Prior to January 1, 1936, the rate of duty on imports of vinyl resins was 6 cents per pound and 30 percent ad valorem under paragraph 2, and 4 cents per pound and 30 percent ad valorem under paragraph 11 of the Tariff Act of 1930. Under the terms of the trade agreement with Canada, the duty under both paragraphs was reduced to 3 cents per pound and 15 percent ad valorem. This rate was generalized to the other countries from which we have received imports, with the exception of Germany.
Exports from the United States.
Exports of vinyl resins are not separately shown in official statistics.
11. OTHER SYNTHETIC RESINS
The synthetic resins already discussed are those in substantial commercial production but, by no means, the only ones known or produced. Several thousand new ones have been reported and the search continues in laboratories throughout the world. A successful new product must be one made from inexpensive raw materials or must possess some property or advantage that will permit its sale at a price level above that of other resins.
No attempt is here made to list the host of less important resins. Certain ones of unusual interest or possessing unique properties are described below. These include resins obtained from adipic acid, aniline, citric acid, diphenyl, furfural, lignin, sugar, and sulphonamide.
Adipic acid resins.
The resins from adipic acid are classed as alkyd resins. Those obtained by the condensation of adipic acid and glycerin are soft and rubbery and are used to some extent in surface coatings and in photographic films. In these the resin is formed in three stages as in other alkyd types: A soluble liquid, a viscous rubbery product, and a form insoluble in the usual solvents.
Commercial domestic production of these resins was reported for the first time in 1935 and the output has increased each year since then.