Smoke composition and method of making same
AssigneeHer Majesty the Queen in right of Canada, as represented by the Minister of National Defence
InventorThomas Liberman
Life of this patent
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Abstract
A composition for producing smoke from phosphorus vapor for use in search and rescue markers and a method of producing such composition. The composition comprises a blended mixture of the following ingredients in the following weight percentage ranges: red phosphorus--55% to 80%; oxidizing agent (sodium nitrate or ammonium nitrate)--10% to 30%; metal fuel--5% to 10%; acid absorber--1% to 5%; and synthetic rubber binder--1% to 8%. Such a composition tends to be more stable and reliable than previous compositions used for this purpose, as well as less hazardous to manufacture. In addition, it permits an increase in the proportion of red phosphorus used, with a resultant increase in burn time and/or flame and smoke emission.
Claims31
A composition for producing smoke from phosphorus vapor, the composition comprising a blended mixture of the following ingredients in the following weight percentage ranges:
- red phosphorus--55% to 80%;
- oxidizing agent selected from the group consisting of sodium nitrate and ammonium nitrate--10% to 30%;
- metal fuel--5% to 10%;
- acid absorber--1% to 5%;
- and
- synthetic rubber binder--1% to 8%.
A method of making a composition for producing smoke from phosphorus vapor, the method comprising the steps of:
- (a) mixing sufficient red phosphorus to give a weight percent in the final composition in the range of 55% to 80% with sufficient metal fuel to give a weight percent in the final composition in the range of 5% to 10% and sufficient acid absorber to provide a weight percent in the final composition in the range of 1% to 5%;
- (b) dissolving the synthetic rubber binder in a suitable organic solvent to provide a binder solution, wherein the weight percent of the binder in the final composition is in the range of 1% to 8%, and adding the binder solution to the mixture resulting from step (a);
- (c) mixing the ingredients of the preceding steps to form a mixture of pasty consistency;
- (d) adding to the mixture sufficient oxidizing agent selected from sodium nitrate and ammonium nitrate to give a weight percent in the final composition in the range of 10% to 30% and stirring the mixture to blend the oxidizing agent evenly into the mixture and form a homogeneous paste;
- and
- (e) drying the mixture to remove substantially all of the solvent.
Dependencies are inferred from the claim text.