Fire extinguishing medium and use in electric energy metering devices

Abstract

The application belongs to the technical field of fire extinguishing medium preparation, and particularly relates to a fire extinguishing medium and application thereof in electric energy metering devices. The fire extinguishing medium is composed of a first fire extinguishing layer, a second fire extinguishing layer and a heat insulation protection layer, and realizes phased progressive fire extinguishing through material modification and structural design. The first fire extinguishing layer adopts molecular sieve loaded perfluorohexanone, can realize rapid response of initial fire extinguishing, the second fire extinguishing layer is modified by grafting flame-retardant polymers on ammonium dihydrogen phosphate, and the fire extinguishing capacity is enhanced, and the heat insulation protection layer takes modified zinc borate as the core, strengthens the synergistic effect of heat insulation and flame retardation, and the three-layer structure interacts to effectively improve the fire protection performance of the equipment.

Description

Technical Field

[0001] This invention belongs to the field of fire extinguishing medium preparation technology, specifically relating to a fire extinguishing medium and its application in an electricity metering device. Background Technology

[0002] Early humans relied primarily on natural materials like water and sand for fire extinguishing. However, with the advancement of the Industrial Revolution, the complexity of fires increased, making traditional extinguishing agents insufficient. Halon fire extinguishing agents, due to their high efficiency, were widely used for a period. However, their severe ozone-depleting effects led to the development of perfluorohexanone (PFH) as a novel extinguishing agent. PFH can be sprayed onto the flame area under high-temperature conditions, rapidly absorbing heat and vaporizing. It can directly absorb heat from the surface of the burning material and the flame, quickly lowering the temperature below the ignition point and effectively preventing continued combustion and reignition. PFH is also a clean gas with excellent electrical insulation properties, leaving no solid or liquid residue after extinguishing the fire. It will not cause short circuits or degrade the insulation performance of precision electronic components and circuit boards, making it commonly used in electrical metering applications.

[0003] Chinese Patent CN118949336B discloses a perfluorohexanone microcapsule fire extinguishing medium and its preparation process. It modifies guar gum with diphenylphosphine chloride, grafting diphenylphosphine groups onto the guar gum, and applies this modification to the shell material of the perfluorohexanone microcapsules, giving the shell material flame-retardant properties. Porous silica is used as the carrier for the perfluorohexanone fire extinguishing medium core material; its porous structure can hold perfluorohexanone, serving as its storage space and reducing the contact area between perfluorohexanone and the external environment. This results in perfluorohexanone microcapsules with excellent heat resistance and long-term stability. Chinese Patent CN118105664A discloses a long-lasting, stable, and aging-resistant perfluorohexanone microcapsule fire extinguishing material and its preparation method. It uses flame-retardant polyurethane formed by polymerizing DOPO derivatives and isocyanates as the shell layer to prepare the perfluorohexanone microcapsule fire extinguishing material, effectively improving the volatility resistance and thermal stability of the core fire extinguishing agent, perfluorohexanone. However, perfluorohexanone has limited fire extinguishing capacity as a single fire extinguishing material, so how to prepare a fire extinguishing medium with long-lasting and good fire extinguishing effect has become the focus of research. Summary of the Invention

[0004] To address at least one of the above problems, the present invention provides a method for preparing a fire extinguishing medium, comprising the following steps:

[0005] S100: The first fire extinguishing layer blank is obtained by pressing raw materials including molecular sieve-loaded perfluorohexanone, nano silica and polyethylene glycol.

[0006] S200 uses raw materials including perfluorohexanone, flame-retardant polymer-grafted ammonium dihydrogen phosphate, montmorillonite, and fluoroelastomer to mix and obtain a second fire extinguishing layer mixture, which is then covered on the surface of the first fire extinguishing layer blank and composited to obtain a composite blank.

[0007] S300 uses raw materials including modified zinc borate, sodium silicate, basalt fiber, and nano magnesium hydroxide to mix and obtain a heat insulation and protective layer slurry, which is then applied to the surface of the composite blank to obtain the fire extinguishing medium.

[0008] Further, step S100 specifically includes: adding nano-silica, polyethylene glycol and silane coupling agent to a sealed container, raising the temperature to 30-40℃ and stirring for 10-20 minutes, then adding molecular sieve-loaded perfluorohexanone, introducing inert gas and continuing to stir at a speed of 100-150 r / min for 5-15 minutes to form a stable slurry, pouring the slurry into a mold, pressing it into shape, and obtaining the first fire extinguishing layer blank.

[0009] Furthermore, the preparation method of molecular sieve-supported perfluorohexanone is as follows: the molecular sieve is calcined at 120-130℃ for 1-3 hours, then placed in a pressure-resistant container, and vacuumed under stirring. Perfluorohexanone is then added to the container under sealed conditions and stirred for 2-4 hours. After adsorption is completed, the molecular sieve-supported perfluorohexanone is obtained.

[0010] Further, step S200 specifically includes: adding flame-retardant polymer-grafted ammonium dihydrogen phosphate, montmorillonite, and fluoroelastomer into a high-speed mixer, controlling the temperature at 25-30℃, mixing at a speed of 1500-2000 r / min for 20-30 min, then adding a crosslinking agent, maintaining a speed of 1500-2000 r / min and continuing to stir for 5-10 min, controlling the temperature at 20-25℃, adding perfluorohexanone, mixing at a speed of 800-1000 r / min for 30-50 min to obtain the second fire extinguishing layer mixture, covering the surface of the first fire extinguishing layer blank in a sealed mold, evacuating and then introducing inert gas, pressurizing and compounding at 2-2.5 MPa and 40-45℃, holding the pressure for 30-50 min, after the pressure holding is completed, lowering the temperature to room temperature, immediately wrapping tightly with aluminum foil, and letting stand at room temperature for 20-25 h to obtain the composite blank.

[0011] Furthermore, the preparation method of flame-retardant polymer-grafted ammonium dihydrogen phosphate is as follows: ammonium dihydrogen phosphate and polyphosphate monomer are placed in a reaction vessel in a certain proportion, and solvent and initiator are added to it. The temperature is raised to 75-90℃, and the mixture is stirred at 200-300 r / min for 2-4 h. After the reaction is completed, the mixture is distilled under reduced pressure, and after washing and drying, flame-retardant polymer-grafted ammonium dihydrogen phosphate is obtained.

[0012] Further, step S300 specifically includes: adding modified zinc borate, sodium silicate, basalt fiber, and nano magnesium hydroxide into a reactor in proportion, adding solvent to it, stirring evenly to obtain a heat insulation and protective layer slurry, coating it on the surface of the composite blank, and drying it to obtain the fire extinguishing medium.

[0013] Furthermore, the modified zinc borate is prepared by immersing zinc borate in an ethanol solution containing a silane coupling agent, and then drying it to obtain the modified zinc borate.

[0014] A fire extinguishing medium is prepared using the fire extinguishing medium preparation method described in any of the above technical solutions.

[0015] An application of a fire extinguishing medium in an electricity metering device involves installing the fire extinguishing medium prepared by the method described in any of the above technical solutions into a key heat-generating part of the electricity metering device.

[0016] The present invention has the following beneficial effects:

[0017] In the preparation of the first fire extinguishing layer, perfluorohexanone is loaded using molecular sieves. The active groups on the surface of the molecular sieves form weak hydrogen bonds with the perfluorohexanone molecules, enhancing the stability of the load. The addition of nano-silica enhances the overall mechanical strength of the material, ensuring structural stability. In the second fire extinguishing layer, fluororubber is used as the matrix material, and ammonium dihydrogen phosphate is used as the main flame retardant component. After grafting with flame retardant polymers, the compatibility with fluoroelastomers is improved. The interaction between the two further slows down the combustion reaction rate and continuously improves the fire extinguishing capability. In the preparation of the heat insulation and protective layer, modified zinc borate is introduced as a flame retardant, and sodium silicate is also introduced. When heated, it reacts with zinc borate to form a glassy melt, which covers the surface of the combustible material, achieving a flame retardant and heat insulation effect. Detailed Implementation

[0018] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] As a key piece of equipment in the power system, electricity metering devices integrate a large number of electronic components and circuits. During long-term operation, they are prone to localized high temperatures or even fires due to poor contact, overload, etc. Many fire extinguishing products have slow response times and cannot function effectively in the initial, crucial stage of fire suppression, leading to the spread of the fire. Furthermore, while some fire extinguishing materials can suppress fire to a certain extent, their sustained fire extinguishing capabilities are insufficient. Therefore, this invention provides a method for preparing a fire extinguishing medium, comprising the following steps:

[0020] S100: The first fire extinguishing layer blank is obtained by pressing raw materials including molecular sieve-loaded perfluorohexanone, nano silica and polyethylene glycol.

[0021] S200 uses raw materials including perfluorohexanone, flame-retardant polymer-grafted ammonium dihydrogen phosphate, montmorillonite, and fluoroelastomer to mix and obtain a second fire extinguishing layer mixture, which is then covered on the surface of the first fire extinguishing layer blank and composited to obtain a composite blank.

[0022] S300 uses raw materials including modified zinc borate, sodium silicate, basalt fiber, and nano magnesium hydroxide to mix and obtain a heat insulation and protective layer slurry, which is then applied to the surface of the composite blank to obtain the fire extinguishing medium.

[0023] Step S100 specifically includes: adding nano-silica, polyethylene glycol, and silane coupling agent to a sealed container, raising the temperature to 30-40℃, stirring at 300-500 r / min for 10-20 min, adding molecular sieve-supported perfluorohexanone, introducing inert gas, and continuing to stir at 100-150 r / min for 5-15 min to form a stable slurry, pouring the slurry into a mold, and pressing it under a pressure of 0.5-1 MPa to obtain the first fire extinguishing layer blank. The mass ratio of nano-silica, polyethylene glycol, silane coupling agent, and molecular sieve-supported perfluorohexanone is 30-40:5-10:1-3:45-60.

[0024] The preparation method of molecular sieve-supported perfluorohexanone is as follows: calcining the molecular sieve at 120-130℃ for 1-3 hours, then placing it in a pressure-resistant container, performing a vacuum operation while stirring, and then adding perfluorohexanone under a sealed condition, stirring for 2-4 hours. After adsorption is complete, the liquid in the reaction container is poured out, and after the excess perfluorohexanone has evaporated completely, the molecular sieve-supported perfluorohexanone is obtained. The mass ratio of molecular sieve to perfluorohexanone is 1:0.2-0.6.

[0025] In this process, calcining the molecular sieve allows for the high-temperature desorption of pre-adsorbed impurities such as moisture and carbon dioxide within the sieve channels, thus regenerating the molecular sieve. Vacuuming removes existing air from the container and prevents the regenerated analytical sieve from re-adsorbing impurities. In step S100, PEG-1000 polyethylene glycol is used, which is solid at room temperature and liquid when heated to 30-40°C. The addition of a silane coupling agent forms covalent bonds between the nano-silica and polyethylene glycol, while its epoxy groups react with the hydroxyl groups on the molecular sieve surface, enhancing the system's stability.

[0026] In the preparation of the first fire extinguishing layer, perfluorohexanone (PFH) is loaded onto a molecular sieve as a carrier. The molecular sieve possesses a rich and regular microporous structure, which allows for the stable fixation of PFH within the pores through physical adsorption. Simultaneously, the active groups such as silanol groups on the surface of the molecular sieve can form weak hydrogen bonds with PFH molecules, further enhancing the loading stability. When a fire occurs, polyethylene glycol undergoes a melting phase transition, loosening the previously tightly bound molecular sieve loading structure and creating conditions for the release of PFH. Upon heating, PFH rapidly volatilizes from the molecular sieve pores. Under the influence of high-temperature flames, PFH decomposes, generating fluorine-containing free radicals. These free radicals combine with active free radicals in the combustion chain, interrupting the chain reaction and inhibiting the combustion process. The addition of nano-silica enhances the overall mechanical strength of the material, ensuring structural stability.

[0027] Step S200 specifically includes: adding flame-retardant polymer-grafted ammonium dihydrogen phosphate, montmorillonite, and fluoroelastomer into a high-speed mixer, controlling the temperature at 25-30℃, mixing at 1500-2000 r / min for 20-30 min, then adding a crosslinking agent, maintaining the speed at 1500-2000 r / min and continuing to stir for 5-10 min, controlling the temperature at 20-25℃, adding perfluorohexanone, mixing at 800-1000 r / min for 30-50 min to obtain the second fire extinguishing layer mixture, covering the surface of the first fire extinguishing layer blank in a sealed mold, evacuating and then introducing inert gas, pressurizing and compounding at 2-2.5 MPa and 40-45℃, holding the pressure for 30-50 min, after the pressure holding is completed, lowering the temperature to room temperature, immediately wrapping tightly with aluminum foil, and letting stand at room temperature for 20-25 h to obtain the composite blank. The fluoroelastomer is a carboxylated nitrosofluororubber; the mass ratio of the flame-retardant polymer grafted with ammonium dihydrogen phosphate, montmorillonite, fluoroelastomer, crosslinking agent and perfluorohexanone is 30-40:5-10:10-15:1-3:30-45.

[0028] The preparation method of flame-retardant polymer-grafted ammonium dihydrogen phosphate is as follows: ammonium dihydrogen phosphate and polyphosphate monomer are placed in a reaction vessel in a certain proportion, and solvent and initiator are added. The temperature is raised to 75-90℃, and the mixture is stirred at 200-300 r / min for 2-4 h. After the reaction is completed, the mixture is distilled under reduced pressure, washed, and dried to obtain the flame-retardant polymer-grafted ammonium dihydrogen phosphate. The solvent is one or a mixture of several selected from ethyl acetate, toluene, ethylene glycol ethyl ether, butyl acetate, and methyl ethyl ketone; the initiator is one or a mixture of several selected from benzoyl peroxide, lauroyl peroxide, and azobisisobutyronitrile; and the polyphosphate monomer is phosphate methacrylate. The mass ratio of ammonium dihydrogen phosphate, polyphosphate monomer, initiator, and solvent is 10:1-3:0.1-0.3:30-45.

[0029] In this step, ammonium dihydrogen phosphate, as the main flame-retardant component, undergoes surface property modification through grafting with flame-retardant polymers, resulting in improved compatibility with fluoroelastomers. Upon exposure to fire, the flame-retardant polymer-grafted ammonium dihydrogen phosphate decomposes thermally, releasing inert gases and phosphates. The inert gases dilute the oxygen concentration in the combustion zone, acting as a gas-phase flame retardant, while the phosphates catalyze the formation of a char layer on the surface of the combustible material, blocking heat and oxygen transfer. Simultaneously, montmorillonite, a layered clay mineral, can adsorb and store a certain amount of perfluorohexanone. As the temperature rises, montmorillonite slowly releases perfluorohexanone, continuously providing a gas-phase flame retardant to the combustion zone and extending the fire extinguishing time. Furthermore, during combustion, montmorillonite intertwines with the char layer, enhancing the strength and density of the char layer and further preventing heat and oxygen transfer into the material. Fluoropolymer rubber, as a base material, not only provides good flexibility and mechanical properties, but also has certain high temperature resistance and flame retardant properties, slows down the combustion reaction rate, and works synergistically with other flame retardant components to jointly enhance the continuous fire extinguishing capability and achieve continuous and effective control of the fire.

[0030] Step S300 specifically includes: adding modified zinc borate, sodium silicate, basalt fiber, and nano magnesium hydroxide to a reactor in a certain proportion, adding 70% ethanol solution, stirring at 200-300 r / min for 20-30 min to obtain a heat insulation protective layer slurry, coating it on the surface of the composite blank, placing it in a constant temperature and humidity drying oven, controlling the temperature at 35-40℃ and the relative humidity ≤40%, while simultaneously introducing dry inert gas, and drying for 1-2 hours; then raising the temperature to 40-45℃, maintaining the relative humidity ≤30%, increasing the inert gas flow rate, and drying for 1-2 hours, weighing every 20-30 min, and when the difference between two consecutive mass measurements is ≤0.5%, drying is complete, removing it and immediately cooling it to room temperature to obtain the fire extinguishing medium; the mass ratio of modified zinc borate, sodium silicate, basalt fiber, and nano magnesium hydroxide is 25-35:10-15:5-10:40-50.

[0031] The modified zinc borate is prepared by immersing zinc borate in a 6% KH550 ethanol solution and then drying it to obtain the modified zinc borate; wherein the ethanol solution is an 80-90% ethanol solution; and the mass ratio of zinc borate to 6% KH550 ethanol solution is 20-35:40-75.

[0032] In this step, modified zinc borate decomposes upon heating, releasing water of crystallization and flame-retardant gases. The water of crystallization vaporizes, absorbing heat and lowering the temperature, while the flame-retardant gases inhibit the combustion reaction. Simultaneously, zinc borate reacts with sodium silicate to form a glassy melt, which covers the surface of the combustible material, isolating it from oxygen and heat. The introduction of basalt fibers provides skeletal support, maintaining the structural stability of the heat insulation layer. Nano-sized magnesium hydroxide decomposes, absorbing heat and releasing water vapor, synergistically enhancing the flame-retardant and heat-insulating effects with zinc borate.

[0033] A fire extinguishing medium is prepared using the fire extinguishing medium preparation method described in any of the above technical solutions.

[0034] An application of a fire extinguishing medium in an electricity metering device involves fixing the fire extinguishing medium prepared by the method described in any of the above technical solutions to the device busbar, metering chip slot, and key heat-generating parts of the power module using a high-temperature resistant adhesive, and providing a polytetrafluoroethylene gasket between the fire extinguishing medium and the metal parts.

[0035] The 13X molecular sieve (chemically pure) used in this invention was purchased from Beijing Chemical Plant, perfluorohexanone (chemically pure) was purchased from Yuanye Biotechnology, nano silica (30nm), polyethylene glycol (PEG-1000), montmorillonite (item number M141491), and zinc borate (anhydrous grade) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., phosphate methacrylate (>99%) was purchased from Wuhan Jiangxin Biotechnology Co., Ltd., ammonium dihydrogen phosphate (superior grade) was purchased from Jinan Jiayang Chemical Co., Ltd., carboxynitrosofluororubber was purchased from Chengdu Senfa Rubber & Plastics Co., Ltd., basalt fiber (model AF53) was purchased from Taian Anfeng New Material Technology Co., Ltd., and nano magnesium hydroxide (model MP-1) was purchased from Qinghe Chaotai Metal Material Co., Ltd. All raw materials used were commercially available.

[0036] Example 1

[0037] A method for preparing a fire extinguishing medium includes the following steps:

[0038] S1. 80 parts by weight of 13X type molecular sieve were calcined at 130℃ for 2 hours, and then placed in a pressure-resistant container. Vacuum operation was performed under stirring. Then, 32 parts by weight of perfluorohexanone were added to it under sealed condition and stirred for 3 hours. After adsorption was completed, the liquid in the reaction container was poured out. After the excess perfluorohexanone was completely evaporated, molecular sieve-supported perfluorohexanone was obtained.

[0039] S2. Add 35 parts by weight of nano-silica, 8 parts by weight of polyethylene glycol and 2 parts by weight of KH550 to a sealed container, raise the temperature to 35°C, stir at 400 r / min for 15 min, then add 55 parts by weight of molecular sieve-supported perfluorohexanone, introduce nitrogen gas and continue stirring at 120 r / min for 10 min to form a stable slurry, pour the slurry into a mold, and press it under a pressure of 0.8 MPa to obtain the first fire extinguishing layer blank.

[0040] S3. Place 10 parts by weight of ammonium dihydrogen phosphate and 2 parts by weight of polyphosphate monomer into a reaction vessel, and add 40 parts by weight of toluene and 0.2 parts by weight of benzoyl peroxide. Raise the temperature to 85°C and stir at 250 r / min for 3 h. After the reaction is completed, distill under reduced pressure, wash three times with anhydrous ethanol, dry in a vacuum drying oven at 60°C for 4 h, grind, and pass through a 200-mesh sieve to obtain flame-retardant polymer-grafted ammonium dihydrogen phosphate.

[0041] S4. Add 35 parts by weight of flame-retardant polymer-grafted ammonium dihydrogen phosphate, 8 parts by weight of montmorillonite, and 12 parts by weight of carboxynitroso fluororubber to a high-speed mixer. Control the temperature at 30°C and mix at 1800 r / min for 25 min. Then add 2 parts by weight of hexamethylenediamine and continue stirring at 1800 r / min for 8 min. Control the temperature at 25°C and add 35 parts by weight of perfluorohexanone. Mix at 900 r / min for 40 min to obtain the second fire extinguishing layer mixture. Cover the surface of the first fire extinguishing layer blank in a sealed mold. After vacuuming, introduce nitrogen gas into the mold and pressurize at 2.2 MPa and 40°C for 40 min. After pressurization, lower the temperature to room temperature and immediately wrap it tightly with aluminum foil. Let it stand at room temperature for 24 h to obtain the composite blank.

[0042] S5. 30 parts by weight of zinc borate were soaked in 55 parts by weight of 6% KH550 ethanol solution for 2 hours and then dried in a vacuum drying oven at 60°C for 2 hours to obtain modified zinc borate; wherein, the ethanol solution was 80% ethanol solution.

[0043] S6. Add 30 parts by weight of modified zinc borate, 12 parts by weight of sodium silicate, 8 parts by weight of basalt fiber, and 45 parts by weight of nano magnesium hydroxide to a reactor. Add 55 parts by weight of 70% ethanol solution and stir at 250 r / min for 25 min to obtain a heat insulation protective layer slurry. Coat the slurry onto the surface of the composite blank and place it in a constant temperature and humidity drying oven. Control the temperature at 35℃ and the relative humidity at ≤40%. Simultaneously, introduce dry nitrogen gas at a flow rate of 2 L / min and dry for 1.5 h. Then raise the temperature to 40℃, maintain the relative humidity at ≤30%, increase the nitrogen flow rate to 3 L / min, and dry for 1.5 h. After drying, weigh every 20 min. When the difference between two consecutive mass measurements is ≤0.5%, drying is complete. Remove the slurry and immediately cool it to room temperature to obtain the fire extinguishing medium.

[0044] Example 2

[0045] This embodiment differs from Embodiment 1 in the following ways:

[0046] In step S1, 80 parts by weight of 13X type molecular sieve and 16 parts by weight of perfluorohexanone are used. In step S2, 30 parts by weight of nano-silica, 5 parts by weight of polyethylene glycol, 1 part by weight of KH550, and 45 parts by weight of perfluorohexanone supported on molecular sieve are used. In step S3, 10 parts by weight of ammonium dihydrogen phosphate, 1 part by weight of polyphosphate, 0.1 part by weight of benzoyl peroxide, and 30 parts by weight of toluene are used. In step S4, 30 parts by weight of flame-retardant polymer-grafted ammonium dihydrogen phosphate, 5 parts by weight of montmorillonite, 10 parts by weight of carboxynitrosofluororubber, 1 part by weight of hexamethylenediamine, and 30 parts by weight of perfluorohexanone are used. In step S5, 20 parts by weight of zinc borate and 40 parts by weight of 6% KH550 ethanol solution are used. In step S6, 25 parts by weight of modified zinc borate, 10 parts by weight of sodium silicate, 5 parts by weight of basalt fiber, and 40 parts by weight of nano-magnesium hydroxide are used.

[0047] Example 3

[0048] This embodiment differs from Embodiment 1 in the following ways:

[0049] In step S1, 80 parts by weight of 13X type molecular sieve and 48 parts by weight of perfluorohexanone; in step S2, 40 parts by weight of nano-silica, 10 parts by weight of polyethylene glycol, 3 parts by weight of KH550, and 60 parts by weight of perfluorohexanone supported on molecular sieve; in step S3, 10 parts by weight of ammonium dihydrogen phosphate, 3 parts by weight of polyphosphate ester, 0.3 parts by weight of benzoyl peroxide, and 45 parts by weight of toluene; in step S4, 40 parts by weight of flame-retardant polymer-grafted ammonium dihydrogen phosphate, 10 parts by weight of montmorillonite, 15 parts by weight of carboxynitrosofluororubber, 3 parts by weight of hexamethylenediamine, and 45 parts by weight of perfluorohexanone; in step S5, 35 parts by weight of zinc borate and 75 parts by weight of 6% KH550 ethanol solution; in step S6, 35 parts by weight of modified zinc borate, 15 parts by weight of sodium silicate, 10 parts by weight of basalt fiber, and 50 parts by weight of nano-magnesium hydroxide.

[0050] Example 4

[0051] This embodiment differs from Embodiment 1 in the following ways:

[0052] In step S1, 80 parts by weight of 13X type molecular sieve and 40 parts by weight of perfluorohexanone; in step S2, 32 parts by weight of nano-silica, 6 parts by weight of polyethylene glycol, 1.2 parts by weight of KH550, and 50 parts by weight of molecular sieve-supported perfluorohexanone; in step S3, 10 parts by weight of ammonium dihydrogen phosphate, 1.2 parts by weight of polyphosphate ester, 0.12 parts by weight of benzoyl peroxide, and 32 parts by weight of toluene; in step S4, 32 parts by weight of flame-retardant polymer-grafted ammonium dihydrogen phosphate, 6 parts by weight of montmorillonite, 11 parts by weight of carboxynitrosofluororubber, 1.2 parts by weight of hexamethylenediamine, and 36 parts by weight of perfluorohexanone; in step S5, 22 parts by weight of zinc borate and 50 parts by weight of 6% KH550 ethanol solution; in step S6, 28 parts by weight of modified zinc borate, 11 parts by weight of sodium silicate, 6 parts by weight of basalt fiber, and 42 parts by weight of nano-magnesium hydroxide.

[0053] Example 5

[0054] Compared with Example 1, in the preparation of the first fire extinguishing layer blank, the molecular sieve-loaded perfluorohexanone is replaced with perfluorohexanone, and the rest is the same as in Example 1.

[0055] Example 6

[0056] Compared with Example 1, in the preparation of the composite preform, the flame-retardant polymer grafted with ammonium dihydrogen phosphate is replaced with ammonium dihydrogen phosphate, and the rest is the same as in Example 1.

[0057] Example 7

[0058] Compared with Example 1, in this embodiment, modified zinc borate is replaced with zinc borate in the preparation process of the heat insulation protective layer slurry, and the rest is the same as in Example 1.

[0059] Comparative Example 1

[0060] Compared with Example 1, this comparative example uses the first fire extinguishing layer blank as the fire extinguishing medium.

[0061] Comparative Example 2

[0062] Compared with Example 1, this comparative example uses the prepared composite preform as the fire extinguishing medium.

[0063] Comparative Example 3

[0064] Compared with Example 1, this comparative example uses a composite of the first fire extinguishing layer blank and the heat insulation protective layer slurry as the fire extinguishing medium, specifically:

[0065] A method for preparing a fire extinguishing medium includes the following steps:

[0066] S1. 80 parts by weight of 13X type molecular sieve were calcined at 130℃ for 2 hours, and then placed in a pressure-resistant container. Vacuum operation was performed under stirring. Then, 32 parts by weight of perfluorohexanone were added to it under sealed condition and stirred for 3 hours. After adsorption was completed, the liquid in the reaction container was poured out. After the excess perfluorohexanone was completely evaporated, molecular sieve-supported perfluorohexanone was obtained.

[0067] S2. Add 35 parts by weight of nano-silica, 8 parts by weight of polyethylene glycol and 2 parts by weight of KH550 to a sealed container, raise the temperature to 35°C, stir at 400 r / min for 15 min, then add 55 parts by weight of molecular sieve-supported perfluorohexanone, introduce nitrogen gas and continue stirring at 120 r / min for 10 min to form a stable slurry, pour the slurry into a mold, and press it under a pressure of 0.8 MPa to obtain the first fire extinguishing layer blank.

[0068] S3. 30 parts by weight of zinc borate were soaked in 55 parts by weight of 6% KH550 ethanol solution for 2 hours and then dried in a vacuum drying oven at 60℃ for 2 hours to obtain modified zinc borate; wherein, the ethanol solution was 80% ethanol solution.

[0069] S4. Add 30 parts by weight of modified zinc borate, 12 parts by weight of sodium silicate, 8 parts by weight of basalt fiber, and 45 parts by weight of nano magnesium hydroxide to the reactor. Add 55 parts by weight of 70% ethanol solution and stir at 250 r / min for 25 min to obtain a heat insulation protective layer slurry. Coat the slurry onto the surface of the first fire extinguishing layer blank and place it in a constant temperature and humidity drying oven. Control the temperature at 35℃ and the relative humidity at ≤40%. Simultaneously, introduce dry nitrogen gas at a flow rate of 2 L / min and dry for 1.5 h. Then raise the temperature to 40℃, maintain the relative humidity at ≤30%, increase the nitrogen flow rate to 3 L / min, and dry for 1.5 h. Weigh the sample every 20 min. When the difference between two consecutive weights is ≤0.5%, the drying is complete. Remove the sample and immediately cool it to room temperature to obtain the fire extinguishing medium.

[0070] The extinguishing media prepared in Examples 1 to 7 and Comparative Examples 1 to 3 were used as samples for relevant tests:

[0071] Fire extinguishing performance test: An 800℃ flame was used as the fire source. The temperature was measured with an infrared thermometer, and the extinguishing time was measured with a stopwatch. The extinguishing patch was fixed to the surface of a stamped steel plate, with the patch facing down at 1.5cm from the outer flame. The extinguishing time and the temperature difference before and after extinguishing the fire were measured. The extinguishing time and temperature difference were used to characterize the fire extinguishing performance. The test results are shown in Table 1.

[0072] Table 1 Fire extinguishing performance test results

[0073]

[0074] Stability test: The fire extinguishing medium samples prepared in each example and comparative example were placed in an indoor environment (temperature 22℃, relative humidity 40%) and stored for 15 days. The weight retention rate of the fire extinguishing medium samples was calculated. The calculation formula is: weight retention rate (%) = (weight after a period of time / original weight) × 100%.

[0075] Heat resistance test: The fire extinguishing medium samples prepared in each example and comparative example were dried in a 60°C oven for 24 hours, and the weight retention rate of the fire extinguishing medium samples was calculated.

[0076] The test results are shown in Table 2.

[0077] Table 2 Results of stability and heat resistance tests

[0078]

[0079] The results above show that the extinguishing media prepared in Examples 1 to 4 have an extinguishing time of <4s, a weight retention rate of over 98.2% during stability testing, and a weight retention rate of over 96.8% during heat resistance testing.

[0080] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0081] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing a fire extinguishing medium, characterized in that Includes the following steps: S100: The first fire extinguishing layer blank is obtained by pressing raw materials including molecular sieve-loaded perfluorohexanone, nano silica and polyethylene glycol. S200 uses raw materials including perfluorohexanone, flame-retardant polymer-grafted ammonium dihydrogen phosphate, montmorillonite, and fluoroelastomer to mix and obtain a second fire extinguishing layer mixture, which is then covered on the surface of the first fire extinguishing layer blank and composited to obtain a composite blank. S300 uses raw materials including modified zinc borate, sodium silicate, basalt fiber, and nano magnesium hydroxide to mix and obtain a heat insulation and protective layer slurry, which is then applied to the surface of the composite blank to obtain the fire extinguishing medium.

2. A method of preparing a fire extinguishing medium according to claim 1, characterized in that, Step S100 specifically includes: adding nano-silica, polyethylene glycol and silane coupling agent to a sealed container, raising the temperature to 30-40℃ and stirring for 10-20 minutes, then adding molecular sieve-loaded perfluorohexanone, introducing inert gas and continuing to stir at a speed of 100-150 r / min for 5-15 minutes to form a stable slurry, pouring the slurry into a mold, pressing it into shape, and obtaining the first fire extinguishing layer blank.

3. A method of preparing a fire extinguishing medium according to claim 1, characterized in that, The preparation method of molecular sieve-supported perfluorohexanone is as follows: the molecular sieve is calcined at 120-130℃ for 1-3 hours, then placed in a pressure-resistant container, and vacuumed under stirring. Perfluorohexanone is then added to the container under sealed conditions and stirred for 2-4 hours. After adsorption is completed, the molecular sieve-supported perfluorohexanone is obtained.

4. The method of claim 1, wherein the fire extinguishing medium is prepared by the steps of: Step S200 specifically includes: adding flame-retardant polymer-grafted ammonium dihydrogen phosphate, montmorillonite, and fluoroelastomer into a high-speed mixer, controlling the temperature at 25-30℃, mixing at 1500-2000 r / min for 20-30 min, then adding a crosslinking agent, maintaining the speed at 1500-2000 r / min and continuing to stir for 5-10 min, controlling the temperature at 20-25℃, adding perfluorohexanone, mixing at 800-1000 r / min for 30-50 min to obtain the second fire extinguishing layer mixture, covering the surface of the first fire extinguishing layer blank in a sealed mold, evacuating and then introducing inert gas, pressurizing and compounding at 2-2.5 MPa and 40-45℃, holding the pressure for 30-50 min, after the pressure holding is completed, lowering the temperature to room temperature, immediately wrapping tightly with aluminum foil, and letting stand at room temperature for 20-25 h to obtain the composite blank.

5. The method of claim 1, wherein the fire extinguishing medium is prepared by the steps of: The preparation method of flame-retardant polymer-grafted ammonium dihydrogen phosphate is as follows: ammonium dihydrogen phosphate and polyphosphate monomer are placed in a reaction vessel in a certain proportion, and solvent and initiator are added. The temperature is raised to 75-90℃, and the mixture is stirred at 200-300 r / min for 2-4 h. After the reaction is completed, the mixture is distilled under reduced pressure, and after washing and drying, flame-retardant polymer-grafted ammonium dihydrogen phosphate is obtained.

6. The method for preparing a fire extinguishing medium according to claim 1, characterized in that, Step S300 specifically includes: adding modified zinc borate, sodium silicate, basalt fiber, and nano magnesium hydroxide into a reactor in a certain proportion, adding solvent to it, stirring evenly to obtain a heat insulation and protective layer slurry, coating it on the surface of the composite blank, and drying it to obtain the fire extinguishing medium.

7. The method of claim 1, wherein the fire extinguishing medium is prepared by the steps of: The modified zinc borate is prepared by immersing zinc borate in an ethanol solution containing a silane coupling agent, and then drying it to obtain the modified zinc borate.

8. A fire extinguishing medium, characterized in that It is prepared by the method for preparing the fire extinguishing medium as described in any one of claims 1-7.

9. Use of a fire extinguishing medium in an electrical energy metering device, characterized in that The fire extinguishing medium prepared by the method of any one of claims 1-7 is installed in the key heat-generating part of the power metering device.

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