EP1013311A1 - Extinguishing compositions - Google Patents

Abstract

Fire extinguisher composition (I) comprises (by weight) (a) at least 1% of an aqueous film-forming foam (AFFF) emulsifier; (b) at least 5% of a combustion inhibitor; (c) 3-20% of an antifreeze solvent; and (d) at least 10% urea, the urea:solvent ratio being at least 1:1. Independent claims are also included for the following: bar. (1) a concentrate (II) comprising (by weight) at least 1 part AFFF emulsifier, at least 5 parts combustion inhibitor, 3-20 parts antifreeze solvent and at least 10 parts urea, the urea:solvent ratio being at least 1:1; (2) an aerosol can containing (I) under pressure, preferably at least 7 bar; (3) an aerosol can containing a (II)-filled cartridge and an aqueous solution under pressure, preferably at least 7 bar; (4) an aerosol can containing: (a) a cartridge containing the AFFF emulsifier, antifreeze solvent and urea; (b) a cartridge containing the combustion inhibitor; and (c) an aqueous solution under pressure, preferably at least 7; and (5) The preparation method of the fire extinguishing composition.

Description

The present invention relates to the field of fire extinguishing and to more particularly for object of portable aerosol cans with water spray usable to extinguish class B fireplaces (combustible liquids) and fireplaces class A (absorbent solid materials such as fabrics, paper, wood ...) as well than oil fires.

For extinguishing fires of absorbent or porous materials, generally combustion-inhibiting products such as, for example, ammonium phosphates or sulfates, which under the action of heat decompose endothermically. Decreasing the heat energy of the hearth, this decomposition inhibits the reaction mechanism in the combustion chain and considerably reduces the emission of combustible gases. The mechanism of fireproofing by phosphates and ammonium sulfates has been described by S. SZONYI and A. CAMBON in the General Safety Review n ° 92, March 1990, pages 68-76, as well as in the book entitled "Ambient Extinguishing Agents and Inerting Gas" from the National Center Prevention and Protection, 1982, chapter 3, pages 79-129.

Combustion inhibitor products are used in particular in solution or aqueous dispersion for extinguishing forest fires (long-term retardants). They also form part of many combustion inhibitor liquids for absorbent materials (US Patents 2,569,714, US 3,293,189, US 4,447,336, US 4,606,831, US 4,983,326, US 3,558,486, US 4,972,414, DE 2,724,162, DE 3 735 707, BE 895 993, BE 721 816, FR 2 019 890, FR 2 663 945 and DE 2,921,306).

Used in solid form, ammonium phosphates and sulfates constitute also the basic elements of the extinguishing powders A B C as described in the patents DE 1,233,276, DE 1,542,506, DE 1,621,718, DE 2,625,351, DE 2,902,948, DE 3,321,174, DE 4,136,398, GB 1,410,469 and FR 1,510,555. The patent US 3,553,127 describes the use of an extinguishing powder, the constituents of which (salts inorganic) are impregnated with a fluorosurfactant to increase the resistance of the powder for re-ignition.

One of the well-known ways to extinguish fires of hydrocarbon liquids consists in projecting onto the hearth a foam obtained by mixing under pressure high water and an emulsifier based on hydrocarbon surfactants and a fluorinated surfactant. In the latter type of foam concentrates, known in the art as an AFFF (Aqueous Film-Forming Foam) foam concentrate, the presence of the surfactant fluorinated produces a foam which, by decantation, forms an aqueous film floating on the surface of the oil. The purpose of this watery film is not only to put out the fire, but also to prevent a possible re-ignition of the surface of the hydrocarbon. Foam concentrates of this type have been described in numerous patents, in particular the following: GB 1,258,299, US 5,086,785, FR 2,347,426, US 3,957,657, FR 2,040,316, US 4,350,206, FR 3,562,156, FR 2,148,442, FR 2,407,724, FR 2,385,413, US 3,772,195, FR 2,397,847, US 3,661,776, US 3,839,425, FR 2 103 669, US 3 957 657, US 3 963 776 and FR 2 296 625. AFFF foam concentrates produce, after dilution with water and addition of air, a foam forming, by decantation, an aqueous film which spreads over the entire surface of the hydrocarbon.

The first document dealing with the mixture between an inhibiting agent and an AFFF is US Patent 5,091,097. The main application of the formula described in this US patent 5,091,097 is the extinction of hydrocarbon fires and more particularly crude oil fires.

In patent EP 0 676 220 in the name of the applicant, an inhibitor of combustion and an AFFF foam concentrate are also combined in a concentrate for portable fire extinguishers. This concentrate is intended to be diluted in water at when using the extinguisher or when filling it.

In application EP-A-0873768, an extinguishing composition is described comprising in aqueous solution at least one AFFF fire-fighting foam concentrate and minus a combustion inhibitor, as well as urea, citric acid and ethylene (or propylene) glycol. According to this document, this composition appears in the form of a homogeneous and clear solution whose appearance is not changed, even after freezing. This composition is used as it is after dilution with water or is placed in a cartridge inside the fire extinguisher filled with water. In both case, we are in the presence of a composition quite sensitive to frost, even if, after freezing and thawing, the appearance of this solution is not changed.

In the above cases, it would also be desirable for the compositions (concentrated or diluted aqueous) have a low freezing point, typically up to -20 ° C. Indeed, aerosols for domestic use, to which particularly applies the invention, must remain usable even in the case where they are stored in a place not protected against frost (garage, shed, vehicle, etc.).

However, good extinguishing properties are difficult to obtain with a formula low freezing point. Indeed, the classic way used to lower the point of gel of an aqueous composition up to very low temperatures (down to -20 ° C) consists in incorporating a water-soluble organic solvent playing the role of antifreeze, by example glycol. However, these compounds harm the extinguishing performance because they are flammable.

We are therefore looking for an extinguishing composition with good properties fire extinguishers while having a low frost point, especially intended for use in typically domestic aerosols (total capacity less than or equal to 2 liters) to extinguish incipient fireplaces (for example class A and B fireplaces described in standard NF 61-084 and oil fires).

Document DE-A-197 08 733 describes a composition comprising a salt ammonium, a fluorinated surfactant, a co-surfactant and an anti-freeze. Anti-freeze comprises a polyol such as a glycol and preferably urea. The weight report glycol: urea is indicated as between 4: 1 and 8: 1. The amount of anti-freeze in the composition of this document is 15 to 40% by weight, preferably 25 to 35% by weight, for a glycol content in the anti-freeze of 70 to 95% by weight (and 30 to 5% urea).

In this document, the anti-freeze effect is obtained by the presence of a quantity important glycol. Although it is stated in this document that the compositions are extinguishing, they contain very large amounts of glycol, which are harmful. In addition, glycol is a relatively expensive compound, which it would good to happen as much as possible.

The invention therefore provides a composition having a low gel point, which is which contains a limited amount of glycol or anti-freeze solvent.

a) au moins 1 % d'un émulseur AFFF ;

b) au moins 5 % d'un inhibiteur de combustion ;

c) de 3 à 20 % d'un solvant antigel ;

d) au moins 10% d'urée, l'urée étant présente en une quantité au moins égale à celle du solvant anti-gel.

Thus, the invention provides such a composition, namely an aqueous extinguishing composition comprising, in% by weight relative to the weight of the composition:

a) at least 1% of an AFFF foam concentrate;

b) at least 5% of a combustion inhibitor;

c) from 3 to 20% of an antifreeze solvent;

d) at least 10% urea, the urea being present in an amount at least equal to that of the anti-freeze solvent.

According to one embodiment, the composition also comprises:
e) a hydrocarbon surfactant, preferably in an amount of at least 0.10% by weight, more preferably from 0.10% to 0.5% by weight.

a) de 1 à 3 % d'émulsion AFFF,

b) de 5 à 15 % d'inhibiteur de combustion,

c) de 5 à 15 % d'un solvant antigel, et

d) de 15 à 30 % d'urée.

According to one embodiment, the composition comprises:

a) from 1 to 3% of AFFF emulsion,

b) from 5 to 15% of combustion inhibitor,

c) from 5 to 15% of an antifreeze solvent, and

d) from 15 to 30% of urea.

a) au moins 1 partie d'un émulseur AFFF ;

b) au moins 5 parties d'un inhibiteur de combustion ;

c) de 3 à 20 parties d'un solvant antigel ;

d) au moins 10 parties d'urée, l'urée étant présente en une quantité au moins égale à celle du solvant anti-gel.

The subject of the invention is also a concentrated extinguishing composition (ie without water), comprising, by weight:

a) at least 1 part of an AFFF foam concentrate;

b) at least 5 parts of a combustion inhibitor;

c) from 3 to 20 parts of an antifreeze solvent;

d) at least 10 parts of urea, the urea being present in an amount at least equal to that of the anti-freeze solvent.

According to one embodiment, the concentrated composition further comprises:
e) a hydrocarbon surfactant, preferably in an amount of at least 0.10 part by weight, more preferably from 0.10 to 0.5 part by weight.

a) de 1 à 3 parties d'émulseur AFFF,

b) de 5 à 15 parties d'inhibiteur de combustion,

c) de 5 à 15 parties d'un solvant antigel, et

d) de 15 à 30 parties d'urée.

According to one embodiment, the concentrated composition comprises:

a) from 1 to 3 parts of AFFF foam concentrate,

b) from 5 to 15 parts of combustion inhibitor,

c) from 5 to 15 parts of an antifreeze solvent, and

d) from 15 to 30 parts of urea.

The invention also relates to an aerosol can comprising a composition according to the invention, under pressure.

The aerosol can may also include a concentrated composition according to the invention in a cartridge, and an aqueous solution, under pressure.

The aerosol can can also include in a first cartridge the components a), c), d) and optionally e) of a concentrated composition according to the invention, and in a second cartridge component b) of a composition concentrated according to the invention, and an aqueous solution, under pressure.

a) au moins 1 % d'un émulseur AFFF ;

b) au moins 5 % d'un inhibiteur de combustion ;

c) de 3 à 20 % d'un solvant antigel ;

d) au moins 10 % d'urée, l'urée étant présente en une quantité au moins égale à celle du solvant anti-gel;

   avec une solution aqueuse.The subject of the invention is also a process for preparing an extinguishing composition comprising the mixture, in one or more stages, of the following compounds, in% by weight of the final composition:

a) at least 1% of an AFFF foam concentrate;

b) at least 5% of a combustion inhibitor;

c) from 3 to 20% of an antifreeze solvent;

d) at least 10% urea, the urea being present in an amount at least equal to that of the anti-freeze solvent;

with an aqueous solution.

The composition thus prepared advantageously has the characteristics preferred given in the present application.

The invention is now described in more detail in the description which follows.

The AFFF foam concentrate most often comprises an aqueous or hydroalcoholic solution, at least one fluorosurfactant, at least one non-fluorosurfactant fluorinated, and at least one co-solvent such as a monoalkyl ether of mono- or di-ethylene- or propylene glycol. Preferably, an emulsifier whose weight content is used in fluorinated surfactant (s) is between 5 and 25%, advantageously between 7 and 18%, that of non-fluorinated surfactant (s) ranging from 2 to 20%, preferably between 4 and 18%, and that of co-solvent which can range from 20 to 50%, preferably 30 to 45%.

• un agent antigel comme l'éthylèneglycol ou le propylèneglycol,
• un anticorrosif tel que le tolyltriazole ou le nitrile de sodium,
• un conservateur tel que le benzoate de sodium, le formaldéhyde, l'o-phénylphénol, ou le dichlorophène,
• un stabilisateur de pH tel que l'ammoniaque, la diéthanolamine, la triéthanolamine ou l'urée.

The foam concentrate can also contain various conventional additives in an amount which generally does not exceed 10% by weight:

• an antifreeze agent such as ethylene glycol or propylene glycol,
• an anticorrosive such as tolyltriazole or sodium nitrile,
• a preservative such as sodium benzoate, formaldehyde, o-phenylphenol, or dichlorophene,
• a pH stabilizer such as ammonia, diethanolamine, triethanolamine or urea.

The constituents of AFFF, namely the (at least one) fluorinated surfactant, the (at at least one) non-fluorinated surfactant, the (at least one) co-solvent are described for example in the application in the name of the plaintiff, published under the number EP-A-0 676 220, at which it is returned for more details.

In the context of the present invention, any of the known combustion inhibitors or a mixture of such inhibitors. As non-limiting examples of combustion inhibitor compounds, there may be mentioned orthophosphates of mono-, di-, or tri-ammonium, pyrophosphates of mono-, di-, tri- or tetra-ammonium, ammonium metaphosphate, polyphosphate ammonium, mixed salts of alkali metal ions and ammonium-ortho-phosphate, -pyrophosphate or -polyphosphate and ammonium sulfates and bisulfates. It is preferred to use orthophosphates and ammonium sulfates, in particular mono-ammonium orthophosphate, di-ammonium orthophosphate and ammonium sulfate or mixtures of these compounds.

R_H-CONH-C₂H₄-NH-C₂H₄OC₂H₄COOM R_H-NH-C₂H₄-COOH R_H-N(C₂H₄COOM)₂

R_H-N(CH₃)₂ → O dans lesquelles R_H, représente un radical alkyle, linéaire ou ramifié, contenant de 4 à 18 atomes de carbone, q est un nombre entier allant de 1 à 16, C₆H₁₀O₅ désigne un groupement glucoside, r est un nombre entier allant de 1 à 6, de préférence égal à 1 ou 2 et M désigne un ion métallique alcalin ou un ammonium quaternaire.The hydrocarbon surfactants which can be used in the formula can be anionic, nonionic or amphoteric compounds. Without limitation, mention may be made of the compounds of the following formula: R _H -OSO ₃ M R _H - (OC ₂ H _{4) q} -OSO ₃ M R _H (OC ₂ H ₄ ) _q -OH H (C ₆ H ₁₀ O ₆ ) _r -OR _H

R _H -CONH-C ₂ H ₄ -NH-C ₂ H ₄ OC ₂ H ₄ COOM R _H -NH-C ₂ H ₄ -COOH R _H -N (C ₂ H ₄ COOM) ₂

R _H -N (CH ₃ ) ₂ → O in which R _H represents a linear or branched alkyl radical containing from 4 to 18 carbon atoms, q is an integer ranging from 1 to 16, C ₆ H ₁₀ O ₅ denotes a glucoside group, r is an integer ranging from 1 to 6, preferably equal to 1 or 2 and M denotes an alkali metal ion or a quaternary ammonium.

The anti-freeze solvent is generally a polyol, advantageously a glycol, of preferably ethylene glycol or propylene glycol.

The presence of urea in this aqueous composition has the effect of lowering its frost point. This antifreeze effect also reduces the amount of antifreeze glycol type to use. In addition, urea makes it possible to obtain in combination with the others constituents a perfectly clear composition. The fact that this composition is limpid, in opposition to a cloudy composition, guarantees the solubilization of each components and therefore the stability of the mixture.

Urea is preferably present in the composition in an amount at least equal to that of the anti-freeze solvent used, more preferably in an amount of at least minus 1.5 times.

Urea may be present in the form of a precursor which in contact with water turns into urea.

a) l'émulseur ou l'inhibiteur est placé dans une cartouche à opercule,

b) l'émulseur ou l'inhibiteur est placé séparé dans une cartouche à opercule, ou

c) l'émulseur et l'inhibiteur sont placés tous deux dans une seule cartouche à opercule,

   les autres constituants étant prémélangés soit avec l'une des constituants ci-dessus ou avec l'eau de l'extincteur.The constituents of the composition of the mixture according to the invention are typically used together in a conventional portable water spray extinguisher. They can all be there in premix with the water from the extinguisher, but also separately, for example according to one of the following methods:

a) the foam concentrate or the inhibitor is placed in a cover cartridge,

(b) the foam concentrate or inhibitor is placed separate in a cover cartridge, or

c) the foam concentrate and the inhibitor are both placed in a single cover cartridge,

the other constituents being premixed either with one of the above constituents or with the water from the extinguisher.

An example of an aerosol can is a can that contains in a cartridge AFFF, antifreeze, urea and possibly the additional surfactant and in a other cartridge the inhibitor (e.g. as a concentrated solution).

In practice, the various constituents are mixed with the water contained in the fire extinguisher at the time of use. Under the effect of pressure, the mixture, i.e. the extinguishing composition, is expelled outside the body of the extinguisher and, by passing through the sprayer, forms a foam capable of extinguishing as well Class B fires (combustible liquids) than Class A fires (materials absorbent) than oil fires.

The pressure in the aerosol will be sufficient to obtain the formation of a foam (i.e. so that the AFFF foam concentrate plays its role). The propellant is an inert gas such as nitrous oxide or nitrogen. Superior results have been obtained with a pressure in the aerosol can greater than or equal to 7 bars.

All the quantities expressed as a percentage are given by weight by relative to the final weight of the compositions in question.

The following examples illustrate the invention without limiting it.

EXAMPLES

33,7 parties d'une solution aqueuse à 31 % d'un mélange de bétaïnes fluorés de formule : C_xF_2x+1CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N^⊕(CH₃)₂CH₂COO^⊖ avant la composition suivante : x % 6 70 8 23 10 5 12 1,5 14 0,4 16 0,1

14,4 parties d'une solution hydroalcoolique (35 % d'éthanol) à 40 % d'oxyde d'amine fluorée de formule : C₆F₁₃-CH₂CH₂-SO₂NH-CH₂CH₂CH₂-N(CH₃)₂ → 0

15,2 parties d'une solution aqueuse à 50% d'alkyl(C₈ et C₁₀)amidoéther propionate de formule : alkyl-CONH-CH₂CH₂-NH-CH₂CH₂-OCH₂CH₂COONa (Rewoteric AMVSF commercialisé par la Société REWO),

4,7 parties d'une solution aqueuse à 70 % d'alkyl(C₈ et C₁₀)-glucoside (Triton BG 10 commercialisé par la Société UNION CARBIDE), et

30 parties de mono-n-butyléther du diéthylène-glycol(C₄H₉-O-C₂H₄-O-C₂H₄-OH).

The foam concentrate is prepared under the following conditions:
At 40 ° C. and with moderate stirring, the following constituents are mixed by weight:

33.7 parts of a 31% aqueous solution of a mixture of fluorinated betaines of formula: C _x F _{2x + 1} CH ₂ CH ₂ -SO ₂ NH-CH ₂ CH ₂ CH ₂ -N ^⊕ (CH ₃ ) ₂ CH ₂ COO ^⊖ before the following composition: x % 6 70 8 23 10 5 12 1.5 14 0.4 16 0.1

14.4 parts of a hydroalcoholic solution (35% ethanol) with 40% fluorinated amine oxide of formula: C ₆ F ₁₃ -CH ₂ CH ₂ -SO ₂ NH-CH ₂ CH ₂ CH ₂ -N (CH ₃ ) ₂ → 0

15.2 parts of a 50% aqueous solution of alkyl (C ₈ and C ₁₀ ) amidoether propionate of formula: alkyl-CONH-CH ₂ CH ₂ -NH-CH ₂ CH ₂ -OCH ₂ CH ₂ COONa (Rewoteric AMVSF marketed by REWO),

4.7 parts of a 70% aqueous solution of alkyl (C ₈ and C ₁₀ ) -glucoside (Triton BG 10 sold by the company UNION CARBIDE), and

30 parts of diethylene glycol mono-n-butyl ether (C ₄ H ₉ -OC ₂ H ₄ -OC ₂ H ₄ -OH).

The mixture is then brought to pH 9.3 by addition of 2 parts of diethanolamine. The foam concentrate is thus obtained.

The combustion inhibitor is di-ammonium orthophosphate.

In the examples, the gel point is measured using the procedure. next :

A DEWART with a capacity of 1 liter is filled with a mixture acetone / dry ice. A double-walled test tube is filled with the compound liquid whose freezing point is to be measured. We introduce a mercury thermometer as well as a system for stirring the liquid in this test tube. The test piece is then placed in the acetone / dry ice mixture. The content of this test piece is regularly agitated so as to homogenize its temperature. We notes the drop in temperature at regular intervals. The freezing point is characterized by a stop of this drop in temperature, a sudden increase in the viscosity of the liquid and in some cases by the appearance of crystals. This operation is renewed three times for each liquid whose freezing point is desired.

Example 1

74 ml of water (74%) are poured into a 250 ml beaker and added to it under a slight agitation (magnetic bar 1 g (1%) of the above-mentioned AFFF agent, 10 g (10%) of the above-mentioned combustion inhibitor and 15 g (15%) of 1,2-propanediol. After a few minutes of stirring, the mixture is homogeneous and its point of measurement is measured gel according to the procedure given previously. Freezing point: -12 ± 1 ° C.

This composition is cloudy and is not extinguishing.

Examples 2 to 11

By proceeding as in Example 1, the mixtures in Table 1 given as a percentage by weight are produced. The gel points obtained for these mixtures as well as the appearance of the mixtures are shown in Table 1. Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Ex. 11 AFFF 1% 1% 1.5% 1.5% 1.5% 1.5% 1.5% Inhibitor 10% 10% 5.5% 5.5% 5.5% 10% 10% 10% 10% 10% Sodium octyl sulfate (42%) 0.35% 0.35% 0.35% 0.35% 0.35% Urea 15% 20% 25% 25% Ammonium nitrate 15% 1,2-propane-diol 20% 25% 15% 20% 25% 15% 15% 15% 5% 15% Demineralized Water 69% 64% 79.5% 74.5% 69.5% 58.15% 53.15% 48.15% 58.15% 58.15% Frost point -14 ± 1 ° C -17 ± 1 ° C -11 ± 1 ° C -14 ± 1 ° C -16 ± 1 ° C -15 ± 1 ° C -18 ± 1 ° C -20 ± 1 ° C -5 ± 1 ° C -20 ± 1 ° C Product aspect Troub. Troub. Troub. Troub. Troub. Limp. Limp. Limp. Limp Troub.

In Examples 7, 8, 9 and 10 in accordance with the invention, the combination of urea / 1,2-propanediol makes it possible to obtain a clear aqueous composition and the gel point of which is weak.

Examples 12 to 14 Hydrocarbon fire tests

The mixtures shown in Table 2 were prepared according to the procedure given in Example 1. Ex. 12 Ex. 13 Ex. 14 AFFF 1% 1.5% 1.5% Inhibitor 10% 10% 10% Sodium octyl sulfate 42% 0.35% 0.35% Urea 25% 25% 1,2-propanediol 15% 25% 15% Demineralized Water 49% 63.15% 48.15%

Aerosols are 600 ml aluminum bottles filled with 240 ml of each of the compositions appearing in Table 2. The propellant gas used is nitrogen. The pressure of this gas in the aerosols is between 8 and 8.5 bars.

The aerosols thus obtained are evaluated according to the procedure below:

3 liters of water are poured into a circular container 56 cm in diameter, then 2 liters heptane. The extinction test with the aerosol can is only undertaken for 60 seconds after lighting the fireplace.

The aerosol is emptied by several successive presses on the diffuser button. For each test, note the complete emptying time of the aerosol as well as the control time at 90% of the focus (time required for the flames to not cover more than 10% of the hearth surface).

This series of tests was carried out outdoors with a temperature of 19.5 ° C and a wind of less than 3 ms ^-1 .

The results obtained are presented in table 3. When the rows of this table include two series of results, this means that two tests were carried out with the same composition. Mixture in aerosol Control time 90% Complete extinction Example 12 10 s 35s Example 13 <10 s no Example 14 <10 s
<10 s 15 s
25s

Examples 12 and 14, in accordance with the invention, are extinguishing compositions.

Example 15

300 ml of the composition of Example 14 are introduced into a 1 liter aerosol. The propellant is nitrogen. The pressure of this gas in the aerosol is between 8 and 8.5 bars. The aerosol is evaluated according to the procedure described in Examples 12 to 14. The only difference is that 5 liters of heptane are used instead of two. The results obtained are reported in Table 4. Mixture in aerosol Control time 90% Complete extinction Example 15 <10 s 65s

Example 16

A test on type A fireplaces was carried out. The composition used for this test is shown in Table 6. Ex. 16 AFFF 1.5% Inhibitor 10% Sodium octyl sulfate 42% 0.35% Urea 25% 1,2-propanediol 15% Demineralized Water 48.15%

The aerosol is an aluminum bottle filled with 600 ml with 250 ml of the composition shown in Table 7. The propellant used is nitrogen. The pressure of this gas in the aerosols is between 8 and 8.5 bars.

The aerosol thus obtained is evaluated according to the procedure described below:

Type A fireplace consists of a stack of 12 pine logs Sylvestris 25 cm long and 4 x 4 cm in section. This stack consists of 4 staggered sticks, each stage consisting of 3 parallel sticks the most distant ends of which are 25 cm apart. This fireplace presents therefore a floor area of 25 cm x 25 cm.

This hearth is kept 21 cm from the ground on a metal support. A tray of 45 cm in diameter and 10 cm high is filled with 2 liters of water and 2 liters heptane. This tank is lit then placed under the stack of wood. He is withdrawn after 2 minutes of combustion. Let the wood fireplace burn for 6 additional minutes before starting the extinction test. Extinction is company by projecting the composition on the hearth using successive pressures on the aerosol dispenser button.

For each extinction test, note the time of complete emptying of the aerosol, the presence of flames after emptying, the presence of flame or points red 3 minutes after switching off.

The result obtained is presented in Table 7 below. Flames after emptying Presence of red dots Resumption of fire no no no

Example 17 Wood fireplace

The composition of Example 16 was evaluated on the type A hearth of the standard NF 61-804. This fireplace is made up of 52 Carolina pine logs of 20 cm long and 2.5 x 2.5 cm in section. This stack consists of 13 floors of staggered logs, each floor consisting of 4 parallel logs including the furthest ends are 20 cm apart. The fireplace therefore has a floor area of 20 cm x 20 cm.

The extinction is obtained with a 1 liter aluminum aerosol in which introduced 300 ml of the composition of Example 16. The nitrogen pressure in the housing is between 8 and 8.5 bars. The extinction is obtained in less than one minute and no re-ignition is observed 3 minutes after switching off.

Example 18 Oil fire test

One liter of peanut oil is poured into a 35 cm diameter container. The container is placed over a heptane fire. Oil ignites after approximately 25 minutes of heating. 30 seconds after the start of combustion, direct the jet of foam on oil. The intensity of the hearth immediately decreases, the fire goes out.

Extinguishing is carried out with an aerosol can containing 300 ml of composition from Example 16; less than 200 ml are used.

The compositions according to the invention are in particular free of citric acid, with the difference in compositions according to document EP-A-0873768.

Claims (15)

Aqueous extinguishing composition comprising, in% by weight relative to the weight of the composition: a) at least 1% of an AFFF foam concentrate; b) at least 5% of a combustion inhibitor; c) from 3 to 20% of an antifreeze solvent; d) at least 10% urea, the urea being present in an amount at least equal to that of the anti-freeze solvent. The composition of claim 1, further comprising
e) a hydrocarbon surfactant, preferably in an amount of at least 0.10% by weight, more preferably from 0.10% to 0.5% by weight. Composition according to claim 1 or 2, comprising a) from 1 to 3% of AFFF emulsion, b) from 5 to 15% of combustion inhibitor. c) from 5 to 15% of an antifreeze solvent, and d) from 15 to 30% of urea. Concentrated extinguishing composition, comprising, by weight a) at least 1 part of an AFFF foam concentrate; b) at least 5 parts of a combustion inhibitor: c) from 3 to 20 parts of an antifreeze solvent; d) at least 10 parts of urea, the urea being present in an amount at least equal to that of the anti-freeze solvent. The composition of claim 4, further comprising:
e) a hydrocarbon surfactant, preferably in an amount of at least 0.10 part by weight, more preferably from 0.10 to 0.5 part by weight. Composition according to claim 4 or 5, comprising a) from 1 to 3 parts of AFFF foam concentrate, b) from 5 to 15 parts of combustion inhibitor, c) from 5 to 15 parts of an antifreeze solvent, and d) from 15 to 30 parts of urea. A composition according to any of claims 1 to 6, wherein the AFFF foam concentrate contains from 5 to 25% by weight, preferably between 7 and 18%, of fluorinated surfactant (s), from 2 to 20% by weight by weight, preferably between 4 and 18% of non-fluorinated surfactant (s), and from 20 to 50% by weight, preferably between 30 and 45%, co-solvent (s). A composition according to any of claims 1 to 7, wherein the inhibitor is chosen from mono-ammonium orthophosphate, orthophosphate of di-ammonium and ammonium sulfate or mixtures of these compounds. Composition according to any one of Claims 2, 3 and 5 to 8, in which the hydrocarbon-based surfactant is chosen from: R _H -OSO ₃ M R _H - (OC ₂ H _{4) q} -OSO ₃ M R _H (OC ₂ H ₄ ) _q -OH H (C ₆ H ₁₀ O ₆ ) _r -OR _H

R _H -CONH-C ₂ H ₄ -NH-C ₂ H ₄ OC ₂ H ₄ COOM R _H -NH-C ₂ H ₄ -COOH R _H -N (C ₂ H ₄ COOM) ₂

R _H -N (CH ₃ ) ₂ → O in which R _H represents an alkyl radical, linear or branched, containing from 4 to 18 carbon atoms, q is an integer ranging from 1 to 16, C ₆ H ₁₀ O ₅ denotes a glucoside group, r is an integer ranging from 1 to 6, preferably equal to 1 or 2 and M denotes an alkali metal ion or a quaternary ammonium. Composition according to any one of Claims 1 to 9, in which the antifreeze solvent is a glycol, preferably ethylene glycol or propylene glycol. Aerosol can comprising a composition according to any one of claims 1 to 3 and 7 to 10, under pressure, preferably at a pressure of at least minus 7 bars. Aerosol can comprising a composition according to any one of claims 4 to 6 in a cartridge, and an aqueous solution, under pressure, of preferably at a pressure of at least 7 bars. Aerosol can comprising in a first cartridge the components a), c), d) and optionally e) of a composition according to any one of claims 4 to 6, and in a second cartridge component b) of a composition according to any one of claims 4 to 6, and an aqueous solution, under pressure, of preferably at a pressure of at least 7 bars. Process for the preparation of an extinguishing composition comprising the mixture, in one or more stages, of the following compounds, in% by weight of the final composition: a) at least 1% of an AFFF foam concentrate; b) at least 5% of a combustion inhibitor; c) from 3 to 20% of an antifreeze solvent; d) at least 10% urea, the urea being present in an amount at least equal to that of the anti-freeze solvent; with an aqueous solution. The method of claim 14, wherein the extinguishing composition has the characteristics of the composition according to any one of claims 2, 3, and 7 to 10.