SAN ANTONIO — Metallocene catalysts have been playing the role of overnight sensations in the plastics industry for the better part of two decades, promising superior qualities in several performance areas.
Speakers at Flexpo 97 in San Antonio maintained the future is still bright for metallocenes, but they also acknowledged the technology's window of opportunity might be limited.
Paolo Galli, president of the Montell Technology unit of Montell Polyolefins BV, said metallocenes have been issued more than 1,000 patents since 1976, but have not reaped the benefit of extensive commercialization.
By comparison, Galli said, the first polypropylene catalyst was commercialized three years after its discovery in the 1950s.
``The risk for metallocenes is: becoming old before they reach maturity,'' said Galli, who is researching metallocene polyolefins. ``Time is their worst enemy.''
Galli added that metallocenes have been held back by being targeted to inter/intramaterial competition, particularly when used with linear low density polyethylene, instead of as a substitute for other engineering polymers.
Galli called for ``a drive and an impact more in line with the present needs'' in metallocene advancement, saying the slow progress to date is ``a pity for a product with so much potential.'' Galli works at Montell's G. Natta Research Center in Ferrara, Italy. Montell Polyolefins is based in Hoofddorp, the Netherlands.
In spite of these concerns, new metallocene alliances and capacities are springing up, as witnessed by the April launch of Univation Technologies, a Houston- based joint venture between Exxon Chemical Co. and Union Carbide Corp.
Univation's Mont Belvieu, Texas, metallocene facility is open with enough catalyst capacity to support 3 billion pounds of PE production annually.
Univation officials have predicted that metallocene PE demand will exceed 4.4 billion pounds annually by 2000. The joint venture is combining Danbury, Conn.-based Union Carbide's Unipol gas-phase PE process technology with Houston-based Exxon's Exxpol metallocene catalyst systems.
A metallocene technology patent dispute remains unsettled between Univation and a similar venture involving Dow Chemical Co. of Midland, Mich., and British Petroleum Chemicals Ltd. of London. Exxon and Dow are the leading developers of metallocene catalyst technology, while Union Carbide and BP Chemicals are leaders in PE production technology.
Gregory McPike, Univation president and chief executive officer, said at Flexpo that the situation is complicating the metallocene field.
``Having a strong patent doesn't guarantee freedom to operate,'' McPike said. ``A significant consumer of metallocenes has to watch what's going on in that area.''
McPike predicted that metallocene grades of LLDPE, the resin that has benefited the most from metallocene technology, soon will be able to replace standard LLDPE, high density PE and polypropylene, as well as paper, metal and glass in many applications.
Metallocenes' ability to match applications precisely without losing toughness, softness, clarity and other properties will help establish them in the marketplace, McPike said.
Other companies have ventured into the metallocene world as well. Phillips Chemical Co. of Bartlesville, Okla., expects to manufacture 20 million to 30 million pounds of metallocene LLDPE in 1997. The company expects that number to climb to 1.75 billion pounds by 2005. Nova Chemicals Ltd. of Calgary, Alberta, will have metallocene capability at a 770 million-pound-capacity PE plant scheduled for a 2000 opening in Joffre, Alberta.
Metallocene costs also have been reduced in the past three years through more efficient ways of assembling the catalyst by using different and less-expensive co-catalysts, according to McPike.
Volume stretch film is another area seeing the impact of metallocenes. Paul German, Exxon marketing development manager, said metallocene LLDPE offers processing times similar to standard LLDPE, but increased toughness.
German said Exxon is developing three new volume film product families: one designed to compete with LDPE; a ``supertough'' LDPE product to compete with LDPE and LLDPE blends; and the next generation of the company's Exceed metallocene LLDPE, which has been available commercially since 1995. The company may produce as much as 300 million pounds of Exceed resin this year, according to German.
The stretch film market is being targeted because of its explosive growth in the past decade. Volume doubled between 1985 and 1990 and again from 1990-95, to reach 1 billion pounds.
German compared progress in metallocenes with that of LLDPE, the benefit of which, according to German, was not fully realized for 10 years.
``There's a lot of interest in the metallocene area because of their huge ability to control and change molecules,'' German said. ``The market can only get bigger.''