| 摘要 |
PURPOSE:To obtain an optical recording element having high information recording sensitivity and C/N and excellent heat resistance and durability as a substrate by incorporating 4-4'-(dihydroxyl diphenyl)-1-1-cyclohexane into a resin compsn. of the transparent plastic substrate. CONSTITUTION:The transparent resin compsn. having the excellent heat resistance and durability includes bisphenol A polycarbonate. The bulky molecular groups such as cyclohexyl groups which induce a steric hindrance are added to the isopropyl group among the isopropyl groups and carbonate groups in the chemical structure thereof. The increase of the specific heat near about 140 deg.C, i.e., sensible heat of melting specific to the bisphenol A polycarbonate is eliminated by using such resin compsn., by which the recording and C/N are eventually improved. |
