US2292956A

US2292956A - Explosive

Info

Publication number: US2292956A
Application number: US282518A
Authority: US
Inventors: Joseph D Mcnutt; Samuel D Ehrlich
Original assignee: Western Cartridge Co
Current assignee: Western Cartridge Co
Priority date: 1939-07-01
Filing date: 1939-07-01
Publication date: 1942-08-11
Anticipated expiration: 1959-08-11

Description

Patented Aug. ll, i942 OFFICE EXPLOSIVE Joseph D. McNutt and Samuel D. Ehrlich, New Haven, Conn, assignors to Western Cartridge Company, East Alton, 111., a corporation of Delaware No Drawing. Application July 1, 193

Serial No. 282,518

7 Claims. (Cl. 52-4) used. The double salts of lead styphnate and lead hypophosphite possess certain advantages for these purposes over many. of the compounds now employed.

Lead styphnate and basic lead styphnate are known detonators and are employed in priming mixtures as initiators in place of mercury fulminate. Lead hypophosphite has also been employed in priming mixtures to lower the decomposition point of priming mixtures containing difiicultly, decomposable oxidizers. The use of lead hypophosphite in priming mixtures is described and claimed in United States Letters patent to Joseph D. McNutt, No. 2,136,801, granted November 15, 1938.

We have found that certain improved results can be obtained in priming mixtures and in other analogous uses when double salts of leadstyphnate and lead hypophosphite are employed'as an ingredient. These compounds are produced from styphnic acid, sodium hydroxide, lead hypophosphite and lead nitrate. By controlling the reaction, a compound may be produced containing two mols. of normal lead styphnate and one 'mol. of lead hypophosphite corresponding to the chemical formula:

Crystals of this double salt are in the form of very thin hexagonal plates. Priming mixtures in which this double salt is employed are more sensitive to friction and have lower instantaneous flash point than priming mixtures containing a mechanical mixture of normal lead styphnate and lead hypophosphite. The double salt of normal lead styphnate and lead hypophosphite may be prepared as follows:

TNR 10 grs.

Adulterant 0.05 gr.

Lead nitrate 13.5 grs. .(theoretical) Sodium hydroxide 8.2 cc. (10 N.) Water 140 cc.

Lead hypophosphite 10 grs.

In forming the double salt, the trinitroresorcinate, adulterant and lead nitrate are stirred with the water at a temperature of approximately 73 C. As adulterants we employ the nitro derivatives of resorufimthe nitro derivatives of indophenol and the nitro derivatives of resazurin. Salts of these compounds may also be used, such as the lead salt of nitroresorufin.-

Mixtures of the above materials may also be used. When carrying out a reaction with the above quantities of materials, 3 grams of lead hypophosphite are then added together with all of the sodium hydroxide. This results in the formation of a temporary gel consisting of amorphous flocs and some needles. This gel breaks very quickly and normal lead styphnate is precipitated. After seven or eight minutes the remainder of the lead hypophosphite is added. The hexagonal plates of the double salt of normal lead styphnate and lead hypophosphite begin to form about fifteen to twenty-five minutes after the addition of the remainder of the lead hypophosphite and the reaction is complete in about one and a half hours. The crystals settle quickly and the mother liquor is decanted hot. The product is then washed with cold water a number of times. We have found that six washings are generally satisfactory. From the above quantities of reacting materials a. yield of 22.5 grams of the double salt is obtained. The product is chiefly in the form of plates with a few rods. It has an instantaneous flash point of 240 C. and a density of 3.34.

By varying the reacting conditions and the quantities of the reacting materials we may also prepare a complex salt containing one mol'. each of lead styphnate, basic lead styphnate and lead hypophosphite. This triple salt also is useful as an initiator and as a substitute for known high explosives. It also possesses the advantage of greater sensitivity to friction and lower flash point than materials now used for these purposes. This compound may be prepared by employing the reacting materials heretofore enumerated in the quantities stated, except that 11 cc. of sodium hydroxide is employed. The

yield is increased, however, if the theoretical While the methods of preparing the compounds set forth above are particularly advantageous in that they produce more uniform products, either the double salt of lead styphnate and lead hypophosphite or the salt containing one mol. each of lead styphnate, basic lead styphnate and lead hypophosphite may be prepared by other methods. For example, the double salt may be prepared from lead styphnate and lead hypophosphite by heating them in water to a temperature of 70 C. or it may be prepared by a reaction of sodium hypophosphite, lead nitrate and lead styphnate. Likewise the complex basic salt may be prepared by heating basic lead styphnate, lead styphnate and lead hypophosphite in water. While the addition of the nitro derivatives of resorufin, the nitro derivatives of indophenol and the nitro derivatives of resazurin, or the salts of one of these compounds is the preferred practice, either the double salt or the complex basic salt may be prepared without the use of these adulterants.

Throughout the remainder of the specification the term double salt of lead styphnate and lead hypophosphite is intended to include both the double salt of normal lead styphnate and lead hypophosphite and the complex basic salt comprising one mol. each of normal lead styphnate, basic lead styphnate and lead hypophosphite.

As stated, the new explosives may be employed in various uses in lieu of the explosives now used. They are particularly useful in the preparation of priming mixtures for small arms ammunition. Priming mixtures containing this double salt; and other conventional ingredients of priming mixtures are more sensitive and have lower flash points than similar mixtures prepared with other initiators.

The following typical formulae may be employed in rim fire, center fire and shot shell ingredients may be substituted for the various oxidizers and fuels to obtain varying results necessary under different conditions. Other explosives; such as diazodinitrophenol, normal lead styphnate or basic lead styphnate maybe usedfor part of the double salt. Also other oxidizers. such as barium-potassium nitrate or lead peroxide may be substituted for the oxidizers in the formulae given without departing from the spirit of the invention.

In preparing priming mixtures the ingredients are first thoroughly and uniformly mixed according to practice well known to those skilled in the art and then formed into individual pellets of the proper size for individual charges in the customary manner. This is generally done by the use of charge plates provided with perforations to mold pellets of the proper size and weight. These pellets are then transferred either into priming cups for shot shell cartridges or for center fire ammunition or into empty rim fire cartridge shells in the usual way. In connection with rim fire ammunition, the charge is forced to distribute itself in the hollow rim by spinning each shell in the customary rim fire loading machines. After the shells have been properly primed, they are loaded with powder and shot or bullets in the usual manner.

When employed as a detonator, the double salt of lead styphnate and lead hypophosphite is loaded under suitable pressure in the usual detonator casing, caps or tubes and employed to detonate high explosives in the same manner that the known initiators or detonators are employed. It may be used to detonate any type of high explosive, such as dynamite, tetryl, trinitro toluol and other known high explosives.

We claim:

1. A priming mixture for small arms ammunition comprising the double salt of lead styphnate and lead hypophosphite.

2. A priming mixture for small arms ammunition comprising the double salt of lead styphnate and lead hypophosphite and an oxidizer.

3. A priming mixture comprising from 30 to percent of the double salt of lead styphnatelead hypophosphite, from 15 to 40 percent lead nitrate and from 10 to 30 percent of glass.

4. A priming mixture comprising from 20 to 50 percent of-the double salt of lead styphnatelead hypophosphite, 30 to 60 percent lead nitrate, 20 to 40 percent antimony sulphide and 5 to 20 percent calcium silicide.

5. A priming mixture comprising from 15 to 40 percent of the double salt of lead styphnatelead hypophosphite, 20 to 60 percent barium nitrate, 15 to 40 percent mercury fulminate, 10 to 25 percent antimony sulphide and from 0 to 15 priming mixtures:

Rimfire Preferred Percent percent Double sult. 30-60 50 Lead nitrate. 15-40 30 Glass 10-30 20 Centerfire Preferred Percent percent Double salt 20-50 35 Lead nitrate 30-60 40 Antimony sulphide. 20-40 18 Calcium silicide. 5-20 7 Shotshell Preferred Percent n Douhlesult.... 15-40 20 Barium nitrate. 20-60 35 V Fulminate mercury 15-40 25 Antimony sulphide. 10-25 15 Calcium silicide 0-15 5 The above formulae are given by way of example and other well known priming mixture percent calcium silicide.

6. A priming mixture for small arms ammunition comprising thecompound containing 2 mols. of normal lead styphnate and 1 mol. of lead hypophosphite.

7. A priming mixture for small arms ammunition comprising the compound containing 1 mol. each of normal lead styphnate, basic lead styphnate and lead hypophosphite.

JOSEPH D. McNUTT. SAMUEL D. EHRLICH.