US2663627A - Priming composition - Google Patents

Description

Patented Dec. 22, 1953 Remington Arms Company, Inc., Bridgeport,

Conn., a corporation of Delaware No Drawing. Application August 24, 1950, Serial No. 181,325

3 Claims.

This invention relates to a novel composition of matter which is a double salt of styphnic and hypophosphoric acids. For convenience, it will be called Potassium Cupric Styphnate-Cupric Hypophosphite. It is explosive in character, and particularly adapted to use as a. combustion initiator for ammunition priming and other deflagrating compositions.

The novel salt may be prepared as follows:

To a suspension of about grams of styphnic acid in 100 cc. of water, at a temperature between about 40 C. and about 60 C., and under agitation, there is added about 10 cc. of S-normal potassium hydroxide solution and 10 grams of sodium hypophosphite. After about ten minutes of continuous stirring, there is added a solution of about grams of copper sulphate in 50 cc. of water, this addition being dropwise and extending over a period of about twenty minutes. A precipitate of long, narrow pale green crystalline plates is formed. This precipitate, which has an apparent density of 0.28 gram/cc, contains 7.64% to 7.85% potassium, 7.19% to 7.20% phosphorous, and 14.7% copper, thus approaching the theoretical analysis of a complex salt of the formula:

The differences between analysis and theoretical composition may well be due to the impurity of the commercial styphnic acid used, the difficulty of analysis for potassium, and/or the presence of some acid cupric styphnate-cupric hypophosphite.

The new compound is not ultra-sensitive to static electricity, requiring the discharge of a 300 mmf. capacitor at 1,000 volts for certain firing. On a temperature gradient bar it explodes instantly at a temperature of 150 C. It is particularly useful as a combustion initiator in ammunition priming compositions, in which it replaces such combustion initiators as lead styphnate with highly desirable results. In a standard drop test. a priming composition utilizing Potassium Cupric Styphnate-Cupric Hypophosphite shows an average sensitivity of 5.74", and a standard deviation of 1.5. A counterpart mixture containing lead styphnate has an average sensitivity of 5.58", and a standard deviation of 1.6". Loaded cartridges primed with a mixture containing the novel salt show an average barrel time of 1.97 milliseconds with a standard deviation of 0.047 millisecond; while corresponding cartridges primed with a lead styphnate mixture have an average barrel time of 2.08 milliseconds Range, percent Preferred, percent Potassium copper styphnate copper hypophosphite Tetrazene. Barium nitrate. 1 Glass Sensitizers other than tetrazene may be used, it being understood that a sensitizer is a substance which explosively decomposes under friction or percussion with the generation of heat or flame. oxidizers other than barium nitrate and frictionators other than glass may also be used, butpreferably all ingredients are so chosen that none of them contain either combined or free lead, or salts such as chlorates which yield toxic. corrosive or hygroscopic reaction products or residues. Corrosive and hygroscopic residues such as potassium chloride are very destructive to gun barrels if not promptly and completely removed. Toxic residues such as free or combined lead are undesirable and, in intensively used indoor ranges, may become hazardous. It will be noted that the priming composition of this invention is entirely free from toxic residue pro ducing lead or mercury compounds, and is also free from corrosion producing potassium salts and chlorates.

The use of priming compositions of this type enables the production of cartridges the firing residues of which are entirely free of toxic ingredients. The firing of cartridges which contain lead, either free or as a compound, inevitably produces a smoke or other residue containing toxic lead. For indoor shooting the production of such residues poses a serious problem, since, in the absence of very abundant ventilation, toxic residues may accumulate in the atmosphere to a concentration which is hazardous to the occupants. It will be noted that the above priming compositionsdo not contain any lead compounds, and the use of compositions of this character with leadless projectiles such as the projectiles nate-Copper Hypophosphite 35% to 40%, tetra-V 4 zene 2% to 5%, barium nitrate 20% to 40%, and glass 20% to 40%.

3. An ammunition priming composition consisting essentially of Potassium Copper Styphnate-Copper Hypophosphite 38%, tetrazene 4%, barium nitrate 25%, glass 33 JOSEPH F. KENNEY.

No references cited.

Claims (2)

1. THE COMPOSITION OF MATTER POTASSIUM CUPIC STYPHNATE-CUPRIC HYPOPHOSPHITE.

2. AN AMMUNITION PRIMING COMPOSITION CONSISTING ESSENTIALLY OF POTASSIUM COPPER STYPHNATE-COPPER HYPOPHOSPHITE 35% TO 40%, TETRAZENE 2% TO 5%, BARIUM NITRATE 20% TO 40%, AND GLASS 20% TO 40%.