JPS6221548B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improvement of a dry powder fire extinguishing agent, the purpose of which is to extinguish a fire without losing the quick extinguishing properties of conventional dry powder fire extinguishers, and to be able to sufficiently float on flammable liquids. Strong water repellent and
To obtain a fire extinguishing agent that is oil repellent, has a cumulative effect, and can reliably prevent re-ignition after extinguishing the fire. In general, dry powder extinguishing agents have high extinguishing ability regardless of whether it is a wood or oil fire, can be filled with a smaller volume of fire extinguisher, and have extremely fast extinguishing properties regardless of the type of fire. It is widely used because of its characteristics. However, such general dry powder extinguishing agents cannot necessarily be expected to be completely effective against all types of fires, and have a drawback in that they are particularly poor in their ability to prevent re-ignition in oil fires. In general, the main agent of dry powder fire extinguishers is a compound that thermally decomposes during a fire and generates nonflammable gas such as carbon dioxide gas or ammonia gas, or that exhibits a negative catalytic effect on combustion.
For example, phosphates such as ammonium and carbonates such as sodium bicarbonate are used as compounds that are easily emitted by fire extinguishers, and additives such as white carbon, mica, and talc are added to these to prevent them from solidifying in the fire extinguisher. In order to make it water-repellent and moisture-proof, it is treated with silicone compounds, metal soap, wax, etc. However, although the silicone compounds used here have the ability to repel water, they have lipophilic properties that make them easily soluble in oil, so they have the disadvantage that they precipitate when they come into contact with flammable liquids. In other words, powder extinguishing agents do not have the ability to accumulate on the surface of flammable liquids and cut off air like foam does, and for this reason, unless the flammable parts are extinguished instantly, other extinguishing parts This means that if there is a fire source, it will inevitably ignite again. Accordingly, the inventors of the present invention have made efforts to solve the above-mentioned problems by treating the main agent and fluidity improver of powder fire extinguishing agents with a fluorine compound. That is, it has been found that it is most preferable to treat the dry powder fire extinguishing agent with an organic fluorine compound in order to make the powder fire extinguishing agent float on the oil surface. The fluorine compound used herein has a fluorinated aliphatic group having 3 to 20 carbon atoms, preferably 6 to 12 carbon atoms, and is water-insoluble (1 at 25°C).
% by weight or less), the main transition temperature (melting point, glass transition point, or softening point) is 20℃ or higher, and the molecular weight is about 700~
Approximately 200,000 non-stick compounds. Examples of such organic fluorine compounds are as follows. (1) A homopolymer of a vinyl monomer having a fluoroalkyl group having 3 to 20 carbon atoms or a copolymer with a vinyl monomer that does not contain fluorine. Examples of vinyl monomers having a fluoroalkyl group include the following. C ₇ F ₁₅ CH ₂ OCOCH=CH ₂ C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OCOCH=CH ₂ C ₈ F ₁₇ SO ₂ N (CH ₃ ) CH ₂ CH ₂ OCOC (CH ₃ )=
CH ₂ C ₇ F ₁₅ CON(C ₂ H ₅ ) CH ₂ CH ₂ OCOC(CH ₃ )=
CH ₂ CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ OCOCH=CH ₂ CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ OCH=CH ₂ C ₈ F ₁₇ (CH ₂ ) ₁₁ OCOC(CH ₃ )=CH ₂ (CF ₃ ) ₂ CFO (CH ₂ ) ₅ OCOCH=CH ₂ C ₈ F ₁₇ SO ₂ N (CH ₂ CH ₂ OCOCH=CH ₂ ) ₂ C ₈ F ₁₇ SO ₂ N (CH ₃ ) (CH ₂ ) ₁₀ COOCH ₂ CH=CH ₂ C ₈ F ₁₇ SO ₂ N (C ₂ H ₅ )CH ₂ CH ₂ OCOCH ＝CHCOOC ₄ H ₉ C ₆ F ₁₃ SO ₂ N(CH ₃ )CH ₂ CH ₂ OCOCH＝CH ₂ C ₈ F ₁₇ SO ₂ NHCH ₂ CH ₂ SO ₂ CH＝CH ₂ Fluorine Examples of vinyl monomers that do not include ethylene, propylene, butylene, butadiene, isoprene, chloroprene, vinyl chloride,
Vinylidene chloride, styrene, ester or amide of (meth)acrylic acid with alcohol or alkylamine (all having 20 or less carbon atoms);
Examples include diacetone acrylamide, N-methylolacrylamide, acrylonitrile, acrylamide, vinyl acetate, and vinyl compounds having a siloxane bond. Any of the monomers can be used in combination. These homopolymers or copolymers can be produced by a known method of vinyl polymerization, for example, solution polymerization using a radical initiator or emulsion polymerization is common. The molecular weight of the polymer can be adjusted within a preferred range depending on the concentration of the initiator and the type and concentration of the chain transfer agent, but it is generally preferably 3000 or more. (2) A (poly)ester of a monohydric or polyhydric alcohol containing a fluoroalkyl group having 3 to 20 carbon atoms and a monohydric or polyhydric carboxylic acid that may be fluorinated. A (poly)ester of a monohydric or polyhydric alcohol which may be fluorinated and a monohydric or polyhydric carboxylic acid having a fluoroalkyl group having 3 to 20 carbon atoms. Examples of ingredients used in this case are listed below. C ₉ F ₁₉ CH ₂ CH ₂ OH C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) CH ₂ CH ₂ OH C ₈ F ₁₇ SO ₂ N (CH ₂ CH ₂ OH) ₂ C ₈ F ₁₇ SO ₂ N ( C ₂ H ₅ ) CH ₂ CH (OH) CH ₂ OH C ₇ F ₁₅ COOH C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) CH ₂ COOH Benzoic acid, adipic acid, sebacic acid, phthalic acid, maleic acid, trimellitic acid, ethylene glycol monomethyl ether, ethylene glycol, propylene glycol, diethylene glycol, glycerin, polypropylene glycol, 2-ethylhexanol, stearyl alcohol. The (poly)ester preferably has a molecular weight of 1000 or more. (3) A monohydric or polyhydric alcohol having a fluoroalkyl group having 3 to 20 carbon atoms (in some cases, a fluorine-free monohydric or polyhydric alcohol may be mixed) and a monohydric or polyhydric isocyanate, e.g. (Poly)urethanes with phenyl hesocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, polymethylene polyphenyl isocyanate. The (poly)urethane preferably has a molecular weight of 700 or more. (4) Epoxy compounds having a fluoroalkyl group having 3 to 20 carbon atoms, e.g. Homopolymers of and preferably copolymers with fluorine-free epoxy compounds such as propylene oxide and epichlorohydrin. The molecular weight of such a polymer is preferably 3000 or more. The organic fluorine compound used here must have 5% by weight or more of fluorine atoms in its molecule, and must also have a hydrophilic functional group or structure in its molecular structure, as well as the presence of gasoline, alcohol, etc. to extinguish the fire. It is preferable that it does not have a functional group or structure that provides easy solubility in organic solvents. However, the organic fluorine compound used here is
Prepare a diluted liquid (solution or dispersion) with a concentration of 0.5% by weight, soak a 100% polyester textured yarn fabric in it, and squeeze it until it reaches 50% (the same weight of the diluted liquid as the fabric has adhered).
AATCC Test of post-treated fabrics dried at ℃ for 3 minutes
When measured by Method 118-1966 method, it should have oil repellency of 4 or more, that is, n-tetradecane does not penetrate into the fabric, and the organic fluorine compound should have an oil repellency of 4 or more, that is, n-tetradecane does not penetrate into the fabric.
Method 22—50 when measured using the 197.1 spray method
In other words, it should exhibit water repellency such that water does not ooze out to the back side of the fabric. The advent of the treatment method using the above-mentioned organic fluorine compounds has confirmed that it is possible to obtain a dry powder fire extinguishing agent that has extremely good extinguishing ability not only for water fires but also for oil fires such as methanol or solvents. However, a fire extinguishing agent prepared by treating the above-mentioned powder fire extinguishing agent with an organic fluorine compound has not yet been put into practical use. In other words, the research results show that the main reason for this is that although organic fluorine compounds are expensive, if sufficient treatment is carried out to make the powder fire extinguisher float on the surface of the flammable liquid, the amount added must be reduced. It is necessary to add more than expected, and as a practical matter, adding a large amount of expensive fluorine compounds not only significantly increases costs, but also the surface adhesion is not very good, so the proportion of the amount added must be adjusted. It was found that the degree of floating on the surface of the combustible liquid did not improve much compared to that of the flammable liquid, so it was not very effective. Therefore, the present inventors conducted further research to fundamentally solve the above-mentioned problems, and found that the reason for the need to add large amounts of expensive fluorine compounds is that each particle of the main agent and fluidity improver of the fire extinguisher is Not only is it porous itself, but it also has many irregularities on its surface, resulting in a significantly large surface area. Therefore, even if each particle is treated with a fluorine compound, most of the fluorine compound is not only absorbed into the porous parts and many irregularities of each particle mentioned above, but also generally affects the surface of the particle. It was found that it was difficult to uniformly deposit the fluorine compound. Therefore, in the present invention, a surface modifier made of various resins such as acrylic resin, polystyrene, or natural organic substances such as rosin and cellulose acetate is added to the main agent and fluidity improver of the powder fire extinguisher by diluting it with a solvent or by heat-melting it. After coating each particle of the fire extinguishing agent using either a spray dryer or a spray dryer, an ideal powder fire extinguishing agent can be obtained by adding an organic fluorine compound having water and oil repellency to the particles. This is what I did. That is, in the present invention, before treatment with an organic fluorine compound, the main agent and fluidity improver of the fire extinguisher are coated with a surface modifier made of various resins such as acrylic or natural organic substances such as rosin. By applying this treatment, the porous surface and irregularities of each particle are smoothed to some extent, thereby reducing the surface area and improving the adhesion of the organic fluorine compound. The amount is extremely reduced, and by adding a small amount, it can be effectively attached and moreover, it can be sufficiently suspended on the surface of a flammable liquid such as methanol. The above-mentioned surface modifier may be any substance that can adhere to the particles of the extinguishing agent and smoothen the porous surface and uneven parts to some extent to reduce the surface area, such as acrylic resin, polystyrene, melamine, etc. Examples include various resins such as resin, epoxy resin, polyethylene, and polypropylene, and natural organic substances such as rosin and cellulose acetate. The method of treating the base agent or fluidity improver with the surface modifier is not particularly limited, but one example is to add a diluted solution of the surface modifier described above while stirring the base agent or fluidity modifier. A primary treatment step of spraying and drying with a spray nozzle;
The process further includes a secondary treatment step in which a dilute solution of an organic fluorine compound is spray-dried while stirring the dried product. However, even if the treatment is performed using a mixture of a surface modifier and an organic fluorine compound without going through the above-mentioned primary and secondary treatment steps, there is almost no deterioration in performance.
Practical processing can be performed. In addition to these methods, thermal melting or coating treatment using a spray dryer is also effective. In addition, as solutions used to dilute the above-mentioned organic fluorine compounds and surface modifiers, inorganic and organic solvents are generally used, although they vary depending on the type of treatment agent. Specific examples include: ●1- 1-1 Trichloroethane ●Dichloromethane ●Methyl/ethyl/ketone ●Isopropyl alcohol ●Acetone ●Toluene, etc. may be used. Furthermore, regarding the amount of surface modifier used, it is sufficient that the amount of surface modifier attached to the base agent or fluidity improver is sufficient to show its effect, but on the other hand, if it is too large, it is not only uneconomical but also has a negative effect on fire extinguishing performance. Generally, the range of 0.001 to 10% by weight is preferable. Additionally, in order to further improve the floating effect of the extinguishing agent, it is also possible to add glass balloons, hollow glass bulbs, etc. As mentioned above, the powder extinguishing agent of the present invention is highly effective against not only general fires but also oil fires, and is also effective against ordinary wood fires, electrical fires, and organic metal fires such as silane compounds and alkyl aluminum fires. Not only is it effective, but it is also highly effective in preventing fires if it is sprayed on surfaces of liquids that are at risk of catching fire. Above all, in the present invention, since the main agent and fluidity improver of the fire extinguisher are treated with an inexpensive surface modifier, the addition of expensive organic fluorine compounds can be reduced to a minimum. Therefore, the cost of this type of powder fire extinguishing agent can be significantly reduced. Example 1 As a surface modifier: Epoxy resin was diluted with MEK to 0.5% and 5% concentration solutions, and ammonium dihydrogen phosphate was added to this solution.
Prepare 100g of the above diluted solution by stirring and mixing a mixture of 100 parts and 4 parts of auxiliary agent (white carbon), dry this at 80℃ for 4 hours, grind it in a mortar, and sieve through a 30 mesh sieve. A treated powder was obtained (primary treatment step). As an organic fluorine compound: C ₈ F ₁₇ SO ₂ N(CH ₃ )CH ₂ CH ₂ OCOCH=CH ₂ 90
10 parts of β-hydroxyethyl methacrylate and 1 part of azobisisobutyronitrile were dissolved in 1000 parts of benzotrifluoride, and the mixture was heated at 80°C for 4 parts.
A copolymer solution having a molecular weight of about 30,000 was obtained by stirring for a period of time, and this solution was further diluted with 1-1-1 trickle ethane to obtain a diluted solution. The powder obtained in the above primary treatment step and the diluted organic fluorine compound were mixed, dried at 80°C for 1 hour, ground in a mortar, and then sieved through a 30-mesh sieve to obtain a treated powder (two (next processing step). Next, 30 ml of flammable liquid was placed on a plurality of sample pins each having a diameter of 30 mm, and 1 g of the above-mentioned treated powder was sprinkled onto each sample pin, and the degree of floating of the treated powder was observed after 1 hour had passed. Furthermore, the lower end of a glass funnel (70φ) was held down with thick paper, and after 60 g of the processing agent was added, the paper was removed and the degree to which it flowed was measured. Finally, 1.2 kg of the above-mentioned treatment agent was filled into a fire extinguisher, and after being left at room temperature for one month, the solidification state was observed. The above observation results are shown in Table 1.
Regarding re-ignitability, the items marked with an ○ did not catch fire even when an open flame was brought close to 1 cm above the liquid surface. According to the results of this experiment, the amount of organic fluorine compound added to the main agent and fluidity improver of the fire extinguisher was approximately 30% lower than when no pretreatment with the surface modifier was performed.
We were able to save 70%.

[Table] Example 2 When an acrylic resin was used as a surface modifier and dichloromethane was used as a diluent in the process of Example 1, the effects shown in Table 2 were confirmed.

【table】

[Table] Example 3 In the process of Example 1, rosin, which belongs to natural organic substances, was used as a surface modifier in the process of Example 2.
When the same dilution solution was used, the effects shown in Table 3 were confirmed.

[Table] Example 4 A diluted solution of the organic fluorine compound was mixed with a diluted MEK solution of an epoxy resin, and while stirring a mixture of 100 parts of ammonium dihydrogen phosphate and 4 parts of a fluidity improver (white carbon), Add the above mixture and dry at 80℃ for 2 hours, then grind in a mortar for 30 minutes.
The mixture was sieved through a mesh sieve to obtain a treated powder. As a result of measurements using this, the effects shown in Table 4 were confirmed.

【table】

Claims (1)

[Claims] 1. For the main agent and fluidity improver of the fire extinguisher, apply a surface modifier made of various resins such as acrylic resin or polystyrene, or natural organic substances such as rosin or cellulose acetate in advance by diluting with a solvent, melting with heat, or using a spray dryer. A powder fire extinguisher obtained by coating each particle of the fire extinguisher by any means, and then adding an organic fluorine compound having water and oil repellency thereto.