| 摘要 |
PROBLEM TO BE SOLVED: To provide a flat sheet, best-suited for a flat panel display, which is of a large size and thin and further, shows outstanding mechanical strength, light permeability, low birefringent characteristics, surface uniformity of birefringent value and transferability and a method for manufacturing the flat sheet. SOLUTION: The flat sheet for a flat display panel is manufactured through (1) a preheating step for preheating two mold parts, i.e., a top force and a bottom force upto a specified temperature level, (2) a molten resin mass forming step for forming a molten resin mass by melting, in a heating cylinder, a thermoplastic resin having a weight-average molecular weight of 15,000 to 500,000, a molecular weight distribution of not more than 4 and a melt flow rate of 5 to 250 g/10 min at 280 deg.C and under a load of 2.16 kgf, (3) a molten resin mass supplying step for supplying the molten resin mass onto the cavity surface of the bottom force of a press-molding machine from a heating cylinder discharging aperture without passing the resin mass through the interior of the mold, (4) a pressing step for pressing the supplied molten resin mass at a specified temperature, and (5) a cooling step for cooling the resin mass after pressing. |
