edited by JOHN H. WOTlZ Southern Illinois University Carbondale, Illinois 62901
A Case History of Transmuting an Idea into Money Milton Orehin University of Cincinnati Cincinnati, Ohio 45221 U.S. patent 2,939,851 dated June 7, 1960 describes the "Preparation of Urethanes Wherein Triethylene Diamine is Used as the Catalyst" and was issued to Milton Orchin, Cincinnati, Ohio, assignor to Houdry Process Corporation, Wilmington, Delaware. Triethylenediamine was given the Trademark Dahco, by the Houdry Co., an acronym for its systematic (Von Baeyer) name, 1,4-Diazabicyclo[2.2.2]octane:
This catalyst revolutionized Houdry's business and was for years, and is still, one of its biggest money earners. The patent expired in 1977 and so it is an appropriate time to tell thestory of how its use as a catalyst for the preparation of polyurethanes was discovered and oatented. The history of the assignment is easy to dispose of; it consisted of a three sentence letter to the author: "Enclosed herewith is the Assignment for the above-identified patent aoplication. Please sien this form where indicated. insert date. have notarized, and return to us. Three dollars is~nclosedfor assianment and cost of notarization." 1; April 1953 I accepted an appointment as Associate Professor in the Applied Science Department of the Universitv tfCincinnati.~i'hisDepartmen; was a graduate depsrte sChemistry and mcnt of the University and awarded d e ~ ~ ein Physics. Its work was supported exclusively by grants and contracts. One of the contracts I inherited was a program sponsored by the Bureau of Aeronautics, Department of Navy, on protecting the leading edges of jet aircraft from rain erosion. Various organic polymeric reagents had been tried hut the adhesion to the aluminum surface under impad was vew. poor. . Aticr ahout a year's wurk with only modest success concerned with altering existing furmulations, I decided to switch to a completely differentkind of polymer, namely, the polyurethanes about which glowing reports were coming in via technical articles, principally from Germany. At that time (1954) the basic chemistry of polyurethane formulations was fairly well known but there was relatively little kinetic data available. I t was, of course, well known that the relative rates of reaction of isocvanates with active hvdroeen comoounds was: R2NH > R N H ~ >NH3> ArNH2> ROH> HOH > RC02H. The chemistrv of the chain extension reactions was also well known hut thkre was relatively little published material on 782 1 Journal of Chemical Education
one of the cross-linking reactions, namely, the reaction of substituted ureas with free isocyanate. We accordingly undertook a program designed to secure kinetic data on this and related reactions (Reilly, C. B., and Orchin, M., Ind. Eng. Chem., 48,59 (1956); C. Reilly, M. R. Huev and M. Orchin., Wrieht " Air Development Center Tech. Report 58-100 (1958). In 1956 I left the Applied Science Deoartment to become .. Head of the Chem:str). Drpartmrnt at the I.'niversity of C~ncinnatiand drnpptd the work on urethanei. Huwmw, I had a contract with the Huudry Process (:~,rporariondoing work in modificar~unof t h 0x0 ~ I'rowsi and when I rnowd. this was the on[, contract I moved with me. 111add~tionto the contract, which pro\,ded fur a graduate f1:lluwship, I had a consulring arrangement with Houdry and visited their lahoratories in Linwoud, Pennsylvani;~several tunes a year. On one #rim\,visits in 1957 or 8. we dis~:ussedthe oos=ible structure of a high melting white solid which had been'isolated in small quantity as a by-product from some reactions utilizing ethanolamine and related compounds. The chemists a t Houdrv ultimatelv.proved its structure: it was triethvlene. diamine. Once the structure was established and we started to discuss the chemistry of Dabco, I became excited about the possibility of usine it in oolvurethane formulations since I had some backgrirund f0.r the reaction and its c~tillysis.Dahco was a rrlatively w t ~ hase ~ k rompared to Yalkvlpipt:ridines but the availahiiity of those lone pair electron; projecting out from the nearly spherical bicyclo structure convinced me that it should be agood nucleophile, especially in reactions where steric requirements were of over-riding importance-as in the catalvsis of the ~olvurethanecross-linkine reactions. I had ~ o u i r send y me' a small bottle of Dabco f i r trial. One dav while visitine a neiehhorine " " lahoratorv where one of my former graduate students was performing some typical ~olvurethanefoaming reactions in which ~olvestersterminated with hydroxyl Goups were being treaiedwith tolylenediisocyanate in the presence of aqueous N-methyhorpholine, I suggested that Dabco be substituted as the catalyst. I recommended 1110ththe molar quantity of the morpholine. Not only did the Dabco give the same rise but the foamed urethane seemed to be considerably (about '12) less dense and the cell structure seemed very uniform. Later the same day I phoned my liaison at Houdry and told them of the exciting results. The research people a t Houdry convinced their management (with some outside pressure) to undertake the manufacture of a comoletelv new catalvst in a non-netroleum venture. The highly skilled and creative people in the lab at Houdry picked UD the idea and verv soon mastered the art as well as the science of polyurvthane foam trchnology. Such is thr. history of 1J.J. Patent 2.9:19,851 and 20 or so foreign patents corresponding to it. This column is a series of short articles on the less known events that contributed to important and interesting developments in chemistrv. Manuscriots. of about two double-soaced. tvoewritten
