US974900A - Explosive compound. - Google Patents

Description

UNITED STATES PATENT OFFICE.

HUDSON MAXIM, OF NEW YORK, N. Y.

EXPLOSIVE COMPOUND.

No Drawing.

Specification of Letters Patent.

Application and March 24, 1905.

Patented Nov. 8, 1910.

Serial No. 251,866.

To all whom it may concern.

Be it known that I, Henson MAXIM, of the boron h of Brooklyn, city of New York, State of r ew York, have invented anew and useful Improvement in Explosive Comounds, which invention is fully set forth in the following specification.

The present invention relates to improvements in explosive compounds, and has especial reference to the manufacture of smokeless gunpowder.

The object of the invention is to provide a pyroxylin compound which shall be suiticiently plastic at ordinary temperatures or at slightly elevated temperatures, to permit of the material being molded or formed into any desirable shape of grains suited to use in firearms or cannon, and without the use or employment of any volatile matter as a solvent. In other words, to provide a material ca able of gelatinating pyroxylin without tlie employment of any volatile solvent requiring to be evaporated from the compound after it has been granulated or otherwise formed; and furthermore to provide a solid non-volatile solvent of pyroxylin, as well as a novel process for the manufacture of smokeless gunpowder.

It is a further object of the invention to provide a smokeless powder compound 1r colloid which shall be capable of fusion and 5 capable of being fused-at a temperature. below the point of ignition, so that when the powder is fired in a gun fusion shall take place in advance of and proceed in advance of and simultaneously with combustion. Consequently, the two processes, fusion and combustion, going on to ether, cause the powder to burn more rapi l and to be consumed through a greater we thickness durlng a given period of time and under a given ressure in a gun, than would be the case if no fusion occurred.

By being able to consume the powder through a greater web thickness, the granulation may-be much coarser, and the web thickness or wall thickness between multiperforations much reater, and consequently the amount of acce eration due to the multiperforations greatly enhanced. lleretofore, this result has been attempted by making smokeless powders very rich in nitroglycerin or other oxidizing agents, and by making them both soft and rich in nitro-glycerin, like British eordite. No fusion taking place 'in these compounds the. oxidizing agents have been depended upon to produce rapidity of combustion, and for this reason the products of combustion are much hotter and richer in oxygen, and consequently erode the gun with much greater rapidity than the smokeless powder like that described in the present invention, which is not over-rich in oxygen or oxidizin agents. Furthermore, such smokeless ow ers rich in oxidizing agents, under hig ier pressures become dangerous, for the reason that the rate of combustion is more likely to change and proceed toward detonation-in other words, such powders rich in oxidizing agents have what is known as a critical point, and are liable to produce dangerous pressures and blow up the gun, especiall when high pressures are employed. Furt iermore, obviously, when a smokeless powder compound like the present compound, is capable of being consumed. through a relatlvely great thickness of material under a given pressure, the initial area per unit of weight of material is correspondingly decreased, and consequently the initial pressure in the gun is proportionately decreased, and a quantity of powder capable of maintaining a nearly uniform pressure to the muazle may be em ployed and without undue initial pressure.

Heretofore, in the manufacture of smokeless gunpowder, it has been the general practice to dissolve pyroxylin or gelatinate the same to render it of suitable plasticity by means of a volatile solvent, such as a mixture of. ether and alcohol or of acetone. etc., and which solvent mustbe dried out of the material to .fit it for use. frequently requires months to effectually accomplish the drying, and even then-in grains of inassive proportions such as are necessary for large cannon, there isa' certain residual quantity of solvent which cannot be racti-.

cally eliminated even in several mont is, especially with such a compound as thenitrocellulose smokeless powder at "resent employed by the United States overnment, consisting solely of a grade of p' roxylin known as pyro-nitro-cellulose, atinated by the ether and alcohol mixture.

It has been found in practice that such a smokeless powder as the lastnamed, even though great care be taken in drying it, will burn more rapidly after having been kept for ayear or so, owing to the continued loss of more or less of the residual solvent which causes the powder not only to burn with i ture about that of the fusion the drying of the greater rapidity but to be more brittle, so that the ballistic results after keeping the powder for a long time'are inferior to those results when it is first finished. Higher pressures are produced with lower velocities after the powder has become overdry from keeping for a long time,--that is to say, for

a year or more. i

In carrying out my invention, I preferably employ about 40% of tri-nitranisol or tri-nitro-methyl-phenyl ether, and 60% of pyroxylin, preferably that known as pyro- .nitro-cellulose. The tri-nitranisol is a pow erful solvent of all grades of pyroxylin when a mixture of the tri-nitranisol and the pyroxylin are heated together to a temperaoint of the tr i-nitranisol, that is to say, about 65 C. I have found, however, that it is not neces sary in practlce to heat the material to this temperature in order to effect the gelatinization of the pyrox lin in the method of manufacture hereina er described; but renter rapidity of incorporation is secure and therefore it is preferable to employ such a ,te'mperatuxe or thereabouts. I have found that more rapid incorporation and gelatinization is effected if the pyroxylin be wet and the ingredients min led in a wet condition, the wet condition eing maintained until near the end of the operation whereat thefinished powder grain is turned out.

In manufacture, I preferably proceed as follows :--Tri-nitranisol and the pyroxylin are mixed without being dried; which saves un cotton. A mixer or incorporating machine is used. This is preferably done at normal atmospheric temperature and below the melting point of the solid solvent. from the mixer and passed and repassed. be tween rolls, by which the-more perfect incorporation and gelatimzation of the guncotton is effected; the temperature of the rolls being maintained at about or above 65 C.,and in'order to prevent the too rapid drying of the material, hot water is dropped, or

allowed to trickle upon the material while being rolled. When the material has been thoroughly incorporated and the guncotton thoroughly gelatinated by the tri-nitranisol, the material in sheets from the rolls is passed to another and cooler pair ,of rolls, preferably running in a warm room or one maintained at. high summer heat, that is to say, from 80 to 100 F. These are the finishing rolls, and are not maintained at quite so high a temperature as the first-mentioned .rolls, for the reason that the powder is now cutting up into powder grains.

rolled in the absence of water until the moisture remainingin it is eliminated, when the powder'is rolled into a desired thickness for I "sometimes, however, proceed by drying the 's'lieets of material from the first rolling before re The material is then taken -temperature of the sheets When, however, the tern erature is mainture, for the reason that the material is apt to become brittle while in thin sheets if the room is allowed to become too cold, or the tofall too low.

tained as above describe the material is maintained in a lastic condition and is readily rolled and molded as may be desired, and at a temperature not exceeding that at which the stability of the powder is unaffected, that is to say, without overheat-- ing the powder materia Of course, I may roll the material into grains while yet in a wet state on the first pair of rolls, and then dry the water from the grains afterward, but I preferably pro-v ceed as above set forth. I have found, furthermore, that the addition of nitroglycerin produces a smokeless owder which is very much more elastic an flexible and. burns with greater rapidity than that consistmg of only nitrocellulose and trinitranisol. This modified formula may be about 15 per cent. of nitro-glycerin, 40 per cent. of tri-nitranisol and 5 er cent. of ym-nitrocellulose, mixed and incorporated as before described. The addition of this quantity of nitroglycerin is not suflicientto render the products of combustion injurious in their erosive action u on the gun, while it facilitates considerab y the process of manufacture, and reduces the required tem-- perature for gelatinization, and at the same time produces a more flexible powder grain, which may be made in the form of long rods or strips that may be handled and transported without danger of breaking.

While I have described a mixture of 40. parts tr'i-nitranisol to 60 parts pyro-nitrocellulose as the preferable mixture when employing these two ingredients alone, still I may vary this composition. I may, forinstance, employ equal parts of these ingredi ents, or I may emplo as low as 25 per cent. of tri-nitranisol and 5 per cent. pyro-nitrocellulose, and I have actually succeeded in making homogenous and perfectly gelatinated' powder glrains with this mixture, but it is considerab' y more difficult than whenemploying the ingredients in the preferred I proportions.

The plasticity of'thecompound may be varied within. wide limits by increasing or decreasing the proportion of the pyroxylin; without varying the proportion with respect to each other of the tri-nitranisol and nltroglycerin.

When itis required to make a compound which shall be very stiff and rigid, then a larger percentage of the pyroxylin is used. When a softer and more plastic consistency is required, then the proportion of thepyroxylin is reduced. Furthermore, when main constant.

a slower burning powder is required or when it is desired to lessen the temperature of the products of combustion, then the roportion of the tri-nitranisol is increased and the pro ortion of the nitroglycerin is reduced, whi e the proportion of pyroxylin may re- And when a more rapidly burning powder is 'wanted and one which will be consumed through a. greater thickness of material in the gun, then the proportion of the tri-nitranisol is reduced-and the pro 'ortion of the nitrolycerin increased, whi the proportion 0 the 'pyroxylin may remain unchanged.

While I have expressly mentioned, and prefer to use tri-nitranisol, I may use trinitro-phenetol, or a mixture of them, but I prefer to use tri-nitranisol because it contains a higher percentage of oxy en as well as being a more active solvent of pyroxylin and a urge percents. e may be used with pyroxylin without ma ing a smoke-producmg powder, while at the same time a smaller percentage is required toefl'ec't its gelatini zation. It is much more diflicult to thoroughly gelatinate the pyroxylin to form an amorphous product which shall contain a low enough percentage of tri-nitro-phenetol to produce a smokeless powder without the use of additional oxidizing agents, such as nitrate of barium. or an unduly large per-.-

centage of nitro-glycerin.

Tri-nitro-toluene may be employed in conjunction with tri-nitro-phenetol or tri-hitroanisol. The fusion po nt of the compound is considerably lowered below that of trinitro-toluene which has 'a fusion point of 75 C. By loweringthe fusiolr pointthe process of gelatinization of the pyroxylin is facilitated and is effected ata lower temperature than when'trinitro-toluene is em-- ployed without'another solid solvent having a lower fusion point than itself.

In efl'ecting,as hereiuheforc described. the gelatinization of the pyro ylin with tri-nitranisol, a temperature maintained during the incorporation and 'gelatinization some what elevated. and preferably at. or slightly above the fusion point of the tri-nitranisol, uamely; 64 to 65 C. \Vhen, however, nitro-glycerin, especially a large percentage, is' employed, which is a solvent of the tri'ni- .tranisol and which may he a solvent of the pyroxylin also, then the gelatinization may be affected at ordinary temperature. but the work is always facilitated by the employmcnt of a somewhat elevated temperature. Obviously,furthermore. a volatile. and common solvent of thctri-nitranisol and pyroxylin. such as acetone. may be employed. which would greatly facilitate the incor un'ation and gelatinizat ion of the pyroxylin at. ordinary tcumerature. but as such a volatile solvent must necessarily be evaporated from the compound afterward. and iltfflfl. granu lation, it is better not. to employ such volatile solvent, but instead to employ a somewhat elevated tcmperature. This obviates the necessity of drying the powder after it has been gramilated, in order to remove the volatile matter.

What is claimed is 3-" 1. A smokeless gunpowder, consisting of a mixture of tri-nitranisol. pyroxylin, and

an oxidizing agent, as described.

2. A smokeless gunpowder consisting of a mixture of tri-nitranisol, pyroxylin, and nitroglycerin, as described.

3. An explosive consisting of a gelatinated mixture of pyro-nitro-cellul0se and minitranisol.

4. The hereindescribcd process of making smokeless gunpowder, which consists in mixingtogether-pyroxylin, intro-glycerin and tri-nitranisol and gelatinizing the resulting mixture.

The hereil'idescribcd process of gelatimating pyroiiylin, which consists in inc-orporating with pyroxylin, t-rinitranisol and intro-glycerin heating the said mixture, maintaining the pyroxylin wet during the gelatinization thereof and subsequently drying tliecompound.

(l. A smokeless gunpowder, consisting of a mixture of a tri-nilro-alkylphenyl ether, and nitro-cellnlose made into a. colloid.

7. A smokeless gunpowder. consisting of a mixture of a tri-nilro-alkyl-phenyl ether,

intro-cellulose and an oxidizing agent made into a colloid.

8. A smokeless gunpowder, consisting of a mixtureof a tri-nitro-alkylsphenyl ester, intro-cellulose. and.nitro-glycerm made into a. colloid.

9. A smokeless gunpowder, consisting of a mixture of a tri-nitro-alkyl-phenyl ether and pyro-nitro-cellulose made into a. colloid.

10. A smokeless gunpowder, consisting of a mixture of a tri-nitro-alkyl-phcnyl ether, pyro-nitro-celluloseand an oxidizing agent made into a colloid.

11. A smokeless gunpowder, consisting of a mixture of tri-nitro-alkyl-phenyl ether, pyro-nitro-cellulose and nitro-glycerin made into a colloid.

12. A smokeless powder comprising a mixture of tri-nitranisol and .tri-nitro-phenc tol and pyroxylin made into a colloid.

13. A smokeless powder comprising a mixture of tri-nitraniml, tri-nitro-phe|ietol, pyroxylin and an oxidizing compound made into a. colloid.

In te timony whereof l have signed this HUDSON MAXTW.