Tear-resistant low-temperature-resistant PE plastic film and preparation method thereof

Abstract

The invention relates to the field of plastic films, in particular to a tear-resistant low-temperature-resistant PE (polyethylene) plastic film and a preparation method thereof, and aims to solve the problem that the application of a traditional PE film in an extreme environment is limited due to the fact that the traditional PE film has remarkable defects in the aspects of tear resistance and low-temperature resistance. The PE plastic film takes modified polyethylene as a main raw material, and the modified polyethylene is obtained by modifying polyethylene, so that the flexibility and toughness of the polyethylene are improved, the PE plastic film can effectively absorb and disperse stress when being stressed, the generation and development of cracks are reduced, and further the tear resistance of the PE plastic film is effectively improved; the modified carbon fibers are added into the PE plastic film, so that the strength and the impact resistance of the PE plastic film can be improved, and the PE plastic film can still keep good and stable mechanical properties in a low-temperature environment.

Description

Technical Field

[0001] This invention relates to the field of plastic films, specifically to a tear-resistant and low-temperature resistant PE plastic film and its preparation method. Background Technology

[0002] Polyethylene (PE) plastic film is widely used in packaging, agriculture, and other fields due to its excellent processing performance, good chemical stability, and low cost. In the packaging industry, PE film is widely used as packaging material for food, pharmaceuticals, and daily necessities. Its lightweight properties and barrier properties effectively extend product shelf life and reduce transportation costs. However, traditional PE film has significant shortcomings in tear resistance and low-temperature resistance. It easily becomes brittle and loses flexibility at low temperatures, resulting in a significant deterioration in impact and tear strength, which limits its application in extreme environments.

[0003] Therefore, developing a tear-resistant and low-temperature resistant PE plastic film and its preparation method is of great significance. Summary of the Invention

[0004] In order to overcome the above-mentioned technical problems, the purpose of this invention is to provide a tear-resistant and low-temperature resistant PE plastic film and its preparation method, which solves the problem that traditional PE films have significant deficiencies in tear resistance and low-temperature resistance, thus limiting their application in extreme environments.

[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a tear-resistant and low-temperature resistant PE plastic film, comprising the following components in parts by weight: The mixture contains 80-90 parts modified polyethylene, 0.8-4.6 parts modified carbon fiber, 0.5-2.5 parts lubricant, 0.3-0.9 parts antioxidant, and 0.3-0.5 parts light stabilizer. The modified polyethylene is prepared by the following steps: Polyethylene, OP-10 emulsifier, deionized water, and toluene were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 20-25°C and 200-300 r / min for 10-20 min. Then, the temperature was raised to 70-75°C and the mixture was stirred for another 30-40 min. After that, isooctyl methacrylate, triallyl cyanurate, and benzoyl peroxide were added, and the temperature was raised to 80-90°C and the mixture was stirred for another 2-4 h. After the reaction was completed, the product was cooled to room temperature and then vacuum filtered. The filter cake was washed 2-3 times with acetone and then placed in a vacuum drying oven and dried at 50-60°C for 2-3 h to obtain modified polyethylene.

[0006] In a preferred embodiment of the present invention, the ratio of polyethylene, OP-10 emulsifier, deionized water, toluene, isooctyl methacrylate, triallyl cyanurate, and benzoyl peroxide is 10g:0.03-0.05g:30-40mL:70-80mL:1-11g:0.8-2.6g:0.2-0.4g. In a preferred embodiment of the present invention, the polyethylene is LLDPE 2045G.

[0007] In a preferred embodiment of the present invention, the modified carbon fiber is prepared by the following steps: Step s1: Add carbon fiber and acetone to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection. Stir and react for 10-20 min at a temperature of 20-25℃ and a stirring rate of 200-300 r / min. Then raise the temperature to 60-70℃ and continue stirring for 2-4 h. After the reaction is complete, cool the reaction product to room temperature and then filter under vacuum. Wash the filter cake 2-3 times with ethanol and deionized water. Then place it in a vacuum drying oven and dry at a temperature of 80-90℃ for 2-3 h to obtain pretreated carbon fiber. Step s2: Add the pretreated carbon fiber and deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection. Stir and react for 20-30 min at a temperature of 10-15℃ and a stirring rate of 200-300 r / min. Then adjust the pH to 8.5-9 with sodium hydroxide solution. Then raise the temperature to 40-45℃ and add tris(hydroxymethyl)aminomethane hydrochloride and dopamine hydrochloride. Continue stirring and react for 5-6 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Wash the precipitate 2-3 times with distilled water. Then place it in a vacuum drying oven and dry at a temperature of 70-80℃ for 2-3 h to obtain pre-modified carbon fiber. Step s3: Add silane coupling agent KH560, acetic acid, anhydrous ethanol, and deionized water to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir at 20-25℃ and 200-300 r / min for 30-40 min. Then add pre-modified carbon fiber and continue stirring at 60-70℃ for 1-2 h. Then raise the temperature to 80-90℃ and continue stirring for 3-5 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, wash the precipitate 2-3 times with distilled water, and then place it in a vacuum drying oven and dry at 70-80℃ for 2-3 h to obtain modified carbon fiber.

[0008] In a preferred embodiment of the present invention, the ratio of carbon fiber to acetone in step s1 is 2g:25-30mL.

[0009] In a preferred embodiment of the present invention, the carbon fiber in step s1 is T700 carbon fiber with an average length of 5 mm.

[0010] In a preferred embodiment of the present invention, the ratio of the amount of pretreated carbon fiber, deionized water, tris(hydroxymethyl)aminomethane hydrochloride and dopamine hydrochloride in step s2 is 3g:70-80mL:0.9-1.1g:0.2-0.3g.

[0011] In a preferred embodiment of the present invention, the sodium hydroxide solution in step s2 has a mass fraction of 20-30%.

[0012] In a preferred embodiment of the present invention, the ratio of the amount of silane coupling agent KH560, acetic acid, anhydrous ethanol and deionized water in step s3 is 1-5 mL: 1-2 mL: 80-90 mL: 10-15 mL.

[0013] As a preferred embodiment of the present invention, a method for preparing a tear-resistant and low-temperature resistant PE plastic film includes the following steps: Step 1: Weigh out 80-90 parts of modified polyethylene, 0.8-4.6 parts of modified carbon fiber, 0.5-2.5 parts of lubricant, 0.3-0.9 parts of antioxidant, and 0.3-0.5 parts of light stabilizer according to the weight ratio, and set aside. Step 2: Add modified polyethylene, modified carbon fiber, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 20-30 minutes at a temperature of 70-80℃ and a stirring speed of 800-1200r / min to obtain a mixture. Step 3: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 100-200r / min. Then blow-mold the mixture using a blown film extruder to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0014] Secondly, this application provides that the lubricant is calcium stearate.

[0015] Secondly, this application provides that the antioxidant is antioxidant 1010.

[0016] Secondly, this application provides that the light stabilizer is light stabilizer 119.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a tear-resistant and low-temperature resistant PE plastic film and its preparation method. Modified polyethylene, modified carbon fiber, lubricant, antioxidant, and light stabilizer are stirred and mixed to obtain a mixture. The mixture is then melt-blended and blown into shape using a blown film machine to obtain a tear-resistant and low-temperature resistant PE plastic film. This PE plastic film uses modified polyethylene as the main raw material. Modified polyethylene is derived from polyethylene, which improves the flexibility and toughness of polyethylene. This allows the PE plastic film to effectively absorb and disperse stress under load, reducing the generation and development of cracks, thereby effectively improving the tear resistance and low-temperature resistance of the PE plastic film. Modified carbon fiber is then added, effectively playing a reinforcing role, increasing the strength and impact resistance of the PE plastic film, further improving its ability to maintain good and stable mechanical properties even at low temperatures.

[0018] In the preparation of tear-resistant and low-temperature resistant PE plastic film, a modified polyethylene was first prepared. This involved grafting isooctyl methacrylate and triallyl cyanurate onto polyethylene under the initiation of benzoyl peroxide. Isooctyl methacrylate provided flexible long carbon chains, and triallyl cyanurate provided multiple alkenyl groups to construct a rich cross-linked network structure, resulting in the modified polyethylene. The introduced long carbon chains on this modified polyethylene can insert into the polyethylene molecular chains, forming a "lubricating" effect that reduces the frictional resistance between molecular chains, thereby improving the flexibility and low-temperature resistance of the PE plastic film. The introduced cross-linked network structure can effectively transfer and disperse stress, significantly improving the tear resistance of the PE plastic film.

[0019] In the process of preparing tear-resistant and low-temperature resistant PE plastic film, a modified carbon fiber was also prepared. Acetone was used to remove impurities from the carbon fiber surface to obtain pretreated carbon fiber. Polydopamine was then used to coat the pretreated carbon fiber to obtain pre-modified carbon fiber. The pre-modified carbon fiber was then modified using a silane coupling agent, KH560. The silanol formed after the hydrolysis of KH560 reacts with the hydroxyl and imino groups on the pre-modified carbon fiber in conjunction with the epoxy groups, simultaneously introducing a large amount of silanol and epoxy groups to obtain modified carbon fiber. Through its high specific strength and rigidity, the carbon fiber can effectively bear and transmit externally applied loads, thereby significantly improving the overall strength of the PE plastic film. After modification, it can be uniformly dispersed in the PE plastic film, and the silanol and epoxy groups are used to achieve chemical bonding, significantly improving the interfacial bonding force of the modified carbon fiber, thus fully exerting its reinforcing effect and greatly improving the tear resistance of the PE plastic film. Attached Figure Description

[0020] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram showing the performance test results of the tear-resistant and low-temperature resistant PE plastic film of the present invention. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1: This embodiment describes a method for preparing a tear-resistant and low-temperature resistant PE plastic film, comprising the following steps: Step S1: Add 10g of LLDPE 2045G, 0.03g of OP-10 emulsifier, 30mL of deionized water, and 70mL of toluene to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir at 20℃ and 200r / min for 10min. Then, raise the temperature to 70℃ and continue stirring for 30min. After that, add 1g of isooctyl methacrylate, 0.8g of triallyl cyanurate, and 0.2g of benzoyl peroxide and raise the temperature to 80℃ and continue stirring for 2h. After the reaction is complete, cool the reaction product to room temperature, then vacuum filter. Wash the filter cake twice with acetone and then place it in a vacuum drying oven and dry at 50℃ for 2h to obtain modified polyethylene. Step S2: Add 2g of T700 carbon fiber with an average length of 5mm and 25mL of acetone to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 20℃ and 200r / min for 10min. Then raise the temperature to 60℃ and continue stirring for 2h. After the reaction is completed, cool the reaction product to room temperature and then filter under vacuum. Wash the filter cake twice with ethanol and deionized water, and then place it in a vacuum drying oven and dry at 80℃ for 2h to obtain pretreated carbon fiber. Step S3: Add 3g of pretreated carbon fiber and 70mL of deionized water to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir for 20min at 10℃ and 200r / min. Then adjust the pH to 8.5 with 20% sodium hydroxide solution. Then raise the temperature to 40℃ and add 0.9g of tris(hydroxymethyl)aminomethane hydrochloride and 0.2g of dopamine hydrochloride. Continue stirring for 5h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, wash the precipitate twice with distilled water, and then place it in a vacuum drying oven and dry at 70℃ for 2h to obtain pre-modified carbon fiber. Step S4: Add 1 mL of silane coupling agent KH560, 1 mL of acetic acid, 80 mL of anhydrous ethanol and 10 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 20°C and 200 r / min for 30 min. Then add pre-modified carbon fiber and continue stirring at 60°C for 1 h. Then stir at 80°C for 3 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, wash the precipitate twice with distilled water, and then place it in a vacuum drying oven and dry at 70°C for 2 h to obtain modified carbon fiber. Step S5: Weigh out 80 parts of modified polyethylene, 0.8 parts of modified carbon fiber, 0.5 parts of lubricant, 0.3 parts of antioxidant, and 0.3 parts of light stabilizer according to the following weight proportions, and set aside for later use; the lubricant is calcium stearate; the antioxidant is antioxidant 1010; and the light stabilizer is light stabilizer 119. Step S6: Add modified polyethylene, modified carbon fiber, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 20 minutes at a temperature of 70℃ and a stirring speed of 800r / min to obtain a mixture; Step S7: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 100r / min. Then blow-mold the mixture using a blown film extruder to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0024] Example 2: This embodiment describes a method for preparing a tear-resistant and low-temperature resistant PE plastic film, comprising the following steps: Step S1: Add 10g of LLDPE 2045G, 0.04g of OP-10 emulsifier, 35mL of deionized water, and 75mL of toluene to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir at 22℃ and 250r / min for 15min. Then, raise the temperature to 72℃ and continue stirring for 35min. Next, add 6g of isooctyl methacrylate, 1.7g of triallyl cyanurate, and 0.3g of benzoyl peroxide and raise the temperature to 85℃ and continue stirring for 3h. After the reaction is complete, cool the reaction product to room temperature, then vacuum filter. Wash the filter cake twice with acetone and then place it in a vacuum drying oven at 55℃ for 2.5h to obtain modified polyethylene. Step S2: Add 2g of T700 carbon fiber with an average length of 5mm and 28mL of acetone to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 22℃ and 250r / min for 15min. Then raise the temperature to 65℃ and continue stirring for 3h. After the reaction is complete, cool the reaction product to room temperature and then filter under vacuum. Wash the filter cake twice with ethanol and deionized water, and then place it in a vacuum drying oven and dry at 85℃ for 2.5h to obtain pretreated carbon fiber. Step S3: Add 3g of pretreated carbon fiber and 75mL of deionized water to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir at 12℃ and 250r / min for 25min. Then adjust the pH to 8.5 with 25% sodium hydroxide solution. Then raise the temperature to 42℃ and add 1g of tris(hydroxymethyl)aminomethane hydrochloride and 0.25g of dopamine hydrochloride. Continue stirring for 5.5h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, wash the precipitate twice with distilled water, and then place it in a vacuum drying oven and dry at 75℃ for 2.5h to obtain pre-modified carbon fiber. Step S4: Add 3 mL of silane coupling agent KH560, 1.5 mL of acetic acid, 85 mL of anhydrous ethanol and 12 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 22°C and 250 r / min for 35 min. Then add pre-modified carbon fiber and continue stirring at 65°C for 1.5 h. Then stir at 85°C for 4 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, wash the precipitate twice with distilled water, and then place it in a vacuum drying oven and dry at 75°C for 2.5 h to obtain modified carbon fiber. Step S5: Weigh out 85 parts of modified polyethylene, 2.7 parts of modified carbon fiber, 1.5 parts of lubricant, 0.6 parts of antioxidant, and 0.4 parts of light stabilizer according to the following weight proportions, and set aside for later use; the lubricant is calcium stearate; the antioxidant is antioxidant 1010; and the light stabilizer is light stabilizer 119. Step S6: Add modified polyethylene, modified carbon fiber, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 25 minutes at a temperature of 75℃ and a stirring speed of 1000r / min to obtain a mixture. Step S7: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 150r / min. Then blow-mold the mixture to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0025] Example 3: This embodiment describes a method for preparing a tear-resistant and low-temperature resistant PE plastic film, comprising the following steps: Step S1: Add 10g of LLDPE 2045G, 0.05g of OP-10 emulsifier, 40mL of deionized water, and 80mL of toluene to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir at 25℃ and 300r / min for 20min. Then, raise the temperature to 75℃ and continue stirring for 40min. After that, add 11g of isooctyl methacrylate, 2.6g of triallyl cyanurate, and 0.4g of benzoyl peroxide and raise the temperature to 90℃ and continue stirring for 4h. After the reaction is complete, cool the reaction product to room temperature, then vacuum filter. Wash the filter cake three times with acetone and then place it in a vacuum drying oven and dry at 60℃ for 3h to obtain modified polyethylene. Step S2: Add 2g of T700 carbon fiber with an average length of 5mm and 30mL of acetone to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25℃ and 300r / min for 20min. Then raise the temperature to 70℃ and continue stirring for 4h. After the reaction is completed, cool the reaction product to room temperature and then filter under vacuum. Wash the filter cake three times with ethanol and deionized water, and then place it in a vacuum drying oven and dry at 90℃ for 3h to obtain pretreated carbon fiber. Step S3: Add 3g of pretreated carbon fiber and 80mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir for 30min at 15℃ and 300r / min. Then adjust the pH to 9 with 30% sodium hydroxide solution. Then raise the temperature to 45℃ and add 1.1g of tris(hydroxymethyl)aminomethane hydrochloride and 0.3g of dopamine hydrochloride. Continue stirring for 6h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Wash the precipitate three times with distilled water and then place it in a vacuum drying oven at 80℃ for 3h to obtain pre-modified carbon fiber. Step S4: Add 5 mL of silane coupling agent KH560, 2 mL of acetic acid, 90 mL of anhydrous ethanol and 15 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25°C and 300 r / min for 40 min. Then add pre-modified carbon fiber and continue stirring at 70°C for 2 h. Then stir at 90°C for 5 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, wash the precipitate three times with distilled water, and then place it in a vacuum drying oven and dry at 80°C for 3 h to obtain modified carbon fiber. Step S5: Weigh out 90 parts of modified polyethylene, 4.6 parts of modified carbon fiber, 2.5 parts of lubricant, 0.9 parts of antioxidant, and 0.5 parts of light stabilizer according to the following weight proportions, and set aside for later use; the lubricant is calcium stearate; the antioxidant is antioxidant 1010; and the light stabilizer is light stabilizer 119. Step S6: Add modified polyethylene, modified carbon fiber, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 30 minutes at a temperature of 80℃ and a stirring rate of 1200r / min to obtain a mixture. Step S7: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 200r / min. Then blow-mold the mixture to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0026] Comparative Example 1: This comparative example illustrates a method for preparing a tear-resistant and low-temperature resistant PE plastic film, comprising the following steps: Step S1: Weigh out 90 parts of LLDPE 2045G, 2.5 parts of lubricant, 0.9 parts of antioxidant, and 0.5 parts of light stabilizer according to the following weight proportions, and set aside for later use; the lubricant is calcium stearate; the antioxidant is antioxidant 1010; and the light stabilizer is light stabilizer 119. Step S2: Add polyethylene LLDPE 2045G, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 30 minutes at a temperature of 80℃ and a stirring speed of 1200r / min to obtain a mixture; Step S3: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 200r / min. Then blow-mold the mixture to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0027] Comparative Example 2: This comparative example illustrates a method for preparing a tear-resistant and low-temperature resistant PE plastic film, comprising the following steps: Step S1: Add 10g of LLDPE 2045G, 0.05g of OP-10 emulsifier, 40mL of deionized water, and 80mL of toluene to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir at 25℃ and 300r / min for 20min. Then, raise the temperature to 75℃ and continue stirring for 40min. After that, add 11g of isooctyl methacrylate, 2.6g of triallyl cyanurate, and 0.4g of benzoyl peroxide and raise the temperature to 90℃ and continue stirring for 4h. After the reaction is complete, cool the reaction product to room temperature, then vacuum filter. Wash the filter cake three times with acetone and then place it in a vacuum drying oven and dry at 60℃ for 3h to obtain modified polyethylene. Step S2: Weigh out 90 parts of modified polyethylene, 2.5 parts of lubricant, 0.9 parts of antioxidant, and 0.5 parts of light stabilizer according to the following weight proportions, and set aside; the lubricant is calcium stearate; the antioxidant is antioxidant 1010; and the light stabilizer is light stabilizer 119. Step S3: Add modified polyethylene, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 30 minutes at a temperature of 80℃ and a stirring speed of 1200r / min to obtain a mixture; Step S4: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 200r / min. Then blow-mold the mixture to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0028] Comparative Example 3: This comparative example illustrates a method for preparing a tear-resistant and low-temperature resistant PE plastic film, comprising the following steps: Step S1: Weigh out 90 parts by weight of LLDPE 2045G polyethylene, 4.6 parts by weight of T700 carbon fiber with an average length of 5mm, 2.5 parts by weight of lubricant, 0.9 parts by weight of antioxidant, and 0.5 parts by weight of light stabilizer, and set aside; the lubricant is calcium stearate; the antioxidant is antioxidant 1010; the light stabilizer is light stabilizer 119; Step S2: Add polyethylene LLDPE 2045G, T700 carbon fiber with an average length of 5mm, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 30 minutes at a temperature of 80℃ and a stirring speed of 1200r / min to obtain a mixture. Step S3: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 200r / min. Then blow-mold the mixture to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0029] Comparative Example 4: This comparative example illustrates a method for preparing a tear-resistant and low-temperature resistant PE plastic film, comprising the following steps: Step S1: Add 2g of T700 carbon fiber with an average length of 5mm and 30mL of acetone to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25℃ and 300r / min for 20min. Then raise the temperature to 70℃ and continue stirring for 4h. After the reaction is completed, cool the reaction product to room temperature and then filter under vacuum. Wash the filter cake three times with ethanol and deionized water, and then place it in a vacuum drying oven and dry at 90℃ for 3h to obtain pretreated carbon fiber. Step S2: Add 3g of pretreated carbon fiber and 80mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 15℃ and 300r / min for 30min. Then adjust the pH to 9 with 30% sodium hydroxide solution. Then raise the temperature to 45℃ and add 1.1g of tris(hydroxymethyl)aminomethane hydrochloride and 0.3g of dopamine hydrochloride. Continue stirring for 6h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge. Wash the precipitate three times with distilled water and then place it in a vacuum drying oven at 80℃ for 3h to obtain pre-modified carbon fiber. Step S3: Add 5 mL of silane coupling agent KH560, 2 mL of acetic acid, 90 mL of anhydrous ethanol and 15 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25°C and 300 r / min for 40 min. Then add pre-modified carbon fiber and continue stirring at 70°C for 2 h. Then stir at 90°C for 5 h. After the reaction is complete, cool the reaction product to room temperature, centrifuge, wash the precipitate three times with distilled water, and then place it in a vacuum drying oven and dry at 80°C for 3 h to obtain modified carbon fiber. Step S4: Weigh out 90 parts of LLDPE 2045G, 4.6 parts of modified carbon fiber, 2.5 parts of lubricant, 0.9 parts of antioxidant, and 0.5 parts of light stabilizer according to the following weight proportions, and set aside for later use; the lubricant is calcium stearate; the antioxidant is antioxidant 1010; and the light stabilizer is light stabilizer 119. Step S5: Add polyethylene LLDPE 2045G, modified carbon fiber, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 30 minutes at a temperature of 80℃ and a stirring speed of 1200r / min to obtain a mixture. Step S6: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 200r / min. Then blow-mold the mixture to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

[0030] The tear-resistant and low-temperature resistant PE plastic films of Examples 1-3 and Comparative Examples 1-4 were subjected to performance tests according to GB / T 16578.2-2009. The test results are as follows: Figure 1 As shown.

[0031] See Figure 1Based on the data in the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen that the PE plastic film of this application has high tear strength at both room temperature and low temperature, indicating that the PE plastic film of this application has excellent tear resistance and low temperature resistance.

[0032] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A tear-resistant and low-temperature resistant PE plastic film, characterized in that, Includes the following components by weight: The mixture contains 80-90 parts modified polyethylene, 0.8-4.6 parts modified carbon fiber, 0.5-2.5 parts lubricant, 0.3-0.9 parts antioxidant, and 0.3-0.5 parts light stabilizer. The modified polyethylene is prepared by the following steps: Polyethylene, OP-10 emulsifier, deionized water and toluene were stirred and reacted. Then, isooctyl methacrylate, triallyl cyanurate and benzoyl peroxide were added and the reaction was continued. After the reaction was completed, the reaction product was cooled and then vacuum filtered. The filter cake was washed and dried to obtain modified polyethylene.

2. The tear-resistant and low-temperature resistant PE plastic film according to claim 1, characterized in that, The ratio of polyethylene, OP-10 emulsifier, deionized water, toluene, isooctyl methacrylate, triallyl cyanurate, and benzoyl peroxide is 10g:0.03-0.05g:30-40mL:70-80mL:1-11g:0.8-2.6g:0.2-0.4g; the polyethylene is LLDPE 2045G.

3. The tear-resistant and low-temperature resistant PE plastic film according to claim 1, characterized in that, The modified carbon fiber is prepared by the following steps: Step s1: Stir carbon fiber and acetone to react. After the reaction is complete, cool the reaction product, then filter it under vacuum. Wash and dry the filter cake to obtain pretreated carbon fiber. Step s2: The pretreated carbon fiber and deionized water are stirred and reacted. Then the pH is adjusted with sodium hydroxide solution. Tris(hydroxymethyl)aminomethane hydrochloride and dopamine hydrochloride are added and the reaction is continued. After the reaction is completed, the reaction product is cooled, centrifuged, and the precipitate is washed and dried to obtain pre-modified carbon fiber. Step s3: Stir the reaction of silane coupling agent KH560, acetic acid, anhydrous ethanol and deionized water, then add pre-modified carbon fiber and continue stirring. After the reaction is completed, cool the reaction product, then centrifuge, wash and dry the precipitate to obtain modified carbon fiber.

4. The tear-resistant and low-temperature resistant PE plastic film according to claim 3, characterized in that, The ratio of carbon fiber to acetone used in step s1 is 2g:25-30mL; the carbon fiber is T700 carbon fiber with an average length of 5mm.

5. The tear-resistant and low-temperature resistant PE plastic film according to claim 3, characterized in that, In step s2, the ratio of the pretreated carbon fiber, deionized water, tris(hydroxymethyl)aminomethane hydrochloride, and dopamine hydrochloride is 3g:70-80mL:0.9-1.1g:0.2-0.3g; the mass fraction of the sodium hydroxide solution is 20-30%.

6. The tear-resistant and low-temperature resistant PE plastic film according to claim 3, characterized in that, The ratio of the amount of silane coupling agent KH560, acetic acid, anhydrous ethanol and deionized water used in step s3 is 1-5 mL: 1-2 mL: 80-90 mL: 10-15 mL.

7. A method for preparing a tear-resistant and low-temperature resistant PE plastic film as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Weigh out 80-90 parts of modified polyethylene, 0.8-4.6 parts of modified carbon fiber, 0.5-2.5 parts of lubricant, 0.3-0.9 parts of antioxidant, and 0.3-0.5 parts of light stabilizer according to the weight ratio, and set aside. Step 2: Add modified polyethylene, modified carbon fiber, lubricant, antioxidant and light stabilizer to a high-speed mixer and mix for 20-30 minutes at a temperature of 70-80℃ and a stirring speed of 800-1200r / min to obtain a mixture. Step 3: Add the mixture to a twin-screw extruder and melt-blend it under the following conditions: zone 1 temperature 160℃, zone 2 temperature 175℃, zone 3 temperature 185℃, zone 4 temperature 190℃, zone 5 temperature 185℃, die temperature 180℃, and screw speed 100-200r / min. Then blow-mold the mixture using a blown film extruder to obtain a 30μm thick tear-resistant and low-temperature resistant PE plastic film.

8. The method for preparing a tear-resistant and low-temperature resistant PE plastic film according to claim 7, characterized in that, The lubricant is calcium stearate.

9. The method for preparing a tear-resistant and low-temperature resistant PE plastic film according to claim 7, characterized in that, The antioxidant is antioxidant 1010.

10. The method for preparing a tear-resistant and low-temperature resistant PE plastic film according to claim 7, characterized in that, The light stabilizer is light stabilizer 119.

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