Antibacterial PET sheet and preparation method thereof

Abstract

The invention discloses an antibacterial PET sheet and a preparation method thereof, and belongs to the technical field of high polymer materials. The antibacterial PET sheet comprises the following components in parts by weight: 60-80 parts of PET resin, 8-10 parts of a compatilizer, 10-20 parts of modified glass fibers, 5-10 parts of a composite antibacterial agent, 1-2 parts of a lubricant and 1-2 parts of an antioxidant. According to the antibacterial PET sheet, PET resin is used as a base material, functional additives such as the compatilizer, the lubricant and the antioxidant are compounded, and the modified glass fibers and the composite antibacterial agent are introduced, so that the prepared antibacterial PET sheet has good long-acting antibacterial, mechanical and flame-retardant properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to an antibacterial PET sheet and a preparation method thereof. Background Art

[0002] PET is the abbreviation of polyethylene terephthalate, a thermoplastic, highly crystalline polymer. PET plastic has excellent optical properties, weather resistance, wear and friction resistance, dimensional stability, electrical insulation, high strength, good transparency, non-toxicity, impermeability, light weight, and high production efficiency. Therefore, it is widely used in food packaging, daily chemical products, medical treatment, electronic appliances and other fields.

[0003] However, PET lacks inherent antimicrobial properties and readily breeds bacteria, mold, and other microorganisms in humid environments. This limits its application in cleanliness-critical applications such as healthcare and high-end food packaging. To impart antimicrobial properties to PET, antimicrobial agents are often added. While traditional inorganic antimicrobial agents (such as nanosilver and nanozinc oxide) exhibit promising antimicrobial effects, they tend to aggregate within the PET matrix, resulting in poor dispersion and impacting the material's transparency and mechanical properties.

[0004] Chinese patent document CN107286601A discloses a long-lasting antibacterial PET masterbatch and its preparation method. The raw material formula of the antibacterial PET masterbatch is, by weight, 3-8% Unined RM antibacterial agent, 0.5% polyethylene wax, 0.2% coupling agent, and the balance PET plastic resin. The antibacterial masterbatch of the present invention utilizes multiple compounds, exhibiting excellent dispersibility and compatibility with the PET plastic resin. When added to polyester plastics such as PET and PBT, it exhibits excellent aging resistance and improved mechanical properties, significantly extending its service life. It also resists common pathogens and inhibits drug-resistant pathogens, exhibits high efficiency, lasting water resistance, and is washable. It purifies the environment, eliminates odors, and provides self-cleaning and health benefits. It is environmentally friendly and has no side effects on the human body, thus providing greater health benefits. However, the antibacterial agent of the present invention is primarily added to the PET resin matrix via blending, resulting in weak interfacial bonding with the resin matrix. Consequently, the resulting antibacterial PET masterbatch's mechanical and flame retardant properties require further improvement. Summary of the Invention

[0005] The main purpose of the present invention is to provide an antibacterial PET sheet and a preparation method thereof. The antibacterial PET sheet prepared by the present invention has excellent flame retardant, antibacterial and mechanical properties.

[0006] To achieve the above objectives, the present invention proposes an antibacterial PET sheet, comprising the following components by weight: 60-80 parts of PET resin, 8-10 parts of compatibilizer, 10-20 parts of modified glass fiber, 5-10 parts of composite antibacterial agent, 1-2 parts of lubricant, and 1-2 parts of antioxidant.

[0007] Preferably, the compatibilizer is ethylene-methyl acrylate-glycidyl methacrylate.

[0008] Preferably, the preparation method of the modified glass fiber is as follows: The glass fiber is soaked in a sodium hydroxide aqueous solution, taken out, washed, dried, and added with dopamine in a Tris-HCl buffer solution for reaction at room temperature. The reaction product is centrifuged, washed, and vacuum dried to obtain a coated modified glass fiber. The coated modified glass fiber is added to N,N-dimethylformamide, and isophorone diisocyanate is added dropwise. After the addition is complete, linolenic alcohol is added and stirred evenly. Then, dibutyltin dilaurate is added as a catalyst, and the reaction is heated under nitrogen protection. After the reaction is completed, the reaction mixture is cooled to room temperature, filtered, washed, and dried to obtain a modified glass fiber.

[0009] Further preferably, the mass ratio of the glass fiber, dopamine, isophorone diisocyanate, linolenic alcohol, and dibutyltin dilaurate is 1:2-4:1.5-2.5:0.8-1.2:0.2-0.4; the heating reaction temperature is 60-70° C., and the reaction time is 2-4 h.

[0010] The preparation of the modified glass fiber of the present invention is first to etch the glass fiber with a sodium hydroxide aqueous solution, which not only increases the number of hydroxyl groups, but also increases the surface roughness and specific surface area, providing more attachment space for subsequent reactants, and then in situ polymerization is generated on the surface of the glass fiber to coat and modify it. The surface of the polydopamine film with antibacterial properties is rich in a large number of active groups such as hydroxyl groups and amino groups, which on the one hand provides anchoring sites for subsequent reactions, and on the other hand is easy to cross-link with the compatibilizer ethylene-methyl acrylate-glycidyl methacrylate in the subsequent processing process, thereby strengthening the glass fiber. The interfacial bonding force of the fiber makes the stress more evenly dispersed, thereby improving the mechanical properties and antibacterial properties of the PET sheet; finally, through the reaction of isophorone diisocyanate with some active groups in polydopamine, isocyanate groups are introduced into the coated modified glass fiber and react with the hydroxyl groups on linolenic alcohol, and flexible chain segments are introduced on the surface of the polydopamine-coated glass fiber. When the modified glass fiber is mixed into the molten PET resin, the long chain of linolenic alcohol can extend into the PET matrix, physically entangled and penetrated with the surrounding PET molecular chains to form a strong whole, further enhancing the interfacial bonding force.

[0011] Preferably, the preparation method of the composite antibacterial agent is as follows: 1) adding nano-zirconium phosphate and tetrabutyl titanate to an ethanol aqueous solution, stirring the mixture evenly, then adding ammonia water to adjust the pH value of the system to 9-10, and conducting a hydrothermal reaction. After the reaction is completed, filtering and collecting the solid matter, washing, and calcining to obtain a nano-zirconium phosphate composite; 2) adding the nano zirconium phosphate complex to an ethanol aqueous solution, adding vinyl triethoxysilane, and heating to react to obtain the vinyl nano zirconium phosphate complex; 3) Adding 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to N,N-dimethylformamide, adding a vinyl nano-zirconium phosphate complex and 2,2-dimethoxy-2-phenylacetophenone, and reacting under ultraviolet light. After the reaction is completed, filtering and collecting the solid, washing, drying, and adding it to water, adding zinc acetate dihydrate and mixing evenly, then adding an ethanol solution of oxalic acid, stirring the reaction, centrifuging and collecting the precipitate, and roasting to obtain a composite antibacterial agent.

[0012] Further preferably, in step 1), the mass ratio of nano-zirconium phosphate to tetrabutyl titanate is 3-5:1; the hydrothermal reaction temperature is 130-140°C, and the time is 6-8 hours; the calcination temperature is 500-700°C, and the calcination time is 1-2 hours.

[0013] Further preferably, in step 2), the mass ratio of the nano zirconium phosphate complex to vinyltriethoxysilane is 10-20:1-3; the heating temperature is 40-60° C., and the heating time is 4-6 hours.

[0014] Further preferably, in step 3), the mass ratio of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, vinyl nano-zirconium phosphate complex, and zinc acetate dihydrate is 2-4:2-4:1-3.

[0015] The preparation of the composite antibacterial agent of the present invention firstly generates titanium dioxide in situ on the surface of the flame retardant nano zirconium phosphate by a hydrothermal method. On the one hand, the hydrothermal reaction makes the combination of titanium dioxide and nano zirconium phosphate more firmly and avoids the agglomeration of nano zirconium phosphate. On the other hand, the antibacterial property and flame retardancy of the material can be improved. Then, the nano zirconium phosphate composite is surface treated to introduce carbon-carbon double bonds on its surface. Then, the vinyl nano zirconium phosphate composite is reacted with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to convert 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole into 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole. 4-triazole is introduced into the nano-zirconium phosphate composite. On the one hand, the amino group on its molecule can be cross-linked with the compatibilizer ethylene-methyl acrylate-glycidyl methacrylate during the subsequent processing, thereby enhancing the interfacial binding force of the composite antibacterial agent. On the other hand, the more heteroatoms on 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole can coordinate with zinc ions, thereby enhancing the binding force between zinc ions and the nano-zirconium phosphate composite. After calcination, zinc oxide and the nano-zirconium phosphate composite are tightly combined, thereby improving the antibacterial and flame retardant properties of the PET sheet.

[0016] Preferably, the lubricant is at least one of calcium stearate, zinc stearate, barium stearate, polyethylene wax, and butyl stearate.

[0017] Preferably, the antioxidant is one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and dilauryl thiodipropionate.

[0018] The present invention also discloses a method for preparing the antibacterial PET sheet, comprising the following steps: The components are weighed according to the formula, the PET resin is dried and then evenly mixed with a compatibilizer, modified glass fiber, a composite antibacterial agent, a lubricant, and an antioxidant to obtain a mixture, the mixture is melt-extruded and granulated at 250-270° C. to obtain a PET composite material; the PET composite material is added to a twin-screw extruder, melt-plasticized, extruded, rolled and pulled, and cooled to shape to obtain an antibacterial PET sheet.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides an antibacterial PET sheet, which uses PET resin as a base material, and is compounded with functional additives such as a compatibilizer, a lubricant, and an antioxidant, and introduces modified glass fiber and a composite antibacterial agent. The prepared antibacterial PET sheet has excellent long-term antibacterial, mechanical and flame retardant properties, making it applicable to more complex application scenarios; (2) The present invention enhances the interfacial bonding strength of the glass fiber by cross-linking the modified glass fiber added to the antibacterial PET sheet with the compatibilizer ethylene-methyl acrylate-glycidyl methacrylate, thereby making the stress more evenly dispersed, thereby improving the mechanical properties and antibacterial properties of the PET sheet; when the modified glass fiber is mixed into the molten PET resin, the long flexible linolenic alcohol chains on its surface can extend into the PET matrix, physically entangle and penetrate with the surrounding PET molecular chains, forming a strong whole, and further enhancing the interfacial bonding strength; (3) The composite antibacterial agent added to the antibacterial PET sheet of the present invention can improve the long-term antibacterial and flame retardant properties of the material, and the amino groups on its molecules can be cross-linked with the compatibilizer ethylene-methyl acrylate-glycidyl methacrylate during the subsequent processing process, thereby enhancing the interfacial binding force of the nano-zirconium phosphate complex. On the other hand, the more heteroatoms on 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole can coordinate with zinc ions, thereby enhancing the binding force between zinc ions and the nano-zirconium phosphate complex. After calcination, zinc oxide and the nano-zirconium phosphate complex are tightly combined, thereby improving the antibacterial and flame retardant properties of the PET sheet. DETAILED DESCRIPTION

[0020] To avoid redundancy, the items used in the following examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods unless otherwise specified.

[0021] The sources of some raw materials used in the present invention are as follows: Glass fiber, 3-15 mm, was purchased from Wuhe County Weijia Composite Materials Co., Ltd.

[0022] Nano-zirconium phosphate, with an average particle size of 0.5-2 μm, was purchased from Jining Fangyu Chemical Co., Ltd.

[0023] PET resin, model 3541, was purchased from Kangdis Chemical (Hubei) Co., Ltd.

[0024] Example 1 A method for preparing an antibacterial PET sheet comprises the following steps: 70 g of PET resin was dried and uniformly mixed with 9 g of ethylene-methyl acrylate-glycidyl methacrylate, 15 g of modified glass fiber, 8.5 g of a composite antibacterial agent, 1.6 g of calcium stearate, and 1.4 g of dilauryl thiodipropionate to obtain a mixture. The mixture was melt-extruded and granulated at 260° C. to obtain a PET composite material. The PET composite material was added to a twin-screw extruder and subjected to melt plasticization, extrusion, roller traction, and cooling and shaping to obtain an antibacterial PET sheet.

[0025] The preparation method of the modified glass fiber is as follows: 10 g of glass fiber was soaked in a 1 mol / L sodium hydroxide aqueous solution for 2 h, then taken out and washed until the pH value of the filtrate was 7. After drying, it was added to 300 mL of Tris-HCl buffer with a pH value of 9 with 30 g of dopamine, and oxygen was introduced to react at room temperature for 2 h. The reaction product was centrifuged, washed, and vacuum-dried to obtain a coated modified glass fiber. The coated modified glass fiber was added to 150 mL of N,N-dimethylformamide, and 20 g of isophorone diisocyanate was added dropwise. After the addition was complete, 10 g of linolenic alcohol was added and stirred evenly, and then 3 g of dibutyltin dilaurate was added as a catalyst. The reaction was heated at 60° C. under nitrogen protection for 3 h. After the reaction was completed, the reaction mixture was cooled to room temperature, the solid was collected by filtration, washed, and dried to obtain a modified glass fiber.

[0026] The preparation method of the composite antibacterial agent is as follows: 1) 40 g of nano-zirconium phosphate and 10 g of tetrabutyl titanate were added to 500 mL of a 50 wt % ethanol aqueous solution, mixed and stirred, and then 25 wt % ammonia water was added to adjust the pH of the system to 9-10. The mixture was then hydrothermally reacted at 140°C for 7 h. After the reaction, the solid was filtered, washed, and calcined at 600°C for 2 h to obtain a nano-zirconium phosphate composite. 2) Add 30 g of the nano-zirconium phosphate complex to 300 mL of a 50 wt% ethanol aqueous solution, add 4 g of vinyltriethoxysilane, and heat at 50° C. for 5 h. Collect the solid by filtration, wash, and dry to obtain the vinyl nano-zirconium phosphate complex; 3) Add 15 g of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to 200 mL of N,N-dimethylformamide, add 15 g of vinyl nano-zirconium phosphate complex and 0.6 g of 2,2-dimethoxy-2-phenylacetophenone, and react under 365 nm ultraviolet light for 30 min. After the reaction, the solid was collected by filtration, washed, dried, and added to 200 mL of water. 10 g of zinc acetate dihydrate was added and mixed evenly. Then, 40 mL of ethanol solution containing 5 g of oxalic acid was added. The reaction was stirred at room temperature for 30 min, the precipitate was collected by centrifugation, and calcined at 550°C for 2 h to obtain a composite antibacterial agent.

[0027] Example 2 A method for preparing an antibacterial PET sheet comprises the following steps: 60 g of PET resin was dried and uniformly mixed with 8 g of ethylene-methyl acrylate-glycidyl methacrylate, 10 g of modified glass fiber, 5 g of composite antibacterial agent, 1 g of calcium stearate, and 1 g of dilauryl thiodipropionate to obtain a mixture. The mixture was melt-extruded and granulated at 250° C. to obtain a PET composite material. The PET composite material was added to a twin-screw extruder, melt-plasticized, extruded, rolled and pulled, and cooled to form an antibacterial PET sheet.

[0028] The preparation method of the modified glass fiber is as follows: 10 g of glass fiber was soaked in a 1 mol / L sodium hydroxide aqueous solution for 2 h, then taken out and washed until the pH value of the filtrate was 7. After drying, it was added to 300 mL of Tris-HCl buffer with a pH value of 9 with 20 g of dopamine, and oxygen was introduced to react at room temperature for 2 h. The reaction product was centrifuged, washed, and vacuum-dried to obtain a coated modified glass fiber. The coated modified glass fiber was added to 150 mL of N,N-dimethylformamide, and 15 g of isophorone diisocyanate was added dropwise. After the addition was complete, 8 g of linolenic alcohol was added and stirred evenly, and then 2 g of dibutyltin dilaurate was added as a catalyst. The reaction was heated at 70°C under nitrogen protection for 2 h. After the reaction was completed, the reaction mixture was cooled to room temperature, the solid was collected by filtration, washed, and dried to obtain a modified glass fiber.

[0029] The preparation method of the composite antibacterial agent is as follows: 1) 30 g of nano-zirconium phosphate and 10 g of tetrabutyl titanate were added to 500 mL of a 50 wt % ethanol aqueous solution, mixed and stirred, and then 25 wt % ammonia water was added to adjust the pH of the system to 10. The mixture was then hydrothermally reacted at 140°C for 7 h. After the reaction, the solid was filtered, washed, and calcined at 600°C for 2 h to obtain a nano-zirconium phosphate composite. 2) Add 20 g of the nano-zirconium phosphate complex to 300 mL of a 50 wt% ethanol aqueous solution, add 2 g of vinyltriethoxysilane, and heat at 50° C. for 5 h. Collect the solid by filtration, wash, and dry to obtain the vinyl nano-zirconium phosphate complex; 3) Add 10 g of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to 200 mL of N,N-dimethylformamide, add 10 g of vinyl nano-zirconium phosphate complex and 0.5 g of 2,2-dimethoxy-2-phenylacetophenone, and react under 365 nm ultraviolet light for 30 min. After the reaction, the solid was collected by filtration, washed, dried, and added to 200 mL of water. 8 g of zinc acetate dihydrate was added and mixed evenly. Then, 40 mL of ethanol solution containing 4 g of oxalic acid was added. The reaction was stirred at room temperature for 30 min, the precipitate was collected by centrifugation, and calcined at 550°C for 2 h to obtain a composite antibacterial agent.

[0030] Example 3 A method for preparing an antibacterial PET sheet comprises the following steps: 80 g of PET resin was dried and uniformly mixed with 10 g of ethylene-methyl acrylate-glycidyl methacrylate, 20 g of modified glass fiber, 10 g of a composite antibacterial agent, 2 g of calcium stearate, and 2 g of dilauryl thiodipropionate to obtain a mixture. The mixture was melt-extruded and granulated at 270° C. to obtain a PET composite material. The PET composite material was added to a twin-screw extruder, melt-plasticized, extruded, rolled and pulled, and cooled to form an antibacterial PET sheet.

[0031] The preparation method of the modified glass fiber is as follows: 10 g of glass fiber was soaked in a 1 mol / L sodium hydroxide aqueous solution for 2 h, then taken out and washed until the pH value of the filtrate was 7. After drying, it was added to 300 mL of Tris-HCl buffer with a pH value of 9 with 40 g of dopamine, and oxygen was introduced to react at room temperature for 2 h. The reaction product was centrifuged, washed, and vacuum-dried to obtain a coated modified glass fiber. The coated modified glass fiber was added to 150 mL of N,N-dimethylformamide, and 25 g of isophorone diisocyanate was added dropwise. After the addition was complete, 12 g of linolenic alcohol was added and stirred evenly, and then 4 g of dibutyltin dilaurate was added as a catalyst. The reaction was heated at 70° C. under nitrogen protection for 4 h. After the reaction was completed, the reaction mixture was cooled to room temperature, the solid was collected by filtration, washed, and dried to obtain a modified glass fiber.

[0032] The preparation method of the composite antibacterial agent is as follows: 1) 50 g of nano-zirconium phosphate and 10 g of tetrabutyl titanate were added to 500 mL of a 50 wt % ethanol aqueous solution, mixed and stirred, and then 25 wt % ammonia water was added to adjust the pH of the system to 10. The mixture was then hydrothermally reacted at 140°C for 7 h. After the reaction, the solid was filtered, washed, and calcined at 600°C for 2 h to obtain a nano-zirconium phosphate composite. 2) Add 40 g of the nano-zirconium phosphate complex to 500 mL of a 50 wt% ethanol aqueous solution, add 6 g of vinyltriethoxysilane, and heat at 50° C. for 5 h. Collect the solid by filtration, wash, and dry to obtain the vinyl nano-zirconium phosphate complex; 3) Add 20 g of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to 200 mL of N,N-dimethylformamide, add 20 g of vinyl nano-zirconium phosphate complex and 0.8 g of 2,2-dimethoxy-2-phenylacetophenone, and react under 365 nm ultraviolet light for 30 min. After the reaction, the solid was collected by filtration, washed, dried, and added to 200 mL of water. 13 g of zinc acetate dihydrate was added and mixed evenly. Then, 40 mL of ethanol solution containing 7 g of oxalic acid was added. The reaction was stirred at room temperature for 30 min, the precipitate was collected by centrifugation, and calcined at 550°C for 2 h to obtain a composite antibacterial agent.

[0033] Comparative Example 1 A method for preparing an antibacterial PET sheet comprises the following steps: 70 g of PET resin was dried and uniformly mixed with 9 g of ethylene-methyl acrylate-glycidyl methacrylate, 15 g of glass fiber, 8.5 g of a composite antibacterial agent, 1.6 g of calcium stearate, and 1.4 g of dilauryl thiodipropionate to obtain a mixture. The mixture was melt-extruded and granulated at 260° C. to obtain a PET composite material. The PET composite material was added to a twin-screw extruder and subjected to melt plasticization, extrusion, roller traction, and cooling and shaping to obtain an antibacterial PET sheet.

[0034] The preparation method of the composite antibacterial agent is as follows: 1) 40 g of nano-zirconium phosphate and 10 g of tetrabutyl titanate were added to 500 mL of a 50 wt % ethanol aqueous solution, mixed and stirred, and then 25 wt % ammonia water was added to adjust the pH of the system to 9-10. The mixture was then hydrothermally reacted at 140°C for 7 h. After the reaction, the solid was filtered, washed, and calcined at 600°C for 2 h to obtain a nano-zirconium phosphate composite. 2) Add 30 g of the nano-zirconium phosphate complex to 300 mL of a 50 wt% ethanol aqueous solution, add 4 g of vinyltriethoxysilane, and heat at 50° C. for 5 h. Collect the solid by filtration, wash, and dry to obtain the vinyl nano-zirconium phosphate complex; 3) Add 15 g of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to 200 mL of N,N-dimethylformamide, add 15 g of vinyl nano-zirconium phosphate complex and 0.6 g of 2,2-dimethoxy-2-phenylacetophenone, and react under 365 nm ultraviolet light for 30 min. After the reaction, filter and collect the solid, wash, and dry to obtain a composite antibacterial agent.

[0035] Comparative Example 2 A method for preparing an antibacterial PET sheet comprises the following steps: 70 g of PET resin was dried and uniformly mixed with 9 g of ethylene-methyl acrylate-glycidyl methacrylate, 15 g of modified glass fiber, 8.5 g of nano-zirconium phosphate complex, 1.6 g of calcium stearate, and 1.4 g of dilauryl thiodipropionate to obtain a mixture. The mixture was melt-extruded and granulated at 260° C. to obtain a PET composite material. The PET composite material was added to a twin-screw extruder and subjected to melt plasticization, extrusion, roller traction, and cooling and shaping to obtain an antibacterial PET sheet.

[0036] The preparation method of the modified glass fiber is as follows: 10 g of glass fiber was soaked in a 1 mol / L sodium hydroxide aqueous solution for 2 h, then taken out and washed until the pH value of the filtrate was 7. After drying, it was added to 300 mL of Tris-HCl buffer with a pH value of 9 with 30 g of dopamine, and oxygen was introduced to react at room temperature for 2 h. The reaction product was centrifuged, washed, and vacuum-dried to obtain a coated modified glass fiber. The coated modified glass fiber was added to 150 mL of N,N-dimethylformamide, and 20 g of isophorone diisocyanate was added dropwise. After the addition was complete, 10 g of linolenic alcohol was added and stirred evenly, and then 3 g of dibutyltin dilaurate was added as a catalyst. The reaction was heated at 60° C. under nitrogen protection for 3 h. After the reaction was completed, the reaction mixture was cooled to room temperature, the solid was collected by filtration, washed, and dried to obtain a modified glass fiber.

[0037] The preparation method of the nano zirconium phosphate composite is as follows: 40 g of nano-zirconium phosphate and 10 g of tetrabutyl titanate were added to 500 mL of 50 wt% ethanol aqueous solution, mixed and stirred evenly, and then 25 wt% ammonia water was added to adjust the pH value of the system to 9-10. Then, a hydrothermal reaction was carried out at 140 ° C for 7 h. After the reaction was completed, the solid was filtered and collected, washed, and calcined at 600 ° C for 2 h to obtain a nano-zirconium phosphate composite.

[0038] Comparative Example 3 A method for preparing an antibacterial PET sheet comprises the following steps: 70 g of PET resin was dried and uniformly mixed with 9 g of ethylene-methyl acrylate-glycidyl methacrylate, 15 g of modified glass fiber, 8.5 g of a composite antibacterial agent, 1.6 g of calcium stearate, and 1.4 g of dilauryl thiodipropionate to obtain a mixture. The mixture was melt-extruded and granulated at 260° C. to obtain a PET composite material. The PET composite material was added to a twin-screw extruder and subjected to melt plasticization, extrusion, roller traction, and cooling and shaping to obtain an antibacterial PET sheet.

[0039] The preparation method of the modified glass fiber is as follows: 10 g of glass fiber was soaked in a 1 mol / L sodium hydroxide aqueous solution for 2 h, then taken out and washed until the pH value of the filtrate was 7. After drying, it was added to 300 mL of Tris-HCl buffer with a pH value of 9 with 30 g of dopamine, and oxygen was introduced to react at room temperature for 2 h. The reaction product was centrifuged, washed, and vacuum-dried to obtain a coated modified glass fiber. The coated modified glass fiber was added to 150 mL of N,N-dimethylformamide, and 20 g of isophorone diisocyanate was added dropwise. After the addition was complete, 10 g of linolenic alcohol was added and stirred evenly, and then 3 g of dibutyltin dilaurate was added as a catalyst. The reaction was heated at 60° C. under nitrogen protection for 3 h. After the reaction was completed, the reaction mixture was cooled to room temperature, the solid was collected by filtration, washed, and dried to obtain a modified glass fiber.

[0040] The preparation method of the composite antibacterial agent is as follows: 1) 40 g of nano-zirconium phosphate and 10 g of tetrabutyl titanate were added to 500 mL of a 50 wt % ethanol aqueous solution, mixed and stirred, and then 25 wt % ammonia water was added to adjust the pH of the system to 9-10. The mixture was then hydrothermally reacted at 140°C for 7 h. After the reaction, the solid was filtered, washed, and calcined at 600°C for 2 h to obtain a nano-zirconium phosphate composite. 2) Add 30 g of nano-zirconium phosphate complex to 300 mL of 50 wt% ethanol aqueous solution, add 4 g of vinyltriethoxysilane, and heat to react at 50 ° C for 5 h. The solid is collected by filtration, washed and dried, and then added to 200 mL of water. 10 g of zinc acetate dihydrate is added and mixed evenly. Then, 40 mL of ethanol solution containing 5 g of oxalic acid is added. The reaction is stirred at room temperature for 30 min. The precipitate is collected by centrifugation and calcined at 550 ° C for 2 h to obtain a composite antibacterial agent.

[0041] Performance Testing Tensile strength test: Refer to GB / T1040.2-2022 "Determination of tensile properties of plastics Part 2: Test conditions for molded and extruded plastics" standard, and perform tensile tests on dumbbell-shaped 50×10×4mm standard specimens. The specimens are stretched at a rate of 50mm / min at room temperature. Limiting oxygen index test: Tested in accordance with GB / T 2406.2-2009 "Plastics - Determination of combustion behavior by oxygen index method - Part 2: Room temperature test"; Impact strength test: Tested in accordance with GB / T1843-2008 "Determination of Izod Beam Impact Strength of Plastics"; Antibacterial performance test: 1ml concentration of 10 8 Escherichia coli bacterial solution with a CFU / ml was added dropwise to the surface of the sterilized antibacterial PET sheet samples prepared in Examples 1-3, and cultured at 37°C for 8 h. 20 μL of the cultured bacterial solution was transferred and evenly spread on the solid culture medium. After cultured at 37°C for 24 h, the number of colonies on the culture medium was counted, and a blank experiment was performed at the same time. The antibacterial rate was calculated using the following formula (I): Antibacterial rate = (AB) / A×100%, formula (I) Among them, A is the number of colonies in the blank experiment, B is the number of colonies in the sample group experiment, The test results are shown in Table 1: Table 1 Antibacterial PET sheet performance test results It can be seen from the experimental results in Table 1 that the antibacterial PET sheet obtained by the present invention has excellent flame retardant, mechanical and antibacterial properties.

[0042] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. An antibacterial PET sheet, characterized in that, The invention comprises the following components in parts by weight: 60-80 parts of PET resin, 8-10 parts of compatibilizer, 10-20 parts of modified glass fiber, 5-10 parts of composite antibacterial agent, 1-2 parts of lubricant and 1-2 parts of antioxidant.

2. The antibacterial PET sheet according to claim 1, characterized in that: The compatibilizer is ethylene-methyl acrylate-glycidyl methacrylate.

3. The antibacterial PET sheet according to claim 1, characterized in that: The preparation method of the modified glass fiber is as follows: The glass fiber is soaked in a sodium hydroxide aqueous solution, taken out, washed, dried, and added with dopamine in a Tris-HCl buffer solution for reaction at room temperature. The reaction product is centrifuged, washed, and vacuum dried to obtain a coated modified glass fiber. The coated modified glass fiber is added to N,N-dimethylformamide, and isophorone diisocyanate is added dropwise. After the addition is complete, linolenic alcohol is added and stirred evenly. Then, dibutyltin dilaurate is added as a catalyst, and the reaction is heated under nitrogen protection. After the reaction is completed, the reaction mixture is cooled to room temperature, filtered, washed, and dried to obtain a modified glass fiber.

4. The antibacterial PET sheet according to claim 3, characterized in that: The mass ratio of the glass fiber, dopamine, isophorone diisocyanate, linolenic alcohol and dibutyltin dilaurate is 1:2-4:1.5-2.5:0.8-1.2:0.2-0.

4.

5. The antibacterial PET sheet according to claim 1, characterized in that: The preparation method of the composite antibacterial agent is as follows: 1) adding nano-zirconium phosphate and tetrabutyl titanate to an ethanol aqueous solution, stirring the mixture evenly, then adding ammonia water to adjust the pH value of the system to 9-10, and conducting a hydrothermal reaction. After the reaction is completed, filtering and collecting the solid matter, washing, and calcining to obtain a nano-zirconium phosphate composite; 2) adding the nano zirconium phosphate complex to an ethanol aqueous solution, adding vinyl triethoxysilane, and heating to react to obtain the vinyl nano zirconium phosphate complex; 3) Adding 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to N,N-dimethylformamide, adding a vinyl nano-zirconium phosphate complex and 2,2-dimethoxy-2-phenylacetophenone, and reacting under ultraviolet light. After the reaction is completed, filtering and collecting the solid, washing, drying, and adding it to water, adding zinc acetate dihydrate and mixing evenly, then adding an ethanol solution of oxalic acid, stirring the reaction, centrifuging and collecting the precipitate, and roasting to obtain a composite antibacterial agent.

6. The antibacterial PET sheet according to claim 5, characterized in that: In step 1), the mass ratio of nano-zirconium phosphate to tetrabutyl titanate is 3-5:1; the hydrothermal reaction temperature is 130-140° C., and the reaction time is 6-8 hours.

7. The antibacterial PET sheet according to claim 5, characterized in that: In the step 2), the mass ratio of the nano zirconium phosphate complex to vinyl triethoxysilane is 10-20:1-3; the heating temperature is 40-60° C., and the heating time is 4-6 hours.

8. The antibacterial PET sheet according to claim 5, characterized in that: In the step 3), the mass ratio of 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole, vinyl nano-zirconium phosphate complex, and zinc acetate dihydrate is 2-4:2-4:1-3.

9. The antibacterial PET sheet according to claim 1, characterized in that: The lubricant is at least one of calcium stearate, zinc stearate, barium stearate, polyethylene wax, and butyl stearate.

10. A method for preparing the antibacterial PET sheet according to any one of claims 1 to 9, characterized in that: The steps include: The components are weighed according to the formula, the PET resin is dried and then evenly mixed with a compatibilizer, modified glass fiber, a composite antibacterial agent, a lubricant, and an antioxidant to obtain a mixture, the mixture is melt-extruded and granulated at 250-270° C. to obtain a PET composite material; the PET composite material is added to a twin-screw extruder, melt-plasticized, extruded, rolled and pulled, and cooled to shape to obtain an antibacterial PET sheet.

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