Twelve years after debuting in Japan and being hailed as an impact player in optical resins, cyclic olefin copolymers have carved out only niche markets. But as with any resin, market development depends on supplier economies-of-scale, which lead to lower resin prices.

Current pricing levels, approximately three times higher than other optical resins like acrylic and polycarbonate, have limited COCs — copolymers of norbornene and ethylene — to niche roles in medical devices, packaging, and electronics.

But the latest indications are that suppliers are committed to elevate COCs to the next level. For example, Zeon Corp., Tokyo, which has 5300 tonnes/yr of capacity for its Zeonex homopolymer resins and Zeonor copolymer resins in Mizushima, Japan, is planning to raise capacity to over 20,000 tonnes/yr, although its schedule was not disclosed. This facility would join Ticona’s 30,000-tonne/yr plant in Oberhausen, Germany — on line since last September — as the second commercial-scale facility in the world.

Last year, Ticona concentrated on film and full-color toner binder applications, as it saw these yielding large market volumes. “This proved to be the most promising approach and it should yield increased results in 2003,” a company spokesman notes. While Ticona believes it will break even financially in COCs in 3 to 4 years, it is evaluating options to reduce its load.

Ticona has scored successes in packaging film applications and medical and diagnostic devices. Since last September, BioTech Solutions Inc., Mt. Laurel, NJ, has employed the supplier’s Topas COC in its Multi-Tier Micro Plates that hold vials for tasks such as high-throughput screening in drug research and combinatorial chemistry. The switch from abs enabled re-use of the plates, as COC could be steam-sterilized or dry autoclaved (at about 250ºF).

The plates are molded by J.G. Finneran Associates, Vineland, NJ, using tooling originally designed to mold glass-filled polypropylene. The only tool modifications were a larger gate size and angle, and a more polished surface to prevent drag marks, says Randy Eccles, the molder’s special projects manager. “Topas processes very much like [general-purpose polystyrene].”

Pharmaceutical blister packaging is another potential market, with companies wanting to shift away from halogenated barrier materials such as polyvinylidene chloride (PVDC) and polychlorotrifluoroethylene (pctfe). COC can be used in a 3-layer barrier structure with pp on both sides.

Ticona says that tests with Topas blister film, and practical application in Southeast Asia by pharmaceuticals oem Schering-Plough, have proved its ability to provide barrier protection in tropical conditions. Water-vapor permeability for a 300-µm COC barrier layer is 0.2 g/m² per day at 100°F and 90% relative humidity. Schering-Plough and Ticona say that Topas can be processed on existing rigid-PVC blister pack thermoforming machines.

Another study by Eli Lilly and Co. and Tekni-Films Europe NV, Erembodegem, Belgium, however, notes that because of film stretching and thinning, COC loses moisture barrier upon thermoforming. Tests showed that while a 300-µm pp/coc/pp structure has a moisture barrier that is 6.5% higher than a PVDC/polyethyl-ene/PVC structure with 90-g/m² permeability, and 34% higher than a 15-µm pctfe/PVC structure prior to thermoforming, after forming a PVDC structure has a 10.1% better barrier. A PCTFE structure alone has a 27% better barrier.

“Although COC has its merits as the only 100% halogen-free high-barrier resin, one has to understand its limitations,” says Johan Declerck, business development manager of pharmaceutical products at Tekni-Films Europe. “For instance, very deep-draw blister cavities are difficult to achieve, and to obtain a truly high moisture barrier, one needs to select a very thick (film) gage, [in the range of 400 to 500 µm]. This may, however, jeopardize the blister pack’s functionality due to the very rigid cavity compromising push-through of the tablet or capsule.”

In packaging, Pactiv Corp., Lake Forest, IL, is using a 3 to 20% Topas/ low-density pe blend in its Slide-Rite bag closures to increase the opening force required to pull the tracks apart. In the closures, a slider opens and closes the tracks. Topas imparts improved stiffness and strength to the tracks. Current applications include shredded cheese, garden soil, and pet food packaging.

Electronics are targeted in Japan

In Japan, COC suppliers are firmly focused on optical applications, particularly film and sheet for liquid crystal displays (LCD). In fact, without the rapid growth of the LCD business in recent years, Japanese suppliers may well have struggled to make COCs viable, notes one observer.

Since last October, Zeon started extruding Zeonor film at its Optes Co. subsidiary in Sano, Japan. Previously, solution casting was the only process capable of producing optical film with the necessary surface finish and tolerances. Zeon says conventional film extrusion left die lines on the surface that affected optical properties. While declining to reveal details, Zeon says it is possible to extrude film of 100 µm to within +/-1 µm.

JSR Corp., Tokyo, recently announced plans to hike capacity for its Arton COC resins at Chiba, Japan, from 1000 tonnes/yr to 3000 tonnes/yr by January 2004, in response to LCD demand. The company is also constructing a facility to manufacture, starting in September, 5 million m²/yr of Arton film, primarily for flat-panel LCD television applications. Consultant iSuppli/Stanford Resources, El Segundo, CA, estimates global LCD TV production will grow from 2.98 million sets this year to 18.81 million in 2006.

Currently, JSR outsources Arton film production, but it has decided to move production in-house to add value and improve margins. Arton film is used as a retardation film in LCD TVs. It corrects birefringence, thereby eliminating light distortion and expanding viewing angle and brightness. George Ohgaki, president of consultant Infinite Resources Inc., Tokyo, estimates retardation films sell for around $28/m². JSR also believes the films could penetrate the personal digital assistant (PDA) market.

Mitsui Chemicals, Tokyo, has 3000 tonnes/yr capacity for its Apel COC, and has no expansion plans. The company says it is focused on leveraging the high refractive index, low birefringence, and low water absorption of COCs in uses. Mitsui Chemicals has confidential agreements with Ticona covering production technology, and it is also the exclusive Japanese agent for Topas.

Light-guide panels (LGP) for LCDs are perhaps the most titillating market for COC suppliers in Japan. These are essentially plastic-sheet components that disperse point or linear sources of light across the entire LCD. However, despite the advantages they command over widely-used acrylic (PMMA) in optical properties and weight, COCs have struggled to significantly penetrate the market due to cost.

One sector where progress has been made is laptop computers, where weight savings justify the cost premium. Zeon estimates COC LGPs are, on average, 20% lighter than PMMA LGPs. It claims Zeonor is fast becoming the defacto material for 14.1- and 15.1-in laptop screens. Another promising area is “front-light” LGPs in color PDA and cellular-phone screens.

Observers estimate that penetration in LGPs is in the single digits. Infinite’s Ohgaki says, “With LCD-module prices continuing to fall, component prices are falling in unison and this will make it harder to justify COC use at current pricing levels.” Ohgaki forecasts LGP prices will fall an average 8.6%/yr through 2007.

Acrylic resin suppliers appear confident that they will continue to dominate the LGP market. Some have announced capacity expansions. For example, in June, Kuraray, Osaka, Japan, will debottleneck its 38,600-tonne/yr plant in Nakajo, Japan, by 6000 tonnes/yr. LG MMA, Seoul, Korea, also is adding capacity, as are Mitsubishi Rayon and Sumitomo Chemical, both in Tokyo. Suppliers estimate 37,000 tonnes of acrylic were used in LGPs last year.