US1889116A - Priming composition - Google Patents

Description

dangers to health Patented Nov. 29, 1932 EDMUND VON HERZ, OF COLOGNE-DELLBRUCK, AND HANS RATHSBURG, OF FURTH, GER- MANY, ASSIGNORS, BY MESNE ASSIGNMENTS, TO REMINGTON ARMS COMPANY, IN- CORPORATED, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE ranmwe 'comrosrrron No Drawing. Application filed February 20,- 1930, Serial $0. 430,138, and in Great Britain March 8, 1929.

This invention relates to priming compositions for aminunition and particularly to the class of priming compositions'which are noncorrosive, that is, which do not leave in the bore of the firearm a residue which upon subsequent exposure to a humid atmosphere causes corrosion. The present application is a continuation-in-part of our co-pending application Serial No. 352,893, filed April 5, 1929.

The function of a priming composition in a cartridge is to provide a flame of suflicient intensity of heat to effectively ignite the propellant powder, the priming composition itself being ignited by theoblow of thefiring pin upon the riming mixture container. Until comparatively recently substantially all commercially successful priming compositions have included, as their chief ingredients, mercury fulminate, potassium chlorate, and a fuel to be burned withthe oxygen lib-' 'erated from the potassium chlorate; the principal fuels being antimony sulphide and/or lead sulphocyanate. Mercury fulminate alone doesn'ot function well as a primer for the reason that it explodes with too great violence when struck a blow, and produces very little flame and heat. Its function in prim ing compositions is to initiate a reaction between the oxidizer and the'fuel, such reaction furnishing the hot flame of substantial liength and duration which ignites the pow- Both mercury fulmina-te and potassium chlorate are objectionable in priming mix tures. The potassium chlorate breaks down into a highly hygroscopic potassium chloride, which is the a ent responsible for after corrosion. It has een found possible, by a careful selection and accurate proportion of ingredients, to replace potassium chlorate with certain other oxidizers which do, not leave corrosive residues. Mercury fulminate, however has remained a standard sensitizer or combustion initiator for practically all ammunition rimers It isobjectionable not only byn ason of its high and in-.\ creasing cost but also on account of its highly poisonouscharacter with the consequent the workmen-engaged in handling, mixing and loading it into cartridge shells and primer cups. Furthermore, mercury fulminate tends to react' with many materials which otherwise are desirable primer mixture ingredients, thus greatly limiting the number of available oxidizers and fuels; It also amalgamates readily with many metals, such as the zinc in brass, necessitating the use of expensive copper or nickel plated primer cups. The elimination of dangerous, poisonous and troublesome mercury fulminate has, for these reasons, been the ideal of am-c mun1t1on manufacturers for a great many yea'rs.

In the United States Patent No. 1,443,328

to Edmund Von Herz there is described the production of the normal lead salt of styphnic I acid, commonly called lead trinitroresorcimate; and the use of this substance generally as a priming mixture ingredient. Experiment and test have indicated the desirability i of a sensitizer in such mixtures, and the pending application of J. E. Burns, Serial No. 177 ,848, filed March 23,1927, discloses mixtures including lead trinitrore'sorcinate with substantial amounts of mercury fulminate. In these prior disclosures, however, as well as in all prior primer mixtures of any kind,

the sensitizing ingredient has been present in such proportions as to constitute a sub- -which does not have the disadvantages of mercury fulminate.

The sensitizing agent utilized in the-present invention is selected from the class of compounds known as tetracenes, said compounds being descrihed in the British patent to Rathsburg, No. 201,009 of June 30, 1922. In said co-pending application, Serial No. 352,893, filed April 5, 1929, we have, dis-- ,particularly the health of closed our discovery that a tetracene, for

guanylnitrosaminoguanyltetracene to secure example guanylnitrosaminoguanyltetracene (C H ON possesses suchvalue as a sensitizer for priming mixtures that itmay be used in extremely small quantities, even to the surprisingly small amount of .5 of one per cent. In connection with the furtherance of our experiments it has been found that the small amount of 0.5% of guanylnitrosaminoguanyltetracene is in sensitizing eifect equivalent to that of a very much larger amount of mercury fulminate. More specifically, 0.5% of guanylnitrosaminoguanyltetracene has been foundto produce the same result as about 18% of mercury fulminate and 1% of guanylnitrosaminoguanyltetracene has been found substantially equivalent to 30% of mercury fulminate. While 0.5% is a sufficient quantity of proper ignition of most powders, it is desirable in preparing large quantities of priming mixture to use a somewhat greater amount. This is done to insure that every part of the batch will contain a minimum of 0.5%. In commercial practice priming mixture is prepared in lots of 5 to 10 pounds While the individual charge for each cartridge is from .25 grain to about 1 grain. Obviously, it is very difiicult to secure such a perfectly uniform distribution of an ingredient present in the amount of only one-half of 1% that each individual charge would contain no less than this amount, and the difiiculty is augmented by the light, fluify, voluminous character of guanylnitrosaminoguanyltetracene. For this reason, in actual practice 1.5% or 2% or for special types of mixtures as much as 4% is'ordinarily used. 0.5% has been definitely determined as the minimum which will consistently effect satisfactory priming.

The other ingredients of the mixture may include lead trinitroresorcinate, one or more non-corrosive oxidizers, such as barium nitrate and/or lead peroxide, and one or more fuels, preferably of a hard and gritty nature, such as antimony sulphide and/or calcium silicide.

A typically successful mixture is as follows:

' P Guanylnitrosaminoguanyltetracene- 0. Lead trinitroresorcinate 20 +45 Barium nitrate 30 ,5O

Antimony sulphide and/or other fuel, as for example, calcium sili- Lead peroxide .7 12

Antimony sulphide 0 5 Calcium silicide 6 12- Glass 1 7 0 3 It will be noted that each' of the above formulas includes guanylnitrosaminoguanyltetracene in an extremely small amount, these percentages of guanylnitrosaminoguanyltetracene as above stated being equivalent in their effects to 18% to 30% of mercury fulminate.

tiveness of guanylnitrosaminoguanyltetracene to, shock and friction is substantially the same as. that of mercur fulmi'nate- .Their sensitiveness is so near t e same that there is a difierence of opinion as to whichis really the more sensitive. The present invention is believed to comprise the first discovery of a priming mixture in which a fundamental and essential ingredient is present in an amount of the general order of 1%, and for this reason, the appended claims are to be broadly construed.

What is claimed is: v

1. A priming mixture containing guanylnitrosaminoguanyltetracene in an amount not greater than 4%.

2. A priming mixture containing between 0.5% and 4% guanylnitrosaminoguanyltetracene.

x 3. A priming mixture containing a non- This discovery is rendered even more remarkable by the fact that the semi-- corrosive oxidizer, a fuel, and'not more than 4% of guanylnitrosaminoguanyltetracene.

.4. A priming mixture containing lead -tri-' nitroresorcinate, and 9.5% to 4% of guanylnitrosaminoguanyltetracene.

5. A priming mixture containing lead tri- .6. A priming mixture containing lead trinitroresorcinate, barium nitrate, antimony sulphide, and not more than 4% of guanylnitrosaminoguanyltetracene.

7. A priming mixture containing lead trinitroresorcinate a non-corrosive oxidizer, antimony .sulphlde, calcium silicide, and not more than 4% of guanylnitrosaminoguanyltetracene.

8. A priming mixture containing lead trinitroresorcinate, barium nitrate, antimony sulphide, calcium silicide, and not more than 4% of guanylnitrosaminoguanyltetracene.

9. A priming mixture contalni ng approximately:

- Per cent Guanylnitrosaminoguanyltetracene-; 0. 5-. 2 Lead trinitroresorcinat 35 -40 Barium nitrate l 35 42 Lead peroxide 7 12 Antimony sul hide 0 5 Calcium silici e 6 -12 Glass 0 3 10. A priming mixture containing barium nitrate, lead peroxide, antimony sulphide,

calcium silicide, and a quantity of guanylnitrosaminoguanyltetracene not greater than 47. I 0 EDMUND VON HERZ. HANS RATHSBURG.