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F. K. ROGERS and D. J. KENNEDY Shawinigan Chemicals, Ltd., Montreal, Quebec, C a n a d a
Crotonic Acid Poor location
+ undeveloped market + unrealistic pricing = product failure
Twhyothis company undertook some of the reasons production APPRECIATE
of crotonic acid, it is necessary to understand the company background, particularly as it stood at the end of the war when crotonic acid production began. Shawinigan Chemicals is a Canadian company and a wholly owned subsidiary of Shawinigan Water and Power Co. which develops and distributes hydroelectric power in the province of Quebec. At the time this project was contemplated, all chemicals produced by Shawinigan Chemicals derived from acetylene, in turn derived from calcium carbide which is a substantial consumer of power. Because of this strong energy position, and also because of the relatively small potential for chemicals in Canada, a large part of production went to the export market. At that time about 60% of sales were exported to the United States, to the United Kingdom, and other parts of the world. With this background, there was a tendency to give the export market credit for a greater potential than would be true of a company which sells only in the domestic market. On the technical side, there had been a good deal of work on organic oxidations, and a considerable knowledge of the field had been built up. This work resulted in the 1930's in the discovery and development of the dual process for oxidation of acetaldehyde to acetic acid and acetic anhydride. Laboratory work on a commercial process for crotonic acid commenced in 1942 and was carried on until the pilot plant started operation in 1944. I t culminated in the granting of a patent (U. S. 2,413,235) which was not basic in nature but covered improvements in recovery of crotonic acid produced by crotonaldehyde oxidation. Crotonaldehyde was produced as an intermediate for n-butyl alcohol and also as a by-product in production of acetaldehyde by hydration of acetylene. The latter crotonaldehyde at that time could
be considered by-product as it had not been found suitable for conversion to butyl alcohol. Since then it has been found that this crotonaldehyde may be hydrogenated to butyl alcohol satisfactorily.
Applications
A study of the literature indicated many possible fields of application for the acid and its esters, most of which took advantage of the double bond in the a, 0 position: in resin modification; drying oil modification ; surface coatings, particularly the alkyds ; plasticizers ; perfumery; and as a chemical intermediate. The double bond in the a, B position allows the formation of two stereoisomers of the cis-trans geometric type. The trans isomer is more stable and has a higher melting point (72' C. us. 14.6' C. for the cis isomer). With the olefinic double bond conjugated with the double bond of the carboxyl group, the reactivity of both double bonds is considerably decreased. Crotonic acid, however, will undergo most of the additions and condensations peculiar to the ethylenic bond and the carboxyl group under the correct conditions. With the ethylenic bond, halogen and halogen acid addition may be made; the acid will copolymerize with monomers such as styrene, butadiene, vinyl acetate, and vinyl chloride and will undergo Diels-Alder type condensation with conjugated dienes. The carboxyl group permits formation of salts, esters, amides, and related compounds. This myriad of possibilities led the company to believe that crotonic acid could find an important place in the chemical world. How large and how soon was problematical. There had been some experience previously in launching new products, such as acetylene black, poly(viny1 acetate), poly(viny1 formal), acetal, and butyral.
However, crotonic acid was in a different category as it was a chemical intermediate rather than a more finished product. Its fields of application proved impossible to define, and they could not be determined by study of existing markets as the acid was not at that time an article of commerce. A case might be made for the necessity of application research. With the multitude of end-use possibilities and the long, tedious, and costly program this would have entailed, it was decided that it was better to launch the product without delay, and this was the course of action followed. The acid had been produced on a small scale by other firms, and it was found after the war that I. G. Farben had operated a plant of 6 tons per month capacity at Hoechst and another of 67 tons per month at Huls. The latter production was used for thiodibutyl butyrate manufacture. Other producers had offered it as a high-priced chemical specialty.
Production and Problems
A pilot plant of 5 tons per month capacity went into operation in December 1944. The pilot plant suffered a few birth pangs but on the whole ran quite well. The process consisted essentially of the catalytic air oxidation of crotonaldehyde in the presence of an inert diluent which acted as a solvent for the oxidation products. The oxidation catalyst, an organic salt of copper, manganese, or cobalt, was present to the extent of 2y0 or less. After distillation of the crude, it was purified by centrifuging. Caking. A technical problem which proved troublesome was caking. The product acid was centrifuged before loading in the wooden barrels used for shipment. In spite of this: the crystals still contained some liquid, chiefly the low melting cis isomer. After the VOL. 52, NO. 1
JANUARY 1960
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product had been stored for some time, liquid settled to the bottom causing caking. Experimental work proved that caking could be overcome by recrystallization out of hot water, which gave a freeflowing product of improved color and purity but, of course, added to the product cost. Pricing. A brochure on the acid, containing results of a complete literature survey, was distributed to a wide list of companies in Canada, the United States, and the United Kingdom, Press announcements were made. and a limited amount of advertising was done in trade magazines. There followed a flood of requests for samples and requests for quo tation. In considering sales price there \vas the question of whether to price the product at a level M-hich would show a profit in which case its application would be limited to rather specialized fields, or to sell at a loss in the expectation that sales would improve rapidly and commercial production could be started with a minimum of delay. The latter course was chosen, and the price was set at 25 cents per pound Canadian funds, f.0.b. the plant. This price was considerably below cost, as operation rate was 10,000 pounds per month, and labor cost alone at this capacity accounted for sales return. At that time the duty on crotonic acid entering the United States was 25y0 ad valorem so the price was actually 31 cents per pound for accounts in the United States with the Canadian dollar a t par. Applications iMarket. As part of the sales development work, a series of crotonic acid esters. including those of lower aliphatic alcohols, allyl and vinyl esters, and crotonic anhydride. Sample quantities of these were offered along with the acid, although manufacture of these esters was not intended. I t was expected that interested accounts would do so
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with company assistance. Very little application research was done, as most of the companies dealt with were quite capable of doing this work for themselves and did not solicit help. \Vith the formidable U.S. tariff and the difficulties oflaunching a new product off-shore, it was hoped that the Canadian market Fvould soon begin to account for substantial quantities of the product. In this the company was disappointed. Xlost of the Canadian companies were controlled outside the country. This meant that frequently when a Canadian manufacturer was approached with the new raw material, his response lvould be that his company's research rvork was conducted outside Canada and that the people to discuss this were in the United States or the United Kingdom. Thus, before the product would see utilization in Canada, it would have to be screened outside the country and probably be used there commercially before it would find commercial application in Canada. Competition. In the United States, production of crotonic acid was undertaken by Tennessee Eastman (now Eastman Chemical Products, Inc.), joined at a later date by Carbide and Carbon Chemicals (now Union Carbide, Chemicals Division). This had the effect of diverting many of the previous inquiries from U. S. customers and of taking over in large measure the small markets rhe company had managed to create. The pilot plant was operated off and on for about three years and accumulatcd enough product to be able to shut down and continue to supply for some time subsequently. I t had become apparent that the market was not going to develop rapidly and that, in spite of the relatively l o ~ vprice, only small volume markets had been found. When the time came to start u p the pilot plant again, en-
INDUSTRIAL AND ENGINEERING CHEMISTRY
thusiasm had waned and even the most optimistic could not avoid acknowledging that the period of losses was to be an extended one.
Hindsight Since that time the price of crotonic acid has risen in keeping with inflation, and it is now slightly over 50 cents per pound. Eastman Chemical Products discontinued manufacture but have recently resumed again. Several uses have becomr commercial. Copolymers of vinyl acetate and crotonic acid are enjoying increasing use in applications which utilize their alkali solubility. The vinyl ester of crotonic acid is being used as a cross-linking agent for polymers. I t has found application as an insect repellent based on the butyl ester of a crotonic acid-butadiene adduct. It is also reported to be used in alkyds. These applications are not large but growing. Markets in Canada are still extremely small, not large enough to be reported in import statistics. In retrospect, the errors made were establishment of an unnecessarily low price and production in the wrong country. The slow gro\vth rate in the market for crotonic acid could not have been anticipated; that is the gamble anyone must take in embarking on production of an organic intermediate rvhen others are expected to find uses for the product. If the operation had been established in the United States and if a price had been set which would have shown at least a modest return, the company would have been preparcd for the long pull. As it was, however, it was prepared for losses of limited duration but not for the extended period of time it has taken crotonic acid to become commercial.
