Water-based film-forming firefighting foam

Abstract

To provide an aqueous film-forming foam extinguishing agent that is free of PFOS and PFOA.SOLUTION: An aqueous film-forming foam extinguishing agent has a composition shown by (1), which includes an anionic surfactant (A) with a fluorinated hydrocarbon group and an ampholytic surfactant (C). The anionic surfactant (A) has 7 or fewer carbon atoms bound to fluorine atoms in each molecule (except those with a perfluoroheptyl group). The ampholytic surfactant (C) is at least one selected from the group consisting of lauryldimethylaminoacetate betaine and lauric acid amide propyl betaine.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to aqueous film-forming foams. [Background technology]

[0002] Foam fire extinguishing agents are used to extinguish oil fires (fires of oil, gasoline, etc.) that are difficult to extinguish with water, and there are various types such as aqueous film-forming foam fire extinguishing agents, protein foam fire extinguishing agents, and synthetic surfactant foam fire extinguishing agents.

[0003] Aqueous film-forming foams have excellent oil resistance, resistance to oil contamination, and excellent fluidity and spreadability, and therefore have been used in foam fire extinguishing systems for parking lots, aircraft fires, and fires at hazardous materials facilities, etc. In particular, for foam fire extinguishing systems installed in parking lots, most foams used are aqueous film-forming foams due to legally mandated equipment standards.

[0004] Aqueous film-forming foam fire extinguishing agents generally contain fluorosurfactants, which have properties such as oil repellency and water repellency, making them an essential component for providing aqueous film-forming foam with excellent fire extinguishing performance.

[0005] As an example of a fire extinguishing agent, there is one that discloses a fire extinguishing agent that uses a fluorine-containing surfactant having a fluorinated aliphatic group having 3 to 20 carbon atoms as an anionic hydrophilic group-containing surfactant (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-269421 Summary of the Invention [Problem to be solved by the invention]

[0007] However, fluorosurfactants contain perfluorooctane sulfonic acid (PFOS) and / or perfluorooctanoic acid (PFOA) as a main component or by-product. In recent years, international regulations on the manufacture and use of PFOS and PFOA have been strengthened due to their persistence, bioaccumulation potential, and health effects. In Japan, they are also regulated as Type 1 specified chemical substances under the Act on the Evaluation of Chemical Substances and Regulation of Their Manufacture, etc. Conventional aqueous film-forming firefighting foams may contain PFOS and / or PFOA as a main component or by-product due to the fluorosurfactants contained therein, raising concerns about the environmental impact of using these firefighting foams.

[0008] On the other hand, among foam fire extinguishing agents, synthetic surfactant foam fire extinguishing agents do not contain fluorine-based surfactants, but tend to be inferior to aqueous film-forming foam fire extinguishing agents in oil resistance, oil contamination resistance, fluidity, etc., and cannot be used for fires in oil tanks and hazardous material facilities, which are difficult to extinguish.Furthermore, protein foam fire extinguishing agents do not contain fluorine-based surfactants and are excellent in fire resistance, heat resistance, etc., and are used for fires in oil tanks and hazardous material facilities, but are rarely used in foam fire extinguishing equipment installed in parking lots, for example.

[0009] The present invention has been made in view of the above, and an object of the present invention is to provide an aqueous film-forming foam fire-extinguishing agent that does not contain PFOS or PFOA. [Means for solving the problem]

[0010] Specific means for solving the problems include the following aspects. <1> It has the composition shown in (1) below, The following anionic surfactant (A) has, in one molecule, 7 or less carbon atoms bonded to fluorine atoms (excluding those having a perfluoroheptyl group), and An aqueous film-forming fire-extinguishing foam agent, wherein the amphoteric surfactant (C) is at least one selected from the group consisting of lauryl dimethyl amino acetic acid betaine and lauric acid amidopropyl betaine. (1) Contains an anionic surfactant (A) having a fluorinated hydrocarbon group and an amphoteric surfactant (C).

[0011] <2> Further, it contains a cationic surfactant (B) having a fluorinated hydrocarbon group, The cationic surfactant (B) has, in one molecule, 7 or less carbon atoms bonded to fluorine atoms (excluding those having a perfluoroheptyl group), <1> The aqueous film-forming foam fire extinguishing agent according to claim 1. <3> Furthermore, the water-soluble polymer (D) has a number average molecular weight of 5,000 or more. <1> or <2> The aqueous film-forming foam fire extinguishing agent according to claim 1. <4> The water-soluble polymer (D) contains a nitrogen atom. <3> The aqueous film-forming foam fire extinguishing agent according to claim 1. <5> Furthermore, polybasic acid (E) is included <1> ~ <4> 1. An aqueous film-forming foam fire extinguishing agent according to any one of the preceding claims. <6> Further, the composition contains a compound (F) selected from aliphatic diols having 1 to 5 carbon atoms and glycol ether compounds. <1> ~ <5> 1. An aqueous film-forming foam fire extinguishing agent according to any one of the preceding claims. [Effects of the Invention]

[0012] According to the present invention, there is provided an aqueous film-forming fire-fighting foam agent that is free of PFOS and PFOA. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure is not limited to the following embodiments, which may be modified as appropriate within the scope of the present disclosure.

[0014] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical value before "to" as the lower limit and the numerical value after "to" as the upper limit. In the numerical ranges described in stages in the present disclosure, the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in the present disclosure, the upper limit or lower limit described in a certain numerical range may be replaced with a value shown in the Examples.

[0015] In the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the corresponding substances present in the composition, unless otherwise specified.

[0016] In the present disclosure, the term "step" encompasses not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the intended purpose is achieved.

[0017] In the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0018] The aqueous film-forming foam fire-extinguishing agent of the present invention has the composition shown in (1) below, and each composition may further contain other components as necessary. Composition (1): Contains an anionic surfactant (A) having a fluorinated hydrocarbon group and an amphoteric surfactant (C). In composition (1), the anionic surfactant (A) has seven or fewer carbon atoms bonded to fluorine atoms per molecule (excluding those having a perfluoroheptyl group). The amphoteric surfactant (C) is at least one selected from the group consisting of lauryl dimethylaminoacetic acid betaine and lauric acid amidopropyl betaine. The aqueous film-forming foam of the present invention may further contain a cationic surfactant (B) having a fluorinated hydrocarbon group, and the cationic surfactant (B) has seven or fewer carbon atoms bonded to fluorine atoms per molecule (excluding those having a perfluoroheptyl group).

[0019] The aqueous film-forming foam of the present invention contains a specific anionic surfactant (A) as a fluorine-based surfactant, and optionally a specific cationic surfactant (B). The anionic surfactant (A) and the optional cationic surfactant (B) contained in the aqueous film-forming foam both have short-chain or branched-chain molecular structures with a carbon atom count of 7 or less, thereby achieving a composition that is free of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). In other words, surfactants with a large number of carbon atoms in their molecular chains are prone to contamination with PFOS and PFOA, for example, as by-products of the perfluoroheptyl structure. However, the short-chain or branched-chain molecular structures of the surfactants contained in the aqueous film-forming foam reduce the amount of PFOS and PFOA that is introduced as a result of the surfactant. Therefore, while the aqueous film-forming foam is free of PFOS and PFOA, the use of fluorine-based surfactants allows the performance of aqueous film-forming foams to be maintained at levels equivalent to or superior to conventional aqueous film-forming foams, i.e., oil resistance, fluidity, and spreadability. This allows the foam fire extinguishing equipment to demonstrate good fire extinguishing capabilities while minimizing adverse environmental impacts (such as deterioration of the working environment) when extinguishing fires such as those in parking lots, aircraft fires, and fires at hazardous material facilities.

[0020] The term "fluorinated hydrocarbon group" refers to a hydrocarbon group in which at least one hydrogen atom has been substituted with a fluorine atom, and includes a fluoroalkyl group, a fluoroalkenyl group, a fluoroalkynyl group, and the like, and may be, for example, a perfluoroalkyl group in which all of the hydrogen atoms in the hydrocarbon group have been substituted with fluorine atoms.

[0021] The phrase "free of PFOS and PFOA" means that the amount of PFOS and PFOA contained in the fluorosurfactant is below the detection limit, preferably 0 (zero). The amount of PFOS and PFOA is measured by high-performance liquid chromatography (HPLC) using a liquid chromatograph mass spectrometer (LC-MS / MS), and the detection limit is 10 ppb. The LC-MS / MS is a device that combines a high-performance liquid chromatograph (HPLC) with a triple quadrupole mass spectrometer (MS / MS), and for example, the API-3200 manufactured by ABSCIEX can be used.

[0022] The aqueous film-forming foam fire-extinguishing agent of the present invention has the composition shown in (1) above (hereinafter referred to as composition (1)). The anionic surfactant (A) contained in composition (1) has 7 or less carbon atoms bonded to fluorine atoms per molecule and does not have a perfluoroheptyl group.

[0023] The aqueous film-forming fire-extinguishing foam contains at least an anionic surfactant (A) having a fluorinated hydrocarbon group and a predetermined amphoteric surfactant (C). The fire-extinguishing foam of the present invention preferably contains a water-soluble polymer, a polybasic acid, an aliphatic diol, etc., and may further contain other components as necessary.

[0024] -Anionic surfactant (A)- The anionic surfactant (A) is a surfactant whose hydrophilic group ionizes to an anion in water, has at least a fluorinated hydrocarbon group, and has 7 or less carbon atoms bonded to fluorine atoms among the carbon atoms forming one molecule. However, the anionic surfactant (A) does not contain a perfluoroheptyl group (-CF 15 ) is not available.

[0025] The anionic surfactant (A) is preferably a compound having a fluorinated hydrocarbon group in which the number of carbon atoms to which fluorine atoms are bonded is 7 or less, and is preferably a compound having a short-chain or branched-chain fluorinated hydrocarbon group in which the number of consecutively bonded carbon atoms is 7 or less. Furthermore, the "number of carbon atoms bonded to fluorine atoms" is more preferably 4 or more and 7 or less, in that PFOS and PFOA are less likely to be contained.

[0026] The anionic surfactant (A) is preferably a compound having a branched chain structure in which the number of carbon atoms bonded to fluorine atoms is 7 or less, more preferably a compound having a perfluoroalkenyl group having a branched chain structure in which the number of carbon atoms bonded to fluorine atoms is 7 or less, and even more preferably a compound having a perfluoroalkenyl group represented by the following formula (1) or formula (2). In addition, "*" in formula (1) and formula (2) represents a bond.

[0027] [ka]

[0028] Specific examples of the anionic surfactant (A) include perfluoroalkenyloxybenzenesulfonates (e.g., sodium perfluoroalkenyloxybenzenesulfonate), perfluoroalkenyloxybenzylphosphonic acid, and perfluoroalkenyloxyphenylsulfonyl-N-methylcarboxylates (e.g., sodium perfluoroalkenyloxyphenylsulfonyl-N-methylcarboxylate).

[0029] The content of the anionic surfactant (A) is preferably 0.5 to 10 mass %, more preferably 1 to 5 mass %, based on the total mass of the aqueous film-forming foam agent, from the viewpoints of foaming performance and surface tension.

[0030] -Water-soluble polymer (D)- From the viewpoint of foam durability, the aqueous film-forming foam of the present invention preferably further contains a water-soluble polymer (D) having a number average molecular weight of 5,000 or more.

[0031] The term "water-soluble" means that the amount of the water-soluble polymer dissolved in 100 parts by mass of water at 25°C is 3 parts by mass or more (preferably 5 parts by mass or more).

[0032] Specific examples of water-soluble polymers include proteins, starches, polyacrylic acids, polyacrylamides, polyethylene oxides, polyvinylpyrrolidones, polyvinyl alcohols, polyvinylamides, polyethyleneimines, polyamines, polyethylene glycols, and polysaccharides.

[0033] Examples of polysaccharides include xanthan gum, pectin, carrageenan, guar gum, gum arabic, and cellulose derivatives (e.g., methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, etc.).

[0034] The number average molecular weight of the water-soluble polymer is 5000 or more. A high molecular weight of 5000 or more makes it easier to maintain the generated foam (foam retention). The number average molecular weight is more preferably 50000 or more, and more preferably in the range of 80000 to 150000.

[0035] The number average molecular weight of the water-soluble polymer is a value measured by a viscosity method.

[0036] As the water-soluble polymer (D), a cationic water-soluble polymer is preferred from the viewpoint of exhibiting cationicity and interacting with anionic moieties of surfactants, etc., and a water-soluble polymer containing a nitrogen atom is preferred. Suitable examples of the water-soluble polymer containing a nitrogen atom include polyacrylamide, polyethyleneimine, polyamine, etc., for the same reasons as above, and polyethyleneimine is preferred.

[0037] When the water-soluble polymer (D) is contained, the content of the water-soluble polymer is preferably 0.1% by mass to 10% by mass, more preferably 0.2% by mass to 5% by mass, relative to the mass of the aqueous film-forming foam extinguishing agent, from the viewpoints of foam retention and the viscosity of the aqueous film-forming foam extinguishing agent.

[0038] -Polybasic acid (E)- The aqueous film-forming foam of the present invention preferably further contains a polybasic acid (E). By containing a polybasic acid, the pH can be adjusted as desired and foam retention can be improved compared to when a monobasic acid is used.

[0039] Examples of the polybasic acid (E) include polybasic acids having 3 to 24 carbon atoms and having an aromatic group, an aliphatic group, or a heterocyclic ring, such as dibasic acids, tribasic acids, tetrabasic acids, pentabasic acids, hexabasic acids, and alkali metal salts or ammonium salts thereof. Examples of the acid group include a carboxylic acid group, a sulfonic acid group, a phosphate group, etc.

[0040] Specific examples of polybasic acids are shown below.

[0041] [ka]

[0042] [ka]

[0043] [ka]

[0044] Among these, the polybasic acid is preferably a polybasic acid having 4 to 18 carbon atoms, and from the viewpoint of foam retention, an aliphatic dicarboxylic acid (diabasic acid) represented by the following formula is more preferred: In the formula, n represents 4 to 18, and preferably 4 to 10.

[0045] [ka]

[0046] When a polybasic acid is contained, the content of the polybasic acid is preferably 20% by mass to 200% by mass, more preferably 40% by mass to 100% by mass, relative to the mass of the water-soluble polymer, from the viewpoint of foam retention.

[0047] -Aliphatic diol glycol ether compounds (F)- The aqueous film-forming foam of the present invention may further contain a compound selected from an aliphatic diol having 2 to 5 carbon atoms and a glycol ether-based compound (F). The inclusion of the aliphatic diol and / or glycol ether-based compound improves the solubility of the surfactant and also provides antifreeze properties.

[0048] Examples of the aliphatic diols and glycol ether compounds having 2 to 5 carbon atoms include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, and hexyl carbitol.

[0049] When an aliphatic diol and a glycol ether compound are contained, the content of the aliphatic diol and the glycol ether compound is preferably 10% by mass to 50% by mass, and more preferably 15% by mass to 40% by mass, relative to the mass of the aqueous film-forming foam extinguishing agent, from the viewpoint of surfactant solubility and antifreeze properties.

[0050] -Cationic surfactant (B)- Cationic surfactant (B) is a surfactant whose hydrophilic group ionizes into a cation in water, and the number of carbon atoms bonded to fluorine atoms among the carbon atoms forming one molecule is 7 or less. However, cationic surfactant (B) does not contain a perfluoroheptyl group (-CF) in the molecule. 15 Among these, cationic surfactants having a short-chain or branched-chain fluorinated hydrocarbon group with 7 or less consecutively bonded carbon atoms are preferred.

[0051] As the cationic surfactant (B), a compound having a branched chain structure in which the number of carbon atoms bonded to fluorine atoms is 7 or less is preferred, a compound having a perfluoroalkenyl group having a branched chain structure in which the number of carbon atoms bonded to fluorine atoms is 7 or less is more preferred, and a compound having a perfluoroalkenyl group represented by the above formula (1) or formula (2) is even more preferred.

[0052] Examples of the cationic surfactant (B) include perfluoroalkenyl quaternary ammonium salts, etc. The perfluoroalkenyl quaternary ammonium salts are specific examples of compounds having a perfluoroalkenyl group represented by the formula (1).

[0053] When the aqueous film-forming foam fire-extinguishing agent contains an anionic surfactant (A) and a cationic surfactant (B), from the viewpoints of solubility and surface tension, the content ratio of the anionic surfactant (A) to the cationic surfactant (B) (A:B [mass ratio]) is preferably in the range of 1:0.1 to 1:2, and more preferably in the range of 1:0.5 to 1:1.

[0054] When the cationic surfactant (B) is contained, the content of the cationic surfactant (B) is preferably 0.1 mass % to 5 mass %, and more preferably 0.2 mass % to 2.5 mass %, relative to the total mass of the aqueous film-forming foam fire-extinguishing agent, from the viewpoints of solubility and surface tension.

[0055] -Amphoteric surfactant (C)- The amphoteric surfactant (C) is a surfactant whose hydrophilic group changes to a positive or negative charge depending on the pH in water. The amphoteric surfactant (C) contained in the aqueous film-forming foam extinguishing agent of the present invention is at least one selected from the group consisting of lauryl dimethylaminoacetic acid betaine and lauric acid amidopropyl betaine. The aqueous film-forming foam may contain an amphoteric surfactant other than the amphoteric surfactant (C) (hereinafter referred to as "other amphoteric surfactant"). The other amphoteric surfactant may be a hydrocarbon surfactant, and if it has a fluorinated hydrocarbon group in the molecule, it may be a surfactant in which the number of carbon atoms to which fluorine atoms are bonded in one molecule is 7 or less (excluding those having a perfluoroheptyl group).

[0056] Other amphoteric surfactants include, for example, compounds having structures represented by the following general formulas (C1) to (C4) (excluding lauryldimethylaminoacetic acid betaine and lauric acid amidopropyl betaine).

[0057] [ka]

[0058] In the general formulae (C1) to (C4), R represents a hydrocarbon group having 7 to 18 carbon atoms. Examples of the hydrocarbon group having 7 to 18 carbon atoms represented by R include a linear saturated hydrocarbon group and an unsaturated hydrocarbon group. Examples of the linear saturated hydrocarbon group include C7H 15 -, C9H 19 -, C 11 H 23 -, C 13 H 27 , C 17 H 35 Examples of the unsaturated hydrocarbon group include unsaturated hydrocarbon groups derived from fatty acids such as palmitoleic acid, oleic acid, linolenic acid, and eleostearic acid. The fatty acid may also be a mixture of fatty acids derived from coconut oil.

[0059] Examples of the surfactant represented by the general formula (C1) include compounds having the structure shown below.

[0060] [ka]

[0061] Examples of surfactants represented by the general formula (C2) include compounds having the structures shown below.

[0062] [ka]

[0063] Examples of surfactants represented by the general formula (C3) include compounds having the structures shown below.

[0064] JPEG0007818784000009.jpg107120

[0065] Examples of the surfactant represented by the general formula (C4) include compounds having the structure shown below.

[0066] JPEG0007818784000010.jpg107120

[0067] Specific examples of compounds having a structure represented by general formula (C1) include amidopropyl betaine-type amphoteric surfactants. Specific examples of compounds having a structure represented by general formula (C2) include aminoacetic acid betaine-type amphoteric surfactants. Specific examples of compounds having a structure represented by general formula (C3) include imidazoline-type amphoteric surfactants. Specific examples of compounds having a structure represented by general formula (C4) include hydroxysulfobetaine-type amphoteric surfactants.

[0068] The content of the amphoteric surfactant (C) in the aqueous film-forming foam extinguishing agent is preferably 8% by mass to 30% by mass, more preferably 10% by mass to 20% by mass, based on the total mass of the aqueous film-forming foam extinguishing agent, from the viewpoints of foaming properties and surface tension.

[0069] When the aqueous film-forming foam fire-extinguishing agent contains an anionic surfactant (A) and an amphoteric surfactant (C), from the viewpoints of foaming ability and surface tension, the content ratio of the amphoteric surfactant (C) to the anionic surfactant (A) (C / A [mass ratio]) is preferably in the range of 3 / 1 to 30 / 1, more preferably in the range of 5 / 1 to 20 / 1.

[0070] Furthermore, when the aqueous film-forming foam fire-extinguishing agent contains an anionic surfactant (A), a cationic surfactant (B), and an amphoteric surfactant (C), from the viewpoints of foaming property and surface tension, the content ratio of the amphoteric surfactant (C) to the anionic surfactant (A) and the cationic surfactant (B) (C / (A+B) [mass ratio]) is preferably in the range of 3 / 1 to 30 / 1, and more preferably in the range of 5 / 1 to 20 / 1.

[0071] The aqueous film-forming foam extinguishing agent of the present invention preferably comprises an anionic surfactant (A), a cationic surfactant (B), and an amphoteric surfactant (C). Both the anionic surfactant (A) and the cationic surfactant (B) in the present invention have a short-chain or branched-chain molecular structure with a carbon atom number of 7 or less, which may make it difficult to adjust the surface tension to a low level. However, by using a composition containing both the anionic surfactant (A) and the cationic surfactant (B) in the present invention, it becomes easier to adjust the surface tension to a low level.

[0072] -Other ingredients- In addition to the above components, the aqueous film-forming foam fire-extinguishing agent of the present invention may contain an anionic surfactant other than the above anionic surfactant (A), a cationic surfactant other than the above cationic surfactant (B), an additional foam stabilizer, a freezing point depressant, a rust inhibitor, a pH adjuster, etc., within a range that does not significantly impair the effects of the present invention.

[0073] Examples of fixed fire extinguishing equipment that uses aqueous film-forming foam include foam fire extinguishing equipment (especially for parking lots, but also for tanks, SSI, etc.), special water spray equipment, and on-board fire engines (especially for civilian and Self-Defense Force airports, aircraft fires, etc.). When installed on fire engines or carried by fire brigades, foam dispensers and nozzles used in firefighting activities include aspirating types such as low-foaming nozzles and medium-foaming nozzles, and non-aspirating types such as constant-flow nozzles and gun nozzles, and different types are used depending on the type of burning material and the fire conditions.

[0074] The surface tension of the aqueous film-forming foam of the present invention at 20°C is preferably 18.5 mN / m to 20.5 mN / m when the foam concentration in the aqueous foam solution is approximately 3%. The surface tension of conventional aqueous film-forming foams is 17.0 mN / m to 19.0 mN / m under the same conditions, which is roughly equivalent.

[0075] In addition, foam extinguishing devices and nozzles used in foam firefighting equipment at facilities handling hazardous or flammable materials include aspirating types such as foam heads and fixed foam outlets (Types I to IV, special types), and their performance changes depending on the foam extinguishing agent they are combined with. Therefore, the foam extinguishing device to be installed should be foamed with the foam extinguishing agent that will actually be used to check the foam properties before use. If the foam properties do not meet the standard performance, the foam extinguishing device design may need to be changed. Foam heads are installed in parking lots and aircraft hangars, as well as indoor storage and handling facilities for hazardous materials. Fixed foam outlets are installed on outdoor storage tanks. Although not a foam extinguishing device, fire extinguishing equipment using non-aspirating heads such as spray heads and sprinkler heads can achieve fire extinguishing effects by mixing and discharging aqueous film-forming foam. Due to the penetration effect caused by the low surface tension, it has the same enhanced extinguishing effect on Class A fires as conventional aqueous film-forming foam.

[0076] The aqueous film-forming foam of the present invention preferably has foam properties when foamed with a foam head, such that when the foam concentration in the foam solution is about 3%, the foam expansion ratio is 5 times or more and the 25% reduction time is 1 minute or more. When a conventional aqueous film-forming foam is foamed with a foam head, the foam properties at the foam head are about 6.5 to 9.0 times and the 25% reduction time is about 90 to 180 seconds when the foam concentration in the foam solution is about 3%, and when the aqueous film-forming foam of the present invention is used, the foam properties are roughly equivalent to those of conventional aqueous film-forming foams. Furthermore, when the aqueous film-forming foam of the present invention is foamed using a fixed foam outlet (Type I, Type II, or special type), the foam properties are preferably such that, when the foam concentration in the foam solution is about 3%, the foaming ratio is 5 times or more and the 25% reduction time is 1 minute or more.When a conventional aqueous film-forming foam is foamed using a fixed foam outlet (Type I, Type II, or special type), the foaming ratio is about 7.5 to 10.0 times and the 25% reduction time is about 150 to 300 seconds when the foam concentration in the foam solution is about 3%, and when the aqueous film-forming foam of the present invention is used, foam properties roughly equivalent to those of conventional aqueous film-forming foams are obtained. Furthermore, when the aqueous film-forming foam extinguishing agent of the present invention is foamed using a fixed foam outlet (Type III, Type IV), the foam properties are such that, when the foam extinguishing agent concentration in the foam aqueous solution is approximately 3%, the foam expansion ratio is 2 to 4 times and the 25% reduction time is preferably 1 minute or more.

[0077] When the aqueous film-forming foam of the invention is foamed using a low-foaming nozzle, the foam properties are such that, when the foam concentration in the foam solution is approximately 3%, the foaming ratio is 5 times or more and the 25% reduction time is 1 minute or more.When a conventional aqueous film-forming foam is foamed using a low-foaming nozzle, the foaming ratio is 8.0 to 12.0 times and the 25% reduction time is 180 to 300 seconds when the foam concentration in the foam solution is approximately 3%, and performance is roughly equivalent to that of conventional aqueous film-forming foam. When the aqueous film-forming foam of the invention is foamed with a medium foaming nozzle, the foam properties are such that, when the foam concentration in the foam solution is about 3%, the foaming ratio is 20 times or more and the 25% reduction time is 1 minute or more.When a conventional aqueous film-forming foam is foamed with a medium foaming nozzle, the foaming ratio is 50 to 80 times and the 25% reduction time is about 3 to 5 minutes when the foam concentration in the foam solution is about 3%, and performance roughly equivalent to that of conventional aqueous film-forming foam is obtained. [Example]

[0078] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. Unless otherwise specified, "%" and "parts" are based on mass, and "Mn" indicates number average molecular weight.

[0079] (Test Example 1) Water, solvent, and hydrocarbon surfactant in the composition shown below were placed in a four-neck flask equipped with a stirrer, thermometer, and nitrogen inlet line under a nitrogen atmosphere and stirred until uniform. Subsequently, a fluororesin surfactant was added and the mixture was stirred again until uniform. After stirring, a water-soluble polymer and an organic acid were added and the mixture was further stirred until uniform. In this way, an aqueous film-forming foam fire extinguishing agent (Sample 1) was prepared. -composition- Fluorosurfactant (anionic) 1% (Perfluorononenyloxybenzenesulfonate) Fluorocarbon surfactant (cationic) 1% (Perfluorononenyltrimethylammonium salt) Hydrocarbon surfactant (amphoteric) 20% (Lauryl amidopropyl betaine) Water-soluble polymer (cationic) 2% (Polyethyleneimine, Mn=100,000) ·Organic acid (adipic acid (polybasic acid)) ···1% Solvent (butyl diglycol) 12% Solvent (ethylene glycol) 6% ·Water ··Remainder

[0080] (Test Example 2) Water, solvent, and hydrocarbon surfactant in the composition shown below were placed in a four-neck flask equipped with a stirrer, thermometer, and nitrogen inlet line under a nitrogen atmosphere and stirred until uniform. Subsequently, a fluororesin surfactant was added and the mixture was stirred again until uniform. After stirring, a water-soluble polymer and an organic acid were added and the mixture was further stirred until uniform. In this way, an aqueous film-forming foam fire extinguishing agent (Sample 2) was prepared. -composition- Fluorosurfactant (anionic) 1% (Perfluorononenyloxybenzenesulfonate) Fluorocarbon surfactant (cationic) 1% (Perfluorononenyltrimethylammonium salt) Hydrocarbon surfactant (amphoteric) 20% (Lauryl dimethylaminoacetic acid betaine) Water-soluble polymer (cationic) 2% (Polyethyleneimine, Mn=100,000) ·Organic acid (adipic acid (polybasic acid)) ···1% Solvent (butyl diglycol) 12% Solvent (ethylene glycol) 6% ·Water ··Remainder

[0081] (Test Example 3) Water, solvent, and hydrocarbon surfactant in the composition shown below were placed in a four-neck flask equipped with a stirrer, thermometer, and nitrogen inlet line under a nitrogen atmosphere and stirred until uniform. Subsequently, a fluororesin surfactant was added and the mixture was stirred again until uniform. After stirring, a water-soluble polymer and an organic acid were added and the mixture was further stirred until uniform. In this way, an aqueous film-forming foam fire extinguishing agent (Sample 3) was prepared. -composition- Fluorosurfactant (anionic) 1% (Perfluorononenyloxybenzenesulfonate) Fluorocarbon surfactant (cationic) 1% (Perfluorononenyltrimethylammonium salt) Hydrocarbon surfactant (amphoteric) 20% (Lauryl dimethylaminoacetic acid betaine) Water-soluble polymer (cationic) 5% (Polyethyleneimine, Mn=100,000) ·Organic acid (adipic acid (polybasic acid)) ···1% Solvent (butyl diglycol) 12% Solvent (ethylene glycol) 6% ·Water ··Remainder

[0082] (Reference Test Example 1) Water, solvent, and hydrocarbon surfactant in the composition shown below were placed in a four-neck flask equipped with a stirrer, thermometer, and nitrogen inlet line under a nitrogen atmosphere and stirred until uniform. Subsequently, a fluororesin surfactant was added and the mixture was stirred again until uniform. After stirring, a water-soluble polymer and an organic acid were added and the mixture was further stirred until uniform. In this way, an aqueous film-forming fire-extinguishing foam agent (Sample 4) was prepared. -composition- Fluorosurfactant (anionic) 1% (Perfluorononenyloxybenzenesulfonate) Fluorocarbon surfactant (cationic) 1% (Perfluorononenyltrimethylammonium salt) Hydrocarbon surfactant (amphoteric) 20% (coconut oil fatty acid amidopropyl betaine) Water-soluble polymer (cationic) 2% (Polyethyleneimine, Mn = 50,000 to 100,000) ·Organic acid (adipic acid (polybasic acid)) ···1% Solvent (butyl diglycol) 12% Solvent (ethylene glycol) 6% ·Water ··Remainder

[0083] Samples 1 to 4 (aqueous film-forming foam fire-extinguishing agents) prepared in the above test examples and reference test examples were used to conduct foaming performance tests and fire extinguishing tests. The foaming performance test was conducted according to the method prescribed in Article 12, Paragraph 1 of Ordinance No. 26 of the Ministry of Home Affairs of 1975. The large-scale fire extinguishing test was conducted according to the method prescribed in Article 13, Paragraph 1 of Ordinance No. 26 of the Ministry of Home Affairs of 1975. The small-scale fire extinguishing test was conducted according to the following method. The test results are shown in Table 1.

[0084] (Small-scale fire extinguishing test) 400 mL–500 mL of cyclohexane fuel was placed in a 14 cm diameter x 7.5 cm deep container. After a one-minute pre-ignition, approximately 120 mL of foam foamed using a standard foaming nozzle for aqueous film-forming foam fire extinguishing agent testing (aqueous film-forming foam calibration nozzle) as specified in the Ministerial Ordinance was added. The flame and foam extinguishing status were confirmed, and the time to extinguishing or foam extinguishing was measured. Furthermore, the foam was exposed to flame to confirm the foam combustion and extinguishing status. The foam on the fuel was then removed, and approximately 600 mL of foam foamed using the aqueous film-forming foam calibration nozzle was added and allowed to stand. Approximately 10 minutes after foam addition, the foam was exposed to flame to confirm the foam extinguishing status and combustion status. If sufficient foam remained, a fuel surface approximately 2 cm in diameter was exposed near the center of the container and ignited, and the expansion of the fuel surface was confirmed.

[0085] (Large-scale fire extinguishing test) 320L of water and 200L of normal heptane as fuel are placed in a square container measuring 2m on a side and 0.3m deep, and after a 1-minute pre-burn, foam is generated using a standard foaming nozzle for aqueous film-forming foam fire extinguishing agent testing (aqueous film-forming foam certification nozzle) as specified in the Ministerial Ordinance and supplied continuously for 5 minutes. 15 minutes after foaming has finished, a flame is brought close to the foam surface using an igniter to check re-ignition (sealing). 15 minutes after foaming has finished, an oil surface is exposed in the center of the foam surface so that it forms a square with a side of 15cm, ignited, and allowed to burn for 5 minutes to check the burning area. When the burning area is 900cm 2 If the fire resistance is below 900cm, it is judged to be acceptable (marked as "〇" in the table). 2 If the value exceeded this, the fire resistance was judged to be unacceptable (marked as "x" in the table).

[0086] [Table 1] -: Not implemented

[0087] As shown in Table 1, the aqueous film-forming foam fire extinguishing agent of the present invention, which contains an anionic surfactant (A) having seven or fewer carbon atoms bonded to fluorine atoms per molecule (not having a perfluoroheptyl group) and a specified amphoteric surfactant (C), is environmentally friendly because each component does not contain PFOS or PFOA, and it is clear that it retains fire extinguishing ability despite having a short-chain or branched-chain molecular structure with a carbon atom number of 7 or less.

Claims

1. It has the composition shown in (1) below, The following anionic surfactant (A) has, in one molecule, 7 or less carbon atoms bonded to fluorine atoms (excluding those having a perfluoroheptyl group), and An aqueous film-forming fire-extinguishing foam agent, wherein the amphoteric surfactant (C) is at least one selected from the group consisting of lauryl dimethyl amino acetic acid betaine and lauric acid amide propyl betaine. (1) It contains an anionic surfactant (A) having a fluorinated hydrocarbon group and an amphoteric surfactant (C), but does not contain PFOS or PFOA.

2. further comprising a cationic surfactant (B) having a fluorinated hydrocarbon group, 2. The aqueous film-forming foam fire extinguishing agent according to claim 1, wherein the cationic surfactant (B) has seven or fewer carbon atoms bonded to fluorine atoms per molecule (excluding those having a perfluoroheptyl group).

3. The aqueous film-forming foam fire-extinguishing agent according to claim 1, further comprising a water-soluble polymer (D) having a number average molecular weight of 5,000 or more.

4. The aqueous film-forming foam fire-extinguishing agent according to claim 2, wherein the water-soluble polymer (D) contains a nitrogen atom.

5. The aqueous film-forming foam fire-extinguishing agent according to claim 1 or 2, further comprising a polybasic acid (E).

6. 3. The aqueous film-forming foam fire-extinguishing agent according to claim 1, further comprising a compound (F) selected from aliphatic diols having 1 to 5 carbon atoms and glycol ether compounds.

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