Antibacterial plastic packaging material and preparation method thereof

Abstract

The invention discloses a bacteriostatic plastic packaging material and a preparation method thereof, and relates to the technical field of packaging materials, the packaging material is prepared from the following components by weight: 90-120 parts of plastic resin, 10-20 parts of maleic anhydride grafted polyethylene, 5-15 parts of poly-p-benzamide fiber, 4-12 parts of modified titanium dioxide, 3-10 parts of polyvinyl alcohol, 1-3 parts of a coupling agent, 1-3 parts of a lubricant, and 1-3 parts of a plasticizer. The prepared packaging material combines the photocatalytic antibacterial property of the modified titanium dioxide, the toughening effect of the poly-p-benzamide fiber and the synergistic effect of all functional aids, and has excellent antibacterial property, mechanical property and processability.

Description

Technical Field

[0001] The invention relates to the technical field of packaging materials, and in particular to an antibacterial plastic packaging material and a preparation method thereof. Background Art

[0002] At present, the most commonly used traditional plastic packaging materials include polyethylene (PE), polypropylene (PP) and polystyrene (PS). Polyethylene has excellent chemical stability, corrosion resistance and electrical insulation, and has good processing performance and low cost. Among them, low-density polyethylene (LDPE) has good flexibility and transparency, and is mainly used to make packaging films and bags; high-density polyethylene (HDPE) has good rigidity and is often used to make bottle containers and rigid packaging. Polypropylene has high heat resistance (melting point is about 165°C), mechanical strength and toughness, and has good chemical resistance and low water vapor permeability. It is suitable for hot filling containers, microwave heating packaging, etc. Polystyrene has excellent transparency and rigidity, good processing performance, but poor impact resistance and prone to stress cracking. It is mainly used to make transparent containers and disposable tableware.

[0003] In order to improve the antibacterial properties of packaging materials, researchers have developed a variety of modification schemes. Although the addition of inorganic nanomaterials such as nanosilver, nanozinc oxide, and nanotitanium dioxide has good antibacterial effects, it has problems such as high cost and poor dispersibility. The use of organic antibacterial agents such as quaternary ammonium salts, organic acids and their salts for modification may have disadvantages such as strong migration and volatility. The use of natural antibacterial agents such as chitosan and plant essential oils for modification has the advantages of safety and environmental protection, but the durability of the antibacterial effect needs to be improved.

[0004] CN117304546A discloses an antistatic and antibacterial modified polyethylene plastic film for packaging and a preparation method thereof. The polyethylene plastic film is prepared by spraying and depositing a dispersion containing transition metal polyphthalocyanine and chain Ag-Ag2S nanomaterial on the surface of the polyethylene film. The transition metal polyphthalocyanine is one of the polymers of iron phthalocyanine, manganese phthalocyanine, copper phthalocyanine, cobalt phthalocyanine, nickel phthalocyanine and zinc phthalocyanine, and the chain Ag-Ag2S nanomaterial is prepared by reacting elemental sulfur with silver on the surface of silver nanowires to generate silver sulfide.

[0005] Existing antibacterial plastic packaging materials still face many technical challenges. The uneven dispersion of antibacterial agents in the matrix material affects the durability and stability of the antibacterial effect; some chemical antibacterial agents have potential safety risks and may migrate into food; the introduction of antibacterial function often reduces the mechanical properties and processing properties of the material; and the high cost of high-performance antibacterial packaging materials is not conducive to industrial application.

[0006] Therefore, it is of great practical significance to develop a plastic packaging material with excellent antibacterial performance, safety, environmental protection, good comprehensive performance and economy. This is also the technical problem that the present invention is committed to solving. Summary of the invention

[0007] In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide an antibacterial plastic packaging material and a preparation method thereof, which combines the photocatalytic antibacterial properties of modified titanium dioxide, the toughening effect of polyparabenzamide fiber and the synergistic effect of various functional additives, and the prepared packaging material has excellent antibacterial properties, mechanical properties and processing properties.

[0008] In order to achieve the above object, the present invention adopts the following technical solution: An antibacterial plastic packaging material is made of the following components, measured by weight: 90-120 parts of plastic resin, 10-20 parts of maleic anhydride grafted polyethylene, 5-15 parts of polyparabenzamide fiber, 4-12 parts of modified titanium dioxide, 3-10 parts of polyvinyl alcohol, 1-3 parts of coupling agent, 1-3 parts of lubricant, and 1-3 parts of plasticizer.

[0009] Preferably, the preparation method of the modified titanium dioxide comprises the following steps: (1) dispersing nano-titanium dioxide in anhydrous toluene, ultrasonically treating, adding 3-mercaptopropyltrimethoxysilane, continuously introducing nitrogen, stirring at room temperature, heating to reflux for reaction, centrifuging, washing, and drying the product to obtain mercapto-titanium dioxide; Silane surface modification reaction: The surface of nano-titanium dioxide is rich in hydroxyl groups (-OH), which react with the methoxy groups (-OCH3) in 3-mercaptopropyltrimethoxysilane. The process begins with the hydrolysis of silane molecules to form silanol (Si-OH) intermediates, which then undergo dehydration condensation with surface hydroxyl groups to form Si-O-Ti covalent bonds, thus achieving covalent modification of the organic chain containing mercapto groups (-SH) on the surface of titanium dioxide.

[0010] Preferably, in step (1), the usage ratio of nano-titanium dioxide, anhydrous toluene and 3-mercaptopropyltrimethoxysilane is 10 g: 80-120 mL: 10-25 mL.

[0011] Preferably, in step (1), the ultrasonic treatment is performed for 10 to 30 minutes; the stirring time at room temperature is 0.5 to 2 hours; and the heating reflux reaction conditions are heating to 80 to 110° C. and reflux reaction for 4 to 18 hours.

[0012] (2) dispersing the thiolated titanium dioxide in tetrahydrofuran, ultrasonically treating it, adding 4-vinylbenzeneboronic acid and AIBN, stirring the reaction under a nitrogen atmosphere, centrifuging, washing, and drying the product to obtain boric acid-modified titanium dioxide; Thermally initiated thiol-ene addition reaction: AIBN thermally decomposes to generate free radicals, which initiate homolysis of the surface thiol (-SH) to generate thiol free radicals, which then undergo free radical addition with the carbon-carbon double bond of 4-vinylphenylboronic acid. The addition process forms a carbon free radical intermediate, which forms a stable thioether bond (-S-CH2-CH2-) through chain transfer, while regenerating thiol free radicals to maintain the chain reaction, and finally introduces phenylboronic acid groups on the titanium dioxide surface.

[0013] Preferably, in step (2), the usage ratio of thiolated titanium dioxide, tetrahydrofuran, 4-vinylbenzeneboronic acid and AIBN is 10 g: 80-120 mL: 8-15 g: 0.5-2 g.

[0014] Preferably, in step (2), the ultrasonic treatment is carried out for 10 to 30 minutes, and the stirring reaction conditions are 50 to 65° C. and the reaction is carried out for 6 to 12 hours.

[0015] (3) Dispersing boric acid-modified titanium dioxide in an ethanol / water mixture, ultrasonically treating it, adding salicylic acid, stirring the reaction, centrifuging the product, washing it with alcohol, and drying it to obtain modified titanium dioxide.

[0016] Chelation coordination reaction of boric acid and salicylic acid: The surface phenylboronic acid group (-B(OH)2) undergoes dehydration coordination with the carboxyl group (-COOH) and the ortho-phenolic hydroxyl group (-OH) in the salicylic acid molecule to form a six-membered ring borate ester chelate structure containing a BOC bond.

[0017] Preferably, in step (3), the volume ratio of anhydrous ethanol to deionized water in the ethanol / water mixture is 6-9:4-1; the dosage ratio of boric acid-modified titanium dioxide, ethanol / water mixture, and salicylic acid is 10 g:80-120 mL:6-12 g.

[0018] Preferably, in step (3), the ultrasonic treatment is performed for 10 to 30 minutes; and the stirring reaction conditions are 45 to 55° C. and 2 to 6 hours.

[0019] Preferably, the plastic resin is one of polyethylene, polypropylene and polystyrene; the coupling agent is an aminosilane coupling agent; the lubricant is ethylene bisstearamide; and the plasticizer is tributyl citrate.

[0020] The present invention also claims protection for a method for preparing the antibacterial plastic packaging material, comprising the following steps: adding each raw material into a batching container according to weight portion, stirring evenly, adding the mixed material into a single-screw extruder, melting, extruding and drawing, cooling, pelletizing, and film blowing or cast film to obtain the antibacterial plastic packaging material.

[0021] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention provides an antibacterial plastic packaging material, which uses polyethylene, polypropylene or polystyrene as a base resin and achieves excellent comprehensive performance through the synergistic effect of multifunctional components: modified titanium dioxide provides a lasting photocatalytic antibacterial effect, maleic anhydride grafted polyethylene improves the compatibility and dispersibility of each component, polyparabenzamide fiber significantly improves the toughness of the material, and polyvinyl alcohol enhances the gas barrier performance through its dense molecular arrangement and polar hydroxyl network. At the same time, with the assistance of coupling agents, lubricants and plasticizers, the material has good processing performance and use performance, so that it has broad application prospects in the fields of food packaging.

[0022] 2. The present invention provides a modified titanium dioxide. The surface-modified titanium dioxide achieves multiple performance improvements by gradually introducing different functional groups: First, the hydroxyl groups on the surface of nano-titanium dioxide are eliminated by modification with mercaptosilane, effectively preventing the agglomeration of nanoparticles. At the same time, this step not only introduces active thiol groups to provide reaction sites for further modification, but also improves the compatibility of modified titanium dioxide with plastic resins, ensuring its uniform dispersion in the matrix. Secondly, the aromatic ring structure of the phenylboronic acid group introduced by the thiol-ene addition reaction increases the molecular rigidity, inhibits the movement of the molecular chain, and improves the heat resistance of the material. At the same time, the introduction of the boron element also gives the material certain flame retardant properties. Finally, a stable six-membered ring structure is formed through the chelation coordination of boric acid and salicylic acid. This ring structure has the following characteristics: (1) The conformation of the ring structure itself limits the free rotation of the molecular chain segments and increases the rigidity of the structural unit; (2) The stable chemical bonds formed within the ring jointly construct a rigid skeleton, limiting the flexibility of the molecular chain; (3) The six-membered ring structure can also form a larger scale ordered arrangement through intermolecular forces, further improving the rigidity of the overall structure. In the final material, nano-titanium dioxide can fill the micropores of the polymer film at the nanoscale, significantly improving the barrier properties of the material. Titanium dioxide generates electron-hole pairs under light conditions, which then generate active free radicals with strong oxidizing properties, including hydroxyl radicals (·OH) and superoxide ion radicals (·O 2- ), these active species can decompose organic matter in bacteria through oxidation and eventually convert it into CO2 and H2O, achieving a lasting photocatalytic antibacterial effect. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with embodiments. Of course, the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0024] Unless otherwise specified, the chemical reagents and materials in the present invention are purchased from commercial sources or synthesized from raw materials purchased from commercial sources.

[0025] Polyethylene resin was purchased from Yanshan Petrochemical, with the grade 1C7A; Polypropylene resin was purchased from Ningxia Coal Industry, brand 1100N; Polyvinyl alcohol was purchased from Hefei Tianyi New Materials Co., Ltd., model PVA088-50; Maleic anhydride grafted polyethylene was purchased from Dongguan Taotao Plastic Raw Materials Co., Ltd., brand number 4288; Poly(p-phenylene phthalamide) fibers were purchased from Sigma-Aldrich; Nano-titanium dioxide was purchased from Hebei Botai Chemical Co., Ltd. with a particle size of 1780-1800 mesh.

[0026] A method for preparing an antibacterial plastic packaging material comprises the following steps: (1) Disperse 10 g of nano-titanium dioxide in 80-120 mL of anhydrous toluene, ultrasonicate for 10-30 min, add 10-25 mL of 3-mercaptopropyltrimethoxysilane, continuously introduce nitrogen, stir at room temperature for 0.5-2 h, heat to 80-110 °C and reflux for 4-18 h, centrifuge the product, wash with toluene and anhydrous ethanol three times respectively, and vacuum dry to obtain mercaptolated titanium dioxide; (2) Disperse 10 g of thiolated titanium dioxide in 80-120 mL of tetrahydrofuran, ultrasonically treat for 10-30 min, add 8-15 g of 4-vinylbenzeneboronic acid and 0.5-2 g of AIBN, stir and react at 50-65 °C in a nitrogen atmosphere for 6-12 h, centrifuge the product, wash it three times with tetrahydrofuran, and vacuum dry it to obtain boric acid-modified titanium dioxide; (3) Disperse 10 g of boric acid-modified titanium dioxide in 80-120 mL of ethanol / water mixture (the volume ratio of anhydrous ethanol to deionized water is 6-9:4-1), ultrasonically treat for 10-30 min, add 6-12 g of salicylic acid, stir and react at 45-55 °C for 2-6 h, centrifuge the product, wash with alcohol, and dry to obtain modified titanium dioxide; (4) Add 90-120 parts by weight of a plastic resin (one of polyethylene, polypropylene, and polystyrene), 10-20 parts of maleic anhydride grafted polyethylene, 5-15 parts of poly(p-phenylene amide) fibers, 4-12 parts of modified titanium dioxide, 3-10 parts of polyvinyl alcohol, 1-3 parts of 3-aminopropyltriethoxysilane, 1-3 parts of ethylenebisstearamide, and 1-3 parts of tributyl citrate into a mixing container, stir evenly, add the mixed materials into a single-screw extruder, melt, extrude and draw strips, cool and pelletize, and then blow mold or cast film to obtain the antibacterial plastic packaging material.

[0027] The present invention will be further described below through specific embodiments.

[0028] Example 1

[0029] A method for preparing an antibacterial plastic packaging material comprises the following steps: (1) Disperse 10 g of nano-titanium dioxide in 120 mL of anhydrous toluene, ultrasonicate for 30 min, add 25 mL of 3-mercaptopropyltrimethoxysilane, continue to introduce nitrogen, stir at room temperature for 2 h, heat to 110 °C and reflux for 4 h, centrifuge the product, wash with toluene and anhydrous ethanol for 3 times, and vacuum dry to obtain mercapto-titanium dioxide; (2) Disperse 10 g of thiolated titanium dioxide in 120 mL of tetrahydrofuran, ultrasonicate for 30 min, add 15 g of 4-vinylbenzeneboronic acid and 2 g of AIBN, stir and react at 65 °C in a nitrogen atmosphere for 6 h, centrifuge the product, wash with tetrahydrofuran three times, and vacuum dry to obtain boric acid-modified titanium dioxide; (3) Disperse 10 g of boric acid-modified titanium dioxide in 120 mL of ethanol / water mixture (the volume ratio of anhydrous ethanol to deionized water is 9:1), ultrasonically treat for 30 min, add 12 g of salicylic acid, stir and react at 55 °C for 2 h, centrifuge the product, wash with alcohol, and dry to obtain modified titanium dioxide; (4) Add 1200 g of polypropylene resin, 200 g of maleic anhydride grafted polyethylene, 150 g of poly(p-phenylene phthalate), 120 g of modified titanium dioxide, 100 g of poly(vinyl alcohol), 30 g of 3-aminopropyltriethoxysilane, 30 g of ethylenebis(stearic acid amide) and 30 g of tributyl citrate into a mixing container according to weight parts, stir evenly, add the mixed materials into a single-screw extruder, melt, extrude and draw strips, cool and pelletize, and cast a film to obtain the antibacterial plastic packaging material.

[0030] Example 2

[0031] A method for preparing an antibacterial plastic packaging material comprises the following steps: (1) Disperse 10 g of nano-titanium dioxide in 100 mL of anhydrous toluene, ultrasonicate for 20 min, add 20 mL of 3-mercaptopropyltrimethoxysilane, continue to introduce nitrogen, stir at room temperature for 1.5 h, heat to 100 °C and reflux for 8 h, centrifuge the product, wash with toluene and anhydrous ethanol three times respectively, and vacuum dry to obtain mercapto-titanium dioxide; (2) Disperse 10 g of thiolated titanium dioxide in 100 mL of tetrahydrofuran, ultrasonically treat for 20 min, add 12 g of 4-vinylbenzeneboronic acid and 1.5 g of AIBN, stir and react at 60 °C in a nitrogen atmosphere for 8 h, centrifuge the product, wash with tetrahydrofuran three times, and vacuum dry to obtain boric acid-modified titanium dioxide; (3) Disperse 10 g of boric acid-modified titanium dioxide in 100 mL of ethanol / water mixture (the volume ratio of anhydrous ethanol to deionized water is 8:2), ultrasonically treat for 20 min, add 10 g of salicylic acid, stir and react at 50 °C for 4 h, centrifuge the product, wash with alcohol, and dry to obtain modified titanium dioxide; (4) Add 1100 g of polypropylene resin, 160 g of maleic anhydride grafted polyethylene, 120 g of poly(p-phenylene phthalate), 100 g of modified titanium dioxide, 80 g of poly(vinyl alcohol), 20 g of 3-aminopropyltriethoxysilane, 20 g of ethylenebis(stearic acid amide) and 20 g of tributyl citrate into a mixing container according to weight parts, stir evenly, add the mixed materials into a single-screw extruder, melt, extrude and draw strips, cool and pelletize, and cast a film to obtain the antibacterial plastic packaging material.

[0032] Example 3

[0033] A method for preparing an antibacterial plastic packaging material comprises the following steps: (1) Disperse 10 g of nano-titanium dioxide in 100 mL of anhydrous toluene, ultrasonicate for 20 min, add 15 mL of 3-mercaptopropyltrimethoxysilane, continuously introduce nitrogen, stir at room temperature for 1 h, heat to 90 °C and reflux for 12 h, centrifuge the product, wash with toluene and anhydrous ethanol three times respectively, and vacuum dry to obtain mercapto-titanium dioxide; (2) Disperse 10 g of thiolated titanium dioxide in 100 mL of tetrahydrofuran, ultrasonically treat for 20 min, add 10 g of 4-vinylbenzeneboronic acid and 1 g of AIBN, stir and react for 10 h at 55 °C under a nitrogen atmosphere, centrifuge the product, wash it three times with tetrahydrofuran, and vacuum dry it to obtain boric acid-modified titanium dioxide; (3) Disperse 10 g of boric acid-modified titanium dioxide in 100 mL of ethanol / water mixture (the volume ratio of anhydrous ethanol to deionized water is 8:2), ultrasonically treat for 20 min, add 8 g of salicylic acid, stir and react at 50 °C for 4 h, centrifuge the product, wash with alcohol, and dry to obtain modified titanium dioxide; (4) Add 1000 g of polyethylene resin, 140 g of maleic anhydride grafted polyethylene, 80 g of poly(p-phenylene phthalate), 80 g of modified titanium dioxide, 60 g of poly(vinyl alcohol), 20 g of 3-aminopropyltriethoxysilane, 20 g of ethylenebis(stearic acid amide) and 20 g of tributyl citrate into a mixing container according to weight parts, stir evenly, add the mixed materials into a single-screw extruder, melt, extrude and draw strips, cool and pelletize, and cast a film to obtain the antibacterial plastic packaging material.

[0034] Example 4

[0035] A method for preparing an antibacterial plastic packaging material comprises the following steps: (1) Disperse 10 g of nano-titanium dioxide in 80 mL of anhydrous toluene, ultrasonicate for 10 min, add 10 mL of 3-mercaptopropyltrimethoxysilane, continue to introduce nitrogen, stir at room temperature for 0.5 h, heat to 80 °C and reflux for 18 h, centrifuge the product, wash with toluene and anhydrous ethanol three times respectively, and vacuum dry to obtain mercapto-titanium dioxide; (2) Disperse 10 g of thiolated titanium dioxide in 80 mL of tetrahydrofuran, ultrasonically treat for 10 min, add 8 g of 4-vinylbenzeneboronic acid and 0.5 g of AIBN, stir and react for 12 h at 50 °C under nitrogen atmosphere, centrifuge the product, wash it three times with tetrahydrofuran, and vacuum dry it to obtain boric acid-modified titanium dioxide; (3) Disperse 10 g of boric acid-modified titanium dioxide in 80 mL of ethanol / water mixture (the volume ratio of anhydrous ethanol to deionized water is 8:2), ultrasonically treat for 10 min, add 6 g of salicylic acid, stir and react at 45 °C for 6 h, centrifuge the product, wash with alcohol, and dry to obtain modified titanium dioxide; (4) Add 900 g of polyethylene resin, 100 g of maleic anhydride grafted polyethylene, 50 g of poly(p-phenylene phthalate), 40 g of modified titanium dioxide, 30 g of poly(vinyl alcohol), 10 g of 3-aminopropyltriethoxysilane, 10 g of ethylenebis(stearic acid amide) and 10 g of tributyl citrate into a mixing container according to weight parts, stir evenly, add the mixed materials into a single-screw extruder, melt, extrude and draw strips, cool and pelletize, and cast a film to obtain the antibacterial plastic packaging material.

[0036] Comparative Example 1

[0037] A method for preparing a plastic packaging material comprises the following steps: (1) Disperse 10 g of nano-titanium dioxide in 120 mL of anhydrous toluene, ultrasonicate for 30 min, add 25 mL of 3-mercaptopropyltrimethoxysilane, continue to introduce nitrogen, stir at room temperature for 2 h, heat to 110 °C and reflux for 4 h, centrifuge the product, wash with toluene and anhydrous ethanol for 3 times, and vacuum dry to obtain mercapto-titanium dioxide; (2) Disperse 10 g of thiolated titanium dioxide in 120 mL of tetrahydrofuran, ultrasonicate for 30 min, add 15 g of 4-vinylbenzeneboronic acid and 2 g of AIBN, stir and react at 65 °C in a nitrogen atmosphere for 6 h, centrifuge the product, wash with tetrahydrofuran three times, and vacuum dry to obtain boric acid-modified titanium dioxide; (3) Add 1200 g of polypropylene resin, 200 g of maleic anhydride grafted polyethylene, 150 g of poly(p-phenylene phthalate), 120 g of boric acid modified titanium dioxide, 100 g of poly(vinyl alcohol), 30 g of 3-aminopropyl triethoxysilane, 30 g of ethylene bis(stearic acid amide) and 30 g of tributyl citrate into a mixing container according to weight parts, stir evenly, add the mixed materials into a single screw extruder, melt, extrude and draw strips, cool and pelletize, and cast a film to obtain the plastic packaging material.

[0038] Comparative Example 2

[0039] A method for preparing a plastic packaging material comprises the following steps: (1) Disperse 10 g of nano-titanium dioxide in 120 mL of anhydrous toluene, ultrasonicate for 30 min, add 25 mL of 3-mercaptopropyltrimethoxysilane, continue to introduce nitrogen, stir at room temperature for 2 h, heat to 110 °C and reflux for 4 h, centrifuge the product, wash with toluene and anhydrous ethanol for 3 times, and vacuum dry to obtain mercapto-titanium dioxide; (2) 1200 g of polypropylene resin, 200 g of maleic anhydride grafted polyethylene, 150 g of poly(p-phenylene phthalate) fiber, 120 g of mercaptolated titanium dioxide, 100 g of poly(vinyl alcohol), 30 g of 3-aminopropyltriethoxysilane, 30 g of ethylenebisstearamide and 30 g of tributyl citrate are added to a mixing container according to weight parts, and stirred evenly. The mixed materials are added to a single-screw extruder for melting, extrusion, stranding, cooling, pelletizing and casting to obtain the plastic packaging material.

[0040] The plastic packaging materials prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were tested for performance. The tensile properties were tested with reference to GB / T1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for films and sheets"; the antibacterial properties under light conditions were tested with reference to JIS-Z-2801 "Antibacterial test methods for antibacterial processed products", and the test bacteria were Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 653; the oxygen permeability of the plastic packaging materials was tested at 23°C-0%RH using a MOCON OX-TRAN2 / 21 oxygen permeability tester; the limiting oxygen index was tested with reference to GB / T 2406.1-2008 "Determination of combustion behavior of plastics by oxygen index method Part 1: Guidelines". Specific data are shown in Table 1.

[0041] Table 1 Test results of plastic packaging material performance

[0042] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An antibacterial plastic packaging material, characterized in that: The invention is made of the following components in parts by weight: 90-120 parts of plastic resin, 10-20 parts of maleic anhydride grafted polyethylene, 5-15 parts of polyparabenzamide fiber, 4-12 parts of modified titanium dioxide, 3-10 parts of polyvinyl alcohol, 1-3 parts of coupling agent, 1-3 parts of lubricant and 1-3 parts of plasticizer.

2. The antibacterial plastic packaging material according to claim 1, characterized in that: The preparation method of the modified titanium dioxide comprises the following steps: (1) dispersing nano-titanium dioxide in anhydrous toluene, ultrasonically treating, adding 3-mercaptopropyltrimethoxysilane, continuously introducing nitrogen, stirring at room temperature, heating to reflux for reaction, centrifuging, washing, and drying the product to obtain mercapto-titanium dioxide; (2) dispersing the thiolated titanium dioxide in tetrahydrofuran, ultrasonically treating it, adding 4-vinylbenzeneboronic acid and AIBN, stirring the reaction under a nitrogen atmosphere, centrifuging, washing, and drying the product to obtain boric acid-modified titanium dioxide; (3) Dispersing boric acid-modified titanium dioxide in an ethanol / water mixture, ultrasonically treating it, adding salicylic acid, stirring the reaction, centrifuging the product, washing it with alcohol, and drying it to obtain modified titanium dioxide.

3. The antibacterial plastic packaging material according to claim 2, characterized in that: In step (1), the usage ratio of nano-titanium dioxide, anhydrous toluene and 3-mercaptopropyltrimethoxysilane is 10 g: 80-120 mL: 10-25 mL.

4. The antibacterial plastic packaging material according to claim 2, characterized in that: In step (1), the ultrasonic treatment is performed for 10 to 30 minutes; the stirring time at room temperature is 0.5 to 2 hours; and the heating reflux reaction conditions are heating to 80 to 110° C. and reflux reaction for 4 to 18 hours.

5. The antibacterial plastic packaging material according to claim 2, characterized in that: In step (2), the usage ratio of thiolated titanium dioxide, tetrahydrofuran, 4-vinylbenzeneboronic acid and AIBN is 10 g: 80-120 mL: 8-15 g: 0.5-2 g.

6. The antibacterial plastic packaging material according to claim 2, characterized in that: In step (2), the ultrasonic treatment is performed for 10 to 30 minutes, and the stirring reaction conditions are 50 to 65° C. and the reaction is carried out for 6 to 12 hours.

7. The antibacterial plastic packaging material according to claim 2, characterized in that: In step (3), the volume ratio of anhydrous ethanol to deionized water in the ethanol / water mixture is 6-9:4-1; the dosage ratio of boric acid-modified titanium dioxide, ethanol / water mixture, and salicylic acid is 10 g:80-120 mL:6-12 g.

8. The antibacterial plastic packaging material according to claim 2, characterized in that: In step (3), the ultrasonic treatment is performed for 10 to 30 minutes; and the stirring reaction conditions are 45 to 55° C. and the stirring reaction is performed for 2 to 6 hours.

9. The antibacterial plastic packaging material according to claim 1, characterized in that: The plastic resin is one of polyethylene, polypropylene and polystyrene; the coupling agent is an aminosilane coupling agent; the lubricant is ethylenebisstearamide; and the plasticizer is tributyl citrate.

10. A method for preparing the antibacterial plastic packaging material according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: adding each raw material into a batching container according to weight, stirring evenly, adding the mixed material into a single screw extruder, melting, extruding and drawing, cooling, pelletizing, and performing film blowing or film casting to obtain the antibacterial plastic packaging material.

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