Metallocene technology

Ethylene-cyclo-olefin copolymers have been known since 1954 (DuPont USP2 721 189) but these materials only became of importance in the late 1990s with the development of copolymers of ethylene and 2-norbomene by Hoechst and Mitsui using metallocene technology developed by Hoechst. The product is marketed as Topas by Ticona. By adjustment of the monomer ratios polymers with a wide range of Tg values may be obtained including materials that are of potential interest as thermoplastic elastomers. This section considers only thermoplastic materials, cyclo-olefins of interest as elastomers are considered further in Section 11.10. 

Perfluorinated phenylboranes and perfluorinated phenylborates are well-established activators in the metallocene-initiated polymerization of olefins. With the increasing commercial importance of metallocene technology for the polymerization of ethylene and the copolymerization of ethylene and 1-alkenes, perfluorinated phenylboranes and perfluorinated phenylborates became more readily accessible. As a consequence, a few studies on the influence of these highly fluorinated activators on Nd-catalysis are available in literature. 

Combining Metallocene Technology with Gas Phase EPDM, PE, Feb. 2003. 

Deals can create value on the technology side if they unite players with different (and, ideally, complementary) skills and strengths. That has been the rationale behind a number of recent technology-focused alliances, such as the one between Union Carbide and Exxon in polyolefines the former excels in process technology, the latter in metallocene technology. Clear synergies exist, since a producer can tailor a process to the specific needs and opportunities of new metallocene products. 

The new single-site metallocene technology can be employed to yield new polyolefin materials (polyolefin plastomers (POP) and polyolefin elastomers (POE)) as noted by Schwank in the above noted reference. POP and POE materials are based on ethylene-octene copolymers and should show promise in various future blend combinations. 

Benelkt, George M. (1999) Metallocene Technology in Commercial Applications, Brookfield, CT, Society of Plastics Engineers... 

Begishev VP, Ya MaUdn A (1999) Reactive processing of polymers. ChemTec, Toronto, Canada Belfiore LA (2003) Transport phenomena for chemical reactor design. Wiley, Hoboken, NJ Benedikt GM (1999) Metallocene technology in commercial applications. Plastic Design Library, Norwich, NY... 

A recent development in metallocene technology results in the production of cost-effective metallocene-based polyolefin and cyclo-olefin materials by the use of... 

In the USA Exxon Chemical and Dow Plastics were the leaders in the metallocene technology. While Exxon explored both mono- and bis-cyclopentadienyl metallocenes, Dow focused on constrained geometry catalysts based on Ti-monocyclopentadienyl metallocenes. Exxon first produced metallocene-based polymers with its Exxpol catalysts in 1991. Dow uses its INSITE technology to make ethylene-octene copolymers, introduced in 1993. Copolymers with up to 20 wt% octene are sold as AFFINITY plastomers, competing with specialty polymers in packaging, medical devices, and other applications. Dow, producing its own catalyst, considers that it leads to the uniform introduction of comonomers and long-chain branches that improve processability of otherwise linear polymers. 

Affinity Polyolefin plastomer, containing 0-20 wt% comonomer based on Insite metallocene technology, with long chain branching Dow Chem. Co. 

Metallocene Technology Seminar, Conference Proceedings, Rapra Technology, Shrewsbury, UK, 1997. 

AA Montagna, RM Burkhardt, AH Dekmezian. Single site catalysis its evolution and impact on the polymer field. Proceedings of Metallocene Technology 97 Conference. Chicago, 1997, pp 1-9. 

Recent metallocene technology widened the range of properties and applications of polyolefins. 

When copolymerization using metallocenes is compared with conventional processes, metallocene technology offers several advantages (1)... 

EPDM and EPR are used to modify polyolefins, primarily in the automotive industry. The largest volume is in automotive PP bumpers. This application is gradually being replaced by impact-resistant polymers produced by metallocene technology, providing better performance and economics. DuPont Dow and Exxon are leading producers in North America. When used with plastics such as nylon, PET, and PBT, the EPDM and EPR are often modified with a functionalized monomer to allow them to react with the plastic. Additionally, the shell of a core-shell modifier can also be modified to include a reactive group. Suppliers of fimctionalized modifiers include Rohm Haas, AtoFina, Shell, and Exxon. 

G. M. Benedikt, ed.. Metallocene Technology in Commercial Applications, Plastics Design Library, New York, 1999. 

J. W. Harwood, "Industrial Applications of Organometallic Compounds," Reinhold, New York (1963). J. C. Johnson, jr. "Metallocene Technology," Noyes Data Corporation, Park Ridge, New Jersey (1973). 

Metallocene Technology 8c Modern Catalytic Methods in Commercial Applications, PDL, 1999. 

Borealis has started up its metallocene-based slurry loop polyethylene (PE) plant at Ruenningen, Norway. Borealis will produce 30,000 t/yr of metallocene-based products at the plant in 1997. Borealis has agreed a licensing deal with Exxon Chemical which should avoid future patent conflicts over the companies respective metallocene technologies. In 1996... 

Exxon Chemical and Union Carbide formed a joint venture to develop metallocene technologies. Exxon and DSM also set up a metallocene joint venture in 1996. Dow began production of 65,000 t/yr of metallocene products at Tarragona, Spain in 1996. 

Figure 34 lays out the playing field in metallocene polyolefin development [59]. Activity in the various metallocene technologies is proceeding on a global basis, with many participants already involved in alliance arrangements. These materials have key properties which provide opportunities in many existing markets. 

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