Synthetic resins and their raw materials / A survey of the types and uses of synthetic resins, the organization of the industry, and the trade in resins and raw materials, with particular references to factors essential to tariff consideration. Under the general provisions of section 332, title III, part II, Tariff act of 1930. - United States Tariff Commission

Year	Production¹	Imports²	Apparent consumption³	Percent supplied by imports
	1,000 pounds	1,000 pounds	1,000 pounds
1923	53,325	20,992	74,317	28
1927	53,601	6,577	60,178	11
1929	39,263	35,007	74,270	47
1931	20,934	30,971	51,905	60
1932	13,593	27,002	40,595	66
1933	30,621	42,786	73,407	58
1934	37,922	47,995	85,917	56
1935	47,653	48,455	96,108	50
1936	89,536	39,806	129,342	31
1937⁴	115,979	52,664	168,643	31

¹ From table [33].

² From table [43].

³ Production plus imports.

⁴ Preliminary.

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

Description and uses.

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 a perfume 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.