| 摘要 |
PURPOSE:To obtain polycarbonate sheet good in surface conditions and excellent in transparency by a method wherein a sheet-like material is cooled by a polishing roll having a plating layer of a specific thickness on its surface. CONSTITUTION:Polycarbonate or polycarbonate composition is kneaded, melted and extruded by using an extruder into the form of a sheet. The resulting sheet-like material is then cooled by using a specific polishing roll to obtain a polycarbonate sheet. This polishing roll has a hard chrome plating layer having a thickness of 20-80mum on its surface. The polycarbonate is the resin which is obtained by the condensation polymerization of divalent phenol compound, glycol monomer or the mixture thereof and carbonic acid derivative or by allowing phosgene to react with divalent phenol compound, glycol monomer or the mixture thereof in the presence of alkali. |
