US2033196A - Explosive composition - Google Patents

Description

Patented Mar. 10, 1936 UNlTEDi' STATES r PATENT OFFICE EIG'LOSIVE COMPOSITION Norman G. Johnson and Harold A. Lewis, Woodbury, N. J., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del.,

ration of Delaware 2. corpo- No Drawing. Application April 21, 1933, Serial No. 667,229

8 Claims. This invention relates to pulverulent dynamite compositions and more particularly to such compositions containing only a relatively small amount of sensitive liquid ingredient, but yet suilicient of such liquid ingredient that the hazard In recent years, the tendency has increasingly been to replace nitroglycerin by ammonium nitrate as far as possible because of Various advantages obtained, the replacement being limited, however, by the necessity ofmaintaining the proper degree of sensitiveness to detonation and propagation.

Nitroglycerin dynamites have been used with considerable satisfaction over a long period of years, and no other explosive material has been available that possessed the generally desirable properties of this compound as the desired sensitized ingredient. Nitroglycerin, however, has one objectionable property that has been a draw-back to its use, namely, that of causing severe headaches in the case of persons coming in contact with it, or breathing its vapors. This toxic property is possessed not only by nitroglycerin, but by all the aliphatic liquid nitric esters.

,Various explosives have been suggested and used on a. limited scale which consisted of all solid ingredients. and such explosives have been free from the undesirable physiological effects produced by nitroglycerin and explosives containing it. The various nitrostarch dynamites are one example of such explosives and have had considerable use in America. Nitrostarch, however, is a material relatively insensitive to detonation, and considerable difiiculty has been encountered in producing uniformly sensitive and satisfactory explosives of this type. Moreover, it is an amorphous material, dusty in nature, so that there is a certain degree of hazard connected with the mixing and handling of such explosives. Nitrostarch also is of a lower order of stability than nitroglycerin, so much so that its use has never been approved in European explosives.

The object of our invention is to provide an improved explosive composition free from headacheproducing. properties. A further object is such an explosive, the sensitiveness of which is uniform and can be readily controlled within the desired limit. A still further object is an explosive consisting essentially of solid ingredients, but one which is not dusty in nature and not unduly sensitive to shock. Further objects will present 5 themselves as the description of the invention proceeds. I

The foregoing objects are accomplished, according to our invention, by the production of a pulverulent dynamite composition containing 10 pentaerythritol tetranitrate and a relatively small amount of a liquid ingredient. While the use of any liquid will be advantageous in reducing the dusty nature of such solid explosives, it is essential for our purpose that a non-volatile liquid 15 be employed in order that no change in composition may take place in the explosive during storage. Water is not a suitable liquid for this use because of its solvent and hydration effects on various inorganic ingredients that may be 20 present in the explosive composition.

Preferably ammonium nitrate will be an ingredient of the explosive composition according to our invention, along with the pentaerythritol tetranitrate. Ammonium nitrate is economically 5 available and possesses great strength as an explosive when present with satisfactory sensitizing agents, and for these reasons is a desirable component. Pentaerythritol tetranitrate in such explosive compositions not only acts as a very power- 30 ful explosive itself, but serves also as a sensitizer and booster in bringing about the complete detonation of the ammonium nitrate at its maximum strength.

As stated previously, various non-volatile and 35 non-aqueous liquids may be used in our explosive compositions with the object of reducing the dusty nature of the pulverulent mixtures. For example, we may employ a non-volatile oil, such as engine oil. Also, a relatively small amount of a 40 non-volatile liquid aromatic nitrocompound may be used, such as, for example, liquid dinitrotoluene. We may also incorporate in the explosive composition an aliphatic liquid nitric ester of a polyhydroxy alcohol. ferred liquid compound of this class, and it is this type of explosive which we find most valuable.

The choice of liquid ingredient in the explosive compositions will affect the proportions of other ingredients present. If engine oil or other petro- 50 leum hydrocarbon is used, this ingredient has a marked desensitizing effect and a higher percentage of sensitive explosive material, such as pentaerythritol tetranitrate will then be necessary.

If nitroglycerin is present, on the other hand, it 55 Nitroglycerin is the pre- 45 will be possible to use a decreased amount of pentaerythritol tetranitrate and a correspondingly larger percentage of ammonium nitrate, and still obtain a satisfactory degree of sensitiveness. In such a composition nitroglycerin will be the primary sensitizing agent. Liquid dinitrotoluene and other liquid aromatic nitrocompounds are intermediate, with respect to sensitizing effect, between'the two types of liquids previously discussed. Preferably we use the liquid ingredient of our explosives in an amount between 0.2 and 5.0%. The use of less than 5% of engine oil for example is desirable, since a larger amount would make the explosive composition too insensitive to detonation and propagation. In the case of liquid aliphatic nitric esters, the use of not more than 5% has the advantage that the explosive thus obtained is essentially a non-headache dynamite because of the small percentage of liquid nitric ester present. Less than 0.2% of liquid is undesirable, since such small amounts do not have tile desired efi'ect on the properties of the explos ve.

As previously stated, ammonium nitrate will preferably be included in our explosive compositions. Similarly, sodium nitrate may be present in its usual capacity as oxidizing agent, as well as carbonaceous combustible ingredients, acidaccepting materials, and other customary constituents of dynamite compositions.

The following examples are illustrative of compositions made according to our invention, containing pentaerythritol tetranitrate and the three types of liquids described in the foregoing:

I 11 HI Pentaerytliritol tetranitrate. 35.0 12.0 16.0

ngine 0. 5 Liquid dinitrotoluene N itroglycerin 3. 0 Ammonium nitrat 66. 5 50. 0 Sodium nitrate 56. 0 10.0 21. 0 Sulf 5. 0 Carbonaceous combustible materials 9. 0 9. 5 h lk 3. 5 0. 5 0. 5

sive compositions containing ammonium nitrate in which PE'I'N was present. His compositions, however, contained solid ingredients only and did not include any liquid ingredient such as is present in our compositions and which is advanta- Von Herz, for example, discloses geous in reducing the hazard of dustiness during mixing and handling, and which gives a beneficial sensitizing effect, when nitroglycerin or other similar liquid nitric ester is employed.

Pentaerythritol tetranitrate compositions have been disclosed by Stettbacher also, and U. S. Patent 1,867,287, for example, illustrates his compositions. Stettbacher, however, was considering plastic explosives only, and his .invention was directed to such compositions. A plastic mixture was obtained by the combined use of nitroglycerin and pentaerythritol tetranitrate in varying proportions, and these plastic mixtures were then diluted with oxidizing agents and other ingredients. A plastic mixture was maintained throughout, and such explosives are quite different from the pulverulent dynamites of the present application.

Our invention has been described in detail in the foregoing, but it will be apparent that various departures may be made from the specific compositions disclosed in the foregoing example. While nitroglycerin has been employed as the liquid nitric ester, it will be understood that we may substitute for this various other liquid aliphatic nitric esters such as ethyl nitrate, ethylene glycol dinitrate, nitrated chlorhydrins, tetranitrodiglycerin and the like.

We intend, therefore, to be limited only as indicated in the following patent claims.

We claim:

1. A pulverulent high explosive composition, comprising pentaerythrite tetranitrate and a relatively small amount of a non-volatile liquid aromatic nitrocompound.

2. A pulverulent high explosive composition,-

comprising pentaerythrite tetranitrate and a relatively small amount of liquid dinitrotoluene.

3. A pulverulent dynamite composition, comprising pentaerythrite tetranitrate and a relatively small amount of a non-volatile liquid nitric ester.

4. A pulverulent dynamite composition, comprising pentaerythrite tetranitrate and a liquid nitric ester of a polyhydroxy alcohol in the amount of 0.2 to 5.0%.

5. A pulverulent dynamite composition, comprising pentaerythrite tetranitrate, at least one inorganic oxidizing agent, and a liquid nitric ester of a polyhydroxy alcohol in the amount of 0.2 to 5.0%

6. A pulverulent dynamite composition, comprising pentaerythrite tetranitrate and 0.2 to 5.0% nitroglycerin.

7. A pulverulent dynamite composition, comprising pentaerythrite tetranitrate, ammonium nitrate, carbonaceous combustible material, and 0.2 to 5.0% of nitroglycerin.

8. A pulverulent dynamite composition comprising pentaerythrite tetranitrate and a liquid nitrated organic compound.

NORMAN G. JOHNSON. HAROLD A. LEWIS.