CA1131000A - Concentrate for range, brush and forest fire retardant compositions - Google Patents

Abstract

ABSTRACT
Fire retardant compositions which comprise:
a) a solid component selected from the group consisting of monoammonium orthophosphate; diammonium orthophosphate;
monoammonium pyrophosphate; diammonium pyrophosphate; triammonium pyrophosphate;
tetra-ammonium pyrophosphate; ammonium polyphosphates; ammonium-alkali metal mixed salts of ortho-, pyro- and polyphos-phates; ammonium-alkaline earth metal mixed salts of ortho-, pyro- and polyphosphates;
ammonium sulfate; ammonium sulfamate; urea phosphate; phosphoramides and mixtures thereof;
b) a liquid component which contains a material selected from the group con-sisting of phosphorus-containing acids and ammonium-containing salts thereof, ammonium polyphosphates, phosphorus-containing esters, ammonium sulfate, ammonium sulfamate and mixtures thereof; and c) a rheological property control agent which imparts thixotropic flow properties to the composition;

wherein the weight percentages of said components in the compositions are from about 20 percent to about 70 percent for the solid component, from about 20 per-cent to about 70 percent for the liquid component and from about 0.01 to about 10 percent for the rheological property control agent, and the weight percent of P2O5 and SO3, taken collectively, in the compositions is at least 40 percent.

Description

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-1- 43-4505A -''' CONCENTRATED FIRE RETARDANT COMPOSITIONS ' i' BACKGROUND OF THE INVENTION '''' Field of the Invention ''' The present invention relates to lmproved chemical compositions useful for preventing and con- -' trolling forest~ rangeland and brush fires. More specifically, this invention relates to concentrated -retardant compositions which are readily adaptable for -use in fixed, portable or mobile fire-fighting facilities.
lO These concentrated compositions can be kept separate "' from the customary dilution water until dispensing becomes '' necessary at' the time of use. -Description of the Prior Art --Forest fires, rangeland fires and brush fires annually result in the loss of millions of dolIars worth of timber and other property. Not only is the direct ''' property loss due to such fires catastrophic, but asso-ciated soil erosion and watershed problems are often of even greater magnitude. It is important, therefore, to minimize and control the spread of such fires whenever possibleO
Known fire-fighting techniques for forest and - rangelands are widely di~erse. One method employs physical removal' of the "fuel" (brush, foliage, etc.) from -25 the path of the oncoming holocaust. Another method applies a cooling medium, e.g., water or thickened water, directly :
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on the flames. Still another method employs chem~cal f~re retardants which modify the fuel to make it less flammable. Often all three of these methods are employed, essentially simultaneously, in order to con-tain and control a single situation. ~arious methodsof distributing fire-fighting solution, including direct spraying and aerial dropping, have been employed.
Aerial dropping is often advantageous to more quickly reach areas which are not easily accessible.
According to U.S. Patent No. 3,553,128 issued January 5, 1971, there are two broad kypes of fire retardants commonly employed in fighting forest, range, grass and brushland wildfires. These fire retardants can be classified as '~short-term" and "long-term"
retardants. Short-term retardants, as defined in U.S.
3,553,128, rely upon the water they contain to retard combustion. They are thus effective only until their contained water evaporates. Long-term retardants con-tain, in addition to water~ a chemical that effeckively retards ~laming combustion even after any contained water has evaporated. The latter type, which can be employed ror fire prevention as well as to contain existing fires, are relevant to this invention.
At present, the most commonly used long-term retardant chemicals-are ammonium salts of phosphoric acid and sulfuric acid. In some cases, fertilizer solutîons containing mixtures of ammonium ortho-, pyro-and polyphosphates are utilized~
In addition to the active fire retardant chemical, most retardant compositions contain a number of other components which are varied dependlng upon the recommended usage and mode of application. ~hese other components are employed either to enhance the overall performance or the ease of using the composition. ~or example, additives are frequently employed to alter the rheological properties of the composition in such a manner " ,, ~

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that the fire retardant will exhib-~t lmproved free-fall characteristics when dropped from high altitudes; will adhere to the wildland fuels in thicker layers, and will flow in such a manner as to cover all surfaces of the fuel~ Other additives found to be of benefit include dyes or pigments to improve vlsibility, a variety of materials which reduce the metal corrosivity of the composition, and bactericides which improve liquid storage stability. The desirability and level of usage Of these additives depend on the particular fire retard-ant employed, the utili.zation of the product (prevention or control) and the type of apparatus used to deliver the material to the fuel. Formulations containing such additives are disclosed in U.S. Patent No. 3,409,550; U.SO
Patenk NoO 3~585,135; and.U.S. Patent No. 3,634,234.
In practice, concentrated (solid or liquid) fire retardant compositions are generally diluted with water prior to application. The term dilution encompasses both dissolving and dispersing of solids in water~ The fire retardant properties of long-term retardants are dependent on the chemicals present, and the dissolution media has an insignificant in~luence on these properties.
It does, on the other hand, contri~ute to the ease of handling the product and improves its distribution on and adherence to the fuel. The concentration of the - dilute retardant solution may be varied depending on the needs of the fire situation and the per~ormance charac-teristics of the delivery apparatus. Concentrated ~ire retardant compositions are disclosed in U.S. 3,730,890 and U.SO 3,809g653.
In addition to performance, two other factors associated with con.centrated fire retardant compositions are o~ extreme importance, namely, logistics and ease and simplicity of handling and dilution. Product logis-tics relate to the weight and volume of ~ire retardantconcentrate which must be utilized per unit volume of 1~3~000 dilute solution. Dilution water is generally available in close proximity to the fire. The smaller the volume and weight of concentrate, the easier it becomes to '' supply the needed vo'lume of dilute product at the fire f site at the time that it is required. In 'this respect, diluent-~ree products have significant logistical advantages over concentrates containing diluentsO For 5.
example, dry powder'products have improved logistics in comparison with concentrated water solutions in which the water diluent has no significant influence on product performance. On the other hand, the handling,!`'.'.' sto~age and dilution with water of dry powders usually ' requires somewhat more sophisticated equipment in compari- -' son with liquid concentrates.
C'onsiderable effort has been expended in recent~' years to reduce the complexities of dry powder usage. '-Exemplary of such efforts is UOS. Patent No. 3,777~775, issued December 11, 1973~ which discloses a portable semibulk handling system for reducing the problems 20 associated with the use o~ dry-powder chemical retard- i' ants. While these efforts have been highly successful, further improvements are desirable in certain situations. ~-:
For example, the weight and volume o~ mixing equlpment , required to use dry powder retardants on small wildland fire vehicles can restrict the amoun~ of fire-fighting chemical which can be transported to the fire. ' Whether to use plain water or chemical retardant solution often depends upon the severity and danger of the particular fire. Ideally, the operator should have the option of incorporating chemical retardants into a water stream on a "demand basis"~ In this context, a "demand basis" refers to a scheme in which the concen-trated chemical retardant is kept separate from the dilution water until actual application on the fire line '' is desired. Thus, the decision whether to apply plain water or chemical retardant solution, and the concen-_, ~
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tration o~ that solution on the fire, can be made atthe application sike with no contamination of one with the other. Storage and stability problems associated with advance preparation of chemical retardant solutions 5 could thereby be circumvented. Handlin~ and transport ~
difficulties could thereby be minimized. t'.
It is an ob~ect o-~ the present invention, there-~ore, to provide novel highly concentrated forest and rangeland fire retardant compositions. Since the compo~
sitions o~ this invention are highly concentrated fluids, they combine the logistical advantages of dry powder systems with the ease and simplicity o~ handling and -dilution Or less concentrated liquid systems. These novel compositions are adaptable to usage in a 7Idemand~
15 manner. Such concentrated compositions would be advan- -tageous in groùnd or aerial application of fire retardant solutions~ They ~ould be especially appropriate for mobile operations such as exemplified in present day wildland fire vehicles.
Other objects of the present invention will become apparent from a consideration of the ~ollowin~
description and claims. -SUMMARY OF THE INV~NTION
The concentrated ~ire retardant compositions o~
~his invention comprise:
a) a solid component selected ~rom the group consisting of monoammonium orthophosphate 7 diammonium orthophosphate;
monoammonium pyrophosphate; diammonium pyrophosphate~ triammonium pyrophosphate;
tetra-ammonium pyrophosphateg ammonium ,;
polyphosphates, ammonium-alkali metal mixed salts o~ ortho-, pyro- and poly- .
phosphates, ammonium-alkaline earth metal mixed salts o~ ortho-, pyro- and polyphos-phates; ammonium sul~ate; ammonium sulfamate, ~3~6~0 urea phosphatej phosphoramides and mixtures thereof, b) a liquid component which con-tains a material~selected from the group consisting of phosphorus-containing acids and ammonium-containing salts thereof~ ;
ammonium polyphosphates, phosphorus-containing estersg ammonium su]fate, ammonium sulfamate and mixtures thereof; and c) a rheological property control agent which imparts thl~otropic flow properties to the composition;
wherein the weight percentages of said components in the compositions are from about 20 percent to about 70 percent -for the solid component, from about 20 percent to about 70 percent for the liquid component and from about 0.1 to about 10 percent for the rheological property control agent, and the weight percent of P205 and S03, taken collectively~ in said compositions is at least Llo percent.
The concentrate compositions of this invention, which eould be considered pastes or slurries, were found to exhibit easily extrudable fluid rheological properties.
These concentrates can be readily transported and stored near the fire base and can easily be mixed with water, if desired, on demand. Exceptionally high concentrations of flame retardant chemicals are obtained with the concentrated compositions of this in~ention. This inven~
tion thus provides compositions with a combination of iogistical and handling features heretofore not achieved with compositions known in the art.
DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS
The solid component (a) of the compositions of the present invention is selected from the group con-sisting of monoammonium orthophosphate; diammonium orthophosphate~ monoammonium-pyrophosphate; diammonium - pyrophosphate, triammonium pyrophosphate, tetra-ammonium pyrophosphate; ammonium polyphosphates;~ammonium~alkali ., " - I' 113~00 metal mixed salts of ortho-, pyro--and polyphosphates, ammonium-alkaline earth metal mixed salts of ortho-, :
pyro- or polyphosphates; ammonium sulfate; ammonium sulfamate; urea phosphate; phosphoramides and mixtures 5 thereof. The phosphorus-containing materials are pre- ~
ferred. ~-The materials which can be employed as compo-nent (a) are well-known in the art. Those skilled in the art will recognize that these materials can be -derived from phosphorus- or sulfur-containing acids by reaction with an appropriate cation. In general, the cations in these cPmpounds are thermally fugltive (volatile)3 which means that they volatilize or degrade to volatilizable fragments at temperatures below the ignition temperature of forest a~d rangeland fuels.
Typical mixed cation salts include NH4MHPO
4)2 4~ NH4M2P04~ NH4M3P207 and (NH~)2M2p2o7 wherein M is an alkali metal cation, i.e., a metal from Group Ia of the Periodic Table of the Elements, e.g., sodiurn or potassiumO Magnesium an~onium phosphate (MgNH4Po4-6H2o) exempli~ies an alkaline earth metal amrnonium orthophosphate. Alkaline earth metals are well known to be metals of Group IIa of the Periodic Table of the Elements.
The ammonium polyphosphates utilized in this invention can be prepared in general by heat treating phosphoric acid or ammonium phosphates such as diammonium phosphate with a combined ammoniating and condensing agent such as urea. These amrnonium polyphosphates are 30 of the formula !~
H(n m)+2(NH4)mPn3n+1 wherein n is an integer having an average value between 3 and about 800, n has an average value between 0.7 and about 1.1, and m has a maximum value equal to n~2. The physical characteristics of these ammoniurn polyphosphates and the various processes for preparing them are described in U.S~ Patent 3~397,035 dated August 13, 1968.
The average value of n in the foregoing formula is determined by the end group titrakion method [Van ~azer et al, Anal. Chem. 26~ 1755 (1954)]. When n is below r::
20 the ammonium polyphosphates are substantially water soluble, and much less soluble products result when n is greater than 20.
The liquid component (b) of the compositions of this invention contains a material selected from the -group consisting of phosphorus-containing acids and ammonium-containlng salts thereof, ammonium polyphosphates, phosphorus-containing esters, ammonium sulfate, ammonium sulfamate and mixtures thereof. These materials thus provide a liquid component which contains fire retardant 15 chemicals. Typically, component (b) will be an aqueous -solution containing the aforementioned materials, although liquids other than water may be employed in component (b).
It is desirable to maximize the amount of the aforemen-tioned materials in the liquid component to provide high levels of fire retardant chemicals in the compositions of this invention. The phosphorus-containing materials are preferred for use in the compositions of this invention. :
The phosphorus-containing acids which may be present in component (b) are typically provided by employing commercially available aqueous phosphorus-containing acid solutions. Preferred acid solutions are those corresponding to the highest concentration of P2O5.
One such preferred acid is orthophosphoric acid at 85 percent concentration in water. This form is available commercially as a colorless oil, miscible with water, and having a speci~ic gravity of 1.7 at room temperature.
Also preferred are phosphoric acid solutions containing condensed moieties which result in very high P2O5 contents for such solutions, for example, such solutions are known to have P2O5 weight percents from about 76 to about 83 percent. Orthophosphoric acid with greater dilution, ..
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_9_ i.e.~ in concentration less than 85 percent, is also uselul ~n preparing component (b) of these compositions.
The liquid component (b) may also be obkained -by employing typical liquid ammonium phosphate fertilizer 5 solutions which have long been available commercially. -One such commercially available material is designated in the fertilizer trade as '~8-24-o!' and contains 8 weight percen~ nitrogen in the form of the ammonium ion and 24 weight percent phosphorus expressed as the anhydride P2O5. ~he composition and concentration of "8-24-0"
can be varied as desired by the addition of ammonia, water and/or phosphoric acid. Solutions such as "8-24-01' are obtained by neutralization of phosphoric acid having t strengths between about-25 and 71 weight percent phos-15 phorus (as P2O5) with anhydrous or aqueous ammonia.
The heat o~ neutra~ization can be removed by indirect heat exchange or by flashing a portion of the water content of the neutralization zone. The reactants are admixed in suitable proportions to obtain an aqueous 20 fertilizer solution having a pH bekween about 5.1 and about 7.8j preferably the fertilizer solution pH is r between about 6.o and 7.8.
Many similar liquid fert-ili%er solutions can be employed to obtain the liquid component (b) of the 25 compositions of the present invention. Exemplary of such liquid fertilizers, commonly referred to as liquid ammonium polyphosphates but more properly described as polyammonium phosphates, are fertilizers known as 10-34-0 11-37-0, 13-39-0, 12-40-0 and 13-42-0. The numerical 30 designatlons for these compounds represent the weight percent nitrogen; phosphorus and potassium, respectively, present in the fertilizer solutions, wherein phosphorus and potassium are given in terms of P2O5 and K2O, respectively.
The liquid component (b) o~ the concentrated fluid compositions of this invention may comprlse water-3L~3~L~0~3 ~

soluble phosphate esters having liquid properties in .
their pure form. Phosphate ester fluids have long been known as fire resistant hydraulic fluids having satis-factory lubricating characteristics. Typical of such liquid phosphate esters are trialkyl phosphates. The latter can be branched-chain alkyl esters of phosphoric ,.
acid hav~ng a low pour point and-high viscosity index.
Usually the alkyl groups will contain 2 to 20 carbon atoms each~ may be alike or diffèrent~ and are obtained by a synthesis route employing the "oxo" process. The total number of carbon atoms in a typical trialkyl phosphate fluid useful in the present invention would be.in the range of ~ to 32~ ~
Certain triaryl phosphates, such as tricresyl ' phosphate, are other phosphate esters which have the necessary liquid properties to satisfy the requirements .
of the solution..phase for the concentrates of the present invention. .
Solutions of monoammonium phosphate or dlammonium phosphate are yet other examples of materials which may be employed to obtain component (b). Those skilled in the art will recognize other salts of phosphorus- ,.
containing acids which are sufficie.ntly soluble in water or other liquids. which may be employed in component (b).
The ammonium polyphosphates which may be employed in component (b) are the previously described ammonium polypho.sphates wherein n is generally less than 20.
The materials present in.component (b) may be mixtures of the various aforementioned materials.
~arious materials which may be present in the liquid component (b) may also be present in a solid state as component (a).
The concentrated fluid compositions of this invention also compr~se a rheological property control agent which imparts thixotropic flow properties to the ~L~3~

composition. The presence of this component, designated component (c) herein, allows for the achievement of a viscosity for the concentrated composition which is suitable for easily transporting and diluting with water, and at the same time results in compositions after dilution containing suitable rheological properties for placement and formation of the fire retarding composi-tion upon the fuel surface. Concentrated fluid composi-tions containing materials corresponding to surprisingly high levels of P2O5 and/or SO3 in the compositions are thus obtained. The use of such agents is described in U.S.
Patent No. 4,101,485 issued to D. L. Brooks et al on July 18, 1978.
While not to be construed in a limitiny sense, preferred rheological property control agents for use herein are cross-linked interpolymers of C2-C~ olefins and maleic anhydride. Particularly effective results have been achieved with ethylene maleic anhydride inter-polymers.
Preparation of cross-linked ethylene maleic anhydride interpolymers is described in U.S. Patent Nos. 3,073,805 and 3,165,486. Thus, many cross-linking agents are known for use in the production of cross-linked C2-C4 olefin maleic anhydride interpolymers.
Vinyl esters of crotonic acid such as vinyl crotonate have found considerable utility in this regard - see U.S. Patent No. 3,165,486.
Another preferred type of rheological property control agent for use in the present invention are galactomannan gums, sometimes referred to as polygalac-tomannans or polysaccharides. The use of such gums is described in U.S. Patent No. 3,634,234. Particularly preferred for use in -the present invention are derivatized guar gums, more particularly carboxyalkyl ethers and , . . .
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hydroxyalkyl ethers of guar gum. ~till more preferred are hydroxyethyl and hydroxypropyl ethers of guar gum.
The use of ~uch derivatized polygalactomannans is des cribed in copending Canadian Application Serial No~ 328,346 filed on May 25, 1979.
Other rheological property control agents useful in this invention are cross-linked polyacrylic acids, certain natural and modified bentonite clays, cellulose derivatives such as hydroY~yethyl cellulose and carboxy-methylcellulose, and the like, so long as they impart the desired thixotropic flow properties to the composi-tions of this invention. The desired thixotropic flow properties will be dependent upon the mode of application intended for the composition after dilution. For example, application as a stream or spray from a fire hose requires a much lower sheared viscosity for the diluted composition than that required when the diluted solution is applied by gravity dropping from an aircraft.
Although its presence is not necessary in the concentrates of this invention, a humectant can often provide improved handling and other properties. Typical humectants which may be employed are polyhydric alcohols such as ethylene glycol, diethylene glycol, polyethylene glycols, propylene glycol, glycerine, dipropylene glycol, sorbitol, mannitol and the like.
The humectant is present, if at all, in rela-tively small amounts to avoid undesirable reduction of available fire retardant chemicals in the finished concentrate composition. For optimum fire-fighting efficiency, it is desirable to maximize the presence of the fire retardant chemical, typically the P2O5.
To illustrate the slurry concentrate compositions of this invention, numerous formulations were prepared and tested. Viscosity, pH and corrosion properties were observed on various concentrates within the scope of this invention. Surprisingly high concentration of flame 3~0 retardant chemicals (e.g., P2O5) were maintained in the final concentrate formulations thus assuring superior fire fighting capabilities when employed in admixture with water ~or dispensing from application equipment.
The following Example I illustrates the prepara~
tion of a concentrated fluid cornposition of this inven- ~
tion containing a solid component, a liquid component, ~`
and a viscosity control agent.
All parts and percentages in any of the following examples~ unless otherwise speci~ied, are by weight.
Viscosity determinations were at 22C~ and, unless indi-cated as having been obtained with a Brookfield viscometer, were made according to hSTM D-1823~66 (Reapproved 1972) entitled "Standard Methods o~ Test for Apparent Viscosity of Plastisols and Organosols at High Shear Rates ~y Castor-Severs Viscometert!.
EXAMPLE I
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To 133 grams of diammonium phosphate (solid component) was added 66 grams of 10-34-0 liquid fertilizer j:
solution (liquid component) and 0.4 grams of a vinyl crotonate cross-linked ethylene maleic anhydride copolymer (rheological property control agent). The components were vigorously mixed together at room temperature to obtain a i~
concentrated fluid containing 52.5 percent by weight P2O5.
The viscosity of the fluid concentrate was 103000 centipoise.
The following Example II illustrates a fluid concentrate composition of the present invention employing a humectant (polyhydric alcohol).
3o EXAMPLE II r To 134 grams of diammonium phosphate was added 46 grams of 10-34-0 liquid fertilizer solution, 3.5 grams o~ a propylene oxide derivative of guar gum and 8 grams of sorbitol (humectant)~ The resulting concentrate contained 45 percent by weight P205! The fluid concen-trate had a viscosity greater than 52,000 centipoise and .. ~.

exhibited adequate fluid flow propertles. After dilu-tion to a 20 percent solution, the composition exhibited a Brookfield viscosit~ of 150 centipoise and a pH of 8.4.
The follo~ing examples illustrate formulations !l and properties of additional ~luid concentrate composi- t~.'' tions within the scope of the present invention. The same procedure was followed in each of the following ~, Examples as set forth in Examples I and II above. l~
EXAMPLE III l:
Solid - 127 grams of diammonium phosphate Liquid - 64 grams of 10-34-0 liquid fertiliæer solution Rheological Property Control Agent ~ 9 grams of a propylene oxide derivative of --guar gum The resultant fluid concentrate had a viscosity greater than 52,000 centipoise and exhibited adequate fluid flow properties. The composition contained 44.5 percent by weight P205. After dilution to a 20 percent solution the composition had a Brookfield viscosity of 2063 centipoise and a pH 7.6.
EXAMPLE IV
Solid - 132 grams monoammonium phosphate Liquid - 44 grams 10-34-0 liquid fertilizer solution and 24 grams 85 percent ortho-phosphoric acid Rheological Property Control Agent - 0.4 gram vinylcrotonate cross-linked ethylene maleic anhydride copolymer `
The resultant fluid concentrate exhibited adequate fluid flow properties and contained 55.8 percent E
P2O5 and had a p~ 1.4.

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-15- l EXAMPLE ~ Ir:
Solid - 66 grams of diammonium phosphate and 76 grams of monoammonium ~:
phosphate ~L
Liquid - 29 grams of 10-34-0 liquid fertilizer solution and 29 grams of water Rheological Property Gontrol Agent ~ 1 gram of a vinylcrotonate cross-linked ethylene maleic anhydride copolymer The resultant fluid concentrate contained 45.8 percent by weight P205 and exhibited a Brookfield viscosity of 3000 centipoise prior to further dilutlon.
EXhMPLE VI !.
Solid - 161 grams of a triammonium hydrogen pyrophosphate -(NH4)3H P207 - containing 61.4 percent water solu-ble P205.
Liq1lid - 39 grams of water Rheological Property 1-Control Agent - 1 gram of a vinyl crotonate cross-linked-ethylene maleic anhydride copolymer - resin The resultant fluid concentrate contained 49 percent P205 and exhibited a Brookfield viscosity of 1128 centipoise and a pH of 6.7.
EXAMPLE VII
Solid - 79 grams of monoammonium phosphate and 90 grams -of diammonium phosphate Liquid - 31 grams of water Rheological Property Control Agent - 0.6 gram of a vinyl crotonate cross-linked ethylene maleic anhydride copolymer t' The resulting fluid concentrate contained 48.5 percent P205 and exhibited a Brookfield viscosity of 2000 cent~poise.

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EXAMPLE ~III ..
Solid - 292.5 grams diammonium ::
phosphate Liquid - 99.4 grams of 10-34 0 liquid fertilizer ~
Polyhydric - 38.3 grams sorbitol ~-Alcohol i:.
Rheological Property .
Control Agent ~ 7.5 grams derivati.zed r!
polysaccharide of ....
the guar gum type The resulting fluid concenkrate contained 43.1 E
percent P205 and had~adequate fiuid flow properties~ A E.
20 percent aqueous solution thereof exhlbited a pH of 8.4 and a viscosity of 150 centipoise as measured with '-.
a Brookfield No. 4 Spindle. ..
EXAMPLE IX .
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Solid - 292.5 grams diammonium -phosphate ...
Liquid - 127.8 grams 10-34-0 fertillzer ..
solution and 18.3 grams ..
of 85 percent concen- .
trated phosphoric acid .:
Rheological Property . -.
. 25 Control Agent - 7.5 grams derivatized ,:.
polysaccharide of the -- guar gum type The resulting concentrate contained 49 percent .-.
P205 and had.adequate fluid flow properties. A 20 per- .
30 cent-aqueous solution thereof had a Brookfield viscosity ..
of 65 centipoise and a pH of 6.9. ..
EXAMPLE X .. :
Solid - 292.5 grams diammonium .:.
phosphate `.
Liquid - 99.4 grams 10-34-0 ferti- .
lizer solution~ 55.0 --grams 85 percent ,-.
phosphoric acid Rheological Property Control Agent - 7.5 grams derivatized -.
polysaccharide of the ~:
guar gum type : . .
....
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The resulting concenkrate contained 50.1 percent ~:
P2O5 and had adequate fluid ~low propertiesO A 20 per-cent aqueous solution thereof had a Brookfield viscosity ~
of 55 centipoise and a pH of 6.5. l:
From the above Examples, therefore, it can be seen that the fire retardant fluid concentrate composi~
tionsof this invention are exemplified by numerous different concentrations and combinations of the respec- ~
tive ingredients~ Furthermorea the fluid concentrate ir compositions can be prepared according to numerous con-venient proceduresg including simply blending or mixing together o~ the appropriate amounts of the respectlve ingredients. A flow conditioner such as tricalcium phosphate or magnesium carbonate can be advantageously incorporated in the solid phase to facilitate handling during processing.
Other additives such as corrosion inhibitors, antifoaming agents, coloring agents and the like may be conveniently incorporated into the fluid concentrates 20 of this invention. -Weight concentration of the solid component (or components) within the total composition may vary within rather broad limits depending upon the parkicular appli-cation involved. Thus, the solid component (a) will usually comprise from about 20 percent to about 70 percent by weight of the composition. Preferably, the solid comprises from about 30 percent to about 60 percent by - weight of the composition.
Weight concentration of the liquid component (b) in the fluid concentrate composition is often about the same as that of the solid phase~ It is to be understood, however, that the liquid component concentration may be allowed to vary as dictated by the conditions of appli-cation and the mixing or blending equipment to which the 35 fluid concentrate is ultimately expected to be exposed. !:
Typically, the liquid component comprises from about 20 to about 70 percent by weight o~ the composition, pre~erably about 30 to 60 percenk. Liquid component (b) typically contains from about 10 percent to about 85 percent by weight P205 and S03, taken collectively~ k preferably about 30 percent to about 85 percent.
The rheological property control agent is typically present in a concentration from about 0.1 percent to about 10 percent by weight of the total composition. c It is desirable to ad~ust the concentrations of materials in the compositions of this invention to achieve maximum concentrations o~ the ~lame retardant chemicals (measured, for example, as P205) and at the same time achieve acceptable rheological and other properties. Flame retardancy is imparted by the phos-phorous or sulfur-conta~ning chemicals and the weight percentage o~ ~lame retardant chemicals is hereln measured by the weight percentage of the total P205 and -S03 corresponding to the materials present in the total compositionO It is to be understood that although P205 and S03 are considered collectively ~or this purpose, we do not mean to imply that both must be present. It should be apparent that either may be present alone~ or both may be present in the compositions of the present invention. In general, the compositions contain a minimum of about 40 percent by weight of P205 and S03, taken collectively. Preferred compositions contain a minimum of about 45 percent by welght of P205 and S03, and a minimum o~ about 50 percent is even more preferred.
The maximum concentration of flame retardant chemicals achievable is limited only by the materials themselves and the requirement that the composition exhibit acceptable fluid properties.
The concentrated compositions of this invent~on are generally diluted with water prior to application in the field. Dilution may be varied depending on the needs .
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of the fire situation. Typically ~he concentrated compositions are diluted to about 10 percent to about ~:
25 percent by weight solutions thereof.
The novel compositions of this invention 5 provide concentrated fluids with exceptionally high levels of flame retardant chemicals. There is thus F
provided compositions with a combination of the afore-mentioned handling advantages of a fluid and the logistical advantages of highly concentrated compo-10 sitions. Compositions with these combined features have hereto~ore not been disclosed in the art.
While this invention has been described with respect to specific examples and embodiments, it is to be understood that the invention is not limited thereto 15 and that it can be variously practiced within thé scope of the following claims~

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Claims (4)

The embodiments of this invention in which an exclusive property or privilege is claimed are defined as follows:

1. A fire retardant composition which comprises:
(a) a solid component selected from the group consisting of monoammonium orthophosphate; diammonium orthophosphate;
monoammonium pyrophosphate; diammonium pyrophosphate; triammonium pyrophosphate;
tetra-ammonium pyrophosphate; ammonium polyphosphates; ammonium-alkali metal mixed salts of ortho-, pyro- and polyphos-phates; ammonium-alkaline earth metal mixed salts of ortho-, pyro- and polyphosphate;
ammonium sulfate; ammonium sulfamate; urea phosphate; phosphoramides and mixtures thereof;
(b). a liquid component which contains a material selected from the group con-sisting of phosphorus-containing acids and ammonium-containing salts thereof ammonium polyphosphates, phosphorus-containing esters, ammonium sulfate, ammonium sulfamate and mixtures thereof, and (c) a rheological property control agent which imparts thixotropic flow properties to the composition;
wherein the weight percentages of said components in the composition are from about 20 percent to about 70 percent for the solid component, from about 20 percent to about 70 percent for the liquid component and from about 0.1 to about 10 percent for the rheological property control agent, and the weight percent of P2O5 and SO3, taken collectively, in said composition is at least 40 percent.

2. A composition according to Claim 1 wherein the total weight percent of P2O5 and SO3, taken collec-tively, is at least 45 percent.

3. A composition according to Claim 1 or 2 wherein the rheological property control agent is a cross-linked C2-C4 olefin-maleic anhydride interpolymer.

4. A composition according to Claim 1 or 2 wherein the rheological property control agent is a derivatized guar gum.