BUSINESS
Thermoplastic Elastomers Target Rubber And Plastics Markets • Distinction between traditional elastomers, plastics blurs as newer elastomers expand into rubber and plastics turf
tury. That growth rate actually § represents a quickening pace J from the 1% average annual | growth of the worldwide rub- £ ber industry during the past | decade. | Rubber has been a big busi- ^ ness ever since rubber tires were c developed for the burgeoning § Marc S. Reisch automobile industry and rubber C&EN Northeast News Bureau belts were developed for machinery in myriad manufacturhe traditional rubber business ing processes. Although elashas little bounce to the ounce tomers are now a component in these days, although it continues innumerable parts in consumer to lope along at about the same rate as and industrial products, vehicuthe gross national product in consum- lar tires still account for more ing countries. But one small segment of than half of the 33 billion lb of the overall rubber business—thermo- natural and synthetic rubber plastic elastomers—is outrunning the consumed in 1995. rest of the pack and capturing markets And although no one expects traditionally held not only by other the traditional high-volume elastomers but by a number of thermo- elastomers that constitute the plastics too. bulk of this market to disappear Thermoplastic elastomers—which any time soon, the newer updiffer from more traditional thermo- start specialty elastomers, such setting rubber types in thermal charac- as thermoplastic elastomers, are teristics as well as cost and ease of beginning to make a dent in processing—include styrenic block co- their big cousins' markets. Acpolymers, polyolefins blended with cording to a recently issued synthetic or natural rubber, polyure- study on world thermoplastic Technician molds protective automotive boot thanes, and polyamides. According to elastomers from the business re- made of thermoplastic olefin elastomer. the International Institute of Synthetic search firm Freedonia Group, Rubber Producers (IISRP), based in based in Cleveland, producers' ag- nology will increase the variety of maHouston, consumption of thermoplas- gressive product development efforts" terials available to thermoplastic elastic elastomers will grow 5.6% per year have helped displace synthetic rubber tomer users as new olefin-based mateduring the next five years, from 1.9 bil- in under-the-hood and interior auto- rial from the DuPont Dow Elastomers lion lb last year to 2.5 billion lb in 2000. motive applications. In addition, the joint venture and Exxon comes into the That's more than double the rate for study notes, "ongoing advances in poly- market. New catalyst technology that thermoset elastomers—the more famil- merization, alloying, and catalyst tech- Union Carbide and Netherlands-based iar natural rubber (derived from the nology will enhance the cost, competi- DSM are developing to produce therHevea brasiliensis trees, mainly in Asia tiveness, and performance of thermo- moset ethylene-propylene and ethylene-propylene-diene elastomers may and Africa) and synthetic rubbers, plastic elastomers." which include styrene-butadiene rubHoward R. Blum, vice president of expand applications for compounds ber (SBR), polybutadiene, ethylene- consulting firm the Catalyst Group, with polypropylene to make thermopropylene, and nitrile rubber. Accord- Springhouse, Pa., agrees that catalyst plastic olefin elastomers. ing to IISRP, worldwide consumption technology may improve the competiIndeed, the range of materials with of these thermoset synthetic and natu- tive advantage of materials such as ole- elastomeric properties has blurred the ral elastomers will grow 2.7% per year fin-derived thermoplastic elastomers distinction between elastomeric and between 1995 and 2000, reaching a total produced via Ziegler-Natta technology. plastic materials. Thermoplastic elasof 38.2 billion lb by the turn of the cen- He also predicts that metallocene tech- tomers have a number of advantages
T
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AUGUST 5,1996 C&EN
North America is the leader in world rubber consumption that have allowed them to muscle in on turf that once belonged to plastics and thermoset rubber. Because fewer steps are required to manufacture them than to manufacture and vulcanize thermoset rubber, thermoplastic elastomer parts are more economical to produce. Thermoplastic elastomers are easy to process on widely used and inexpensive equipment for plastic extrusion or injection molding. Thermoset rubber is more difficult to process in slowcycling, capital-intensive rubber processing equipment. In addition, parts producers may grind and reuse thermoplastic elastomer factory scrap. Thermoset rubber producers cannot simply grind and remelt scrap. Once a thermoset rubber piece is vulcanized, manufacturers often discard rubber waste produced in the part's manufacture. As a result, the production costs for a thermoplastic elastomer product are lower than a simple comparison of costs of materials on a pound-forpound basis would suggest. But thermoplastic elastomers have their limitations, too. They just do not have the combination of abrasion resistance, flexural strength, deformation resistance, and high-temperature use that thermoset elastomers display. Those limitations immediately prevent thermoplastic elastomers from substituting for the 18.7 billion lb of natural and synthetic rubber currently used to produce automobile and truck tires. However, based on 1995 data, manufacturers of thermoplastic elastomers can target a 14.7 billion-lb global market for nontire rubber uses. As a result, their products are gradually infiltrating thermoset rubber markets where they can provide a processing, cost, or performance advantage, or any combination of those advantages. In addition, some manufacturers have set their sights on traditional plastics markets. Such markets include medical tubing and packaging as well as wire and cable jacketing. They each consume hundreds of millions of pounds of resins annually. Freedonia Group predicts worldwide demand for thermoplastic elastomers in the medical products category will grow faster than any other use through the end of the decade: up 11.9% per year from 99 million lb in 1995 to 174 million lb in 2000. The group projects that wire and cable applications will grow more modestly—
by 4.9% per year to Thermoplastic Total elastomers Natural Synthetic 165 million lb in Millions of lb 2000—while other 9,911 831 2,461 6,619 North America uses will grow fast1,872 26 576 1,270 Latin America er. Consumer prod7,853 695 2,062 5,096 Western Europe ucts will be up 8% to 814 na 176 638 Central Europe 346 million lb; con1,259 39 106 1,114 C.I.S.a struction, up 77% to 795 13 419 363 Mideast & Africa 90 million lb; motor 9,812 321 4,697 4,794 Asia & Oceania vehicles parts, up 3,038 na 1,894 1,144 Chinab 73% to 1.1 billion lb; 21,038 12,391 1,925 35,354 TOTAL and industrial mab Includes Note: 1995 consumption, a Commonwealth of Independent States. chinery and equipNorth Korea and Vietnam, na = not available. ment parts, up 7.1% Source: International Institute of Synthetic Rubber Producers to 653 million lb. Freedonia speculates that demand for thermoplastic elastomers will rise nearly 7% annually beTotal rubber use to exceed tween 1995 and 2000, considerably high40 billion lb by 2000 er growth than IISRFs 5.6% forecast. In the North American market (inBillions of lb 30 cluding the U.S., Canada, and Mexico), Synthetic rubber Freedonia predicts that demand for 25 ^^^^^^ thermoplastic elastomers will rise 6% annually between 1995 and 2000 and 20 that construction uses will grow fastest, Natural rubber up 10.4% per year on a small base of 15 \^^^^^^^m 18 million lb in 1995 to 29 million lb in 2000. Other fast-growing North Ameri10 can markets will include medical prodThermoplastic elastomers 5 ucts, rising 9.5% annually to 74 million \ lb; appliances and business machines, t i l l 0 up 7.9% annually to 136 million lb; and 1994 95 96 97 98 99 2000 transportation equipment, up 6.8% anNote: World consumption. Source: International nually to 473 million lb. Institute of Synthetic Rubber Producers IISRP projects a similar, but slightly slower, 5.6% annual growth for thermoplastic elastomers in North America four basic groups and one miscelladuring that period, rising from 831 mil- neous group. The largest group of therlion lb in 1995 to nearly 1.1 billion lb in moplastic elastomers in 1995 was the 2000. The growth potential of thermo- styrenic block copolymers, with about plastic elastomers, according to IISRP, 50% of the market, followed by olefinis much greater than that for both nat- based materials at about 27%, ureural and synthetic rubber. In contrast to thanes at about 11%, copolyester-ethers the 5.6% growth rate for thermoplastic at about 5%, and a miscellaneous elastomers, the institute expects con- group including polyamides and visumption of natural rubber to decline nyls at about 7%. The market share of each group will 0.3% per year to 2.4 billion lb, and use of synthetic rubber to grow only 0.7% not change very significantly by 2000, Blum says, with olefins gaining 2% for per year to 6.8 billion lb. While most thermoplastic elastomer a 29% share of the market and ureproducers C&EN interviewed predict thanes losing 1% for a 5% share, and double-digit growth rates over the next the "other" category also losing 1% for few years for the largest categories of a 6% share. Blum cautions that his estimates do thermoplastic elastomers, consultants' predictions are more restrained. Cata- not include a new generation of polylyst Group's Blum says world thermo- ethylene-based materials that "are not plastic elastomer demand will rise at pure elastomers, but have elastomeric about 6% per year between 1995 and properties/' An example of such mate2000, from 2.1 billion lb to nearly 2.9 bil- rials is the Engage line of polyethylenebased materials Dow Chemical devellion lb. Blum breaks down market share into oped and which are now a part of the AUGUST 5,1996 C&EN
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BUSINESS DuPont Dow Elastomers joint venture formed earlier this year. DuPont Dow Elastomers predicts 50%-per-year growth rates over the next few years for their metallocenebased polyethylene elastomeric material called Engage. Paul R. Graves, group leader for Engage technical services, says Engage is a soft, flexible, elastic material with excellent processing characteristics. Parts manufacturers may use the Engage materials alone to produce flexible tubing, appliance parts such as foam and gaskets, and children's toys. They may be compounded with paraffinic oils, plasticizers, and fillers for use in slipper soles and tennis shoes. In many of these applications, they could compete with styrenic block copolymers or vinyl plastics, says Graves. The Engage elastomers could compete with foamed polyvinyl chloride (PVC) and nitrile rubber in insulation, toys, and footwear. In addition, in some cases Engage replaces ethylene-propylene rubber in compounds with polypropylene to make thermoplastic olefins. However, cautions Graves, use of Engage elastomers for now is limited to applications at room temperature to about 110 ° F. "But we expect to extend the material's temperature-use range well beyond present limitations over the next five years," he says. Engage elastomers sell for between 80 cents and $1.10 per lb, depending on the grade. According to John D. Cowperthwait, new business development manager for Montell, the Netherlands-based joint venture of Montedison and Royal Dutch Shell, there is so far little evidence of metallocene elastomers in the marketplace. He thinks its use will be limited to ethylene-propylene rubber replacements in thermoplastic olefin compounds. Montell produces thermoplastic olefins and thermoplastic vulcanizates. The company's Hifax line of thermoplastic olefins consists of compounds of nonvulcanized ethylenepropylene-diene elastomer and polypropylene. The ethylene-propylenediene rubber acts as a toughener and gives the material some flexibility and good impact strength. The company's line of Hifax MXL is a combination of cross-linked rubber and polypropylene. (Other thermoplastic vulcanizates also include blends of rubber with other plastics such as PVC.) 12
AUGUST 5,1996 C&EN
Transparent anesthetic tubing made of aromatic polyether-based thermoplastic poly methanes can survive repeated sterilizations. By and large, "thermoplastic elas- tectural seals, and "lots of small parts such tomers are good enough for many parts, as faucet seals and toilet ballcock seals." but the really demanding applications Thermoplastic olefins are generally priced may still need thermoset rubber," says between 75 cents and $1.00 per lb, whereCowperthwait. Thermoplastic elas- as thermoplastic vulcanizates are priced tomers cannot yet replace transmission from $1.40 to $2.00 per lb. seals, for instance, because of the deAdvanced Elastomer Systems' Lynell manding pressure under which such Maenza, manager of marketing and elastomers have to function. It cannot re- technical services, says flat out: "We place the thermoset rubber in a tire. are in the business of replacing thermo"Some manufacturers spent years trying set rubber." The Akron, Ohio-based to replace military tank pad tracks. Ther- company, a joint venture of Exxon and moplastic elastomers performed well Monsanto, produces a proprietary when the tanks went straight ahead," compound of rubber, such as ethylenesays Cowperthwait. "The tank pads propylene diene, vulcanized in the showed good abrasion resistance. But presence of a plastic matrix such as they melted when the tank turned be- polypropylene and sold under the Sancause of the heat buildup." toprene name. Automotive side moldHowever, thermoplastic olefins and ings and trim as well as plumbing, pipe vulcanizates can outperform therIn North America, thermoplastic elastomers moset elastomers in flex fatigue repredicted to grow faster than others sistance. That % annual makes them an growth % tire use Millions of lb 1995 2000 1995-2000 ideal thermoset rubber replace0.7% 6,861 6,618 45% Synthetic rubber ment for the 84 2,000 0.6 1,943 Styrene butadiene boots protecting 5 208 0.9 199 Styrene butadiene latex shock-absorbing 1,413 0.8 1,358 0 Carboxylated latex McPherson struts 75 1,219 0.9 1,166 Polybutadiene and the boots 4 615 0.9 589 Ethylene propylene protecting stan157 0.4 154 0 Polychloroprene dard shock ab197 1.3 1 185 Nitrile solid 82 82 0 0 sorbers in many Nitrile latex 942 49 970 0.6 Other3 cars, says Cow5.6 831 0 1,089 Thermoplastic elastomers perthwait. Other 2,430 -0.3 76 2,461 Natural rubber markets for thermoplastic olefins 0.9% 49% 10,380 9,910 TOTAL and vulcanizates a Includes butyl, polyisoprene, and other rubbers . Source: International Institute of include automoSynthetic Rubber Producers tive trim, archi-
Medical products are world's fastestgrowing market for thermoplastic elastomers • · · Because of its focus on automotive Millions of lb 1995 2000 markets, D&S may Motor vehicles 798 7.3% 1,133 soon have one new Footwear 593 503 3.3 owner. Gerlach says Industrial machinery & 7.1 463 653 Dexter wants to sell equipment its interest in D&S 236 8.0 346 Consumer products because "automo130 165 4.9 Wire & cable tive is no longer one Medical products 174 99 11.9 of [its] chosen marConstruction 62 7.7 90 kets." Gerlach deOther 44 64 7.8 clines to speculate TOTAL 2,335 6.6% 3,218 on when any transaction might occur. The partners formed • . . but in North America, construction is the joint venture in the fastest growing market 1990. Still another joint Average annual growth venture, HoustonMillions of lb 1995 1995-2000 2000 based Dexco, proTransportation equipment 341 473 6.8% duces thermoplastic Industrial machinery & 291 220 5.8 elastomers based on equipment styrenic block co2.7 182 159 Footwear polymers. The comAppliances & business 93 136 7.9 pany, which Dow machines Chemical and ExxWire & cable 4.1 66 80 on jointly own, has Medical products 47 74 9.5 a production facility Construction 10.4 18 29 in Plaquemine, La. Other 50 65 5.6 With the capacity to TOTAL 994 1,330 6.0% produce 100 million Source: Freedonia Group lb per year of styrenic block copolymers, the company seals, and weather seals are "double- claims it is the second largest U.S. prodigit growth" markets for the compa- ducer after Shell. ny's products worldwide, says Maenza. According to Dexco commercial Maenza says Advanced Elastomer manager David A. Trout, at least part Systems also has its eye on the poten- of the focus of styrenic block copolytial use of metallocene-based polyolefin mers is in replacing thermoset rubber materials in thermoplastic elastomers. in uses including footwear and adhe"We have access to the technology and sives. It also competes with SBR and materials for use in compounds old ground-up tires as an asphalt modthrough one of our parents, Exxon," ifier for better wearing roads and roofsays Maenza. "We have nothing close ing. The styrenic block copolymers give to commercialization yet, but it is un- asphalt improved thermal properties der investigation," he says. and thus reduce road rutting in hot Another joint venture, D&S Plastics weather and road cracking in winter. International, also views automotive Trout says styrenic block copolymarkets as an important customer for mer producers are pushing to have its thermoplastic polyolefins. Bob their materials specified in federal Gerlach, vice president of sales and standards for road making because marketing for the Auburn Hills, Mich.- the material's inclusion can extend the based company, a joint venture of Dex- life of a road five times beyond an unter and Solvay, says parts manufactur- modified asphalt road. Styrenic block ers use elastomer-modified polypro- copolymer prices range from 80 cents pylene the company produces to make to $2.50 per lb for specialty hydrogefront and rear auto fascia, exterior auto nated polymers. bumper trim, and auto rocker panels. According to Bayer's Joachim D&S also sees opportunities to replace Franke, vice president for global mar"anything painted in the interior of a keting of Texin and Desmopan thermocar," such as molded panels. plastic polyurethanes, Bayer is a leader Average annual growth 1995-2000
worldwide in the production of thermoplastic urethanes. BASF is another leader and other players include BF Goodrich and Dow Chemical. Applications for the company's elastomers cover a wide spectrum of uses from in-line skate boots, fire hoses, medical tubing, and joint sealants to auto and electrical cable and wire coatings. The company has recently begun to offer thermoplastic polyurethanes with greater longterm light stability by incorporating an aliphatic isocyanate (at a $2.00-per-lb premium) into the elastomer in place of the aromatic isocyanate now widely in use. The aromatic-isocyanate-based thermoplastic polyurethanes sell for $2.00 to $3.50 per lb. Friedhelm Lehrich, a business manager for BASF, says the company's Elastollan polyurethane thermoplastic elastomers cover many of the same uses Franke names. He adds they compete with PVC, SBR, and natural rubber in many cable and tubing applications. In addition, the thermoplastic polyurethanes replace polypropylene in ski boot and skate boot applications because the polyurethanes last longer and maintain their appearance better over time. Other markets for thermoplastic urethanes include use as a binder for magnetic particles to the polyethylene terephthalate film that forms the base of an audio or video recording tape, says Goodrich's senior commercial manager for Estane thermoplastic urethane, Michael J. Marasch. But, he adds, "most of our growth has come from replacing synthetic and natural rubber," such as gasoline pump hoses that take advantage of thermoplastic urethanes' flexibility, abrasion resistance, and hydrocarbon resistance. Hoechst makes a copolyester-ether elastomer, Riteflex, that is useful where flexibility and toughness are required in applications including industrial and automotive hydraulic tubing, hoses, gaskets, and bellows. Typical use temperatures range from -40 to 250 °F, says James E. Maldovan, program executive in Hoechst's technical polymers division. Prices range from $2.95 to $3.25 per lb. N. Wayne Ladd, business market manager for Eastman Chemical, says his company's copolyester ether, named Ecdel, is largely used in medical applications in which its chemical resistance, clarity, and ability to withstand the rigors of an autoclave at 250 °F and AUGUST 5,1996 C&EN
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BUSINESS 15 lb psi have made it a "drug storage package of last resort." Priced at $3.70 per lb, it can be used to package drugs that PVC cannot. Among the more rarefied thermoplastic elastomers are Elf Atochem's polyether block amides. James P. McAliney, marketing manager for technical polymers, says the company's Pebax line, produced in Birdsboro, Pa., substitutes for natural rubber. In fact, says McAliney, "Pebax outperforms rubber that will weaken after repeated use, particularly in demanding sports applications." Pebax is therefore used to make snowboards, snowshoes, in-line skates, and professional swim fins. It can also be used as an additive to wire coatings and paint spray hoses because it is hydrophilic and can absorb a static charge. In addition, Pebax is used as an additive to make thermoplastic urethanes easier to process. Prices for Pebax range from $4.50 to $5.50 per lb. The variety of thermoplastic elastomers and the new materials that
m.
Styrenics dominate global thermoplastic elastomer demand Styrenic block copolymers 50%
Styrenic block copolymers 50%
Olefins ^ ^ 27%
29%/
Urethanes
11%
JÈ
10%
Copolyester ethers -
Other —
Global 1995 demand: 2.14 billion lb
Global 2000 demand : 2.87 billion lb
Source: Catalyst Group
promise to expand thermoplastic elastomer applications can replace many nontire thermoset rubbers and plastics. Such a wide variety of materials with elastomeric properties makes it difficult to distinguish a rubber product from a plastic product, notes Catalyst Group's
Kl
Blum. Ultimately, customers will not focus on whether they need a rubber or plastic material, he says, but "will look at the great variety of materials now available for those that provide a perfect solution" to manufacture the parts they require. •
DuPont chemist Tim Krizan couldn't be
m*Qzgm§mËÊHm ^^E
more proud of how slowly DBE solvents evaporate. Of course that's why they're considered to be excellent tail solvents for can and coil coatings. Their flash
HE HAS A WORD
point of > 100 C makes them a very low
FOR THOSE
fire hazard. Also, they can produce less
WHO CALL
waste than solvents like methylene chlo-
DBE SOLVENTS
ride or acetone. As for the rest, you can take that up with Tim. Call 1-800-231-0998
SLOW.
for a free sample and to find out about all our diacids, diamines and diesters.
THANKS.
And check out our Web site at www. dupont.com/intermediates.
Tim Krizan, Du Pont Chemist
mm Nylon Intermediates & Specialties
DuPont
CIRCLE 3 ON READER SERVICE CARD
14 AUGUST 5,1996 C&EN
