Growth of the industry.

The coal-tar synthetic resin industry in the United States began on a small scale some years before the World War. The output then was confined to a few types of tar-acid resins and the applications were quite limited until 1927, when certain of the basic patents expired. The output of about 1.5 million pounds in 1921 had increased to more than 13 million pounds in 1927 and the average unit value of sales had dropped from 81 cents per pound to 47 cents. Production continued to increase and the unit value to decrease annually until 1932 when general economic conditions forced a slight curtailment for 1 year. Since then the annual increase in volume and variety has been rapid. Production of non-coal-tar synthetic resins was started on a small scale in 1929 when both urea and vinyl resins entered the picture. Commercial production of the petroleum resins began in 1936 and of the acrylate resins in 1937. Table [1] shows the production and sales of coal-tar resins and of non-coal-tar resins, from 1921 through 1937.

Table 1.—Synthetic resins: United States production and sales, 1921-37

Year	Production	Sales
Year	Production	Quantity	Value	Unit value
	Pounds	Pounds
Coal-tar resins:¹
1921	1,643,796	1,674,456	$1,352,166	$0.81
1922	5,944,133	6,415,931	4,315,196	.67
1923-26	(²)
1927	13,452,230	13,084,313	6,094,656	.47
1928	20,411,465	20,778,856	7,211,958	.35
1929	33,036,490	30,660,513	10,393,397	.33
1930	30,867,752	24,014,093	7,323,656	.30
1931	34,179,000	29,343,000	7,862,000	.27
1932	29,039,000	23,891,000	5,001,000	.21
1933	41,628,485	31,657,653	7,238,560	.23
1934	56,059,489	43,350,876	10,126,849	.23
1935	90,913,162	65,923,334	12,777,195	.19
1936	117,301,780	86,213,735	17,056,099	.20
1937	141,098,844	108,284,175	20,165,064	.19
Non-coal-tar resins:
1932	1,898,000	1,787,000	796,000	.45
1933	3,571,717	3,256,411	1,745,102	.54
1934	(²)	3,500,829	1,491,145	.43
1935	(²)	(²)	(²)
1936	15,611,041	14,766,640	3,591,467	.24
1937	21,005,869	18,891,277	5,680,600	.30

¹ Does not include resins from adipic acid, coumarone and indene, hydrocarbon, polystyrene, succinic acid and sulfonamides. With the exception of coumarone and indene resins in recent years production of the resins not included was small.

² Not publishable. Figures would reveal operations of individual producers.

Source: Compiled from annual reports of the Tariff Commission on dyes and other synthetic organic chemicals in the United States.

Many factors have contributed to the growth of the synthetic resin industry. Among these are the intensive research and development work carried on by many individuals and firms; their widespread application in many fields competing with wood, metal, and glass; and the development of processes for raw materials which have greatly reduced their cost and made their wider use possible.

Raw materials.—Although the chief raw materials consumed in the synthetic resin industry are coal-tar derivatives and formaldehyde, many others are utilized. The rapid expansion of the industry has created new demands for materials in increasing quantities and has not only increased the markets for well-known materials but has resulted in the production on a huge scale of materials entirely new to commerce. Practically all the raw materials now used can be derived from a few natural substances, such as air, water, coal, petroleum crudes, salt, sulphur, and limestone. The air yields nitrogen which may be converted to ammonia, a raw material for urea, one of the components of the urea resins. Coal, as is well known, yields a great variety of substances, many of which are essential to synthetic resin manufacture. Benzene is the starting point for synthetic phenol; naphthalene is used to make phthalic anhydride and maleic anhydride; coke is converted to calcium carbide, which in turn yields acetylene, acetic acid, and many other synthetics; carbon monoxide which is converted to methanol and formaldehyde; and the natural tar acids such as phenol, the cresols, and the xylenols. Limestone is a component of calcium carbide, and salt yields needed alkalies and acids. Water is broken down, and the hydrogen is converted to ammonia, methanol, formaldehyde, and ethylene.

Some idea of the expansion in production of these raw materials whose principal use is in synthetic resins may be had by comparing the output in 1923 of tar acids, formaldehyde, phthalic anhydride, maleic anhydride, urea, vinyl acetate, and vinyl chloride, which amounted to 35 million pounds, with the output of 270 million pounds in 1936. The manufacture of these materials is largely by coal-tar distilling companies and makers of chemicals.

Resins.—The coal-tar resins are the most important in quantity, value, and variety of application. This class includes four groups: (a) tar acid, (b) alkyd, (c) coumarone and indene, and (d) polystyrene. Of these, resins from tar acids (phenol, cresols, and xylenols) are produced in the largest quantity, the output having increased from about 15 million pounds in 1932 to about 80 million pounds in 1937. In the latter year about 40 percent of the consumption of tar acid resins was in molded articles, 25 percent in paint and varnishes, 20 percent in laminated products, and 15 percent in miscellaneous uses.

The alkyd resins have shown a remarkable increase in output. Production totaled slightly less than 10 million pounds in 1933; in 1937 it amounted to about 61 million pounds. Practically all of the alkyds have been consumed in paints and varnishes.

The coumarone and indene resins have increased steadily over a number of years and are now one of the most important groups.

The polystyrene resins have been in an experimental stage for a long time, with the volume of production small. In 1937, however, commercial production of a water-white product was announced, and it is believed that the output of these resins will increase sharply in the near future.

The non-coal-tar resins were of little importance prior to 1930 and production amounted to less than 2 million pounds in 1932. Since then, however, progress has been rapid, both in types and output. Resins from urea constitute an important part of this class and the output has increased practically every year since 1929 when production was started. Most of the output is used in molded articles where light and pastel shades are required. In 1936, for the first time, appreciable quantities were consumed in laminating and in surface coatings.

The vinyl resins have been produced in increasing quantities for the past 8 years. Production reached a new high in 1937, and with the acceptance of this type of resin for safety glass laminations it is expected that the output will increase materially in the near future. In 1937 the application in surface coatings, molded articles, and laminations were of approximately equal importance.

The acrylate resins are among the newest commercial developments in this industry. Of the several types now manufactured, one appears valuable in surface coatings and adhesives and another, in the form of its cast or molded polymer, in airplane windows, machined articles, and lenses.

Petroleum resins were first produced in commercial quantities in 1936, but the output in that year was appreciable. These low-priced synthetics are used in surface coatings, laminations, and miscellaneous uses.