Classifications

• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D1/00—Fire-extinguishing compositions; Use of chemical substances in extinguishing fires
  • A62D1/0071—Foams
  • A62D1/0085—Foams containing perfluoroalkyl-terminated surfactant

Definitions

• the present invention relates to the extinction of fires and more particularly relates to versatile fire-fighting foam concentrates, effective both against hydrocarbon fires and against polar liquids fires.
• the emulsifiers according to the invention do not contain a high molecular weight thixotropic hydrophilic polymer of the polysaccharide type and are therefore perfectly fluid even at low temperature.
• the emulsifiers according to the invention have a rheological profile of the Newtonian fluid type, that is to say that their viscosity is independent of the shear rate; this facilitates their flow in the injection and dilution systems at the time of their use.
• Fire-fighting foam concentrates are an effective means of fighting fires involving combustible liquids. When in use, they are diluted in city water or sea water, generally at a volume concentration of 3% (i.e. 3 volumes of foam concentrate for 97 volumes of water ) or 6% (6 volumes of foam concentrate for 94 volumes of water).
• the quantity of active ingredients necessary to satisfy the minimum extinguishing performance required being identical in the two cases of dilution, the emulsifiers dilutable at 3% are therefore twice as concentrated as those dilutable at 6%; they allow users to store lesser amounts of foam concentrate, save space and reduce their storage costs.
• Recently, the demand for even more concentrated products has led manufacturers to develop 1% dilutable foam concentrates which are particularly useful in the protection of ships or oil platforms where the available space is very limited.
• the resulting mixture After diluting the foam concentrate with water, the resulting mixture produces an aqueous foam by incorporating air and supplying mechanical energy by means of a fire-fighting lance or any other foam generator.
• This foam is poured over fires of combustible liquids and acts by suffocation and cooling until total extinction.
• AFFF Aqueous Film Forming Foam
• these are aqueous solutions comprising as main ingredients a mixture of fluorinated surfactants, hydrocarbon surfactants and foam stabilizing solvents, generally belonging to the glycol family.
• AFFF foam concentrates are described, for example, in US Patents 3,562,156, US 3,772,195, FR 2,347,426 and US 5,085,786.
• Fluoro-protein foam concentrates constitute the other large family of foam concentrates.
• the base foaming agent consists of a hydrolyzate of animal proteins to which fluorinated surfactants and foam stabilizing solvents are added.
• emulsifiers are described for example in patents GB 1,280,508 and GB 1,368,463.
• polar liquids is taken here in the sense accepted by those skilled in the art, that is to say to designate liquids having a certain affinity for water, the most common of which are alcohols (for example, methanol, ethanol and isopropanol), ketones (e.g. dimethyl ketone and methyl isobutyl ketone), esters (e.g. n-butyl acetate) and ethers (e.g. methyl tert-butyl ether ).
• alcohols for example, methanol, ethanol and isopropanol
• ketones e.g. dimethyl ketone and methyl isobutyl ketone
• esters e.g. n-butyl acetate
• ethers e.g. methyl tert-butyl ether
• the most common method of fighting polar solvent fires is to incorporate a high molecular weight hydrophilic polymer into either of the two types of foam concentrates described above; a polysaccharide of thixotropic and alcoophobic character is generally used.
• a versatile foam concentrate is thus obtained, that is to say usable both on hydrocarbon fires and on polar liquid fires.
• the polysaccharide contained in the foam precipitates on contact with the polar liquid and forms a protective gelatinous sheet which isolates the foam against the destructive action of the polar liquid.
• the foam can then spread over the gelatinous sheet and extinguish the fire.
• Such versatile emulsifiers are described in US Patents 4,464,267, US 4,149,599, FR 2,206,958 and WO 92/15371.
• 3x3 foam concentrates (dilutable to 3% both on hydrocarbon fires and on polar liquid fires) have been developed.
• the advantage of these 3x3 foam concentrates compared to 6x6 foam concentrates is that it is sufficient for an identical efficiency to store them half as much; compared to 3x6 foam concentrates, they have the advantage of being able to be used with a single mixing system whatever the type of fire and thus eliminating the risk of dosage error.
• Patent EP 595,772 describes the association of a polysaccharide with an anionic hydrophilic polymer making it possible to prepare low viscosity solutions, these solutions forming part of the composition of 3 ⁇ 3 polyvalent emulsifiers.
• Patent EP 609 827 describes the association of a polysaccharide and an alginate and indicates that the viscosity of a polyvalent 3 ⁇ 3 foam concentrate can be reduced by controlling the relative proportions of the polysaccharide and the alginate; viscosity can also be reduced by controlling the ratio of the concentration of aryl or alkylaryl sulfonic acid salts to the concentration of other hydrocarbon surfactants.
• the polysaccharide in aqueous solution leads to pseudoplastic emulsifiers whose viscosity varies with the shear rate.
• the polysaccharide is in dispersed form using hydrophobic colloidal silica and the amount of water in the foam concentrate is minimized so that the polysaccharide, which is only soluble in l water, does not increase the final viscosity of the foam concentrate.
• the polysaccharide level can be increased until a 1x1 foam concentrate is obtained, dilutable to only 1% in water, both on hydrocarbon fires and on fires of polar liquids.
• the dispersing medium is a water-miscible solvent of the glycol family. Under these conditions, the need to replace the dilution water with an equivalent quantity of solvent leads to emulsifiers having a high cost price.
• Patent EP 524 138 relates to versatile emulsifiers combining a polysaccharide with a fluorinated co-telomer.
• the fluorinated co-telomer is obtained by radical telomerization of a fluorinated telogen on a mixture of non-fluorinated acrylic or methacrylic monomers.
• the association of the co-telomer with the polysaccharide reinforces its effectiveness and allows the incorporation of lower quantities, therefore obtaining less versatile viscous emulsifiers.
• these emulsifiers nevertheless retain a pseudoplastic character, the viscosity of which varies with the shear rate.
• Multipurpose emulsifiers containing no polysaccharide are described in US Pat. No. 4,536,298.
• the polysaccharide is replaced by a cationic, water-soluble homopolymer, from the family of polyamines, polyamides and polyimines neutralized by acids.
• polyfunctional carboxylic the association of the two families of products leads to a synergy which reinforces the resistance of the extinguishing foam on polar liquid.
• US Patent 4,563,287 describes an extinguishing composition for cooking oil fires, containing a high molecular weight copolymer comprising perfluoroalkylated side chains and hydrophilic side chains; the hydrophilic monomer level is high enough to make the copolymer soluble in water.
• Patent FR 2 438 484 describes the use of a copolymer prepared from a hydrophilic monomer and from a perfluorinated chain monomer. To be sufficiently soluble in water, the copolymer must comprise 1 to 10 hydrophilic units for each unit with a perfluorinated chain.
• the present invention aims to overcome all the problems associated with the use of polysaccharides and to prepare versatile foam concentrates containing a copolymer with a high fluorine content so as to increase the performance of the foam concentrate on polar liquid fires.
• the level of fluorinated monomer is high, the copolymer becomes generally insoluble in water.
• the units M 1 are preferably those of formula: in which R f represents a linear or branched perfluoroalkyl radical containing 4 to 16 carbon atoms, B represents a bivalent chain linked to O by a carbon atom and which may contain one or more oxygen, sulfur and / or nitrogen, and R represents a hydrogen atom or a methyl radical.
• R f (CH 2 ) n - (X) p - (CH 2 ) m -OH (III-a) R f (CH 2 ) r (OCH 2 CH 2 ) q -OH (III-b) R f - CH CH - (CH 2 ) m -OH (III-c) in which R f has the same meaning as above, X represents an oxygen or sulfur atom or a group COO, SO 2 , CONR'-, -SO 2 NR'-, R 'representing a hydrogen atom or an alkyl radical containing 1 to 4 carbon atoms, n represents an integer ranging from 0 to 20 (preferably equal to 0 or 2), n not being zero if X is an oxygen or sulfur atom, p is equal to 0 or 1, the symbols m, q and r, identical or
• the units M 2 are preferably chosen from the units of acrylic or methacrylic monomers, optionally quaternized, of general formula: in which R 'represents a hydrogen atom or a methyl radical, B' represents an alkylene radical, linear or branched, containing 1 to 4 carbon atoms (preferably the radical CH 2 CH 2 ), the symbols R 1 and R 2 , identical or different, each represent a hydrogen atom or an alkyl radical, linear or branched, containing 1 to 12 carbon atoms (preferably 1 to 4), hydroxyethyl or benzyl or R 1 and R 2 together with the nitrogen atom to which they are attached form a morpholino, piperidino or pyrrolidinyl-1 radical.
• acrylates and methacrylates of the following amino alcohols dimethylamino-2-ethanol, diethylamino-2-ethanol, dipropylamino-2-ethanol, di -isobutylamino-2-ethanol, N-tertiobutylamino-2-ethanol, N-tertiobutyl-N-methylamino-2-ethanol, morpholino-2-ethanol, N-methyl-N-dodecylamino-2-ethanol, N-ethyl-N - (ethyl-2-hexyl) amino-2-ethanol, piperidino-2-ethanol, (pyrrolidinyl-1) -2-ethanol, diethylamino-3-propanol-1, diethylamino-2-propanol-1, dimethylamino-1- propanol-2, diethylamino-4-butanol-2.
• the units M 3 which come from acrylic, methacrylic or vinyl monomers with nonionic side chain, preferably hydrophobic, are advantageously chosen from those of general formula: in which R "represents a hydrogen atom or a methyl radical, Y represents the group COO or OCO or an oxygen atom, and R 3 denotes an alkyl, hydroxyalkyl or methoxyalkyl group containing 1 to 18 carbon atoms.
• the copolymer (a) can be prepared by any known method of radical copolymerization of the monomers, preferably in solution in an inert solvent or a mixture of inert solvents.
• the synthetic solvent can be miscible or immiscible with water.
• the copolymer (a) must be in solution in a water-miscible solvent.
• the synthesis solvent of the copolymer is immiscible with water, it should be replaced by an organic solvent miscible with water in which the copolymer (a) is soluble.
• the solvent for the copolymer (a) may optionally be the constituent (d).
• the hydrocarbon surfactant (b) makes it possible, in combination with the solvent (d), to obtain a stable dispersion of the copolymer (a); having a foaming effect, it also makes it possible to improve the expansion of the foam concentrate.
• the hydrocarbon-based surfactants which can be used in the emulsifier may be of anionic, cationic, nonionic or amphoteric nature.
• Non-limiting examples that may be mentioned include the compounds of the following formulas: R H -CONH-CH 2 CH 2 -NH-CH 2 CH 2 OCH 2 CH 2 COOM (VI-d) R H -N (CH 3 ) 2 ⁇ O R H -N (CH 2 CH 2 OH) 2 ⁇ O H (C 6 H 10 O 5 ) s -OR H (VI-j) R H - (OCH 2 CH 2 ) t -OH (VI-k) R H -SO 3 M (VI-m) R H -OSO 3 M (VI-n) R H - (OCH 2 CH 2 ) t ' -OSO 3 M (VI-q) R H -COOM (VI-s) R H -CON (CH 3 ) CH 2 COOM (VI-t) in which R H denotes an al
• the fluorinated surfactant (s) to be used according to the invention can be chosen, without limitation, from the compounds of formulas: R F - (CH 2 ) u ' - S - (CH 2 ) v - CONH - C (CH 3 ) 2 -CH 2 SO 3 Na (VII-g) in which R F represents a linear or branched perfluoroalkyl radical containing at least 6 carbon atoms, u is an integer ranging from 0 to 6, R 4 represents a hydrogen atom or a methyl or ethyl radical, v and w are whole numbers ranging from 1 to 5, w 'is equal to 2 or 3, the symbols R 5 , R 6 and R 7 , identical or different, each represent a methyl or ethyl radical, and u' is an integer ranging from 1 to 6.
• fluorinated surfactants (c) the following compounds may be mentioned more particularly: VS 6 F 13 - CH 2 CH 2 - N / A 2 NH - CH 2 CH 2 CH 2 - N (CH 3 ) 2 ⁇ OC 6 F 13 - CH 2 CH 2 - N / A 2 N (CH 3 ) - CH 2 CH 2 CH 2 -N (CH 3 ) 2 ⁇ O as well as the betaine mixtures of formula: mixtures of sulfobetaines of formula: mixtures of amine oxides of formula: VS k F 2k + 1 - CH 2 CH 2 - N / A 2 NH - CH 2 CH 2 CH 2 - N (CH 3 ) 2 ⁇ O formulas in which k is an even whole number ranging from 6 to 16, the content of the mixture of compound with radical C 6 F 13 being at least 50% by weight.
• the water-miscible organic solvent (d) must be inert and a good solvent for the copolymer (a). It can be a single solvent miscible with water or a mixture of several solvents; in this case, the mixture must be generally miscible with water, even if it contains one or more solvents immiscible with water.
• ком ⁇ онентs of mono- or di-ethylene (or propylene) glycol, ketones such as acetone, methyl ethyl ketone or methyl isobutyl ketone, alcohols such as methanol, ethanol, isopropanol or tertiobutanol, N-methylpyrrolidone, ⁇ -butyrolactone, DMSO.
• Certain glycol ethers such as n-butyl diglycol, or the tert-butyl ether of propylene glycol, also have good foam stabilizing power and they increase the expansion of the foam concentrate. It is therefore recommended to use them in admixture with the solvents described above. It is the same for the well-known antifreeze power of ethylene glycol, the latter solvent can then be used in combination with one or more other solvents.
• the foam concentrate according to the invention is advantageously stabilized at a pH at least equal to 4, preferably between 6 and 8.
• the preparation of the foam concentrate is carried out by simple mixing of the constituents (a), (b), (c), (d) and others optionally at room temperature or by heating to a moderate temperature and with stirring.
• the foam concentrate is then diluted with tap water or sea water at a rate of 0.5 to 6 parts by volume, preferably 1 to 3 parts by volume per 100 parts by volume in total.
• the resulting extinguishing composition is used to fight fires of hydrocarbons and polar liquids.
• the overrun (or expansion rate) is the ratio of the volume of foam produced from a 3% aqueous solution of foam concentrate to the volume of initial liquid.
• 100 ml of 3% aqueous emulsifier solution is introduced into a 1 liter test tube, then the solution is beaten for one minute at the rate of one beat per second using a circular piston perforated (30 holes of 5 mm in diameter representing 25% of the surface) and fixed in its center to a metal rod.
• This test which indicates the speed of formation of the aqueous film on the surface of the hydrocarbons is carried out by pouring 50 ml of hydrocarbon into a Petri dish (diameter: 11.8 cm) whose outer face is painted black in order to be able to observe the film.
• a Petri dish diameter: 11.8 cm
• 0.5 ml of a 3% aqueous solution of emulsifier is deposited using a micro pipette.
• the solution should be applied dropwise starting from the center and making an eccentric movement.
• the stopwatch is started when the first drop is deposited and stopped when the film has covered the entire surface of the hydrocarbon. We note the time. If the total recovery is not obtained in less than a minute, the percentage of surface covered after one minute is noted.
• the most efficient foam concentrates to give a foam which is impermeable to polar liquid vapors are those with the lowest evaporation in mg / min.
• Tests are also carried out under more severe conditions on polar liquid fires.
• the procedure is identical but the polar liquid is ignited and allowed to burn for 90 seconds before pouring the foam to extinguish it.
• the amount of polar liquid used is 150 ml and about 50 g of foam are poured.
• the acetone evaporation rate should be less than 85 mg / min for the cold test and less than 150 mg / min for the fire test.
• B 2 N-lauryl- ⁇ -iminodipropionate of formula: sold in 30% aqueous solution under the name Deriphat 160C by the company HENKEL.
• B 3 (C 8 and C 10 ) alkylamidoetherpropionate of formula: Alkyl - CONH - CH 2 CH 2 - NH - CH 2 CH 2 OCH 2 CH 2 COONa marketed in 50% aqueous solution under the name Rewoteric AMVSF by the company REWO.
• B 4 (C 8 and C 10 ) alkyl glucoside sold in a 60% aqueous solution under the name Triton CG-110 by the company UNION CARBIDE.
• B 5 (C 12 and C 14 ) N-hydroxyethylimidazoline alkyl of formula: sold in 40% aqueous solution under the name Sochamine A7527 by the company WITCO.
• B 6 sodium octyl sulfate sold in 42% aqueous solution under the name Texapon 842 by the company HENKEL.
• B 7 lauryl ether sulfate of formula: C 12 H 25 - (OCH 2 CH 2 ) 2 - OSO 3 Na sold in 30% aqueous solution under the name Neopon LOS by the company WITCO.
• B 8 sodium lauroyl sarcosinate sold in a 30% aqueous solution under the reference GM 9011 by the company ZSCHIMMER & SCHWARTZ.
• B 9 alkyl (copra radical) amine oxide of formula: Alkyl - N (CH 2 CH 2 OH) 2 ⁇ O marketed in 30% aqueous solution under the name Noxamine C2-30 by the company CECA.
• B 10 alkyl salt (copra radical) quaternary ammonium of formula: alkyl - N ⁇ (CH 3 ) 3 Cl ⁇ sold in 50% aqueous solution under the name Noramium MC 50 by the company
• CECA B 11 alkyl salt (copra radical) quaternary ammonium of formula: Alkyl - N ⁇ (CH 3 ) (CH 2 CH 2 OH) 2 Cl ⁇ sold in 50% aqueous solution under the name Noxamium MS 2-50 by the company
• CECA B 12 lauryl dimethyl amine oxide: VS 12 H 25 -N (CH 3 ) 2 ⁇ O marketed in a 30% aqueous solution under the name Rewominox L408 by the company REWO.
• C 1 fluorinated amine oxide of formula: VS 6 F 13 - CH 2 CH 2 - N / A 2 NH - CH 2 CH 2 CH 2 - N (CH 3 ) 2 ⁇ O marketed by the Applicant in the form of a 40% hydroalcoholic solution.
• C 2 fluorinated betaine of formula: C 6 F 13 - CH 2 CH 2 - SO 2 NH - CH 2 CH 2 CH 2 - ⁇ N (CH 3 ) 2 CH 2 COO - marketed by the Applicant in the form of a 27% hydroalcoholic solution.
• C 3 mixture of fluorinated betaines of formula: C n F 2n + 1 - CH 2 CH 2 - SO 2 NH - CH 2 CH 2 CH 2 - ⁇ N (CH 3 ) 2 CH 2 COO ⁇ having the following weight composition:
• P 1 denotes a fluorinated copolymer obtained by radical polymerization of a mixture of monomers having the following composition: monomers contents% M 1a 85 M 2a 15
• copolymer P1 and the other constituents are mixed at ambient temperature and with moderate stirring, then the mixture is adjusted to pH 7 by addition of diethanolamine.
• An emulsifier according to the invention is thus obtained, the contents of active materials of which are as follows: constituents contents% P 1 2.4 B 1 4.5 C 2 1.4 ethanol 1.7 butyl diglycol 15 acetone 0.5 N-methyl pyrrolidone 2.3 water (qs 100%) 72.2
• P 2 denotes a fluorinated copolymer obtained by radical polymerization of a mixture of monomers having the following composition: monomers contents% M 1a 76 M 2a 15 M 3b 9
• the procedure is as for the synthesis of P 1 , but after the addition of the 15 g of monomer M 2a , 9 g of monomer M 3b are added and then 76 g of monomer M 1a .
• the copolymer P 2 is thus obtained in solution with 27.9% of dry extract.
• copolymer P 2 and the other constituents are mixed at ambient temperature and with moderate stirring, then the mixture is adjusted to pH 7 by addition of diethanolamine.
• An emulsifier according to the invention is obtained, the contents of active materials of which are as follows:
• Example foam concentrate Cyclohexane spreading test Leak test with acetone (mg / min) Cold test Fire test 3 60% 51 98 4 9s 40 76 5 11s 33 71 6 7s 61 101 7 10 s 64 95 8 9s 67 91 9 8s 61 107 10 58s 31 89 11 65% 70 97 12 12s 56 141 13 95% 53 90 14 8s 58 89 15 9s 54 86 16 4s 46 108 17 6s 47 80 18 8s 40 79 19 7s 42 82 20 12s 38 69 21 6s 37 72 22 25s 36 66 23 25s 37 66
• An emulsifier is prepared by proceeding as in Example 3 but the copolymer P 2 is removed which does not replace an equivalent amount of water (Example 24).
• Example 25 the procedure is as in Example 1-b but the fluorinated surfactant C 2 is removed, which is replaced by an equivalent amount of water (Example 25).
• Example foam concentrate Cyclohexane spreading test Leak test with acetone (mg / min) Cold test Fire test 24 11s 125 385 25 not filming 47 95
• Example Foam concentrate Foam application time (seconds) Power off (seconds) Re-ignition time (seconds) 90% 99% Extinction 26

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
• Fire-Extinguishing Compositions (AREA)
• Fireproofing Substances (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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Citations (3)

• 1995
  • 1995-09-28 FR FR9511385A patent/FR2739295A1/fr active Pending
• 1996
  • 1996-08-26 EP EP96401822A patent/EP0765676A1/de not_active Withdrawn
  • 1996-09-17 JP JP24496996A patent/JPH09124884A/ja active Pending
  • 1996-09-26 AU AU65863/96A patent/AU6586396A/en not_active Abandoned
  • 1996-09-27 CA CA 2186773 patent/CA2186773A1/fr not_active Abandoned

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