US2498684A - Chemical product - Google Patents

Description

Patented Feb. 28, 1950 UNITED STATES PATENT OFFICE CHEMICAL PRODUCT Jack K. Y. Hum, United States Army No Drawing. Application May 1, 1945,

1 Serial No. 591,292

(Granted under the act of March 3, 1883, as

1 Claim.

known to those skilled in the art as Levinstein mustard.

The expression Levinstein mustard is commonly used to designate the mustard manufactured according to the Levinstein process. Levinstein mustard is relatively impure, and it has ,a pure mustard (dichlorethyl sulphide) content in the neighborhood of about 70%. The balance of the composition is made up of impurities, the exact composition of the impurities being rather complex.

Although Levinstein mustard is a very efiective vesicantnot withstanding the fact that it only has a purity of around 70%, it does have the serious defect of being unstable when stored in steel drums or l-ton containers over'fairly long periods, especially at tropical temperatures.

The instability of Levinstein mustard over long I periods of storage has been recognized ever since World War I when this agent was first used on a large scale.

However, this defect has becomemore serious and acute during the present war,

when for strategical reasons it has been necessary to store mustard in tropical, or near-tropical, areas. I

Considerable research has been devoted to the problem of Levinstein mustard stability, and extensive investigations have been conducted in an efiort to determine the exact causes for themstability with aview of developing suitable preventive measures. For present purposes, it is unnecessary to discuss at length the results of the previous research and investigations.

The object of this invention, generally stated, is the provision of practical and economical means of stabilizing Levinstein mustard so as to enable it to be stored in steel drums and l-ton containers under all climatic conditions and for reasonably long periods of time.

A specific object of this invention is the provision of a very efiective stabilizer for Levinstein mustard which is readily available in adequate amounts at reasonable cost.

One of the methods worked on for stabilization of Levinstein mustard, was the addition thereto of certain compounds which it was hoped would act as effective stabilizers. A multitude of compounds, estimated to be in the neighborhood of at least 100, were tested as stabilizing agents of Levinstein mustard prior to my invention. None amended April 30, 1928; 370 0. G. 757) were found that could be considered as reasonably satisfactory.

However, according to this invention, it was unexpectedly found that the compound hexamethylenetetramine was especially effective as a stabilizing agent for Levinstein mustard, particularly, when used in the critical amount of at least 1% by weight.

The usual method of determining the comparative stability of the systems of mustard with stabilizers is to determine the change in chemi-L cal composition of a sample (by melting point decrease) and to measure increases in pressure. The most severe test which it is considered necessary for mustard to meet, is storage in the presence of iron for a period of 110 days at a temperature of C. Numerous tests have been made under these conditions so as to conclusively prove the effectiveness of 1% ofhexamethylenetetramine as a stabilizer for Levinstein mustard. -A typical result for such tests is as follows: Levinstein mustard stored in the presence of iron, but without a stabilizer, was found to contain approximately 30% solids (considered to be the decomposition limit for usable mustard) after 21 days at 65 C. Similar samples of Levinstein mustard containing 1% hexamethylenetetramine as a stabilizer showed only 3% solids after 110 days under the same conditions of storage. After this 110 days storage at 65 C., the decrease, in the Levinstein mustard content of the test sample containing hexamethylenetetramine was only 5.2% as determined by the melting point.

The recognition of the value of the present invention isshown by the fact that the addition of 1% hexamethylenetetramine to Levinstein mustard has been adopted as a standard measure by the Chemical Warfare Service.

I claim:

Dichlorethyl sulphide mixed with the impurities of its composition and stabilized with hexamethylene tetramine, said dichlorethyl sulphide constituting approximately said impurities constituting approximately 30%, and said hexamethylene tetramine constituting at least 1% of said mixture.

JACK K. Y. HUM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,719,168 Chamberlain July 2, 1929 2,043,259 Missbach June 9, 1936