US2174914A - Explosive and method for its production - Google Patents

Description

Patented t; 13, 1939 PATENT --omos I 2.174.914 n Exrwsms AND METHOD ms in raonpc rrox Willard do 0. Crater. N

ewarLDclL,

Hercules Powder Company, not, a corporation oi Delaware No Drawing.

rlsiml application April :0. 1m,

Serial No. 721,545. Dividedandflak application May 12, 1932, Serial No. 142.821

8 Claims.

This invention relates to a new type oi explosive and to methods for its production.

It has been Mom to attempt the nitration of various crude cellulosic materials, as, for example wood pulps, to obtain nitrocellulose. Inorder to render the nitrocellulose so -obtained utilizable in smokeless powders, etc. it was essential to obtain a high degree of nitration (around 13%) and the resultant product was always too unstable for satisfactory use.

Now in accordance with this invention it has been found possible to produce nitrated materials from crude cellulosio n t als such as, for ex ample, balsa wood, bagasse, oat hulls, wood flour,

15 etc., which can be successfully formulated into high explosives. Thenitrated materials in ac cordance with this invention will contain only from 9-11.5% nitrogen, and will accordingly be sufllciently stable for satisfactory use. In lormulating an explosive in accordance with this invention, the nitrated material as, for example, nitrated balsa, nitrated bagasse, nitrated oat hulls, nitrated wood flour, etc. will be impregnated with what may be termed an explosive oxidant, as, for

example, ammonium nitrate, onium perchlorate, potassium chlorate, etc. The term "explosive oxidant" is meant to desiwate those materials, well known in the explosives art, which, while not themselves explosive in the ordinary meaning of the word, are capable of forming a detonatable mixture when combined with organic materials, and which when present in an explosive actually take part in the explosion. The

explosive in accordance with this invention will accordingly comprise a nitrated cellulosic material impregnated with an explosive oxidant.

The nitrated cellulosic material in accordance with this invention may be produced by nitration of the comminuted raw material, as, for example,

40 balsa pulp, bagasm pulp, oat hulls, wood flour, etc.

with mixed nitric and sulphuric acids in the manner well known to the art, for pie, as flaked starch is nitrated. (See U. 8. t. 1,908,857 to George M. Norman.) to give a product of from about 9% to about 11.5% nitrogen. V The nitratedceiluiosio material will be found to retain ementially the e is s cal apance and properties M the raw product irom which it was made, and will aces a; highly absorptive. The :-tion or this nitrated material with an le omdant canbeaccomplished in various do liainoeth invention, the enmixed acids are chosen plosive oxidant dissolved in water to form a concentrated solution, the nitrated cellulosic example, 20 grams of ammonium nitrate maybe dissolved in 3 to! cc. of water at -80 0., and

5 grams of drynitrat'ed balsa pulp-are then stirred into the solution. The. product is then dried to 105 F. until it becomes crisp and free-flowing. l0 The explosive so produced may be detonated by a #8 electric blasting cap, andhas a weight strength oi about 63.3%. I

In order to avoid the necessity oi drying the nitrated celulosicmaterial before the impregnay-JB/ tion (which presents some ilre' hazard owing to the dusty nature oi the dry' material), the wet nitrated material as taken from" the final stabilizing wash or boil may be mixed with the finally ground explosive oxidant, the residual water act- 20 ing as a solvent for the salts and eflecting impresnation. The product may then be dried as described above. For example, wet nitrated balsa pulp may be thoroughly mixed with four times its dry-weight of ammonium nitrate, or of equal parts 25 ammonium and sodium nitrates, and then dried at 105 h. until crisp and tree flowing. The use of nium nitrate alone gives an explosive having a 100 lb. count of 509 and a weight strength of about 65.3%. The explosive containin: sodium nitrate has a lb. count of 498 and,

a weight strength of about 28.3%.

By using this method water-insoluble materials may also be incorporated. For example, an explosive may be made from wet nitrated balsa 7 having the following compositions and properties:

Impation oi the nitrated cellulosic material o be enacted by treating the pulp with a solution oi ammonium nitrate in liquid am- 50 monia (Diver's liquid), or by a mixture of ammoniumnitrate and hydrated magnesium nitrate in with the method shown in U. S. ,t'iiii w to B. I. Stoops. These methods 55 I Ir -W avoid the necessity of "WBE the. impregnated material at an elevated temperature.

Ii the nitrated celluloslc materiel is suiilclenh ly absorptive and does not contein more than about 10% nitrogen, the nitreted impregnated material produced as dosoribed above may be further impregnated with nitroglycerin to give e. stronger explosive. Ihus on terminated 8012311812.

seicent f Nitrated mm. pulp mmmmm so Ammonium nitrat 3d Nltrogly so In addition to the nltrated snide cellulomo materials, so balsa wood, bogcsse, out hulls, ol

ready referred to, nitroted starch fishes end hi trooellulose can also be impregnated in. accordspice with-this invention to form a. poweidul ex plosive.

not as greet us that oi the crude celluloslc meterials.

However, since these carbonaceous materials- (staroh and cotton) can be obtolne'ccl' in scub 'stantiolly pure iorm, they may be nitrates to give products having more nitrogen than 11.5% with out beco unstable.

Thus. for example, '75 g. of ammonium nitrate may be dissolved at ?M@ C. in o of Water, and 25 g. oi dry nitroted starch flakes, produced, for example, by the method described in U. S. Pot. 1,908.85"! to Norman, so he stirred into the solution. The material, when dried at about 1.05 ER, is granular and free flowing and has a weight strength oi 326.3%.

Also, wet nitrostarch fishes may he treated with the finely ground explosive oxidant in the manner heretofore described. By this method an explosive of. the iollowing composition was producm:

. I Per cent Nitrostarch flakes (dryweightl Ammonium nitra v 25 Sodium nitrate so Balsa p p 1 4 The-balsa pulp is added to increase the absorptiveness. oi'the mixture and so to old impregnalion.

A solution of 89 oi ammonium nitmteine um of water may be used to impregnate g. Of dry nitrocotton (13%N). The dried product has o. weight strength oi vow...

' From, the various examples glveu above it will have bmn seen that various common ingredients of explosives other than explosive oxidants, for. example, sodium nitrate, charcoal, sulfur, unnitrated wood pulps, may be used in conjunction with meexplosive oxidant in producing explosl in accordance with this invention.

while'eonium nitrate has been indicated as the explosive oxidant used in the examples given, other'explosive oxidants, as for example ammomum perch1orate,'etc. may be wsed to replace 7 the onium nitrate either in whole or in part. For example, explosives in .rdsnce with this explosive mey he Their natural ehsorhencv. however, is

invention may have the following compositions:

' Per cent Nitrated balsa 20 onlum perchlorate 80 By way of recapitulation the iollowing table shows. solely as examples, various types of explo ,sives produced ln'occordance with this invention:

Detonatcs Weight Material Per cent Dons. with to strength E.B.cep per cent balsa .50 80 .33 Yes-.- M134 bagmeou 2G I 74 .35 Yes 653.78 oat hulls"- 33% 66% .22 Yes"-.- 14.16 wood flour. 29 80 41 Yes wood flour. 20 80 36 Yes 71. 33

s t arch 75 .46 Yes.-. 70.33 cotton'. 20 80 44 Yes--.-. 70. W

' e explosives in accordance with this inventlon have many desirable properties. They are poweriul, relatively insensitive to shock yet easily detonated by proper means, inexpensive, and (if they do not contain nitroglycerin or the like) non-freezing and non-headeche'producing.

Explosives in accordance with this invention will also be found to be freefiowing and accordingly'may be reedily cartridged', or, if desired, may be poured directly into bore holes.

This application is a. division of application QSeriol No. @1545 filed by me April 20, 1934 for improvement. in Explosive.

What I claim is:

1. Method of producing an explosive which includes treating on absorptive, nitrated, cellu-= loslc material with 2. solution of an explosive oxidant in liquid, anhydrous ammonia.

2. Method of producing an explosive'which includes treating an absorptive, nitruted, cellu=- loslc material with a. solution of an explosive oxidant in liquid, anhydrous ammonia, and then evaporating the liquid ammonia.

3. Meth od of producing an explosive which includes treating nitrated balsa wood with a solution of an explosive oxidant in solution in weight of sulfur and about 10 parts by weight of nltroted balsa wood containing from about 9% to about 11.5% nitrogen and impregnated with about 10 parts by weight of ammonium nitrate and about 65 parts by weight of sodium nitrate.

6. An explosive composition comprising about 10 parts by weight of nitroglycerlne and about 20 parts by weight of nitrated balsa wood containing from about 9% to about 11.5% nitrogen and impregnated with'about 70 parts by weight.

of ammonium nitrate.

' WILLARD n! C. CRATER.