| 摘要 |
PURPOSE: To obtain an optical compensating film having good properties and excellent economicity by using a poly-4,4'-dioxydiphenyl-2,2-propane carbonate film having a specific physical value as a substrate. CONSTITUTION: The substrate is composed of the poly-4,4'-dioxydiphenyl-2,2- propane carbonate having >=30000 average molecular weight and made by forming the polycarbonate film having >=150 deg.C glass transition point on the substrate. As a result, the properties, that is <=20nm in retardation, <=15 deg. in absolute value of lag axial angle distribution and <=0.8% in haze value, are provided as the optical properties and simultaneously the dimensional stability of <=0.10% even after being treated at 120 deg.C for 1hr and <=0.10% after being treated at 150 deg.C for 30min is attained. When the polycarbonate film has <=30000 average molecular weight, it is difficult to obtain >=150 deg.C glass transition point and problems are generated in heat durability. |
