US2410801A - Igniting composition - Google Patents

Description

Patented Nov. 12, 1946 ENT OFFICE IGNITING, COMPOSITION Ludwig Audrieth, Dover, N. J.

No Drawing. Application March 13, 1945, Serial No. 582,478

(Granted undenthe act of March 3, 1883, as

4 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention deals with new and improved igniting compositions which are characterized (a) by the fact that they contain polymeric thiocyanogen and (b) by the superior functioning characteristics of such mixtures due to the incorporation-of polymeric thiocyanogen which serves as a more efiicient fuel and reducing agent and in certain instances as a sensitizer.

While igniting compositions are being used for a wide variety of purposes, such as for example in'primers, delay elements, fuzes and the like, it is significant that all of them consist essentially of an oxidizing agent or oxygen rich material in combination with a reducing agent or fuel.

oxidizing agents which are used include, for example, such materials as the alkali and alkaline earth perchlorates, chlorates, chlorites, nitrates, oxides, peroxides, chromates, permanganates, brornates, iodates and periodates. Fuels and reducingagents maybe chosen from among the following types of chemical substances: (a) metals, such as magnesium, aluminum, boron, silicon, zirconium, (b) non-metals such as sulfur, selenium, tellurium, carbon, alloys such as magnesium-aluminum, calcium-silicon and (d) compounds such as lead and copper thiocyanate, metallic sulfides, selenides and tellurides. Other agents are also added to the oxidizing agent-fuel combination to achieve specific effects for particular uses and purposes. Thus, sensitizer-s and high explosives are added to priming compositions in order to increase both friction and stab sensitivity, as well as flame volume. Binders consisting of natural or synthetic resins, waxes, and phaltum are often added to delay and igniter compositions to make such mixtures more readily pelletable and more easily ignitable. However, in spite of the aforementioned modifying agents it is still the oxidizing agent fuel combination which serves as the basis for these compositions of matter.

The particular combination of oxidizing agent plus fuel determines largely whether the mixture under consideration will be (a) friction or stab sensitive in which event such a product will serve as a primer, (1)) will ignite readily with the evolution of considerable heat which characteristics amended April 30, 1928; 370 O. G. 757) trains of fuzes or as the delay components of fuzes. From a practical point of View many other factors must also beconsidered in the developmentof such compositions as for example: (a) stability on magazine storage and also at the high and low temperatures and the extremely dry and very humid conditions met with under present conditions of warfare; (b) ease of blending of the ingredients to insure homogeneity and uniformity in chemical composition; and (0) safety in the manufacture, loading and handling of these mixtures.

I have found that polymeric thiocyanogen is an exceptionally eflicient fuel in combination with a wide variety of oxidizing agents yielding primer, delay, fuze and igniter compositions which possess marked advantages over materials now used in the military arts; both with respect to stability and functioning characteristics. Insofar as can be discerned from atho-rougli examination of the pertinent literature and of the priorart no compositionscontaining polymeric thiocyanogen have ever been suggested or used for the purpose outlined lierein.

Lest there be some confusion concerning polymeric thiocyanogen and its properties, I shall present herewith a, short description of this newand superior ingredient of primer, delay, fuze and igniter' compositions. Polymeric thiocyanogen is also designated in the literature as polythiocyan ogen and as parathiocyanogen and is represented by the formula (SCNM. Actually its composition does not conform exactly with this empirical formula since it contains chemically combined both o ygen and hydrogen with the result that an elementary analysis gives values varying from 45-55% sulfur. It is significant, however, that irrespective of the mode of preparation, all products' produce essentially similar X-ray diffraction patterns demonstratingthat such materials while not identical with respect to exact chemical composition nevertheless do possess the same molecular structure. It thus makes little diiference whether polymeric thiocyanogen is prepared (a) by anodicoxiclation or (b) by chemical interaction of oxidizing agents such as hydrogen peroxide, the halogens and the like with thiocyanic acid and/or thiocyanates, in aqueous or non- In presenting the examples'given herein I do not wish to limit myself to the exact proportions of the various ingredients nor to the particular oxidizing agent cited for purposes of illustration. Thi is especially true in the case of delay and fuze powders where changes in proportions will make it possible to change the burning times to adapt such compositions for use in a particular component. That changes in the ratios of polymeric thiocyanogen to other ingredients makes it possible to vary the burning time may be looked upon as one of the advantages to be derived in the practical use of such mixtures. In all of the examples noted herein manufacture of the com- Example I As examples where polymeric thiocyanogen is employed, in non-fulminate containing primer mixtures, there may be cited the following compositions:

I II

Potassium chlorate; 51 64 Antimony sulfide 21 Polythiocyanogen Lead azide 5 Both compositions function with the rapid and even ignition of the entire charge and with the production of a hot flame which will insure transmittal to the remainder of the explosive train. Composition I is somewhat oxygen deficient in that a ratio of 60:40 parts of potassium chlorate to antimony sulfide is employed. In this instance polymeric thiocyanogen serves both as an auxiliary fuel as well' as a sensitizer, for without this agent much greater force is needed to effect functioning of the mixture. Composition II contains sufficient chlorate to take care of the oxygen demand of both the antimony sulfide and the polymeric thiocyanogen. These examples are given inorder to indicate that the proportions of .the oxidizing agent to fuel may be varied appreciably without affecting the functioning characteristics of such mixtures. It is also pertinent in this connection to refer to the advantage of polymeric thiocyanogen over metallic thiocyanates, such as lead thiocyanate, which are widely used as constituents of priming compositions.

Whereas only approximately ten percent by weight of polymeric thiocyanogen is required to obtain maximum effectiveness and sensitivity to stab action of compositions such as those given above, twenty to twenty-five percent of lead thiocyanate is required in order to even approach the very superior results obtained by incorporation of my new and improved fuel and reducing agent. It is furthermore significant that polymeric thiocyanogen is superior to sulfur as a sensitizer since it is non-volatile and insoluble.

Example II 4 solvents, serving under these conditions as a primer mixture for chemical fuzes.

Example III Fuze powders used in time trains are commonly modifications of black powder consisting of potassium nitrate, carbon and sulfur in the proportions 75:10:15. The manufacture of such-powders must be carefully controlled and incorporation of the ingredients to insure homogeneity must be effected so that the proper burning time can be obtained. It is obvious that such homogeneity is much more readily obtainable when only two ingredients are to be mixed. Thus a mixture of potassium nitrate and polymeric thiocyanogen, in equal parts by weight, produces a slow burning fuze powder which is all the more exceptional in that it burns progressively yet uniformly, even if at a slow rate, and is also readily and easily ignitable. Replacement of the non-volatile polymeric thiocyanogen for sulfur is another advantage of this composition over black powder.

Polymeric thiocyanogen contains the necessary carbon and sulfur in chemical combination and, as pointed out under Example I, is non-volatile and in this respect preferable over the sulfur ordinarily employed in black powder compositions. The addition of potassium perchlorate or other oxidizing agent in percentages up to ten percent will markedly speed up the burning time if a faster powder is desired.

Example IV Thecombination of barium peroxide and polymeric thiocyanogen in proportions of 95 to 5 or to 10 gives mixtures which are easily ignitable, evolve little gas and undergo reaction at an extremely rapid rate with the evolution of considerable heat. For the purposes of prepelleting in order to facilitate loading operations in tracer components the addition of 1 to 2% of some binder, such as asphaltum, wax, natural or synthetic resins is desirable although not necessary. Such mixtures serve admirably as igniter compositions for tracer components. Increase in the percentage of polymeric thiocyanogen gives compositions which burn more slowly and may therefore serve as delay compositions.

I have cited above typical cases to indicate that polymeric thiocyanogen in combination with various oxidizing agents will give mixtures which will serve a variety of useful purposes. I do not wish to be limited in the scope of my invention to the specific examples given herein since it is indicated by laboratory tests that compositions containing polymeric thiocyanogen in combination with a wide variety of oxidizing agents will function quite as satisfactorily as those described above.

I claim:

1. An igniting composition consisting essentially of polymeric thiocyanogen and an oxidizing agent.

2. An igniting composition comprising potassium chlorate, polymeric thiocyanogen, antimony sulfide and lead azide.

3. An igniting composition consisting essentially of potassium nitrate and polymeric thiocyanogen.

4. An igniting composition consisting essen tially of polymeric thiocyanogen and barium peroxide.

LUDWIG F. AUDRIETH.