PROCESS FOR PRODUCING POLARIZING ELEMENT, POLARIZING ELEMENT, POLARIZING PLATE, OPTICAL FILM, AND IMAGE DISPLAY

摘要

A process for producing a polarizing element which comprises subjecting a polyvinyl alcohol film to at least a dyeing step, a crosslinking step, and a stretching step and then to a drying step.In the drying step, the film which has undergone the preceding steps and has a water content of 25-55 wt.% is dried to lower the water content of the film by at least 15 wt.%, whereby the water content of the film is regulated to 5-35 wt.%. The drying step includes a rapid drying stage in which the water content of the film is lowered by at least 10 wt.% in a period which accounts for 1/2 to 1/30 the overall drying time. A polarizing element obtained by this process has durability and has satisfactory optical properties in a wide region.