US2247392A - Process of making smokeless powder - Google Patents

Description

pended in water by agitation.

' Patented July 1, 1941 UNITED STATE S PATENT OFFICE PROCESS OF MAKING SMOKELESS POWDER Milton r. I llndsley, in, Kings Mills, Ohio, assignor, by mesne assignments, to E. I. du Pont de Nemours In Comp ny, a corporation oi Dela- The finely divided particles of nitrocellulose colloided with nitroglycerine may be otherwise produced according to any one of several well-known processes. The nitrocellulose should be, of course, predominantly of the collodion type.

According to the present invention, these finely divided particles of nitrocellulose colloided with nitroglycerine are formed into powder grains by suspending them in water by means of agitation and dispersing through said suspension, globules of an explosive material possessed of a solvent action on colloided particles. Preferably, the explosive solvent is of such nature that it is a solid at all normal temperatures to which the powder might be subjected in storage or in use, but has a melting point sufllciently low to permit its introduction in liquid form into the suspension of the-colloided particles. Dinitrotoluol and likewise trinitrotoluol are examples of explosives highly suitable for this purpose.

In practicing the invention the colloided particles of nitrocellulose and nitroglycerine are sus- Dinitrotoluol or trinitrotoluol is then melted in the presence of water and agitated therewith to form minute globules slightly smaller in size than the size of the desired powder grains. The temperature of the suspension of the coil ded particles of nitrocellulose and nitroglyce ne is maintained at a point slightly. above the melting point of the dinitrotoluol or trinitrotoluol.

The suspension of the dinitro'toluol or trinitrotoluol in'water is then dded to a' suspension of the nitrocellulose-nitro lycerine particles in such a way and at such a. rate that the size of the globules of the dinitrotoluol or trinitrotoluol are substantially maintained. The agitation is continued causing the globules of'the dinitrotoluol or the trinltrotoluol to attack the finely divided particles oi the nitroglycerineenitrocellulose. thereby forming small, irregular powder grains.

The globules of molten explosive tend to agglomerate the nitrocellulose-nitroglycerine particles about themselves as a nucleus.

- After-the agitation has been continued for a time suflicient to permit the dinitrotoluol or the trinitrotoluol to attack and coagulate the nitrocellulose-nitroglycerine particles, the suspension is chilled to a temperature below the melting point of the dinitrotoluol or trinitrotoluol. The result of the process is small, irregular powder grains. The agitation is continued until after these grains have hardened by reason of the lowering of the temperature. The grains may then be surface treated and finished as desired.

The smokeless powders produced by this process comprise nitrocellulose-nitroglycerine and either dinitrotpluol or trinitrotoluol and are suitable for use as slow burning propellant powders. They are adapted for certain uses by themselves, but for other uses may be blended with other types of smokeless powder or other powders of more rapid burning characteristics.

To assist the skilled in the art in practicing this invention, the following example is provided. Substantially 800 pounds of finely divided nitrocellulose colloided with nitroglycerine is suspended in approximately 300 gallons of water. The suspension is agitated at such a rate that all of the nitrocellulose-nitroglycerine particles are in suspension but the movement of the particles is not greater than necessary to effect this end.

Substantially 89 pounds of trinitrotoluol is then mixed with substantially its own weight of water at a temperature slightly above the melting point 01' the trlnitrotoluol or approximately 83 C. This mixture of trinitrotoluol and water is then agitilted to a degree necessary to provide globules oi the trinitrotoluol in the water slightly smaller than the size of the desired powder grains.

The two suspensions are then rapidly admixed. Tile agitation is continueduntil the molten trinltrotoluol has colloided the particles of nitrocellulose and nitroglycerine into powder grains. With the quantities of materials disclosed this action requires substantially flve minutes. The suspension is then chilled below 80 C. (approximately C.) agitation being continued all the while in order to maintain the suspension. The

grains may then be finished and dried according to well-known processes.

when dinitrotoluol is' used instead of trinitrotoluol, it is recommended that the dinitrotoluol selected have a melting point of at least to 0. Generally speaking, it is believed at the present time that the use 01 the trinitrotoluol is preferable to the use of the dinitrotoluol as the resulting powder is suitable for a greater variety of uses at the present time. The dinitrotoluol or trinitrotoluol may comprise substantially 8 to 16% finished powder and the nitrocellulose-nitroglycerine colloid 92 to 84%. The nitrocellulosenitroglycerine colloid may comprise substantially 85 to 60% nitrocellulose and 15 to 40% nitroglycerine. The process is characterized by a great safety in the handling of the materials in view of the fact that it takes place under water and by th fact that the resulting product comprises three of the most powerful explosives known formed into powder grains suitable for use or for blending as propellant powder.

By the term finely divided particles of nitrocellulose, as used herein, I mean comminuted Pyro powder, because this is the material which I used in conducting my experiments.

Having described my invention, I desire to be limited only by the ensuing claims:

1. The process of making grains of powder suitable for use as propellant powder, said process comprising, suspending finely divided particles of nitrocellulose colloided with nitroglycerine in a body of water at a temperature above the melting point of an explosive which is solid at normal temperatures but which is a solvent for the nitrocellulose-nitroglycerine colloid when molten, suspending said explosive in molten condition in water and forming the explosive into globules in the; water by agitation, admixing the suspensions and continuing said suspension whereby the globules of molten explosive attack and agglomerate the finely divided particles of nitrocellulose colloided with nitroglycerine and form small grains of powder, and chilling said suspension below the melting point of the explosive, mlaintaim'ng the suspension by agitation all the w ile.

2. The process of making grains of powder suitable for use as propellant powder, said process comprising, suspending particles of nitrocellulose colloided with nitroglycerine in a body of water by agitation, suspending molten trinitrotoluol in a body of water by agitation and thereby forming the molten trinitrotoluol into small globules slightly smaller in size than the size of the desired powder grains, admixing said suspensions while maintaining the molten trinitrotoluol in globular condition, continuing said agitation until small grains of powder have been formed about the globules of molten trinitrotoluol, and chilling the suspension below the melting point of the trinitrotoluol while still maintaining it as a suspension by agitation.

3. The process of making grains of powder suitable for use as propellant powder, said process comprising, suspending particles of nitrocellulose colloided with nitroglycerine in a body of water by agitation, suspending molten dinitrotoluol in a. body of water by agitation and thereby forming the molten dinitrotoluol into small globules slightly smaller in size than the size of the desired powder grains, admixing said suspensions while maintaining the molten dinitrotoluol in globular condition, continuing said agitation until small grains of powder have been formed about the globules of molten dinitrotoluol, and chilling the suspension below the melting point of the dinitrotoluol while still maintaining it as a suspension by agitation.

4. The process of making propellant powder grains, said process comprising, suspending finely divided particles of dense colloided nitrocellulose in a body or water; suspending in a body of hot water a solid nitrotoluene, liqueflable at the temperature of the water, agitating said water nitrotoluene suspension to produce globules of molten nitrotoluene dispersed in the water, admixing the two suspensions, and chilling said admixture below the melting point 01' the nitrotoluene, while agitating the admixture.

MILTON F. LINDSLEY, JR.