Perfluorohexanone fire extinguishing agent as well as preparation method and application thereof

Abstract

The invention discloses a perfluorohexanone fire extinguishing agent and a preparation method and application thereof.The perfluorohexanone fire extinguishing agent is prepared from, by mass, 60-70 parts of perfluorohexanone microcapsules, 10-20 parts of aluminum hydroxide, 6-10 parts of graphite, 5-10 parts of titanium dioxide, 4-8 parts of ultraviolet absorbent, 2-6 parts of ammonium polyphosphate, 3-6 parts of calcium oxide, 1-3 parts of fumed silica, 1-3 parts of nano-silica and 1-3 parts of trimethyl phosphate. According to the formula and process of the fire extinguishing agent, through triple technical innovation of shell layer modification, nano compounding and supercritical deposition, the breakthrough of efficient explosion suppression, long-acting anti-after-combustion, low toxicity and environment friendliness of the fire extinguishing agent is achieved, and the industrial popularization potential is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of perfluorohexanone fire extinguishing agents, and particularly relates to a perfluorohexanone fire extinguishing agent and a preparation method and application thereof. Background Art

[0002] Halon fire extinguishing agents have been banned worldwide due to their ozone depletion effects. However, perfluorohexanone-based fire extinguishing agents are attracting significant attention as highly effective, clean, and environmentally friendly fire extinguishing agents. Perfluorohexanone-based fire extinguishing agents, with their excellent arc-extinguishing and insulating properties, are primarily used as arc-extinguishing protective gases in power systems subject to frequent operation and high-speed interruption. They can also be super-pressurized with nitrogen and stored in high-pressure cylinders as part of fire extinguishing systems. Typical applications include fires in computer rooms, data centers, aviation, ships, vehicles, libraries, and oil and gas production. However, due to its low boiling point, perfluorohexanone quickly vaporizes at high temperatures during fire extinguishing, making it difficult to suppress chemical reactions within batteries in new energy vehicles that can lead to re-ignition.

[0003] Perfluorohexanone fire extinguishing agent is characterized by its clean, rapid, and low-toxic properties in extinguishing fires in power equipment. However, when perfluorohexanone reacts with water, it produces mild hydrofluoric acid (HF), which is corrosive to power equipment and can also cause damage to the human body. Therefore, optimizing and improving perfluorohexanone fire extinguishing agent is of great significance for protecting power equipment and personal safety.

[0004] In the prior art, the fire extinguishing agent can be optimized and improved by adding the following substances to perfluorohexanone, specifically including:

[0005] 1. Add coolant. Use 1,1,2,2,3,3,4-heptafluorocyclopentane (HFC) as coolant and add it to perfluorohexanone fire extinguishing agent to increase the fire extinguishing speed of the fire extinguishing agent.

[0006] During the vaporization process, HFC absorbs a large amount of heat, acting as a heat-absorbing cooling agent, rapidly reducing the temperature of the fire source and extinguishing the fire. Furthermore, after the HFC is fully sprayed, it affects the specific heat of the sprayed material and continues to absorb heat, further reducing the temperature of the fire source after it is extinguished, preventing it from reigniting.

[0007] A certain amount of HFC is added to perfluorohexanone fire extinguishing agent to form a mixed fire extinguishing agent. Pure perfluorohexanone fire extinguishing agent extinguishes fires in approximately 25 seconds, with the fastest extinguishing time of approximately 12 seconds when 15% HFC is added. This is because perfluorohexanone is the primary fire extinguishing agent, while HFC acts as a coolant, reducing the combustion-supporting effect of perfluorohexanone during low-concentration combustion. This also demonstrates that perfluorohexanone and HFC have a good synergistic fire-extinguishing effect.

[0008] 2. Add adsorbent. NH2-MIL-125 (Ti) is an adsorbent with a metal organic framework. Its molecular structure contains a large number of -OH and -NH2 polar functional groups, which can effectively absorb water (H2O) and hydrofluoric acid (HF), thereby reducing the corrosiveness of perfluorohexanone fire extinguishing agent to power equipment.

[0009] At present, perfluorohexanone fire extinguishing agent has the following defects: the storage and release reliability of the composite fire extinguishing agent in high temperature and high humidity environments is insufficient, the dynamic interaction mechanism between coolant, adsorbent and fire extinguishing agent has not been fully analyzed, and the high cost of MOFs materials and nanoadditives limits large-scale application. With the widespread application of perfluorohexanone fire extinguishing agent in various fields, how to solve the above problems is the key to promoting the development of perfluorohexanone fire extinguishing agent. Summary of the Invention

[0010] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0011] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0012] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a perfluorohexanone fire extinguishing agent.

[0013] In order to solve the above technical problems, the present invention provides the following technical solution: based on the mass fraction of the fire extinguishing agent raw materials, it includes:

[0014] 60-70 parts of perfluorohexanone microcapsules, 10-20 parts of aluminum hydroxide, 6-10 parts of graphite, 5-10 parts of titanium dioxide, 4-8 parts of ultraviolet absorber UV-327, 2-6 parts of ammonium polyphosphate, 3-6 parts of calcium oxide, 1-3 parts of fumed silica, 1-3 parts of nano-silicon dioxide, and 1-3 parts of trimethyl phosphate.

[0015] As a preferred embodiment of the perfluorohexanone fire extinguishing agent of the present invention, the perfluorohexanone microcapsules are embedded in the core part of the microcapsules with perfluorohexanone as the core material, and the shell layer is formed by polymerization reaction of isophorone diisocyanate, trimethylolpropane and 1,4-butanediol.

[0016] As a preferred embodiment of the perfluorohexanone fire extinguishing agent of the present invention, the mass ratio of the perfluorohexanone microcapsules to aluminum hydroxide is 3 to 5:1, the mass ratio of the ammonium polyphosphate to graphite is 1:1 to 5, and the mass ratio of the nano-titanium dioxide to the ultraviolet absorber UV-327 is 5:3 to 5.

[0017] Another object of the present invention is to provide a method for preparing perfluorohexanone fire extinguishing agent.

[0018] As a preferred embodiment of the method for preparing the perfluorohexanone fire extinguishing agent of the present invention, the pretreated perfluorohexanone microcapsules are mixed with a nano-titanium dioxide suspension, added to a reactor, heated and sheared, and dried to remove ethanol after the reaction to obtain nano-titanium dioxide-microcapsules;

[0019] Nano-titanium dioxide-microcapsules, aluminum hydroxide, expanded graphite, ammonium polyphosphate, calcium oxide, and fumed silica are mixed and stirred under vacuum conditions, and then crushed and sieved to obtain a mixture I;

[0020] Mixture I was placed in a fluidized bed, and dry nitrogen was introduced. UV-327 and nano-silica were pre-dispersed in supercritical CO2 and uniformly loaded on the particle surface by supercritical fluid deposition technology. Fluidized adsorption was performed to obtain the fire extinguishing agent based on perfluoroacetone material microcapsules in this embodiment.

[0021] As a preferred embodiment of the preparation method of the perfluorohexanone fire extinguishing agent of the present invention, the pretreatment of the perfluorohexanone microcapsules is to immerse the perfluorohexanone microcapsules in an ethanol solution containing 0.3-0.8% ethylenediamine at 20-30° C. for 1.5-2.5 hours.

[0022] As a preferred solution of the method for preparing the perfluorohexanone fire extinguishing agent of the present invention, the mass concentration of the nano-titanium oxide suspension is 5-15%.

[0023] As a preferred embodiment of the method for preparing the perfluorohexanone fire extinguishing agent of the present invention, the reaction temperature of the heating shear reaction is 35-45° C., the reaction time is 15-25 min, and the rotation speed is 4500-5500 rpm.

[0024] As a preferred solution of the method for preparing the perfluorohexanone fire extinguishing agent of the present invention, the stirring speed of the mixing and stirring under vacuum conditions is 20 to 30 rpm, and the stirring time is 10 to 50 minutes.

[0025] As a preferred embodiment of the method for preparing the perfluorohexanone fire extinguishing agent of the present invention, the temperature of the fluidized adsorption is 25-35° C., and the time is 50-70 minutes.

[0026] Another object of the present invention is to provide a use of perfluorohexanone fire extinguishing agent in fighting fires in power equipment.

[0027] Beneficial effects of the present invention:

[0028] The present invention provides a perfluorohexanone fire extinguishing agent, which uses perfluorohexanone microcapsules as the active ingredient of the fire extinguishing agent. After the microcapsules are cross-linked with ethylenediamine, the thermal decomposition temperature of the shell is increased, thereby avoiding premature leakage of the core material caused by high temperature in the early stage of a fire, ensuring that the fire extinguishing agent releases perfluorohexanone in a concentrated manner during the fire expansion stage, and improving fire extinguishing efficiency.

[0029] The introduction of a trimethyl phosphate coating layer promotes directional rupture of the shell and shortens the response time of perfluorohexanone release; the expanded graphite expands when heated to form a porous carbon layer, isolating oxygen and reflecting radiant heat; the introduction of ammonium polyphosphate can catalyze the carbonization of combustibles and form a "solid-gas" synergy with the capture of gas-phase free radicals of perfluorohexanone; in addition, aluminum hydroxide can reduce the temperature of the combustion zone to the effective action range of perfluorohexanone by decomposing and absorbing heat.

[0030] Nano-TiO2 evenly attached to the surface of the microcapsule generates reactive oxygen species (ROS) in the afterglow of the fire, decomposing residual combustible gases and inhibiting smoldering and re-ignition. The ultraviolet absorber is loaded through supercritical deposition to absorb 280-400nm ultraviolet rays, delaying the light aging of the shell and maintaining long-term flame retardant properties.

[0031] Add gas phase SiO2 as a flow aid to reduce powder friction static (surface resistivity <10 8 Ω), preventing uneven distribution of the fire extinguishing agent caused by microcapsule agglomeration during the spraying process, and the reaction of CaO with HF generated by the thermal decomposition of perfluorohexanone, with a neutralization efficiency of >90%.

[0032] The above formula and process have achieved a breakthrough in the fire extinguishing agent's "high-efficiency explosion suppression, long-term prevention of re-ignition, low toxicity and environmental protection" through the triple technological innovations of shell modification-nanocomposite-supercritical deposition, and have the potential for industrial promotion. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0036] Unless otherwise specified, the raw materials used in the present invention are commonly available in the market.

[0037] The fire extinguishing effect of the fire extinguishing agent of the present invention is characterized by the fire extinguishing time. Specifically, with an 800°C flame as the fire source, the microcapsules are fixed on the surface of a steel plate at a distance of 10 cm from the fire source, and the fire extinguishing time is recorded. The re-ignition situation is also recorded.

[0038] The method for determining the amount of harmful gas generated by the fire extinguishing agent of the present invention is as follows: the fire extinguishing agent is placed in a quartz tube, air is introduced (flow rate 50 mL / min), and heated to 600°C (simulating the high temperature environment of a fire) for 30 minutes, and the HF concentration of the gas generated downstream is monitored.

[0039] The preparation method of perfluorohexanone microcapsules used in the specific embodiment of the present invention is as follows:

[0040] Isophorone diisocyanate and perfluorohexanone were mixed in a mass-to-volume ratio of 1:5, and a co-solvent, methyl nonafluorobutyl ether, was added thereto, and the mixture was stirred uniformly to obtain an oil phase;

[0041] Sorbitol monooleate, polyoxyethylene sorbitan monooleate and sodium lauryl sulfate are compounded in a mass ratio of 5:5:1 to obtain a composite emulsifier, and the composite emulsifier is dissolved in deionized water to obtain an emulsion with a concentration of 20%;

[0042] The emulsion and the oil phase were mixed in a volume ratio of 6:1 and emulsified at a rotation speed of 2000 rpm for 15 min to obtain emulsion I;

[0043] Trimethylolpropane, 1,4-butanediol, and dibutyltin dilaurate were added to emulsion I. The mass ratio of trimethylolpropane to isophorone diisocyanate was 3.5:5, the mass ratio of 1,4-butanediol to isophorone diisocyanate was 1:10, and the amount of dibutyltin dilaurate was 5% compared to the system. Emulsion II was stirred at 40°C for 3 hours at a speed of 300 rpm for polymerization reaction. The product was filtered and freeze-dried for 12 hours to obtain microencapsulated perfluorohexanone. The microcapsules used perfluorohexanone as the core material embedded in the core part of the microcapsule, and the shell was formed by polymerization reaction of isophorone diisocyanate, trimethylolpropane and 1,4-butanediol.

[0044] Example 1

[0045] This embodiment provides a method for preparing a perfluorohexanone fire extinguishing agent, specifically:

[0046] 1) Weigh the raw materials according to the following formula:

[0047] 60 parts of perfluorohexanone microcapsules, 15 parts of aluminum hydroxide, 10 parts of graphite, 10 parts of titanium dioxide, 8 parts of ultraviolet absorber UV-327, 4 parts of ammonium polyphosphate, 4 parts of calcium oxide, 2 parts of fumed silica, 2 parts of nano-silicon dioxide, and 2 parts of trimethyl phosphate;

[0048] At this time, the mass ratio of perfluorohexanone microcapsules to aluminum hydroxide is 4:1, the mass ratio of ammonium polyphosphate to graphite is 2:5, and the mass ratio of nano-titanium dioxide to ultraviolet absorber UV-327 is 5:4;

[0049] 2) Preparation of fire extinguishing agent:

[0050] The perfluorohexanone microcapsules were immersed in an ethanol solution containing 0.5% ethylenediamine at 25° C. for 2 hours to obtain pretreated perfluorohexanone microcapsules;

[0051] The pretreated perfluorohexanone microcapsules were mixed with a 10% nano-titanium dioxide suspension and added to a reactor. Under nitrogen protection, the mixture was sheared and dispersed at 40°C and 5000 rpm for 20 minutes to allow the nanoparticles to evenly adhere to the surface of the microcapsules. The ethanol was then removed by drying to obtain nano-titanium dioxide-microcapsules.

[0052] Nano-titanium dioxide microcapsules, aluminum hydroxide, expanded graphite, ammonium polyphosphate, calcium oxide, and fumed silica were mixed at 25 rpm under vacuum conditions (-0.08 MPa) for 45 minutes and then sieved (200 mesh) to remove undispersed agglomerates to obtain a mixture I;

[0053] Mixture I was placed in a fluidized bed and introduced with dry nitrogen. UV-327 and nano-silica were pre-dispersed in supercritical CO2 and uniformly loaded on the particle surface by supercritical fluid deposition technology. The temperature was adjusted to 30°C and the fluidized state was maintained for 1 hour to ensure stable adsorption. Thus, the fire extinguishing agent based on perfluoroacetone material microcapsules of this embodiment was obtained.

[0054] Example 2

[0055] The difference between this embodiment and embodiment 1 is that the formula is adjusted to:

[0056] 60 parts of perfluorohexanone microcapsules, 20 parts of aluminum hydroxide, 8 parts of graphite, 5 parts of titanium dioxide, 4 parts of ultraviolet absorber UV-327, 2 parts of ammonium polyphosphate, 2 parts of calcium oxide, 1 part of fumed silica, 1 part of nano-silicon dioxide, and 1 part of trimethyl phosphate; the remaining steps and processes are the same as in Example 1 to obtain the fire extinguishing agent of this embodiment.

[0057] Example 3

[0058] The difference between this embodiment and embodiment 1 is that the formula is adjusted to:

[0059] 70 parts of perfluorohexanone microcapsules, 20 parts of aluminum hydroxide, 10 parts of graphite, 10 parts of titanium dioxide, 8 parts of ultraviolet absorber UV-327, 6 parts of ammonium polyphosphate, 6 parts of calcium oxide, 3 parts of fumed silica, 3 parts of nano-silicon dioxide, and 3 parts of trimethyl phosphate; the remaining steps and processes are the same as in Example 1 to obtain the fire extinguishing agent of this embodiment.

[0060] Comparative Example 1

[0061] The difference between this comparative example and Example 1 is that the raw material perfluorohexanone microcapsules are replaced with perfluorohexanone, and the remaining steps and processes are referred to Example 1 to obtain the fire extinguishing agent of this comparative example.

[0062] Comparative Example 2

[0063] The difference between this comparative example and Example 1 is that titanium dioxide is omitted, and the remaining formulas and steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this comparative example.

[0064] Comparative Example 3

[0065] The difference between this comparative example and Example 1 is that the ultraviolet absorber UV-327 is omitted, and the remaining formulas and steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this comparative example.

[0066] Comparative Example 4

[0067] The difference between this comparative example and Example 1 is that ammonium polyphosphate is omitted, and the remaining formulas and steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this comparative example.

[0068] Comparative Example 5

[0069] The difference between this comparative example and Example 1 is that trimethyl phosphate is omitted, and the remaining formulas and steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this comparative example.

[0070] Comparative Example 6

[0071] The difference between this comparative example and Example 1 is that the fumed silica is omitted, and the remaining formulas and steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this comparative example.

[0072] Comparative Example 7

[0073] The difference between this comparative example and Example 1 is that nano-silicon dioxide is omitted, and the remaining formulas and steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this comparative example.

[0074] The properties of the fire extinguishing agents prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were measured, and the results are shown in Table 1.

[0075] Table 1

[0076] Fire extinguishing time / s HF concentration / ppm Is there smoke? Resurgence Example 1 3.8 0.34 none No recurrence within 2 hours Example 2 4.3 1.45 none No recurrence within 2 hours Example 3 4.1 1.41 none No recurrence within 2 hours Comparative Example 1 8.8 5.81 none No recurrence within 2 hours Comparative Example 2 6.5 4.53 none No recurrence within 2 hours Comparative Example 3 7.0 4.76 have The temperature increased significantly within 2 hours Comparative Example 4 6.7 3.58 none No recurrence within 2 hours Comparative Example 5 6.6 2.68 none No recurrence within 2 hours Comparative Example 6 6.0 1.65 none No recurrence within 2 hours Comparative Example 7 6.9 3.01 none No recurrence within 2 hours

[0077] As can be seen in Table 1, each component of the present invention significantly impacts the performance of the fire extinguishing agent. Through the synergistic action of these components, a trinity of fire extinguishing systems—shell strengthening, precise release, and toxicity suppression—is constructed. The omission of any component disrupts the system's equilibrium. For example, omitting titanium dioxide, due to its lack of photocatalytic degradation of HF, requires the fire extinguishing agent to neutralize corrosive substances for a longer time, resulting in increased HF concentration and prolonged fire extinguishing time. Omitting ammonium polyphosphate hinders the formation of the flame-retardant char layer, preventing effective oxygen isolation and resulting in a loose and porous char layer, which loses NH3 release and increases HF concentration.

[0078] Omitting trimethyl phosphate will cause the shell to lose flexibility and the microcapsules to rupture prematurely, resulting in insufficient continuous protection and a decrease in the initial flame suppression ability; omitting fumed silica will cause the particles to agglomerate during the preparation of the fire extinguishing agent and the density of the fire extinguishing agent deposition layer will decrease. Omitting nano-silica will lead to a decrease in the mechanical strength of the shell, an increase in the rupture rate of the microcapsules during the injection process, uncontrolled release of perfluorohexanone, and the failure to effectively block the HF generation stage.

[0079] Example 4

[0080] The difference between this embodiment and Example 1 is that the amount of perfluorohexanone microcapsules was adjusted to 30, 45, 60, 75, and 90 parts, respectively, so that the mass ratio of perfluorohexanone microcapsules to aluminum hydroxide was 2:1, 3:1, 4:1, 5:1, and 6:1, respectively. The remaining steps and processes were similar to those in Example 1 to obtain the fire extinguishing agent of this embodiment. The fire extinguishing time and HF concentration thereof were measured, and the results are shown in Table 2.

[0081] Table 2

[0082]

[0083]

[0084] Table 2 shows that the ratio of perfluorohexanone microcapsules to aluminum hydroxide significantly affects the performance of the fire extinguishing agent. In the present invention, the endothermic decomposition of aluminum hydroxide lowers the fire temperature, delaying premature rupture of the microcapsule shell and ensuring concentrated release of perfluorohexanone during the fire's expansion phase. The endothermic vaporization of perfluorohexanone and the endothermic cooling of aluminum hydroxide create a "dual thermal management" mechanism, significantly shortening fire extinguishing time.

[0085] When the ratio of perfluorohexanone microcapsules to aluminum hydroxide is too low, excessive cooling causes delayed shell rupture, delayed perfluorohexanone release, and prolonged fire extinguishing time. When the ratio is too high, the fire scene temperature rises rapidly, the microcapsules rupture prematurely, and perfluorohexanone escapes ineffectively in the early stages of the fire, resulting in reduced fire extinguishing efficiency.

[0086] Example 5

[0087] The difference between this embodiment and Example 1 is that the amount of graphite is adjusted to 2, 4, 10, 20, and 25 parts, respectively, so that the mass ratios of ammonium polyphosphate to graphite are 4:2, 4:4, 4:10, 4:20, and 4:25, respectively. The remaining steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this embodiment. The fire extinguishing time and HF concentration thereof are measured, and the results are shown in Table 3.

[0088] Table 3

[0089] Ammonium polyphosphate: graphite Fire extinguishing time / s HF concentration / ppm 4：2 7.2 1.06 4：4 5.6 0.68 4：10 3.8 0.34 4：20 5.1 0.52 4：25 6.9 0.98

[0090] As can be seen from Table 3, the ammonium polyphosphate:graphite composition of the present invention has a significant impact on the performance of the prepared fire extinguishing agent. This is because the ammonium polyphosphate and graphite in the present invention can form a carbonization-expansion synergistic barrier. APP decomposes at high temperatures to form polyphosphoric acid, which catalyzes the formation of a dense carbonized layer on the surface of the combustible, isolating oxygen and blocking the release of combustible gases. Expanded graphite rapidly expands at high temperatures (>300°C) to form a porous worm-like structure, further covering the burning surface and reflecting heat.

[0091] In the appropriate proportion, the carbonized layer and the expansion layer form a "dense-porous" composite structure, which not only blocks oxygen but also delays heat backflow, shortening the fire extinguishing time. When the proportion is unbalanced, such as when there is insufficient graphite, the expansion layer is not fully covered, oxygen penetration leads to re-ignition, and the fire extinguishing time is prolonged. When there is excessive graphite, the catalytic carbonization of APP is hindered, the carbon layer is loose (porosity > 70%), and the barrier effect is reduced.

[0092] Example 6

[0093] The difference between this embodiment and Example 1 is that the amount of ultraviolet absorber UV-327 is adjusted to 4, 6, 8, 10, and 12 parts, respectively, so that the mass ratio of nano-titanium dioxide to ultraviolet absorber UV-327 is 10:4, 10:6, 10:8, 10:10, and 10:12, respectively. The remaining steps and processes are the same as those in Example 1 to obtain the fire extinguishing agent of this embodiment. The fire extinguishing time and HF concentration thereof are measured, and the results are shown in Table 4.

[0094] Table 4

[0095] Nano titanium dioxide: UV-327 Fire extinguishing time / s HF concentration / ppm 10：4 8.4 1.35 10：6 5.3 0.47 10：8 3.8 0.34 10：10 4.9 0.52 10：12 6.8 0.98

[0096] As can be seen from Table 4, the ratio of nano-titanium dioxide to UV-327 has a significant impact on the performance of the prepared fire extinguishing agent. In the scheme of the present invention, UV-327 absorbs 280-400nm ultraviolet rays, reduces the photodegradation of the microcapsule shell (IPDI-TMP-BDO polymer), delays the rupture of the shell, and ensures the precise release of perfluorohexanone during the high temperature stage of the fire (rather than during storage or transportation). Under visible light or residual ultraviolet light, TiO2 produces reactive oxygen species (ROS), decomposes residual combustible gases (such as CO, CH4) and some HF, and suppresses re-ignition. At the appropriate ratio, UV-327 can effectively protect the shell while allowing sufficient ultraviolet light to penetrate to activate the catalytic activity of TiO2, minimizing the fire extinguishing time.

[0097] In summary, the present invention provides a perfluorohexanone fire extinguishing agent, which uses perfluorohexanone microcapsules as the active ingredient of the fire extinguishing agent. After the microcapsules are cross-linked with ethylenediamine, the thermal decomposition temperature of the shell is increased, thereby avoiding premature leakage of the core material caused by high temperature in the early stage of a fire, ensuring that the fire extinguishing agent releases perfluorohexanone in a concentrated manner during the fire expansion stage, and improving fire extinguishing efficiency.

[0098] The introduction of a trimethyl phosphate coating layer promotes directional rupture of the shell and shortens the response time of perfluorohexanone release; the expanded graphite expands when heated to form a porous carbon layer, isolating oxygen and reflecting radiant heat; the introduction of ammonium polyphosphate can catalyze the carbonization of combustibles and form a "solid-gas" synergy with the capture of gas-phase free radicals of perfluorohexanone; in addition, aluminum hydroxide can reduce the temperature of the combustion zone to the effective action range of perfluorohexanone by decomposing and absorbing heat.

[0099] Nano-TiO2 evenly attached to the surface of the microcapsule generates reactive oxygen species (ROS) in the afterglow of the fire, decomposing residual combustible gases and inhibiting smoldering and re-ignition. The ultraviolet absorber is loaded through supercritical deposition to absorb 280-400nm ultraviolet rays, delaying the light aging of the shell and maintaining long-term flame retardant properties.

[0100] Add gas phase SiO2 as a flow aid to reduce powder friction static (surface resistivity <10 8 Ω), preventing uneven distribution of the fire extinguishing agent caused by microcapsule agglomeration during the spraying process, and the reaction of CaO with HF generated by the thermal decomposition of perfluorohexanone, with a neutralization efficiency of >90%.

[0101] A large number of experiments have proved that the above formula and process have achieved a breakthrough in the fire extinguishing agent's "high-efficiency explosion suppression, long-term prevention of re-ignition, low toxicity and environmental protection" through the triple technological innovations of shell modification-nanocomposite-supercritical deposition. Replacing any of the components cannot achieve the effect of the present invention, and it has the potential for industrial promotion.

[0102] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A perfluorohexanone fire extinguishing agent, characterized in that: Calculated by weight of the fire extinguishing agent raw materials, it includes: 60-70 parts of perfluorohexanone microcapsules, 10-20 parts of aluminum hydroxide, 6-10 parts of graphite, 5-10 parts of titanium dioxide, 4-8 parts of ultraviolet absorber UV-327, 2-6 parts of ammonium polyphosphate, 3-6 parts of calcium oxide, 1-3 parts of fumed silica, 1-3 parts of nano-silicon dioxide, and 1-3 parts of trimethyl phosphate.

2. The perfluorohexanone fire extinguishing agent according to claim 1, wherein: The perfluorohexanone microcapsules use perfluorohexanone as a core material embedded in the core part of the microcapsule, and the shell layer is formed by polymerization reaction of isophorone diisocyanate, trimethylolpropane and 1,4-butanediol.

3. The perfluorohexanone fire extinguishing agent according to claim 2, wherein: The mass ratio of the perfluorohexanone microcapsules to aluminum hydroxide is 3-5:1, the mass ratio of the ammonium polyphosphate to graphite is 1:1-5, and the mass ratio of the nano titanium dioxide to the ultraviolet absorber UV-327 is 5:3-5.

4. The method for preparing the perfluorohexanone fire extinguishing agent according to claim 1, wherein: include, The pretreated perfluorohexanone microcapsules are mixed with a nano-titanium dioxide suspension, added to a reactor, heated and sheared, and dried to remove ethanol after the reaction to obtain nano-titanium dioxide-microcapsules; Nano-titanium dioxide-microcapsules, aluminum hydroxide, expanded graphite, ammonium polyphosphate, calcium oxide, and fumed silica are mixed and stirred under vacuum conditions, and then crushed and sieved to obtain a mixture I; Mixture I was placed in a fluidized bed, and dry nitrogen was introduced. UV-327 and nano-silica were pre-dispersed in supercritical CO2 and uniformly loaded on the particle surface by supercritical fluid deposition technology. Fluidized adsorption was performed to obtain the fire extinguishing agent based on perfluoroacetone material microcapsules in this embodiment.

5. The method for preparing the perfluorohexanone fire extinguishing agent according to claim 4, wherein: The pretreatment of the perfluorohexanone microcapsules is to immerse the perfluorohexanone microcapsules in an ethanol solution containing 0.3-0.8% ethylenediamine at 20-30° C. for 1.5-2.5 hours.

6. The method for preparing the perfluorohexanone fire extinguishing agent according to claim 4, wherein: The mass concentration of the nano titanium oxide suspension is 5-15%.

7. The method for preparing the perfluorohexanone fire extinguishing agent according to claim 6, wherein: The reaction temperature of the heating shear reaction is 35-45° C., the reaction time is 15-25 min, and the rotation speed is 4500-5500 rpm.

8. The method for preparing the perfluorohexanone fire extinguishing agent according to claim 4, wherein: The stirring speed of the mixing and stirring under the vacuum condition is 20-30 rpm, and the stirring time is 10-50 min.

9. The method for preparing the perfluorohexanone fire extinguishing agent according to claim 8, wherein: The temperature of the fluidized adsorption is 25-35° C., and the time is 50-70 minutes.

10. Use of the perfluorohexanone fire extinguishing agent prepared by the preparation method according to any one of claims 4 to 9 in extinguishing fires in power equipment.

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