Curing agent and curing method for low energy consumption type fuse quartz sand filler

Abstract

The application provides a low-energy fuse quartz sand filler curing agent and a curing method, relates to the technical field of fuses, and comprises a functional phase, a hardener and a reinforcing phase, characterized in that: the functional phase is a water glass solution with silicate as a main component, is used for forming a three-dimensional network structure through a hydrolysis-polycondensation reaction, and gives the quartz sand mechanical strength after dehydration by heating, and the functional phase accounts for 70wt%-90wt% of the total material; the application forms a three-dimensional network structure through the reaction of the functional phase and the hardener, cooperates with the strength enhancement and the hydrophilic improvement of the reinforcing phase, effectively improves the compactness, the compressive strength and the toughness of the quartz sand filler, can not only reduce the arc channel expansion of the metal melt during high-voltage and high-current breaking, reduce the post-arc time and the arc energy, but also can resist the erosion of moisture and other substances in the environment, and greatly improves the long-term use reliability and the environmental adaptability of the fuse product.

Description

Technical Field

[0001] This invention relates to the field of fuse technology, and more particularly to a curing agent and curing method for quartz sand filler in low-energy-consumption fuses. Background Technology

[0002] As an overcurrent protector based on the principle of current-induced thermal effect, a fuse mainly consists of a fusible element, a fuse tube, and filler. The filler, typically composed of silica sand particles with a specific particle size distribution, is placed inside the fuse tube. Its core function is to rapidly absorb arc energy and limit the arc path expansion, making it a key material for high-breaking-capacity fuses. With the miniaturization of fuses and the continuous increase in breaking capacity requirements, the technology of solidifying silica sand filler to further limit arc path expansion and improve arc voltage and arc extinguishing capability is widely used. Existing curing processes for quartz sand fillers have significant limitations, typically requiring dedicated curing ovens under high temperature and pressure with steam for several hours or even tens of hours to complete curing. This traditional process not only consumes a large amount of energy, resulting in high production energy consumption, but also significantly increases production costs due to reliance on specialized equipment. Furthermore, the investment in such equipment raises the threshold for fixed asset investment for enterprises. Therefore, this invention proposes a low-energy-consumption curing agent and curing method for quartz sand fillers used in fuses to address the problems existing in the prior art. Summary of the Invention

[0003] To address the aforementioned issues, this invention proposes a curing agent and curing method for low-energy-consumption quartz sand filler in fuses. Through the reaction of functional phases and hardeners, a three-dimensional network structure is formed. Combined with the strength enhancement and hydrophilicity improvement effects of the reinforcing phase, the density, compressive strength, and toughness of the quartz sand filler are effectively improved. This not only reduces the arc channel expansion of molten metal during high-voltage, high-current interruption, reducing post-arc time and arc energy, but also resists the corrosion of moisture and other substances in the environment.

[0004] To achieve the objectives of this invention, the following technical solution is employed: a curing agent for low-energy-consumption fuse quartz sand filler, comprising a functional phase, a hardener, and a reinforcing phase. The functional phase is a water glass solution primarily composed of silicates, used to form a three-dimensional network structure through a hydrolysis-condensation reaction. After heating and dehydration, it imparts mechanical strength to the quartz sand. The functional phase accounts for 70wt%-90wt% of the total material. The hardener is a metal salt compound that can react with silicates, used to react with the functional phase to generate silica gel for curing, and the hardener accounts for 5wt%-20wt% of the total material; The reinforcing phase is an organosilicon compound or a polyacrylamide-like substance, used to improve the strength and hydrophobicity of the cured quartz sand. The reinforcing phase accounts for 1wt%-10wt% of the total material.

[0005] A further improvement is that the functional phase is a water glass solution prepared from at least one of sodium silicate and potassium silicate.

[0006] A further improvement is that the hardener is at least one of magnesium chloride, magnesium sulfate, magnesium nitrate, calcium chloride, and calcium carbonate.

[0007] A further improvement is that the reinforcing phase is at least one of silicone, dimethyl silicone oil, silicone resin, and polyacrylamide.

[0008] A further improvement is that it also contains 0wt%-5wt% of a retarder, wherein the retarder is at least one of tartaric acid, citric acid, borax, sodium dihydrogen phosphate, and disodium hydrogen phosphate.

[0009] A further improvement is that it also contains 0wt%-5wt% of a coagulant, wherein the coagulant is at least one of calcium chloride, sodium sulfate, and sodium fluorosilicate.

[0010] The curing method for the curing agent of the quartz sand filler in low-energy-consumption fuses includes the following steps: S1: Prepare the functional liquid by dissolving the functional phase in water, adding the reinforcing phase and optional retarder and accelerator, and mixing thoroughly. S2: Prepare the hardening solution by dissolving the hardener in water to form a transparent solution, colloid, or suspension; S3: Mix curing liquid, add the curing liquid to the functional liquid and stir to generate silica gel; S4: Sand mixing, mixing silica gel with quartz sand to coat the surface of sand particles with a silica gel film; S5: Sand filling, the mixed sand is pressed into the fuse tube through the sand filling hole and vent hole on the fuse terminal; S6: Curing. The molten tube filled with quartz sand mixture is placed in an oven and heated to form a three-dimensional network structure that cures the quartz sand filler.

[0011] A further improvement is made when it is necessary to prevent the functional liquid from reacting prematurely after mixing with the hardening liquid, thereby increasing the working time and the uniformity of sand mixing. Steps S3 and S4 above can be replaced with the following two steps: Functional liquid sand mixing: Add the functional liquid to the quartz sand filler according to the ratio and stir evenly so that a thin layer of functional liquid film is evenly attached to the surface of the quartz sand. Hardening liquid mixed with sand: The hardening liquid is added to the quartz sand filler that has been coated with the membrane according to the ratio and stirred evenly, so that the surface of the functional liquid membrane is covered with another layer of hardening liquid membrane, forming a silica gel layer adhesive membrane.

[0012] A further improvement is that, in S5, sand is filled using a manual or automatic dispensing process through pre-drilled sand-filling holes and venting holes in the fuse terminals.

[0013] A further improvement is that, in S6, the oven temperature is 60℃-100℃ and the heating time is 20min-120min.

[0014] The beneficial effects of this invention are as follows: 1. This invention forms a three-dimensional network structure through the reaction of functional phase and hardener. Combined with the strength enhancement and hydrophilicity improvement of the reinforcing phase, it effectively improves the density, compressive strength and toughness of quartz sand filler. This not only reduces the arc channel expansion of molten metal during high-voltage and high-current interruption, reducing the after-arc time and arc energy, but also resists the corrosion of moisture and other substances in the environment, greatly improving the long-term reliability and environmental adaptability of fuse products.

[0015] 2. The curing process of this invention can be completed in a short time at 60℃-100℃, without the need for specially customized curing ovens and pressurization equipment, which fundamentally reduces the fixed asset investment of enterprises. At the same time, the low temperature and short curing time significantly reduce energy consumption in the production process, directly driving down the production cost of fuse products.

[0016] 3. For fuse products that use high-temperature resistant plastic shells as fuse tubes, traditional high-temperature curing processes may damage the shells. However, the low-temperature curing process of this invention is perfectly suited for such products. The curing process using quartz sand filler effectively improves the breaking capacity. In addition, the selective addition of retarder and accelerator in the curing agent system can flexibly control the curing reaction rate, improve the operability and stability of the production process, and further optimize production efficiency. Attached Figure Description

[0017] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0018] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0019] Example 1 according to Figure 1 As shown, this embodiment proposes a curing agent for low-energy-consumption fuse quartz sand filler, comprising a functional phase, a hardener, and a reinforcing phase. The functional phase enables the quartz sand filler particles to first form a three-dimensional network structure through hydrolysis-condensation reaction, and then obtain the required mechanical strength after heating and dehydration. The functional phase is a water glass solution mainly composed of at least one of sodium silicate, potassium silicate, etc.; the amount of the functional phase added accounts for 70wt%-90wt% of the curing agent material of this invention.

[0020] The function of the hardener is to react with the functional phase to form a three-dimensional network structure, thereby achieving curing. The hardener is at least one of magnesium chloride, magnesium sulfate, magnesium nitrate, calcium chloride, and calcium carbonate; the amount of the hardener added is 5wt%-20wt% of the curing agent material of the present invention.

[0021] The reinforcing phase is added to increase the strength of the cured quartz sand filler, thereby improving the product's breaking ability. The reinforcing phase is one of the following: silicone rubber, dimethyl silicone oil, silicone resin, polyacrylamide, etc., and its addition amount accounts for 1wt%-10wt% of the curing agent material described in this invention. The addition of the reinforcing phase can also improve the hydrophilicity of the silica gel, enhancing the product's environmental adaptability and long-term reliability.

[0022] A certain amount of retarder can also be added. The retarder is a material selectively added to prolong the curing time, such as tartaric acid, citric acid, borax, sodium dihydrogen phosphate, or disodium hydrogen phosphate, to prevent the curing reaction of the functional phase from being too vigorous or the working time from being too short. These retarders can form complexes with metal ions, such as magnesium ions, reducing the activity of the metal ions and thus slowing down the reaction rate. The amount of the retarder added is 0wt%-5wt% of the curing agent material of this invention.

[0023] A certain amount of accelerator may also be added. The accelerator is a material selectively added to accelerate the curing reaction of the functional phase, such as calcium chloride, sodium sulfate, or sodium fluorosilicate. These accelerators increase the ion concentration in the solution, promoting reactions such as those between magnesium ions and silicate ions, thereby accelerating the curing speed. The amount of the accelerator added is 0wt%-5wt% of the curing agent material of this invention.

[0024] The curing method for the curing agent of the quartz sand filler in low-energy-consumption fuses includes the following steps: S1. Preparation of functional liquid: Dissolve the functional phase in water to prepare a water glass solution. If available, add the retarder, the coagulant, and the reinforcing phase to the water glass solution and mix evenly to obtain the functional liquid. S2. Preparation of hardening solution: Dissolve the hardener in water to prepare a hardening solution. The hardening solution can be a transparent solution, a gel or a suspension. It is prepared in a liquid state so that it can be more conveniently and evenly mixed between the quartz sand particles.

[0025] S3. Preparation of curing solution: Add the curing solution prepared by S2 to the functional solution prepared by S1, and stir continuously until homogeneous. The silicate ions (SiO3) in the functional solution... 2- It will react with metal ions, such as magnesium ions, in the hardening solution to form silica gel.

[0026] S4. Curing liquid mixed with sand: The silica gel mixture obtained in S3 is added to the quartz sand according to the ratio and stirred continuously to make a layer of silica gel film evenly attached to the surface of the quartz sand particles, connecting adjacent sand particles to form a bonding bridge, so that the mixed sand has sufficient adhesion.

[0027] S5. Sand Filling: Two holes are pre-drilled on one side of the fuse terminal, one for filling with sand and the other for venting. The cured liquid mixed with sand obtained above is added to the dispensing cartridge. Using a manual / automatic dispensing process, pressure is applied to force the mixed sand through the filling hole into the fuse tube. During the filling process, the gas in the fuse tube is discharged through the venting hole, thereby ensuring that the filling density meets the design requirements.

[0028] S6. Sand Curing: Place the fused tube filled with quartz sand mixture in an oven at 60℃-100℃ and heat for 20min-120min (curing time is related to the volume of the fused tube, the amount of sand mixture inside, the number of products placed, etc., and is not limited; curing can be completed at temperatures below 60℃ or even at room temperature, but the curing time will be too long; excessively high curing temperatures also contradict the purpose of reducing energy consumption in this invention). The functional liquid film and hardening liquid film on the surface of the quartz sand particles react faster under high temperature, and the aluminum silicate gel forms a three-dimensional network structure that encapsulates the quartz sand particles; then, as the reaction proceeds, the moisture evaporates at high temperature, and curing is completed.

[0029] In order to increase the working time and prevent the mixture from agglomerating or even solidifying during the stirring process, a retarder can be added to S1 to extend the curing time.

[0030] To prevent premature reaction between the functional liquid and the hardening liquid, and to increase the working time and the uniformity of the mixed sand, steps S3 and S4 can be replaced by the following two steps: S3. Functional liquid mixed with sand: Add the functional liquid to the quartz sand filler according to the ratio and stir evenly so that a thin layer of functional liquid film is evenly attached to the surface of the quartz sand.

[0031] S4. Hardening liquid mixing with sand: Add the hardening liquid to the quartz sand filler that has completed S3 according to the specified ratio and stir evenly. This will allow another layer of hardening liquid film to cover the surface of the functional liquid film, thereby increasing the silicate ions (SiO3) in the functional liquid film. 2- It reacts with metal ions, such as magnesium ions, in the hardening liquid film to initially form a silica gel layer adhesive film. Adjacent sand particles are connected through the adhesive film to form an adhesive bridge, giving the mixed sand sufficient adhesion.

[0032] Example 2 according to Figure 1As shown, this embodiment proposes a curing agent for low-energy-consumption fuse quartz sand filler, comprising sodium silicate with a modulus of 3.0 as the functional phase, nano-calcium carbonate as the hardener, citric acid as the retarder, and silicone resin as the reinforcing phase. The proportions of each component are as follows:

[0033] In this embodiment, nano-calcium carbonate is used as a curing agent for sodium silicate curing, mainly based on its high surface activity, alkalinity regulation ability and micronucleus induction effect. Curing can be achieved through processes such as ion exchange, interfacial adsorption, carbonation reaction and silica polymerization.

[0034] Nano-sized calcium carbonate (particle size 10-100 nm) possesses extremely high specific surface area (50-100 m² / g) and surface energy, with a large number of hydroxyl (-OH) groups and active sites on its surface. The hydroxyl groups on the surface of nano-CaCO₃ undergo partial dissociation in alkaline water glass solution, releasing Ca... 2+ and OH - : .

[0035] This process causes the particle surface to become positively charged (Ca). 2+ (enrichment), and negatively charged silicate ions (SiO3) in water glass. 2- Electrostatic attraction is generated, forming Ca 2+ -O-Si coordination bonds act as "molecular bridges" connecting different silicate segments, promoting the polymerization of linear silicate into a three-dimensional network gel with a more uniform and dense structure.

[0036] In addition, Na in water glass + by Ca 2+ The substitution process generates insoluble calcium silicate (CaSiO3) microclusters, which serve as initial nuclei for adsorbing more silicate groups and accelerating the formation of the gel network.

[0037] Nano-calcium carbonate can also react with CO2 in the air and OH- in water glass. - Synergistic reaction occurs:

[0038] The generated secondary CaCO3 microcrystals (with a particle size comparable to nano-CaCO3) are deposited in the pores of the silica gel, forming a "gel-crystal interpenetrating network" that enhances the density and strength of the hardened body. Nano-CaCO3 also exhibits a nanoscale interfacial transition region with the silica gel, where its surface hydroxyl groups bond with silica segments via hydrogen bonds, reducing interfacial defects and stress concentration, lowering the risk of cracking in the hardened body, while simultaneously improving impact resistance and fatigue resistance, and enhancing the overall structural toughness.

[0039] Alkaline sites (such as OH groups) on the surface of nano-CaCO3 - Ca 2+ It can catalyze the dehydration condensation reaction of silicate ions:

[0040] The high surface activity of nanoparticles enhances catalytic efficiency and shortens gelation time. Nano-CaCO3 can also inhibit excessive hydrolysis by adsorbing silicate ions and adjusting pH, promoting the direct condensation of silicate ions in oligomeric states (such as dimer and trimer silicates) to form a denser gel network. This dense gel-crystal network structure reduces the number of capillaries within the hardened body, lowers its hygroscopicity, and resists corrosion from environmental media such as CO2 and SO2. This allows fuse products using this embodiment as a curing agent to be used in harsher environments without performance degradation.

[0041] When organosilicon resin (viscosity < 500 mPa·s) is added as a reinforcing phase to the water glass-nano calcium carbonate system, the interaction between the main chain -Si-O- bonds and side chain organic groups of the organosilicon resin can be divided into the following levels: The silanol groups (-Si-OH) in organosilicon resins can be adsorbed onto the surface of nano-calcium carbonate (CaCO3 becomes polar after hydroxylation) through hydrogen bonding or condensation reactions, forming an organic-inorganic hybrid interface layer. On the one hand, this can reduce the aggregation of calcium carbonate nanoparticles and improve their dispersion performance; on the other hand, organic groups (such as methyl groups) can also make the interface layer hydrophobic, reducing the hygroscopicity of the system. Organosilicon resins can also penetrate into the nanoscale pores (pore size 5-20 nm) of calcium silicate gel and enhance the network toughness through physical entanglement.

[0042] In addition, the -Si-OH groups in the organosilicon resin can condense with the -Si-OH groups generated by the hydrolysis of water glass to form Si-O-Si cross-chain bonds, covalently incorporating organosilicon molecules into the inorganic gel network, further enhancing the network toughness. (-Si-OH) 水玻璃 +(-Si-OH) 有机硅 →(-Si-O-Si-)+H2O Ca released by nano-calcium carbonate 2+ It can form coordinate bonds with ether bonds (-Si-OR) or polar groups (such as -COOH, -OH) in organosilicon resins, which is beneficial to enhancing the bonding force at the organic-inorganic phase interface.

[0043] The addition of citric acid can lower the pH of the functional solution from the initial 12-13 to 9-10, thus preserving the hardening activity of water glass while inhibiting the hydrolysis of organosilicon under strong alkaline conditions.

[0044] This embodiment of the low-temperature solid agent material utilizes nano-calcium carbonate and organosilicon resin in a water glass system. Through physical adsorption to enhance interfacial compatibility, chemical cross-linking to construct an interpenetrating network, and synergistic optimization of performance by functional groups, a composite structure is formed where "an inorganic skeleton bears stress, and an organic phase regulates toughness and environmental adaptability." This overcomes the limitations of traditional hardeners in terms of uniformity, durability, and environmental friendliness, and possesses advantages such as low-temperature rapid curing, high strength, water resistance, and heat resistance. The main advantages are: The elastic segments of silicone resin can absorb stress and inhibit crack propagation, giving the hardened body a combination of rigidity and flexibility. The silicone groups (such as -CH3) are oriented on the gel surface, forming a hydrophobic barrier that can reduce the water absorption rate from 15% to below 5%. At the same time, the chemical stability of the Si-O-Si bond can resist the long-term hydrolytic degradation of water glass. The high-temperature resistance of silicone resin (decomposition temperature >300℃) can compensate for the lack of heat resistance of water glass. These properties will greatly improve the breaking capacity and long-term reliability of fuse products using the system curing agent.

[0045] The curing method for the curing agent of the quartz sand filler in low-energy-consumption fuses includes the following steps: Preparation of S1 functional solution: First, add 74.6g of sodium silicate to 200g of water and stir to dissolve. Then add 3.3g of citric acid and 8.3g of organosilicon resin and mix evenly to obtain the functional solution.

[0046] Preparation of S2 hardening solution: Then disperse 13.8g of nano calcium carbonate into 100g of water and stir thoroughly to obtain the hardening solution.

[0047] Preparation of S3 curing liquid: While the functional liquid obtained from S1 is being stirred at a constant speed on a stirrer, the curing liquid is slowly added until it is completely added. Then, stir for about 30 minutes to ensure that the two are fully mixed and homogeneous, thus obtaining the curing liquid described in this invention.

[0048] S4 curing liquid sand mixing: First, add 4Kg of 50-120 mesh quartz sand to the sand mixer, then add the curing liquid obtained from S3, and stir at 100 rpm for 1 hour at room temperature so that the curing liquid can be evenly adhered to the surface of the quartz sand particles.

[0049] S5 Sand Filling: Two holes are pre-drilled on one side of the fuse terminal, one for filling with sand and the other for venting. The cured liquid mixed with sand obtained above is added to the dispensing cartridge. Using an automatic dispensing process, pressure is applied to force the mixed sand through the filling hole into the fuse tube. During the filling process, the gas in the fuse tube is discharged through the venting hole, thereby ensuring that the filling density meets the design requirements.

[0050] S6 Sand Mixing Curing: The fusion tube filled with quartz sand mixture is placed in an oven at 100°C and heated for 90 minutes. The functional liquid film and hardening liquid film on the surface of the quartz sand particles react faster under high temperature. The aluminum silicate gel forms a three-dimensional network structure that encapsulates the quartz sand particles. Then, as the reaction proceeds, the moisture evaporates at high temperature, and curing is completed.

[0051] Performance verification: By comparing the fuse product obtained by using the quartz sand mixed filler of the present invention with the fuse product obtained by the existing high temperature and high pressure curing process, the fuse product under the same breaking voltage and current conditions has a post-arc time and arc energy that are more than 40% shorter than the product obtained by the existing curing process. Moreover, after the terminals on both sides of the product are opened and immersed in water for 48 hours, no obvious quartz sand particles are seen flowing out, and the curing strength does not deteriorate significantly.

[0052] Example 3 according to Figure 1 As shown, this embodiment proposes a curing agent for low-energy-consumption fuse quartz sand filler, comprising sodium silicate with a modulus of 2.6 as the functional phase, magnesium chloride as the hardener, and silicone rubber as the reinforcing phase. The proportions of each component are as follows:

[0053] Magnesium chloride is used as a curing agent for sodium silicate water glass. Through a series of processes, including ion exchange, hydrolysis, and interaction with silicate ions, it promotes the curing of water glass, forming a cured product with certain strength and properties. The specific reaction process is as follows: 1) Ion exchange and hydrolysis reactions: Sodium silicate undergoes hydrolysis in water, producing silicate ions (SiO3). 2- ) and hydroxide ions (OH) - This makes the solution alkaline. Magnesium chloride (MgCl2) completely ionizes in water, producing magnesium ions (Mg²⁺). 2+ ) and chloride ions (Cl - When magnesium chloride is added to a water glass solution, magnesium ions combine with hydroxide ions produced by the hydrolysis of water glass to form magnesium hydroxide (Mg(OH)2) precipitate. This reaction consumes hydroxide ions in the solution, shifting the hydrolysis equilibrium of the water glass to the right and producing more silicate ions.

[0054] 2) Formation and polymerization of silicic acid: As the hydrolysis reaction proceeds, the concentration of silicate ions in the solution increases. Simultaneously, due to the relatively low concentration of hydrogen ions in the solution, silicate ions combine with hydrogen ions to form silicic acid (H₂SiO₃).

[0055] Silicic acid is a weak acid that undergoes polymerization in solution. Multiple silicic acid molecules combine through dehydration condensation to form silicic acid gel. The reaction process can be simply represented as: nH₂SiO₃ → (H₂SiO₃) n As the polymerization reaction continues, the silica gel gradually forms a three-dimensional network structure, thereby solidifying the water glass.

[0056] 3) The role of magnesium ions: Besides promoting the hydrolysis of water glass by consuming hydroxide ions, magnesium ions may also interact with silicate ions. Magnesium ions can form complex compounds or complexes with silicate ions, which help to enhance the structure of silica gels and make the cured product more robust.

[0057] Furthermore, the presence of magnesium ions can affect the formation rate and morphology of silica gel, thereby influencing the curing effect of water glass. Appropriate amounts of magnesium ions can make the network structure of silica gel more uniform and dense, improving the strength and water resistance of the cured product.

[0058] Adding silicone can further increase the strength of the cured sand mixture by: 1) Physical Filling and Network Enhancement: Organosilicone has a unique molecular structure containing silicon-oxygen bonds (Si-O-Si) in its molecular chains. This structure gives organosilicone excellent flexibility and adhesion. In the water glass-magnesium chloride curing system, organosilicone can fill the pores of the silica gel network formed after water glass curing, acting as a physical filler, reducing porosity, and making the structure of the cured product more compact. Simultaneously, the organosilicone molecular chains can interpenetrate and entangle with the silica gel network, forming a structure similar to an interpenetrating network, thereby enhancing the mechanical properties of the entire curing system and increasing the strength of the cured product.

[0059] 2) Chemical interaction and interfacial bonding: Organosilicon molecules contain active groups such as hydroxyl groups (-OH) on their surface. These groups can chemically react with silicate ions produced by the hydrolysis of water glass and magnesium ions produced by the hydrolysis of magnesium chloride. On one hand, the hydroxyl groups of the organosilicon undergo a dehydration condensation reaction with the silanol groups (-Si-OH) of silicic acid molecules, forming silicon-oxygen bonds (Si-O-Si). This integrates the organosilicon molecules into the silicic acid gel network, covalently linking the organosilicon and silicic acid gel through chemical bonds, significantly enhancing the interfacial adhesion. On the other hand, the polar groups such as hydroxyl groups and ether bonds (-O-) in organosilicon molecules contain lone pairs of electrons, which can act as ligands to react with magnesium ions. 2+ Coordination bonds are formed. Multiple hydroxyl groups in silicone rubber can coordinate with Mg through bidentate coordination. 2+ Cross-linking to form "organosilicone-Mg" 2+The bridging structure of "silicic acid gel" enhances the network crosslinking density, further strengthening the bond between the silicone and the water glass-magnesium chloride curing system. This allows the cured product to better transfer stress when subjected to external forces, thereby improving the strength and toughness of the cured product.

[0060] In summary, the mixed sand phase obtained using this curing agent system has significant advantages over other curing systems: Strength Enhancement: The formation of chemical and coordination bonds allows stress to be effectively transferred through the interface, preventing cracking caused by stress concentration. Experiments show that adding 5% silicone rubber can increase the compressive strength of the cured body by 20%-30%.

[0061] Improved toughness: The flexible segments of silicone can absorb impact energy, alleviate the brittleness of silica gel, and give the cured product a combination of rigidity and flexibility.

[0062] Enhanced water resistance: The dense interpenetrating network structure reduces porosity, while the hydrophobic properties of the silicon-oxygen bonds reduce the erosion of the solidified body by water, thus improving water resistance stability.

[0063] A curing process for a low-temperature curing agent material for quartz sand filler used in fuses includes the following steps: Preparation of S1 functional solution: First, add 74.4g of sodium silicate to 200g of water and stir to dissolve. Then add 4.8g of silicone and mix well to obtain the functional solution.

[0064] Preparation of S2 hardening solution: Then dissolve 20.8g of magnesium chloride in 100g of water and stir thoroughly to obtain the hardening solution.

[0065] S3 Functional Liquid Sand Mixing: Add 4Kg of 50-120 mesh quartz sand to the sand mixer, then add the functional liquid prepared by S1, and stir at 100 rpm for half an hour to make a thin layer of functional liquid film evenly adhere to the surface of the quartz sand.

[0066] S4 Hardening Solution Mixing: Add the hardening solution prepared from S2 to the sand mixer, maintaining a constant speed, and stir for another hour to coat the surface of the functional liquid film with another layer of hardening solution, thereby enhancing the silicate ions (SiO3) in the functional liquid film. 2- It will react with the metal ions in the hardening liquid film to initially form a silica gel layer adhesive film. Adjacent sand particles are connected through the adhesive film to form an adhesive bridge, giving the mixed sand sufficient adhesion.

[0067] S5 Sand Filling: Two holes are pre-drilled on one side of the fuse terminal, one for filling with sand and the other for venting. The cured liquid mixed with sand obtained above is added to the dispensing cartridge. Using an automatic dispensing process, pressure is applied to force the mixed sand through the filling hole into the fuse tube. During the filling process, the gas in the fuse tube is discharged through the venting hole, thereby ensuring that the filling density meets the design requirements.

[0068] S6 Sand Mixing Curing: The fusion tube filled with quartz sand mixture is placed in an oven at 80°C and heated for 120 minutes. The functional liquid film and hardening liquid film on the surface of the quartz sand particles react faster under high temperature. The aluminum silicate gel forms a three-dimensional network structure, which encapsulates the quartz sand particles. Then, as the reaction proceeds, the moisture evaporates at high temperature and curing is completed.

[0069] Performance verification: By comparing the fuse product obtained by using the quartz sand mixed filler of the present invention with the fuse product obtained by the existing high temperature and high pressure curing process, the fuse product under the same breaking voltage and current conditions has a post-arc time and arc energy that are more than 40% shorter than the product obtained by the existing curing process. Moreover, after the terminals on both sides of the product are opened and immersed in water for 48 hours, no obvious quartz sand particles are seen flowing out, and the curing strength does not deteriorate significantly.

[0070] Example 4 according to Figure 1 As shown, this embodiment proposes a curing agent for low-energy-consumption fuse quartz sand filler, comprising sodium silicate with a modulus of 2.6 as the functional phase, nano-calcium carbonate as the hardener, sodium dihydrogen phosphate as the retarder, and nonionic polyacrylamide powder as the reinforcing phase. The proportions of each component are as follows:

[0071] In this embodiment, when nano-calcium carbonate is used as a hardener for sodium silicate curing, the curing triggering mechanism includes the following three aspects: (1) The surface of nano-calcium carbonate contains hydroxyl groups (-OH) and a small amount of calcium ions (Ca). 2+ In a strongly alkaline solution of water glass (pH≈11-13), its surface hydroxyl groups can react with silicate ions (SiO3). 2- Si2O5 2- (2) Na in water glass adsorbs through hydrogen bonding or electrostatic interaction to form a "silicate-calcium carbonate" complex core, catalyzing the condensation reaction of silicate ions and accelerating the formation of silica gel (SiO2·nH2O). + With Ca on the surface of nano-calcium carbonate 2+ A weak ion exchange may occur, producing soluble Na₂CO₃ and adsorbed Ca. 2+ Adsorbed Ca 2+It can further combine with silicate ions to form calcium silicate microprecipitates (CaSiO3), which serve as physical cross-linking points to enhance the strength of the gel network. (3) Nanoscale calcium carbonate (particle size <100 nm) has an extremely high specific surface area, which can provide a large number of reaction sites, significantly shorten the curing time of water glass, and refine the pore size of silica gel, making the cured body structure more compact.

[0072] Nonionic polyacrylamide (PAM) contains a large number of amide groups (-CONH2) in its molecular chain. These groups can form a hydrogen bond network with the hydroxyl groups (-OH) on the surface of silica gel and on the surface of nano-calcium carbonate, allowing PAM molecular chains to be physically adsorbed onto the gel particles and calcium carbonate surfaces, forming a "gel-polymer-filler" interpenetrating structure. This adsorption is charge-independent (because PAM is uncharged), avoiding potential charge repulsion problems and resulting in superior compatibility. Nano-calcium carbonate is prone to agglomeration, while the polymer chains of PAM can inhibit calcium carbonate particle aggregation through steric hindrance, improving the dispersion uniformity of the system. The thickening effect of nonionic PAM can increase the viscosity of the slurry, making it more suitable for dispensing processes.

[0073] Upon contact with water, PAM powder swells to form linear polymer chains. During gelation and curing, these chains entangle and fill the pores of the silica gel, delaying water evaporation and extending the workable time during mixing. Once the gel network has solidified, the PAM chains act as a "flexible bridging agent," connecting rigid calcium silicate / silica gel particles, improving the material's flexural strength and toughness, and reducing the risk of cracking. The swelling process of nonionic PAM consumes some water, which may slightly slow down the diffusion rate of silicate ions, thus extending the initial curing time, but it does not significantly inhibit the hardening reaction (because it does not involve charge interference).

[0074] Adding sodium dihydrogen phosphate to the system can lower the pH value, thereby preventing the hydrolysis reaction of the amide group of PAM in the strongly alkaline solution of water glass (—CONH2+OH). - →—COO - +NH3).

[0075] The fuse product using the curing agent material system of this embodiment as the hardener filling of quartz sand has the following properties after curing: Nano-calcium carbonate, as a rigid filler, improves the compressive strength of the cured body through the "micro-aggregate reinforcement" effect; PAM improves the flexural strength through flexible chain toughening, forming a "rigid and flexible" composite structure. Compared with the pure nano-calcium carbonate-water glass system, the compressive strength can be increased by 10%-20%, and the flexural strength can be increased by 30%-50%; the water retention effect of PAM can delay the migration of water during the gel curing process and reduce porosity; at the same time, its molecular chain entanglement can close some interconnecting pores, reducing the water absorption rate of the cured body by 15%-25% and enhancing the resistance to water erosion.

[0076] A curing process for a low-temperature curing agent material for quartz sand filler used in fuses includes the following steps: Preparation of S1 functional solution: First, add 77.8g of sodium silicate to 200g of water and stir to dissolve. Then, add 3.5g of sodium dihydrogen phosphate to obtain the functional solution. Slowly sprinkle PAM powder into the warm water (40-50℃) while stirring to prepare a 0.1%-0.5% dilute solution. Stir thoroughly until completely dissolved (about 30 minutes).

[0077] Preparation of S2 hardening solution: Then disperse 17.3g of nano calcium carbonate into 100g of water and stir thoroughly to obtain the hardening solution.

[0078] Preparation of S3 curing solution: While the functional liquid obtained from S1 is being stirred at a constant speed on a stirrer, the curing liquid is slowly added until it is completely added. Then, the dilute PAM solution prepared in S1 is slowly added to it, and stirring is continued for about 30 minutes to ensure that the system is fully mixed and uniform, thus obtaining the curing solution described in this invention.

[0079] The S4-S6 process is as described in Example 1, and the final product is a fuse filled with quartz sand using the curing agent of this example. The performance of the product is also comparable to that of the product obtained in Example 1.

[0080] Validation data: Taking the 750Vdc 350A product filled with 35-120 mesh quartz sand as an example, the quartz sand was filled using the same vibration sand filling process. A 20kA breaking capacity test was conducted to compare the traditional curing process with the curing processes shown in Examples 2, 3, and 4. The arc pre-time, arc burning time, and arc pre-I of the product were measured and calculated. 2 T, Total I 2 The following table shows the T values:

[0081] As shown in the table above, from the perspective of arc time, the low-temperature curing process of this invention, by adding a reinforcing phase to the curing agent to increase the filling density of the cured quartz sand, thereby strengthening the restriction on the expansion of the arc channel during the arc extinguishing process and greatly reducing the arc time of the product. For example, the arc time of the sample obtained in Example 2 was reduced by 41.2% compared with the traditional curing process, the arc time of the sample in Example 3 was reduced by 42.3% compared with the traditional curing process, and the arc time of the sample in Example 4 was reduced by about 38.3% compared with the traditional curing process. In addition, the samples obtained in each example and the samples obtained by the traditional curing process were disassembled to expose the quartz sand part inside the tube, and then soaked in water for 48 hours. The cured sand obtained by the traditional curing process showed obvious loosening and quartz sand flow-out; while the cured sand obtained by the various examples of this invention remained tightly fixed in the tube, indicating that the hydrophilicity of the cured sand was greatly reduced.

[0082] This invention utilizes the reaction of functional phases and hardeners to form a three-dimensional network structure. Combined with the strength enhancement and hydrophilicity improvement effects of the reinforcing phase, it effectively improves the density, compressive strength, and toughness of the quartz sand filler. This not only reduces the arc path expansion of molten metal during high-voltage, high-current interruption, lowering post-arc time and arc energy, but also resists corrosion from moisture and other substances in the environment, significantly improving the long-term reliability and environmental adaptability of fuse products. Furthermore, the curing process of this invention can be completed in a short time at 60℃-100℃, eliminating the need for specially customized curing ovens and pressurizing equipment, fundamentally reducing the company's fixed asset investment. Simultaneously, the low-temperature, short-time curing conditions significantly reduce energy consumption during production, directly driving down the production cost of fuse products. Meanwhile, for fuse products that use high-temperature resistant plastic shells as fuse tubes, traditional high-temperature curing processes may damage the shells. However, the low-temperature curing process of this invention is perfectly suited for such products. The curing process using quartz sand filler effectively improves the breaking capacity. In addition, the selective addition of retarder and accelerator in the curing agent system allows for flexible control of the curing reaction rate, improving the operability and stability of the production process and further optimizing production efficiency.

[0083] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A curing method for a curing agent of a low-energy-consumption fuse quartz sand filler, the curing agent comprising a functional phase, a hardener, and a reinforcing phase, characterized in that: The functional phase is a water glass solution with silicate as the main component, which is used to form a three-dimensional network structure through hydrolysis-condensation reaction. After heating and dehydration, it imparts mechanical strength to the quartz sand. The functional phase accounts for 70wt%-90wt% of the total material. The hardener is a metal salt compound that can react with silicates, used to react with the functional phase to generate silica gel for curing, and the hardener accounts for 5wt%-20wt% of the total material; The reinforcing phase is an organosilicon compound or a polyacrylamide-based substance, used to improve the strength and hydrophobicity of the cured quartz sand; the reinforcing phase accounts for 1 wt%-10 wt% of the total material. The functional phase is a water glass solution prepared from at least one of sodium silicate and potassium silicate; The hardening agent is at least one of magnesium chloride, magnesium sulfate, magnesium nitrate, calcium chloride, and calcium carbonate. The reinforcing phase is at least one of silicone, dimethyl silicone oil, silicone resin, and polyacrylamide; It also contains 0wt%-5wt% of a retarder, wherein the retarder is at least one of tartaric acid, citric acid, borax, sodium dihydrogen phosphate, and disodium hydrogen phosphate; It also contains 0wt%-5wt% of a coagulant accelerator, wherein the coagulant accelerator is at least one of calcium chloride, sodium sulfate, and sodium fluorosilicate; The curing method for the curing agent of the quartz sand filler in low-energy-consumption fuses includes the following steps: S1: Prepare the functional liquid by dissolving the functional phase in water, adding the reinforcing phase, retarder, and accelerator, and mixing thoroughly. S2: Prepare the hardening solution by dissolving the hardener in water to form a transparent solution, colloid, or suspension; S3: Mix curing liquid, add the curing liquid to the functional liquid and stir to generate silica gel; S4: Sand mixing, mixing silica gel with quartz sand to coat the surface of sand particles with a silica gel film; S5: Sand filling, the mixed sand is pressed into the fuse tube through the sand filling hole and vent hole on the fuse terminal; S6: Curing. The molten tube filled with quartz sand mixture is placed in an oven and heated to form a three-dimensional network structure that cures the quartz sand filler.

2. The curing method for the curing agent of the low-energy-consumption fuse quartz sand filler according to claim 1, characterized in that: When it is necessary to prevent the functional liquid from reacting prematurely after mixing with the hardening liquid, thereby increasing the working time and the uniformity of sand mixing, replace S3 and S4 with the following two steps: Functional liquid sand mixing: Add the functional liquid to the quartz sand filler according to the ratio and stir evenly so that a thin layer of functional liquid film is evenly attached to the surface of the quartz sand. Hardening liquid mixed with sand: The hardening liquid is added to the quartz sand filler that has been coated with the membrane according to the ratio and stirred evenly, so that the surface of the functional liquid membrane is covered with another layer of hardening liquid membrane, forming a silica gel layer adhesive membrane.

3. The curing method for the curing agent of the low-energy-consumption fuse quartz sand filler according to claim 1, characterized in that: In step S5, the mixed sand is filled using a manual or automatic dispensing process through the pre-drilled sand filling holes and vent holes in the fuse terminals.

4. The curing method for the curing agent of the low-energy-consumption fuse quartz sand filler according to claim 1, characterized in that: In step S6, the oven temperature is 60℃-100℃, and the heating time is 20min-120min.

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