| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-quality polycarbonate which has good adhesion property with a recording film and does not corrode the recording film when the polycarbonate is used for a disk substrate such as an optical disk and a magnetic disk, and which causes no corrosion of the molding die when the polycarbonate is molded, and thereby, which results in a long life of a stamper. SOLUTION: This polycarbonate for a disk substrate is produced by an interfacial polymn. condensation method from bisphenols and phosgene as the source materials in a solvent of methylene chloride. The contents of impurities are <2 wt.% of the low mol.wt. component by Soxhlet extraction in an acetone solvent, <=20 ppm unreacted bisphenols and <=20 ppm methylene chloride. |
