Optical information recording medium

摘要

Optical information recording mediums are provided that include an improved substrate comprising a polycarbonate resin wherein the content of free chlorine present in the substrate and chlorine present as terminal chloroformate groups of the polycarbonate resin are defined to be within certain ranges. The substrate further having limited amounts of a halogenated hydrocarbon used as a solvent for the preparation of the polycarbonate resin. The composition suppresses corrosion of a recording layer formed on the substrate. The substrate may further comprises a releasing agent having a defined hydroxyl value. When the polycarbonate resin or its composition is injection molded, the resin temperature is defined in a certain range, by which hydrolysis of the polycarbonate resin can be prevented. Thus, the medium has a reduced number of defects and long-term reliability.