| 摘要 |
The present invention provides an improved solution casting method to manufacture, with high productivity, a polysulfone resin film superior in quality including appearance, surface smoothness, transparency and thickness accuracy. A polysulfone resin film is cast using the solution casting method wherein a solution of polysulfone resin by at least one solvent chosen from among anisole, dioxane or tetrahydropyrane is used as a resin solution for solution casting. To shorten the drying time even further, at least one solvent chosen from among acetone, methylethylketone, ethyl acetate, toluene and phenol can be mixed in the casting solution of polysulfone resin. The polysulfone film obtained by the present invention can produce a high-quality retardation film with superior optical properties. |
