US2676878A

US2676878A - Gelatinized high explosive compositions

Info

Publication number: US2676878A
Application number: US208650A
Authority: US
Inventors: Glogau Richard Clyde
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1951-01-30
Filing date: 1951-01-30
Publication date: 1954-04-27
Anticipated expiration: 1971-04-27

Description

Patented Apr. 27, 1954 UNITED STATES ATENT OFFICE GELATINIZED HIGH EXPLOSIVE COMPOSITIONS No Drawing. Application January 30, 1951, Serial No. 208,650

7 Claims.

The present invention relates to a gelatin type dynamite composition, and, more particularly, to such a composition formulated in a Way to show improved characteristics.

This case is a continuation-in-part of my copending application Serial Number 14,159, filed March 10, 1948, now abandoned.

Dynamites produced for industrial uses must be manufactured to provide a variety of specific characteristics, such as strength, density, plasticity, and oxygen balance. The characteristics of an explosive composition are determined by the ingredients and the proportions of these ingredients. Dynamites having specified characteristics are prepared following strict formulations.

Due to the requirements of commercial users that for many operations the explosive composition be solid, cohesive and deformable, the socalled "gelatin dynamites constitute a very important type of dynamite. These dynamites are actually prepared in two categories, the true gelatin, which is a relatively smooth soft solid, and the semi-gelatin, which is more crumbly.

The gelatin compositions are produced by gelatinizing a liquid explosive nitric ester with nitrocellulose, and incorporating therein a number of solid materials. The solids most frequently introduced are oxidizing salts, combustible carbonaceous materials, and stabilizers. Nitroglycerin is the most commonly used liquid explosive nitric ester, and is generally mixed with other nitric esters which affect properties such as freezing point, etc. Throughout this description, the term nitroglycerin refers not only to the pure nitrocompound, but also that modified with additives such as ethylene glycol dinitrate.

The gelatin dynamites are packaged in paper shells, usually by an extrusion process. The complete combustion of this wrapper must be considered in formulating a dynamite composition to prevent the formation of objectionable lay-products from the explosion.

Addition of inorganic oxidizing salts not only permits supplying oxygen for the wrapper, but also affords a method of regulating the strength of the explosive per unit weight. By increasing the quantity of a salt such as sodium nitrate in the composition, a progressively weaker detonation strength may be obtained per unit weight of explosive, as well as an increase in the amount of available oxygen. The excess oxygen thus provided may, if desired, be utilized by including combustible carbonaceous materials in the composition' Since the inorganic nitrate does contribute to the force of the detonation, the eificiency of the charge is much greater than would be the case if inert materials were addedv to dilute the principal explosive ingredient.

A very important type of gelatin dynamites are the so-called ammonia gelatins, where a por tion of the liquid explosive nitric ester is replaced with ammonium nitrate. Ammonium nitrate is a high strength explosive compound, and. within limits, can be substituted for nitroglycerin without substantially altering the explosive characteristics of the composition. Such replacement is economically desirable, since the liquid nitric ester is more expensive than the ammm nium nitrate.

There is a definite limiting point, however, in the amount of solids which may be introduced without loss of the plasticity essential to extrusion and field use. This point is frequently reached before the desired explosive characteristics can be obtained, or before the replacement of the liquid explosive by ammonium nitrate is as great as desired. Since the plasticity require-- ment for use is similar to that for extrusion, for purposes of this invention, plasticity will be referred to in terms of extrudibility.

It is an object of the present invention to provide a means for increasing the amount of solid material which may be introduced into a gelatin without loss of plasticity. A further object of the present invention is to provide a means for increasing the proportion of liquid explosive nitric ester which may be replaced by ammonium nitrate without loss of plasticity in gelatin dynamites. Further objects will become apparent as the invention is further described hereinafter.

I have found that the foregoing objects may be attained by incorporating into a gelatin dynamite composition a small proportion of a salt of triethanolamine and a higher fatty acid blended with at least one monohydric aliphatic alcohol containing from 10 to 18 carbon atoms in the chain. Preferably, I employ triethanolamine oleate and blend it with a commercially obtainable mixture of monohydric aliphatic alcohols having from 10 to 18 carbon atoms. I further find it convenient, although not essential, to dilute this blend with a lower monohydric a1- cohol containing not more than five carbon atoms.

A suitable amount of triethanolamine oleatehigher alcohol blend is between 0.005 and 0.5% of the weight ofthe entire "composition, the blend being a 5U-50 ,mi ture. .A satisfact ry liquid 3 mixture is obtained by including a lower alcohol such as isopropyl alcohol to form a 25-25-50 ratio of oleate, higher alcohol, and lower alcohol respectively.

The following examples will serve as specific embodiments to illustrate compositions according to the present invention and the advantages inherent in them, but it will be understood that the invention is not limited to the specific examples.

Example 1 An 8000 gram mixing of a 40% ammonia gelatin was made in the following formula:

Percent Nitroglycerin 20.0 Dinitrotoluene 2.0 Nitrocotton 0.3 Ammonium nitrate 14.0 Sodium nitrate 49;0 Carbonaceous combustibles a- 7.9 Sulfur 6.5

Chalk 0.3

The ingredient designated as nitroglycerin-above was actually not that compound alone but a 70-30 blend with ethylene glycol dinitrate. In making the mixing, the nitroglycerin blend was introduced into the mixing bowl and 2 cc, of triethanolamine oleate and 2 cc. of a mixture of higher monohydrie aliphatic alcohols containing from 10 to 18 carbon atoms were added. The dinitrotoluene was added and then the nitrocotton, after which the mixture was agitated for about 5 min. until a viscous homogeneous liquid had resulted. Theremaining solid ingredients were then introduced and the whole was mixed for additional minutes. The plastic, gelatinous mass was removed from the bowl and extruded into openended paper shells of 1 A; in. diameter and 8 in. length, closedat one end. After filling, the open ends-of the shells were closed by'a crimp fold.

The explosive composition described extruded readily whereas .a similar composition, to which no addition of triethanolamine .oleate and higher alcohols had been made, could not be extruded. Actually, it had been the practice previously to include as much a 25% nitroglycerin or its equivalents in order to assure satisfactory working properties.

In a similar mixing, instead of additions of separate 2 cc. portions of triethanolamine oleate and higher alcohols, a single 2 cc. amount. of a 50-50 mixture-oi the two was added. Again satisfactory extrusion resulted.

Example 2 Mixings, amounting to 6000 grams each, were made in a similar manner of 40% and 60% ammonia gelatins respectively, the compositions being as follows:

The explosive mixings were made in accordance with the procedure of Example 1, except that in the case oi both the compositions of the present example a blend of triethanolamine oleate, higher aliphatic alcohols such as used in Example 2, and isopropyl alcohol was added in the amount of 0.12% by weight of this entire composition, the three ingredients of the blend being present in a proportion of 25%, 25% and 50%, respectively. Both grades of ammonia gelatins extruded without difficulty, although the customary minimum percentages of liquid explosive nitric ester used were 25% ;in the 40% grade and 29% in the 60% grade, instead of the 21% and 23.5% employed in the present example. Without the presence of any added blend, gelatinous explosives of such low percentages of nitroglycerin would be altogether unworkable.

Example 3 A 6000 gram mixing of what is known as a semi-gelatin was made, the following composition being used:

Per cent ,Nitroglycerin 16.0 Nitrocotton 0.3 Ammonium nitrate 67.2

Sodium nitrate 5.4 Carbonaceous combustibles 9.8

Sulfur 1.0

Chalk 0.3

In carrying out the mixing, the nitroglycerin was introduced into a mixingbowl maintained at around 52 C. The nitrocotton was then added, as well as an amount of 0.05% by weight of a blend of triethanolamine oleate, a mixture of higher aliphatic alcohols such as used in Example 2, and isopropyl alcohol, theselatter constituents of the liquid mixture being present in respective proportions of 25,25 and 50%. Agitation of the liquids in the mixing'bowl was then started and continued for-5 min.,after which the other solid ingredients were added and mixing continued until the proper plastic consistency was obtained. The explosive was then removed from the mixing bowl and charged into cartridges of "1%, in. diameter and8 in. length. Theuse'of the triethanolamine oleate blend made it possible to reduce the customary amount of liquid explosive nitric ester from 18.0% 0016.0 with no impairment of-the desired properties.

Example 4 A one hundred poundmixof a high strength, high oxygen contentgelatin dynamite composition was made in accordance with the following formulation:

Per cent Nitroglycerin 50.0 Nitrocotton 1.7 Sodium nitrate 2 39.0 carbonaceous combustibles 6.3 Sulfur 2.5 Chalk 0.5

During the mixing, 2 ounces of 2. 25-25-50 blend of triethanolamine' oleate, higher aliphatic alcohols, and isopropyl alcohol were added. The final composition extruded readily, and had the desired plasticity. Without the additionuof the blend, a composition of this type isunextrudable. This example illustrates the applic ability of the present invention to the non-ammonia type gelatins.

Example A one hundred pound mixing of an 80% ammonia gelatin dynamite composition was made following this formulation:

Per cent Nitroglycerin 31.5 Nitrocotton 1.2 Ammonium nitrate 54.7 Sodium nitrate 7.0 Combustibles 3.6 Sulfur 1.5 Chalk 0.5

During the mixing of the nitroglycerin and nitrocotton, 2 ounces of a 25-25-50 blend of triethanolamine oleate, higher aliphatic alcohol and isopropyl alcohol were included. The composition was readily extruded. Prior compositions of similar characteristics required 35% nitroglycerin to provide proper plasticity.

In carrying out the present invention, the reduction in the quantity of liquid explosive nitric ester is made possible by the introduction of the triethanolamine compound blended with a mixture of higher aliphatic monohydric alcohols containing from to 18 carbon atoms. In the examples, the mixture designated as Lorol alcohols was used, having a composition of 2.6% decyl alcohols, 61.0% lauryl alcohols, 23.0% myristyl alcohols, 11.2% cetyl alcohols and 2.2% steryl alcohols. Ihe addition of at least one monohydric alcohol containing not more than five carbon atoms, preferably isopropyl alcohol, is also desirable since it provides sufiicient dilution to facilitate proportioning and handling.

In the examples, the triethanolamine oleate blend was added prior to gelatinization for convenience. Experiments have shown that the results are similar if the blend is added during any stage of the mixing. Since the blend becomes dispersed in liquid nitric esters, better distribution is obtained by adding it prior to gelatinization. Also, while only triethanolamine oleate has been illustrated, similar results may be obtained using triethanolamine stearate, laurate, and other such soaps.

It is believed that the effectiveness of the blend is due to a lowering of the interfacial tensions between the liquid explosive nitric ester gel and the solid ingredients by the blend. This has been substantiated by experiments with nitroglycerin and ammonium nitrate, where greater wetting of the ammonium nitrate by the nitroglycerin was obtained in the presence of the blend.

The present invention is applicable to all types of gelatin dynamites where solid ingredients are to be included. For practical purposes, it may be stated that the present invention may find its greatest utility in compositions containing from to 70% liquid nitric ester, the remainder of the composition being solids such as inorganic oxidizing salts, carbonaceous combustible ingredients, and stabilizers. The invention is particularly important in the case of ammonia gelatins since a greater replacement of the liquid nitric ester is now practicable. In such dynamites, the liquid explosive nitric ester would constitute from 15 to 50% of the composition.

While the invention has been fully described in the foregoing, modifications in methods of procedure and details of composition may be made without departure from the scope of the invention.

I intend, therefore, to be limited only by the following claims.

I claim:

1. A gelatinized high explosive composition comprising from 15 to 70 parts by weight of at least one liquid explosive nitric ester, nitrocellulose, an inorganic oxidizing agent and from 0.005 to 0.5 part by weight of a blend of triethanolamine-fatty acid salt with at least one monohydric aliphatic alcohol having from 10 to 18 carbon atoms.

2. A gelatinized high explosive composition comprising from 15 to 70 parts by weight of at least one liquid explosive nitric ester, nitrocellulose, and from 0.005 to 0.5 part by weight of a blend of a triethanolamine-fatty acid salt with at least one monohydric aliphatic alcohol having from 10 to 18 carbon atoms.

3. A gelatinized high explosive composition as claimed in claim 2, wherein the blend consists of triethanolamine-oleate and a mixture of monohydric aliphatic alcohols having from 10 to 18 carbon atoms.

4. An ammonia gelatin type high explosive composition comprising from 15 to 50 parts by weight of at least one liquid explosive nitric ester, nitrocellulose, ammonium nitrate, and from 0.005 to 0.5 part by weight of a blend of a triethanolamine-fatty acid salt and at least one monohydric aliphatic alcohol having from 10 to 18 carbon atoms.

5. A gelatinized high xplosive composition comprising from 15 to 50 parts by weight of nitroglycerin, nitrocellulose, ammonium nitrate, sodium nitrate, carbonaceous combustible materials, and from 0.005 to 0.5 part by weight of a blend of triethanolamine oleate with a mixture of aliphatic monohydric alcohols having from 10 to 18 carbon atoms.

6. A gelatinized high explosive composition as claimed in claim 5, wherein the blend consists of equal parts of the triethanolamine oleate and the aliphatic alcohols.

7. A gelatinized high explosive composition as claimed in claim 5, wherein the blend is diluted with a monohydric alcohol of less than five carbon atoms.

References Cited in the file Of this patent UNITED STATES PATENTS Number Name Date 1,845,156 Kramer Feb. 16, 1932 2,009,028 Sibley July 23, 1935 2,211,738 Cairns Aug. 13, 1940 2,235,298 Olsen Mar. 18, 1941 2,272,847 Macht Feb. 10, 1942 2,545,270 Fordham et al Mar; 13, 1951 2,554,180 Fordham May 22, 1951 OTHER REFERENCES The Chemistry of Powder and Explosives, by T. D. Davis, vol. II, John Wiley and Sons, N. Y. (1943) pp. 288-289. (Copy in Scientific Library.)