US2920949A - Process of producing an incendiary composition - Google Patents

Description

PROCESS OF PRODUCING AN INCENDIARY COB POSITION Morris S. Kharasch, Chicago, Ill., assignor to the United States of America as represented by the Secretary of War No Drawing. Application December 30, 1943 Serial No. 516,313

3 Claims. (CI. 52-23) there was little likelihood of using such a compound directly as an incendiary agent, because in the first place such substances are highly volatile, and in the second place they quickly absorb oxygen to form peroxides which explode violently on the slightest touch. However, I have discovered that polymerized derivatives of acetylenes have properties which adapt them for use as incendiary agents.

An object of this invention is to utilize suitably stable polymers of acetylenes including copolymers, particularly polymers of divinyl acetylene and the like, as incendiary agents.

Another object of this invention is to provide a process for forming solid incendiary materials comprising polymers of acetylenes.

A further object of this invention is to provide useful warfare munitions comprising incendiary agents in which suitable polymers of acetylenes are utilized.

It has now been found that there are derivatives of acetylene, particularly vinyl acetylenes, which are very suitable for use as incendiary agents. One of these derivatives is polymerized divinyl acetylene. This substance which comprises principally the trimer with some tetramer can be available in fairly large quantities as an industrial by-product. It has been commercially sold as an 80% solution in toluene or xylene. It is used as an acid-proof coating for materials. This material, when properly handled, is not unduly hazardous. It does not ignite too readily and burns with a smoky flame. Nevertheless, it has been possible to adopt this substance as an organic component of a very effective incendiary material which has proved to be of considerable interest as fillers for grenades.

The incendiary substances containing polymers may also be used to fill large incendiary munitions, such as bombs; and they have proved to be useful as binders for propellants.

There are two types of grenades or hand incendiaries in which the acetylenic polymer incendiary compositions have been found to be very effective. They are paper tubes and magnesium tubes with the incendiary agent compressed therein. In both types, a button of matchhead composition was attached to one end of the tube, this end being closed with a removable cap coated with a friction material. The finished incendiary resembled in outward appearance a shortened railway fuze. It was easily ignited by striking the match-head with the removable cap. Hand incendiaries of this type with total weights of 90 to 250 grams were subjected to tests. The sizes mentioned are arbitrary, for tubes of any size can be filled with the incendiary agent.

The distinguishing characteristics of these incendiaries are as follows: they burn with a vigorous torch-like flame which extends a foot or more from the mouth of the tube. The burning polymer incendiary agent ignites magnesium; and when magnesium tubes are used, much longer flames are often obtained during the time when the polymer incendiary agent and magnesium are burning simultaneously.

The polymer incendiaries were tested on wooden attictype structures. In all instances, they were at least as effective as any other type of incendiary tested in producing sustaining fires; i.e., fires which cause complete confiagration of a structure.

If the incendiary tubes or containers for the acetylene polymer agent are coated on the outside with paraffin, they may be soaked for several hours in water without impairing either their ignition or their burning properties.

In comparison with'hand incendiaries using thickened kerosene in Celluloid containers, acetylenic polymer incendiaries have the following advantages: they are hard tubes filled with a solid; hence, they cannot be crushed readily and contain no liquid to escape from a damaged container. As long as the igniting agent or match-head composition is not exposed, it is almost impossible to Example A mixture is prepared to contain about 30% of an solution of divinyl acetylene polymer in an aromatic hydrocarbon, about 10% heavy petroleum oil and about 60% crude sodium nitrate; and the liquid divinyl acetylene polymer is then further polymerized by heating the mass to C. in air forabout 16 hours. A solid mass thus formed is rolled to produce a uniform granular material. The product is stable and can at any time be loaded into tubes, for example, using a pressure of about 2,000 lbs. per square inch.

For a given acetylene polymer mixture, the burning time of the incendiaries thus prepared is proportional to the length of the tube and, Within wide limits, dependent on the cross section. The burning rate varies somewhat with the quantity of heavy oil used and with the mesh and nature of the oxidizing salt; of these, the latter is the more important. By controlling these factors, there have been prepared 7-inch incendiaries having combustion periods varying from about 1 /2 to 6 minutes.

The magnesium tubing used in some of the hand incendiaries submitted for test had a wall thickness of inch. Each tube was one inch in diameter and 6 /2 inches long; the filled tubes weighed about grams. The polymerized acetylene agent burned for about 1 to 1 /2 minutes before the magnesium tubing ignited. The magnesium andthe filling then burned together, and a vigorous burning of the magnesium took place in less than another minute. There was further burning which lasted for several minutes. It was found possible to vary, under wide limits, the time before the ignition of the magnesium casing and the time during which this casing burns vigorously, particularly by varying the mesh of the nitrate and the type of the oxidizing agent. For maximum effect, it is advantageous to have the magnesium burn rapidly.

addition products.

The polymerized acetylen'es may be usedin mixtures and in conjunction with other incendiary agents, such as thickened gasoline, Thermit type agents, phosphorus, granular magnesium and the like. They 'may-be used with various types of oxidizing agents, stabilizing agents, also with starting and igniting agents generally employed for incendiaries.

It is to be understood that the invention is not to be limited by the specific illustrative examples and'that' modifications come within the spirit and scope of the invention. I claim: V 1. A process for producing an incendiary material granular mixture is finally compressed by comprising preparing a mixture of about of an solution of the polymer of divinyl acetylene in an aromatic hydrocarbon, about 10% heavy mineral oil and about 60% sodium nitrate, exposing said mixture to air until a solid mass adapted to be crumbled is formed, and then rolling said mass, until the mixture is uniformly granulated;

2. The processof claim 1 in which the temperature i of the air is maintained at approximately C.

3. The process of claim l in which said air is maintained at a temperatureof approximately 85 C. and the a pressure of about 2000# per square inch. 7

References Cited in'the file of this patent V UNITED" STATES PATENTS 1,361,286 Patrick Dec. 7, 1920 1,436,248 Hammond Nov. 21, 1922 1,812,541 Nieuwland' June 30, 1931 1 ,896,162 Carter Feb. 7, 1933 2,294,415 McBride Sept. 1, 1942 2,329,522 Duncan "Sept. 14, 1943 FOREIGN' PATENTS 127,050 Great Britain May 29, 1919

Claims (1)

1. A PROCESS FOR PRODUCING AN INCENDIARY MATERIAL COMPRISING PREPARING A MIXTURE OF ABOUT 30% OF AN 80% SOLUTION OF THE POLYMER OF DIVINYL ACETYLENE IN AN AROMATIC HYDROCARBON, ABOUT 10% HEAVY MINERAL OIL AND ABOUT 60% SODUIM NITRATE, EXPOSING SAID MIXTURE TO AIR UNTIL A SOLID MASS ADAPTED TO BE CRUMPLED IS FORMED, AND THEN ROLLING SAID MASS, UNTIL THE MIXTURE IS UNIFORMLY GRANULATED.