US2425310A - Explosive - Google Patents

Description

Patented Aug. 12, 19 47 ZAZSJ a EXPLOSIVE Hartwell Henry Fassnacht, Wenonah, N. J., and Clifford Akeley Woodbury, Media, Pa., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application April 28-, 1943, Serial No. 484,862

4 Claims. 1

This invention relates to a new type of high explosive composition and more particularly to a plastic composition possessing very desirable properties.

The usual type. of plastic high explosive for commercial use comprises the gelatin dynamites, which are based on gelatinized nitroglycerin as the principal explosive ingredient. Such explosives are excellently adapted for certain applications in that they possess high densities and consequent high loading strength, fill the borehole compactly :because of their plasticity, and. have high water resistance. One drawback comes in the fact that such explosives, while possessing initial high velocity of detonation, do not retain this velocity after storage for considerable periods. of time.

Plastic explosives. of the above highdensity characteristics would be valuable for military uses also, but it is essential there that consistently high velocity be attained in avery short intervalof time even with relatively small charges-and that such velocity be retained even after long period storage- Itwould" be desirablealso, insuch uses that the explosive charge should be sufficiently insensitive to shock that it'would be incapable of initiation by. a rifle bullet, for example.

An object of thepresent invention is a plastic explosive composition possessing a high velocity of detonation and capable of retaining such high velocity characteristics for a long periodof time. An additional object issuch an explosive that possesse'shigh strength and high detonation velocity; A further object is a plastic explosive that is relatively insensitive to shock. A still further object is an explosive composition containing tetryland nitroglycerin orother liquid nitrate'd; organic compound. Additional objects will be disclosed as the invention is described more at length in the following.

We have found that the foregoing objects are attained by our invention, according to which the explosive composition contains a liquid-nitrated organic compound capable of gelatini'zation with nitrocellulose, tetryl and nitrocellulose. The liquid gelatinizable compound will in many cases be nitroglycerin, 'but may include also materials dissolved in nitroglycerin and; functioning as freezing point depressants. or. otherwise. Furthermore, the composition may-be free from nitroglycer-in and may comprise liquid nitrated compounds such as the aromatic nitrocompounds, for example a suitable blend of nitrotoluenes. Tetryl will be present and will serve to give a'satisfactory degree of sensitiveness to the compositions. The nitrocotton or other form of nitrocellulose will be dissolved in the liquid nitrated compound and will efiect gelatinization thereof, so that a desirable degree of plasticity will be assured.

Mononitrotoluene Dinitrotoluene. Trinitrotoluene gitrocotton etr Calcium Carbonate- Velocity ofD etonation, M/Sec In the foregoing compositions, A contains nitroglycerin, with a certain amount of dissolved dinitrotoluene and a high percentage of tetryl. The compositions B and C are free from nitro-' glycerin and contain blends of mono-, di--, and trinitrotoluene such as to make fluid mixtures capable of gelatinization by means of the nitrocotton present. D and E are gelatinous compositions of higher nitroglycerin content and free from nitrocompound's; E- representing a blasting gelatin type. All'the foregoing compositions-are sensitive to the action of a blasting cap, but the inclusion of'nitrocompounds in A,-B, and C rendered these incapable of'initiation by the impact of a rifle bullet. Such insensitive gelatinous" explo'sives would b'e desirable in military operations where relatively safe but powerful demolition agents are desirable.

While the compositions cited have been such as to be'sensitive' to theaction of a commercial blasting cap, this degree of sensitiveness is riot essential. Our invention is intended to include also compositionsfof a lower degree of sensitiveness where not even se'veral blasting capstogether will-bring about detonation and where the action' of an intermediate booster charge of a powerful explosive is'necessaryi The plastic explosives of our invention may Vary widely in'composition'. We'findit desirable in the case of nitroglycerin compositions, however, to employ between 5 and% nitroglycerin; 0.1 to 7.0% nitrocotton'; 7.0 to;0% tetryl; and 0.1 to 1.0% calcium carbonate as an antacid material. When nitrotoluenes' or other nitrated compounds are used alongwith the nitroglycerin, they will replace aportion of this latter. When no nitroglycerin is present, the content 'of'nitro- 3 As has been stated, dissolved materials may be present in the nitroglycerin, and such compounds as tetranitrodiglycerin, ethyleneglycoldinitrate, nitrated products of higher aliphatic alcohols and aromatic nitrocompounds may be used for the pursugars, nitrochlorhydrins, nitration The above compositions are of the straight dynamite type, where tetryl replaces a portion of the nitroglycerin, where the percent strength is designated by the nitroglycerin content, since no other explosive ingredient is ordinarily present, In the case of compositions F and G, these pose of inhibiting freezing, controlling sensitive-.

ness, etc. As nitrocompounds for use, we may employ nitrobenzene, nitrotoluenes, nitroxylenes, nitronaphthalenes, and the like. If such nitrocompounds are used in the absence of nitroglycerin or other such liquid explosive compounds, it is desirable that a liquid mixture be formed in which crystallization or freezing will not occur under wide temperature variations. A blend of nitrotoluenes of varying degrees of nitration is suitable for such use.

Various forms of nitrocellulose are applicable as the gelatinization agent for the liquid ingre dient, but nitrocotton of the type commonly used in gelatin dynamites is very suitable. Small amounts of gelatinization accelerants or plasticizers may be employed to control or improve the qualities of the gelatins, for example dimethyl formamide, monoethylglycollate and the like.

The tetryl may be the typical grade in common use. In order to prevent dustiness and unduly high sensitiveness of the dry ingredient, however, it will be preferable to employ a tetryl product coated with a small amount of wax, oil, or grease such as a suitable petrolatum product applied by any desired method. We may, for example, use tetryl having a coating of 0.1 to 5.0% of a parafiin hydrocarbon not fluid at ordinary temperatures, i. e., having a melting point distinctly above the temperatures encountered during storage and use of the explosive.

The compositions cited'in the foregoing examples are deficient in oxygen content for complete combustion of the carbon and hydrogen to carbon dioxide and water respectively. The large amount of carbon monoxide formedon explosion will make such explosives unsuitable for use in confined places such as tunnels and underground metal mines. The matter of fumes is of less importance in many types of military applications and for certain commercial blasting. If an improvement in fumes is desired, this may be accomplished by the inclusion of oxygen-supplying ingredients in the formula, for example sodium nitrate or ammonium nitrate, in amounts sufiicient to effect complete combustion of carbon and hydrogen. The use of such oxidizing agents will be understood to be included within the scope of this invention.

The explosive compositions described in the foregoing have been of the gelatinous type where either nitroglycerin or other liquid nitrated organic compound has been gelatinized by means of nitrocotton. The invention is intended to include also all nitroglycerin compositions containing tetryl to supplement the explosive force of hi. troglycerin. The following will serve as specific embodiments of such compositions:

may be considered as of 50% strength each, as tetryl is substantially the equivalent of nitro glycerin in strength at the oxygen balances shown.

The explosives according to our invention have many outstanding advantages. They possess the property of high velocity detonation, which is retained for long periods of time even under adverse storage conditions. When explosion takes place, the explosives detonate consistently at high velocities. They possess, also, high strength and high explosion pressures, good fragmentation capabilities, and excellent cutting and demolition properties. In addition, they are resistant to the effects of Water and moisture and remain plastic over a wide temperature range (0-110" F.), so that they can be molded as desired. This latter property is important in demolition explosives. Along with their satisfactory sensitiveness to blasting caps, the preferred gelatins are insensitive to the action of rifle bullets and other similar impacts.

Our invention has been described fully in the foregoing, but it will be understood that many variations may be introduced in the compositions of explosives used without departure from the scope of the invention. We intend to be limited only by the following patent claims.

We claim:

1. An explosive composition comprising 'between 5 and of a liquid nitrated organic compound taken from the group consisting of aliphatic liquid nitric esters and aromatic nitrocompounds, to 7% tetryl and 0.1 to 7.1% nitrocellulose.

2. An explosive composition comprising between 5 and 85% nitroglycerin; 0.1 and 7.0% nitrocellulose, and 89.8 and 7.0% tetryl.

3. The explosive composition of claim 2, in which at least a portion of the nitroglycerin has been replaced by an aromatic nitrocompound.

4. An explosive composition comprising a blend of nitrotoluenes in liquid form in the amount of 10 to 50%, between 0.1 and 3.0% nitrocellulose, and 40-90% tetryl.

HARTWEIL HENRY FASSNACHT. CLIFFORD AKELEY WOODBURY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number