Fire extinguishing agent composition

Abstract

The problem that this invention aims to solve is to provide a fire extinguishing agent composition that can be used as a fire extinguishing agent that enables continuous cooling by being in close contact with the source of the fire. [Solution] The fire extinguishing agent composition of the present invention comprises a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, and water. The fire extinguishing agent composition of the present invention has a viscosity of 10 after discharge. 8 It is preferable that the temperature is Pa·s or less, and that the 10-hour half-life temperature of the polymerization initiator is 80°C or higher.

Description

[Technical Field]

[0001] This invention relates to a fire extinguishing agent composition used in fire extinguishing agents and the like. [Background technology]

[0002] Fire extinguishing agents can be broadly classified into powder, water, and gas types. Among these, water-based agents have the advantage of a very high cooling effect and the ability to prevent re-ignition, and are widely used as fire extinguishing agents. However, conventional water-based fire extinguishing agents have low viscosity and good fluidity, which leads to water damage problems due to runoff and scattering during firefighting, requiring continuous water discharge for long periods of time. For example, when extinguishing a fire in a high-rise building, a large amount of water may flow down, causing flooding in lower floors that are not directly related to the fire, potentially leading to damage to household goods and, in some cases, causing fires involving electrical systems. Furthermore, during earthquakes, water sources may be limited due to burst water pipes or cracks in fire cisterns, which can hinder firefighting efforts. Furthermore, in firefighting operations in arid areas such as forests, bushes, grasslands, and mountains, aerial firefighting methods, which involve spraying firefighting water from helicopters or small airplanes, are commonly used. However, this method has problems such as scattering of water during aerial spraying, requiring large amounts of firefighting water, and potentially leading to the spread of fire.

[0003] Numerous polymer gel additives, particularly those aimed at suppressing water loss from burning materials, are known to solve the aforementioned drawbacks of water-based fire extinguishing agents, as described in the following Patent Documents 1-7. All of these Patent Documents 1-7 emphasize the use of polymer additives and describe improved methods for preventing water loss by dispersing a cross-linked polymer having a certain particle size in a water-miscible medium and improving the adhesion of the gel absorbed during firefighting to the surface of the burning material. However, all of these are mixtures obtained by adding water-insoluble powdered, granular, or liquid-dispersed superabsorbent polymer gel to fire extinguishing water. For example, when using current standard fire extinguishing equipment, adhesion to the fire extinguishing equipment occurs, and in particular, blockage of the equipment due to aggregation of gel particles often leads to inoperability, which is extremely dangerous in actual use and therefore remains in the experimental stage.

[0004] Furthermore, lithium-ion batteries, which are increasingly used in electric vehicles and other devices, are difficult to extinguish once they catch fire and require continuous cooling. While methods such as immersion in water have been proposed, these are practically impractical. Additionally, firefighting by spraying water presents a problem: the low viscosity of water prevents it from staying in close contact with the source of the fire, requiring prolonged and large-volume water spraying to maintain cooling. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] U.S. Patent No. 3758641 [Patent Document 2] U.S. Patent No. 4978460 [Patent Document 3] U.S. Patent No. 5190110 [Patent Document 4] Japanese Patent Application Publication No. 7-255870 [Patent Document 5] Japanese Patent Application Publication No. 9-140826 [Patent Document 6] Japanese Patent Application Publication No. 10-155932 [Patent Document 7] Japanese Patent Application Publication No. 10-192444 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The problem that this invention aims to solve is to provide a fire extinguishing agent composition that can be used as a fire extinguishing agent that allows for continuous cooling by being in close contact with the source of the fire. [Means for solving the problem]

[0007] As a result of investigations to solve the above problems, the inventors of the present invention found that water-soluble organic monomers and the like can be used as a fire extinguishing agent composition, and thus completed the present invention.

[0008] In other words, the present invention relates to the following: [1] A fire extinguishing agent composition comprising a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, and water. [2] The fire extinguishing agent composition according to [1], wherein the polymerization initiator has a 10-hour half-life temperature of 80°C or higher. [3] Viscosity before radiation is 10 8 A fire extinguishing agent composition according to [1] or [2], wherein the Pa·s is less than or equal to [2]. [Effects of the Invention]

[0009] The fire extinguishing agent composition of the present invention is useful as a water-based fire extinguishing agent because it has the effect of enabling continuous cooling by adhering closely to the source of the fire. Furthermore, since the reaction does not proceed at room temperature and the gelation reaction proceeds when exposed to the heat of the fire, it is possible to achieve both long-term dischargeability and viscosity increase when heated, thereby achieving dischargeability and continuous cooling due to improved adhesion to the burning material. [Modes for carrying out the invention]

[0010] The following describes one embodiment of the present invention. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications without impairing the effects of the present invention.

[0011] [Fire extinguishing agent composition] The fire extinguishing agent composition of the present invention comprises a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, and water. Polymerization of the fire extinguishing agent composition of the present invention is initiated by the heat of a fire, resulting in an organic-inorganic composite hydrogel in which the water-soluble organic monomer (an organic substance) and the water-swellable clay mineral (an inorganic substance) form a three-dimensional network structure with water as the matrix. The fire extinguishing agent composition of the present invention may also contain other components, such as a catalyst, in addition to these components.

[0012] (Water-soluble organic monomers) The water-soluble organic monomer is not particularly limited, and examples thereof include (meth)acrylamide group-containing monomers, (meth)acryloyloxy group-containing monomers, hydroxyl group-containing acrylic monomers, etc. The water-soluble organic monomer may be used alone or in combination of two or more kinds.

[0013] Examples of the above (meth)acrylamide group-containing monomers include acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-methylacrylamide, N-ethylacrylamide, N-isopropylacrylamide, N-cyclopropylacrylamide, N,N-dimethylaminopropylacrylamide, N,N-diethylaminopropylacrylamide, acryloylmorpholine, methacrylamide, N,N-dimethylmethacrylamide, N,N-diethylmethacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-isopropylmethacrylamide, N-cyclopropylmethacrylamide, N,N-dimethylaminopropylmethacrylamide, N,N-diethylaminopropylmethacrylamide, etc.

[0014] Examples of the above (meth)acryloyloxy group-containing monomers include methoxyethyl acrylate, ethoxyethyl acrylate, methoxyethyl methacrylate, ethoxyethyl methacrylate, methoxymethyl acrylate, ethoxymethyl acrylate, etc.

[0015] Examples of the above hydroxyl group-containing acrylic monomers include hydroxyethyl acrylate, hydroxyethyl methacrylate, etc.

[0016] Of these, as the water-soluble organic monomer, it is preferable to use a monomer containing a (meth)acrylamide group from the viewpoint of solubility and the physical properties of the resulting hydrogel, and it is more preferable to use acrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N-isopropylacrylamide, and acryloylmorpholine, and it is even more preferable to use N,N-dimethylacrylamide and acryloylmorpholine, and from the viewpoint of easy polymerization, N,N-dimethylacrylamide is particularly preferred.

[0017] The content of water-soluble organic monomers in the fire extinguishing agent composition of the present invention is preferably 1 to 50% by mass, and more preferably 5 to 30% by mass, based on the total mass. A content of 1% by mass or more of water-soluble organic monomers is preferable because it allows for the production of a hydrogel with excellent mechanical properties. On the other hand, a content of 50% by mass or less of water-soluble organic monomers is preferable because it facilitates the preparation of the dispersion.

[0018] (Water-swellable clay mineral) Examples of water-swellable clay minerals include water-swellable smectite and water-swellable mica, although these are not particularly limited. Water-swellable clay minerals may be used individually or in combination of two or more types.

[0019] Examples of the above-mentioned water-swellable smectites include water-swellable hectorite, water-swellable montmorillonite, and water-swellable saponite. Examples of water-swellable mica include water-swellable synthetic mica. Of these, from the viewpoint of dispersion stability, it is preferable to use water-swellable hectorite and water-swellable montmorillonite as the water-swellable clay mineral, and it is more preferable to use water-swellable hectorite.

[0020] Water-swellable clay minerals can be naturally occurring, synthetic, or surface-modified. Examples of surface-modified water-swellable clay minerals include pyrophosphate-added synthetic hectorite and fluorine-modified synthetic hectorite.

[0021] The viscosity in water of water-swellable clay minerals is 10 8 It is preferable that it be less than or equal to Pa·s. 7 It is more preferable that it be less than or equal to Pa·s, and 1 to 10 7 It is even more preferable that it be Pa·s, 10-10 5 It is especially preferable that it be Pa·s. 2 ~10 4 It is most preferable that the viscosity of the water-swellable clay mineral is 10 8 A viscosity of Pa·s or less is preferable because it allows for easy mixing with organic monomers and the like during dispersion in water. Furthermore, it is preferable because the water-swellable clay mineral disperses more easily in the dispersion, in other words, the water-swellable clay mineral does not aggregate, resulting in a greater number of polymerization initiators being present near the water-swellable clay mineral, which can facilitate polymerization. In this specification, the value of "water viscosity of water-swellable clay mineral" shall be the value measured using a B-type viscometer (TVB-10 viscometer, manufactured by Toki Sangyo Co., Ltd.) when 2 g of water-swellable clay mineral is dispersed in 100 mL of water so that the shear stress is 0.1 Pa, and the temperature of the dispersion is 20°C.

[0022] The content of water-swellable clay minerals in the fire extinguishing agent composition of the present invention is preferably 1 to 20% by mass, and more preferably 2 to 10% by mass, based on the total mass. A content of 1% by mass or more of water-swellable clay minerals is preferable because it allows for the synthesis of a hydrogel with excellent mechanical properties. On the other hand, a content of 20% by mass or less of water-swellable clay minerals is preferable because it facilitates the preparation of the dispersion.

[0023] The fire extinguishing agent composition of the present invention requires water as a solvent, but other organic solvents that can be mixed with water may also be used. As such organic solvents, alcohols are preferred, methanol, ethanol, n-propyl alcohol, and isopropyl alcohol are more preferred, and methanol and ethanol are even more preferred.

[0024] (Polymerization initiator) The polymerization initiator in the fire extinguishing agent composition of the present invention is preferably water-soluble because it has the function of polymerizing water-soluble organic monomers. While not particularly limited, examples of polymerization initiators include water-soluble peroxides and water-soluble azo compounds. Examples of water-soluble peroxides include potassium peroxodisulfate, ammonium peroxodisulfate, sodium peroxodisulfate, and t-butyl hydroperoxide. Examples of water-soluble azo compounds include 2,2'-azobis(2-methylpropionamidine) dihydrochloride and 4,4'-azobis(4-cyanovaleric acid). The polymerization initiator may be used alone or in combination of two or more.

[0025] As a polymerization initiator, since it is used as a fire extinguishing agent, it is required that it does not decompose easily by heat, so it is preferable that it has a 10-hour half-life temperature of 80°C or higher. Furthermore, it is preferable that it is easily soluble in water. Examples of such polymerization initiators include the water-soluble azo derivative 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide) [also known as VA-086] and t-butyl hydroperoxide ("Perbutyl (registered trademark) H-69," manufactured by NOF Corporation).

[0026] The solubility of the polymerization initiator in water is preferably 5 g / 100 mL or more, more preferably 10 g / 100 mL or more, even more preferably 30 g / 100 mL or more, and particularly preferably 50 to 100 g / 100 mL or more. A solubility of 5 g / 100 mL or more in water is preferable because it makes it easy to dissolve the polymerization initiator, and as a result of the polymerization initiator being dispersed in the dispersion, polymerization proceeds favorably, and the physical properties of the resulting organic-inorganic composite hydrogel can be improved. In this specification, "solubility of the polymerization initiator in water" means the weight of the polymerization initiator when the visible light transmittance of the aqueous solution becomes 95% or less after dissolving the polymerization initiator in 100 mL of water at 20°C.

[0027] The molar ratio of the polymerization initiator to the water-soluble organic monomer content in the fire extinguishing agent composition of the present invention (polymerization initiator / water-soluble organic monomer) is, for example, 0.005 or more, preferably 0.01 or more, more preferably 0.02 to 0.1, and even more preferably 0.04 to 0.1. If the molar ratio (polymerization initiator / water-soluble organic monomer) is less than 0.005, polymerization of the water-soluble organic monomer cannot be suitably carried out in an air atmosphere.

[0028] The content of the polymerization initiator in the fire extinguishing agent composition of the present invention is preferably 0.1 to 10% by mass, and more preferably 0.2 to 10% by mass, based on the total mass. A polymerization initiator content of 0.1% by mass or more is preferable because it enables polymerization of organic monomers even in an air atmosphere. On the other hand, a polymerization initiator content of 10% by mass or less is preferable because the dispersion can be used without agglomerating before polymerization, improving handling.

[0029] The catalyst described above has the function of increasing the polymerization rate when polymerizing water-soluble organic monomers. The catalyst is not particularly limited, but examples include tertiary amine compounds, thiosulfates, and ascorbic acids. Examples of tertiary amine compounds include N,N,N',N'-tetramethylethylenediamine and 3-dimethylaminopropionitrile. Examples of thiosulfates include sodium thiosulfate and ammonium thiosulfate. Examples of ascorbic acids include L-ascorbic acid and sodium L-ascorbate. Of these, from the viewpoint of dispersion stability, it is preferable to use a tertiary amine compound as the catalyst, and more preferably N,N,N',N'-tetramethylethylenediamine.

[0030] The content of the catalyst in the composition for fire extinguishing agent of the present invention is preferably 0.01 to 1% by mass, more preferably 0.05 to 0.5% by mass, based on the total mass of the dispersion. When the content of the catalyst is 0.01% by mass or more, it is preferable because the synthesis of the organic monomer of the obtained hydrogel can be efficiently promoted. On the other hand, when the content of the catalyst is 1% by mass or less, it is preferable because the dispersion can be used without agglomerating before polymerization, and the handleability is improved.

[0031] (Method for preparing a composition for fire extinguishing agent) The method for preparing the composition for fire extinguishing agent of the present invention is not particularly limited and can be prepared by a known method. Specifically, a one-liquid mixing method in which a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, a catalyst, etc. are all added to a solvent; a multi-liquid mixing method in which different components are added to two or more solvents and the two or more obtained dispersions are mixed, etc. can be mentioned. As the solvent, a water-soluble solvent such as water or alcohol can be used. Among these, from the viewpoints of dispersibility, storage stability, viscosity control, etc., the multi-liquid mixing method is preferable, from the viewpoint of productivity, the two-liquid mixing method or the three-liquid mixing method is more preferable, and the two-liquid mixing method is even more preferable. Hereinafter, the two-liquid mixing method will be described in detail.

[0032] In the two-liquid mixing method, a first dispersion precursor solution and a second dispersion precursor solution are prepared, and the first dispersion precursor solution and the second dispersion precursor solution are mixed. The first dispersion precursor solution is a water-soluble organic monomer, a water-swellable clay mineral, and a solvent, and the second dispersion precursor solution is a polymerization initiator and a solvent. By making it into two liquids in this way, it is possible to avoid the contact between the water-soluble organic monomer and the polymerization initiator before polymerization. The mixing may be carried out by stirring or shaking as necessary.

[0033] The viscosity (23 °C) of the composition for fire extinguishing agent of the present invention before spraying is preferably 10 8 Pa·s or less, more preferably 10 7 Pa·s or less, even more preferably 1 to 10 7 Pa·s, and further preferably 10 to 105 It is particularly preferable that it be Pa.s. 2 ~10 4 It is most preferable that the viscosity of the fire extinguishing agent composition of the present invention does not increase at temperatures of about 40°C, from the viewpoint of storage stability during storage.

[0034] The fire extinguishing agent composition of the present invention, after being discharged in the event of a fire, begins polymerization due to the heat of the fire, forming an organic-inorganic composite hydrogel in which polymers of water-soluble organic monomers (organic substances) and water-swellable clay minerals (inorganic substances) form a three-dimensional network structure with water as the matrix, and its viscosity increases. The viscosity of the organic-inorganic composite hydrogel after polymerization following discharge is, for example, 0.1 to 10 2 The pressure is Pa.s, preferably 0.1 to 1 Pa.s. [Examples]

[0035] The present invention will be specifically described below with reference to examples and comparative examples.

[0036] [Example 1: Preparation of a fire extinguishing agent composition] In a flat-bottomed glass container, 90 mL of pure water, 2.4 g of phosphonic acid-modified hectorite (Laponite RDS, manufactured by Bic Chemie Japan Co., Ltd.), and 10 g of dimethylacrylamide (DMAA) were added, and a homogeneous, transparent aqueous solution (A-1) was prepared by stirring. Next, 10 mL of pure water and 0.5 g of 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide] were added to another flat-bottomed glass container and stirred to prepare a homogeneous, transparent initiator aqueous solution. The entirety of the above aqueous solution (A-1) was placed in a 200 mL glass beaker, and while stirring, the initiator aqueous solution prepared above was added, and stirring continued until it was uniformly mixed to obtain the fire extinguishing agent composition (1).

[0037] [Comparative Example 1: Preparation of Fire Extinguishing Agent Composition] In a flat-bottomed glass container, 90 mL of pure water, 2.4 g of phosphonic acid-modified hectorite (Laponite RDS, manufactured by Bic Chemie Japan Co., Ltd.), and 10 g of dimethylacrylamide (DMAA) were added, and a homogeneous, transparent aqueous solution (A-1) was prepared by stirring. Next, 10 mL of pure water and 0.5 g of sodium persulfate (hereinafter abbreviated as "NPS") were added to another flat-bottomed glass container and stirred to prepare a homogeneous, transparent NPS aqueous solution. The entirety of the above aqueous solution (A-1) was added to a 200 mL glass beaker, and while stirring, the NPS aqueous solution prepared above was added, and stirring continued until it was uniformly mixed to obtain the fire extinguishing agent composition (2).

[0038] [Evaluation: Presence or absence of gelation due to storage stability] Eleven g each of the fire extinguishing agent compositions (1) and (2) obtained above was placed in a 20 mL glass bottle and stored in a drying oven set to the following storage temperature to check whether or not gelation occurred.

[0039] [Table 1]

[0040] The fire extinguishing agent composition (1) of Example 1 does not gel at low temperatures, so it can be discharged from fire extinguishing equipment. On the other hand, the fire extinguishing agent composition (2) of Comparative Example 1 gels even at low temperatures, so it has poor storage properties.

[0041] [Evaluation: Fire resistance] The fire resistance of the fire extinguishing agent composition (1) of Example 1, the sample before gelation, water, and the sample without adhesion was evaluated using the following method. (1) Measure a fixed amount of each sample and attach it to the tip of a wooden stick, approximately 3 cm from the end. *However, for the pre-gelation sample and water, the sample viscosity was low, making it difficult to increase the amount that adhered to the wooden stick, so 0.1g was used. (2) Expose the covered end to the flame of a gas burner. (3) Record how long it takes for the wooden stick to char and / or burn.

[0042] [Table 2]

[0043] The fire extinguishing agent composition (1) of Example 1 can be said to be useful as a fire extinguishing agent because it takes more than 2 minutes for a wooden stick to char, indicating that it has a certain degree of fire resistance.

Claims

1. A fire extinguishing agent composition comprising a water-soluble organic monomer, a water-swellable clay mineral, a polymerization initiator, and water.

2. The fire extinguishing agent composition according to claim 1, wherein the polymerization initiator has a 10-hour half-life temperature of 80°C or higher.

3. Viscosity before radiation is 10 ８ The fire extinguishing agent composition according to claim 1 or 2, wherein the Pa·s is less than or equal to Pa·s.

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