Mineral volcanic cast refractory bus duct and method of making same

Abstract

The present application relates to bus duct technical field, especially relates to a kind of mineral volcanic rock pouring fire-resistant bus duct and its preparation method, the preparation method includes the following steps: providing a castable;Bus is fixed in mould, the castable is injected and solidified to obtain the fire-resistant bus duct;The castable includes the following weight parts of raw materials: 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, the fire-resistant bus duct has the characteristics of high flame-retardant corrosion resistance, especially suitable for chemical production environment etc..

Description

Technical Field

[0001] This invention relates to the field of busbar technology, and in particular to a mineral volcanic rock cast refractory busbar and its preparation method. Background Technology

[0002] Cast-in-place busbar trunking is a specially designed type of busbar trunking where the core conductive busbars (copper or aluminum) are encapsulated in epoxy resin or other high-performance insulating materials to form a highly protected and highly insulated integrated power distribution device.

[0003] Due to its high fire resistance, volcanic rock composite material used in the casting of busbar trunking has significantly improved the temperature resistance, fire resistance, aging resistance, and corrosion resistance compared to busbar trunking made by traditional methods. However, due to problems such as poor bonding between volcanic rock and resin matrix, poor fluidity of the casting material, high viscosity, and high shrinkage rate of epoxy resin, problems such as pores or cracks appearing after the casting material has cured, and delamination at high temperatures often occur, which seriously affect the quality of the busbar trunking. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a mineral volcanic rock cast refractory busbar trunking and its preparation method, which has high flame retardancy, meets the safety requirements of dense wiring, has good corrosion resistance, and is particularly suitable for chemical and other production environments.

[0005] This invention first provides a method for preparing a refractory busbar trough cast from mineral volcanic rock. The preparation method includes the following steps: providing a casting material; fixing a busbar in a mold; injecting the casting material and curing it to obtain the refractory busbar trough; 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 nitroisocyanate prepolymer;

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

[0007] The modified phenolic epoxy resin is obtained by reacting 100 parts of the aforementioned boron, nitrogen, and phosphorus-containing polymer, 160-180 parts of phenolic epoxy resin, and 1-3 parts of triphenylphosphine at 110-120°C for 3-4 hours; the filler includes volcanic rock, wollastonite, and silica, and the filler is pretreated using KH-550 and carboxylated polyethylene glycol maleimide.

[0008] The modified phenolic epoxy forms urea bonds (-NH-CO-NH-) through the reaction of amino groups with isocyanates, forming linear or branched prepolymers. The excess -NCO in MDI / HDI further reacts with the -NH- in the already formed urea bonds to generate biuret or urea carbamate, which can further improve the branching degree of the modified phenolic epoxy.

[0009] The NCO residue in the prepolymer reacts with the hydroxyl groups of diethyl (2-hydroxyethyl) phosphate to incorporate into the 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 undergoes ring-opening grafting with the epoxy groups of phenolic epoxy resin, forming a cross-linked network under the action of a phosphine catalyst, ultimately yielding a modified resin with high char residue, heat resistance, and flame retardancy.

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

[0011] In one embodiment, the coarse particles have a particle size of 1–3 mm, the fine particles have a particle size of 200–400 mesh, and the wollastonite has a particle size of 5–20 μm. The filler uses a blend of high and low melting point fillers, which has a significant cost advantage. The molten phase fills the pores, improving the density of the carbon layer. The filler formulation with progressively decreasing particle size also ensures the density and strength of the castable.

[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 aminated filler, wherein the ratio of filler, KH-550, and ethanol is 100 g: 5 g: 500 mL.

[0013] In one embodiment, the aminated filler is reacted with the product of the reaction of carboxylated polyethylene glycol maleimide, PBS buffer, 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 groups in carboxylated polyethylene glycol maleimide. 1-Ethyl-(3-dimethylaminopropyl)carbodiimide reacts with the carboxyl groups of carboxylated polyethylene glycol maleimide to generate an unstable O-acylisourea intermediate. N-hydroxysuccinimide replaces the 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 generate amide bonds.

[0015] In one embodiment, the toughening agent is prepared by reacting 1,1,3,3-tetramethyl-1,3-bis[3-(epoxyethylmethoxy)propyl]disiloxane with 4,5-dihydro-1,3-oxazol-2-amine at 50-60°C for 4-5 hours at a molar ratio of 1:(0.8-1); subsequently, the obtained product is reacted 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 backbone and alkoxy flexible segments in the toughening agent can reduce the internal stress of epoxy resin and improve its crack resistance. Part of the epoxy group in 1,1,3,3-tetramethyl-1,3-bis[3-(epoxyethylmethoxy)propyl]disiloxane undergoes a ring-opening reaction with the amino group in 4,5-dihydro-1,3-oxazol-2-amine. The remaining epoxy group then undergoes a ring-opening reaction with the hydroxyl group in (5-((diethylamino)methyl)furan-2-yl)methanol under the catalysis of a weak base triethylamine, thus preserving the oxazolline ring.

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

[0018] Anhydride curing agents are used instead of conventional amine curing agents to avoid side reactions between amine curing agents and the boron-nitrogen-phosphorus flame retardant system. 2-Ethyl-4-methylimidazole can promote curing and reduce the ring-opening activation energy of anhydrides.

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

[0020] In another aspect, the present invention provides a fire-resistant busbar trough prepared by the method described above. The fire-resistant busbar trough exhibits high flame retardancy and corrosion resistance, making it particularly suitable for chemical and other production environments.

[0021] This invention provides a mineral volcanic rock cast refractory busbar trough. The castable formulation features high temperature resistance and low shrinkage. It is made by compounding bisphenol F epoxy resin and modified phenolic epoxy resin. The phenolic epoxy resin with multiple active sites is modified to form a substance with a boron-nitrogen-phosphorus triple synergistic flame retardant effect. The boron-nitrogen-phosphorus system can form a dense expanded char layer, which has a good fire resistance and flame retardant effect. At the same time, the aliphatic long chain of HDI is introduced into the modified phenolic epoxy resin, which can counteract the brittleness of phenolic epoxy and improve toughness.

[0022] The toughening agent contains long silicon chains, which form a hybrid system with epoxy resin. At high temperatures, a Si-OC ceramic layer can be formed, giving the castable good high-temperature strength and stability. The polar groups in the toughening agent can enhance the hydrogen bonding with boron, nitrogen, and phosphorus. The toughening agent also introduces furan rings, which interact π-π with epoxy resin, improving the compatibility between the toughening agent and the resin matrix and preventing 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 derived from (5-((diethylamino)methyl)furan-2-yl)methanol in the toughening agent can undergo a reversible reaction with the maleimide group in the filler, achieving self-repair of microcracks. The oxazoline ring can also undergo a ring-opening reaction with epoxy groups under the catalysis of the curing agent, accompanied by volume expansion, effectively offsetting the effects of curing shrinkage. Detailed Implementation

[0024] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand 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 embodiments, and 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, the bisphenol F epoxy resin was purchased from Dow Chemical Company DER 354, the phenolic epoxy resin was purchased from Hansen EPON160, the volcanic rock had a service temperature of 2200℃ (coarse particle size 1-3mm, fine particle size 200-400 mesh, from Jilin Wudalianchi Refractory Materials Factory), the wollastonite was purchased from Xinyu Siyuan Mining Co., Ltd. (particle size 5-20μm), and the silica was 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 Yake Technology Co., Ltd.; diethyl(2-hydroxyethyl) phosphate was purchased from Shandong Qianyuan Polymer Materials Co., Ltd.; KH-550 was purchased from Gaizhou Hengda Chemical Co., Ltd.; carboxylated polyethylene glycol maleimide was purchased from Guangzhou Carbon Technology Co., Ltd.; 1,1,3,3-tetramethyl-1,3-bis[3-(epoxyethylmethoxy)propyl]disiloxane was purchased from Zhengzhou Alpha Chemical Co., Ltd.; 4,5-dihydro-1,3-oxazol-2-amine and (5-((diethylamino)methyl)furan-2-yl)methanol were purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0027] Example 1

[0028] A method for preparing a refractory busbar cast from mineral volcanic rock includes 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. The temperature was raised to 60°C, and the mixture was stirred until the isocyanate was completely melted. 0.5 parts of dibutyltin dilaurate were added and stirred until homogeneous. 100 parts of dried 2-aminopyridine-4-boronic acid were added in four batches, with an interval of 10 minutes between each batch. The mixture was reacted at 70°C for 2 hours. After purification, the boron nitrogen isocyanate prepolymer was obtained.

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

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

[0033] (2) Packing material pretreatment:

[0034] Volcanic rock, wollastonite, and silica were mixed in a weight ratio of 5:2:1, with a coarse to fine particle weight ratio of 1.5:1. Impurities were removed by soaking in 10% hydrochloric acid to expose the silanol groups. KH-550 was dissolved in a 70% ethanol solution, and the filler was added. The mixture was stirred at 60°C for 2 hours, and after washing and drying, an aminated filler was obtained. The ratio of filler, KH-550, and ethanol was 100g:5g:500mL.

[0035] Ten parts of carboxylated polyethylene glycol maleimide were dissolved in 500 parts of PBS buffer, and five parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and three parts of N-hydroxysuccinimide were added to activate the mixture at room temperature for 30 min. Then, 100 parts of aminated filler were added and reacted at 50 °C for 3 hours. After washing and drying, the pretreated filler was obtained.

[0036] (3) Preparation of toughening agent

[0037] 100 parts of 1,1,3,3-tetramethyl-1,3-bis[3-(epoxyethylmethoxy)propyl]disiloxane were reacted with 20 parts of 4,5-dihydro-1,3-oxazol-2-amine and 36 parts of anhydrous ethanol at 50°C for 4 hours under nitrogen protection. 70 parts of the purified product, 25 parts of (5-((diethylamino)methyl)furan-2-yl)methanol, 0.6 parts of triethylamine, and 20 parts of xylene were refluxed at 70°C for 2 hours to remove water and purified to obtain the toughening agent.

[0038] (4) Mixing and curing

[0039] 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 were mixed and pre-degassed to form a casting refractory. The busbar was placed in a mold and fixed. After pouring in the casting refractory, it was placed on a vibration platform and vibrated for 3 minutes. After degassed again, it was cured and demolded to obtain a fire-resistant busbar trough. The curing conditions were: pre-curing at 60℃ for 2 hours, then heating to 100℃ and curing for 3 hours, and finally heating to 140℃ and curing for 2 hours (heating rate 2℃ / min). In this embodiment, the curing agent used was methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazolium in a weight ratio of 30:1.

[0040] Example 2

[0041] A method for preparing a refractory busbar cast from mineral volcanic rock includes the following steps:

[0042] (1) Modified phenolic epoxy resin:

[0043] Under nitrogen protection, 120 parts MDI, 40 parts HDI, and 50 parts DMF were added to a four-necked flask. The temperature was raised to 60°C, and the mixture was stirred until the isocyanate was completely melted. One part dibutyltin dilaurate was added and stirred until homogeneous. 100 parts of dried 2-aminopyridine-4-boronic acid were added in four batches, with an interval of 10 minutes between each batch. The mixture was reacted at 80°C for 3 hours. After purification, the boron nitrogen isocyanate prepolymer was obtained.

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

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

[0046] (2) Packing material pretreatment:

[0047] Volcanic rock, wollastonite, and silica were mixed in a weight ratio of 6:2:1, with the coarse to fine particles of the volcanic rock in a weight ratio of 2:1. Impurities were removed by soaking in 10% hydrochloric acid to expose the silanol groups. KH-550 was dissolved in a 70% ethanol solution, and the filler was added. The mixture was stirred at 60°C for 2 hours, and after washing and drying, an aminated filler was obtained. The ratio of filler, KH-550, and ethanol was 100g:5g:500mL.

[0048] Ten parts of carboxylated polyethylene glycol maleimide were dissolved in 500 parts of PBS buffer, and five parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and three parts of N-hydroxysuccinimide were added to activate the mixture at room temperature for 30 min. Then, 100 parts of aminated filler were added and reacted at 50 °C for 3 hours. After washing and drying, the pretreated filler was obtained.

[0049] (3) Preparation of toughening agent

[0050] 100 parts of 1,1,3,3-tetramethyl-1,3-bis[3-(epoxyethylmethoxy)propyl]disiloxane were reacted with 20 parts of 4,5-dihydro-1,3-oxazol-2-amine and 36 parts of anhydrous ethanol at 50°C for 4 hours under nitrogen protection. 70 parts of the purified product, 25 parts of (5-((diethylamino)methyl)furan-2-yl)methanol, 0.6 parts of triethylamine, and 20 parts of xylene were refluxed at 70°C for 2 hours to remove water and purified to obtain the toughening agent.

[0051] (4) Mixing and curing

[0052] 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 were mixed and pre-degassed to form a casting refractory. The busbar was placed in a mold and fixed. After pouring in the casting refractory, it was placed on a vibration platform and vibrated for 3 minutes. After degassed again, it was cured and demolded to obtain a fire-resistant busbar trough. The curing conditions were: pre-curing at 70℃ for 1 hour, then heating to 110℃ for 2 hours, and finally heating to 150℃ for 1 hour (heating rate 2℃ / min). In this embodiment, the curing agent used was methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazole in a weight ratio of 40:1.

[0053] Example 3

[0054] A method for preparing a refractory busbar cast from mineral volcanic rock includes the following steps:

[0055] (1) Modified phenolic epoxy resin:

[0056] Under nitrogen protection, 110 parts of MDI, 40 parts of HDI, and 40 parts of DMF were added to a four-necked flask. The temperature was raised to 60°C, and the mixture was stirred until the isocyanate was completely melted. 0.5 parts of dibutyltin dilaurate were added and stirred until homogeneous. 100 parts of dried 2-aminopyridine-4-boronic acid were added in four batches, with an interval of 10 minutes between each batch. The mixture was reacted at 70°C for 2 hours. After purification, the boron nitrogen isocyanate prepolymer was obtained.

[0057] 38 parts of diethyl(2-hydroxyethyl) phosphate and 0.4 parts of dibutyltin dilaurate were slowly added to 100 parts of boron-nitrogen isocyanate prepolymer at a reaction temperature of 50°C for 1 hour to obtain a polymer containing boron, nitrogen and phosphorus.

[0058] 170 parts of phenolic epoxy resin were mixed with 100 parts of a polymer containing boron, nitrogen, and phosphorus, and 35 parts of anhydrous xylene were added. Then, 1 part of triphenylphosphine catalyst was added, and the mixture was reacted at 110°C for 3 hours to obtain the modified phenolic epoxy resin.

[0059] (2) Packing material pretreatment:

[0060] Volcanic rock, wollastonite, and silica were mixed in a weight ratio of 5:2:1, with a coarse to fine particle weight ratio of 1.5:1. Impurities were removed by soaking in 10% hydrochloric acid to expose the silanol groups. KH-550 was dissolved in a 70% ethanol solution, and the filler was added. The mixture was stirred at 60°C for 2 hours, and after washing and drying, an aminated filler was obtained. The ratio of filler, KH-550, and ethanol was 100g:5g:500mL.

[0061] Ten parts of carboxylated polyethylene glycol maleimide were dissolved in 500 parts of PBS buffer, and five parts of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and three parts of N-hydroxysuccinimide were added to activate the mixture at room temperature for 30 min. Then, 100 parts of aminated filler were added and reacted at 50 °C for 3 hours. After washing and drying, the pretreated filler was obtained.

[0062] (3) Preparation of toughening agent

[0063] 100 parts of 1,1,3,3-tetramethyl-1,3-bis[3-(epoxyethylmethoxy)propyl]disiloxane were reacted with 20 parts of 4,5-dihydro-1,3-oxazol-2-amine and 36 parts of anhydrous ethanol at 50°C for 4 hours under nitrogen protection. 70 parts of the purified product, 25 parts of (5-((diethylamino)methyl)furan-2-yl)methanol, 0.6 parts of triethylamine, and 20 parts of xylene were refluxed at 70°C for 2 hours to remove water and purified to obtain the toughening agent.

[0064] (4) Mixing and curing

[0065] 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 were mixed and pre-degassed to form a casting refractory. The busbar was placed in a mold and fixed. After pouring in the casting refractory, it was placed on a vibration platform and vibrated for 3 minutes. Degassed again, then cured and demolded to obtain a fire-resistant busbar trough. The curing conditions were: pre-curing at 60℃ for 2 hours, then heating to 100℃ for 3 hours, and finally heating to 140℃ for 2 hours (heating rate 2℃ / min). In this embodiment, the curing agent used was methyltetrahydrophthalic anhydride and 2-ethyl-4-methylimidazolium in a weight ratio of 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 with bisphenol A epoxy resin.

[0068] Comparative Example 2

[0069] The process of Comparative Example 2 is similar to that of Example 1, except that carboxylated 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, the difference being that the toughening agent used is a commercially available hyperbranched polymer ( H30).

[0072] evaluate

[0073] Performance evaluations were performed on Examples 1-3 and Comparative Examples 1-3.

[0074] (1) Elongation at break: GB / T 1040.1-2018 was used as the reference standard, and a universal testing machine was used for the test environment: 25℃, 50%;

[0075] (2) Tensile strength: Based on GB / T2567 as the reference standard, the tensile properties of the specimens were tested using a universal testing machine. The test was conducted in a dumbbell shape, with a tensile speed of 2 mm / min and an experimental environment of 25℃ and 50%.

[0076] (3) Fire resistance time: Using GA / T537 as a reference standard, the fire resistance time of the test sample to maintain the integrity of the circuit at a temperature of 1100℃ is tested.

[0077] Table 1 Performance Evaluation Table of Examples and Comparative Examples

[0078]

[0079] As can be seen from Table 1, the fire-resistant busbar trough prepared in this application has the characteristics of both 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, it has obvious advantages in terms of flexibility and fire resistance compared to Comparative Example 1. In Comparative Example 2, due to the absence of carboxyl polyethylene glycol maleimide modified filler, the compatibility between the filler and the resin matrix deteriorates, affecting the elongation at break, tensile strength and fire resistance time. In Comparative Example 3, a commercially available toughening agent was used, which has a certain toughening effect, but due to the lack of a siloxane skeleton, the strength and fire resistance are inferior to those of Example 1.

[0080] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may 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. In addition to the specific methods, devices, and materials used in the embodiments, based on the knowledge of those skilled in the art and the description of the present invention, any prior art methods, devices, and materials similar to or equivalent to those described, used, and materials in the embodiments of the present invention can be used to implement the present invention. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a refractory busbar trough cast from mineral volcanic rock, characterized in that: The preparation method includes the following steps: Provide a casting refractory; The busbar is placed in a mold and fixed, the castable material is injected and cured to obtain the refractory busbar trough; The casting material comprises the following raw materials in parts by weight: 35-40 parts bisphenol F epoxy resin, 20-25 parts modified phenolic epoxy resin, 30-35 parts filler, 25-30 parts curing agent and 5-8 parts toughening agent. The preparation of the modified phenolic epoxy resin includes: 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 were reacted at 70-80°C for 2-3 hours to obtain a boron nitroisocyanate prepolymer. 100 parts of the boron nitrogen isocyanate prepolymer, 30-40 parts of diethyl (2-hydroxyethyl) phosphate, and 0.3-0.5 parts of dibutyltin dilaurate were reacted at 50-60°C for 1-1.5 hours to obtain a polymer containing boron nitrogen phosphorus. The modified phenolic epoxy resin is obtained by reacting 100 parts of the aforementioned boron-nitrogen-phosphorus polymer, 160-180 parts of phenolic epoxy resin, and 1-3 parts of triphenylphosphine at 110-120°C for 3-4 hours. The filler includes volcanic rock, wollastonite and silica. The filler is pretreated using KH-550 and carboxylated polyethylene glycol maleimide. The toughening agent is prepared by: 1,1,3,3-Tetramethyl-1,3-bis[3-(epoxyethylmethoxy)propyl]disiloxane was reacted with 4,5-dihydro-1,3-oxazol-2-amine at 50-60°C for 4-5 hours at a molar ratio of 1:(0.8-1). The obtained product was then reacted with (5-((diethylamino)methyl)furan-2-yl)methanol and triethylamine at 70-75°C for 2-3 hours to obtain the toughening agent.

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 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, characterized in that: The coarse particles have a particle size of 1-3 mm, the fine particles have a particle size of 200-400 mesh, and the wollastonite has a particle size of 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 aminated filler, wherein the ratio of filler, KH-550 and ethanol is 100 g: 5 g: 500 mL.

5. The preparation method according to claim 4, characterized in that: The aminated filler was reacted with the product of the reaction of carboxylated polyethylene glycol maleimide, PBS buffer, 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to obtain the pretreated filler.

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

1.

7. The preparation method according to claim 1, characterized in that, The curing process includes pre-curing at 60-70°C for 1-2 hours, then curing at 100-110°C for 2-3 hours, and finally curing at 140-150°C for 1-2 hours.

8. The refractory busbar obtained by any one of the preparation methods according to claims 1-7.

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