US1999828A - Nitrated polyhydric alcohol emulsion and process of producing - Google Patents

Description

Patented Apr. 30, 1935 NITRATED POLYHYDRIC ALCOHOL EMUL- SION AND PROCESS OF PRODUCING David R. Wiggam, Centerville, Del., assignor to Hercules Powder Company, Wilmington, DeL, a corporation of Delaware No Drawing.

Application November 28, 1932,

Serial N 0. 644,690

18 Claims.

This invention relates to a nitrated polyhydric alcohol emulsion and process of producing.

' Primarily the emulsion, in accordance with this invention, comprises a stable emulsion of a nitrated polyhydric alcohol in an aqueous solution of a water-soluble carbohydrate ether. The emulsion, in accordance with this invention, may be used as such an explosive for various blasting requirements, or it may be otherwise variously used, as, for example, for treating nitrocellulose gunpowder for the production of a double base powder.

In the preparation of the emulsion, in accordance with this invention, the sensitivity of the finished emulsion may be controlled within wide limits through regulation of the amount of water-soluble carbohydrate ether and/orwater included, Likewise the consistency of the finished emulsion may be controlled within wide limits, as from high viscosity to a semisolid, through regulation of the amount of nitrated polyhydric al cohol and/or water-soluble carbohydrate ether included in the composition.

As illustrative, the emulsion may comprise as the nitrated polyhydric alcohol, for example, nitroglycerin, a nitroglycol, a nitropolyglycol, etc., or mixtures thereof. The water-soluble carbohydrate ether may, for example, be methyl cellulose, a low substituted water-soluble ethyl cellulose, a water-soluble glycol cellulose, etc., etc.

In the preparation of the emulsion, the carbo hydrate ether will, preferably, be dissolved in water and the nitrated polyhydric alcoholadded gradually in small portions with vigorous agitation. The amount of nitrated polyhydric alcohol and of carbohydrate ether, and the relative proportions thereof, may vary widely and are not essential. However, the water-soluble carbohydrate ether will desirably be used in amount within, say, the range 3-10 parts in, say, 97-90 parts of water. The nitrated polyhydric alcohol will desirably be present in amount within, say, about the range 50%-95% of the finished emul- As illustrative of practical procedure, in accordance with this invention, for providing an emulsion embodying this invention, for example, 5 parts of methyl cellulose are dissolved in parts of hot water and the solution is allowed to cool. Then to 15 parts of the methyl cellulose solution are added 85 parts of nitroglycerin, the nitroglycerin being added in portions amounting to, say, about one part each and with vigorous agitation to eifect emulsification.

The product, which will contain 85% of nitroglycerin, will be highly viscous; will be relatively insensitive to shock, and will be adaptable for transportation with relative safety and for use, for example, as an explosive in shooting oil wells, underwater blasting, etc. 5

As more specifically illustrative of the safety of the emulsion, for example, compositions containing respectively, 66% and 75% nitroglycerin emulsified in a 6% methyl cellulose solution will not be detonated by a cm. drop in the stand- 10 ard impact test. By comparison nitroglycerin will be detonated consistently by a 5 cm. drop and tetryl will be detonated by a 75 cm. drop.

The emulsion in accordance with this invention may be rendered resistant to freezing, or 15 in other words, the emulsion may be rendered stable at low temperature, by the addition of an anti-freeze, as, for example, sugar, glycerin, glycol, or the like, to the water used in making the emulsion. An antifreeze, as, for example, sugar, 20 may be added in any suitable amount, as, for example, in amount within say the range 5%-50%.

By virtue of the use of a water-soluble carbohydrate ether in preparing the explosive in 25 accordance with this invention, as compared with a substance such as soap, gelatin, and the like, heretofore used in making nitroglycerin colloids, the emulsion is very stable chemically and resistant to the action of alkalis, acids, bacteria, 30 molds, etc. Superiority appears over soap which is alkaline and would afiect the nitroglycerin; over an acid emulsifying agent which would tend to cause decomposition of the nitroglycerin, and overgelatin which has a tendency to cause mold. 35

The emulsion embodying this invention also lends itself, as has been indicated, for use in the treating of nitrocellulose powder for the production of double base powder. Thus, for example, a double base powder may be produced through 40 surface treatment, by thoroughly mixing finely ground nitrocellulose powder with the emulsion described, allowing the mixture to stand and finally spreading out on trays anddrying in the ordinary smokeless powder dry house. The water will gradually evaporate from the emulsion, leaving on the surface of the grains of powder the nitroglycerin which will gradually penetrate the grains and come to an equilibrium through- 50 out the grains. The relatively small amount of nitroglycerin left on the surface of the grains will be too small to exert any appreciable effect on the ballistics of the double base powder so produced.

What I claim and desire to protect by Letters Patent is:

1. An emulsion comprising a liquid nitrated polyhydric alcohol, water and a water-soluble carbohydrate ether.

2. An emulsion comprising a liquid nitrated polyhydric alcohol from about 50% to about 95%, water and a water-soluble carbohydrate ether from about 0.1% to about 5%.

3. An emulsion comprising a liquid nitrated polyhydric alcohol, water and methyl cellulose.

4. An emulsion comprising nitroglycerin, water and a water-soluble carbohydrate ether.

5. An emulsion comprising nitroglycerin, water and methyl cellulose.

6. The method of emulsifying a liquid nitrated polyhydric alcohol which includes forming an aqueous solution of a water-soluble carbohydrate ether and adding a nitrated polyhydric alcohol to the said solution while agitating the solution.

7. The method of emulsifying a liquid nitrated polyhydric alcohol which includes forming an aqueous solution of a water-soluble carbohydrate emulsion of a liquid nitrated polyhydric alcohol in an aqueous solution of a water-soluble carbohydrate ether with grains of nitrocellulose powder to eflfect a coating of the grains with the emulsion and drying the powder grains.

10. An emulsion comprising a liquid nitrated polyhydric alcohol, water, an antifreeze and a water-soluble carbohydrate ether.

11. An emulsion comprising a liquid nitrated polyhydric alcohol, water, sugar and a watersoluble carbohydrate ether.

12. The method of emulsifying a liquid nitrated polyhydric alcohol which includes forming an aqueous solution of a water-soluble carbohydrate ether, and an antifreeze and adding a nitrated polyhydric alcohol to the said solution while agitating the solution.

13. An emulsion comprising a nitroglycol and a water-soluble carbohydrate ether.

14. An emulsion comprising a nitroglycol,-'