Method and apparatus for dyeing polyvinylalcohol film, method and apparatus for producing polarizing film, polarizing film and polarizing plate

Unevenness in dyeing, which is occurred in a process of dyeing a polyvinyl alcohol film 10 as a base member for producing a polarizing film used for a liquid crystal display, is minimized by plural guiding means, which are arranged in a dyeing solution 12 in a dyeing bath 11, comprising cylindrical low-pressure dyeing solution discharge rollers 16. Each of rollers 16 has a plurality of dyeing solution discharge holes 17 opening on the film-guiding peripheral surface part and being distant from one another axially and about the axis, and each end portion fixed to a low-pressure supply pipe 18 or rotatably supported by the supply pipe 18 via a bearing 21. The rollers 16 are arranged along the guide direction for the polyvinyl alcohol film 10 so as to position alternately in the upper part and the lower part of the dyeing bath 11. The film 10 can be guided in such a zigzag pattern that the front and back sides of the film 10 are sequentially opposed to the rollers 16.