SUBSTRATE FOR RECORDING MEDIUM, METHOD FOR MANUFACTURING SUBSTRATE FOR RECORDING MEDIUM AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide a substrate consisting of thermoplastic resin, wherein few blisters are generated on its surface even after the substrate is left in the condition of high temperature/high humidity and low temperature for a long period and to provide a method for manufacturing the substrate and a recording medium using the substrate. SOLUTION: Degraded/oxidized sub-products of a substrate constituent material for the recording medium consisting of the thermoplastic resin is controlled to be <=30 ppb based on the weight of the substrate. The substrate is obtained by being annealed under the atmosphere of inert gas having <=7% oxygen concentration after the substrate is molded of the thermoplastic resin.