Silica sol composite curing agent, method of making and use in fuses

Abstract

This invention provides a silica sol composite curing agent, its preparation method, and its application in fuses. The silica sol composite curing agent incorporates acidic silica sol and calcium oxide powder as raw materials. The self-heating reaction between calcium oxide and water in the acidic silica sol enables rapid curing, significantly reducing curing time and improving production efficiency. The raw materials also include nano-Fe powder and a Cu corrosion inhibitor, which enhances the oxidation and corrosion resistance of Cu, further improving the oxidation resistance of the silver-copper composite fusible material in the fuse. This allows fuses using the curing agent to prevent oxidation and corrosion of the silver-copper composite fusible material, ensuring stable resistivity and interfacial bonding strength. Simultaneously, the uniform mixing of the raw materials in the curing agent improves the uniformity of the fuse arc-extinguishing filler, effectively reducing copper strip corrosion and maintaining the stable resistivity of the silver-copper composite fusible material in the fuse.

Description

Technical Field

[0001] This invention relates to the field of fuses, and in particular to a silica sol composite curing agent, its preparation method, and its application. Background Technology

[0002] A fuse is a circuit protection component. When the circuit current exceeds a threshold, the overcurrent heats up, causing the fusible element to melt, thus protecting the circuit. However, a short circuit can generate a high-temperature arc, especially for DC fuses, which have higher requirements for arc extinguishing. Currently, the common process involves adding water glass to quartz sand and solidifying it at high temperature to form an arc-extinguishing filler.

[0003] For example, Chinese patent application CN103588461A discloses a curing agent for fuses and its preparation method. It uses a mixture of 90-95% sodium silicate and 5-10% potassium silicate as the curing agent. The preparation method of the curing agent includes steps such as mixing and batching, hot fusion, heat preservation and drying, inspection, adding desiccant, and sealing and packaging. Thus, the main component of the curing agent, sodium silicate, often needs to be cured in a high temperature (150-200℃) and high humidity environment, which has high requirements for the curing environment and high investment costs.

[0004] For example, Chinese patent application CN 108911541 A discloses a filled enclosed fuse, its curing agent, and curing method. This patent application uses alkaline silica sol as the curing agent for the filled enclosed fuse to cure the filler. The curing temperature is 80–120℃, and the total curing time is 34–40 hours. This method can cure the filler of the filled enclosed fuse and obtain a stable and high breaking insulation resistance. While the above patent application uses alkaline silica sol as the curing agent, and its curing process does not require a high-temperature environment, heating is still necessary. Furthermore, the potassium, sodium, and iron content in the alkaline silica sol must be controlled to be less than or equal to 1500 ppm. Thus, this process still requires additional heating and still suffers from problems such as long curing time, cumbersome procedures, and high operational requirements.

[0005] Furthermore, when existing curing processes are applied to new silver-copper composite fuses in the current DC fuse market, the copper strip is prone to oxidation and blackening during curing and product use. This black oxide is more densely distributed at the silver-copper interface, causing a decline in the quality of the composite interface, severely affecting the resistivity of the melt material, and leading to premature failure and fracture. Figure 1 As shown, this results in a persistently high scrap rate for fuses.

[0006] Therefore, simplifying the curing process, shortening the curing cycle, preventing melt oxidation, ensuring stable resistivity, and improving the arc-extinguishing function of DC fuses are urgent problems that need to be solved. Summary of the Invention

[0007] In view of this, one object of the present invention is to provide a silica sol composite curing agent and its preparation method, which introduces acidic silica sol and calcium oxide powder. The calcium oxide reacts with water in the acidic silica sol to generate heat, enabling rapid curing, significantly reducing curing time, and improving production efficiency. Specifically, a silica sol composite curing agent, by weight fraction, comprises the following uniformly mixed raw materials: 65-75 parts acidic silica sol, 3-5 parts calcium oxide, and 4-6 parts gelling agent.

[0008] To further improve the corrosion resistance of the silver-copper composite melt material, reduce copper strip corrosion, and maintain the stability of the resistivity of the silver-copper composite melt material in the fuse, the raw materials of the silica sol composite curing agent also include 3-5 parts of nano-Fe powder and 1-3 parts of Cu corrosion inhibitor by weight fraction.

[0009] This invention provides a method for preparing a silica sol composite curing agent, comprising the following steps:

[0010] First, the CaO powder and the gelling agent are ball-milled and mixed to obtain a first mixture, and then the first mixture is dried to obtain a dried first mixture.

[0011] Simply add the dried first mixture to the acidic silica sol and mix evenly.

[0012] Furthermore, to improve the corrosion resistance of the silver-copper composite melt material, the above preparation method may include the following steps: first, ball milling and mixing nano-Fe powder, CaO powder and NaCl to obtain a first mixture, and then drying the first mixture to obtain a dried first mixture;

[0013] In an inert environment, the acidic silica sol and Cu corrosion inhibitor are uniformly mixed to obtain a second mixture;

[0014] Simply add the first mixture to the second mixture and mix thoroughly.

[0015] The above-mentioned silica sol composite curing agent is prepared by uniformly mixing all raw materials, which effectively improves the uniformity of the obtained curing agent and further helps to improve the strength and texture uniformity of the arc-extinguishing filler of the fuse.

[0016] The second objective of this invention is to provide an arc-extinguishing filler for fuses comprising the above-mentioned silica sol composite curing agent, which is mainly prepared by curing quartz sand and the above-mentioned silica sol composite curing agent, wherein the mass ratio of the quartz sand to the silica sol composite curing agent is 6:1 to 10:1.

[0017] The curing method of the arc-extinguishing filler mainly includes uniformly mixing the quartz sand and the silica sol composite curing agent, controlling the mixing time to within 5 minutes, pouring the mixture into a mold, vibrating the material, and curing the filler.

[0018] Therefore, the arc-extinguishing filler for fuses provided by the present invention can prevent oxidation of the molten material in the fuse, especially the oxidation of silver-copper composite molten material, and ensure stable resistivity and interfacial bonding strength.

[0019] A third objective of this invention is to provide a fuse containing the aforementioned arc-quenching filler. Because the curing agent in the filler effectively improves the oxidation resistance of the silver-copper composite melt material in the fuse, preventing oxidation and corrosion of the melt in the fuse, the fuse thus possesses stable resistivity and interfacial bonding strength.

[0020] The silica sol composite curing agent and its preparation method, the arc-extinguishing filler for fuses and the fuses provided by the present invention have the following advantages: 1) short curing time, shortening the production cycle and improving production efficiency; 2) able to prevent oxidation of the silver-copper composite melt material in the fuse, ensuring stable resistivity and interface bonding strength; 3) the filler solid body has uniform texture and guaranteed strength. Attached Figure Description

[0021] Figure 1 This is a diagram showing the fracture failure state of the silver-copper composite melt in existing DC fuses.

[0022] Figure 2 The images are SEM images of the surface morphology of silver-copper composite melts formed by curing with curing agents of different formulations. In Figure (a), the curing agent provided in Comparative Example 3 of the present invention is used, and in Figure (b), the curing agent provided in Example 3 of the present invention is used. Detailed Implementation

[0023] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0024] This invention primarily improves the curing agent for arc-extinguishing fillers in fuses. It uses acidic silica sol as the main raw material and introduces calcium oxide powder, which facilitates rapid curing, significantly shortens curing time, reduces production cycle time, and improves production efficiency. The addition of nano-Fe powder and Cu corrosion inhibitors to the curing agent raw materials enhances the oxidation and corrosion resistance of Cu, further improving the oxidation resistance of the silver-copper composite molten material in the fuse. This allows fuses using the aforementioned curing agent to prevent oxidation and corrosion of the silver-copper composite molten material, ensuring stable resistivity and strong interfacial bonding.

[0025] Specifically, one object of the present invention is to provide a silica sol composite curing agent, which, by weight fraction, comprises the following uniformly mixed raw materials: 65-75 parts of acidic silica sol, 3-5 parts of calcium oxide powder, and 4-6 parts of gelling agent.

[0026] In this invention, the acidic silica sol undergoes a dehydration condensation reaction to form a network structure, which serves as a curing and sealing agent. The CaO powder reacts with water in the acidic silica sol, generating heat. The simultaneous increase in temperature and water loss promotes the curing of the acidic silica sol, achieving rapid curing and significantly reducing curing time. Furthermore, the CaO products can adjust the pH value of the curing agent, reducing the acidity of the acidic silica sol and providing a good neutral environment for the silver-copper composite melt material in the fuse, thus reducing copper oxidation and corrosion. Therefore, the concentration of the acidic silica sol is preferably 20-40%, such as 20%, 35%, 30%, 35%, 40%, etc. The silica particle size in the acidic silica sol is preferably 8-20 nm. To ensure that the alkaline substance formed by the reaction of calcium oxide with water in the acidic silica sol can precisely neutralize the pH value of the acidic silica sol, the mass fraction of calcium oxide is preferably 3.5-4.5 parts, such as 3.5 parts, 4 parts, 4.5 parts, etc.

[0027] In addition, acidic silica sol works synergistically with CaO to neutralize the acidic environment, and the gelling agent in the curing agent further dilutes the pH value, ultimately achieving a neutral environment that generates its own heat to provide curing conditions and protect the copper material, without the need for additional drying and heating; however, alkaline silica sol or neutral silica sol cannot achieve the above objectives.

[0028] The main function of the gelling agent is to promote the condensation reaction of silica sol and further dilute the pH value, while ensuring that no harmful components are introduced, thus achieving environmental protection of the product; therefore, the gelling agent can be one or more of NaCl, KCl, Na2SO4, K2SO4, etc.

[0029] To prevent oxidation and corrosion at the copper strip and interface of the silver-copper composite strip, the silica sol composite curing agent provided by this invention also incorporates nano-Fe powder and Cu corrosion inhibitor. Preferably, by weight fraction, the silica sol composite curing agent further comprises the following raw materials: 3-5 parts nano-Fe powder and 1-3 parts Cu corrosion inhibitor. The nano-Fe powder is preferably 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, etc. The Cu corrosion inhibitor is preferably 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.

[0030] Among them, nano-Fe powder mainly utilizes the cathodic protection method of sacrificial anode, where Fe undergoes an oxidation reaction, preventing oxidation of the copper strip and interface of the silver-copper composite strip, effectively ensuring the stability of interface strength and resistivity; on the other hand, the fine particles, large specific surface area, and hybridization increase the adhesion of the silica sol, which is beneficial to improving the strength of the filler.

[0031] If the particle size of nano-Fe powder is not greater than 50 nm, the Fe powder is prone to agglomeration during the preparation of the curing agent mixture, and cannot be uniformly dispersed in the curing agent, and thus cannot be uniformly dispersed in the arc-quenching filler, forming defects and losing its purpose of protecting the copper material as an anode sacrifice. If the particle size of nano-Fe powder is greater than 200 nm, since Fe itself is a good conductor, its use as a filler component in the fuse will affect the fuse's function of quickly responding to interrupt current. Therefore, the particle size of nano-Fe powder is preferably 50-200 nm, such as 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, etc.

[0032] The Cu corrosion inhibitor primarily functions to remove scale and prevent corrosion in the silver-copper composite molten material, protect it from oxidation, and reduce damage to the composite interface of the molten material in the fuse. Preferably, the Cu corrosion inhibitor is morpholine.

[0033] Therefore, the raw materials in the curing agent provided by the present invention work together synergistically to effectively improve the oxidation resistance of the silver-copper composite melt material, prevent the oxidation of the silver-copper composite melt material in the fuse, and ensure stable resistivity and interfacial bonding strength.

[0034] This invention also provides a method for preparing a silica sol composite curing agent, comprising the following steps:

[0035] First, the CaO powder and the gelling agent are ball-milled and mixed to obtain a first mixture, and then the first mixture is dried to obtain a dried first mixture.

[0036] Simply add the dried first mixture to the acidic silica sol and mix evenly.

[0037] Furthermore, to improve the corrosion resistance of the silver-copper composite melt material, the above preparation method may include the following steps:

[0038] First, nano Fe powder, CaO powder and NaCl are ball-milled and mixed to obtain a first mixture, and then the first mixture is dried to obtain a dried first mixture.

[0039] In an inert environment, the acidic silica sol and Cu corrosion inhibitor are uniformly mixed to obtain a second mixture;

[0040] Simply add the dried first mixture to the second mixture and mix thoroughly.

[0041] The purpose of ball milling in the first mixing process is to achieve uniform mixing without affecting the implementation effect. Preferably, the ball-to-material ratio is 15:1-25:1, the rotation speed is 250-350 r / min, and the mixing time is 0.5-1 h. To ensure that the first mixture is fully dried, the drying temperature is preferably 60-80℃, such as 60℃, 65℃, 70℃, 75℃, 80℃, etc.; the holding time is preferably 30-50 min, such as 30 min, 35 min, 40 min, 45 min, 50 min, etc.

[0042] The step of preparing the second mixture includes: in the inert environment, magnetically stirring the acidic silica sol and Cu etchant for 5-7 minutes at a speed of 150-200 r / min. The purpose of heating and magnetic stirring in this step is to ensure uniform mixing.

[0043] The first mixture and the acidic silica sol or the second mixture are mixed by ultrasonic vibration and stirring, with a mixing time preferably of 1-3 minutes. This ensures that the first mixture and the acidic silica sol or the second mixture are mixed evenly, which facilitates full contact and mixing of CaO powder and water in the acidic silica sol, resulting in a self-generating heat reaction. This self-generating heat provides the necessary curing conditions and a neutral environment for the copper material to be protected, thereby accelerating subsequent curing and significantly shortening the curing time. In addition, the uniform mixing of the raw materials in the curing agent also helps to improve the texture uniformity of the arc-extinguishing filler for fuses.

[0044] A second objective of the present invention is to provide an arc-extinguishing filler for a fuse comprising the above-mentioned silica sol composite curing agent, comprising uniformly mixed quartz sand and the above-mentioned silica sol composite curing agent, wherein the mass ratio of the quartz sand to the silica sol composite curing agent is 6:1 to 10:1.

[0045] The arc-quenching filler is mainly produced by uniformly mixing quartz sand and the silica sol composite curing agent, with the mixing time controlled within 5 minutes, to avoid the raw materials solidifying and forming a large amount of solidified filler due to excessive mixing time.

[0046] In the arc-extinguishing filler provided by this invention, the raw material quartz sand acts as a skeleton material, which helps to improve the strength of the filler formed by curing the curing agent. If the mass ratio of quartz sand to curing agent is too high, there will be too much quartz sand, and the curing agent will not be able to fully coat the mixed quartz sand, resulting in low strength and premature collapse of the subsequently formed filler, or even failure to cure. If the mass ratio of quartz sand to curing agent is too low, the role of quartz sand as a strength enhancer of the filler will no longer be obvious, and it will not be able to provide sufficient strength support for the overall filler. Therefore, the preferred mass ratio of quartz sand to curing agent is 6:1 to 10:1, such as 6:1, 7:1, 8:1, 9:1, 10:1, etc., and the curing time is 1-2 hours.

[0047] Therefore, the arc-extinguishing filler for fuses provided by the present invention can not only prevent the oxidation of the molten material in the fuse, especially the oxidation of the silver-copper composite molten material, and ensure the stability of resistivity and the strength of the interface bonding; it can also improve the uniformity of the filler material formed by the solidification of the raw materials and ensure the strength of the filler.

[0048] A third objective of this invention is to provide a fuse containing the aforementioned arc-extinguishing filler. This fuse is a conventional structure, comprising a fusible material, an arc-extinguishing filler, and a housing containing the fusible material and the arc-extinguishing filler. The main difference between the fuse protected by this invention and the prior art lies in the arc-extinguishing filler; this invention uses the arc-extinguishing filler described above.

[0049] The fuse can be a DC fuse or an AC fuse, or a high-voltage fuse or a low-voltage fuse.

[0050] The melt material can be pure silver melt or silver-copper composite melt. Preferably, the melt material is silver-copper composite melt, because the nano-Fe powder and Cu corrosion inhibitor introduced into the arc-extinguishing filler used in the fuse can effectively improve the oxidation and corrosion resistance of Cu, thereby preventing the melt in the fuse from being oxidized and corroded, and giving the melt a stable resistivity and interfacial bonding strength.

[0051] The technical solutions provided by the present invention will be further illustrated below with specific embodiments.

[0052] (1) Curing agent and its preparation method

[0053] Embodiments 1-5 of the present invention provide curing agents for arc-extinguishing fillers in fuses. The composition and mass ratio of each curing agent by weight are shown in Table 1, and the curing agents are prepared according to the following method:

[0054] Prepare the raw materials according to the formula shown in Table 1;

[0055] Nano Fe powder with a particle size of 100 nm, CaO powder, and NaCl were mixed in a ball mill at a ratio of 20:1, a speed of 300 r / min, and a mixing time of 0.5 h to obtain the first mixture.

[0056] The first mixture was placed in a drying oven and dried at a temperature of about 70°C for about 40 minutes to obtain a dried first mixture.

[0057] Add 30% acidic silica sol and morpholine to a reactor vessel, purge with nitrogen, and stir magnetically for about 6 minutes at a speed of 150 r / min to obtain the second mixture;

[0058] The dried first mixture is added to the reactor containing the second mixture, and the corresponding curing agent is obtained by ultrasonic vibration and stirring for about 2 minutes.

[0059] The formulations of the curing agents in the arc-extinguishing fillers for fuses provided in the comparative examples are shown in Table 1, and each comparative example is an adjustment based on Example 1. Specifically, Comparative Examples 1-5 are variations of Example 1, and each variation affects the final curing effect in order to verify that the components of the curing agent are synergistically compounded. Comparative Example 6 uses pure water glass with a modulus of 3.0 and is cured at 180°C using a conventional curing process. The preparation methods of the curing agents provided in Comparative Examples 1-5 are basically the same as those provided in Example 1, with the main difference being the different formulations; other processes and parameters are the same. Among them, the iron oxide in Comparative Example 5 has a particle size of 100 nm.

[0060] In this article, Examples 1-5 are labeled as S1, S2, S3, S4, and S5, respectively, and Comparative Examples 1-6 are labeled as D1, D2, D3, D4, D5, and D6, respectively.

[0061] Table 1. Mass ratio of curing agent components

[0062]

[0063] (2) Performance tests of curing agents and fillers

[0064] Resistivity testing method: First, a silver-copper composite strip (total length 68 mm, width 10 mm, thickness 0.15 mm, composed of 4 silver strips and 5 copper strips of equal width and thickness, each copper strip 10 mm long and each silver strip 4.5 mm long) is fixed in a 40×40×10 mm demoldable mold. Then, the curing agents provided by S1-S5 and D1-D6 are mixed with quartz sand at a mass ratio of 1:8, and the mixing time is controlled within 5 minutes. The mixture is poured into the demoldable mold, the filler is vibrated and cured, and then the mold is demolded to obtain the cured silver-copper composite strip. The cured silver-copper composite strip is energized with 70% of the rated current for 48 hours. Then, the filler is removed and the surface morphology is observed. The morphology of the silver-copper composite strip cured using the curing agents provided by S3 and D3 is as follows. Figure 2 As shown; the resistivity was tested using a DC resistance meter. Silver-copper composite strips with a width of 5 mm and uniform length were cut for testing. The test temperature was 20℃. The blank sample was uncured silver-copper composite strip, and its resistivity was measured to be 1.6882 × 10⁻⁶. -8 The experimental results are shown in Table 2. Ω·m.

[0065] Table 2. Performance test data of the curing agent and filler provided in the examples and comparative examples.

[0066]

[0067] After curing the arc-extinguishing filler, the silver-copper composite strip, after being energized for 48 hours, showed a discolored and rusted appearance under macroscopic visual inspection of the copper material cured with the curing agent provided in the comparative example. SEM observation revealed obvious oxide-rich areas that were connected in sheets and formed a layered structure, with a more concentrated distribution at the silver-copper interface. Figure 2 As shown in (a), the appearance of this corrosion structure deteriorates the joint strength and adversely affects the stability of resistivity; conversely, the morphology of the copper region in the composite strip cured with the curing agent provided in the example remains good, the copper strip retains its original metallic color macroscopically, and only partially oxidized spots appear in the microscopic SEM image, which have not yet expanded further, as shown in the example. Figure 2 As shown in (b), this proves that the formulation and process of the curing agent and filler provided in the embodiments of the present invention have obvious anti-oxidation effects, which can effectively improve the anti-oxidation and corrosion resistance of copper materials, prevent the silver-copper composite melt in the fuse from being oxidized and corroded, and make the melt have stable resistivity and interfacial bonding strength.

[0068] Further analysis of Table 2 reveals that, compared to the comparative examples, the curing agent provided in this invention and the arc-extinguishing filler for fuses using this curing agent exhibit shorter curing times, more uniform texture, less impact on melt resistivity, and are less prone to discoloration. Although D1 contains nano-iron powder and morpholine as corrosion inhibitors, the acidic environment of the acidic silica sol itself prevents neutralization by CaO, resulting in copper oxidation in the melt cured with D1. This demonstrates the synergistic effect of CaO and the corrosion inhibitors. The copper material cured with D2 does not discolor primarily because the absence of NaCl significantly affects only the gelation time; oxidation does not occur when other corrosion inhibitors are present. D3-D5 all show oxidation due to the absence of nano-iron oxide, morpholine, and other corrosion inhibitors. D6 has the most missing corrosion inhibitors and involves a high-temperature heating process, resulting in the most severe oxidation in the melt cured with D6.

[0069] Therefore, the above experimental scheme further verifies that the synergistic compounding of the curing agent and arc-quenching filler components provided in the embodiments of the present invention results in short curing time, shortened production cycle, and improved production efficiency. It also prevents oxidation of the silver-copper composite melt material in the fuse, ensuring stable resistivity and interfacial bonding strength. Furthermore, the arc-quenching filler exhibits uniform texture and guaranteed strength. Specifically, the curing agent provided by S3 enables the arc-quenching filler to have the shortest solidification time and uniform texture, and the resistivity and surface morphology of the silver-copper composite melt using this filler remain good.

[0070] (3) Fuse

[0071] This embodiment provides a DC fuse, which includes a silver-copper composite melt material, an arc-quenching filler of the curing agent provided in Example 3, and a shell that contains the silver-copper composite melt material and the arc-quenching filler; wherein, the arc-quenching filler completely encapsulates the silver-copper composite melt material and fills the through holes in the silver-copper composite melt material.

[0072] Therefore, in the silica sol composite curing agent and arc-extinguishing filler for fuses provided in this embodiment of the invention, the nano-Fe powder with a particle size of 50-200 nm in the silica sol composite curing agent and arc-extinguishing filler for fuses provided in this invention prevents the oxidation of copper strips by using the cathodic protection method of sacrificial anode, and also improves the strength of the arc-extinguishing filler by using hybridization strengthening effect; the acidic silica sol with a concentration of 20-40% and a particle size requirement of 8-20 nm works synergistically with CaO powder, and CaO can react with water in it to generate heat, achieving rapid curing, greatly reducing curing time, and the product can adjust the pH value of the curing agent; the Cu corrosion inhibitor can achieve surface descaling and improve the oxidation resistance of the melt material; the gelling agent can act as a gelling agent for silica sol and further dilute the pH value of the curing agent; quartz sand serves as the skeleton structure of the arc-extinguishing filler and a reinforcing material.

[0073] Therefore, the raw materials in the silica sol composite curing agent and arc-quenching filler provided by the present invention work together synergistically to prevent oxidation of the silver-copper composite melt material in the fuse, and ensure stable resistivity and interfacial bonding strength.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An arc quenching filler for a fuse, characterized in that, The quartz sand and silica sol composite curing agent is mainly prepared by curing quartz sand and silica sol composite curing agent, and the mass ratio of the quartz sand and silica sol composite curing agent is 6:1-10:1; wherein, the silica sol composite curing agent is mainly prepared by uniformly mixing the following raw materials in weight fraction: 65-75 parts of acidic silica sol, 3-5 parts of calcium oxide, 4-6 parts of gelling agent; the mass concentration of the acidic silica sol is 20%-40%, and the particle size of silicon dioxide is 8-20 nm; the gelling agent is a combination of one or more of NaCl, KCl, Na2SO4 and K2SO4.

2. The arc extinction packing according to claim 1, characterized in that The silica sol composite curing agent further comprises 3-5 parts of nano Fe powder and 1-3 parts of Cu corrosion inhibitor in weight fraction.

3. The arc extinction packing according to claim 2, characterized in that The particle size of the nano Fe powder is 50-200 nm.

4. The arc extinction packing of claim 3, wherein, The Cu corrosion inhibitor is morpholine.

5. The arc extinction packing according to claim 1 or 2 or 3 or 4, characterized in that, The calcium oxide is 3.5-4.5 parts.

6. The arc extinction packing according to claim 1 or 2 or 3 or 4, characterized in that, The method for curing the quartz sand and silica sol composite curing agent comprises the following steps: firstly, uniformly mixing the quartz sand and silica sol composite curing agent, and the mixing time is controlled within 5 min to obtain a mixture; and secondly, performing vibration treatment on the mixture until complete curing.

7. The arc extinction packing of claim 1, wherein, The preparation method of the silica sol composite curing agent comprises the following steps: firstly, ball-milling and mixing CaO powder and the gelling agent to obtain a first mixture, and performing drying treatment on the first mixture at 60-80℃, and keeping warm for 30-50 min to obtain a dried first mixture; adding the dried first mixture into the acidic silica sol and uniformly mixing to obtain the silica sol composite curing agent.

8. The arc extinction packing of claim 2, wherein, The preparation method of the silica sol composite curing agent comprises the following steps: firstly, ball-milling and mixing CaO powder, the gelling agent and nano Fe powder to obtain a first mixture, and performing drying treatment on the first mixture at 60-80℃, and keeping warm for 30-50 min to obtain a dried first mixture; firstly, uniformly mixing the acidic silica sol and Cu corrosion inhibitor in an inert environment to obtain a second mixture; and secondly, adding the dried first mixture into the second mixture and uniformly mixing to obtain the silica sol composite curing agent.

9. The arc extinction packing according to claim 7 or 8, characterized in that In the process of obtaining the first mixture, the related parameters of the ball-milling and mixing are as follows: the ball-to-material ratio is 15:1-25:1, the rotation speed is 250-350 r / min, and the mixing time is 0.5-1 h.

10. The arc extinction packing of claim 8, wherein, The step of obtaining the second mixture comprises: magnetically stirring the acidic silica sol and Cu corrosion inhibitor in the inert environment for 5-7 min at a rotation speed of 150-200 r / min.

11. The arc extinction packing of claim 10, wherein, The dried first mixture and second mixture are mixed by means of ultrasonic oscillation and stirring for 1-3 min.

12. A fuse containing the arc-extinguishing filler according to any one of claims 1-11.

13. The fuse of claim 12, wherein, The fuse is a direct current fuse or an alternating current fuse.

14. The fuse of claim 12 or 13, characterized in that The fuse comprises a fuse material, the arc-extinguishing filler and a shell containing the fuse material and the arc-extinguishing filler.

15. The fuse of claim 14, wherein, The fuse material is a silver-copper composite fuse material.

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