US2055403A - Explosive - Google Patents

Description

Patented Sept. 22, 1936 PATENT OFFICE EXPLOSIVE Willard de G. Crater, Newark, Del, assignor. to

Hercules Powder Company, Wilmingto n, DeL,

a corporation of melaware NoDrawing. Application April 10, 1934, Serial This invention relates to an explosive and method for its production.

The; explosive in accordance with this invention is characterized, more particularly, by the fact that it is a porous, granular, free-flowing material, substantially free from any solvent and of a colloidal nature comprising an explosive salt in crystalline form intimately mixed with and surrounded by a colloided nitrocarbohydrate.

The method in accordance with this invention more particularly involves admixing an explosive salt and a nitrated carbohydrate together with a solvent for the nitrated carbohydrate which is normally substantially non-solvent for the explosive salt, with the formation of a gel and finally drying the gel by removal of the solvent therefrom.

The carrying out of the method in accordance with this invention and the production of the product in accordance herewith appears to depend upon the peculiar phenomenon that solvents capable ofdissolving nitrated carbohydrates, but which are normally substantially non-solvent for explosive salts are in the form of a nitrated carbohydrate solution capable of enabling the formation of a gel between explosive salts and nitrated carbohydrates.

In proceeding to carry out the method in accordance with this invention for production of the product in accordance therewith any suitable nitrated carbohydrate may be used. As illustrative, for example, nitrated starch, which may be ordinary nitrated starch or which may preferably be nitrated flaked starch, which is preferable due to more uniform nitration obtainable on nitrating flaked starch, nitrated cellulose, as, for example, nitrated cotton or other nitrated cellulose maybe used. Additional nitrated compounds such as, for example, nitrated inulin, may be used and it will be understood that in connection with the following description of this invention and the claims appended hereto, for example, nitrated inulin and other operable nitrated compounds are to be regarded as equivalents for nitrated carbohydrates, such as nitrated starch and nitrated cotton.

, In carrying out the method in accordance with this invention for the production of the product contemplated, any of the well known explosive salts may be used. Thus, for example, ammonium nitrate, ammonium perchlorate, potassium perchlorate, potassium chlorate, sodium chlorate, etc., may be used and it will be also understood that in the following description of this invention and in the claims appended hereto it s contemused. For illustration, for example, methanol, 10

acetone, ethyl acetate, etc., or mixtures thereof, may be used.

In the practical adaptation of the method in accordance with this invention. for example, the

explosive salt and nitrated carbohydrate are ad- 16 mixed with a solvent to produce a gel which is thoroughly admixed and broken up and then dried, as, for example, by the evaporation of the solvent, leaving the finished explosive in ac cordance with this invention, which may be used as such or which may be admixed with various ingredients of explosives, as, for example, carbonaceous material, as wood meal, balsa wood, ivory nut meal, or the like, other explosives, as, for example, nitrolactose, nitromannitol, TNT, DNT, or the like, or with oxidizing agents, as, for example, ferrosilicon, sodium nitrate, etc. Likewise, if desired, in order to sensitize the explosive nitroglycerin in relatively small quantity may be used.

In proceeding, any desired practice may be followed. However, it will generally be found desirable to add a quantity of the explosive salt to the solvent and then add a part of the nitrated carbohydrate while stirring the solution, then add more explosive salt and then more nitrated carbohydrate, until the desired amount of nitrated carbohydrate has been added, with finally the addition of the balance of explosive salt. The whole is stirred and the gel which will form, broken up. The consistency of the gel will depend upon the ainount of solvent relative to nitrated carbohydrate and explosive salt. The gel is finally dried by elimination of solvent. Varlous modifications of the practice may, of course, be made. Thus, for example, the entire amount of explosive salt can be added to the solvent and then the entire amount of nitrated carbohydrate added, or the order of addition may be reversed, that is, the nitrated carbohydrate may be added to the solvent first, either in total quantity or in part, followed by addition of the explosive salt, in total quantity or in part. Generally speaking, however, the addition of the explosive salt and nitrated carbohydrate to the solvent in successive portions will be preferred.

The method in accordance with this invention will, as will be obvious, be capable of being carried out in any suitable form of apparatus. However, it will be found convenient to use a mixer of the conventional type used for mixing gelatin dynamite or smokeless powder and the mixer will be preferably of the jacketed type.

Satisfactory gels for the ultimate production of explosive in accordance with this invention by drying out of the solvent may be produced on the formulae shown in the following table: titatiztli -t 2 a in a 2 53 a Methanol per 50.

gms ccl5 i5 15 15 20 2o 20 as The explosive in accordance with this invention will be found to be somewhat hygroscopic, but to have a moisture pick-up less than that of ammonium nitrate. Thus, for example, by exposure of a sample of the explosive at 20 C. in an atmosphere of 90% humidity, ammonium nitrate will be practically in solution after 96 hours, whereas the explosive in accordance with this invention will not 'show any free solution until after a minimum of about 350 hours exposure to such an atmosphere.

The explosive'will have a very high water resistance as compared with that of ammonium nitrate and will show a pendulum friction test indicating relative insensitivity of the explosive and consequent safety in handling. same time, the explosive may be readily detonated with an ordinary blasting cap and will show good ballistic mortar test.

Generally speaking, the proportions of nitrated carbohydrate and of ammonium nitrate may be widely varied. As illustrative, but in no way limiting, for example, the nitrated carbohydrate may vary within the range 5-20%, while the ammonium nitrate may vary within the range 95-80%.

As illustrative of the use of solvent other than methanol, for example, a satisfactory explosive in accordance with the method of this invention may be made up on the following formula:

Ammonium nitrate 90% 90% Nitrostarch flakes 10% 10% Ethyl acetate-cc/50 gms 20 cc. Acetone-cc/50 gms 20 cc.

As illustrative of an explosive in accordance with this invention prepared in accordance with the method of this invention, for example, a satisfactory explosive may be made up on the following formula:

Nitrostarch flakes 10% 10% Ammonium perchlorate 90 Potassium chlorate 90 Methyl alc. /50 gms 20 15 At the corporation of such additional ingredients, or, if desired, the additional ingredients may be mixed with the explosive in accordance with this invention after drying. As typical of explosive mixtures including various ingredients in addition to the explosive, for example, various mixtures as shown in the following tables may be made.

As illustrative of the preparation of explosives in accordance with this invention using, for example, nitrocotton or nitrated inulin. indicated as equivalent for nitrated starch, for example, an explosive may be made on the formula shown in the following table:

Table D Nitrated inulin 107 Nitrocot f A nlh'ntn 95 90 Methyl alc. cc/50 gms Further, if desired, various waxes or wax-like substances may be included in the explosive in accordance with this invention, as, for example, paraflin, stearic acid, zinc stearate, etc. A satisfactory explosive in accordance with this invention may be prepared in accordance with the following formula:

Table E Nitrostarch flakes Ammonium nitrate Paraflin Stearic Zinc steal- It will be understood that in preparing an explosive in accordance with the method involving this invention, it will not be necessary to use the nitrated carbohydrate in a dry condition. Thus, for example, wet nitrated starch or nitrated cotton dehydrated with alcohol may be used wet with alcohol directly without drying. This is believed to be a distinct advantage in that it will be unnecessary to dry and the dust hazard will be eliminated. Also, the use of wet nitrated carbohydrate eliminates the explosive hazard, since, for example, alcohol-wet nitrated starch cannot be detonated even with a standard blasting cap.

It will be understood that the various description and formulae of the method embodying this invention and of the explosives in accordance therewith are given by way of illustration only and are not to be considered as limiting, since it will-be understood that the invention broadly involves from the method standpoint the formation of a gel with the use of an explosive salt and a nitrated carbohydrate or equivalently of nitrated inulin and the drying of the gel, the gel being broken up by stirring or in the admixing of .the ingredients. The explosive, as will be understood, from the broad standpoint comprises the dried gel produced by the method.

Further, it will be understood that this invention contemplates the incorporation in the gel of various ingredients other than the nitrated carbohydrate and explosive salt, as indicated, or other suitable ingredients not specifically mentioned. It will also be understood that the explosive in accordance with this invention will be used as such or with such ingredients as may be incorporated therewithin its production or in admixture with other ingredients adapted for the production of an explosive of desired characteristics, as, for example, oxygen balance, sensitiveness, rate, free flowing, etc.

What I claim and desire to protect by Letters Patent is:

1. The method of producing a granular, freeflowing detonating explosive which includes forming,a gel including a crystalline explosive salt in solution and a non-crystalline nitrated carbohydrate and drying the gel.

2. The method of producing a granular, freefiowing detonating explosive which includes admixing a non-crystalline nitrated carbohydrate, a crystalline explosive salt in solution and a solvent for the formation of a gel and eliminating the solvent. 1

3. The method of producing a granular, freeflowing detonating explosive which includes admixing a non-crystalline nitrated carbohydrate and a crystalline explosive salt in solution in a solvent for the nitrated carbohydrate which is normally substantially a non-solvent for the explosive salt for the formation of a gel and drying the gel.

4. The method of producing a granular, freefiowing detonating explosive which includes forming a gel including nitrated starch and a crystalline explosive salt in solution and drying the gel.

5. The method of producing a granular, freefiowing detonating explosive which includes forming a gel including nitrated starch and ammonium nitrate in solution and drying the gel.

6. The method of producing a granular, freeflowing detonatingexplosive which includes forming a gel including nitrated cellulose and an explosive salt in solution and drying the gel.

'7. A granular, free-flowing detonating explosive including a dried gel containing a non-crystalline nitrated carbohydrate and a crystalline explosive salt.

8. A granular, free-flowing detonating explosive including an explosive salt in crystalline form, the crystals of which are substantially encased and bound together by a dry colloided non-crystalline nitrated carbohydrate.

9. A granular, free-flowing detonating explosive including a dried gel containing a non-crystalline nitrated carbohydrate and a crystalline explosive salt and another explosive.

10. A granular, free-flowing detonating explosive including a dried gel containing ammonium nitrate and colloided nitrated starch.

11. A granular, free-flowing detonating explosive including an explosive salt and colloided nitrocellulose.

12. The method of producing an explosive which includes forming a gel including a crystalline explosive salt in solution, a wax and a non-crystalline, nitrated carbohydrate and drying the gel.

13. A granular, free-flowing, detonating explosive including a dried gel containing a noncrystalline, nitrated carbohydrate in amount within about the range 5-20% and a crystalline explosive salt in amount within about the range 95-80%.

14. A granular, free-flowing, detonating explo sive including a dried gel containing colloided,

nitrated starch in amount within about the range WILLARD DE C. CRATER.