firms in Germany, the United Kingdom, France, Italy, Canada, and Japan.
The two principal American makers of urea resins have or have had
agreements as to patents, exchange of technical information, and probably
markets, with producers in Great Britain. Similar conditions exist with
other types of resins.
In 1937 production of all synthetic resins in the United States amounted
to 162 million pounds and imports to less than 674,000 pounds (see table
13, p. 58). Production of tar-acid resins in that year amounted to 79.8
million pounds; alkyd resins to 61.2 million pounds and all coal-tar
resins to 141 million pounds. Imports of all coal-tar synthetic resins
(which would include both tar acid and alkyd as well as others) amounted
to only 19,000 pounds. Coal-tar resins are dutiable at 7 cents per pound
and 45 percent ad valorem based on American selling price. On the small
imports in 1937 the duty collected averaged 54 percent ad valorem on
American selling price and would have averaged much higher had it been
calculated upon foreign value as are most duties.
In 1937 the production of non-coal-tar resins totaled about 21 million
pounds. In that year imports of non-coal-tar resins totaled 65,000
pounds. Imports of non-coal-tar resins, other than vinyl resins, amounted
to less than 2,000 pounds. These were dutiable at 4 cents per pound and
30 percent ad valorem on foreign value, equivalent on the average to 48
percent ad valorem. The vinyl resins have been imported into the United
States in increasing quantities in recent years. The principal foreign
producer, in Canada, developed markets in the United States, but is a
joint owner of a plant now under construction in this country. Imports of
vinyl resins in 1937 were 653,000 pounds. These were dutiable at 3 cents
per pound and 15 percent ad valorem on foreign value, equivalent to 25
percent ad valorem.
It is apparent that foreign competition with United States producers
in the home market has been and is likely to continue insignificant
under existing duties. With a large home market and generally favorable
conditions with respect to the necessary raw materials and the technical
skills, this situation would probably continue even under lower duties.
Moreover, as international trade develops in these materials, this
country is more likely to be a net exporter than a net importer.
3. TAR-ACID RESINS
The tar-acid resins were the first true synthetic resins to appear in
commerce, but they were preceded by two plastics, celluloid and casein.
Probably the first successful attempt to make a semisynthetic or modified
natural product as a substitute for natural materials was the discovery
of celluloid in 1868 by John Wesley Hyatt. By treating cotton with nitric
acid he obtained a material which could be substituted for ivory in
billiard balls. The Celluloid Corporation grew out of this discovery and
the product was widely used to replace amber, ivory, mother-of-pearl,
tortoise shell and other materials.
The discovery of casein plastic took place in 1890. Adolph Spitteler of
Hamburg, Germany, in trying to make a white blackboard, found that casein
(from milk) could be hardened by treating it with formaldehyde. Casein
plastics are now widely used in buttons, buckles, and other ornaments.
As early as 1872 the reactions between coal-tar acids and aldehydes were
being studied, and by 1900 many research workers were investigating
phenol-formaldehyde condensation products. During the period 1900-1910,
the study of these products increased greatly, both with regard to
process of production and to applications, such as its substitution for
shellac and other natural resins. United States Patents Nos. 942,699 and
942,809 issued December 7, 1909, to Dr. L. H. Baekeland and commonly
known as the heat and pressure patents were probably the basic patents on
phenol-formaldehyde resins. Baekeland so modified these resins by methods
of hardening under heat and pressure that rigid molded articles could be
made. The range of uses of tar-acid-formaldehyde molding compositions
has steadily widened. Molded articles such as pencil and pen barrels,
ash trays, bottle closures, parts for automobiles, cameras, precision
instruments, dynamos, motors, and other electrical equipment, cafeteria
trays, table and counter tops are well known to the public.
During the life of these and other basic patents issued about 1909 the
domestic production of phenol-formaldehyde molding compositions was
practically restricted to one company. Since the expiration of these
patents in 1926 a number of other producers have been established. In
1937 there were 36 domestic makers of tar-acid-formaldehyde resins for
molding, laminating, and surface coating applications.
The early work done on phenol-formaldehyde resins gave dark-colored
products which were too hard and brittle to be machined or worked on
a lathe. Investigations by F. Pollak and A. Ostersetzer, in Vienna,
resulted in a process for the manufacture of cast phenolic resin with
a range of color possibilities from water-white transparency through
all shades and degrees of translucency and opaqueness. This product is
cast into sheets, rods, tubes, and special castings, all of which may
be turned or milled on automatic machines. United States Patent No.
1,854,600, issued April 19, 1932, to F. Pollak and A. Ostersetzer and
assigned to Pollopas, Ltd., London, is considered the basic patent for
cast phenolic resins. American rights under this and related patents
are owned by the Catalin Corporation of America who have licensed other
domestic makers. The German equivalent of rights under this patent is
owned by a subsidiary of I. G. Farbenindustrie Aktiengesellschaft and
rights under the French equivalent by Établissements Kuhlmann.
In the early days of the phenol-formaldehyde resin industry (1909-16)
there was considerable uneasiness about the supply of phenol. World
production was not large and Germany and England controlled most of
it. The output of the United States was almost entirely for medicinal
use, although our potential production was large (see p. 111). This
situation caused many research workers to study the resins made from
other tar acids, principally meta and para cresols and the xylenols. The
investigations resulted in many new types of resins and in modifications
of the phenol-formaldehyde type. The World War changed conditions
materially. Imports of phenol were shut off and prices soared. Production
of synthetic phenol was begun, and, although the wartime production
went into explosives, its development had an important bearing on the
synthetic resin industry. Unusual demand for phenol, toluene, and other
coal-tar crudes resulted in a great expansion of production. With the
cessation of hostilities there was an ample supply of cheap phenol and
the expansion of the coal-tar industry continued so that the supply of
tar acids kept pace with the new demand for use in the production of
synthetic resin.
In 1926, the early patents on resins from tar acids began to expire
and the second era of the industry began. Since that year most of
the research work has been for materials that would give different
properties to the resultant resins. The past 10 years have seen a
greater diversification in the manufacture of resins from tar acids and
substantial reductions in their prices. Tar-acid resins averaged $1.29
per pound in 1920, 23 cents per pound in 1934, and 19 cents per pound in
1937. The production of certain resins of this class which are soluble in
drying oils has been an important achievement. They yield varnishes of
improved type that are quick-drying.
The three stages of a tar-acid resin.
About 28 years ago the Journal of Industrial and Engineering Chemistry
published the original paper of Dr. Leo H. Baekeland on the Synthesis,
Constitution, and Uses of Bakelite. According to Baekeland’s theory, the
reaction between phenol and formaldehyde consists of condensation and
polymerization taking place in three stages. The first product formed,
called “initial condensation product A” is usually a liquid or semisolid
which on continued heating is converted to “intermediate condensation
product B.” B is an insoluble solid which can be softened by heat, and is
the material used by molders, laminators, and other fabricators.
The final stage, known as “final condensation product C,” is probably
the result of polymerization of B, by heat and pressure. C product is
infusible, indifferent to all solvents, and cannot be distilled or
melted; hence the tar-acid resins belong to the thermosetting group.
The conversion to C takes place in the presses of the molder or final
fabricator of the resin. This theory is generally accepted and the
designations of the several stages are in universal use in the trade.
Classification of tar-acid resins.
All the synthetic resins obtained by the condensation of a tar acid, or
a mixture of tar acids, with an aldehyde are popularly called phenolic
resins, regardless of whether they are made from phenol, the isomeric
cresols, xylenols, other high boiling tar acids, or any mixture of these
materials. A more accurate designation and that used in this survey is
tar-acid resins, reserving the term phenolic resins for those made from
pure phenol.
The tar-acid resins might be classified in a number of ways; for example,
by composition, physical form, or general application. Each of these has
its shortcomings. To classify them by composition, that is, by the kind
of tar acid used, is not satisfactory because of the vast number of types
made from mixed tar acids. For the purpose of this discussion it seems
best to classify the tar-acid resins by their general application into
six groups: for molding, for casting, for laminating, for surface coating
(paints, varnishes, and lacquers), for adhesives, and for miscellaneous
uses.
In 1937 approximately 66 percent of the United States production of
tar-acid resins was made from phenol; 18 percent from phenol-cresol
mixtures; 13 percent from cresol-cresylic acid mixtures; and 3 percent
from cresol-xylenol mixtures. Table 2 shows for recent years production
and sales of tar-acid resins by type of raw material. Pure phenol is used
for cast resins. Molding resins are usually made from pure phenol or from
tar-acid mixtures, chiefly phenol. Laminating and coating resins are
usually made from mixtures containing substantial amounts of the cresols
and xylenols (frequently spoken of by the trade as cresylic acid).
TABLE 2.—_Tar-acid resins: United States production and sales, by type of
raw material, 1933-37_
----+--------------------------------+---------------------------------
| Phenol | Tar-acid mixtures[1]
+----------+----------+----------+----------+----------------------
| | Sales | | Sales
Year|Production+----------+----------+Production+----------+-----------
|(net resin| Quantity | |(net resin| Quantity |
| content) |(net resin| Value | content) |(net resin| Value
| | content) | | | content) |
----+----------+----------+----------+----------+----------+-----------
| _1,000 | _1,000 | _1,000 | _1,000 | _1,000 | _1,000
| pounds_ | pounds_ | dollars_ | pounds_ | pounds_ | dollars_
| | | | | |
1933| 25,163 | 21,851 | 5,383 | 6,535 | 6,152 | 1,182
1934| 29,777 | 27,995 | 7,332 | 10,887 | 8,091 | 1,705
1935| 36,323 | 34,597 | 6,568 | 16,654 | 12,371 | 2,200
1936| 51,603 | 49,053 | 9,419 | 18,747 | 12,908 | 2,325
1937| 52,472 | 50,209 | 8,616 | 27,373 | 23,337 | 4,685
+----------+----------+----------+----------+----------+-----------
| Phenol-cresol | Cresol-cresylic | Cresol-xylenol
| mixtures | acid mixtures | mixtures
+----------+----------+----------+----------+----------+-----------
| | | | | |
|Production|Sales (net|Production|Sales (net|Production|Sales (net
|(net resin| resin |(net resin| resin |(net resin| resin
| content) | content) | content) | content) | content) | content)
+----------+----------+----------+----------+----------+-----------
| _1,000 | _1,000 | _1,000 | _1,000 | _1,000 | _1,000
| pounds_ | pounds_ | pounds_ | pounds_ | pounds_ | pounds_
1937| 14,046 | 13,238 | 10,702 | 8,467 | 2,625 | 1,632
----+----------+----------+----------+----------+----------+-----------
[1] Includes phenol-cresol mixtures, cresol-cresylic acid
mixtures, and cresol-xylenol mixtures. For 1937, where it is
possible, the totals of tar-acid mixtures are broken down into
these three groups.
Source: Dyes and Other Synthetic Organic Chemicals in the United
States, U. S. Tariff Commission.
Processes of resin manufacture.
The processes of and patents for the manufacture of tar-acid-formaldehyde
resins are numerous. No attempt is made here to describe in detail the
several processes of manufacture or the endless number of variations and
modifications. In general the processes in operation may be designated
(_a_) one stage wet, (_b_) two stage wet, and (_c_) dry.
The one-stage wet process consists in heating molecular proportions of
tar acid and formaldehyde (40-percent solution) in the presence of an
acid or alkaline catalyst. The formaldehyde is added all at once and the
reaction proceeds with the elimination of water. The difficulty with
this process is that of obtaining uniform batches because it cannot be
controlled exactly.
The two-stage process is probably the one most widely used today and
consists in introducing formaldehyde in two or more stages as the
reaction progresses. Much better process control and more uniform results
are so obtained. A soluble, fusible resin is formed from which the water
is easily removed. Fillers and pigments may be added during the latter
part of the operation.
The dry process is the least important and is used only where cast resins
are being made. Light-colored, transparent resins are obtained and the
operation is carried on to the final stage (C resin). In this process the
aldehyde used is solid paraformaldehyde or hexamethylenetetramine. These
materials are more costly than formaldehyde solution.
Proportions of raw materials used vary widely—Baekeland suggested 7
mols of formaldehyde and 6 mols of phenol (210 parts of 100-percent
formaldehyde to 564 parts of phenol), with a yield of resin equivalent
to 118 percent of the phenol. Larger proportions of formaldehyde are said
to increase the yield to as much as 140 percent of the phenol.
Catalysts used to aid in the condensation of the reacting bodies may be
acids or bases. Certain properties of the resins may be varied by the
kind and quantity of catalyst used. Large proportions of basic or acidic
catalysts may affect the filler or metal inserts. Basic catalysts used
include caustic soda, caustic potash, ammonia, carbonates, and alkali
sulphites. Acid catalysts are usually one of the mineral acids such as
hydrochloric acid or sulphuric acid.
While formaldehyde in the form of a 40-percent solution is the principal
aldehyde used with the tar acids, certain other aldehydes are used in
small amounts. Among these are acetaldehyde, butyraldehyde, benzaldehyde,
and others. Resins from furfural and phenol are discussed as “Furfural
Resins,” page 51.
Production in the United States.
The production of tar-acid resins in the United States has increased
markedly in the last 10 years. Table 3 shows the production and sales
of all coal-tar resins in 1927 and 1928 (when there was no further
break-down available but when this classification was made up chiefly of
tar-acid resins) and of tar-acid resins from 1929 to 1937. The figures
given are in net resin content and do not include fillers, modifiers, or
pigments. From 1929 to 1937 production increased from 26 million pounds
to 80 million pounds; sales from 25 million pounds valued at 9.9 million
dollars to 74 million pounds valued at 13.3 million dollars; the value
per pound dropped from 39 cents to 19 cents.
In 1937 the production of tar-acid resins for molding accounted for about
40 percent of the total; those for surface coatings, about 25 percent;
those for lamination, about 20 percent; and those for miscellaneous uses,
about 15 percent.
TABLE 3. _Tar-acid resins: United States production and sales 1927-37_
--------+-------------+----------------------------------------
| | Sales
| Production +------------+--------------+------------
Year | (net resin | Quantity | |
| content) | (net resin | Value | Unit value
| | content) | |
--------+-------------+------------+--------------+------------
| _Pounds_ | _Pounds_ | |
1927[1] | 13,452,230 | 13,084,313 | $6,094,656 | $0.47
1928[1] | 20,411,465 | 20,778,856 | 7,211,958 | .35
1929[2] | 26,235,792 | 25,129,701 | 9,869,274 | .39
1930[2] | 18,338,389 | 17,428,687 | 6,576,023 | .38
1931[2] | 22,647,000 | 21,496,000 | 6,646,000 | .31
1932[2] | 17,163,000 | 15,042,000 | 3,946,000 | .26
1933[2] | 31,697,780 | 28,002,799 | 6,564,670 | .23
1934[2] | 40,663,565 | 36,086,008 | 9,037,861 | .25
1935[2] | 52,731,728 | 46,733,378 | 8,730,438 | .19
1936[2] | 70,349,328 | 61,961,200 | 11,743,978 | .19
1937[2] | 79,844,825 | 73,545,880 | 13,300,870 | .19
--------+-------------+------------+--------------+----------
[1] All coal-tar resins.
[2] Resins from tar acids only.
Source: Compiled from annual reports of the Tariff Commission on
dyes and other synthetic organic chemicals in the United States.
Imports into the United States.
Imports of tar-acid resins into the United States are dutiable under
paragraph 28 at 7 cents per pound and 45 percent ad valorem based upon
American selling price. Discussion of this rate, other restrictions upon
imports in the earlier years, and of the rates upon articles made of
these resins will be found on pages 59 to 61.
Imports of tar-acid resins are not shown separately in official
statistics; the classification under which such imports are entered
includes all synthetic resins of coal-tar origin. Table 4 shows the
quantity and value of imports of all coal-tar resins since 1918, and
table 5 shows the principal sources of imports for certain years.
Invoice analyses of imports in the last 3 years show only very small
quantities of phenolic resins being imported. In 1934 there was an
importation of 950 pounds of Bakelite molding compound; in 1935 imports
of 100 pounds of molding compound and 22 pounds of aminophenol resin are
recorded, and in 1936 imports of Bakelite filament compound totaled 250
pounds and other resins 8,851 pounds.
Even if in the years up to 1933 all of the imports of resins of coal-tar
origin were tar-acid resins, imports of tar-acid resins have been
negligible when compared with production. The smallness of imports may
be accounted for by a combination of factors, (1) the prohibition of
imports of certain types, which conflicted with patent rights; (2) the
rate of duty upon imports; (3) the fact that the manufacture of tar-acid
resins developed more rapidly in the United States than in most foreign
countries; and (4) the allocation of markets through agreements between
affiliated producers in different countries. (See p. 58.)
TABLE 4.—_Synthetic resins of coal-tar origin: United States imports for
consumption, 1919-37_
--------+----------+----------+-----------+------------+---------------
| | | | Computed | Computed
Year | Quantity | Dutiable | Value per | ad valorem | specific
| | value | pound | rate | rate
--------+----------+----------+-----------+------------+---------------
| _Pounds_ | | | _Percent_ | _Per pound_
1919 | 1,114 | $2,860 | $2.57 | 32.0 | $0.82
1920 | 2,479 | 2,681 | 1.08 | 34.6 | .37
1921 | 1,420 | 2,366 | 1.67 | 33.0 | .55
1922 | 2,518 | 3,498 | 1.39 | 52.3 | .73
1923 | 3,183 | 10,512 | 3.30 | 62.1 | .20
1924 | 8,756 | 4,183 | .48 | 68.9 | .33
1925 | 1,537 | 889 | .58 | 57.1 | .33
1926 | 1,649 | 1,298 | .79 | 53.9 | .42
1927 | 11,359 | 4,266 | .38 | 63.6 | .24
1928 | 60,547 | 10,984 | .18 | 83.6 | .15
1929 | 67,529 | 17,503 | .26 | 72.0 | .19
1930 | 46,464 | 10,417 | .22 | 76.2 | .17
1931 | 6,074 | 6,180 | 1.02 | 51.9 | .53
1932 | 6,403 | 3,905 | .61 | 56.5 | .34
1933 | 3,776 | 2,508 | .66 | 55.5 | .37
1934 | 15,711 | 8,680 | .55 | 57.7 | .32
1935 | 18,015 | 6,075 | .34 | 65.8 | .22
1936 | 18,598 | 13,643 | .73 | 54.5 | .40
1937[1] | 18,977 | 14,278 | .75 | 54.3 | .41
--------+----------+----------+-----------+------------+---------------
[1] Preliminary.
Source: Foreign Commerce and Navigation of the United States.
TABLE 5.—_Synthetic resins of coal-tar origin: United States imports for
consumption, by principal sources, in specified years, 1929-37_
---------------+--------+-------+-------+-------+-------+-------+-------
Imported from— | 1929 | 1931 | 1933 | 1934 | 1935 | 1936 |1937[1]
+--------+-------+-------+-------+-------+-------+-------
| Quantity (pounds)
+-------+-------+-------+-------+-------+-------+-------
Germany | 50,770 | 3,166 | 2,724 | 9,801 | 2,220 |10,750 | 13,950
France | 20 | 2,331 | 740 | | 297 | 168 |
United Kingdom | 336 | | | 1,065 |13,242 | 1,979 | 2,215
Switzerland | 3,473 | 1,781 | 4,384 | 1,716 | | |
Canada | 1,372 | 135 | 1,266 | 594 | | |
All other | | | | | | |
countries | 16,403 | 577 | 312 | | 340 | 51 | 502
+--------+-------+-------+-------+-------+-------+-------
Total | 67,529 | 6,074 | 3,776 |15,711 |18,015 |18,598 | 18,977
+--------+-------+-------+-------+-------+-------+-------
| Value
+-------+-------+-------+-------+-------+-------+-------
Germany |$11,771 |$4,053 |$1,913 |$5,303 |$1,959 |$9,700 |$11,960
France | 21 | 1,760 | 465 | | 236 | 177 |
United Kingdom | 2,235 | | | 255 | 2,476 | 1,090 | 659
Switzerland | | | | 2,621 | 1,308 | 2,154 | 1,197
Canada | | | | 501 | 46 | 486 | 214
All other | | | | | | |
countries | 3,476 | 367 | 130 | | 50 | 36 | 248
+--------+-------+-------+-------+-------+-------+-------
Total | 17,503 | 6,180 | 2,508 | 8,680 | 6,075 |13,643 | 14,278
+--------+-------+-------+-------+---------------+-------
| Unit value
+--------+-------+-------+-------+-------+-------+-------
Germany | $0.23 | $1.28 | $0.70 | $0.54 | $0.88 | $0.90 | $0.86
France | 1.05 | .76 | .63 | | .79 | 1.05 |
United Kingdom | 6.65 | | | .24 | .19 | .55 | .30
Switzerland | | | | .75 | .73 | .49 | .70
Canada | | | | .37 | .34 | .38 | .36
All other | | | | | | |
countries | .21 | .64 | .42 | | .15 | .71 | .49
+--------+-------+-------+-------+-------+-------+-------
Average | .26 | 1.02 | .66 | .55 | .34 | .73 | .75
+--------+-------+-------+-------+-------+-------+-------
| Percent of total quantity
+--------+-------+-------+-------+-------+-------+-------
Germany | 75.2 | 52.1 | 72.1 | 62.4 | 12.3 | 57.8 | 73.5
France | .1 | 38.4 | 19.6 | | 1.6 | .9 |
United Kingdom | .5 | | | 6.8 | 73.5 | 10.6 | 11.7
Switzerland | | | | 22.1 | 9.9 | 23.6 | 9.1
Canada | | | | 8.7 | .8 | 6.8 | 3.1
All other | | | | | | |
countries | 24.2 | 9.5 | 8.3 | | 1.9 | .3 | 2.6
---------------+--------+-------+-------+-------+-------+-------+-------
[1] Preliminary.
Source: Foreign Commerce and Navigation of the United States.
Exports from the United States.
Appreciable quantities of phenolic resins are exported annually in the
form of molding compounds and as finished articles of wide variety.
Statistics of these exports are not compiled separately by the Department
of Commerce.
Exportation is limited by a number of factors, such as licensing
agreements, patents, allocation of markets, and high tariffs or embargoes
in certain countries. The largest domestic maker is affiliated with
producers in Great Britain, Germany, France, Italy, Canada, and Japan.
Other domestic firms have agreements as to patents and markets with
producers in England, Germany, and other countries.
TAR-ACID RESINS FOR MOLDING