Development of UV-curable resin for Blu-ray disc protective layer

In order to meet the demand for a greater storage capacity than digital versatile disks (DVDs), the Blu-ray disk (BD) format was proposed in 2002 to store high definition (HD) digital moving pictures for a long time. Since the structure of the BD is different from that of the DVD, the development of novel processes for BD media is required. In this study, we investigated the development of a UV-curable resin composition for the cover and the hard coat layer of BD systems.In the BD media, the newly developed UV-curable resin was spin coated as a protective layer on the production line and has been used for BD media. The obtained conclusions are summarized as follows: 1) The transparency in the visible wavelength region is greater than 95%. 2) The angular deviation of tilt including the environmental storage test at 80degC is less than 0.2 deg. 3) SER was less than 1x10^-5 and only slightly increased even after storage at 80degC, 85% RH for 1000 h, and has satisfactory environmental storage properties. 4) For the hard coat layer, the silicone resin is used to reduce the SER and has good anti-smudge properties after the artificial fingerprint test.