US1478892A - Smokeless propellant powder - Google Patents

Description

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TY L. DAVIS 9F SOMERVILLE, MASSACHUSETTS.

SMO Y 3 E Drawing.

To all whomit may concern:

I Be it known that l Tanner L. DAVIS, a citizen of the Unitedtates, and a resident of Somervillc, county of Middlesex, and State of'Massachusetts, have invented an Improvement in Smokeless Propellant Powder, of"

which the following is a specification.

The subject of this invention is smokeless proplellant powder.

T elmain objects of the invention are the production of a powder having the ballistic advantages of colloided nitrocellulose powders while at the same time possessing perfect stability and which may be p pared without the useof volatile and hyg oscopic solvents thereby rendering the powder nonhygroscopic and constant in its ballistic properties and which may be so combined that the rate and temperature of combustion may be regulated to any desired degree.

Pentaerythrite tentranitrate or tetranitropentaerythrite, as it is commonly but incorrectly called, is an excellent explosive which has found considerable use in detonators, detonating fuses, etc. It is a very powerful explosive, being somewhat more powerful than nitroglycerine.

It is Very hot and for this reason'perhaps, has found little application foruse in fire arms. Like nitro glycerine it contains more oxygen than is needed for its own combustion, and like nitroglycerine it can submit to being mixed with other substances, either explosive or nonex'plosive, which contain an amount of oxygen, for the preparation'of mixtures which are. suitable for use either as shattering explosives or as propellant powders. Q

'lPentaerythrite te'ntranitrate exists in the form of white crystals which while sensitive to shock and friction, are nevertheless perfectly stable in themselves an'd'do not decompose spontaneously, as do nitrocellulose and nitroglycerineewith the evolution of acid producing oxides of nitrogen. The

great stability. of ,the substance renders it especially suitable for the preparation of perfectly stable smokeless powder. The

' high temperatureand rapid rate of combustion of pentaerythrite tetranitrate make it desirable that this substance should not be used alone as a propellant owder but should be incorporated or mixe with some other i substances which will diminish the rapidity of its burning and lower its temperature 0% combustion. 'Such propellant mixtures insuiiicient' ss rnoirntnanr. rownnn.

. Application filed. April 16, 19 21. Serial EmeSL BvQO.

at best wouldbe somewhat coarse and their time of burning and the consequent ballistic properties could not be regulated as precisely as can now be done with colloided nitrocellulose powder. The best material for the purpose will be one which forms with pentaerythrite a uniform homogenous' mass sufiiciently plastic to be molded or squeezed into perfectly solid and non-porous powder grains.

Since'pentaerythrite is a tetrabasic alcohol it forms in addition to the tetranitrate, a whole series of other derivatives, esters and others, similar to those which are formed by any of the alcohols. derivatives with the aromatic aldehydes. Being a tetra-basic alcohol it forms derivatives in which one, two, three or four of the hydroxyl groups. are substituted in the same or different ways.

I have discovered that certain derivatives of pentaerythrite form with pentaerytbrite tetranitrate homogenous mixtures which, sometimes in the presence of solvents and It forms cvstalline sometimes not, are plastic and can conveniently be molded. I have found, for instance,

that pentaerythrite tetrabenzoate is suitable taery t-hrite tetranitrate and an ester of pentaerythrite.

3. A propellant powder, comprising a plasticised pentaerythrite.

4. A propellant powder, comprising pentaerythrite tetranitrate and a benzoate of pentaery'thrite.

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5. A propellant powder comprising pentag I erythrite tetranitrate and pentaerythrite tetra-benzoate.

6. A propellant powder, comprising a plasticised pentaerythrite derivative.

7. The process of producing a smokeless propellant powder comprising mixingpeutaerythrite derivatives, at least one ofwhich taerythrite derivatives, at least one of which possesses explosive properties to' form a possesses explosive properties, in the presence plastic mass and then dividing said plastic of a solvent to form a plastic mass, and then 10 mass into grains of the desired shape and dividing the plastic mass into grains of the 5 size; desired shape and size.

8. The process of-produing a smokeless propellant powder, comprising mixing pen= TENN EY L. DAVIS.