US1386437A - Nitrostarch explosive - Google Patents

Description

PATENT OFFICE,

' UNITED STATES WALTER o. Sunni-me, or ALLENTOWN, immisvnvnnm, ns'srenon, BY MESNE ASSIGNMENTS,- TO TROJAN'POWDEB, PORATION OF NEW YORK j COMPANY, OF NEW YORK, iv. Y.,.A con nnrnosre'non nxrLosIvEj.

No Drawing.

To all whom it may concern: 7

.Be it known that I, WALTER O. SNELLING,

a citizen of the United States, andresident' an explosive which will have great strength and at the same time be relatively insensitive to blows or friction. This combination of qualities is essential or desirable in certain classes of military. explosives, for ex-v ample for use as an explosive charge" in drop-bombs, and sea-mines, and for other uses. 7

Nitro-starch is itself a powerful explosive, and its strength is not materially. decreased by the presence of alimited amount The water does not prevent detonation by an initial detonating means of suflicient strength, and owing to the-intense heat produced at the instant'of explosion, the water present serves to increase the volume of gas which is produced. The pres ence of water in sufiicient quantity to thoroughly wet thenitro-starch grains has the effect of rendering the explosive relatively insensitive toflblo ws or friction.

As however the water will evaporate when the wet nitro-starchis exposed to the air. the properties of the explosive mixture will rapidly change underthe conditions ciclent to practical use. To avoid this, I- mix with the nitro-starch and water, in suitable proportions, a substance soluble in water and having sufficient affinity therefor to pre-' vent ready evaporation of the water when the mixture is exposed to the air, and I have discovered that in this manner highly useful explosives can be prepared having both the required strength and insensitiven'es's to blows or friction, Y

I have found both inorganic and organic substances possessingthe required hygro scopicity for the purpose stated. Examples of inorganic salts" are calcium chlorid and magnesium chlorid.- As howeverthese' salts are explosively inert, and to obtain maximum strength it is desirable that no .inert material shouldbe present, I prefer'to use a salt which is not only highly deliquescent, but which through its decomposition upondetonation of the mixture, adds .to the Specification of Letters Patent.

Application filed October a, 1918.. Serial No. gsavsl Y Patented Aug. 2,1921.

v, strength of theexplosive. As active inorganie agents, Iinstance thenitrates of am mon1um, calcium, iron and lithium, which are highly hygroscopic" and particularly well adapted to the purpose of my inven tlon. Ammonium nitrate is the salt: preferred.

Of organic materials suitable to the prajct1ce of my invention, dextrose and levulose have been found to .be quite satisfactory, either alone or admixed-1 Ordinary invert sugar serves very well, and commercial glucose is satisfactory, Other organic'materials possessin may be employed,

By varying the proportions of'the several ingredients referred to, the physical char-v actertstics of the explosive (32111136 regulated as desired, to suit different purposes. For example, with v a mixture containing 50% 'nitro-starch, the deliquescent ingredient, say ammonium nitrate may represent 40% and the "water 10%. This mixture is soft andplastic. A mixture containing50% nitroestarch, 45% ammonium nitrate and nitrate, and 13%- consistency. r

f With mixtures containing a higher percentage-of nitro-starch, as from to 75%, the ammonium nitrate and-water will represent from 40% to 25%, and of the :soluti0n 0f ammonium nitrate in water, less tl1anl,65 should be ammonium nitrate. such mixture the percentage of Water is ofwater, is of semi-fluid preferably more than 10% ofthe entire mixtemperature thewater' will nothold insm lution more than approximately double its 105 weight of ammoniumnitrate, it willbe ap I parent that in some ofthe examples given the water willnot be suflicient to hold in solution the entire amount of deliquescent salt-present, but as'in'any event the water 1 10 9; sufficient hydroscopicity of water, is quite while one con 7 taming 50% nit-ro-starch, 37% ammonium present Willbe in excess of 5% of thetotal mixture,'it Will be sufiicient to hold in solution a substantial amount of thedeliques cent salt.

The proportions given for ammonium ni- V trate apply substantially with other hygro scopic ingredients employed for the same purpose, including named. V V

In the preparation of nitro starch explosives according tomy invention, I may. directly mix together the three constituents in suitable proportions, using any type of mixer which will insure thorough incorporation, or I may add together the Water and the water soluble ingredient to obtaina concentrated solution, and this solution may then be 'added to the nitro-starch With properincorporation. -t i It will be understood thatinstead'of a sink gle deliquescent material, I can use a combination of such materials. For example, the deliquescence, of ammonium nitrate can be increased by the addition thereto of a. small amount-say 1%--of a related .deliquescent salt, such as lithium nitrate or sodium'nitrate. k i I It Will also be understood thatin' utilizing the explosive described, it can be incorporated with a suitable carbonaceous or, combustible ingredient, in accordance with the practice in. this art. e

A characteristic of explosives made in accordance- With my invention is their great strength, particularly their exceptional shatv tering strength and their relativelygreat insensitiveness. Their insensitivenessis due; to the fact that the nitro-starch grains are thoroughly wet with the solution of the deliquescent material in Water, andtheaction of the deliquescent material prevents the ready evaporation of the Water from any exposed surface of the material. The exceptional strength which these explosives show is due to the fact that nitro-starch is capable of detonating, even ,in the Wet condition, that this nitro-starch is.capable of bringing about the simultaneous detonation of the wet ammo nium nitrate-in those explosives in which ammoniumnit-rate is the deliquescent agent used, and that even thewater which. is pres.- entin'the mixture causes an increased gas volume at the moment of detonation owing to-the intense heat producedat the time of explosion, all of the constituents thus assisting in the production ofa very great gas volume at the moment of explosion. V V

AlthoughI have described certain specific mixtures of nitro -starch, ater and Water soluble materials having afiinity for'water, I

, do not Wish in the broader .aspect of theinvention, to be limited to thehygroscopic materials specified, nor proportions named, since my invention is broadly applicable tovexplosives containing nitro-starch, a deliquescent soluble material.

those herein specifically insuch amount-as to becapableot'holding in solution-a substantial amount of the Water ,I la I deliquescent salt, and sufiicient Water to hold in solution a substantial amount of the deliquescent salt.

- 2. A nitrostarch' explosive comprising nitro-starch mainta ned in Wet-condition by theadditlon ,of rvater containlng a dissolved salt having great afiinity. for Water.

A ,nitro-starch explosive containing Water, and an ingredient having suflicient afiinity for. Water to prevent itsready evaporation through exposure to air.

4i. nitro-starch"explosivecontaining a saturated solution of a deliquescent salt;

- 5, .A nitro-starch explosive I comprising 50% of nitroEstarch, i0% of ammonium nitrate and 10%: of Water.

. 6. A nitro-starch'explosive comprising nitro-starch, a. deliquescent nitrate, suflicient Water to hold a substantial amount of the deliquescentnitratein solution, and a suitable carbonaceous or combustible ingredient.

.7. A nitro-starch explosive comprising nitro-starch, a .saturated solution of-an inorganic nitrate, and-combustible constituent.

8; An explosive consisting of n1tro-starch contalning Water suf icient to render it saie in handling,,bntinsufiicien'tto prevent its detonation,substantially as described.

. 9. An explosive consisting of nitro-starch containing a substantial percentage of Water and, ammonium nitrate, substantially as dc scribed. 0, 10. An explosive consisting of nitro-starch than 10%; ofammonium nitrate, substantially as described. I 11. An explosive consisting of nitro-starch containing more than 10% ofwater and more than. 10% of ammonium nitrate, substantially asdescribed.

12. An explosive consisting of approximately50% ofnitro-starch, more than 10% ammonium nitrate, and approximately 15% of Water. .7 7. l3. Anexplosive consisting of 60% to 375% offnitro-starch and from 25% to 40% of a solution of ammonium nitrate in Water, substantially as described. 0 a i 14. An I explosive consisting of 60% to 75 .ofnitro-starch and from 25% to 40% of a solution ofammonium nitrate in Water, said solution containing less' than 65% of ammonium] nitrate, substantially as described.

j WALTERQ. S LU TQ It is hereby certified that in Letters Patent No. 1 ,386,47 ,"g r ented August 2, 1921, upon the application of Walter O. Snellihg iffllento tr Pennsylvania, for an improvement in N itrostarch Explosiyes, a'n rrti eppears ihithe printed specificetion requiring correction as follows; Page 2, "not 'iine to 106, comprising present claim 10 and insert the following as 1Q- 10. An explosive consisting of nitrosta rch substantially as described; 1 v

and that the said Letters Patent should be'withlthrs orrectior rtherein. that the same may conform to the record of the 1- Signed and sealed this 11th day of October 1 [BEALJ I t i v WM. re 31mm,

Actintrj gpmmifissiibner of Patents.

It is hereby certified that in Letters Patent No. 1,386,437, granted August 2, 1921, upon the application of Walter O. Snelling, of Allentown,Pennsylvania, for an improvement in Nitrostarch Explosives, an error appears in the printed specification requiring correction as follows: Page 2, strike out lines 104 to 106, comprising present claim 10 and insert the following as claim 10: g

10. An explosive consisting of nitrostarch containing more than 10% of water,

substantially as described. and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 11th day of October A. 1) 1921.

[sEAn] WM. A. KINNAN,

Acting Commissioner of Patents.