CA2121654A1 - Emulsifiers for portable extinguisher - Google Patents

Abstract

An emulsifier according to the invention consists of an aqueous solution containing by weight: (a) 1 to 15% of at least one fluorinated betaine; (b) 1 to 20% of at least one fluorinated amine oxide; (c) 2 to 8% of at least one alkylglucoside; (d) 2 to 10% of at least one other anionic, nonionic or amphoteric hydrocarbon surfactant; (e) 20 to 50% of at least one monoalkyl ether of mono- or di-ethylene (or propylene) glycol, the content of fluorinated compounds (a) and (b) being between 5 and 25% and the weight ratio ( a + b) / (c + d) being between 1 and 2.

Description

21216 ~
-.

EMULSE FOR PORTABLE FIRE EXTINGUISHERS

~ a present invention relates to the field of fire extlnclion and to more particularly for the purpose of foam concentrates for portable water extinguishers verified.
One of the well known means for extinguishing fires of hydrocarbon liquids good ~ s consists in projecting on the hearth a rnousse obtained by mixing under high water pressure and foam concentrate ~ based on surfactants. Most of foam concentrates available on the market can be ran in two main categories.
gorTs according to the nature of the foaming base. In a first ~ emile ~ emille sours, the foaming basa usually consists of a protein hydrolyzate anim ~ les (hairs, horns, hooves, hemoglobin). On this basis the proline ~ be added fluorosurfactants ~ s to obtain a booster f! uoroproteini-than; such emulsifiers are described, for example, in patents GB 1 28 ~ 508, lS GB 1 368 463, US 4 424 133, EP 49958, US 4 460 480, FR 2 230 384, GB 2,011,784 and WO 8803425.
In the other large family of foam concentrates, the foam base is composed a m ~ lan ~ e of a ~ Qnts hydroc3rbones surfactants. Fluorescent surfactants forming film can ~ 0alement be incorporated. In this last type of foam concentrate, 20 known in the art as AFFF emulsours, the presence of fluorinated surfactant permot will produce a foam which by decantation forms an aqueous film floating above above the surface of the oil. This aqueu film ~ has for bul not only ~ to extinguish the fire, but au5! 3i to prevent a possible reinflammalion of the sur ~ ace of the hydrocarbon. ~ Emulsers of this type have been described in numerous 2s patents, in particular the following: GB 1 258 299, US 5 085 786, FR 2 347 426, US 3 957 657, FR 2 04 ~ 316, US 4 350 206, FR 3 562 156, FR 2 148 442, FR 2 4a7 724, FR 2 385 413, US 3 772 195, FR 2 397 847, US 3 661 776, US 3,839 42 ~, FP <2 1Q3 669, US 3,957 ~ 57, US 3,963,776 and FR 2,296,625.
In order to obtain a good resistance to re-inflammation, the foam concentrate after ~ s 31) diluted ~ ion ~ water and ~ air supply must produce a foam forming, by decantation;
an aqusux film which spreads over the entire surface of the hydrocarbon and whose stability thermal is the most possible ~ lev ~ e. ~ on condition of thermodynamic equilibrium ~ necessary to form 10 aqueous film is linked to the spreading coefficient (CE) which must be positive.
3s ~ E - ~ c - (~ s + rl) where CE ~ co ~ fficient of ~ talement in mNlm `~ 21216 ~:
^ ~
.
YHc = surface tension of the hydrocarbon y5 ~ surface tension of the extinguishing composition after dilution of The foam concentrate y; = interfacial tension between the hydrocarbon and the extinguishing composition after dilution of the foam concentrate Although the spreading coefficient should be positive, care should be taken that the interfacial tension tYi) is not too low in order to avoid emulsification of the hydro-carbide by the extinguishing composition or too great a thinning of the film aqueous. The emulsification of the hydrocarbon by the extinguishing composition risks o effect of causing the entrainment of part of the hydrocarbon inside the foam, contaminate it and ignite it.
Another important factor vis-à-vis the phenomenon of reinfl ~ mmation is the thermal resistance of the aqueous film. In this regard, excessive spreading speed leads to the formation of a very thin film which is not very resistant to heat; reverse-the most heat-resistant films are those whose speed of formation is the slowest. It is therefore important to find a compromise between speed of spreading and the thermal resistance of the aqueous film, this property being essential thinkable to obtain a good resistance to re-ignition. Indeed, the film aqueous which removes hydrocarbon vapors can at any time, for example 20 by stirring, be separated from the foam from which it comes and be found directly in contact with an inflamed part. If its thermal resistance is ~ too low, the film can be destroyed and release hydrocarbon vapors which ignite immediately and continue to destroy the rest of the film.
AFFF foam concentrates which are generally used with short-lance 25 fire not suitable pa ~ in a portable fire extinguisher designed to be re ~ worn and used in the hand and which, in working order, has a mass less than or ~ equal to 20 kg. In a portable extinguisher ~, the amount of water available to dilute the foam concentrate up to use concentration tO, 5 to 6%, most often 1 to 3% ~ is limited and fixed generally at 6 or 9 liters, while in the application system by means 30 of a lance the quantity of water available is not limited. Therefore, to satisfy to the approval standards relating to foaming liquids for hyclrocarbon fires res, a portable foam extinguisher ~ eur must be ~ much more effective than classic foam concentrate for fire hoses. For example, to obtain certification oation of a 6 liter fire extinguisher for type 144 B fires, the portable fire extinguisher 35 will have to extinguish with only 6 liters of solution ~ foam concentrate diluted to 3%
(French standard S61-900), whereas in the case of extinction with a lance has fire the maximum available quantity of 3% diluted emulsifier solution go up to ~ 28.5 liters (French standard S60-220) or 22.3 liters (standard l) i 162).

"3 2 ~ L21 ~

The present invention now relates to an emulsifier for fire extinguishers portable, characterized in that it consists of an aqueous solution containing weight:
(a) from 1 to 15% ~ preferably 2 to 12%) of at least one fluorinated betaine of 5 general formula:

Rf (CH2) m ~ - (CH2) n ~ (cH ~) py (l) o R R2 (b) from 1 to 20% (preferably 3 to 15%) of at least one amine oxide fluorine of general formula:

RF (CH2) m'-Xr- (CH2) n ~ -N ~ O (Il) R R2 ' (c) from 2 to 8% ~ preferably 3 to 6% 3 of at least one alkyl glycoside of ~ general rule:

H (C6H1o5) qR3 (1 ~ l) ~ d ~ from 2 to 10% ~ of preference ~ 3 ~ 8% 3 of at least one a ~ in ~ non-surfactant ~:
anionic, non-ionic or amphoteric fluoride other than those of the formula III; ~:
(Q) from 20 to 50% (preferably 30 to 45 ~) of at least one monoalkyl ether mono- or di-ethylbne (or propylene) glycol;
the total content of fluorinated compounds a and b being between 5 and 2 ~%
(preferably between 7 and 18%) el the weight ratio ~ a ~ b) t ~ c ~ d) é ~ ant understood between 1 and 2 (preferably between 1.3 and 1.7).
In formulas 1, ll and lil above, l ~ s different symbol ~ have 10s signifi-3s following cations ~:
- RF and RF. identical or different, each represents a perfluo- radical roalkyl, linear or branched, containing at least 6 carbon atoms, of preference ds 6 to 16 carbon atoms;
- m and m ', identical or different, are each an integer ranging from ~ 0 ~ 6 ~ preferably ~ equal b 0 OIJ 2, '' - ".

:: r ~

"21 2 ~ 6 ~

^ X and X ', identical or different, each denote a group CO or SO2,: 1 preferably a group ~; 2;
- R and R ', identical or different, each represent a hydro- atom.
gene or methyl or ethyl radical; :
- n and n ', identical or different, are each an integer ranging from ds 1 to 5, preferably equal to 3;
- R1, R1, R2 and R2, identical or different, each represents a radical methyl or ethyl; ~ ~;
- p is an integer ranging from 1 to 5, preferably equal to 1 or 2;
o - Y (3d designates a group So3 ~? OSO3 ~) or CO (~, - q is an integer ranging from 1 to 6, preferably equal to 1 or 2;
- R3 represents an alkyl radical, linear or branched, containing from 6 to 18 carbon atoms, preferably 8 to 14 carbon atoms.
Without limitation, the non-fluorinated surfactant (d) can be chosen from lS the compounds of the following formulas:
-R4-oSo3M (IV ~

R4- (oC2H4) roSo3M (IV-2) R4 (OC2H4) rQtl (IV-3) R4 ~ (oc2H4) r-oH (1 ~ -4) HOC2tl4-N ll R4 -: ~

~, N (IV-53 R4 CoNH-c2ll4-NH-c2H4oc2H4cooM (IV4) ~ 4-NH-C211 14-GOOH (1 ~ 1-7) R4-N (c2H4c ~ OM) 2 (IV-8 .

I
: 1 ~ ' "5,212 ~ 65 ~

R4-N (IV-9 C2H4COOM ' R4-CoNH-C3H6-N (CH3) 2CH2Coo (iV-1 0) o R4-N (CH3) 2 ~ O (IV-11) in which R4 represents an alkyl radical, linear or branched, containing 8 with 18 carbon atoms, r is an integer ranging from 1 to 16, M denotes an ion alkali metal or quaternary ammonium and M 'an alkali metal ion.
As non-limiting examples of monoalkyl ethers (e), mention may be made of ether.
monoethyl or monobutyl of ethylene glycol and monobutyl ether of diethylene glycol, the latter being preferred.
More particularly preferred foam concentrates are those which contain:
- as constituents (a), a mixture of fluorinated betaines of formula:

~.
CXF2x ~ 1-cH2cH2-so2NH-cH2cH2cH2-N (cH3) 2cH2coo. ~.

in which x is an even integer ranging from 6 to 16, the content of the mixture in ~:
2S betaine ~ radical C6F13 being at least 50% by weight;
- as constituent (b), fluorinated mine oxide of formula:

C6F13CH2C ~ 2-S02NH-CH2CH2CH2-N (CH3) 2 ~ ' ~? tO - as a constituent ~ (d), an amido ether propionate of ~ ormule (IV ~), a alkyl ~ -iminodipropionate of forrrlule ~ IV-8) or an alkylamidopropylbetaine formula (IV-10).
L0s foam concentrates according to the invention can be prepared by simple mixing different constituents ~ until homogeneous ~ isation. To accelerate homogenization -: I `35 tion, we can operate in Ehauffane ~ a temperature between the temperature ambient and that of ebulli ~ ion of the mixture, preferably, 3 a temperature com-taken between 30 and e, ooc.
The pH of the foam concentrate is avan ~ steadily stabilized at a value at least equal to 7 (preferably between 8 and 10) by means of a weak base, for example ammonia or an organic ba ~ e such as diethanolamine, ia triethanola-mine, urea.

`` ''';"`

If desired, the foam concentrates can optionally be incorporated according to the invention.
various additives such as:
- an antifreeze agent such as ethylene glycol or propylene glycol, a co-solvent, for example a lower alcohol (C1 to C4), s - an anticorrosive te! than tolyltriazole or sodium nitrite, - a preservative such as sodium benzoate, fomaldehyde, o-phe-nylphenol or dichlorophene.
The foam concentrates according to the invention can be used in a fire extinguisher portable at a rate of 0.5 to 6 parts by weight (preferably 1 to 3 parts ~ of foam concentrate per 100 parts by weight of water.
The performance of the foam concentrates according to the invention can be evaluated by the following tests T ~ st spreading This test which indicates the speed of formation of the aqueous film on the surface of the hydrocarbon is produced by pouring 50 ml of hydrocarbon (heptane) into a box Petri dish (diameter: 11.5 cm), the outer facP of which is painted black to see watch the film. When the surface is stationary, it is deposited using a medium cropipette 0.1 ml of an aqueous solution ~ 3/0 of foam concentrate. The solution must be - 20 applied drop by drop, starting from the center and making an eccentric movement than. The stopwatch is started at the time of filing the first stop and stop stopped when the film has covered the entire surface of the oil. We note the time.
If the ~ otal recovery is not obtained in less than a minute, we note the percentage of surface covered after one minute.
The spreading is satisfactory if the total recovery is obtained in less than 30 seconds, preferably between 5 and 25 seconds.
'' Thermal resistance test The evaluation of the thermal resistance of the aqueous film is obtained by measuring the Film Stability Limit Temperature (TLSF). This test which cannot be ef-carried out only in the case where the totali ~ e of the surface of the hydrocarbon is covered by the fllm is made in a brass measuring container with a diameter of 6.5 cm and a total volume of 100 ml, placed on a thermostated heating plate. In this container, 80 ml of hydrocarbon ~ heptan is poured) and, when the surface is im-rnobile, there is deposited ~ 0.1 ml of an aqueous solution of 3% foam concentrate as indicated for the calibration test. After 60 seconds, place the end of a thermometer on contact with the aqueous film and a flame about 1 cm above the film. The ther-21216a ~
- ~ - 7 -mostat is set for a temperature increase of 4C / min. We note the time temperature (TLSF) at which the ignition of the hydrocarbon occurs.
A good foam concentrate should lead to a TLSF higher than 35C, preferably higher than about 40C
s Spreading The amount of expansion) is the ratio of the volume of foam produced from a 3% aqueous solution of foam concentrate at the initial volume. To de-finish the expansion, we introduce into a test tube of 1 liter 100 ml of solution o tion in aqueous 3% foam concentrate, then the solution is beaten for one minute at rhythm of one beat per second using a perforated circular piston (30 holes 5 mm in diameter representing 25% of the surface) and fixed in its center to a metal ti ~ e.
A satisfactory foam concentrate must lead to an expansion at least equal to 8.

Suf rficial and inte ~ acial tensions Surface tension ~ (~ s) with city water and interfacial tension (y;) with heptane are measured using a LAUDA blood pressure monitor in accordance with ISO 304 and ISO 6889 standards, but operating at 2SC.
In the following examples which illustrate the invention without limiting it, the percentages indicated are expressed by weight and the main constituents used are designated, for simplicity, by the following abbreviations: ~.
A = Melan ~ e of fluorinated betaines of formula: ~:

2 ~ CxF2x ~ 1 CH2cH2-so2NH-cH2 (~ H2cH2-N ~ 3 (cH3) 2cH2coo having the following weight composition:
x%

12 1.5 14 0.4 3s 16 0.1 used as a 45% aqueous solution.

~ 1.

2l 216 ~ A
.
B - Fluorinated amine oxide of formula:

C6F13-CH2CH2-S02NH-CH2CH2CH2-N (cH3) 2 _ ~ o marketed by D ~ manderesse in the form of a hydroalcoholic solution than 40%. ~.
C = Alkyl (Cg and C10) -glucoside marketed in the form of a solution 70% aqueous by UNION CARBIDE So ~ iété under the name tion Triton BG 10.
o D1 = Alkyl (Cg and C10) amidoether propionate of formula:.
.
Alkyl-CONlt-CH2CH2-NH-CH2CH2-OCH ~ 2CH2COONa marketed in the form of a 50% aqueous solu ~ ion by the Company REWO under the name Rewoteric AMVSF
o D2 = N-lauryl- ~ -iminodipropionate of formula:

CH2C: H2COONa marketed in 30% aqueous solution by HENKEL under the name Deriphat 160C.
D3 - Alkyl (C12 and C14) -amidopropylbetaine of f ~ rmule:

Alkyl- ~ oNl ~ -cH2 ~ H ~ c ~ 2-N ~ H3) 2 sold in 30% aqueous solution under the name Ampho-tensid B4 by the company ZSCHIMMER and SCHWARTZ.
~ - D4 8 Decyl ether sulfate of formula:

(~ 1 0H21 (OC2H4) 2OSO3Na utili ~ ~ n aqueous solution ~ ~ 30%.
~ E = Mono-n.butylether of diethyl ~ ne ~ lycoi:

4 ~ C4Hgo-c2H4- ~ -c2H4 ~ H

9-212 ~ 6 ~

. .
a3 By mixing at 40C with moderate stirring the adequate quantities ~ ~:
commercial products preci ~ ed, cn prepares an foam concentrate according to the invention, the contents of active materials of which are as follows:

Constituents Teneursf% l A 10.8 B 6.2

3.3 ~:
D1 7.9:
E 40.0 ethanol 5.4 ~ '' water (qs 100%) 26.4 This composition, brought to pH 9.3 p ~ r addition of diethanolamine, has the following features:
- temperature of con ~ iation: -22 + 2C
- density: 1.065 - viscosity: 18 mP ~. s - r ~ fraction index: 1.414 - Ys (3% city water) 16.4 mNlm - Yi (3% city water / heptane) 2.5 mN / m :: - flash point (in cross section ~: 50 C '' Submitted awc tests described above ~ demment, c ~ t foam concentrate leads to perfor-following:
- also: 2Qsecond ~ ~
-TLSF: 47C - -- ~ idling: 10.2 90 ml of c ~ foam concentrate are placed in the cartridge of an ex ~ porta ~ ifctor da : ~ 30 6 liter ~ s, pUi5 50n efficiency is tested on a heptane 144 B hearth (standard NF S61-900).
The extinction was obtained with an excel ~ ent behavior towards ph ~ nomene ds re-inflammation. Indeed, if after the extinction one breaks l ~ f; lm aqueous floating and -:
ignites the hydrocarbon vapors ~ brought into contact with air, the film is reformed immediately ct again completely covers the surface of the hydrocarbon, extinguishing so the new home.
b) By way of comparison, gold has prepared two foam concentrates (b1) and (b2 ~ not conforming ~) rne% to the pr ~ sento invention and brings their pH to 8.5 to mo ~ Jen of diethanolamine; - '~' - ' Their composition and performance are summarized in the following table:
,. ~ '.

~ 21 ~
~ o .` ~. .
_. . .
B1 b2 emulsifier _ _ Constituents (%) A 4.2 17.0 B 2.4 C 6.5 3.3 D1 15.1 7.9 E 40.0 40.0 ethanol 6.0 3.0 water 25.8 28.8.
. . _ _.
Performances:. .:
spread 15 15 TLSF (C) 27 2 ~
10 10 9.3 ___. . ._: ~

In the thermal resistance test (TLSF), the foam concentrates (b1) and (b2) are less efficient than the foam concentrate of Example 1-a.
s We repeat ~ example 1-a, but we modify the proportions of the different constituents eVou rernplace the agen ~ tansio-active D1 by the compound D2.
The following table indicates the sum and the parameters of three emuls:
10 sisters thus obtained.

~,. . :. , ~ ,. .............
9} '''''.

, ~ - - -::
WRAPPER 2a 2b 2c . _. . . ..
Constituents (%): .A 2, ~ 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 ethanol 12.6 12.6 5.4 water 19.4 19.4 26.5 . . .
Performances: n spread (s) 7 6 10. :
TLSF (C) 50 43 40 profusion _ _ _. 1 0.6 11. .
.
~ `
One operates as in example 1-a, but one replaces a part of the ether E
by monoethyleneglycol (hereinafter MEG) el the proportions of the different are varied ~ -rents surfactants.
We thus prepare four foam concentrates which are brought to pH 8.5 by the addition of di ~ thanolamine. Their composition and performances are gathered in the next table.

"~ ,, ~;

.

- `12 , ~

. . _. . . . .
FULLY 3a 3b 3c 3d , _. _ Constituents (%) A 1.2 1.5 2.7 4.1 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 ethanol 6.85 8.6 6.3 6 aau 33.15 29.3 33.8 34 . ~ ~. . _ Performance ~:
spread (s) 5 7 8 16 TLSF ~ C) 41 43 42 40 f ~ j-ODn-nV, nl 10 9.2 __ ~ _; :

One operates as in example 1-a, but one replaces part of the ether E
5 with moneethylene glycol and at least one of the surfactants D2, D3 is used and D4 in place of D1 eU or in place of alkylglucoside C.
Thus, ~ ix different foam concentrates are prepared:
- 5 foam concentrates ~ according to in ~ ention (4a, 4b, 4c, 4d and 4e) - 5 non-compliant foam concentrates (4f, 4g, 4h, 4i and 4d) lo that is brought to pH 8.5 using di ~ thanolamine before performing the tests.
: ~ The composition and performance of these different foam concentrates are combined in the following table:
.

- "

2l21 _. _ ._ ~ a ~ ~ o ~
~ ~, o - U ~.,, ~ o ..
,. _, ._ I` ~ CO ~ ~
~ (D ~ '~ D''OO ~ U) ~ ~., _. ~.
. ~ U ~ .., , oo, - - ~ ~ ~ -_., t ~, ,, oo - U ~ ~. o. .
.
_ _ ..
, `, C ~
~ 3. . . o ~ ~ ~, ~ t _ ~ ~ ~
~ ~ ~ ~ ~ ~ ,, $ ~ - ,, oo ~ ~ oo Cl ~ _ ~ '~

~ ~ ~ ,, OO ~ U ~ ~ -_ _ _. ~ ':
~ t` a ~, ~ o ~ C, ~ ~ ~ r ~ o 2 _ n ~ ~ ~ ~ ~ ~ ~ D
~ ~ ~ _ ~ _ _ _ _ U ~ ~ ~
_.
n ~ ~ OD
oo ~ ~ ~
~. .

~ c ~ o ~

1 ~, oc ~ ~ r ~

-`` ^ 2 ~ 216 ~

The examan of the results showed that in the absence of alkylglucoside ( 4g, 4h, 4i and 4j) we do not obtain a very satisfactory ~ eou a high TLSF, but that this hydrocarbon co-surfactant alone (4f foam concentrate) leads ~ once-not enough.

Claims (13)

1. Foam concentrate for portable fire extinguishers, characterized in that it consists of an aqueous solution containing by weight:
(a) from 1 to 15% of at least one fluorinated betaine of general formula:

(I) in which Rf represents a perfluoroalkyl radical, linear or branched, containing at least 6 carbon atoms, m is an integer ranging from 0 to 6, X represents a CO or SO2 group, R represents a hydrogen atom or a methyl radical or ethyl, n is an integer ranging from 1 to 5, R1 and R2, identical or different, each represent a methyl or ethyl radical, p is an integer ranging from 1 to 5, and Y? represents a group SO3 ?, OSO3? or COO ?;
(b) from 1 to 20% of at least one fluorinated amine oxide of general formula:

(II) in which the symbols RF, m ', n', X, R ', R1' and R2 'have respectively same general meanings as Rf, m, n, X, R, R1 and R2;
(c) from 2 to 8% of at least one alkylglucoside of general formula:

(III) in which q is an integer ranging from 1 to 6 and R3 represents a linear or branched alkyl radical containing from 6 to 18 carbon atoms;
(d) from 2 to 10% of at least one anionic non-fluorinated surfactant, ionic or amphoteric other than those of formula III;
(e) from 20 to 50% of at least one monoalkyl ether of mono- or di-ethylene (or propylene glycol;
the total content of fluorinated compounds a and b being between 5 and 25% and the weight ratio (a + b) / (c + d) being between 1 and 2. 2. foam concentrate according to claim 1, characterized in that it contains from 2 to 12% fluorinated betaine (s), 3 to 15% fluorinated amine oxide (s), 3 to 6%
of alkylglucoside (s), 3 to 8% of surfactant (s) other than those of the formula III, and 30 to 45% of monoalkyl ether (s) of mono- or di-ethylene (or propylene) glycol. 3. foam concentrate according to claim 1, wherein the total content of fluorinated compounds is between 7 and 18%. 4. foam concentrate according to claim 1, 2 or 3, wherein the ratio weight (a + b) / (c + d) is between 1.3 and 1.7. 5. foam concentrate according to claim 1, 2 or 3, in which the radicals Rf and / or RF contain from 6 to 16 carbon atoms, 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, q is equal to 1 or 2, and the radical R3 contains 8 to 14 carbon atoms. 6. foam concentrate according to claim 5, containing a mixture of betaines fluorine of formula:

CxF2x + 1CH2CH2-SO2NH-CH2CH2CH2-N? (CH3) 2CH2COO?
in which x is an even integer ranging from 6 to 16, the content of the mixture in betaine with radical C6F13 being at least 50% by weight. 7. foam concentrate according to claim 5, in which the amine oxide is compound C6F13-CH2CH2-SO2NH-CH2CH2CH2-N (CH3) 2? O. 8. An emulsifier according to claim 1, 2, 3, 6 or 7, in which the surface-active agent non-fluorinated active ingredient (d) is chosen from the compounds of formulas:

R4-OSO3M (IV-1) R4- (OC2H4) 1-OSO3M (IV-2) R4- (OC2H4) 1-OH (IV-3) (IV-4) (IV-5) R4-CONH-C2H4-NH-C2H4OC2H4COOM '(IV-6) R4-NH-C2H4-COOH (IV-7) R4-N (C2H4COOM ') 2 (IV-8) (IV-9) R4-CONH-C3H6 -? (CH3) 2CH2COO? (IV-10) R4-N (CH3) 2? O (IV-11) in which R4 represents an alkyl radical, linear or branched, containing 8 has 18 carbon atoms, r is an integer ranging from 1 to 16, M denotes an ion alkali metal or quaternary ammonium and M 'an alkali metal ion. 9. foam concentrate according to claim 1, 2, 3, 6 or 7, in which the ether is diethylene glycol monobutyl ether. 10. foam concentrate according to claim 1, 2, 3, 6 or 7, stabilized at a pH at less than 7. 11. foam concentrate according to claim 1, 2, 3, 6 or 7, further comprising a alcoholic co-solvent, antifreeze, preservative and / or anti-corrosion agent if we. 12. foam concentrate according to claim 10, in which said pH is between 8 and 10. 13. Use of a foam concentrate as claimed cation 1, 2, 3, 6, 7 or 10, in a portable fire extinguisher, 0.5 to 6 parts by weight, preferably 1 to 3 parts, of foam concentrate per 100 parts by weight of water.