Alcohol-resistant protein foam fire extinguishing agent containing no organofluorine compound

Abstract

To provide a protein foam fire extinguishing agent containing no PFAS, which has a desired alcohol resistance without containing PFAS that has become a problem in environmental contamination.SOLUTION: A protein foam fire extinguishing agent is composed mainly of a hydrolyzed protein solution, and contains, as an essential component, a compound whose structural formula includes an iron ion and amino acid, but contains no organofluorine compound (PFAS).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an alcohol-resistant protein foam fire extinguishing agent that does not contain per- and polyfluoroalkyl substances (PFAS) contained in existing products.

Background Art

[0002] Per- and polyfluoroalkyl substances (hereinafter also referred to as PFAS) have a very strong chemical bond between carbon and fluorine, so they do not decompose in nature, accumulate in the sea and soil, and there is concern about adverse effects on the environment and health. Therefore, the use and waste treatment of PFAS are regulated, and efforts are being made to minimize the impact on the environment.

[0003] On the other hand, many of the conventional foam fire extinguishing agents contain a fluorosurfactant, which is a type of PFAS, in order to improve the fluid spreading property on the surface of the liquid combustible of the foam and to have an effective fire extinguishing ability particularly against alcohol-based liquid fires, as shown in Patent Document 1 below. Therefore, the development of high-performance foam fire extinguishing agents that do not contain PFAS is required. In addition, Cited Document 2 describes a protein foam fire extinguishing agent containing PFAS, although the alcohol resistance performance is not considered. Having an effective fire extinguishing ability against alcohol-based liquid fires is referred to as "alcohol resistance performance" or "alcohol-resistant type".

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, existing foam fire extinguishing agents with alcohol resistance have generally been classified as follows. 1) Metallic soap type protein foam fire extinguishing agent 2) Protein foam fire extinguishing agent added with fluorosurfactant 3) Synthetic surfactant foam fire extinguishing agent added with fluorosurfactant 4) Aqueous film-forming foam fire extinguishing agent added with fluorosurfactant (see, for example, Patent Document 1 above)

[0006] Among these, 2) to 4) are widely used as existing fire extinguishing agents, and the above effects are achieved by using the effects of PFAS and thickeners, etc. These are used in different applications depending on price and performance. However, these products are difficult to dispose of due to current regulations and cannot be used for training, increasing the risk in case of an emergency. Also, a large amount of PFAS is released into the environment during a fire, and high-concentration PFAS contamination in neighboring areas has become a problem.

[0007] On the other hand, 1) the metallic soap type protein foam fire extinguishing agent is mainly a mixture of soap and aluminum lactate, etc. in the protein foam fire extinguishing agent. When diluted in an aqueous solution of a specified concentration, the chelate bond of aluminum lactate weakens, and aluminum and soap combine to form a water-insoluble metallic soap, exhibiting alcohol resistance performance.

[0008] However, since 1) produces water-insoluble metallic soap immediately upon dilution, it may cause clogging in the pore part of the foaming device. Moreover, the effect decreases if foaming is not carried out immediately after dilution. Also, it cannot meet the physical property tests such as the dilution test of the ordinance (Ordinance of the Ministry of Home Affairs No. 26 of December 9, 1975. Hereinafter referred to as the "standard") that defines the technical standards for foam fire extinguishing agents, which is a current domestic sales requirement, so it has not been commercially available for more than four and a half decades.

[0009] Therefore, the present inventors focused on the time from dilution to the formation of insolubles in the agent of (1) (hereinafter referred to as the transit time), and in a protein foam fire extinguishing agent containing iron ions with a hydrolyzed protein solution as the main component, by containing a predetermined compound containing an amino acid in its structural formula, they have arrived at the finding that a protein foam fire extinguishing agent having a desired alcohol resistance can be obtained without adding PFAS.

[0010] The present invention has been made based on such findings, and an object thereof is to provide a PFAS-free protein foam fire extinguishing agent having a desired alcohol resistance without containing PFAS, which is a problem in environmental pollution.

Means for Solving the Problems

[0011] In order to solve the above problems, the invention according to claim 1 is a protein foam fire extinguishing agent in the standard classification, which is characterized by having a hydrolyzed protein solution as the main component, containing iron ions and a compound containing an amino acid in its structural formula as essential components, and not containing an organic fluorine compound (PFAS).

[0012] The invention according to claim 2 is the invention according to claim 1, wherein the hydrolyzed protein solution is a keratin alkali-hydrolyzed protein solution having a molecular weight with a peak of 300 to 8,000 and 0.1 to 8% of sulfur bonded to the protein chain.

[0013] The invention according to claim 3 is the invention according to claim 1 or 2, characterized by containing 0.1 to 3.0% by weight of the above iron ions.

[0014] The invention according to claim 4 is the invention according to claim 1 or 2, wherein the compound containing an amino acid in its structural formula is any one of the following structural formulas having 0 or 1 to 5 peptide bonds and a total of 1 to 6 carboxyl groups contained in the terminal or amino acid side chain.

[0015] TIFF2025077700000001.tif20170

[0016] R1 is an alkyl group having 20 or less carbon atoms or a mixture thereof, R is an amino acid side chain, M is a hydrogen atom, an alkali metal, or a primary to tertiary alkylamine having 6 or less carbon atoms (the carboxyl group in the case of being included in the amino acid side chain is the same), and n is 1 to 5

Advantages of the Invention

[0017] According to the present invention, it is possible to provide a white foam fire extinguishing agent that eliminates concerns about environmental pollution and contains no PFAS at all. Furthermore, it is possible to provide a white foam fire extinguishing agent having effective fire extinguishing ability against fires of alcoholic liquids. Thereby, in fire fighting activities and industrial applications, environmental protection and safety can be achieved simultaneously.

Modes for Carrying Out the Invention

[0018] The present invention will be specifically described below.

[0019] The white stock solution, which is the main agent used in the present invention, is subjected to alkali hydrolysis under normal pressure or pressurized conditions for 12 hours or less in order to improve the chelating power with the added iron and enhance the foaming performance. As a result, a white stock solution is obtained that maintains the stability and fluidity of the foam in the fire extinguishing ability and has a molecular weight distribution peak of 300 to 8,000. Moreover, the chelating power can be enhanced by carefully reducing the disulfide bond portion and leaving a large amount of sulfur in the keratin-derived protein.

[0020] The iron added to generate the above iron ions is preferably introduced as acidic water-soluble iron, and by adding it to the white stock solution produced for this purpose at 0.1 to 3.0% by weight, a composition with adjusted alcohol resistance performance and transit time can be obtained.

[0021] The iron that forms iron ions is preferably mainly divalent iron, and ferrous sulfate, ferrous chloride, ferrous nitrate, ferrous citrate, etc. are preferred. In order to chelate the iron salts represented above in aqueous solution state evenly and firmly with the anionic part centered on the mercapto group generated by the cleavage of the disulfide bond by the alkali hydrolysis of hoof horn, it is desirable to add it over a sufficient period of time. Preferably, it is desirable to add the iron aqueous solution over about 1 hour to produce 100 L of the product.

[0022] The compound containing an amino acid in its structural formula has good compatibility with the main protein stock solution. By restricting the number of peptide bonds and the number of fatty acids, when the composition it contains is diluted, it binds loosely to iron ions, and the alcohol resistance performance and transit time can be controlled.

[0023] More specifically, examples of the above compounds include cetylalanine triethanolamine, sodium lauroyl glycinate, potassium myristoyl glycylalanine, coconut fatty acid alanyl glycine diethanolamine, potassium myristoyl glycylalanylarginate monoethanolamine, triethanolamine laurylalanyl glycylaspartate, diethanolamine palmitic acid tyrosylphenylalanine, potassium palmitoylalanine isoleucine, diethanolamine stearic acid glycylalanine, diethanolamine myristoyl isoleucine, potassium lauric acid alanine, potassium salt of potassium myristoyl alanyl glycylalanine, diethanolamine palmitic acid leucylglycylglycine, monoethanolamine coconut fatty acid phenylalanylglycylalanylarginate, triethanolamine laurylalanyl glycylaspartate, diethanolamine palmitic acid tyrosylphenylalanine, potassium palmitoylalanoyl isoleucylglycylalanine, diethanolamine stearic acid tyrosylglycylalanyl isoleucylglycine, etc.

[0024] In the above compound, the more peptide bonds there are, the longer the transit time becomes and the alcohol resistance performance deteriorates. The carboxyl groups of the fatty acids exist as acids, alkali salts or amine salts, and the alcohol resistance performance and transit time change depending on the number thereof.

[0025] The optimal structural formula of the above compound used in the present invention is a structure having 0 or 1 to 5 peptide bonds and containing 1 to 6 carboxyl groups, which has the best compatibility with the main agent and has achieved satisfactory performance.

[0026] Hereinafter, the present invention will be specifically described by way of examples shown in Table 1 below, but the present invention is not limited thereto. The 3% dilution sedimentation and foaming ratio were carried out in accordance with the "standards". In the fire extinguishing test, from the separate table 4 of the Ministry of Internal Affairs and Communications Notification No. 559, representative substances of water-soluble liquids were selected as methanol from alcohols and acetone from ketones, and the test was carried out with a coefficient of 1.

Examples

[0027]

Table 1

Claims

1. A protein foam fire extinguishing agent classified under the "Ministry of Internal Affairs and Communications Ordinance Prescribing Technical Standards for Foam Fire Extinguishing Agents (December 9, 1975, Ministry of Home Affairs Ordinance No. 26; hereinafter referred to as the "Standards")," which is characterized by having a hydrolyzed protein solution as its main component, containing iron ions and compounds containing amino acids in its structural formula as essential components, and not containing any organic fluorine-containing compounds (PFAS).

2. The protein foam fire extinguishing agent according to claim 1, characterized in that the hydrolyzed protein solution is a hoof horn alkaline hydrolyzed protein solution having a molecular weight distribution peak of 300 to 8,000 and having 0.1 to 8% sulfur bonded to the protein chain.

3. 3. The protein foam fire extinguishing agent according to claim 1 or 2, characterized in that it contains 0.1 to 3.0% by weight of said iron ions.

4. The protein foam fire extinguishing agent according to claim 1 or 2, characterized in that the compound containing the amino acid in its structural formula is a compound represented by any one of the following structural formulas, which has 0 or 1 to 5 peptide bonds and a total of 1 to 6 carboxyl groups contained in the terminal or amino acid side chain. R1 is an alkyl group having 20 or less carbon atoms or a mixture thereof, R is an amino acid side chain, M is a hydrogen atom, an alkali metal, or a primary, secondary, or tertiary alkylamine having 6 or less carbon atoms (the same applies to carboxyl groups contained in amino acid side chains), and n is 1 to 5.

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