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

Abstract

The invention discloses a corrosion-resistant anti-aging plastic packaging barrel and a preparation method thereof, belongs to the technical field of plastic product processing, and aims to solve the technical problem that the corrosion resistance and the aging resistance of a plastic packaging barrel in the prior art need to be further improved. The anti-aging polypropylene composite material is specifically prepared from the following raw materials in parts by weight: 60 to 70 parts of modified silicon resin, 3 to 5 parts of modified anti-aging filler, 8 to 12 parts of polypropylene, 12 to 18 parts of maleic anhydride grafted polypropylene and 3 to 5 parts of auxiliary additive. The preparation method comprises the following steps: adding the polypropylene, the maleic anhydride grafted polypropylene, the modified silicon resin, the modified anti-aging filler and the auxiliary additive into a twin-screw melt extruder; according to the plastic packaging barrel, the corrosion resistance and the aging resistance of the plastic packaging barrel are improved, and the mechanical performance of the plastic packaging barrel is also improved.

Description

Technical Field

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

[0002] In recent years, with the rapid development of the chemical, food and logistics industries, plastic packaging barrels have gradually replaced traditional metal containers due to their light weight, easy molding and cost advantages, and have become the mainstream choice for the transportation and storage of liquid or solid materials. However, conventional plastic packaging barrels have significant shortcomings in flame retardancy, corrosion resistance and aging resistance. During long-term outdoor use, plastic packaging barrels are prone to swelling, cracking and even leakage risks due to long-term contact with corrosive substances such as chemical raw materials, acid and alkali solutions. In addition, under the long-term action of ultraviolet radiation, the polymer chain in the plastic packaging barrel will be accelerated to break, which manifests as surface powdering and a sudden drop in mechanical properties, significantly shortening the service life of the packaging barrel. Although attempts have been made to improve performance by adding antioxidants, UV absorbers or surface coatings, there are still problems such as additive precipitation, coating shedding or rapid weather resistance degradation, which makes it difficult to meet the stringent requirements of high-end application scenarios for long-term stability.

[0003] In the existing technology, the root cause of the insufficient flame retardancy, corrosion resistance and aging resistance of plastic packaging barrels is mainly due to the limitations of the material's molecular structure and interface design. The carbon-carbon main chain of polyolefin materials is easily affected by thermal oxygen and photooxidation to trigger free radical chain reactions, resulting in an imbalance between chain scission and cross-linking. Polar corrosive media can destroy the regularity of molecular chains through diffusion and penetration, aggravating material degradation. In order to improve the corrosion resistance and flame retardancy of plastic packaging barrels, inorganic fillers or flame retardants are often added to improve the performance. However, the added reinforcing materials have poor compatibility with the polymer matrix and are prone to form stress concentration points, inducing microcrack propagation under long-term stress corrosion or thermal cycling. In addition, traditional modification technologies mostly rely on physical blending, and functional components are easily migrated to the surface and lost, reducing the service life. Summary of the Invention

[0004] The object of the present invention is to provide a corrosion-resistant and aging-resistant plastic packaging barrel and a preparation method thereof, so as to solve the technical problem in the prior art that the corrosion resistance and aging resistance of plastic packaging barrels need to be further improved.

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

[0006] The auxiliary additives are composed 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 kettle, raise the temperature to 110-120°C, add a catalyst, and keep the temperature for reaction for 4-6 hours. Add 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane, keep the temperature for reaction for 3-5 hours, and post-treat to obtain a modified silicone resin precursor.

[0009] The preparation reaction principle of the modified silicone resin precursor is:

[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, and the silanols further undergo condensation reaction to obtain long-chain polysiloxane. 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane is added as a capping agent to obtain a modified silicone resin precursor with an olefin unsaturated double bond in the side chain and hydroxyl end-capping.

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

[0012] The preparation reaction formula of modified silicone resin is:

[0013]

[0014] Where: Flame retardant microspheres:

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

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

[0017] Further, in step A1, the amount ratio of the 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, the catalyst is a 50wt% sulfuric acid solution, and the post-treatment step comprises: after the reaction is completed, the temperature of the reaction system is lowered to room temperature, 1wt% sodium hydroxide solution is added to the reaction system, the pH of the system is adjusted to 7±0.5, and the liquid is allowed to stand. The organic phase is washed with deionized water until neutral and then dried, transferred to a rotary evaporator at a temperature of 90-100° C., and distilled under reduced pressure until no liquid is extracted to obtain a modified silicone resin precursor; in step A2, the amount ratio of the modified silicone resin precursor, polyethylene glycol, stannous octoate, tetrahydrofuran, trimethylolpropane and flame retardant microspheres is 10-12 g: 2-4 g: 0.5-1 g: 250-300 mL: 1-2 g: 1-1.5 g, and in the reaction, the amount of hexamethylene diisocyanate is 0.55 times the molar amount of hydroxyl groups in the reaction system. The post-processing step includes: after the reaction is completed, distilling off low boiling points under reduced pressure to obtain a 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 water are placed in a reactor, stirred for 5-10 minutes, ethyl orthosilicate and (2-aminoisopropyl)triethoxysilane are added, the temperature is raised to 35-45° C., the reaction is kept warm for 1-2 hours, and the flame retardant microspheres are obtained by post-processing.

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

[0020] During the reaction, under the catalytic action of ammonia water, ethyl orthosilicate and (2-aminoisopropyl)triethoxysilane undergo a hydrolysis reaction to generate silicic acid, and dehydration condensation occurs between the silicic acid molecules. The generated siloxane oligomers form a stable sol in an ethanol / water mixed solvent. Under the action of OP-10, ammonium polyphosphate is stably dispersed in the solvent. The phosphate groups on its surface combine with the positively charged siloxane oligomers in the sol through electrostatic interaction. With 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 amount ratio of the deionized water, ethanol, ammonium polyphosphate, OP-10, ammonia water, ethyl orthosilicate and (2-aminoisopropyl) triethoxysilane is 8-10 mL: 20-25 mL: 5-6 g: 1-2 g: 1-2 g: 15-20 mL: 10-12 g: 5-8 g, the concentration of the ammonia water is 25-30 wt %, and the post-treatment step includes: after the reaction is completed, the reaction liquid is cooled to room temperature, filtered, the filter cake is washed with deionized water 1-2 times, transferred to an oven at a temperature of 70-80 ° C, 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 kettle, perform ultrasonic dispersion for 1-5 minutes, add nitric acid solution to adjust the pH to 3-4, heat to 55-65°C, keep the temperature for reaction for 5-6 hours, and perform post-treatment to obtain activated carbon nanotubes;

[0024] The preparation reaction principle of activated carbon nanotubes is:

[0025] During the reaction, nitric acid provides strong acidic conditions, promotes the protonation of carboxyl groups, and enhances their electrophilicity. Nitric acid can also act as an oxidant to oxidize sp 2 Carbon atoms generate more oxygen-containing functional groups such as hydroxyl and carboxyl groups to obtain activated carbon nanotubes.

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

[0027] The preparation reaction principle of modified aging-resistant filler is:

[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-glycidyloxypropyltriethoxysilane to form a chemical bond. The silicon-oxygen bonds of 3-glycidyloxypropyltriethoxysilane and γ-methacryloxypropyltrimethoxysilane are further hydrolyzed to form silanols, which undergo a condensation reaction with the hydroxyl groups on the surface of the activated carbon nanotubes to obtain a modified aging-resistant filler with an olefin unsaturated double bond on the surface.

[0029] Furthermore, in step B1, the ratio of the carboxylated carbon nanotubes to the ethanol is 1-2 g: 200-300 mL, the concentration of the nitric acid solution is 50-60 wt%, and the post-treatment step comprises: after the reaction is completed, the reaction is cooled to room temperature, filtered, the filter cake is washed 2-3 times with deionized water, transferred to an oven at a temperature of 60-70 ° C, dried to constant weight, ground, and passed through a 200 mesh sieve to obtain activated carbon nanotubes; in step B2, the 2,2,4-trimethyl-1,2-dihydro The amount ratio of quinoline, 3-glycidyloxypropyltriethoxysilane, 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 step includes: after the reaction is completed, the reaction liquid is cooled to room temperature, filtered, the filter cake is washed with ethanol 2-3 times, transferred to an oven at a temperature of 60-70°C, and dried to constant weight to obtain a modified aging-resistant filler.

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

[0031] The preparation reaction principle of plastic packaging barrels is:

[0032] During the reaction process, maleic anhydride grafted polypropylene is compatible with polypropylene, and the polar groups of maleic anhydride form hydrogen bonds with the modified silicone resin and modified aging-resistant filler to reduce interfacial tension. Under the high temperature and strong shearing action of the twin-screw extruder, dicumyl peroxide is thermally decomposed into isopropylphenoxy free radicals. The isopropylphenoxy free radicals capture hydrogen atoms from the polypropylene main chain to generate polypropylene macromolecular free radicals, which further undergo free radical polymerization reaction with the modified silicone resin and modified aging-resistant filler, and are melt-extruded and injection-molded to obtain plastic packaging barrels.

[0033] The auxiliary additives are 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 temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 170°C, 170°C, 185°C, 185°C, 200°C, 200°C, 210°C, and 210°C, respectively. The main engine speed of the twin-screw extruder is 120-160rpm, and the pressure is 80-120bar.

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

[0036] 1. The present invention is to prepare flame-retardant microspheres coated with ammonium polyphosphate by a sol-gel method, prepare a modified silicone resin precursor with a hydroxyl-terminated side chain containing an olefin unsaturated bond, further form a covalent bond between the modified silicone resin precursor and the flame-retardant microspheres to obtain a modified silicone resin, prepare activated carbon nanotubes by acidification, and obtain a modified aging-resistant filler by modifying the surface of the activated carbon nanotubes with 2,2,4-trimethyl-1,2-dihydroquinoline and an olefin unsaturated double bond, add polypropylene, maleic anhydride grafted polypropylene, modified silicone resin, modified aging-resistant filler and auxiliary additives into a twin-screw melt extruder, melt extrude, and inject into a mold to obtain a plastic. Material packaging barrel; the present invention uses amino-modified silica as a shell layer and ammonium polyphosphate as a core, and prepares flame-retardant microspheres through a sol-gel method. The silica shell forms a dense barrier through a Si-O-Si network. The amino groups on its surface are covalently bonded when preparing the modified silicone resin, thereby improving the flame retardant properties of the modified silicone resin. The ammonium polyphosphate core decomposes when heated to produce polyphosphoric acid with a catalytic carbonization effect and ammonia with a gas-phase flame retardant effect, realizing a condensed phase and gas-phase synergistic flame retardant mechanism, thereby improving the flame retardant properties of the plastic packaging barrel. The silica shell protects the ammonium polyphosphate core from premature decomposition during the melt processing process, thereby further improving the flame retardant properties of the plastic packaging barrel.

[0037] 2. The present invention also prepares a modified silicone resin precursor containing an olefin unsaturated double bond and a fluorine atom in the side chain through a condensation reaction, and obtains a hydroxyl-terminated modified silicone resin precursor by adding a capping group. The modified silicone resin precursor is combined with the flame retardant microspheres through a covalent bond to obtain a modified silicone resin. The trifluoropropyl group introduced into the structure of the modified silicone resin precursor has strong hydrophobicity and chemical inertness, which can significantly reduce the reactivity of the surface of the plastic packaging barrel with organic solvents, acids, alkalis and other substances, and improve its corrosion resistance. The olefin unsaturated double bond in the side chain can be free radical copolymerized with the polymer when preparing the packaging barrel. The combination of propylene and modified aging-resistant filler improves the compatibility between substrates and further improves the mechanical properties of plastic packaging barrels. Hexamethylene diisocyanate reacts with the hydroxyl group of modified silicone resin precursor to generate a three-dimensional urethane cross-linked network, which significantly enhances the binding force between polymer chains. The modified silicone resin is mainly composed of a siloxane skeleton and has very strong chemical stability, making the plastic packaging barrel less likely to decompose or age in high temperature, ultraviolet radiation, oxidation and other environments. At the same time, these silicon-oxygen structures can effectively absorb and scatter ultraviolet rays, reducing their damage to the surface of the plastic packaging barrel and increasing its service life.

[0038] 3. The present invention also prepares activated carbon nanotubes to increase their reaction activity, and further modifies 2,2,4-trimethyl-1,2-dihydroquinoline and olefin unsaturated double bonds on their surface to obtain a modified aging-resistant filler. 2,2,4-trimethyl-1,2-dihydroquinoline serves as a free radical scavenger, stabilizes the active free radicals in the plastic matrix through the conjugated structure of the benzene ring, and inhibits the main chain breakage during the thermal oxidative aging process. It is covalently bonded to 3-glycidyloxypropyltriethoxysilane and is further modified to the activated carbon nanotubes through hydrolysis and condensation of a silane coupling agent, thereby delaying migration and precipitation and extending the protective effect. Through the cross-linking effect of the activated carbon nanotubes and the modified silane, the modified aging-resistant filler not only improves the rigidity of the plastic packaging barrel, but also enhances the toughness of the plastic packaging barrel. Carbon nanotubes, as nano-reinforced fillers, have excellent impact resistance and can effectively disperse external forces during use, reducing the cracking or deformation of the plastic packaging barrel due to external impact, thereby improving the mechanical properties of the material. DETAILED DESCRIPTION

[0039] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] The maleic anhydride grafted polypropylene used in the present invention was purchased from Dongguan Shangpin New Material Technology Co., Ltd., with the brand name QF500T.

[0041] The polypropylene used in the present invention was purchased from Huizhou Yishengyuan Trading Co., Ltd., with the brand name K8009.

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

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

[0044] The polyethylene glycol used in the present invention was purchased from Nanjing Yanheng Chemical Co., Ltd. and has a density of 1.27 g / cm 3 , molecular weight is 600.

[0045] Example 1

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

[0047] Weigh: 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 water and place them in a reactor. Stir for 5 minutes, add 100 g of ethyl orthosilicate and 50 g of (2-aminoisopropyl)triethoxysilane, raise the temperature to 35 ° C, and keep the reaction for 1 hour. After the reaction is completed, the reaction liquid is cooled to room temperature and filtered. The filter cake is washed once with deionized water, transferred to an oven at a temperature of 70 ° C, and dried to constant weight to obtain flame retardant microspheres.

[0048] Example 2

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

[0050] Weigh: 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 reactor. Stir for 7 minutes, add 110 g of ethyl orthosilicate (2-aminoisopropyl)triethoxysilane and 60 g of triethoxysilane. Heat to 40 ° C. and keep warm for 1.5 hours. After the reaction is completed, the reaction liquid is cooled to room temperature and filtered. The filter cake is washed twice with deionized water, transferred to an oven at 75 ° C., and dried to constant weight to obtain flame retardant microspheres.

[0051] Example 3

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

[0053] Weigh: 100 mL of deionized water, 250 mL of ethanol, 60 g of ammonium polyphosphate, 200 mL of OP-10 and 30 wt% ammonia water and place them in a reactor. Stir for 10 min, add 120 g of ethyl orthosilicate (2-aminoisopropyl)triethoxysilane 80 g, heat to 45 ° C, and keep the reaction for 2 h. After the reaction is completed, the reaction liquid is cooled to room temperature, filtered, and the filter cake is washed twice with deionized water. Transfer it to an oven at 80 ° C and dry it to constant weight to obtain flame retardant microspheres.

[0054] Example 4

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

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

[0057] Weigh: 20 g of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, 70 g of tetramethyltetravinylcyclotetrasiloxane and 1000 mL of xylene and place them in a reactor, heat to 110 ° C, add 40 mL of 50 wt% sulfuric acid solution, keep warm and react for 4 hours, add 5 g of 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane, keep warm and react for 3 hours. 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, the pH of the system is adjusted to 7, and the mixture is allowed to stand and separate. The organic phase is washed with deionized water until neutral and then dried, transferred to a rotary evaporator at a temperature of 90 ° C, and distilled under reduced pressure until no liquid is produced to obtain a modified silicone resin precursor.

[0058] Step II: Preparation of modified silicone resin

[0059] Weigh: 100 g of modified silicone resin precursor, 20 g of polyethylene glycol, 5 g of stannous octoate and 2500 mL of tetrahydrofuran are placed in a reactor protected by a nitrogen atmosphere and equipped with a condenser, and stirred for 5 minutes. The reactor is heated to 60°C, and the amount of hexamethylene diisocyanate added is calculated as 0.55 times the total molar amount of hydroxyl groups in the modified silicone resin precursor and polyethylene glycol. It is added to the reactor and kept warm for 0.5 h. 20 g of trimethylolpropane and 10 g of flame retardant microspheres prepared in Example 1 are added and kept warm for 0.5 h. After the reaction is completed, low-boiling substances are evaporated under reduced pressure to obtain a modified silicone resin.

[0060] Example 5

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

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

[0063] Weigh: 25 g of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, 80 g of tetramethyltetravinylcyclotetrasiloxane and 1250 mL of xylene and place them in a reactor, heat to 115 ° C, add 50 mL of 50 wt% sulfuric acid solution, keep warm for 5 hours, add 7 g of 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane, keep warm for 4 hours, 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, the pH of the system is adjusted to 7.02, and the mixture is allowed to stand for separation. The organic phase is washed with deionized water until neutral and then dried, transferred to a rotary evaporator at a temperature of 95 ° C, and distilled under reduced pressure until no liquid is produced to obtain a modified silicone resin precursor.

[0064] Step II: Preparation of modified silicone resin

[0065] Weigh: 110 g of modified silicone resin precursor, 30 g of polyethylene glycol, 7 g of stannous octoate and 2800 mL of tetrahydrofuran are placed in a reactor protected by a nitrogen atmosphere and equipped with a condenser, and stirred for 10 minutes. The reactor is heated to 62°C, and the amount of hexamethylene diisocyanate added is calculated as 0.55 times the total molar amount of hydroxyl groups in the modified silicone resin precursor and polyethylene glycol. It is added to the reactor and kept warm for 1 hour. 30 g of trimethylolpropane and 13 g of flame retardant microspheres prepared in Example 2 are added and kept warm for 1.5 hours. After the reaction is completed, low-boiling substances are evaporated under reduced pressure to obtain a modified silicone resin.

[0066] Example 6

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

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

[0069] Weigh: 30 g of 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, 90 g of tetramethyltetravinylcyclotetrasiloxane and 1500 mL of xylene and place them in a reactor, heat to 120 ° C, add 60 mL of 50 wt% sulfuric acid solution, keep warm for 6 hours, add 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane 10 g, keep warm for 5 hours, 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, the pH of the system is adjusted to 7.5, and the mixture is allowed to stand for separation. The organic phase is washed with deionized water until neutral and then dried, transferred to a rotary evaporator at a temperature of 100 ° C, and distilled under reduced pressure until no liquid is produced to obtain a modified silicone resin precursor.

[0070] Step II: Preparation of modified silicone resin

[0071] Weigh: 120 g of modified silicone resin precursor, 40 g of polyethylene glycol, 10 g of stannous octoate and 3000 mL of tetrahydrofuran are placed in a reactor protected by a nitrogen atmosphere and equipped with a condenser, and stirred for 15 minutes. The reactor is heated to 65° C., and the amount of hexamethylene diisocyanate added is calculated as 0.55 times the total molar amount of hydroxyl groups in the modified silicone resin precursor and polyethylene glycol. It is added to the reactor and kept warm for 1 hour. 40 g of trimethylolpropane and 15 g of flame retardant microspheres prepared in Example 3 are added and kept warm for 2 hours. After the reaction is completed, low-boiling substances are evaporated under reduced pressure to obtain a modified silicone resin.

[0072] Example 7

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

[0074] Step ①: Preparation of activated carbon nanotubes

[0075] Weigh: 10 g of carboxylated carbon nanotubes and 2000 mL of ethanol are placed in a reactor, ultrasonically dispersed for 1 min, 50 wt% nitric acid solution is added to adjust the pH to 3, the temperature is raised to 55°C, and the reaction is kept warm for 5 h. After the reaction is completed, the reaction mixture is cooled to room temperature, filtered, and the filter cake is washed twice with deionized water, transferred to an oven at 60°C, dried to constant weight, ground, and passed through a 200-mesh sieve to obtain activated carbon nanotubes.

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

[0077] Weigh: 40g of 2,2,4-trimethyl-1,2-dihydroquinoline and 50g of 3-glycidyloxypropyltriethoxysilane are placed in a reactor, heated to 130°C, condensed and refluxed for 3h, then cooled to 55°C, 2500mL of ethanol, 150mL of deionized water, 10g of γ-methacryloyloxypropyltrimethoxysilane and 20g of activated carbon nanotubes are added, heated to 75°C, condensed and refluxed for 5h. After the reaction is completed, the reaction solution is cooled to room temperature, filtered, and the filter cake is washed twice with ethanol, transferred to an oven at 60°C, and dried to constant weight to obtain a modified aging-resistant filler.

[0078] Example 8

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

[0080] Step ①: Preparation of activated carbon nanotubes

[0081] Weigh: 15 g of carboxylated carbon nanotubes and 2500 mL of ethanol are placed in a reactor, ultrasonically dispersed for 3 minutes, 55 wt% nitric acid solution is added to adjust the pH to 3.5, the temperature is raised to 60°C, and the reaction is kept warm for 5.5 hours. After the reaction is completed, the reaction is cooled to room temperature, filtered, and the filter cake is washed twice with deionized water, transferred to an oven at a temperature of 65°C, dried to constant weight, ground, and passed through a 200-mesh sieve to obtain activated carbon nanotubes.

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

[0083] Weigh: 45g of 2,2,4-trimethyl-1,2-dihydroquinoline and 55g of 3-glycidyloxypropyltriethoxysilane are placed in a reactor, heated to 135°C, condensed and refluxed for 3.5h, then cooled to 60°C, added with 2700mL of ethanol, 170mL of deionized water, 15g of γ-methacryloyloxypropyltrimethoxysilane and 25g of activated carbon nanotubes, heated to 80°C, condensed and refluxed for 5.5h. After the reaction is completed, the reaction solution is cooled to room temperature, filtered, and the filter cake is washed twice with ethanol, transferred to an oven at 65°C, and dried to constant weight to obtain a modified aging-resistant filler.

[0084] Example 9

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

[0086] Step ①: Preparation of activated carbon nanotubes

[0087] Weigh: 20 g of carboxylated carbon nanotubes and 3000 mL of ethanol are placed in a reactor, ultrasonically dispersed for 5 minutes, 60 wt% nitric acid solution is added to adjust the pH to 4, the temperature is raised to 65°C, and the reaction is kept warm for 6 hours. After the reaction is completed, the reaction mixture is cooled to room temperature, filtered, and the filter cake is washed three times with deionized water, transferred to an oven at a temperature of 70°C, dried to constant weight, ground, and passed through a 200-mesh sieve to obtain activated carbon nanotubes.

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

[0089] Weigh: 50g of 2,2,4-trimethyl-1,2-dihydroquinoline and 60g of 3-glycidyloxypropyltriethoxysilane are placed in a reactor, heated to 140°C, condensed and refluxed for 4h, then cooled to 65°C, 3000mL of ethanol, 200mL of deionized water, 20g of γ-methacryloxypropyltrimethoxysilane and 30g of activated carbon nanotubes are added, heated to 85°C, condensed and refluxed for 6h. After the reaction is completed, the reaction solution is cooled to room temperature, filtered, and the filter cake is washed with ethanol 3 times, transferred to an oven at 70°C, and dried to constant weight to obtain a modified aging-resistant filler.

[0090] Example 10

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

[0092] Dicumyl peroxide, dibutyl phthalate and alkylphenol polyoxyethylene ether are mixed uniformly in a mass ratio of 1:5:1 to obtain an auxiliary additive for later use;

[0093] Weigh 60 parts by mass 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 into a twin-screw melt extruder, melt extrude, and inject into a mold to obtain a plastic packaging barrel;

[0094] The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 170°C, 170°C, 185°C, 185°C, 200°C, 200°C, 210°C, and 210°C, respectively. The main engine speed of the twin-screw extruder is 120rpm and the pressure is 80bar.

[0095] Example 11

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

[0097] Dicumyl peroxide, dibutyl phthalate and alkylphenol polyoxyethylene ether are mixed uniformly in a mass ratio of 1:5:1 to obtain an auxiliary additive for later use;

[0098] Weigh 65 parts by mass 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 into a twin-screw melt extruder, melt extrude, and inject into a mold to obtain a plastic packaging barrel;

[0099] The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 170°C, 170°C, 185°C, 185°C, 200°C, 200°C, 210°C, and 210°C, respectively. The main engine speed of the twin-screw extruder is 140rpm and the pressure is 100bar.

[0100] Example 12

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

[0102] Dicumyl peroxide, dibutyl phthalate and alkylphenol polyoxyethylene ether are mixed uniformly in a mass ratio of 1:5:1 to obtain an auxiliary additive for later use;

[0103] Weigh 70 parts by mass 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 into a twin-screw melt extruder, melt-extrude, and inject into a mold to obtain a plastic packaging barrel;

[0104] The temperatures of the eight temperature zones of the twin-screw extruder from the feed port to the discharge port are 170°C, 170°C, 185°C, 185°C, 200°C, 200°C, 210°C, and 210°C, respectively. The main engine speed of the twin-screw extruder is 160rpm and the pressure is 120bar.

[0105] Comparative Example 1

[0106] The difference between this comparative example and Example 12 is that, in step II, the flame retardant microspheres are not used 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 is not used in the preparation of the plastic packaging barrel.

[0109] Comparative Example 3

[0110] The difference between this comparative example and Example 12 is that when preparing the plastic packaging barrel, the modified aging-resistant filler is replaced by an equal amount of activated carbon nanotubes.

[0111] Performance testing:

[0112] Refer to standard HG / T 3984-2007 "Chemically resistant modified polypropylene storage tanks" to test the corrosion resistance of plastic packaging barrels;

[0113] The tensile strength and elongation at break of the plastic packaging barrels prepared in Examples 10-12 and Comparative Examples 1-3 were measured in accordance with the standard GB / T 1040.3-2006 “Determination of tensile properties of plastics Part 3: Test conditions for film and sheeting”;

[0114] The vertical combustion ratings of the plastic packaging barrels prepared in Examples 10-12 and Comparative Examples 1-3 were measured with reference to the standard GB / T 2408-2021 “Determination of Combustion Properties of Plastics—Horizontal and Vertical Methods”. 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 with reference to the standard GB / T 16422.3-2022 "Plastics Laboratory Light Source Exposure Test Methods Part 3: Fluorescent Ultraviolet Lamp". The tensile strength and elongation at break retention rates of the materials were determined with reference to the standard GB / T1040.3-2006, 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 "Chemically 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 ultraviolet aging

[0119]

[0120]

[0121] Data Analysis:

[0122] A comparative analysis of the data in Table 1 above shows that the plastic packaging barrels prepared by the present invention are resistant to corrosion by a saturated calcium hydroxide solution and a 10 wt% nitric acid solution, have a tensile strength of 82.3 MPa, an elongation at break of 126.4%, and a vertical burning rating of V-0. A comparative analysis of the data in Table 2 above shows that the plastic packaging barrels prepared by the present invention are still resistant to corrosion by a saturated calcium hydroxide solution and a 10 wt% nitric acid solution after ultraviolet aging, have a tensile strength retention rate of 95.1%, and an elongation at break retention rate of 96.9%.

[0123] By comparing the test data of Example 12 and Comparative Example 1, it can be found that the vertical combustion rating of the plastic packaging barrel prepared in Comparative Example 1 is significantly reduced, indicating that the flame-retardant microspheres prepared by the sol-gel method in the present invention are prepared using amino-modified silica as a shell layer and ammonium polyphosphate as a core. The silica shell layer forms a dense barrier through a Si-O-Si network. The amino groups on its surface are covalently bonded during the preparation of the modified silicone resin, thereby improving the flame retardancy of the modified silicone resin. The ammonium polyphosphate core decomposes when heated to produce polyphosphoric acid that catalyzes carbonization and ammonia that is a gas-phase flame retardant, thereby achieving a condensed phase and gas-phase synergistic flame retardancy mechanism, thereby improving the flame retardancy of the plastic packaging barrel. The silica shell protects the ammonium polyphosphate core from premature decomposition during the melt processing process, further improving the flame retardancy of the plastic packaging barrel.

[0124] By 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 barrel prepared in Comparative Example 2 are significantly reduced, and it is not resistant to corrosion by saturated calcium hydroxide solution and 10wt% nitric acid solution. The corrosion resistance, tensile strength retention and elongation at break retention after ultraviolet aging are significantly reduced, indicating that the present invention prepares a modified silicone resin precursor having an olefin unsaturated double bond and a fluorine atom in the side chain by a condensation reaction, obtains a hydroxyl-terminated modified silicone resin precursor by adding a blocking group, and combines the modified silicone resin precursor with the flame retardant microspheres by covalent bonds to obtain a modified silicone resin. The trifluoropropyl group introduced into the structure of the modified silicone resin precursor has strong hydrophobicity and chemical inertness, which can significantly reduce the contact between the surface of the plastic packaging barrel and the flame retardant microspheres. The reactivity of organic solvents, acids, bases and other substances improves 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, thereby improving the compatibility between substrates and further enhancing the mechanical properties of plastic packaging barrels. Hexamethylene diisocyanate reacts with the hydroxyl groups of the modified silicone resin precursor to form a three-dimensional urethane cross-linked network, which significantly enhances the binding force between polymer chains. The modified silicone resin is mainly composed of a siloxane skeleton and 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 silicon-oxygen structures can effectively absorb and scatter ultraviolet rays, reducing damage to the surface of the plastic packaging barrels and increasing their service life.

[0125] By comparing the test data of Example 12 and Comparative Example 3, it can be found that the elongation at break and the tensile strength of the plastic packaging barrel prepared in Comparative Example 3 are significantly reduced, and the tensile strength retention and elongation at break retention after ultraviolet aging are significantly reduced, indicating that the present invention prepares activated carbon nanotubes, increases their reactivity, and further modifies 2,2,4-trimethyl-1,2-dihydroquinoline and olefin unsaturated double bonds on their surfaces to obtain modified aging-resistant fillers. 2,2,4-trimethyl-1,2-dihydroquinoline acts as a free radical scavenger, stabilizes the active free radicals in the plastic matrix through the conjugated structure of the benzene ring, and inhibits The main chain breaks during the thermal oxidative aging process, and it combines with 3-glycidyloxypropyltriethoxysilane through covalent bonds, and is further modified to the activated carbon nanotubes through hydrolysis and condensation of the silane coupling agent, which delays migration and precipitation and extends the protection time. Through the cross-linking effect of activated carbon nanotubes and modified silane, the modified aging-resistant filler not only improves the rigidity of the plastic packaging barrel, but also enhances the toughness of the plastic packaging barrel. Carbon nanotubes, as nano-reinforced fillers, have excellent impact resistance. They can effectively disperse external forces during use, reduce the cracking or deformation of the plastic packaging barrel due to external impact, and improve the mechanical properties of the material.

[0126] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. 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 barrel, characterized in that: The composition comprises the following raw materials by weight: 60-70 parts of modified silicone resin, 3-5 parts of modified aging-resistant filler, 8-12 parts of polypropylene, 12-18 parts of maleic anhydride grafted polypropylene and 3-5 parts of auxiliary additives; The auxiliary additives are composed of an initiator, a plasticizer and an antistatic agent in a mass ratio of 1:5:

1.

2. The corrosion-resistant and aging-resistant plastic packaging barrel according to claim 1, characterized in that: 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 kettle, raise the temperature to 110-120°C, add a catalyst, and keep the temperature for reaction for 4-6 hours. Add 1,3-bis(3-hydroxyisobutyl)tetramethyldisiloxane, keep the temperature for reaction for 3-5 hours, and post-treat to obtain a modified silicone resin precursor. A2. Under a nitrogen atmosphere, a modified silicone resin precursor, polyethylene glycol, stannous octoate, and tetrahydrofuran were placed in a reactor equipped with a condenser, stirred for 5-15 minutes, a condenser was placed, and the temperature was raised to 60-65°C. A calculated amount of hexamethylene diisocyanate was added to the reactor, and the reaction was kept warm for 0.5-1 hour. Trimethylolpropane and flame retardant microspheres were added, and the reaction was kept warm for 1-2 hours. The modified silicone resin was obtained by post-processing.

3. The corrosion-resistant and aging-resistant plastic packaging barrel according to claim 2, characterized in that: In step A1, the amount ratio of the 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, and the catalyst is a 20 wt% sulfuric acid solution; in step A2, the amount ratio of the modified silicone resin precursor, polyethylene glycol, stannous octoate, tetrahydrofuran, trimethylolpropane and flame retardant microspheres is 10-12 g:2-4 g:0.5-1 g:250-300 mL:2-4 g:1-1.5 g, and in the reaction, the hexamethylene diisocyanate is 0.55 times the molar amount of hydroxyl groups in the reaction system.

4. The corrosion-resistant and aging-resistant plastic packaging barrel according to claim 2, characterized in that: The flame-retardant microspheres are prepared by placing deionized water, ethanol, ammonium polyphosphate, OP-10 and ammonia water in a reaction kettle, stirring for 5-10 minutes, adding ethyl orthosilicate and (2-aminoisopropyl)triethoxysilane, heating to 35-45° C., keeping the temperature for reaction for 1-2 hours, and post-processing to obtain the flame-retardant microspheres.

5. The corrosion-resistant and aging-resistant plastic packaging barrel according to claim 4, characterized in that: The usage ratio of the deionized water, ethanol, ammonium polyphosphate, OP-10, ammonia water, ethyl orthosilicate and (2-aminoisopropyl)triethoxysilane is 8-10 mL: 20-25 mL: 5-6 g: 1-2 g: 1-2 g: 15-20 mL: 10-12 g: 5-8 g, and the concentration of the ammonia water is 25-30 wt %.

6. The corrosion-resistant and aging-resistant plastic packaging barrel according to claim 1, characterized in that: The modified aging-resistant filler is prepared by the following steps: B1. Place carboxylated carbon nanotubes and ethanol in a reaction kettle, perform ultrasonic dispersion for 1-5 minutes, add nitric acid solution to adjust the pH to 3-4, heat to 55-65°C, keep the temperature for reaction for 5-6 hours, and perform post-treatment to obtain activated carbon nanotubes; B2. Place 2,2,4-trimethyl-1,2-dihydroquinoline and 3-glycidyloxypropyltriethoxysilane in a reaction kettle, heat to 130-140°C, condense and reflux for 3-4 hours, then cool to 55-65°C, add ethanol, γ-methacryloxypropyltrimethoxysilane and activated carbon nanotubes, heat to 75-85°C, condense and reflux for 5-6 hours, and perform post-treatment to obtain a modified aging-resistant filler.

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

8. A method for preparing the corrosion-resistant and aging-resistant plastic packaging barrel according to any one of claims 1 to 7, characterized in that: The following steps are involved: Polypropylene, maleic anhydride grafted polypropylene, modified silicone resin, modified aging-resistant filler and auxiliary additives are added into a twin-screw melt extruder, melt-extruded, and injected into a mold to obtain a plastic packaging barrel.

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