| 摘要 |
PURPOSE:To obtain an optical recording medium having excellent sensitivity and degree of modulation and superior light resistance by forming a laser-beam absorbing layer onto a substrate and containing a light absorbing dyestuff having heat characteristics, in which the exotherm rate value and a weight-loss rate value in thermal analysis take specific values, in the laser-beam absorbing layer. CONSTITUTION:In the optical recording medium, a laser-beam absorbing layer is formed onto a substrate, and a reflecting layer is formed onto the laser-beam absorbing layer. A light absorbing dyestuff having thermal characteristics, in which an exotherm rate S1 value in thermal analysis (a temperature rise rate:10 deg.C/min and the quantity of a sample:10mg) takes a value from 5mcal/sec to 15mcal/sec and a weight-loss rate S2 value takes a value from 300%/min to 1,000%/min, is contained in the laser-beam absorbing layer. The optical recording medium having sufficient sensitivity and degree of modulation cannot be acquired when the exotherm rate S1 value is less than 5mcal/min or the weight-loss rate S2 value is less than 300%/min, and the stability of light absorbing dyestuff itself and shelf stability thereof are deteriorated and the dyestuff is easy to be decomposed by the irradiation of light when the exotherm rate S1 value exceeds 15mcal/sec or the weight-loss rate S2 value exceeds a 1,000% section. |
