US2012866A - Pyrotechnic composition - Google Patents

Description

Patented Aug. 27, 1935 I re v 4 Claims. .,,This invention relates to, a pyrotechniccome position designed'to be employed in the manuf a rare earth metalor an element of periodic facture of fireworks generallyfiinf which the object is' to obtaina spectacular fiare'or flash, with or without a detonative report, with a selective color range .for the flash, and if desired, with theeifusion of scintillating sparks or stars into thefield of the flash.

The broad concept of the invention is the group IVa such'forexample' as, zirconium, or an alloyof the same is burned in mixture with a suitable oxidizing agent.

It isoldin the art-to employ a compound of group IVa as an oxidant in mixture with some other combustible as a fuel, but since zirconium and others of the above indicated elements have ""a luminosity when burned far morebrilliant than substances heretofore used for a similar purpose,.it is obvious that the gist of the present invention lies in the fact of one of these substances or alloys of the same being used as the fuel and not as-the oxidant.

Whether the combustion shall take the form of a flare or a flash depends upon the selection of the oxidant. Color may in a few instances be ,an attribute of the oxidant, but in general it is obtained by the addition to the mixture of a specific color producing ingredient. Detonation lected from the group exemplified by, zirconium,

- a is employed in a comminuted state.

titanium, thorium, yttrium and selenium, and

It is characteristic of these elements and of their alloys that they burn with an exceptionally brilliant flame, that they enhance the combustive or fulminative sensitivity of the oxidizing agents with which they may be used in mixture, and that the sensitivity of the mixture depends not only on'the inherent nature of the oxidant, but also upon the'quantity ratio of the rare earth metal or its alloy to the oxidant.

Taking zirconium for example, one part of 3 this rare earth metal mixed with three parts of 5 an oxidizing agent, such for instance, as barium nitrate, makes a flash mixture which explodes when ignited by a fuse, butwhich is not sufliciently sensitive to explode by impact. By increasing the ratio of the zirconium to N two parts to three, relative to the oxidant, a mixture is produced which readily explodes by impact. The sensitivity control afforded by vary: ing the proportions of the rare earth metal or alloy relative to the oxidizing agent renders available a number of oxidizing agents of diiferent co-efiicients of sensitivity, such for example, as potassimn nitrate, barium nitrate, oxalates, trinitro compounds, chlorates and perchlorates. The oxidizing agent is selected according to the use to which it is to be put. If the py otechnic device is of the type which is to be exploded, by impact, the oxidant is chosen with a View to giving the mixture a critical fulminative sensitivity, the detonating point of which can be very delicately determined by adjusting the quantity ratio of the oxidant to the detonative ingredient or alloy.

For example, by using a mixture of zirconium, two parts and barium nitrate, three parts, the exact proportions being adjusted to control the detonating point, a torpedo can be made so critical as to its fulminative sensitivity as to be altogether safe with respect to the shocks incident to its manufacture and transportation, and which will explode reliably under impact blows of a definite value above that of the incidental shocks referred to.

Where a particular color of the flash or flare is a desideration, an oxidant is chosen which will 40 produce a basic white color in the flame so that the imposed color will not be contaminated. For this purpose, the perchlorates are particularly suitable, for they not only burn the detonative ingredients with a white colorless flame which does not impair the purity of the imposed color,

but they release a greater volume of gas, thus extending the field of the flash.

One of the important characteristics of the pyrotechnic composition of the present invention wn-c Zirconium Perchlorates Strontium carbonate.

flash or The last named ingredient gives a red color to the flash. The first two factors mixed in ratio of one to two give a mixture ignitible by a fuse, and in the ratio of two to three a mixture fulmlnating by impact.

For producing stars or scintillating sparks in the field of fiash, the detonative ingredient is ground coarser than when intended for. instantaneous combustion. Thelarger granules do not consume immediately but are thrown out as highly incandescent burning particles or "stars.

' Each of the elements has a spark of characteristic visual appearance. The zirconium spark for example, appears as an amoeba-shapedstar, which shape is modified in alloys of zirconium. The

characteristic sparks from burning. iron appear as" having thin radiating points.. In, a ferrous zirconium'alloy, the shape of the spark is a, com.- promise between the zirconium and the 'iron sparks, the area ofthe amoeba shaped star characteristic of Zirconium being smaller, and the radiating points being thinner and more deeply V indenting the central area.

A composition which'includes in the mixture,

several of the detonative ingredients exhibits an interesting variety of, incandescent spark forms.

It is obvious from the above description that the new pyrotechnic composition ,is not confined mixture.

to any single field of application in the art of pyrotechnics, but that it is applicable to devices,

in which the composition isburned openly, without detonative eflfects, as in sparklers; in salutes which are ignited by a fuse, or in devices explod:

ing upon impact, such as torpedoes; What we claim is:

1. Pyrotechnic composition comprising a mix- Y ture of zirconium; and a perchlorate in proportion to detonate when confined, and a. color imparting ingredient, the latter being present in such proportion as to give a decided colorto the flash yeventuating fromthe detonation of such mix- 7 ture, the perchlorate functioning 'as an oxidizing I, agent.

2. Pyrotechniccomposition with fulminating V characteristic comprising. a mixture of zirconium, a perchlorate; andfa color producing ingredient, the perchlorate functioning as an oxidizing agent and the zirconium being comminuted to adegree of coarseness producing stars in the field of the flashqeventuating from the detonation of said 3. Pyrotechnic composition capable of detonatingcomprising a mixture of an element selected from the following group, zirconium, titanium,

thorium, yttrium, selenium, with an oxidizing agent, said element'being comminuted'to a. state of suflicient coarseness to produce stars in the flash.

4., Pyrotechnic composition capable of detonating comprising a mixture of a fuel element selected 'from the following grou'pf zirconium, titanium,

thorium, yttrium, selenium with a perchlorate and a. color producing agentusedin sumcient proportion to produce a. decided color in the flash,

the fuel element being comminuted to such degree I of coarseness as to produce stars in the flash.

- JOSEPH'WB. DECKER.

HERBERT c. CLAUSER.