JP2575289B2 - Liquid foam concentrate for portable fire extinguisher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to the field of fire extinguishing and, more particularly, to liquid foam concentrates of water spray portable fire extinguisher.

[0002]

BACKGROUND OF THE INVENTION One of the well-known means of extinguishing a hydrocarbon liquid fire is to spray a foam obtained by mixing a liquid foam concentrate containing a surfactant as a main component with water at a high pressure to a fire spot. That is. Most commercially available liquid foam concentrates can be divided into two broad categories according to their foam-based nature. In the first family of liquid foam concentrates, the foam base generally consists of hydrolysates of animal proteins (hair, horns, hooves and hemoglobin). To obtain a fluorinated protein liquid foam concentrate, a fluorinated surfactant may be added to the protein base, such a liquid foam concentrate being described, for example, in British Patent No. 1,280,508, United Kingdom. Patent No. 1,368,463
No. 4,424,133; European Patent No. 4
No. 9,958, U.S. Pat. No. 4,460,480, French Patent 2,230,384, British Patent 2,011,784 and WO 8803,425.

[0003] In another large family of liquid foam concentrates, the foam base is composed of a mixture of hydrocarbon surfactants. A thin film forming fluorinated surfactant is also included.
In this latter type of liquid foam concentrate, known in the industry as an AFFF liquid foam concentrate, the presence of the fluorinated surfactant causes the foam that adheres to form an aqueous film floating on the surface of the hydrocarbon. Brought. The role of this aqueous film is not only to extinguish the fire, but also to prevent possible reignition of the hydrocarbon surface. Liquid foam concentrates of this type have been described in a number of patents, in particular: UK Patent No. 1,258,299
No. 5,085,786, French Patent No. 2,3
No. 47,426, U.S. Pat. No. 3,957,657, French Patent No. 2,040,316, U.S. Pat. No. 4,350,206.
No. 3,562,156, French Patent No.
2,148,442, French Patent 2,407,724,
French Patent 2,385,413; U.S. Patent 3,772,
No. 195, French Patent No. 2,397,847, U.S. Pat. No. 3,661,776, U.S. Pat. No. 3,839,425, French Patent No. 2,103,669, U.S. Pat. 6
57, U.S. Pat. No. 3,963,776 and French Patent 2,296,625.

[0004] In order to obtain good resistance to reignition, the liquid foam concentrate, after dilution with water and the addition of air, fixes an aqueous film covering the entire surface of the hydrocarbon and having as high a thermal stability as possible. To form a foam. The thermodynamic equilibrium necessary to form the aqueous thin film must be positive.
ent of spreading) (CS). CS = γ _HC − (γ _S + γ _i ) CS = coating coefficient expressed in mN / m γ _HC = surface tension of hydrocarbon γ _S = surface tension of fire-extinguishing composition after dilution of liquid foam concentrate γ _i = hydrocarbon Tension between the fire extinguishing composition and the liquid foam concentrate after dilution The coating coefficient must be positive, but the interfacial tension (γ _i ) is too low to avoid emulsification of hydrocarbons by the fire extinguishing composition Care must be taken not to be too high, and not too high to avoid thinning the aqueous film. In fact, emulsification of hydrocarbons by the fire-extinguishing composition entrains some of the hydrocarbons inside the fire-extinguishing foam, contaminating the fire-extinguishing foam and increasing the risk of igniting it.

Another important factor related to the reignition phenomenon is the heat resistance of the aqueous thin film. At this point, if the coating speed is excessively high, a very thin thin film having low heat resistance will be formed. Conversely, the most heat-resistant thin film is
This is a thin film having the lowest formation speed. Therefore, it is important to find a compromise between the coating speed and the heat resistance of the aqueous thin film, and this property is essential for obtaining good resistance to reignition. In fact, an aqueous film that suppresses hydrocarbon vapors can in all cases, for example, even during agitation, cause it to separate from the foam in which it is in direct contact with the part in the flame . If its heat resistance is too low, the thin film will be destroyed, and the hydrocarbon vapor will be released, igniting immediately and continuing to destroy the remaining thin film.

[0006] AFFF liquid foam concentrates commonly used in fire-fighting jet pipes are designed to be carried and used by hand, and to be used in normal use.
Not suitable for portable fire extinguisher with weight less than or equal to kg. With portable fire extinguishing media, the amount of water available to dilute a liquid foam concentrate to an operating concentration (0.5-6%, most usually 1-3%) is limited, generally to 6 or 9 liters. While fixed, the system applied by the jet pipe does not limit the amount of water available. As a result, portable fire-extinguishing liquid foam concentrates have more performance than standard liquid foam concentrates for fire-fighting jet pipes to meet the approval criteria for liquid foam concentrates for hydrocarbon fires. Have to do. For example, 1
In order to obtain approval for a 6 liter fire extinguisher of type 44B, a portable fire extinguishing agent requires three liquid foam concentrates.
% Must be extinguished with only 6 liters of the fire-extinguishing composition obtained by diluting to a concentration of 5% (French standard S61-900), whereas in the case of fire extinguishing with a fire-fighting jet pipe, liquid foam The maximum available fire extinguishing composition obtained by diluting the concentrate to a concentration of 3% is 28.5 liters (French standard S6).
0-220) or 22.3 liters (reference UL 162).

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid foam concentrate for portable fire extinguisher which has good resistance to reignition.

[0008]

Accordingly, the subject of the present invention is an aqueous solution containing the following compounds (a) to (e), wherein the total content of the fluorinated compounds (a) and (b) is 5 to 5.
25% by weight (preferably 7 to 18% by weight), and the weight ratio ((a) + (b)) / ((c) + (d)) is 1 to 2
(Preferably 1.3 to 1.7), which is a liquid foam concentrate for portable fire extinguisher. (A) 1 to 15% by weight (preferably 2 to 12% by weight) of at least one fluorinated betaine of the following general formula:

[0009]

Embedded image

(B) 1 to 20% by weight (preferably 3 to 1) of at least one fluorinated amine oxide of the following general formula
5% by weight):

[0011]

Embedded image

(C) 2 to 8% by weight (preferably 3 to 6% by weight) of at least one alkyl glucoside of the following general formula:

[0013]

Embedded image

(D) 2 to 10% by weight (preferably 3 to 8% by weight) of at least one anionic, nonionic or amphoteric non-fluorinated surfactant other than the surfactant of formula III 20 to 50% by weight (preferably 30 to 45% by weight) of a monoalkyl ether of at least one mono- or diethylene (or propylene) glycol. The symbols in the above formulas I, II and III have the following meanings. R _f and R _F may be the same or different and each represents a linear or branched perfluoroalkyl group containing at least 6 carbon atoms, preferably 6 to 16 carbon atoms, m and m ′ may be the same or different and are each an integer equal to 0 to 6, preferably 0 or 2, and X and X ′ may be the same or different and each represent a CO or SO ₂ group, preferably Represents a SO ₂ group, R and R ′ may be the same or different and each represents a hydrogen atom, a methyl or ethyl group, and n and n ′
May be the same or different and are each an integer equal to 1 to 5, preferably 3, and R ¹ , R ² , R ¹ ′ and R ² ′ may be the same or different and are each methyl or Represents an ethyl group, p is an integer from 0 to 5, preferably 1 or 2, Y ⁻ represents SO ₃ ⁻ , OSO ₃ ⁻ or COO ⁻ , q is 1 to 6, preferably 1 Or an integer equal to 2 and R ³ represents a linear or branched alkyl group containing 6 to 18 carbon atoms, preferably 8 to 14 carbon atoms. Without implying any limitation, the non-fluorinated surfactant (d) may be selected from compounds of the formula:

[0015]

Embedded image

Wherein R ⁴ represents a linear or branched alkyl group containing 8 to 18 carbon atoms, and r represents 1 to 1
An integer of 6, M represents an alkali metal ion or a quaternary ammonium ion, and M 'represents an alkali metal ion. ) Does not imply any limitation,
Examples of monoalkyl ethers (e) which may be mentioned are ethylene glycol monoethyl or monobutyl ether and diethylene glycol monobutyl ether, with diethylene glycol monobutyl ether being preferred. Particularly preferred liquid foam concentrates have the formula as component (a):

[0017]

Embedded image

A mixture of fluorinated betaines wherein x is an even integer from _{6 to 16 wherein the} content of betaines of C ₆ F ₁₃ groups is at least 50% by weight, component (b) As the formula:

[0019]

Embedded image

A fluorinated amine oxide of the formula: amide ether propionate of the formula (IV-6) as component (d), alkyl-β-iminodipropionate of the formula (IV-8),
Or containing an alkylamidopropylbetaine of formula (IV-10). The liquid foam concentrate according to the invention can be prepared by simply mixing the various components until a homogeneous state is obtained. To accelerate the homogenous state, the mixture may be heated from room temperature to the boiling temperature of the mixture, preferably at a temperature of 30 to 60C. Advantageously, the pH of the liquid foam concentrate is stabilized with a weak base, for example an ammonia solution or an organic base such as diethanolamine, triethanolamine or urea, at a value equal to at least 7 (preferably 8 to 10). . If it is desired to do so, it is optional to add various additives to the liquid foam concentrate according to the invention, such as: an antifreeze such as ethylene glycol or propylene glycol, a co-solvent, for example (C ₁ -C ₄₎ lower alcohol, such as anticorrosion agents tolyltriazole or sodium nitrite, sodium benzoate, formaldehyde, such as preservatives o- phenylphenol or dichlorophen. The liquid foam concentrate according to the invention may be used as a portable fire extinguisher in a proportion of 0.5 to 6 parts by weight (preferably 1 to 3 parts by weight) of the liquid foam concentrate per 100 parts by weight of water. The performance of the liquid foam concentrate according to the invention can be evaluated by the following test.

Coating test This test, which shows the rate of formation of an aqueous thin film on a hydrocarbon surface, was conducted in a Petri dish (diameter: 11.5 cm) with its outer surface painted black so that the thin film could be seen. It is done by pouring (heptane). When the surface is still, 0.1 ml of a 3% strength liquid foam concentrate aqueous solution is dropped off using a micropipette. The solution must be added dropwise starting from the center and moving away from the center.
The stopwatch starts when the first drop is dropped and stops when the thin film covers the entire hydrocarbon surface. Record the time. If not completely covered within one minute, record the percentage of surface covered after one minute. A satisfactory coating has been obtained if it is completely covered within 30 seconds, preferably within 5 to 25 seconds.

Heat Resistance Test The heat resistance of the aqueous thin film was evaluated by the thin film stability limit temperature (FS).
LT). This test, which can only be performed when the entire surface of the hydrocarbon is covered by a thin film, is carried out in a brass measuring vessel 6.5 cm in diameter and having a total volume of 100 ml on a thermostatically heated heating plate. Do. 80 ml of hydrocarbon (heptane)
Into the container, and when the surface is stationary, 3
0.1 ml of a liquid foam concentrate aqueous solution at a concentration of 0.1% is dropped on it as indicated by the coating test. After 60 seconds, the tip of the thermometer is brought into contact with the aqueous film and a flame is brought about 1 cm above the film. The thermostat is adjusted to a temperature increase of 4 ° C./min. The temperature at which the hydrocarbon ignites (FSLT) is recorded. Good liquid foam concentrates have an FS above 35 ° C.
It should exhibit an LT, preferably an FSLT above about 40 ° C.

Volume Expansion Rate The volume expansion rate (or expansion rate) is the ratio of the volume of foam generated from a 3% strength aqueous solution of liquid foam concentrate to the starting volume. To measure the volume expansion coefficient, 100 ml of a 3% strength aqueous solution of the liquid foam concentrate was placed in a 1 liter measuring cylinder and then a perforated circular piston (5 mm diameter) fixed at its center to a metal rod. With 30 holes (corresponding to 25% of the surface) at a rate of 1 stroke per second for 1 minute. A satisfactory liquid foam concentrate should exhibit a volume expansion of at least equal to 8.

Surface and interfacial tension The surface tension in tap water (γ _S ) and the interfacial tension in heptane (γ _i ) are measured with a LAUDA tensiometer at 25 ° C. according to ISO 304 and ISO 6889. In the following examples, which do not imply any limitation, and which illustrate the invention, the percentages given are by weight and the main constituents used are represented by the following abbreviations for simplicity: A = 45% A mixture of fluorinated betaines of the following formula having the following composition by weight used in the form of an aqueous solution of concentration:

[0025]

Embedded image

The concentration of x% 6 70 8 23 10 5 12 1.5 14 0.4 16 0.1 · B = 40% water - of the formula sold by the applicant in the form of an alcoholic solution Fluorinated amine oxide:

[0027]

Embedded image

Alkyl (C ₈ and C ₁₀ ) glucosides sold under the name Triton BG10 by Union Carbide in the form of an aqueous solution with a C = 70% concentration: D1 = 50% concentration Alkyl (C ₈ and C ₁₀ ) amide ether propionates of the following formula sold under the name Rewoteric AMVSF by the company REWO in the form of an aqueous solution:

[0029]

Embedded image

D2 = Deriphat 16 by HENKEL as an aqueous solution with a concentration of 30%.
N-lauryl-β- of the following formula sold under the name OCC
Iminodipropionate:

[0031]

Embedded image

D3 = alkyl (C ₁₂ and C ₁₄ ) amidopropyl of the following formula sold under the name Amphotensid B4 by the companies ZSCHIMMER and SCHWARTZ as aqueous solutions with a concentration of 30%: Betaine:

[0033]

Embedded image

D4 = decyl ether sulfate used as an aqueous solution having a concentration of 30% of the following formula:

[0035]

Embedded image

E = diethylene glycol mono-n-butyl ether:

[0037]

Embedded image

[0038]

EXAMPLE 1 a) A liquid foam concentrate according to the invention was prepared by mixing appropriate amounts of the commercial products listed above at 40 ° C. with gentle stirring. The active substance content for the liquid foam concentrate is as follows. Component content (%) A 10.8 B 6.2 C 3.3 D1 7.9 E 40.0 Ethanol 5.4 Water (amount to become 100%) 26.4 Diethanolamine was added to pH 9.3. This composition had the following properties: Freezing temperature: -22 ± 2 ° C. Specific gravity: 1.065 Viscosity: 18 mPa.S Refractive index: 1.414 γ _S (3% tap water): 16.4 mN / m γ _i (3% tap water / heptane): 2.5 mN / m Flash point (in closed cup): 50 ° C. When subjected to the above test, this liquid foam concentrate exhibited the following performance: Coating: 20 seconds FSLT: 47 ° C. Volume expansion: 10.2 90 ml of this liquid foam concentrate is placed in a 6 liter portable fire extinguisher cartridge and its efficiency is measured on a 144B heptane flame (French standard NF S61-900). Tested. Regarding the phenomenon of reignition, the fire extinguished with excellent behavior. In fact, even if the floating aqueous film is destroyed after the fire is extinguished and the hydrocarbon vapor that comes into contact with the air ignites, the film immediately reforms and completely covers the entire surface of the hydrocarbon, causing the flame to grow. The fire was extinguished.

B) For comparison, two liquid foam concentrates (b1) and (b2) not according to the invention were prepared and their pH was adjusted to 8.5 with diethanolamine. Their composition and their performance are summarized in the following table.

[0040]

[Table 1] In the heat resistance test (FSLT), the liquid foam concentrate (b1)
And (b2) was found to work less well than the liquid foam concentrate of Example 1-a.

Example 2 Example 1-a was repeated except that the proportions of the various components were changed and / or surfactant D1 was replaced by compound D2. The composition and performance of the three liquid foam concentrates thus obtained are shown in the following table.

[0042]

Table 2 Liquid foam concentrate 2a 2b 2c component (%): A 2.5 2.5 10.8 B 14.4 14.4 6.15 C 5.6 5.6 3.25 D1 5.5 --D2-5.5 7.9 E 40 40 40 Ethanol 12.6 12.6 5.4 Water 19.4 19.4 26.5 Performance : Coating (sec) 7610 FSLT (° C) 50 43 40 Volume expansion rate 9.4 10.6 11

Example 3 A part of ether E was converted to monoethylene glycol (MEG)
Example 1-a, except that the ratio of various surfactants was changed. Four liquid foam concentrates were prepared in this way, and diethanolamine was added to adjust the pH.
8.5. Their composition and their performance are summarized in the following table.

[0044]

[Table 3] Liquid foam concentrate 3a 3b 3c 3d component (%): A 1.2 1.5 2.7 7.1 B 7 8.8 5.4 4.1 C 3.4 3.4 3. 4 3.4 D2 3.4 3.4 3.4 3.4 3.4 E 30 30 30 30 MEG 15 15 15 15 Ethanol 6.85 8.6 6.36 Water 33.15 29.3 33.8 34 Performance : Coating (second) 57 8 16 FSLT (° C.) 41 43 42 40 Volume expansion coefficient 10 9.2 9 9.2

EXAMPLE 4 At least one of the surfactants D2, D3 and D4 is substituted for a part of the ether E by monoethylene glycol and instead of D1 and / or alkyl glucoside C.
The procedure was as in Example 1-a, except that seeds were used. 10
Different liquid foam concentrates were thus prepared: Five liquid foam concentrates according to the invention (4a, 4b, 4
c, 4d and 4e) Five liquid foam concentrates (4f, 4g,
4h, 4i and 4j) These are added with diethanolamine before the test is carried out.
H8.5. The composition and performance of these various liquid foam concentrates are summarized in the following table.

[0046]

[Table 4]

The results of these tests show that in the absence of alkylglucosides (liquid foam concentrates 4 g, 4 h, 4 i and 4
j) does not provide sufficient coverage and / or high FSLT, whereas this hydrocarbon co-surfactant alone (liquid foam concentrate 4f) shows only an insufficient volume expansion coefficient. ing.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ivan de Vaux France 60180 Nogen Sur Le Oise Arecarle Baudreille 1 (72) Inventor Kashmir Karinka France 60870 Ville Saint-Paul Le Aristide Briand 76

Claims (12)

(57) [Claims] 1. An aqueous solution containing the following compounds (a) to (e), wherein the total content of the fluorinated compounds (a) and (b) is 5 to 25% by weight, and the weight ratio ((a) +
(B)) / ((c) + (d)) is 1 to 2, wherein the liquid foam concentrate for a portable fire extinguisher is characterized in that: (A) 1 to 15% by weight of at least one fluorinated betaine of the following general formula: (In the formula, R _f represents a linear or branched perfluoroalkyl group containing at least 6 carbon atoms, and m represents 0
X is a CO or SO ₂ group, R is a hydrogen atom, a methyl or ethyl group, n is an integer of 1 to 5, and R ¹ and R ² are the same or different. Well,
Each represent a methyl or ethyl group, it is an integer of p base 0-5, and Y ^- is SO ₃ ^-, OSO ₃ ^- or COO ^-
Represents a group. (B) 1 to 20% by weight of at least one fluorinated amine oxide of the following general formula: (Wherein R _F , m ′, n ′, X ′, R ′, R ¹ ′ and R ² ′)
_Has the same meaning as R _f , m, n, X, R, R ¹ and R ² , respectively. (C) 2 to 8% by weight of at least one alkyl glucoside of the following general formula: (In the formula, q is an integer of 1 to 6, and R ³ represents a linear or branched alkyl group containing 6 to 18 carbon atoms.) (D) Other than the surfactant of the formula III At least one anionic, nonionic or amphoteric non-fluorinated surfactant 2
(E) monoalkyl ether of at least one mono- or diethylene (or propylene) glycol
50% by weight. 2. 2 to 12% by weight of a fluorinated betaine, 3 to 15% by weight of a fluorinated amine oxide, 3 to 6% by weight of an alkyl glucoside, 3 to 8% by weight of a surfactant other than the surfactant of formula III, and Monoalkyl ether of mono or diethylene (or propylene) glycol 30 to 45
The liquid foam concentrate according to claim 1, characterized in that it contains% by weight. 3. The liquid foam concentrate according to claim 1, wherein the total content of the fluorine compound is 7 to 18% by weight. 4. Weight ratio ((a) + (b)) / ((c) +
The liquid foam concentrate according to any one of claims 1 to 3, wherein (d)) is from 1.3 to 1.7. Wherein R _f and / or R _F is contains carbon atoms 6 to 16, m and / or m 'is equal to 0 or 2, n
And / or n 'is equal to 3, p is equal to 1 or 2, and
q is equal to 1 or 2, and R ³ contains from 8 to 14 carbon atoms, liquid foam concentrate according to claim 1. 6. A mixture of a fluorinated betaine of the following formula:
And C of the mixture₆F ₁₃Low fluorinated betaine content
6. The liquid foam concentrate according to claim 5, which is at least 50% by weight.
Stuff. Embedded image(In the formula, x is an even integer of 6 to 16.) 7. The liquid foam concentrate according to claim 5, wherein the fluorinated amine oxide is the following compound. Embedded image 8. The liquid foam concentrate according to claim 1, wherein the non-fluorinated surfactant (d) is selected from compounds of the following formula: Embedded image (Wherein, R ⁴ represents a linear or branched alkyl group containing 8 to 18 carbon atoms, r is an integer of 1 to 16, and M is an alkali metal ion or a quaternary ammonium ion. And M ′ represents an alkali metal ion.) 9. The monoalkyl ether (e) is diethylene glycol monobutyl ether.
The liquid foam concentrate according to any one of the above. 10. The method according to claim 1, which is stabilized at a pH equal to at least 7, preferably 8 to 10.
Item 7. A liquid foam concentrate according to item 1. 11. An alcoholic auxiliary solvent, an antifreezing agent,
The liquid foam concentrate according to any one of claims 1 to 10, further comprising a preservative and / or a corrosion inhibitor. 12. The proportion of 0.5 to 6 parts by weight, preferably 1 to 3 parts by weight, per 100 parts by weight of water in the portable fire extinguisher of the liquid foam concentrate according to any one of claims 1 to 11. Use in.