Mineral volcanic rock pouring fire-resistant bus duct and preparation method thereof

Abstract

The invention relates to the technical field of bus ducts, in particular to a mineral volcanic rock pouring fire-resistant bus duct and a preparation method thereof, and the preparation method comprises the following steps: providing a pouring material; fixing a bus in a mold, injecting the castable, and curing to obtain the fire-resistant bus duct; the castable comprises the following raw materials in parts by weight: 35-40 parts of bisphenol F epoxy resin, 20-25 parts of modified novolac epoxy resin, 30-35 parts of a filler, 25-30 parts of a curing agent and 5-8 parts of a flexibilizer, and the fire-resistant bus duct has the characteristics of high flame retardance and corrosion resistance, and is particularly suitable for production environments such as chemical engineering.

Description

Technical Field

[0001] The present invention relates to the technical field of bus ducts, and particularly to a mineral volcanic rock cast refractory bus duct and a preparation method thereof. Background Art

[0002] The cast bus duct is a specially designed bus duct, and its core conductive bus bar (copper bar or aluminum bar) is encapsulated by casting with epoxy resin or other high-performance insulating materials to form a high-protection and high-insulation integrated power distribution device.

[0003] Due to the high fire resistance of mineral volcanic rock, the bus duct formed by casting with volcanic rock composite materials has been greatly improved in terms of temperature resistance, fire prevention, aging resistance, and corrosion resistance compared with the bus duct of traditional processes. However, due to problems such as poor interfacial bonding between volcanic rock and resin matrix, poor fluidity of the casting material, high viscosity, and high shrinkage rate of epoxy resin, there are often problems such as pores or cracks in the casting body after curing, and delamination at high temperatures, which seriously affect the quality of the bus duct. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a mineral volcanic rock cast refractory bus duct and a preparation method thereof, which have the characteristics of high flame retardancy, meet the safety requirements of dense wiring, have good corrosion resistance, and are particularly suitable for production environments such as chemical industry.

[0005] The present invention first provides a preparation method of a mineral volcanic rock cast refractory bus duct, and the preparation method includes the following steps: providing a casting material; fixing a bus bar in a mold, injecting the casting material and curing to obtain the refractory bus duct; the casting material includes the following raw materials in parts by weight: 35-40 parts of bisphenol F epoxy resin, 20-25 parts of modified phenolic epoxy resin, 30-35 parts of filler, 25-30 parts of curing agent, and 5-8 parts of toughening agent; wherein, the preparation of the modified phenolic epoxy resin includes: reacting 100 parts of 2-aminopyridine-4-boric acid, 100-120 parts of 4,4'-diphenylmethane diisocyanate, 30-40 parts of hexamethylene diisocyanate, and 0.5-1 part of dibutyltin dilaurate at 70-80 °C for 2-3 hours to obtain a boron-nitrogen isocyanate prepolymer;

[0006] Reacting 100 parts of the boron-nitrogen isocyanate prepolymer with 30-40 parts of diethyl (2-hydroxyethyl) phosphate and 0.3-0.5 part of dibutyltin dilaurate at 50-60 °C for 1-1.5 hours to obtain a polymer containing boron, nitrogen, and phosphorus;

[0007] 100 parts of the boron, nitrogen and phosphorus-containing polymer, 160 - 180 parts of phenolic epoxy resin, and 1 - 3 parts of triphenylphosphine are reacted at 110 - 120 °C for 3 - 4 hours to obtain the modified phenolic epoxy resin; the filler includes volcanic rock, wollastonite and silica, and the filler is pretreated, and the pretreatment is carried out with KH-550 and carboxyl polyethylene glycol maleimide.

[0008] The above-mentioned modified phenolic epoxy reacts through the amino group and isocyanate to form a urea bond (-NH-CO-NH-), forming a linear or branched prepolymer. The excessive -NCO in MDI / HDI further reacts with -NH- in the formed urea bond to generate biuret or urethane, which can further improve the degree of branching of the modified phenolic epoxy.

[0009] The residual NCO in the prepolymer reacts with the hydroxyl group of diethyl (2-hydroxyethyl) phosphate to introduce a phosphate ester structure (-P=O), enhancing the catalytic char formation and condensed-phase flame retardant effect. The unreacted NCO in the boron, nitrogen and phosphorus-containing polymer opens the ring and grafts with the epoxy group of the phenolic epoxy resin, and forms a cross-linked network under the action of a phosphine catalyst, finally obtaining a modified resin with both high char residue rate, heat resistance and flame retardancy.

[0010] In one embodiment, the weight ratio of the volcanic rock, wollastonite and silica is (5 - 6):2:1. The volcanic rock includes coarse particles and fine particles, and the weight ratio of the coarse particles to the fine particles is (1.5 - 2):1.

[0011] In one embodiment, the particle size of the coarse particles is 1 - 3 mm, the particle size of the fine particles is 200 - 400 mesh, and the particle size of the wollastonite is 5 - 20 μm. The filler is compounded with high and low melting point fillers, which has obvious cost advantages. After the molten phase fills the pores, the compactness of the carbon layer can be improved, and the compactness and strength of the castable can also be ensured through the filler formula with gradually decreasing particle size.

[0012] In one embodiment, the pretreatment includes: dissolving KH-550 in a 70 v% ethanol solution and mixing it with the filler to obtain an amino-functionalized filler, where the ratio of the filler, KH-550 and ethanol is 100 g:5 g:500 mL.

[0013] In one embodiment, the amino-functionalized filler is reacted with the product obtained by reacting carboxyl polyethylene glycol maleimide, PBS buffer solution, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to obtain a pretreated filler.

[0014] 1-Ethyl-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS) are used to activate the carboxyl group in carboxyl polyethylene glycol maleimide. 1-Ethyl-(3-dimethylaminopropyl)carbodiimide reacts with the carboxyl group of carboxyl polyethylene glycol maleimide to form an unstable O-acylisourea intermediate, and N-hydroxysuccinimide replaces O-acylisourea to generate a more stable N-hydroxysuccinimide ester (PEG-Mal-CO-O-NHS). The -NH2 on the filler surface attacks PEG-Mal-CO-O-NHS to form an amide bond.

[0015] In one embodiment, the preparation of the toughening agent includes: reacting 1,1,3,3-tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane with 4,5-dihydro-1,3-oxazol-2-amine at 50-60 °C for 4-5 hours, with a molar ratio of 1:(0.8-1); subsequently, reacting the obtained product with (5-((diethylamino)methyl)furan-2-yl)methanol and triethylamine at 70-75 °C for 2-3 hours to obtain the toughening agent.

[0016] The siloxane skeleton and alkoxy flexible chain segments in the toughening agent can reduce the internal stress of the epoxy resin and improve the anti-cracking performance. Some epoxy groups in 1,1,3,3-tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane undergo ring-opening reaction with the amino group in 4,5-dihydro-1,3-oxazol-2-amine, and the remaining epoxy groups subsequently undergo ring-opening reaction with the hydroxyl group in (5-((diethylamino)methyl)furan-2-yl)methanol under the catalysis of weak base triethylamine, so that the oxazoline ring can be retained.

[0017] In one embodiment, the curing agent includes methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazole, and the weight ratio of methyltetrahydrophthalic anhydride to 2-ethyl-4-methylimidazole is (30-40):1.

[0018] The use of acid anhydride curing agent instead of conventional amine curing agent is to avoid side reactions between amine curing agent and boron-nitrogen-phosphorus flame retardant system. 2-Ethyl-4-methylimidazole can promote curing and reduce the ring-opening activation energy of acid anhydride.

[0019] In one embodiment, the curing includes pre-curing at 60-70 °C for 1-2 hours, then heating to 100-110 °C for post-curing for 2-3 hours, and finally heating to 140-150 °C for curing for 1-2 hours.

[0020] On the other hand, the present invention also provides a fire-resistant busbar trunking prepared by the above-mentioned preparation method. The fire-resistant busbar trunking has the characteristics of high flame retardancy and corrosion resistance, and is particularly suitable for production environments such as chemical industry.

[0021] A mineral volcanic rock cast refractory busway provided by the present invention has a casting material formula with the characteristics of high temperature resistance and low shrinkage. It uses a blend of bisphenol F epoxy resin and modified phenolic epoxy resin. After modifying the phenolic epoxy with multiple active sites, a substance with a triple synergistic flame retardant effect of boron-nitrogen-phosphorus is formed. The boron-nitrogen-phosphorus system can form a dense expanded carbon layer, having a good fire resistance and flame retardant effect. At the same time, a long aliphatic chain of HDI is introduced into the modified phenolic epoxy resin, which can offset the brittleness of the phenolic epoxy and improve the toughness.

[0022] The toughening agent has a long silicon chain and forms a hybrid system with the epoxy. At high temperatures, a Si-O-C ceramic layer can be formed, making the casting material have good high-temperature strength and stability. The polar groups in the toughening agent can enhance the hydrogen bond interaction with boron, nitrogen, and phosphorus. A furan ring is also introduced into the toughening agent, which has a π-π interaction with the epoxy resin, improving the compatibility between the toughening agent and the resin matrix and avoiding phase separation. The tertiary amino group in 1-ethyl-(3-dimethylaminopropyl)carbodiimide in the toughening agent can also act as a latent curing accelerator to promote curing.

[0023] The furan ring from (5-((diethylamino)methyl)furan-2-yl)methanol in the toughening agent can undergo a reversible reaction with the maleimide group in the filler to achieve self-repair of microcracks. The oxazoline ring can also undergo a ring-opening reaction with the epoxy group under the catalysis of the curing agent and is accompanied by volume expansion, effectively offsetting the influence brought by curing shrinkage. Specific embodiments

[0024] The following specific examples illustrate the implementation manners of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0025] In the following examples, bisphenol F epoxy resin is purchased from DER 354 of Dow Chemical Company, phenolic epoxy resin is purchased from EPON160 of Hexion, the service temperature of volcanic rock is high temperature resistance of 2200 °C (coarse particle size specification is 1 - 3 mm, fine particle size specification is 200 - 400 mesh, Jilin Wudalianchi Refractory Materials Factory), wollastonite is purchased from Xinyu Siyuan Mining Co., Ltd. (particle size is 5 - 20 μm), and silica is fumed silica, HDK@H17, sourced from Wacker Chemie (China) Co., Ltd.

[0026] 2-Aminopyridine-4-boronic acid was purchased from Shanghai Longsheng Chemical Co., Ltd., 4,4'-Diphenylmethane diisocyanate was purchased from Wuhan Jiyesheng Chemical Co., Ltd., Hexamethylene diisocyanate was purchased from Suzhou Yakoo Science & Technology Co., Ltd., Diethyl (2-hydroxyethyl) phosphate was purchased from Shandong Qianyuan High Polymer Materials Co., Ltd., KH-550 was purchased from Gaizhou Hengda Chemical Co., Ltd., Carboxyl polyethylene glycol maleimide was purchased from Guangzhou Carbohydrate Technology Co., Ltd., 1,1,3,3-Tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane was purchased from Zhengzhou Alfa Chemical Co., Ltd., 4,5-Dihydro-1,3-oxazol-2-amine and (5-((diethylamino)methyl)furan-2-yl)methanol were purchased from Shanghai Yuanye Bio-Technology Co., Ltd.

[0027] Example 1

[0028] A preparation method of a mineral volcanic rock cast refractory busway, comprising the following steps:

[0029] (1) Modified phenolic epoxy resin:

[0030] Under nitrogen protection, 100 parts of MDI, 30 parts of HDI and 30 parts of DMF were added to a four-necked flask, heated to 60 °C, stirred until the isocyanate was completely melted, 0.5 part of dibutyltin dilaurate was added, stirred evenly, and 100 parts of dry 2-aminopyridine-4-boronic acid were added in 4 batches, with an interval of 10 minutes between each batch, and reacted at 70 °C for 2 hours, and a boron-nitrogen isocyanate prepolymer was obtained through purification.

[0031] 30 parts of diethyl (2-hydroxyethyl) phosphate and 0.3 part of dibutyltin dilaurate were slowly added to 100 parts of the boron-nitrogen isocyanate prepolymer, the reaction temperature was 50 °C, and the reaction time was 1 hour to obtain a polymer containing boron, nitrogen and phosphorus.

[0032] 160 parts of phenolic epoxy resin were mixed with 100 parts of the polymer containing boron, nitrogen and phosphorus, 30 parts of anhydrous xylene were added, and 1 part of the catalyst triphenylphosphine was added, and the mixture was reacted at 110 °C for 3 hours to obtain the modified phenolic epoxy resin.

[0033] (2) Filler pretreatment:

[0034] Volcanic rock, wollastonite and silica were mixed according to a weight ratio of 5:2:1, and the weight ratio of the coarse particles to the fine particles of the volcanic rock was 1.5:1. 10% hydrochloric acid was used for soaking to remove impurities and expose silanol groups; KH-550 was dissolved in a 70 v% ethanol solution, the filler was added, and the mixture was stirred at 60 °C for 2 hours, and after washing and drying, an amino-functionalized filler was obtained, where the ratio of the filler, KH-550 and ethanol was 100 g:5 g:500 mL.

[0035] Dissolve 10 parts of carboxyl polyethylene glycol maleimide in 500 parts of PBS buffer solution, add 5 parts of 1-ethyl-(3-dimethylaminopropyl) carbodiimide and 3 parts of N-hydroxysuccinimide, activate at room temperature for 30 min, then add 100 parts of amino-functionalized filler, react at 50 °C for 3 hours, and obtain the pretreated filler after washing and drying.

[0036] (3) Preparation of toughening agent

[0037] React 100 parts of 1,1,3,3-tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane with 20 parts of 4,5-dihydro-1,3-oxazol-2-amine and 36 parts of absolute ethanol at 50 °C for 4 h under nitrogen protection. Take 70 parts of the purified product, 25 parts of (5-((diethylamino)methyl)furan-2-yl)methanol, 0.6 part of triethylamine and 20 parts of xylene, reflux and dehydrate at 70 °C for 2 hours, and obtain the toughening agent after purification.

[0038] (4) Mixing and curing

[0039] Take 35 parts of bisphenol F epoxy resin, 20 parts of modified phenolic epoxy resin, 30 parts of filler, 25 parts of curing agent, and 5 parts of toughening agent, mix them and pre-degas to form a casting material. Place the busbar in a mold and fix it. Inject the casting material and place it on a vibrating platform, vibrate for 3 minutes, degas again, and then cure and demold to obtain a fire-resistant busbar trunking. The curing conditions are pre-cure at 60 °C for 2 hours, then heat up to 100 °C and cure for 3 hours, and finally heat up to 140 °C and cure for 2 hours (heating rate 2 °C / min). In this example, the curing agent uses methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazole, and the weight ratio is 30:1.

[0040] Example 2

[0041] A preparation method of a mineral volcanic rock cast fire-resistant busbar trunking, comprising the following steps:

[0042] (1) Modified phenolic epoxy resin:

[0043] Under nitrogen protection, add 120 parts of MDI, 40 parts of HDI and 50 parts of DMF to a four-necked flask, heat up to 60 °C, stir until the isocyanate is completely melted, add 1 part of dibutyltin dilaurate, stir evenly, add 100 parts of dry 2-aminopyridine-4-boronic acid in 4 batches, with an interval of 10 minutes between each batch, react at 80 °C for 3 hours, and obtain a boron-nitrogen isocyanate prepolymer after purification.

[0044] 40 parts of diethyl(2-hydroxyethyl) phosphate and 0.5 part of dibutyltin dilaurate were slowly added to 100 parts of a boron-nitrogen isocyanate prepolymer. The reaction temperature was 60 °C and the reaction time was 1.5 hours to obtain a boron-nitrogen-phosphorus-containing polymer.

[0045] 180 parts of a phenolic epoxy resin were mixed with 100 parts of the boron-nitrogen-phosphorus-containing polymer, and 50 parts of anhydrous xylene were added. Then 3 parts of a catalyst triphenylphosphine were added, and the reaction was carried out at 120 °C for 4 hours to obtain the modified phenolic epoxy resin.

[0046] (2) Filler pretreatment:

[0047] Volcanic rock, wollastonite, and silica were mixed in a weight ratio of 6:2:1. The weight ratio of the coarse particles to the fine particles of the volcanic rock was 2:1. 10% hydrochloric acid was used for soaking to remove impurities and expose silanol groups. KH-550 was dissolved in a 70 v% ethanol solution, the filler was added, and stirring was carried out at 60 °C for 2 hours. After washing and drying, an aminated filler was obtained, where the ratio of the filler, KH-550, and ethanol was 100 g:5 g:500 mL.

[0048] 10 parts of carboxyl polyethylene glycol maleimide were dissolved in 500 parts of PBS buffer solution. 5 parts of 1-ethyl-(3-dimethylaminopropyl) carbodiimide and 3 parts of N-hydroxysuccinimide were added and activated at room temperature for 30 min. Then 100 parts of the aminated filler were added, and the reaction was carried out at 50 °C for 3 hours. After washing and drying, a pretreated filler was obtained.

[0049] (3) Preparation of toughening agent

[0050] 100 parts of 1,1,3,3-tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane, 20 parts of 4,5-dihydro-1,3-oxazol-2-amine, and 36 parts of anhydrous ethanol were reacted at 50 °C for 4 h under nitrogen protection. 70 parts of the purified product, 25 parts of (5-((diethylamino)methyl)furan-2-yl)methanol, 0.6 part of triethylamine, and 20 parts of xylene were refluxed for dehydration at 70 °C for 2 hours, and after purification, the toughening agent was obtained.

[0051] (4) Mixing and curing

[0052] Take 40 parts of bisphenol F epoxy resin, 25 parts of modified phenolic epoxy resin, 35 parts of filler, 30 parts of curing agent, and 8 parts of toughening agent. After mixing, pre-degas to form a casting material. Fix the busbar in a mold, inject the casting material, place it on a vibrating platform, vibrate for 3 minutes, degas again, and then cure and demold to obtain a refractory busbar. The curing conditions are pre-curing at 70°C for 1 hour, then heating to 110°C and curing for 2 hours, and finally heating to 150°C and curing for 1 hour (heating rate 2°C / min). In this example, the curing agent uses methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazole, with a weight ratio of 40:1.

[0053] Example 3

[0054] A preparation method of a mineral volcanic rock cast refractory busbar, comprising the following steps:

[0055] (1) Modified phenolic epoxy resin:

[0056] Under nitrogen protection, add 110 parts of MDI, 40 parts of HDI, and 40 parts of DMF to a four-necked flask, heat up to 60°C, stir until the isocyanate is completely melted, add 0.5 part of dibutyltin dilaurate, stir evenly, and add 100 parts of dry 2-aminopyridine-4-boric acid in 4 batches, with an interval of 10 minutes between each batch. React at 70°C for 2 hours, and obtain a boron-nitrogen isocyanate prepolymer through purification.

[0057] Slowly add 38 parts of diethyl (2-hydroxyethyl) phosphate and 0.4 part of dibutyltin dilaurate to 100 parts of the boron-nitrogen isocyanate prepolymer. The reaction temperature is 50°C and the reaction time is 1 hour to obtain a polymer containing boron, nitrogen, and phosphorus.

[0058] Mix 170 parts of phenolic epoxy resin with 100 parts of the polymer containing boron, nitrogen, and phosphorus, add 35 parts of anhydrous xylene, and add 1 part of the catalyst triphenylphosphine. React at 110°C for 3 hours to obtain the modified phenolic epoxy resin.

[0059] (2) Filler pretreatment:

[0060] Mix volcanic rock, wollastonite, and silica in a weight ratio of 5:2:1. The weight ratio of the coarse particles to the fine particles of the volcanic rock is 1.5:1. Use 10% hydrochloric acid to soak and remove impurities, exposing silanol groups; dissolve KH-550 in a 70v% ethanol solution, add the filler, stir at 60°C for 2 hours, and obtain an aminated filler after washing and drying. The ratio of the filler, KH-550, and ethanol is 100g:5g:500mL.

[0061] Dissolve 10 parts of carboxyl polyethylene glycol maleimide in 500 parts of PBS buffer solution, add 5 parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and 3 parts of N-hydroxysuccinimide, activate at room temperature for 30 min, then add 100 parts of amino-functionalized filler, react at 50 °C for 3 hours, and obtain the pretreated filler after washing and drying.

[0062] (3) Preparation of toughening agent

[0063] React 100 parts of 1,1,3,3-tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane with 20 parts of 4,5-dihydro-1,3-oxazol-2-amine and 36 parts of absolute ethanol at 50 °C for 4 h under nitrogen protection. Then, mix 70 parts of the purified product with 25 parts of (5-((diethylamino)methyl)furan-2-yl)methanol, 0.6 part of triethylamine and 20 parts of xylene, reflux and dehydrate at 70 °C for 2 hours, and obtain the toughening agent after purification.

[0064] (4) Mixing and curing

[0065] Take 36 parts of bisphenol F epoxy resin, 22 parts of modified phenolic epoxy resin, 33 parts of filler, 27 parts of curing agent, and 6 parts of toughening agent, mix them and pre-degas to form a casting material. Fix the busbar in a mold, inject the casting material, place it on a vibration platform, vibrate for 3 minutes, degas again, and then cure and demold to obtain a fire-resistant busbar trunking. The curing conditions are pre-cure at 60 °C for 2 hours, then heat up to 100 °C and cure for 3 hours, and finally heat up to 140 °C and cure for 2 hours (heating rate 2 °C / min). In this example, the curing agent used is methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazole, and the weight ratio is 30:1.

[0066] Comparative example 1

[0067] The process of comparative example 1 is similar to that of example 1, except that bisphenol F epoxy resin is replaced by bisphenol A epoxy resin.

[0068] Comparative example 2

[0069] The process of comparative example 2 is similar to that of example 1, except that carboxyl polyethylene glycol maleimide is not used to modify the filler.

[0070] Comparative example 3

[0071] The process of comparative example 3 is similar to that of example 1, except that the commercially available hyperbranched polymer ( H30) is selected as the toughening agent.

[0072] Evaluation

[0073] Perform performance evaluation on examples 1-3 and comparative examples 1-3.

[0074] (1) Elongation at break: Referring to GB / T 1040.1-2018 as the reference standard, it is carried out using a universal testing machine. Experimental environment: 25°C, 50%;

[0075] (2) Tensile strength: Referring to GB / T 2567 as the reference standard, a universal testing machine is used to detect the tensile properties of the test specimen. The test specimen is dumbbell-shaped, the tensile speed is 2 mm / min, and the experimental environment is 25°C, 50%;

[0076] (3) Fire resistance time: Referring to GA / T 537 as the reference standard, the fire resistance time for the test specimen to maintain the integrity of the circuit at a temperature of 1100°C is detected.

[0077] Table 1 Performance evaluation table of examples and comparative examples

[0078]

[0079] As can be seen from Table 1, the fire-resistant busway prepared in this application has the characteristics of both certain strength and toughness and good heat resistance. In Examples 1-3, due to the better compatibility between bisphenol F epoxy resin and modified phenolic epoxy resin, there are obvious advantages in terms of flexibility and fire resistance compared with Comparative Example 1. In Comparative Example 2, since carboxyl polyethylene glycol maleimide-modified filler is not used, the compatibility between the filler and the resin matrix becomes poor, affecting the elongation at break, tensile strength and fire resistance time. In Comparative Example 3, a commercially available toughening agent is used. Although it has a certain toughening effect, due to the lack of a siloxane skeleton, the strength and fire resistance performance are inferior to those of Example 1.

[0080] The above examples only illustrate the principles and effects of the present invention, rather than limiting the present invention. When the examples give numerical ranges, it should be understood that unless otherwise specified in the present invention, any value at both ends of each numerical range and any value between the two ends can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art of this technology. Except for the specific methods, equipment, and materials used in the examples, according to the knowledge of those skilled in the art of this technology and the description of the present invention, any methods, equipment, and materials similar to or equivalent to the methods, equipment, and materials described in the examples of the present invention can also be used to implement the present invention. Any person familiar with this technology can modify or change the above examples without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation method of a mineral volcanic rock cast refractory busway, characterized in that: The preparation method includes the following steps: Provide a castable refractory material; Place the busbar in a mold for fixing, inject the castable refractory material and cure it to obtain the refractory busway; The castable refractory material includes the following raw materials in parts by weight: 35-40 parts of bisphenol F epoxy resin, 20-25 parts of modified phenolic epoxy resin, 30-35 parts of filler, 25-30 parts of curing agent, and 5-8 parts of toughening agent; Among them, the preparation of the modified phenolic epoxy resin includes: React 100 parts of 2-aminopyridine-4-boronic acid, 100-120 parts of 4,4'-diphenylmethane diisocyanate, 30-40 parts of hexamethylene diisocyanate, and 0.5-1 part of dibutyltin dilaurate at 70-80 °C for 2-3 hours to obtain a boron-nitrogen isocyanate prepolymer; React 100 parts of the boron-nitrogen isocyanate prepolymer with 30-40 parts of diethyl(2-hydroxyethyl)phosphate and 0.3-0.5 part of dibutyltin dilaurate at 50-60 °C for 1-1.5 hours to obtain a polymer containing boron, nitrogen, and phosphorus; React 100 parts of the polymer containing boron, nitrogen, and phosphorus with 160-180 parts of phenolic epoxy resin and 1-3 parts of triphenylphosphine at 110-120 °C for 3-4 hours to obtain the modified phenolic epoxy resin; The filler includes volcanic rock, wollastonite, and silica. The filler is pretreated with KH-550 and carboxyl polyethylene glycol maleimide.

2. The preparation method according to claim 1, characterized in that: The weight ratio of the volcanic rock, wollastonite, and silica is (5-6):2:

1. The volcanic rock includes coarse particles and fine particles, and the weight ratio of the coarse particles to the fine particles is (1.5-2):

1.

3. The preparation method according to claim 2, wherein: The particle size of the coarse particles is 1-3 mm, the particle size of the fine particles is 200-400 mesh, and the particle size of the wollastonite is 5-20 μm.

4. The preparation method according to claim 1, characterized in that: The pretreatment includes: dissolving KH-550 in a 70 v% ethanol solution and mixing it with the filler to obtain an amino-functionalized filler, where the ratio of the filler, KH-550, and ethanol is 100 g:5 g:500 mL.

5. The preparation method according to claim 4, wherein: React the amino-functionalized filler with the product obtained by reacting carboxyl polyethylene glycol maleimide, PBS buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, and N-hydroxysuccinimide to obtain a pretreated filler.

6. The preparation method according to claim 1, characterized in that, The preparation of the toughening agent includes: React 1,1,3,3-tetramethyl-1,3-bis[3-(oxiranylmethoxy)propyl]disiloxane with 4,5-dihydro-1,3-oxazol-2-amine at 50-60 °C for 4-5 hours, with a molar ratio of 1:(0.8-1); Subsequently, react the obtained product with (5-((diethylamino)methyl)furan-2-yl)methanol and triethylamine at 70-75 °C for 2-3 hours to obtain the toughening agent.

7. The preparation method according to claim 1, characterized in that, The curing agent includes methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazole, and the weight ratio of methyltetrahydrophthalic anhydride to 2-ethyl-4-methylimidazole is (30-40):

1.

8. The preparation method according to claim 1, wherein, The curing includes pre-curing at 60-70°C for 1-2 hours, then heating up to 100-110°C for post-curing for 2-3 hours, and finally heating up to 140-150°C for curing for 1-2 hours.

9. The fire-resistant busbar trunking prepared by the preparation method according to any one of claims 1-8.

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