1From Germany. No imports under trade agreement rate.2Belgo-Luxemburg trade agreement rate.3Preliminary.Source: Foreign Commerce and Navigation of the United States.
1From Germany. No imports under trade agreement rate.
2Belgo-Luxemburg trade agreement rate.
3Preliminary.
Source: Foreign Commerce and Navigation of the United States.
Table45shows the principal sources of our imports of crude naphthalene in recent years. Germany was the principal source until 1936; the United Kingdom, previously the next most important source, was first in 1936 and 1937. In the last three years appreciable quantities have been received from Poland, Czechoslovakia, and the Soviet Union, hitherto unimportant sources.
Table 45.—Crude naphthalene (solidifying under 79° C.): United States imports for consumption from principal sources, in specified years
1Preliminary.Source: Compiled from official statistics of the United States Department of Commerce.
1Preliminary.
Source: Compiled from official statistics of the United States Department of Commerce.
Exports are not shown separately; it is doubtful if any naphthalene is exported. Demand in the United States has exceeded domestic production.
The commercial development and widespread application of surface coatings and finishes made from alkyd resins, in which phthalic anhydride and glycerin are the principal components, has resulted in a world-wide shortage of naphthalene, which is a raw material used in making phthalic anhydride. In recent years about one-half of domestic requirements of crude naphthalene have been imported (see table46) from Europe, principally Germany and the United Kingdom. Increased demand for the same purposes, in these countries, has so reduced the quantities available for export as to create a serious shortage in the United States. Germany placed an embargo on exports late in 1935 and continued it until late in 1937.
Table 46.—Crude naphthalene: United States production, imports, and apparent consumption in specified years
1From table33.2From table43.3Production plus imports.4Preliminary.
1From table33.
2From table43.
3Production plus imports.
4Preliminary.
Vast quantities of naphthalene potentially available in this country were not recovered because of the low prices prevailing until 1936. Since then an increase in the price of crude naphthalene from 1.55 cents to 2.5 cents and 3 cents per pound has stimulated production and has led to additional recovery.
Phthalic anhydride is an aromatic polybasic organic acid anhydride made from naphthalene by vapor phase catalytic oxidation. It is marketed as white needle-shaped crystals or flakes having a melting point of 130° to 131° C. and boiling at 284° to 285° C. It is the cheapest and most widely used aromatic organic acid. Its most important use is in the manufacture of synthetic resins of the alkyd type. Other important uses are in dye intermediates; in phenolphthalein; in benzoic acid; in dyes such as indigo, phloxines, rhodamines, erythrosines; and in esters such as dibutyl phthalate (widely used as a plasticizer in nitrocellulose lacquers and films and of interest as a greaseless lubricant), diethyl phthalate (used as aperfume fixative and denaturant of alcohol), dimethyl phthalate (used as a plasticizer in cellulose acetate films), and diamyl phthalate (used as a plasticizer). Important new processes using phthalic anhydride as a raw material include the syntheses of anthraquinone, substituted anthraquinones, and benzoyl benzoic acid.
Before the World War phthalic anhydride was made by heating naphthalene with sulphuric acid in the presence of mercury; the sulphuric acid acted as an oxidizer, and sulphur dioxide and carbon dioxide were liberated. This process was used in Europe and in the United States to produce the small quantities of phthalic anhydride needed for the manufacture of certain dyes and intermediates. It proved highly unsatisfactory as to operation; the yield varying widely from batch to batch. The sales price of the phthalic anhydride produced at that time was as high as $4.25 per pound, whereas it is 12 to 14 cents per pound today.
In September 1916, Gibbs and Conover, working in the Color Laboratory of the Bureau of Chemistry and Soils, United States Department of Agriculture, developed a process for the synthesis of phthalic anhydride by the direct vapor phase catalytic oxidation of naphthalene. This work was done under the United States Government’s wartime investigation of the manufacture of intermediates and dyes. Gibbs and Conover were granted United States Patent No. 1,285,117 covering the basic process, and the invention was assigned to the people of the United States. This process revolutionized the manufacture of phthalic anhydride, causing the market price to drop to $2.85 per pound in 1918, to 46 cents per pound in 1920, and to 13 cents in 1930. With each decline in price new outlets were found, and domestic production increased practically every year, rising from 227,000 pounds in 1918 to 23,500,000 pounds in 1935.
By a remarkable coincidence the same basic process was developed in Germany, by Alfred Wohl, in the laboratories of the Interessen Gemeinschaft Industrie A. G. (German I. G.), at almost the same time that Gibbs and Conover made their discovery. In 1920 Wohl applied for a United States patent covering this process, claiming invention in the summer of 1916. There was some doubt whether his discovery had been made 2 months earlier or 3 days later than that of Gibbs and Conover, but in July 1934 the United States Court of Customs and Patent Appeals rendered a decision in favor of the German inventor, allowing Wohl’s claim filed with the German patent office on June 28, 1916. Therefore, Wohl’s claim covering the air oxidization process was upheld and he was granted United States Patent No. 1,971,888, issued August 28, 1934 and assigned to the German I. G.
Several domestic firms began commercial production of phthalic anhydride about 1918 under the patent of Gibbs and Conover and have since operated the process continuously. Such manufacturers are presumably protected from possible patent litigation and the payment of royalties under the Wohl patent by section 3 of the so-called Nolan Act of 1921, which states: “No patent granted or validated ... shall affect the right of any citizen of the United States or his successor in business to continue the manufacture, use, or sale commenced before the passage of this Act, norshall the continued manufacture, use, or sale by such citizen ... constitute an infringement.”
Table47shows the production and sales of phthalic anhydride from 1917 through 1937.
Table 47.—Phthalic anhydride: United States production and sales, 1917-37
1Not available.Source: Compiled from annual reports of the Tariff Commission on dyes and other synthetic organic chemicals in the United States.
1Not available.
Source: Compiled from annual reports of the Tariff Commission on dyes and other synthetic organic chemicals in the United States.
There are six domestic makers of phthalic anhydride, with producing units at Bridgeville, Pa., Buffalo, N. Y., Philadelphia, Pa., Deepwater Point, N. J., Saint Louis, Mo., and Detroit, Mich. Five of these firms have been producing in commercial quantities continuously for a number of years and it is therefore believed that these companies may continue to produce without the payment of royalties. New producers using this process, however, might be at a disadvantage unless licensed to operate without the payment of royalties by the owner of the patent.
The production of phthalic anhydride has increased remarkably since the discovery of the vapor phase catalytic process of manufacture. Until 1922 the only large outlet was the coal-tar dye industry. The development of new uses for phthalic esters, principally dibutyl phthalate, increased the demand during the period 1922-28. With the drop in price of phthalic anhydride, resins made from it and glycerin became of commercial interest and about 1929 their production began to increase sharply. Most of the increased output since that year is accounted for by its use in alkyd resins. As previously stated, surface coatings made from these resins are now applied to practically all “indoor” surfaces, both wood and metal, and to “outdoor” use on metal. Largely as a result of the growing popularity of surface coatings of the alkyd type the domestic production ofphthalic anhydride exceeded 45 million pounds in 1937 and may reach 50 million pounds in 1938. This estimate is based on the present trend of consumption of alkyd resins and current use therein of phthalic anhydride. Should other polybasic acids be used in greater proportion the estimate would have to be revised. Considerable research work is being done on certain polybasic acids, with very promising results in some instances. Maleic anhydride is being used commercially, as are adipic acid, malic acid, and succinic acid. Other possibilities include such acids as citric, tartaric, sebacic, fumaric, and oxalic.
Phthalic anhydride is manufactured in Germany, England, France, Italy, and Japan, but no statistics of foreign production or of international trade are available. The output in Germany is known to be increasing rapidly and is believed to be the principal reason for the German embargo on exports of naphthalene.
In England there are two makers: Imperial Chemical Industries, Ltd., and Monsanto Chemicals, Ltd. The latter is a branch of the American firm of the same name.
In Italy, production was started in 1928 by the A. C. N. A. at Cengio. Capacity is given as 600,000 pounds annually, and the process is essentially the same as in this country.
Japanese production is estimated at 6 million pounds a year. Nihon Seuryo’s plant is the principal one, and the Nishijima mill, at Osaka, the next in importance.
Imports of phthalic anhydride are dutiable under paragraph 27 at 7 cents per pound and 40 percent ad valorem based on American selling price. There were practically no imports since the World War until 1937, when 223,431 pounds were imported from England to relieve a temporary shortage.
Exports, if any, are not shown separately in official statistics.
Phthalic anhydride is the cheapest polybasic organic acid and therefore the most widely used in the production of alkyd resins. The rapid rise in consumption of surface coatings and finishes made from these resins presages greater demand for phthalic anhydride (and glycerin) in the future, particularly if this type of outdoor finish for wood is successful.
The world-wide shortage of naphthalene, with attendant sharp increases in price, raises the question of whether there may not be partial or complete replacement of phthalic anhydride by other polybasic acids in certain types of alkyd resins. The probability of such replacement seems remote unless the use of other polybasic acids, at present much higher priced, so improves the properties of the resins as to give a superior product. Approximately 100 pounds of naphthalene are required to produce 109 pounds of phthalic anhydride. Naphthalene at 3 cents per pound gives phthalic anhydride a raw material cost of 2.75 cents per pound as compared with 1.45 cents per pound when naphthalene was 1.55 cents per pound. Inother words, the increase of 1.5 cents per pound in naphthalene, meant an increase of only about 1⅓ cents per pound in the raw material cost of phthalic anhydride, and only approximately ¼ cent per pound in the raw material cost of an alkyd resin surface coating containing about 20-percent phthalic anhydride.
Maleic anhydride is obtained as a byproduct in the manufacture of phthalic anhydride and as a major product by the vapor phase catalytic oxidation of benzene. Domestic production, still small compared with phthalic anhydride, has increased many fold during the past two or three years. In 1937 there were three producers of maleic anhydride, with an output totaling 2,114,176 pounds. The uses of maleic acid derivatives other than in making resins are minor.
Malic acid is widely distributed in the vegetable kingdom, occurring especially in unripe apples. Commercially it is obtained by synthesis. Domestic production was reported for the first time in 1935. Malomalic acid is formed by heating malic acid. United States Patent No. 1,091,627 covers a resin made from malic acid and glycerin which will increase the toughness of phthalate resins. United States Patent No. 1,667,198 suggests the use of malomalic acid to form resins of glass-like appearance.
Adipic acid is made by oxidation of cyclohexanol. When condensed with glycerin it yields an alkyd resin which is soft and rubbery and which does not harden when heated. Numerous patents have been granted on the preparation of adipic acid and its resins. Commercial production of adipic acid was first reported in 1935, and the output increased in 1936 and in 1937.
Succinic acid is a white crystalline powder melting at 185° C. and boiling at 234° C., with decomposition to succinic anhydride. It may be obtained by the reduction of maleic acid. Condensation with glycerin gives a resin tougher and more flexible than is obtained with phthalic anhydride.
In 1937 there were two commercial producers of succinic acid. It is believed that small quantities are used in combination with phthalic anhydride in alkyd resins.
Fumaric acid is a white crystalline powder obtained by the prolonged heating of or by the action of mineral acids on maleic acid. Fumaric acid and maleic acid are structurally identical and the former decomposes at about 280° C., forming the latter. In 1937 there was one domestic maker of fumaric acid.
Glycerin (glycerol) is a clear, colorless or almost colorless, odorless, syrupy, hygroscopic liquid. It is obtained as a byproduct of the soap and fatty acid (oleic acid or red oil and stearic acid) industries. Other sources are insignificant; glycerin can be produced by the fermentation of carbohydrates such as molasses, but when glycerin prices are low this process is not profitable. The chief commercial grades of crude glycerin are “soap lye” glycerin, a byproduct of the soap industry, containing about 80 percent glycerin, and “saponification” grade, a byproduct of the fatty acid industry, containing about 88 percent glycerin. Chemically pure grades contain about 95 percent and dynamite grades about 98.5 percent glycerin. Other grades include “30° yellow distilled” containing about 96 percent glycerin.
The uses of glycerin are extremely varied, the most important being in the manufacture of alkyd resins and ester gums; in the manufacture of nitroglycerin and dynamite; as a moistening, antiseptic, and sweetening agent in tobacco; in pharmaceutical and medicinal preparations; and in certain soft drinks, soaps, and inks.
The output of both the crude and the refined has increased in recent years, reaching new highs in 1937. Chemically pure glycerin constitutes about 60 percent of the total refined output and dynamite and other grades about 40 percent. In the production statistics shown in table48, grades such as yellow distilled are included with the dynamite grade. Since large soap makers refine their own crude glycerin, the sale of crude is only a small part of the total output.
Table48shows domestic production of glycerin by grades and table49production for sale.
Table 48.—Glycerin: United States production by grades, in specified years, 1919-37
Source: Bureau of the Census, U. S. Department of Commerce.
Source: Bureau of the Census, U. S. Department of Commerce.
Table 49.—Glycerin: United States production for sale, in specified years, 1919-35
1By chemical and soap manufacturing plants only.2Adjusted for comparison with 1933.Source: Bureau of the Census, U. S. Department of Commerce.
1By chemical and soap manufacturing plants only.
2Adjusted for comparison with 1933.
Source: Bureau of the Census, U. S. Department of Commerce.
Crude glycerin is produced by about 200 soap makers and by about 12 producers of fatty acids. Soap factories are located in more than half the States, the principal ones being in Ohio, New York, Massachusetts, New Jersey, Illinois, California, and Pennsylvania; the fatty acid plants are located in five or six States, Ohio being of chief importance. Most of the smaller producers sell their output of crude glycerin. Refiners of glycerin are few in number compared to the producers of crude. The larger soap plants refine their own crude glycerin and in addition purchase crude from other plants for refining.
The process of recovering glycerin consists of chemically treating weak glycerin solutions separated from the soap or fatty acids, and then concentrating and distilling under reduced pressures. The average yield is less than 10 percent but varies from about 9 to 12 percent, depending upon the kinds of oils and fats used. When prices are high every effort is made to recover the maximum yield of glycerin; when prices are low, cost of chemical treatment and distillation makes it advisable to allow more glycerin to remain in the soap or to discard the weak solutions.
As in the United States, glycerin is produced in foreign countries, as a byproduct of the soap and fatty acid industries. The United Kingdom, Germany, and France, and recently the Soviet Union, are the leading producers. The output in each of these countries is estimated to be less than a third of the output in the United States. The British Census of 1930 reports the production of crude glycerin in the United Kingdom at 44 million pounds. Authentic statistics on production in other leading countries are not available, but most estimates show lower figures than for the United Kingdom. In some European countries the normal production of soap results in more glycerin than can be utilized.
France is the principal net exporter of crude glycerin and the United Kingdom of refined glycerin. The Netherlands, Germany,and France are also net exporters of refined glycerin. The international trade of certain of the more important producing countries in crude and refined glycerin is shown in table50.
Table 50.—Glycerin: Imports and exports of principal countries, 1931 and 1933-37
1Imports from Cuba and the Philippines not included in the United States statistics. These imports, consisting of crude glycerin, averaged about 2,200,000 pounds annually for the period 1931-37.2Included, if any, with refined.3Not separately reported.4Preliminary.Source: Official statistics of each country.
1Imports from Cuba and the Philippines not included in the United States statistics. These imports, consisting of crude glycerin, averaged about 2,200,000 pounds annually for the period 1931-37.
2Included, if any, with refined.
3Not separately reported.
4Preliminary.
Source: Official statistics of each country.
Under the Tariff Act of 1922, paragraph 43, imports of crude glycerin were dutiable at 1 cent per pound and refined glycerin at 2 cents per pound. The Tariff Act of 1930, paragraph 42, carries the same rates. Imports of crude glycerin from Cuba enjoy a preferential rate; they were dutiable at 0.8 cent per pound up to September 3, 1934, and at 0.4 cent per pound thereafter. Under the trade agreement with the Netherlands, effective February 1, 1936, the rate on refined glycerin was reduced from 2 cents to 1⅔ cents per pound (⅔ cent plus regular rate on crude, but not more than 1⅔ cents). Under the trade agreement with France, effective June 15, 1936, the rate on crude glycerin was reduced from 1 cent to 0.8 cent, which automatically further reduced the rate on refined glycerin to 1¹⁴⁄₃₀ (approximately 1.47) cents per pound. The rates under these lasttwo trade agreements are generalized to all countries which do not discriminate against our commerce.
The amount of glycerin supplied by imports has greatly declined. Prior to the World War, imports of crude glycerin ranged from 30 million to 40 million pounds annually. After the war imports were less and after 1929 declined to comparatively small quantities, except in 1934. Imports of refined glycerin were relatively unimportant until 1924, except in 1920. They amounted to almost 11 million pounds in 1926, but declined thereafter. Some of the imports are reexported with benefit of drawback. In 1930, 1,006,164 pounds of imported crude glycerin and 396,792 pounds of imported refined were thus reexported, chiefly in the refined grades. Corresponding figures in 1932 and 1933 were 197,331 and 111,753 pounds of crude, and 40,011 and 10,056 pounds of refined.
Statistics of imports other than from Cuba and the Philippines are given in table51. Table52shows imports of crude from Cuba and table53imports of crude from the Philippines.
Table 51.—Glycerin: United States imports1for consumption 1919-20 and 1923-37