US2159973A - Gelatinized high explosive composition and method of preparation - Google Patents

Description

UNITED STATES PATENT OFFICE GELATINIZED HIGH EXPLOSIVE COIVIPOSI- TION AND ll/[ETHOD OF PREPARATION Walter Eastby Lawson, Woodbury, N. J., assignor to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application April 1, 1938, Serial No. 199,446

13 Claims. (Cl. 52-13) This invention relates to the preparation of a e (C 3 N 2), mehemethylfermemide gelatinized high explosives, and more particu- 0H3 larly to the acceleration of the gelatinization of r nitrocellulose with nitroglycerin and with nitro- 5 glycerin solutions of aliphatic nitric esters or H nitrocompounds. dimethylformamide 5 It is known that, when certain otherwise de- CH3 sirable nitrated materials are present dissolved in the nitroglycerin, the gelatinization of the (HTJOTN solution with nitrocotton is undesirably slow and 011i 0 in many cases incomplete. When such incomdimethylacetamid (CH3--CON(CH3) a), diplete gelatinization takes place, the finished exmet-amide ((CH CO) --NH), propionamide, plosive is unsatisfactory in its properties and debutyramide, and many others, t ri rates mar d y under conditions of e It is important to note that dimethylformamide t e St e, Particularly from the Point Of View is the preferred gelatinization accelerant ac- 15 of consistency and plasticity of the gelatinized ng to the present invention. It should be material and exudation nitroglycerin thereunderstood that this particular compound is not r s problem has been Studied Previously, merely the equivalent of the others listed but and proposals have been made for its solution, is superior th re ver,

for example y Moran in Patent 1,640,712 The use of a gelatinization accelerant of the and y FeSSneeht in 3 Patent 1,966,099- acid amide type, according to my invention, will The je t of the Present invention is a new have advantages in gelatinized nitroglycerin high and mpro ed high eXDIOSiVe Composition explosives generally but will be particularly efiiteining e geletihized liquid nitric ester of cacious where tetranitrodiglycerin is present in De p p A further Object is Such a solution in nitroglycerin, since such solutions at- 25 Composition in which the geletinizatieh with tain outstanding improvement thereby. The introcellulose has been accelerated and the propvention is app with high emciency in the erties of the finished Product thereby imprevedcase of the standard straight and ammonia gela- A s ill f rther o e i a nov l pr c ss for ri gtin dynamites, as well as with the so-called semi- :ti) ing about the aforesaid accelerated gelatinizagelatins, where smaller percentages of nitrocel- 0 tion. Additional objects will be disclosed as the lulose are present and less complete gelatinizainvention is described more at length hereintion is effected. By its utilization, not only does after. acceleration result, but a more uniform and I have found that the foregoing objects are completely gelatinized product is obtained. accomplished by incorporating with the nitro- For a more exact understanding of my inven- 35 glycerin an acid amide of a monobasic fatty acid tion, the process of producing the improved geor an alkyl derivative thereof. The acid amide latinous high explosives 'is illustrated below. for use according to my invention will have the Example 1 formula 40 n, The amounts of ingredients used in this ex- 40 ample are based on the production of a 100 lb. mixing of an ammonia gelatin dynamite. 25 lbs.

of nitroglycerin, containing dissolved tetranitroin which R1, R2, and Ra consist either of hyf i was lntrgduceg g i 'g ggzt g g gi drogen or an alkyl radical. As an exam le the mlxmg was ma an y p amide was added to the nitroglycerin and disf m and Its alkyl defwatives very f solved therein. 0.65 lb. of a suitable nitrocotaccelerants accordmg to my mventmn' ton was then introduced into the nitroglycerin. m wmch Case R1 represents hydrogen when The mixture was agitated, while maintaining the represents CH3 group the accelerant Wm be temperature at approximately 120 1?. When the 50 acetamide or an alkyl derivative thereof. R2 and solution had thickened r gelatinized t th R3, likewise, m y represent either hydlegen proper degree, the solid ingredients of the dyalkyl groups- AS Spec examples 0! e pe namite, already thoroughly mixed, were added advantageous for use as gelatinization accelerfor incorporation. These ingredients comprised ants,1may cite formamide (HCONH:),acetapproximately 7.8 lbs. ammonium nitrate, 51.2 5

For the manufacture of a lb. mixing of a semi-gelatin containing a gelatinization accelerant according to my invention, 20 lbs. of nitroglycerin was introduced into the mixing bowl, and 0.15 lb. of dimethylformamide and 0.20 lb. nitrocotton were introduced into, and incorporated with, the nitroglycerin, as in Example 1. The proper amounts of solid ingredients were then thoroughly mixed with the liquid ingredi- 1 ents, a temperature of again being maintained.

The explosive compositions made in accordance with my invention possessed very marked superiority, not only over similar compositions containing no specific gelatinization accelerant, but also over compositions containing accelerants of the prior art. In the case of 40% ammonia gelatins, for example, containing the accelerant of my invention and tetra-nitrodiglycerin dissolved in the nitroglycerin, the explosive was free from leakiness after long-time storage under severe conditions and retained its initial high degree of plasticity, Similar retention of the initial desired properties was observed in the case of the semi-gelatins, also, and other gelatinous high explosives.

The increased acceleration of gelatinization brought about by operation according to my invention may be strikingly illustrated by the results of some smallscale gelatinization tests, where the time of flow of gelatinized nitroglycerin was measured when different accelerants were used. Using 50 grams of nitroglycerin and suificient nitrocotton to give the desired range of flow speeds, the weights of material required for the same rate of flow, and consequently for the same approximately F.

degree of acceleration, were as follows:

Grams Dimethylformamide 0. 15 Ethyleneglycolmonoethyl ether 0.40 'Dinitrotoluene 4. 50

The superiority of dimethylformamide as an example of my invention is illustrated in the above, since only 0.15 gram produced an acceleration equivalent to 0.40 gram of one of the best accelerants of the prior art. This improvement will be appreciated whemit is realized that, with no accelerant present, the amount of nitrocotton used in the foregoing experiments was insufficient to produce the same stage of gelatinization in 24 hours, whereas the results cited were obtained over an interval of 20 minutes.

Varying amounts of the acid amide accelerant may be used, preferably in an amount between 0.1 and 5.0% of the nitroglycerin present. My preferred range is between 0.5 and 2.0% of the weight of nitroglycerin.

In carrying out my invention and obtaining the consequent improved properties, nitroglycerin may be used alone as the liquid explosive nitric ester, if desired. Likewise, other liquid nitric esters may be employed, such as ethylene glycol dinitrate, either by itself or with nitroglycerin. Furthermore, variousother nitric esters and nitrocompounds may be present also, dissolved in the liquid nitric ester, thereby imparting varying properties to the liquid explosive, such as improved resistance to freezing, etc. Such added nitrated materials may be cited as tetranitrodiglycerin, nitrated sugars, nitrochlorhydrins, aromatic nitrocompounds, and the like. While I have described the use of an acid amide according to my invention as the sole accelerant, it should be understood that I may, if desired, also employ such an amide together with an accelerant of the prior art, for example ethyleneglycol monoethylether, and thereby gain important advantages.

It will be understood that many variations, in details and in compositions, from those described in the foregoing may be made without departure from the scope of my invention. I intend to be limited, therefore, only by the following patent claims.

I claim:

1. A high explosive composition comprising a liquid explosive nitric ester gelatinized by means of nitrocellulose, and an acid amide having the formula R in which R1, R2, and R3 are taken from a group consisting of hydrogen and the alkyl radicals.

2. A high explosive composition comprising a liquid explosive nitric ester gelatinized by means of nitrocellulose, and a gelatinization accelerant taken from the group consisting of the acid amides of the monobasic fatty acids and their alkyl derivatives.

3. The explosive composition of claim 2, in hich the gelatinization accelerant is formamide.

4. The explosive composition of claim 2, in which the gelatinization accelerant is acetamide.

5. The explosive composition of claim 2, in which the gelatinization accelerant is dimethylformamide.

6. A high explosive composition comprising a solution of tetranitrodiglycerin in nitroglycerin, said solution being gelatinized by means of nitrocellulose, and a gelatinization accelerant taken from the group consisting of the acid amides of the monobasic fatty acids and their alkyl derivatives.

7. A gelatinized nitroglycerin high explosivecomprising nitroglycerin and nitrocellulose, and a gelatinization accelerant taken from the group consisting of the acid amides of the monobasic fatty acids and their alkyl derivatives, said accelerant being present in an amount between 0.1 and 5.0% of the nitroglycerin present.

8. The process of accelerating the gelatinization of nitrocellulose with a liquid'explosive nitric ester, which process comprises bringing about said gelatinization in the presence of an acid amide having the formula in which R1, R2, and R3 are taken from the group consisting of hydrogen and the alkyl radicals.

9. .The process ofaccelerating the gelatinization of nitrocellulose with nitroglycerin con* taining dissolved tetranitrodiglycerin,- which process comprises bringing about said gelatinization in the presence of a gelatinization accelerant taken from the group consisting of the acid amides of the monobasic fatty acids and their alkyl derivatives.

12. A high explosive composition comprising ethylene glycol dinitrate gelatinized by means of nitrocellulose, and a gelatinization accelerant taken from the group consisting of the acid amides of the monobasic fatty acids and their alkyl derivatives.

13. The explosive composition of claim 12 in which the gelatinization accelerant is dimethyl iormamide.

WALTER EASTBY LAWSON.