Puncture-resistant high-strength packaging film and preparation method thereof

Abstract

The invention relates to the field of packaging materials, in particular to an anti-puncture high-strength packaging film and a preparation method thereof, and is used for solving the problem that although a traditional packaging film can play a protection role to a certain extent, the anti-puncture performance and the strength are difficult to meet actual requirements. According to the packaging film, linear low-density polyethylene, high-density polyethylene and polypropylene are used as main raw materials for reasonable compounding, the packaging film is endowed with mechanical properties under the synergistic effect of the linear low-density polyethylene, the high-density polyethylene and the polypropylene, and after coating modified glass fibers and modified boron nitride are added into the packaging film, the overall performance of the packaging film can be remarkably improved; an effective enhanced network structure is formed in the packaging film, so that the packaging film can effectively resist puncture and tearing when being subjected to external impact, the safety and integrity of internal articles are kept, and more reliable and lasting protection is provided for various articles; moreover, the preparation method is simple in process, easy to control and suitable for large-scale industrial production.

Description

Technical Field

[0001] The present invention relates to the field of packaging materials, and particularly relates to a puncture-resistant high-strength packaging film and a preparation method thereof. Background Art

[0002] With the development of industrialization and commodity economy in modern society, packaging materials play a crucial role in protecting goods and extending the shelf life. With the continuous improvement of the market's requirements for product packaging quality, although ordinary packaging films have good elasticity, their puncture resistance is poor. In addition, some packaging films have certain puncture resistance but low strength, resulting in the risk that the packaging film is often pierced by sharp objects or easily broken when subjected to large external forces during transportation and storage. Once the packaging film is pierced or broken, the product is easily contaminated and damaged, thus affecting the quality and sales of the product.

[0003] Therefore, it is of great practical significance to develop a puncture-resistant high-strength packaging film and a preparation method thereof. Summary of the Invention

[0004] In order to overcome the above technical problems, the purpose of the present invention is to provide a puncture-resistant high-strength packaging film and a preparation method thereof, which solve the problem that although traditional packaging films can play a protective role to a certain extent, they are difficult to meet the actual requirements in terms of puncture resistance and strength.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A puncture-resistant high-strength packaging film, comprising the following components in parts by weight:

[0007] 90-100 parts of linear low-density polyethylene, 10-15 parts of high-density polyethylene, 3-11 parts of polypropylene, 3-15 parts of coated modified glass fiber, 2-10 parts of modified boron nitride, 1-3 parts of lubricant, 0.5-0.9 part of compatibilizer, and 0.3-0.7 part of antioxidant;

[0008] Among them, the coated modified glass fiber is prepared by the following steps:

[0009] Step a1: Place the glass fiber in a muffle furnace, calcine it at a temperature of 400-450 °C for 30-50 min, then cool it with the furnace, then soak it in absolute ethanol for 2-3 h, then vacuum filter, wash the filter cake with distilled water 3-5 times, and then place it in a vacuum drying oven and dry it at a temperature of 50-55 °C for 1-3 h to obtain pretreated glass fiber;

[0010] Step a2: Add p-phenylenediamine, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and N,N-dimethylformamide into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 10 - 15 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 200 - 300 r / min. Then add deionized water and polyvinylpyrrolidone and continue to stir and react for 1 - 3 h. Then add pretreated glass fiber and continue to stir and react for 1 - 3 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Place the precipitate in a vacuum drying oven and dry it for 2 - 3 h under the condition of a temperature of 90 - 100 °C. Then wash it with distilled water 3 - 5 times. Then place it in a muffle furnace and calcine it for 30 - 50 min under the condition of a temperature of 200 - 250 °C. Then raise the temperature to 300 - 350 °C and calcine it for 30 - 50 min. Then cool it with the furnace to obtain coated and modified glass fiber.

[0011] As a further scheme of the present invention: The dosage ratio of the glass fiber to absolute ethanol in step a1 is 5 g: 60 - 70 mL.

[0012] As a further scheme of the present invention: The glass fiber in step a1 is E7CS10-03-568H glass fiber.

[0013] As a further scheme of the present invention: The dosage ratio of p-phenylenediamine, 3,3',4,4'-biphenyltetracarboxylic dianhydride, N,N-dimethylformamide, deionized water, polyvinylpyrrolidone, and pretreated glass fiber in step a2 is 10 mmol: 11 - 13 mmol: 120 - 130 mL: 150 - 180 mL: 0.2 - 0.3 g: 10 g.

[0014] As a further scheme of the present invention: The polyvinylpyrrolidone in step a2 is polyvinylpyrrolidone K30.

[0015] As a further scheme of the present invention: The modified boron nitride is prepared by the following steps:

[0016] Step b1: Add boron nitride, concentrated sulfuric acid, and concentrated nitric acid into a three-necked flask equipped with a stirrer, a thermometer, and a gas guide tube. Introduce nitrogen for protection. Stir and react for 20 - 30 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 200 - 300 r / min. Then raise the temperature to 80 - 85 °C and continue to stir and react for 20 - 25 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Wash the precipitate with distilled water 3 - 5 times. Then place it in a vacuum drying oven and dry it for 2 - 3 h under the condition of a temperature of 60 - 65 °C to obtain hydroxylated boron nitride;

[0017] Step b2: Add hydroxylated boron nitride, deionized water, and absolute ethanol into a three-necked flask equipped with a stirrer and a thermometer. Ultrasonically disperse for 40 - 60 min under the condition that the ultrasonic frequency is 30 - 40 kHz. Then add a titanate coupling agent and stir and react for 10 - 15 min under the conditions that the temperature is 25 - 30 °C and the stirring rate is 200 - 300 r / min. Then adjust to pH 4 with acetic acid, and then continue to stir and react for 4 - 5 h under the condition that the temperature is raised to 80 - 85 °C. After the reaction ends, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 3 - 5 times, and then place it in a vacuum drying oven and dry for 3 - 5 h under the condition that the temperature is 60 - 65 °C to obtain modified boron nitride.

[0018] As a further scheme of the present invention: The dosage ratio of the boron nitride, concentrated sulfuric acid, and concentrated nitric acid in step b1 is 5 g: 20 - 25 mL: 60 - 70 mL.

[0019] As a further scheme of the present invention: The boron nitride in step b1 is nano hexagonal boron nitride with an average particle size of 500 nm; the mass fraction of the concentrated sulfuric acid is 98.3%; the mass fraction of the concentrated nitric acid is 68%.

[0020] As a further scheme of the present invention: The dosage ratio of the hydroxylated boron nitride, deionized water, absolute ethanol, and titanate coupling agent in step b2 is 5 g: 10 - 15 mL: 80 - 90 mL: 0.6 - 2.2 g.

[0021] As a further scheme of the present invention: The titanate coupling agent in step b2 is titanate coupling agent NDZ - 201.

[0022] As a further scheme of the present invention: A preparation method of a puncture-resistant high-strength packaging film includes the following steps:

[0023] Step 1: Weigh 90 - 100 parts of linear low-density polyethylene, 10 - 15 parts of high-density polyethylene, 3 - 11 parts of polypropylene, 3 - 15 parts of coated modified glass fiber, 2 - 10 parts of modified boron nitride, 1 - 3 parts of lubricant, 0.5 - 0.9 part of compatibilizer, and 0.3 - 0.7 part of antioxidant according to weight parts, and set aside;

[0024] Step 2: Add linear low-density polyethylene, high-density polyethylene, polypropylene, coated modified glass fiber, modified boron nitride, lubricant, compatibilizer, and antioxidant into a mixer, and stir and mix for 20 - 30 min under the conditions that the temperature is 25 - 30 °C and the stirring rate is 800 - 1000 r / min to obtain a uniformly mixed material;

[0025] Step 3: Add the mixed materials into a twin-screw extruder, and melt and extrude them under the conditions of a temperature of 190 - 200 °C and a screw rotation speed of 100 - 150 r / min. After cooling and pelletizing, mixed pellets are obtained;

[0026] Step 4: Add the mixed pellets into a film casting forming machine, and perform casting forming under the conditions of a temperature of 170 - 190 °C, a screw rotation speed of 30 - 50 r / min, and a traction speed of 600 - 70 m / min to obtain a puncture-resistant high-strength packaging film.

[0027] As a further solution of the present invention: The linear low-density polyethylene is DFDA-7042.

[0028] As a further solution of the present invention: The high-density polyethylene is DMDA-8008.

[0029] As a further solution of the present invention: The polypropylene is PP K8003.

[0030] As a further solution of the present invention: The lubricant is calcium stearate.

[0031] As a further solution of the present invention: The compatibilizer is PE-g-MAH.

[0032] As a further solution of the present invention: The antioxidant is antioxidant 1010.

[0033] Advantages of the present invention:

[0034] A puncture-resistant high-strength packaging film and a preparation method thereof according to the present invention, by stirring and mixing linear low-density polyethylene, high-density polyethylene, polypropylene, coated and modified glass fibers, modified boron nitride, a lubricant, a compatibilizer, and an antioxidant to obtain mixed materials, melting and extruding the mixed materials, cooling and pelletizing to obtain mixed pellets, and casting and forming the mixed pellets to obtain a puncture-resistant high-strength packaging film; the packaging film is reasonably compounded with linear low-density polyethylene, high-density polyethylene, and polypropylene as the main raw materials, and the mechanical properties of the packaging film are given under the synergistic effect of the three. After adding coated and modified glass fibers and modified boron nitride thereto, the overall performance of the packaging film can be significantly improved, and an effective reinforcing network structure is formed inside the packaging film, enabling it to effectively resist puncture and tearing when subjected to external impacts, maintaining the safety and integrity of the internal items, thereby providing more reliable and durable protection for various items; moreover, the preparation method has a simple process, is easy to control, and is suitable for large-scale industrial production.

[0035] In the process of preparing an anti-puncture high-strength packaging film, a coated modified glass fiber was first prepared. First, the glass fiber was calcined and soaked and rinsed with absolute ethanol to effectively remove the surface impurities of the glass fiber, obtaining pretreated glass fiber. Then, using p-phenylenediamine and 3,3’,4,4’-biphenyltetracarboxylic dianhydride as raw materials to form a polyimide acid solution, and using the polyimide acid solution to wrap the pretreated glass fiber. After that, heat treatment was carried out for amidation to form a polyimide shell layer outside the pretreated glass fiber, obtaining the coated modified glass fiber; the glass fiber has extremely high strength and modulus, and its own structural characteristics enable it to withstand large external forces without being easily deformed. When a sharp object attempts to pierce the packaging film, the glass fiber can effectively disperse and transfer the external force, preventing the further intrusion of the sharp object, thereby avoiding the rupture of the packaging film caused by local stress concentration. After the wrapping treatment, its dispersibility can be improved, enabling it to form a good interfacial bond with the matrix resin, and enhancing the mechanical properties of the glass fiber, further improving the ability of the packaging film to resist puncture and tearing, thus significantly improving the comprehensive performance of the packaging film.

[0036] In the process of preparing an anti-puncture high-strength packaging film, a modified boron nitride was also prepared. First, boron nitride was treated with concentrated sulfuric acid and concentrated nitric acid to introduce a large number of hydroxyl groups to its surface, obtaining hydroxylated boron nitride. Then, the hydroxylated boron nitride was modified with a titanate coupling agent. After the titanate coupling agent was hydrolyzed, it grafted onto the surface of the hydroxylated boron nitride using the hydroxyl groups on the hydroxylated boron nitride, obtaining the modified boron nitride; boron nitride has a high hardness and relatively small particles, which can fill the voids between the matrix resin and the glass fiber, further enhancing the compactness of the material. When subjected to a puncture force, it can resist the extrusion of sharp objects and play an auxiliary strengthening role, forming a three-dimensional strengthening network structure. This network structure can more effectively disperse and absorb the puncture energy, greatly improving the strength and anti-puncture performance of the packaging film. Specific embodiments

[0037] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0038] Example 1:

[0039] This example is a preparation method of an anti-puncture high-strength packaging film, which is characterized by including the following steps:

[0040] Step S1: Place 5g of E7CS10-03-568H glass fiber in a muffle furnace, calcine it at 400 °C for 30 min, then cool it with the furnace, soak it in 60 mL of absolute ethanol for 2 h, then perform vacuum filtration, wash the filter cake with distilled water 3 times, and then place it in a vacuum drying oven and dry it at 50 °C for 1 h to obtain pretreated glass fiber;

[0041] Step S2: Add 10 mmol of p-phenylenediamine, 11 mmol of 3,3’,4,4’-biphenyltetracarboxylic dianhydride, and 120 mL of N,N-dimethylformamide to a three-necked flask equipped with a stirrer and a thermometer, stir and react at 25 °C and a stirring rate of 200 r / min for 10 min, then add 150 mL of deionized water and 0.2 g of polyvinylpyrrolidone K30 and continue to stir and react for 1 h, then add 10 g of pretreated glass fiber and continue to stir and react for 1 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, place the precipitate in a vacuum drying oven and dry it at 90 °C for 2 h, then wash it with distilled water 3 times, and then place it in a muffle furnace and calcine it at 200 °C for 30 min, then raise the temperature to 300 °C and calcine it for 30 min, and then cool it with the furnace to obtain coated and modified glass fiber;

[0042] Step S3: Add 5 g of nano-hexagonal boron nitride with an average particle size of 500 nm, 20 mL of concentrated sulfuric acid with a mass fraction of 98.3%, and 60 mL of concentrated nitric acid with a mass fraction of 68% to a three-necked flask equipped with a stirrer, a thermometer, and a gas guide tube, introduce nitrogen protection, stir and react at 25 °C and a stirring rate of 200 r / min for 20 min, then raise the temperature to 80 °C and continue to stir and react for 20 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 3 times, and then place it in a vacuum drying oven and dry it at 60 °C for 2 h to obtain hydroxylated boron nitride;

[0043] Step S4: Add 5 g of hydroxylated boron nitride, 10 mL of deionized water, and 80 mL of absolute ethanol to a three-necked flask equipped with a stirrer and a thermometer, ultrasonically disperse it at an ultrasonic frequency of 30 kHz for 40 min, then add 0.6 g of titanate coupling agent NDZ-201 and stir and react at 25 °C and a stirring rate of 200 r / min for 10 min, then adjust the pH to 4 with acetic acid, then raise the temperature to 80 °C and continue to stir and react for 4 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 3 times, and then place it in a vacuum drying oven and dry it at 60 °C for 3 h to obtain modified boron nitride;

[0044] Step S5: Weigh 90 parts by weight of linear low density polyethylene, 10 parts of high density polyethylene, 3 parts of polypropylene, 3 parts of coated modified glass fiber, 2 parts of modified boron nitride, 1 part of lubricant, 0.5 part of compatibilizer and 0.3 part of antioxidant, and set aside; wherein, the linear low density polyethylene is DFDA-7042; the high density polyethylene is DMDA-8008; the polypropylene is PP K8003; the lubricant is calcium stearate; the compatibilizer is PE-g-MAH; the antioxidant is antioxidant 1010;

[0045] Step S6: Add the linear low density polyethylene, high density polyethylene, polypropylene, coated modified glass fiber, modified boron nitride, lubricant, compatibilizer and antioxidant into a mixer, and stir and mix for 20 min under the conditions of a temperature of 25°C and a stirring rate of 800 r / min to obtain a uniformly mixed material;

[0046] Step S7: Add the uniformly mixed material into a twin-screw extruder, and melt and extrude under the conditions of a temperature of 190°C and a screw speed of 100 r / min, and obtain mixed pellets after cooling and pelletizing;

[0047] Step S8: Add the mixed pellets into a film casting forming machine, and perform film casting forming under the conditions of a temperature of 170°C, a screw speed of 30 r / min and a traction speed of 60 m / min to obtain a puncture-resistant high-strength packaging film with a thickness of 60 μm.

[0048] Example 2:

[0049] The preparation method of a puncture-resistant high-strength packaging film in this example is characterized by including the following steps:

[0050] Step S1: Place 5 g of E7CS10-03-568H glass fiber in a muffle furnace, calcine it for 40 min under the condition of a temperature of 425°C, then cool it with the furnace, then soak it in 65 mL of absolute ethanol for 2.5 h, then perform vacuum filtration, wash the filter cake 4 times with distilled water, and then place it in a vacuum drying oven and dry it for 2 h under the condition of a temperature of 52°C to obtain pretreated glass fiber;

[0051] Step S2: Add 10 mmol of p-phenylenediamine, 12 mmol of 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 125 mL of N,N-dimethylformamide into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 12 min under the conditions of a temperature of 28 °C and a stirring rate of 250 r / min. Then add 165 mL of deionized water and 0.25 g of polyvinylpyrrolidone K30 and continue to stir and react for 2 h. Then add 10 g of pretreated glass fiber and continue to stir and react for 2 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, place the precipitate in a vacuum drying oven, dry it for 2.5 h under the condition of a temperature of 95 °C, then wash it 4 times with distilled water, then place it in a muffle furnace, calcine it for 40 min under the condition of a temperature of 225 °C, then raise the temperature to 325 °C and calcine it for 40 min, and then cool it with the furnace to obtain coated and modified glass fiber;

[0052] Step S3: Add 5 g of nano-hexagonal boron nitride with an average particle size of 500 nm, 22 mL of concentrated sulfuric acid with a mass fraction of 98.3%, and 65 mL of concentrated nitric acid with a mass fraction of 68% into a three-necked flask equipped with a stirrer, a thermometer, and a gas guide tube. Pass in nitrogen for protection and stir and react for 25 min under the conditions of a temperature of 28 °C and a stirring rate of 250 r / min. Then raise the temperature to 82 °C and continue to stir and react for 22 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate 4 times with distilled water, then place it in a vacuum drying oven, and dry it for 2.5 h under the condition of a temperature of 62 °C to obtain hydroxylated boron nitride;

[0053] Step S4: Add 5 g of hydroxylated boron nitride, 12 mL of deionized water, and 85 mL of absolute ethanol into a three-necked flask equipped with a stirrer and a thermometer. Ultrasonically disperse for 50 min under the condition of an ultrasonic frequency of 35 kHz. Then add 1.4 g of titanate coupling agent NDZ-201 and stir and react for 12 min under the conditions of a temperature of 28 °C and a stirring rate of 250 r / min. Then adjust the pH to 4 with acetic acid, then raise the temperature to 82 °C and continue to stir and react for 4.5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate 4 times with distilled water, then place it in a vacuum drying oven, and dry it for 4 h under the condition of a temperature of 62 °C to obtain modified boron nitride;

[0054] Step S5: Weigh 95 parts by weight of linear low density polyethylene, 12 parts of high density polyethylene, 7 parts of polypropylene, 9 parts of coated modified glass fiber, 6 parts of modified boron nitride, 2 parts of lubricant, 0.7 part of compatibilizer and 0.5 part of antioxidant, and set aside; among them, the linear low density polyethylene is DFDA-7042; the high density polyethylene is DMDA-8008; the polypropylene is PP K8003; the lubricant is calcium stearate; the compatibilizer is PE-g-MAH; the antioxidant is antioxidant 1010;

[0055] Step S6: Add the linear low density polyethylene, high density polyethylene, polypropylene, coated modified glass fiber, modified boron nitride, lubricant, compatibilizer and antioxidant into a mixer, and stir and mix for 25 min under the conditions of a temperature of 28°C and a stirring rate of 900 r / min to obtain a uniformly mixed material;

[0056] Step S7: Add the uniformly mixed material into a twin-screw extruder, and melt and extrude it under the conditions of a temperature of 195°C and a screw rotation speed of 125 r / min, and obtain mixed pellets after cooling and pelletizing;

[0057] Step S8: Add the mixed pellets into a film casting forming machine, and perform film casting forming under the conditions of a temperature of 180°C, a screw rotation speed of 40 r / min and a traction speed of 65 m / min to obtain a puncture-resistant high-strength packaging film with a thickness of 60 μm.

[0058] Example 3:

[0059] This example is a preparation method of a puncture-resistant high-strength packaging film, which is characterized by including the following steps:

[0060] Step S1: Place 5 g of E7CS10-03-568H glass fiber in a muffle furnace, calcine it for 50 min at a temperature of 450°C, then cool it with the furnace, then soak it in 70 mL of absolute ethanol for 3 h, then perform vacuum filtration, wash the filter cake 5 times with distilled water, and then place it in a vacuum drying oven and dry it for 3 h at a temperature of 55°C to obtain pretreated glass fiber;

[0061] Step S2: Add 10 mmol of p-phenylenediamine, 13 mmol of 3,3’,4,4’-biphenyltetracarboxylic dianhydride, and 130 mL of N,N-dimethylformamide into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 15 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then add 180 mL of deionized water and 0.3 g of polyvinylpyrrolidone K30 and continue to stir and react for 3 h. Then add 10 g of pretreated glass fiber and continue to stir and react for 3 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Place the precipitate in a vacuum drying oven and dry it at a temperature of 100 °C for 3 h. Then wash it 5 times with distilled water. Then place it in a muffle furnace and calcine it at a temperature of 250 °C for 50 min. Then raise the temperature to 350 °C and calcine it for 50 min. Then cool it with the furnace to obtain coated and modified glass fiber;

[0062] Step S3: Add 5 g of nano-hexagonal boron nitride with an average particle size of 500 nm, 25 mL of concentrated sulfuric acid with a mass fraction of 98.3%, and 70 mL of concentrated nitric acid with a mass fraction of 68% into a three-necked flask equipped with a stirrer, a thermometer, and a gas guide tube. Introduce nitrogen for protection. Stir and react for 30 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then raise the temperature to 85 °C and continue to stir and react for 25 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Wash the precipitate 5 times with distilled water. Then place it in a vacuum drying oven and dry it at a temperature of 65 °C for 3 h to obtain hydroxylated boron nitride;

[0063] Step S4: Add 5 g of hydroxylated boron nitride, 15 mL of deionized water, and 90 mL of absolute ethanol into a three-necked flask equipped with a stirrer and a thermometer. Ultrasonically disperse for 60 min under the condition of an ultrasonic frequency of 40 kHz. Then add 2.2 g of titanate coupling agent NDZ-201 and stir and react for 15 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then adjust the pH to 4 with acetic acid. Then raise the temperature to 85 °C and continue to stir and react for 5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Wash the precipitate 5 times with distilled water. Then place it in a vacuum drying oven and dry it at a temperature of 65 °C for 5 h to obtain modified boron nitride;

[0064] Step S5: Weigh 100 parts of linear low-density polyethylene, 15 parts of high-density polyethylene, 11 parts of polypropylene, 15 parts of coated modified glass fiber, 10 parts of modified boron nitride, 3 parts of lubricant, 0.9 part of compatibilizer, and 0.7 part of antioxidant by weight, and set aside; among them, the linear low-density polyethylene is DFDA-7042; the high-density polyethylene is DMDA-8008; the polypropylene is PP K8003; the lubricant is calcium stearate; the compatibilizer is PE-g-MAH; the antioxidant is antioxidant 1010;

[0065] Step S6: Add linear low-density polyethylene, high-density polyethylene, polypropylene, coated modified glass fiber, modified boron nitride, lubricant, compatibilizer, and antioxidant to a mixer, and stir and mix for 30 min under the conditions of a temperature of 30°C and a stirring rate of 1000 r / min to obtain a uniformly mixed material;

[0066] Step S7: Add the uniformly mixed material to a twin-screw extruder, and melt and extrude under the conditions of a temperature of 200°C and a screw speed of 150 r / min, and obtain mixed pellets after cooling and pelletizing;

[0067] Step S8: Add the mixed pellets to a film casting forming machine, and perform casting forming under the conditions of a temperature of 190°C, a screw speed of 50 r / min, and a traction speed of 70 m / min to obtain a puncture-resistant high-strength packaging film with a thickness of 60 μm.

[0068] Comparative Example 1:

[0069] A preparation method of a puncture-resistant high-strength packaging film in this comparative example is characterized by including the following steps:

[0070] Step S1: Weigh 100 parts of linear low-density polyethylene, 15 parts of high-density polyethylene, 11 parts of polypropylene, 3 parts of lubricant, 0.9 part of compatibilizer, and 0.7 part of antioxidant by weight, and set aside; among them, the linear low-density polyethylene is DFDA-7042; the high-density polyethylene is DMDA-8008; the polypropylene is PP K8003; the lubricant is calcium stearate; the compatibilizer is PE-g-MAH; the antioxidant is antioxidant 1010;

[0071] Step S2: Add linear low-density polyethylene, high-density polyethylene, polypropylene, lubricant, compatibilizer, and antioxidant to a mixer, and stir and mix for 30 min under the conditions of a temperature of 30°C and a stirring rate of 1000 r / min to obtain a uniformly mixed material;

[0072] Step S3: Add the mixed and homogenized material into a twin-screw extruder, and melt and extrude it under the conditions of a temperature of 200 °C and a screw speed of 150 r / min. After cooling and pelletizing, obtain the mixed pellets;

[0073] Step S4: Add the mixed pellets into a film casting forming machine, and perform casting forming under the conditions of a temperature of 190 °C, a screw speed of 50 r / min, and a traction speed of 70 m / min to obtain a puncture-resistant high-strength packaging film with a thickness of 60 μm.

[0074] Comparative Example 2:

[0075] This comparative example is a method for preparing a puncture-resistant high-strength packaging film, which is characterized by including the following steps:

[0076] Step S1: Place 5 g of E7CS10-03-568H glass fiber in a muffle furnace, calcine it for 50 min under the condition of a temperature of 450 °C, then cool it with the furnace, then soak it in 70 mL of absolute ethanol for 3 h, then perform vacuum filtration, wash the filter cake 5 times with distilled water, then place it in a vacuum drying oven, and dry it for 3 h under the condition of a temperature of 55 °C to obtain pretreated glass fiber;

[0077] Step S2: Add 10 mmol of p-phenylenediamine, 13 mmol of 3,3’,4,4’-biphenyltetracarboxylic dianhydride, and 130 mL of N,N-dimethylformamide into a three-necked flask equipped with a stirrer and a thermometer, stir and react for 15 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min, then add 180 mL of deionized water and 0.3 g of polyvinylpyrrolidone K30 and continue to stir and react for 3 h, then add 10 g of pretreated glass fiber and continue to stir and react for 3 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, place the precipitate in a vacuum drying oven, dry it for 3 h under the condition of a temperature of 100 °C, then wash it 5 times with distilled water, then place it in a muffle furnace, calcine it for 50 min under the condition of a temperature of 250 °C, then raise the temperature to 350 °C and calcine it for 50 min, and then cool it with the furnace to obtain coated and modified glass fiber;

[0078] Step S3: Weigh 100 parts of linear low-density polyethylene, 15 parts of high-density polyethylene, 11 parts of polypropylene, 15 parts of coated and modified glass fiber, 3 parts of lubricant, 0.9 part of compatibilizer, and 0.7 part of antioxidant by weight for standby; wherein, the linear low-density polyethylene is DFDA-7042; the high-density polyethylene is DMDA-8008; the polypropylene is PP K8003; the lubricant is calcium stearate; the compatibilizer is PE-g-MAH; the antioxidant is antioxidant 1010;

[0079] Step S4: Add linear low-density polyethylene, high-density polyethylene, polypropylene, coated and modified glass fiber, lubricant, compatibilizer, and antioxidant into a mixer, and stir and mix for 30 min under the conditions of a temperature of 30°C and a stirring rate of 1000 r / min to obtain a uniformly mixed material;

[0080] Step S5: Add the uniformly mixed material into a twin-screw extruder, melt and extrude under the conditions of a temperature of 200°C and a screw rotation speed of 150 r / min, and obtain mixed pellets through cooling and pelletizing;

[0081] Step S6: Add the mixed pellets into a film casting forming machine, and perform casting forming under the conditions of a temperature of 190°C, a screw rotation speed of 50 r / min, and a traction speed of 70 m / min to obtain a puncture-resistant high-strength packaging film with a thickness of 60 μm.

[0082] Comparative Example 3:

[0083] This comparative example is a preparation method of a puncture-resistant high-strength packaging film, which is characterized by including the following steps:

[0084] Step S1: Add 5 g of nano-hexagonal boron nitride with an average particle size of 500 nm, 25 mL of concentrated sulfuric acid with a mass fraction of 98.3%, and 70 mL of concentrated nitric acid with a mass fraction of 68% into a three-necked flask equipped with a stirrer, a thermometer, and a gas guide tube, introduce nitrogen for protection, stir and react for 30 min under the conditions of a temperature of 30°C and a stirring rate of 300 r / min, then raise the temperature to 85°C and continue to stir and react for 25 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 5 times, and then place it in a vacuum drying oven and dry it at a temperature of 65°C for 3 h to obtain hydroxylated boron nitride;

[0085] Step S2: Add 5 g of hydroxylated boron nitride, 15 mL of deionized water, and 90 mL of absolute ethanol into a three-necked flask equipped with a stirrer and a thermometer, ultrasonically disperse for 60 min under the condition of an ultrasonic frequency of 40 kHz, then add 2.2 g of titanate coupling agent NDZ-201 and stir and react for 15 min under the conditions of a temperature of 30°C and a stirring rate of 300 r / min, then adjust to pH 4 with acetic acid, then raise the temperature to 85°C and continue to stir and react for 5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 5 times, and then place it in a vacuum drying oven and dry it at a temperature of 65°C for 5 h to obtain modified boron nitride;

[0086] Step S3: Weigh 100 parts of linear low density polyethylene, 15 parts of high density polyethylene, 11 parts of polypropylene, 10 parts of modified boron nitride, 3 parts of lubricant, 0.9 part of compatibilizer and 0.7 part of antioxidant by weight, and set aside; among them, the linear low density polyethylene is DFDA-7042; the high density polyethylene is DMDA-8008; the polypropylene is PP K8003; the lubricant is calcium stearate; the compatibilizer is PE-g-MAH; the antioxidant is antioxidant 1010;

[0087] Step S4: Add linear low density polyethylene, high density polyethylene, polypropylene, modified boron nitride, lubricant, compatibilizer and antioxidant into a mixer, and stir and mix for 30 min under the conditions of a temperature of 30 °C and a stirring rate of 1000 r / min to obtain a uniformly mixed material;

[0088] Step S5: Add the uniformly mixed material into a twin-screw extruder, and melt and extrude under the conditions of a temperature of 200 °C and a screw speed of 150 r / min, and obtain mixed pellets after cooling and pelletizing;

[0089] Step S6: Add the mixed pellets into a film casting forming machine, and perform casting forming under the conditions of a temperature of 190 °C, a screw speed of 50 r / min and a traction speed of 70 m / min to obtain a puncture-resistant high-strength packaging film with a thickness of 60 μm.

[0090] Comparative Example 4:

[0091] This comparative example is a preparation method of a puncture-resistant high-strength packaging film, which is characterized by including the following steps:

[0092] Step S1: Weigh 100 parts of linear low density polyethylene, 15 parts of high density polyethylene, 11 parts of polypropylene, 15 parts of E7CS10-03-568H glass fiber, 10 parts of nano-hexagonal boron nitride with an average particle size of 500 nm, 3 parts of lubricant, 0.9 part of compatibilizer and 0.7 part of antioxidant by weight, and set aside; among them, the linear low density polyethylene is DFDA-7042; the high density polyethylene is DMDA-8008; the polypropylene is PP K8003; the lubricant is calcium stearate; the compatibilizer is PE-g-MAH; the antioxidant is antioxidant 1010;

[0093] Step S2: Add linear low density polyethylene, high density polyethylene, polypropylene, E7CS10-03-568H glass fiber, nano-hexagonal boron nitride with an average particle size of 500 nm, lubricant, compatibilizer and antioxidant into a mixer, and stir and mix for 30 min under the conditions of a temperature of 30 °C and a stirring rate of 1000 r / min to obtain a uniformly mixed material;

[0094] Step S3: Add the uniformly mixed materials into a twin-screw extruder, and melt and extrude them under the conditions of a temperature of 200°C and a screw speed of 150 r / min. After cooling and pelletizing, mixed pellets are obtained;

[0095] Step S4: Add the mixed pellets into a film casting forming machine, and perform casting forming under the conditions of a temperature of 190°C, a screw speed of 50 r / min, and a traction speed of 70 m / min to obtain a puncture-resistant high-strength packaging film with a thickness of 60 μm.

[0096] Measure the transverse tensile strength of the puncture-resistant high-strength packaging films of Examples 1-3 and Comparative Examples 1-4 according to GB / T 528-2009, measure the transverse tear strength of the packaging films according to QB / T 1130-91, and measure the puncture strength of the packaging films according to GB / T 37841-2019. The test results are shown in the following table:

[0097] Sample Transverse tensile strength, MPa Transverse tear strength, N / mm Puncture strength, N / mm Example 1 22.1 158.2 421.6 Example 2 23.3 164.8 432.9 Example 3 24.6 170.5 445.1 Comparative Example 1 16.9 72.1 254.5 Comparative Example 2 19.0 129.7 343.9 Comparative Example 3 18.8 120.2 321.8 Comparative Example 4 20.6 147.3 396.1

[0098] Referring to the data in the above table, according to the comparison between Examples 1-3 and Comparative Examples 1-4, it can be known that adding coated modified glass fibers and modified boron nitride to the packaging film can significantly improve its mechanical strength and puncture resistance.

[0099] In the description of this specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0100] The above content is only an example and illustration of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the invention or exceed the scope defined by this application, they should all fall within the protection scope of the present invention.

Claims

1. A puncture-resistant high-strength packaging film, characterized in that, Comprising the following components in parts by weight: 90 - 100 parts of linear low - density polyethylene, 10 - 15 parts of high - density polyethylene, 3 - 11 parts of polypropylene, 3 - 15 parts of coated modified glass fiber, 2 - 10 parts of modified boron nitride, 1 - 3 parts of lubricant, 0.5 - 0.9 part of compatibilizer, and 0.3 - 0.7 part of antioxidant; Among them, the coated modified glass fiber is prepared by the following steps: Step a1: Calcinate the glass fiber, then cool it in the furnace, then soak it in absolute ethanol, then carry out vacuum filtration, wash and dry the filter cake to obtain pretreated glass fiber; Step a2: Stir and react p - phenylenediamine, 3,3’,4,4’ - biphenyltetracarboxylic dianhydride and N,N - dimethylformamide, then add deionized water, polyvinylpyrrolidone and pretreated glass fiber and continue to stir and react. After the reaction is completed, cool the reaction product, then centrifuge, dry the precipitate, then wash, calcinate, and then cool it in the furnace to obtain coated modified glass fiber.

2. The anti-puncture high-strength packaging film according to claim 1, wherein The dosage ratio of the glass fiber to absolute ethanol in step a1 is 5g:60 - 70mL.

3. The puncture-resistant high-strength packaging film according to claim 1, characterized in that The dosage ratio of p - phenylenediamine, 3,3’,4,4’ - biphenyltetracarboxylic dianhydride, N,N - dimethylformamide, deionized water, polyvinylpyrrolidone and pretreated glass fiber in step a2 is 10mmol:11 - 13mmol:120 - 130mL:150 - 180mL:0.2 - 0.3g:10g.

4. The puncture-resistant high-strength packaging film according to claim 1, wherein The modified boron nitride is prepared by the following steps: Step b1: Stir and react boron nitride, concentrated sulfuric acid and concentrated nitric acid. After the reaction is completed, cool the reaction product, then centrifuge, wash and dry the precipitate to obtain hydroxylated boron nitride; Step b2: Ultrasonically disperse hydroxylated boron nitride, deionized water and absolute ethanol, then add titanate coupling agent and stir and react, then adjust the pH with acetic acid, then continue to stir and react. After the reaction is completed, cool the reaction product, then centrifuge, wash and dry the precipitate to obtain modified boron nitride.

5. The puncture-resistant high-strength packaging film according to claim 4, characterized in that, The dosage ratio of boron nitride, concentrated sulfuric acid and concentrated nitric acid in step b1 is 5g:20 - 25mL:60 - 70mL.

6. The anti-puncture high-strength packaging film according to claim 4, wherein The mass fraction of the concentrated sulfuric acid in step b1 is 98.3%; the mass fraction of the concentrated nitric acid is 68%.

7. The puncture-resistant high-strength packaging film according to claim 4, wherein The dosage ratio of hydroxylated boron nitride, deionized water, absolute ethanol and titanate coupling agent in step b2 is 5g:10 - 15mL:80 - 90mL:0.6 - 2.2g.

8. A preparation method of a puncture-resistant high-strength packaging film, characterized in that, Comprising the following steps: Step one: Weigh 90 - 100 parts of linear low - density polyethylene, 10 - 15 parts of high - density polyethylene, 3 - 11 parts of polypropylene, 3 - 15 parts of coated modified glass fiber, 2 - 10 parts of modified boron nitride, 1 - 3 parts of lubricant, 0.5 - 0.9 part of compatibilizer, and 0.3 - 0.7 part of antioxidant in parts by weight and set aside; Step 2: Add linear low density polyethylene, high density polyethylene, polypropylene, coated modified glass fiber, modified boron nitride, lubricant, compatibilizer and antioxidant into a mixer, and stir and mix for 20 - 30 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 800 - 1000 r / min to obtain a uniformly mixed material; Step 3: Add the uniformly mixed material into a twin-screw extruder, and melt and extrude under the conditions of a temperature of 190 - 200 °C and a screw rotation speed of 100 - 150 r / min, and obtain mixed pellets after cooling and pelletizing; Step 4: Add the mixed pellets into a film casting forming machine, and perform film casting forming under the conditions of a temperature of 170 - 190 °C, a screw rotation speed of 30 - 50 r / min and a traction speed of 600 - 70 m / min to obtain a puncture-resistant high-strength packaging film.

9. The preparation method of a puncture-resistant high-strength packaging film according to claim 8, wherein, The linear low density polyethylene is DFDA-7042; The high density polyethylene is DMDA-8008; The polypropylene is PP K8003; The lubricant is calcium stearate; The compatibilizer is PE-g-MAH; The antioxidant is antioxidant 1010.