Phthalic Anhydride: A Statistical Review J O H N R.
SKEEN
S p a r k e d b y n e w a n d e x p a n d e d u s e s , t h e p r o d u c t i o n of p h t h a lic anhydride has steadily increased . . . Future production g o a l s are d e p e n d e n t u p o n a v a i l a b i l i t y of r a w m a t e r i a l s , p a r ticularly n a p h t h a l e n e JfiiTHALic anhydride, produced in this country for 32 years, has had a prominent place in our industrial history. Patent litigation, methods of production, new and expanded uses, and capacity increases, make a long and interesting record. A new factor was introduced by the war demands for phthalic resins, plasticizers, insect repellents, and dyes; production was increased to the maximum consistent with the availability of raw materials, particularly naphthalene. Annual production of phthalic anhydride averaged 114 million pounds during the period 1942^45, or three times the prewar output. Facilities operated at near-capacity rates and sources of naphthalene, the raw material, were taxed to the utmost. This year installations with rated capacity for about 203 million pounds of phthalic anhydride are expected to be in operation and actual production may reach 165 million pounds. Accomplishment now depends upon how much naphthalene can be supplied from abroad and from domestic sources. Eight years ago it was apparent that war was increasing the demand for the anhydride and the industry provided new capacity of 21 million pounds almost immediately. Before this was in full operation the War Production Board sponsored an expansion which brought the total to 107 million pounds. While a further increase followed, WPB requested still greater capacity in 1944. Three chemical producers, new to this field, were authorized to build plants with an aggregate output of 21 million pounds. Subsequently three more plants were built and enlargements made to three others. Mounting military needs impelled this hurried expansion. Vat dyes for uniforms were the first requirement. Then followed large orders to make alkyd coatings for equipment and installations, and dibutyl phthalate and allied esters were diverted entirely to military plastics and smokeless powder. Finally, in 1943, dimethyl phthalate was needed in the tropics as an insect repellent. One thing was added to another and nothing subtracted. It is probable that the military demand was nearly 150 million pounds in 1944 and exceeded a rate of 200 million pounds the next year, of which no more than 2 or 3 % reached the civilian. As the civilian demand was cumulative in great part, the anhydride market continues to exceed the ability to supply. Before 1917 less than 50,000 pounds of 2958
phthalic anhydride were imported annually and consumed in making phenolphthalein, benzoic acid, and a few perfume esters. When the German dyes were cut off, the importance of the chemical was soon appreciated by the lack of fluorescene, the eosines, rhodamines, and other dyes. Price soared and greatly exceeded the old invoice price of imports, 24 cents a pound. Four domestic firms undertook production in 1917 following the German method of treating naphthalene with concentrated sulfuric acid in the presence of mercuric sulfate. However, the Government made the Gibbs-Conover process available the next year. This was immediately adopted and relatively inexpensive and commercially attractive phthalic anhydride was supplied. Simultaneously, the separate efforts of B. H. Jacobson and W. L. Savell brought about the reduction in price of aluminum chloride from over $7.00 a pound to less than 50 cents. As a direct result, anthraquinone was made for the first time by the Friedel-Crafts condensa-
Table I. Phthalic Anhydride: Production and Price Production 0 , Number of prothousand ducers b Price c pounds 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 (1st quarter)
139 227 291 796 n.a. 1,629 2,344 2,787 3,900 4,379 4,550 6,031 9,169 6,693 n.a. 6,259 14,076 20,680 23,422 31,244 45,211 27,650 44,274 57,946 81,309 94,807 114,118 122,723 125,825 112,746 140,981 38,563
4 11 6 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 6 5 6 6
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