| 摘要 |
PURPOSE:To obtain an optical disk-molding material hardly generating a silver streak caused by an entrapment of air when the material is plasticized and melted. CONSTITUTION:In a molding material made of pellets of a polycarbonate having a molecular weight of 10,000-18,000, an average pellet length is in the range of 2.5-3.5mm, and 70% or more of the pellets have a length within + or -0.1 mm from the average length value. |
