A method for preparing 8079 alloy DC cast high performance propellant aluminum foil

Abstract

The application relates to a preparation method of 8079 alloy DC-cast high-performance drug package aluminum foil, and belongs to the technical field of drug package aluminum foil; in the application, a ring-opening esterification reaction is carried out on lauric acid and gamma-(2,3-epoxypropoxy) propyl trimethoxysilane to obtain a lauric acid silane ester adduct; polyvinyl alcohol is dissolved in deionized water, and then the lauric acid silane ester adduct is added and uniformly mixed to obtain a modified polyvinyl alcohol coating liquid; finally, the modified polyvinyl alcohol coating liquid is uniformly coated on the surface of the 8079 alloy DC-cast aluminum foil, and high-performance aluminum foil is obtained after heating and curing treatment. Through chemical bonding formed between the coating and the aluminum foil, the adhesion is enhanced, the coating density is improved, the barrier properties of water vapor and oxygen are improved; the coating flexibility and bending resistance are improved, and the long-term use stability is better; meanwhile, the coating has a contact type antibacterial function, the antibacterial components are not easy to lose, and the antibacterial effect is relatively durable.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical packaging aluminum foil technology, specifically, it relates to a method for preparing high-performance pharmaceutical packaging aluminum foil made of 8079 alloy DC casting. Background Technology

[0002] Pharmaceutical aluminum foil is a key substrate for blister packaging of pharmaceuticals, primarily serving to block oxygen and water vapor and protect the drugs. Uncoated aluminum foil is prone to oxidation and exhibits insufficient compatibility when in direct contact with pharmaceuticals; therefore, a functional coating is typically applied to the aluminum foil surface. Polyvinyl alcohol, due to its strong intermolecular hydrogen bonding and high density, possesses excellent gas barrier properties and has already been applied in the packaging coating field.

[0003] However, polyvinyl alcohol (PVA) coatings still face several technical challenges in practical applications. The PVA molecular chain contains numerous hydrophilic hydroxyl groups, causing the coating to absorb water and swell in humid environments, drastically deteriorating its gas barrier properties. Furthermore, the bond between the PVA coating and the aluminum foil substrate relies primarily on physical adsorption, lacking stable chemical bonds, making the coating prone to peeling and detachment during processing or use. In addition, there is an inherent contradiction between the flexibility and barrier properties of PVA coatings; cross-linking to enhance barrier properties often leads to brittleness and cracking, while adding traditional small-molecule plasticizers carries the risk of migration and precipitation. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing high-performance pharmaceutical packaging aluminum foil made of 8079 alloy DC casting, in order to solve the problems mentioned in the background art.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for preparing high-performance pharmaceutical packaging aluminum foil made of 8079 alloy DC casting includes the following steps: S1: Lauric acid undergoes a ring-opening esterification reaction with γ-(2,3-epoxypropoxy)propyltrimethoxysilane to give lauric acid silane ester adducts; Reaction equation:

[0006] S2: First, dissolve polyvinyl alcohol in deionized water, then add laurate silane ester adduct and mix evenly to obtain modified polyvinyl alcohol coating liquid; S3: The modified polyvinyl alcohol coating liquid is uniformly coated on the surface of 8079 alloy DC cast aluminum foil, and high-performance aluminum foil is obtained after heat curing treatment.

[0007] Furthermore, the molar ratio of lauric acid to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 1:1.0 to 1.3.

[0008] Furthermore, the catalyst used in the ring-opening esterification reaction is calcium acetylacetonate.

[0009] Furthermore, the amount of catalyst used is 1% to 5% of the total mass of lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0010] Furthermore, the ring-opening esterification reaction is carried out at a temperature of 65–80 °C for a reaction time of 8–12 h.

[0011] Furthermore, the polyvinyl alcohol is polyvinyl alcohol 1788, with a degree of alcoholysis of 88% and a degree of polymerization of 1700.

[0012] Furthermore, the ratio of polyvinyl alcohol to deionized water is 8–12 g: 88–92 mL.

[0013] Furthermore, the lauryl silane adducts account for 3% to 5% of the mass of polyvinyl alcohol.

[0014] Furthermore, the heat curing is a three-stage step curing process, in the following order: first, pre-baking at 50-60℃ for 30-45 minutes, then baking at 80-90℃ for 15-25 minutes, and finally cross-linking and curing at 110-120℃ for 20-30 minutes.

[0015] A high-performance pharmaceutical packaging aluminum foil made of 8079 alloy DC casting is prepared by any of the above preparation steps.

[0016] The beneficial effects of this invention are: 1) This invention prepares lauric acid silane ester adducts by selective ring-opening esterification of lauric acid with an epoxy-containing silane coupling agent under anhydrous conditions. The terminal trimethoxysilane group of this adduct is completely retained during preparation. After being compounded with polyvinyl alcohol and coated onto an aluminum foil surface, and cured by heating, the siloxane group hydrolyzes to generate active silanol groups. A portion of these silanol groups condense with hydroxyl groups on the aluminum foil surface to form Si-O-Al covalent bonds, achieving chemical bonding between the coating and the aluminum foil, thus enhancing the coating's adhesion and peel resistance. Another portion of the silanol groups condense within the coating to form a Si-O-Si crosslinked network. This network interpenetrates with the polyvinyl alcohol molecular chains, improving the coating's density and extending the permeation paths of water vapor and oxygen, thereby enhancing the coating's barrier properties. The long-chain alkyl groups grafted onto the silane coupling agent play a steric hindrance regulation role during the silane crosslinking process, slowing down the hydrolysis and condensation rate of the siloxane groups. This allows the coating to have more time to complete leveling and orderly arrangement on the aluminum foil surface before curing, which is conducive to forming a more uniform and dense crosslinking network.

[0017] 2) This invention utilizes the insertion of long-chain alkyl groups from laurate silane ester adducts between polyvinyl alcohol (PVA) molecular chains, weakening the original hydrogen bond cohesive forces between molecules and acting as an internal plasticizer, thus endowing the coating with good flexibility and bending resistance. These long-chain alkyl groups are covalently linked to the coating's cross-linking network via ester bonds, making them less prone to free migration. Compared to conventional free small-molecule plasticizers, they can maintain the isolation and lubrication effect on the PVA molecular chains for a longer period, ensuring the coating's flexibility remains stable during long-term use. Simultaneously, because the internal plasticizer component is covalently anchored to the cross-linking network, the enhanced flexibility of the coating does not come at the expense of the cross-linking network's density, thus reconciling to some extent the contradiction between flexibility and barrier properties in traditional PVA coatings.

[0018] 3) This invention uses lauric acid silane ester adducts as multifunctional adjuvants. Lauric acid, as a medium-chain fatty acid, mainly achieves its antibacterial effect by disrupting the integrity of bacterial cell membranes, increasing cell membrane permeability, and causing leakage of intracellular substances, thereby inhibiting bacterial growth. Lauric acid residues are covalently anchored in the coating cross-linking network by ester bonds, exerting antibacterial effects in a contact manner. Compared with physical blending, this reduces the free migration of antibacterial components and helps to prolong the duration of antibacterial effect. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.

[0020] The raw materials used in this invention are not particularly restricted in terms of their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art. Example 1

[0021] S1: Under nitrogen protection and anhydrous conditions, lauric acid and anhydrous toluene were mixed and stirred to dissolve. Then, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and calcium acetylacetonate catalyst were added and stirred until uniformly dispersed. The reaction was carried out at 65°C for 8 hours. After the reaction was completed, the mixture was cooled to room temperature and the solvent toluene and a small amount of unreacted free γ-(2,3-epoxypropoxy)propyltrimethoxysilane were removed by vacuum distillation to obtain lauric acid silane ester adducts. The molar ratio of lauric acid to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 1:1.0, the amount of calcium acetylacetone is 1% of the total mass of lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and the ratio of anhydrous toluene to reactants is 80 mL / 10 g.

[0022] S2: Add polyvinyl alcohol 1788 to deionized water and stir at 85°C for 2 hours until completely dissolved. Then cool to 30°C, add the wetting agent fatty alcohol polyoxypropylene ether, stir at low speed for 5 minutes to mix, then add gas phase nano SiO2 (particle size 20-50nm), stir at high speed and disperse ultrasonically for 20 minutes, then add lauric acid silane ester adduct in small amounts in batches, stir at low speed for 50 minutes, let stand to remove bubbles, and the modified polyvinyl alcohol coating liquid is obtained. The ratio of polyvinyl alcohol 1788 to deionized water is 8g:92mL, the amount of fatty alcohol polyoxypropylene ether accounts for 0.1% of the mass of polyvinyl alcohol 1788, the amount of fumed nano-SiO2 (particle size 20-50nm) accounts for 8% of the mass of polyvinyl alcohol 1788, and the amount of laurate silane ester adduct accounts for 3% of the mass of polyvinyl alcohol 1788.

[0023] S3: The modified polyvinyl alcohol coating liquid is uniformly coated onto the surface of the degreased 8079 alloy DC cast aluminum foil using a wire bar coater. The wet film thickness is 20μm. After three-stage step curing treatment, a high-performance aluminum foil is obtained. It should be further explained that the three-stage step curing process is as follows: first, pre-bake at 50℃ for 30 minutes, then bake at 80℃ for 15 minutes, and finally cross-link and cure at 110℃ for 20 minutes. Degreasing process: Immerse the aluminum foil in an alkaline aqueous solution with a total concentration of 0.9 mol / L prepared from sodium hydroxide and sodium carbonate, wash at 50°C for 1 minute, then wash with deionized water and dry. Example 2

[0024] S1: Under nitrogen protection and anhydrous conditions, lauric acid and anhydrous toluene were mixed and stirred to dissolve. Then, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and calcium acetylacetonate catalyst were added and stirred until uniformly dispersed. The reaction was carried out at 72°C for 10 hours. After the reaction was completed, the mixture was cooled to room temperature and the solvent toluene and a small amount of unreacted free γ-(2,3-epoxypropoxy)propyltrimethoxysilane were removed by vacuum distillation to obtain lauric acid silane ester adducts. The molar ratio of lauric acid to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 1:1.15, the amount of calcium acetylacetonate is 3% of the total mass of lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and the ratio of anhydrous toluene to reactants is 105 mL / 10 g.

[0025] S2: Add polyvinyl alcohol 1788 to deionized water and stir at 85°C for 2 hours until completely dissolved. Then cool to 30°C, add the wetting agent fatty alcohol polyoxypropylene ether, stir at low speed for 5 minutes to mix, then add gas phase nano SiO2 (particle size 20-50nm), stir at high speed and disperse ultrasonically for 20 minutes, then add lauric acid silane ester adduct in small amounts in batches, stir at low speed for 50 minutes, let stand to remove bubbles, and the modified polyvinyl alcohol coating liquid is obtained. The ratio of polyvinyl alcohol 1788 to deionized water is 10g:90mL, the amount of fatty alcohol polyoxypropylene ether accounts for 0.3% of the mass of polyvinyl alcohol 1788, the amount of fumed nano-SiO2 (particle size 20-50nm) accounts for 12% of the mass of polyvinyl alcohol 1788, and the amount of laurate silane ester adduct accounts for 4% of the mass of polyvinyl alcohol 1788.

[0026] S3: The modified polyvinyl alcohol coating liquid is uniformly coated onto the surface of the degreased 8079 alloy DC cast aluminum foil using a wire bar coater. The wet film thickness is 20μm. After three-stage step curing treatment, a high-performance aluminum foil is obtained. It should be further explained that the three-stage curing process is as follows: first, pre-bake at 55℃ for 37 minutes, then bake at 85℃ for 20 minutes, and finally cross-link and cure at 115℃ for 25 minutes. Degreasing process: Immerse the aluminum foil in an alkaline aqueous solution with a total concentration of 0.9 mol / L prepared from sodium hydroxide and sodium carbonate, wash at 50°C for 1 minute, then wash with deionized water and dry. Example 3

[0027] S1: Under nitrogen protection and anhydrous conditions, lauric acid and anhydrous toluene were mixed and stirred to dissolve. Then, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and calcium acetylacetonate catalyst were added and stirred until uniformly dispersed. The reaction was carried out at 80°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature and the solvent toluene and a small amount of unreacted free γ-(2,3-epoxypropoxy)propyltrimethoxysilane were removed by vacuum distillation to obtain lauric acid silane ester adducts. The molar ratio of lauric acid to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 1:1.3, the amount of calcium acetylacetonate is 5% of the total mass of lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and the ratio of anhydrous toluene to reactants is 130 mL / 10 g.

[0028] S2: Add polyvinyl alcohol 1788 to deionized water and stir at 85°C for 2 hours until completely dissolved. Then cool to 30°C, add the wetting agent fatty alcohol polyoxypropylene ether, stir at low speed for 5 minutes to mix, then add gas phase nano SiO2 (particle size 20-50nm), stir at high speed and disperse ultrasonically for 20 minutes, then add lauric acid silane ester adduct in small amounts in batches, stir at low speed for 50 minutes, let stand to remove bubbles, and the modified polyvinyl alcohol coating liquid is obtained. The ratio of polyvinyl alcohol 1788 to deionized water is 8g:92mL, the amount of fatty alcohol polyoxypropylene ether accounts for 0.5% of the mass of polyvinyl alcohol 1788, the amount of fumed nano-SiO2 (particle size 20-50nm) accounts for 15% of the mass of polyvinyl alcohol 1788, and the amount of laurate silane ester adduct accounts for 5% of the mass of polyvinyl alcohol 1788.

[0029] S3: The modified polyvinyl alcohol coating liquid is uniformly coated onto the surface of the degreased 8079 alloy DC cast aluminum foil using a wire bar coater. The wet film thickness is 20μm. After three-stage step curing treatment, a high-performance aluminum foil is obtained. It should be further explained that the three-stage curing process is as follows: first, pre-bake at 60℃ for 45 minutes, then bake at 90℃ for 25 minutes, and finally cross-link and cure at 120℃ for 30 minutes. Degreasing process: Immerse the aluminum foil in an alkaline aqueous solution with a total concentration of 0.9 mol / L prepared from sodium hydroxide and sodium carbonate, wash at 50°C for 1 minute, then wash with deionized water and dry. Example 4

[0030] S1: Under nitrogen protection and anhydrous conditions, lauric acid and anhydrous toluene were mixed and stirred to dissolve. Then, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and calcium acetylacetonate catalyst were added and stirred until uniformly dispersed. The reaction was carried out at 68°C for 9 hours. After the reaction was completed, the mixture was cooled to room temperature and the solvent toluene and a small amount of unreacted free γ-(2,3-epoxypropoxy)propyltrimethoxysilane were removed by vacuum distillation to obtain lauric acid silane ester adducts. The molar ratio of lauric acid to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 1:1.05, the amount of calcium acetylacetonate is 1.5% of the total mass of lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and the amount of anhydrous toluene to reactants is 88 mL / 10 g.

[0031] S2: Add polyvinyl alcohol 1788 to deionized water and stir at 85°C for 2 hours until completely dissolved. Then cool to 30°C, add the wetting agent fatty alcohol polyoxypropylene ether, stir at low speed for 5 minutes to mix, then add gas phase nano SiO2 (particle size 20-50nm), stir at high speed and disperse ultrasonically for 20 minutes, then add lauric acid silane ester adduct in small amounts in batches, stir at low speed for 50 minutes, let stand to remove bubbles, and the modified polyvinyl alcohol coating liquid is obtained. The ratio of polyvinyl alcohol 1788 to deionized water is 9g:91mL, the amount of fatty alcohol polyoxypropylene ether accounts for 0.15% of the mass of polyvinyl alcohol 1788, the amount of fumed nano-SiO2 (particle size 20-50nm) accounts for 9% of the mass of polyvinyl alcohol 1788, and the amount of laurate silane ester adduct accounts for 3.3% of the mass of polyvinyl alcohol 1788.

[0032] S3: The modified polyvinyl alcohol coating liquid is uniformly coated onto the surface of the degreased 8079 alloy DC cast aluminum foil using a wire bar coater. The wet film thickness is 20μm. After three-stage step curing treatment, a high-performance aluminum foil is obtained. It should be further explained that the three-stage step curing process is as follows: first, pre-bake at 52℃ for 32 minutes, then bake at 82℃ for 17 minutes, and finally cross-link and cure at 112℃ for 22 minutes. Degreasing process: Immerse the aluminum foil in an alkaline aqueous solution with a total concentration of 0.9 mol / L prepared from sodium hydroxide and sodium carbonate, wash at 50°C for 1 minute, then wash with deionized water and dry. Example 5

[0033] S1: Under nitrogen protection and anhydrous conditions, lauric acid and anhydrous toluene were mixed and stirred to dissolve. Then, γ-(2,3-epoxypropoxy)propyltrimethoxysilane and calcium acetylacetonate catalyst were added and stirred until uniformly dispersed. The reaction was carried out at 78°C for 11 hours. After the reaction was completed, the mixture was cooled to room temperature and the solvent toluene and a small amount of unreacted free γ-(2,3-epoxypropoxy)propyltrimethoxysilane were removed by vacuum distillation to obtain lauric acid silane ester adducts. The molar ratio of lauric acid to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 1:1.25, the amount of calcium acetylacetonate accounts for 4.5% of the total mass of lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane, and the ratio of anhydrous toluene to reactants is 122 mL / 10 g.

[0034] S2: Add polyvinyl alcohol 1788 to deionized water and stir at 85°C for 2 hours until completely dissolved. Then cool to 30°C, add the wetting agent fatty alcohol polyoxypropylene ether, stir at low speed for 5 minutes to mix, then add gas phase nano SiO2 (particle size 20-50nm), stir at high speed and disperse ultrasonically for 20 minutes, then add lauric acid silane ester adduct in small amounts in batches, stir at low speed for 50 minutes, let stand to remove bubbles, and the modified polyvinyl alcohol coating liquid is obtained. The ratio of polyvinyl alcohol 1788 to deionized water is 11g:89mL, the amount of fatty alcohol polyoxypropylene ether accounts for 0.45% of the mass of polyvinyl alcohol 1788, the amount of fumed nano-SiO2 (particle size 20-50nm) accounts for 14% of the mass of polyvinyl alcohol 1788, and the amount of laurate silane ester adduct accounts for 4.7% of the mass of polyvinyl alcohol 1788.

[0035] S3: The modified polyvinyl alcohol coating liquid is uniformly coated onto the surface of the degreased 8079 alloy DC cast aluminum foil using a wire bar coater. The wet film thickness is 20μm. After three-stage step curing treatment, a high-performance aluminum foil is obtained. It should be further explained that the three-stage curing process is as follows: first, pre-bake at 58℃ for 42 minutes, then bake at 88℃ for 23 minutes, and finally cross-link and cure at 118℃ for 28 minutes. Degreasing process: Immerse the aluminum foil in an alkaline aqueous solution with a total concentration of 0.9 mol / L prepared from sodium hydroxide and sodium carbonate, wash at 50°C for 1 minute, then wash with deionized water and dry.

[0036] Comparative Example 1 The difference between this comparative example and Example 1 is that the lauric acid silane ester adduct is not prepared separately. Instead, lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane are added to the polyvinyl alcohol 1788 solution by physical blending. The remaining steps are the same as in Example 1.

[0037] Experimental Example 1 The aluminum foils obtained in Examples 1-5 and Comparative Example 1 were subjected to performance tests.

[0038] The coating adhesion was tested according to GB / T 9286-2021 "Paints and Varnishes Cross-cut Test". The cutting interval was 2mm, and the adhesion grade was evaluated by cross-cut method. The lower the grade, the better the adhesion. The test was carried out after the coating was fully cured. Oxygen permeability was tested in accordance with GB / T 1038.1-2022 "Test method for gas permeability of plastic films and sheets - Part 1: Differential pressure method". The test temperature was 23℃ and the relative humidity was 0%RH. The oxygen permeability was expressed as the volume of oxygen permeating a unit area of ​​coating per unit time. The system was degassed before the test. Water vapor transmission rate was tested according to GB / T 1037-2021 "Determination of Water Vapor Transmission Performance of Plastic Films and Sheets - Cup Method for Weight Gain and Weight Loss", with a test temperature of 38℃ and a relative humidity of 90%RH. The result was expressed as the mass of water vapor passing through a unit area of ​​the coating in 24 hours. The surface water contact angle was tested in accordance with GB / T 30693-2014 "Measurement of the contact angle between plastic film and water". The static droplet method was used, with deionized water as the test liquid and a droplet volume of 5μL. The measurement was completed within a few seconds after the droplet contacted the coating surface. The larger the contact angle, the stronger the hydrophobicity of the coating. The antibacterial rate was tested according to GB / T 31402-2023 "Determination of antibacterial activity of plastics and other non-porous materials". The test bacteria were Staphylococcus aureus and Escherichia coli, and the contact time was 24 hours. The antibacterial rate is used to express the coating's ability to inhibit bacteria. The higher the antibacterial rate, the better the antibacterial effect. The antibacterial durability was evaluated by the antibacterial rate after accelerated aging. The coating sample was immersed in deionized water for 24 hours, then removed and dried at room temperature. The antibacterial rate of the coating after immersion treatment was determined according to GB / T 31402-2023. The pot life of a coating is evaluated by viscosity change: the prepared coating solution is left to stand at room temperature, and its viscosity is measured every hour. The time required for the viscosity to double is used as the indicator for judging the pot life of the coating. The longer the pot life, the better the storage stability of the coating solution. The coating flexibility was tested according to GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets". The coating flexibility was expressed as elongation at break; a higher elongation at break indicated better coating flexibility. The test results are shown in Table 1. Table 1

[0039] As shown in Table 1, the coatings prepared in Examples 1-5 are superior to Comparative Example 1 in terms of adhesion, oxygen permeability, water vapor permeability, water contact angle, antibacterial rate, pot life, and elongation at break. The pot life of the coatings in each example is significantly longer than that in Comparative Example 1. In Comparative Example 1, lauric acid and epoxy-containing silane coupling agent are added by physical blending, and the pot life of the coating solution is 3.5 hours; while in Examples 1-5, lauric acid and epoxy-containing silane coupling agent are pre-prepared as an adduct through chemical bonding, extending the pot life to 5.0-7.0 hours, and improving the storage stability and application window of the coating solution. Combined analysis of elongation at break and water vapor permeability shows that Examples 1-5 significantly improve elongation at break while greatly reducing water vapor permeability, with both indicators being superior to Comparative Example 1. After 24 hours of accelerated aging treatment by immersion in water, the antibacterial rate against Staphylococcus aureus and Escherichia coli in Examples 1-5 remains above 85%, while the antibacterial rate of Comparative Example 1 decreases significantly after aging.

[0040] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing high-performance pharmaceutical packaging aluminum foil made of 8079 alloy DC casting, characterized in that, Includes the following steps: S1: Lauric acid reacts with γ-(2,3-epoxypropoxy)propyltrimethoxysilane under anhydrous conditions to undergo a ring-opening esterification reaction to obtain lauric acid silane ester adducts. S2: First, dissolve polyvinyl alcohol in deionized water, then add laurate silane ester adduct and mix evenly to obtain modified polyvinyl alcohol coating liquid; S3: The modified polyvinyl alcohol coating liquid is uniformly coated on the surface of 8079 alloy DC cast aluminum foil, and high-performance aluminum foil is obtained after heat curing treatment.

2. The method for preparing a high-performance pharmaceutical foil made of 8079 alloy DC casting according to claim 1, characterized in that, The molar ratio of lauric acid to γ-(2,3-epoxypropoxy)propyltrimethoxysilane is 1:1.0 to 1.

3.

3. The method for preparing a high-performance pharmaceutical foil made of 8079 alloy DC casting according to claim 1, characterized in that, The catalyst used in the ring-opening esterification reaction is calcium acetylacetonate.

4. The method for preparing a high-performance pharmaceutical foil made of 8079 alloy DC casting according to claim 1, characterized in that, The amount of catalyst used is 1% to 5% of the total mass of lauric acid and γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

5. The method for preparing a high-performance pharmaceutical foil made of 8079 alloy DC casting according to claim 1, characterized in that, The ring-opening esterification reaction is carried out at a temperature of 65–80℃ for 8–12 hours.

6. The method for preparing a high-performance pharmaceutical packaging aluminum foil made of 8079 alloy DC casting according to claim 1, characterized in that, The polyvinyl alcohol is polyvinyl alcohol 1788, with a degree of alcoholysis of 88% and a degree of polymerization of 1700.

7. The method for preparing a high-performance pharmaceutical foil made of 8079 alloy DC casting according to claim 1, characterized in that, The ratio of polyvinyl alcohol to deionized water is 8-12 g: 88-92 mL.

8. The method for preparing a high-performance pharmaceutical foil made of 8079 alloy DC casting according to claim 1, characterized in that, Laurate silane ester adducts account for 3% to 5% of the mass of polyvinyl alcohol.

9. The method for preparing a high-performance pharmaceutical foil made of 8079 alloy DC casting according to claim 1, characterized in that, The heat curing process involves three stages: pre-baking at 50–60°C for 30–45 minutes, baking at 80–90°C for 15–25 minutes, and finally cross-linking and curing at 110–120°C for 20–30 minutes.

10. A high-performance pharmaceutical packaging aluminum foil made of 8079 alloy DC casting, characterized in that, 8079 alloy DC casting high-performance pharmaceutical packaging aluminum foil is prepared by the preparation method described in any one of claims 1 to 9.

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