US2008808A - Explosive composition - Google Patents

Description

Patented July 23, 1935 'EXPLOSIVE COMPQSITION Vernon Harcourt Williams, Ardrossan, Scotland, H

assignor to Imperial Chemical Industries Limitcd, a corporation of Great Britain No Drawing. Application April '29, 1932, Serial No. 608,343. In Great Britain May 13, 1931,

6 Claims; (01. 52-13) ,Myi'invention relates to stabilized explosive compositions, and moreparticularly to dynamite compositions in which a mildly alkaline soluble salt is included as the stabilizing ingredient.

in: explosives. containing nitroglycerin, it is the practice to incorporate with the other ingredients an acid-accepting material, in order that the presence of small traces of acidity may be removed at the time of formation. This slight amount of acidity may result because of the hydrolysis of the nitroglycerin, and the continued presence of such acidity tends to pro- -.mote the further decomposition of the nitroglycerin.

The use'of acid acceptors in the presence of nitroglycerin is advantageous in the case of both propellent and disruptive explosives. In the for mer case, the nitroglycerin is present usually together with nitrocotton, while in disruptive explosives the other ingredients include inorganic oxidizing agents such as nitrates, carbonaceous combustible absorbents, etc.

Heretofore, various acid-accepting materials have been proposed. In propellent explosives,

for example, it has been customary to use small quantities of a weak organic base such as di phenylamine. In dynamite compositions, on the other hand, the usual base for the purpose has been calcium carbonate, though other materials such as zinc oxide, magnesium carbonate, etc.

' have been used.

-' ties for the purpose otherwise.

The object of my invention is to provide an explosive composition containing as an ingredient an acid-accepting material having an unusually beneficial eifect on the explosive.

.A further object is to provide a composition containing a mildly alkaline inorganic phosphate as such ant-'acidmaterial. A still further object is U to provide an improved gelatin dynamite composition containing such an acid acceptor. Further objects will be disclosed as the invention is described in detail.

I advantage in such explosive compositions. I prefer, however, to use di-ammonium orthophosphate, since this compound has the desired mild alkaline reaction and the most suitable proper- While varying amounts of the above material may be-u sedas stabilizer and acid acceptor,- I find the most desirable limits to be between 0.1 and 5.0 percent, since an amount less than 0.1 per cent is insufli- '.cient to havetliedesired effect on the-explosive properties, while more than'5.0 per cent. detracts from the strength of the explosive without adding any improvement.

My new stabilizing ingredient has many advantages over materials used heretofore for the same purpose. One particular advantage may be cited in the fact that naturally-occurring sodium nitrate frequently contains as impurities the Water-soluble nitrates of calcium and magnesium, the presence of which has undesirable effects on the stability of explosive compositions. When diammonium orthophosphate or other similar phosphate is present as the ingredient in explosives containing sodium nitrate, the phosphate tends to react with said magnesium and calcium salts, so that their harmful effect is counteracted and overcome. This results because "of the formation of insoluble phosphates of calcium and magnesium.

While the use of a mildly alkaline inorganic phosphate is advantageous in propellent explosives containing nitroglycerin, it is beneficial also in those types of propellent powder known as singlebase powders, containing only nitrocellulose as the nitric ester.

I find a particular advantage, however, in the use of the above-mentioned phosphates in the blasting explosives known asdynamites, since it is in this form of explosive that sodium nitrate is used in large amounts. Stability tests of such explosives, particularly of gelatinous dynamite explosives, have shown that the presence of diammonium phosphate, for example, adds greatly to the stability of the explosive, as shown by gas evolution tests.

While various compositions of explosives may be used, containing soluble alkaline phosphates, the examples below will illustrate three types of compositions that are satisfactory.

Of the above compositions, I illustrates a powder indicated in, the

of the straight dynamite type, II shows a gelatinous dynamite, while III illustrates a gelatin dynamite in which ammonium nitrate has been substituted for a portion of the nitroglycerin.

The incorporation of the ingredients of the explcsive composition cited is carried out in thev v usual manner.

phosphate zwill be mixed with the other solid in- Preferably the diammonium .gredientsprevious'to their addition to' the nitroglycerin, or to their mixing with the gelatinized nitroglycerin.

It will be understoodthat variousdepartures maybe made from the compositions citedheretofore in this description; "For example, nitroglycerin may be replacedbya-s01ution of anyof,

the usual freezing point depressants in nitroglycerin, such as ethylene glyco1-dinitrate,'nitro,-

toluenes, nitrated sugars, )nitratejd polymerized glycerin, and like compounds; Also, other antacid materials such as chalk may be present with a liquid explosive ingredient, a gelatiniz ing agent,

a material havin'g'a hydrolyzing tendency with :respect to the liquid explosive ingredient, a oombustible absorbent material, and a mildly alkaline,

water-soluble, inorganic phosphate 3 .2., A gelatin dynamite composition nitroglycerin, nitrocellulosqammonium nitrate, sodium nitrate; a combustible absorbent material and'a mildly "alkalina'walter-soluble, inorganic g c i y r phosphate. I

3. The composition of claim 2 in which thein-.- organiciphosphate is di-sodium orthophosphate.

' 4a.v 'I'he compositio n of claim 2 in which the in- V organic phosphate is sodiunr-hydrogen orthophosphate. 5. A gelatin dynamite composition comprising and diammonium 'orthophosphate.

' 6. A gelatin dynamite composition comprisingnitroglycerin, nitrocellu1ose, ammonium nitrate, sodium nitrateya combustible absorbent material 1" nitroglycerin, nitrocellulose; ammonium nitrate,

sodium nitrate, a. combustible absorbentmaterial and diammonium orthophosphate in the amount of 0.1 to 5.0 per cent,

VERNON HARCOURT WILLIAMS. 7