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

Abstract

The application discloses a kind of corrosion-resistant anti-aging plastic packaging barrels and preparation method thereof, belong to plastic product processing technical field, to solve the technical problems that corrosion resistance and anti-aging performance of plastic packaging barrel in prior art need to be further improved, specifically including the following raw material composition by portion: 60-70 parts modified silicone, 3-5 parts modified aging-resistant filler, 8-12 parts polypropylene, 12-18 parts maleic anhydride grafted polypropylene and 3-5 parts auxiliary additive, the application is that polypropylene, maleic anhydride grafted polypropylene, modified silicone, modified aging-resistant filler and auxiliary additive are added into double-screw melt extruder, melt extrusion, injection mold, obtain plastic packaging barrel, not only improve its corrosion resistance and anti-aging performance, also improve its mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of plastic product processing technology, specifically to a corrosion-resistant and anti-aging plastic packaging barrel and its preparation method. Background Technology

[0002] In recent years, with the rapid development of the chemical, food, and logistics industries, plastic packaging drums have gradually replaced traditional metal containers and become the mainstream choice for the transportation and storage of liquid or solid materials due to their lightweight, easy molding, and cost advantages. However, conventional plastic packaging drums have significant shortcomings in flame retardancy, corrosion resistance, and aging resistance. During long-term outdoor use, plastic packaging drums are prone to swelling, cracking, and even leakage risks due to prolonged contact with corrosive substances such as chemical raw materials and acid and alkali solutions. Furthermore, under the long-term effects of ultraviolet radiation, the polymer chains in plastic packaging drums will break down faster, resulting in surface powdering, a sharp drop in mechanical properties, and a significant shortening of the packaging drum's service life. Although attempts have been made to improve performance by adding antioxidants, ultraviolet absorbers, or surface coatings, problems such as additive precipitation, coating peeling, or rapid weather resistance degradation still exist, making it difficult to meet the stringent requirements for long-term stability in high-end application scenarios.

[0003] In existing technologies, the root cause of insufficient flame retardancy, corrosion resistance, and aging resistance of plastic packaging barrels lies primarily in the limitations of material molecular structure and interface design. The carbon-carbon backbone of polyolefin materials is susceptible to free radical chain reactions triggered by heat and oxygen, as well as photo-oxidation, leading to chain breakage and cross-linking imbalance. Furthermore, polar corrosive media can disrupt the regularity of molecular chains through diffusion and penetration, exacerbating material deterioration. To improve the corrosion resistance and flame retardancy of plastic packaging barrels, inorganic fillers or flame retardants are often added to enhance performance. However, the added reinforcing materials have poor compatibility with the polymer matrix, easily forming stress concentration points. Under long-term stress corrosion or thermal cycling, this can induce the propagation of microcracks. In addition, traditional modification techniques often rely on physical blending, where functional components easily migrate to the surface and are lost, reducing service life. Summary of the Invention

[0004] The purpose of this invention is to provide a corrosion-resistant and anti-aging plastic packaging barrel and its preparation method, in order to solve the technical problem that the corrosion resistance and anti-aging properties of plastic packaging barrels in the prior art need to be further improved.

[0005] The objective of this invention can be achieved through the following technical solution: a corrosion-resistant and anti-aging plastic packaging barrel, comprising the following raw materials by weight: 60-70 parts modified silicone resin, 3-5 parts modified anti-aging filler, 8-12 parts polypropylene, 12-18 parts maleic anhydride grafted polypropylene and 3-5 parts auxiliary additives.

[0006] The auxiliary additives consist of an initiator, a plasticizer, an antistatic agent, and an antibacterial agent in a mass ratio of 1:5:1:0.5.

[0007] Furthermore, the modified silicone resin is prepared by the following steps:

[0008] A1. Place 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and xylene in a reaction vessel, heat to 110-120℃, add catalyst, keep the reaction at this temperature for 4-6 h, add 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane, keep the reaction at this temperature for 3-5 h, and then perform post-treatment to obtain the modified silicone resin precursor;

[0009] The reaction principle for preparing modified silicone resin precursors is as follows:

[0010] During the reaction, under the catalysis of 50wt% sulfuric acid solution, 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane and tetramethyltetravinylcyclotetrasiloxane are hydrolyzed into silanols. The silanols further undergo a condensation reaction to obtain long-chain polysiloxanes. 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane is added as a capping agent to obtain a modified silicone resin precursor with olefin unsaturated double bonds in the side chain and hydroxyl-capped ends.

[0011] A2. Under a nitrogen atmosphere, the modified silicone resin precursor, polyethylene glycol, stannous octoate, and tetrahydrofuran are placed in a reactor equipped with a condenser. The mixture is stirred for 5-15 minutes, heated to 60-65°C, and a calculated amount of hexamethylene diisocyanate is added to the reactor. The mixture is kept at this temperature for 0.5-1 hour. Trimethylolpropane and flame-retardant microspheres are then added, and the mixture is kept at this temperature for 1-2 hours. The modified silicone resin is obtained after post-treatment.

[0012] The preparation reaction formula for modified silicone resin is as follows:

[0013]

[0014] In the formula: , .

[0015] The preparation reaction principle of modified silicone resin is as follows:

[0016] During the reaction, under the catalysis of stannous octoate, the isocyanate groups of hexamethylene diisocyanate and the hydroxyl groups of the modified silicone resin precursor and polyethylene glycol undergo an addition reaction. By controlling the excess of isocyanate groups, flame-retardant microspheres with silica shells are further added. The excess isocyanate groups condense with the amino groups on the surface of the flame-retardant microspheres to form covalent links, thus obtaining the modified silicone resin.

[0017] Further, in step A1, the ratio of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, xylene, catalyst, and 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane is 2-3 g:7-9 g:100-150 mL:4-6 mL:0.5-1 g, the catalyst is a 50 wt% sulfuric acid solution, and the post-treatment step includes: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, 1 wt% sodium hydroxide solution is added to the reaction system to adjust the pH of the system to 7 ± 0.5, and the mixture is allowed to stand and separate. The organic phase is washed with deionized water until neutral and then dried. It is then transferred to a rotary evaporator at a temperature of 90-100℃ and distilled under reduced pressure until no liquid is collected, thus obtaining the modified silicone resin precursor. In step A2, the ratio of the modified silicone resin precursor, polyethylene glycol, stannous octoate, tetrahydrofuran, trimethylolpropane, and flame-retardant microspheres is 10-12g:2-4g:0.5-1g:250-300mL:1-2g:1-1.5g. In the reaction, hexamethylene diisocyanate is 0.55 times the molar amount of hydroxyl groups in the reaction system. The post-treatment step includes: after the reaction is completed, removing low-boiling substances by reduced pressure evaporation to obtain the modified silicone resin.

[0018] Furthermore, the preparation method of the flame-retardant microspheres is as follows: deionized water, ethanol, ammonium polyphosphate, OP-10 and ammonia are placed in a reaction vessel and stirred for 5-10 min. Tetraethyl orthosilicate and (2-aminoisopropyl)triethoxysilane are added, the temperature is raised to 35-45℃, and the reaction is maintained for 1-2 h. The flame-retardant microspheres are then obtained after post-treatment.

[0019] The preparation reaction principle of flame-retardant microspheres is as follows:

[0020] During the reaction, under the catalysis of ammonia, tetraethyl orthosilicate and (2-aminoisopropyl)triethoxysilane undergo hydrolysis to generate silicic acid. The silicic acid molecules undergo dehydration condensation, and the resulting siloxane oligomers form a stable sol in an ethanol / water mixed solvent. Ammonium polyphosphate is stably dispersed in the solvent under the action of OP-10. The phosphate groups on its surface combine with the positively charged siloxane oligomers in the sol through electrostatic interaction. Using ammonium polyphosphate as a heterogeneous nucleation site, the siloxane oligomers condense on its surface to form flame-retardant microspheres with ammonium polyphosphate as the core and amino-modified silica as the shell.

[0021] Furthermore, the ratio of deionized water, ethanol, ammonium polyphosphate, OP-10, ammonia, tetraethyl orthosilicate, and (2-aminoisopropyl)triethoxysilane is 8-10 mL: 20-25 mL: 5-6 g: 1-2 g: 15-20 mL: 10-12 g: 5-8 g, and the concentration of ammonia is 25-30 wt%. The post-treatment steps include: after the reaction is completed, the reaction solution is cooled to room temperature, filtered, the filter cake is washed 1-2 times with deionized water, transferred to an oven at 70-80℃, and dried to constant weight to obtain flame-retardant microspheres.

[0022] Furthermore, the modified aging-resistant filler is prepared by the following steps:

[0023] B1. Place carboxylated carbon nanotubes and ethanol in a reaction vessel, ultrasonically disperse for 1-5 min, add nitric acid solution to adjust pH=3-4, heat to 55-65℃, keep the reaction at this temperature for 5-6 h, and then perform post-treatment to obtain activated carbon nanotubes.

[0024] The reaction principle for preparing activated carbon nanotubes is as follows:

[0025] During the reaction, nitric acid provides strong acidic conditions, promotes carboxyl protonation, and enhances its electrophilicity. Nitric acid can also act as an oxidant to oxidize sp² carbon atoms on the surface of carbon nanotubes, generating more oxygen-containing functional groups such as hydroxyl and carboxyl groups, thus obtaining activated carbon nanotubes.

[0026] B2. Place 2,2,4-trimethyl-1,2-dihydroquinoline and 3-glycidyl etheroxypropyltriethoxysilane in a reaction vessel, heat to 130-140℃, reflux for 3-4 hours, cool to 55-65℃, add ethanol, deionized water, γ-methacryloyloxypropyltrimethoxysilane and activated carbon nanotubes, heat to 75-85℃, reflux for 5-6 hours, and then perform post-treatment to obtain the modified aging-resistant filler.

[0027] The preparation reaction principle of modified aging-resistant fillers is as follows:

[0028] During the reaction, the secondary amine of 2,2,4-trimethyl-1,2-dihydroquinoline undergoes a nucleophilic reaction with the epoxy group of 3-glycidyl etheroxypropyltriethoxysilane to form a chemical bond. The silicon-oxygen bond of 3-glycidyl etheroxypropyltriethoxysilane and γ-methacryloyloxypropyltrimethoxysilane is further hydrolyzed to generate silanol, which undergoes a condensation reaction with the hydroxyl groups on the surface of activated carbon nanotubes to obtain a modified aging-resistant filler with olefin unsaturated double bonds on its surface.

[0029] Further, in step B1, the ratio of carboxylated carbon nanotubes to ethanol is 1-2g:200-300mL, the concentration of the nitric acid solution is 50-60wt%, and the post-treatment steps include: after the reaction is complete, waiting for the reaction to cool to room temperature, filtering, washing the filter cake 2-3 times with deionized water, transferring it to an oven at 60-70℃, drying to constant weight, grinding, and passing it through a 200-mesh sieve to obtain activated carbon nanotubes; in step B2, the 2,2,4-trimethyl-1,2-dihydro... The ratio of quinoline, 3-glycidyl etheroxypropyltriethoxysilane, ethanol, deionized water, γ-methacryloxypropyltrimethoxysilane, and activated carbon nanotubes is 4-5g:5-6g:250-300mL:15-20mL:1-2g:2-3g. The post-treatment steps include: after the reaction is completed, the reaction solution is cooled to room temperature, filtered, the filter cake is washed with ethanol 2-3 times, transferred to an oven at 60-70℃, and dried to constant weight to obtain the modified aging-resistant filler.

[0030] The present invention also proposes a method for preparing a corrosion-resistant and anti-aging plastic packaging barrel, comprising the following steps: adding polypropylene, maleic anhydride-grafted polypropylene, modified silicone resin, modified anti-aging filler and auxiliary additives into a twin-screw melt extruder, melting and extruding, and injecting into a mold to obtain a plastic packaging barrel.

[0031] The reaction principle for preparing plastic packaging buckets is as follows:

[0032] During the reaction, maleic anhydride-grafted polypropylene is compatible with polypropylene, while the polar groups of maleic anhydride form hydrogen bonds with modified silicone resin and modified aging-resistant filler, reducing interfacial tension. Under the high temperature and strong shear of the twin-screw extruder, dicumyl peroxide decomposes into cumyl phenoxy free radicals. The cumyl phenoxy free radicals abstract hydrogen atoms from the polypropylene backbone to generate polypropylene macromolecular free radicals, which further undergo free radical polymerization with modified silicone resin and modified aging-resistant filler. The mixture is then melt-extruded and molded to obtain plastic packaging buckets.

[0033] The auxiliary additive is composed of an initiator, a plasticizer, and an antistatic agent in a mass ratio of 1:5:1; the initiator is dicumyl peroxide, the plasticizer is one or more of dibutyl phthalate, diisononyl phthalate, or dioctyl sebacate, and the antistatic agent is one or more of alkylphenol polyoxyethylene ether, amide phosphate, or tricresyl phosphate.

[0034] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 170℃, 170℃, 185℃, 185℃, 200℃, 200℃, 210℃, and 210℃ respectively. The main motor speed of the twin-screw extruder is 120-160 rpm, and the pressure is 80-120 bar.

[0035] The present invention has the following beneficial effects:

[0036] 1. This invention involves preparing flame-retardant microspheres coated with ammonium polyphosphate via a sol-gel method, preparing a modified silicone resin precursor with hydroxyl-terminated olefin unsaturated bonds in the side chains, further covalently bonding the modified silicone resin precursor with the flame-retardant microspheres to obtain modified silicone resin, preparing activated carbon nanotubes through acidification, and modifying the surface of the activated carbon nanotubes with 2,2,4-trimethyl-1,2-dihydroquinoline and olefin unsaturated double bonds to obtain a modified aging-resistant filler. Polypropylene, maleic anhydride-grafted polypropylene, modified silicone resin, modified aging-resistant filler, and auxiliary additives are added to a twin-screw melt extruder, melt-extruded, and injected into a mold to obtain a plastic product. This invention relates to a flame-retardant microsphere for plastic packaging drums. The microspheres are prepared using an amino-modified silica shell and an ammonium polyphosphate core via a sol-gel method. The silica shell forms a dense barrier through a Si-O-Si network. During the preparation of the modified silicone resin, the amino groups on its surface are covalently bonded, improving the flame-retardant properties of the modified silicone resin. The ammonium polyphosphate core decomposes upon heating, producing polyphosphoric acid with catalytic carbonization and ammonia gas with flame-retardant properties in the gas phase. This achieves a synergistic flame-retardant mechanism between the condensed and gas phases, improving the flame-retardant performance of the plastic packaging drum. Furthermore, the silica shell protects the ammonium polyphosphate core from premature decomposition during the melt processing, further enhancing the flame-retardant properties of the plastic packaging drum.

[0037] 2. This invention also prepares a modified silicone resin precursor containing olefin unsaturated double bonds and fluorine atoms in the side chain through a condensation reaction. By adding end-capping groups, a hydroxyl-terminated modified silicone resin precursor is obtained. The modified silicone resin precursor is then covalently bonded to flame-retardant microspheres to obtain the modified silicone resin. The trifluoropropyl group introduced into the modified silicone resin precursor structure has strong hydrophobicity and chemical inertness, which can significantly reduce the reactivity of the plastic packaging barrel surface with organic solvents, acids, alkalis, and other substances, thereby improving its corrosion resistance. The olefin unsaturated double bonds in the side chain can be copolymerized and polymerized during the preparation of the packaging barrel. The combination of propylene and modified aging-resistant fillers improves the compatibility between the substrates and further enhances the mechanical properties of the plastic packaging drums. The reaction of hexamethylene diisocyanate with the hydroxyl groups of the modified silicone resin precursor generates a three-dimensional urethane cross-linked network, which significantly improves the bonding force between polymer chains. Moreover, the modified silicone resin is mainly composed of a siloxane skeleton, which has very strong chemical stability, making the plastic packaging drums less prone to decomposition or aging in environments such as high temperature, ultraviolet radiation, and oxidation. At the same time, these siloxane structures can effectively absorb and scatter ultraviolet rays, reducing their damage to the surface of the plastic packaging drums and increasing their service life.

[0038] 3. This invention also prepares activated carbon nanotubes to increase their reactivity, and further modifies their surface with 2,2,4-trimethyl-1,2-dihydroquinoline and olefin unsaturated double bonds to obtain a modified aging-resistant filler. 2,2,4-trimethyl-1,2-dihydroquinoline acts as a free radical scavenger, stabilizing active free radicals in the plastic matrix through the benzene ring conjugated structure and inhibiting main chain breakage during thermo-oxidative aging. It is covalently bonded to 3-glycidyl etheroxypropyltriethoxysilane and further modified onto the activated carbon nanotubes through silane coupling agent hydrolysis condensation, delaying migration and precipitation and extending the protective effect. Through the crosslinking effect of activated carbon nanotubes and modified silane, the modified aging-resistant filler not only improves the rigidity of plastic packaging barrels but also enhances their toughness. As a nano-reinforcing filler, carbon nanotubes have excellent impact resistance and can effectively disperse external forces during use, reducing the cracking or deformation of plastic packaging barrels caused by external impacts and improving the mechanical properties of the material. Detailed Implementation

[0039] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] The maleic anhydride-grafted polypropylene used in this invention was purchased from Dongguan Shangpin New Material Technology Co., Ltd., and its grade is QF500T.

[0041] The polypropylene used in this invention was purchased from Huizhou Yishengyuan Trading Co., Ltd., and its grade is K8009.

[0042] The ammonium polyphosphate used in this invention was purchased from Jinan Xinnuo Chemical Co., Ltd., with a specification of 25Kg and CAS number 68333-79-9;

[0043] The carboxylated carbon nanotubes used in this invention were purchased from Dongguan Shangpin New Material Technology Co., Ltd., model number szbknm2010;

[0044] The polyethylene glycol used in this invention was purchased from Nanjing Renheng Chemical Co., Ltd., and its density is 1.27 g / cm³. 3 Its molecular weight is 600.

[0045] Example 1

[0046] This embodiment provides a method for preparing flame-retardant microspheres using modified silicone resin for corrosion-resistant and anti-aging plastic packaging barrels, including the following steps:

[0047] Weigh out 80 mL of deionized water, 200 mL of ethanol, 50 g of ammonium polyphosphate, 10 g of OP-10 and 150 mL of 25 wt% ammonia and place them in a reaction vessel. Stir for 5 min, add 100 g of tetraethyl orthosilicate and 50 g of (2-aminoisopropyl)triethoxysilane, heat to 35 °C and keep the temperature for 1 h. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter, wash the filter cake once with deionized water, transfer it to an oven at 70 °C and dry to constant weight to obtain flame-retardant microspheres.

[0048] Example 2

[0049] This embodiment provides a method for preparing flame-retardant microspheres using modified silicone resin for corrosion-resistant and anti-aging plastic packaging barrels, including the following steps:

[0050] Weigh out 90 mL of deionized water, 220 mL of ethanol, 55 g of ammonium polyphosphate, 15 g of OP-10 and 170 mL of 28 wt% ammonia water and place them in a reaction vessel. Stir for 7 min, add 110 g of tetraethyl orthosilicate and 60 g of (2-aminoisopropyl)triethoxysilane, heat to 40 °C and keep the temperature for 1.5 h. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter, wash the filter cake twice with deionized water, transfer it to an oven at 75 °C and dry to constant weight to obtain flame-retardant microspheres.

[0051] Example 3

[0052] This embodiment provides a method for preparing flame-retardant microspheres using modified silicone resin for corrosion-resistant and anti-aging plastic packaging barrels, including the following steps:

[0053] Weigh out 100 mL of deionized water, 250 mL of ethanol, 60 g of ammonium polyphosphate, 20 g of OP-10 and 200 mL of 30 wt% ammonia and place them in a reaction vessel. Stir for 10 min, add 120 g of tetraethyl orthosilicate and 80 g of (2-aminoisopropyl)triethoxysilane, heat to 45 °C and keep the temperature for 2 h. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter, wash the filter cake twice with deionized water, transfer it to an oven at 80 °C and dry to constant weight to obtain flame-retardant microspheres.

[0054] Example 4

[0055] This embodiment provides a method for preparing a modified silicone resin for corrosion-resistant and aging-resistant plastic packaging barrels, including the following steps:

[0056] Step I: Preparation of modified silicone resin precursor

[0057] Weigh 20g of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, 70g of tetramethyltetravinylcyclotetrasiloxane, and 1000mL of xylene and place them in a reaction vessel. Heat the vessel to 110℃, add 40mL of 50wt% sulfuric acid solution, and maintain the temperature for 4h. Add 5g of 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane and maintain the temperature for 3h. After the reaction is complete, lower the temperature of the reaction system to room temperature, add 1wt% sodium hydroxide solution to the reaction system, adjust the pH of the system to 7, allow it to stand and separate the liquids. Wash the organic phase with deionized water until neutral, dry it, and transfer it to a rotary evaporator at 90℃. Distill under reduced pressure until no liquid is collected to obtain the modified silicone resin precursor.

[0058] Step II: Preparation of modified silicone resin

[0059] Weigh out 100g of modified silicone resin precursor, 20g of polyethylene glycol, 5g of stannous octoate, and 2500mL of tetrahydrofuran and place them in a reactor under nitrogen atmosphere protection and equipped with a condenser. Stir for 5 minutes, heat the reactor to 60°C, calculate the amount of hexamethylene diisocyanate to be added based on 0.55 times the total molar amount of hydroxyl groups in the modified silicone resin precursor and polyethylene glycol, and add it to the reactor. Keep the reaction temperature for 0.5h, add 20g of trimethylolpropane and 10g of flame-retardant microspheres prepared in Example 1, keep the reaction temperature for 0.5h, and after the reaction is completed, remove the low-boiling-point substances by vacuum distillation to obtain the modified silicone resin.

[0060] Example 5

[0061] This embodiment provides a method for preparing a modified silicone resin for corrosion-resistant and aging-resistant plastic packaging barrels, including the following steps:

[0062] Step I: Preparation of modified silicone resin precursor

[0063] Weigh 25g of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, 80g of tetramethyltetravinylcyclotetrasiloxane, and 1250mL of xylene and place them in a reaction vessel. Heat the vessel to 115℃, add 50mL of 50wt% sulfuric acid solution, and maintain the temperature for 5h. Then add 7g of 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane and maintain the temperature for 4h. After the reaction is complete, lower the temperature of the reaction system to room temperature, add 1wt% sodium hydroxide solution to the reaction system, adjust the pH of the system to 7.02, allow it to stand and separate the liquids. Wash the organic phase with deionized water until neutral, dry it, and transfer it to a rotary evaporator at 95℃. Distill under reduced pressure until no liquid is collected to obtain the modified silicone resin precursor.

[0064] Step II: Preparation of modified silicone resin

[0065] Weigh out 110g of modified silicone resin precursor, 30g of polyethylene glycol, 7g of stannous octoate, and 2800mL of tetrahydrofuran and place them in a reactor under nitrogen atmosphere protection and equipped with a condenser. Stir for 10min, heat the reactor to 62℃, calculate the amount of hexamethylene diisocyanate to be added based on 0.55 times the total molar amount of hydroxyl groups in the modified silicone resin precursor and polyethylene glycol, and add it to the reactor. Keep the reaction temperature for 1h, add 30g of trimethylolpropane and 13g of flame retardant microspheres prepared in Example 2, keep the reaction temperature for 1.5h, and after the reaction is completed, remove low-boiling substances by vacuum distillation to obtain modified silicone resin.

[0066] Example 6

[0067] This embodiment provides a method for preparing a modified silicone resin for corrosion-resistant and aging-resistant plastic packaging barrels, including the following steps:

[0068] Step I: Preparation of modified silicone resin precursor

[0069] Weigh out 30g of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, 90g of tetramethyltetravinylcyclotetrasiloxane, and 1500mL of xylene and place them in a reaction vessel. Heat the vessel to 120℃, add 60mL of 50wt% sulfuric acid solution, and maintain the temperature for 6h. Add 10g of 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane and maintain the temperature for 5h. After the reaction is complete, lower the temperature of the reaction system to room temperature, add 1wt% sodium hydroxide solution to the reaction system, adjust the pH of the system to 7.5, allow it to stand and separate the liquids. Wash the organic phase with deionized water until neutral, dry it, transfer it to a rotary evaporator at 100℃, and distill it under reduced pressure until no liquid is collected to obtain the modified silicone resin precursor.

[0070] Step II: Preparation of modified silicone resin

[0071] Weigh 120g of modified silicone resin precursor, 40g of polyethylene glycol, 10g of stannous octoate, and 3000mL of tetrahydrofuran and place them in a reactor under nitrogen atmosphere protection and equipped with a condenser. Stir for 15min, heat the reactor to 65℃, calculate the amount of hexamethylene diisocyanate to be added based on 0.55 times the total molar amount of hydroxyl groups in the modified silicone resin precursor and polyethylene glycol, and add it to the reactor. Keep the reaction temperature for 1h, add 40g of trimethylolpropane and 15g of flame-retardant microspheres prepared in Example 3, keep the reaction temperature for 2h, and after the reaction is completed, remove the low-boiling substances by vacuum distillation to obtain the modified silicone resin.

[0072] Example 7

[0073] This embodiment provides a method for preparing a modified aging-resistant filler for corrosion-resistant and aging-resistant plastic packaging drums, including the following steps:

[0074] Step ①: Preparation of activated carbon nanotubes

[0075] Weigh 10g of carboxylated carbon nanotubes and 2000mL of ethanol and place them in a reaction vessel. Disperse the mixture by sonication for 1min. Add 50wt% nitric acid solution to adjust the pH to 3. Heat the mixture to 55℃ and keep it at that temperature for 5h. After the reaction is complete, wait for the reaction to cool to room temperature, filter the mixture, wash the filter cake twice with deionized water, transfer it to an oven at 60℃, dry it to constant weight, grind it, and pass it through a 200-mesh sieve to obtain activated carbon nanotubes.

[0076] Step 2: Preparation of modified aging-resistant fillers

[0077] Weigh 40g of 2,2,4-trimethyl-1,2-dihydroquinoline and 50g of 3-glycidyl etheroxypropyltriethoxysilane and place them in a reaction vessel. Heat to 130℃, reflux for 3 hours, then cool to 55℃. Add 2500mL of ethanol, 150mL of deionized water, 10g of γ-methacryloyloxypropyltrimethoxysilane and 20g of activated carbon nanotubes. Heat to 75℃, reflux for 5 hours. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter, wash the filter cake twice with ethanol, transfer it to an oven at 60℃, and dry to constant weight to obtain the modified aging-resistant filler.

[0078] Example 8

[0079] This embodiment provides a method for preparing a modified aging-resistant filler for corrosion-resistant and aging-resistant plastic packaging drums, including the following steps:

[0080] Step ①: Preparation of activated carbon nanotubes

[0081] Weigh 15g of carboxylated carbon nanotubes and 2500mL of ethanol and place them in a reaction vessel. Disperse the mixture by sonication for 3min. Add 55wt% nitric acid solution to adjust the pH to 3.5. Heat the mixture to 60℃ and keep it at that temperature for 5.5h. After the reaction is complete, wait for the reaction to cool to room temperature, filter the mixture, wash the filter cake twice with deionized water, transfer it to an oven at 65℃, dry it to constant weight, grind it, and pass it through a 200-mesh sieve to obtain activated carbon nanotubes.

[0082] Step 2: Preparation of modified aging-resistant fillers

[0083] Weigh 45g of 2,2,4-trimethyl-1,2-dihydroquinoline and 55g of 3-glycidyl etheroxypropyltriethoxysilane and place them in a reaction vessel. Heat to 135℃, reflux for 3.5h, then cool to 60℃. Add 2700mL of ethanol, 170mL of deionized water, 15g of γ-methacryloyloxypropyltrimethoxysilane and 25g of activated carbon nanotubes. Heat to 80℃, reflux for 5.5h. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter, wash the filter cake twice with ethanol, transfer it to an oven at 65℃, and dry to constant weight to obtain the modified aging-resistant filler.

[0084] Example 9

[0085] This embodiment provides a method for preparing a modified aging-resistant filler for corrosion-resistant and aging-resistant plastic packaging drums, including the following steps:

[0086] Step ①: Preparation of activated carbon nanotubes

[0087] Weigh 20g of carboxylated carbon nanotubes and 3000mL of ethanol and place them in a reaction vessel. Disperse the mixture by sonication for 5min. Add 60wt% nitric acid solution to adjust the pH to 4. Heat the mixture to 65℃ and keep it at that temperature for 6h. After the reaction is complete, wait for the reaction to cool to room temperature, filter the mixture, wash the filter cake three times with deionized water, transfer it to an oven at 70℃, dry it to constant weight, grind it, and pass it through a 200-mesh sieve to obtain activated carbon nanotubes.

[0088] Step 2: Preparation of modified aging-resistant fillers

[0089] Weigh 50g of 2,2,4-trimethyl-1,2-dihydroquinoline and 60g of 3-glycidyl etheroxypropyltriethoxysilane and place them in a reaction vessel. Heat to 140℃, reflux for 4 hours, then cool to 65℃. Add 3000mL of ethanol, 200mL of deionized water, 20g of γ-methacryloyloxypropyltrimethoxysilane and 30g of activated carbon nanotubes. Heat to 85℃, reflux for 6 hours. After the reaction is complete, wait for the reaction solution to cool to room temperature, filter, wash the filter cake three times with ethanol, transfer to an oven at 70℃, and dry to constant weight to obtain the modified aging-resistant filler.

[0090] Example 10

[0091] This embodiment provides a method for preparing a corrosion-resistant and aging-resistant plastic packaging bucket, including the following steps:

[0092] Dicumyl peroxide, dibutyl phthalate and alkylphenol polyoxyethylene ether were mixed evenly in a mass ratio of 1:5:1 to obtain an auxiliary additive, which was then set aside.

[0093] Weigh out the following by weight: 60 parts of the modified silicone resin prepared in Example 4, 3 parts of the modified aging-resistant filler prepared in Example 7, 8 parts of polypropylene, 12 parts of maleic anhydride-grafted polypropylene, and 3 parts of auxiliary additives. Add them to a twin-screw melt extruder, melt extrude, and inject into a mold to obtain a plastic packaging barrel.

[0094] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 170℃, 170℃, 185℃, 185℃, 200℃, 200℃, 210℃, and 210℃ respectively. The main motor speed of the twin-screw extruder is 120 rpm, and the pressure is 80 bar.

[0095] Example 11

[0096] This embodiment provides a method for preparing a corrosion-resistant and aging-resistant plastic packaging bucket, including the following steps:

[0097] Dicumyl peroxide, dibutyl phthalate and alkylphenol polyoxyethylene ether were mixed evenly in a mass ratio of 1:5:1 to obtain an auxiliary additive, which was then set aside.

[0098] Weigh out the following by weight: 65 parts of the modified silicone resin prepared in Example 5, 4 parts of the modified aging-resistant filler prepared in Example 8, 10 parts of polypropylene, 16 parts of maleic anhydride-grafted polypropylene, and 4 parts of auxiliary additives. Add them to a twin-screw melt extruder, melt extrude, and inject into a mold to obtain a plastic packaging barrel.

[0099] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 170℃, 170℃, 185℃, 185℃, 200℃, 200℃, 210℃, and 210℃ respectively. The main motor speed of the twin-screw extruder is 140 rpm, and the pressure is 100 bar.

[0100] Example 12

[0101] This embodiment provides a method for preparing a corrosion-resistant and aging-resistant plastic packaging bucket, including the following steps:

[0102] Dicumyl peroxide, dibutyl phthalate and alkylphenol polyoxyethylene ether were mixed evenly in a mass ratio of 1:5:1 to obtain an auxiliary additive, which was then set aside.

[0103] Weigh out the following by weight: 70 parts of the modified silicone resin prepared in Example 6, 5 parts of the modified aging-resistant filler prepared in Example 9, 12 parts of polypropylene, 18 parts of maleic anhydride-grafted polypropylene, and 5 parts of auxiliary additives. Add them to a twin-screw melt extruder, melt extrude, and inject into a mold to obtain a plastic packaging barrel.

[0104] The twin-screw extruder has eight temperature zones from the feed inlet to the discharge outlet, with temperatures of 170℃, 170℃, 185℃, 185℃, 200℃, 200℃, 210℃, and 210℃ respectively. The main motor speed of the twin-screw extruder is 160 rpm, and the pressure is 120 bar.

[0105] Comparative Example 1

[0106] The difference between this comparative example and Example 12 is that, in step II, flame-retardant microspheres were omitted when preparing the modified silicone resin.

[0107] Comparative Example 2

[0108] The difference between this comparative example and Example 12 is that the modified silicone resin was not used when preparing the plastic packaging bucket.

[0109] Comparative Example 3

[0110] The difference between this comparative example and Example 12 is that, in the preparation of the plastic packaging bucket, an equal amount of activated carbon nanotubes were used to replace the modified aging-resistant filler.

[0111] Performance testing:

[0112] The corrosion resistance of plastic packaging drums was tested in accordance with the standard HG / T 3984-2007 "Chemical Corrosion Resistant Modified Polypropylene Storage Tanks".

[0113] The tensile strength and elongation at break of the plastic packaging barrels prepared in Examples 10-12 and Comparative Examples 1-3 were determined in accordance with the standard GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets".

[0114] The vertical flammability ratings of the plastic packaging drums prepared in Examples 10-12 and Comparative Examples 1-3 were determined according to the standard GB / T 2408-2021 "Determination of flammability of plastics - Horizontal and Vertical Methods". The specific data are shown in Table 1.

[0115] The plastic packaging barrels prepared in Example 12 and Comparative Examples 1-3 were subjected to ultraviolet aging tests in accordance with the standard GB / T 16422.3-2022 "Laboratory Light Source Exposure Test Methods for Plastics - Part 3: Fluorescent Ultraviolet Lamps". The tensile strength and elongation at break retention rates of the materials were determined in accordance with the standard GB / T 1040.3-2006, and the tensile strength retention rate and elongation at break retention rate were calculated. The corrosion resistance of the materials was determined in accordance with the standard HG / T 3984-2007 "Chemical Corrosion-Resistant Modified Polypropylene Storage Tanks". The specific data are shown in Table 2.

[0116] Table 1 - Performance test data of each sample

[0117]

[0118] Table 2 - Performance test data of each sample after UV aging

[0119]

[0120] Data Analysis:

[0121] Comparative analysis of the data in Table 1 shows that the plastic packaging bucket prepared by this invention is resistant to corrosion from saturated calcium hydroxide solution and 10wt% nitric acid solution, has a tensile strength of 82.3 MPa, an elongation at break of 126.4%, and a vertical flammability rating of V-0. Comparative analysis of the data in Table 2 shows that the plastic packaging bucket prepared by this invention remains resistant to corrosion from saturated calcium hydroxide solution and 10wt% nitric acid solution after ultraviolet aging, retains a tensile strength of 95.1%, and an elongation at break of 96.9%.

[0122] By comparing the test data of Example 12 and Comparative Example 1, it can be found that the vertical burning rating of the plastic packaging bucket prepared in Comparative Example 1 is significantly reduced. This indicates that the present invention uses amino-modified silica as the shell and ammonium polyphosphate as the core to prepare flame-retardant microspheres through the sol-gel method. The silica shell forms a dense barrier through the Si-O-Si network. When the surface amino groups are prepared, they are covalently bonded to improve the flame-retardant performance of the modified silicone resin. When the ammonium polyphosphate core is heated, it decomposes to produce polyphosphoric acid with catalytic carbonization and ammonia gas with flame retardant properties in the gas phase, realizing a synergistic flame-retardant mechanism between the condensed phase and the gas phase, which improves the flame-retardant performance of the plastic packaging bucket. The silica shell protects the ammonium polyphosphate core from premature decomposition during the melt processing, further improving the flame-retardant performance of the plastic packaging bucket.

[0123] Comparing the test data of Example 12 and Comparative Example 2, it can be found that the elongation at break and tensile strength of the plastic packaging bucket prepared in Comparative Example 2 decreased significantly, and it was not resistant to corrosion from saturated calcium hydroxide solution and 10wt% nitric acid solution. The corrosion resistance, tensile strength retention, and elongation at break retention after UV aging also decreased significantly. This indicates that the present invention prepares a modified silicone resin precursor containing olefin unsaturated double bonds and fluorine atoms in the side chain through a condensation reaction. By adding end-capping groups, a hydroxyl-terminated modified silicone resin precursor is obtained. The modified silicone resin precursor is then covalently bonded to flame-retardant microspheres to obtain modified silicone resin. The trifluoropropyl group introduced into the modified silicone resin precursor structure has strong hydrophobicity and chemical inertness, which can significantly reduce the corrosion resistance of the plastic packaging bucket surface. The reactivity of organic solvents, acids, alkalis, and other substances enhances its corrosion resistance. The unsaturated double bonds of olefins in the side chains can be combined with polypropylene and modified aging-resistant fillers through free radical copolymerization during the preparation of packaging barrels, improving the compatibility between the substrates and further enhancing the mechanical properties of the plastic packaging barrels. The reaction of hexamethylene diisocyanate with the hydroxyl groups of the modified silicone resin precursor generates a three-dimensional urethane cross-linked network, significantly improving the bonding force between polymer chains. Moreover, the modified silicone resin is mainly composed of a siloxane skeleton, which has very strong chemical stability, making the plastic packaging barrels less prone to decomposition or aging in environments such as high temperature, ultraviolet radiation, and oxidation. At the same time, these siloxane structures can effectively absorb and scatter ultraviolet rays, reducing their damage to the surface of the plastic packaging barrels and increasing their service life.

[0124] Comparing the test data of Example 12 and Comparative Example 3, it can be found that the elongation at break and tensile strength of the plastic packaging bucket prepared in Comparative Example 3 decreased significantly, and the retention rates of tensile strength and elongation at break after UV aging also decreased significantly. This indicates that the present invention, by preparing activated carbon nanotubes to increase their reactivity and further modifying their surface with 2,2,4-trimethyl-1,2-dihydroquinoline and olefin unsaturated double bonds, obtains a modified aging-resistant filler. 2,2,4-trimethyl-1,2-dihydroquinoline acts as a free radical scavenger, stabilizing active free radicals in the plastic matrix through the benzene ring conjugated structure and inhibiting... During thermo-oxidative aging, the main chain breaks down and covalently bonds with 3-glycidyl etheroxypropyltriethoxysilane. This is further modified onto activated carbon nanotubes via hydrolysis and condensation using a silane coupling agent, delaying migration and precipitation and extending the protective effect. Through the cross-linking effect of activated carbon nanotubes and modified silane, the modified aging-resistant filler not only improves the rigidity of plastic packaging drums but also enhances their toughness. Carbon nanotubes, as nano-reinforcing fillers, possess excellent impact resistance and can effectively disperse external forces during use, reducing cracking or deformation of plastic packaging drums caused by external impacts and improving the mechanical properties of the material.

[0125] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A corrosion-resistant and anti-aging plastic packaging bucket, characterized in that, It comprises the following raw materials by weight: 60-70 parts modified silicone resin, 3-5 parts modified aging-resistant filler, 8-12 parts polypropylene, 12-18 parts maleic anhydride-grafted polypropylene and 3-5 parts auxiliary additives. The auxiliary additive is composed of an initiator, a plasticizer, and an antistatic agent in a mass ratio of 1:5:1; The modified silicone resin is prepared by the following steps: A1. Place 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and xylene in a reaction vessel, heat to 110-120℃, add catalyst, keep the reaction at this temperature for 4-6 h, add 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane, keep the reaction at this temperature for 3-5 h, and then perform post-treatment to obtain the modified silicone resin precursor; A2. Under a nitrogen atmosphere, the modified silicone resin precursor, polyethylene glycol, stannous octoate, and tetrahydrofuran are placed in a reactor equipped with a condenser. The mixture is stirred for 5-15 minutes, a condenser is placed, and the temperature is raised to 60-65°C. A calculated amount of hexamethylene diisocyanate is added to the reactor, and the reaction is maintained at this temperature for 0.5-1 hour. Trimethylolpropane and flame-retardant microspheres are then added, and the reaction is maintained at this temperature for 1-2 hours. The modified silicone resin is obtained after post-treatment. The method for preparing the flame-retardant microspheres is as follows: Deionized water, ethanol, ammonium polyphosphate, OP-10 and ammonia are placed in a reaction vessel and stirred for 5-10 min. Tetraethyl orthosilicate and (2-aminoisopropyl)triethoxysilane are added, the temperature is raised to 35-45℃, and the reaction is kept at this temperature for 1-2 h. The flame-retardant microspheres are then obtained after post-treatment. The modified aging-resistant filler was prepared by the following steps: B1. Place carboxylated carbon nanotubes and ethanol in a reaction vessel, ultrasonically disperse for 1-5 min, add nitric acid solution to adjust pH=3-4, heat to 55-65℃, keep the reaction at this temperature for 5-6 h, and then perform post-treatment to obtain activated carbon nanotubes. B2. Place 2,2,4-trimethyl-1,2-dihydroquinoline and 3-glycidyl etheroxypropyltriethoxysilane in a reaction vessel, heat to 130-140℃, reflux for 3-4 hours, cool to 55-65℃, add ethanol, γ-methacryloyloxypropyltrimethoxysilane and activated carbon nanotubes, heat to 75-85℃, reflux for 5-6 hours, and then perform post-treatment to obtain the modified aging-resistant filler.

2. The corrosion-resistant and anti-aging plastic packaging bucket according to claim 1, characterized in that, In step A1, the ratio of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, xylene, catalyst, and 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane is 2-3g:7-9g:100-150mL:4-6mL:0.5-1g, and the catalyst is a 20wt% sulfuric acid solution; in step A2, the ratio of the modified silicone resin precursor, polyethylene glycol, stannous octoate, tetrahydrofuran, trimethylolpropane, and flame-retardant microspheres is 10-12g:2-4g:0.5-1g:250-300mL:2-4g:1-1.5g, and in the reaction, hexamethylene diisocyanate is 0.55 times the molar amount of hydroxyl groups in the reaction system.

3. The corrosion-resistant and anti-aging plastic packaging bucket according to claim 1, characterized in that, The ratio of deionized water, ethanol, ammonium polyphosphate, OP-10, ammonia, tetraethyl orthosilicate, and (2-aminoisopropyl)triethoxysilane is 8-10 mL: 20-25 mL: 5-6 g: 1-2 g: 15-20 mL: 10-12 g: 5-8 g, and the concentration of ammonia is 25-30 wt%.

4. The corrosion-resistant and anti-aging plastic packaging bucket according to claim 1, characterized in that, In step B1, the ratio of carboxylated carbon nanotubes to ethanol is 1-2g:200-300mL, and the concentration of the nitric acid solution is 95-98wt%. In step B2, the ratio of 2,2,4-trimethyl-1,2-dihydroquinoline, 3-glycidyl etheroxypropyltriethoxysilane, ethanol, deionized water, γ-methacryloyloxypropyltrimethoxysilane, and activated carbon nanotubes is 4-5g:5-6g:250-300mL:15-20mL:1-2g:2-3g.

5. A method for preparing a corrosion-resistant and anti-aging plastic packaging barrel as described in any one of claims 1-4, characterized in that, Includes the following steps: Polypropylene, maleic anhydride-grafted polypropylene, modified silicone resin, modified aging-resistant filler, and auxiliary additives are added to a twin-screw melt extruder, melt-extruded, and injected into a mold to obtain a plastic packaging barrel.

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