Anti-aging compound additive for polyethylene weather-resistant film and preparation method of anti-aging compound additive

Abstract

The invention relates to the field of anti-aging additives, in particular to an anti-aging compound additive for a polyethylene weather-proof film and a preparation method of the anti-aging compound additive, which are used for solving the problems that the anti-aging performance of the existing polyethylene weather-proof film is improved by adding the anti-aging additive in the production process, but the anti-aging effect of the existing anti-aging additive is limited, so that the anti-aging performance of the polyethylene weather-proof film is poor. The long-term use requirement of the polyethylene weather-proof film in a complex environment is difficult to meet. The talcum powder, the difunctional weather-resistant agent, the weather-resistant reinforcing agent, the strength reinforcing agent, the nucleating agent, the lubricating agent and the dispersing agent are reasonably compounded, all the components have a good synergistic effect and can give full play to respective advantages, the aging degradation reaction of polyethylene under the action of light, heat and oxygen can be effectively inhibited, and the service life of polyethylene is prolonged. The tensile strength of the polyethylene weather-resistant film is improved, the light aging resistance and the thermal oxidation aging resistance of the polyethylene weather-resistant film are remarkably improved, and the high performance can be kept for a long time.

Description

[0001] The present invention relates to the field of anti-aging additives, and particularly to an anti-aging composite additive for polyethylene weather-resistant films and a preparation method thereof. Background Art

[0002] Due to its good processing performance, physical properties, and chemical stability, polyethylene (PE) is widely used in the manufacture of weather-resistant films and is widely applied in multiple fields such as agricultural greenhouses, building sunshades, and packaging materials. However, during long-term use, especially under the action of environmental factors such as ultraviolet rays, oxygen, and high temperatures, polyethylene weather-resistant films are prone to aging. After aging, problems such as surface powdering, cracking, yellowing of color, reduction in transparency, and decline in mechanical properties will occur in polyethylene weather-resistant films, seriously affecting their service performance and service life.

[0003] In order to improve the anti-aging performance of polyethylene weather-resistant films, anti-aging additives are usually added during the production process. Currently, most anti-aging additives on the market are single-functional additives, such as single antioxidants, light stabilizers, etc. The anti-aging effect of single additives is limited and it is difficult to meet the long-term use requirements of polyethylene weather-resistant films in complex environments.

[0004] Therefore, developing an anti-aging composite additive for polyethylene weather-resistant films and a preparation method thereof to comprehensively improve the anti-aging performance of polyethylene weather-resistant films has important practical significance. Summary of the Invention

[0005] In order to overcome the above technical problems, the purpose of the present invention is to provide an anti-aging composite additive for polyethylene weather-resistant films and a preparation method thereof, which solves the problem that the existing polyethylene weather-resistant films improve their anti-aging performance by adding anti-aging additives during the production process, but the current anti-aging additives have limited anti-aging effects and it is difficult to meet the long-term use requirements of polyethylene weather-resistant films in complex environments.

[0006] The purpose of the present invention can be achieved by the following technical solutions: An anti-aging composite additive for polyethylene weather-resistant films, comprising the following components in parts by weight: 30 - 35 parts of talcum powder, 12 - 26 parts of bifunctional weathering agent, 5 - 11 parts of weathering enhancer, 3 - 9 parts of strength enhancer, 4 - 8 parts of nucleating agent, 6 - 10 parts of lubricant, and 1 - 3 parts of dispersant; Among them, the bifunctional weathering agent is prepared by the following steps: Step a1: Add 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and chloroform into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel. Stir and react for 10 - 20 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 200 - 300 r / min. Then, while stirring, gradually add thionyl chloride dropwise, controlling the dropping rate at 1 - 2 drops / s. After the addition is complete, continue to stir and react for 10 - 20 min. Then, raise the temperature to 50 - 55 °C and continue to stir and react for 5 - 7 h. After the reaction is completed, cool the reaction product to room temperature, and then rotary evaporate to remove the solvent to obtain an acyl chloride hindered phenol intermediate; Step a2: Add the acyl chloride hindered phenol intermediate, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and anhydrous toluene into a three-necked flask equipped with a stirrer, a thermometer and a constant pressure dropping funnel. Stir and react for 1 - 1.5 h under the conditions of a temperature of -5 - 0 °C and a stirring rate of 200 - 300 r / min. Then, while stirring, gradually add sodium hydroxide solution dropwise, controlling the dropping rate at 1 - 2 drops / s. After the addition is complete, raise the temperature to 70 - 75 °C and continue to stir and react for 10 - 15 h. After the reaction is completed, cool the reaction product to room temperature, then add it to distilled water, and then extract it with ethyl acetate 2 - 3 times. Combine the extraction solutions and dry them with anhydrous sodium sulfate, then vacuum filter. Rotary evaporate the filtrate to remove the solvent to obtain a bifunctional weathering agent.

[0007] As a further scheme of the present invention: The dosage ratio of the 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, chloroform and thionyl chloride in step a1 is 20 mmol: 50 - 60 mL: 8 - 10 mL.

[0008] As a further scheme of the present invention: The dosage ratio of the acyl chloride hindered phenol intermediate, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, anhydrous toluene and sodium hydroxide solution in step a2 is 10 mmol: 10 mmol: 40 - 50 mL: 10 - 15 mL.

[0009] As a further scheme of the present invention: The mass fraction of the sodium hydroxide solution in step a2 is 20 - 22%.

[0010] As a further scheme of the present invention: The weather resistance enhancer is prepared by the following steps: Add the ethanol solution to a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. While stirring, add acetic acid drop by drop at a temperature of 25 - 30 °C and a stirring rate of 200 - 300 r / min, controlling the dropping rate to be 1 - 2 drops / s until the pH is 3 - 4. Then add nano-titanium dioxide and 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8 - heptadecafluorooctyltriethoxysilane and continue stirring and reacting at 80 - 85 °C for 4 - 5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge, wash the precipitate with distilled water 2 - 3 times, and then place it in a vacuum drying oven and dry it at 60 - 65 °C for 2 - 3 h to obtain the weather resistance enhancer.

[0011] As a further scheme of the present invention: the dosage ratio of the ethanol solution, nano-titanium dioxide, and 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8 - heptadecafluorooctyltriethoxysilane is 90 - 100 mL: 10 g: 1.5 - 5.5 mL.

[0012] As a further scheme of the present invention: the volume fraction of the ethanol solution is 50 - 60%; the average particle size of the nano-titanium dioxide is 100 nm.

[0013] As a further scheme of the present invention: the strength enhancer is prepared by the following steps: Add deionized water and absolute ethanol to a three-necked flask equipped with a stirrer and a thermometer, stir and react at a temperature of 25 - 30 °C and a stirring rate of 200 - 300 r / min for 3 - 5 min, then adjust to pH 8 - 9 with ammonia water, then add aluminum borate whiskers and silane coupling agent Z - 6030 and continue stirring and reacting at 80 - 85 °C for 1 - 2 h. After the reaction is completed, cool the reaction product to room temperature, then ultrasonically disperse it at an ultrasonic frequency of 30 - 40 kHz for 30 - 50 min, then centrifuge, wash the precipitate with distilled water 2 - 3 times, and then place it in a vacuum drying oven and dry it at 60 - 65 °C for 2 - 3 h to obtain the strength enhancer.

[0014] As a further scheme of the present invention: the dosage ratio of the deionized water, absolute ethanol, aluminum borate whiskers, and silane coupling agent Z - 6030 is 15 - 20 mL: 60 - 70 mL: 10 g: 0.8 - 3.6 g.

[0015] As a further scheme of the present invention: the mass fraction of the ammonia water is 20 - 25%; the diameter of the aluminum borate whiskers is 0.5 - 1 μm and the length is 10 - 20 μm.

[0016] As a further scheme of the present invention: a preparation method of an anti-aging composite auxiliary agent for a polyethylene weather-resistant film, comprising the following steps: Step 1: Weigh 30 - 35 parts by weight of talcum powder, 12 - 26 parts of bifunctional weathering agent, 5 - 11 parts of weathering enhancer, 3 - 9 parts of strength enhancer, 4 - 8 parts of nucleating agent, 6 - 10 parts of lubricant, and 1 - 3 parts of dispersant, and set aside. Step 2: Add the talcum powder, bifunctional weathering agent, weathering enhancer, strength enhancer, nucleating agent, lubricant, and dispersant into a high - speed mixer, and stir and mix for 30 - 60 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 800 - 1000 r / min to obtain an anti - aging composite additive for polyethylene weather - resistant film.

[0017] As a further scheme of the present invention: The talcum powder is TYT - 777A talcum powder with a particle size of 3000 mesh.

[0018] As a further scheme of the present invention: The nucleating agent is Millad 3988 nucleating agent.

[0019] As a further scheme of the present invention: The lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1.

[0020] As a further scheme of the present invention: The dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1.

[0021] The beneficial effects of the present invention: An anti - aging composite additive for polyethylene weather - resistant film and its preparation method of the present invention obtain an anti - aging composite additive for polyethylene weather - resistant film by adding talcum powder, bifunctional weathering agent, weathering enhancer, strength enhancer, nucleating agent, lubricant, and dispersant into a high - speed mixer and stirring and mixing them. The composite additive is reasonably compounded with talcum powder, bifunctional weathering agent, weathering enhancer, strength enhancer, nucleating agent, lubricant, and dispersant. There is a good synergistic effect among the components, which can give full play to their respective advantages, effectively inhibit the aging and degradation reaction of polyethylene under the action of light, heat, and oxygen, improve the tensile strength of the polyethylene weather - resistant film, significantly enhance the anti - photo - aging and thermal - oxidative aging performance of the polyethylene weather - resistant film, and can maintain high performance for a long time. The preparation method has a simple process, is easy to control, is suitable for large - scale industrial production, and reduces the production cost.

[0022] In the process of preparing the anti-aging composite additive for polyethylene weather-resistant film, a bifunctional weathering agent was first prepared. By reacting 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with thionyl chloride, the carboxyl group on 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid was converted into an acyl chloride group to enhance its reaction activity, obtaining an acyl chloride hindered phenol intermediate. Then, the acyl chloride hindered phenol intermediate reacted with N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, and the acyl chloride group on the acyl chloride hindered phenol intermediate reacted with the secondary amino group connected to the butyl group on N-butyl-2,2,6,6-tetramethyl-4-piperidinamine to obtain the bifunctional weathering agent. The molecular structure of this bifunctional weathering agent contains a hindered phenol structure and a hindered amine structure. The phenolic hydroxyl group in the hindered phenol structure has active hydrogen atoms, which can react with the free radicals generated during the oxidation of polyethylene, capture the free radicals, and generate relatively stable phenoxy free radicals, thus interrupting the chain process of the oxidation reaction. At the same time, the hindered amine structure can capture the peroxy free radicals generated during the photooxidation process and convert them into stable nitroxide free radicals, thereby effectively inhibiting the progress of the photooxidation reaction. Through this dual action mechanism, the bifunctional weathering agent can protect the polyethylene weather-resistant film from both thermal-oxidative aging and photo-oxidative aging, significantly improving its weather resistance.

[0023] In the process of preparing the anti-aging composite additive for polyethylene weather-resistant film, a weathering enhancer was also prepared. By modifying nano-titanium dioxide with tridecafluorooctyltriethoxysilane, the silanol formed by the hydrolysis of the siloxane on tridecafluorooctyltriethoxysilane can graft onto the surface of the nano-titanium dioxide particles, and a large number of fluorine atoms are introduced to obtain the weathering enhancer. The nano-titanium dioxide in this weathering enhancer has excellent ultraviolet absorption, endowing it with excellent photooxidation shielding effect. After modification, its dispersibility can be significantly improved, avoiding its agglomeration, enabling it to be evenly distributed in the polyethylene weather-resistant film, thereby effectively absorbing ultraviolet rays. Moreover, the large number of fluorine atoms introduced can improve the chemical corrosion resistance of the polyethylene weather-resistant film, further enhancing the weather resistance of the polyethylene weather-resistant film.

[0024] In the process of preparing the anti-aging composite additive for polyethylene weather-resistant film, a strength enhancer was also prepared. By modifying aluminum borate whiskers with silane coupling agent Z-6030, the silanol formed by the hydrolysis of the siloxane on silane coupling agent Z-6030 can graft onto the surface of the aluminum borate whiskers to obtain the strength enhancer. Aluminum borate whiskers are an inorganic fiber material with high strength and high modulus. After modification, its dispersibility can be significantly improved, avoiding its agglomeration, enabling it to be evenly distributed in the polyethylene weather-resistant film, enhancing the interfacial bonding force between the two. When the polyethylene weather-resistant film is subjected to external forces, the aluminum borate whiskers can effectively transfer the stress to the polyethylene matrix, giving full play to its high strength and high modulus characteristics, thus significantly improving the mechanical properties of the polyethylene weather-resistant film. Detailed implementation mode

[0025] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. 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. Example 1

[0026] This example is a preparation method of an anti-aging composite auxiliary for polyethylene weather-resistant film, including the following steps: Step S1: Add 20 mmol of 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionic acid and 50 mL of chloroform into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 10 min at a temperature of 25°C and a stirring rate of 200 r / min. Then, while stirring, gradually add 8 mL of thionyl chloride dropwise, control the dropping rate at 1 drop / s. After the dropping is completed, continue to stir and react for 10 min. Then, continue to stir and react for 5 h under the condition of heating to 50°C. After the reaction is completed, cool the reaction product to room temperature, and then rotate and evaporate to remove the solvent to obtain an acyl chloride hindered phenol intermediate; Step S2: Add 10 mmol of acyl chloride hindered phenol intermediate, 10 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidineamine and 40 mL of anhydrous toluene into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 1 h at a temperature of -5°C and a stirring rate of 200 r / min. Then, while stirring, gradually add 10 mL of a 20% sodium hydroxide solution dropwise, control the dropping rate at 1 drop / s. After the dropping is completed, heat to 70°C and continue to stir and react for 10 h. After the reaction is completed, cool the reaction product to room temperature, then add it to distilled water, and then extract it twice with ethyl acetate. Combine the extraction solutions and dry them with anhydrous sodium sulfate, and then vacuum filter. Rotate and evaporate the filtrate to remove the solvent to obtain a bifunctional weathering agent; Step S3: Add 90 mL of an ethanol solution with a volume fraction of 50% into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. While stirring, gradually add acetic acid dropwise at a temperature of 25°C and a stirring rate of 200 r / min, control the dropping rate at 1 drop / s until the pH is 3. Then, add 10 g of nano-titanium dioxide with an average particle size of 100 nm and 1.5 mL of trifluorooctyltriethoxysilane and heat 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 twice with distilled water, and then place it in a vacuum drying oven and dry it at a temperature of 60°C for 2 h to obtain a weathering enhancer; Step S4: Add 15 mL of deionized water and 60 mL of absolute ethanol into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 3 min at a temperature of 25°C and a stirring rate of 200 r / min. Then adjust the pH to 8 with 20% ammonia water by mass. After that, add 10 g of aluminum borate whiskers and 0.8 g of silane coupling agent Z-6030, and continue to stir and react at 80°C for 1 h. After the reaction is completed, cool the reaction product to room temperature. Then, ultrasonically disperse it for 30 min under the condition of an ultrasonic frequency of 30 kHz. After that, centrifuge, wash the precipitate twice with distilled water, and then place it in a vacuum drying oven and dry it at 60°C for 2 h to obtain a strength enhancer; Step S5: Weigh 30 parts of talcum powder, 12 parts of bifunctional weathering agent, 5 parts of weathering enhancer, 3 parts of strength enhancer, 4 parts of nucleating agent, 6 parts of lubricant, and 1 part of dispersant by weight for standby; the talcum powder is TYT-777A talcum powder with a particle size of 3000 mesh; the nucleating agent is Millad 3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1; Step S6: Add the talcum powder, bifunctional weathering agent, weathering enhancer, strength enhancer, nucleating agent, lubricant, and dispersant into a high-speed mixer, and stir and mix for 30 min at a temperature of 25°C and a stirring rate of 800 r / min to obtain an anti-aging composite additive for polyethylene weathering film. Example 2

[0027] This example is a preparation method of an anti-aging composite additive for polyethylene weathering film, including the following steps: Step S1: Add 20 mmol of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 55 mL of chloroform into a three-necked flask equipped with a stirrer, a thermometer, and a constant-pressure dropping funnel. Stir and react for 15 min at a temperature of 28°C and a stirring rate of 250 r / min. Then, while stirring, gradually add 9 mL of thionyl chloride dropwise, control the dropping rate at 1 drop / s. After the dropping is completed, continue to stir and react for 15 min. Then, continue to stir and react at 52°C for 6 h. After the reaction is completed, cool the reaction product to room temperature. Then, rotate and evaporate to remove the solvent to obtain an acyl chloride hindered phenol intermediate; Step S2: Add 10 mmol of acyl chloride hindered phenol intermediate, 10 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, and 45 mL of anhydrous toluene into a three-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel. Stir and react for 1 h under the conditions of a temperature of -3°C and a stirring rate of 250 r / min. Then, while stirring, gradually add 12 mL of a 21% sodium hydroxide solution dropwise, controlling the dropping rate at 1 drop / s. After the addition is complete, continue to stir and react at 72°C for 12 h. After the reaction is completed, cool the reaction product to room temperature, then add it to distilled water, extract it twice with ethyl acetate, combine the extracts and dry them with anhydrous sodium sulfate, then perform vacuum filtration, and rotary evaporate the filtrate to remove the solvent to obtain a bifunctional weather-resistant agent; Step S3: Add 95 mL of an ethanol solution with a volume fraction of 55% into a three-necked flask equipped with a stirrer, a thermometer, and a constant pressure dropping funnel. While stirring, gradually add acetic acid dropwise under the conditions of a temperature of 28°C and a stirring rate of 250 r / min, controlling the dropping rate at 1 drop / s until the pH reaches 3.5. Then, add 10 g of nano-titanium dioxide with an average particle size of 100 nm and 3.5 mL of trifluorooctyltriethoxysilane, and continue to stir and react at 82°C for 4.5 h. After the reaction is completed, cool the reaction product to room temperature, then centrifuge it, wash the precipitate twice with distilled water, and then place it in a vacuum drying oven and dry it at 62°C for 2.5 h to obtain a weather-resistant enhancer; Step S4: Add 18 mL of deionized water and 65 mL of anhydrous ethanol into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 4 min under the conditions of a temperature of 28°C and a stirring rate of 250 r / min. Then, adjust the pH to 8.5 with 22% ammonia water. Then, add 10 g of aluminum borate whiskers and 2.2 g of silane coupling agent Z-6030, and continue to stir and react at 82°C for 1.5 h. After the reaction is completed, cool the reaction product to room temperature, then ultrasonically disperse it for 40 min under the condition of an ultrasonic frequency of 35 kHz, then centrifuge it, wash the precipitate twice with distilled water, and then place it in a vacuum drying oven and dry it at 62°C for 2.5 h to obtain a strength enhancer; Step S5: Weigh 32 parts by weight of talc powder, 19 parts of bifunctional weather-resistant agent, 8 parts of weather-resistant enhancer, 6 parts of strength enhancer, 6 parts of nucleating agent, 8 parts of lubricant, and 2 parts of dispersant, and set aside; the talc powder is TYT-777A talc powder with a particle size of 3000 mesh; the nucleating agent is Millad 3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1; Step S6: Add talcum powder, bifunctional weathering agent, weathering enhancer, strength enhancer, nucleating agent, lubricant and dispersant into a high-speed mixer, and stir and mix for 45 min under the conditions of a temperature of 28 °C and a stirring rate of 900 r / min to obtain an anti-aging composite additive for polyethylene weather-resistant film. Example 3

[0028] This example is a preparation method of an anti-aging composite additive for polyethylene weather-resistant film, including the following steps: Step S1: Add 20 mmol of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 60 mL of chloroform into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel, and stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then, while stirring, gradually dropwise add 10 mL of thionyl chloride, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 20 min, and then continue to stir and react for 7 h under the condition of raising the temperature to 55 °C. After the reaction is completed, cool the reaction product to room temperature, and then rotate and evaporate to remove the solvent to obtain an acyl chloride hindered phenol intermediate; Step S2: Add 10 mmol of acyl chloride hindered phenol intermediate, 10 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and 50 mL of anhydrous toluene into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel, and stir and react for 1.5 h under the conditions of a temperature of 0 °C and a stirring rate of 300 r / min. Then, while stirring, gradually dropwise add 15 mL of a sodium hydroxide solution with a mass fraction of 22%, control the dropping rate at 2 drops / s. After the dropping is completed, raise the temperature to 75 °C and continue to stir and react for 15 h. After the reaction is completed, cool the reaction product to room temperature, then add it to distilled water, and then extract it 3 times with ethyl acetate. Combine the extraction solutions and dry them with anhydrous sodium sulfate, and then perform vacuum filtration. Rotate and evaporate the filtrate to remove the solvent to obtain a bifunctional weathering agent; Step S3: Add 100 mL of an ethanol solution with a volume fraction of 60% into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel, and while stirring, gradually dropwise add acetic acid under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min, control the dropping rate at 2 drops / s until the pH is 4. Then, add 10 g of nano-titanium dioxide with an average particle size of 100 nm and 5.5 mL of trifluorooctyltriethoxysilane and 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 3 times with distilled water, and then place it in a vacuum drying oven and dry it at a temperature of 65 °C for 3 h to obtain a weathering enhancer; Step S4: Add 20 mL of deionized water and 70 mL of absolute ethanol into a three-necked flask equipped with a stirrer and a thermometer. Stir and react for 5 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then adjust the pH to 9 with 25% ammonia water. After that, add 10 g of aluminum borate whiskers and 3.6 g of silane coupling agent Z-6030, and continue to stir and react for 2 h under the condition of heating to 85 °C. After the reaction is completed, cool the reaction product to room temperature. Then, under the condition of an ultrasonic frequency of 40 kHz, ultrasonically disperse for 50 min. Then centrifuge, wash the precipitate with distilled water three times, and then place it in a vacuum drying oven and dry for 3 h at a temperature of 65 °C to obtain a strength enhancer; Step S5: Weigh 35 parts of talcum powder, 26 parts of bifunctional weathering agent, 11 parts of weathering enhancer, 9 parts of strength enhancer, 8 parts of nucleating agent, 10 parts of lubricant, and 3 parts of dispersant by weight, and set aside; the talcum powder is TYT-777A talcum powder with a particle size of 3000 mesh; the nucleating agent is Millad 3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1; Step S6: Add the talcum powder, bifunctional weathering agent, weathering enhancer, strength enhancer, nucleating agent, lubricant, and dispersant into a high-speed mixer, and stir and mix for 60 min under the conditions of a temperature of 30 °C and a stirring rate of 1000 r / min to obtain an anti-aging composite additive for polyethylene weather-resistant film.

[0029] Comparative Example 1: This comparative example is a preparation method of an anti-aging composite additive for polyethylene weather-resistant film, including the following steps: Step S1: Weigh 35 parts of talcum powder, 8 parts of nucleating agent, 10 parts of lubricant, and 3 parts of dispersant by weight, and set aside; the talcum powder is TYT-777A talcum powder with a particle size of 3000 mesh; the nucleating agent is Millad 3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1; Step S2: Add the talcum powder, nucleating agent, lubricant, and dispersant into a high-speed mixer, and stir and mix for 60 min under the conditions of a temperature of 30 °C and a stirring rate of 1000 r / min to obtain an anti-aging composite additive for polyethylene weather-resistant film.

[0030] Comparative Example 2: This comparative example is a preparation method of an anti-aging composite additive for polyethylene weather-resistant film, including the following steps: Step S1: Add 20 mmol of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid and 60 mL of chloroform into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 20 min under the conditions of a temperature of 30 °C and a stirring rate of 300 r / min. Then, while stirring, gradually add 10 mL of thionyl chloride dropwise, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 20 min. Then, continue to stir and react for 7 h under the condition of heating to 55 °C. After the reaction is completed, cool the reaction product to room temperature, and then remove the solvent by rotary evaporation to obtain an acyl chloride hindered phenol intermediate; Step S2: Add 10 mmol of acyl chloride hindered phenol intermediate, 10 mmol of N-butyl-2,2,6,6-tetramethyl-4-piperidinamine and 50 mL of anhydrous toluene into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. Stir and react for 1.5 h under the conditions of a temperature of 0 °C and a stirring rate of 300 r / min. Then, while stirring, gradually add 15 mL of a sodium hydroxide solution with a mass fraction of 22% dropwise, control the dropping rate at 2 drops / s. After the dropping is completed, continue to stir and react for 15 h under the condition of heating to 75 °C. After the reaction is completed, cool the reaction product to room temperature, then add it to distilled water, and then extract it 3 times with ethyl acetate. Combine the extraction liquids and dry them with anhydrous sodium sulfate. Then, perform vacuum filtration, and rotary evaporate the filtrate to remove the solvent to obtain a bifunctional weathering agent; Step S3: Weigh 35 parts of talcum powder, 26 parts of bifunctional weathering agent, 8 parts of nucleating agent, 10 parts of lubricant and 3 parts of dispersant by weight for standby; the talcum powder is TYT-777A talcum powder with a particle size of 3000 mesh; the nucleating agent is Millad 3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1; Step S4: Add the talcum powder, bifunctional weathering agent, nucleating agent, lubricant and dispersant into a high-speed mixer, and stir and mix for 60 min under the conditions of a temperature of 30 °C and a stirring rate of 1000 r / min to obtain an anti-aging composite additive for polyethylene weathering film.

[0031] Comparative Example 3: This comparative example is a preparation method of an anti-aging composite additive for polyethylene weathering film, including the following steps: Step S1: Add 100 mL of ethanol solution with a volume fraction of 60% into a three-necked flask equipped with a stirrer, a thermometer and a constant-pressure dropping funnel. While stirring at a temperature of 30 °C and a stirring rate of 300 r / min, add acetic acid drop by drop, control the dropping rate at 2 drops / s until the pH is 4. Then add 10 g of nano-titanium dioxide with an average particle size of 100 nm and 5.5 mL of tridecafluorooctyltriethoxysilane, and continue to stir and react at 85 °C for 5 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 65 °C for 3 h to obtain a weather resistance enhancer; Step S2: Weigh 35 parts of talcum powder, 11 parts of weather resistance enhancer, 8 parts of nucleating agent, 10 parts of lubricant and 3 parts of dispersant by weight for standby; the talcum powder is TYT-777A talcum powder with a particle size of 3000 mesh; the nucleating agent is Millad3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1; Step S3: Add the talcum powder, weather resistance enhancer, nucleating agent, lubricant and dispersant into a high-speed mixer, and stir and mix at a temperature of 30 °C and a stirring rate of 1000 r / min for 60 min to obtain an anti-aging composite additive for polyethylene weather-resistant film.

[0032] Comparative Example 4: This comparative example is a preparation method of an anti-aging composite additive for polyethylene weather-resistant film, which includes the following steps: Step S1: Add 20 mL of deionized water and 70 mL of absolute ethanol into a three-necked flask equipped with a stirrer and a thermometer, stir and react at a temperature of 30 °C and a stirring rate of 300 r / min for 5 min, then adjust to pH 9 with 25% ammonia water by mass, then add 10 g of borate whiskers and 3.6 g of silane coupling agent Z-6030, and continue to stir and react at 85 °C for 2 h. After the reaction is completed, cool the reaction product to room temperature, then ultrasonically disperse it at an ultrasonic frequency of 40 kHz for 50 min, then centrifuge, wash the precipitate with distilled water 3 times, and then place it in a vacuum drying oven and dry it at 65 °C for 3 h to obtain a strength enhancer; Step S3: Weigh 35 parts of talcum powder, 9 parts of strength enhancer, 8 parts of nucleating agent, 10 parts of lubricant, and 3 parts of dispersant by weight, and set aside; the talcum powder is TYT-777A talcum powder with a particle size of 3000 mesh; the nucleating agent is Millad 3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1. Step S3: Add the talcum powder, strength enhancer, nucleating agent, lubricant, and dispersant to a high-speed mixer, and stir and mix for 60 min under the conditions of a temperature of 30 °C and a stirring rate of 1000 r / min to obtain an anti-aging composite additive for polyethylene weather-resistant film.

[0033] Comparative Example 5: This comparative example is a preparation method of an anti-aging composite additive for polyethylene weather-resistant film, including the following steps: Step S1: Weigh 35 parts of talcum powder, 26 parts of N-butyl-2,2,6,6-tetramethyl-4-piperidineamine, 11 parts of nano-titanium dioxide, 9 parts of aluminum borate whiskers, 8 parts of nucleating agent, 10 parts of lubricant, and 3 parts of dispersant by weight, and set aside; the talcum powder is TYT-777A talcum powder with a particle size of 3000 mesh; the nucleating agent is Millad 3988 nucleating agent; the lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; the dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1. Step S2: Add the talcum powder, N-butyl-2,2,6,6-tetramethyl-4-piperidineamine, nano-titanium dioxide, aluminum borate whiskers, nucleating agent, lubricant, and dispersant to a high-speed mixer, and stir and mix for 60 min under the conditions of a temperature of 30 °C and a stirring rate of 1000 r / min to obtain an anti-aging composite additive for polyethylene weather-resistant film.

[0034] The anti-aging composite additives for the polyethylene weather-resistant films in Examples 1-3 and Comparative Examples 1-5 were added to polyethylene resin (LDPE LD607) at an addition amount of 2 wt%, and then added to a twin-screw extruder. Extrusion granulation was carried out under the conditions that the temperature of the first zone was 130 °C, the temperature of the second zone was 150 °C, the temperature of the third zone was 170 °C, the temperature of the fourth zone was 190 °C, the temperature of the die head was 200 °C, and the screw speed was 200 r / min. Then, it was blown into a film with a thickness of 0.08 mm ± 0.002 mm by a blown film machine to obtain a polyethylene weather-resistant film, and the performance of the polyethylene weather-resistant film was tested. The tensile strength was tested in accordance with GB / T 1040.3-2006; the xenon lamp artificial accelerated aging test was carried out in accordance with GB / T 16422.2-1999, and the tensile strength after aging was tested after aging for 1000 h under the conditions of a temperature of 65 °C and a relative humidity of 65%.

[0035] The test results are shown in the following table:

[0036] Referring to the data in the above table, according to the comparison between Examples 1-3 and Comparative Examples 1-5, it can be known that adding a bifunctional weathering agent and a weathering enhancer can significantly improve the anti-aging and weathering performance of the polyethylene weather-resistant film, and adding a strength enhancer can significantly improve the mechanical properties of the polyethylene weather-resistant film. Under the synergistic action of the bifunctional weathering agent, the weathering enhancer, and the strength enhancer, the polyethylene weather-resistant film is endowed with excellent anti-aging and weathering performance and mechanical properties.

[0037] In the description of this specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means 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 expressions 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.

[0038] The above content is only an example and explanation 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 to replace them, as long as they do not deviate from the invention or exceed the scope defined by this application, they should all belong to the protection scope of the present invention.

Claims

1. An anti-aging composite additive for polyethylene weather-resistant film, characterized in that, Comprising the following components in parts by weight: 30 - 35 parts of talcum powder, 12 - 26 parts of bifunctional weathering agent, 5 - 11 parts of weathering enhancer, 3 - 9 parts of strength enhancer, 4 - 8 parts of nucleating agent, 6 - 10 parts of lubricant, and 1 - 3 parts of dispersant; Among them, the bifunctional weathering agent is prepared by the following steps: Step a1: Stir and react 3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl) propionic acid and chloroform, then dropwise add thionyl chloride drop by drop while stirring. After the addition is complete, continue stirring and reacting. After the reaction is completed, cool the reaction product, and then perform rotary evaporation to obtain an acyl chloride hindered phenol intermediate; Step a2: Stir and react the acyl chloride hindered phenol intermediate, N - butyl - 2,2,6,6 - tetramethyl - 4 - piperidinamine, and anhydrous toluene, then dropwise add sodium hydroxide solution drop by drop while stirring. After the addition is complete, continue stirring and reacting. After the reaction is completed, cool the reaction product, then add it to distilled water, then perform extraction. Combine the extraction liquids and dry them with anhydrous sodium sulfate, then perform vacuum filtration, and rotary evaporate the filtrate to obtain the bifunctional weathering agent.

2. The anti-aging composite additive for polyethylene weather-resistant film according to claim 1, wherein The dosage ratio of 3-(3,5 - di - tert - butyl - 4 - hydroxyphenyl) propionic acid, chloroform, and thionyl chloride in step a1 is 20 mmol:50 - 60 mL:8 - 10 mL.

3. An anti-aging composite additive for a polyethylene weather-resistant film according to claim 1, characterized in that, The dosage ratio of the acyl chloride hindered phenol intermediate, N - butyl - 2,2,6,6 - tetramethyl - 4 - piperidinamine, anhydrous toluene, and sodium hydroxide solution in step a2 is 10 mmol:10 mmol:40 - 50 mL:10 - 15 mL; the mass fraction of the sodium hydroxide solution is 20 - 22%.

4. An anti-aging composite additive for a polyethylene weather-resistant film according to claim 1, characterized in that The weathering enhancer is prepared by the following steps: Adjust the pH of the ethanol solution with acetic acid, then add nano - titanium dioxide and 1H,1H,2H,2H - perfluorooctyltriethoxysilane and stir and react. After the reaction is completed, cool the reaction product, then centrifuge, wash and dry the precipitate to obtain the weathering enhancer.

5. An anti-aging composite additive for polyethylene weather-resistant film according to claim 4, characterized in that, The dosage ratio of the ethanol solution, nano - titanium dioxide, and 1H,1H,2H,2H - perfluorooctyltriethoxysilane is 90 - 100 mL:10 g:1.5 - 5.5 mL; the volume fraction of the ethanol solution is 50 - 60%; the average particle size of the nano - titanium dioxide is 100 nm.

6. An anti-aging composite additive for a polyethylene weather-resistant film according to claim 1, characterized in that, The strength enhancer is prepared by the following steps: Stir and react deionized water and absolute ethanol, then adjust the pH with ammonia water, then add aluminum borate whiskers and silane coupling agent Z - 6030 and continue stirring and reacting. After the reaction is completed, cool the reaction product, then perform ultrasonic dispersion, then centrifuge, wash and dry the precipitate to obtain the strength enhancer.

7. An anti-aging composite additive for a polyethylene weather-resistant film according to claim 6, characterized in that, The dosage ratio of deionized water, absolute ethanol, aluminum borate whiskers, and silane coupling agent Z - 6030 is 15 - 20 mL:60 - 70 mL:10 g:0.8 - 3.6 g; the mass fraction of the ammonia water is 20 - 25%; the diameter of the aluminum borate whiskers is 0.5 - 1 μm and the length is 10 - 20 μm.

8. A preparation method of an anti-aging composite auxiliary for a polyethylene weather-resistant film, characterized in that, Comprising the following steps: Step 1: Weigh 30 - 35 parts by weight of talcum powder, 12 - 26 parts of bifunctional weathering agent, 5 - 11 parts of weathering enhancer, 3 - 9 parts of strength enhancer, 4 - 8 parts of nucleating agent, 6 - 10 parts of lubricant and 1 - 3 parts of dispersant, and set aside; Step 2: Add the talcum powder, bifunctional weathering agent, weathering enhancer, strength enhancer, nucleating agent, lubricant and dispersant into a high - speed mixer, and stir and mix for 30 - 60 min under the conditions of a temperature of 25 - 30 °C and a stirring rate of 800 - 1000 r / min to obtain an anti - aging composite additive for polyethylene weather - resistant film.

9. The preparation method of an anti-aging composite auxiliary for a polyethylene weather-resistant film according to claim 8, characterized in that, The talcum powder is TYT - 777A talcum powder with a particle size of 3000 mesh; The nucleating agent is Millad 3988 nucleating agent; The lubricant is a mixture of polyethylene wax LP1022P and calcium stearate in a mass ratio of 2:1; The dispersant is a mixture of sodium dodecyl sulfate and polyethylene glycol 400 in a mass ratio of 1:1.

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