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.

by United States Tariff Commission

Tar-acid resins for miscellaneous uses.—The chief uses for tar-acid resins other than for molding, casting, laminating, and in coatings are as a bonding material, and as an adhesive. These resins form a valuable bonding agent for asbestos in brake linings and chemical tanks, for abrasives and for ground cork in special uses. As an adhesive they are used in making moisture-resistant plywood.

In 1937 there were five producers of tar-acid resins for miscellaneous uses, including the largest, who confined their activities to the making of resins and two, including the second largest, who also made products in which these resins were consumed.

Alkyd resins made from phthalic anhydride.—The rapid increase in the production of alkyd resins for use in coatings is one of the most remarkable in the whole resin industry. They go into varnishes, lacquers, and enamels for spraying, brushing, and dipping. The coatings may be air-dried, with a wide range of drying time, or dried by oven baking. The volume of alkyd resins used by the coating industry has grown so large that a number of coating firms have gone into the production of alkyds and now make part or all of their own requirements. In 1937 there were 24 paint, varnish, and lacquer firms producing alkyd resins. Included in this number were the first and second largest producers of such resins. Eleven producers of these resins, including the third and fourth largest, made alkyd resins for sale only. Each of these groups included one firm which also made phthalic anhydride.

Alkyd resins made from maleic anhydride.—In 1937 there were seven producers of alkyd resins from maleic anhydride who produced for sale only. This group included the two largest producers and also one firm which produced maleic anhydride. In addition there were five paint, varnish, and lacquer firms producing part or all of their needs of resins of this type. The general conditions under which these resins are consumed are the same as for alkyd resins made from phthalic anhydride.

Urea resins for molding.—The conditions under which urea resins are molded are not greatly different from those already discussed for tar-acid resins. The molding cycle is somewhat longer and, because of the light colors used, special precautions must be taken to prevent discoloration of the molded product by dirt or flecks of molding powder from other operations, carried through the air or upon the person of the laborer. In 1937 there were four producers of urea resins for molding. Three of them, including the two largest, produced for sale only; the other consumed his own production.

Urea resins for other uses.—Until recently urea resins were thought of exclusively for molding, but they are now being used for laminating, for surface coatings, and also as an adhesive. Ordinarily the ureas are used only in impregnating the outside laminae of a laminated sheet where they are valuable for the light colors they make possible. The volume of urea resins used in surface coatings is small compared with the alkyd or tar-acid resins used for this purpose, but is increasing. The use of urea resins in adhesives is still new but promises to become important.

In 1937 there were four producers of the ureas for uses other than molding, who produced for sale only; and two producers who consumed their own product.

Coumarone and indene resins.—Coumarone and indene resins are produced in connection with the production of solvent naphtha. There were three producers in 1937, all of whom sold their product. These resins go into varnishes, where they replace natural resins or ester gum.

Other resins.—In 1937 there were four producers of vinyl resins in the United States, and two of these also produced their raw materials. The vinyl resins were used chiefly in surface coatings, molding, and in safety glass. The polystyrene resins, used chiefly for molding and laminating, were offered by two producers for the first time in 1937. Two other producers offered acrylate resins, which are cast, molded, or used in surface coatings. In the same year petroleum resins were sold in good volume, their only producer obtaining them as a byproduct of the oil industry.