| 摘要 |
PURPOSE: To provide a method of manufacturing optical disc-molding substrates being thin and having excellent birefringency and small warpage, and optical discs obtained by using the molded substrates by employing transparent acrylic resin not obtained in a conventional manner through an injection compression molding method. CONSTITUTION: Acrylic resin is, under the condition of a molding temperature of 270-290 deg.C and a mold temperature of 60-90 deg.C, and the mold cramping pressure controlled into two stages, a first stage of 2-5 tons and a second stage of 5-40 tons, molded by an injection compression method into an optical disc of at most 1.0mm in its thickness. |
