US1311910A - Propellent explosive - Google Patents

Description

ARTHUR SAMUEL ONEE, or wrnmme'ron, DELAWARE, Assie von TOE. I. DU Pom: DE NEMOURS AND COMPANY, or WIIMINGTON, DEL W RnA CORPORATION or Specification of Letters Patent. Patented Aug. 5-, 1919.,

I DELAWARE. g

' rnOrEL Enr EXPLOSIVE.

No Drawing.

'known as a progressive powder, that is to say, a powder which produces a lower initial pressure without lowering the velocity of the projectile. My invention is applicable to the various kinds of rifle and cannon powders.

The object of my invention is to produce a powder of this character which avoids many of the disadvantages of previous powders of this type. More particularly, the object of my invention is to provide a powder of this character which is obtained by applying to the surface of powder grains, as for example, grains of nitrocellulose powder, a deterrent material which is a solvent of the explosive contained in the powder grains so that it may be caused to penetrate the powder grains, and which is substantially non-volatile and which, further, provides on the surface of the grains an explosive of sufficient potential to obtain satisfactory ignition. A further ObJQCt of my invention is to provide a material for application to the surface of the powder grains which has substantially no odor, an which is so slightly volatile that the powder produced in accordance with my invent on may be stored at the temperatures to which powders are ordinarily subjected without producing any substantial balllstic change.

hile my invention is capable of being carried out in many different wa vs. for the a purpose of illustration I shall describe only one form of my invention hereinafter.

A powder made in accordance with my 1nvention maybe prepared in the following manner V A quantity of granulated mtrocellulose powder in introduced into a revolving barrel provided with means for heat ng the same. A mixture of a nitro-hydrocarbon such as dinitrotoluene with camphor or with camphor and diphenylamin is introduced ing Application filed. August 17, 1916. Serial No. 115,452.

into the barrel with the powder grains. The barrel is then warmed sutliciently to partially liquefy th mixture of dinitrotoluene, camphor and diphenylamin, and held at this temperature for about 30 minutes, while the barrel is rotated to insure a uniform coating of the nitrocellulose powder grains with the mixture of dinitrotoluene, camphor and diphenylamin. The temperature of the barrel is then gradually ra-ised to about centigrade, and this temperature is maintained while the barrel is rotated from one to one and one-half hours to impregnate the nitrocellulose powder grains with the dinitrotoluene. During this latter rotation the excess camphor is driven off. The powder grains if allowed to cool in this condition would adhere to one another so that a small.

amount of graphite is added, and the mixing continued until the powder has become dry, which takes about 20 minutes. An additional amount of graphite is then added and the glazing is continued until the powder grains no longer adhere to one another. The powder grains are then heated at about 45 centigrade for several days until the odor of camphor disappears.

The dinitrotoluene used may be any one of the several isomers or it may be a mix ture of isomers formed bythe direct nitration of toluene. Pure dinitrotoluene which is usually described as 1, 2, 4 isomer (0. p.;

dinitrotoluene) gives very satisfactory results. To lower the melting point of pure dinitrotoluene and also assist in bringing the dinitrotoluene into a high state of fluidity, to promote the impregnation of the nitrocellulose powder grains with the dinitrotoluene, the dinitrotoluene is treated with a mixture of camphor and diphenylamin. Any suitable proportions of the impregnating substances may be used, but I have found for example that a mixture contain- 84 parts dinitrotoluene, 16 parts camphor and 4 parts diphenylainin provides an excellent impregnating composition. If the nitrocellulose powder grains to be treated have been provided with incorporated diphenylamin as a stabilizer, the

amount ofdiphenylamin used in the mixture may be decreased. The impregnating mixture having the diphenyl-amin therein has a still further advantage that any slight decomposition of the powder grains during the impregnating operation, or later, is-

taken care of by the stabilizing action of the diphenylamin. The relatively high melting point of the dinitrotoluene is decreased by the addition of camphor and diphenylamin a highly fluid state when the mixture is heated to a temperature of centigrade, whereas 1, 2, 4: dinitrotoluene melts at about Z'().5 centigrade. The powder grains thus obtained will be found to be impregnated on their outer surfaces with dinitrotoluene, and their surfaces composed of nitrocellulose colloided with dinitrotoluene, nitrocellulose colloided with camphor and dinitrotoluene, nitrocellulose colloided with dinitrotoluene, camphor and diphenylamin, or a mixture of any or all of these. The powder thus produced produces a lower pressure initially at the breech of a gun and without producing an unduly high pressure along the barrel or at the muzzle. At the same time, it will also be found that the presence of the material applied to the surface of the grains produces substantially no change in the velocity of the projectile. The fact that the coating material used penetrates the surface of the grains is very important as it is found that many coating materials which do not penetrate the surjface of the powder grains are liable to produce delay in ignition and are apt, furthermore, to produce powders too'low in gravimetric density. By the use of my invention the coated material is made to penetrate the powder grains sufiiciently to form a dense surface which contains, however, suflicient nitrocellulose to beeasy of ignition. Furthermore, the powder so produced has practically no odor and is so slightly volatile that storage at the temperatures at which powders are stored produces substantially no ballistic change. While I have described my invention above in 'detail, I wish it to be understood that many changes may be made therein without departing from the spirit of my invention.

I claim l. A nitrocellulose powder grain having a surface layer comprising. a dinitrotoluene and camphor.

2. A nitrocellulose'powder grain having a surface layer comprising a dinitrotoluene, camphor and diphenylamin.

3. A nitrocellulose powder grain having an impregnated surface comprising a solidified colloid containing a nitrotoluene, diphenylamin and nitrocellulose dissolved in a nitrotoluene.

4. A nitrocellulose powder grain having an impregnated surface comprising a solidified colloid containing a dinitrotoluene, diphenylamin and nitrocellulose dissolved in a dinitrotoluene.

5. A nitrocellulose owder grain having a surface comprising a solidified colloid containing a dinitrotoluene, camphor, diphenylamin and dinitrocellulose dissolved in a dinitrotoluene.

6. A nitrocellulose powder grain having a .surface comprising a solidified colloid, con- 'taining nitrocellulose dissolved in a nitrohydrocarbon and camphor.

, 7. A nitrocellulose powder grain having a surface comprising a solidified colloid containing nitrocellulose dissolved in a nitrohydrocarbon, camphor and diphenylamin.

8. A nitrocellulose powder grain having a surface comprising diphenylamin and a solidified colloid containing nitrocellulose dissolved in a dinitrotoluene and camphor.

9. A nitrocellulose powder grain having a surface layer comprising dinitrotoluene and diphenylamin, with nitrocellulose dissolved therein.

10. A nitrocellulose powder grain having a surface comprising dinitrotoluene, diphenylamin and camphor, with nitrocellulose dissolved therein.

In testimony that I claim the foregoing T have hereunto set my hand.

ARTHUR SAMUEL ONETL.