C&EN commodity survey
elastomers WALTER S. FEDOR, Senior Associate Editor Stereoregulated synthetic rubbers are bringing about farreaching changes in the U.S. rubber industry. These new elastomers—polyisoprene and polybutadiene—are mainly invading the markets of natural rubber and styrenebutadiene (SBR). Their penetration could eventually go deep enough to make the stereo rubbers the basic elastomers of the industry. Polyisoprene, a man-made replacement for natural rubber, could be used in all of natural rubber's applications. Furthermore, it could relieve the U.S. of dependence on imported rubber. On the other hand, polybutadiene is regarded mainly as an extender, being compatible with both natural rubber and SBR. Much progress is also being made in developing products containing 1 0 0 % polybutadiene. Already, the industry plans 2 3 9 , 0 0 0 tons of annual capacity for these new materials. And it's a fairly safe bet that much greater capacity will be forthcoming. But before the industry has time to digest these two new elastomers, various synthetic rubber producers are hailing the merits of ethylene-propylene polymers. These new rubbers can also be made in facilities for producing stereoregulated materials. Hence, the rubber industry is faced with absorbing three new major synthetic rubbers over the next five or so years. Something like this has never happened before. But the extent to which these new rubbers will invade the markets of older elastomers is limited by the growth in rubber production and consumption. In 1 9 6 1 , the supply of new rubber in the U.S. was 1.8 million tons (all tonnage figures here are long tons). This supply should in88
C&EN
MARCH
12,
1962
crease at an average rate of about 4 % a year and reach 2.2 million tons in 1967. And over the same period, the U.S. demand should increase roughly 3 . 3 % a year to 1.8 million tons in 1967, compared to 1.5 million in 1 9 6 1 . Last year, 7 2 % of the rubber consumed in the U.S. was synthetic, and this figure should rise to 8 0 % in 1967. Quite naturally, the rubber industry's future depends on tire markets—replacement and original tires, plus the demand for retreads. The replacement segment tends to grow fairly steadily each year, while the original equipment business fluctuates with annual automobile and truck production. Auto tire output should reach about 124 million units in 1 9 6 7 — a 2 0 % increase over the 1 9 6 1 figure. Today, automobile tires average 10.4 pounds of rubber, and this may decline to 8.5 pounds in five years. The main reason is the increasing popularity of smaller cars, which require smaller tires. Truck, f a r m , and other tire production should reach 24 million units in 1 9 6 7 — u p 2 2 % over last year. Truck tires contain an average of about 33 pounds of elastomer; and this figure may not change much in the immediate future. By 1967, automobile production should reach 7.4 million cars, compared to 6.6 million predicted for 1962. And the U.S. gross national product, which will reach about $ 5 6 0 billion this year, should total $ 6 5 0 billion in 1967 (in terms of 1960 dollars). In fact, all of the rubber industry's barometers point upward, except exports. These exports amounted to 2 9 6 , 0 0 0 tons (including 6 0 0 0 tons of re-exported natural rubber) in 1 9 6 1 . This U.S. annual figure should dip to about 2 0 0 , 0 0 0 tons in five years because of the increasing production of synthetic rubber overseas. In 1963, other
Stereo regulated rubbers are expected to make appreciable inroads into the markets now held by the older synthetic rubbers. One of the most promising of these newer materials is pol\ butadiene, made by Goodyear at Beaumont, Tex., plant shown here and by others. Among the older synthetics are nit rile rubber, used in shoe soles and other products, and styrene-butadiene rubber, which finds its primary market in auto tires
NEWCOMERS TOUCH OFF A REVOLUTION Free World nations will have annual capacity to produce: 909,000 tons of styrene-butadiene rubber 205,000 tons of stereoregulated elastomers 90,000 tons of nitrile rubber 43,000 tons of neoprene 85,000 tons of butyl rubber And Iron Curtain nations will have total annual potential to make about 740,000 tons of various synthetic rubbers. Finding markets for the new rubbers will be a real challenge to the industry. And keen technological and price competition is sure to develop as the older elastomers attempt to fight off the upstarts. Natural Rubber Needs Decrease Before World War II, the U.S. depended almost entirely on natural rubber to meet its elastomer needs. Some nitrile rubber, neoprene, and SBR were produced, but in 1941 this output totaled only 8400 tons. The forced expansion during World War II started the U.S. toward a synthetic rubber economy. As a result, U.S. consumption of natural rubber, except for a brief spurt after World War II, has decreased in relative importance. Today, the U.S. gets its natural rubber primarily from Malaya and Indonesia and to a lesser extent from Ceylon and Liberia. Last year, 425,400 tons of dry and latex natural rubber was consumed domestically. Over the past decade, U.S. consumption of natural rubber has grown very little. It may increase to 430,000 tons in 1962. Thereafter, however, demand should decline steadily as the new synthetics and the more established ones combine to push natural rubber farther into the MARCH
12, 1962 C & E N
89
U.S. Consumption of Natural and Synthetic Rubber 11
Total Natural and Synthetic
Natural
Total Synthetic
lousarias υι/ i^ony ι οι!S
SBR
Neoprene
742.0
72.9 74.9 75.7
1955 1956
1529.7 1436.5
634.8 562.1
894.9 874.4
1957
1464.6
538.8
925.9
724.0 767.2
Butyl 54.0
Nitrite 26.0
49.6
25.9 27.2
Polyisoprene
EthylenePropylene Rubber
—
—
—
—
—
—
—
— —
Polybutadiene
1958
1364.0
484.5
730.2
69.7
26.6
—
—
—
1959 1960
1627.8
555.0
879.9 1072.7
55.8 63.4
886.3
86.2
66.5
33.8
—
—
1558.0
479.0
1079.2
904.4
61.6
32.2
—
—
—_
1961* 1962*
1516.6 1625.0
425.4
1091.2
889.0
81.1 80.4
1190.0
900.0
80.0
61.5 70.0
34.3 35.0
22.0 95.0
4.0
430.0
1963*
1640.0
405.0
1235.0
885.0
85.0
130.0
12.0
10.0
395.0
1285.0
870.0
88.0
40.0
160.0
25.0
1965*
1680·. 0 1730.0
75.0 80.0
38.0
1964*
385.0
1345.0
863.0
90.0
85.0
42.0
190.0
35.0
22.0 40.0
1966*
1770.0
370.0
1400.0
91.0
86.0
43.0
225.0
40.0
65.0
1967*
1805.0
350.0
1455.0
850.0 840.0
92.0
87.0
44.0
270.0
50.0
72.0
Sources:
U.S.
Deparlmtmt of Commerce, Rubber Manufacturers • Associât i'on, and *C1#EN
background. By 1967, consumption may total only 350,000 tons. Roughly 6 4 % of the natural rubber used in the U.S. goes into tires and tire products. The balance goes into mechanical goods, wire and cable coatings, oil- and waterproofed goods, foamed products, and other materials. About 1 0 % is consumed in latex form. Although in the future the amount of natural rubber used in the U.S. will decline, its tire and nontire use pattern should not change significantly over the next five years. The most important changes expected will be declines in price. Currently, No. 1 ribbed smoke sheet sells for 28 cents a pound. More important, however, are grades 3 and 4, which are the ones usually used in tires. These types sell for 271/ 2 cents a pound, although sometimes they sell for as much as 3 to 4 cents a pound less than No. 1 sheet. On the other hand, the current price of latex types is 5 to 7 cents above that of No. 1 sheet. For the future, a continuous world-wide oversupply of natural rubber is expected. Production was 2.1 million tons in 1961 and could reach 2.3 million in 1967. As a result, the tendency will be for prices to fall. The best estimate is that the price of No. 1 sheet in 1967 will have dropped to 20 cents a pound. This will put pressures on synthetic rubber producers to lower their prices also. Polybutadiene Sets the Pace Last year saw the first significant production and consumption of stereoregulated rubbers. It was a year in which polybutadiene was off and running, while polyisoprene was barely stumbling. Industry men expect that 90
C&EN
MARCH
12, 1962
8.0
— 2.0
estimates
polybutadiene will continue to far outpace the isoprenebased elastomer, at least through 1967. Total production of stereo rubber was about 42,000 tons in 1961. About 30,000 tons of this consisted of polybutadiene, made mostly by Phillips and Firestone, with a lesser amount by Goodyear. This year's polybutadiene output should climb to 105,000 tons (just about equaling capacity), with American Rubber & Chemical and Goodrich-Gulf also producing. In 1964, TexasU.S. Chemical is slated to produce the elastomer, and the trade expects General Tire & Rubber, U.S. Rubber, Shell, and Copolymer Rubber & Chemical to climb on the bandwagon also. With probable expansions by existing producers and the entry of additional companies, the nation's polybutadiene capacity could total 350,000 tons in a few years. And since production is expected to approach 320,000 tons in 1967, producers would be operating at a fairly high level. Meanwhile, consumption is rising in a merry spiral. About 22,000 tons of polybutadiene was consumed in 1961, and this figure should soar to 95,000 tons this year. The reason is polybutadiene's rapid acceptance in the tire field, mainly in blends with SBR, where it is used in treads for passenger, snow, and small-truck tires. A typical composition contains 7 5 % SBR and 2 5 % polybutadiene. In these uses, polybutadiene provides the advantages of excellent abrasion resistance, good resistance to oxidation and low temperatures, and low hysteresis (and thus relatively low heat buildup). Early reports indicate that polybutadiene treads wear about 1 % better for each per cent they contain of the stereo elastomer. In its earlier days, polybutadiene was considered for use almost exclusively in natural rubber. Little was said
U.S. P r o d u c t i o n of A u t o m o b i l e s and T r u c k s Millions of Units 8
ψ
