| 摘要 |
A product and a method for producing a product consisting of a thermoplastic substrate having a cured coating thereon. The coating consists of the ultra-violet radiation cured product of a brominated epoxy acrylate oligomer, a polyfunctional acrylate monomer, a silicone hard coat and a photoinitiator. The coated thermoplastic substrate has a low birefringence (<25 nm), and a low delta refractive index between the coating and thermoplastic substrate and a smooth upper surface having a gloss of at least 90% and a surface roughness of about 10.0 mum or less. In order to obtain such a product, the thermoplastic substrate must be prepared by first producing a substrate having a smooth lower surface and a textured upper surface to which is applied the curable coating. A thermoplastic substrate, particularly an aromatic polycarbonate substrate, is prepared by passing a heated substrate between a pair of rolls wherein the upper roll has a textured surface and the lower roll has a smooth polished surface. The coated thermoplastic substrate has utility and optical media applications such as CD's or CD-ROM discs because the coated thermoplastic substrate has excellent properties of low stress, low birefringence, virtually matching index of refraction of the coating and substrate and a smooth upper surface having minimal roughness. These properties allow transmission rather than reflection of light thus making the coated substrate acceptable for optical applications. The thermoplastic substrate is preferably an aromatic polycarbonate.
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