Protective film for polarizing filter and method for producing thereof and polarizing filter

摘要

In a polarizing filter, first and second protective films are adhered to a polarized film. The first protective film has rigidity at less than 320 kPa.m and degree of curl at more than 10 mm. The second protective film is not curled and has rigidity at more than 320 kPa.m. The protective films are produced in a solution casting method in which a solution is cast on a substrate continuously fed. The solution is dried to form the protective film. When a remaining solvent in the protective film is less than 60%, then the protective film is peeled from the substrate.