US4060489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fire fighting with thixotropic foam
Assignee: Kidde Fire Fighting Inc
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Filing: 1976-03-25
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Granted: 1977-11-29
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Expires: 1996-03-25
Abstract
Abstract Aqueous foam formed with solution containing thixotropic polysaccharide in addition to foaming agent, will gel when projected onto a burning hydrophilic liquid, and such foam is not destroyed by the liquid, so that it is suitable to fight fires on hydrophilic liquids as well as on hydrophobic liquids and on solids that are compatible with the foam. The thixotropic character enables the ready pumping of the foam and of the solution from which it is formed. A substantial content of N-methyl pyrrolidone-2 in a concentrate for such foam-producing solution can make such concentrate more adaptable for ready dilution and also improves its stability. Urea can be added to help solubilize the polysaccharide, and it will also reduce the viscosity of a concentrate. Other ingredients can also be included such as to form films over hydrophobic liquids to improve the stability of the foam that is formed and to increase the thixotropic action.
Inventors
- 👤 Peter J. Chiesa, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:37
CPC Classifications
A; A62; A62C; A62C99/00; A62C99/0009; A62C99/0036; A62D; A62D1/00; A62D1/0071; A62D1/0085
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
80 words
An aqueous pumpable fire-fighting concentrate for dilution with at least about ten times its volume of water and foaming with air to produce a fire-fighting foam, said concentrate containing (a) a foaming agent that causes the diluted concentrate to form a foam having an expansion of at least about 3, and (b) a water-soluble thixotropic polysaccharide dissolved in an amount that causes the foam to undergo syneresis and form a floating gel mat when applied to a non-aqueous polar solvent.
Claim 2
Dependent Claim
80 words
An aqueous pumpable fire-fighting concentrate for dilution with at least about ten times its volume of water and foaming with air to produce a fire-fighting foam, said concentrate containing (a) a foaming agent that causes the diluted concentrate to form a foam having an expansion of at least about 3, and (b) a water-soluble thixotropic polysaccharide dissolved in an amount that causes the foam to undergo syneresis and form a floating gel mat when applied to a non-aqueous polar solvent.
Claim 3
Dependent Claim
12 words
The concentrate of claim 1 which also contains a foam-stabilizing hydrophilic resin.
Claim 4
Dependent Claim
12 words
The concentrate of claim 1 in which the thixotropic polysaccharide is scleroglucan.
Claim 5
Dependent Claim
22 words
the concentrate of claim 3 in which the ingredients are dissolved in a solvent a major portion of which is N-methyl pyrrolidone-2.
Claim 6
Dependent Claim
29 words
The concentrate of claim 4 in which the solvent also includes water and sufficient ethylene glycol to keep the water from freezing at temperatures as low as -20° C.
Claim 7
Dependent Claim
32 words
The concentrate of claim 1 which also contains film-forming material in an amount that causes the foam to form an aqueous film over a liquid hydrocarbon to which the foam is applied.
Claim 8
Dependent Claim
38 words
The concentrate of claim 6 in which the film-forming material is a mixture of fluorocarbon surfactant and silicone surfactant that together reduce the surface tension of the water in the foam to 19 dynes or less per centimeter.
Claim 9
Dependent Claim
27 words
The concentrate of claim 1 in which the aqueous solvent includes sufficient butyl carbitol to keep the water from freezing at temperatures as low as -20° C.
Claim 10
Dependent Claim
51 words
A fire-fighting composition which is essentially an aqueous solution of (I) a foaming agent that causes the composition to form a foam having an expansion of at least about 3, and (II) a thixotropic polysaccharide in a concentration that causes the solution to gel when contacted with a non-aqueous polar solvent.
Claim 11
Dependent Claim
51 words
A fire-fighting composition which is essentially an aqueous solution of (I) a foaming agent that causes the composition to form a foam having an expansion of at least about 3, and (II) a thixotropic polysaccharide in a concentration that causes the solution to gel when contacted with a non-aqueous polar solvent.
Claim 12
Dependent Claim
12 words
The composition of claim 9 which also contains a foam-stabilizing hydrophilic resin.
Claim 13
Dependent Claim
12 words
The composition of claim 9 in which the thixotropic polysaccharide is scleroglucan.
Claim 14
Dependent Claim
32 words
The composition of claim 9 which also contains film-forming material in an amount that causes the foam to form an aqueous film over a liquid hydrocarbon to which the foam is applied.
Claim 15
Dependent Claim
35 words
The composition of claim 12 in which the film-forming material is a mixture of fluorocarbon surfactant and silicone surfactant that together reduce the surface tension of the composition to 19 dynes or less per centimeter.
Claim 16
Dependent Claim
85 words
The composition of claim 10 in which the resin is a hydrophilic film-forming polymeric material having about 1/2 to 5 repeating hydrocarbon groups for every one of repeating groups of a half-amide of succinic acid, the hydrocarbon groups are phenyl ethylene groups, and the half-amide is the half-amide of a primary or secondary alkyl amine in which the alkyl has up to 5 carbons and which can be substituted on any carbon with a group selected from the class consisting of amino and carboxyl groups.
Claim 17
Dependent Claim
11 words
The concentrate of claim 1 in which the polysaccharide is heteropolysaccharide-7.
Claim 18
Dependent Claim
39 words
The concentrate of claim 1 in which at least about 1/3 of the foaming agent is selected from the class having hydrophilic and hydrophobic moieties of which the hydrophilic moiety weighs at least 80% more than the hydrophobic moiety.
Claim 19
Dependent Claim
26 words
The concentrate of claim 1 which also contains locust bean gum in an amount from about one-third to about three times that of the thixotropic polysaccharide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |