Metal ion catalytic co-extrusion packaging material with surface sterilization and ethylene decomposition functions and manufacturing method of metal ion catalytic co-extrusion packaging material

Abstract

The invention relates to the technical field of co-extrusion packaging materials, and discloses a metal ion catalytic co-extrusion packaging material with surface sterilization and ethylene decomposition functions and a manufacturing method thereof, the metal ion catalytic co-extrusion packaging material comprises the following raw materials by mass: 50-60 parts of an outer layer raw material, 60-80 parts of a middle layer raw material, and 50-60 parts of an inner layer raw material; the middle layer is prepared from the following raw materials in parts by mass: 90 to 100 parts of polybutylene terephthalate, 10 to 15 parts of composite filler, 2 to 5 parts of plasticizer, 1 to 5 parts of lubricant and 1 to 2 parts of antioxidant. The composite filler is uniformly dispersed in the polyester packaging material, so that the antibacterial property of the polyester packaging material and the catalytic decomposition property on ethylene gas are improved, and the composite filler can play a role in steric hindrance and lubrication, so that the mechanical property of the polyester packaging material is improved.

Description

Technical Field

[0001] This invention relates to the field of co-extruded packaging materials technology, specifically to a metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions, and its manufacturing method. Background Technology

[0002] Packaging materials play an important role in daily life. Whether it is food preservation, cargo transportation or item storage, packaging materials are needed. Packaging materials are not only lightweight but also have good packaging effect, and they hold an important position in the packaging industry. Among them, co-extruded packaging materials are composite films formed by extruding multiple layers of plastic at the same time. They can achieve interlayer thermal fusion bonding without adhesives. They are mostly produced by blown film or casting processes and have the characteristics of high tensile strength and puncture resistance.

[0003] Co-extruded packaging materials made from polyester resin are characterized by biodegradability, high toughness, high temperature resistance, moisture resistance, easy molding, and low moisture absorption, and are widely used in the fruit and vegetable packaging field. However, polyester resin has poor antibacterial properties, which affects the application of co-extruded packaging materials in the fruit and vegetable packaging field. In addition, the ethylene released by fruits and vegetables exists in gaseous form at room temperature, which accelerates fruit ripening or spoilage and leads to fruit and vegetable deterioration. Furthermore, co-extruded packaging materials made from polyester resin are easily subjected to external forces during the packaging process, resulting in tearing and other phenomena. Summary of the Invention

[0004] This invention provides a metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions, and its manufacturing method, which solves the problem of poor antibacterial and mechanical properties of co-extruded packaging materials.

[0005] The technical solution of the present invention: A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions, comprising the following raw materials in parts by weight: 50-60 parts of outer layer raw material, 60-80 parts of middle layer raw material, and 50-60 parts of inner layer raw material; The intermediate layer raw material comprises the following parts by weight: 90-100 parts of polybutylene terephthalate, 10-15 parts of composite filler, 2-5 parts of plasticizer, 1-5 parts of lubricant, 2-3 parts of coupling agent, and 1-2 parts of antioxidant. The composite filler is obtained by loading potassium permanganate with a composite antibacterial agent and then modifying the surface with stearic acid. The composite antibacterial agent is obtained by synthesizing rare earth-doped nano-titanium dioxide on the surface of functionalized carbon fibers, and then reacting it with glucose.

[0006] A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, plasticizer, lubricant and antioxidant, and stir at 80-100 r / min for 30-50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material.

[0007] Further, in step S2, the outer layer raw material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:(10-15):(20-30).

[0008] Further, in step S2, the inner layer raw material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:(15-20):(25-30).

[0009] Furthermore, in step S2, the melting and plasticizing temperatures of both the outer and inner layer raw materials are 180-190℃; Furthermore, in step S2, the melting and plasticizing temperature of the intermediate layer raw material is 170-190℃; Furthermore, in step S3, the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 220-230℃, the extrusion speed ratio of the outer layer, middle layer and inner layer is 1:1:1, the winding speed is 5-8m / min, and the cooling roller cooling temperature is 10℃.

[0010] Furthermore, the co-extruded packaging material has a thickness of 0.3-0.4 mm, a length of 200-220 mm, and a width of 150-180 mm.

[0011] Furthermore, the plasticizer is selected from any one of tributyl citrate, acetylated tributyl citrate, and glycerin.

[0012] Furthermore, the lubricant is selected from any one of stearic acid, zinc stearate, calcium stearate, and lauric acid.

[0013] Furthermore, the antioxidant is selected from any one of antioxidant 1010, antioxidant 1076, and antioxidant 1178.

[0014] Furthermore, the composite filler is prepared by the following steps: A1. Add carbon fiber to nitric acid solution, impregnate, remove, wash, and dry to obtain functionalized carbon fiber; A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid and concentrated nitric acid are mixed and stirred evenly. After stirring and reacting, functionalized carbon fibers are added and the stirring and reaction are continued. The mixture is allowed to stand, taken out, dried, placed in a sintering furnace, sintered, and cooled to room temperature to obtain carbon fibers loaded with rare earth doped nano-titanium dioxide. A3. Add carbon fibers loaded with rare earth-doped nano-titanium dioxide and tannic acid to ethanol, stir evenly, add glucose, stir until the reaction is complete, filter, wash, dry, place in a tube furnace, add potassium hydroxide solution, purge with nitrogen, carbonize, cool to room temperature, take out, wash, dry, and obtain composite antibacterial agent. A4. Add the composite antibacterial agent to the potassium permanganate aqueous solution, and after ultrasonic vibration until the composite antibacterial agent is completely impregnated, filter and dry until the water evaporates to obtain the composite antibacterial agent loaded with potassium permanganate. A5. Add the potassium permanganate-loaded composite antibacterial agent and stearic acid to deionized water, stir evenly, add sodium hydroxide aqueous solution to adjust the pH, stir and react at 60-80℃ for 20-30 min, filter, wash and dry to obtain composite filler.

[0015] Furthermore, during the A1 reaction process described above, the carbon fiber is surface-treated with concentrated nitric acid, which causes the carbon fiber surface to carry a large number of oxygen-containing functional groups, thereby improving the surface activity of the carbon fiber and enabling it to serve as a synthesis site for rare earth-doped nano-titanium dioxide.

[0016] Furthermore, during the A2 reaction described above, tetrabutyl titanate undergoes hydrolysis and condensation to form titanium dioxide sol, which can adsorb rare earth cerium ions and lanthanum ions into the titanium dioxide sol. The hydroxyl groups generated during the hydrolysis and condensation of tetrabutyl titanate can chemically bond with the oxygen-containing functional groups on the surface of the functionalized carbon fiber, allowing the titanium dioxide sol to be deposited on the surface of the carbon fiber. After high-temperature sintering, rare earth-doped nano-titanium dioxide is synthesized on the surface of the functionalized carbon fiber, resulting in carbon fiber loaded with rare earth-doped nano-titanium dioxide.

[0017] Furthermore, in the A3 reaction process described above, tannic acid acts as a linker, allowing glucose to be adsorbed onto the surface of rare earth-doped nano-titanium dioxide carbon fibers through tannic acid. After high-temperature carbonization, the glucose decomposes upon heating to form a dense carbon layer. Potassium hydroxide acts as an activator, decomposing upon heating to form channels on the surface of the dense carbon layer, thereby achieving the formation of a porous carbon layer on the rare earth-doped nano-titanium dioxide carbon fibers and obtaining a composite antibacterial agent.

[0018] Furthermore, in the A4 reaction process described above, the composite antibacterial agent and potassium permanganate solution are mixed. The porous carbon structure on the surface of the composite antibacterial agent has a porous structure and high adsorption performance, which can adsorb potassium permanganate solution onto the surface of the composite antibacterial agent. After adsorption is complete, the water is removed by drying to obtain a composite antibacterial agent loaded with potassium permanganate.

[0019] Furthermore, during the A5 reaction process described above, under alkaline conditions, the hydroxyl groups on the surface of the potassium permanganate-loaded composite antibacterial agent can react with the carboxyl groups of stearic acid, thereby grafting stearic acid onto the surface of the potassium permanganate-loaded composite antibacterial agent to obtain a composite filler.

[0020] Further, in step A1, the mass ratio of carbon fiber to nitric acid solution is (4-5):(80-90).

[0021] Further, in step A2, the mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid and functionalized carbon fiber is (2-3):(30-35):(10-15):(1.5-2):(0.2-0.5):(3-3.5).

[0022] Further, in step A3, the mass ratio of carbon fiber loaded with rare earth-doped nano-titanium dioxide, tannic acid, ethanol, glucose and potassium hydroxide solution is (3-4):(0.8-1):(100-120):(2-3):(1-2).

[0023] Further, in step A4, the mass ratio of the compound antibacterial agent to the potassium permanganate aqueous solution is (3-4):(150-160).

[0024] Further, in step A5, the mass ratio of the potassium permanganate-loaded composite antibacterial agent, stearic acid, and deionized water is (3-3.4):(1-1.2):(140-150).

[0025] Furthermore, the carbon fiber has a length of 5-7 mm and a diameter of 5-8 μm.

[0026] The present invention has the following beneficial effects: (1) In the technical solution of the present invention, after the carbon fiber is surface treated with concentrated nitric acid, the carbon fiber surface carries a large number of oxygen-containing functional groups, which improves the surface activity of the carbon fiber. This allows the functionalized carbon fiber to serve as a synthesis site for rare earth-doped nano-titanium dioxide and be added to the packaging material to improve the antibacterial properties of the packaging material. On the one hand, the synthesized rare earth-doped nano-titanium dioxide has excellent antibacterial activity, which can improve the antibacterial properties of the packaging material. On the other hand, the carbon fiber, as a carrier of rare earth-doped nano-titanium dioxide particles, can load more rare earth-doped nano-titanium dioxide and improve the dispersibility of rare earth-doped nano-titanium dioxide in the polyester packaging material. On the other hand, the carbon fiber, as an inorganic reinforcing material, has high mechanical strength and can enhance the mechanical properties of the polyester packaging material.

[0027] (2) In the technical solution of the present invention, a porous carbon layer is formed on the carbon fiber loaded with rare earth doped nano titanium dioxide. It has a high porous structure and adsorption performance, which can adsorb and fix the rare earth doped nano titanium dioxide on the surface of the carbon fiber, avoid the migration and precipitation of rare earth doped nano titanium dioxide, and affect the antibacterial performance of the polyester packaging material. In addition, the porous carbon layer increases the surface roughness of the carbon fiber, thereby increasing the contact area between the carbon fiber loaded with rare earth doped nano titanium dioxide and the microbial strain, and improving the antibacterial performance. Furthermore, the porous carbon can serve as an adsorption site for the oxidant potassium permanganate, which is conducive to the adsorption of potassium permanganate into the composite antibacterial agent and play a role in catalyzing the decomposition of ethylene gas released by fruits and vegetables.

[0028] (3) In the technical solution of the present invention, potassium permanganate is adsorbed into the porous structure on the surface of the composite antibacterial agent. On the one hand, potassium permanganate, as an oxidant, can catalytically decompose the ethylene gas released by fruits and vegetables at room temperature and without light, thus avoiding the high content of ethylene gas and accelerating the ripening or spoilage of fruits and vegetables. Moreover, the porous carbon layer on the surface of the composite antibacterial agent contains a large number of microporous structures, which can adsorb ethylene molecules. The adsorbed ethylene molecules contact potassium permanganate and catalytically oxidize it, decomposing it into harmless substances such as carbon dioxide and water, thus completing the removal of ethylene gas. In addition, the porous carbon can also adsorb the manganese dioxide impurities produced after the catalytic oxidation of potassium permanganate, thus preventing the impurities from falling into the fruits and vegetables. On the other hand, potassium permanganate exists in the form of crystals on the pore walls of the porous carbon layer. As the skeleton structure of the porous carbon layer, it can improve the impact resistance of the porous carbon and prevent the pores of the porous carbon from collapsing under the external force of the polyester packaging material, which would cause potassium permanganate to migrate and precipitate out, affecting the removal efficiency of ethylene gas by the polyester packaging material.

[0029] (4) In the technical solution of the present invention, stearic acid is grafted onto the surface of the composite antibacterial agent loaded with potassium permanganate, which makes the composite filler hydrophobic, avoiding the easy hygroscopicity of potassium permanganate and affecting the catalytic decomposition of ethylene gas by the polyester packaging material. Moreover, the hydrophobic chain of stearic acid can extend into the polyester matrix, so that the composite filler is uniformly dispersed in the polyester packaging material, improving the antibacterial performance and catalytic decomposition performance of the polyester packaging material. In addition, the composite filler can play a role in steric hindrance and lubrication, improving the mechanical properties of the polyester packaging material. Furthermore, carbon fiber, rare earth doped nano titanium dioxide particles and porous carbon, as inorganic materials, are dispersed in the polyester packaging material, which can improve the mechanical properties of the polyester packaging material. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] The raw materials used in the embodiments of this invention are shown below, and all reagents used are analytical grade.

[0032] Among them, polybutylene terephthalate (P909269) and polylactic acid (P742385) were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0033] The polyethylene glycol is polyethylene glycol 200.

[0034] The plasticizer is tributyl citrate, the lubricant is calcium stearate, and the antioxidant is antioxidant 1010.

[0035] The carbon fiber is 6mm in length and 7μm in diameter, and was purchased from Nantong Woyuan New Material Technology Co., Ltd.

[0036] Example 1 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions, comprising the following raw materials in parts by weight: 50 parts of outer layer raw material, 60 parts of middle layer raw material, and 50 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 90 parts of polybutylene terephthalate, 10 parts of composite filler, 2 parts of tributyl citrate, 1 part of calcium stearate, and 1 part of antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, tributyl citrate, calcium stearate and antioxidant 1010, and stir at 80 r / min for 30 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 180℃; The melting and plasticizing temperature of the intermediate layer raw material is 170℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:10:20; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:15:25. S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 220℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 5m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material is 0.3mm thick, 200mm long, and 150mm wide.

[0037] The composite filler is prepared by the following steps: A1. Add carbon fiber to a 70% nitric acid solution and immerse it at 70°C for 4 hours. Remove the carbon fiber, wash it with deionized water until the pH of the washing solution is neutral, and dry it in a 100°C oven for 10 minutes to obtain functionalized carbon fiber. The mass ratio of carbon fiber to nitric acid solution is 4:80. A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, and concentrated nitric acid were mixed and stirred evenly. After stirring at 25℃ and 150 r / min for 1.5 h, functionalized carbon fibers were added, and stirring was continued for another 1.5 h. After standing for 12 h, the mixture was removed and dried in an oven at 105℃ for 10 min. It was then placed in a sintering furnace and sintered at 500℃ for 1 h. After cooling to room temperature, carbon fibers loaded with rare earth-doped nano-titanium dioxide were obtained. The mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid, and functionalized carbon fibers was 2:30:10:1.5:0.2:3. A3. Carbon fibers loaded with rare earth-doped nano-titanium dioxide and tannic acid were added to ethanol and stirred evenly. Glucose was added, and the mixture was stirred at 70°C for 30 min. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min. The mixture was then placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain a composite antibacterial agent. The mass ratio of carbon fibers loaded with rare earth-doped nano-titanium dioxide, tannic acid, ethanol, glucose, and potassium hydroxide solution was 3:0.8:100:2:1. A4. The composite antibacterial agent was added to a potassium permanganate aqueous solution with a concentration of 0.4 g / L and ultrasonically vibrated at 40 kHz for 3 hours. After the composite antibacterial agent was completely impregnated, it was filtered and dried in an oven at 100 ℃ until the water evaporated to obtain a composite antibacterial agent loaded with potassium permanganate. The mass ratio of the composite antibacterial agent to the potassium permanganate aqueous solution was 3:150. A5. Add the potassium permanganate-loaded composite antibacterial agent and stearic acid to deionized water, stir evenly, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, stir and react at 60℃ for 20 min, filter, wash 3 times with deionized water, and dry in a 70℃ oven for 10 min to obtain the composite filler; the mass ratio of potassium permanganate-loaded composite antibacterial agent, stearic acid and deionized water is 3:1:140.

[0038] Example 2 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions comprises the following raw materials in parts by weight: 55 parts of outer layer raw material, 70 parts of middle layer raw material, and 55 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 95 parts polybutylene terephthalate, 13 parts composite filler, 4 parts tributyl citrate, 4 parts calcium stearate, and 1.5 parts antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, tributyl citrate, calcium stearate and antioxidant 1010, and stir at 90 r / min for 40 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 185℃; The melting and plasticizing temperature of the intermediate layer raw material is 180℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:13:25; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:18:28. S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 225℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 6m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material has a thickness of 0.35mm, a length of 210mm, and a width of 160mm.

[0039] The composite filler is prepared by the following steps: A1. Add carbon fiber to a 70% nitric acid solution and immerse it at 70°C for 4 hours. Remove the carbon fiber, wash it with deionized water until the pH of the washing solution is neutral, and dry it in a 100°C oven for 10 minutes to obtain functionalized carbon fiber. The mass ratio of carbon fiber to nitric acid solution is 4.5:85. A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, and concentrated nitric acid were mixed and stirred evenly. After stirring at 25℃ and 150r / min for 1.5h, functionalized carbon fibers were added, and stirring was continued for another 1.5h. The mixture was allowed to stand for 12h, then removed and dried in an oven at 105℃ for 10min. The mixture was then placed in a sintering furnace and sintered at 500℃ for 1h. After cooling to room temperature, carbon fibers loaded with rare earth-doped nano-titanium dioxide were obtained. The mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid, and functionalized carbon fibers was 2.5:33:13:1.8:0.4:3.3. A3. Carbon fibers loaded with rare earth-doped nano-titanium dioxide and tannic acid were added to ethanol and stirred evenly. Glucose was added, and the mixture was stirred at 70°C for 30 min. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min. The mixture was then placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain a composite antibacterial agent. The mass ratio of carbon fibers loaded with rare earth-doped nano-titanium dioxide, tannic acid, ethanol, glucose, and potassium hydroxide solution was 3.5:0.9:110:2.5:1.5. A4. The composite antibacterial agent was added to a potassium permanganate aqueous solution with a concentration of 0.4 g / L and ultrasonically vibrated at 40 kHz for 3 hours. After the composite antibacterial agent was completely impregnated, it was filtered and dried in an oven at 100 ℃ until the moisture evaporated to obtain a composite antibacterial agent loaded with potassium permanganate. The mass ratio of the composite antibacterial agent to the potassium permanganate aqueous solution was 3.5:155. A5. Add the potassium permanganate-loaded composite antibacterial agent and stearic acid to deionized water, stir evenly, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, stir and react at 70℃ for 25 min, filter, wash 3 times with deionized water, and dry in a 70℃ oven for 10 min to obtain the composite filler; the mass ratio of potassium permanganate-loaded composite antibacterial agent, stearic acid and deionized water is 3.2:1.1:145.

[0040] Example 3 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions comprises the following raw materials in parts by weight: 60 parts of outer layer raw material, 80 parts of middle layer raw material, and 60 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 100 parts of polybutylene terephthalate, 15 parts of composite filler, 5 parts of tributyl citrate, 5 parts of stearic acid, and 2 parts of antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, tributyl citrate, stearic acid and antioxidant 1010, and stir at 100 r / min for 50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 190℃; The melting and plasticizing temperature of the intermediate layer raw material is 190℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:15:30; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:20:30; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 230℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 8m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material is 0.4mm thick, 220mm long, and 180mm wide.

[0041] The composite filler is prepared by the following steps: A1. Add carbon fiber to a 70% nitric acid solution and immerse it at 70°C for 4 hours. Remove the carbon fiber, wash it with deionized water until the pH of the washing solution is neutral, and dry it in a 100°C oven for 10 minutes to obtain functionalized carbon fiber. The mass ratio of carbon fiber to nitric acid solution is 5:90. A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, and concentrated nitric acid were mixed and stirred evenly. After stirring at 25℃ and 150r / min for 1.5h, functionalized carbon fibers were added, and stirring was continued for another 1.5h. The mixture was allowed to stand for 12h, then removed and dried in an oven at 105℃ for 10min. The mixture was then placed in a sintering furnace and sintered at 500℃ for 1h. After cooling to room temperature, carbon fibers loaded with rare earth-doped nano-titanium dioxide were obtained. The mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid, and functionalized carbon fibers was 3:35:15:2:0.5:3.5. A3. Carbon fibers loaded with rare earth-doped nano-titanium dioxide and tannic acid were added to ethanol and stirred evenly. Glucose was added, and the mixture was stirred at 70°C for 30 min. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min. The mixture was then placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain a composite antibacterial agent. The mass ratio of carbon fibers loaded with rare earth-doped nano-titanium dioxide, tannic acid, ethanol, glucose, and potassium hydroxide solution was 4:1:120:3:2. A4. The composite antibacterial agent was added to a potassium permanganate aqueous solution with a concentration of 0.4 g / L and ultrasonically vibrated at 40 kHz for 3 hours. After the composite antibacterial agent was completely impregnated, it was filtered and dried in an oven at 100 ℃ until the water evaporated to obtain a composite antibacterial agent loaded with potassium permanganate. The mass ratio of the composite antibacterial agent to the potassium permanganate aqueous solution was 4:160. A5. Add the potassium permanganate-loaded composite antibacterial agent and stearic acid to deionized water, stir evenly, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, stir and react at 80℃ for 30 min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain the composite filler; the mass ratio of potassium permanganate-loaded composite antibacterial agent, stearic acid and deionized water is 3.4:1.2:150.

[0042] Comparative Example 1 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions comprises the following raw materials in parts by weight: 60 parts of outer layer raw material, 80 parts of middle layer raw material, and 60 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 100 parts of polybutylene terephthalate, 15 parts of composite filler, 5 parts of tributyl citrate, 5 parts of stearic acid, and 2 parts of antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, tributyl citrate, stearic acid and antioxidant 1010, and stir at 100 r / min for 50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 190℃; The melting and plasticizing temperature of the intermediate layer raw material is 190℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:15:30; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:20:30; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 230℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 8m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material is 0.4mm thick, 220mm long, and 180mm wide.

[0043] The composite filler is prepared by the following steps: A1. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, and concentrated nitric acid were mixed and stirred evenly. After stirring at 25℃ and 150r / min for 1.5h, carbon fiber was added, and stirring was continued for another 1.5h. The mixture was allowed to stand for 12h, then removed and dried in an oven at 105℃ for 10min. The mixture was then placed in a sintering furnace and sintered at 500℃ for 1h. After cooling to room temperature, composite carbon fiber was obtained. The mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid, and carbon fiber was 3:35:15:2:0.5:3.5. A2. Composite carbon fiber and tannic acid were added to ethanol and stirred evenly. Glucose was added, and the mixture was stirred at 70°C for 30 minutes. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 minutes. The mixture was then placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 hours. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 minutes to obtain the composite antibacterial agent. The mass ratio of composite carbon fiber, tannic acid, ethanol, glucose, and potassium hydroxide solution was 4:1:120:3:2. A3. The composite antibacterial agent was added to a potassium permanganate aqueous solution with a concentration of 0.4 g / L and ultrasonically vibrated at 40 kHz for 3 hours. After the composite antibacterial agent was completely impregnated, it was filtered and dried in an oven at 100 ℃ until the water evaporated to obtain a composite antibacterial agent loaded with potassium permanganate. The mass ratio of the composite antibacterial agent to the potassium permanganate aqueous solution was 4:160. A4. Add the potassium permanganate-loaded composite antibacterial agent and stearic acid to deionized water, stir evenly, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, stir and react at 80℃ for 30 min, filter, wash 3 times with deionized water, and dry in a 70℃ oven for 10 min to obtain the composite filler; the mass ratio of potassium permanganate-loaded composite antibacterial agent, stearic acid and deionized water is 3.4:1.2:150.

[0044] Comparative Example 2 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions comprises the following raw materials in parts by weight: 60 parts of outer layer raw material, 80 parts of middle layer raw material, and 60 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 100 parts of polybutylene terephthalate, 15 parts of composite filler, 5 parts of tributyl citrate, 5 parts of stearic acid, and 2 parts of antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, tributyl citrate, stearic acid and antioxidant 1010, and stir at 100 r / min for 50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 190℃; The melting and plasticizing temperature of the intermediate layer raw material is 190℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:15:30; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:20:30; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 230℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 8m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material is 0.4mm thick, 220mm long, and 180mm wide.

[0045] The composite filler is prepared by the following steps: A1. Add carbon fiber to a 70% nitric acid solution and immerse it at 70°C for 4 hours. Remove the carbon fiber, wash it with deionized water until the pH of the washing solution is neutral, and dry it in a 100°C oven for 10 minutes to obtain functionalized carbon fiber. The mass ratio of carbon fiber to nitric acid solution is 5:90. A2. Functionalized carbon fibers and tannic acid were added to ethanol and stirred evenly. Glucose was added, and the mixture was stirred at 70°C for 30 min. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min. The mixture was then placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain a composite antibacterial agent. The mass ratio of functionalized carbon fibers, tannic acid, ethanol, glucose, and potassium hydroxide solution was 4:1:120:3:2. A3. The composite antibacterial agent was added to a potassium permanganate aqueous solution with a concentration of 0.4 g / L and ultrasonically vibrated at 40 kHz for 3 hours. After the composite antibacterial agent was completely impregnated, it was filtered and dried in an oven at 100 ℃ until the water evaporated to obtain a composite antibacterial agent loaded with potassium permanganate. The mass ratio of the composite antibacterial agent to the potassium permanganate aqueous solution was 4:160. A4. Add the potassium permanganate-loaded composite antibacterial agent and stearic acid to deionized water, stir evenly, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, stir and react at 80℃ for 30 min, filter, wash 3 times with deionized water, and dry in a 70℃ oven for 10 min to obtain the composite filler; the mass ratio of potassium permanganate-loaded composite antibacterial agent, stearic acid and deionized water is 3.4:1.2:150.

[0046] Comparative Example 3 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions comprises the following raw materials in parts by weight: 60 parts of outer layer raw material, 80 parts of middle layer raw material, and 60 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 100 parts of polybutylene terephthalate, 15 parts of composite filler, 5 parts of tributyl citrate, 5 parts of stearic acid, and 2 parts of antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, tributyl citrate, stearic acid and antioxidant 1010, and stir at 100 r / min for 50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 190℃; The melting and plasticizing temperature of the intermediate layer raw material is 190℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:15:30; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:20:30; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 230℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 8m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material is 0.4mm thick, 220mm long, and 180mm wide.

[0047] The composite filler is prepared by the following steps: A1. Add carbon fiber to a 70% nitric acid solution and immerse it at 70°C for 4 hours. Remove the carbon fiber, wash it with deionized water until the pH of the washing solution is neutral, and dry it in a 100°C oven for 10 minutes to obtain functionalized carbon fiber. The mass ratio of carbon fiber to nitric acid solution is 5:90. A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, and concentrated nitric acid were mixed and stirred evenly. After stirring at 25℃ and 150r / min for 1.5h, functionalized carbon fibers were added, and stirring was continued for another 1.5h. The mixture was allowed to stand for 12h, then removed and dried in an oven at 105℃ for 10min. The mixture was then placed in a sintering furnace and sintered at 500℃ for 1h. After cooling to room temperature, carbon fibers loaded with rare earth-doped nano-titanium dioxide were obtained. The mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid, and functionalized carbon fibers was 3:35:15:2:0.5:3.5. A3. Add the carbon fiber loaded with rare earth doped nano-titanium dioxide to a potassium permanganate aqueous solution with a concentration of 0.4 g / L, and sonicate at 40 kHz for 3 h. After the carbon fiber loaded with rare earth doped nano-titanium dioxide is completely impregnated, filter it and dry it in an oven at 100 ℃ until the water evaporates to obtain a mixture; the mass ratio of carbon fiber loaded with rare earth doped nano-titanium dioxide to potassium permanganate aqueous solution is 4:160. A4. Add the mixture and stearic acid to deionized water, stir evenly, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, stir and react at 80℃ for 30 min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain the composite filler; the mass ratio of the mixture, stearic acid and deionized water is 3.4:1.2:150.

[0048] Comparative Example 4 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions comprises the following raw materials in parts by weight: 60 parts of outer layer raw material, 80 parts of middle layer raw material, and 60 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 100 parts of polybutylene terephthalate, 15 parts of composite filler, 5 parts of tributyl citrate, 5 parts of stearic acid, and 2 parts of antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, composite filler, tributyl citrate, stearic acid and antioxidant 1010, and stir at 100 r / min for 50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 190℃; The melting and plasticizing temperature of the intermediate layer raw material is 190℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:15:30; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:20:30; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 230℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 8m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material is 0.4mm thick, 220mm long, and 180mm wide.

[0049] The composite filler is prepared by the following steps: A1. Add carbon fiber to a 70% nitric acid solution and immerse it at 70°C for 4 hours. Remove the carbon fiber, wash it with deionized water until the pH of the washing solution is neutral, and dry it in a 100°C oven for 10 minutes to obtain functionalized carbon fiber. The mass ratio of carbon fiber to nitric acid solution is 5:90. A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, and concentrated nitric acid were mixed and stirred evenly. After stirring at 25℃ and 150r / min for 1.5h, functionalized carbon fibers were added, and stirring was continued for another 1.5h. The mixture was allowed to stand for 12h, then removed and dried in an oven at 105℃ for 10min. The mixture was then placed in a sintering furnace and sintered at 500℃ for 1h. After cooling to room temperature, carbon fibers loaded with rare earth-doped nano-titanium dioxide were obtained. The mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid, and functionalized carbon fibers was 3:35:15:2:0.5:3.5. A3. Carbon fibers loaded with rare earth-doped nano-titanium dioxide and tannic acid were added to ethanol and stirred evenly. Glucose was added, and the mixture was stirred at 70°C for 30 min. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min. The mixture was then placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain a composite antibacterial agent. The mass ratio of carbon fibers loaded with rare earth-doped nano-titanium dioxide, tannic acid, ethanol, glucose, and potassium hydroxide solution was 4:1:120:3:2. A4. Add the composite antibacterial agent and stearic acid to deionized water, stir evenly, add 1 mol / L sodium hydroxide aqueous solution to adjust the pH to 10, stir and react at 80℃ for 30 min, filter, wash 3 times with deionized water, and dry in an oven at 70℃ for 10 min to obtain the composite filler; the mass ratio of composite antibacterial agent, stearic acid and deionized water is 3.4:1.2:150.

[0050] Comparative Example 5 A metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions comprises the following raw materials in parts by weight: 60 parts of outer layer raw material, 80 parts of middle layer raw material, and 60 parts of inner layer raw material; The intermediate layer raw materials include the following parts by weight: 100 parts of polybutylene terephthalate, 15 parts of composite antibacterial agent loaded with potassium permanganate, 5 parts of tributyl citrate, 5 parts of stearic acid, and 2 parts of antioxidant 1010. A method for manufacturing a metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions includes the following steps: S1. Mix polybutylene terephthalate, potassium permanganate-loaded composite antibacterial agent, tributyl citrate, stearic acid and antioxidant 1010, and stir at 100 r / min for 50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; The melting and plasticizing temperature of both the outer and inner layer raw materials is 190℃; The melting and plasticizing temperature of the intermediate layer raw material is 190℃; The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:15:30; The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:20:30; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material; the extruder is a three-layer co-extrusion cast film machine, the extrusion temperature is 230℃, the extrusion speed ratio of the outer layer, middle layer, and inner layer is 1:1:1, the winding speed is 8m / min, and the cooling roller cooling temperature is 10℃; The co-extruded packaging material is 0.4mm thick, 220mm long, and 180mm wide.

[0051] The potassium permanganate-loaded composite antibacterial agent is prepared by the following steps: A1. Add carbon fiber to a 70% nitric acid solution and immerse it at 70°C for 4 hours. Remove the carbon fiber, wash it with deionized water until the pH of the washing solution is neutral, and dry it in a 100°C oven for 10 minutes to obtain functionalized carbon fiber. The mass ratio of carbon fiber to nitric acid solution is 5:90. A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, and concentrated nitric acid were mixed and stirred evenly. After stirring at 25℃ and 150r / min for 1.5h, functionalized carbon fibers were added, and stirring was continued for another 1.5h. The mixture was allowed to stand for 12h, then removed and dried in an oven at 105℃ for 10min. The mixture was then placed in a sintering furnace and sintered at 500℃ for 1h. After cooling to room temperature, carbon fibers loaded with rare earth-doped nano-titanium dioxide were obtained. The mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid, and functionalized carbon fibers was 3:35:15:2:0.5:3.5. A3. Carbon fibers loaded with rare earth-doped nano-titanium dioxide and tannic acid were added to ethanol and stirred evenly. Glucose was added, and the mixture was stirred at 70°C for 30 min. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min. The mixture was then placed in a tube furnace, and a 30% potassium hydroxide solution was added. Nitrogen gas was introduced, and the mixture was carbonized at 800°C for 4 h. After cooling to room temperature, the mixture was removed, washed three times with deionized water, and dried in an oven at 70°C for 10 min to obtain a composite antibacterial agent. The mass ratio of carbon fibers loaded with rare earth-doped nano-titanium dioxide, tannic acid, ethanol, glucose, and potassium hydroxide solution was 4:1:120:3:2. A4. Add the composite antibacterial agent to a potassium permanganate aqueous solution with a concentration of 0.4 g / L, and sonicate at 40 kHz for 3 hours. After the composite antibacterial agent has completely impregnated the solution, filter it and dry it in an oven at 100 ℃ until the moisture evaporates to obtain a composite antibacterial agent loaded with potassium permanganate. The mass ratio of the composite antibacterial agent to the potassium permanganate aqueous solution is 4:160.

[0052] The performance of the co-extruded packaging materials prepared in Examples 1-3 and Comparative Examples 1-5 was then tested.

[0053] Mechanical property testing: The tensile strength and elongation at break of the co-extruded packaging material prepared above were tested in accordance with GB / T1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets".

[0054] Antibacterial performance test: The antibacterial performance of the co-extruded packaging material prepared above was tested according to the national standard GB / T 31402-2023 "Determination of antibacterial activity of plastics and other non-porous materials".

[0055] Ethylene decomposition performance test: Collect ethylene gas produced by fruits and vegetables, put the co-extruded packaging material prepared above into a sealed container, then inject the collected ethylene gas (concentration C0), seal the container, and place it in a constant temperature chamber. After 24 hours at 25℃, use a gas chromatograph to determine the concentration of the remaining ethylene gas in the sealed container, and calculate the ethylene removal rate = (C0-C1) / C0×100%.

[0056] As shown in Table 1 below.

[0057] As can be seen from the data in Table 1, the co-extruded packaging materials prepared in Examples 1-3 have high mechanical and antibacterial properties, and have a high removal efficiency for ethylene gas generated by fruits and vegetables.

[0058] Comparative Example 1 showed that when functionalized carbon fibers were replaced with composite fillers prepared from carbon fibers and added to co-extruded packaging materials, their antibacterial and mechanical properties decreased. This demonstrates that after carbon fibers were surface-treated with concentrated nitric acid, the carbon fiber surface carried a large number of oxygen-containing functional groups, which improved the surface activity of the carbon fibers. This allowed the functionalized carbon fibers to serve as synthesis sites for rare earth-doped nano-titanium dioxide and be added to the packaging materials to improve their antibacterial properties. Furthermore, the rare earth-doped nano-titanium dioxide particles, as inorganic materials dispersed in the polyester packaging materials, could improve the mechanical properties of the polyester packaging materials.

[0059] Comparative Example 2 showed that replacing the carbon fiber loaded with rare earth-doped nano-titanium dioxide with a composite filler prepared by functionalized carbon fiber and adding it to the co-extruded packaging material resulted in a decrease in its antibacterial and mechanical properties. This demonstrates that carbon fiber, as a carrier of rare earth-doped nano-titanium dioxide particles, can load a large amount of rare earth-doped nano-titanium dioxide, improve the dispersibility of rare earth-doped nano-titanium dioxide in polyester packaging materials, and thus improve the antibacterial properties of the packaging materials. Furthermore, carbon fiber and rare earth-doped nano-titanium dioxide particles, as inorganic reinforcing materials, have high mechanical strength.

[0060] Comparative Example 3 replaced the composite antibacterial agent with a composite filler prepared from carbon fibers loaded with rare earth-doped nano-titanium dioxide and added it to the co-extruded packaging material. Its antibacterial performance, ethylene removal rate and mechanical properties decreased, which proved that the porous carbon layer formed on the carbon fibers loaded with rare earth-doped nano-titanium dioxide can adsorb and fix the rare earth-doped nano-titanium dioxide on the surface of the carbon fibers. Moreover, the porous carbon layer increases the surface roughness of the carbon fibers, thereby increasing the contact area between the carbon fibers loaded with rare earth-doped nano-titanium dioxide and the microbial strains and improving the antibacterial performance.

[0061] In Comparative Example 4, the composite antibacterial agent loaded with potassium permanganate was replaced with a composite filler prepared from the composite antibacterial agent and added to the co-extruded packaging material. The ethylene removal rate and mechanical properties decreased, which proved that the potassium permanganate adsorbed into the porous structure on the surface of the composite antibacterial agent can adsorb ethylene molecules. The adsorbed ethylene molecules contact the potassium permanganate and catalytically oxidize it, decomposing it into harmless substances such as carbon dioxide and water, thus completing the removal of ethylene gas. Moreover, the potassium permanganate exists in crystalline form on the pore walls of the porous carbon layer, serving as the skeleton structure of the porous carbon layer and improving the impact resistance of the porous carbon.

[0062] Comparative Example 5 showed that when the composite filler was replaced with a composite antibacterial agent loaded with potassium permanganate and added to the co-extruded packaging material, its antibacterial properties, ethylene removal rate, and mechanical properties decreased. This demonstrated that the grafting of stearic acid onto the surface of the composite antibacterial agent loaded with potassium permanganate allowed the composite filler to be uniformly dispersed in the polyester packaging material, thereby improving the antibacterial properties and the catalytic decomposition performance of the polyester packaging material for ethylene gas.

[0063] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0064] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A metal ion-catalyzed co-extruded packaging material with surface sterilization and ethylene decomposition functions, characterized in that, The raw materials include the following parts by weight: 50-60 parts of outer layer raw material, 60-80 parts of middle layer raw material, and 50-60 parts of inner layer raw material; The intermediate layer raw material comprises the following parts by weight: 90-100 parts of polybutylene terephthalate, 10-15 parts of composite filler, 2-5 parts of plasticizer, 1-5 parts of lubricant, and 1-2 parts of antioxidant. The composite filler is obtained by loading potassium permanganate with a composite antibacterial agent and then modifying the surface with stearic acid. The composite antibacterial agent is obtained by synthesizing rare earth-doped nano-titanium dioxide on the surface of functionalized carbon fibers, and then reacting it with glucose.

2. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 1, characterized in that, The composite filler is prepared by the following steps: A1. Add carbon fiber to nitric acid solution, impregnate, remove, wash, and dry to obtain functionalized carbon fiber; A2. Tetrabutyl titanate, ethanol, deionized water, glacial acetic acid and concentrated nitric acid are mixed and stirred evenly. After stirring and reacting, functionalized carbon fibers are added and the stirring and reaction are continued. The mixture is allowed to stand, taken out, dried, placed in a sintering furnace, sintered, and cooled to room temperature to obtain carbon fibers loaded with rare earth doped nano-titanium dioxide. A3. Add carbon fibers loaded with rare earth-doped nano-titanium dioxide and tannic acid to ethanol, stir evenly, add glucose, stir until the reaction is complete, filter, wash, dry, place in a tube furnace, add potassium hydroxide solution, purge with nitrogen, carbonize, cool to room temperature, take out, wash, dry, and obtain composite antibacterial agent. A4. Add the composite antibacterial agent to the potassium permanganate aqueous solution, and after ultrasonic vibration until the composite antibacterial agent is completely impregnated, filter and dry until the water evaporates to obtain the composite antibacterial agent loaded with potassium permanganate. A5. Add the potassium permanganate-loaded composite antibacterial agent and stearic acid to deionized water, stir evenly, add sodium hydroxide aqueous solution to adjust the pH, stir and react at 60-80℃ for 20-30 min, filter, wash and dry to obtain composite filler.

3. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 2, characterized in that, In step A1, the mass ratio of the carbon fiber to the nitric acid solution is (4-5):(80-90).

4. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 2, characterized in that, In step A2, the mass ratio of tetrabutyl titanate, ethanol, deionized water, glacial acetic acid, concentrated nitric acid and functionalized carbon fiber is (2-3):(30-35):(10-15):(1.5-2):(0.2-0.5):(3-3.5).

5. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 2, characterized in that, In step A3, the mass ratio of the carbon fiber loaded with rare earth-doped nano-titanium dioxide, tannic acid, ethanol, glucose and potassium hydroxide solution is (3-4):(0.8-1):(100-120):(2-3):(1-2).

6. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 2, characterized in that, In step A4, the mass ratio of the composite antibacterial agent to the potassium permanganate aqueous solution is (3-4):(150-160).

7. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 2, characterized in that, In step A5, the mass ratio of the potassium permanganate-loaded composite antibacterial agent, stearic acid, and deionized water is (3-3.4):(1-1.2):(140-150).

8. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 1, characterized in that, The outer layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:(10-15):(20-30).

9. The metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions according to claim 1, characterized in that, The inner layer material is a mixture of polybutylene terephthalate, polyethylene glycol, and polylactic acid in a mass ratio of 100:(15-20):(25-30).

10. A method for manufacturing a metal ion catalytic co-extruded packaging material with surface sterilization and ethylene decomposition functions as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Mix polybutylene terephthalate, composite filler, plasticizer, lubricant and antioxidant, and stir at 80-100 r / min for 30-50 min to obtain the middle layer raw material; S2. The outer layer raw material, the middle layer raw material, and the inner layer raw material are melted and plasticized separately to obtain the outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt; S3. The outer layer raw material melt, the middle layer raw material melt, and the inner layer raw material melt are co-extruded and cast into a film using an extruder to obtain a co-extruded packaging material.

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