Perfluorohexanone nano microcapsule multi-time fire extinguishing tablet and preparation method thereof

Abstract

The invention relates to a perfluorohexanone nano microcapsule multi-time fire extinguishing tablet and a preparation method thereof, and belongs to the technical field of fire extinguishing material processing. The invention discloses a preparation method of a perfluorohexanone nano microcapsule multi-time fire extinguishing tablet. The preparation method comprises the following steps: (1) preparing an oil phase for later use; (2) preparing a water phase for later use; (3) stirring the oil phase and the water phase at a high speed to obtain an emulsion; and (4) adding an initiating monomer into the emulsion, heating, preserving heat, filtering, washing and drying to obtain the perfluorohexanone nano microcapsule. And (5) mixing with a base material, introducing into a mold, curing, drying, and spraying a high-molecular polymer on the surface to obtain the perfluorohexanone nano microcapsule multi-time fire extinguishing tablet. According to the perfluorohexanone nano microcapsule, lignin-based polyurethane is used as an outer shell, a polyurea / polyurethane composite structure is used as an inner shell to form a double-shell structure, and therefore the perfluorohexanone nano microcapsule prepared through the method has a compact and stable capsule wall structure, the embedding rate is high, and the fire extinguishing property is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of fire extinguishing material processing and relates to a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet and a preparation method thereof. Background Art

[0002] As my country's electricity consumption and electrical equipment are bound to continue to increase, and electricity consumption methods are becoming more diverse, the situation of electrical fires is becoming increasingly severe, and the society must pay enough attention to and prevent them. In response to fires caused by electrical distribution cabinets, some fire extinguishing products have also been produced on the market. The more mature product is the fire detection tube type automatic fire detection and fire extinguishing system. Although the fire detection tube can sensitively detect the specific location of the fire, in practice, the fire extinguishing agent cannot be accurately sprayed to the fire point through the breach of the fire detection tube, and the application efficiency is low. The second product uses various electronic detectors, such as smoke sensors, ultraviolet flame detectors, thermal sensors, etc. for fire detection, and then starts the fire extinguishing system to extinguish the fire. This type of product is prone to false alarms during application, and on the other hand, the cost is high, and the fire extinguishing effect in actual scenarios is not very ideal.

[0003] Perfluorohexanone is a new type of fluorine-containing fire extinguishing agent that is liquid at room temperature. It has high fire extinguishing efficiency and excellent environmental performance. It is considered to be the most ideal substitute for halon fire extinguishing agent. In view of the characteristics of perfluorohexanone such as non-conductive, volatile, and leaving no trace residue after extinguishing the fire, it is very suitable for safety protection of electrical fires. However, due to the fluidity and rapid volatility of perfluorohexanone, it is difficult to form a high coverage of the fire source. Microencapsulation of perfluorohexanone can effectively form a flame retardant material, but microcapsules are prone to low embedding rate and poor mechanical properties. Therefore, the perfluorohexanone nano-microcapsules provided by the present invention have the characteristics of effectively solidifying and stabilizing perfluorohexanone, stable preparation process, and large perfluorohexanone loading capacity. When used, it can form a highly dispersed fire extinguishing effect by throwing it into the fire source. Summary of the invention

[0004] The present invention relates to a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet and a preparation method thereof, and belongs to the technical field of fire extinguishing material processing. The preparation method of the perfluorohexanone nano-microcapsule multiple fire extinguishing tablet disclosed in the present invention comprises the following steps: (1) preparing an oil phase for standby use; (2) preparing an aqueous phase for standby use; (3) stirring the oil phase and the aqueous phase at high speed to obtain an emulsion; (4) adding an initiating monomer to the emulsion, heating and preserving, filtering, washing, and drying to obtain the perfluorohexanone nano-microcapsule; (5) then mixing with a matrix material, introducing into a mold for curing, drying, and spraying a high molecular polymer on the surface to obtain the perfluorohexanone nano-microcapsule multiple fire extinguishing tablet. The perfluorohexanone nano-microcapsule has a double shell structure formed by a lignin-based polyurethane as an outer shell and a polyurea / polyurethane composite structure as an inner shell. Therefore, the perfluorohexanone nano-microcapsule prepared by the present invention has a dense and stable capsule wall structure, a high embedding rate, and excellent fire extinguishing performance.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet, the method comprising the following steps: (1) perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether are mixed to form an oil phase for standby use; (2) dissolving the emulsifier in distilled water to prepare an aqueous phase for later use; (3) mixing the oil phase and the water phase and stirring at high speed to obtain an emulsion; (4) adding an initiating monomer to the emulsion, heating and maintaining the temperature, filtering, washing the solid with distilled water, and drying to obtain perfluorohexanone nano-microcapsules; (5) The perfluorohexanone nano-microcapsules are mixed with a matrix material, introduced into a mold for curing, dried, and sprayed with a high molecular polymer on the surface to obtain a perfluorohexanone nano-microcapsule multiple fire extinguishing sheet.

[0006] Furthermore, in the step (1), the mass ratio of perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether is 4-6:0.65-0.8:20-30, wherein the pretreated isophorone diisocyanate is prepared by compounding isophorone diisocyanate and modified aluminum hydroxide, and the mass ratio of isophorone diisocyanate to modified aluminum hydroxide is 10-12:0.13-0.15.

[0007] Furthermore, in step (2), the ratio of the emulsifier to distilled water is 10-15 g:30 mL, wherein the emulsifier is composed of linear sodium alkylbenzene sulfonate and a fluorocarbon surfactant in a mass ratio of 1:1.

[0008] Furthermore, in the step (3), the volume ratio of the oil phase to the water phase is 1-2:1.5, and the time and rotation speed of the high-speed stirring are 10-20 min and 2000 rpm, respectively.

[0009] Furthermore, in the step (4), the ratio of the emulsion to the monomer is 200-250 mL:5-6 g, wherein the monomer is composed of diethylenetriamine, β-cyclodextrin and lignin in a mass ratio of 1:1:2, the heating and insulation time and temperature are 2-3 h and 40-50 ° C, respectively, and the drying time and temperature are 10-12 h and 5 ° C, respectively.

[0010] Furthermore, in the step (5), the mass ratio of perfluorohexanone nano-microcapsules to the matrix material is 5-8:2-3, wherein the matrix material refers to a polymer adhesive, the polymer is an acrylic resin, and the spraying thickness is 100-120 μm.

[0011] Furthermore, the preparation method of the modified aluminum hydroxide comprises the following steps: A1: Put aluminum hydroxide powder into anhydrous ethanol, stir and then perform ultrasonic treatment; A2: Then add the modifier, continue stirring, and then filter. Wash the solid with distilled water and dry it to obtain modified aluminum hydroxide.

[0012] Furthermore, in step A1, the ratio of aluminum hydroxide powder to anhydrous ethanol is 1 g:15 mL, and the time and temperature of the ultrasonic treatment are 8-10 min and 40-50° C., respectively.

[0013] Furthermore, in step A2, the mass ratio of aluminum hydroxide powder to modifier is 1:0.05-0.2, wherein the modifier is composed of sodium stearate and sodium oleate in a mass ratio of 1:1, the continuous stirring time is 2-3h, and the drying time and temperature are 30-40min and 80°C, respectively.

[0014] Beneficial effects of the present invention: Using two surfactants, linear alkylbenzene sodium sulfonate and fluorocarbon surfactant, the emulsification ability is improved, so that the perfluorohexanone and the polymerization monomer can be evenly dispersed in the emulsion, the perfluorohexanone nano-microcapsules of uniform size are prepared, and the embedding rate of the microcapsules is improved; The present invention uses sodium stearate and sodium oleate to modify aluminum hydroxide, reduce its polarity, enhance its compatibility with isophorone diisocyanate, and introduce modified aluminum hydroxide into the capsule wall. When the microcapsule is broken, the aluminum hydroxide in the capsule wall absorbs heat and decomposes, thereby playing an auxiliary flame retardant role. The perfluorohexanone nano-microcapsules have a double-shell structure with lignin-based polyurethane as the outer shell and a polyurea / polyurethane composite structure as the inner shell, which ensures the embedding rate of perfluorohexanone in the microcapsules. At the same time, the double-shell structure ensures the mechanical stability of the microcapsules. DETAILED DESCRIPTION

[0015] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with embodiments.

[0016] The linear alkylbenzene sulfonate in all the embodiments and comparative examples of the present invention was purchased from: Runfeng / 25155-30-0, the fluorocarbon surfactant was purchased from: CAPSTONE FS-3100 / TF Taifu, the lignin was purchased from: Runfeng / 8068-03-9, the polymer adhesive was purchased from: Beijing Dongfang / 24937-78-8, the acrylic resin was purchased from Sany Resin, and the aluminum hydroxide powder was purchased from: Qiaowei / 006.

[0017] A method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet, the method comprising the following steps: (1) perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether are mixed to form an oil phase for standby use; (2) dissolving the emulsifier in distilled water to prepare an aqueous phase for later use; (3) mixing the oil phase and the water phase and stirring at high speed to obtain an emulsion; (4) adding an initiating monomer to the emulsion, heating and maintaining the temperature, filtering, washing the solid with distilled water, and drying to obtain perfluorohexanone nano-microcapsules; (5) The perfluorohexanone nano-microcapsules are mixed with a matrix material, introduced into a mold for curing, dried, and sprayed with a high molecular polymer on the surface to obtain a perfluorohexanone nano-microcapsule multiple fire extinguishing sheet.

[0018] In the step (1), the mass ratio of perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether is 4:0.65:20, wherein the pretreated isophorone diisocyanate is prepared by compounding isophorone diisocyanate and modified aluminum hydroxide, and the mass ratio of isophorone diisocyanate to modified aluminum hydroxide is 10:0.13.

[0019] In the step (2), the ratio of the emulsifier to distilled water is 10 g:30 mL, wherein the emulsifier is composed of linear sodium alkylbenzene sulfonate and a fluorocarbon surfactant in a mass ratio of 1:1.

[0020] In the step (3), the volume ratio of the oil phase to the water phase is 1:1.5, and the time and speed of the high-speed stirring are 10 min and 2000 rpm, respectively.

[0021] In the step (4), the ratio of the emulsion to the monomer is 200 mL:5 g, wherein the monomer is composed of diethylenetriamine, β-cyclodextrin and lignin in a mass ratio of 1:1:2, the heating and insulation time and temperature are 2 h and 40° C. respectively, and the drying time and temperature are 10 h and 5° C. respectively.

[0022] In the step (5), the mass ratio of perfluorohexanone nano-microcapsules to the matrix material is 5:2, wherein the matrix material refers to a polymer adhesive, the polymer is an acrylic resin, and the spraying thickness is 100 μm.

[0023] The preparation method of the modified aluminum hydroxide comprises the following steps: A1: Put aluminum hydroxide powder into anhydrous ethanol, stir and then perform ultrasonic treatment; A2: Then add the modifier, continue stirring, and then filter. Wash the solid with distilled water and dry it to obtain modified aluminum hydroxide.

[0024] In the step A1, the ratio of aluminum hydroxide powder to anhydrous ethanol is 1 g:15 mL, and the time and temperature of the ultrasonic treatment are 8 min and 40° C., respectively.

[0025] In step A2, the mass ratio of aluminum hydroxide powder to modifier is 1:0.05, wherein the modifier is composed of sodium stearate and sodium oleate in a mass ratio of 1:1, the continuous stirring time is 2 hours, and the drying time and temperature are 30 minutes and 80°C, respectively.

[0026] A method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet, the method comprising the following steps: (1) perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether are mixed to form an oil phase for standby use; (2) dissolving the emulsifier in distilled water to prepare an aqueous phase for later use; (3) mixing the oil phase and the water phase and stirring at high speed to obtain an emulsion; (4) adding an initiating monomer to the emulsion, heating and maintaining the temperature, filtering, washing the solid with distilled water, and drying to obtain perfluorohexanone nano-microcapsules; (5) The perfluorohexanone nano-microcapsules are mixed with a matrix material, introduced into a mold for curing, dried, and sprayed with a high molecular polymer on the surface to obtain a perfluorohexanone nano-microcapsule multiple fire extinguishing sheet.

[0027] In the step (1), the mass ratio of perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether is 5:0.7:25, wherein the pretreated isophorone diisocyanate is prepared by compounding isophorone diisocyanate and modified aluminum hydroxide, and the mass ratio of isophorone diisocyanate to modified aluminum hydroxide is 11:0.14.

[0028] In the step (2), the ratio of the emulsifier to distilled water is 13 g:30 mL, wherein the emulsifier is composed of linear sodium alkylbenzene sulfonate and a fluorocarbon surfactant in a mass ratio of 1:1.

[0029] In the step (3), the volume ratio of the oil phase to the water phase is 1:1, and the time and speed of the high-speed stirring are 15 min and 2000 rpm, respectively.

[0030] In the step (4), the ratio of the emulsion to the monomer is 225 mL:5-6 g, wherein the monomer is composed of diethylenetriamine, β-cyclodextrin and lignin in a mass ratio of 1:1:2, the heating and insulation time and temperature are 2.5 h and 45 ° C, respectively, and the drying time and temperature are 11 h and 5 ° C, respectively.

[0031] In the step (5), the mass ratio of perfluorohexanone nano-microcapsules to the matrix material is 6:2.5, wherein the matrix material refers to a polymer adhesive, the polymer is an acrylic resin, and the spraying thickness is 110 μm.

[0032] The preparation method of the modified aluminum hydroxide comprises the following steps: A1: Put aluminum hydroxide powder into anhydrous ethanol, stir and then perform ultrasonic treatment; A2: Then add the modifier, continue stirring, and then filter. Wash the solid with distilled water and dry it to obtain modified aluminum hydroxide.

[0033] In the step A1, the ratio of aluminum hydroxide powder to anhydrous ethanol is 1 g:15 mL, and the time and temperature of the ultrasonic treatment are 9 min and 45° C., respectively.

[0034] In the step A2, the mass ratio of aluminum hydroxide powder to modifier is 1:0.1, wherein the modifier is composed of sodium stearate and sodium oleate in a mass ratio of 1:1, the continuous stirring time is 2.5 hours, and the drying time and temperature are 35 minutes and 80°C, respectively.

[0035] A method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet, the method comprising the following steps: (1) perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether are mixed to form an oil phase for standby use; (2) dissolving the emulsifier in distilled water to prepare an aqueous phase for later use; (3) mixing the oil phase and the water phase and stirring at high speed to obtain an emulsion; (4) adding an initiating monomer to the emulsion, heating and maintaining the temperature, filtering, washing the solid with distilled water, and drying to obtain perfluorohexanone nano-microcapsules; (5) The perfluorohexanone nano-microcapsules are mixed with a matrix material, introduced into a mold for curing, dried, and sprayed with a high molecular polymer on the surface to obtain a perfluorohexanone nano-microcapsule multiple fire extinguishing sheet.

[0036] In the step (1), the mass ratio of perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether is 6:0.8:30, wherein the pretreated isophorone diisocyanate is prepared by compounding isophorone diisocyanate and modified aluminum hydroxide, and the mass ratio of isophorone diisocyanate to modified aluminum hydroxide is 12:0.15.

[0037] In the step (2), the ratio of the emulsifier to distilled water is 15 g:30 mL, wherein the emulsifier is composed of linear sodium alkylbenzene sulfonate and a fluorocarbon surfactant in a mass ratio of 1:1.

[0038] In the step (3), the volume ratio of the oil phase to the water phase is 2:1.5, and the time and speed of the high-speed stirring are 20 min and 2000 rpm, respectively.

[0039] In the step (4), the ratio of the emulsion to the monomer is 250 mL:6 g, wherein the monomer is composed of diethylenetriamine, β-cyclodextrin and lignin in a mass ratio of 1:1:2, the heating and insulation time and temperature are 3 h and 50° C. respectively, and the drying time and temperature are 12 h and 5° C. respectively.

[0040] In the step (5), the mass ratio of perfluorohexanone nano-microcapsules to the matrix material is 8:3, wherein the matrix material refers to a polymer adhesive, the polymer is an acrylic resin, and the spraying thickness is 120 μm.

[0041] The preparation method of the modified aluminum hydroxide comprises the following steps: A1: Put aluminum hydroxide powder into anhydrous ethanol, stir and then perform ultrasonic treatment; A2: Then add the modifier, continue stirring, and then filter. Wash the solid with distilled water and dry it to obtain modified aluminum hydroxide.

[0042] In the step A1, the ratio of aluminum hydroxide powder to anhydrous ethanol is 1 g:15 mL, and the time and temperature of the ultrasonic treatment are 10 min and 50° C., respectively.

[0043] In the step A2, the mass ratio of aluminum hydroxide powder to modifier is 1:0.2, wherein the modifier is composed of sodium stearate and sodium oleate in a mass ratio of 1:1, the continuous stirring time is 3 hours, and the drying time and temperature are 40 minutes and 80°C, respectively.

[0044] Comparative Example 1 On the basis of Example 2, the linear alkylbenzene sulfonate sodium in the emulsifier was removed, and other conditions were consistent with Example 2.

[0045] Comparative Example 2 On the basis of Example 2, the fluorocarbon surfactant in the emulsifier was removed, and other conditions were consistent with Example 2.

[0046] Comparative Example 3 On the basis of Example 2, the pretreated isophorone diisocyanate was prepared from modified aluminum hydroxide and isophorone diisocyanate, and the modified aluminum hydroxide was replaced with an equal mass of aluminum hydroxide powder, and the other conditions were consistent with Example 2.

[0047] Comparative Example 4 On the basis of Example 2, the pretreated isophorone diisocyanate was removed and replaced with isophorone diisocyanate of equal mass, and other conditions were consistent with Example 2.

[0048] Comparative Example 5 On the basis of Example 2, β-cyclodextrin in the monomer was removed, and other conditions were consistent with Example 2.

[0049] Comparative Example 6 On the basis of Example 2, lignin in the monomer was removed, and other conditions were consistent with Example 2.

[0050] 1. Performance Testing Particle size uniformity measurement: The perfluorohexanone nano-microcapsules prepared in Example 2 and Comparative Example 1-2 were used as samples, and the particle size was measured using a laser particle size Zeta potential meter. Specifically, the sample was diluted 100 times with distilled water, and then injected into a standard sample cell of 1 cm×1 cm×4.8 cm, and finally placed in a laser particle size Zeta potential meter, scanned 2 to 3 times, and the particle size uniformity was recorded and analyzed; Determination of embedding rate: The perfluorohexanone nano-microcapsules prepared in Example 2, Comparative Examples 1-2 and Comparative Example 5 were used as samples. The total mass of the samples was first weighed, and then they were repeatedly ground, and an equal mass of chloroform was added to dissolve the core material in the microcapsules. Then, the samples were placed in an oven at 120°C and dried to constant weight. The difference between the two was the mass of the core material of the microcapsules. The specific formula is: ; Stability test: The perfluorohexanone nano-microcapsules prepared in Example 2 and Comparative Examples 5-6 were used as samples. The microcapsules were placed in a freeze dryer for 12 hours to fully dry and remove surface moisture. They were weighed immediately after being taken out and then placed in an electric constant temperature drying oven to dry at 100° C. for 12 hours. The mass loss rate was obtained by calculating the mass change of the sample. The weight loss formula of the sample was specifically calculated as follows: ; W L is the mass loss rate, m1 is the original mass of the microcapsules, and m2 is the mass of the microcapsules after drying; Fire extinguishing performance test: The perfluorohexanone nano-microcapsule multiple fire extinguishing tablets prepared in Example 2 and Comparative Examples 3-4 were used as samples, and an 800°C flame was used as the fire source. The temperature was measured with an infrared thermometer, and the fire extinguishing time was measured with a stopwatch. The sample was fixed on the surface of the stamped steel plate, and the sample was placed downward at 1.5 cm from the outer flame of the flame. The fire extinguishing time of 6 locations of the sample was measured, and the average value was taken to indicate the fire extinguishing performance.

[0051] The above test results are shown in Table 1.

[0052] Table 1 Test results Sample Particle size uniformity Embedding rate% Mass loss rate% Fire extinguishing time / s Example 2 Good uniformity 96.7 4.2 1.54 Comparative Example 1 Different sizes 87.3 - - Comparative Example 2 Different sizes 86.1 - - Comparative Example 3 - - - 1.84 Comparative Example 4 - - - 2.07 Comparative Example 5 - 90.4 8.9 - Comparative Example 6 - - 11.3 - It can be concluded from Table 1 that Example 2 has good particle size uniformity, the largest embedding rate, the smallest mass loss rate, and the shortest fire extinguishing time. In Comparative Examples 1-2, if any component of the emulsifier is removed, the emulsification effect of the emulsion is reduced, the surface tension of perfluorohexanone is affected, and the uneven dispersion leads to different sizes of microcapsules, and the embedding rate is reduced accordingly. In Comparative Example 5, no β-cyclodextrin is added, which also reduces the embedding rate of the microcapsules. The β-cyclodextrin not added in Comparative Example 5 has a reinforcing effect, and in Comparative Example 6, no lignin is added to form a shell structure of lignin-based polyurethane. Therefore, the mechanical properties of the microcapsule wall obtained in Comparative Examples 5-6 are reduced, and the mass loss rate is large. The aluminum hydroxide added in Comparative Example 3 is not modified, its polarity is large, and its compatibility with isophorone diisocyanate is poor, and no inorganic flame retardant is added in Comparative Example 4, so the fire extinguishing time of Comparative Examples 3-4 is greater than that of Example 2. Since modified aluminum hydroxide is used in Example 2 to reduce its polarity and enhance its compatibility with isophorone diisocyanate, when the microcapsules are broken, the aluminum hydroxide in the capsule wall absorbs heat and decomposes after being heated, which plays an auxiliary flame retardant role.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet, characterized in that: The preparation method of the fire extinguishing tablet comprises the following steps: (1) perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether are mixed to form an oil phase for standby use; (2) dissolving the emulsifier in distilled water to prepare an aqueous phase for later use; (3) mixing the oil phase and the water phase and stirring at high speed to obtain an emulsion; (4) adding an initiating monomer to the emulsion, heating and maintaining the temperature, filtering, washing the solid with distilled water, and drying to obtain perfluorohexanone nano-microcapsules; (5) The perfluorohexanone nano-microcapsules are mixed with a matrix material, introduced into a mold for curing, dried, and sprayed with a high molecular polymer on the surface to obtain a perfluorohexanone nano-microcapsule multiple fire extinguishing sheet.

2. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 1, characterized in that: In the step (1), the mass ratio of perfluorohexanone, pretreated isophorone diisocyanate and methyl nonafluorobutyl ether is 4-6:0.65-0.8:20-30, wherein the pretreated isophorone diisocyanate is prepared by compounding isophorone diisocyanate and modified aluminum hydroxide, and the mass ratio of isophorone diisocyanate to modified aluminum hydroxide is 10-12:0.13-0.

15.

3. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 1, characterized in that: In the step (2), the ratio of the emulsifier to distilled water is 10-15 g:30 mL, wherein the emulsifier is composed of linear sodium alkylbenzene sulfonate and a fluorocarbon surfactant in a mass ratio of 1:

1.

4. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 1, characterized in that: In the step (3), the volume ratio of the oil phase to the water phase is 1-2: 1.5, the time and speed of high-speed stirring are 10-20 min and 2000 rpm respectively.

5. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 1, characterized in that: In the step (4), the ratio of the emulsion to the monomer is 200-250 mL:5-6 g, wherein the monomer is composed of diethylenetriamine, β-cyclodextrin and lignin in a mass ratio of 1:1:2, the heating and insulation time and temperature are 2-3 h and 40-50 ° C, respectively, and the drying time and temperature are 10-12 h and 5 ° C, respectively.

6. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 1, characterized in that: In the step (5), the mass ratio of perfluorohexanone nano-microcapsules to the matrix material is 5-8:2-3, wherein the matrix material refers to a polymer adhesive, the polymer is an acrylic resin, and the spraying thickness is 100-120 μm.

7. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 2, characterized in that: The preparation method of the modified aluminum hydroxide comprises the following steps: A1: Put aluminum hydroxide powder into anhydrous ethanol, stir and then perform ultrasonic treatment; A2: Then add the modifier, continue stirring, and then filter. Wash the solid with distilled water and dry it to obtain modified aluminum hydroxide.

8. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 7, characterized in that: In the step A1, the ratio of aluminum hydroxide powder to anhydrous ethanol is 1 g:15 mL, and the time and temperature of the ultrasonic treatment are 8-10 min and 40-50° C., respectively.

9. The method for preparing a perfluorohexanone nano-microcapsule multiple fire extinguishing tablet according to claim 7, characterized in that: In step A2, the mass ratio of aluminum hydroxide powder to modifier is 1:0.05-0.2, wherein the modifier is composed of sodium stearate and sodium oleate in a mass ratio of 1:1, the continuous stirring time is 2-3h, and the drying time and temperature are 30-40min and 80°C, respectively.