclability and is poised to replace glass bottles for traditional Chinese medicine oral liquid packaging, becoming an emerging packaging material in the oral liquid market and a viable option for mass production.

[0020] (4) Compared with oral liquids in glass bottles, Chinese medicine oral liquid strip packs have the advantages of being environmentally friendly and recyclable, having a short production process, being light in weight and having low transportation costs, being green and environmentally friendly, not easy to break, having strong impact resistance, being highly safe, and being easy to carry. They are expected to replace the mainstream form of Chinese medicine oral liquid packaging in glass bottles in the market, and the industry has huge room for development. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the water vapor and oxygen barrier rate test results of the environmentally friendly recyclable pharmaceutical packaging composite films of various comparative examples;

[0022] Figure 2 Schematic diagram of the peel strength between the transition layer and the heat-sealing layer in the cast polypropylene film of the environmentally friendly and recyclable drug packaging composite film of each comparative example;

[0023] Figure 3 Schematic diagram of the heat-sealing strength between the transition layer and the heat-sealing layer in the cast polypropylene film of the environmentally friendly and recyclable drug packaging composite film of each comparative example. DETAILED DESCRIPTION

[0024] The following examples are intended to further illustrate the present invention, but are not intended to limit the scope of protection of the present invention.

[0025] Example 1

[0026] The environmentally friendly and recyclable pharmaceutical packaging composite film of this embodiment includes a biaxially oriented polypropylene film (BOPP), a vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) and a cast polypropylene film (CPP) which are sequentially composited on top of each other; wherein the vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) includes a biaxially oriented polypropylene layer and a vacuum aluminumized layer, and the vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) is composited with the biaxially oriented polypropylene film (BOPP) through the vacuum aluminumized layer; the cast polypropylene film (CPP) includes a transition layer, an adhesive layer and a heat-sealing layer composited in sequence, and the cast polypropylene film (CPP) is composited with the vacuum aluminumized biaxially oriented polypropylene film (BOPP) through the transition layer. The thickness of the biaxially oriented polypropylene film (BOPP) is 18μm, which can withstand high-temperature cooking at 121°C. The thickness of the vacuum aluminized biaxially oriented polypropylene film (VMBOPP) is 18μm. It is a vacuum aluminized packaging film based on BOPP. It is a flexible packaging material with excellent metallic luster and barrier properties. It has high barrier properties to water vapor and oxygen. It is a recyclable single-material packaging that can be obtained commercially or customized. The thickness of the cast polypropylene film is 40μm. This material has the characteristics of good gloss, softness and easy tearing, strong moisture and oxygen barrier properties, excellent heat resistance, and easy heat sealing.

[0027] The method for preparing the environmentally friendly and recyclable drug packaging composite film of this embodiment comprises the following steps:

[0028] (1) 20 g of γ-glycidyloxypropyltrimethoxysilane, 100 mL of anhydrous ethanol and 10 mL of deionized water were added to a flask, and hydrochloric acid was added to the flask to adjust the pH of the material in the flask to 3. Then, 8 g of nanoporous silica was added to the flask under stirring, and the material in the flask was heated to 70 ° C, stirred and refluxed for 7 h, filtered, and the filter cake was washed with ethanol to obtain epoxy group-modified nanoporous silica.

[0029] (2) 80 g of nanofibrous wollastonite and 10 g of γ-glycidyloxypropyltrimethoxysilane were added to 900 g of anhydrous ethanol, heated to 60 °C and stirred for reaction for 2 h. After the reaction was completed, the mixture was filtered, and the filter cake was rinsed with ethanol and dried to obtain epoxy group-modified nanofibrous wollastonite.

[0030] (3) Maleic anhydride grafted polypropylene, epoxy group modified nanoporous silica and epoxy group modified nanofibrous wollastonite in a mass ratio of 100:2:4 were melt-extruded and granulated to obtain a bonding layer material.

[0031] (4) The transition layer material (homopolymer polypropylene for cast film), the adhesive layer material and the heat-sealing layer material (the heat-sealing layer material is composed of ternary copolymer polypropylene for cast film, a heat-sealing agent, an anti-blocking agent and a lubricant in a mass ratio of 72:8:12:8, the heat-sealing agent is propylene-butene copolymer, the lubricant is erucamide, and the adhesive is silica) are respectively placed into the three extruders of the three-layer co-extrusion film unit. Each extruder heats and melt-extrudes the internal material to the co-extrusion die head, and then blows and air-cools to obtain the inner layer cast polypropylene film; wherein, the melt extrusion temperature of the barrier layer material is 210℃~220℃, the melt extrusion temperature of the adhesive layer material is 150℃~170℃, and the melt extrusion temperature of the heat-sealing layer material is 190℃~200℃.

[0032] (5) Apply solvent-free polyurethane two-component glue (the glue amount is 1.5) between the biaxially oriented polypropylene film (BOPP) and the vacuum aluminum biaxially oriented polypropylene film (VMBOPP) ), and then composite curing is carried out at 45°C to obtain a composite layer. The solvent-free polyurethane two-component glue includes a polyester polyol material and a polyurethane curing agent, which are mixed in a mass ratio of 1:1 when used.

[0033] The preparation method of the polyester polyol material is as follows: 65g of poly (neopentyl adipate) (molecular weight 2500), 30g of poly (1,4-butylene adipate) (molecular weight 1000) and 22g of neopentyl glycol are added to a reaction vessel, heated to 120°C, vacuumed for dehydration, and then 1.2g of an adhesion modifier is added and stirred evenly to obtain a polyester polyol material; the preparation method of the adhesion modifier is as follows: at 0°C, a chloroform solution of diethylphosphine chloride (mass fraction 20%) is added dropwise to the reaction vessel. The mixture was added to a chloroform solution of 2,2,2-triaminotriethylamine (mass fraction of 40%, molar ratio of diethylphosphine chloride and 2,2,2-triaminotriethylamine of 1:1), stirred and reacted for 5 hours after the addition was completed, and then a chloroform solution of triethoxychlorosilane (mass fraction of 20%, molar ratio of triethoxychlorosilane and 2,2,2-triaminotriethylamine of 1:1) was continued to be added dropwise. After the addition was completed, the mixture was stirred and reacted for 6 hours, filtered, and the filtrate was distilled under reduced pressure to remove chloroform to obtain an adhesion modifier.

[0034] The preparation method of the polyurethane curing agent is as follows: 45 g of polyoxypropylene glycol (molecular weight 2500) is added to a reaction container, heated to 120°C, vacuumed for dehydration, then cooled to 60°C, 60 g of 4,4-diphenylmethane diisocyanate and 0.5 g of 2-aminoethylphosphonic acid are added, heated to 80°C, stirred and reacted for 2 hours to obtain a polyurethane curing agent.

[0035] (4) Glue is applied between the composite layer and the cast polypropylene film (CPP), and then the composite layer and the cast polypropylene film (CPP) are compounded using a dry laminating machine to obtain an environmentally friendly and recyclable drug packaging composite film.

[0036] Example 2

[0037] The environmentally friendly and recyclable pharmaceutical packaging composite film of this embodiment includes a biaxially oriented polypropylene film (BOPP), a vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) and a cast polypropylene film (CPP) which are sequentially composited on top of each other; wherein the vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) includes a biaxially oriented polypropylene layer and a vacuum aluminumized layer, and the vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) is composited with the biaxially oriented polypropylene film (BOPP) through the vacuum aluminumized layer; the cast polypropylene film (CPP) includes a transition layer, an adhesive layer and a heat-sealing layer composited in sequence, and the cast polypropylene film (CPP) is composited with the vacuum aluminumized biaxially oriented polypropylene film (BOPP) through the transition layer. The biaxially oriented polypropylene layers of the VMBOPP are composited together; the thickness of the biaxially oriented polypropylene film (BOPP) is 15μm, and it can withstand high-temperature cooking at 121°C; the thickness of the vacuum aluminized biaxially oriented polypropylene film (VMBOPP) is 18μm. It is a vacuum aluminized packaging film based on BOPP. It is a flexible packaging material with excellent metallic luster and barrier properties. It has high barrier properties to water vapor and oxygen. It is a recyclable single-material packaging that can be obtained commercially or through customization; the thickness of the cast polypropylene film is 80μm. This material has the characteristics of good gloss, softness and easy tearing, strong moisture and oxygen barrier properties, excellent heat resistance, and easy heat sealing.

[0038] The method for preparing the environmentally friendly and recyclable drug packaging composite film of this embodiment comprises the following steps:

[0039] (1) 23 g of γ-glycidyloxypropyltrimethoxysilane, 120 mL of anhydrous ethanol and 13 mL of deionized water were added to a flask, and hydrochloric acid was added to the flask to adjust the pH of the material in the flask to 4.5. Then, 10 g of nanoporous silica was added to the flask under stirring, and the material in the flask was heated to 70-80 ° C, stirred and refluxed for 10 h, filtered, and the filter cake was washed with ethanol to obtain epoxy group-modified nanoporous silica.

[0040] (2) 100 g of nanofibrous wollastonite and 10 g of γ-glycidyloxypropyltrimethoxysilane were added to 1000 g of anhydrous ethanol, heated to 70 °C and stirred for reaction for 4 h. After the reaction was completed, the mixture was filtered, and the filter cake was rinsed with ethanol and dried to obtain epoxy group-modified nanofibrous wollastonite.

[0041] (3) Maleic anhydride grafted polypropylene, epoxy group modified nanoporous silica and epoxy group modified nanofibrous wollastonite in a mass ratio of 100:3:5 were melt extruded and granulated to obtain a bonding layer material.

[0042] (4) The transition layer material (homopolymer polypropylene for cast film), the adhesive layer material and the heat-sealing layer material (the heat-sealing layer material is composed of ternary copolymer polypropylene for cast film, a heat-sealing agent, an anti-blocking agent and a lubricant in a mass ratio of 72:8:12:8, the heat-sealing agent is propylene-butene copolymer, the lubricant is erucamide, and the adhesive is silica) are respectively placed into the three extruders of the three-layer co-extrusion film unit. Each extruder heats and melt-extrudes the internal material to the co-extrusion die head, and then blows and air-cools to obtain the inner layer cast polypropylene film; wherein, the melt extrusion temperature of the barrier layer material is 210℃~220℃, the melt extrusion temperature of the adhesive layer material is 150℃~170℃, and the melt extrusion temperature of the heat-sealing layer material is 190℃~200℃.

[0043] (5) Apply solvent-free polyurethane two-component glue (the glue amount is 1.5) between the biaxially oriented polypropylene film (BOPP) and the vacuum aluminum biaxially oriented polypropylene film (VMBOPP) ), and then composite curing is carried out at 45°C to obtain a composite layer. The solvent-free polyurethane two-component glue includes a polyester polyol material and a polyurethane curing agent, which are mixed in a mass ratio of 1:1 when used.

[0044] The preparation method of the polyester polyol material is as follows: 65g of poly (neopentyl adipate) (molecular weight 2500), 30g of poly (1,4-butylene adipate) (molecular weight 1000) and 22g of neopentyl glycol are added to a reaction vessel, heated to 120°C, vacuumed for dehydration, and then 1.2g of an adhesion modifier is added and stirred evenly to obtain a polyester polyol material; the preparation method of the adhesion modifier is as follows: at 0°C, a chloroform solution of diethylphosphine chloride (mass fraction 20%) is added dropwise to the reaction vessel. The mixture was added to a chloroform solution of 2,2,2-triaminotriethylamine (mass fraction of 40%, molar ratio of diethylphosphine chloride and 2,2,2-triaminotriethylamine of 1:1), stirred and reacted for 5 hours after the addition was completed, and then a chloroform solution of triethoxychlorosilane (mass fraction of 20%, molar ratio of triethoxychlorosilane and 2,2,2-triaminotriethylamine of 1:1) was continued to be added dropwise. After the addition was completed, the mixture was stirred and reacted for 6 hours, filtered, and the filtrate was distilled under reduced pressure to remove chloroform to obtain an adhesion modifier.

[0045] The preparation method of the polyurethane curing agent is as follows: 45 g of polyoxypropylene glycol (molecular weight 2500) is added to a reaction container, heated to 120°C, vacuumed for dehydration, then cooled to 60°C, 60 g of 4,4-diphenylmethane diisocyanate and 0.5 g of 2-aminoethylphosphonic acid are added, heated to 80°C, stirred and reacted for 2 hours to obtain a polyurethane curing agent.

[0046] (4) Glue is applied between the composite layer and the cast polypropylene film (CPP), and then the composite layer and the cast polypropylene film (CPP) are compounded using a dry laminating machine to obtain an environmentally friendly and recyclable drug packaging composite film.

[0047] Example 3

[0048] The environmentally friendly and recyclable pharmaceutical packaging composite film of this embodiment includes a biaxially oriented polypropylene film (BOPP), a vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) and a cast polypropylene film (CPP) which are sequentially composited on top of each other; wherein the vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) includes a biaxially oriented polypropylene layer and a vacuum aluminumized layer, and the vacuum aluminumized biaxially oriented polypropylene film (VMBOPP) is composited with the biaxially oriented polypropylene film (BOPP) through the vacuum aluminumized layer; the cast polypropylene film (CPP) includes a transition layer, an adhesive layer and a heat-sealing layer composited in sequence, and the cast polypropylene film (CPP) is composited with the vacuum aluminumized biaxially oriented polypropylene film (BOPP) through the transition layer. The thickness of the biaxially oriented polypropylene film (BOPP) is 16μm, which can withstand high-temperature cooking at 121°C. The thickness of the vacuum aluminized biaxially oriented polypropylene film (VMBOPP) is 18μm. It is a vacuum aluminized packaging film based on BOPP. It is a flexible packaging material with excellent metallic luster and barrier properties. It has high barrier properties to water vapor and oxygen. It is a recyclable single-material packaging that can be obtained commercially or customized. The thickness of the cast polypropylene film is 60μm. This material has the characteristics of good gloss, softness and easy tearing, strong moisture and oxygen barrier properties, excellent heat resistance, and easy heat sealing.

[0049] The method for preparing the environmentally friendly and recyclable drug packaging composite film of this embodiment comprises the following steps:

[0050] (1) 22 g of γ-glycidyloxypropyltrimethoxysilane, 110 mL of anhydrous ethanol and 12 mL of deionized water were added to a flask, and hydrochloric acid was added to the flask to adjust the pH of the material in the flask to 4. Then, 9 g of nanoporous silica was added to the flask under stirring, and the material in the flask was heated to 75 ° C. and stirred under reflux for 8 h. After filtering, the filter cake was washed with ethanol to obtain epoxy group-modified nanoporous silica.

[0051] (2) 90 g of nanofibrous wollastonite and 10 g of γ-glycidyloxypropyltrimethoxysilane were added to 950 g of anhydrous ethanol, heated to 65 °C and stirred for reaction for 3 h. After the reaction was completed, the mixture was filtered, and the filter cake was rinsed with ethanol and dried to obtain epoxy group-modified nanofibrous wollastonite.

[0052] (3) Maleic anhydride grafted polypropylene, epoxy group modified nanoporous silica and epoxy group modified nanofibrous wollastonite in a mass ratio of 100:2.5:4.5 were melt extruded and granulated to obtain a bonding layer material.

[0053] (4) The transition layer material (homopolymer polypropylene for cast film), the adhesive layer material and the heat-sealing layer material (the heat-sealing layer material is composed of ternary copolymer polypropylene for cast film, a heat-sealing agent, an anti-blocking agent and a lubricant in a mass ratio of 72:8:12:8, the heat-sealing agent is propylene-butene copolymer, the lubricant is erucamide, and the adhesive is silica) are respectively placed into the three extruders of the three-layer co-extrusion film unit. Each extruder heats and melt-extrudes the internal material to the co-extrusion die head, and then blows and air-cools to obtain the inner layer cast polypropylene film; wherein, the melt extrusion temperature of the barrier layer material is 210℃~220℃, the melt extrusion temperature of the adhesive layer material is 150℃~170℃, and the melt extrusion temperature of the heat-sealing layer material is 190℃~200℃.

[0054] (5) Apply solvent-free polyurethane two-component glue (the glue amount is 1.5) between the biaxially oriented polypropylene film (BOPP) and the vacuum aluminum biaxially oriented polypropylene film (VMBOPP) ), and then composite curing is carried out at 45°C to obtain a composite layer. The solvent-free polyurethane two-component glue includes a polyester polyol material and a polyurethane curing agent, which are mixed in a mass ratio of 1:1 when used.

[0055] The preparation method of the polyester polyol material is as follows: 65g of poly (neopentyl adipate) (molecular weight 2500), 30g of poly (1,4-butylene adipate) (molecular weight 1000) and 22g of neopentyl glycol are added to a reaction vessel, heated to 120°C, vacuumed for dehydration, and then 1.2g of an adhesion modifier is added and stirred evenly to obtain a polyester polyol material; the preparation method of the adhesion modifier is as follows: at 0°C, a chloroform solution of diethylphosphine chloride (mass fraction 20%) is added dropwise to the reaction vessel. The mixture was added to a chloroform solution of 2,2,2-triaminotriethylamine (mass fraction of 40%, molar ratio of diethylphosphine chloride and 2,2,2-triaminotriethylamine of 1:1), stirred and reacted for 5 hours after the addition was completed, and then a chloroform solution of triethoxychlorosilane (mass fraction of 20%, molar ratio of triethoxychlorosilane and 2,2,2-triaminotriethylamine of 1:1) was continued to be added dropwise. After the addition was completed, the mixture was stirred and reacted for 6 hours, filtered, and the filtrate was distilled under reduced pressure to remove chloroform to obtain an adhesion modifier.

[0056] The preparation method of the polyurethane curing agent is as follows: 45 g of polyoxypropylene glycol (molecular weight 2500) is added to a reaction container, heated to 120°C, vacuumed for dehydration, then cooled to 60°C, 60 g of 4,4-diphenylmethane diisocyanate and 0.5 g of 2-aminoethylphosphonic acid are added, heated to 80°C, stirred and reacted for 2 hours to obtain a polyurethane curing agent.

[0057] (4) Glue is applied between the composite layer and the cast polypropylene film (CPP), and then the composite layer and the cast polypropylene film (CPP) are compounded using a dry laminating machine to obtain an environmentally friendly and recyclable drug packaging composite film.

[0058] Comparative Example 1

[0059] The only difference between the environmentally friendly recyclable drug packaging composite film of this comparative example and the environmentally friendly recyclable drug packaging composite film of Example 1 is that the bonding layer material used in the environmentally friendly recyclable drug packaging composite film of this comparative example is obtained by melt extrusion granulation of maleic anhydride grafted polypropylene, nanoporous silica and nanofibrous wollastonite in a mass ratio of 100:2:4.

[0060] Comparative Example 2

[0061] The only difference between the environmentally friendly recyclable drug packaging composite film of this comparative example and the environmentally friendly recyclable drug packaging composite film of Example 1 is that the bonding layer material used in the environmentally friendly recyclable drug packaging composite film of this comparative example is obtained by melt extrusion granulation of maleic anhydride grafted polypropylene and epoxy group modified nanoporous silica in a mass ratio of 100:6.

[0062] Comparative Example 3

[0063] The only difference between the environmentally friendly recyclable drug packaging composite film of this comparative example and the environmentally friendly recyclable drug packaging composite film of Example 1 is that the bonding layer material used in the environmentally friendly recyclable drug packaging composite film of this comparative example is obtained by melt extrusion granulation of maleic anhydride grafted polypropylene and epoxy group modified nanofibrous wollastonite in a mass ratio of 100:6.

[0064] Comparative Example 4

[0065] The only difference between the environmentally friendly recyclable drug packaging composite film of this comparative example and the environmentally friendly recyclable drug packaging composite film of Example 1 is that the bonding layer material used in the environmentally friendly recyclable drug packaging composite film of this comparative example is obtained by melt extrusion granulation of maleic anhydride grafted polypropylene, epoxy group modified nano-silica (nano-silica without porous structure) and epoxy group modified nano-fibrous wollastonite in a mass ratio of 100:2:4.

[0066] Comparative Example 5

[0067] The only difference between the environmentally friendly recyclable drug packaging composite film of this comparative example and the environmentally friendly recyclable drug packaging composite film of Example 1 is that the bonding layer material used in the environmentally friendly recyclable drug packaging composite film of this comparative example is obtained by melt extrusion granulation of maleic anhydride grafted polypropylene, epoxy group modified nanoporous silica and epoxy group modified nano flaky wollastonite in a mass ratio of 100:2:4.

[0068] Effect Example 1

[0069] In order to evaluate the application effect of the environmentally friendly recyclable pharmaceutical packaging composite films of each embodiment and comparative example in pharmaceutical packaging, the water vapor and oxygen barrier rates of the environmentally friendly recyclable pharmaceutical packaging composite films of each embodiment and comparative example were respectively measured using a water vapor transmission rate meter and a gas transmission rate meter. The results are shown in Table 1. At the same time, the peel strength between the transition layer and the heat seal layer in the cast polypropylene film was tested according to the method in the standard YBB00102003-2015 "Peel Strength Determination Method", and the heat seal strength of the heat seal layer in the cast polypropylene film was tested according to the method in the standard YBB00122003-2015 "Heat Seal Strength Determination Method". The results are shown in Table 1. Figure 1-3 shown. Figure 1 The units of water vapor transmission rate and oxygen transmission rate are .

[0070] Table 1 Water vapor and oxygen barrier rates of the environmentally friendly recyclable drug packaging composite films of each embodiment and comparative example, peel strength between the transition layer and the heat seal layer in the cast polypropylene film, and heat seal strength

[0071] Material <![CDATA[Water vapor transmission rate (cc / m 2 ·24hr·atm)]]> <![CDATA[Oxygen Transmission Rate (cc / m 2 ·24hr·atm)]]> Peel strength (N / 15mm) Heat sealing strength (N / 15mm) Example 1 <0.5 <0.5 Non-peelable 49 Example 2 <0.5 <0.5 Non-peelable 52 Example 3 <0.5 <0.5 Non-peelable 51 Comparative Example 1 1.0 1.2 11.7 29 Comparative Example 2 0.8 0.9 13.2 35 Comparative Example 3 0.7 0.9 10.8 33 Comparative Example 4 0.8 0.8 11.4 37 Comparative Example 5 0.9 1.0 12.5 35

[0072] Table 1 shows that the environmentally friendly, recyclable pharmaceutical packaging composite film of the present invention exhibits high water vapor and oxygen barrier properties, and the peel strength and heat seal strength between the transition layer and the heat seal layer in the cast polypropylene film are high. The environmentally friendly, recyclable pharmaceutical packaging composite film of the present invention also exhibits high mechanical strength, excellent pressure resistance, and is easy to transport and carry. It also exhibits excellent water and oxygen barrier properties, as well as aroma preservation, and can effectively maintain the stability of pharmaceutical products.

[0073] Effect Example 2

[0074] In order to investigate the bonding effect of solvent-free polyurethane two-component glues prepared with different polyester alcohols and different adhesion modifiers on biaxially oriented polypropylene film (BOPP) and vacuum aluminum-plated biaxially oriented polypropylene film (VMBOPP), the test was repeated according to step (5) of Example 1, except that the poly(neopentyl adipate) used in the preparation of the polyester polyol material was replaced by polyethylene adipate of equal molecular weight, or the 2,2,2-triaminotriethylamine used in the preparation of the adhesion modifier was replaced by 1,4-butanediamine, or the 2-aminoethylphosphonic acid used in the preparation of the polyurethane curing agent was replaced by phosphoric acid. Then, the prepared solvent-free polyurethane two-component glue was coated between the biaxially oriented polypropylene film (BOPP) and the vacuum aluminum-plated biaxially oriented polypropylene film (VMBOPP) and then compounded. After the glue was cured, the peel strength between the biaxially oriented polypropylene film (BOPP) and the vacuum aluminum-plated biaxially oriented polypropylene film (VMBOPP) was tested, and the presence of aluminum transfer was observed. The test results are shown in Table 2. Among them, the solvent-free polyurethane two-component glue prepared by replacing poly(neopentyl adipate) with poly(diethylene adipate) of equal molecular weight was named glue A, the solvent-free polyurethane two-component glue prepared by replacing 2,2,2-triaminotriethylamine with 1,4-butanediamine was named glue B, the solvent-free polyurethane two-component glue prepared by replacing 2-aminoethylphosphonic acid with phosphoric acid was named glue C, and the solvent-free polyurethane two-component glue prepared in Example 1 was named glue D.

[0075] Table 2 Bonding effect of different solvent-free polyurethane two-component glues

[0076] Solvent-free polyurethane two-component glue Peel strength (N / 15mm) Whether aluminum transfer occurs Glue A 1.2 have Glue B 1.5 have Glue C 1.5 have Glue D ≥2.5 none

[0077] As shown in Table 2, by introducing phosphate ester and siloxane into small molecule active amino compounds as adhesion modifiers, and simultaneously introducing 2-aminoethylphosphonic acid into the curing agent as an active monomer, the prepared solvent-free polyurethane two-component adhesive can achieve high bonding strength between biaxially oriented polypropylene film (BOPP) and vacuum aluminum-plated biaxially oriented polypropylene film (VMBOPP). At the same time, it can optimize the product appearance, avoid aluminum transfer, and ensure the water barrier, oxygen barrier, and fragrance retention properties of the composite film.

Claims

1. An environmentally friendly and recyclable composite film for drug packaging, characterized in that: The invention comprises a biaxially oriented polypropylene film, a vacuum aluminum-plated biaxially oriented polypropylene film and a cast polypropylene film which are sequentially composited; wherein the vacuum aluminum-plated biaxially oriented polypropylene film comprises a biaxially oriented polypropylene layer and a vacuum aluminum-plated layer, and the vacuum aluminum-plated biaxially oriented polypropylene film is composited with the biaxially oriented polypropylene film through the vacuum aluminum-plated layer; the cast polypropylene film comprises a transition layer, an adhesive layer and a heat-sealing layer which are composited in sequence, and the cast polypropylene film is composited with the biaxially oriented polypropylene layer of the vacuum aluminum-plated biaxially oriented polypropylene film through the transition layer; the transition layer is made of a transition layer material. The transition layer material is homopolymer polypropylene, the heat seal layer is made of ternary copolymer polypropylene, heat sealant, anti-blocking agent and slip agent, and the bonding layer is made of bonding layer material, which is made by melt extrusion granulation of maleic anhydride grafted polypropylene, epoxy group modified nanoporous silica and epoxy group modified nanofibrous wollastonite in a mass ratio of 100:2~3:4~5; the biaxially oriented polypropylene film and the vacuum aluminum-plated biaxially oriented polypropylene film are compounded together by solvent-free polyurethane two-component glue, and the solvent-free polyurethane two-component glue includes polyester polyol material and polyurethane curing agent. agent; the preparation method of the polyester polyol material is as follows: 65g of polyneopentyl adipate, 30g of poly1,4-butylene adipate and 22g of neopentyl glycol are vacuum dehydrated at 120°C and then mixed with 1.2g of adhesion modifier to obtain a polyester polyol material; the preparation method of the adhesion modifier is as follows: at 0°C, a chloroform solution of diethylphosphine chloride is added dropwise to a chloroform solution of 2,2,2-triaminotriethylamine, and the reaction is stirred for 5h after the addition is completed, and then a chloroform solution of triethoxysilyl chloride is added dropwise, and the reaction is stirred after the addition is completed. 6h, filtered, and the filtrate was distilled under reduced pressure to remove chloroform to obtain an adhesion modifier, wherein the molar ratio of diethylphosphine chloride and 2,2,2-triaminotriethylamine was 1:1, and the molar ratio of triethoxysilane chloride and 2,2,2-triaminotriethylamine was 1:1; the preparation method of the polyurethane curing agent was as follows: 45g of polyoxypropylene glycol was vacuum dehydrated at 120°C, then cooled to 60°C, 60g of 4,4-diphenylmethane diisocyanate and 0.5g of 2-aminoethylphosphonic acid were added, heated to 80°C, and stirred for reaction for 2h to obtain a polyurethane curing agent.

2. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 1, characterized in that: The preparation method of the epoxy group-modified nanoporous silica is as follows: γ-glycidyloxypropyltrimethoxysilane, ethanol and water are mixed, the pH is adjusted to 3-4.5 with acid, the nanoporous silica is added, and then the mixture is heated to 70-80° C. and mixed for reaction for 7-10 hours.

3. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 2, characterized in that: The mass ratio of the γ-glycidyloxypropyltrimethoxysilane to the nanoporous silica is 20-23:8-10.

4. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 1, characterized in that: The preparation method of the epoxy group-modified nanofibrous wollastonite is as follows: nanofibrous wollastonite and γ-glycidyloxypropyltrimethoxysilane are mixed in ethanol at 60-70° C. for reaction for 2-4 hours.

5. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 4, characterized in that: The mass ratio of the nanofibrous wollastonite to γ-glycidyloxypropyltrimethoxysilane is 80-100:

10.

6. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 1, characterized in that: The mass ratio of the ternary copolymer polypropylene, the heat sealant, the anti-blocking agent and the slip agent is 72:8:12:

8.

7. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 6, characterized in that: The heat sealant is propylene-butene copolymer.

8. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 6, characterized in that: The lubricant is erucamide.

9. The environmentally friendly and recyclable pharmaceutical packaging composite film according to claim 6, characterized in that: The adhesive is silicon dioxide.

10. A method for preparing the environmentally friendly and recyclable drug packaging composite film according to claim 1, characterized in that: The method comprises the following steps: co-extruding a transition layer material, an adhesive layer material and a heat-sealing layer material to obtain a cast polypropylene film; coating glue between the biaxially oriented polypropylene film and the vacuum aluminum-plated biaxially oriented polypropylene film, and then laminating them to obtain a composite layer; and finally coating glue between the composite layer and the cast polypropylene film, and then laminating them to obtain an environmentally friendly and recyclable composite film for drug packaging.

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