| 摘要 |
PURPOSE: Provided is a method for making a polyethersulfone film for a display panel, which is environment-friendly and is amenable to a continuous process to give a high productivity and to reduce optical anisotropic phase contrast significantly. CONSTITUTION: The method for making a polyethersulfone film comprises the steps of: (a) melting a polyethersulfone resin in an extruder; (b) extruding the melted polyethersulfone resin through a die into a film having a predetermined thickness and width; (c) annealing and cooling the extruded film; and (d) heat-treating the cooled film by irradiating the film with NIR(Near Infrared). Particularly, in step (c), the extruded film is annealed by passing it through a first roller under 130-200 deg.C, a second roller under 130-200 deg.C and a third roller under 180-240 deg.C, successively, and then cooled to room temperature.
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