A microcapsule fire extinguishing agent, its preparation method and application

Abstract

This application relates to the field of fire extinguishing materials technology, and in particular to a microcapsule fire extinguishing agent, its preparation method, and its application. A microcapsule fire extinguishing agent includes a core material and an outer shell layer; the core material is encapsulated within the outer shell layer; the core material is a low-boiling-point liquid fire extinguishing agent, and the outer shell layer comprises a first shell layer and a second shell layer from the inside out; the first shell layer includes a polymer material with multiple active hydrogen atoms, a crosslinking agent, and an antifoaming agent, and the second shell layer is a polysulfone resin; the active hydrogen atoms in the polymer material of the first shell layer enhance the adhesion performance of the second shell layer on the first shell layer and the synergistic performance of both; further, the crosslinking agent is used in the second shell layer to improve the density and water resistance of the first shell layer; the combined use of the polymer material with multiple active hydrogen atoms in the first shell layer, the crosslinking agent, and the polysulfone resin in the second shell layer results in a microcapsule fire extinguishing agent with excellent encapsulation rate, water resistance, and fire extinguishing performance, thereby improving its stability during storage and use.

Description

Technical Field

[0001] This application relates to the field of fire extinguishing materials technology, and in particular to a microcapsule fire extinguishing agent, its preparation method and application. Background Technology

[0002] With the development of technology, electricity consumption and the number of electrical products are constantly increasing, making electrical fires increasingly serious. These fires not only cause significant financial losses but also claim human health and lives. Therefore, fire prevention and the use of fire prevention and extinguishing products have received widespread attention.

[0003] Fire extinguishing products can be divided into active fire extinguishing products and passive fire extinguishing products. Active fire extinguishing products are fire protection products that rely on energy or electricity to drive them and can actively detect and extinguish fires. Common active fire extinguishing products include automatic fire alarm systems, sprinkler systems, and foam extinguishing systems. Passive fire extinguishing products refer to fire protection products that do not rely on power or energy and are consumed directly. Common passive fire extinguishing products include firewalls, fire doors, fireproof glass, and other products that passively control the spread of fire.

[0004] Low-boiling-point liquid fire extinguishing agents have advantages such as low toxicity, rapid extinguishing speed, easy volatility, leaving no residue after extinguishing, no environmental pollution, and no damage to damaged property, making them widely used in various important locations. However, low-boiling-point liquid fire extinguishing agents have poor stability and are inconvenient to store and carry.

[0005] As an emerging fire extinguishing medium, microcapsule fire extinguishing agents can overcome the problems of instability, inconvenience in storage and carrying of existing low-boiling-point liquid fire extinguishing agents by preparing them into microcapsules. In recent years, microcapsule fire extinguishing agents have been widely used in the fire protection field.

[0006] However, existing microcapsule fire extinguishing agents typically use natural polymer materials, such as sodium carboxymethyl cellulose and chitosan, or polymer materials such as epoxy resin, polyurethane, or acrylic resin as wall materials. The resulting microcapsule fire extinguishing agents have poor encapsulation effect and water resistance, resulting in the wall material of the microcapsule fire extinguishing agent not providing ideal protection for the core material. Summary of the Invention

[0007] To address the issues of poor coating effect and water resistance in existing microcapsule fire extinguishing agents, this application provides a microcapsule fire extinguishing agent, its preparation method, and its application.

[0008] Firstly, this application provides a microcapsule fire extinguishing agent:

[0009] A microcapsule fire extinguishing agent comprises a core material and an outer shell layer with a mass ratio of (0.27-12):1; the core material is encapsulated within the outer shell layer.

[0010] The core material is a low-boiling-point liquid fire extinguishing agent, and the outer shell layer comprises a first shell and a second shell from the inside out; the raw materials of the first shell include a polymer material containing multiple active hydrogens, a crosslinking agent and a defoamer, and the polymer material reacts with the crosslinking agent to form a network structure; the second shell is polysulfone resin.

[0011] Polysulfone membranes have good rigidity and toughness, and excellent resistance to high temperature, thermal oxidation and creep. However, the structure of polysulfone contains a lot of benzene rings and the chains are relatively rigid, resulting in poor adhesion of the membrane layer. This may lead to poor adhesion between the polysulfone membrane and other membrane layers, thus affecting the overall performance of polysulfone resin microencapsulated fire extinguishing agents.

[0012] By adopting the above technical solution, the microcapsule fire extinguishing agent uses polysulfone resin as the second shell, which improves the heat resistance of the microcapsule fire extinguishing agent and thus enhances its storage stability.

[0013] Furthermore, a first shell is used between the core material and the second shell layer. The first shell layer includes a polymer material containing multiple active hydrogen atoms, a crosslinking agent, and a defoamer. The polymer material containing multiple active hydrogen atoms encapsulates the core material, forming latex particles with smaller particle sizes, thereby improving the encapsulation rate of the outer shell layer on the core material and the stability of the core material. In addition, the active hydrogen atoms in the polymer material of the first shell layer improve the adhesion performance of the second shell layer on the first shell layer. The polymer material containing multiple active hydrogen atoms is compatible with polysulfone resin with good toughness, which improves the problem of poor adhesion performance of the polysulfone film in the second shell layer, enhances the synergistic effect between the first shell layer and the second shell layer, and thus makes the prepared microcapsule fire extinguishing agent have high stability, encapsulation rate, fire extinguishing effect, and water resistance, thereby improving the stability of the microcapsule fire extinguishing agent during storage and use.

[0014] However, the first shell of polymer materials with multiple active hydrogens may reduce the water resistance of the microcapsule fire extinguishing agent; furthermore, a crosslinking agent is used in the second shell. Under the premise of ensuring good adhesion between the second shell and the first shell, the crosslinking agent improves the density and water resistance of the first shell.

[0015] By combining the polymer material containing multiple active hydrogen atoms in the first shell with a crosslinking agent and a polysulfone resin with good toughness and high temperature resistance, the prepared microcapsule fire extinguishing agent has excellent stability, encapsulation rate, fire extinguishing performance and water resistance, thereby improving the stability of the microcapsule fire extinguishing agent during storage and use.

[0016] Preferably, the mass ratio of the first shell layer to the second shell layer is (1.87-15):1; the mass ratio of the polymer material to the crosslinking agent is (0.33-4.17):1; the polymer material is one or more of gelatin, sodium alginate, chitosan, gum arabic, polyglutamic acid, β-cyclodextrin, sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose, and octenyl succinate starch; and the polysulfone has a molecular weight of 10,000-50,000.

[0017] By adopting the above technical solution, optimizing the mass ratio of the first shell and the second shell, the mass ratio of polymer materials and crosslinking agents, the type of polymer materials and the molecular weight of polysulfone, the encapsulation rate, stability and water resistance of microcapsule fire extinguishing agents can be further improved.

[0018] Preferably, the polymer material is a combination of gelatin and sodium alginate; the crosslinking agent is glutaraldehyde and / or calcium chloride.

[0019] Preferably, the crosslinking agent is glutaraldehyde and calcium chloride; the mass ratio of sodium alginate, gelatin, calcium chloride and glutaraldehyde is (0.1-5):(0.24-2.4):(0.5-10):(0.1-2).

[0020] By adopting the above technical solutions and optimizing the types and weights of polymer materials and crosslinking agents, the encapsulation rate and water resistance of microcapsule fire extinguishing agents can be further improved.

[0021] The polymer material is formulated with gelatin and sodium alginate. The carboxyl groups in sodium alginate and the amino groups in gelatin have a strong interaction, which enhances the density and strength of the first shell.

[0022] Furthermore, crosslinking agents glutaraldehyde and / or calcium chloride are used. Calcium chloride reacts with sodium alginate, and glutaraldehyde reacts with active hydrogen in gelatin and sodium alginate to further improve the density and strength of the first shell layer, thereby improving the encapsulation rate and water resistance of the microcapsule fire extinguishing agent.

[0023] Preferably, the core material is at least one of tetrafluorodibromoethane, dibromomethane, decafluoro-3-methoxy-4-(trifluoromethyl)pentane, trifluorodichloroethane, bromotrifluoropropylene, and perfluorohexanone.

[0024] Preferably, the particle size of the microcapsule fire extinguishing agent is 100-500 μm.

[0025] By adopting the above technical solutions and optimizing the type of core material and the compatibility of the core material with the outer shell, the prepared microcapsule fire extinguishing agent has better encapsulation rate, water resistance, stability and fire extinguishing effect.

[0026] Secondly, this application provides a method for preparing a microcapsule fire extinguishing agent:

[0027] A method for preparing a microcapsule fire extinguishing agent includes the following preparation steps:

[0028] Preparation of aqueous solutions of polymer materials: Each polymer material is prepared into a solution with a mass fraction of 0.1-5%;

[0029] Preparation of fire extinguishing agent emulsion: Mix and emulsify the aqueous solution of polymer material, defoamer and core material to obtain fire extinguishing agent emulsion;

[0030] Preparation of fire extinguishing agent latex particles: The fire extinguishing agent emulsion is added to a solution of 0.1-10% crosslinking agent by mass and stirred.

[0031] Fire extinguishing agent latex particles were prepared by allowing the mixture to stand, filtering, washing, and drying.

[0032] Preparation of microcapsule fire extinguishing agent: Fire extinguishing agent latex particles are added to water, polysulfone solution is added while stirring, and then the mixture is stirred, filtered, washed and dried to obtain microcapsule fire extinguishing agent.

[0033] By adopting the above technical solution, a microcapsule fire extinguishing agent with good coating rate, water resistance and stability was prepared.

[0034] Preferably, the polymer material aqueous solution is composed of a sodium alginate aqueous solution with a mass fraction of 0.1%-5% and a gelatin aqueous solution with a mass fraction of 0.8%; the mass ratio of the sodium alginate aqueous solution, the gelatin aqueous solution, the defoamer, and the core material is 1:(0.3-3):(0.001-0.05):(0.05-0.3).

[0035] The extinguishing agent emulsion is added dropwise to an aqueous solution of calcium chloride with a mass fraction of 0.5%-10% to carry out a gelation reaction. Then, it is allowed to stand, filtered, and washed to prepare a preliminary extinguishing agent latex particle. Next, the preliminary extinguishing agent latex particle is placed in an aqueous solution of dialdehyde with a mass fraction of 0.1%-2% and allowed to stand for 12-48 hours. After filtration, washing, and drying, the extinguishing agent latex particles are prepared. The polysulfone solution is a dichloromethane solution of polysulfone with a mass fraction of 2%-10%. The mass ratio of the extinguishing agent latex particles to water is 1:(7.28-30).

[0036] By adopting the above technical solution, and by optimizing the concentrations of sodium alginate aqueous solution and gelatin aqueous solution, as well as the mass ratio of sodium alginate aqueous solution, gelatin aqueous solution, defoamer, and core material, the prepared microcapsule fire extinguishing agent has better encapsulation rate, water resistance, and fire extinguishing effect.

[0037] The order of crosslinking agent treatment of fire extinguishing agent emulsion is optimized to further improve the density and strength of the second shell layer; thereby improving the encapsulation rate, water resistance and fire extinguishing effect of the prepared microcapsule fire extinguishing agent.

[0038] Preferably, in the preparation of the fire extinguishing agent emulsion, the stirring speed is 1000-3000 r / min, the stirring time is 5-30 min, and the temperature is 10-40℃;

[0039] In the preparation of the fire extinguishing agent latex particles, the prototype fire extinguishing agent latex particles are placed in an aqueous solution of dialdehyde and then left to stand for 12-48 hours at -5-10℃.

[0040] By adopting the above technical solution, the reaction conditions of the fire extinguishing agent emulsion with the aqueous solutions of calcium chloride and glutaraldehyde are optimized, thereby further improving the encapsulation rate, water resistance and fire extinguishing effect of the prepared microcapsule fire extinguishing agent.

[0041] At lower temperatures, the reaction rate between glutaraldehyde and the primordial latex particles of the extinguishing agent is slower, which better increases the crosslinking density of the second shell and thus improves the water resistance of the prepared microcapsule extinguishing agent.

[0042] After the extinguishing agent emulsion reacts with the calcium chloride aqueous solution, a network structure with a certain cross-linking density is formed. At higher temperatures, glutaraldehyde reacts in large quantities on the surface of the network structure, leading to a rapid increase in the cross-linking density on the surface. This reduces the amount of glutaraldehyde entering the first shell, resulting in a decrease in the cross-linking density inside the first shell, which in turn reduces the water resistance of the prepared microcapsule extinguishing agent. Under lower temperatures and longer settling times, glutaraldehyde can better penetrate into the first shell and react, thereby improving the water resistance of both the first shell and the microcapsule extinguishing agent.

[0043] Thirdly, this application provides an application of a microcapsule fire extinguishing agent:

[0044] A microcapsule fire extinguishing agent can be used in passive fire extinguishing products and fire prevention and extinguishing products. Specifically, it can be added to resin or rubber as a fire extinguishing agent filler; it can be prepared into passive fire extinguishing products such as fireproof stickers, sheets, coatings, strips, room temperature curing slurries, and boards; and it can be applied to fire prevention and extinguishing products such as enclosures and cables.

[0045] The microcapsule fire extinguishing agent prepared in this application has good water resistance, stability and fire extinguishing performance. Not only is the microcapsule fire extinguishing agent easy to store and transport, but it also broadens the application scenarios of the prepared passive fire extinguishing products and fire prevention and extinguishing products.

[0046] In summary, this application has the following beneficial effects:

[0047] 1. A microcapsule fire extinguishing agent, comprising a core material and an outer shell layer; the core material is encapsulated within the outer shell layer; the core material is a low-boiling-point liquid fire extinguishing agent, and the outer shell layer comprises a first shell layer and a second shell layer from the inside out; the first shell layer comprises a polymer material with multiple active hydrogen atoms, a crosslinking agent, and an antifoaming agent, and the second shell layer is a polysulfone resin; the active hydrogen atoms in the polymer material of the first shell layer enhance the adhesion performance of the second shell layer on the first shell layer, as well as the synergistic performance of the two; further, a crosslinking agent is used in the second shell layer to enhance the density and water resistance of the first shell layer; the combination of the polymer material with multiple active hydrogen atoms in the first shell layer, the crosslinking agent, and the polysulfone resin in the second shell layer results in a microcapsule fire extinguishing agent with excellent encapsulation rate, water resistance, and fire extinguishing performance, thereby improving its stability during storage and use.

[0048] 1. Preferably, the polymer material is sodium alginate and gelatin, and the crosslinking agent is glutaraldehyde and calcium chloride; the mass ratio of sodium alginate, gelatin, calcium chloride and glutaraldehyde is (0.1-5):0.24:(0.5-10):(0.1-2); the preferred types and weights of polymer materials and crosslinking agents further improve the encapsulation rate and water resistance of the microcapsule fire extinguishing agent.

[0049] 3. Preferably, in the preparation of the fire extinguishing agent latex particles, the stirring conditions during the gelation reaction are 1000-3000 r / min, the time is 5-30 min, and the temperature is 10-40℃; the prototype fire extinguishing agent latex particles are placed in an aqueous solution of glutaraldehyde at -5-10℃ for 12-48 h; by optimizing the reaction conditions of the fire extinguishing agent emulsion with the aqueous solution of calcium chloride and the aqueous solution of glutaraldehyde in sequence, the encapsulation rate, water resistance and fire extinguishing effect of the prepared microcapsule fire extinguishing agent are further improved. Attached Figure Description

[0050] Figure 1 Example 1: Schematic diagram of the structure of the microcapsule fire extinguishing agent.

[0051] Figure 2 Thermogravimetric curves of microcapsule fire extinguishing agents in Examples 1, 2, 1, and 2.

[0052] Explanation of reference numerals in the attached figures:

[0053] 1. Extinguishing agent; 2. First shell (sodium alginate / gelatin shell); 3. Second shell (polysulfone shell); 4. Thermogravimetric curve of microencapsulated fire extinguishing agent in Example 1; 5. Thermogravimetric curve of microencapsulated fire extinguishing agent in Example 2; 6. Thermogravimetric curve of microencapsulated fire extinguishing agent in Comparative Example 1; 7. Thermogravimetric curve of microencapsulated fire extinguishing agent in Comparative Example 2. Detailed Implementation

[0054] Example

[0055] Example 1: A microcapsule fire extinguishing agent, using raw materials as shown in Table 1, includes a core material and an outer shell layer; the core material is encapsulated within the outer shell layer; the outer shell layer comprises a first shell layer and a second shell layer from the inside out. A schematic diagram of the microcapsule fire extinguishing agent is shown below. Figure 1 Its preparation method includes the following steps:

[0056] Preparation of aqueous solutions of polymer materials: Prepare a 1.5% sodium alginate aqueous solution (sodium alginate: food grade, national standard, 99% effective ingredient content, white powder particles) and a 0.8% gelatin aqueous solution (gelatin molecular weight 50,000, food grade).

[0057] Preparation of fire extinguishing agent latex granules:

[0058] Sodium alginate aqueous solution, gelatin aqueous solution, defoamer and core material (using perfluorohexanone) were mixed and stirred at a stirring speed of 2000 r / min for 20 min at a temperature of 25℃ to obtain fire extinguishing agent emulsion;

[0059] The fire extinguishing agent emulsion was slowly dripped into a 1% calcium chloride aqueous solution to carry out a gelation reaction (reaction temperature 20±10℃). The precipitated particles were filtered, washed three times with deionized water, placed in an aqueous solution containing 1% glutaraldehyde, and allowed to stand at 0℃ for 24 hours. After filtration, washing, and drying, fire extinguishing agent latex particles were obtained.

[0060] Preparation of microcapsule fire extinguishing agent: Polysulfone (molecular weight 20000) was dissolved in dichloromethane to obtain an 8% polysulfone solution. Then, the obtained fire extinguishing agent latex particles were added to 100g of deionized water (the mass ratio of fire extinguishing agent latex particles to water was 1:7.28) and stirred at a speed of 200r / min. At the same time, the polysulfone solution was slowly added while stirring was maintained until the solvent was completely evaporated. The mixture was then filtered, washed, and dried to obtain the microcapsule fire extinguishing agent.

[0061] Example 2, a microcapsule fire extinguishing agent, differs from Example 1 in that the core material is tetrafluorodibromoethane and the molecular weight of polysulfone is 25,000.

[0062] Examples 3 to 5 describe a microcapsule fire extinguishing agent that differs from Example 1 in the types of raw materials used, the weight of the raw materials, and the settings of the preparation process parameters, as shown in Table 1.

[0063] Table 1: List of raw material types, raw material weights, and preparation process parameters used in the microencapsulated fire extinguishing agents of Examples 1 to 5

[0064]

[0065]

[0066] Sodium alginate, gelatin, calcium chloride, dialdehyde, polysulfone, and defoamer are considered as raw materials for the outer shell layer.

[0067] The weight of the extinguishing agent latex particles is the sum of the weights of the core material, polymer material, and crosslinking agent raw materials.

[0068] Example 6, a microcapsule fire extinguishing agent, differs from Example 1 in that sodium alginate is used in an equal amount to replace gelatin.

[0069] Example 7, a microcapsule fire extinguishing agent, differs from Example 1 in that it uses hydroxypropyl methylcellulose (7wt% hydroxypropoxy content and 27wt% methoxy content) to replace gelatin in equal amounts.

[0070] Example 8, a microcapsule fire extinguishing agent, differs from Example 1 in that it uses an equal amount of calcium chloride and glutaraldehyde.

[0071] Example 9, a microcapsule fire extinguishing agent, differs from Example 1 in that it uses glutaraldehyde in equal amounts of calcium chloride.

[0072] Example 10, a microcapsule fire extinguishing agent, differs from Example 1 in that, in the preparation of the fire extinguishing agent latex particles, the prototype fire extinguishing agent latex particles are placed in an aqueous solution of dialdehyde and then left to stand for 15 hours at 15°C.

[0073] Example 11, a microcapsule fire extinguishing agent, differs from Example 1 in that, in the preparation of the fire extinguishing agent latex particles, the prototype fire extinguishing agent latex particles are placed in an aqueous solution of dialdehyde and then left to stand for 55 hours at -8°C.

[0074] Comparative Example

[0075] Comparative Example 1, a microcapsule fire extinguishing agent, differs from Example 1 in that it does not use a polysulfone solution;

[0076] Raw materials used: 10g perfluorohexanone; 100g sodium alginate aqueous solution; 30g gelatin aqueous solution; 100g calcium chloride aqueous solution; 100g glutaraldehyde aqueous solution; 0.3g defoamer.

[0077] The preparation steps are as follows:

[0078] A 1.5 wt% sodium alginate aqueous solution, a 0.8 wt% gelatin aqueous solution, an antifoaming agent, and perfluorohexanone were mixed and stirred at a stirring speed of 2000 r / min for 20 min at a temperature of 25℃ to obtain a perfluorohexanone-sodium alginate / gelatin emulsion.

[0079] Perfluorohexanone-sodium alginate / gelatin emulsion was slowly added dropwise to a 1wt% calcium chloride aqueous solution to carry out a gelation reaction. The precipitated particles were filtered, washed three times with deionized water, placed in an aqueous solution containing 1wt% glutaraldehyde, and allowed to stand at 0℃ for 24 hours. After filtration, washing, and drying, microcapsule fire extinguishing agent was obtained.

[0080] Comparative Example 2, a microcapsule fire extinguishing agent, differs from Example 1 in that it does not use polysulfone solution; nor does it use gelatin aqueous solution or glutaraldehyde aqueous solution;

[0081] Raw materials used: 10g perfluorohexanone; 100g sodium alginate aqueous solution; 100g calcium chloride aqueous solution; 0.3g defoamer.

[0082] The preparation steps are as follows:

[0083] A 1.5 wt% sodium alginate aqueous solution, defoamer, and perfluorohexanone were mixed and stirred at a stirring speed of 2000 r / min for 20 min at a temperature of 25℃ to obtain a perfluorohexanone-sodium alginate emulsion. The perfluorohexanone-sodium alginate emulsion was then slowly added dropwise to a 1.0 wt% calcium chloride aqueous solution to carry out a gelation reaction. The precipitated particles were filtered, washed, and dried to obtain a microcapsule fire extinguishing agent.

[0084] Comparative Example 3, a microcapsule fire extinguishing agent, differs from Example 1 in that it does not use a cross-linking agent.

[0085] Comparative Example 4, a microcapsule fire extinguishing agent, differs from Example 1 in that resorcinol-formaldehyde resin replaces polysulfone resin in an equal amount.

[0086] Comparative Example 5, a microcapsule fire extinguishing agent, differs from Example 1 in that it does not use polysulfone solution; it does not use glutaraldehyde aqueous solution and defoamer;

[0087] Raw materials used: 10g perfluorohexanone; 100g sodium alginate aqueous solution; 30g gelatin aqueous solution; 100g calcium chloride aqueous solution.

[0088] The preparation steps are as follows:

[0089] A 1.5 wt% sodium alginate aqueous solution, a 0.8 wt% gelatin aqueous solution, and perfluorohexanone were mixed and stirred at a stirring speed of 2000 r / min for 20 min at a temperature of 25℃ to obtain a perfluorohexanone-sodium alginate / gelatin emulsion.

[0090] Perfluorohexanone-sodium alginate / gelatin emulsion was slowly added dropwise to a 1.0wt% calcium chloride aqueous solution to carry out a gelation reaction. The precipitated particles were filtered, washed, and dried to obtain microcapsule fire extinguishing agent.

[0091] The comparative example produced a large amount of foam during emulsification, resulting in emulsification failure.

[0092] Performance testing

[0093] Experiment 1: Encapsulation rate and release temperature

[0094] Referencing GB / T 27761-2011, a thermogravimetric analyzer was used to confirm the embedding rate and release temperature of the test samples using thermogravimetric analysis.

[0095] Experiment 2: Extinguishing Time

[0096] 60g of microcapsule powder was added to 80g of water-soluble melamine-formaldehyde resin and stirred for 10 minutes. The mixture was then poured into a mold and dried at 40℃ to obtain a perfluorohexanone fire extinguishing pad. A layer of polyurea about 50μm thick was coated on the surface of the fire extinguishing pad, and a double-sided adhesive film was applied to the back of the fire extinguishing pad to make a 2mm thick fire extinguishing patch containing microcapsule fire extinguishing agent.

[0097] Apply the fire extinguishing sticker to the top of the 0.1L container, place the kerosene-filled combustion plate at the bottom of the container, ignite the kerosene in the combustion plate, close the container door, and calculate the time it takes for the flame to extinguish.

[0098] Test 3: Water resistance

[0099] Take 15±5g of test sample and place it in 500mL of water. Observe the morphological changes of the test sample (microcapsule fire extinguishing agent) at the same time every day and record whether swelling occurs. Observe continuously for 20 days.

[0100] Test samples: The microcapsule fire extinguishing agents of Examples 1 to 11 were used as example samples; the microcapsule fire extinguishing agents of Comparative Examples 1 to 4 were used as comparative example samples.

[0101] Test results: The encapsulation rate and release temperature of the microcapsule fire extinguishing agents of Examples 1 to 11 and Comparative Examples 1 to 4, and the fire extinguishing time of the fire extinguishing patches prepared using the microcapsule fire extinguishing agents of Examples 1 to 11 and Comparative Examples 1 to 4 are shown in Table 2.

[0102] Table 2: List of test results for the encapsulation rate and release temperature of the microcapsule fire extinguishing agents of Examples 1 to 11 and Comparative Examples 1 to 4, and the fire extinguishing time of the fire extinguishing patches prepared using the microcapsule fire extinguishing agents of Examples 1 to 11 and Comparative Examples 1 to 4.

[0103]

[0104]

[0105] Combining Examples 1 to 11 and Comparative Examples 1 to 4, and referring to Table 2, it can be seen that:

[0106] Compared with Comparative Examples 1 to 3, the microcapsule fire extinguishing agent of Example 1 exhibits higher encapsulation efficiency and release temperature, shorter extinguishing time, and better water resistance. This indicates that the use of a first shell containing multiple active hydrogen molecules, a crosslinking agent, and an antifoaming agent in the microcapsule fire extinguishing agent, along with a second shell (polysulfone resin), results in excellent encapsulation efficiency, water resistance, and fire extinguishing effect, as well as a higher release temperature. This may be due to the active hydrogen molecules in the first shell enhancing the adhesion of the second shell to the first shell, and the synergistic effect between the two. Furthermore, the use of a crosslinking agent in the second shell, while ensuring good adhesion of the second shell to the first shell, also improves the density and water resistance of the first shell. The combination of a first shell containing multiple active hydrogen molecules, a crosslinking agent, and a second shell made of polysulfone resin results in a microcapsule fire extinguishing agent with a higher release temperature, better water resistance, encapsulation efficiency, and fire extinguishing effect.

[0107] Compared with Comparative Example 4, the microcapsule fire extinguishing agent of Example 1 has a higher encapsulation rate and release temperature, shorter extinguishing time, and better water resistance. This indicates that the polysulfone resin used in the second shell has a good compatibility with the first shell. This may be because polysulfone resin has better stability than resorcinol-formaldehyde resin, which makes the microcapsule fire extinguishing agent more stable. Furthermore, the good toughness of polysulfone resin is conducive to the adhesion of polysulfone to the first shell of polymer materials containing multiple active hydrogens, resulting in a better synergistic effect between the two.

[0108] Compared to Example 3, the microcapsule fire extinguishing agent of Example 5 has a lower encapsulation rate, lower release temperature, and longer extinguishing time. This may be because, compared to Example 3, the microcapsule fire extinguishing agent of Example 5 uses less sodium alginate aqueous solution in its preparation, resulting in a lower mass ratio of the first shell to the second shell. The lighter weight of the first shell leads to a poorer emulsification effect of the core material, resulting in a lower encapsulation rate and a longer extinguishing time. In addition, with a certain amount of crosslinking agent, the reduced sodium alginate content reduces the active hydrogen in the first shell, weakening the interaction between the first and second shells. This may allow moisture to easily penetrate and remain between the first and second shells, leading to a decrease in the water resistance of the microcapsule fire extinguishing agent.

[0109] Compared with Examples 5 to 9, the microcapsule extinguishing agent of Example 1 has a higher encapsulation rate and release temperature, a shorter extinguishing time, and better water resistance. This indicates that the use of sodium alginate, gelatin, calcium chloride, and glutaraldehyde in the first shell improves the encapsulation rate, release temperature, and water resistance of the microcapsule extinguishing agent, and reduces the extinguishing time. The higher encapsulation rate may result in a shorter extinguishing time for the fire extinguishing patch using the microcapsule extinguishing agent. The combination of sodium alginate and gelatin may provide a better emulsification effect for the core material. There is a strong interaction between sodium alginate and gelatin, and the reactions of calcium chloride with sodium alginate and glutaraldehyde with sodium alginate and gelatin enhance the strength, density, and encapsulation rate of the extinguishing agent latex particles, reduce the hydrophilic groups on the surface of the extinguishing agent latex particles, and thus improve the water resistance of the microcapsule extinguishing agent.

[0110] Compared with Examples 10 and 11, the microcapsule fire extinguishing agent of Example 1 has a higher encapsulation rate, release temperature, and better water resistance. This indicates that in the preparation of the fire extinguishing agent latex particles, after the prototype fire extinguishing agent latex particles are placed in an aqueous solution of dialdehyde, they exhibit good water resistance under conditions of -5 to 10°C and a standing time of 12 to 48 hours. This may be because after the fire extinguishing agent emulsion reacts with the aqueous solution of calcium chloride, a network structure with a certain cross-linking density has been formed. At higher temperatures, glutaraldehyde will bind in large quantities on the surface of the network structure, increasing the cross-linking density. This reduces the amount of glutaraldehyde entering the first shell, lowers the cross-linking density, and consequently reduces the water resistance of the prepared microcapsule fire extinguishing agent. Under conditions of lower temperature and longer standing time, glutaraldehyde can better penetrate into the interior of the first shell and react, thereby improving the water resistance, strength, and encapsulation rate of the first shell and the microcapsule fire extinguishing agent.

[0111] When the temperature is too low during static placement, the extinguishing agent latex particles with a certain cross-linking density shrink, the gaps between polymer materials decrease, glutaraldehyde has difficulty entering, and the cross-linking density inside the first shell layer decreases, resulting in a decrease in the water resistance of the prepared microcapsule extinguishing agent.

[0112] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A microcapsule fire extinguishing agent, characterized in that, It includes a core material and an outer shell layer with a mass ratio of (0.27-12):1; the core material is encased within the outer shell layer; The core material is a low-boiling-point liquid fire extinguishing agent, and the outer shell layer comprises a first shell and a second shell from the inside out; the raw materials of the first shell include a polymer material containing multiple active hydrogens, a crosslinking agent and an antifoaming agent, and the network structure formed by the reaction of the polymer material and the crosslinking agent; the second shell is polysulfone resin. The mass ratio of the first shell layer to the second shell layer is (1.87-15):1; the mass ratio of the polymer material to the crosslinking agent is (0.33-4.17):1; the molecular weight of the polysulfone is 10000-50000; The polymer material is a composition of gelatin and sodium alginate; the crosslinking agent is glutaraldehyde and calcium chloride; the mass ratio of sodium alginate, gelatin, calcium chloride and glutaraldehyde is (0.1-5):(0.24-2.4):(0.5-10):(0.1-2). The core material is at least one of tetrafluorodibromoethane, dibromomethane, decafluoro-3-methoxy-4-(trifluoromethyl)pentane, trifluorodichloroethane, bromotrifluoropropylene, and perfluorohexanone.

2. The microcapsule fire extinguishing agent according to claim 1, characterized in that, The microcapsule fire extinguishing agent has a particle size of 100-500 μm.

3. A method for preparing a microcapsule fire extinguishing agent according to any one of claims 1-2, characterized in that, The preparation steps include the following: Preparation of aqueous solutions of polymer materials: Each polymer material is prepared into a solution with a mass fraction of 0.1-5%; Preparation of fire extinguishing agent emulsion: Mix and emulsify the aqueous solution of polymer material, defoamer and core material to obtain fire extinguishing agent emulsion; Preparation of fire extinguishing agent latex particles: Fire extinguishing agent emulsion is added to a solution of crosslinking agent with a mass fraction of 0.1-10% and stirred. After standing, it is filtered, washed and dried to prepare fire extinguishing agent latex particles. Preparation of microcapsule fire extinguishing agent: Fire extinguishing agent latex particles are added to water, polysulfone solution is added while stirring, and then the mixture is stirred, filtered, washed and dried to obtain microcapsule fire extinguishing agent.

4. The method for preparing the microcapsule fire extinguishing agent according to claim 3, characterized in that, The polymer material aqueous solution is composed of a sodium alginate aqueous solution with a mass fraction of 0.1%-5% and a gelatin aqueous solution with a mass fraction of 0.8%; the mass ratio of the sodium alginate aqueous solution, the gelatin aqueous solution, the defoamer, and the core material is 1:(0.3-3):(0.001-0.05):(0.05-0.3). Fire extinguishing agent emulsion is added dropwise to an aqueous solution of calcium chloride with a mass fraction of 0.5%-10% to carry out a gelation reaction. Then, it is allowed to stand, filtered, and washed to prepare a preliminary fire extinguishing agent latex particle. Next, the preliminary fire extinguishing agent latex particle is placed in an aqueous solution of dialdehyde with a mass fraction of 0.1%-2% and allowed to stand for 12-48 hours. After filtration, washing, and drying, the fire extinguishing agent latex particles are prepared. The polysulfone solution is a dichloromethane solution containing 2%-10% polysulfone by mass; the mass ratio of the fire extinguishing agent latex particles to water is 1:(7.28-30).

5. The method for preparing the microcapsule fire extinguishing agent according to claim 3, characterized in that, In the preparation of the fire extinguishing agent emulsion, the stirring speed is 1000-3000 r / min, the stirring time is 5-30 min, and the temperature is 10-40℃; In the preparation of the fire extinguishing agent latex particles, the prototype fire extinguishing agent latex particles are placed in an aqueous solution of dialdehyde and then left to stand for 12-48 hours at -5-10℃.

6. The application of a microencapsulated fire extinguishing agent according to any one of claims 1-2, characterized in that, It can be applied to passive fire extinguishing products and fire prevention and extinguishing products.

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