Fire extinguishing tablet composition, fire extinguishing tablet and preparation method and application thereof

Abstract

This invention discloses a fire extinguishing tablet composition, fire extinguishing tablets, their preparation method, and applications, belonging to the technical field of fire extinguishing products. It solves one of the problems in existing technologies: inconvenient storage and transportation of liquid fire extinguishing agents, easy clumping and slow dissolution of powder fire extinguishing agents due to moisture absorption, poor storage stability of conventional disintegrating tablets, and easy failure in humid environments. The fire extinguishing tablet composition comprises: 40-75 wt% of a disintegrating agent, 20-50 wt% of a flame retardant, 1-5 wt% of a disintegrating aid, and 1-10 wt% of a composite functional component; wherein the composite functional component is a polyethylene glycol-coated surfactant. The fire extinguishing tablets of this invention have advantages such as rapid disintegration, high-efficiency fire extinguishing, good long-term storage stability in humid environments, strong resistance to reignition, and environmental friendliness.

Description

Technical Field

[0001] This invention belongs to the technical field of fire extinguishing products, and specifically relates to a fire extinguishing tablet composition, fire extinguishing tablets, their preparation method and application. Background Technology

[0002] In forest fires and fires involving renewable energy sources, two main categories of extinguishing agents are typically used: traditional liquids and water-soluble powders, to improve fire suppression efficiency. While liquid extinguishing agents such as water and foam are effective, their transportation and storage are extremely inconvenient: they are heavy, prone to leakage, and require special containers for freeze and corrosion protection, making resupply difficult in remote or emergency situations. Water-soluble powder extinguishing agents are easy to transport and can be dissolved in water on-site, but the dissolution time is long and they are easily affected by environmental factors (such as strong winds); furthermore, the powder is prone to clumping due to moisture, has poor long-term storage stability, and changes in humidity or temperature can cause it to become ineffective.

[0003] Therefore, there is an urgent need in the field of fire extinguishing technology for a new type of fire extinguishing solution that can overcome transportation limitations, simplify operating procedures, and achieve rapid response. Addressing the challenges of transporting liquid fire extinguishing agents, the operational complexity of powder fire extinguishing agents, their environmental sensitivity, and reaction delays, developing a fire extinguishing tablet technology that can disintegrate instantly, act rapidly, and is easy to store and transport has significant practical value and market potential.

[0004] In existing technologies, insufficient attention is generally paid to the long-term storage stability of fire extinguishing tablets in high humidity environments. While conventional disintegrating tablets emphasize initial disintegration speed, they often fail to adequately consider the impact of environmental humidity. Under humid conditions, tablet components easily absorb moisture, leading to decreased activity of the disintegrating agent and clumping of the flame retardant, resulting in slow disintegration or even ineffectiveness. This severely limits their reliability and shelf life in real-world scenarios such as humid regions, rainy season storage, and vehicle-mounted emergency applications. For example, although the fire extinguishing tablet in CN115400385A can disintegrate rapidly, its core material only contains flame retardant and gel precursor. During long-term storage, the flame retardant and gel precursor will adhere to each other and clump together, failing to achieve the "disintegration" effect. The dissolution time in water also increases, making the fire extinguishing tablet unsuitable for long-term storage and failing to meet the requirements for commercialization.

[0005] Therefore, there is an urgent need for a fire extinguishing tablet that can not only achieve rapid disintegration, but also has excellent storage stability and excellent moisture resistance, which has become a problem that needs to be solved in this field. Summary of the Invention

[0006] In view of the above, the present invention aims to provide a fire extinguishing tablet composition, fire extinguishing tablet and its preparation method and application, in order to at least solve one of the problems existing in the prior art: (1) The long-term storage stability of existing fissile fire extinguishing tablets is not fully guaranteed, especially in humid environments, the fissile performance is easily reduced or even ineffective due to moisture absorption; (2) The existing fissile fire extinguishing tablets have a slow fissile rate and insufficient dissolution, which causes problems such as nozzle blockage and uneven fire extinguishing solvent, affecting the fire extinguishing efficiency or the stability of the fire extinguishing effect, and the anti-reignition ability is insufficient. Especially for deep fires or fires that are prone to reignition, such as fires involving new energy batteries, existing tablets often cannot continue to suppress thermal runaway or deep smoldering after the open flame is extinguished, resulting in a high risk of reignition; (3) Existing fissile tablets still rely on fluorine-containing components to improve spreading and film-forming properties, which poses an environmental pollution problem.

[0007] The objective of this invention is mainly achieved through the following technical solutions:

[0008] The first aspect of the present invention provides a fire extinguishing tablet composition, characterized in that the fire extinguishing tablet composition comprises: 40-75 wt% of a fracturing agent, 20-50 wt% of a flame retardant, 1-5 wt% of a fracturing aid, and 1-10 wt% of a composite functional component. The composite functional component is a surfactant coated with polyethylene glycol.

[0009] Furthermore, in the composite functional component, the mass ratio of polyethylene glycol to surfactant is 2-8:1.

[0010] Furthermore, the surfactant is selected from sodium dodecylbenzenesulfonate and / or sodium dodecyl alcohol ether sulfate.

[0011] Furthermore, the average molecular weight of the polyethylene glycol is 2000-6000 g / mol.

[0012] Furthermore, the destructive agent comprises acidic destructive agents and basic destructive agents.

[0013] Furthermore, the mass ratio of the acidic destructive agent to the basic destructive agent is 1:0.9-1.3.

[0014] Furthermore, the acidic decomposing agent is selected from at least one of citric acid, tartaric acid, and aluminum sulfate; the alkaline decomposing agent is selected from at least one of sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate.

[0015] Furthermore, the flame retardant is selected from at least one of ammonium polyphosphate, ammonium phosphate, water-soluble magnesium hydroxide, and water-soluble aluminum hydroxide.

[0016] Furthermore, the disintegration aid is selected from at least one of urea, cross-linked polyvinylpyrrolidone, sodium carboxymethyl cellulose, hydroxyethyl cellulose, and xanthan gum.

[0017] A second aspect of the present invention provides a method for preparing fire extinguishing tablets, comprising: S1. After melting polyethylene glycol, add surfactant and mix evenly under stirring to obtain composite functional components; S2. After uniformly mixing the composite functional components, cracking agent, flame retardant and cracking aid, the mixture is molded to obtain a fire extinguishing tablet.

[0018] Furthermore, the mass ratio of polyethylene glycol to surfactant is 2-8:1.

[0019] Furthermore, based on the total weight of the composite functional component, the cracking agent, the flame retardant, and the cracking aid, the amount of the composite functional component is 1-10 wt%, the amount of the cracking agent is 40-75 wt%, the amount of the flame retardant is 20-50 wt%, and the amount of the cracking aid is 1-5 wt%.

[0020] Furthermore, in step S1, the melting temperature is 60-90°C.

[0021] Furthermore, the stirring conditions include: a stirring rate of 200-400 r / min and a stirring time of 10-30 min.

[0022] Furthermore, in step S2, the molding pressure is 2-4 MPa, and the molding time is 1-5 seconds.

[0023] A third aspect of the present invention provides a fire extinguishing tablet prepared by the preparation method described in the first aspect.

[0024] The fourth aspect of this invention provides the application of the fire extinguishing tablets described in the third aspect in Class A fires and fires involving new energy sources.

[0025] Furthermore, the application includes: dissolving fire extinguishing tablets in water, rapidly disintegrating and dissolving them to form a fire extinguishing agent, and then spraying the fire extinguishing agent onto the fire source to extinguish the fire.

[0026] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: (1) This invention uses polyethylene glycol to coat a surfactant, forming a shell-core structure. Fire extinguishing is achieved through a "time-controlled collapse-rapid dispersion extinguishing" mechanism. The coating layer gradually dissolves and releases upon contact with water, delaying the time it takes for the surfactant to enter the aqueous phase. This allows the acid-base decomposing agent inside the tablet to fully contact the water first, rapidly undergoing a neutralization reaction and generating a large amount of carbon dioxide gas. The gas quickly accumulates inside the tablet, forming a bubble network that propels the tablet to rapidly collapse from the inside out. While ensuring a short collapse time, this significantly improves the tablet's storage stability (after being placed in a constant temperature and humidity environment of 21°C and 78% for 90 days, the collapse rate is still no less than 32 seconds), thus providing a rapid dispersion solution basis for subsequent fire extinguishing. Furthermore, the foam exhibits good stability and is not easily dissipated.

[0027] (2) The fire extinguishing tablets of the present invention are based on the synergistic mechanism of "rapid disintegration-deep penetration-continuous coverage". After the tablet disintegrates, the water-soluble flame retardant released rapidly forms a covering layer on the surface of the burning material and decomposes to generate free radicals, interrupting the chain reaction; at the same time, the surfactant is gradually released, reducing the surface tension of the solution, enhancing the wetting and spreading ability, and achieving a synergistic fire extinguishing effect of rapid cooling, oxygen isolation and suppression of reignition.

[0028] (3) In the fire extinguishing tablets of the present invention, the surfactant is coated with polyethylene glycol, which improves the isolation from external moisture. When stored in a humid environment for a long time, it is not easy to absorb moisture and clump or become ineffective, and can maintain good cracking performance and fire extinguishing effect. Experiments have verified that after storage under temperature and humidity conditions, the cracking time is still stable within 1 minute, which is suitable for storage in complex environments such as the field and vehicles.

[0029] (4) This invention does not rely on fluorinated surfactants or other harmful components throughout the entire process. Among the raw materials, flame retardants can also be used as phosphate fertilizers, surfactants are widely used in detergents, and disintegrating agents and polyethylene glycol can be used in food or pharmaceuticals. The disintegrating aid is a bio-based material, and all raw materials are biodegradable or environmentally compatible. The solution after the tablets disintegrate has low corrosivity to common metals and meets green and environmental protection requirements in both use and disposal, making it suitable for various civilian and industrial applications. Attached Figure Description

[0030] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0031] Figure 1 The images show scanning electron microscope (SEM) images of LAS and PEG@LAS-1 from Preparation Example 1, where a is the SEM image of LAS and b is the SEM image of PEG@LAS-1.

[0032] Figure 2The image shows the tools used to form fire extinguishing tablets, where a is the tablet press and b is the tablet mold.

[0033] Figure 3 This is an image showing the appearance of the fire extinguishing tablets in Example 1.

[0034] Figure 4 The image shows the phenomenon of a fire extinguishing tablet completely disintegrating in water. In the image, a represents the fire extinguishing tablet just being put into the water, b represents the initial stage of disintegration, c represents the complete disintegration of the fire extinguishing tablet with foam continuously rising, and d represents the complete disintegration of the fire extinguishing tablet with stable foam.

[0035] Figure 5 This is a comparison diagram of the collapse process of Example 1 under different storage times.

[0036] Figure 6 This is a comparison diagram of the collapse process under different storage times for Comparative Example 1.

[0037] Figure 7 This is a comparison diagram of the collapse process under different storage times for Comparative Example 12. Detailed Implementation

[0038] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0039] Because conventional fire extinguishing tablets in the prior art have slow disintegration speed or poor foam stability after disintegration, resulting in low fire extinguishing efficiency, easy reignition, and easy failure due to improper storage, their practical application is severely limited. Therefore, the first aspect of the present invention provides a fire extinguishing tablet composition, wherein the fire extinguishing tablet comprises: 40-75wt% of a disintegrating agent, 20-50wt% of a flame retardant, 1-5wt% of a disintegration aid, and 1-10wt% of a composite functional component; The composite functional component is a surfactant coated with polyethylene glycol.

[0040] In this invention, the components of the rapid-disintegration fire extinguishing tablet provided by this invention work synergistically within the stated content range to achieve an integrated function of rapid disintegration, efficient fire extinguishing, and long-lasting anti-reignition. The tablet contains 40-75 wt% fracturing agent, which rapidly neutralizes upon contact with water, generating a large amount of carbon dioxide gas that causes the tablet to shatter quickly from the inside. 20-50 wt% water-soluble flame retardant is then released, forming a coating layer on the surface of the burning material and interrupting the combustion chain reaction through thermal decomposition, thus exerting flame retardant and anti-reignition effects. 1-5 wt% fracturing aid accelerates water penetration through its strong hydrophilicity, forming microporous channels within the tablet to further promote thorough shattering. Meanwhile, 1-10 wt% of the composite functional components achieve a time-release function through an encapsulation structure: initially delaying surfactant dissolution to ensure a full fracturing reaction; and gradually releasing surfactant after shattering, significantly reducing solution surface tension, enhancing the spreading, wetting, and adhesion capabilities of the agent, forming a durable protective layer. The fracturing aid, through its strong hydrophilicity, accelerates water penetration into every corner of the burning material, achieving thorough fire extinguishing and inhibiting reignition.

[0041] In this invention, the inventors, through extensive research, have determined that the above-mentioned components meet the above-mentioned proportions, enabling them to work synergistically and maximize their functional integration, allowing the tablets to rapidly disintegrate upon contact with water and exert a sustained fire-extinguishing effect.

[0042] If the content of the disintegrant is less than 40 wt%, the amount of gas generated upon contact with water will be insufficient, resulting in a slow tablet disintegration rate and difficulty in achieving sufficient dispersion in a short time, thus reducing the extinguishing efficiency. If it is higher than 75 wt%, it will affect the extinguishing efficacy and the ability to resist reignition, and the excessive reactivity will affect the molding stability during the subsequent tableting process. For example, the content of the disintegrant can be 40 wt%, 43 wt%, 50 wt%, 55 wt%, 58 wt%, 60 wt%, 70 wt%, 73 wt%, 75 wt%, or any two of the above values, preferably 50-60 wt%.

[0043] If the flame retardant content is less than 20 wt%, its flame retardant and anti-reignition effects are insufficient, and reignition is likely to occur after fire is extinguished, especially reducing its ability to suppress deep-seated fires or battery fires. If it is higher than 50 wt%, it will lead to a slower disintegration rate, and the hygroscopicity of the flame retardant will affect the molding stability during tablet compression. For example, the content of the flame retardant can be 20 wt%, 35 wt%, 38 wt%, 39 wt%, 40 wt%, 50 wt%, or any two of the above values, preferably 35-40 wt%.

[0044] If the content of the disintegration aid is less than 1 wt%, its effect on promoting water penetration is limited, the tablet disintegration rate decreases, and there is insufficient aid to form flow channels, affecting the depth of coverage of the burning material by flame retardants and other components, thus reducing the fire extinguishing effect. If it is higher than 5 wt%, it will affect the tableting and storage stability due to excessive hydrophilicity, and the excessive aid will interfere with the synergistic effect of other components. For example, the content of the disintegration aid can be 1 wt%, 2 wt%, 3 wt%, 5 wt%, or any two of the above values, preferably 1-3 wt%.

[0045] If the content of the composite functional component is less than 1 wt%, it affects the tablet's molding and the spreading and wetting properties of the solution after disintegration; if it is greater than 10 wt%, the excessive coating material will delay the overall disintegration process and affect the proportion of the effective extinguishing component in the tablet. For example, the content of the composite functional component can be 1 wt%, 2 wt%, 3 wt%, 5 wt%, 8 wt%, 10 wt%, or any combination of two of the above values, preferably 5-10 wt%.

[0046] According to some embodiments of the present invention, in the composite functional component, the mass ratio of polyethylene glycol to surfactant is 2-8:1.

[0047] In this invention, the mass ratio of polyethylene glycol to surfactant meets the above-mentioned range, ensuring that the coating structure of the composite functional components can effectively isolate the surfactant to ensure rapid disintegration reaction, and can also release the surfactant in a timely manner after the tablet is dispersed, giving full play to its role in reducing surface tension and enhancing the penetration and coverage of the extinguishing liquid, thereby synergistically achieving rapid disintegration and efficient fire extinguishing. If the mass ratio is less than 2:1, the amount of polyethylene glycol is relatively insufficient, which will lead to incomplete coating of the surfactant. After contact with water, the surfactant will dissolve too early and too quickly, inhibiting the nucleation and growth of bubbles in the early stage of the disintegrating agent reaction, thus significantly prolonging the overall disintegration time of the tablet. If the mass ratio is greater than 8:1, the coating layer is too thick, which will excessively delay the release of surfactant in the fire extinguishing stage, affecting the final spreading and wetting properties of the solution, thereby reducing the fire extinguishing efficiency.

[0048] According to some embodiments of the present invention, the surfactant is selected from sodium dodecylbenzenesulfonate and / or sodium dodecyl alcohol ether sulfate.

[0049] In this invention, the composite functional component is preferably sodium dodecylbenzenesulfonate coated with polyethylene glycol.

[0050] According to some embodiments of the present invention, considering that the average molecular weight of polyethylene glycol directly affects its melt characteristics, the coating effect on sodium dodecylbenzenesulfonate, and the dissolution and release of the final coating layer in water, the average molecular weight of the polyethylene glycol is 2000-6000 g / mol. For example, it can be 2000 g / mol, 4000 g / mol, 6000 g / mol, or any range between the above two values.

[0051] Composite functional components can be obtained by melting polyethylene glycol, adding surfactants, and mixing them evenly under stirring.

[0052] Composite functional components have a shell-core structure, such as PEG@LAS, which presents a prismatic blocky appearance and is larger than LAS spheres.

[0053] According to some embodiments of the present invention, the destructive agent comprises an acidic destructive agent and an alkaline destructive agent.

[0054] This invention ensures that the ratio of acidic to basic fracturing agent meets the stoichiometric relationship for a neutral state, guaranteeing a rapid and complete reaction upon contact with water to generate a large amount of carbon dioxide gas. This gas rapidly forms and accumulates pressure inside the tablet, physically disrupting its structure and causing rapid disintegration. Specifically, the acidic and basic fracturing agents need to maintain an acid-base balance to ensure the extinguishing agent remains neutral. If the mass ratio of acidic to basic fracturing agent does not meet the above range, unreacted components will remain in the solution, affecting the pH environment and chemical stability of the extinguishing agent, and insufficient gas generation will lead to incomplete disintegration. For example, a mass ratio of 1:0.9-1.3 of acidic to basic fracturing agent in this invention satisfies the stoichiometric relationship for a neutral state, preferably 1:1.2.

[0055] According to some embodiments of the present invention, the acidic cracking agent is selected from at least one of citric acid, tartaric acid, and aluminum sulfate, and the alkaline cracking agent is selected from at least one of sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate.

[0056] According to some embodiments of the present invention, the flame retardant is selected from at least one of ammonium polyphosphate, ammonium phosphate, water-soluble magnesium hydroxide, and water-soluble aluminum hydroxide.

[0057] In this invention, the aforementioned flame retardant is a water-soluble flame retardant that can rapidly dissolve and release into the fire environment after the tablet shatters upon contact with water. It decomposes at high temperatures to generate active free radicals such as PO· and HPO2·, which efficiently quench free radicals such as H· and OH· in the combustion chain reaction. At the same time, its decomposition products can catalyze the formation of a dense and continuous charcoal covering layer on the surface of combustibles. This covering layer has both heat insulation and oxygen barrier functions, thereby continuously inhibiting deep smoldering and heat backflow after the open flame is extinguished, significantly improving the thoroughness of fire extinguishing and the ability to resist reignition. It is especially suitable for scenarios such as fires involving new energy batteries that are prone to reignition.

[0058] According to some embodiments of the present invention, the disintegration aid is selected from at least one of urea, cross-linked polyvinylpyrrolidone (PVPP), sodium carboxymethyl cellulose, hydroxyethyl cellulose, and xanthan gum.

[0059] In this invention, the aforementioned disintegration aids, through their strong hydrophilicity and swelling properties, form internal microporous channels, promoting water penetration and gas escape, thus achieving rapid tablet disintegration. Simultaneously, because the disintegration aids facilitate rapid and thorough tablet disintegration, it ensures that other components in the tablet, such as flame retardants and surfactants, are instantly and uniformly dispersed in water, forming a fine-particle, highly stable fire-extinguishing foam system. This highly dispersed state significantly improves the spreading and covering efficiency and deep penetration capability of the extinguishing agent on the burning surface, allowing the flame retardant to quickly form a uniform covering layer, and the surfactant to effectively reduce the overall surface tension, thereby synergistically enhancing the cooling, suffocation, and chemical inhibition effects. Furthermore, the disintegration aid can also have a certain water-retention effect, assisting in cooling and working synergistically with the flame retardant.

[0060] A second aspect of the present invention provides a method for preparing fire extinguishing tablets, comprising: S1. After melting polyethylene glycol, add surfactant and mix evenly under stirring to obtain composite functional components; S2. After uniformly mixing the composite functional components, cracking agent, flame retardant and cracking aid, the mixture is molded to obtain a fire extinguishing tablet.

[0061] In this invention, polyethylene glycol is first melted to transform it into a highly fluid liquid matrix, providing a foundation for subsequent uniform coating. Then, a surfactant is added to form a core-shell composite functional component with polyethylene glycol as the continuous phase and the surfactant as the dispersed phase, achieving polyethylene glycol coating of the surfactant. Preferably, the composite functional component is pulverized to 5-20 mesh and then thoroughly mixed with a decongestant, flame retardant, and decongestant aid to ensure uniform distribution of each component. Finally, a fire extinguishing tablet with a consistent structure is obtained through tablet compression molding, ensuring that the decongestant reaction and surface activity upon contact with water are released sequentially and synergistically.

[0062] In this invention, based on the total amount of raw materials, the amount of the cracking agent is 40-75 wt%, the amount of the flame retardant is 20-50 wt%, the amount of the cracking aid is 1-5 wt%, the amount of polyethylene glycol is 0.5-5 wt%, and the amount of the surfactant is 0.5-5 wt%.

[0063] According to some embodiments of the present invention, specifically, the acidic cracking agent is selected from at least one of citric acid, tartaric acid, and aluminum sulfate, and the alkaline cracking agent is selected from at least one of sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate.

[0064] According to some embodiments of the present invention, specifically, the surfactant is selected from at least one of sodium dodecylbenzenesulfonate and sodium dodecyl alcohol ether sulfate.

[0065] According to some embodiments of the present invention, specifically, the flame retardant is selected from at least one of ammonium polyphosphate, ammonium phosphate, water-soluble magnesium hydroxide, and water-soluble aluminum hydroxide.

[0066] According to some embodiments of the present invention, specifically, the disintegration aid is selected from at least one of urea, cross-linked polyvinylpyrrolidone, sodium carboxymethyl cellulose, hydroxyethyl cellulose and xanthan gum.

[0067] According to some embodiments of the present invention, in step S1, the melting temperature is 60-90°C.

[0068] In this invention, polyethylene glycol can be fully melted into a low-viscosity liquid, which facilitates uniform mixing with surfactants and the formation of a structurally stable coating structure during subsequent cooling. This coating structure enables delayed release of surfactants, ensures rapid tablet disintegration, and achieves synergistic effects of efficient fire extinguishing.

[0069] According to some embodiments of the present invention, in step S1, the stirring conditions include: a stirring rate of 200-400 r / min and a stirring time of 10-30 min.

[0070] According to some embodiments of the present invention, considering both ensuring sufficient mechanical strength of the tablets to guarantee storage and transportation stability, and maintaining a suitable internal porosity, the molding pressure in step S2 is 2-4 MPa, and the molding time is 1-5 seconds. If the pressure is less than 2 MPa and the molding time is less than 1 second, the bonding force between the powder particles will be insufficient, the structure will be loose, and it will be brittle during storage and transportation. Furthermore, it will disintegrate prematurely upon contact with water, resulting in incomplete cracking and thus affecting the fire extinguishing effect.

[0071] In this invention, the tablets are not limited to tablets, but can also be rod-shaped, spherical, etc.

[0072] The third aspect of this invention provides the application of the fire extinguishing tablets described in the first aspect in Class A fires and fires involving new energy sources.

[0073] According to some embodiments of the present invention, the application includes: dissolving fire extinguishing tablets in water, rapidly disintegrating and dissolving them to form a fire extinguishing agent, and then spraying the fire extinguishing agent onto the fire source to extinguish the fire.

[0074] In this invention, the fire extinguishing tablets account for 1-10 wt% of the water. The amount of fire extinguishing tablets used within this range is sufficient to achieve the desired fire extinguishing effect. If the amount added is too low, the fire extinguishing effect will be poor; if the amount added is too high, the tablets will not be fully dissolved, affecting the spraying of the fire extinguishing agent, clogging the nozzle, and reducing the fire extinguishing efficiency.

[0075] In this invention, when performing fire extinguishing operations, the spraying pressure of the fire extinguishing agent is 1-3 MPa, and the spraying flow rate is about 1-10 L / min. In order to achieve a better effect of suppressing reignition, it is preferable to continue spraying the fire extinguishing agent for 10-30 seconds after the flame is completely extinguished.

[0076] In this invention, the surface tension of the fire extinguishing agent is 16.9-21.8 mN / m, the foaming ratio is 18.6-26.5, the pH value is 7-8, and the corrosion rate on Q235 steel sheets is 1.1-2.0 mg / (d·dm³). 2 The corrosion rate of LF2 aluminum sheets is 3.5-5.8 mg / (d·dm³). 2 ).

[0077] It should be noted that the extinguishing mechanism is as follows: First, the tablet rapidly ruptures upon contact with water, immediately releasing the water-soluble flame retardant inside. This flame retardant quickly forms a dense covering layer on the surface of the burning material. This layer not only provides heat and oxygen insulation but also decomposes at high temperatures to generate free radicals, interrupting the combustion chain reaction and inhibiting reignition at its source. Second, the surfactant is encapsulated with polyethylene glycol, enabling controlled release of the surfactant: in the initial rupture stage, the acid-base reaction is fully generated to promote dispersion; subsequently, the surfactant continues to dissolve, significantly reducing the surface tension of the solution and enhancing the wettability, spreadability, and adhesion of the extinguishing agent on complex surfaces (such as inside battery packs or in wood crevices), forming a durable, moist protective layer. Simultaneously, the flame retardant can penetrate into the crevices within the burning material, further improving the extinguishing effect and inhibiting reignition. This process not only allows the extinguishing agent to quickly reach deep-seated fire sources but also, through the dual effects of flame-retardant coverage and wetting cooling, provides long-term suppression of smoldering and thermal backdraft, thereby achieving complete fire extinguishing and significantly improving the ability to resist reignition.

[0078] The advantages of the present invention will be illustrated below through examples.

[0079] In the following embodiments, scanning electron microscopy was used to test the morphology of the fire extinguishing tablets.

[0080] In the preparation of fire extinguishing tablets, to ensure the stability of experimental data, this invention uses the same tablet press and the same mold, and adds 5g of powder for each tableting process. The tablet press manufacturer is Tianjin Hengyueda Technology Co., Ltd.; the tablet mold manufacturer is Rishunxing Milk Tablet Mold Shop. The tablet press is as follows... Figure 2 As shown in Figure a, the tablet compression mold is as follows: Figure 2 As shown in b.

[0081] The following preparation examples illustrate the preparation method of the composite functional components in fire extinguishing tablets. Preparation Example 1 S1. Add 60g of polyethylene glycol (PEG, average molecular weight 4000g / mol) to a three-necked flask and melt it completely at 75°C. S2. Add 15g of sodium dodecylbenzenesulfonate (LAS) to a three-necked flask and stir at 200r / min for 20min to obtain a suspension, wherein the ratio of PEG to LAS is 4:1. S3. Pour the stirred suspension into a petri dish to form a film and cool it. Take the cooled sample, crush it, pass it through a 5-mesh sieve and then through a 20-mesh sieve. Take the sample between 5 and 20 mesh to obtain PEG@LAS-1.

[0082] LAS and PEG@LAS-1 were analyzed by scanning electron microscopy, such as Figure 1 As shown in Figure a, LAS is a spherical object with granular material on its surface. Figure 1 b shows the morphology after PEG coating. PEG@LAS-1 exhibits a prismatic blocky appearance, larger than the LAS spheres. This is because the mass of PEG is four times that of LAS, resulting in complete encapsulation of LAS. The analysis results indicate that PEG successfully coated LAS.

[0083] Preparation Example 2 The method of Preparation Example 1 was followed, except that the amount of LAS used was 30g, so that the ratio of PEG to LAS was 2:1; finally, PEG@LAS-2 was obtained.

[0084] Preparation Example 3 The method of Preparation Example 1 was followed, except that the amount of LAS used was 20g, so that the ratio of PEG to LAS was 3:1; finally, PEG@LAS-3 was obtained.

[0085] Preparation Example 4 The method of Preparation Example 1 was followed, except that the amount of PEG was 80g and the amount of LAS was 10g, so that the ratio of PEG to LAS was 8:1; finally, PEG@LAS-4 was obtained.

[0086] Preparation Example 5 The method of Example 1 was followed, except that LAS was replaced with sodium lauryl ether sulfate (SLES). The final product was PEG@SLES.

[0087] Comparative Preparation Example 1 The method of Example 1 was followed, except that LAS was replaced with sodium α-alkenylbenzenesulfonate (AOS) to obtain PEG@AOS. AOS can dissolve in the PEG melt and cannot be coated.

[0088] Comparative Preparation Example 2 The method is the same as in Example 1, except that the amount of PEG is 40g and the amount of LAS is 40g, so that the ratio of PEG to LAS is 1:1, resulting in PEG@LAS-5.

[0089] The following examples illustrate the preparation method of the fire extinguishing tablets of the present invention. Example 1 S1. Weigh out 38g of ammonium polyphosphate, 25g of citric acid, 30g of sodium bicarbonate, 5g of PEG@LAS-1, and 2g of urea. Mix the above-mentioned drugs thoroughly to obtain a powder. S2. Take 5g of the above powder and compress it into tablets using a tablet press at a pressure of 3MPa for 3s to obtain fire extinguishing tablet A1.

[0090] Fire extinguishing tablet A1 Figure 3 As shown, the tablet has a uniform and firm texture, a diameter of 25mm, and a height of 6mm.

[0091] Example 2-14 The method of Example 1 is followed, except that the types and amounts of cracking agents, flame retardants, cracking aids, and composite functional components are varied, as detailed in Table 1.

[0092] Table 1

[0093] Comparative Example 1 S1. Weigh out 38g of ammonium polyphosphate, 25g of citric acid, 30g of sodium bicarbonate, 4g of PEG, 1g of LAS, and 2g of urea, and mix the above-mentioned drugs thoroughly. S2. Add 5g of powder to the mold, compress it using a tablet press at a pressure of 3MPa for 3s to obtain fire extinguishing tablet D1.

[0094] Comparative Example 2 S1. Weigh out 38g of ammonium polyphosphate, 25g of citric acid, 30g of sodium bicarbonate, 1g of PEG, 4g of LAS, and 2g of urea, and mix the above-mentioned drugs thoroughly. S2. Add 5g of powder to the mold and compress it using a tablet press at a pressure of 3MPa for 3s to obtain fire extinguishing tablet D2.

[0095] Comparative Example 3 S1. Weigh out 38g of ammonium polyphosphate, 25g of citric acid, 30g of sodium bicarbonate, 3g of PEG, 2g of LAS, and 2g of urea, and mix the above-mentioned drugs thoroughly. S2. Add 5g of powder to the mold, compress it using a tablet press at a pressure of 3MPa for 3s to obtain fire extinguishing tablet D3.

[0096] Comparative Example 4 S1. Weigh out 38g of ammonium polyphosphate, 25g of citric acid, 30g of sodium bicarbonate, 4.5g of PEG, 0.5g of LAS, and 2g of urea, and mix the above-mentioned drugs thoroughly. S2. Add 5g of powder to the mold, compress it using a tablet press at a pressure of 3MPa for 3s to obtain fire extinguishing tablet D4.

[0097] Comparative Example 5 S1. Weigh out 38g of ammonium polyphosphate, 25g of citric acid, 30g of sodium bicarbonate, 5g of PEG, and 2g of urea, and mix the above-mentioned drugs thoroughly. S2. Add 5g of powder to the mold, compress it using a tablet press at a pressure of 3MPa for 3s to obtain fire extinguishing tablet D5.

[0098] Comparative Example 6 The method is the same as in Example 1, except that in step S2, the pressure is 6 MPa and the compression time is 3 s to obtain fire extinguishing tablet D6.

[0099] Comparative Example 7 The method is the same as in Example 1, except that in step S2, the pressure is 0.5 MPa and the tableting time is 3 seconds. Due to the low pressure, it is impossible to obtain a formed fire extinguishing tablet.

[0100] Comparative Examples 8-11 The method of Example 1 is followed, except that the types and amounts of cracking agents, flame retardants, cracking aids, and composite functional components are varied, as detailed in Table 2.

[0101] Table 2

[0102] Comparative Example 12 S1. Weigh out 38g of ammonium polyphosphate and store it separately; mix 25g of citric acid, 30g of sodium bicarbonate, 5g of PEG@LAS-1, and 2g of urea thoroughly to obtain drug S1-1. S2. Add 1.98g of ammonium polyphosphate to the mold as the inner core layer, and then use the mixed medicine S1-1 as the outer shell layer. Compress the mixture using a tablet press at a pressure of 3MPa and a compression time of 3s to obtain fire extinguishing tablet D12.

[0103] Test case The fire extinguishing tablets prepared in the examples and comparative examples were subjected to disintegration time tests.

[0104] Disintegration time: Add 100 mL of tap water to a 250 mL beaker, and immerse a 5 g fragmentation fire extinguishing tablet in the water. Record this as the start time. Observe the fragmentation of the tablet in the water. Record the end time when the tablet completely disintegrates. The difference between the end time and the start time is the fragmentation time of the fragmentation fire extinguishing tablet. The results are shown in Table 3 and Table 3 (continued).

[0105] The complete disintegration of the tablet is observed through phenomena in water, such as... Figure 4 As shown, Figure 4 'a' indicates that the pill has just been added to the water; Figure 4 b indicates that the tablet is present in the initial stage of dissolving in water; Figure 4 "c" indicates that the solid tablet is not visible, but the foam continues to rise. Figure 4 d indicates that the foam no longer rises and there is no solid matter or flocculent sediment, which is considered as the tablet completely breaking apart.

[0106] The foaming ratio was determined in accordance with GB / T 15308-2006.

[0107] Table 3

[0108] Table 3 (continued)

[0109] Comparative Examples 1-5 show that the addition of a fracturing agent significantly affects the disintegration rate of the fire extinguishing tablets. As the amount of surfactant added increases, the disintegration time also lengthens; this is because the surfactant affects the formation of the fracturing agent foam.

[0110] Take the reaction of citric acid and sodium bicarbonate as an example: 3NaHCO3+C6H8O7→ Na3C6H5O7+3H2O+3CO2↑ The CO2 gas produced by the reaction of citric acid and sodium bicarbonate does not arise spontaneously. It needs to accumulate at the point of contact with the fire extinguishing pellet, overcoming surface tension and liquid pressure to form tiny bubble buds—a process called nucleation. These small bubbles then merge and grow, eventually escaping from the solution—a process called escape. Without surfactants, the surface tension of the solution is high, making bubble nucleation relatively difficult, but once formed, the gas quickly enters and causes it to grow.

[0111] In the presence of surfactants, the surface tension of the solution decreases, facilitating bubble nucleation. This results in numerous tiny bubbles forming on the surface of the fire extinguishing tablet. Simultaneously, the surfactant adsorbs onto the surface of these bubbles, with its hydrophobic tail facing the gas interior and its hydrophilic head facing the aqueous solution. This forms a negatively charged monomolecular film with a certain mechanical strength around the bubbles. This film acts like a shell, preventing the bubbles from easily merging and also hindering the diffusion rate of CO2 gas molecules from the solution or reaction system into the bubbles. This makes it difficult for the reaction to proceed in the forward direction, slowing down the rate of carbon dioxide production. The inability of these tiny bubbles to escape properly prevents the effective ionization of the acid-base disintegrating agent in the fire extinguishing tablet, thus preventing the reaction from proceeding normally.

[0112] The above analysis shows that the type and amount of surfactant significantly affect the disintegration rate of fire extinguishing tablets. In Comparative Example 1, during the disintegration process in water, a large number of bubbles are generated the instant the fire extinguishing tablet is added to the water, such as... Figure 4 As shown in a, this is due to the absence of surfactant in the water; as the tablet breaks apart, the surfactant dissolves into the water, reducing the surface tension of the solution and generating a large amount of fine foam. Furthermore, the tablet's breaking rate slows down. Figure 4 As shown in b. The foam has low stability and is prone to reignition when used for fire extinguishing.

[0113] Due to the complexity and high cost of fire extinguishing experiments, in order to verify the effectiveness of fire extinguishing tablets, this invention selected Examples 1, 8, 9, 11, Comparative Example 2, and Comparative Example 5 as samples to investigate the impact on the fire extinguishing capability for new energy fires and Class A fires. Fire extinguishing agents were prepared by dissolving the fire extinguishing tablets in tap water (95wt%) at a dosage of 5wt%, with each formulation yielding 25kg of fire extinguishing agent.

[0114] Dissolve the fire extinguishing tablets in tap water at a dosage of 5 wt%, and each formula prepares 25 kg of fire extinguishing agent.

[0115] Application Example A The fire extinguishing tablets prepared in the examples and comparative examples were subjected to new energy fire extinguishing experiments (tablet mass fraction 5 wt%, water mass fraction 95 wt%). Specifically: We use SBP-01-3140 square aluminum shell 314Ah battery cells manufactured by Sunwoda.

[0116] (1) The tablets of the examples and comparative examples were put into water to break them apart to obtain fire extinguishing agent; then an overcharge device was arranged at the positive and negative terminals of the battery cell, and thermocouples were arranged on the front and back sides to detect the temperature of the battery cell. (2) Overcharge the battery cell with a constant current of 140A; (3) When the safety valve of the battery cell opens and begins to release a large amount of gas (smoke), ignite the battery cell and stop the overcharge device; (4) One minute after ignition, start spraying the extinguishing agent. The spraying pressure of the extinguishing agent is 2.5 MPa and the spraying flow rate is about 2.5 L / min. (5) After the battery flame is completely extinguished, continue to spray the extinguishing agent for 30 seconds; (6) Continuously monitor the temperature of the battery surface and observe for 30 minutes; After spraying, observe for 48 hours to see if the battery reignites. According to the test items in GB17835-2024 "Water-based Fire Extinguishing Agents", test the extinguishing time and whether reignition occurs after extinguishing. The results are shown in Table 5. The extinguishing time includes 30 seconds of continuous spraying in step (5).

[0117] Table 4

[0118] Application Example B To further illustrate that the fire extinguishing tablets of the present invention also have excellent effects on Class A fires, a timber stack model was constructed in an open space. The specific experimental steps are as follows (the mass fraction of the tablets is 5 wt%, and the mass fraction of the water is 95 wt%): (1) The model is constructed from 6 5×2×10cm pine strips, with 2 strips per layer for a total of three layers; (2) Place the crystallizing dish containing alcohol under the woodpile to ignite it; (3) Ignite the wood stack with alcohol for 90 seconds, then remove the crystallizing dish and let it burn freely for about 80 seconds until the flame is stable; (4) Start spraying the extinguishing agent. The spraying pressure of the extinguishing agent is 0.8MPa and the spraying flow rate is about 1.2L / min. (5) After extinguishing the fire, record the extinguishing time and continue spraying the extinguishing agent for 20 seconds; (6) Observe continuously for 30 minutes to check if the wood block reignites; (7) After spraying, continue to observe for 24 hours to see if the wood blocks reignite.

[0119] According to the test items in GB17835-2024 "Water-based Fire Extinguishing Agents", the extinguishing time of the above-mentioned different samples and whether reignition occurred after extinguishing were tested, as a reflection of the extinguishing ability of the fire extinguishing agents. The test results are shown in Table 5.

[0120] Table 5

[0121] This invention delays the dissolution process of the surfactant by coating it. After the tablet completely or mostly disintegrates, the surfactant gradually diffuses into the solution, reducing the surface tension of the solution and improving its fire extinguishing ability. Example 1 illustrates the disintegration process in water, as follows: Figure 5 As shown, when the extinguishing tablet is placed in water, it produces a large number of bubbles. Since there is no surfactant present during the tablet's disintegration, the reaction continues, generating even more bubbles. The time in the diagram starts from the moment the extinguishing tablet is placed. Comparative Example 2 shows relatively good initial foaming ability, but the foam is small, unstable, and easily dissipates, making it prone to reignition after extinguishing the fire.

[0122] From Example 1 to Example 4, the ratio of polyethylene glycol to sodium dodecylbenzenesulfonate during the coating process was changed (between 2:1 and 8:1). As the ratio of sodium dodecylbenzenesulfonate increased, the cracking time was prolonged, but the cracking time was less than 1 minute.

[0123] As shown in Example 5, increasing the amount of urea, a disintegrating agent, increases the disintegration rate, while in Comparative Example 11, without the disintegrating agent, the disintegration rate is noticeably slower. This is because urea is highly soluble in water, and after dissolving, it forms tiny pores or channels inside the extinguishing tablet, allowing water to more easily penetrate into the tablet, and carbon dioxide to escape through these pores or channels. These structural weaknesses make the tablet more prone to disintegration from the inside under pressure. Similarly, comparing Examples 1 and 11, the disintegration effects are similar.

[0124] Comparing Examples 1, 8, and 9, it can be seen that increasing the amount of delaminant and reducing the amount of flame retardant can improve the delamination rate of the fire extinguishing tablets.

[0125] Comparing Example 1 and Example 10, it can be seen that changing the disintegration system to aluminum sulfate and potassium bicarbonate slightly prolongs the disintegration time. This is because the reaction between aluminum sulfate and potassium bicarbonate produces aluminum hydroxide colloid, which hinders the generation of carbon dioxide bubbles and prolongs the disintegration time of the fire extinguishing tablet.

[0126] Comparing Comparative Examples 6 to 8 with Example 1, it can be seen that if the pressure is too low during the tableting process, the extinguishing tablets cannot be formed; if the pressure is too high or the tableting time is too long, the extinguishing tablets will break down at a faster rate.

[0127] To further illustrate the storage stability of the fire extinguishing tablets of the present invention, durability tests were conducted on Example 1, Comparative Example 1, and Comparative Example 12. Referring to the moisture absorption test environment in Section 6.4.2.2 of GB 4006-2017, the fire extinguishing tablets were placed in a constant temperature and humidity environment of 21°C and 78% relative humidity for 0 days, 7 days, 30 days, and 90 days, respectively, to examine the durability of the samples. The results are shown in Table 6.

[0128] Table 6

[0129] Note: Day 0 indicates that the tablets were immediately added to water after preparation. Based on the test results in Table 6, the phenomena during the dissolution process are as follows: Figure 5 As shown in Example 1, the disintegration time inevitably increases slightly with the increase of storage time, but after 90 days of storage, it can still completely disintegrate within 32 seconds, still meeting the purpose of rapid disintegration of fire extinguishing tablets. Figure 6 As a comparative example, the disintegration time of the fire extinguishing tablets increased significantly with the increase of storage time, from the initial 157s to 339s, which could not meet the purpose of rapid disintegration of the fire extinguishing tablets. Figure 7 As a comparative example 12, with the increase of storage time, the sample can rapidly disintegrate within 20 seconds after 7 days. However, with the extension of storage time, i.e. after 30 days and 90 days, undissolved lumps can be seen in the solution, which require a long time to slowly dissolve (362 seconds). The foaming ratio is also significantly affected, which cannot meet the purpose of rapid disintegration of the fire extinguishing tablet.

[0130] In Example 1, because the destructive agent and flame retardant can be fully mixed, the dispersed flame retardant particles cannot come into contact with each other. Even when stored for a long time in a high humidity environment of 21°C and 78% relative humidity, the flame retardants cannot aggregate under the action of van der Waals forces. As a small amount of water molecules penetrate into the extinguishing tablet, crystal bridges cannot be formed between the flame retardant particles. Once the tablet is put into water, the flame retardant can be rapidly dispersed and dissolved under the action of the destructive agent, achieving the purpose of rapid dissolution. However, the penetration of a small amount of water molecules into the extinguishing tablet will affect the destructive agent. Therefore, as the storage time is extended, the destructive time of Example 1 is prolonged, but it can still destructively decompose within 32 seconds.

[0131] In Comparative Example 1, although the deflamming agent and flame retardant were thoroughly mixed, the exposed surfactant affected the deflamming rate, resulting in an excessively long deflamming time. In Comparative Example 15, initially, due to the absence of flame retardant in the outer shell, the outer shell could deflammable rapidly, and the flame retardant could quickly disperse into the solution under the impact of deflammation. However, as the storage time increased to 30 days and 90 days, the flame retardant particles in the inner shell became densely packed, and the flame retardant molecules gradually combined under the action of van der Waals forces. Furthermore, as a small amount of water molecules penetrated into the extinguishing tablet, crystal bridges formed between the flame retardant particles, and the flame retardant gradually clumped together. Once the tablet was placed in water, the deflamming agent initially deflammed rapidly and impacted the inner shell of the flame retardant, causing a small amount of flame retardant to dissolve. However, due to the clumping of the flame retardant, the foam generated by the deflammation could not disperse the flame retardant clumps. In the later stages, the clumps of flame retardant could only dissolve slowly in water, resulting in an excessively long dissolution time.

[0132] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A fire extinguishing tablet composition, characterized in that, The fire extinguishing tablet composition comprises: 40-75 wt% of a fracturing agent, 20-50 wt% of a flame retardant, 1-5 wt% of a fracturing aid, and 1-10 wt% of a composite functional component. The composite functional component is a surfactant coated with polyethylene glycol.

2. The fire extinguishing tablet composition of claim 1, wherein In the composite functional component, the mass ratio of polyethylene glycol to surfactant is 2-8:1; The surfactant is selected from sodium dodecylbenzene sulfonate and / or sodium dodecyl alcohol ether sulfate; And / or, the average molecular weight of the polyethylene glycol is 2000-6000 g / mol.

3. The fire extinguishing tablet composition of claim 1, wherein The destructive agent includes acidic destructive agents and basic destructive agents; And / or, the mass ratio of the acidic fracturing agent to the basic fracturing agent is 1:0.9-1.3; And / or, the acidic cracking agent is selected from at least one of citric acid, tartaric acid, and aluminum sulfate; the alkaline cracking agent is selected from at least one of sodium bicarbonate, potassium bicarbonate, sodium carbonate, and potassium carbonate.

4. The fire extinguishing tablet composition according to any one of claims 1 to 3, wherein The flame retardant is selected from at least one of ammonium polyphosphate, ammonium phosphate, water-soluble magnesium hydroxide, and water-soluble aluminum hydroxide. And / or, the disintegration aid is selected from at least one of urea, cross-linked polyvinylpyrrolidone, sodium carboxymethyl cellulose, hydroxyethyl cellulose and xanthan gum.

5. A method of preparing a fire extinguishing tablet, characterized by, include: S1. After melting polyethylene glycol, add surfactant and mix evenly under stirring to obtain composite functional components; S2. After uniformly mixing the composite functional components, cracking agent, flame retardant and cracking aid, the mixture is molded to obtain a fire extinguishing tablet.

6. The preparation method according to claim 5, characterized in that, The mass ratio of polyethylene glycol to surfactant is 2-8:1; And / or, based on the total weight of the composite functional component, cracking agent, flame retardant and cracking aid, the amount of the composite functional component is 1-10 wt%, the amount of the cracking agent is 40-75 wt%, the amount of the flame retardant is 20-50 wt%, and the amount of the cracking aid is 1-5 wt%.

7. The preparation method according to claim 5, characterized in that, In step S1, the melting temperature is 60-90℃; And / or, the stirring conditions include: a stirring rate of 200-400 r / min and a stirring time of 10-30 min; And / or, in step S2, the molding pressure is 2-4 MPa and the molding time is 1-5 s.

8. Fire extinguishing tablets prepared by the preparation method according to any one of claims 5-7.

9. The application of the fire extinguishing tablets according to claim 8 in Class A fires and new energy fires.

10. Use according to claim 9, characterized in that, The application includes: dissolving fire extinguishing tablets in water, rapidly disintegrating and dissolving them to form a fire extinguishing agent, and then spraying the fire extinguishing agent onto the fire source to extinguish the fire.

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