JPS6244270A - Thixotropic fire suppressing composition containing carboxy polymer gelling agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a fire suppressant (fir·-1 uppr@ss
1 ng) regarding the composition.

BACKGROUND OF THE INVENTION Liquefied gases have been used to disperse fine powders including pesticides, pharmaceuticals, cosmetics, and fire extinguishing powders. Gelling agents such as CAB-0-8IL (Cabot Corporation, 1 ml) have been used to prevent these powders from clumping and clogging. Gelled Liquid Fire Suppression Suspension U.S. Patent No. 4.2247
No. 27 and No. 4,234,432.

The above patents disclose the use of the following gelling agents: pyrogenic silica, montmorillonite clay, lipophilic vinyl addition polymers, pyrogenic titanium dioxide, aluminum or magnesium salts of fatty acids, colloidal attapulgite clays. Quaternized bentonite, submicron magnesium oxide, submicron potassium bicarbonate.

PROBLEM SOLVED BY THE INVENTION Ammonium salts are useful fire suppressants in powder form. It has been found that a suspension of the powder with improved stability results from the addition of a small amount of carboxy polymer as a gelling agent.

a nonpolar liquid to be thixotropically gelled; and an effective amount of a carboxydarimer gelling agent to gel the liquid;
ammonium salt. The composition may include as further additives a viscosity modifier that functions at low temperatures, a desiccant, or both.

The invention further relates to a method of applying said composition to extinguish a fire.

All percentages mentioned herein are to be understood as weight percentages unless otherwise specified.

DETAILED DESCRIPTION OF THE INVENTION A suspension of powdered ammonium in a non-polar liquid that is gelled results from the present invention. A carboxypolymer gelling agent is used to form a suspension that is thixotropic and exhibits excellent stability.

The gelling liquid component of the present invention combines one or more fire-gusnching liquids with one or more fire-gusnching liquefied gases and/or one or more overpressurized gases. Includes both. If a fire quench liquefied gas (eg trifluorobromomethane) is used, the fire quench liquid can be omitted.

The liquid component to be gelled must be able to fill the interparticle spaces in suspension under pressure, ie when the suspension is at rest. Preferably, the liquid component to be gelled is capable of expanding upon release of pressure into a cloud of gaseous vapor or droplets carrying extinguishing particles. Finally, the gelling liquid component must provide some measure of fire quenching capability.

Useful fire quenching liquids in the gelling liquid component include, but are not limited to: methylene bromide, methyl iodide, tetrafluorodibromoethane, trifluorotrichloroethane, 7. A/Orotrichloromethane, chloroform, bromoform, carbon tetrachloride, etc.

Liquefied gases that can be used in accordance with the present invention include, but are not limited to, nitrifluorobromomethane, difluorochlorobromomethane, perfluoropropane, perfluorosilobutane, dichlorotetradifluoromethane, tetrafluoromethane, methyl bromide. , trifluoromethane, trifluorochloromethane, hexafluoroethane, etc. Some of these gases have been referred to as Halon materials. "Halon" is the National Fire Protection Association's name for halogenated fire extinguishing materials. Halon products are available from Great Lakes Chemical Company, Dugin Company, and ICr Americas Inc.

Halon 1211 (difluorochlorobromomethane), Halon 1301 (difluorobromomethane), and mixtures thereof are useful. Mixtures containing about 50 to about 60% difluorochlorobromomethane and about 40 to about 50% trifluorobromomethane are particularly useful at low temperatures.

Overpressure gases useful in the gelling liquid component include nitrogen, carbon dioxide, helium, argon, and the like.

The gelling liquid component constitutes about 70 to about 30% by weight of the composition according to the invention.

The solid components constituting 3.0 to 70% by weight of this composition are:
Contains one or more powdered ammonium salts and one or more carboxyhyrimer gelling agents. Non-limiting examples of suitable powdered ammonium salts include heptanosy and triammonium phosphates, calcium ammonium phosphates,
Includes sodium ammonium phosphate, ammonium sulfate, ammonium chloride and aluminum ammonium sulfate. Monoammonium phosphate (MAP) powder is particularly useful. ABC' dry chemical fire extinguishing powder having a MAP of 90-95% is preferred.

Other fire suppression powders can be used with one or more ammonium salts. Such powders include sodium bicarbonate, potassium bicarbonate, the urea adduct of potassium bicarbonate such as available from ICI under the trademark "MONAx", sodium chloride, potassium chloride, and the like. If a non-fire suppressant is selected as a powdered ammonium salt, an auxiliary fire suppressant powder is required.

Gelling agents are polymers containing carboxyl groups in their free acid form. Excluded from the present invention are polymeric substances whose carboxyl groups are substantially neutralized or salted. These drugs were found to be unsuitable due to their lack of conversion to free acids.

Included in the invention are polymers that are functional derivatives of free polycarboxylic acids whose functional groups have been substantially hydrolyzed to the free acid form, such as polyacrylamide. By way of example, a 40% hydrolyzed polyacrylamide, available from the National Starch and Chemical Company under the trademark POLYHALL 40-JJ, satisfies the nonpolar liquid component of the composition in the presence of an ammonium salt. It was found that 40% of the nitrile groups in this polyacrylamide were hydrolyzed to the corresponding nitrile functionality; on the other hand, 2) 33% of the IJ groups
Polypho N55-J, which is only hydrolyzed, forms a much weaker suspension. In the case of polymers having groups that are functional derivatives of carboxyl, one skilled in the art can readily determine by routine experimentation the extent to which such groups must first be converted to the free acid form in order for gelation of non-polar liquids to occur. could be asked for.

Carboxy polymers useful in the present invention include carboxy vinyl polymers such as B, F, Gudrich (B
, F. Goodrieh) to “Carbobol (C
Polymers available under the trade name ARBOPOL J )!Synthetic resins containing free carboxyl groups, such as AMBERLITE IPC from Rohm and Haas Company, Philadelphia, Pennsylvania.
-50J trademark, which is a copolymer of methacrylic acid and divinylbenzene.

Other polymeric materials having free carboxyl groups or groups that are easily convertible to the free acid form functionally equivalent to carboxyl are known to those skilled in the art and can be used in the present invention.

Many excellent thickeners and/or
Alternatively, it has been found that suspending agents do not gel non-polar liquids in the presence of ammonium compounds.

Without wishing to be bound by any theory or mechanism of action, we believe that the anti-sedimentation powder that sensitizes nonpolar liquids due to the carboxypolymer gelling agent described is due to the synergistic interaction of free carboxyl functions and ammonium compounds. . No gel was formed when the gelling agent was mixed with difluorochlorobromomethane or a blend of difluorochlorobromomethane and trifluorobromomethane in the absence of an ammonium compound. The gelling agent is insoluble in the liquid and spreads over the surface.

A preferred gelling agent is carboxyvinyl polymer.

"CARBOPOL J 934 and 9
41 is particularly suitable. "Carbol" is provided by the manufacturer to raise and suspend insolubles and stabilize the emulsion primarily in the aqueous thread. When using "carbohydrates" for less polar liquids, manufacturers recommend adding large amounts of long chain fatty amines as gelling aids. Carbobol was found to be ineffective as a gelling agent for the liquefied halogenated hydrocarbon gas that forms the liquid component of the composition, even in the presence of the recommended gelling aid.

What is surprising is that "Carbozal" gels the non-polar liquid in the presence of ammonium compounds, if added to a liquid component with an ammonium compound, such as a powder.
It has been discovered that carboxy polymers gel relatively non-polar fire extinguishing fluids and liquefied gases that make up the gelling liquid component without the need for polar gelling aids. The resulting suspension is thixotropic and exhibits excellent performance as a fire extinguishing composition even after long-term storage. Satisfactory storage stability of up to 18 months has been demonstrated using "Riki-Bobol". The powdered MAP did not solidify or clog, but remained suspended to form a thixotropic composition that was not easily spread. In the case of 15-4.0% by weight of "Carbobol", it is possible to use MAP of 40-66% by weight, and the solid content is 45%, and the liquefied gas of difluorobromomethane and ζtrifluorobromomethane is 55%. A composition of the invention was prepared according to Example 1 containing monoammonium phosphate 415% Cargo Gil J94j 3.5% difluorochlorobromomethane 44.0% trifluorobromomethane 1tO% MAP and gelling. The above ratio between the agent and the liquefied gas is determined by the standard Underwriter's Laboratory (Underwriter@Laboratory).
) 2- B-grade fire test (5 square feet (i4
Approximately 216 grams or 50 g of fire extinguisher (* xt
Using 1 ngui content, the fire was extinguished in 55 seconds.

As the weight percent solids in the composition was increased by 45%, I performance decreased. More flame extinguishing agent is required to extinguish a fire of the same size, and the concentration of solids is constantly high enough to prevent discharge of extinguishing agents by the action of liquefied gas. Reduce solids level by 1 to 45%
(and the proportion of liquefied gas in the composition increases proportionately), the extinguishing agent begins to act as a conventional halon-type extinguishing agent, eventually extinguishing a 2-B-class fire. I can no longer do it.

Fire extinguishing powder (KECO) in addition to ammonium salts
, ) is as follows: r Example 2 Monoammonium phosphate 10%?
KHCO, ao% "Carbobol J941 4% difluorochlorobromomethane 44.8%Ih@y))
The following experiments were conducted demonstrating the increased I fire extinguishing efficacy of the present gelling concentrate compositions compared to using 112% halon or monoammonium phosphate alone. ~Example 5 Monoammonium phosphate (ABc powder) 2 in nitrogen pressurized to 100 psi (7'+9/Cl11")
oo# was discharged onto an Underwriters Laboratory 1-B-grade fire (2.5 square feet (α23m! of burning hebutane) with a 30 second pre-buym). Although 95% by weight of the contents of the container were ignited, the fire was not extinguished.

Example 4 Blend 20 containing 80% by weight difluorochlorobromomethane and 20% by weight trifluorobromomethane in the same fire extinguishing hardware used in Example 3.
0 grams was released onto the same fire. Although 95% by weight of the contents of the container were set on fire, the fire was not extinguished.

Example 5 In the same fire extinguishing hardware used in Examples 3 and 4, 200 grams of the composition according to Example 1 was discharged onto the same fire. The fire was extinguished when 71% of the contents of the container were released.

The synergistic interaction between MAP and various cal-buffalo cipilimer gelling agents was demonstrated by the following procedure.

Example 6 "Carbo Volco 941 18.S+ was ball milled to fine particle size and triblended with 50 grams of MAP. The mixture was added to 80 wt. difluorochlorobromomethane and shaken for t - overnight. Next day , a homogeneous gel suspension was observed.

Other agents were tested according to the procedure of Example 6, except that 2X-3Xffi of gelling agent was required to cause initial suspension. The results appear in Table 1 below. A minus sign (-) indicates complete absence of suspension with MAP precipitated to the bottom of the container. The trout were prevented from resuspending when shaken. A plus sign (+) indicates gelation, - some sedimentation of the MAP overnight, which was easily resuspended with just one or two gentle shakes by hand. A double plus sign (++) indicates the presence of a highly homogeneous gel structure with no sedimentation or little observable sedimentation of MAP.

Table 1 (KELACrD)J, Kelco (K@1eO)) 9 Polyvinylpyrrolidone (GAF) t8
- Sodium Salt (Vercules) (converted to the free acid form) After converting Jaguar CMGJ, a carboxymethylated guar gum derivative available as the sodium salt from the manufacturer, to the free acid form in a 70% aqueous solution of methanol, Calibrated with glacial acetic acid (c@rtlf1eatlon) and stirred. The solution was allowed to stand overnight, then filtered and washed with pure methanol to remove any acetic acid.

For Experiments 7 and 8, 1 of the gelling agent was not recorded but is believed to be between 5 and 11 grams.

"Cado-15", an amphoteric starch available from the National Starch Company used in Experiment 16, contains carboxylic acid groups, but these groups are neutralized by the presence of amine functions in the same molecule. Therefore, gelation did not occur.

The effect of ammonium compound integrity on gelation,
In Examples 7 to 15, 4 grams of "Carbobol 941",
The procedure of Example 6 was followed using 60 grams of difluorochlorobromomethane and 36 grams of ammonium compound. The results are listed in Table 2.

Table 2 7 Monoammonium phosphate ++
8 Sodium ammonium phosphate ++
9 Ammonium sulfate ++1
0 Ammonium chloride ++1
1 Diammonium phosphate ++1
2 Aluminum ammonium sulfate ++1
3 Ammonium Alginate - "Carbobol 941J was unsuccessful in forming an acceptable suspension of ammonium alginate in difluorochlorobromomethane (Example 1S), but negative results were This is thought to be due to the hard, coarse nature of the sodium alginate powder, rather than the absence of interaction between turned out to be very difficult.

The ammonium salts used according to the invention are hygroscopic.

In particular, monoammonium phosphate readily absorbs moisture from the atmosphere, thereby adding water to the composition. Abundance of water is undesirable for two reasons. First, water is HB
Promotes the production of r and HF. Halon materials decompose at high temperatures and readily react with any free water present to form these acids. HF and HBr are highly corrosive and attack the metal components of the discharge container. Second, liquefied gases such as halon substances have a cooling effect. If free water is present in the composition, it easily freezes to form ice and clog the drainage system. To protect against the formation of alcohol and ice, it is necessary that the composition be free of free water.

Thus, the composition can include a sufficient amount of desiccant to sequester any moisture within the system, depending on the particular application. Preferably, the desiccant is a non-corrosive material that does not damage the metal components of the discharge system. Suitable desiccants include metal salts and oxides. Molecular sheep can also be used for this purpose. Other desiccant agents are known to those skilled in the art.

Sodium sulfate, calcium sulfate, calcium chloride, and calcium oxide were found to be effective.

Calcium oxide is preferred due to its secondary effect as a neutralizing agent in counteracting acids that may be produced by decomposition of halon materials.

Depending on the application, the fire suppression compositions of the present invention may also include an effective amount of at least one viscosity modifier. The viscosity modifier acts to prevent gel separation at concentrations as low as -40'F (-40 °C) and prevents excessive thinning of the composition at temperatures up to 120'F (49 °C).
) is ideal.

Chlorides of sodium, magnesium, aluminum, potassium can be used. Other gold a salts can also be used.

The same salt may function as both a desiccant and a viscosity modifier.

The gelled liquid composition according to the present invention is prepared by first mixing the various solid components in a high-intensity mixer, and then adding the liquid components with continuous mixing. can do. Alternatively, the solid component can be added to the liquid component with intensive mixing.

Examples 14-24 below are included to illustrate the invention in which the gelling liquid component comprises a mixture of difluorochlorobromomethane and trifluorobromomethane.

Quantities of ingredients are expressed in Durhams.

The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. Accordingly, reference should be made to the claims rather than the foregoing specification as indicating the scope of the invention.

Procedural amendment dated October 3, 1985 Mr. Michibu Uga, Commissioner of the Patent Office Display of the case 1985 Patent Application No. 181942 Person making the amendment/Relationship with case 1f Name of patent applicant Name Fire Control Chiknorrhea, Inc. Horated

Claims (1)

[Scope of Claims] 1. (a) a nonpolar liquid that is thixotropically gelled; (b) a carboxypolymer gelling agent in an amount effective to thixotropically gel the liquid; (c) ammonium salt. 2.Ammonium salts include monoammonium phosphate, diammonium phosphate, triammonium phosphate, calcium ammonium phosphate, sodium ammonium phosphate,
A composition according to claim 1 selected from the group consisting of ammonium sulfate, ammonium chloride and ammonium aluminum phosphate. 3. A carboxypolymer gelling agent is freed to the extent necessary to cause gelation of (i) a carboxyvinyl polymer and (ii) a polysaccharide, polyacrylamide, synthetic resin having free pendant carboxyl groups, or a nonpolar liquid. and their functional equivalents converted into acids. 4. About 70-30% gelling liquid and about 0.5-8% gelling agent
．． 4. A composition according to any one of claims 1 to 3, comprising 0% and about 30-70% ammonium salt. 5. Claims 1 to 5 further include additives selected from desiccants, viscosity modifiers that function at low temperatures, and combinations thereof.
4. The composition according to any one of item 4. 6. The composition according to any one of claims 1 to 5, wherein the fire suppression powder is selected from the group consisting of sodium bicarbonate, potassium bicarbonate, urea adduct of potassium bicarbonate, sodium chloride, and potassium chloride. . 7. At least one type of fire quenching liquid, nitrogen, carbon dioxide,
7. The composition according to claim 1, further comprising at least one overpressure gas selected from the group consisting of helium and argon. 8. The composition according to any one of claims 1 to 6, wherein at least one fire-quenching liquefied gas is used as a gelling liquid. 9. The composition according to claim 8, wherein the gelling liquid is at least one kind of fire quenching liquid and at least one kind of fire quenching liquefied gas. 10. The fire quenching liquid is selected from the group consisting of methylene bromide, methyl iodide, tetrafluorodibromoethane, trifluorotrichloroethane, fluorotrichloromethane, chloroform, bromoform, and carbon tetrachloride according to claim 7 or 9. Composition. 11. Fire quenching liquefied gas with trifluorobromomethane,
Claim 8 or 9, which is selected from the group consisting of difluorochlorobromomethane, perfluoropropane, perfluorocycloptane, dichlorodifluoromethane, tetrafluoromethane, methyl bromide, trifluoromethane, trifluorochloromethane, and hexafluoroethane. Composition. 12. The composition according to claim 11, wherein the gelling liquid is a blend of difluorochlorobromomethane and trifluorobromomethane. 13. The composition of claim 12 which is a blend of about 50 to about 60% difluorochlorobromomethane and about 40 to about 50% trifluorobromomethane. 14. The composition according to claim 12 or 13, wherein the gelling agent is a carboxyvinyl polymer. 15. 70-30% liquefied gas that is a blend of about 50-60% difluorochlorobromomethane and about 40-50% trifluorobromomethane, and about 0.5-8.0% carboxyvinyl polymer gelling agent. % and about 35-50% monoammonium phosphate. 16. A composition comprising: (a) a nonpolar liquid that is thixotropically gelled; (b) an effective amount of a carboxypolymer gelling agent to thixotropically gel the liquid; and (c) an ammonium salt. A fire suppression method characterized by applying a substance.