# US 12,109,446 B2 · Long-term fire retardant with corrosion inhibitors and methods for making and using same

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- Number: US 12,109,446 B2
- Document ID: US12109446B2
- Status: Granted
- Kind: B2
- Application number: 18/602,657
- Filed: 2024-03-12
- Published: 2024-08-15
- Granted: 2024-10-08
- Earliest claimed: 2022-03-31
- 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; Gerald S. Frankel
- Web page: https://patentgrep.com/patent/US12109446B2

## CPC

- A62D 1/0042: {"Wet" water, i.e. containing surfactant}
- A62D 1/005: {Dispersions; Emulsions}
- A62D 1/0014: {Powders; Granules}
- A62D: CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS

## Abstract

A forest fire retardant composition contains a retardant compound that includes a potassium salt. The potassium salt may include a potassium salt of an organic acid, a potassium salt of an inorganic acid, or mixtures thereof. The organic acid may include formic acid, acetic acid, propanoic acid, butanoic acid, lactic acid, oxalic acid, malic acid, gluconic acid, tartaric acid, uric acid, malic acid, or citric acid. The inorganic acid may include sulfuric acid, phosphoric acid, carbonic acid, or hydrochloric acid. 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 concentrate, comprising:
a potassium citrate salt, wherein the potassium citrate salt comprises at least one of monopotassium citrate, dipotassium citrate, tripotassium citrate, or tripotassium citrate monohydrate;
a corrosion inhibitor for at least one of steel, brass, aluminum, or magnesium, present in the concentrate in an amount having a weight percent of about 0.05% to about 25.0% relative to the weight of the potassium citrate salt in the concentrate;
a thickening agent, present in the concentrate in an amount having a weight percent of about 0.2% to about 30.0% relative to the weight of the potassium citrate salt in the concentrate; and
a colorant, present in the concentrate in an amount having a weight percent of about 0.3% to about 10.0% relative to the weight of the potassium citrate salt in the concentrate.

### Claim 2 (depends on 1)

The concentrate of claim 1, wherein the potassium citrate salt is tripotassium citrate monohydrate.

### Claim 3 (depends on 1)

The concentrate of claim 1, wherein the corrosion inhibitor comprises at least one of:
an alkyl amine;
an azole;
iron pyrophosphate;
disodium molybdate;
sodium lauryl sulfate; or
sodium stearate.

### Claim 4 (depends on 1)

The concentrate of claim 1, wherein the thickening agent comprises a polysaccharide gum.

### Claim 5 (depends on 4)

The concentrate of claim 4, wherein the polysaccharide gum comprises at least one of xanthan gum, guar gum, rhamsan gum, Welan gum, or diutan gum.

### Claim 6 (depends on 1)

The concentrate of claim 1, wherein the colorant comprises at least one of a red dye, an orange dye, a purple dye, a pink dye, iron oxide, an inorganic pigment, or a fluorescent pigment.

### Claim 7 (depends on 1)

The concentrate of claim 1, further comprising a buffering agent present in the concentrate in a weight percent of about 0.3% to about 40.0% relative to the weight of the potassium citrate salt in the concentrate.

### Claim 8 (depends on 7)

The concentrate of claim 7, wherein the buffering agent comprises a weak acid.

### Claim 9 (depends on 1)

The concentrate of claim 1 further comprising at least one of a sodium salt or a potassium salt of an organic acid.

### Claim 10 (depends on 1)

The concentrate of claim 1, wherein:
the concentrate is a dry concentrate; and
the potassium citrate salt is present in the concentrate in an amount having a weight percent of about 60% to about 99.5% relative to the total weight of the concentrate.

### Claim 11 (depends on 1)

The concentrate of claim 1, wherein:
the concentrate is a liquid concentrate further comprising water; and
the potassium citrate salt is present in the liquid concentrate in an amount having a weight percent of about 20% to about 80% relative to the total weight of the liquid concentrate.

### Claim 12

A forest fire retardant concentrate, comprising:
a potassium citrate salt, wherein the potassium citrate salt comprises at least one of monopotassium citrate, dipotassium citrate, tripotassium citrate, or tripotassium citrate monohydrate;
an organic amine, present in the concentrate in an amount having a weight percent of about 0.05% to about 25.0% relative to the weight of the potassium citrate salt in the concentrate; and
a gum, present in the concentrate in an amount having a weight percent of about 0.4% to about 25.0% relative to the weight of the potassium citrate salt in the concentrate.

### Claim 13 (depends on 12)

The concentrate of claim 12, wherein the potassium citrate salt is tripotassium citrate monohydrate.

### Claim 14 (depends on 12)

The concentrate of claim 12, wherein the gum comprises a polysaccharide gum.

### Claim 15 (depends on 14)

The concentrate of claim 14, wherein the polysaccharide gum comprises at least one of xanthan gum, guar gum, Welan gum, rhamsan gum, or diutan gum.

### Claim 16 (depends on 12)

The concentrate of claim 12, wherein the organic amine comprises at least one of triethanolamine, N,N,N′,N′-Tetrakis(2-hydroxyethyl)ethylenediamine, or tris(hydroxymethyl)aminomethane (TRIS).

### Claim 17 (depends on 12)

The concentrate of claim 12, further comprising at least one of a sodium salt or a potassium salt of an organic acid.

### Claim 18 (depends on 12)

The concentrate of claim 12, further comprising a colorant present in the concentrate in an amount having a weight percent of about 0.3% to about 10.0% relative to the weight of the potassium citrate in the concentrate.

### Claim 19 (depends on 18)

The concentrate of claim 18, wherein the colorant comprises at least one of a red dye, an orange dye, a purple dye, a pink dye, iron oxide, an inorganic pigment, or a fluorescent pigment.

### Claim 20 (depends on 12)

The concentrate of claim 12, further comprising a weak acid.

### Claim 21 (depends on 12)

The concentrate of claim 12, further comprising at least one of:
an azole;
iron pyrophosphate;
disodium molybdate;
sodium lauryl sulfate; or
sodium stearate.

### Claim 22 (depends on 12)

The concentrate of claim 12, wherein:
the concentrate is a dry concentrate; and
the potassium citrate salt is present in the concentrate in an amount having a weight percent of about 60% to about 99.5% relative to the total weight of the concentrate.

### Claim 23 (depends on 12)

The concentrate of claim 12, wherein:
the concentrate is a liquid concentrate further comprising water; and
the potassium citrate salt is present in the liquid concentrate in an amount having a weight percent of about 20% to about 80% relative to the total weight of the liquid concentrate.

### Claim 24

A forest fire retardant final diluted product, comprising:
a potassium citrate salt present in the final diluted product in an amount having a weight percent of about 4% to about 30% relative to the total weight of the final diluted product, wherein the potassium citrate salt comprises at least one of monopotassium citrate, dipotassium citrate, tripotassium citrate, or tripotassium citrate monohydrate;
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 0.05% to about 25.0% relative to the weight of the potassium citrate salt in the final diluted product;
a thickening agent, present in the final diluted product in an amount having a weight percent of about 0.2% to about 30.0% relative to the weight of the potassium citrate salt in the final diluted product; and
water;
wherein:
the final diluted product is intended for use to suppress, retard, or contain forest fires.

### Claim 25 (depends on 24)

The final diluted product of claim 24, wherein:
the final diluted product is a long-term fire retardant; and
the long-term fire retardant has a viscosity between 150 cP and 1500 cP.

### Claim 26 (depends on 25)

The final diluted product of claim 25, wherein the viscosity is between 150 cP and 800 cP.

### Claim 27 (depends on 24)

The final diluted product of claim 24 further comprising at least one of a sodium salt or a potassium salt of an organic acid.

### Claim 28 (depends on 24)

The final diluted product of claim 24, further comprising a colorant present in the final diluted product in an amount having a weight percent of about 0.3% to about 10.0% relative to the weight of the potassium citrate in the final diluted product.

### Claim 29 (depends on 28)

The final diluted product of claim 28, wherein the colorant comprises at least one of a red dye, an orange dye, a purple dye, a pink dye, iron oxide, an inorganic pigment, or a fluorescent pigment.

### Claim 30 (depends on 24)

The final diluted product of claim 24, further comprising a buffering agent present in the final diluted product in a weight percent of about 0.3% to about 40.0% relative to the weight of the potassium citrate salt in the final diluted product.