HOW NEW CHEMICAL PRODUCTS ARE INVENTED D. B. KEYBS,
UNIVERSITY OP
ILLINOIS, URBANA, ILLINOIS
One of the most fascinating types of industrial chemical research involves the invention of a new chemical product to take the place of an old and well-known product. Naturally, the new one must have some advantages over the old. The methods used in such research, strange to say, have been more or less standardized by the various industrial research laboratories working on this type of problem. It is a common opinion that the research man merely imagines the type of product he wants and then goes about building it. There seems to he a certain amount of mesmerism involved. Men in this type of work are often thought of as peculiar individuals and sometimes their minds are considered to be more or less unbalanced. The facts of the case are far from this viewpoint. The method of attack is quite simple. The advantages and disadvantages of the old product are first carefully reviewed. A very careful analysis is made to find out just what the faults of the old product really are. Though this sounds extremely simple, experience has shown that this first step is rather difficult and only the most level-headed of research men are capable of discovering the real defects in the old'material. The second step in this standardized method is the listing of a series of chemical substances which have never previously been used for the particular purpose of the old product hut bear some resemblance to it. An excellent example of this would he artificial resins which have been known ever since the first man worked dn organic chemistry and the natural resin. It is only very recently that artificial resins have been modified so that they could take the place of natural resins in varnishes, etc. The third step is quite evident. A selection must be made from this list of likely chemical substances, of one which exhibits the fewest possible faults as compared to the old substance. The fourth step in the general scheme is even more evident. After this selection has been made the substance must he modified to meet the new use. In order to illustrate this method of attack an example of a recent development a t the University of Illinois will be given. I t is a well-known fact that tincture of iodine is far from an ideal household antiseptic. The 7'3" iodine content specified by the United States Pharmacopeia is about one hundred times the concentration needed for ordinary purposes, with the result that in an open cut the iodine burns the flesh badly and may cause more harm than good. The remainder of the tincture of iodine is 95% ethyl alcohol. This has relatively little antiseptic value hut in turn has a tendency to burn the flesh badly. It is quite clear that the iodine content should be cut down and the
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alcohol should be removed. Such a recommendation immediately brings to mind a water solution of iodine with potassium iodide. This solution, however, has its practical faults. It would not be a satisfactory thing to carry in one's hip pocket, neither would it be a pleasant thing to carry in a trunk or traveling bag. It also requires large quantities and the ideal substance should be in a more concentrated form. Some years ago this situation was investigated and a dry powder containing potassium iodide, potassium iodate, and aluminum sulfate was recommended as a substitute.' This compound proved to be a stable powder; could be carried around in.a cardboard box or other container and when thrown in warm water would liberate 60% of its weight as free iodine. A dilute solution used as a gargle was found very effective. In some cases a solution having a bactericidal power of pure. phenol could be put in the mouth without excessive irritation. Solutions of greatly varying strengths could be made up and even the dry powder could be used in the presence of a small amount of moisture on the surface of the skin without causing bad burns. Recently it was thought possible that another antiseptic could be made by utilizing the corresponding chlorine compounds. An attempt was made to make magnesium hypochloride in a dry state. Though considerable research was done on this preparation we were unable to make the dry compound. Attempts were then made to make a calcium hypochlorite free from chloride. The best method found after a rather thorough investigation of this subject was the MacMuflin2 method. The underlying principle of this method was the preparation frrseof an alkyl hypochlorite by treating an alcohol with hypochlorous acid. The alkyl hypochlorite was then made to react with calcium hydroxide to form the calcium hypochlorite. It was hoped that calcium hypochlorite would be unstable in water but stable when dry. It was fairly stable when dry but too stable in water for practical purposes. Dry aluminum sulfate was then added to the calcium hypochlorite. This mixture liberated chlorine when placed in water and was satisfactory. Sodium dihydrogen phosphate was substituted for the aluminum sulfate and seemed to be a little better for this purpose. This mixture is fairly stable and can be carried around in an ordinary bottle without developing any real pressure. It will dissolve readily in warm water and laboratory tests have shown that it is about ten times as effective as phenol, weight for weight. Though no clinical tests have been made on this compound there is 1 See U. S. Patent 1,557266, issued October 13, 1925, to W. C. Moore, Research Department, U. S. Industrial Alcohol Company. 'See U. S. Patent 1,632,484 issued June 14. 1927, assigned to the Mathieson Alkali Co.
no reason, apparently, why i t should not prove to be a satisfactory general antiseptic. It is described in this paper, however, solely because its development represents a very excellent example of what is now a more or less standardized method of research for the production of a new chemical substance to take the place of an old and faulty substance.
