| 摘要 |
PURPOSE:To obtain an optical disk excellent in transparency, heat resistance, moisture resistance, mechanical strength and optical homogeneity and small in retardation, by molding it by using a specified polycarbonate resin having a spiro ring skeleton as a base material. CONSTITUTION:A composition obtained by mixing a polycarbonate resin, as a base material, comprising repeating units of, for example, the formula and having a spiro ring skeleton and an m.p. of 180-330 deg.C with, optionally, a silicone, a fatty acid metal salt or the like as a mold release improver and a higher alcohol sulfonate or the like as an antistatic agent is molded into a disk base by, for example, injection molding or press molding in a mold in which a stamper is set while bits which serve as a recording signal are transferred to the disk base. An optical disk is formed from this disk base. |
