HOUSTON — As the metallocene march continues, resin producers are admitting the pace is a steady one and not the headlong sprint some had anticipated when the materials were being developed earlier in the decade.
``There's been a lot of hyperbole and cynicism about metallocenes, but the reality of the situation lies between these two extremes that we often hear about,'' said Darryl Fahey, manager of specialty resins research and development for Phillips Petroleum Co. of Bartlesville, Okla.
``The metallocene market still has a good future and is developing at a very healthy rate,'' he added.
Reality added up to about 700 million pounds of metallocene and single-site polyethylene sold in North America last year, according to industry sources, and should top the 1 billion-pound mark in 2000. Most of those sales were generated by metallocene leaders Dow Chemical Co. of Midland, Mich., and Exxon Chemical Co. of Houston. The floodgates aren't open, but there's definitely some water flowing through.
Industry officials dealt with the reality of their surroundings at MetCon 99, an industry conference held June 9-10 in Houston.
Officials from Phillips, Dow, Exxon and Nova Chemicals Ltd. of Calgary, Alberta — companies that produce commercial metallocene PE — all declined to estimate what sort of growth rate metallocene sales enjoyed in 1998. All agreed sales were up, however, led primarily by sales of metallocene linear low density PE into the film market.
Use of metallocene LLDPE in film applications is expected to grow 30 percent annually through 2010, according to David Simpson, an international product support representative with Univation Technologies. Univation is a technology-licensing joint venture between Exxon and Union Carbide Corp. of Danbury, Conn.
Metallocene resins made using Exxon's Exxpol technology and Union Carbide's Unipol PE production process are making inroads in markets for trash bags, pallet wrap and heavy-duty shipping sacks, Simpson added. Combined, those three markets consume about 2.5 billion pounds of PE each year in North America.
Simpson estimated that a pallet-wrap stretch film maker could save 1-11/2 cents per pound by using half metallocene content in just one layer of trilayer film. Using 75 percent metallocene in one layer could save a processor 11/2-2 cents per pound, Simpson said.
Such savings are important in light of the 3-4 cent-per-pound premium metallocenes traditionally have held over standard PE.
Univation sees tremendous potential for its metallocene technology because of the widespread use of Unipol. From 1979-1999, half of the third-party PE production licenses granted worldwide belonged to Unipol, Simpson said.
Producers are looking beyond film to other markets. Phillips has used cross-linked metallocene PE to produce rotomolded containers that stand 6 feet tall and can hold as much as 2,000 gallons of liquid. The company also has produced a metallocene PE for the blow molding market to make a squeezable water bottle with a very soft feel and high gloss.
Nova also is looking at the rotomolding market, where metallocenes' ability to control specific molecular performance is a good fit for the narrow specifications of rotomolded products, according to Nova senior research scientist Steve Brown.
As the metallocene market grows, selecting the right catalyst becomes even more important, according to Doug Selman, Exxon's vice president of polymers technology.
``The limit [of entering the metallocene market] may be the cost of developing all these catalysts,'' Selman said. ``Even at Exxon, we have to be selective. We can't chase dozens of different catalysts to make polyethylene. You have to fully understand the market and make sure you're making a material that your customers can fabricate in their plants.''
Dow's production of its Elite-brand single-site PE is sold out, due in part to processors' growing experience with the material, according to Bruce Story, intellectual asset manager for Dow's polyolefins technology.
``There's a great deal more acceptance of these materials in many areas than there was in the past,'' Story said. ``Processors are more open with it. As a result, we're sold out in what's considered a trough period.''