POLYVINYL ALCOHOL FILM AND METHOD FOR PRODUCING OPTICAL FILM USING SAME

摘要

Provided are: a PVA film capable of, even when having a small thickness, suppressing generation of swell wrinkles in a swelling step when producing an optical film; and a method for producing an optical film using said PVA film.　The polyvinyl alcohol film according to the present invention satisfies formula 0.15≤(Ds-Da)/Da<0.3, where Ds represents a crystal long period obtained from a small angle X-ray scattering measurement performed in a water/methanol solvent mixture (volume ratio: 2/8), and Da represents a crystal long period obtained from a small angle X-ray scattering measurement performed before the film is immersed in the solvent mixture.