# US 12,214,237 B2 · Long-term fire retardant with corrosion inhibitors and methods for making and using same

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- Number: US 12,214,237 B2
- Document ID: US12214237B2
- Status: Granted
- Kind: B2
- Application number: 18/404,387
- Filed: 2024-01-04
- Published: 2024-05-09
- Granted: 2025-02-04
- Earliest claimed: 2020-12-15
- Assignees: FRS Group, LLC
- Applicants: FRS Group, LLC
- Inventors: Dennis Hulbert; Robert J. Burnham; Michael S. Schnarr; Gerald Geissler; David W. Wilkening; Joseph McLellan; Michael White
- Web page: https://patentgrep.com/patent/US12214237B2

## CPC

- A62D 1/005: {Dispersions; Emulsions}
- A62C 3/02: for area conflagrations, e.g. forest fires, subterranean fires
- A62D 1/0007: {Solid extinguishing substances}
- A62D 1/0035: {Aqueous solutions}
- C01F 5/40: Magnesium sulfates (double sulfates of magnesium with sodium or potassium C01D5/12, with other alkali metals {C01D15/00}, C01D17/00)
- C09K 21/04: containing phosphorus
- A62D: CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
- A62C: FIRE-FIGHTING (fire-extinguishing compositions, use of chemical substances in extinguishing fires A62D1/00; spraying, applying liquids or other fluent materials to surfaces in general B05; alarm arrangements G08B, e.g. fire alarms actuated by smoke or gases G08B17/10)
- C01F: COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B17/42; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia or cyanogen containing nitrogen and non-metals and optionally metals C01B21/082; amides or imides of silicon C01B21/087}; metal {imides or} amides C01B21/092, {C01B21/0923}; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20; {double sulfates of magnesium with sodium or potassium C01D5/12; with other alkali metals C01D15/00, C01D17/00})
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

A forest fire retardant composition contains a retardant compound that includes a phosphate salt. The phosphate salt may include diammonium phosphate, diammonium orthophosphate, monoammonium phosphate, monoammonium orthophosphate, monosodium phosphate, disodium phosphate, disodium phosphate hydrate, sodium ammonium phosphate, sodium ammonium phosphate hydrate, sodium tripolyphosphate, trisodium phosphate, or dipotassium phosphate, and combinations thereof. The forest fire retardant composition may include an ammonium source. The composition may be in the form of a dry concentrate, a liquid concentrate, or a final diluted product. The final diluted product is effective in suppressing, retarding, and controlling forest fires while exhibiting corrosion resistance and low toxicity.

## Claims

### Claim 1

A forest fire retardant final diluted product, comprising:
a mixture of phosphates comprising:
at least one of diammonium phosphate or monoammonium phosphate; and
at least one of disodium phosphate, monosodium phosphate, dipotassium phosphate, or monopotassium phosphate;
a corrosion inhibitor for at least one of steel, brass, aluminum, or magnesium, present in the final diluted product in an amount having a weight percent of about 0.02% to about 2.0% relative to total weight of the final diluted product; and
water;
wherein:
the final diluted product has a pH of about 6.0 to about 8.0; and
the final diluted product is intended for use to suppress, retard, or contain forest fires.

### Claim 2 (depends on 1)

The final diluted product of claim 1, wherein the final diluted product has a pH of about 6.2 to about 7.8.

### Claim 3 (depends on 1)

The final diluted product of claim 1, wherein the mixture of phosphates is present in the final diluted product in an amount having a weight percent of about 6% to about 28% relative to the total weight of the final diluted product.

### Claim 4 (depends on 1)

The final diluted product of claim 1, wherein:
the final diluted product is a long-term fire retardant;
the long-term fire retardant has a viscosity between 150 cP and 1500 cP; and
the long-term fire retardant does not exceed a corrosion rate of 2.0 mils-per-year for aluminum, 5.0 mils-per-year for steel, and 5.0 mils-per-year for brass.

### Claim 5 (depends on 4)

The final diluted product of claim 4, wherein the long-term fire retardant does not exceed a corrosion rate of 4.0 mils-per-year for magnesium.

### Claim 6 (depends on 4)

The final diluted product of claim 4, wherein the viscosity is between 150 cP and 400 cP.

### Claim 7 (depends on 4)

The final diluted product of claim 4, wherein the viscosity is between 401 cP and 800 cP.

### Claim 8 (depends on 4)

The final diluted product of claim 4, wherein the viscosity is between 801 cP and 1500 cP.

### Claim 9 (depends on 1)

The final diluted product of claim 1, wherein the corrosion inhibitor comprises at least one of:
an alkyl amine;
one or more azoles; or
disodium molybdate dihydrate.

### Claim 10 (depends on 1)

The final diluted product of claim 1, further comprising a thickening agent, present in the final diluted product in an amount having a weight percent of about 0.025% to about 5.0% relative to total weight of the final diluted product.

### Claim 11 (depends on 10)

The final diluted product of claim 10, wherein the thickening agent comprises at least one of a polyurethane, a polyvinyl alcohol, an acrylic polymer, a gum, a cellulosic, a sulfonate, a saccharide, a clay, an organosilicone, or a protein.

### Claim 12 (depends on 1)

The final diluted product of claim 1, further comprising a colorant, present in the final diluted product in an amount having a weight percent of about 0.06% to about 5.0% relative to total weight of the final diluted product.

### Claim 13 (depends on 12)

The final diluted product of claim 12, wherein the colorant comprises an inorganic pigment and an organic pigment.

### Claim 14 (depends on 1)

The final diluted product of claim 1, further comprising at least one of sodium ammonium phosphate, sodium ammonium phosphate hydrate, sodium tripolyphosphate, trisodium phosphate, monocalcium phosphate, dicalcium phosphate, tricalcium phosphate, octacalcium phosphate, dicalcium diphosphate, calcium triphosphate, hydroxyapatite, apatite, tetracalcium phosphate, or tripotassium phosphate.

### Claim 15 (depends on 1)

The final diluted product of claim 1, wherein:
the final diluted product is formed by diluting a forest fire retardant concentrate with water; and
the forest fire retardant concentrate is a dry concentrate having no more than about 3% by weight of water relative to the total weight of the dry concentrate.

### Claim 16

A forest fire retardant final diluted product, comprising:
a mixture of phosphates comprising:
diammonium phosphate;
monoammonium phosphate; and
at least one of a sodium phosphate salt, a calcium phosphate salt, or a potassium phosphate salt;
a corrosion inhibitor for at least one of steel, brass, aluminum, or magnesium, present in the final diluted product in an amount having a weight percent of about 0.02% to about 2.0% relative to total weight of the final diluted product;
a thickening agent, present in the final diluted product in an amount having a weight percent of about 0.025% to about 5.0% relative to total weight of the final diluted product; and
water;
wherein:
the final diluted product has a pH of about 6.2 to about 7.8; and
the final diluted product is intended for use to suppress, retard, or contain forest fires.

### Claim 17 (depends on 16)

The final diluted product of claim 16, wherein the sodium phosphate salt, the calcium phosphate salt, or the potassium phosphate salt comprises at least one of monosodium phosphate, disodium phosphate, disodium phosphate hydrate, sodium ammonium phosphate, sodium ammonium phosphate hydrate, sodium tripolyphosphate, trisodium phosphate, monocalcium phosphate, dicalcium phosphate, tricalcium phosphate, octacalcium phosphate, dicalcium diphosphate, calcium triphosphate, hydroxyapatite, apatite, tetracalcium phosphate, monopotassium phosphate, dipotassium phosphate, or tripotassium phosphate.

### Claim 18 (depends on 16)

The final diluted product of claim 16, wherein the final diluted product has a pH of about 6.5 to about 7.5.

### Claim 19 (depends on 16)

The final diluted product of claim 16, wherein the mixture of phosphates is present in the final diluted product in an amount having a weight percent of about 6% to about 28% relative to the total weight of the final diluted product.

### Claim 20 (depends on 16)

The final diluted product of claim 16, wherein:
the final diluted product is a long-term fire retardant;
the long-term fire retardant has a viscosity between 150 cP and 1500 cP; and
the long-term fire retardant does not exceed a corrosion rate of 2.0 mils-per-year for aluminum, 5.0 mils-per-year for steel, and 5.0 mils-per-year for brass.

### Claim 21 (depends on 20)

The final diluted product of claim 20, wherein the long-term fire retardant does not exceed a corrosion rate of 4.0 mils-per-year for magnesium.

### Claim 22 (depends on 20)

The final diluted product of claim 20, wherein the viscosity is between 150 cP and 400 cP.

### Claim 23 (depends on 20)

The final diluted product of claim 20, wherein the viscosity is between 401 cP and 800 cP.

### Claim 24 (depends on 20)

The final diluted product of claim 20, wherein the viscosity is between 801 cP and 1500 cP.

### Claim 25 (depends on 16)

The final diluted product of claim 16, wherein the corrosion inhibitor comprises at least one of:
an alkyl amine;
one or more azoles; or
disodium molybdate dihydrate.

### Claim 26 (depends on 16)

The final diluted product of claim 16, wherein the thickening agent comprises at least one of a polyurethane, a polyvinyl alcohol, an acrylic polymer, a gum, a cellulosic, a sulfonate, a saccharide, a clay, an organosilicone, or a protein.

### Claim 27 (depends on 26)

The final diluted product of claim 26, wherein the thickening agent comprises the gum.

### Claim 28 (depends on 16)

The final diluted product of claim 16, further comprising a colorant, present in the final diluted product in an amount having a weight percent of about 0.06% to about 5.0% relative to total weight of the final diluted product.

### Claim 29 (depends on 28)

The final diluted product of claim 28, wherein the colorant comprises an inorganic pigment and an organic pigment.

### Claim 30 (depends on 16)

The final diluted product of claim 16, wherein:
the final diluted product is formed by diluting a forest fire retardant concentrate with water; and
the forest fire retardant concentrate is a dry concentrate having no more than about 3% by weight of water relative to the total weight of the dry concentrate.