Cyclo Olefin Copolymers (COC)

Properties and Applications

Cyclo olefin copolymers (COC) are transparent amorphous thermoplastics produced by copolymerization of norbornene or docyclopentadiene with ethylene using a metallocene catalyst. These copolymers have many attractive optical properties including high clarity, high light transmissivity, low birefringence, and high refractive index. Other performance benefits include excellent biocompatibility, very low moisture absorption, good chemical resistance, excellent melt processability and flowability as well as high rigidity, elastic modulus, and strength which are retained over a wide temperature range, from about -50 °C to near their glass transition temperature.¹

COCs are often a good alternative to polycarbonates (PC) and polymethacrylates (PMMA). Their optical properties are comparable to those of PMMA, and their heat resistance is superior to that of PC, whereas their dimensional stability is superior to both polymers.

COCs find growing use as a shatter-resistant substitute for glass in (thin) optical lenses and films particularly in medical and electronic applications such as diagnostic tubes, touch screens (ITO film), light guides, and reflection films. Their excellent biocompatibility, chemical resistance and superior water vapor barrier also makes them a good choice for primary packaging of pharmaceuticals and for medical diagnostic disposables.