Abstract A thixotropic high internal phase ratio emulsion which is essentially nonflammable is employed as a fire extinguishing agent. In the preferred embodiment the emulsion contains an aqueous internal phase which makes up the major part of the emulsion, usually in excess of 90%, but preferably in excess of 95%, and a minor amount of an external phase which is of low volatility and/or flammability such as a heavy oil and an emulsifying material. Because it is thixotropic and cohesive, it forms a blanket over a fire, and coats adjacent surfaces, preventing the spread of the fire. This composition is particularly useful in fighting forest fires where the emulsion can be dropped or sprayed from aircraft with a minimum loss due to dispersion in air currents. The invention also comprises a fire extinguisher comprising a container containing a high internal phase ratio emulsion and means for expelling said emulsion onto or in the path of a fire.
Inventors
👤 Larry R. Hopper
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-23 18:00
CPC Classifications
A; A62; A62D; A62D1/00; A62D1/0028; A62D1/005
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
120 words
A fire extinguisher comprising a container containing (1) an essentially nonflammable thixotropic high internal phase ratio water-in-oil emulsion, said emulsion having the characteristics of an elastic solid when at rest, of an extremely viscous liquid at low shear conditions and of a low viscosity medium under moderate shear rates, said emulsion being highly resistant to destruction by radiant heat, said emulsion comprising water, an emulsifiable oil and a biodegradable oxyalkylated emulsifying agent not presistent and harmful to wild life, said water being present in said emulsion in an amount of at least 60% by volume of the emulsion and (2) means for expelling said thixotropic emulsion through an opening in the container onto or in the path of a fire.
Claim 2
Dependent Claim
120 words
A fire extinguisher comprising a container containing (1) an essentially nonflammable thixotropic high internal phase ratio water-in-oil emulsion, said emulsion having the characteristics of an elastic solid when at rest, of an extremely viscous liquid at low shear conditions and of a low viscosity medium under moderate shear rates, said emulsion being highly resistant to destruction by radiant heat, said emulsion comprising water, an emulsifiable oil and a biodegradable oxyalkylated emulsifying agent not presistent and harmful to wild life, said water being present in said emulsion in an amount of at least 60% by volume of the emulsion and (2) means for expelling said thixotropic emulsion through an opening in the container onto or in the path of a fire.
Claim 3
Dependent Claim
21 words
The fire extinguisher of claim 1 wherein the water in said emulsion is present in at least about 90% by volume.
Claim 4
Dependent Claim
15 words
The fire extinguisher of claim 1 wherein the emulsion contained therein includes a fire retardant.
Claim 5
Dependent Claim
20 words
The fire extinguisher of claim 1 wherein the emulsion contained therein has as an emulsifying agent an oxyalkylated hydroxy compound.
Claim 6
Dependent Claim
28 words
The fire extinguisher of claim 4 wherein the oxyalkylated hydroxy compound is prepared by oxyalkylating 1,3-butanediol with butylene oxide, propylene oxide and ethylene oxide in the order given.
Claim 7
Dependent Claim
17 words
The fire extinguisher of claim 1 wherein the emulsifiable oil in the emulsion contained therein is kerosine.