Cycloolefine copolymer

Table 9 compares the most important properties of substrate materials based on BPA-PC, PMMA, and CPO (three different products) (216,217). The future will prove if the current disadvantages of CPO against BPA-PC regarding warp, processibiUty (melt viscosity), and especially cost can be alleviated. CycHc polyolefins (CPO) and, especially cycloolefin copolymers (COC) (218) and blends of cycloolefin copolymers with suitable engineering plastics have the potential to be interesting materials for substrate disks for optical data storage. 

Amorphous polymers are characterized by the following properties They are transparent and very often soluble in common organic solvents at room temperature. The following amorphous polymers have gained industrial importance as thermoplastic materials polyfvinyl chloride), polystyrene, polyfmethyl methacrylate), ABS-polymers, polycarbonate, cycloolefine copolymers, polysulfone, poly( ether sulfone), polyfether imide). 

High magnetic fields and in particular C-NMR spectroscopy allow the analysis of even longer configurational sequences (tetrads up to nonads). This proved to be important in particular for the analysis of polyolefins like polypropylene or cycloolefin copolymers (COC). These polymers are available via transition-metal mediated (Ziegler-Natta, metallocene) insertion polymerizations, and the configurational analysis provides deep insight into the respective polymerization mechanisms as well as into the structure-property relationships. 

H. Cherdron, M.-J. Brekner, R Osan, Cycloolefin Copolymers, Angew. Makromol. Chem. 223, 121 (1994)... 

For example, it is possible to synthesize isotactic as well as syndiotactic polypropylene in high configurational purity and high yields. The same holds for syndiotactic polystyrene. Furthermore, metallocene catalysts open the possibility to absolutely new homopolymers and copolymers like, e.g., cycloolefin copolymers (COG) and even (co)polymers of polar monomers.The simplest metallocene catalyst consists of two components. The first one is a n-complex (the actual metallocene) that can be bridged via a group X and therefore can become chiral ... 

Depending on the application, different demands are placed on the melt viscosity of the polymer. For injection molding applications, lower melt viscosities are required than for extrusion applications. For a given comonomer composition and processing temperature, the melt viscosity of the cycloolefin copolymers increases with the mean molecular weight. 

An example of such a catalyst system is racemic isopropylene bis(l-indenyl) zirconium dichloride in combination with an alumi-noxane (21). The reaction is carried out in hydrocarbon solvents, e.g., toluene. A solution of norbornene in toluene with the catalyst is degassed and then pressurized with ethene. The polymerization is carried out while stirring at 70°C under constant ethylene pressure at 18 bar. After completion, the polymer is precipitated in acetone and filtered (21). The cycloolefin copolymers obtained in this way have a high thermal shape stability and it is possible to use the polymers as thermoplastic molding compositions. 

K. Ohkita, T. Imamura, and N. Oshima, Cycloolefin copolymer formed by ring-opening polymerization, process for producing the same, and optical material, US Patent 7056999, assigned to JSR Corporation (Tokyo, JP), June 6,2006. 

T. Weller, F. Osan, F. Kuber, and M. Aulbach, Process for preparing cycloolefin copolymers, US Patent 5698645, assigned to Hoechst Ak-tiengesellschaft (Frankfurt, DE), December 16,1997. 

D.A. Hammond and D. Heukelbach, Cycloolefin copolymer resins having improved optical properties, US Patent 6951898, assigned to Ticona LLC (Summit, NJ), October 4,2005. 

T. Penttinen, K. Nevalainen, and J. Jarvinen, Method for manufacturing heat-sealable packaging material having barrier layer containing cycloolefin copolymer, US Patent 7 344 759, assigned to Stora Enso Oyj (Helsinki, FI), March 18, 2008. 

R.D. Jester, Cycloolefin copolymer heat sealable films, US Patent 7288316, assigned to Topas Advanced Polymers, Inc. (Florence, KY), October 30, 2007. 

M. Donner and W. Kaminsky, Chemical recycling of cycloolefin-copolymers (COC) in a fluidized-bed reactor, /. Anal. Appl. Pyrolysis, 74 (l-2) 238-244, August 2005. 

Cyclic Polyolefins (CPO) and Cycloolefin Copolymers (COC). Japanese and European companies are developing amorphous cyclic polyolefins as substrate materials for optical data storage (213—217). The materials are based on dicyclopentadiene and/or tetracyclododecene (10), where R = H, alkyl, or COOCH3. Products are formed by Ziegler-Natta polymerization with addition of ethylene or propylene (11) or so-called metathesis polymerization and hydrogenation (12), (101,216). These products may still contain about 10% of the dicyclic structure (216). 

In the early 1990s supported metallocenes were introduced to enable gas phase polymerisation. Also ethene/a-olefin copolymers with high comonomer content, cycloolefin copolymers and ethene-styrene interpolymers became available. In 1990 Stevens at Dow [22] discovered that titanium cy-clopentadienyl amido compounds (constrained geometry catalysts) are very beneficial for the copolymerisation of ethene and long-chain a-olefins. 

Metallocenes are very versatile catalysts for the production of polyolefins, polystyrene and copolymers. Some polymers such as syndiotaetic polypropene, syndiotactic polystyrene, cycloolefin copolymers, optically active oligomers, and polymethylenecycloalkenes can be produced only by metallocene catalysts. It is possible to tailor the microstructure of polymers by changing the ligand structure of the metallocene. The effect and influence of the ligands can more and more be predicted and understood by molecular modeling and other calculations. 

Single-site metallocene catalysts are also highly reactive vis-a-vis cycloolefins such as cyclobutene, cyclopentene or norbornene. While homopolymers of these cycloolefins have melting temperatures (>380°C), much too high for technical processability, ethylene-cycloolefin copolymers (COC s) - e.g. ethylene-norbornene copolymers - are amorphous materials with glass transition temperatures, above which they become soft and processable [W. Kaminsky, J. Polym. Sci. A, Polym. Chem., 2004, 42, 3911]. 

Metallocenes and methylalumoxanes can further be used to synthesize isotactic polypropylene [70, 71], syndiotactic polypropylene [38], other propylene polymers or oligomers [72], ethylene/cycloolefin copolymers [10-13], syndiotactic polystyrene [14, 61], and ethylene/styrene copolymers [64]. Cycloolefin copolymers are amorphous, with high glass transition temperatures [10-13]. The syndiotactic polystyrenes are semicrystalline polymers with a glass transition temperature around 100 °C and a melting point of 270 °C [14]. 

Within the past five years, commercial interest in metallocene catalyst components for the polymerization of olefins has increased enormously. Commercial production of a rising number of polyolefin types from different companies is creating a burgeoning and highly diversified demand for metallocenes. New brand names (e. g., Metocene (Basell), Elite (Dow Chemical), Engage (DuPont), Exact (ExxonMobil), Luflexen (Basell), Apel (Mitsui Chemicals), Borecene (Borealis), Finathene (TotalFinaElf), Topas (Ticona), just to name a few) characterize polyolefins such as PE, elastomers, PP, cycloolefin copolymers (COCs) and PS from metallocene-type catalysts [1-3]. 

---