Corrosion-resistant anti-aging plastic packaging film and preparation method thereof

Abstract

The invention discloses a corrosion-resistant and anti-aging plastic packaging film and a preparation method thereof, and is used for solving the technical problem that the corrosion resistance and ultraviolet aging resistance of a packaging film in the prior art need to be further improved. The polypropylene composite material comprises the following raw materials in parts by weight: 60-80 parts of modified polypropylene resin, 1-2 parts of a compound nucleating agent, 10-15 parts of a modified filler, 1-2 parts of an antioxidant, 1-2 parts of an ultraviolet light absorber, 1-2 parts of a light stabilizer and 3-5 parts of a plasticizer, the tensile property of the material is improved through crystal form remolding, and the flame retardant property of the material is improved through synergistic cooperation of an internal phosphate structure, an aluminum element and thiocyanuric acid and siloxane chain segments in the material; and the ultraviolet light absorber cross-linked by the compound nucleating agent, the modified filler and the siloxane chain segment are synergistically matched, so that the ultraviolet aging resistance of the material is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of plastic packaging film preparation, and in particular to a corrosion-resistant and aging-resistant plastic packaging film and a preparation method thereof. Background Art

[0002] The development of corrosion-resistant and anti-aging plastic packaging films has undergone continuous innovation from traditional single-functional materials to high-performance composite materials;

[0003] In the early days, ordinary plastics such as polyethylene and polypropylene were widely used due to their low cost and basic moisture-proof and corrosion-resistant properties, but their resistance to UV rays and chemical corrosion was limited, and they were prone to aging and failure under sunlight, oxidation and other environments. In the 1980s, with the development of polymer material modification technology, functional additives such as antioxidants and UV absorbers were introduced into plastic films, greatly improving their anti-aging ability. At the same time, fluorination treatment, copolymerization modification and other technologies improved the chemical corrosion resistance of packaging films. In recent years, the introduction of nanotechnology has promoted the development of composite packaging films, which combine functional fillers such as nano-titanium dioxide and graphene with polymer materials, and the corrosion resistance, UV resistance and mechanical strength of plastic films have been significantly improved.

[0004] Prior art CN2020101488978 discloses a corrosion-resistant packaging material and a preparation method thereof, which is obtained by melt blending and injection molding of polyphenylene ether, polyphenylene sulfone and modified polyurethane resin. The specific preparation method is to mix and dry polyphenylene ether, polyphenylene sulfone and modified polyurethane resin, then add the dried materials to an injection molding machine for injection molding, and finally add the obtained injection molding strip to a film blowing machine for film blowing molding, heat sealing and fixing, and reel molding, so as to obtain a finished corrosion-resistant packaging material;

[0005] The addition of polyphenylene sulfone can improve the thermal stability and impact resistance of polyphenylene ether, increase the heat resistance of polyphenylene ether, and enhance the impact strength of polyphenylene ether. The highly cross-linked modified polyurethane resin structure gives polyphenylene ether good solvent resistance and acid and alkali resistance. After melt blending, the obtained packaging material has good corrosion resistance and can be used for packaging applications of acidic and alkaline substances.

[0006] However, the above patent achieves excellent composite properties by melt blending multiple materials, but the performance of the materials themselves is limited and the microstructure is imperfect. Although polyphenylene ether, polyphenylene sulfone and modified polyurethane resin have good chemical stability, they will undergo structural degradation under strong corrosive or high temperature environments, resulting in performance degradation; and the material formula lacks special ingredients for resistance to ultraviolet aging, making it prone to brittleness or oxidative degradation under long-term ultraviolet irradiation. The interface compatibility of the blended materials is insufficient, resulting in local susceptibility to environmental influences, making the corrosion resistance and ultraviolet resistance of the materials need to be further improved.

[0007] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0008] The object of the present invention is to provide a corrosion-resistant and aging-resistant plastic packaging film and a preparation method thereof, so as to solve the technical problem in the prior art that the corrosion resistance and UV aging resistance of the packaging film need to be further improved.

[0009] The object of the present invention can be achieved by the following technical scheme: a corrosion-resistant and anti-aging plastic packaging film, comprising the following raw material components in parts by weight: 60-80 parts of modified polypropylene resin, 1-2 parts of compound nucleating agent, 10-15 parts of modified filler, 1-2 parts of antioxidant, 1-2 parts of ultraviolet absorber, 1-2 parts of light stabilizer and 3-5 parts of plasticizer;

[0010] The preparation method of modified polypropylene resin comprises the following steps:

[0011] A1. Add chain-extended polypropylene resin, 5,5,5-trifluoropentanal, aluminum chloride and N,N-dimethylformamide into a reactor, raise the temperature of the reactor to 100-120° C., keep the reaction temperature for 1-2 hours, and post-treat to obtain a modified polypropylene resin precursor;

[0012] A2. Add modified polypropylene resin precursor, hydrogen-containing silicone oil and N,N-dimethylformamide into a reactor. After the temperature of the reactor is raised to 100-120°C, add chloroplatinic acid into the reactor, keep the temperature for 1-2 hours, and post-treat to obtain modified polypropylene resin.

[0013] The reaction equation for preparing modified polypropylene resin is:

[0014]

[0015] Where: ; ; “*” indicates the active connection site of the organic chain segment.

[0016] The reaction principle for preparing the modified acrylic resin is as follows: the nitrogen atom in the secondary amino group on the chain-extended polypropylene resin has a lone pair of electrons and exhibits nucleophilicity. At the beginning of the reaction, the nitrogen atom of the secondary amino group will perform a nucleophilic attack on the carbon of the aldehyde group to form a transition state, i.e., a hydroxylamine-type intermediate having a hydroxyl group and a new CN bond, and further undergoes a dehydration reaction, loses a water molecule, forms a double bond, and produces an eneamino group, and finally prepares a modified polypropylene resin precursor. The double bond structure inside the precursor undergoes silylation under the promotion of high temperature and a catalyst, so that the hydrogen-containing silicone oil is cross-linked inside the polypropylene chain segment to obtain a modified acrylic resin.

[0017] Furthermore, in step A1, the amount ratio of the extended polypropylene resin, 5,5,5-trifluoropentanal, aluminum chloride and N,N-dimethylformamide is 8-10 g: 1-2 g: 0.3-0.5 g: 30-36 mL, and the post-treatment includes: after the reaction is completed, the reactor is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80-100° C., and the reaction solution is distilled under reduced pressure until no liquid is extracted to obtain a modified polypropylene resin precursor;

[0018] Furthermore, in step A2, the amount ratio of the modified polypropylene resin precursor, hydrogen-containing silicone oil, N,N-dimethylformamide and chloroplatinic acid is 5-6g:2-3g:24-30mL:0.5-0.6g, and the post-treatment includes: after the reaction is completed, the reactor is cooled to room temperature, the reaction liquid is added to a rotary evaporator with a water bath temperature of 80-100°C, and distilled under reduced pressure until no liquid is extracted to obtain a modified polypropylene resin.

[0019] Furthermore, the antioxidant is one or more of tri-tert-butyl hydroxyphenyl acrylate, tetramethyl dihydroxyphenyl acrylate and tri-tert-butyl hydroxyphenyl acrylate; the UV inhibitor is one or more of 2-hydroxy-4-octyloxybenzophenone, 2-(2'-hydroxy-5'-methylphenyl)benzotriazine and 2-hydroxy-4-methoxybenzophenone; the light stabilizer is one or two of 2-hydroxy-4-octyloxybenzophenone and bis(2,2,6,6-tetramethylpiperidinyl)sebacate; the plasticizer is one or more of dioctyl phthalate, diisononyl phthalate and tributyl citrate.

[0020] Furthermore, the preparation method of the composite nucleating agent is as follows: diphenylphosphoric acid, aluminum isopropoxide, triethylamine and toluene are added to a three-necked flask and stirred, and after stirring at room temperature for 10-15 minutes, the three-necked flask is heated to reflux the reaction system, and after constant temperature reflux for 2-3 hours, 2-hydroxy-4-methoxy-5-sulfonic acid dibenzophenone is added to the reactor, and constant temperature reflux is performed for 1-2 hours, and post-treatment is performed to obtain the composite nucleating agent.

[0021] The reaction equation for preparing the composite nucleating agent is:

[0022]

[0023] Where: ; “*” indicates the active connection site of the organic chain segment.

[0024] The reaction principle for preparing the composite nucleating agent is as follows: diphenylphosphoric acid and 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone are activated by triethylamine to enhance their nucleophilicity, and diphenylphosphoric acid and 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone are cross-linked with aluminum isopropoxide by ester exchange and control of the reaction dosage ratio, and finally the composite nucleating agent is prepared. The mass spectrometry analysis data of the composite nucleating agent are: m / z: 768.06 (100.0%), 769.07 (41.8%), 770.12 (10.9%), 770.07(4.5%),771.13 (2.0%), 771.10 (1.9%).

[0025] Furthermore, the dosage ratio of diphenylphosphoric acid, aluminum isopropoxide, triethylamine, toluene and 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone is 3.5-3.7 g: 1.6-1.8 g: 0.3-0.5 g: 24-27 mL: 2.5-2.7 g, and the post-treatment is as follows: after the reaction is completed, the reactor is cooled to room temperature, and deionized water equal to the volume of toluene is added to the reactor, and the toluene is distilled off, and the reaction liquid is filtered to collect the filter cake, and the filter cake is washed with deionized water for 3-5 times, and then the filter cake is transferred to a drying oven at a temperature of 60-80 ° C and vacuum dried to constant weight to obtain a composite nucleating agent.

[0026] Further, the preparation method of the chain-extended polypropylene resin comprises the following steps:

[0027] B1. Add propylene solution and composite initiator to the reactor, stir at room temperature for 20-30 minutes, add 4-ethylamino-3-pentene-2-one and 1,4-butenediol to the reactor, continue to react at room temperature for 2-3 hours, increase the reaction temperature to 40-50° C., add thiocyanuric acid to the reactor, keep the reaction temperature for 20-30 minutes, and post-treat to obtain a chain-extended polypropylene resin precursor;

[0028] B2. Add the chain-extended polypropylene resin precursor, triethylamine and N,N-dimethylformamide into the reactor, raise the temperature of the reactor to 100-120°C, keep stirring for 10-15 minutes, add 3-(2,3-epoxypropoxy)propyltrimethoxysilane into the reactor, keep the reaction temperature for 20-30 minutes, and post-treat to obtain the chain-extended polypropylene resin.

[0029] The reaction equation for preparing chain-extended polypropylene resin is:

[0030]

[0031] Where: ; “*” indicates the active connection site of the organic chain segment; “·” indicates the active free radical.

[0032] The reaction principle for preparing the chain-extended polypropylene resin is as follows: under the catalysis of a composite initiator, propylene is pre-polymerized, and then 4-ethylamino-3-pentene-2-one and 1,4-butenediol are added to the reactor for further polymerization. Finally, the chain-extended polypropylene resin precursor is obtained by end-capping with thiocyanuric acid, and further modified with a silane coupling agent, which significantly enhances the compatibility of the material with inorganic auxiliary materials, and finally the chain-extended polypropylene resin is prepared.

[0033] Further, in step B1, the amount ratio of propylene solution, composite initiator, 4-ethylamino-3-pentene-2-one, 1,4-butenediol and thiocyanuric acid is 20-30mL:1-1.2g:5-6g:4-5g:2-3g, the propylene solution is prepared by configuring propylene gas and n-hexane at a ratio of 2-3g:8-10mL, and the composite initiator is prepared by mixing benzoyl peroxide and triethylamine at a ratio of 4-5g:1-2g. The post-treatment includes: after the reaction is completed, the reactor is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80-100°C, and the reaction solution is distilled under reduced pressure until no liquid is extracted to obtain a chain-extended polypropylene resin precursor;

[0034] Furthermore, in step B2, the amount ratio of the chain-extended polypropylene resin precursor, triethylamine, N,N-dimethylformamide and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 8-10g:1-1.2g:40-60mL:2-3g, and the post-treatment includes: after the reaction is completed, the reactor is cooled to room temperature, the reaction liquid is added to a rotary evaporator with a water bath temperature of 80-100°C, and the chain-extended polypropylene resin is obtained by distillation under reduced pressure until no liquid is extracted.

[0035] Furthermore, the preparation method of the modified filler comprises the following steps:

[0036] C1, adding 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole and N,N-dimethylformamide into a nitrogen-protected reactor and stirring, raising the temperature of the reactor to 45-50° C., adding isocyanatepropyltriethoxysilane solution dropwise into the reactor, keeping the temperature for reaction for 60-80 min, and post-treating to obtain modified siloxane;

[0037] The reaction equation for preparing modified siloxane is:

[0038]

[0039] Where: ; “*” indicates the active connection site of the organic chain segment.

[0040] The reaction principle for preparing the modified siloxane is as follows: under heating conditions, the isocyanate group on isocyanatepropyltriethoxysilane reacts with the hydroxyl group on 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole to finally prepare the modified siloxane.

[0041] C2. Add nano titanium dioxide, modified siloxane and N,N-dimethylformamide into a reactor, raise the temperature of the reactor to 60-70°C, add saturated sodium hydroxide aqueous solution into the reactor, keep the temperature for 1-2h, and post-treat to obtain a modified filler.

[0042] Principle of preparing modified fillers: Under the catalysis of alkaline conditions and heating conditions, the hydroxyl groups on the nano-titanium dioxide and the silanol bonds produced by the hydrolysis of the siloxane segments of the modified siloxane undergo an elimination reaction, and ultimately the modified siloxane is attached to the surface of the nano-titanium dioxide, and finally the modified filler is prepared.

[0043] Further, in step C1, the amount ratio of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole, N,N-dimethylformamide and isocyanate propyl triethoxysilane solution is 4-5g:20-30mL:10-15mL, and the isocyanate propyl triethoxysilane solution is obtained by mixing isocyanate propyl triethoxysilane and N,N-dimethylformamide at an amount ratio of 3-4g:10-15mL. The post-treatment includes: after the reaction is completed, the reactor is cooled to room temperature, the reaction solution is added to a rotary evaporator with a water bath temperature of 80-100°C, and the reduced pressure distillation is performed until no liquid is produced to obtain modified siloxane;

[0044] Furthermore, in step C2, the dosage ratio of nano-titanium dioxide, modified siloxane, N,N-dimethylformamide and saturated sodium hydroxide aqueous solution is 3-5g:1-2g:15-20mL:1-2mL, and the post-treatment includes: after the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is washed with anhydrous ethanol and deionized water for 3-5 times, and then the filter cake is transferred to a drying oven at a temperature of 65-75°C, and vacuum dried to constant weight to obtain a modified filler.

[0045] The present invention also provides a method for preparing a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0046] S1, adding modified polypropylene resin, compound nucleating agent, modified filler, antioxidant, ultraviolet absorber, light stabilizer and plasticizer into a twin-screw extruder, and melt-extrude to obtain a prefabricated film;

[0047] S2. placing the prefabricated film in a melt stretching device, stretching and shaping it, and then naturally cooling it to obtain a plastic packaging film.

[0048] Further, in step S1, the temperatures of the four temperature sections of the twin-screw extruder are: 170-180°C, 190-200°C, 190-210°C, 180-190°C, and the screw speed is 60-80rpm; in step S2, the stretching and shaping operation is: after maintaining at 180-200°C for 10-20min, the temperature is reduced to 120-130°C, and the speed is 10-15cm / min. -1 The stretching rate is stretched.

[0049] The present invention has the following beneficial effects:

[0050] 1. The present invention prepares a composite nucleating agent of phosphate salts, and improves the tensile strength of the material by remodeling the crystal form. The phosphate structure inside the composite nucleating agent decomposes the phosphoric acid component to produce acidic substances during the combustion process, promotes the carbonization of thiocyanuric acid as a chain extender to produce a carbon layer, and the aluminum group is oxidized at high temperature to produce a flame-retardant aluminum oxide structure, and the siloxane chain segment inside the modified polypropylene resin is thermally decomposed to produce a protective layer to cooperate with each other to block the spread of flames, and the generated phosphorus-containing free radicals capture the active free radicals in the combustion reaction and cooperate with the sulfur group of thiocyanuric acid to interrupt the combustion chain reaction and inhibit the spread of flames. In addition, the ultraviolet absorber structure inside the composite nucleating agent cooperates with the modified filler and the siloxane chain segment to significantly improve the material's anti-ultraviolet aging performance.

[0051] 2. In the process of preparing modified polypropylene resin, a large number of fluorine groups are introduced into the chain segments to make the material have extremely low surface energy, giving the material excellent hydrophobicity, making it difficult for the material surface to absorb water and electrolyte solution, reducing the possibility of corrosion reaction, and making it difficult for water and corrosive media to infiltrate the material surface, forming a physical barrier to reduce the risk of corrosion. At the same time, in the process of introducing fluorine groups, unsaturated double bonds are generated inside the material to embed hydrogen-containing silicone oil into the organic chain segments through silane hydrogen addition. In addition to cooperating with fluorine groups to further reduce the surface energy of the material, a large number of siloxane segments also form a dense cross-linked structure in the material, which acts as a physical barrier. Prevent corrosive media from penetrating the material, slow down or prevent the occurrence of corrosion reactions; by introducing a compound nucleating agent, the composite polypropylene material undergoes crystal remodeling during the melting process to form a β-crystal with stronger mechanical properties. The crystal structure of the β-crystal has high flexibility. Under the action of external force, it is more likely to slip and deform between grains. During the stretching process, the sliding and plastic deformation of the grain boundaries effectively absorb energy to avoid brittle damage to the material; and the grain boundaries of the β-crystal play a crack-blocking role during the stretching process. When the crack propagates to the β-crystal area, the crack will absorb part of the energy due to the deformation of the grains, and the expansion rate will slow down, thereby effectively improving the material's resistance to tensile fracture.

[0052] 3. In the process of preparing the composite nucleating agent, an ultraviolet absorber is introduced into the composite nucleating agent through ester exchange, and the ultraviolet radiation resistance of the material is significantly enhanced by synergistic cooperation with the anti-ultraviolet organic layer coated on the surface of the nano titanium dioxide. The siloxane chain segment inside the modified polypropylene resin absorbs part of the energy of ultraviolet radiation, thereby reducing the energy load of the material matrix exposed to ultraviolet rays. At the same time, by dispersing and reflecting ultraviolet rays, the damage of ultraviolet rays to the internal structure of the material is further reduced. The siloxane chain segment decomposes to generate silicon-containing compounds, which can capture or neutralize free radicals generated on the surface of the material caused by ultraviolet rays, thereby inhibiting the chain propagation of photo-oxidation reactions, and improving the anti-ultraviolet performance of the material through synergistic cooperation. DETAILED DESCRIPTION

[0053] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] The hydrogen-containing silicone oil used in the present invention was purchased from Suzhou Bingsheng New Material Technology Co., Ltd., with the product number MHX-1107;

[0055] The nano titanium dioxide used in the present invention is purchased from Hubei Huifu Nanomaterials Co., Ltd., with the product number being NT-50.

[0056] Example 1

[0057] This embodiment provides a method for preparing a chain-extended polypropylene resin for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0058] Step ①: Preparation of chain-extended polypropylene resin precursor

[0059] Weigh: 200.0 g of propylene gas and 800.0 mL of n-hexane to obtain a propylene solution;

[0060] Weigh: 400.0 g of benzoyl peroxide and 100.0 g of triethylamine and mix to obtain a composite initiator;

[0061] Add 2000.0 mL of propylene solution and 100.0 g of composite initiator to the reactor, stir at room temperature for 20 min, then add 500.0 g of 4-ethylamino-3-pentene-2-one and 400.0 g of 1,4-butenediol to the reactor, continue the reaction at room temperature for 2 h, then increase the reaction temperature to 40 ° C and add 200.0 g of thiocyanuric acid to the reactor, keep the reaction temperature for 20 min, after the reaction is completed, cool the reactor to room temperature, add the reaction solution to a rotary evaporator with a water bath temperature of 80 ° C, and distill under reduced pressure until no liquid is produced to obtain an extended chain polypropylene resin precursor.

[0062] Step ②: Preparation of chain-extended polypropylene resin

[0063] Weigh: 800.0g of extended chain polypropylene resin precursor, 100.0g of triethylamine and 4000.0mL of N,N-dimethylformamide are added to a reactor, the temperature of the reactor is raised to 100°C, and after stirring for 10 minutes, 200.0g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane is added to the reactor, and the reaction is kept warm for 20 minutes. After the reaction is completed, the reactor is cooled to room temperature, and the reaction liquid is added to a rotary evaporator with a water bath temperature of 80°C, and distilled under reduced pressure until no liquid is produced to obtain an extended chain polypropylene resin.

[0064] Example 2

[0065] This embodiment provides a method for preparing a chain-extended polypropylene resin for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0066] Step ①: Preparation of chain-extended polypropylene resin precursor

[0067] Weigh: 300.0 g of propylene gas and 1000.0 mL of n-hexane to obtain a propylene solution;

[0068] Weigh: 500.0 g of benzoyl peroxide and 200.0 g of triethylamine and mix to obtain a composite initiator;

[0069] 3000.0 mL of propylene solution and 120.0 g of composite initiator were added to the reactor. After stirring at room temperature for 30 min, 600.0 g of 4-ethylamino-3-pentene-2-one and 500.0 g of 1,4-butenediol were added to the reactor. After continuing the reaction at room temperature for 3 h, the reaction temperature was increased to 50 ° C and 300.0 g of thiocyanuric acid was added to the reactor. The reaction was kept warm for 30 min. After the reaction was completed, the reactor was cooled to room temperature, and the reaction solution was added to a rotary evaporator with a water bath temperature of 100 ° C., and distilled under reduced pressure until no liquid was produced to obtain an extended chain polypropylene resin precursor.

[0070] Step ②: Preparation of chain-extended polypropylene resin

[0071] Weigh: 1000.0g of extended chain polypropylene resin precursor, 120.0g of triethylamine and 6000.0mL of N,N-dimethylformamide are added to a reactor, the temperature of the reactor is raised to 120°C, and after stirring for 15 minutes, 300.0g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane is added to the reactor, and the reaction is kept warm for 30 minutes. After the reaction is completed, the reactor is cooled to room temperature, and the reaction liquid is added to a rotary evaporator with a water bath temperature of 100°C, and distilled under reduced pressure until no liquid is produced to obtain an extended chain polypropylene resin.

[0072] Example 3

[0073] This embodiment provides a method for preparing a chain-extended polypropylene resin for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0074] Step ①: Preparation of chain-extended polypropylene resin precursor

[0075] Weigh: 250.0 g of propylene gas and 900.0 mL of n-hexane to obtain a propylene solution;

[0076] Weigh: 450.0 g of benzoyl peroxide and 150.0 g of triethylamine and mix to obtain a composite initiator;

[0077] 2500.0 mL of propylene solution and 110.0 g of composite initiator were added to the reactor. After stirring at room temperature for 25 min, 550.0 g of 4-ethylamino-3-pentene-2-one and 450.0 g of 1,4-butenediol were added to the reactor. After continuing the reaction at room temperature for 3 h, the reaction temperature was increased to 45 ° C and 250.0 g of thiocyanuric acid was added to the reactor. The reaction was kept warm for 25 min. After the reaction was completed, the reactor was cooled to room temperature, and the reaction solution was added to a rotary evaporator with a water bath temperature of 90 ° C., and distilled under reduced pressure until no liquid was produced to obtain an extended chain polypropylene resin precursor.

[0078] Step ②: Preparation of chain-extended polypropylene resin

[0079] Weigh: 900.0g of extended chain polypropylene resin precursor, 110.0g of triethylamine and 5000.0mL of N,N-dimethylformamide are added to the reactor, the temperature of the reactor is raised to 110°C, and after stirring for 12 minutes, 250.0g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane is added to the reactor, and the reaction is kept warm for 25 minutes. After the reaction is completed, the reactor is cooled to room temperature, and the reaction liquid is added to a rotary evaporator with a water bath temperature of 90°C, and distilled under reduced pressure until no liquid is produced to obtain an extended chain polypropylene resin.

[0080] Example 4

[0081] This embodiment provides a method for preparing a composite nucleating agent for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0082] Weigh: 350.0g of diphenylphosphoric acid, 160.0g of aluminum isopropoxide, 30.0g of triethylamine and 2400.0mL of toluene are added to a three-necked flask and stirred. After stirring at room temperature for 10 minutes, the three-necked flask is heated to reflux the reaction system. After constant temperature reflux for 2 hours, 250.0g of 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone is added to the reactor and refluxed at a constant temperature for 1 hour. After the reaction is completed, the reactor is lowered to room temperature, and deionized water equal to the volume of toluene is added to the reactor. After distilling toluene, the reaction liquid is filtered to collect the filter cake, and the filter cake is washed with deionized water 3 times, and then the filter cake is transferred to a drying oven at a temperature of 40°C and vacuum dried to constant weight to obtain a composite nucleating agent.

[0083] Example 5

[0084] This embodiment provides a method for preparing a composite nucleating agent for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0085] Weigh: 370.0g of diphenylphosphoric acid, 180.0g of aluminum isopropoxide, 50.0g of triethylamine and 2700.0mL of toluene are added to a three-necked flask and stirred. After stirring at room temperature for 15 minutes, the three-necked flask is heated to reflux the reaction system. After constant temperature reflux for 3 hours, 270.0g of 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone is added to the reactor and refluxed at a constant temperature for 2 hours. After the reaction is completed, the reactor is lowered to room temperature, and deionized water equal to the volume of toluene is added to the reactor. After distilling toluene, the reaction liquid is filtered to collect the filter cake, and the filter cake is washed with deionized water 5 times, and then the filter cake is transferred to a drying oven at a temperature of 80°C and vacuum dried to constant weight to obtain a composite nucleating agent.

[0086] Example 6

[0087] This embodiment provides a method for preparing a composite nucleating agent for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0088] Weigh: 360.0g of diphenylphosphoric acid, 170.0g of aluminum isopropoxide, 40.0g of triethylamine and 2500.0mL of toluene are added to a three-necked flask and stirred. After stirring at room temperature for 12 minutes, the three-necked flask is heated to reflux the reaction system. After constant temperature reflux for 3 hours, 260.0g of 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone is added to the reactor and refluxed at a constant temperature for 2 hours. After the reaction is completed, the reactor is lowered to room temperature, and deionized water equal to the volume of toluene is added to the reactor. After distilling toluene, the reaction liquid is filtered to collect the filter cake. After washing the filter cake 4 times with deionized water, the filter cake is transferred to a drying oven at a temperature of 70°C and vacuum dried to constant weight to obtain a composite nucleating agent.

[0089] Example 7

[0090] This embodiment provides a method for preparing a modified filler for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0091] Step I: Preparation of modified siloxane

[0092] Weigh: 300.0 g of isocyanate propyl triethoxysilane and 1000.0 mL of N,N-dimethylformamide and mix to obtain an isocyanate propyl triethoxysilane solution;

[0093] Weigh: 400.0g 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole and 2000.0mL N,N-dimethylformamide are added to a nitrogen-protected reactor and stirred. The temperature of the reactor is raised to 45°C. 1000.0mL of isocyanatepropyltriethoxysilane solution is added dropwise to the reactor. The reaction is kept warm for 60 minutes. After the reaction is completed, the reactor is cooled to room temperature. The reaction solution is added to a rotary evaporator with a water bath temperature of 80°C, and distilled under reduced pressure until no liquid is produced to obtain modified siloxane.

[0094] Step II: Preparation of modified filler

[0095] Weigh: 300.0g of nano titanium dioxide, 100.0g of modified siloxane and 1500.0mL of N,N-dimethylformamide and add them to a reactor. The temperature of the reactor is raised to 60°C. 100.0mL of saturated sodium hydroxide aqueous solution is added to the reactor. The reaction is kept warm for 1h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is washed 3 times with anhydrous ethanol and deionized water. The filter cake is transferred to a drying oven at a temperature of 65°C and vacuum dried to constant weight to obtain a modified filler.

[0096] Example 8

[0097] This embodiment provides a method for preparing a modified filler for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0098] Step I: Preparation of modified siloxane

[0099] Weigh: 400.0 g of isocyanate propyl triethoxysilane and 1500.0 mL of N,N-dimethylformamide and mix to obtain an isocyanate propyl triethoxysilane solution;

[0100] Weigh: 500.0g2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole and 3000.0mLN,N-dimethylformamide are added to a nitrogen-protected reactor and stirred. The temperature of the reactor is raised to 50°C, and 1500.0mL of isocyanatepropyltriethoxysilane solution is added dropwise to the reactor. The reaction is kept warm for 80 minutes. After the reaction is completed, the reactor is cooled to room temperature, and the reaction liquid is added to a rotary evaporator with a water bath temperature of 100°C, and distilled under reduced pressure until no liquid is produced to obtain modified siloxane.

[0101] Step II: Preparation of modified filler

[0102] Weigh: 500.0g of nano titanium dioxide, 200.0g of modified siloxane and 2000.0mL of N,N-dimethylformamide and add them to a reactor. The temperature of the reactor is raised to 70°C. 200.0mL of saturated sodium hydroxide aqueous solution is added to the reactor. The reaction is kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature. The reaction liquid is filtered to collect the filter cake. After washing the filter cake with anhydrous ethanol and deionized water for 5 times, the filter cake is transferred to a drying oven at a temperature of 75°C and vacuum dried to constant weight to obtain a modified filler.

[0103] Example 9

[0104] This embodiment provides a method for preparing a modified filler for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0105] Step I: Preparation of modified siloxane

[0106] Weigh: 350.0 g of isocyanate propyl triethoxysilane and 1200.0 mL of N,N-dimethylformamide and mix to obtain an isocyanate propyl triethoxysilane solution;

[0107] Weigh: 450.0g 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole and 2500.0mL N,N-dimethylformamide are added to a nitrogen-protected reactor and stirred. The temperature of the reactor is raised to 48°C. 1200.0mL of isocyanatepropyltriethoxysilane solution is added dropwise to the reactor. The reaction is kept warm for 70 minutes. After the reaction is completed, the reactor is cooled to room temperature. The reaction solution is added to a rotary evaporator with a water bath temperature of 90°C, and distilled under reduced pressure until no liquid is produced to obtain modified siloxane.

[0108] Step II: Preparation of modified filler

[0109] Weigh: 400.0g of nano titanium dioxide, 150.0g of modified siloxane and 1800.0mL of N,N-dimethylformamide and add them to a reactor. The temperature of the reactor is raised to 65°C. 150.0mL of saturated sodium hydroxide aqueous solution is added to the reactor. The reaction is kept warm for 2h. After the reaction is completed, the temperature of the reactor is lowered to room temperature. The reaction liquid is filtered to collect the filter cake. After washing the filter cake with anhydrous ethanol and deionized water for 4 times, the filter cake is transferred to a drying oven at a temperature of 70°C and vacuum dried to constant weight to obtain a modified filler.

[0110] Example 10

[0111] This embodiment provides a method for preparing a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0112] Step 1: Preparation of modified polypropylene resin precursor

[0113] Weigh: 800.0g of the extended chain polypropylene resin prepared in Example 1, 100.0g of 5,5,5-trifluorovaleraldehyde, 30.0g of aluminum chloride and 3000.0mL of N,N-dimethylformamide are added to a reactor, the temperature of the reactor is raised to 100°C, and the reaction is kept warm for 1h. After the reaction is completed, the reactor is cooled to room temperature, and the reaction liquid is added to a rotary evaporator with a water bath temperature of 80°C, and distilled under reduced pressure until no liquid is extracted to obtain a modified polypropylene resin precursor.

[0114] Step 2: Preparation of modified polypropylene resin

[0115] Weigh: 500.0g of modified polypropylene resin precursor, 200.0g of hydrogen-containing silicone oil and 2400.0mL of N,N-dimethylformamide are added to a reactor. After the temperature of the reactor is raised to 100°C, 50.0g of chloroplatinic acid is added to the reactor and the reaction is kept warm for 1h. After the reaction is completed, the reactor is cooled to room temperature and the reaction liquid is added to a rotary evaporator with a water bath temperature of 80°C. Reduced pressure distillation is performed until no liquid is produced to obtain a modified polypropylene resin.

[0116] Step 3: Prepare prefabricated membrane

[0117] Weigh: 6000.0g modified polypropylene resin, 100.0g composite nucleating agent prepared in Example 4, 1000.0g modified filler prepared in Example 7, 100.0g tri-tert-butyl hydroxyphenyl acrylate, 100.0g 2-hydroxy-4-octyloxybenzophenone, 100.0g bis(2,2,6,6-tetramethylpiperidinyl)sebacate and 300.0g dioctyl phthalate and add them into a twin-screw extruder. The temperatures of the four temperature sections of the twin-screw extruder are: 170°C, 190°C, 190°C, 180°C, the screw speed is 60rpm, and melt extrusion is performed to obtain a prefabricated film.

[0118] Step 4: Prepare plastic packaging film

[0119] The prefabricated film was placed in a melt stretching device and maintained at 180°C for 10 min. The temperature was then lowered to 120°C and the film was stretched at a speed of 10 cm / min. -1 The film is stretched at a stretching rate of and cooled naturally to obtain a plastic packaging film.

[0120] Embodiment 11

[0121] This embodiment provides a method for preparing a modified polypropylene resin for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0122] Step 1: Preparation of modified polypropylene resin precursor

[0123] Weigh: 1000.0g of the extended chain polypropylene resin prepared in Example 2, 200.0g of 5,5,5-trifluorovaleraldehyde, 50.0g of aluminum chloride and 3600.0mL of N,N-dimethylformamide are added to a reactor, the temperature of the reactor is raised to 120°C, and the reaction is kept warm for 2h. After the reaction is completed, the reactor is cooled to room temperature, and the reaction liquid is added to a rotary evaporator with a water bath temperature of 100°C, and distilled under reduced pressure until no liquid is extracted to obtain a modified polypropylene resin precursor.

[0124] Step 2: Preparation of modified polypropylene resin

[0125] Weigh: 500.0g of modified polypropylene resin precursor, 200.0g of hydrogen-containing silicone oil and 2400.0mL of N,N-dimethylformamide are added to a reactor. After the temperature of the reactor is raised to 120°C, 60.0g of chloroplatinic acid is added to the reactor and the reaction is kept warm for 2h. After the reaction is completed, the reactor is cooled to room temperature and the reaction liquid is added to a rotary evaporator with a water bath temperature of 1000°C. Reduced pressure distillation is performed until no liquid is produced to obtain a modified polypropylene resin.

[0126] Step 3: Prepare prefabricated membrane

[0127] Weigh: 8000.0g modified polypropylene resin, 200.0g composite nucleating agent prepared in Example 5, 1500.0g modified filler prepared in Example 8, 200.0g tri-tert-butyl hydroxyphenyl acrylate, 200.0g 2-hydroxy-4-octyloxybenzophenone, 200.0g bis(2,2,6,6-tetramethylpiperidinyl)sebacate and 500.0g dioctyl phthalate and add them into a twin-screw extruder. The four temperature sections of the twin-screw extruder are 180°C, 200°C, 210°C, and 190°C, respectively. The screw speed is 80rpm, and melt extrusion is performed to obtain a prefabricated film.

[0128] Step 4: Prepare plastic packaging film

[0129] The prefabricated film was placed in a melt stretching device and maintained at 200°C for 20 min. The temperature was then lowered to 130°C and the film was stretched at a speed of 15 cm / min. -1 The film is stretched at a stretching rate of and cooled naturally to obtain a plastic packaging film.

[0130] Example 12

[0131] This embodiment provides a method for preparing a modified polypropylene resin for a corrosion-resistant and aging-resistant plastic packaging film, comprising the following steps:

[0132] Step 1: Preparation of modified polypropylene resin precursor

[0133] Weigh: 900.0g of the extended chain polypropylene resin prepared in Example 3, 150.0g of 5,5,5-trifluorovaleraldehyde, 40.0g of aluminum chloride and 3200.0mL of N,N-dimethylformamide were added to the reactor, the temperature of the reactor was raised to 110°C, and the reaction was kept warm for 2h. After the reaction was completed, the reactor was cooled to room temperature, and the reaction solution was added to a rotary evaporator with a water bath temperature of 90°C, and distilled under reduced pressure until no liquid was extracted to obtain a modified polypropylene resin precursor.

[0134] Step 2: Preparation of modified polypropylene resin

[0135] Weigh: 550.0g of modified polypropylene resin precursor, 250.0g of hydrogen-containing silicone oil and 2800.0mL of N,N-dimethylformamide are added to a reactor. After the temperature of the reactor is raised to 110°C, 55.0g of chloroplatinic acid is added to the reactor and the reaction is kept warm for 2h. After the reaction is completed, the reactor is cooled to room temperature and the reaction liquid is added to a rotary evaporator with a water bath temperature of 90°C. Reduce pressure distillation is performed until no liquid is produced to obtain a modified polypropylene resin.

[0136] Step 3: Prepare prefabricated membrane

[0137] Weigh: 7000.0g modified polypropylene resin, 150.0g composite nucleating agent prepared in Example 6, 1200.0g modified filler prepared in Example 9, 150.0g tri-tert-butyl hydroxyphenyl acrylate, 150.0g 2-hydroxy-4-octyloxybenzophenone, 150.0g bis(2,2,6,6-tetramethylpiperidinyl)sebacate and 400.0g dioctyl phthalate and add them into a twin-screw extruder. The four temperature sections of the twin-screw extruder are 175°C, 195°C, 200°C, and 185°C, respectively. The screw speed is 70rpm, and melt extrusion is performed to obtain a prefabricated film.

[0138] Step 4: Prepare plastic packaging film

[0139] The prefabricated film was placed in a melt stretching device and maintained at 190°C for 15 min. The temperature was then lowered to 125°C and the film was stretched at a speed of 12 cm / min. -1 The film is stretched at a stretching rate of and cooled naturally to obtain a plastic packaging film.

[0140] Comparative Example 1

[0141] The difference between this comparative example and Example 12 is that step 2 is omitted, and an equal amount of the modified polypropylene resin precursor prepared in step 1 is used to replace the modified polypropylene resin.

[0142] Comparative Example 2

[0143] The difference between this comparative example and Example 12 is that step one and step two are omitted, and an equal amount of the chain-extended polypropylene resin prepared in Example 3 is used to replace the modified polypropylene resin.

[0144] Comparative Example 3

[0145] The difference between this comparative example and Example 12 is that, in step three, the use of compound nucleating agent and modified filler is omitted.

[0146] Performance Test:

[0147] The corrosion resistance of the test sample was tested with reference to the standard HG / T 3984-2007 "Chemical Corrosion Resistant Modified Polypropylene Storage Tank";

[0148] The tensile strength and elongation at break of the plastic packaging films prepared in Examples 10-12 and Comparative Examples 1-3 were measured with reference to the standard GB / T 1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for films and sheets";

[0149] The vertical burning grades of the plastic packaging films prepared in Examples 10-12 and Comparative Examples 1-3 were measured with reference to the standard GB / T 2408-2021 "Horizontal and vertical methods for determination of combustion performance of plastics". The specific data are shown in Table 1.

[0150] The composite polypropylene prepared in Example 12 and Comparative Examples 1-3 was subjected to an ultraviolet aging test with reference to the standard GB / T 16422.3-2022 "Plastics Laboratory Light Source Exposure Test Method Part 3: Fluorescent Ultraviolet Lamp", and the tensile strength and elongation at break retention rates of the materials were determined with reference to the standard GB / T 1040.3-2006, and the tensile strength retention rates and elongation at break retention rates were calculated; the corrosion resistance of the materials was determined with reference to the standard HG / T 3984-2007, and the specific data are shown in Table 2.

[0151] Table 1-Performance test data of each sample

[0152] Table 2-Performance test data of each sample after UV aging

[0153] Data Analysis:

[0154] Comparing and analyzing the data in Table 1 above, the plastic packaging film prepared by the present invention is resistant to corrosion by saturated calcium hydroxide solution and 10wt% nitric acid solution, has a tensile strength of 64.8MPa, an elongation at break of 346.3%, and a vertical burning grade of V-0; Comparing and analyzing the data in Table 1 above, the plastic packaging film prepared by the present invention is still resistant to corrosion by saturated calcium hydroxide solution and 10wt% nitric acid solution after ultraviolet aging, has a tensile strength retention rate of 99.3%, and an elongation at break retention rate of 98.2%;

[0155] By comparing the test data of corrosion resistance, it can be found that the corrosion resistance of the plastic packaging film prepared in Comparative Example 1 is slightly reduced compared with that of the plastic packaging film prepared in Example 12, and the corrosion resistance of the plastic packaging film prepared in Comparative Example 2 is significantly reduced compared with that of the plastic packaging film prepared in Example 12, indicating that in the process of preparing the modified polypropylene resin, a large number of fluorine groups are introduced into the chain segments, so that the material has an extremely low surface energy, and the material is given excellent hydrophobicity, so that it is difficult for the material surface to adsorb moisture and electrolyte solution, reducing the possibility of corrosion reaction, and making it difficult for water and corrosive media to infiltrate the material surface, forming a physical barrier to reduce the risk of corrosion. At the same time, in the process of introducing fluorine groups, unsaturated double bonds are generated inside the material, so that hydrogen-containing silicone oil is embedded in the organic chain segments through silane hydrogenation. In addition to cooperating with fluorine groups to further reduce the surface energy of the material, a large number of siloxane segments also form a dense cross-linked structure in the material, which acts as a physical barrier to prevent the corrosive medium from penetrating the material, and slow down or prevent the occurrence of corrosion reactions.

[0156] By comparing the test data of tensile resistance, it can be found that the tensile resistance of the plastic packaging film prepared in Comparative Example 3 is significantly lower than that of the plastic packaging film prepared in Example 12, indicating that the introduction of the compound nucleating agent causes the composite polypropylene material to undergo crystal remodeling during the melting process to form a β-crystal with stronger mechanical properties. The crystal structure of the β-crystal has high flexibility. Under the action of external force, it is easier for the grains to slip and deform. During the stretching process, the sliding and plastic deformation of the grain boundaries effectively absorb energy to prevent the material from being brittlely damaged. In addition, the grain boundaries of the β-crystal play a crack-blocking role during the stretching process. When the crack propagates to the β-crystal region, the crack will absorb part of the energy due to the deformation of the grains, and the expansion speed will slow down, thereby effectively improving the tensile fracture resistance of the material.

[0157] By comparing the flame retardant test data, it can be found that the flame retardant properties of the plastic packaging films prepared in Comparative Examples 1-3 are significantly lower than those of the plastic packaging films prepared in Example 12, indicating that the introduction of the composite nucleating agent decomposes the phosphoric acid component during combustion to produce acidic substances, promotes the carbonization of thiocyanuric acid as a chain extender to produce a carbon layer, and the aluminum group is oxidized at high temperature to produce a flame-retardant aluminum oxide structure, and the siloxane chain segment inside the modified polypropylene resin is thermally decomposed to produce a protective layer to cooperate with each other to block the spread of flames, and the generated phosphorus-containing free radicals capture the active free radicals in the combustion reaction and cooperate with the sulfur group of thiocyanuric acid to interrupt the combustion chain reaction and inhibit the spread of flames;

[0158] By comparing the data of the anti-ultraviolet performance of the materials, it can be found that the anti-ultraviolet performance of the plastic packaging film prepared in Comparative Examples 1-2 is significantly lower than that of the plastic packaging film prepared in Example 12, and the flame retardant performance of the plastic packaging film prepared in Comparative Example 3 is slightly lower than that of the plastic packaging film prepared in Example 12, indicating that in the process of preparing the composite nucleating agent, the ultraviolet absorber is introduced into the composite nucleating agent through ester exchange, and the ultraviolet radiation resistance of the material is significantly enhanced by synergistic cooperation with the anti-ultraviolet organic layer coated on the surface of the nano titanium dioxide, and the siloxane segment inside the modified polypropylene resin absorbs part of the energy of ultraviolet radiation, thereby reducing the energy load of the material matrix exposed to ultraviolet rays, and at the same time, by dispersing and reflecting ultraviolet rays, further reducing the damage of ultraviolet rays to the internal structure of the material, and the siloxane segment decomposes to generate silicon-containing compounds, which can capture or neutralize the free radicals generated on the surface of the material by ultraviolet rays, thereby inhibiting the chain propagation of the photooxidation reaction, and the anti-ultraviolet performance of the material is improved by synergistic cooperation;

[0159] The present invention prepares a composite nucleating agent of phosphate salts, improves the tensile strength of the material by reshaping the crystal form, and the internal phosphate structure cooperates with the aluminum element and the chain extender thiocyanuric acid and siloxane segments in the organic chain segment to improve the flame retardant performance of the material, and the ultraviolet absorber structure in the composite nucleating agent cooperates with the modified filler and the siloxane segment to significantly improve the material's resistance to ultraviolet aging.

[0160] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A corrosion-resistant and aging-resistant plastic packaging film, characterized in that: The raw material composition includes the following parts by weight: 60-80 parts of modified polypropylene resin, 1-2 parts of compound nucleating agent, 10-15 parts of modified filler, 1-2 parts of antioxidant, 1-2 parts of ultraviolet absorber, 1-2 parts of light stabilizer and 3-5 parts of plasticizer; The preparation method of the modified polypropylene resin comprises the following steps: A1. Add chain-extended polypropylene resin, 5,5,5-trifluoropentanal, aluminum chloride and N,N-dimethylformamide into a reactor, raise the temperature of the reactor to 100-120° C., keep the reaction temperature for 1-2 hours, and post-treat to obtain a modified polypropylene resin precursor; A2. Add modified polypropylene resin precursor, hydrogen-containing silicone oil and N,N-dimethylformamide into a reactor. After the temperature of the reactor is raised to 100-120°C, add chloroplatinic acid into the reactor, keep the temperature for 1-2 hours, and post-treat to obtain modified polypropylene resin.

2. The corrosion-resistant and aging-resistant plastic packaging film according to claim 1, characterized in that: In step A1, the amount ratio of chain-extended polypropylene resin, 5,5,5-trifluoropentanal, aluminum chloride and N,N-dimethylformamide is 8-10g:1-2g:0.3-0.5g:30-36mL; in step A2, the amount ratio of modified polypropylene resin precursor, hydrogen-containing silicone oil, N,N-dimethylformamide and chloroplatinic acid is 5-6g:2-3g:24-30mL:0.5-0.6g.

3. The corrosion-resistant and aging-resistant plastic packaging film according to claim 1, characterized in that: The preparation method of the composite nucleating agent comprises the following steps: adding diphenylphosphoric acid, aluminum isopropoxide, triethylamine and toluene into a three-necked flask and stirring; stirring for 10-15 minutes at room temperature; heating the three-necked flask until the reaction system refluxes; refluxing at a constant temperature for 2-3 hours; adding 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone into a reaction kettle; refluxing at a constant temperature for 1-2 hours; and post-treating to obtain the composite nucleating agent.

4. The corrosion-resistant and aging-resistant plastic packaging film according to claim 3, characterized in that: The usage ratio of diphenylphosphoric acid, aluminum isopropoxide, triethylamine, toluene and 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone is 3.5-3.7 g:1.6-1.8 g:0.3-0.5 g:24-27 mL:2.5-2.7 g.

5. The corrosion-resistant and aging-resistant plastic packaging film according to claim 1, characterized in that: The preparation method of the chain-extended polypropylene resin comprises the following steps: B1. Add propylene solution and composite initiator to the reactor, stir at room temperature for 20-30 minutes, add 4-ethylamino-3-pentene-2-one and 1,4-butenediol to the reactor, continue to react at room temperature for 2-3 hours, increase the reaction temperature to 40-50° C., add thiocyanuric acid to the reactor, keep the reaction temperature for 20-30 minutes, and post-treat to obtain a chain-extended polypropylene resin precursor; B2. Add the chain-extended polypropylene resin precursor, triethylamine and N,N-dimethylformamide into the reactor, raise the temperature of the reactor to 100-120°C, keep stirring for 10-15 minutes, add 3-(2,3-epoxypropoxy)propyltrimethoxysilane into the reactor, keep the reaction temperature for 20-30 minutes, and post-treat to obtain the chain-extended polypropylene resin.

6. The corrosion-resistant and aging-resistant plastic packaging film according to claim 5, characterized in that: In step B1, the amount ratio of propylene solution, composite initiator, 4-ethylamino-3-pentene-2-one, 1,4-butenediol and thiocyanuric acid is 20-30mL:1-1.2g:5-6g:4-5g:2-3g, the propylene solution is prepared by configuring propylene gas and n-hexane at a ratio of 2-3g:8-10mL, and the composite initiator is prepared by mixing benzoyl peroxide and triethylamine at a ratio of 4-5g:1-2g; in step B2, the amount ratio of chain-extended polypropylene resin precursor, triethylamine, N,N-dimethylformamide and 3-(2,3-epoxypropoxy)propyltrimethoxysilane is 8-10g:1-1.2g:40-60mL:2-3g.

7. The corrosion-resistant and aging-resistant plastic packaging film according to claim 1, characterized in that: The preparation method of the modified filler comprises the following steps: C1, adding 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole and N,N-dimethylformamide into a nitrogen-protected reactor and stirring, raising the temperature of the reactor to 45-50° C., adding isocyanatepropyltriethoxysilane solution dropwise into the reactor, keeping the temperature for reaction for 60-80 min, and post-treating to obtain modified siloxane; C2. Add nano titanium dioxide, modified siloxane and N,N-dimethylformamide into a reactor, raise the temperature of the reactor to 60-70°C, add saturated sodium hydroxide aqueous solution into the reactor, keep the temperature for 1-2h, and post-treat to obtain a modified filler.

8. The corrosion-resistant and aging-resistant plastic packaging film according to claim 7, characterized in that: In step C1, the amount ratio of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-benzotriazole, N,N-dimethylformamide and isocyanate propyl triethoxysilane solution is 4-5g:20-30mL:10-15mL, and the isocyanate propyl triethoxysilane solution is obtained by mixing isocyanate propyl triethoxysilane and N,N-dimethylformamide in an amount ratio of 3-4g:10-15mL; in step C2, the amount ratio of nano titanium dioxide, modified siloxane, N,N-dimethylformamide and saturated sodium hydroxide aqueous solution is 3-5g:1-2g:15-20mL:1-2mL.

9. The method for preparing a corrosion-resistant and aging-resistant plastic packaging film according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, modified polypropylene resin, compound nucleating agent, modified filler, antioxidant, ultraviolet absorber, light stabilizer and plasticizer are added into a twin-screw extruder, melt-extruded to obtain a prefabricated film; S2. placing the prefabricated film in a melt stretching device, stretching and shaping it, and then naturally cooling it to obtain a plastic packaging film.

10. The method for preparing a corrosion-resistant and aging-resistant plastic packaging film according to claim 9, characterized in that: In step S1, the four temperature sections of the twin-screw extruder are: 170-180°C, 190-200°C, 190-210°C, 180-190°C, and the screw speed is 60-80rpm; in step S2, the stretching and shaping operation is: after maintaining at 180-200°C for 10-20min, the temperature is reduced to 120-130°C, and the speed is 10-15cm / min. -1 The stretching rate is stretched.

Images