Water-added fire extinguishing agent

Abstract

To provide a fire extinguisher that is excellent in fire extinguishing property such as peat fire etc., and less in load on human bodies, creatures and natural environment.SOLUTION: The fire extinguisher of the present invention is a water addition type fire extinguisher containing a surfactant component, a chelate component, and a solvent, wherein the surfactant component is at least one selected from the group consisting of fatty acid sodium salts and fatty acid potassium salts, and the fatty acid in the fatty acid sodium salt and the fatty acid potassium salt is at least one selected from the group consisting of lauric acid, myristic acid, palmitic acid, and oleic acid; the chelate component is at least one selected from the group consisting of tetrasodium L-aspartate-(N,N)-diacetate and trisodium methylglycine diacetate, and the solvent is water or a mixed solvent containing water.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a water-added fire extinguishing agent. [Background technology]

[0002] The foams widely used for ordinary fires (house, wood, paper, etc.) include protein foams, synthetic surfactant foams, aqueous film-forming foams, and combinations of these with fluorine-based surfactants. All of these are effective fire extinguishing agents, and can extinguish fires more quickly and with less liquid than water alone. However, fire extinguishing agents containing synthetic chemicals may decompose and produce toxic substances, or the residues may remain for a long time and have a negative impact on living organisms. Therefore, when considering situations where fire extinguishing agents are to be widely sprayed in the natural environment, such as forest fires, they are required to have a low environmental impact.

[0003] Meanwhile, Indonesia is experiencing not only forest fires but also peat fires, in which peat soil burns. Peat fires are difficult to extinguish because they burn inside the peat soil. Even after a fire has been extinguished, the temperature inside the peat soil may rise and the fire may start burning again. As such, peat fires are more difficult to extinguish than regular fires or forest fires. As a fire extinguishing agent that can be used for peat fires, for example, a foam-forming composition containing a carbonized carbohydrate composition, a surfactant, and water has been proposed (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2005-511215 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the aqueous foamable composition described in Patent Document 1 was not primarily intended for fires that burn inside peat soil, such as peat fires, and was not a fire extinguishing agent suitable for peat fires. Moreover, commercially available fire extinguishing agents for peat fires are insufficient in terms of fire-extinguishing performance for peat fires, and also have the problem of causing itching to firefighters.

[0006] Therefore, an object of the present invention is to provide a fire extinguishing method that has excellent fire extinguishing performance in peat fires and that places little strain on the human body, living organisms, and the natural environment. [Means for solving the problem]

[0007] The water-addition type fire extinguishing agent of the present invention is a water-addition type fire extinguishing agent containing a surfactant component, a chelating component, and a solvent, wherein the surfactant component is at least one selected from the group consisting of fatty acid sodium salts and fatty acid potassium salts, and the chelating component is at least one selected from the group consisting of tetrasodium L-glutamate diacetate, tetrasodium L-aspartate-(N,N)-diacetate, disodium N-2-hydroxyethyliminodiacetate, trisodium methylglycine diacetate, ethylenediaminesuccinic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetate, succinic acid, iminodisuccinic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetate, and the solvent is at least one selected from the group consisting of 2-hydroxypropanetriacetic acid, triethylenetetraminehexaacetic acid, 1,3-propanediaminetetraacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, dihydroxyethylglycine, glycol ether diaminetetraacetic acid, 1,2,4-butanetricarboxylic acid, dihydroxyethylethylenediaminediacetic acid, sodium gluconate, sodium glucoheptonate, inositol hexaphosphate, hydroxyethanoic acid, 2-hydroxypropanoic acid, 2-hydroxysuccinic acid, 2,3-dihydroxybutanedioic acid, and 2-hydroxy-1,2,3-propanetricarboxylic acid, and the solvent is water or a mixed solvent containing water.

[0008] In the water-addition type fire extinguishing agent of the present invention, it is preferable that the content of the surfactant component is 8% by mass or more and 50% by mass or less, and the content of the chelating component is 1% by mass or more and 50% by mass or less, based on the total amount of the composition. In the water-addition type fire extinguishing agent of the present invention, it is preferable that the mixed solvent contains at least one selected from the group consisting of propylene glycol, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether in an amount of 10% by mass or more and 50% by mass or less of the total amount of the composition. In the water-addition type fire extinguishing agent of the present invention, it is preferable that the mixed solvent further contains at least one selected from the group consisting of dipropylene glycol, normal propanol, normal butanol, octanol, 1,3-butylene glycol, hexylene glycol, 3-methoxy-3-methyl-1-butanol, 3-methyl-1,5-pentadiol, diethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, methyl glycolate, triethyl citrate, sodium lactate, and glycerin in an amount of 1% by mass or more and 15% by mass or less, based on the total mass of the composition.

[0009] In the water-addition type fire extinguisher of the present invention, the surfactant component preferably contains at least one selected from the group consisting of potassium oleate and sodium oleate in an amount of 4% by mass to 15% by mass, both inclusive, relative to the total amount of the composition, and at least one selected from the group consisting of potassium laurate, potassium myristate, potassium palmitate, and potassium stearate in an amount of 1% by mass to 7% by mass, both inclusive, relative to the total amount of the composition. In the water-addition type fire extinguishing agent of the present invention, it is preferable that the fire extinguishing agent further contains a pH adjusting component, and that the pH adjusting component is at least one selected from the group consisting of gluconic acid, phytic acid, tartaric acid, malic acid, and lactic acid. The method for extinguishing a peat fire of the present invention is a method characterized by using the water-added fire extinguishing agent to extinguish a peat fire. [Effects of the Invention]

[0010] According to the present invention, a method for extinguishing a peat fire can be provided which has excellent fire-extinguishing performance and which places less strain on the human body, living organisms, and the natural environment. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is an explanatory diagram for explaining a method of primary fire extinguishing in a test of fire extinguishing performance. [Figure 2] FIG. 1 is an explanatory diagram for explaining a method of secondary fire extinguishing in a fire extinguishing performance test. [Figure 3] Photographs showing the results of a fire extinguishing performance test using a 1% aqueous fire extinguishing agent solution of Example 1, where (A) shows the state before combustion, (B) shows the state after secondary fire extinguishing, and (C) shows the state 10 months after the fire extinguishing performance test. [Figure 4] Photographs showing the results of a fire extinguishing performance test using the fire extinguishing agent (water) of Comparative Example 2, where (A) shows the state before combustion, (B) shows the state after secondary fire extinguishing, and (C) shows the state 10 months after the fire extinguishing performance test. [Figure 5] 1 is a graph showing the relationship between the extinguishing agent concentration and the chelating component concentration in the extinguishing agent and the permeability into tropical peat soil. [Figure 6] 1 is a graph showing the relationship between surfactant component concentration and permeability into peat moss. [Figure 7] 1 is a graph showing the relationship between chelate component concentration and permeability into peat moss. [Figure 8] 1 is a graph showing the relationship between pH and permeability to peat moss. [Figure 9] 1 is a graph showing the relationship between the type of chelating component and its permeability into peat moss. [Figure 10] 1 is a graph showing the relationship between the type of fatty acid added to the fire extinguishing agent of Example 6 and the permeability into peat moss. [Figure 11] 10 is a graph showing the penetration into peat moss when potassium oleate is replaced with sodium oleate in the fire extinguishing agent of Example 6 and when the pH is adjusted. [Figure 12] 1 is a graph showing the relationship between extinguishing agent concentration and permeability into peat moss. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the water-addition type fire extinguishing agent and the method for extinguishing a peat fire of the present invention will be described. [Fire extinguishing agent] First, the water-added type fire extinguishing agent of this embodiment will be described. The water-added type fire extinguishing agent of this embodiment is a water-added type fire extinguishing agent containing a surfactant component, a chelating component, and a solvent, which will be described below.

[0013] [Surfactant ingredients] The surfactant component used in this embodiment is not a synthetic surfactant, but a fatty acid salt, which is a natural surfactant. Examples of the fatty acid salt include fatty acid sodium salts and fatty acid potassium salts. Among these, it is preferable to use vegetable fatty acid salts. Examples of fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid. Among these, from the viewpoints of solubility in water, stability, and surfactant properties (foaming properties, penetration properties, etc.), it is more preferable to use lauric acid, myristic acid, palmitic acid, and oleic acid, and it is particularly preferable to use lauric acid and oleic acid. These fatty acid salts may be used alone or in combination of two or more. These fatty acid salts are not synthetic surfactants and therefore have a low impact on the human body, other living organisms, and the natural environment.

[0014] Among these fatty acid salts, the main ones will be described in detail. (i) Potassium oleate [CH3(CH2)7CH=CH(CH2)7COOK] and sodium oleate [CH3(CH2)7CH=CH(CH2)7COOK] When comparing sodium soap and potassium soap with the same fatty acid ratio, sodium soap has stronger penetration power, while potassium soap is more likely to become liquid. Oleate salts tend to have lower surface tension than laurate salts. This lower surface tension increases the penetration of water into combustible materials during a fire, making them effective in extinguishing the fire quickly and preventing re-ignition. (ii) Potassium laurate [CH3(CH2) 10 COOK] It has excellent foaming power and produces a large amount of good, slightly rough foam. The foam clings to the surface of combustible materials in the event of a fire, creating a suffocating effect that blocks the supply of oxygen, enabling early extinguishing of the fire. The short alkyl group makes it highly wettable. Sodium laurate tends to solidify, so potassium laurate is preferred.

[0015] The content of the surfactant component is preferably 8% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 20% by mass or less, based on the total amount of the composition. If the content is 8% by mass or more, the fire extinguishing performance can be further improved, and if the content is 50% by mass or less, gelation of the fire extinguishing agent can be sufficiently suppressed. Furthermore, from the viewpoint of fire extinguishing performance, a higher content of the surfactant component is preferable.

[0016] When two or more fatty acid salts are used in combination as surfactant components, it is preferable to contain at least one selected from the group consisting of potassium oleate and sodium oleate in an amount of 4% to 15% by mass of the total composition, and at least one selected from the group consisting of potassium laurate, potassium myristate, potassium palmitate, and potassium stearate in an amount of 1% to 7% by mass of the total composition. This allows for better water penetration into deposits and flammable materials, and better foaming.

[0017] [Chelating ingredient] The chelating component used in this embodiment has the effect of capturing metal components, which are hardness components in water, to prevent the loss of soap components due to soap scum formation and to prevent soap scum from interfering with foam formation. In other words, in a composition containing a natural fatty acid salt used in this embodiment as a surfactant, metal components in water and the soap component (fatty acid salt) tend to bond, resulting in the formation of soap scum. The formation of soap scum tends to reduce penetration into peat soil, which in turn tends to reduce peat fire extinguishing performance. Therefore, in this embodiment, a chelating component is used to suppress the formation of soap scum and improve peat fire extinguishing performance. From the perspective of its impact on the natural environment, the chelating component used in this embodiment is preferably biodegradable.

[0018] Such chelating components include tetrasodium L-glutamate diacetate (GLDA·4Na), tetrasodium L-aspartate-(N,N)-diacetate (ASDA), disodium N-2-hydroxyethyliminodiacetate (HIDA), trisodium methylglycine diacetate (MGDA), ethylenediaminesuccinic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, succinic acid, iminodisuccinic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, trisodium methylglycinediacetate, ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid, ethylenediaminetri ... Examples of such an acid include ethylenetetramine hexaacetic acid, 1,3-propanediaminetetraacetic acid, 1,3-diamino-2-hydroxypropanetetraacetic acid, dihydroxyethylglycine, glycol ether diaminetetraacetic acid, 1,2,4-butanetricarboxylic acid, dihydroxyethylethylenediaminediacetic acid, sodium gluconate, sodium glucoheptonate, inositol hexaphosphate, hydroxyethanoic acid, 2-hydroxypropanoic acid, 2-hydroxysuccinic acid, 2,3-dihydroxybutanedioic acid, and 2-hydroxy-1,2,3-propanetricarboxylic acid. These may be used alone or in combination of two or more. Among these, GLDA·4Na, ASDA, HIDA, MGDA, ethylenediamine succinic acid, diethylenetrinosine pentaacetic acid, hydroxyethylethylenediamine triacetic acid, succinic acid, iminodisuccinic acid, and nitrilotriacetic acid are preferred from the viewpoint of biodegradability. Furthermore, GLDA·4Na, ASDA, HIDA, and MGDA are more preferred from the viewpoint of biodegradability and compatibility with surfactant components.

[0019] The content of the chelate component is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 20% by mass or less, and particularly preferably 10% by mass or more and 20% by mass or less, based on the total amount of the composition. If the content is 1% by mass or more, the generation of soap scum can be sufficiently suppressed and the fire extinguishing performance can be further improved, and if it is 50% by mass or less, the viscosity of the fire extinguishing agent can be reduced and the gelation of the fire extinguishing agent can be sufficiently suppressed.

[0020] However, there is a drawback in that when the surfactant component and the chelate component are mixed, they gel even at room temperature, making them unusable. There is no problem if the surfactant component and the chelating component are added separately to water at the time of use, but at an actual fire scene, mixing the surfactant component and the chelating component separately is time-consuming, troublesome, and can be difficult to deal with. Therefore, it is preferable to add an additive to prevent gelation when mixing the surfactant component and the chelating component into a composition.

[0021] [solvent] The solvent used in this embodiment is water or a mixed solvent containing water. In order to solve the gelation phenomenon described above, it is preferable to use a mixed solvent in which alcohols or esters are added to the water solvent. When the solvent is water alone, the fire extinguisher will gel when the surfactant content of the liquid reaches about 20 to 30 mass %. In contrast, adding a solvent such as an alcohol can suppress gelation and produce a fire extinguisher with a high concentration of surfactant components.

[0022] Examples of solvents that can be mixed with water include alcohols and esters. Specific examples include propylene glycol, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol, normal propanol, normal butanol, octanol, 1,3-butylene glycol, hexylene glycol, 3-methoxy-3-methyl-1-butanol, 3-methyl-1,5-pentadiol, diethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, methyl glycolate, triethyl citrate, sodium lactate, and glycerin. These may be used alone or in combination of two or more.

[0023] The mixed solvent preferably contains propylene glycol. The use of propylene glycol (PG) can more reliably suppress gelation of the fire extinguisher. PG also functions as an antifreeze, and its addition significantly lowers the pour point, enabling the fire extinguisher to be used in cold climates. The PG content is preferably 10% by mass or more and 50% by mass or less, and more preferably 15% by mass or more and 40% by mass or less, relative to the total amount of the composition. If the content is within the range of 10% by mass or more and 50% by mass or less, gelation of the fire extinguisher can be suppressed without excessively lowering the flash point.

[0024] The mixed solvent preferably further contains at least one selected from the group consisting of dipropylene glycol, normal propanol, normal butanol, octanol, 1,3-butylene glycol, hexylene glycol, 3-methoxy-3-methyl-1-butanol, 3-methyl-1,5-pentanediol, diethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, methyl glycolate, triethyl citrate, sodium lactate, and glycerin. Among these, from the viewpoint of the stability of the fire extinguishing agent, 3-methoxy-3-methyl-1-butanol, 3-methyl-1,5-pentanediol, diethylene glycol monobutyl ether, dipropylene glycol, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether are more preferred, and 3-methoxy-3-methyl-1-butanol and 3-methyl-1,5-pentanediol are particularly preferred. The content of these solvents is preferably 1% by mass or more and 15% by mass or less, and more preferably 3% by mass or more and 15% by mass or less, based on the total amount of the composition. If the content is within the range of 1% by mass or more and 15% by mass or less, gelation of the fire extinguisher can be suppressed without excessively lowering the flash point.

[0025] From the viewpoint of suppressing gelation of the fire extinguishing agent, the content of the solvent is preferably 10% by mass or more and 85% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and particularly preferably 40% by mass or more and 75% by mass or less, based on the total amount of the composition.

[0026] [Other additives] The fire extinguishing agent of this embodiment may further contain a pH adjusting component. For example, if the pH of the fire extinguishing agent becomes too high, the pH value can be suppressed to, for example, 9 by the pH adjusting component. Examples of pH adjusting components include gluconic acid, phytic acid, tartaric acid, malic acid, and lactic acid, which may be used singly or in combination of two or more. From the viewpoint of adjusting the pH of the fire extinguishing agent within an appropriate range, the content of the pH adjusting component is preferably 0.001% by mass or more and 5% by mass or less, and more preferably 0.002% by mass or more and 1% by mass or less, relative to the total amount of the composition.

[0027] In addition to the above components, the fire extinguishing agent of the present embodiment may contain additives such as a gelation suppressing component, a metal corrosion inhibitor, a foam stabilizer (such as polyethylene glycol), a rust inhibitor, and an antioxidant, as needed. In order not to impair the effects of the present invention, the content of these additives is preferably 0.01% by mass or more and 10% by mass or less, and more preferably 0.05% by mass or more and 5% by mass or less, relative to the total amount of the composition.

[0028] [Physical properties of fire extinguishing agents] From the viewpoint of reducing the burden on the storage container and the natural environment, the fire extinguishing agent of this embodiment preferably has the mass loss due to corrosion of iron, aluminum, and copper satisfying the following conditions (1a) to (1c): The mass loss due to corrosion can be measured by the method described in the Examples below. Condition (1a): The mass loss due to corrosion of iron is 3 mg / 20 cm 2 / day or less is preferred, and 2mg / 20cm 2 / day or less is more preferable, and 1 mg / 20 cm 2 / day or less is particularly preferred. Condition (1b): The mass loss due to aluminum corrosion is 3 mg / 20 cm 2 / day or less is preferred, and 2mg / 20cm 2 / day or less is more preferable, and 1 mg / 20 cm 2 / day or less is particularly preferred. Condition (1c): The mass loss due to copper corrosion is 3 mg / 20 cm 2 / day or less is preferable, and 1 mg / 20 cm 2 / day or less is more preferable, and 0.5 mg / 20 cm 2 / day or less is particularly preferred.

[0029] [How to extinguish peat fires] Next, a method for extinguishing a peat fire according to this embodiment will be described. The method for extinguishing a peat fire of this embodiment is a method characterized by extinguishing a peat fire using the fire extinguishing agent of this embodiment. Peat is mud containing organic carbon and is broadly divided into tropical peat and boreal peat. Tropical peat is peat collected in low-latitude regions of the Earth and is derived from trees. The pH of tropical peat is usually around 3.5. On the other hand, boreal peat is peat collected in high-latitude regions of the Earth and is derived from mosses, lichens, and litter (such as fallen branches and leaves). The pH of boreal peat is usually in the range of 4 to 4.5. In this embodiment, the extinguishing agent is diluted with water and used as an aqueous fire extinguishing solution. Here, the content of the extinguishing agent (extinguishing agent concentration) is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 5% by mass or less, even more preferably 0.3% by mass or more and 3% by mass or less, and particularly preferably 0.5% by mass or more and 2% by mass or less, based on the total amount of the aqueous fire extinguishing solution. A content of the extinguishing agent of 0.1% by mass or more is preferable from the viewpoint of improving fire extinguishing performance, while a content of the extinguishing agent of 10% by mass or less is preferable from the viewpoint of cost. Note that the higher the content of the extinguishing agent, the more the fire extinguishing performance tends to improve. In this embodiment, a peat fire is extinguished by spraying an aqueous fire extinguishing solution on the burning area using fire extinguishing equipment. Any known fire extinguishing equipment can be used as appropriate. In this embodiment, the fire may be extinguished primarily by spraying an aqueous fire extinguishing solution on the burning area using fire extinguishing equipment that can extinguish the fire from a distance, and then the fire may be extinguished secondary by spraying an aqueous fire extinguishing solution on the high-temperature area using fire extinguishing equipment that can extinguish the fire from a short distance.

[0030] From the viewpoint of improving fire extinguishing performance, the aqueous fire extinguishing solution used in this embodiment preferably has foaming performance (magnification, reduction time) that satisfies the following conditions (2a) and (2b): The foaming performance (magnification, reduction time) can be measured by the method described in the Examples below. Condition (2a): The expansion ratio is preferably 5 times or more, and more preferably 7 times or more. Condition (2b): The reduction time is preferably 60 seconds or more, and more preferably 120 seconds or more. [Example]

[0031] Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0032] [Example 1] First, the surfactant component was prepared as follows. Potassium laurate production (tank A) 7.067 kg of purified water was added to a reaction vessel (vessel A), followed by 2.507 kg of propylene glycol (PG). The reaction vessel was placed in a warm bath at 60°C, and 2.160 kg of lauric acid was added while stirring with a stirrer, followed by 0.891 kg of an aqueous potassium hydroxide solution (48% by mass KOH) to allow the reaction to proceed. Thus, potassium laurate was obtained. Potassium oleate production (tank B) 7.067 kg of purified water was added to a reaction vessel (vessel B), followed by 3.963 kg of propylene glycol (PG). The reaction vessel was placed in a 60°C warm bath, and while stirring with a stirrer, 3.415 kg of oleic acid (purity: 80.7% by mass) was added, followed by 1.409 kg of potassium hydroxide aqueous solution (48% by mass KOH), and the mixture was allowed to react. Thus, potassium oleate was obtained.

[0033] The fire extinguishing agent was then prepared as follows. A mixing tank was charged with 10.200 kg of a chelating agent (methylglycine trisodium diacetate (MGDA), pure content: 81% by mass), 0.005 kg of lactic acid (purity: 50% by mass), and 7.066 kg of purified water. While stirring with a stirrer, 3.475 kg of hexylene glycol, 0.650 kg of Cheleslite ALF manufactured by Cheleslite Corporation, and 0.125 kg of Cheleslite WP-10 manufactured by Cheleslite Corporation were added to the mixing tank. Next, 12.625 kg of potassium laurate (purity: 20.4% by mass) obtained in Tank A and 15.854 kg of potassium oleate (purity: 19.7% by mass) obtained in Tank B were added to prepare a fire extinguisher. The composition of the fire extinguisher is shown in Table 1 below.

[0034] [Table 1]

[0035] [Comparative Example 1] A commercially available fire extinguishing agent for peat fires ("FLAME FREEZE" manufactured by PT. BASUKI ENERGI INDONESIA) was obtained and used as the fire extinguishing agent of Comparative Example 1. Comparative Example 2 Water (tap water) was used as the fire extinguishing agent of Comparative Example 2.

[0036] <Fire extinguishing agent evaluation> The fire extinguishing agents were evaluated (appearance, specific gravity, kinematic viscosity, pH, corrosion, foaming performance (1% fire extinguishing agent aqueous solution), effects on humans, surface tension (1% fire extinguishing agent aqueous solution), and penetration into peat soil (1% fire extinguishing agent aqueous solution)) using the following methods. Note that for Comparative Example 2, only penetration into peat soil was evaluated. The results obtained for Example 1, Comparative Example 1, and Comparative Example 2 are shown in Table 2. In addition, in this specification, "1% fire extinguishing agent aqueous solution" refers to an aqueous solution consisting of 1% by mass of fire extinguishing agent and 99% by mass of water. (1) Appearance The appearance of the fire extinguishing agent was visually observed, and light transmittance and color were evaluated. (2) Specific gravity The specific gravity of the fire extinguishing agent was measured in accordance with the method described in JIS Z8804. Specifically, 400 mL of the fire extinguishing agent was placed in a 500 mL measuring cylinder as a sample and allowed to stand for 10 minutes in a thermostatic chamber set at 20°C. After that, a hydrometer (hydrometer) was immersed in the sample and gently poked from above several times to submerge it. If the hydrometer and the bottom of the measuring cylinder are in contact at this time, change the hydrometer number and repeat the same procedure as above. Then, the part where the scale of the hydrometer that has naturally risen to the surface meets the liquid level is read to determine the specific gravity (unit: g / cm). 3 ) was measured.

[0037] (3)Kinematic viscosity The kinematic viscosity at 20°C and 30°C was measured in accordance with the method described in JIS K2283. Specifically, first, a viscometer (Ubbelohde viscometer) with a capillary tube and two time standards, and a thermostatic bath in which the viscometer could be fully immersed were prepared. Next, a sample of fire extinguishing agent was placed in the viscometer, which was then set in a holder and left to stand at the measurement temperature (20°C, 30°C) for 30 minutes. The sample was then allowed to flow downward, and the time required for the sample to pass from one time standard to the other (measurement time, unit: seconds) was measured. Then, using the viscometer constant of the viscometer used, the kinematic viscosity (unit: mm 2 / s) was calculated. (4) pH The pH of the fire extinguishing agent was measured in accordance with the method described in JIS Z8802. (5) Corrosion First, test pieces (made of three types of material: iron (Fe), aluminum (Al), and copper (Cu)) were prepared, and the length, width, and thickness of the test pieces were measured using a vernier caliper and a micrometer. From these results, the surface area of ​​the test pieces (unit: cm 2 ) was calculated. Next, the mass (unit: mg) of the test piece before the test was measured using an electronic balance. Next, the test piece was placed in a test bottle containing the fire extinguishing agent and stored in a thermostatic chamber set at 38°C for 21 days. After the test, the test piece was removed and its mass (unit: mg) was measured using an electronic balance. Then, from the following formula (F1), the surface area of ​​the test piece (20 cm2) was calculated. 2and mass loss per day was calculated. Mass loss = {(mass change (mg)) / (surface area (cm 2 ))}×20 / 21…(F1) After the test, the surface of the test piece was visually inspected for discoloration or pitting. If there was no discoloration or pitting, it was rated as "A," and if there was discoloration or pitting, it was rated as "C."

[0038] (6) Foaming performance (1% fire extinguishing agent aqueous solution) First, the fire extinguishing agent was diluted with water (tap water) to prepare a 1% fire extinguishing agent solution. 4 L of this 1% fire extinguishing agent solution was poured into a mechanical foam fire extinguisher, and the temperature was kept in the range of 18°C ​​to 22°C. Next, a nitrogen gas injection valve was attached to the mechanical foam fire extinguisher, and nitrogen gas was injected so that the pressure inside the mechanical foam fire extinguisher became approximately 0.85 MPa. Next, water was sprayed from the mechanical foam extinguisher so that 1% aqueous solution of fire extinguishing agent was poured into the foam collector. After the water was sprayed, the height of the foam in the foam collector (unit: cm) was immediately measured. The foaming ratio was then calculated using the following formula (F2). Foaming ratio = [(foam height (cm)) x (foam collector area (cm) 2 ))} / (Volume of 1% fire extinguishing agent solution (cm 3 ))]…(F2) In addition, the time required for 1 / 4 of the volume of the sprayed foam to return to a 1% aqueous fire extinguishing agent solution, i.e., the time required for the height of the foam in the foam collector to reach 3 / 4 of the height after spraying, was measured as the reduction time (unit: seconds). (7) Impact on humans The fire extinguishing agent was applied to human skin to evaluate its effect on humans. If it caused itching, it was rated as "C," and if there was no effect on the skin, it was rated as "A."

[0039] (8) Surface tension (1% fire extinguishing agent aqueous solution) First, the fire extinguishing agent was diluted with water (purified water) to prepare a 1% aqueous solution of the fire extinguishing agent. This 1% aqueous solution of the fire extinguishing agent was poured into a glass petri dish, and the glass petri dish was maintained at each temperature (20°C, 30°C, and 40°C). Then, the surface tension of the 1% aqueous solution of the fire extinguishing agent was measured by the Wilhelmy method using a surface tensiometer ("DY-500" manufactured by Kyowa Interface Science Co., Ltd.). (9) Penetration into peat soil (1% aqueous solution of fire extinguishing agent) First, peat soil was collected from Indonesia and dried in an oven set at 105°C to obtain a dried peat soil sample. Note that the volume of the dried peat soil sample decreased to 46% of its pre-drying volume. Next, the fire extinguishing agent was diluted with water (groundwater) to prepare a 1% fire extinguishing agent aqueous solution. Next, 10 g of the dried peat soil sample was placed in a glass dish, and 200 μL of a 1% aqueous solution of the fire extinguishing agent was dropped onto it. The time (unit: seconds) required for the 1% aqueous solution of the fire extinguishing agent to completely penetrate the dried peat soil sample was measured.

[0040] [Table 2]

[0041] As is clear from the results shown in Table 2, it was confirmed that the fire extinguishing agent of Example 1 has less impact on humans than the fire extinguishing agent of Comparative Example 1. This confirms that the fire extinguishing agent of the present invention has less impact on the human body and living organisms. It was also confirmed that the 1% aqueous fire extinguishing agent solution of Example 1 had higher permeability into peat soil compared to the 1% aqueous fire extinguishing agent solution of Comparative Example 1 and the fire extinguishing agent (water) of Comparative Example 2. Since it is known that there is a correlation between extinguishing performance in peat fires and permeability into peat soil, it is estimated that the fire extinguishing agent of the present invention has excellent fire extinguishing performance in peat fires.

[0042] <Fire extinguishing and environmental performance evaluation> The fire extinguishing performance and environmental performance were evaluated by the following method: The 1% aqueous fire extinguishing agent solution of Example 1 and the fire extinguishing agent (water) of Comparative Example 2 were used as evaluation liquids to be evaluated. (10) Fire extinguishing performance The fire extinguishing performance was evaluated as shown in Figures 1 and 2. Specifically, first, a 7m x 7m area of ​​land in Indonesia with peat soil 2 was surrounded by a non-flammable fence 1. Then, 416 pieces of fire starters were placed in the center of the land (ignition range: 2.34m x 2.56m). Next, the peat soil was set on fire using an ignition agent and left for 4 hours. After that, as shown in Figure 1, approximately 3 L / m of water was poured into the peat soil area 2 surrounded by a fence 1. 2 The test liquid was sprayed using fire extinguishing equipment 3 (primary fire extinguishing). As fire extinguishing equipment 3, a chemical injector ("Line Proportioner" manufactured by YONE), a spray nozzle ("Quadra Fog Nozzle" manufactured by YONE), and a pump ("Fire Pack" manufactured by HALE) were prepared, and the test liquid was injected into the pump. Note that, if the peat soil land 2 surrounded by the fence 1 was still burning, the test liquid was sprayed again at a rate of about 3 L / m onto the peat soil land 2 surrounded by the fence 1. 2 The evaluation liquid is sprayed using the fire extinguishing equipment 3. This operation is repeated until the peat soil land 2 surrounded by the fence 1 is extinguished. 2 Amount of liquid evaluated per unit (required amount for primary fire extinguishing, unit: L / m 2 ) are shown in Table 3. After the primary firefighting was completed, as shown in Figure 2, the evaluation liquid was sprayed onto hot spots still above 100°C in the peat soil land 2 surrounded by the fence 1 using a simple water bag 4 and a thermal imaging camera 5 (secondary firefighting). The simple water bag 4 was a "Jet Shooter" manufactured by Ashimori Kogyo Co., Ltd., and the thermal imaging camera 5 was a "CPA-E4" manufactured by Nissoden Kogyo Co., Ltd. Specifically, the thermal imaging camera 5 was used to find hot spots still above 100°C, and the evaluation liquid was sprayed onto those hot spots using the simple water bag 4 until the temperature of the hot spots dropped to 50°C or below. This procedure was repeated until no hot spots could be found in the peat soil land 2 surrounded by the fence 1. The distance of 1m required for secondary firefighting was 1m. 2 Amount of liquid evaluated per unit (secondary fire extinguishing required amount, unit: L / m 2 ) are shown in Table 3. In addition, the time required for primary and secondary fire extinguishing is 2 Total amount of evaluation liquid per unit (total amount required for extinguishing fire, unit: L / m 2) are shown in Table 3. After the second fire extinguishing, the temperature in the peat soil area 2 surrounded by the fence 1 was measured using a thermal imaging camera 5, and the maximum temperature was measured. The results are shown in Table 3.

[0043] [Table 3]

[0044] As is clear from the results shown in Table 3, it was confirmed that the 1% aqueous fire extinguishing solution of Example 1 required a smaller amount of liquid for primary and secondary fire extinguishing compared to the fire extinguishing agent (water) of Comparative Example 2. Furthermore, when the fire was extinguished using the fire extinguishing agent (water) of Comparative Example 2, it was found that there were areas (hot spots) in the peat soil where the temperature rose again and exceeded 100°C. In contrast, after the fire was extinguished using the 1% aqueous fire extinguishing agent of Example 1, no areas were confirmed to exceed 100°C. These results confirmed that the fire extinguishing agent of the present invention has excellent fire extinguishing performance in peat fires.

[0045] (11) Environmental performance In the (10) Fire Extinguishing Performance Test, photographs were taken showing the condition before combustion and after secondary fire extinguishing. In addition, photographs were taken showing the condition 10 months after the (10) Fire Extinguishing Performance Test. Photographs of the 1% aqueous fire extinguishing solution of Example 1 before combustion (FIG. 3(A)), after secondary extinguishing (FIG. 3(B)), and after 10 months have passed since the fire extinguishing performance test (FIG. 3(C)) are shown in FIG. 3. Furthermore, for the fire extinguishing agent (water) of Comparative Example 2, photographs showing the state before combustion (FIG. 4(A)), the state after secondary extinguishing (FIG. 4(B)), and the state 10 months after the fire extinguishing performance test (FIG. 4(C)) are shown in FIG. 4. As shown in Figures 3 and 4, in the state before combustion (Figures 3(A) and 4(A)), the green color of the vegetation remains. In addition, in the state after secondary fire extinguishing (Figures 3(B) and 4(B)), the land has been burned and is black or gray. Then, in the state 10 months after the fire extinguishing performance test (Figures 3(C) and 4(C)), new grass has grown and is green. Thus, it was confirmed that even when the 1% fire extinguishing agent aqueous solution of Example 1 was used, vegetation regenerated sufficiently, just as when water was used. This confirms that the fire extinguishing agent of the present invention has a low impact on the natural environment.

[0046] [Examples 2 to 5 and Comparative Example 3] A fire extinguishing agent was prepared in the same manner as in Example 1, except that the materials were mixed according to the composition shown in Table 4 below.

[0047] [Table 4]

[0048] <Investigation into the relationship between extinguishing agent concentration and chelating component concentration in extinguishing agents and their permeability into tropical peat soil> The permeability (tropical peat soil) was investigated by varying the extinguishing agent concentration and the chelating component concentration in the extinguishing agent. The permeability (tropical peat soil) was measured using the following method. For Comparative Example 3 (chelating component concentration: 0 mass%), Example 2 (chelating component concentration: 4.05 mass%), and Example 3 (chelating component concentration: 8.1 mass%), permeability was measured at extinguishing agent concentrations of 1 mass% and 5 mass%. For Example 4 (chelating component concentration: 12.15 mass%), permeability was measured at an extinguishing agent concentration of 5 mass%. Furthermore, for Example 5 (chelating component concentration: 16.524 mass%), permeability was measured at extinguishing agent concentrations of 1 mass%, 3 mass%, and 5 mass%.

[0049] (12) Permeability (tropical peat soil) A tropical peat soil sample (peat soil sample from Indonesia, soil moisture content: approximately 48% by mass) was prepared. Five grams of this tropical peat soil sample was placed in a glass petri dish, and 200 μL of a fire extinguishing agent sample prepared to a specified concentration was dropped onto it. The time (unit: seconds) required for the fire extinguishing agent sample to completely penetrate the tropical peat soil sample was then measured. The results are shown in Figure 5. This measurement was performed twice, and the average values ​​were plotted on a graph, with error bars indicating the range of the measurements. The results shown in Figure 5 confirm that the higher the extinguishing agent concentration, the higher the permeability. Furthermore, when the extinguishing agent concentration is 1% by mass, the higher the concentration of the chelating component in the extinguishing agent, the higher the permeability.

[0050] [Examples 6 to 10] A fire extinguishing agent was prepared in the same manner as in Example 1, except that the materials were mixed according to the composition shown in Table 5 below. [Examples 11 to 15] A fire extinguishing agent was prepared in the same manner as in Example 1, except that the materials were mixed according to the composition shown in Table 6 below. [Examples 16 to 20] A fire extinguishing agent was prepared in the same manner as in Example 1, except that the materials were mixed according to the composition shown in Table 7 below. [Examples 21 to 25] A fire extinguishing agent was prepared in the same manner as in Example 1, except that the materials were mixed according to the composition shown in Table 8 below. [Examples 26 to 28] A fire extinguishing agent was prepared in the same manner as in Example 1, except that the materials were mixed according to the composition shown in Table 9 below.

[0051] <Fire extinguishing agent evaluation> The fire extinguishing agents were evaluated (pH, penetration into peat moss (1% aqueous solution of fire extinguishing agent)). The pH was evaluated using the method described in (4) pH above, and the penetration into peat moss (1% aqueous solution of fire extinguishing agent) was evaluated using the following method. The results obtained for Examples 6 to 10 are shown in Table 5, the results obtained for Examples 11 to 15 are shown in Table 6, the results obtained for Examples 16 to 20 are shown in Table 7, the results obtained for Examples 21 to 25 are shown in Table 8, and the results obtained for Examples 26 to 28 are shown in Table 9.

[0052] (13) Penetration into peat moss (1% aqueous solution of fire extinguishing agent) First, the fire extinguishing agent was diluted with water (purified water) to prepare a 1% aqueous solution of the fire extinguishing agent. Next, 5 g of peat moss (a type of northern peat, "peat moss" manufactured by Horticultural Materials Green Kitakyushu Co., Ltd., moisture content in soil: 48% by mass) was placed in a glass petri dish, and 200 μL of a 1% aqueous solution of fire extinguishing agent was dropped onto it. The time (unit: seconds) required for the 1% aqueous solution of fire extinguishing agent to completely penetrate the peat moss was then measured. This measurement was performed four times, and the average value was calculated.

[0053] [Table 5]

[0054] [Table 6]

[0055] [Table 7]

[0056] [Table 8]

[0057] [Table 9]

[0058] As is clear from the results shown in Tables 5 to 9, it was confirmed that the 1% fire extinguishing agent aqueous solutions of Examples 6 to 28 have high permeability into peat moss, i.e., high permeability into peat soil. Since it is known that fire extinguishing performance in peat fires is correlated with permeability into peat soil, the fire extinguishing agents of the present invention have excellent fire extinguishing performance in peat fires.

[0059] To confirm how the permeability into peat moss changes when the surfactant component concentration is changed, Examples 6 and 13 to 22 were selected from the Examples and compared. For Examples 6 and 13 to 22, the relationship between the surfactant component concentration and the permeability into peat moss is shown in Figure 6. The surfactant component concentration is expressed as the ratio (surfactant component concentration in the fire extinguishing agent of each Example / 11.094) to the surfactant component concentration in the fire extinguishing agent of Example 6 (11.094 mass%). The permeability into peat moss was measured four times, and the average values ​​were plotted on the graph, with error bars indicating the range of the measured values. The results shown in Figure 6 indicate that the higher the surfactant component concentration, the higher the penetration into peat moss.

[0060] In order to confirm how the permeability into peat moss changes when the chelating component concentration is changed, Examples 6 to 9 and 11 were selected from the Examples and compared. For Examples 6 to 9 and 11, the relationship between the chelating component concentration and the permeability into peat moss is shown in FIG. 7. The chelating component concentration is expressed as the ratio (concentration of the chelating component in the fire extinguishing agent of each Example / 15.334) to the chelating component concentration in the fire extinguishing agent of Example 6 (15.334 mass%). The permeability into peat moss was measured four times, and the average values ​​were plotted on the graph, with error bars indicating the range of the measured values. The results shown in FIG. 7 show that even if the chelate component concentration was changed within the range of Examples 6 to 9 and 11, the permeability into peat moss did not change significantly.

[0061] In order to confirm how the permeability into peat moss changes when the pH is changed, Examples 10 to 13 were selected from the Examples and compared. For Examples 10 to 13, the relationship between pH and permeability into peat moss is shown in Figure 8. Examples 10 and 11 are examples in which the chelating component concentration is 1.2 times higher than that of Example 6, and Examples 12 and 13 are examples in which the active agent component concentration is 0.8 times lower than that of Example 6. Permeability into peat moss was measured four times, and the average values ​​were plotted on a graph, with error bars indicating the range of the measured values. The results shown in Figure 8 indicate that the lower the pH, the higher the permeability to peat moss.

[0062] In order to confirm how the permeability into peat moss changes when the type of chelating component is changed, Examples 6, 23, and 24 were selected from the Examples and compared. Figure 9 shows the relationship between the type of chelating component and the permeability into peat moss for Examples 6, 23, and 24. The permeability into peat moss was measured four times, and the average values ​​were plotted on the graph, with error bars indicating the range of the measured values. The results shown in Figure 9 indicate that ASDA, MGDA, or EDTA as the chelating component have good permeability into peat moss. Furthermore, ASDA is more preferable from the viewpoint of permeability.

[0063] In order to confirm how the permeability into peat moss changes when various fatty acids are added to the fire extinguishing agent of Example 6, Examples 6, 25, 26, and 27 were selected from the Examples and compared. Figure 10 shows the relationship between the type of fatty acid added to the fire extinguishing agent of Example 6 and the permeability into peat moss for Examples 6, 25, 26, and 27. The permeability into peat moss was measured four times, and the average values ​​were plotted on the graph, with error bars indicating the range of the measured values. The results shown in Figure 10 show that when various fatty acids (potassium caprate (C10), potassium myristate (C14), potassium palmitate (C16)) were added to the fire extinguishing agent of Example 6, all of them had good penetration into peat moss.

[0064] In order to confirm how the permeability into peat moss changes when potassium oleate is replaced with sodium oleate in the fire extinguisher of Example 6 and when the pH is then adjusted, Examples 6 and 28 were selected from the Examples and compared. Figure 11 shows the permeability into peat moss of Examples 6 and 28 when the potassium oleate in the fire extinguisher of Example 6 is replaced with sodium oleate and the pH is then adjusted. The permeability into peat moss was measured four times, and the average values ​​were plotted on the graph, with error bars indicating the range of the measured values. The results shown in FIG. 11 show that when potassium oleate was replaced with sodium oleate in the fire extinguishing agent of Example 6 and the pH was further adjusted, the permeability into peat moss increased.

[0065] <Investigation into the relationship between fire extinguishing agent concentration and its penetration into peat moss> The permeability into peat moss was investigated by changing the concentration of the extinguishing agent. The permeability into peat moss was measured using the following method. The permeability (peat moss) of the extinguishing agent of Example 6 was measured when the extinguishing agent concentration was 0.5 mass%, 1 mass%, 1.5 mass%, 3 mass%, 5 mass%, and 10 mass%.

[0066] (14) Permeability (peat moss) Peat moss (a type of northern peat, "peat moss" manufactured by Horticultural Materials Green Kitakyushu Co., Ltd., soil moisture content: 48% by mass) was prepared. Five grams of this peat moss was placed in a glass petri dish, and 200 μL of a fire extinguishing agent sample prepared to a specified concentration was dropped onto it. The time (unit: seconds) required for the fire extinguishing agent sample to completely penetrate the peat moss was then measured. The results are shown in Figure 12. This measurement was performed four times, and the average values ​​were plotted on a graph, with error bars indicating the range of the measurements. The results shown in Figure 12 confirm that the higher the concentration of the fire extinguishing agent, the greater the penetration into peat moss.

Claims

1. A water-addition type fire extinguishing agent containing a surfactant component, a chelating component, and a solvent, the surfactant component is at least one selected from the group consisting of fatty acid sodium salts and fatty acid potassium salts, and the fatty acid in the fatty acid sodium salts and fatty acid potassium salts is at least one selected from the group consisting of lauric acid, myristic acid, palmitic acid, and oleic acid; the chelating component is tetrasodium L-aspartic acid-(N,N)-diacetate, the solvent is water or a mixed solvent containing water, the content of the surfactant component is 11.094% by mass or more and 50% by mass or less with respect to the total amount of the composition, the content of the chelate component is 10% by mass or more and 20% by mass or less based on the total amount of the composition, The fire extinguishing agent is diluted with water to obtain an aqueous fire extinguishing solution that satisfies all of the following conditions (i) and (ii), and the aqueous fire extinguishing solution is used to extinguish a fire. A fire extinguishing agent characterized by: (i) The content of the extinguishing agent in the aqueous solution of the fire extinguishing agent is 0.5% by mass or more and 10% by mass or less with respect to the total amount of the aqueous solution of the fire extinguishing agent. (ii) When 5 g of peat moss (a type of northern peat, "peat moss" manufactured by Horticultural Materials Green Kitakyushu Co., Ltd., moisture content in soil: 48% by mass) is collected in a glass petri dish and 200 μL of the aqueous fire extinguishing agent solution is dropped onto the peat moss, the time required for the aqueous fire extinguishing agent solution to completely penetrate the peat moss is 119 seconds or less.

2. 2. The fire extinguishing agent according to claim 1, The surfactant component contains sodium oleate. A fire extinguishing agent characterized by:

3. The fire extinguishing agent according to claim 1 or 2, The mixed solvent contains propylene glycol in an amount of 10% by mass or more and 50% by mass or less based on the total amount of the composition. A fire extinguishing agent characterized by:

4. 4. The fire extinguishing agent according to claim 3, The mixed solvent further contains at least one selected from the group consisting of hexylene glycol and 3-methyl-1,5-pentanediol in an amount of 1% by mass to 15% by mass based on the total amount of the composition. A fire extinguishing agent characterized by:

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