Disc shaped high density recording medium

摘要

This invention relates to an optical recording medium in which at least a recording layer and a light transmitting layer are sequentially formed on a substrate and in which the light is illuminated from the light transmitting layer side for recording and / or reproducing information signals, said substrate comprising an injection molded part or have an injection molded sandwich structure with a molded surface layer (skin layer) and a molded core layer or a two injection molded parts which are UV-bonded, and said substrate having a Young's modulus E of at least 2.15 GPa and a Q factor of lower than 160 measured at 25°C at 2000 Hz in accordance to ASTM E 756-05.