Preparation method of fireproof insulating ceramic silica gel and application of fireproof insulating ceramic silica gel to high-voltage copper-aluminum bar
By preparing fire-resistant and insulating ceramic silicone, and utilizing phosphorus free radicals and nitrogen-expanded carbon layers in the modifier to form a stable ceramic protective layer, the problem of easy combustion and corrosion of high-voltage copper-aluminum busbar materials at high temperatures is solved, achieving efficient insulation and mechanical performance improvement.
Patent Information
- Application Number
- CN202511714554.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-01-13
AI Technical Summary
Existing high-voltage copper-aluminum busbar insulation and fireproofing materials are prone to combustion, carbonization, and cracking at high temperatures, failing to form a continuous and effective protective layer. Furthermore, they have weak resistance to oil and chemical corrosion, affecting insulation and mechanical properties.
A fire-resistant and insulating ceramic silicone preparation method is adopted. Phosphite and nitrogen groups in the modifier decompose to generate phosphorus free radicals and inert gases, forming a dense carbon layer. This layer combines with silane to form a ceramic protective layer, which enhances the rigidity of the molecular chain and the interfacial bonding force, thereby improving the fire resistance, insulation and mechanical properties of the material.
Provides stable insulation protection in the event of a fire in a high-voltage electrical cabinet, increases the thermal decomposition temperature and chemical inertness of the material, resists oil and chemical corrosion, and ensures that the high-voltage copper-aluminum busbar maintains insulation and stable operation under special working conditions.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of ceramic silicone technology, specifically relating to a method for preparing fire-resistant and insulating ceramic silicone and its application in high-voltage copper-aluminum busbars. Background Technology
[0002] As a key conductive connection component in the power system, the operational safety of high-voltage copper-aluminum busbars directly affects the stability of the entire power system, and insulation protection and fire resistance are the core elements to ensure their safe operation.
[0003] Currently, commonly used insulating and fireproofing materials for high-voltage copper-aluminum busbars mainly include ordinary silicone rubber, mica tape, and refractory coatings. However, all of them have significant performance shortcomings. Mica tape and refractory mortar, as traditional fireproofing materials, have acceptable high-temperature resistance, but suffer from complex construction and poor flexibility. Conventional flame-retardant coatings can delay combustion, but their high-temperature resistance is short, and they are prone to carbonization and cracking at high temperatures, failing to form a continuous and effective protective layer and thus failing to meet long-term operational requirements. While ordinary silicone rubber has excellent flexibility and electrical insulation, its inherent defects cannot be ignored in the harsh application environment of high-voltage copper-aluminum busbars. For example, pure silicone rubber itself is non-flammable and flame-retardant, but it is easily ignited under direct impact from high-temperature open flames and lacks self-extinguishing properties, failing to form effective protection in a fire. To improve fire resistance, existing technologies often add traditional flame retardants such as aluminum hydroxide and magnesium hydroxide, but these flame retardants have weak interfacial bonding with the silicone rubber matrix, severely impairing mechanical properties. Therefore, simple physical mixing cannot construct an efficient flame-retardant and fireproofing system at the molecular level, making it difficult to form a high-strength fire barrier. Meanwhile, although silicone rubber itself is an excellent electrical insulator, it is not very resistant to non-polar solvents such as mineral oil and fuel oil. Prolonged contact can cause swelling, resulting in serious swelling, softening and a decline in mechanical properties, which severely damages its insulation properties.
[0004] Based on this, the present invention will provide a method for preparing fire-resistant and insulating ceramic silicone and its application in high-voltage copper-aluminum busbars. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing fire-resistant and insulating ceramic silicone and its application in high-voltage copper-aluminum busbars, in order to solve the problems mentioned in the background art.
[0006] The objective of this invention can be achieved through the following technical solutions:
[0007] A method for preparing fire-retardant and insulating ceramic silicone includes the following steps:
[0008] Step 1: Add perfluoroalkyl propylene oxide, aminostyrene and ethanol to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at room temperature for 5-6 hours. After cooling to room temperature, rotary evaporate to remove the solvent, extract with ethyl acetate and retain the organic phase, dry the organic phase and elute by column chromatography to obtain the modifier precursor.
[0009] The second step involves adding the modifier precursor, phosphorus trichloride, acid-binding agent, anhydrous magnesium chloride, and acetonitrile to a three-necked flask, attaching a condenser and thermometer, turning on the magnetic stirrer, and reacting at 70–80°C for 2–4 hours. Then, the temperature is raised to 80–90°C and the reaction is continued for 18–22 hours. After the reaction is complete, the reaction solution is poured into deionized water to precipitate the solid. The solid is then filtered out, washed with deionized water, and dried to obtain the modifier.
[0010] The third step involves adding the modifier, methyl vinyl silane, ceramic filler, and fumed silica to a mixer and mixing them thoroughly. Then, potassium hydroxide is added, and the mixture is transferred to a vacuum drying oven for vacuum degassing for 15–25 minutes. After curing at 80–90°C for 1–2 hours, it is then cured at 120–140°C for 2–4 hours to obtain a uniform adhesive. The adhesive is then subjected to thin-pass processing and molding to obtain fire-resistant and insulating ceramic silicone.
[0011] Furthermore, the perfluoroalkyl propylene oxide in the first step is one of perfluorohexyl propylene oxide, perfluorooctyl propylene oxide, and perfluorodecyl propylene oxide.
[0012] Furthermore, the aminostyrene in the first step is one of 2-aminostyrene, 3-aminostyrene, and 4-aminostyrene.
[0013] Furthermore, in the first step, the mass ratio of perfluoroalkyl propylene oxide, aminostyrene, and ethanol is 8–10:2–3:40–50.
[0014] Furthermore, the acid-binding agent in the second step is one of triethylamine, 4-dimethylaminopyridine, and N,N-diisopropylethylamine.
[0015] Furthermore, in the second step, the mass ratio of the modifier precursor, phosphorus trichloride, acid-binding agent, anhydrous magnesium chloride, and acetonitrile is 6–8.8: 0.5–0.7: 1–1.6: 0.2–0.6: 30–40.
[0016] Furthermore, the ceramic filler in the third step is at least one of glass powder, kaolin, and muscovite.
[0017] Furthermore, in the third step, the mass ratio of the modifier, methyl vinyl silane, ceramic filler, fumed silica, and potassium hydroxide is 4–6:40–50:20–30:20–30:0.1–0.3.
[0018] Application of the fire-resistant and insulating ceramic silicone prepared by the above method in high-voltage copper-aluminum busbars.
[0019] The beneficial effects of this invention are:
[0020] 1) The phosphite groups in the modifier of this invention decompose upon heating during combustion, releasing phosphorus free radicals, which inhibit the combustion chain reaction and prevent the spread of flames. They also promote the carbonization of combustible surfaces, forming a dense protective char layer that blocks heat and oxygen. Simultaneously, the nitrogen in the modifier decomposes upon heating to produce inert gases, causing the char layer to expand. The silicon element in the silane in the ceramic silica gel forms a more stable ceramic protective layer at higher temperatures. Thus, the overall system presents a highly efficient fireproofing system where phosphorus promotes char formation, nitrogen expands the char layer, and silicon solidifies the char to form ceramic. This enables the fireproof and insulating ceramic silica gel applied to high-voltage copper-aluminum busbars to provide stable insulation and protection under normal conditions, while maintaining power supply to the power control system in the event of a short circuit or fire in the high-voltage electrical cabinet.
[0021] 2) The modifier of this invention contains multiple phenyl groups, which, when incorporated into the silicone, increase the rigidity of the molecular chain and raise the thermal decomposition temperature of the material, effectively addressing overheating caused by equipment failure. Simultaneously, the modifier also contains multiple perfluoroalkyl groups, which possess strong chemical inertness, effectively resisting the corrosion of oils and chemicals. This prevents damage to the ceramic silicone structure caused by oil leaks or chemical corrosion during equipment failures, ensuring that the high-voltage copper-aluminum busbar maintains good insulation and stable operation even under the pressure of oil and chemical corrosion.
[0022] 3) The multiple amino groups in the ceramic silicone of this invention can form hydrogen bonds with the hydroxyl groups in the ceramic filler, effectively improving the uniformity of filler dispersion in the silicone matrix, preventing filler agglomeration, and improving the compatibility between silicone and filler. Simultaneously, the amino groups can form strong coordination bonds with the metal oxides on the surface of the high-voltage copper-aluminum busbar, thereby establishing a strong interfacial bond between the rubber matrix and the metal busbar. This enhances the overall mechanical properties of the ceramic silicone, giving the high-voltage copper-aluminum busbar better insulation and a longer lifespan. Detailed Implementation
[0023] The technical solutions of the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.
[0024] The raw materials used in this invention are not particularly restricted in terms of their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.
[0025] Example 1
[0026] A method for preparing fire-retardant and insulating ceramic silicone includes the following steps:
[0027] Step 1: Add 8g of perfluorohexyl propylene oxide, 2g of 2-aminostyrene and 40g of ethanol to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at room temperature for 6 hours. After cooling to room temperature, rotary evaporate to remove the solvent, extract with ethyl acetate and retain the organic phase, dry the organic phase and elute by column chromatography to obtain the modifier precursor.
[0028] Step 2: Add 6g of modifier precursor, 0.5g of phosphorus trichloride, 1g of triethylamine, 0.2g of anhydrous magnesium chloride and 30g of acetonitrile to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at 70℃ for 4h. Then raise the temperature to 80℃ and react for 22h. After the reaction is completed, pour the reaction solution into deionized water to precipitate. Then filter out the solid, wash it with deionized water and dry it to obtain the modifier.
[0029] The third step involves adding 4g of modifier, 40g of methyl vinyl silane, 20g of glass powder, and 20g of fumed silica to a mixer and mixing them thoroughly. Then, 0.1g of potassium hydroxide is added. The mixture is transferred to a vacuum drying oven for vacuum degassing for 15 minutes, and then cured at 80°C for 2 hours. After that, it is cured at 120°C for 4 hours to obtain a uniform adhesive. The adhesive is then subjected to thin-pass processing and molding to obtain fire-resistant and insulating ceramic silicone.
[0030] Application of the fire-resistant and insulating ceramic silicone prepared by the above method in high-voltage copper-aluminum busbars.
[0031] Example 2
[0032] A method for preparing fire-retardant and insulating ceramic silicone includes the following steps:
[0033] Step 1: Add 9g of perfluorooctyl propylene oxide, 2.5g of 3-aminostyrene and 45g of ethanol to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at room temperature for 5.5h. After cooling to room temperature, rotary evaporate to remove the solvent, extract with ethyl acetate and retain the organic phase, dry the organic phase and elute by column chromatography to obtain the modifier precursor.
[0034] Step 2: Add 7.9g of modifier precursor, 0.6g of phosphorus trichloride, 1.3g of 4-dimethylaminopyridine, 0.4g of anhydrous magnesium chloride and 35g of acetonitrile to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at 75℃ for 3h. Then raise the temperature to 85℃ and react for 20h. After the reaction is completed, pour the reaction solution into deionized water to precipitate, then filter out the solid, wash with deionized water and dry to obtain the modifier.
[0035] The third step involves adding 5g of modifier, 45g of methyl vinyl silane, 25g of kaolin, and 25g of fumed silica to a mixer and mixing them thoroughly. Then, 0.2g of potassium hydroxide is added. The mixture is transferred to a vacuum drying oven for vacuum degassing for 20 minutes, and then cured at 85°C for 1.5 hours. After that, it is cured at 130°C for 3 hours to obtain a uniform adhesive. The adhesive is then subjected to thin-pass processing and molding to obtain fire-resistant and insulating ceramic silicone.
[0036] Application of the fire-resistant and insulating ceramic silicone prepared by the above method in high-voltage copper-aluminum busbars.
[0037] Example 3
[0038] A method for preparing fire-retardant and insulating ceramic silicone includes the following steps:
[0039] Step 1: Add 10g of perfluorodecyl propylene oxide, 5g of 4-aminostyrene and 50g of ethanol to a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring, and react at room temperature for 5 hours. After cooling to room temperature, evaporate by rotary evaporation to remove the solvent, extract with ethyl acetate and retain the organic phase, dry the organic phase and elute by column chromatography to obtain the modifier precursor.
[0040] Step 2: Add 8.8g of modifier precursor, 0.7g of phosphorus trichloride, 1.6g of N,N-diisopropylethylamine, 0.6g of anhydrous magnesium chloride and 40g of acetonitrile to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at 80℃ for 2 hours. Then raise the temperature to 90℃ and react for 18 hours. After the reaction is completed, pour the reaction solution into deionized water to precipitate, then filter out the solid, wash with deionized water and dry to obtain the modifier.
[0041] The third step involves adding 6g of modifier, 50g of methyl vinyl silane, 30g of muscovite, and 30g of fumed silica to a mixer and mixing them thoroughly. Then, 0.3% potassium hydroxide is added, and the mixture is transferred to a vacuum drying oven for vacuum degassing for 25 minutes. After curing at 90°C for 1 hour, it is then cured at 140°C for 2 hours to obtain a uniform adhesive. The adhesive is then subjected to thin-pass processing and molding to obtain fire-resistant and insulating ceramic silicone.
[0042] Application of the fire-resistant and insulating ceramic silicone prepared by the above method in high-voltage copper-aluminum busbars.
[0043] Comparative Example 1
[0044] The difference between this comparative example and Example 2 is that the modifier is replaced with the commercially available phosphorus-based flame retardant VOPP-co-St, while the other raw materials and preparation steps remain unchanged.
[0045] Experimental Example 1
[0046] The ceramic silicone materials in Examples 1-3 and Comparative Example 1 were subjected to performance tests. The limiting oxygen index of each group of ceramic silicone materials was tested according to GB / T10707-2008 "Determination of Burning Performance of Rubber". The tensile strength and elongation at break of each group of ceramic silicone materials were tested according to GB / T20028-2018 "Test Methods for Vulcanized Rubber or Thermoplastic Rubber Materials". The tensile strength retention rate and elongation at break of each group of ceramic silicone materials after soaking in Kunlun Lubricating Oil 10W-30 at 120°C for 240 hours were tested according to GB / T1690-2010 "Test Methods for Liquid Resistance of Vulcanized Rubber". The initial decomposition temperature of each group of ceramic silicone materials was tested according to GB / T31850-2015 "Determination of Thermal Decomposition Temperature of Non-metallic Sealing Materials". The test results are shown in Table 1.
[0047] Table 1
[0048]
[0049] As shown in Table 1, Examples 1-3 exhibit higher limiting oxygen index, tensile strength, elongation at break, tensile strength retention rate, elongation at break retention rate, and initial decomposition temperature compared to Comparative Example 1. This indicates that the ceramic silicone in Examples 1-3 has superior fire resistance, mechanical properties, oil and corrosion resistance, and heat resistance compared to the ceramic silicone in Comparative Example 1. Combined with Comparative Example 1, it can be seen that the addition of the modifier significantly improves the fire resistance, mechanical properties, oil and corrosion resistance, and heat resistance of the ceramic silicone. This ensures that the prepared ceramic silicone maintains excellent insulation performance even under special working conditions when used for high-voltage copper-aluminum busbar insulation protection, thus ensuring stable operation of the high-voltage copper-aluminum busbar.
[0050] The foregoing provides a detailed description of the method for preparing fire-resistant and insulating ceramic silicone and its application in high-voltage copper-aluminum busbars. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of these embodiments are merely illustrative of the method and core ideas of this invention, including the optimal mode, and are intended to enable any person skilled in the art to practice this invention, including manufacturing and using any device or system, and implementing any combination method. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A method for preparing fire-retardant and insulating ceramic silicone, characterized in that, Includes the following steps: Preparation of the modifier: The modifier precursor was obtained by nucleophilic substitution reaction of perfluoroalkyl propylene oxide with aminostyrene; the modifier precursor was then obtained by nucleophilic substitution reaction of phosphorus trichloride with an acid-binding agent. Preparation of fire-resistant and insulating ceramic silicone: Modifier, methyl vinyl silane, ceramic filler and fumed silica are blended, cured twice and then molded to obtain fire-resistant and insulating ceramic silicone.
2. The method for preparing fire-resistant and insulating ceramic silicone according to claim 1, characterized in that, Perfluoroalkyl propylene oxide is one of perfluorohexyl propylene oxide, perfluorooctyl propylene oxide, and perfluorodecyl propylene oxide.
3. The method for preparing fire-resistant and insulating ceramic silicone according to claim 1, characterized in that, Aminostyrene is one of 2-aminostyrene, 3-aminostyrene, and 4-aminostyrene.
4. The method for preparing fire-retardant and insulating ceramic silicone according to claim 1, characterized in that, The mass ratio of perfluoroalkyl propylene oxide to aminostyrene is 8-10:2-3.
5. The method for preparing fire-resistant and insulating ceramic silicone according to claim 1, characterized in that, The acid-binding agent is one of triethylamine, 4-dimethylaminopyridine, or N,N-diisopropylethylamine.
6. The method for preparing fire-retardant and insulating ceramic silicone according to claim 1, characterized in that, The mass ratio of the modifier precursor, phosphorus trichloride, and acid binder is 6–8.8:0.5–0.7:1–1.
6.
7. The method for preparing fire-retardant and insulating ceramic silicone according to claim 1, characterized in that, The ceramic filler is at least one of glass powder, kaolin, and muscovite.
8. The method for preparing fire-resistant and insulating ceramic silicone according to claim 1, characterized in that, The temperature for the first curing is 80–90℃ and the time is 1–2 hours. The temperature for the second curing is 120–140℃ and the time is 2–4 hours.
9. The method for preparing fire-resistant and insulating ceramic silicone according to claim 1, characterized in that, The mass ratio of modifier, methyl vinyl silane, ceramic filler, and fumed silica is 4–6:40–50:20–30:20–30.
10. The application of the fire-resistant and insulating ceramic silicone prepared by the preparation method according to any one of claims 1 to 9 on high-voltage copper-aluminum busbars.