Aqueous film-forming fire extinguishing foam using a perfluoropolyether fluorine compound

Abstract

The present invention provides an aqueous film-forming foam fire extinguishing agent that does not contain PFOA or other substances that are causing environmental pollution problems and is primarily composed of an organic fluorine compound with a perfluoropolyether structure. [Solution] The aqueous film-forming foam fire extinguishing agent contains 0.5% to 5.0% by mass of an organic fluorine compound with a perfluoropolyether structure, 2.4% to 6.0% by mass of an anionic surfactant, 2.0% to 8.0% by mass of a nonionic surfactant, 0.5% to 20.0% by mass of an alkanolamine, 20.0% to 40.0% by mass of a solvent, 1.0% to 4.0% by mass of a metal salt, and 5.0% to 60.0% by mass of water, and does not contain PFOA, etc.

Description

[Technical Field]

[0001] The present invention relates to an aqueous film-forming foam fire-extinguishing agent that uses a fluorine compound having a perfluoropolyether structure, unlike the organic fluorine compounds used in conventional aqueous film-forming foam fire-extinguishing agents. [Background technology]

[0002] The organic fluorine compounds used in conventional aqueous film-forming firefighting foams (referring to aqueous film-forming firefighting foams as classified in the "Ministry of Home Affairs Ordinance Prescribing Technical Standards for Firefighting Foams (December 9, 1975, Ordinance No. 26 of the Ministry of Home Affairs; hereinafter referred to as the "Standards")") include perfluorooctanoic acid (PFOA), its salts, and PFOA-related substances; perfluorooctane sulfonic acid (PFOS), its salts, and PFOS-related substances; perfluorohexane sulfonic acid (PFHxS), its salts, and PFHxS-related substances; and perfluorohexanoic acid (PFHxA), its salts, and PFHxA-related substances (hereinafter referred to as "PFOA, etc."). Because carbon and fluorine are chemically bonded very strongly, they do not decompose in nature and are prone to deposits in the ocean and soil, raising concerns about adverse environmental and health effects. For this reason, there are regulations regarding the use and waste disposal of PFOA, etc., and efforts are being made to minimize their impact on the environment. Many conventional aqueous film-forming firefighting foams are described, for example, in Patent Documents 1 and 2 below.

[0003] Patent Document 1 discloses a foam fire-extinguishing agent for large-volume foam systems, which contains the following components: a fluorine-based surfactant (A), an amphoteric surfactant (B) having an alkyl chain with 7 to 12 carbon atoms, a polysaccharide (C), a water-soluble polymer compound (D), and a glycol ether solvent (E), characterized in that, when the total amount of components (A) to (E) is taken as 100% by mass, the foam fire-extinguishing agent contains 25 to 45% by mass of component (A), 6 to 25% by mass of component (B), 1.5 to 8% by mass of component (C), 0.1 to 1.5% by mass of component (D), and 30 to 50% by mass of component (E).

[0004] Patent Document 2 discloses an aqueous film-forming foam fire extinguishing agent that contains, as essential components, polyallylamine (A), a copolymer of dimethyldiallylammonium salt and maleic acid (B), and a perfluoroalkyl group-containing nonionic surfactant (C), and further contains a perfluoroalkyl group-containing amphoteric surfactant, a hydrocarbon-based nonionic surfactant, and a hydrocarbon-based amphoteric surfactant. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-285350 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-126327 Summary of the Invention [Problem to be solved by the invention]

[0006] The technologies described in Patent Documents 1 and 2 mentioned above use organic fluorine compounds such as PFOA, which provide the required diffusion coefficient and effective fire extinguishing capabilities. However, large amounts of PFOA and other compounds are released into the environment during fire extinguishing, causing problems with high concentrations of PFOA and other compounds contaminating nearby areas. Therefore, there is a demand for high-performance aqueous film-forming fire extinguishing foam agents that use organic fluorine compounds that do not contain PFOA and other compounds.

[0007] However, if PFOA and other substances are not used, it will be difficult to satisfy the diffusion coefficient and fire extinguishing performance required for aqueous film-forming foam fire extinguishing agents as specified in the "Ministry of Home Affairs Ordinance Prescribing Technical Standards for Foam Fire Extinguishing Agents" (Ministry of Home Affairs Ordinance No. 26, December 9, 1975) (hereinafter referred to as the "Standards"), which are currently mandatory requirements for domestic sales.

[0008] Therefore, the present invention aims to provide an aqueous film-forming foam fire extinguishing agent that meets the requirements of the desired standard without substantially containing PFOA and other substances that are causing environmental pollution problems. [Means for solving the problem]

[0009] The first invention is an aqueous film-forming foam fire-extinguishing agent characterized by containing 0.5% by mass to 5.0% by mass of an organic fluorine compound having a perfluoropolyether structure, 2.4% by mass to 6.0% by mass of an anionic surfactant, 2.0% by mass to 8.0% by mass of a nonionic surfactant, 0.5% by mass to 20.0% by mass of an alkanolamine, 20.0% by mass to 40.0% by mass of a solvent, 1.0% by mass to 4.0% by mass of a metal salt, and 5.0% by mass to 60.0% by mass of water.

[0010] The second invention is characterized in that, in the first invention, the organic fluorine compound having a perfluoropolyether structure is a perfluoropolyether dicarboxylic acid compound having two carboxylic acid structures in the molecule, or a salt thereof.

[0011] The third invention is characterized in that, in the first invention, the anionic surfactant has 8 or less carbon atoms.

[0012] A fourth aspect of the present invention is characterized in that, in the first aspect of the present invention, the nonionic surfactant is a nonionic surfactant having 16 or less carbon atoms.

[0013] The fifth invention of the present invention is characterized in that, in the first invention, the alkanolamine is a tertiary or lower alkanolamine.

[0014] A sixth aspect of the present invention is the first aspect of the present invention, wherein the solvent is a glycol-based solvent.

[0015] The seventh invention of the present invention is characterized in that, in the first invention, the metal salt is a divalent metal salt.

[0016] These and other objects of the present invention will become apparent from the following detailed description. [Effects of the Invention]

[0017] According to the present invention, an aqueous film-forming foam fire extinguishing agent is provided that is primarily composed of a fluorine compound with a perfluoropolyether structure and is substantially free of PFOA and other compounds. This not only satisfies the standard diffusion coefficient and fire extinguishing performance requirements, but also simultaneously achieves environmental protection and safety in firefighting activities and industrial applications. DETAILED DESCRIPTION OF THE INVENTION

[0018] The best mode for carrying out the present invention will be described below using examples. [Example]

[0019] The organic fluorine compound having a perfluoropolyether structure, which is the main component used in the present invention, is a compound having two carboxylic acids in the molecule represented by the following formula (1) or a salt thereof. [ka] (In the formula, Rf1 is a perfluoroalkyl group having 1 to 4 carbon atoms. n is an integer of 0 to 5. R 1 R is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may be substituted with at least one heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom. The number of heteroatoms is preferably 1 to 10, and more preferably 1 to 6. When the hydrocarbon group is substituted with at least one heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom, the hydrocarbon group has at least one of the following groups: -O-, -N<, >N+<, -S-, -SO2-, -(C=O)-, -(C=O)O-, -O(C=O)-, -NH(C=O)-, -(C=O)NH-, -NH(C=O)O-, or -O(C=O)NH-, and the hydrocarbon chain is interrupted by these groups. 1 In the formula, the hydrocarbon group is substituted with a heteroatom, so that R 1 may have a structure having a heterocycle.)

[0020] In the present invention, the content of the organic fluorine compound having a perfluoropolyether structure (when multiple types of fluorine-based surfactants are included, the total content) is preferably 0.5% by mass to 5.0% by mass in order to satisfy the diffusion coefficient and fire extinguishing performance.

[0021] The organic fluorine compounds having a perfluoropolyether structure can be used singly or in combination of two or more.

[0022] In addition to the organic fluorine compound having a perfluoropolyether structure, the composition contains 2.4% by mass to 6.0% by mass of an anionic surfactant, 2.0% by mass to 8.0% by mass of a nonionic surfactant, 0.5% by mass to 20.0% by mass of an alkanolamine, 20.0% by mass to 40.0% by mass of a solvent, 1.0% by mass to 4.0% by mass of a metal salt, and 5.0% by mass to 60.0% by mass of water.

[0023] The anionic surfactant is preferably an anionic surfactant having a carbon number of 8 or less. Examples of the anionic surfactant having a carbon number of 8 or less that improves the diffusion coefficient and fire extinguishing performance of the organic fluorine compound having a perfluoropolyether structure include alkyl ether sulfate salts, alkyl sulfate salts, alkyl ether sulfates, alkyl aryl sulfonates, alkyl phosphate salts, and alkyl ether phosphate salts.

[0024] The anionic surfactants can be used alone or in combination of two or more.

[0025] The nonionic surfactant is preferably a nonionic surfactant having 16 or less carbon atoms, such as alkyl glucoside, polyoxyethylene alkyl ether, polyethylene glycol alkyl ester, polyoxyalkylene glycol rosinate, sorbitan fatty acid ester, glycerin fatty acid ester, glycerin fatty acid ester borate ester, polyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene pentaerythritol fatty acid ester, polyoxyethylene alkylamine, fatty acid monoethanolamide, fatty acid diethanolamide, etc.

[0026] The nonionic surfactants can be used alone or in combination of two or more.

[0027] The alkanolamine is preferably a tertiary or lower alkanolamine, such as triethanolamine, diethanolamine, monoethanolamine, ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentanamine, or aminoethylethanolamine.

[0028] The alkanolamines can be used alone or in combination of two or more.

[0029] The solvent is preferably a glycol-based solvent, such as ethylene glycol, polyethylene glycol, hexylene glycol, propylene glycol, polypropylene glycol, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and dipropylene glycol monomethyl ether acetate.

[0030] The solvents may be used alone or in combination of two or more.

[0031] The metal salt is preferably a divalent metal salt. Among these, magnesium salts or calcium salts are preferred, with magnesium salts being particularly preferred, from the viewpoint of the liquid stability of the fire extinguishing agent. Examples of magnesium salts include magnesium sulfate, magnesium chloride, magnesium acetate, magnesium phosphate, and magnesium citrate. Examples of calcium salts include calcium sulfate, calcium chloride, calcium acetate, calcium phosphate, and calcium citrate.

[0032] The metal salts can be used singly or in combination of two or more.

[0033] The aqueous film-forming fire-extinguishing foam of the present invention can be blended with various additives within the scope of the present invention. Examples of additives include hydrocarbon-based amphoteric surfactants (e.g., alkylbetaine, alkylamine oxide, etc.), rust inhibitors (e.g., sodium tungstate, sodium molybdate, sodium nitrite, sodium sulfite, sodium benzoate, etc.), preservatives (e.g., methylparaben, ethylparaben, benzoates, phenoxyethanol, hydrazine monohydrate, etc.), foam stabilizers (e.g., polyethyleneimine, polyallylamine, natural proteins, hydrolyzed proteins obtained by hydrolyzing natural proteins, polyacrylamide, etc.), buffers, etc. These may be used alone or in combination of two or more.

[0034] The organic fluorine compound having a perfluoropolyether structure used in the present invention must be 0.5% by mass or more in order to satisfy the diffusion coefficient and fire extinguishing performance, and the highest fire extinguishing performance is achieved when added at 3.0% by mass.

[0035] In the present invention, it is preferable that PFOA, etc. are substantially not contained. In the present application, "substantially not contained" means that PFOA, etc. are not actively added to the aqueous film-forming foam fire-extinguishing agent of the embodiment, and does not mean that PFOA, etc. are not contained at all. The amount of PFOA, etc. is preferably less than 10 ppb, and more preferably 50 ppt or less.

[0036] The present invention will be specifically described below with reference to the examples shown in Table 1 below, but the present invention is not limited thereto. The diffusion coefficient, foaming performance, and aqueous film formation tests for 3% dilution in fresh water and 3% dilution in seawater were conducted in accordance with the standards. Fire extinguishing performance was evaluated in a simple fire resistance test. The evaluation method involved placing 1 L of normal heptane in a combustion dish (inner diameter 30 cm) with a cylinder (outer diameter 6 cm) in the center, pouring 3 L of foamed foam conforming to the standard into the cylinder, and leaving it to stand for 15 minutes. The cylinder was then removed, and the exposed oil surface was ignited. Five minutes later, the area of ​​the burning oil surface was measured. Based on the correlation with the fire resistance test specified in the standard, the passing range of the simple fire resistance test was 100 cm. 2 The comparative examples are conventional aqueous film-forming foam fire extinguishing agents. All contents in Table 1 are in mass %.

[0037] Fluorine-based surfactant 1 in Examples 1 and 2 is an organic fluorine compound with a perfluoropolyether structure, Fluorine-based surfactant 2 in Comparative Example 1 is an amphoteric fluorinated polymer, the anionic surfactant in Examples 1, 2 and Comparative Example 1 is an alkyl ether sulfate salt, the nonionic surfactant in Examples 1 and 2 is an alkyl glucoside, the alkanolamine in Examples 1 and 2 is triethanolamine, the glycol-based solvent in Examples 1, 2 and Comparative Example 1 is ethylene glycol and ethylene glycol monobutyl ether, and the magnesium salt in Examples 1 and 2 is magnesium sulfate. [Table 1]

[0038] As can be seen from Table 1 above, the aqueous film-forming foam fire-extinguishing agent of the present invention (Examples 1 and 2), which is substantially free of PFOA and other substances, satisfies the diffusion coefficient and other requirements stipulated in the standards, has good fire resistance, and can be judged to have effective fire-extinguishing capabilities, just like the conventional aqueous film-forming foam fire-extinguishing agent (Comparative Example 1) which contains PFOA and other substances.

[0039] <Effects>... According to the embodiments described above, the aqueous film-forming foam fire-extinguishing agent has an organic fluorine compound with a perfluoropolyether structure as its main component, and preferably contains 0.5% by mass to 5.0% by mass of the organic fluorine compound with a perfluoropolyether structure, as well as 2.4% by mass to 6.0% by mass of anionic surfactant, 2.0% by mass to 8.0% by mass of nonionic surfactant, 0.5% by mass to 20.0% by mass of alkanolamine, 20.0% by mass to 40.0% by mass of solvent, 1.0% by mass to 4.0% by mass of metal salt, and 5.0% by mass to 60.0% by mass of water.

[0040] Therefore, by providing an aqueous film-forming foam fire extinguishing agent whose main component is a fluorine compound with a perfluoropolyether structure and which is substantially free of PFOA and other substances, it is possible to meet the standard diffusion coefficient and fire extinguishing performance, while simultaneously achieving environmental protection and safety in firefighting activities and industrial applications.

[0041] The above-described embodiment is merely an example, and can be modified as appropriate within the scope of achieving the same effect. [Industrial Applicability]

[0042] According to the present invention, there is provided an aqueous film-forming foam fire-extinguishing agent, the main component of which is an organic fluorine compound having a perfluoropolyether structure, and preferably containing 0.5% by mass to 5.0% by mass of the organic fluorine compound having a perfluoropolyether structure, as well as 2.4% by mass to 6.0% by mass of an anionic surfactant, 2.0% by mass to 8.0% by mass of a nonionic surfactant, 0.5% by mass to 20.0% by mass of an alkanolamine, 20.0% by mass to 40.0% by mass of a solvent, 1.0% by mass to 4.0% by mass of a metal salt, and 5.0% by mass to 60.0% by mass of water.

[0043] As a result, it is possible to provide an aqueous film-forming foam fire extinguishing agent that is primarily composed of a fluorine compound with a perfluoropolyether structure, is substantially free of PFOA and other substances, meets the standard diffusion coefficient and fire extinguishing performance, and simultaneously achieves environmental protection and safety in firefighting activities and industrial applications.

Claims

1. Contains 0.5% by mass to 5.0% by mass of an organic fluorine compound having a perfluoropolyether structure, 2.4% by weight to 6.0% by weight of an anionic surfactant; 2.0% by mass to 8.0% by mass of a nonionic surfactant; 0.5% to 20.0% by weight of an alkanolamine; 20.0% by weight to 40.0% by weight of a solvent; 1.0% to 4.0% by weight of a metal salt; 5.0% by mass to 60.0% by mass of water; An aqueous film-forming foam fire extinguishing agent comprising:

2. 2. The aqueous film-forming foam fire extinguishing agent according to claim 1, wherein the organic fluorine compound having a perfluoropolyether structure is a perfluoropolyether dicarboxylic acid compound having two carboxylic acid structures in the molecule, or a salt thereof.

3. 2. The aqueous film-forming foam fire-extinguishing agent according to claim 1, wherein the anionic surfactant is an anionic surfactant having 8 or less carbon atoms.

4. 2. The aqueous film-forming foam fire extinguishing agent according to claim 1, wherein the nonionic surfactant is a nonionic surfactant having 16 or less carbon atoms.

5. 2. The aqueous film-forming foam fire-extinguishing agent according to claim 1, wherein the alkanolamine is a tertiary or lower alkanolamine.

6. 2. The aqueous film-forming foam fire extinguishing agent according to claim 1, wherein the solvent is a glycol-based solvent.

7. 2. The aqueous film-forming foam fire-extinguishing agent according to claim 1, wherein the metal salt is a divalent metal salt.

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