light and which has an onionlike odor. When polymerized liquids are
formed, then as the reaction progresses viscous products and finally
insoluble, infusible, inert resins. By arresting the reaction before the
gel point is reached, an amber colored heavy liquid, soluble in aromatic
hydrocarbons, is obtained. Since divinyl acetylene will continue to
polymerize at ordinary temperatures, this property is taken advantage of
in using it as a basis for paints, under the name “synthetic drying oil.”
Clear, amber films are obtained from solutions of this oil in solvent
naphtha. Divinyl acetylene is quick drying, is many times more impervious
to moisture than linseed oil, and is thermosetting. It is not attacked
by solvents but is attacked by strong oxidizing agents, and the gelled
material may ignite spontaneously.
Although not classified as a resin, synthetic rubber is discussed here
because of its close chemical relationship to the vinyl resins. It is
made commercially by E. I. du Pont de Nemours & Co., Wilmington, Del.,
and is marketed as Neoprene. It is sold as a plastic polymer which is
vulcanized and processed much the same as natural rubber except that
sulphur is not essential to vulcanization. Synthetic rubber is higher in
price than natural rubber, but it has certain properties which make it
suitable for service conditions where natural rubber is unsatisfactory.
Among these properties are its resistance to gasoline, oils, and greases,
and to elevated temperatures. It does not check or crack on exposure to
sunlight, nor does it oxidize as rapidly as natural rubber. Its principal
applications are in special gaskets, printing rolls, jackets for high
tension cable, linings for gasoline or oil hose lines, balloon fabrics,
diaphragms for regulators, and packing for compressors. Its existence
acts as a limit to the increase in the price of natural rubber and
assures a supply in emergencies.
Production in the United States.
Some of the products described are commercially produced in the United
States; others in Canada or in Germany. Those made in the United States
are usually not made by more than one firm, so that statistics of
production and sales are not publishable. The vinyl acetate resins have
been produced principally in Canada; the copolymers of vinyl chloride and
vinyl acetate are domestic products. In 1935 the United States output of
all vinyl resins exceeded 1,000,000 pounds, a figure that was increased
in 1936 and 1937.
The Canadian output of Gelva and Alvar has reached commercial quantities;
that of Formvar is still confined to experimental plant lots.
The acceptance of vinyl resin sheets for safety glass will greatly
increase the output in 1938. The basic patent, known as the
Morrison-Blaike patent, United States No. 2,036,092 issued on March 31,
1936, is owned by Shawinigan Chemicals, Ltd., Montreal, Canada, who have
licensed several domestic producers. The monomer (vinyl acetate) is now
produced at Niagara Falls, N. Y., by the Niacet Chemicals Corp., which
is jointly owned by this Canadian firm, Carbide and Carbon Chemicals
Corporation, and E. I. du Pont de Nemours & Co. It is also produced by
du Pont at Belle, W. Va. It is shipped, in tank cars, to polymerization
and sheet-forming plants at Indian Orchard, Mass., Arlington, N. J., and
Charleston, W. Va. The Indian Orchard plant, known as the Shawinigan
Resin Products Co., and jointly owned by the Canadian firm and the
Fiberloid Corporation, is now in operation. The plant of the du Pont
Company at Arlington, N. J., began production in May 1938, and that
of Carbide and Carbon Chemicals Corp, at Charleston, W. Va., is in
production. These plants have a combined annual capacity of about 10
million pounds of vinyl resin sheets. According to present plans this
new safety glass will be available for 1939 model automobiles. The resin
sheet to be used is 0.0015 inch thick as compared with the 0.0025 inch
thickness of the present cellulose acetate and nitrocellulose sheet.
Several trade names have been adopted for the vinyl resin sheets, among
which are Vinylite X, and Butvar. The licenses granted to domestic makers
under the Morrison-Blaike patent also permit them to make vinyl acetate
resins for purposes other than safety-glass sheets. Considerable progress
has been made in adapting these resins to injection molding operations
for the production of tooth-brush handles, combs, closures, and other
parts.
Imports into the United States.
The official statistics of imports of vinyl resins prior to 1936 are not
satisfactory for purposes of comparison. Imports could be entered under
either paragraph 2 or paragraph 11 and could be included either with the
statistics of imports of vinyl acetate (see table 91, page 141) or be
thrown into a general group of non-coal-tar synthetic gums and resins, n.
s. p. f., which in addition to vinyl resins would include the acrylates
and ureas. Table 10 gives imports of synthetic resins under paragraph 11
of the Tariff Act of 1930.
TABLE 10.—_Synthetic resins classified under paragraph 11:[1] United
States imports for consumption 1931-37_
--------+----------+-------+-----------
Year | Quantity | Value | Unit value
--------+----------+-------+-----------
| _Pounds_ | |
1931 | 453 | $173 | $0.38
1932 | 454 | 29 | .06
1933 | 1,120 | 496 | .44
1934 | 4,084 | 1,576 | .39
1935 | 3,105 | 1,804 | .58
1936 | 146 | 65 | .45
1937[2] | 1,963 | 439 | .22
--------+----------+-------+-----------
[1] Statistical classification 838.914, synthetic gums and
resins, n. s. p. f. (not coal tar) 1931-35; 838.939 same, other
than those in chief value of vinyl acetate, 1936 and 1937.
[2] Preliminary.
Source: Compiled by the U. S. Tariff Commission from official
statistics of the U. S. Department of Commerce.
A better idea of the imports of vinyl resins prior to 1936 is obtained
by an invoice analysis of imports through the Port of New York under
paragraphs 2 and 11. Table 11 shows imports of vinyl acetate resins based
on such an analysis for 1934 and 1935 and on official statistics for the
years 1936 and 1937.
Similarly table 12 shows imports of Mowilith resins based upon import
analysis for the period 1932-1935, and upon official statistics for 1936
and 1937.
TABLE 11.—_Vinyl acetate resins: United States imports for consumption,
1934-37_
----------+----------+--------+-----------
Year | Quantity | Value | Unit value
----------+----------+--------+-----------
| _Pounds_ | |
----------+----------+--------+-----------
1934[1] | 42,000 | |
1935[1] | 240,000 | |
1936[2] | 600,808 |$144,782| $0.24
1937[2][3]| 652,730 | 201,213| .31
----------+----------+--------+-----------
[1] Invoice analysis of imports entered through the New York
customs district.
[2] Statistical classification 817.58 (par. 2), vinyl acetate,
polymerized, and synthetic resins made in chief value from vinyl
acetate, n. s. p. f. (excluding imports from Germany) and 838.938
(par. 11), synthetic resins made in chief value from vinyl
acetate, n. e. s.
[3] Preliminary.
Source: Compiled by the U. S. Tariff Commission from official
statistics of the U. S. Department of Commerce.
TABLE 12.—_Mowilith resins: United States imports for consumption,
1932-37_
----------+----------+--------+-----------
Year | Quantity | Value | Unit value
----------+----------+--------+-----------
| _Pounds_ | |
----------+----------+--------+-----------
1932[1] | 555 | $229 | $0.41
1933[1] | 741 | 247 | .33
1934[1] | 2,950 | 1,668 | .57
1935[1] | 3,372 | 3,175 | .94
1936[2] | 7,056 | 2,410 | .34
1937[2][3]| 220 | 308 | 1.40
----------+----------+--------+-----------
[1] Analysis of invoices of imports entered through the New York
customs district.
[2] Imports from Germany under statistical classification 817.58
(par. 2), vinyl acetate, polymerized, and synthetic resins made
in chief value of vinyl acetate.
[3] Preliminary.
Source: Compiled by the U. S. Tariff Commission from official
statistics of the U. S. Department of Commerce.
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.
Aniline resins.
Resins obtained by condensing aniline and formaldehyde have been
developed in recent years. Much of the research on this type of resin
was done in Switzerland by the Ciba Co., which holds a number of patents
on it. The Swiss product, called Cibanite, has excellent electrical and
mechanical properties. At least one domestic manufacturer is licensed
under the Swiss-owned patents.
Citric acid resins.
Considerable interest has recently been manifest in synthetic resins
derived from citric acid. The sharp decline in the price of citric acid,
as a result of large scale synthesis from sugar has placed it within the
realm of possibility as a raw material for synthetic resins.
The citric acid resins, classed as alkyd resins, are obtained by
condensing citric acid and glycerin. Commercial production is said to
have started in Europe, but there is no known domestic production as yet.
Diphenyl resins.
A series of products known as Aroclors and made by chlorinating diphenyl
are available in commercial quantities.
Diphenyl was commercially produced for the first time by Swann Research,
Inc., at Anniston, Ala., about 1928. The demand for it as a heat-transfer
medium resulted in large scale output. Later it was found that certain of
the chlorinated compounds of diphenyl possess valuable resin properties.
The Aroclors range from a clear mobile oily liquid to an amber colored
transparent solid. They are thermoplastic, do not polymerize or oxidize,
and are therefore nondrying. They may be dissolved in varnish oils, such
as tung oil and linseed oil, to give varnishes which are resistant to
alkali and water. The diphenyl resins are good adhesives on metal and
glass and give strong joints between such surfaces. They have a high
dielectric constant, resistivity, and a low power factor. Their chief use
is in wire insulation.
The domestic production of chlorinated diphenyls is, at present, solely
by the Monsanto Chemical Company, St. Louis, Mo.
Furfural resins.
Large scale commercial production of furfural, an aldehyde obtained from
oat hulls and other farm waste, has made it available for synthetic resin
manufacture.
Tar-acid furfural resins possess certain outstanding properties, such
as great dimensional accuracy, great reaction speed to the infusible
solid stage, and unusual strength and toughness. They are available in
dark shades only. Printing plates as large as those of metropolitan
daily papers are molded from them as are radio tube bases, all sorts
of electrical parts, and machined parts requiring great dimensional
accuracy. Other uses are in abrasive wheels, varnishes, and adhesives.
Probably the largest domestic maker of furfural resins is the Durite
Plastics Division of Stokes and Smith Company, Philadelphia, Pa.
Resins from sugar.
Many attempts have been made to utilize sugar as a raw material for
synthetic resins. United States Patent No. 1,949,831, dated March 6,
1934, claims a process for the manufacture of molding compounds by
condensing saccharide with aldehydes and urea. Pure sucrose yields a
clear, colorless, nonresilient resin, while molasses and cane sugar
give dark-colored resins. The trade name Sakaloid is used to designate
certain of these resins; there is, however, no known domestic production.
Sucrolite is the trade name of a brand of resins from sugar produced in
Europe.
Sulphonamide resins.
The sulphonamide resins were developed from para toluenesulphonamide, a
byproduct obtained in the manufacture of saccharin (synthetic sweetening
agent).
Para toluenesulphonamide, condensed with formaldehyde or other aldehyde,
forms a viscous mass which, on heating, is converted to a hard
colorless resin. Such resins are compatible with cellulose acetate or
nitrocellulose in lacquers, the combination yielding clear, colorless
lacquers of good gloss and adhesion. Other possible uses are as an
adhesive in safety glass, in certain molding compositions, in insulating
materials, and to deluster artificial silk.
Domestic production of sulphonamide resin is entirely by the Monsanto
Chemical Co., St. Louis, Mo. It is marketed under the trade name
Santolite.
12. ORGANIZATION OF THE SYNTHETIC RESIN INDUSTRY
The discussion of the various synthetic resins on pages 11 to 52 carries
in each case, under the heading of production, a notation of the number
of companies producing that particular resin; and the discussion on pages
86 to 141 of important raw materials for these resins describes briefly
the conditions under which these materials are produced. We shall now
consider the interrelationships between industries producing the several
resins, and the relation of the resin industries to their raw materials
and to some of the important resin-consuming industries.
No description of the organization of a rapidly expanding industry can be
expected to remain accurate for long. But regardless of future changes
that may be expected, the general pattern seems definite enough to
make possible a few broad generalizations. At present the producers of
synthetic resins may be classified in two groups: those making alkyd and
tar-acid resins, and those making all other synthetic resins.
The alkyd resins and the tar-acid resins are produced in large volume,
and for these resins the patent situation is such that there is nothing
to exclude new producers. The result has been that new firms have entered
the field and there has been a marked tendency for concerns using these
resins on a large scale to produce them. This general situation may be
expected to continue as long as the volume of consumption of these resins
is rising. But when consumption levels off, it would not be surprising if
increased competition for new business resulted in consolidations of some
of the producing units.
Each of the other synthetic resins is produced by a small number of
firms and this may be expected to continue as long as the production of
a particular resin is small, or basic patents dominate the situation.
When and if the situation in these respects changes for some of the other
resins, they will probably develop the same tendencies as now exist in
the production of the tar-acid and alkyd resins.
Horizontal relationships between resin producers.
Horizontal relationships between companies are those between different
units in the same industry (say two tar-acid resin producers), or in
different industries each operating at the same stage of industrial
production (say a tar-acid resin producer and a producer of urea
resin). As a rule, extensive horizontal relationships are not common
in relatively young industries, and this is true of the production
of synthetic resins. In general, it has not been necessary to absorb
competitors to achieve a greater volume of sales, and efforts have been
directed to exploiting the possibilities of expansion in a growing
market. This necessitated solving technical problems concerning
improvement of the product and its production on an ever larger scale;
legal problems regarding patents (protection of those owned, and the
policy to be adopted toward unadjudicated patents owned by others); and
the marketing problem of convincing prospective customers of the worth
of a new product. These and other problems incidental to successful
competitive production and sale of a given type of synthetic resin have
been sufficient to restrain the desire to produce more than one type.
The patent situation of most synthetic resins is extremely complicated.
In the case of tar-acid molding resins the basic Baekeland patents have
expired, but for other synthetic resins either the basic patent is
still in force, or it is difficult to say which is the basic patent,
because of lack of adjudication by the courts. In all cases dozens of
supplementary patents are in force and sometimes hundreds. As a result
the patent situation, though one of the bars against entering into a new
field, frequently forces some relationship between producing units in
the same synthetic resin field. Cast phenolic resins afford an example
of patent-licensing of several corporations by another with the payment
of royalties as compensation. In a number of other branches of the resin
industry, such as the laminated tar-acid resins and the alkyd resins, the
mutual desire of producers to avoid litigation has apparently resulted in
“gentlemen’s agreements” not to sue.
Vertical relationships of resin producers.
A vertical relationship is one between producers operating at different
stages of industrial production, such as a firm producing resin and a
firm producing a resin raw material or between the former and a firm that
is a resin consumer. The incentive for a consuming industry operating on
a large scale to make its own resins is naturally greater than for one
using only small quantities. Therefore we may expect to find instances
where a process consuming the resin in quantity and resin manufacture are
both performed by the same company provided other conditions (such as the
patent situation and knowledge of the art of manufacture) are favorable.
_Tar-acid resins for molding._—The present practice of molding resins
is favorable to large-scale production. The shaping of the mold is
expensive, involving skilled labor upon hardened steel; but once the mold
is made it may be used to produce tens or hundreds of thousands of units.
Subsequent labor upon the molded product is usually limited to the simple
task of smoothing the line where the flash is broken off, since the
product comes from the mold in the color and with the surface and shape
desired.
The usual arrangement at the present time is to have a battery of
presses, grouped around central units which supply hydraulic pressure
and steam for heat. A measured amount of molding powder or a pellet
of compressed molding powder is applied to each cavity by the press
operator, who controls by hand the time of application of heat and
pressure and removes the article from the press. The cycle is a matter of
minutes, and since each cycle produces a finished article if the molding
is large, or a number of them if it is small, daily production per worker
is high. The estimated average costs of the different elements in the
process have been apportioned as follows: the cost of raw material is
about one-third the cost of the finished product; and the combined cost
of the mold allocated per unit, the labor cost per unit, and overhead
the remaining two thirds.[5] On small runs labor cost and particularly
allocated mold cost would be much higher, so that molding is usually
uneconomic where only small quantities of the finished product are
desired.
In 1937 there were eight molders that produced their own tar-acid resins
in whole or in part. One of these molders was the third largest producer
of such resins. In the same year six producers of tar-acid resins for
molding, including the first, second, fourth, and fifth largest, confined
their activities to resin making. One producer of raw materials for
tar-acid resins also made the resin on a moderate scale.
This picture of interstage relationship as it existed in 1937 may be
somewhat modified by new developments in molding presses. There are
now available self-contained presses which are not dependent upon
other units for their supplies of heat and pressure and which are
either semiautomatic or automatic. The semiautomatic press requires an
operator for charging the cavity and removing the molded product, but
once adjusted automatically applies the heat and pressure and controls
the time of the pressing cycle. The automatic press, adapted as yet
only to the simpler moldings, requires no attention whatever. These
presses are more expensive, but may be set up anywhere and require less
skilled labor. There is the possibility that they may be installed by
some industrial users of molded articles, and thus take some business
from the custom molder. If this occurs, such molders will presumably buy
their resin from companies that are primarily resin makers, since their
requirements of the material would not ordinarily be large enough to
justify making their own.
_Tar-acid resins for laminating._—The manufacture of laminated resin
products is most economic when done on a large scale, in which case the
impregnation of the paper or fabric becomes a continuous process, the
material feeding from a roll through resin sirup and then through drying
towers, where time and heat may be controlled. The impregnated material
contains resin in the B-stage. The material is then cut up and the sheets
piled together (the number depending on the thickness desired) and sent
to huge presses which, with heat and pressure, compact and unite the
layers and convert the resin to the C-stage. If it is desired to produce
decorative panels with a smooth surface, the top sheet used is one
colored or printed with a design (perhaps a photographic reproduction
of the surface of a cabinet wood) and placed between polished
chromium-plated metal sheets before going to the press. Rods and coil
forms as well as flat sheets are commonly made from laminated material.
Any of these forms may undergo subsequent fabrication; rods and coil
forms cut to required length, thin sheets stamped to shape, gear blanks
cut to final form on automatic gear machines, and decorative panels sawed
to shape.
Many laminators purchase all their resin requirements, but a number of
them make part or all of the tar-acid resin they use. In 1937 there
were seven laminators who made tar-acid resins (including the second,
third, and fourth largest producers of such resins) and four producers
of tar-acid resins for this use (including the largest) which did no
laminating.